JP2007065079A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner with which low-temperature fixability and high-temperature offset resistance are both made compatible with high level, preservation stability is maintained and the occurrence of wrapping of the toner around a fixing means is highly prevented. <P>SOLUTION: As for the toner containing a binder resin, a colorant, and if necessary, resin particulates, (a) the ratio of a storage modulus G' (160°C) at 160°C is set at 1.0×10<SP>3</SP>to 8.0×10<SP>3</SP>Pa, (b) the ratio G' (140°C)/G' (200°C) of the storage modulus G' (140°C) at 140°C and the storage modulus G' (200°C) at 200°C is set at 0.8 to 4.0, (c) the relaxation modulus G (0.1s) at relaxation time 0.1 second and measuring temperature 120°C is set at 1×10<SP>3</SP>to 2.0×10<SP>4</SP>Pa, and (d) the ratio G (0.007s)/G (0.1s) of the relaxation modulus G (0.007s) at the relaxation time 0.007 second and the measuring temperature 120°C and G (0.1s) is set at 50 to 200, respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner used as a developer in an image forming process.

In an image forming apparatus such as an electrophotographic system or an electrostatic recording system, it is required to suppress power consumption from the viewpoints of economy and environment, and the toner can be fixed at a lower temperature. Is required to do.
In order to improve the low-temperature fixability of the toner, it is considered effective to use a binder resin (binder resin) having a low softening point. However, simply reducing the softening point of the binder resin tends to cause offset in the high temperature range (decrease in high temperature offset resistance), and adhesion of toner to fixing means such as a fixing roller and fixing belt. (Accordingly, wrapping of the transfer object around the fixing unit) tends to occur easily. Further, when trying to improve the high temperature offset resistance, the low temperature fixability tends to decrease.

On the other hand, Patent Document 1 is a toner having a color toner particle and an external additive, and using a polyester resin crosslinked with a crosslinking agent as a binder resin of the color toner particle, and having a storage elasticity at 130 ° C. The rate G ′ (130 ° C.) is 2 × 10 ² to 2 × 10 ³ Pa, the storage elastic modulus G ′ (170 ° C.) at 170 ° C. is 5 × 10 ^{2 to} 5 × 10 ³ Pa, and the ratio of the two A color toner in which (G ′ (170 ° C.) / G ′ (130 ° C.)) is set to 0.25 to 10 is described.

Patent Document 2 discloses a toner obtained by fusing and coalescing resin fine particles, colorant fine particles, and release agent fine particles at a temperature equal to or higher than the glass transition temperature of resin fine particles, and relaxing at 100 to 160 ° C. The relaxation elastic modulus G (0.01 s) at a time of 0.01 seconds was adjusted to 2.0 × 10 ^{2 to} 3.0 × 10 ⁴ Pa, and the relaxation elastic modulus G (0.01 s) and the relaxation time were set to 0. A toner in which the ratio (G (0.01 s) / G (0.1 s)) to the relaxation elastic modulus G (0.1 s) in 1 second is adjusted to 1.0 to 18.0 is described.
Japanese Patent Laid-Open No. 11-237766 JP 2000-81721 A

However, in the toner described in Patent Document 1, although the storage elastic modulus G ′ that causes a significant offset is not observed in the high temperature region, the storage elastic modulus G ′ has a low overall value. Therefore, the effect of preventing high temperature offset is insufficient.
In addition, although the toner disclosed in Patent Document 2 has improved and improved low-temperature fixability, since the relaxation elastic modulus is too low, the high-temperature offset resistance is insufficient, and the storage stability of the toner is also low. descend.

  Accordingly, an object of the present invention is a toner in which both low-temperature fixability and high-temperature offset resistance are compatible at a high level, the storage stability is maintained, and the occurrence of winding around the fixing means is highly suppressed. Is to provide.

In order to achieve the above object, the present invention provides:
(1) A toner containing a binder resin and a colorant and having a storage elastic modulus G ′ (160 ° C.) at 160 ° C. of 1.0 × 10 ^{3 to} 8.0 × 10 ³ Pa, 140 The ratio G ′ (140 ° C.) / G ′ (200 ° C.) of the storage elastic modulus G ′ at 140 ° C. (140 ° C.) and the storage elastic modulus G ′ at 200 ° C. (200 ° C.) is 0.8 to 4.0. The relaxation modulus G (0.1 s) at a relaxation time of 0.1 second and a measurement temperature of 120 ° C. is 1.0 × 10 ^{3 to} 2.0 × 10 ⁴ Pa, the relaxation time is 0.007 seconds, and the measurement temperature. The ratio G (0.007 s) / G (0.1 s) between the relaxation elastic modulus G (0.007 s) at 120 ° C. and the G (0.1 s) is 50 to 200, toner,
(2) The toner according to (1), further comprising resin fine particles, wherein the resin fine particles have a glass transition temperature Tg higher than a melting temperature Tm of the binder resin.
Is to provide.

In the present invention, the storage elastic modulus G ′ (T) of the toner indicates the real part of the shear complex elastic modulus G ^* (T) at the measurement temperature T [° C.], specifically, JIS K 7244-6. It is measured by a viscoelasticity measuring device according to the method prescribed in “Plastics—Testing method for dynamic mechanical properties—Part 6: Shear vibration—Non-resonance method”.
In the present invention, the relaxation elastic modulus G (t) of the toner is the time t when the stress relaxation is measured by applying a constant strain γ ₀ to the toner at a measurement temperature of 120 ° C. and at a time t = 0. The ratio σ (t) / γ ₀ of the stress σ (t) and γ ₀ in [s] is shown. Specifically, according to the frequency dispersion measuring method by the sinusoidal vibration method, the viscoelasticity measuring device It is to be measured.

  According to the toner of the present invention, both low-temperature fixability and high-temperature offset resistance can be achieved at a high level, and the winding of the toner around the fixing unit can be highly suppressed.

The toner of the present invention contains a binder resin and a colorant, and
(A) The storage elastic modulus G ′ (160 ° C.) at 160 ° C. is 1.0 × 10 ^{3 to} 8.0 × 10 ³ Pa,
(B) The ratio G ′ (140 ° C.) / G ′ (200 ° C.) of the storage elastic modulus G ′ at 140 ° C. (140 ° C.) and the storage elastic modulus G ′ at 200 ° C. (200 ° C.) is 0.8-4. .0,
(C) The relaxation elastic modulus G (0.1 s) at a relaxation time of 0.1 second and a measurement temperature of 120 ° C. is 1.0 × 10 ^{3 to} 2.0 × 10 ⁴ Pa,
(D) The ratio G (0.007 s) / G (0.1 s) between the relaxation elastic modulus G (0.007 s) at a relaxation time of 0.007 seconds and a measurement temperature of 120 ° C. and the G (0.1 s) is 50 to 200.

In the toner, in order to achieve both the low-temperature fixability and the high-temperature offset resistance of the toner at a high level, the storage elastic modulus G ′ (T) of the toner is appropriately low in a wide temperature range, and It is set not to fluctuate greatly.
That is, the storage elastic modulus G ′ (160 ° C.) of the toner at 160 ° C. is 1.0 × 10 ^{3 to} 8.0 × 10 ³ Pa, preferably 2.0 × 10 ^{3 to} 7.0 × 10. ³ Pa, more preferably 3.5 × 10 ^{3 to} 5.5 × 10 ³ Pa.

The ratio G ′ (140 ° C.) / G ′ (200 ° C.) of the storage elastic modulus G ′ at 140 ° C. (140 ° C.) and the storage elastic modulus G ′ at 200 ° C. (200 ° C.) is 0.8-4. 0, preferably 0.9 to 3.2, and more preferably 1.1 to 2.5.
When the storage elastic modulus G ′ (160 ° C.) is less than 1.0 × 10 ³ Pa, or when the ratio G ′ (140 ° C.) / G ′ (200 ° C.) is more than 4, high temperature offset tends to occur. In addition, there is a problem that toner adheres to the fixing unit and the transfer target is easily wound in a high temperature region.

On the other hand, when the storage elastic modulus G ′ (160 ° C.) is higher than 8.0 × 10 ³ Pa, or when the ratio G ′ (140 ° C.) / G ′ (200 ° C.) is lower than 0.8, the formed image This causes problems such as low light transmittance and low temperature fixability.
G ′ (140 ° C.) is preferably 1.5 × 10 ^{3 to} 8.4 × 10 ³ Pa, more preferably 2.0 × 10 ^{3 to} 8.0 × 10 ³ Pa. , more preferably ^{3.0 × 10 3 ~7.6 × 10 3} Pa. G ′ (200 ° C.) is preferably 1.5 × 10 ^{3 to} 8.4 × 10 ³ Pa, more preferably 2.0 × 10 ^{3 to} 8.0 × 10 ³ Pa. More preferably, it is 3.2 × 10 ^{3 to} 7.5 × 10 ³ Pa.

Further, in the above toner, in order to maintain the storage stability while improving the low temperature fixability, the relaxation elastic modulus G (t in a very short relaxation time such as contact between the toners by stirring in the developing device. ) Is high, and on the other hand, the relaxation elastic modulus G (t) in a relatively long relaxation time, such as the time for passing through the nip portion of the fixing roller, is set to be low.
That is, the toner has a relaxation elastic modulus G (0.1 s) at a relaxation time of 0.1 second and a measurement temperature of 120 ° C. of 1.0 × 10 ^{3 to} 2.0 × 10 ⁴ Pa, preferably 3. 0 × a ¹⁰ 3 ^~1.5 × ¹⁰ 4 Pa, more preferably from ^{5.0 × 10 3 ~1.0 × 10 4} Pa.

The ratio G (0.007 s) / G (0.1 s) between the relaxation elastic modulus G (0.007 s) at a relaxation time of 0.007 seconds and a measurement temperature of 120 ° C. and the G (0.1 s) is: It is 50-200, Preferably, it is 70-180, More preferably, it is 90-150.
When the relaxation elastic modulus G (0.1 s) at 120 ° C. exceeds 2.0 × 10 ⁴ Pa, or the relaxation elastic modulus ratio G (0.007 s) / G (0.1 s) at 120 ° C. is 200. If it exceeds the upper limit, the deformation of the toner at the time of fixing becomes insufficient, causing a problem that low temperature offset is caused.

On the other hand, when the relaxation elastic modulus G (0.1 s) at 120 ° C. is less than 1.0 × 10 ³ Pa, or the ratio G (0.007 s) / G (0.1 s) of the relaxation elastic modulus at 120 ° C. When it is less than 50, there is a problem that the durability and storage stability of the toner are lowered.
The relaxation elastic modulus G (0.007 s) at 120 ° C. is preferably 2.0 × 10 ^{5 to} 1.4 × 10 ⁶ Pa, more preferably 3.0 × 10 ^{5 to} 1.2. It is * 10 < ⁶ > Pa, More preferably, it is 5.0 * 10 < ⁵ > -1.0 * 10 < ⁶ > Pa.

The measurement temperature of the relaxation elastic modulus G was set to 120 ° C., because the toner state is affected not only during fixing but also during stirring and storage, so the relaxation elastic modulus G This is because the evaluation of G is not performed at the fixing temperature of the toner but is evaluated at a temperature lower than the fixing temperature.
Examples of the binder resin that forms the toner include polyester resins (for example, polyethylene terephthalate and polybutylene terephthalate), styrene resins (for example, polystyrene), and acrylic resins (for example, polymethyl methacrylate). ), Styrene-acrylic resins (for example, copolymers of styrene and acrylic acid monomers or methacrylic acid monomers), olefin resins (for example, polyethylene, polypropylene, etc.), polyamide resins, epoxy resins. Examples thereof include resins and mixed resins thereof. Of these, polyester resins are preferable.

The resin forming the binder resin has a relatively low molecular weight (hereinafter referred to as “L-form”) from the viewpoint of setting the storage elastic modulus G ′ (T) and relaxation elastic modulus G (t) of the toner within the above ranges. And a mixture having a relatively high molecular weight (hereinafter sometimes referred to as “H-form”).
For example, when a polyester resin is used as the resin for forming the binder resin, the L-form having a weight average molecular weight of about 8000 to 30000, preferably about 9000 to 20000, and the weight average molecular weight of about 100,000 to 300000, preferably Is preferably a mixture with H-form which is about 150,000 to 250,000.

  The mixing ratio of the L form and the H form of the binder resin is appropriately set according to the kind of the binder resin to be used, viscoelastic characteristics required for the toner, and the like, and is not particularly limited. When a polyester resin is used as the resin, the L form: H form (weight ratio) is preferably 45:55 to 75:35, and more preferably 50:50 to 70:30.

Although melting temperature Tm of binder resin is not specifically limited, Preferably it is 105-125 degreeC, More preferably, it is 110-120 degreeC.
I The colorant used in the toner is not particularly limited, and examples thereof include various colorants used in the production of black toner and color toner. Specifically, for example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine, malachite green oxalate, lamp black, rose bengal, carmine 6B , C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 184, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Solvent Yellow 162, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 3.

Although content of a coloring agent is not specifically limited, For example, Preferably it is 1-10 weight part with respect to 100 weight part of binder resin, More preferably, it is 2-6 weight part.
The toner preferably contains resin fine particles together with a binder resin and a colorant.
When the glass transition temperature Tg of the resin fine particles is high, high elasticity can be maintained even in a high temperature region. For example, even when the melting temperature Tm of the binder resin is low, by forming a toner in which resin fine particles having a high glass transition temperature Tg are internally added (internally added), high temperature resistance is secured while ensuring low temperature fixability. The offset property can be improved, and toner adhesion to the fixing means (wrapping of the transfer medium) in the high temperature region can be suppressed.

  The resin fine particles are not particularly limited except that the glass transition temperature Tg thereof is higher than the melting temperature Tm of the binder resin. Examples of the material include polyester resins (for example, polyethylene terephthalate, Polybutylene terephthalate, etc.), styrene resin (eg, polystyrene, etc.), acrylic resin (eg, polymethyl methacrylate, etc.), styrene-acrylic resin (eg, styrene, acrylic acid monomer or methacrylic acid type). A copolymer with a monomer, etc.), an olefin resin (for example, polyethylene, polypropylene, etc.), a polyamide resin, an epoxy resin, and a mixed resin thereof. Among these, for example, when the binder resin is a polyester resin, the material of the resin fine particles is preferably a styrene-acrylic resin.

The glass transition temperature Tg of the resin fine particles is not particularly limited, but is preferably 140 to 160 ° C, and more preferably 145 to 155 ° C.
Further, the difference (Tg−Tm) between the melting temperature Tm [° C.] of the binder resin and the glass transition temperature Tg [° C.] of the resin fine particles is not particularly limited, but is preferably 15 ° C. or more, more preferably It is 20-45 degreeC, More preferably, it is 30-40 degreeC.

When the difference (Tg−Tm) is less than the above range, there is a risk that the effect of the internal addition of the resin fine particles, which improves the high temperature offset resistance while securing the low temperature fixability of the toner, may not be obtained sufficiently. is there.
The difference (Tg−Tm) is not particularly limited, but is preferably 50 ° C. or less. When the difference (Tg−Tm) exceeds 50 ° C., the glass transition temperature Tg of the resin fine particles may be too high, and as a result, the low-temperature fixability of the toner may be impaired.

  The blending amount of the resin fine particles is appropriately set according to the kind of the binder resin, the blending ratio of the H body and the L body, the kind of the resin fine particles, the viscoelastic characteristics of the binder resin and the resin fine particles, the above difference (Tg−Tm), and the like. Although not particularly limited, it is usually 4 parts by weight or less, preferably 0.5 to 3.5 parts by weight, more preferably 1 part per 100 parts by weight of the binder resin. 0.0 to 3.0 parts by weight.

The toner contains a binder resin, a colorant, and, if necessary, various additives such as a release agent, a charge control agent (or charge control resin), and magnetic powder, together with resin fine particles. Also good.
The release agent is not particularly limited, and examples thereof include various waxes such as polyethylene wax, polypropylene wax, carnauba wax, rice wax, sazol wax, montan ester wax, monta wax, and Fischer-Tropsch wax. Of these, Fischer-Tropsch wax is preferable.

The content of the release agent is not particularly limited. For example, the content is preferably 5 parts by weight or less, more preferably 0.5 to 5 parts by weight, and still more preferably, with respect to 100 parts by weight of the binder resin. Is 2.0 to 4.5 parts by weight.
The charge control agent is not particularly limited, and may be either a negative charge control agent or a positive charge control agent. Examples of the negative charge control agent include boron complex compounds (for example, boron benzyl acid complexes), metal-containing salicylic acid compounds, metal-containing monoazo compounds, metal-containing acetylacetone compounds, aromatic hydroxycarboxylic acids or metal salts thereof. , Aromatic monocarboxylic acid or metal salt thereof, aromatic polycarboxylic acid or metal salt thereof, phenol compound (for example, bisphenol etc.), urea compound, metal-containing naphthoic acid compound, quaternary ammonium salt, calixarene, Examples thereof include a silicon compound, a styrene-acrylic acid copolymer, a styrene-methacrylic acid copolymer, a styrene-acrylic acid-sulfonic acid copolymer, and a metal-free corbonic acid-based compound. Of these, boron complex compounds, metal-containing salicylic acid compounds, calixarene, and the like are preferable from the viewpoint of chargeability and color. Examples of the positive charge control agent include quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate, nigrosine pigments, fatty acid metal salts, and guanidine compounds. , Imidazole compounds, onium salts such as phosphonium salts or lake pigments containing these, triphenylmethane dyes or lake pigments containing these, metal salts of higher fatty acids, diorganotin such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide Examples include borates. Examples of the lake forming agent for forming the lake pigment include phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyan compound, ferrocyan compound, and the like.

  The charge control resin is not particularly limited. For example, an ionic monomer having an ionic functional group such as an ammonium salt (for example, N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium. p-toluenesulfonate, etc.) and a monomer capable of copolymerization with such an ionic monomer (for example, styrene monomer, acrylic monomer, etc.) were copolymerized. Things.

The content of the charge control agent or the charge control resin is not particularly limited, but is preferably 10 parts by weight or less, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. More preferably, it is 1.0-5.0 weight part.
The magnetic powder is used in the binder resin when the toner is used as a magnetic toner. The magnetic powder is not particularly limited, and examples thereof include ferrite particles, magnetite particles, and iron powder.

The toner is prepared by blending the binder resin, colorant, and if necessary, resin fine particles and other compounding agents, melt-kneading, and then pulverizing the obtained melt-kneaded product. Alternatively, the toner particles obtained by the pulverization and the external additive are mixed and stirred as necessary.
The external additive is not particularly limited, and includes various external additives used for the purpose of adjusting the fluidity of the toner. Specific examples include fine particles such as silica, alumina, and titanium oxide.

  A blend obtained by blending a binder resin, a colorant, and if necessary, resin fine particles and other compounding agents may be mixed and stirred by a mixer (for example, a Henschel mixer). Moreover, what is necessary is just to melt and knead | mix the mixture obtained in this way with a kneading machine (for example, twin-screw extruder etc.). The pulverization of the melt-kneaded product can be divided into, for example, two or more steps of coarse pulverization and fine pulverization. For the coarse pulverization, various pulverization apparatuses and crushing apparatuses such as a ball mill, a vibration mill, a jet mill, and a pin mill can be used. For fine pulverization, for example, a collision airflow pulverizer can be used.

  The toner has both low-temperature fixability and high-temperature offset resistance at a high level, and the occurrence of winding around the fixing means is highly suppressed. In addition, the storage stability is good. Therefore, the toner is preferably used in, for example, an image forming apparatus that requires fixing at a lower temperature as power consumption is reduced.

The components used for the production of toners in the following examples and comparative examples are shown below.
Polyester A: Polyester resin (L) having a number average molecular weight of 4300, a weight average molecular weight of 9800, a glass transition temperature of Tg of 58 ° C., and a melting temperature of Tm of 102 ° C.
Polyester B: Polyester resin (H body) having a number average molecular weight of 2500, a weight average molecular weight of 200,000, a glass transition temperature Tg of 60 ° C., and a melting temperature of Tm of 130 ° C.
Fischer-Tropsch wax: paraffin wax, trade name “FT-100”, Nippon Seiki Co., Ltd.
Carbon black: product number “Pr-90”, manufactured by Cabot Corporation, resin fine particles: resin fine particles obtained in Reference Example 1 below, silica fine particles: average particle diameter 20 nm, hydrophobization degree 60, specific resistance 10 ¹² Ωcm
The “hydrophobicity” of the silica fine particles is an index indicating the degree of hydrophobicity of the silica fine particles. This index value is the value obtained when methanol was added dropwise while stirring the dispersion of silica fine particles until the total amount of 0.2 g of silica fine particles added in 50 mL of water was wet, and when the total amount of silica fine particles was wet. It is calculated | required by expressing the content rate of methanol in a dispersion liquid in percentage.

Reference example 1
In a reaction vessel equipped with a stirrer, a cooler and a temperature controller, 380 parts by weight of ion-exchanged water and 3 parts by weight of a nonionic surfactant (product number “MON2”, manufactured by Sanyo Chemical Co., Ltd.) are blended, The mixture was stirred while maintaining the liquid temperature at 80 ° C., and a liquid in which 1 part by weight of ammonium persulfate (polymerization initiator) was dissolved in 10 parts by weight of ion-exchanged water was blended. Next, a mixed solution consisting of 49 parts by weight of methyl methacrylate, 49 parts by weight of styrene, and 2 parts by weight of n-butyl methacrylate is dropped into the obtained solution over 60 minutes. By stirring for 60 minutes, an emulsion having a nonvolatile content of 20% was obtained. Furthermore, the obtained emulsion was spray-dried to obtain resin fine particles having a particle size of 0.03 to 0.05 μm and a glass transition temperature Tg of 150 ° C.

Example 1
(Manufacture of toner)
60 parts by weight of polyester A, 40 parts by weight of polyester B, 3 parts by weight of Fischer-Tropsch wax, 95 parts by weight of carbon black and 2 parts by weight of resin fine particles are put into a Henschel mixer, stirred and mixed, and then put into a twin screw extruder. And the resin composition was obtained by melt-kneading at 130 degreeC. Further, the obtained resin composition was finely pulverized with an airflow type pulverizer and classified with an air classifier to obtain toner particles (core particles) having a volume average particle diameter of 9 μm. Next, the toner particles and the silica fine particles are put into a Henschel mixer so that the coverage of the silica fine particles with respect to the toner particles is 80%, and stirred and mixed at 3000 rpm for 10 minutes. Toner A was obtained.

(Evaluation of fixability)
Next, using the solid black image formed using the toner, the toner fixability (low-temperature fixability and high-temperature offset resistance) was evaluated.
First, the toner A and a carrier were blended so that the toner concentration would be 10%, and the developer was obtained by uniformly stirring and mixing with a ball mill. Next, using the obtained developer, an image forming process was performed by a color printer (product number “LS-5016”, manufactured by Kyocera Mita Corporation). The formed image was a solid black image having a width of 2 cm and a length of 3 cm, and the amount of toner fixed on the transfer medium (plain paper) was set to 1.5 mg / cm ² . The surface temperature of the fixing roller was set to 140 ° C. when evaluating the low-temperature fixability, and the surface temperature was set to 200 ° C. when evaluating the high-temperature offset resistance. The nip time during the fixing process was set to be 0.1 seconds in all cases.

  The evaluation method of the low temperature fixability is as follows. First, the fixing surface of the plain paper was turned to the front side, and the black solid image was folded in half, and then the surface of the black solid image was rubbed with a cotton cloth under a load of about 9.8 N. . Subsequently, the solid black image was visually observed, and a case where the width of the scraped image was 1 mm or less was rated as ◯, and a case where the width exceeded 1 mm was rated as x. Further, in particular, the case where the width was within 0.5 mm was marked as ◎.

The high temperature offset resistance was evaluated by visually observing the surface of the fixing roller after the fixing process, and determining whether or not the offset occurred and the degree of offset. The case where no offset was observed was marked as ◯, the case where an offset was observed as Δ, and the case where the offset was significant as x.
Example 2
Toner B was obtained in the same manner as in Example 1 except that the resin composition was prepared using 50 parts by weight of polyester A and 50 parts by weight of polyester B. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner B was used instead of the toner A.

Example 3
Toner C was obtained in the same manner as in Example 1 except that the resin composition was prepared with 70 parts by weight of polyester A and 30 parts by weight of polyester B. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner C was used instead of the toner A.
Examples 4-5
Toners D and E were obtained in the same manner as in Example 1 except that the resin composition was prepared with 1 part by weight (Example 4) or 3 parts by weight (Example 5) of resin fine particles. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner D (Example 4) or the toner E (Example 5) was used instead of the toner A.

Examples 6 and 7
Except that the resin composition was prepared by using 55 parts by weight of polyester A, 45 parts by weight of polyester B, and 0.8 parts by weight (Example 6) or 2.5 parts by weight (Example 7) of resin fine particles. In the same manner as in Example 1, toners F and G were obtained. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner F (Example 6) or the toner G (Example 7) was used instead of the toner A.

Examples 8 and 9
Except that the resin composition was prepared with 65 parts by weight of polyester A, 35 parts by weight of polyester B, and 1.5 parts by weight (Example 8) or 3.5 parts by weight (Example 9) of resin fine particles. In the same manner as in Example 1, toners H and I were obtained. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner H (Example 8) or the toner I (Example 9) was used instead of the toner A.

Comparative Example 1
Toner J was obtained in the same manner as in Example 1 except that the resin composition was prepared using 40 parts by weight of polyester A and 60 parts by weight of polyester B. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner J was used instead of the toner A.
Comparative Example 2
Toner K was obtained in the same manner as in Example 1 except that the resin composition was prepared using 80 parts by weight of polyester A and 20 parts by weight of polyester B. Further, the toner fixability was evaluated in the same manner as in Example 1 except that toner K was used instead of toner A.

Comparative Examples 3 and 4
Toners L and M were prepared in the same manner as in Example 1 except that no resin fine particles were blended (Comparative Example 3) or that resin fine particles were used in 4 parts by weight (Comparative Example 4). Got. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner L (Comparative Example 3) or the toner M (Comparative Example 4) was used instead of the toner A.

Comparative Example 5
Toner N was obtained in the same manner as in Example 1 except that the resin composition was prepared by using 45 parts by weight of polyester A, 55 parts by weight of polyester B, and 3.5 parts by weight of resin fine particles. Further, the toner fixability was evaluated in the same manner as in Example 1 except that toner N was used instead of toner A.

Comparative Example 6
Toner O was obtained in the same manner as in Example 1 except that the resin composition was prepared with 75 parts by weight of polyester A, 25 parts by weight of polyester B, and 0.8 parts by weight of resin fine particles. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner O was used instead of the toner A.

Comparative Example 7
Toner P was obtained in the same manner as in Example 2 except that the resin composition was prepared with 4 parts by weight of resin fine particles. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner P was used instead of the toner A.
Comparative Example 8
Toner Q was obtained in the same manner as in Example 3 except that the resin composition was prepared without blending resin fine particles. Further, the toner fixability was evaluated in the same manner as in Example 1 except that the toner Q was used instead of the toner A.

Measurement of Storage Elastic Modulus For toners A to Q obtained in Examples 1 to 9 and Comparative Examples 1 to 8, storage elastic modulus G ′ (T) at 140 ° C., 160 ° C. and 200 ° C. (that is, G ′ (140 C), G ′ (160 ° C.) and G ′ (200 ° C.)), and the ratio of G ′ (140 ° C.) to G ′ (200 ° C.) (G ′ (140 ° C.) / G ′ ( 200 ° C)).

  For measuring the storage elastic modulus G ′ (° C.), a viscoelasticity measuring apparatus (model number “ARES”, manufactured by TA Instruments) was used. A parallel plate having a diameter of 7.9 mm was used as the measurement jig, and the measurement sample was melted with the toners A to Q obtained in the examples and comparative examples, and then had a diameter of 7.9 mm and a height of 3 to 5 mm. What was compression-molded in the column shape was used. The measurement conditions are as follows. In the automatic measurement mode of the viscoelasticity measuring device, the frequency is 6.28 rad / s, the initial strain is 0.1%, the temperature T is in the range of 50 to 220 ° C., and 2 ° C. per minute. The storage elastic modulus G ′ (° C.) was measured while raising the temperature at a rate.

Measurement of Relaxation Elastic Modulus For toners A to Q obtained in Examples 1 to 9 and Comparative Examples 1 to 8, the relaxation elastic modulus G (0.1 s) at a measurement temperature of 120 ° C. and a relaxation time of 0.1 second was obtained. The relaxation elastic modulus G (0.007 s) at a relaxation time of 0.007 seconds was measured, and the ratio of G (0.007 s) to G (0.1 s) (G (0.007 s) / G ( 0.1 s)).

  For measurement of the relaxation modulus G (t), a viscoelasticity measuring device (model number “ARES”, manufactured by TA Instruments Co., Ltd.) was used. A parallel plate with a diameter of 25 mm was used as the measurement jig, and the measurement sample was compressed into a cylindrical shape with a diameter of 25 mm and a height of 3 to 5 mm after melting the toners A to Q obtained in the examples and comparative examples. The molded one was used. The measurement conditions were a measurement temperature of 120 ° C. and a frequency of 6.28 rad / s (constant) in the stress relaxation mode of the viscoelasticity measuring apparatus. Further, the amount of strain at the time of measurement of the relaxation elastic modulus is G ′ and when the storage elastic modulus G ′ and loss elastic modulus G ″ of the toner are measured while gradually increasing the strain amount in the range of 0.1 to 200%. The maximum amount of distortion was set in a region where the change in G ″ was linear. In the stress relaxation measurement mode, a preset amount of distortion is abruptly applied to the sample (toner). Then, as time elapses, the magnitude of the stress necessary to maintain the preset strain amount is measured.

  Compositions of resin compositions used in Examples 1 to 9 and Comparative Examples 1 to 8, measured values of storage elastic modulus G ′ (T) and relaxation elastic modulus G (t), and evaluation results of fixability (low temperature fixing) Properties, high temperature offset) are shown in Tables 1-8.

As apparent from Tables 2, 4, 6 and 8, the storage elastic modulus G ′ (160 ° C.) falls within the range of 1.0 × 10 ^{3 to} 8.0 × 10 ³ Pa, and the ratio G ′ (140 ° C.) / G ′ (200 ° C.) is in the range of 0.8 to 4.0, relaxation elastic modulus G (0.1 s) at 120 ° C. is in the range of 1.0 × 10 ^{3 to} 2.0 × 10 ⁴ Pa, and According to the toners of Examples 1 to 9 in which the ratio G (0.007 s) / G (0.1 s) is set in the range of 50 to 200, both the low temperature fixability and the high temperature offset resistance are obtained. It was possible to achieve compatibility at a high level, maintain storage stability, and suppress the occurrence of winding around the fixing means.

In Comparative Example 8, the fixability evaluation results were good for both low temperature fixability and high temperature offset, but the ratio G (0.007 s) / G (0.1 s) was less than 50. As a result, the toner had low durability and storage stability.
The present invention is not limited to the above description, and various design changes can be made within the scope of the matters described in the claims.

Claims (2)

A toner containing a binder resin and a colorant,
The storage elastic modulus G ′ (160 ° C.) at 160 ° C. is 1.0 × 10 ^{3 to} 8.0 × 10 ³ Pa, the storage elastic modulus G ′ (140 ° C.) at 140 ° C. and the storage elastic modulus at 200 ° C. The ratio G ′ (140 ° C.) / G ′ (200 ° C.) of G ′ (200 ° C.) is 0.8 to 4.0, the relaxation time G is 0.1 seconds, and the relaxation elastic modulus G is 120 ° C. 0.1 s) is 1.0 × 10 ^{3 to} 2.0 × 10 ⁴ Pa, the relaxation time is 0.007 seconds, the relaxation elastic modulus G (0.007 s) at a measurement temperature of 120 ° C., and the G (0 The toner is characterized in that the ratio G (0.007 s) / G (0.1 s) to .1 s) is 50 to 200.   The toner according to claim 1, further comprising resin fine particles, wherein the resin fine particles have a glass transition temperature Tg higher than a melting temperature Tm of the binder resin.