JPH07295290A - Toner for energy saving heat fixing - Google Patents

Abstract

PURPOSE:To produce a toner capable of energy saving heat fixing and high speed heat fixing without deteriorating various characteristics of the toner, low in minimum fixing temp. and capable of providing sufficient release property and fluidity and capable of providing compatibility of high picture and productivity. CONSTITUTION:This toner is used at developing and heat fixing of electrostatic image, and a composition constituting this toner has a rheological characteristic such as a starting temp. of depression of storage modulus of elasticity (G') is >=80 deg.C and less than 95 deg.C and the loss tangent (tan delta) at a starting temp. of depression is <=0.020 and a peak temp. of loss modulus of elasticity (G'') is 110 deg.C (where tan delta=G''/G) when measured under the conditions of the measured frequency 1Hz and the measured distortion of 1 degree.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used for developing and thermally fixing an electrostatic charge image in electrophotography or the like, and more specifically, it relates to a toner without deteriorating various characteristics of the toner. The present invention relates to a toner that enables energy-saving heat fixing and high-speed heat fixing.

[0002]

2. Description of the Related Art As a developer for developing an electrostatic charge image formed on an electrophotographic photosensitive member, it comprises a fixing resin and a coloring agent such as carbon black and, if necessary, a releasing agent such as a low molecular weight olefin resin. A powder toner obtained by molding a composition containing an agent into a certain particle size is widely used. If necessary, this powder toner is charged in combination with a magnetic carrier or the like, conveyed to the surface of the photoconductor, transferred to copy paper after forming a toner image on the surface of the photoconductor, and finally on a copy paper by a heat roller or the like. Is fixed in.

Conventionally, it has been known that the rheological characteristics of a toner, such as storage elastic modulus (G ') and loss elastic modulus (G "), are closely related to toner fixability and offset resistance. JP-A-1-303447 discloses that at least the peak of the molecular weight distribution is 1 * 10 ⁴ or less and 5 * 1.
0 is in the ⁵ or more regions, measured temperature 175 to 177 ° C. in the storage modulus 1 * 10 ³ dyne / cm ² or more, the loss modulus 5 * 10 ³ dyne / cm ² or less of styrene resin the principal resin A toner for developing an electrostatic charge image, which is characterized in that it is contained as a component, is described.

Japanese Patent Laid-Open No. 3-31857 discloses that
In an electrostatic charge image developing toner comprising a composition in which a colorant and a charge control dye are dispersed in a fixing resin, the composition has a loss elastic modulus at a storage elastic modulus of 10 ⁴ dyne / cm ^2. Toners are described which are characterized by having rheological properties of 0.95 to 1.25.

Further, it is already known that a releasing agent such as a low molecular weight olefin resin is used to prevent offset at the time of fixing on a heat roller, as described in, for example, Japanese Patent Publication No. 52-3304. At the time of heat roller fixing, the occurrence of offset development is prevented and excellent fixing performance is imparted. Furthermore, in order to impart fixability and offset resistance to the toner, as a resin for toner,
It is also known to use a bimodal resin having both low and high molecular weight components together with the release agent.

[0006]

All of the above toners have been widely used in the heat roller fixing method.
Recently, there has been a strong demand for further speeding up, energy saving, and higher image quality. In addition, JP-A-59-
As described in Japanese Patent No. 68766, a heating head fixedly arranged, a rotary pressure roller that presses the heating head to form a nip portion, and a heating head is provided in an area corresponding to the nip portion of the heating head. A thermal fixing device which is composed of a heating element and which fixes a toner by allowing a recording sheet to pass through a nip portion is attracting attention from the viewpoint of energy saving and downsizing.

In order to increase the speed and save energy, it is necessary for the toner to have low-temperature fixability and offset resistance. However, when the softening point of the binder resin is lowered, there arises a problem of offset, so that the above-mentioned configuration cannot provide sufficient low temperature fixability.

For example, when the softening point of the above resin is lowered, an offset occurs, so that in order to compensate for it, the content of the release agent must be increased considerably. In that case, the fluidity of the toner is lowered, the developability is lowered, problems such as aggregation occur, and when the toner as a whole is balanced, the fixing temperature is not lowered. Further, as a countermeasure, a method of lowering the softening point of the toner itself with wax cannot be achieved without increasing the amount of addition. To achieve higher image quality, it is generally used to reduce the toner particle size, but it is necessary to make the particle size distribution wider in order to improve productivity, and especially to increase the proportion of fine powder that adversely affects the copying performance. It is necessary and various treatment agents have been proposed, but in reality the ones that are not sufficiently satisfactory have not been obtained.

Accordingly, it is an object of the present invention to provide a toner which eliminates such drawbacks of conventional toners and enables energy-saving heat fixing and high-speed heat fixing without deteriorating various properties of the toner. is there. Another object of the present invention is to
An object of the present invention is to provide a toner having a low minimum fixing temperature, sufficient releasability, fluidity, and high image quality and productivity.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a toner used for developing and heat fixing an electrostatic image. The composition constituting the toner has a measurement frequency of 1 Hz and a measurement distortion of 1
The following rheological characteristics, that is,
(1) The storage elastic modulus (G ') falling start temperature is in the range of 80 ° C or more and less than 95 ° C, and (2) the tangent loss (tan δ) at the storage elastic modulus (G') falling start temperature is 0. It is 0.020 or less, and (3) the loss elastic modulus (G ″) has a peak temperature of 110 ° C. or higher, provided that tan δ = G ″ / G ′.

The toner composition was measured under the conditions of measurement frequencies of 0.1 Hz and 10 Hz, and the following formula (storage elastic modulus (G ') drop start temperature at 10 Hz)-
(Storage elastic modulus (G ') drop start temperature at 0.1 Hz) <
It is particularly desirable to use a material satisfying 20 ° C.

[0012]

The storage elastic modulus (G ′), loss elastic modulus (G ″) and tangent loss (tan δ) are rheological properties, and tangent loss (tan δ) is the loss elastic modulus (G ″) / storage elastic modulus. It is represented by the ratio of (G ′), which is one of the viscoelastic characteristic functions obtained by the vibration method described later, and the real part of the complex elastic modulus is called G ′ and the imaginary part is called G ″. Among them, the storage elastic modulus is related to the cohesive force of the resin composition, while the loss elastic modulus is related to the viscosity of the resin composition, and the tangent loss represents the balance between them.

The conventionally known relationship between the rheological characteristics of toner and the fixing property and offset resistance of toner is as follows.
High temperature of 175 ° C or storage elastic modulus (G ') of 10 ⁴
The values are as small as dyne / cm ^2, and all of them define the rheological properties in a completely molten state of the resin composition. However, if the rheological properties in the above state are specified within a certain range as specified in the prior art, it is considered that excellent heat fixing property and offset resistance can be obtained under the present condition that sufficient heat is applied. However, it has been found that it is difficult to balance the heat fixing property and the offset resistance under the high-speed heat fixing condition and the energy saving heat fixing condition in which the applied heat amount is small.

The problem in the present invention is the temperature at which the storage elastic modulus (G ') starts to fall, which corresponds to the temperature at which the resin composition begins to melt. The storage elastic modulus (G ′) of any toner initially shows a value of about 1.9 × 10 ⁵ dyn / cm ^{2 when} the temperature is raised from room temperature, but soon reaches a certain temperature range. It descends (point A in Figure 1). In the present invention, the rheological characteristics of the storage elastic modulus (G ′) at the start temperature of falling off balance the heat fixing property and the offset resistance under the high-speed heat fixing condition and the energy saving heat fixing condition with a small heat quantity applied. It has been found to be extremely important above.

In the present invention, first, the storage elastic modulus (G ')
It is important that the temperature at which the temperature starts to fall is in the range of 80 to 95 ° C. This drop start temperature is closely related to the fixability and the offset resistance, and if it is 95 ° C. or higher, the fixing temperature does not decrease and the low temperature fixability is poor (see Comparative Examples 2 and 4 described later). On the contrary, when the temperature is 80 ° C. or lower, the low temperature fixability is improved, but offset occurs. From the graph plotting the relationship between the temperature and the storage elastic modulus (G ′), the temperature at which the storage elastic modulus (G ′) begins to fall can be determined from the portion where the storage elastic modulus (G ′) is constant and the storage elastic modulus. A tangent line is drawn to each of the portions where (G ') is lowered, and the temperature at which the temperature starts to fall is determined as the intersection of these tangent lines.

Next, it is important from the viewpoint of offset resistance that the tangent loss (tan δ) (point B in FIG. 1) at the temperature at which the storage elastic modulus (G ') starts to fall is 0.020 or less. That is, when the tangent loss (tan δ) exceeds 0.20, an offset occurs even if the temperature at which the storage elastic modulus (G ′) begins to fall is within the range of the present invention (Comparative Examples 1 and 5 described later). reference). This is considered to be because the ratio of the viscous component (G ″) has already increased compared to the elastic component (G ′) at the start of melting the toner.

Further, in the present invention, the peak temperature of the loss elastic modulus (G ") of 110 ° C. or higher improves the heat resistance of the toner and prevents the toner from blocking in an actual developing device. It is important in order not to impair the fluidity of the toner, that is, as shown in the examples below.
When the peak temperature is 113 ° C., the heat resistant temperature of the toner is 65 ° C. (Example 2), whereas the peak temperature is only slightly decreased to 109 ° C., and the heat resistant temperature of the toner becomes 55 ° C. However, the peak temperature of the loss elastic modulus (G ″) is 110 in view of the heat resistance of the toner.
The criticality of being above ℃ becomes clear.

As described above, according to the present invention, by forming a toner with a resin composition satisfying the above rheological characteristics, (1), (2) and (3), energy saving heat fixing and high speed heat fixing conditions are achieved. Also in this case, a combination of excellent heat fixing property and offset resistance can be achieved.

In energy saving heat fixing and high speed heat fixing,
Since the heat capacity is relatively small and the amount of heat applied is also small, the temperature tends to fluctuate during fixing. In the present invention, it has been found that the G ′ drop start temperature difference due to the difference in the measurement frequency, which is expressed by the equation 1, is closely related to the influence of the temperature variation during fixing. If the difference in G ′ drop start temperature is within 20 ° C., there is almost no effect due to temperature fluctuation in low temperature fixing (Example 3), but if it exceeds 20 ° C. (Comparative Example 3), temperature variation in low temperature fixing occurs. The impact will be significant.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION [Resin] The resin composition used in the present invention satisfies the above-mentioned rheological properties. The rheological properties described above depend on the type of resin and the molecular weight distribution of the resin.

The temperature at which the storage elastic modulus (G ') begins to fall in the above (1) varies depending on the type of resin, but is generally closely related to the low molecular weight peak molecular weight in the resin. This low molecular weight peak molecular weight is in the range of 1.0 × 10 ^{3 to} 3.0 × 10 ⁴ , particularly 3.0 × 10 ^{3 to} 2.
It is preferably in the range of 0 × 10 ⁴ .

On the other hand, the peak temperature of the loss elastic modulus (G ") in the above (3) varies depending on the type of resin, but generally it is closely related to the high molecular weight peak molecular weight in the resin. This high molecular weight peak molecular weight is 8.0 × 10.
It is preferably in the range of ^{4 to} 6.0 × 10 ⁵ , particularly in the range of 1.0 × 10 ^{5 to} 5.0 × 10 ⁵ .

As the resin or resin composition constituting the toner, a fixing resin or resin composition conventionally used in the production of toner can be used as long as the above conditions are satisfied. Suitable examples of such fixing resin include:
Polyester resin, styrene resin, acrylic resin,
Examples thereof include styrene-acrylic copolymer resin and ionomer.

A suitable polyester resin for toner is formed by polycondensation of a polyol and a polycarboxylic acid component. By using a plurality of components of at least one of the polyol and the polycarboxylic acid component, low temperature fixability is improved. It is preferable to use the added copolyester.

As the polyol component, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, triethylene glycol,
1,6-hexylene glycol, neopentyl glycol, cyclohexanedimethanol, bisphenol A,
Besides diols such as ethylene oxide or propylene oxide adducts of bisphenol A, trivalent or higher valent polyols such as pentaerythritol, dipentaerythritol, trimethylolpropane, sorbitol, mannitol and glycerol are used.

As the polycarboxylic acid, terephthalic acid,
Aromatic dicarboxylic acids such as isophthalic acid, phthalic acid and naphthalenedicarboxylic acid: Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid: Aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid and fumaric acid In addition to dibasic acids such as acids, polybasic acids such as trimellitic acid, naphthalenetricarboxylic acid, cyclohexanetricarboxylic acid and octanetetracarboxylic acid are also used.

In order to broaden the molecular weight distribution to obtain the above-mentioned bimodal distribution, it is preferable to use a combination of a divalent component and a trivalent or more component as at least one of the polycarboxylic acid and / or the polyol component. , Trimellitic acid and the like are used for this purpose. Further, in order to balance the low temperature fixability and the heat resistance, it is preferable to use a combination of an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid as the polycarboxylic acid, and bisphenol A as at least a part of the polyols. It is preferable to use the ethylene oxide or propylene oxide adduct of

Examples of suitable copolyester formulations are as follows. Aromatic dicarboxylic acid 20 to 80 mol% Aliphatic dicarboxylic acid 5 to 60 mol% Tricarboxylic or higher polycarboxylic acid 5 to 30 mol% Ethylene oxide or propylene oxide adduct of bisphenol A 30 to 80 mol% Diol 20 to 100 mol %.

Another type of resin suitable for toners is a copolymer of styrene and an acrylic monomer. Acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
(Meth) acrylic acid alkyl ester such as butyl (meth) acrylate and 2-ethylhexyl (meth) acrylic acid; acrylic acid, methacrylic acid; (meth) acrylonitrile: (meth) acrylic amide; (meth) acrylic-2- (Meth) acrylic hydroxyalkyl esters such as hydroxyethyl, (meth) acrylic-3-hydroxypropyl; (meth) acrylic-2-aminoethyl,
(Meth) acryl-3-aminopropyl, N-ethyl (meth) acryl-2-aminoethyl, and other (meth) acryl-aminoalkyl esters; glycidyl (meth) acrylate and the like can be mentioned. The main body is preferably composed of (meth) acrylic acid alkyl ester.

The ratio of styrene to acrylic monomer in the copolymer may vary, but is generally 95: 5.
It is preferably present in a weight ratio of from 20 to 80:80, in particular from 90:10 to 50:50. A particularly suitable styrene-acrylic copolymer has a composition of styrene 90 to 50% by weight methyl methacrylate 20 to 10% by weight n-butyl acrylate 50 to 10% by weight.

[Toner Composition and Preparation] The above-mentioned fixing resin contains the compounding agent for toner known per se, such as a colorant,
A charge control agent, a release agent, etc. are added.

As the colorant, a coloring pigment, an extender pigment,
One kind or a combination of two or more kinds of magnetic pigments and conductive pigments can be used. Of course, these pigments may be pigments having two or more of the above-mentioned functions. For example, carbon black has a function as a conductive pigment together with a black pigment, and iron tetroxide has a function as a magnetic pigment. As is clear from the so-called iron black name, it also has a function as a black pigment.

Suitable examples of color pigments are: Black pigments Carbon black, acetylene black, run black, aniline black. Yellow pigment Yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow G,
Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake. Orange pigment Red lead yellow molybdenum, Molybden orange, Permanent orange GTR, Pyrazolone orange, Balkan orange, Induslen brilliant orange RK, Benzidine orange G, Induslen brilliant orange GK. Red pigment Bengal, cadmium red, red lead, mercury cadmium sulfide, permanent red 4R, resole red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, brilliant carmine 3B. Purple pigment Manganese purple, fast violet B, methyl violet lake. Blue pigment Navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chlorinated compound, fast sky blue, indanthrene blue B
C. Green pigment chrome green, chrome oxide, pigment green B,
Malachite Green Rake, Fanal Yellow Green G. White pigment Zinc white, titanium oxide, antimony white, zinc sulfide. Extender barite powder, barium carbonate, clay, silica, white carbon, talc, alumina white.

Conventional magnetic material pigments include, for example,
Iron oxide (Fe₃O_Four), Ferric oxide (γ-Fe)
₂O₃), Zinc iron oxide (ZnFe₂O_Four), Iron oxide
Thorium (Y ₃Fe_FiveO₁₂), Iron cadmium oxide (Cd
Fe₂O_Four), Gadolinium iron oxide (Gd₃Fe
_FiveO₁₂), Iron oxide copper (CuFe₂O_Four), Lead iron oxide (P
bFe₁₂O₁₉), Iron oxide nickel (NiFe₂O_Four),
Iron oxide neodymium (NdFeO₃), Iron oxide barium
(BaFe₁₂O₁₉), Magnesium iron oxide (MgFe₂
O_Four), Iron manganese oxide (MnFe₂O_Four), Iron oxide
(LaFeO₃), Iron powder (Fe), cobalt powder
(Co), nickel powder (Ni), etc. are known,
Also in the invention, any of fine powders of these known magnetic materials can be used.
Any thing can be used. Particularly suitable for the purposes of the present invention
The magnetic material pigment is ferric oxide.

As the conductive pigment, in addition to the above-described carbon black, any conductive fine particles such as non-conductive inorganic fine powder and various metal powders may be used.

As the charge controlling dye, a metal-containing complex salt dye, particularly a 2: 1 type metal-containing complex salt dye (dye molecule: metal =
2: 1) is preferable, and such a metal-containing complex salt dye is represented by the formula:

[0037]

[Chemical 1]

In the formula, rings A and B may have a condensed ring and may have a substituent such as a halogen atom, a nitro group, an alkyl group or an amide group, and M represents a transition metal. You can The transition metal M is C
Although r, Co, Cu, Fe, Ni, etc. can be mentioned, those containing Cr are preferable. Further, instead of the original metal dye, a salicylic acid metal salt-based charge control agent can be used.

As the release agent, various waxes and low molecular weight olefin resins are used. Among olefin resins, the number average molecular weight (Mn) is 3.0 × 10 ^{3 to} 8.
Those in the range of 0 × 10 ³ , particularly 4.0 × 10 ^{3 to} 7.0 × 10 ³ are preferable. As the olefin resin, polypropylene, polyethylene, and a propylene-ethylene copolymer are used, and polypropylene is particularly preferable.

In the present invention, the colorant is preferably used in an amount of 5 to 15 parts by weight, particularly 8 to 12 parts by weight, and the charge control agent is 0.5 to 5 parts by weight, based on 100 parts by weight of the fixing resin.
It is preferred to use parts by weight, especially 1.5 to 3 parts by weight, and the release agent in amounts of 1 to 5 parts by weight, especially 2 to 4 parts by weight.

These toner components are pre-mixed with a mixer such as a Henschel mixer, and then kneaded with a kneading device such as a twin-screw extruder. The kneaded composition is cooled and then pulverized, if necessary. Classify to make toner. The toner of the present invention is particularly suitable as a fine particle toner, and has excellent developing workability even if the particle size distribution is wide.
It also provides the advantage that the productivity of the toner can be increased.

The particle size of the toner is generally such that the median diameter by a Coulter counter is 5 to 20 μm, especially 7 to 1.
It is preferably within the range of 5 μm. If necessary, the surface of the toner particles is sprinkled with a fluidity improving agent such as hydrophobic vapor phase silica in an amount of 0.05 to 1.0% by weight to obtain a final toner.

In the electrostatographic copying method using the toner of the present invention, the electrostatic latent image can be formed by any method known per se, for example, by uniformly charging the photoconductive layer on the conductive substrate. After that, imagewise exposure can be performed to form an electrostatic latent image.

The development of the electrostatic image is easily carried out by mixing the magnetic brush as it is in the case of the one-component magnetic toner and the magnetic carrier in the case of the two-component toner, and bringing the magnetic brush into contact with the substrate. The toner image formed by the development is transferred onto a copy sheet, and the toner image is fixed by bringing it into contact with a heating roll or a heating head. When the electrostatic image toner of the present invention is used, even in a heating roll fixing method in which the process speed per minute is 500 mm / sec or more,
The toner has good fluidity and does not cause defective fixing or offset phenomenon even during thermal fixing. Even in the energy-saving fixing method using a heating head, a stable and good fixed image can be formed without defective fixing or offset phenomenon. There is an advantage that you can.

[0045]

The present invention will be described in more detail by the following examples. (Synthesis of Fixing Resin) Synthesis Example 1 Synthesis of Polymer Side Resin Composition by Weight Terephthalic Acid 90 Fumaric Acid 40 Trimellitic Acid 20 Polyoxyethylene (2,2) -bis (4-hydroxyphenyl) propane 150 Propylene Glycol 100 dibutyltin oxide 0.01 The above composition was polymerized at 220 ° C. to give a peak molecular weight of 4
90,000 resins were obtained. Synthesis of low molecular weight resin Isophthalic acid 120 Trimellitic acid 5 Polyoxyethylene (2,2) -bis (4-hydroxyphenyl) propane 150 Dibutyltin oxide 0.01 The above composition was polymerized at 220 ° C. to give a peak molecular weight of 9,400 resins were obtained. The high molecular weight resin and the low molecular weight resin were mixed at a weight ratio of 80:20 to obtain a fixing resin of Example 1.

Synthesis Example 2 Polymer side resin Resin having a peak molecular weight of 370,000 in the same manner as in Synthesis Example 1 except that terephthalic acid was 80 parts by weight, fumaric acid was 50 parts by weight and trimellitic acid was 15 parts by weight. Got Low molecular weight resin The peak molecular weight was 1 in the same manner as in Synthesis Example 1 except that 110 parts by weight of isophthalic acid and 7 parts by weight of trimellitic acid were used.
2,000 resins were obtained. The polymer side resin and the low molecule side resin were mixed at a weight ratio of 70:30 to obtain a resin of Example 2.

Synthesis Example 3 Composition parts by weight Xylene 70 Styrene 80 Methylmethacrylate (MMA) 20 BMA 25 Azobisisobutyronitrile 2.5 The above composition was polymerized at 80 ° C. for 6 hours to give a peak molecular weight of 4,000. A low molecular weight resin was obtained. This reaction solution was further polymerized with the following composition: parts by weight xylene 40 styrene 160 BMA 50 azobisisobutyronitrile 3.0 60 ° C. for 8 hours to give a peak molecular weight of 220,00.
0 polymer side resin was obtained. After the polymerization, the reaction solution was desolvated, dried, and pulverized to obtain the resin of Example 3.

Synthesis Example 4 Azobisisobutyronitrile, which is a polymerization initiator, was added in an amount of 3.0 parts by weight for resin polymerization on the low molecular side and 5.0 parts for resin polymerization on the high molecular side.
Polymerization was performed in the same manner as in Synthesis Example 3 except that the polymerization part was used.
A high molecular weight side resin having a peak molecular weight of 122,000 and a low molecular weight side resin having a peak molecular weight of 3,200 were obtained. After the polymerization, this reaction liquid was desolvated, dried and pulverized to obtain a resin of Comparative Example 1.

Synthesis Example 5 Polymerization was carried out in the same manner as in Synthesis Example 3 except that azobisisobutyronitrile, which is a polymerization initiator, was polymerized to 2.0 parts by weight on the low molecular weight side resin, and the peak molecular weight was 220,000. And a low molecular weight resin having a peak molecular weight of 5,500. After the polymerization, this reaction liquid was desolvated, dried, and pulverized to obtain a resin of Comparative Example 2.

Synthesis Example 6 Polymerization was carried out in the same manner as in Synthesis Example 3 except that the polymerization temperature of the resin polymerization on the low molecular weight side was 60 ° C. and 0.5 part by weight of divinylbenzene was added in the resin polymerization on the high molecular weight side. Was obtained and a low molecular weight resin having a peak molecular weight of 7,400 was obtained. After the polymerization, this reaction liquid was desolvated, dried, and pulverized to obtain a resin of Comparative Example 3.

Synthesis Example 7 Polymerization was carried out in the same manner as in Synthesis Example 3 except that the polymerization temperature was 70 ° C. for both the low molecular weight resin polymerization and the high molecular weight resin polymerization,
A high molecular weight side resin having a peak molecular weight of 91,000 and a low molecular weight side resin having a peak molecular weight of 6,100 were obtained. After the polymerization, this reaction liquid was desolvated, dried, and pulverized to obtain a resin of Comparative Example 4.

Synthesis Example 8 Polymerization initiator was 2,2-azobis (2,4-dimethylvaleronitrile) in the low molecular weight resin polymerization, and the polymerization initiator was 2.0 polymerization parts in the high molecular weight resin polymerization. Temperature 7
Polymerization was performed in the same manner as in Synthesis Example 3 except that the temperature was 0 ° C. to obtain a polymer side resin having a peak molecular weight of 130,000 and a low molecular side resin having a peak molecular weight of 3,000. After the polymerization, this reaction liquid was desolvated, dried, and pulverized to obtain a resin of Comparative Example 5.

[0053]

[Table 1]

(Manufacture of Toner) Composition Part by Weight Fixing Resin (Table 1) 100 Parts by Weight Colorant 10 Parts by Weight (“MA-100” Mitsubishi Kasei Co.) Charge Control Agent 2 parts by Weight (“Spiron Black TRH Release agent 2 parts by weight ("NP-505" manufactured by Mitsui Petrochemical Co., Ltd.) The above composition was premixed, melt-kneaded, coarsely pulverized, finely pulverized, classified, and had an average particle size of 10.0 μm. Toner particles are obtained. The toner particles were surface-treated with 0.1 part by weight of "aluminum oxide C" (manufactured by Degussa) and 0.3 part by weight of "TS-720" (manufactured by Cabot).

(Evaluation Test of Toner) 1 Rheological Properties “Solydimeter MR-300” (manufactured by Rheology)
To measure rheological properties. The measurement conditions are as follows. Measurement distortion: 1 deg Measurement jig: Cone plate (φ40, cone angle 2
deg) 2 Toner fixing property Continuous 10 with copier "DC-3585" (manufactured by Mita Kogyo Co., Ltd.)
When 0 sheets are copied and the fixing rate is measured for every 5 sheets, if all 5 sheets have a fixing rate of more than 90%, it is marked with “◯”, and if not, it is marked with “×”. 3 Toner heat resistant temperature measurement Glass cylinder on glass plate (height: 55 mm, external shape:
(30 mm, inner diameter: 25 mm) is stood, sample toner (5 g) is put therein, and a weight (10 g) is placed from above. After heating this test sample at a predetermined temperature for 30 minutes, 5
Allow to cool for a minute and remove the glass cylinder upwards. At this time, if the toner in the glass cylinder is not fused and blocked, the result is “◯”. Thereafter, the same test is performed by increasing the temperature by a predetermined temperature. The maximum temperature at which the evaluation is "○" is the heat resistance test result. The evaluation results are shown in Tables 2 and 3.

[0056]

[Table 2]

[0057]

[Table 3]

[0058]

According to the present invention, by selecting the rheological property at the falling start temperature of the storage elastic modulus (G ') within a certain range, a fast heat fixing condition and a heat saving heat fixing condition with a small heat quantity can be given. However, it has become possible to achieve both low temperature heat fixability and offset resistance.

Therefore, it was possible to provide a toner having a low minimum fixing temperature, sufficient releasability and fluidity, and high image quality and productivity.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between storage elastic modulus (G ′), loss elastic modulus (G ″), tangent loss (tan δ) and temperature of the toner of the present invention.

Claims (2)

[Claims] 1. A toner used for the development and heat fixing of an electrostatic image, wherein the composition constituting the toner is measured under the conditions of a measurement frequency of 1 Hz and a measurement strain of 1 degree, and the following rheological Characteristics, that is, (1) the temperature at which the storage elastic modulus (G ') starts to fall is in the range of 80 ° C or higher and lower than 95 ° C.
(2) The tangent loss (tan δ) at the temperature at which the storage elastic modulus (G ′) begins to fall is 0.020 or less, and (3)
A toner for energy-saving heat fixing, which has a loss elastic modulus (G ″) peak temperature of 110 ° C. or higher, provided that tan δ = G ″ / G ′. 2. The toner composition has a measurement frequency of 0.
Measured under the conditions of 1 Hz and 10 Hz, the following formula (storage elastic modulus (G ') drop start temperature at 10 Hz)-
(Storage elastic modulus (G ') drop start temperature at 0.1 Hz) <
The energy-saving thermal fixing toner according to claim 1, wherein the toner satisfies 20 ° C.