JP4339710B2 - Spherical toner - Google Patents

Description

The present invention relates to a spherical toner that is excellent in low-temperature fixability, high-temperature offset resistance, blocking resistance, fluidity, and transfer efficiency, and has a sharp edge to obtain a very fine printed image.

A dry development method is frequently used as a method for developing an electrostatic image in electrophotography or the like. In the dry development system, the toner is usually charged by friction with iron powder, glass beads, etc., called a carrier, which adheres to the electrostatic latent image on the photoreceptor by electrical attraction, and then transferred onto the paper, It is fixed by a heating roller or the like and becomes a permanent visible image.

As a toner used in an electrophotographic apparatus, conventionally, a lump obtained by mixing a resin composition, a colorant, a carrier and the like is pulverized by a physical means such as a pulverizer and classified into a certain particle diameter. It was done. While such a toner can be manufactured inexpensively and easily, its shape is non-spherical and irregular.
In contrast, in recent years, spherical toners having a substantially spherical shape have been developed and put on the market. Such a spherical toner exhibits an excellent performance that an edge stands and an extremely high-definition printed image can be obtained. In addition, demand is expanding because of excellent fluidity in the apparatus and excellent transfer efficiency.

Among such spherical toners, a styrene-acrylic spherical toner mainly composed of a styrene-acrylic resin has a suspension in which a colorant or the like is dissolved in a polymer droplet when the resin composition is polymerized. By employing a turbid polymerization method or an emulsion polymerization method, it can be produced relatively easily.
However, in the case of a polyester toner mainly composed of a polyester resin, unlike a styrene-acrylic resin, it cannot be polymerized by a suspension polymerization method or an emulsion polymerization method, so that it is difficult to produce a spherical toner. It was thought to be.

On the other hand, a method has been proposed in which thermoplastic particles are injected into hot air injected from a hot air injection nozzle, and the surface of the thermoplastic particles is melted by contact with hot air to spheroidize, for example, a patent. In Document 1, an annular raw material supply head is provided on the upper side of the inlet formed in the top plate of the granulation tower, the tip of the hot air injection nozzle is inserted into the raw material supply head, and the raw material supply head is inserted into the raw material supply head. The supplied thermoplastic particles and compressed air-solid mixed fluid are injected into the hot air injected from the hot air injection nozzle from the raw material injection nozzle provided on the inner periphery of the raw material supply head, and the thermoplastic particles are spherical. In the spheroidizing apparatus, the spheroidizing apparatus has been proposed in which the hot air spray nozzle is supported so as to be movable up and down, and provided with lifting means for moving the hot air spray nozzle up and down. Moreover, using such a spheronization technique, Patent Document 2 uses a raw material containing a resin as a main component, a colorant, and a crystalline polyester having higher crystallinity than the resin as a subcomponent. A method for producing a toner is disclosed which includes a step of obtaining a toner production powder and a heat spheronization step of heating the toner production powder to spheroidize. According to these methods, it seemed possible to produce a spherical toner made of a polyester resin.

On the other hand, the toner is required to have high temperature offset resistance and blocking resistance as general performance. The offset phenomenon is a phenomenon in which, in an electrophotographic apparatus, when toner is transferred onto a sheet and fixed by a heating roller or the like, a part of the toner adheres to the surface of the heat fixing roller and retransfers to the paper. The blocking phenomenon is a phenomenon in which toner aggregates due to heat received through various environments. Such an offset phenomenon or blocking phenomenon is mainly caused by an increase in the fluidity of the toner in a high temperature range, so far, by adding a high molecular weight resin component having a weight average molecular weight of 1 million or more to the toner, High temperature offset resistance and blocking resistance are imparted by a method of reducing the fluidity of the toner in a high temperature range.

However, even if an attempt is made to spheroidize a polyester toner containing such a high molecular weight resin component having a weight average molecular weight of 1,000,000 or more using the apparatus described in Patent Document 1 or the method described in Patent Document 2, it has an irregular shape. However, it was not possible to obtain a spherical toner having a high sphericity to the extent that sufficient performance can be exhibited. That is, to date, there has been no spherical toner made of a polyester resin that has achieved sufficient high-temperature offset resistance and blocking resistance.

Further, in recent years, there has been a demand for a toner having excellent low-temperature fixability that can be fixed at a lower temperature in order to improve economics such as power consumption and increase the copying speed. However, when trying to improve the low-temperature fixability, the high-temperature offset resistance and blocking resistance are inferior. Therefore, compatibility between the high-temperature offset resistance, blocking resistance and low-temperature fixability has been an important issue for the toner.

JP 2000-52340 A JP 2003-270856 A

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a spherical toner that is excellent in low-temperature fixability, high-temperature offset resistance, blocking resistance, fluidity, and transfer efficiency, and has an edge and an extremely high-definition printed image. And

In the present invention, a crystalline polymer having a melting point of 180 to 280 ° C. and an endotherm at a melting point of 25 to 150 mJ / mg measured using a differential scanning calorimeter (DSC), and a glass transition temperature of 30 to An amorphous polyester having a temperature of 80 ° C., a resin component having a weight average molecular weight of 1,000,000 or more , a resin composition having a content of the crystalline polymer of 3 to 10% by weight, and having an average It is a spherical toner having a circularity of 0.92 or more.
The present invention is described in detail below.

The spherical toner of the present invention comprises a resin composition containing a crystalline polymer that satisfies certain conditions and an amorphous polyester. In the present specification, the crystalline polymer means a sharp and clear melting point peak when the differential heat is measured by a differential scanning calorimeter, and the crystallinity is 10%.
The non-crystalline polyester means a polyester having a crystallinity of 10% or less without showing a sharp and clear melting point peak when differential heat is measured by a differential scanning calorimeter.

As a result of intensive studies, the inventors of the present invention have a weight average molecular weight of 1 when such a resin composition is used.
It has been found that a toner having excellent low-temperature fixability, high-temperature offset resistance and blocking resistance can be produced without blending 00000 or more high molecular weight resin components, and such weight average molecular weight is 1 million or more. It has been found that a toner containing no high molecular weight resin component can be easily spheroidized by a conventionally known spheronization method and can be made into a spherical toner having a high sphericity, and the present invention has been completed.

In the spherical toner of the present invention, in the resin composition, the crystalline components in the high melting crystalline polymer form a physical cross-linked structure in the amorphous polyester, A non-crystalline component and non-crystalline polyester are entangled to form a kind of network structure. By forming such a network structure, there is little decrease in viscosity at high temperature, and low temperature fixability and storage It is considered that good offset resistance can be exhibited without reducing the properties. Only by forming such a network structure, an excellent effect that cannot be obtained by simply mixing a plurality of resins is exhibited.

That is, in the spherical toner of the present invention, a high-melting crystalline polymer capable of forming a physical crosslinked structure is mixed with an amorphous polyester that does not form a physical crosslinked structure and has a glass transition temperature of 30 to 80 ° C. By using the resin composition, the viscosity in the high temperature range is increased, the high temperature offset resistance and the blocking resistance are improved, and the viscosity is lowered when the pressure is applied by the fixing roll. Increases gloss and improves low-temperature fixability. Since these properties can be realized without blending a high molecular weight resin component having a weight average molecular weight of 1 million or more as in the prior art, it can be easily spheroidized, and fluidity, transfer efficiency, and edge are extremely high. It is possible to produce an excellent spherical toner such that a fine printed image can be obtained.

In the resin composition, to express a uniform fine dispersion structure in the nano order as described above,
In order to form a network structure, it is very important that the compatibility between the crystalline polymer and the non-crystalline polyester is high, and it is important that the crystallinity of the crystalline polymer is high.

The resin composition has a preferred lower limit of the endotherm at the melting point measured using a differential scanning calorimeter (DSC) of 1 mJ / mg, and a preferred upper limit of 20 mJ / mg. If it is less than 1 mJ / mg, the above-mentioned network structure may not be formed and the desired effect such as high-temperature offset resistance may not be obtained. If it exceeds 20 mJ / mg, the viscosity of the polymer during pressurization with a fixing roll may be reduced. In some cases, the surface of the print after fixing may not be sufficiently lowered, resulting in unevenness on the printed surface, resulting in poor gloss or low temperature fixability. A more preferred lower limit is 2 mJ / mg, and a more preferred upper limit is 15 mJ / mg.
mg.

It is preferable that the crystals forming the physical crosslinked structure are uniformly finely dispersed in the resin composition with a size of 5 μm or less. More preferably, the size is 1 μm or less. Due to the fine dispersion of fine crystals, the network structure becomes more stable and exhibits excellent effects. Specifically, the average particle diameter of the crystal particles observed when the spherical toner of the present invention is observed with a polarizing microscope is preferably 5 μm or less. In the present specification, the term “crystal particles” means a particulate structure formed by crystal components in the crystalline polymer forming a physical cross-linked structure.

It does not specifically limit as a method to measure the average particle diameter of the said crystal particle, For example, it can obtain | require by the following method. That is, the spherical toner of the present invention is placed on a slide, heated to about 100 ° C. using a hot plate or the like, softened, and then lightly pressed with a cover glass. Thereafter, the resin is heated to 150 ° C. to recrystallize the amorphous resin, and then returned to room temperature. This is observed using a polarizing microscope having a magnification of 200 times, and the particle diameter of the distinguishable crystal particles is measured, and the average is obtained.

The resin composition has a haze value of 60 measured by a method according to JIS K 7105.
% Or more is preferable. When the haze value is 60% or more, the crystals forming the physical crosslinked structure are uniformly finely dispersed with a size of 5 μm or less, and the spherical toner of the present invention comprising such a resin composition Is excellent in low-temperature fixability, high-temperature offset resistance and blocking resistance, and can perform good color development. If the haze value is less than 60%, the crystals are aggregated and not uniformly dispersed, and the above-described network structure cannot be formed.
Note that the haze value is calculated by a method based on JIS K 7105.
(%) And diffuse transmittance Td (%) can be measured and calculated by the following formula (1).

上記樹脂組成物は、示差走査熱量計（ＤＳＣ）を用いて測定した再結晶開始温度Ｔｉｃと
再結晶ピーク温度Ｔｐｃとの差が３０℃以下であることが好ましい。本発明者らは、鋭意
検討の結果、上記樹脂組成物内の上記物理的架橋構造を形成した結晶の分散の状態が、樹
脂組成物の再結晶温度と相間していることを見出した。即ち、樹脂微粒子中の結晶成分が
偏在している場合には、結晶成分の濃度が高い部分では比較的低い温度で再結晶化が始ま
り、結晶成分の濃度が低い部分では比較的高い温度まで再結晶化が始まらないと考えられ
、一方、樹脂微粒子中の結晶成分が均一である場合には、このような再結晶化の温度の差
異は生じないと考えられる。従って、再結晶開始温度Ｔｉｃと再結晶ピーク温度Ｔｐｃと
の差は、樹脂組成物中における結晶成分の分散の度合いを反映するものと考えられ、この
差が小さいほど結晶成分が均一に分散しているものと考えられる。示差走査熱量計（ＤＳ
Ｃ）を用いて測定した再結晶開始温度Ｔｉｃと再結晶ピーク温度Ｔｐｃとの差が３０℃以
下である場合には、上記物理的架橋構造を形成した結晶は、樹脂組成物中に均一に微分散
しており、このような樹脂組成物からなる本発明の球状トナーは、低温定着性、耐高温オ
フセット性及び耐ブロッキング性に優れ、良好な発色を行うことができる。再結晶開始温
度Ｔｉｃと再結晶ピーク温度Ｔｐｃとの差が３０℃を超えると、結晶成分が均一に分散し
ていないため、ネットワーク構造を形成することができず上述の効果を得ることができな
い。

The resin composition preferably has a difference of 30 ° C. or less between the recrystallization start temperature Tic and the recrystallization peak temperature Tpc measured using a differential scanning calorimeter (DSC). As a result of intensive studies, the present inventors have found that the state of dispersion of crystals forming the physical cross-linked structure in the resin composition is in phase with the recrystallization temperature of the resin composition. That is, when the crystal component in the resin fine particles is unevenly distributed, recrystallization starts at a relatively low temperature in a portion where the concentration of the crystal component is high, and recrystallization is performed up to a relatively high temperature in a portion where the concentration of the crystal component is low. It is considered that crystallization does not start. On the other hand, when the crystal components in the resin fine particles are uniform, it is considered that such a difference in recrystallization temperature does not occur. Therefore, the difference between the recrystallization start temperature Tic and the recrystallization peak temperature Tpc is considered to reflect the degree of dispersion of the crystal component in the resin composition. The smaller this difference, the more uniformly the crystal component is dispersed. It is thought that there is. Differential scanning calorimeter (DS
When the difference between the recrystallization start temperature Tic and the recrystallization peak temperature Tpc measured using C) is 30 ° C. or less, the crystals forming the physical cross-linked structure are uniformly fine in the resin composition. The spherical toner of the present invention, which is dispersed and made of such a resin composition, is excellent in low-temperature fixability, high-temperature offset resistance and blocking resistance, and can perform good color development. If the difference between the recrystallization start temperature Tic and the recrystallization peak temperature Tpc exceeds 30 ° C., the crystal components are not uniformly dispersed, so that the network structure cannot be formed and the above-described effects cannot be obtained.

In the present specification, the recrystallization start temperature Tic means the temperature at the rising point of an exothermic peak showing recrystallization observed when measured using a differential scanning calorimeter (DSC), and The recrystallization peak temperature Tpc means the temperature at the apex of the endothermic peak indicating recrystallization. In addition, the measurement conditions of the differential scanning calorimeter (DSC) are not particularly limited. For example, the measurement can be performed by a method of heating 10 mg of a sample at a heating rate of 10 ° C./min in accordance with JIS K7121.

The recrystallization start temperature Tic is preferably 80 ° C. or higher. If it is lower than 80 ° C., the crystalline state may change during storage of the spherical toner of the present invention. Further, when the recrystallization start temperature Tic is 80 ° C. or higher, crystallization occurs in the kneaded state, so that the crystal component can be more uniformly dispersed.

When the resin composition gave a shear strain of 5% under the condition of 190 ° C., the following formula (2)
It is preferable that the change rate D of the relaxation elastic modulus represented by is 15 to 90.

式中、Ｇ_５％（０．１）は、５％の剪断ひずみを与えて０．１秒後の緩和弾性率を表し、
Ｇ_{５％ｍａｘ}は、剪断ひずみを与えてからの時間を横軸に、緩和弾性率を縦軸にとり緩和
弾性率曲線を描いた場合の緩和弾性率曲線ピーク位置の緩和弾性率を表す。

In the formula, G _5% (0.1) represents a relaxation elastic modulus after 0.1 seconds after applying a shear strain of 5%,
G _{5% max} represents the relaxation elastic modulus at the peak position of the relaxation elastic modulus curve when a relaxation elastic modulus curve is drawn with the time after applying shear strain as the horizontal axis and the relaxation elastic modulus as the vertical axis.

If the rate of change D of the relaxation modulus is less than 15, the viscosity of the toner is not sufficiently lowered when pressed by a fixing roll, resulting in unevenness on the printed surface after fixing, resulting in inferior gloss and poor low-temperature fixability. If it exceeds 90, it is difficult to form the above-mentioned network structure, so that sufficient high-temperature offset resistance may not be obtained.

When the resin composition was subjected to 450% shear strain at 190 ° C., the following formula (
It is preferable that the gradient K of the relaxation modulus curve from 0.02 seconds to 0.1 seconds after applying the shear strain represented by 3) is −27 or more.

式（３）中、Ｇ（０．０２）は、剪断ひずみを与えて０．０２秒後の緩和弾性率を表し、
Ｇ（０．１）は、剪断ひずみを与えて０．１秒後の緩和弾性率を表す。

In Formula (3), G (0.02) represents the relaxation elastic modulus 0.02 seconds after giving a shear strain,
G (0.1) represents the relaxation elastic modulus after 0.1 seconds after applying a shear strain.

The gradient K of the relaxation modulus curve represents the elastic behavior of the substance, and the closer to 0, the closer to rubber elasticity. The slope K of the relaxation elastic modulus curve is −27 or more because the above-mentioned network structure is formed in the resin composition, and it is high mainly in crystals that form the uniformly crosslinked physical crosslinked structure. It is considered that the rubber-like property is expressed by the structure in which the amorphous component in the crystalline polymer having the melting point and the amorphous polyester are entangled with each other. Therefore, the spherical toner of the present invention comprising the resin composition having a slope K of the relaxation elastic modulus curve of −27 or more is excellent in low-temperature fixability, high-temperature offset resistance and blocking resistance, and can exhibit good color development. it can. When the slope K of the relaxation elastic modulus curve is less than −27, the above-described network structure is not formed, and such an effect cannot be obtained.

When the resin composition was subjected to a shear strain of 450% under the condition of 190 ° C., the relaxation elastic modulus G (0.1) 0.1 seconds after the shear strain was applied was 30 to 3000 Pa. Preferably there is. As a result of intensive studies, the present inventors have found that the toner offset phenomenon occurs when the agglomeration force of the melted toner is smaller than the adhesion force between the toner and the heat fixing roller. It was found that there is a relationship between the cohesive strength of the product and the relaxation modulus of the resin composition under large deformation. As a result of further intensive studies, it has been found that if a resin composition having a certain relaxation modulus is used, the low temperature fixability can be improved while maintaining the high temperature offset resistance of the toner. If the relaxation elastic modulus G (0.1) is less than 30 Pa, the resulting toner may have insufficient high-temperature offset resistance, and a sufficiently wide fixing temperature range cannot be obtained. If it exceeds 3000 Pa, the low-temperature fixability of the resulting toner may be insufficient.
Note that the relaxation elastic modulus is obtained by, for example, melting a spherical toner of the present invention and then molding it into a disk having a predetermined size as a test sample, and using a relaxation elastic modulus measuring device (for example, RMS-Rheometers manufactured by Rheometrics Co., Ltd.). 800, etc.).

The resin composition has an angular frequency of 62.8 rad / sec and a strain amplitude of 1% measured at 120 ° C.
The preferred lower limit of the elastic tangent tan δ (120) is 0.5, the preferred upper limit is 2,
The preferable lower limit of the elastic tangent tan δ (160) at 0 ° C. is 0.5, and the preferable upper limit is 5.
If the elastic tangent tan δ (120) is less than 0.5, the low-temperature fixability of the resulting toner may be insufficient, and if it exceeds 2, the high-temperature offset resistance of the resulting toner may be insufficient. There is. If the elastic tangent tan δ (160) is less than 0.5, the low-temperature fixability of the obtained toner may be insufficient. If it exceeds 5, the high-temperature offset resistance of the obtained toner is insufficient. May be.
The elastic tangent tan δ is a viscoelasticity measuring device (for example, RMS-8 manufactured by Rheometrics Co., Ltd.) obtained by compression-molding the spherical toner of the present invention into a disk having a predetermined size.
00 etc.).

The resin composition preferably has a penetration of less than 10 (unit: 0.1 mm) at 60 ° C. If the penetration exceeds 10, the resulting toner may have insufficient blocking resistance.
In addition, the said penetration can be measured by the method based on ASTMD1321.

Next, the components of the resin composition constituting the spherical toner of the present invention will be described.
The resin composition constituting the spherical toner of the present invention contains a crystalline polymer and an amorphous polyester.
The crystalline polymer has an endotherm at a melting point of 25 to 150 mJ / mg measured using a differential scanning calorimeter (DSC). If it is less than 25 mJ / mg, it is difficult to form the above-mentioned network structure, so the desired effect such as high-temperature offset resistance cannot be obtained, and 150 mJ / m.
If it exceeds g, the viscosity of the polymer is not sufficiently lowered when pressed by a fixing roll, unevenness is generated on the printed surface after fixing, the gloss is inferior, and the low-temperature fixing property is inferior. Preferably 40-100mJ / m
g.
In addition, although it does not specifically limit about the measurement conditions of a differential scanning calorimeter (DSC), For example, J
In accordance with IS K 7121, it can be measured by a method of heating 10 mg of a sample at a heating rate of 10 ° C./min.

The melting point of the crystalline polymer is 180 to 280 ° C. If it is lower than 180 ° C., the high temperature hot offset resistance becomes insufficient, or filming is likely to occur, resulting in insufficient durability. When it exceeds 280 ° C., it is necessary to melt at a high temperature exceeding 280 ° C. at the time of mixing with the amorphous polyester, so that the productivity is remarkably deteriorated. Preferably it is 200 to 240 degreeC, and a more preferable minimum is 221 degreeC.

In order to shorten the rise time (warm-up time) after switching on in a copying machine or printer, it is necessary to quickly raise the fixing roller to a predetermined fixing temperature. Initially, it is hotter than a predetermined fixing temperature. Therefore, in order to perform good printing even in this state, the toner must have good hot offset resistance at high temperatures. The lower the fixing temperature and the higher the hot offset temperature, the shorter the warm-up time. Usually, in order to sufficiently increase the hardware design width, the hot offset resistance temperature is required to be 180 ° C. or higher. When the crystalline polymer has a melting point of 180 ° C. or higher, the crystal part of the crystalline polymer is not melted even at a high temperature, and the above-described network structure is maintained, so that the high temperature hot offset resistance is considered to be improved. In addition, as the speed of copying machines and printers increases, there is a demand for a toner that does not generate fine powder and does not cause filming even under high speed operation. In particular, non-magnetic one-component toner that is charged by mechanical contact with the blade has a higher demand for durability. When the melting point of the crystalline polymer is 180 ° C., the cohesive force of the crystalline part of the crystalline polymer is increased, and the above-described network structure is strengthened, so that the durability is considered to be improved.

The crystalline polymer has a preferable lower limit of the weight average molecular weight of 30,000 and a preferable upper limit of 300,000. If it is less than 30,000, the offset resistance and durability of the resulting toner may be insufficient, and if it exceeds 300,000, the low-temperature fixability and gloss may be inferior. This is considered to be because the above-described network structure cannot be sufficiently formed if it is out of this range. A more preferred lower limit is 50,000, a more preferred upper limit is 200,000, a still more preferred lower limit is 80,000, and a still more preferred upper limit is 150,000.

Although it does not specifically limit as said crystalline polymer, Crystalline polyester or crystalline polyamide is suitable. These crystalline polyesters and crystalline polyamides may be used alone or in combination. When used in combination, due to the synergistic effect of the two crystalline polymers,
High temperature offset resistance can be further improved. The crystalline polymer may be a copolymer with an amorphous polymer as long as it satisfies various conditions such as the endothermic amount as described above.

The crystalline polyester can be obtained by condensation polymerization of dicarboxylic acid and diol.
Examples of the dicarboxylic acid include o-phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, and itacone. Examples include acids, decamethylene carboxylic acids, anhydrides and lower alkyl esters thereof. Among these, terephthalic acid, naphthalenedicarboxylic acid, and anhydrides and lower alkyl esters thereof are preferably used for imparting crystallinity.
Examples of the diol include ethylene glycol, 1,3-propanediol, 1,
4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,3 -Butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-
Aliphatic diols such as hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol; 2 , 2-bis (4-hydroxycyclohexyl) propane, 2,2-
Alkylene oxide adduct of bis (4-hydroxycyclohexyl) propane, 1,4
-Alicyclic diols such as cyclohexanediol and 1,4-cyclohexanedimethanol.

Among the crystalline polyesters, polybutylene terephthalate (PBT),
Polyethylene terephthalate (PET) is preferred. Polybutylene terephthalate (P
Since BT) has a high crystallization rate and a high degree of crystallization, a toner comprising a resin composition containing the BT has excellent offset resistance. Further, since the compatibility with the non-crystalline polyester is excellent, the toner composed of the resin composition containing the polyester has excellent low-temperature fixability and gloss.
Since polyethylene terephthalate (PET) has a high crystal melting point, a toner comprising a resin composition containing the polyethylene terephthalate is particularly excellent in offset resistance at high temperatures. Polyethylene terephthalate (PET) has a crystallization rate higher than that of polybutylene terephthalate (PBT).
Although inferior in crystallinity, these points can be improved by adding a crystal nucleating agent.
These crystalline polyesters may be used alone or in combination of two or more.

Examples of the crystalline polyamide include 6-nylon, 6,6-nylon, 4,6-nylon,
11-nylon, 12 nylon, etc. are mentioned. Of these, 6-nylon and 6,6-nylon are preferred because they have high crystal cohesion and are excellent in the effect of improving high-temperature offset resistance. A polyamide-polyester copolymer obtained by copolymerizing polyester with these crystalline polyamides is also preferable because of excellent compatibility with the amorphous polyester. These crystalline polyamides may be used alone or in combination of two or more.
Since the crystalline polyamide has a strong intermolecular cohesive force, the high temperature offset resistance can be exhibited only by using a small amount of the polyester, and the strength of the resin itself can be increased.

The amorphous polyester has a glass transition temperature of 30 to 80 ° C. If it is less than 30 ° C., high-temperature offset resistance and blocking resistance cannot be sufficiently obtained, and if it exceeds 80 ° C., low-temperature fixability is inferior. Preferably it is 50-65 degreeC.
The non-crystalline polyester can be obtained by polycondensing a dicarboxylic acid and a diol.

The glass transition temperature of non-crystalline polyester is such that aromatic dicarboxylic acids such as terephthalic acid improve the glass transition temperature, and long-chain aliphatic dicarboxylic acids such as sebacic acid and adipic acid lower the glass transition temperature. Since it has a function, the target glass transition temperature can be achieved by appropriately combining these dicarboxylic acids. However, even if an objective glass transition temperature can be achieved by appropriately combining an aromatic dicarboxylic acid and a long-chain aliphatic dicarboxylic acid, the softening temperature tends to be too high.
Therefore, the non-crystalline polyester comprises a polyvalent carboxylic acid and a polyhydric alcohol containing at least either a divalent bending monomer capable of introducing a bent molecular structure into the molecular chain or a divalent monomer having a branched chain. It is preferable to polymerize the monomer mixture containing.
A polymer obtained by polymerizing a monomer mixture containing these divalent bending monomers and divalent monomers having a branched chain can easily achieve both a desired glass transition temperature and a low softening temperature, and can be crystallized. It can be effectively suppressed.

As the divalent bending monomer, an aromatic dicarboxylic acid in which the ortho position or the meta position is substituted with a carboxyl group, an aromatic diol in which the ortho position or the meta position is substituted with a hydroxyl group,
Polycarboxylic aromatic dicarboxylic acids having a carboxyl group at an asymmetric position, polycyclic aromatic diols having a hydroxyl group at an asymmetric position, and other monomers that can introduce a molecular structure bent into the molecular chain of the polymer are limited to dicarboxylic acids and diols. For example, it may be an anhydride or lower ester of a dicarboxylic acid, a monohydroxymonocarboxylic acid, etc., for example, phthalic anhydride, o-phthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,7 Dicarboxylic acids such as naphthalenedicarboxylic acid and anhydrides and lower esters thereof; monohydroxymonocarboxylic acids such as salicylic acid and 3-hydroxy-2-naphthalenecarboxylic acid; catechol,
Examples include diols such as 1,4-cyclohexanedimethanol.

A divalent monomer having a branched chain effectively suppresses crystallization of the polymer due to steric hindrance of the branched chain. Examples of the monomer having a branched chain that can effectively suppress crystallization include an aliphatic diol having a branched alkyl chain and an alicyclic diol having a branched alkyl chain. The alicyclic diol is preferably an alicyclic diol in which a plurality of alicyclic diols are linked by a branched alkylene chain.

The divalent monomer having a branched chain is not particularly limited. For example, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane- 1,3-diol), 1,2-hexanediol, 2,5
-Hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1
Aliphatic diols such as 1,3-propanediol and 2,4-diethyl-1,5-pentanediol; 2,2-bis (4-hydroxycyclohexyl) propane and 2,2-bis (4-hydroxycyclohexyl) propane And alicyclic diols such as alkylene oxide adducts.
Among them, terephthalic acid, neopentyl glycol, ethylene glycol and / or
Alternatively, an amorphous polyester obtained by polymerizing a monomer mixture containing 1,4-butanediol as a main component is preferable because it is excellent in low-temperature fixability and transparency.

The amorphous polyester preferably contains two types of amorphous polyesters having different average molecular weights. The melt viscosity of the amorphous polyester is determined by its molecular weight. If a non-crystalline polyester having a low molecular weight is used, the resulting toner has a low melt viscosity, so that excellent low-temperature fixability can be obtained. However, when an amorphous polyester having a small molecular weight is used, the resulting toner is inferior in high temperature offset resistance and storage stability, and it becomes difficult to knead with the crystalline polymer. As a result of intensive studies, the present inventors have used a non-crystalline polyester having a small average molecular weight and a non-crystalline polyester having a large average molecular weight, thereby maintaining high-temperature offset resistance while maintaining excellent low-temperature fixability, It has been found that the storage stability and kneadability with the crystalline polymer can be greatly improved.

The combination of two types of non-crystalline polyesters having different weight average molecular weights is not particularly limited, but non-crystalline polyesters having a weight average molecular weight of 3000 to 20,000 as those having a small average molecular weight are considered to have a large average molecular weight. It is preferable to use an amorphous polyester having a weight average molecular weight of 30,000 to 300,000. When the weight average molecular weight of the non-crystalline polyester having a small average molecular weight is less than 3000, the strength of the resin composition for the toner is lowered, resulting in insufficient durability of the toner. Fixing ability may not be exhibited. A more preferred upper limit is 8000. If the weight average molecular weight of the non-crystalline polyester having a large average molecular weight is less than 30,000, the resulting toner may have insufficient high-temperature offset resistance, storage stability and kneadability with a crystalline polymer. If it exceeds 10,000, the low-temperature fixability of the obtained toner may be insufficient.

Non-crystalline polyester having a weight average molecular weight of 3000 to 20,000 and a weight average molecular weight of 30,000 to
As a compounding ratio with the non-crystalline polyester which is 300,000, the weight average molecular weight is 3000-2.
The weight average molecular weight is 30,000 to 3 with respect to 40 to 90% by weight of non-crystalline polyester.
It is preferable that the non-crystalline polyester which is 100,000 is 10 to 60% by weight. When the blending amount of the amorphous polyester having a weight average molecular weight of 3000 to 20,000 is less than 40% by weight,
The low-temperature fixability of the obtained toner may be insufficient, and if it exceeds 90% by weight, the high-temperature offset resistance, storage stability and kneadability with the crystalline polymer of the obtained toner may be insufficient. is there.

The non-crystalline polyester has a molecular weight of 1000 to 300,000 but a content of 90% by weight or more. Among the non-crystalline polyester having a molecular weight of 1000 to 300,000, the molecular weight is 1000 to 20,000. It is preferable that the content of something is 40 to 90% by weight, and the content of one having a molecular weight of 20,000 to 300,000 is 10 to 60% by weight.

The crystalline polymer and the non-crystalline polyester are preferably compatible. When the crystalline polymer and the non-crystalline polyester are compatible, the above-described network structure can be stably formed. When the crystalline polymer and the non-crystalline polyester are compatible, the resin composition is colorless and transparent, and a color toner capable of performing good color development can be obtained. Since the toner has strength, a toner excellent in durability and high-temperature offset resistance can be obtained.

In the present specification, the term “compatible” refers to a state in which the crystalline polymer and the non-crystalline polyester are uniformly mixed. These are completely compatible or partially compatible. May be.
Thus, in order for the crystalline polymer and the non-crystalline polyester to be compatible, the glass transition temperature of the crystalline polymer is A (° C.), and the glass transition temperature of the non-crystalline polyester is B (° C.). The glass transition temperature C (° C.) of the resin composition preferably satisfies the following formula (4).

式（４）中、ｓは樹脂組成物中の結晶性ポリマーの重量分率を表し、ｔは樹脂組成物中の
非結晶性ポリマーの重量分率を表す。

In formula (4), s represents the weight fraction of the crystalline polymer in the resin composition, and t represents the weight fraction of the amorphous polymer in the resin composition.

When the glass transition temperature of the resin composition satisfies the above formula (4), the crystalline polymer and the amorphous polyester are very well compatible.

If the crystalline polyester is used as the crystalline polymer, and the crystalline polyester and the amorphous polyester have a common monomer component such as terephthalic acid as a constituent monomer, compatibility can be improved. it can. For example, the crystalline polyester may be polybutylene terephthalate (PBT) or polyethylene terephthalate (PE
T) and the non-crystalline polyester is obtained by polymerizing a monomer mixture containing terephthalic acid, neopentyl glycol, and ethylene glycol and / or 1,4-butanediol as a main component. Is well compatible.

As the content of the crystalline polymer and the non-crystalline polyester in the resin composition, the preferred lower limit of the crystalline polymer content is 2% by weight, and the preferred upper limit is 30% by weight. preferred upper limit is 98% by weight of the content of the polyester is the preferred lower limit is 70 wt%. When the content of the crystalline polymer is less than 2% by weight, the high temperature offset resistance may be inferior, and when it exceeds 30% by weight, the low temperature fixability may be inferior. A more preferred lower limit is 3% by weight, a more preferred upper limit is 20% by weight, a still more preferred lower limit is 5% by weight, and a still more preferred upper limit is 15% by weight.

The resin component contained in the resin composition is as described above, but the upper limit of the content of the resin component having a weight average molecular weight of 1,000,000 or more in the resin composition is 5% by weight. In the present invention, a toner excellent in high temperature offset resistance and blocking resistance can be obtained without blending a resin component having a weight average molecular weight of 1,000,000 or more. Further, by not blending a resin component having a weight average molecular weight of 1,000,000 or more in this way, it can be easily spheroidized by the method described later. Therefore, here, the upper limit of the content of the resin component having a weight average molecular weight of 1,000,000 or more is 5% by weight. The high molecular weight generated and mixed in the manufacturing process of the crystalline polymer or the amorphous polyester. If the proportion of the component is 5% by weight or less, it means that it is acceptable, and does not mean that a high molecular weight component is positively blended. When the amount exceeds 5% by weight, a spherical toner having sufficient sphericity may not be obtained even when the spheronization treatment is performed. The preferred upper limit is 1% by weight, and ideally it is not contained at all.

The resin composition preferably contains a crystal nucleating agent. By containing the crystal nucleating agent, crystallization of the crystalline polymer component can be promoted. The crystal nucleating agent is not particularly limited. For example, zinc oxide, magnesium oxide, silicon oxide, iron oxide (II
I), metal oxides such as titanium oxide; inorganic salts such as calcium carbonate, magnesium carbonate, calcium silicate, lead silicate, magnesium silicate, calcium phosphate, calcium sulfate, barium sulfate, potassium titanate; calcium oxalate, Organic acid salts such as sodium acid; clays such as talc, kaolin, clay mica and wollastonite. In addition, the shape of the crystal nucleating agent is not particularly limited, and may be amorphous, in addition to a plate shape and a spherical shape.
Although it does not specifically limit as an acid value of the said resin composition, It is preferable that it is 1-30. Such an acid value is attributed to an acidic functional group at the end of the main chain of the crystalline polymer or the non-crystalline polyester, specifically, for example, a carboxyl group. When the acid value is in this range, the toner obtained is excellent in low-temperature fixability, and the affinity with paper is also improved.

The method for preparing the resin composition is not particularly limited. For example, the crystalline polymer and the non-crystalline polyester are separately prepared, and the obtained crystalline polymer and non-crystalline polyester are crystallized polymer. And a method of mixing at a temperature equal to or higher than the melting point.

In addition to the above resin composition, the spherical toner of the present invention may further comprise a colorant, a charge control agent, a magnetic material, a rubbery polymer, a toner resin comprising a styrene-acrylate copolymer, if necessary. You may contain a carrier, a cleaning property improving agent, etc.

The colorant is not particularly limited. For example, carbon black such as furnace black, lamp black, thermal black, acetylene black, channel black, aniline black, phthalocyanine blue, quinoline yellow lamp black, rhodamine-
B, azo pigment, perylene pigment, perinone pigment, anthraquinone pigment, dioxazine pigment, isoindoline pigment, isoindolinone pigment, selenium pigment, indico pigment, quinophthalone, diketopyrrolopyrrole, quinacridone, etc. Is mentioned. The preferable lower limit of the blending amount of these colorants is 1 part by weight with respect to 100 parts by weight of the resin composition, and the preferable upper limit is 10 parts by weight.

There are two types of charge control agents, positive charge and negative charge. Examples of the charge control agent for positive charge include nigrosine dyes, ammonium salts, pyridinium salts, and azines. Examples of the charge control agent for negative charge include chromium complexes and iron complexes. Among these, an acid-modified charge control agent is suitable, and when it is salicylic acid-modified, it crosslinks with the toner resin composition and develops rubber elasticity. Metal complexes of alkyl-substituted salicylic acid such as di-tert-butylsalicylic acid chromium complex and di-tert-butylsalicylic acid zinc complex are preferable because they are colorless or light-colored and do not affect the color tone of the toner. As the charge control agent, a charge control resin (CCR) can also be suitably used. As the charge control resin, for example,
Examples thereof include a styrene acrylic polymer obtained by copolymerization of a monomer containing a quaternary ammonium salt, an organic fluorine-based monomer, a sulfonic acid group-containing monomer, a phenylmaleimide monomer, and the like. The preferable lower limit of the blending amount of these charge control agents is 0.1 part by weight with respect to 100 parts by weight of the resin composition, and the preferable upper limit is 10 parts by weight.

As said magnetic body, brand name "TAROX BL series" (made by a titanium industry company), for example
, Product name "EPT series", product name "MAT series", product name "MTS series" (
All are manufactured by Toda Kogyo Co., Ltd.), trade name “DCM Series” (manufactured by Dowa Iron Powder Co., Ltd.), trade name “KBC”
Series ”, product name“ KBI series ”, product name“ KBF series ”, product name“ KBP series ”(all manufactured by Kanto Denka Kogyo Co., Ltd.), product name“ Bayoxide E series ”(B
ayer AG).

Examples of the rubbery polymer include natural rubber, polyisoprene rubber, polybutadiene rubber, nitrile rubber (acrylonitrile-butadiene copolymer), chloroprene rubber, butyl rubber, acrylic rubber, polyurethane elastomer, silicone rubber, and ethylene-propylene copolymer. , Ethylene-propylene-diene copolymer, chlorosulfinated polyethylene, ethylene vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, chlorinated polyethylene, epichlorohydrin rubber, nitrile isoprene Synthetic rubber such as rubber, elastomer such as polyester elastomer, urethane elastomer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, steel Down - ethylene butylene - styrene block copolymer, styrene - ethylene propylene - block copolymer of an aromatic hydrocarbon and a conjugated diene hydrocarbon such as styrene block copolymers. The block copolymer contains styrene
A butadiene block copolymer, a styrene-isoprene block copolymer, or the like may be mixed, or these hydrogenated products may be mixed.

Further, a rubbery polymer comprising a block copolymer of an aromatic hydrocarbon having a polar group such as a hydroxyl group, a carboxyl group, an aldehyde group, a sulfonyl group, a cyano group, a nitro group, or a halogen group and a conjugated diene is used as a toner. It is preferable because of its excellent affinity with. These block copolymers having polar groups at the ends can be obtained by living polymerization.
The rubbery polymer can improve the resin strength of the resin contained in the toner. Therefore, the toner containing the rubber-like polymer can prevent the filming phenomenon of the toner, and a toner suitable for the non-magnetic one-component toner requiring high resin strength can be obtained.

Examples of the carrier include simple metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium, and rare earth, alloys, oxides, and ferrites. The surface of the carrier may be oxidized. Carrier surface is polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone polymer, polyester, metal complex of di-tert-butylsalicylic acid, styrene polymer, acrylic polymer, polyamide, polyvinyl butyral, nigrosine base May be coated with a functional dye, silica powder, alumina powder or the like. By coating the carrier, preferable triboelectric chargeability can be imparted to the carrier.

The cleaning property improving agent is not particularly limited as long as the fluidity of the toner is improved by mixing with the toner particles. When the fluidity of the toner is improved, the toner is less likely to adhere to the cleaning blade. For example, fluorine polymer powder such as vinylidene fluoride polymer, acrylic polymer powder such as acrylic ester polymer, fatty acid metal salt powder such as zinc stearate, calcium stearate, lead stearate, zinc oxide powder, titanium oxide powder, etc. Examples thereof include metal oxide powder, fine powder silica powder, silica powder surface-treated with a silane coupling agent, titanium coupling agent, silicon oil, and the like, fumed silica, and the like. In addition, as the cleaning property improver, a sphere having a particle diameter of 0.05 to 0.5 μm made of an acrylic polymer, a styrene polymer, or the like can be suitably used.

The spherical toner of the present invention preferably further contains a low melting point compound having a melting point of 70 to 120 ° C. If it is lower than 70 ° C., the storage stability and fluidity of the resulting toner may be inferior.
If it exceeds 120 ° C., the improvement in low-temperature fixability may be insufficient. The melting point is 70-1
Although it does not specifically limit as a low melting-point compound which is 20 degreeC, Crystalline polyester or wax is suitable.

When a crystalline polyester is used as the low melting point compound having a melting point of 70 to 120 ° C., the crystalline polyester is not particularly limited, but an aliphatic polyester is preferably used. The aliphatic polyester is excellent in compatibility with the above resin composition, and the low melting point compound does not fall off when the toner is pulverized. In addition, since aliphatic polyester has a higher molecular weight than wax, bleeding from the toner hardly occurs, and the storage stability and fluidity of the toner are excellent. When a crystalline polyester is used as the low melting point compound having a melting point of 70 to 120 ° C., the low melting point compound having a melting point of 70 to 120 ° C. may be blended in the toner resin composition.
When a wax is used as the low melting point compound having a melting point of 70 to 120 ° C., the wax can also serve as a release agent.

Examples of the wax include olefin wax and paraffin wax such as polypropylene wax, polyethylene wax, microcrystalline wax, and oxidized polyethylene wax; aliphatic ester wax such as carnauba wax, sazol wax, and montanate ester wax; Acid carnauba wax; valtimic acid, stearic acid,
Saturated aliphatic acid waxes such as montanic acid; Unsaturated aliphatic acid waxes such as pracidic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, seryl alcohol, melyl alcohol Saturated alcoholic waxes and aliphatic alcoholic waxes; polyhydric alcoholic waxes such as sorbitol; saturated fatty acid amide waxes such as linoleic acid amide, oleic acid amide, and lauric acid amide; methylenebisstearic acid amide, ethylenebiscaprin Saturated fatty acid bisamide waxes such as acid amide, ethylene bislauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N′-diole Unsaturated acid amide waxes such as irdipic acid amide and N, N′-dioleyl sebacic acid amide; m-xylene bis-stearic acid amide, N, N ′
-Aromatic bisamide waxes such as distearyl isophthalamide; Fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate; Grafts obtained by graft polymerization of vinyl monomers such as styrene and acrylic acid onto polyolefins Modified wax; Partial ester wax obtained by reacting fatty acid such as behenic acid monoglyceride and polyhydric alcohol; Methyl ester wax having hydroxyl group obtained by hydrogenation of vegetable oil; Ethylene-acetic acid with high content of ethylene component Vinyl copolymer wax; long-chain alkyl acrylate wax such as saturated stearyl acrylate wax such as acrylic acid; aromatic acrylate wax such as benzyl acrylate wax. Of these, long-chain alkyl acrylate wax and aromatic acrylate wax are preferred because they are excellent in compatibility with the resin composition and can provide a highly transparent toner. These waxes may be used alone or in combination of two or more, but it is particularly preferable to use in combination of two or more waxes having a melting point of 30 ° C. or more. The size of the wax in the toner is not particularly limited, but the major axis is preferably 2 μm or less.

In the low melting point compound having a melting point of 70 to 120 ° C., a preferable lower limit of the difference in SP value from the resin composition is 0.2, and a preferable upper limit is 3.0. If it is less than 0.2, the glass transition temperature of the resin composition is remarkably lowered and the storage stability may be inferior. If it exceeds 3.0, the compatibility with the resin composition is insufficient. Low melting point compounds easily fall off and low temperature fixability is poor.
The SP value is an index indicating the affinity of the surface of the substance, and can be evaluated from the solubility in solvents having different SP values.

The preferable lower limit of the dispersion diameter of the low melting point compound having the melting point of 70 to 120 ° C. in the spherical toner of the present invention is 0.2 μm, and the preferable upper limit is 3 μm. If it is less than 0.2 μm, the glass transition point temperature of the resin composition will be remarkably lowered and the storage stability may be poor. If it exceeds 3 μm, the compatibility with the resin composition will be insufficient and low when the toner is pulverized. The melting point compound tends to fall off and the low-temperature fixability may be inferior. A more preferable lower limit is 0.5 μm, and a more preferable upper limit is 2.0 μm.

The preferable lower limit of the blending amount of the low melting point compound having the melting point of 70 to 120 ° C. in the spherical toner of the present invention is 0.2% by weight, and the preferable upper limit is 10% by weight. If it is less than 0.2% by weight, the effect of improving the low-temperature fixability may be insufficient. If it exceeds 10% by weight, the storage stability may be inferior. A more preferred lower limit is 0.5% by weight, and a more preferred upper limit is 4% by weight.

The spherical toner of the present invention is composed of the above resin composition.
The spherical toner of the present invention has an average circularity of 0.92 or more. If it is less than 0.92, various excellent performances resulting from the spherical shape, such as fluidity, transfer efficiency, and an extremely high-definition printed image, are not sufficiently exhibited. Preferably it is 0.95 or more.
The average circularity R is one of parameters indicating how close the particle to be measured is to a true sphere, and can be calculated by the following equation (5).

式（５）中、Ｌ_１は、測定対象である粒子の投影像の周囲長、Ｌ_０は、測定対象である粒
子の投影像の面積に等しい面積の真円（完全な幾何学的円）の周囲長を表す。

In Expression (5), L ₁ is the perimeter of the projected image of the particle to be measured, and L ₀ is a perfect circle (perfect geometric circle) having an area equal to the area of the projected image of the particle to be measured. Represents the perimeter of.

The particle diameter of the spherical toner of the present invention is not particularly limited, but particularly high image quality can be obtained when it is 10 μm or less. More preferably, it is 5 μm or less.

The moisture content of the spherical toner of the present invention is not particularly limited, but the preferred lower limit is 0.01% by weight and the preferred upper limit is 0.2% by weight. If it is less than 0.01% by weight, production becomes difficult due to problems in production, and if it exceeds 0.2% by weight, sufficient charging stability may not be obtained.

The repose angle of the spherical toner of the present invention is not particularly limited, but the preferred lower limit of the repose angle at 23 ° C. and 60% humidity is 1 degree, and the preferred upper limit is 30 degrees. If it is less than 1 degree, handling of the toner may be difficult, and if it exceeds 30 degrees, the fluidity of the toner may be insufficient. The angle of repose of the toner can be measured by, for example, a powder tester (for example, PT-N type manufactured by Hosokawa Micron Corporation).

The surface roughness of the spherical toner of the present invention is not particularly limited, but the preferred lower limit is 0.01 μm.
m, the preferred upper limit is 2 μm. If it is less than 0.01 μm, it may be difficult to perform printing, and if it exceeds 2 μm, the surface gloss of the resulting image may be insufficient.
In addition, the surface roughness is determined based on the printed portion of an image printed using the spherical toner of the present invention.
It can be measured by a method defined in 0601 as a method for measuring arithmetic average roughness (Ra).

When the spherical toner of the present invention is used for applications that are particularly required to have excellent surface gloss,
As the viscosity of the spherical toner of the present invention, the preferred lower limit of the melt viscosity at 150 ° C. is 100.
mPa · s, and a preferable upper limit is 50,000 mPa · s. If it is less than 100 mPa · s, the storage stability may be inferior, and if it exceeds 50,000 mPa · s, sufficient surface gloss may not be obtained. A more preferable upper limit is 10,000 mPa · s.

When the spherical toner of the present invention is measured by gel permeation chromatography,
It is preferable that a peak is observed at a position where the weight average molecular weight is 2000 or less. This improves the fixability. The resin composition preferably has a peak at a position where the weight average molecular weight is 10,000 or more when measured by gel permeation chromatography. Thereby, water resistance improves.

The method for producing the spherical toner of the present invention is not particularly limited.
A crystalline polymer having an endotherm of 25 to 150 mJ / mg at a melting point measured using a differential scanning calorimeter (DSC) of ˜280 ° C. and an amorphous property having a glass transition temperature of 30 to 80 ° C. A step of preparing a powdery body comprising a resin composition containing a polyester and having a weight average molecular weight of 1 million or more and a resin component content of 5% by weight or less, and spheroidizing the obtained powdery body A method having the steps is preferable.
A method for producing such a polyester-based spherical toner is also one aspect of the present invention.

The method for preparing the powdery body is not particularly limited, and examples thereof include a method of pulverizing and classifying a lump body composed of the resin composition and a component to be blended as necessary with a pulverizer or the like.
Further, the method for spheroidizing the powdery body is not particularly limited. For example, the powdery body is heated in a stream of an inert gas such as nitrogen gas or dispersed in a poor solvent. And the like. The heating temperature may be appropriately selected depending on the type of the resin component to be contained, but is usually 200 to 500 ° C, preferably 300 to 450 ° C.

As an apparatus for spheroidizing the powdery body, for example, as described in Patent Document 1,
An annular raw material supply head is provided above the inlet formed in the top plate of the granulation tower, the tip of the hot air injection nozzle is inserted into the raw material supply head, and the thermoplastic supplied into the raw material supply head The solid-gas mixed fluid of particles and compressed air is injected into the hot air injected from the hot air injection nozzle from the raw material injection nozzle provided in the inner periphery of the raw material supply head, thereby making the thermoplastic particles spherical. Examples thereof include a spheroidizing apparatus. In addition, “MR” manufactured by Nippon Pneumatic Industry Co., Ltd.
Commercially available spheronization processing equipment such as “-3” can also be used.

The spherical toner of the present invention can express good fixability in a wide range from low temperature to high temperature, and is excellent in both low temperature fixability, high temperature offset resistance, and blocking resistance.
Since the time from when the switch is turned on until printing is possible can be shortened, it is economical, and the sharpness of the image can be maintained even when the temperature of the roller decreases, so printing speed is high. Can be achieved. In the spherical toner of the present invention, since the resin composition as a raw material is colorless and transparent, a desired color can be easily adjusted by selecting a colorant or the like. The spherical toner of the present invention is excellent in image reproducibility. Furthermore, since the sphere has a sufficient sphericity, it is excellent in fluidity and transfer efficiency, and an extremely high-definition printed image is obtained with an edge.

According to the present invention, it is possible to provide a spherical toner that is excellent in low-temperature fixability, high-temperature offset resistance, blocking resistance, fluidity, and transfer efficiency, and has a sharp edge and provides an extremely high-definition printed image.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
(1) Manufacture of polybutylene terephthalate (PBT) A distillation column, a water separator, a nitrogen gas inlet tube, a thermometer and a stirring measure are installed in a conventional manner in a 60 L reaction vessel, and a dicarboxylic acid component is added under a nitrogen gas atmosphere. As 100 moles of terephthalic acid,
120 mol of 1,4-butanediol was added as a diol component, 0.05 mol of titanium tetrabutoxide (TBB) was charged as an esterification condensation catalyst, and the ester produced while distilling water and methanol produced at 200 ° C. from a distillation column. The reaction was carried out. The esterification reaction was completed when water and methanol no longer distilled from the distillation column.

After completion of the esterification reaction, the opening of the 60 L reaction vessel to the distillation tower is closed, the line from the vacuum pump is opened, the pressure in the reaction system is reduced to 5 mmHg or less, 240 ° C., stirring speed 6
A condensation reaction was carried out at 0 rpm and the free diol produced by the condensation reaction was distilled out of the reaction system to obtain polybutylene terephthalate.

(2) Production of non-crystalline polyester (A) A distillation column, a water separator, a nitrogen gas inlet tube, a thermometer and a stirring measure were installed in a conventional manner in a 60 L reaction vessel, and dicarboxylic acid was added in a nitrogen gas atmosphere. 90 mol of terephthalic acid as component, 5 mol of isophthalic acid as bending monomer component, 5 mol of phthalic anhydride, 60 mol of neopentylene glycol as branched monomer component, 60 mol of ethylene glycol as other diol, titanium tetrabutoxide as esterification condensation catalyst (TBB) Charge 0.05 mol,
The esterification reaction was carried out at 200 ° C. while distilling the produced water and methanol from the distillation column. The esterification reaction was completed when water and methanol no longer distilled from the distillation column.
After completion of the esterification reaction, the opening of the 60 L reaction vessel to the distillation tower is closed, the line from the vacuum pump is opened, the pressure in the reaction system is reduced to 5 mmHg or less, 240 ° C., stirring speed 6
A condensation reaction was carried out at 0 rpm and the free diol produced by the condensation reaction was distilled out of the reaction system to obtain an amorphous polyester (A).

(3) Manufacture of non-crystalline polyester (B) A distillation column, a water separator, a nitrogen gas inlet tube, a thermometer and a stirrer are installed in a conventional manner in a 60 L reaction vessel, and dicarboxylic acid in a nitrogen gas atmosphere. 100 moles of terephthalic acid as an ingredient,
100 mol of ethylene glycol and 1,4-cyclohexanedimethanol as diol
0 mol, 0.05 mol of titanium tetrabutoxide (TBB) was charged as an esterification condensation catalyst, and the esterification reaction was carried out at 200 ° C. while distilling water and methanol produced from the distillation column. The esterification reaction was completed when water and methanol no longer distilled from the distillation column.
After completion of the esterification reaction, the opening of the 60 L reaction vessel to the distillation tower is closed, the line from the vacuum pump is opened, the pressure in the reaction system is reduced to 5 mmHg or less, 240 ° C., stirring speed 6
A condensation reaction was carried out at 0 rpm and the free diol produced by the condensation reaction was distilled out of the reaction system to obtain an amorphous polyester (B).

(4) Preparation of resin composition and powdery body 7.5 parts by weight of high-melting crystalline polyester obtained, 57.5 amorphous polyester (A)
Part by weight and 35 parts by weight of amorphous polyester (B) were melt-kneaded to prepare a resin composition. Further, 100 parts by weight of the obtained resin composition, 1 part by weight of a charge control agent (Bontron N-01, manufactured by Orient Chemical Co., Ltd.), 5 parts by weight of carbon black, aliphatic polyester (Polylite ODX-2555, Dainippon Ink and Chemicals, Inc.) 3 parts by weight of an industrial company (melting point: 77 ° C.) was thoroughly mixed with a Henschel mixer, melt-kneaded at 130 ° C., cooled, and coarsely pulverized. Then, it was pulverized with a jet mill (Lab Jet: manufactured by Nippon Pneumatic Co., Ltd.) to obtain a powder having an average particle size of about 8 μm. Further, this toner powder was classified by a classifier (MDS-2: manufactured by Nippon Pneumatic Co., Ltd.) to obtain a powdery material having an average particle diameter of about 10 μm.

(5) Production of spherical toner The obtained powdery body was spheroidized by heating to 350 ° C. under a nitrogen stream using a spheronization treatment apparatus (MR-3, manufactured by Nippon Pneumatic Industry Co., Ltd.). A spherical toner was obtained. To 100 parts by weight of the spherical toner, 1.0 part by weight of hydrophobic silica (RA200HS: manufactured by Nippon Aerosil Co., Ltd.) was uniformly mixed (externally added) to produce a toner.

(Examples 2 to 4 and Comparative Examples 1 and 2)
A resin composition and a spherical toner were produced in the same manner as in Example 1 except that each component shown in Table 1 was used.

(Evaluation)
The resin compositions or spherical toners prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were evaluated by the following methods.
The results are shown in Table 1.

[Measurement of molecular weight and molecular weight distribution]
(1) As crystalline polyester and crystalline polyamide GPC measuring device, HTR-C manufactured by Nihon Millipore Ltd. is used, and HFIP-806M (2 pieces) manufactured by Showa Denko KK is connected to the column in series. The weight average molecular weight was measured. The measurement conditions were a temperature of 40 ° C., a sample of 0.1 wt% hydroxyfluoroisopropanol (HFIP) solution (passed through a 0.45 μm filter), and an injection amount of 100
As a carrier solvent, HFIP containing 0.68 g of TFA per liter was used as a carrier solvent. Standard polystyrene was used as a calibration sample.
(2) As a non-crystalline polyester GPC measurement apparatus, HTR-C manufactured by Nippon Millipore Limited was used, and KF-800P (1), KF-806M (2), KF- manufactured by Showa Denko K.K. 802.5 (1
Were used in series, and the weight average molecular weight was measured. The measurement condition is that the temperature is 40 ° C.
The sample was a 0.2 wt% THF solution (passed through a 0.45 μm filter), the injection volume was 100 μL, the carrier solvent was THF, and standard polystyrene was used as the calibration sample.
(3) As a resin composition and a spherical toner GPC measuring apparatus, HTR-C manufactured by Nihon Millipore Limited was used, and KF-800P (1), KF-806M (2) manufactured by Showa Denko Co., Ltd. were used as columns. KF-802.5 (1
Were used in series, and the molecular weight and molecular weight distribution were measured. Measurement conditions are temperature 4
At 0 ° C., the sample used was a 0.2 wt% THF solution (passed through a 0.45 μm filter), the injection amount was 100 μL, the carrier solvent was THF, and standard polystyrene was used as a calibration sample.
From the obtained GPC data, the content of a resin component having a weight average molecular weight of 1,000,000 or more in the resin composition was determined.

[Measurement of glass transition temperature (Tg)]
The resin composition was kept at a temperature equal to or higher than the melting point for a while, and then rapidly cooled to prepare a sample in which crystallization was completely suppressed. The sample was measured using a differential scanning calorimeter (DSC-6200R, manufactured by Seiko Denshi Kogyo Co., Ltd.) at a heating rate of 10 ° C./min according to JIS K 7121, and the standard (9.3 “glass” The intermediate glass transition temperature described in “How to determine transition temperature”) was determined.

[Measurement of crystal melting point (Tm) and endotherm]
Using a differential scanning calorimeter (DSC-6200R, manufactured by Seiko Denshi Kogyo Co., Ltd.), the heating rate was 10
10 mg of the sample was heated at 0 ° C./min, measured according to JIS K 7121, and the standard (9
. 1 “How to find the melting temperature”), the melting peak value is obtained and the crystal melting point Tm
In addition, the endothermic amount at the crystalline melting point Tm was determined from the DSC chart.

[Measurement of acid value]
JIS K except that tetrahydrofuran (THF) was used instead of ethyl alcohol.
The acid value was determined by a method based on 6751.

[Evaluation of color tone]
The color of the resin composition was visually observed.

[Measurement of rate of change D of relaxation modulus]
The toner resin composition was melted and then formed into a disk shape having a diameter of 25 mm and a height of 1 mm, and this was used as a test sample. This is attached to a disk-disk jig with a diameter of 25 mm, and a relaxation elastic modulus measuring device (
Rheometrics RMS-800) at 190 ° C. and initial shear strain of 5%, the relaxation elastic modulus G _5% (0.1) and relaxation elastic modulus 0.1 seconds after applying the shear strain The relaxation elastic modulus at the curve peak position was measured, and the gradient of the relaxation elastic modulus curve was calculated by the above formula (2).

[Measurement of relaxation modulus and slope of relaxation modulus curve]
The toner resin composition was melted and then formed into a disk shape having a diameter of 25 mm and a height of 1 mm, and this was used as a test sample. This is attached to a disk-disk jig with a diameter of 25 mm, and a relaxation elastic modulus measuring device (
Rheometrics RMS-800) was used to measure the relaxation modulus at 0.02 seconds and 0.1 seconds after applying shear strain under conditions of 190 ° C. and initial shear strain of 450%. The slope of the relaxation modulus curve was calculated from (3).

[Evaluation of average circularity of spherical toner]
The average circularity of the spherical toner was measured by using an optical detection method in which a dispersion containing spherical toner is passed through an imaging unit detection zone on a flat plate, and a particle image is optically detected and analyzed by a CCD camera.
That is, 0.2 mL of alkylbenzene sulfonate as a dispersant is added to 100 mL of water from which impure solids have been removed in advance, and 0.2 g of spherical toner is added, followed by a dispersion treatment for 3 minutes using an ultrasonic disperser. It was. The obtained dispersion was subjected to flow type particle image analyzer (FPIA-100).
0, manufactured by Toa Medical Electronics Co., Ltd.), and the peripheral length L ₁ of the projected image of the toner and the peripheral length L _{0 of} a perfect circle (complete geometric circle) having an area equal to the area of the projected image The average circularity was determined from the above equation (5).

[Evaluation of toner blocking properties]
Take 10 g of toner in a 100 mL sample bottle, leave it in a thermostatic bath at 50 ° C. for 8 hours, and then screen with a 250 μm filter using a powder tester (manufactured by Hosokawa Micron) to observe whether aggregates remain on the filter. When there was an aggregate, the weight (% by weight) of the aggregate with respect to the toner weight was determined.

[Toner filming evaluation]
After 10,000 sheets were printed, whether the toner adhered to the fixing roller was visually observed. If no toner adhered, the film was evaluated as having no filming.

[Toner gloss evaluation]
Using a gloss meter (gloss meter, UGV-50, manufactured by Suga Test Instruments Co., Ltd.), a test paper painted black with toner was attached to the gloss meter, the optical path was set so that the reflection angle was 75 degrees, and the gloss level was measured.

[Measurement of high temperature offset temperature and low temperature offset temperature of toner]
A developer was prepared by mixing 6.5 parts by weight of toner with 93.5 parts by weight of a ferrite carrier having an average particle size of 60 μm. As an electrophotographic copying machine, a KM-4230 manufactured by Kyocera Mita Co., Ltd., modified so that the set temperature of the heat fixing roller can be changed up to 220 ° C. was used.
The set temperature of the heat fixing roller was changed stepwise to obtain a copy in which the unfixed toner image was fixed on the transfer paper by the heat fixing roller at each set temperature.
It was observed whether the blank portion of the obtained copy and the fixed image were stained with toner, and a temperature region where no contamination occurred was defined as a non-offset temperature region. Further, the maximum value in the non-offset temperature region was set as the high temperature offset temperature, and the minimum value was set as the low temperature offset temperature.

[Measurement of minimum fixing temperature of toner]
Copying is performed by changing the set temperature of the heat fixing roller of the electrophotographic copying machine step by step, and the margin part and the fixed image are not stained with toner without fogging the margin part and the fixed image.
When the fixed image of the obtained copy was rubbed with a sand eraser for typewriters, the case where the decrease in density of the fixed image was less than 10% was judged as good fixing, and the minimum temperature at that time was determined.
The image density was measured using a Macbeth photometer.

[Evaluation of image characteristics]
The fixed image was visually observed and evaluated according to the following criteria. A Macbeth photometer was used to measure the image density.
E: The image is high-definition, there is no fogging or unevenness, the image density is sufficiently high as 1.6 or more, and the resolution, transferability, and gradation are very excellent.
G: Slightly inferior in high-definition image, but without fog and unevenness, and image density of 1.4 to 1.6
Excellent resolution, transferability and gradation.
F: The image lacks high definition, fog and unevenness may occur, and the image density may be insufficient at less than 1.4, but an image capable of fixing evaluation can be obtained.
D: There is fog and unevenness, and a satisfactory image cannot be obtained.

According to the present invention, it is possible to provide a spherical toner that is excellent in low-temperature fixability, high-temperature offset resistance, blocking resistance, fluidity, and transfer efficiency, and has a sharp edge and provides an extremely high-definition printed image.

Claims (2)

A crystalline polymer having a melting point of 180 to 280 ° C. and an endotherm at a melting point of 25 to 150 mJ / mg measured using a differential scanning calorimeter (DSC), and a glass transition temperature of 30 to 80 ° C. Comprising a non-crystalline polyester , a resin composition having a weight average molecular weight of 1,000,000 or more, and comprising 3 to 10% by weight of the crystalline polymer ,
A spherical toner having an average circularity of 0.92 or more. A crystalline polymer having a melting point of 180 to 280 ° C. and an endotherm at a melting point of 25 to 150 mJ / mg measured using a differential scanning calorimeter (DSC), and a glass transition temperature of 30 to 80 ° C. A powdery body comprising a non-crystalline polyester, containing no resin component having a weight average molecular weight of 1,000,000 or more, and comprising a resin composition having a crystalline polymer content of 3 to 10% by weight is prepared. A method for producing a polyester-based spherical toner, comprising: a step; and a step of spheroidizing the powdery body.