JP2746476B2 - Electrostatic image developing toner and heat fixing method - Google Patents

Description

The present invention relates to a toner for an electrostatic image phenomenon in electrophotography, electrostatic recording, electrostatic printing, and the like, and a heat fixing method using the toner.

(Prior Art) Conventionally, many electrophotographic methods have been known as described in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748. However, in general, an electric latent image is formed on a photoreceptor by various means using a photoconductive substance, and then the latent image is developed using toner, and if necessary, paper or the like is used. After transferring the toner image to the transfer material, the image is fixed by heating, pressurizing, heating and pressurizing, or solvent vapor, etc., to obtain an object, and the toner remaining on the photoreceptor without being transferred is various. And the above steps are repeated.

In recent years, such copying apparatuses have begun to be used not only as office work copying machines for copying original manuscripts, but also as printers as personal computer outputs or personal copies for individuals.

For this reason, smaller, lighter, faster, and more reliable devices have been strictly pursued, and machines have become simpler in various respects. As a result, the performance required of the toner becomes higher, and if the performance of the toner cannot be improved, a better machine cannot be realized.

For example, various methods and apparatuses have been developed for a process of fixing a toner image on a sheet such as paper, but the most common method at present is a pressure heating method using a heat roller.

The pressure heating method using a heating roller fixes the toner image by passing the toner image surface of the sheet to be fixed under pressure onto the surface of a heat roller whose surface is formed of a material having a releasing property to the toner. It is. In this method, since the surface of the heat roller and the toner image of the sheet to be fixed come into contact with each other under pressure, the thermal efficiency at the time of fusing the toner image onto the sheet to be fixed is extremely good, and the fixing can be performed quickly. It is very effective in high speed electrophotographic copying machines.

However, in the above method, since the surface of the heat roller and the toner image come into contact with each other under pressure in a molten state, a part of the toner image adheres to and transfers to the surface of the fixing roller, and is transferred again to the next sheet to be fixed. A so-called offset phenomenon occurs, and the sheet to be fixed may be stained. Preventing toner from adhering to the surface of the heat fixing roller is one of the essential conditions of the heat roller fixing method.

Conventionally, for the purpose of preventing the toner from adhering to the surface of the fixing roller, for example, the roller surface is formed of a material having excellent releasability from the toner, such as silicone rubber or a fluorine-based resin, and the surface of the roller is prevented from being offset and the roller surface is formed. In order to prevent fatigue of the roller, the roller surface is coated with a thin film of a liquid having good releasability such as silicone oil.

However, this method is extremely effective in preventing the offset of the toner, but has a problem that the fixing device becomes complicated because a device for supplying the liquid for preventing the offset is required. .

This is in the opposite direction to miniaturization and weight reduction, and moreover, silicon oil and the like may evaporate due to heat and contaminate the inside of the machine. Therefore, without using a silicon oil supply device,
Instead, a method of adding a release agent such as low-molecular-weight polyethylene or low-molecular-weight polypropylene to the toner has been proposed from the viewpoint of supplying the anti-offset liquid from the toner during heating. If a large amount of such an additive is added in order to obtain a sufficient effect, filming on a photoreceptor or contamination of the surface of a toner carrier such as a carrier or a sleeve will deteriorate the image and pose a practical problem. Therefore, a small amount of release agent is added to the toner to such an extent that the image is not deteriorated, and a small amount of release oil is supplied or the offset toner is cleaned by a take-up type device using a member such as a web. It has been practiced to use devices together.

However, in view of recent demands for miniaturization, weight reduction, and high reliability, it is necessary and preferable to remove even these auxiliary devices. Therefore, it cannot be coped with without further improvement of performance such as fixing and offset of the toner, and it is difficult to realize this without further improvement of the binder resin of the toner.

As technology related to improvement of toner binder resin,
For example, Japanese Patent Publication No. 51-23354 discloses a toner using a crosslinked polymer as a binder resin. According to this method, the offset resistance and the winding resistance are improved, but when the degree of cross-linking is increased, the fixing point rises, and the fixing temperature is sufficiently low and the offset resistance and the winding resistance are good. No satisfactory fixing characteristics were obtained.

Generally, in order to improve the fixing property, the binder resin must have a low molecular weight to lower the softening point, which is inconsistent with the offset resistance improvement treatment, and also has a low softening point. Inevitably lowers the glass transition point of the resin,
An undesired phenomenon of blocking the toner during storage also occurs.

On the other hand, Japanese Patent Application Laid-Open No. Sho 56-158340 proposes a toner comprising a low molecular weight polymer and a high molecular weight polymer. Is still insufficient, and it is difficult to satisfy the offset resistance and the fixing property to a high degree.

JP-A-58-203453 proposes a toner comprising a low-temperature softening resin and a high-temperature softening resin. Although the binder resin is improved in offset resistance, it is still insufficient in fixing property, and it is difficult to satisfy the offset resistance and fixing property to a high degree.

JP-A-60-20411 proposes a method for producing a resin composition comprising a low-polymerized polymer and a high-polymerized polymer.However, when this resin is used as a binder resin for a toner, Although the grindability is improved, both the fixing property and the offset resistance are still insufficient, and there is much room for improvement.

Further, with respect to a toner blended with a low molecular weight polymer and a crosslinked polymer, for example, Japanese Patent Application Laid-Open No. 58-86558 proposes a toner comprising a low molecular weight polymer and an insoluble high molecular weight polymer as main resin components. ing. According to this method, the fixability and the pulverizability tend to be improved, but the weight-average molecular weight / number-average molecular weight (M _w / M _n ) of the low molecular weight polymer is 3.
5 or less and the content of insoluble infusible high molecular weight polymer is as large as 40 to 90% by weight. If it is not for a fixing device with a liquid supply device for prevention, fixing properties (especially high-speed fixing), anti-offset properties,
It is extremely difficult to produce a toner that satisfies pulverizability sufficiently.

Further, when the amount of the insoluble infusible high molecular weight polymer increases, the melt viscosity becomes extremely high due to the heat kneading at the time of preparing the toner, so that the heat kneading should be performed at a much higher temperature than usual or the heat kneading with a high share. However, as a result, the former has a problem that the toner properties are deteriorated due to the thermal decomposition of other additives, and the latter has a problem that the molecules of the binder resin are excessively cut and the initial anti-offset performance is hardly obtained.

Also, JP-A-60-166958 discloses a number average molecular weight ( _Mn ).
A toner comprising a resin component obtained by polymerization in the presence of a low molecular weight poly-α-methylstyrene having a molecular weight of 500 to 1,500 has been proposed.

In particular, the publication discloses that the number average molecular weight ( _Mn ) is 9,000 to 30,000.
Although a range of 0 is preferable, if _Mn is increased to further improve the offset resistance, the fixing property and the pulverizability during toner production become practically problematic, and therefore, the offset resistance and the pulverizability are increased. It is difficult to satisfy performance. As described above, the toner having poor pulverizability at the time of producing the toner is not preferable because the production efficiency at the time of producing the toner is lowered and coarse toner is apt to be mixed as a toner characteristic, so that a scattered image may be formed.

In addition, JP-A-56-161144 discloses that the molecular weight distribution by GPC is such that the molecular weight is 10 ³ to 8 × 10 ⁴ and the molecular weight is 10 ⁵ to 2 × 10 ⁶
Has been proposed that contains a binder resin component having at least one maximum value in each of the regions.

JP-A-63-223662 discloses that THF-insoluble components are contained in an amount of 10 to 60% by weight based on the binder resin, and the weight-average molecular weight / number-average molecular weight ( _Mw / _Mn ) ≧ 5, has a peak in the region of molecular weight 2 × 10 ³ to 1 × 10 ⁴ , has a peak or shoulder in the region of molecular weight 1.5 × 10 ⁴ to 1 × 10 ⁵ , and has a molecular weight of 1 × 10 3 ⁴ the following components toner comprising 10 to 50 wt% in the binder resin has been proposed. In this case, the pulverizability, the fixing property, the filming and fusing to the photoreceptor, the image properties, and the offset resistance (particularly, the offset resistance at a high temperature side) are excellent, but the offset resistance and the fixing property of the toner are further improved. Improvement is required. In particular, it is difficult for such a resin to cope with a severe situation in which compatibility between low-temperature fixing property and high-temperature offset resistance is required.

As described above, it is extremely difficult to realize both the performance relating to fixing and the pulverizability with high performance. In particular, the pulverizability at the time of toner production is an important factor in today's direction in which toner particles are made smaller due to demands for higher quality, higher resolution, and higher fine line reproducibility of copied images. Since the process requires a very large amount of energy, it is important to improve the pulverizability from the viewpoint of energy saving.

Also, the phenomenon of fusion of the toner to the inner wall of the pulverizing device is likely to occur in the toner having good fixing performance, and therefore, the pulverizing efficiency is deteriorated. As another aspect, there is a step of cleaning the toner remaining on the photoconductor after the transfer in another copying step. Today, cleaning with a blade (blade cleaning) has become popular in view of miniaturization, weight reduction, and reliability of the apparatus. As the life of the photoconductor has been prolonged, the size of the photoconductor drum and the like have been reduced, and the speed of the system has been increased. In particular, amorphous silicon photoreceptors that have recently been put to practical use have extremely high durability, and the life of OPCs (organic photoreceptors) has also been prolonged. Is coming.

In addition, miniaturization requires that each element be placed in a narrow space. Therefore, the space through which air flows well is reduced, and the heat source of the fixing unit and the exposure system is very close to the toner hopper and the cleaner, so that the toner is exposed to a high-temperature atmosphere. Therefore, the toner cannot be put to practical use unless the toner has better blocking resistance.

For example, various properties required for the toner, such as fixing property and blocking resistance, are almost always in conflict with each other, and it is increasingly desired to satisfy both of them with high performance. There is not enough.

(Problems to be Solved by the Invention) It is an object of the present invention to provide a toner for developing an electrostatic image, which solves the above-mentioned problems, and a heat fixing method using the toner.

That is, an object of the present invention is to provide a toner for developing an electrostatic image, which is fixed at a low temperature and has excellent offset resistance in a wide temperature range from a low temperature to a high temperature, and a heat fixing method using the toner. is there.

Another object of the present invention is to provide a toner for developing an electrostatic charge image which does not occur even in a high-speed system where the fusing and filming to a photoreceptor are performed, and a heat fixing method using the toner. It is in.

Another object of the present invention is to provide a toner for developing an electrostatic charge image which is excellent in blocking resistance and can be used sufficiently even in a high-temperature atmosphere in a small machine, and a heat fixing method using the toner.

Further, an object of the present invention is to provide a toner for developing an electrostatic charge image which can be efficiently and continuously produced because a pulverized material does not fuse to an inner wall of an apparatus in a pulverizing step in the production of a toner, and a heat fixing method using the toner. Is to provide.

(Means for Solving the Problems) The above object is achieved by the present invention described below.

That is, the present invention provides a toner for developing an electrostatic image containing at least a binder resin and a magnetic powder, wherein the magnetic powder contains an iron element in a state of being bonded to an oxygen element, and has an aluminum element bonded to an oxygen element. The aluminum element is contained in the magnetic powder in an amount of 0.05 to 10% by weight, and the binder resin has a THF-insoluble content of 10% by weight based on the binder resin. Less than the GPC of the THF-soluble portion of the binder resin
In the molecular weight distribution in (gel permeation chromatography), the weight average molecular weight / number average molecular weight (M _w / M _n ) is 18 or more, and one molecular weight peak value M _A , molecular weight 38 between 3,000 and 20,000. Between 1 million and 1 million
Two molecular weight peak values M _B , each having a molecular weight minimum value M _d between 20,000 and 380,000, M _B / M _A being 30-150, and the area of the molecular weight distribution curve from 400 to M _d molecular weight S _A , the area of the molecular weight distribution curve from the molecular weight M _d to 5 million is S _B , and the area surrounded by the straight line connecting the peak of the molecular weight peak value M _{A and} the peak of the molecular weight peak value M _B and the area surrounded by the molecular weight distribution curve is S _{where d} , S _A , S _B, and S _d satisfy the following relationship: S _A : S _B : S _d = 1: 0.3 to 0.8: 0.35 to 0.8 .

Further, the present invention provides a method for heating a visible image of toner to a recording material by using a fixedly supported heating member and a pressing member which opposes to the heating member and presses the recording material into contact with the heating member via a film. In the heat fixing method for fixing, the toner contains at least a binder resin and a magnetic powder, and the magnetic powder contains an iron element in a state combined with an oxygen element,
And the aluminum element is contained in a state of being bonded to the oxygen element, and the aluminum element is contained in the magnetic powder in an amount of 0.05 to
The binder resin has a THF-insoluble content of less than 10% by weight based on the binder resin, and the THF-soluble content of the binder resin is GPC (gel permeation chromatography). Weight average molecular weight / number average molecular weight (M _w / M _n ) is 18 or more, and one molecular weight peak value M _A between 3,000 and 20,000 and a molecular weight of 380,000 to 1,000,000 one molecular weight peak value M _B between respectively have a molecular weight minimum value M _d between molecular weight from 20,000 to 380,000, M _B / M _a is 30 to 150, the molecular weight distribution of molecular weight 400 to M _d The area of the curve
S _A , the area of the molecular weight distribution curve from molecular weight M _d to 5 million
_B , when the area surrounded by a straight line connecting the peak of the molecular weight peak value M _{A and} the peak of the molecular weight peak value M _B and the molecular weight distribution curve is S _d , S _A , S _B and S _d are represented by the following relationship S _A : S _B : S _d = 1: 0.3 to 0.8: 0.35 to 0.8.

In a preferred embodiment, the magnetic powder has a magnetic iron oxide containing an aluminum element combined with an oxygen element, and the aluminum element contains 0.05 to 10% by weight of the magnetic iron oxide. It is a toner for developing an electrostatic image contained therein.

Another preferred embodiment has a number average molecular weight of 1,000 or less, a weight average molecular weight of 2,500 or less, a weight average molecular weight / number average molecular weight ( _Mw / _Mn ) of 3.0 or less, and a melting point of 6 or less.
A release agent having a temperature of 0 to 120 ° C, 0.1 to 2 based on the binder resin.
The toner for developing electrostatic images contains 0% by weight.

In still another preferred embodiment, the binder resin is a polymer A having a weight average molecular weight of 5,000 to 30,000 and a weight average molecular weight of 40.
A toner for developing an electrostatic image, which is produced by mixing 10,000 to 1.5 million of the polymer B in a solvent and then removing the solvent.

(Action) As a result of extensive studies by the present inventors in order to achieve the above-mentioned object, the magnetic powder contained in the toner contains iron element in a state of being combined with oxygen element, and aluminum element contains oxygen element. The aluminum element is contained in the magnetic powder in a specific range, and the THF-insoluble content of the binder resin contained in the toner is less than a specific weight%. And that the molecular weight distribution of the THF-soluble component in GPC is achieved when the specific configuration is achieved.

Furthermore, the magnetic powder contains a magnetic iron oxide containing an iron element in a state of being bonded to an oxygen element, and containing an aluminum element in a state of being bonded to an oxygen element. It was found to be good when the content was 0.05 to 10% by weight in the magnetic iron oxide.

In addition, they have found that it becomes remarkable when an anti-offset agent having a specific molecular weight and a molecular weight distribution and having a specific melting point is contained.

In addition, it has been found that the binder resin is favorably achieved particularly when the binder resin is produced by mixing a low molecular weight polymer and a high molecular weight polymer in a solvent and then removing the solvent.

Further, in heating and fixing the visible image of the toner to the recording material, in addition to the conventional heat roll fixing machine, a heating member fixed and supported, and the recording material is heated and pressed against the heating member through a film. It has been found that it is preferable to apply the electrostatic image developing toner to a heat fixing method in which a visible image of the toner is heat-fixed to a recording material by a pressure member that is in close contact with a body. .

(Preferred Embodiment) Next, the present invention will be described in more detail with reference to preferred embodiments.

The magnetic powder used in the toner of the present invention contains an iron element in a state of being bonded to an oxygen element, and contains an aluminum element in a state of being bonded to an oxygen element. -10% by weight, preferably 0.1-5% by weight.

If the aluminum element content is less than 0.05% by weight, the effect of the aluminum element content does not appear, and there is no effect on further improving the high-temperature offset resistance, and if the aluminum element content exceeds 10% by weight, the moisture resistance of the toner is reduced. descend.

As the magnetic powder used in the present invention, a powder containing an aluminum element in an alloy or compound containing a ferromagnetic element is preferably used. For example, magnetite, maghemite, ferrites, and other alloys and compounds such as iron, cobalt, nickel, and manganese, and other ferromagnetic alloys that contain aluminum elements in the manufacturing process of those conventionally known as magnetic materials are used. I can do it.

Above all, in the manufacturing process, by involving the aluminum compound in the form of aluminum hydroxide or aluminum oxide in which the aluminum element and the oxygen element are bonded, the magnetic oxidation containing the aluminum element in a state of being bonded to the oxygen element Iron is preferably used. In particular, those in which the aluminum element exists on the surface of the magnetic powder are preferable.

In the present invention, the content of the aluminum element contained in the magnetic powder is measured by the following method.

Approximately 5 g of magnetic powder is collected in a 1-liter beaker.
Ag) 3N hydrochloric acid aqueous solution is added to make 1 liter. Keep the temperature at about 50 ° C. and continue the reaction with stirring until everything is dissolved and clear. The amount of aluminum element dissolved (this is set to Bmg / liter) is measured from the obtained liquid by plasma emission spectroscopy (ICP). The percentage of the aluminum element based on the weight of the magnetic powder is calculated by the following equation.

Aluminum element abundance (%) = ｛B / (A × 1,000｝ × 100) When analyzing the magnetic powder contained in the toner, an organic solvent such as xylene that dissolves the resin component of the magnetic toner must be used. The solution in which the resin component of the magnetic toner is dissolved is filtered through a 20 A filter paper, and the solution in which the resin component of the magnetic toner is dissolved is collected as magnetic powder remaining on the 20 A filter paper. After the powder is treated in an atmosphere at 600 ° C. to remove organic components, the obtained magnetic powder is analyzed by the above-described method, whereby the abundance of the aluminum element is measured.

The THF-insoluble content of the binder resin constituting the toner is less than 10% by weight, preferably 5% by weight or less based on the binder resin. If the THF-insoluble content is 10% by weight or more, the offset resistance is improved but the fixability tends to be deteriorated, and it is difficult to satisfy both of them at a high level, which is not preferable.

The THF-insoluble content of the binder resin was determined by measuring the molecular weight by GPC according to the following formula: weight average molecular weight / number average molecular weight (M _w / M _n ) ≧
18, one molecular weight peak M _A between 3,000 and 20,000, one molecular weight M _B between 380 and 1,000,000, and a minimum M between 20,000 and 380,000. _d / M _B / M _A = 30 to 150, the area of the molecular weight distribution curve from 400 to M _d molecular weight is S _A , and the area of the molecular weight distribution curve from M _d to 5 million is S _B when the area surrounded by the straight line and the molecular weight distribution curve connecting the vertex of the vertex and molecular weight peak value M _B having a molecular weight peak value M _a was _{S d, S a: S B} : S d = 1: 0.3~0.8: It is preferably 0.35 to 0.8. If at least one of the above conditions is not satisfied, the object of the present invention cannot be achieved.

Weight average molecular weight / number average molecular weight (M _w / M _n ) 18 or more,
It is preferably 20 or more, more preferably 25 to 60. If M _w / M _n is less than 18, the fixing property tends to be improved, but the offset resistance becomes poor.

1 between molecular weight 3,000-20,000 and molecular weight 38-1,000,000
One of a molecular weight peak value (M _A and M _B), and molecular weight 2
10,000 to 380,000 has a minimum value of molecular weight, preferably when the M _B / M _A = 30~150, more preferably a molecular weight from 5,000 to 15,000
And each have a single molecular weight peak value between the molecular weight of from 450,000 to 900,000, and has a minimum value in a molecular weight from 30,000 to 300,000, M _B / M _A
= 40-100. When these conditions are not satisfied, for example, when the molecular weight has a minimum value only in the range of 20,000 to 380,000, the fixing property may be good, but the offset resistance is clearly inferior. Further, the molecular weight peak value M _A is 3,
If less than 000 become blocking resistance poor, Fuirumingu or fusion occurs to the photosensitive member, in the case where M _A is 20,000 or more could fixability poor.
Further, offset resistance becomes poor if the molecular weight peak value M _B is less than 380,000, fused matter were generated in the apparatus in a pulverizing step, a possibility that the fixing poor if the more than one million At the same time, the pulverizability is poor and the productivity is inferior.

The ratio M _B / M _A = 30~150 of the peak value of molecular weight, is preferably from 30 to 120, still if preferably is 30 to 100.

If M _B / M _A is less than 30 or more than 150, it is difficult to achieve a high level of fixing property and offset resistance.

Area ratio of molecular weight distribution curve S _A : S _B : S _d = 1: 0.3 to 0.8: 0.3
5 to 0.8, preferably S _A : S _B : S _d = 1: 0.3 to 0.7: 0.4
To 0.7, more preferably S _A : S _B : S _d = 1: 0.3 to 0.6:
0.5 to 0.7. If, offset resistance becomes poor if the S _B less than 0.3, in the case of a 0.8 or higher becomes the fixing poor tend to be grindability becomes defective. S _d becomes poor fixability and / or offset resistance if less than 0.35, there is a tendency that the offset resistance is poor when a 0.8 or higher.

When a specific magnetic powder of the present invention is combined with a specific binder resin, particularly excellent high-temperature offset resistance is obtained.The polarization of the bond between the aluminum element and the oxygen element is determined by the iron element and the oxygen element. It is stronger than the polarization, and has a stronger power to attract the binder molecular chains than the magnetic powder containing no aluminum element of the present invention. Therefore, the magnetic powder containing an aluminum element strongly attracts the low molecular weight molecular chains contained in the binder of the present invention to the surface of the magnetic substance. For this reason, it is considered that the resistance to the high-temperature offset generated particularly in the portion of the fixing paper where the temperature is increased in the sad paper portion is improved by combining with the aluminum element-containing magnetic powder.

The release agent preferably used in the toner of the present invention has a number average molecular weight of 1,000 or less, a weight average molecular weight of 2,500 or less, a weight average molecular weight / number average molecular weight ( _Mw / _Mn ) ≦ 3, and a melting point of 60 to 60.
120 ° C. and 0.1 to 20% by weight based on the binder resin. More preferably the number average molecular weight is 400 to 70
0, weight average molecular weight 500 to 1,500, M _w / M _n ≦ 2.5, melting point 60 to
At 100 ° C., the release agent is contained at 1 to 10% by weight based on the binder resin.

When the release agent used in the toner of the present invention does not satisfy this condition, for example, when the melting point is 120 ° C. or more, the fixing property is adversely affected. It has an adverse effect on blocking properties. Further, when the content of the release agent is 20% by weight or more, the blocking property and the fixing property when the toner is left at a high temperature are adversely affected. May be inadequate.

The binder resin used in the toner of the present invention comprises a polymer A having a weight average molecular weight of 5,000 to 30,000 and a weight average molecular weight of 40.
It is produced by mixing 10,000 to 1.5 million of polymer B in a solvent and then removing the solvent. Preferably weight average molecular weight
It is produced by mixing a polymer A of 7,000 to 25,000 and a polymer B of a weight average molecular weight of 450,000 to 1,000,000 in a solvent and then removing the solvent. As the solvent, polymer A and polymer B
May be used as long as it dissolves, for example, toluene, xylene, 2-propanone and the like.

In the production of the binder resin used in the toner of the present invention, the polymer A is a solution polymerization method or a suspension polymerization method,
The polymer is produced by a suspension polymerization method or an emulsion polymerization method of the polymer B. Preferably, the polymer A is produced by a solution polymerization method, and the polymer B is produced by a suspension polymerization method.

The mixture of the polymer A and the polymer B is produced by mixing in a solvent and then removing the solvent in order to produce a binder resin having a uniform composition and molecular weight distribution. In other mixing methods, for example, it is difficult to obtain a binder resin having a uniform composition and a molecular weight distribution by a manufacturing method such as heating and melting and mixing using a kneader. It is difficult to satisfy the offset resistance, and the pulverized material is easily fused to the inner wall of the apparatus in the generation or pulverization step of the fused material on the photoconductor, which is not preferable.

When the weight average molecular weight of the polymer A is less than 5,000, the offset resistance becomes poor and the pulverizability also becomes poor. or,
When the weight average molecular weight is 30,000 or more, poor fixability is obtained.

If the weight average molecular weight of the polymer B is less than 400,000, the pulverizability tends to be poor, and at the same time, the offset resistance is reduced, the blocking property is poor, and a fused product is formed on the photoreceptor.

When the weight average molecular weight is 1.5 million or more, the pulverizability is remarkably deteriorated.

Even if each of the polymer A and the polymer B is used alone as a binder resin for a toner, it is difficult to achieve the object of the present invention, and the production method in which the polymer A and the polymer B are melt-mixed is not used. It is difficult to achieve the object of the present invention. It is suitably achieved by a production method in which the solvent is removed after mixing in a solvent. The production method according to the toner of the present invention makes it possible for the polymer B to suitably satisfy conflicting properties such as offset resistance, fixability at low temperatures, and pulverizability.

The THF-insoluble component in the present invention indicates the weight ratio of the polymer component (substantially crosslinked polymer) insoluble in the THF solvent in the resin composition in the toner, and indicates the weight ratio of the resin composition containing the crosslinkable component. It can be used as a parameter indicating the degree of crosslinking. The THF-insoluble matter is defined by a value measured as follows.

That is, 0.5 to 1.0 g of a toner sample is weighed ( ₁ g of W), placed in a cylindrical filter paper (for example, No. 86R made by Toyo Filter Paper), subjected to a Soxhlet extractor, and extracted for 6 hours using 100 to 200 ml of THF as a solvent. After evaporating the soluble component extracted by the solvent, the resultant is dried under vacuum at 100 ° C. for several hours, and the amount of the THF-soluble resin component is weighed (W ₂ g). The weight of a component other than the resin component such as a magnetic substance or a pigment in the toner is expressed by (W ₃
g). The THF-insoluble content is obtained from the following formula.

In the present invention, the peak value of the chromatogram by GPC (gel permeation chromatography) and / or the molecular weight of the shoulder are measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) was passed through the column at this temperature as a solvent at a flow rate of 1 ml / min.
The measurement is performed by injecting 50 to 200 microliters of a THF sample solution of the resin adjusted to a sample concentration of 0.05 to 0.6% by weight.
In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number.
As a standard polystyrene sample for preparing a calibration curve, for example, molecular weight of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , manufactured by Pressure Chemical Co. or Toyo Soda Kogyo Co., Ltd.,
5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ ,
It is appropriate to use 4.48 × 10 ⁶ and to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

In order to accurately measure the molecular weight region of 10 ³ to 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, μ-st manufactured by Waters, Inc.
yragel 500, 10 ³ , 10 ⁴ , 10 ⁵ combination, Showa Denko shodex KF-80M or KF-802, 803, 804, 805 combination, or Toyo Soda TSKgel G 1000H, G 2000
H, G 2500H, G 3000H, G 4000H, G 5000H, G 6000H, G
A combination of 7000H and GMH is preferred.

On the other hand, S _A , S _B and S _d of the molecular weight distribution curve of the binder resin used in the toner of the present invention were obtained by cutting the chromatogram by GPC, calculating the weight ratio, subtracting the weight% of the THF-insoluble component, and reducing the area ratio. Calculated.

In the present invention, the molecular weight distribution of the release agent is measured by GPC (gel permeation chromatography) under the following conditions.

(GPC measurement conditions) Apparatus LC-GPC 150C (Waters) Column GMH6 (Toyo Soda) 60cm Column temperature 140 ℃ Solv. O-Dichlorobenzene Measured under the above conditions, the molecular weight distribution of the sample is prepared using a polyethylene standard sample It was calculated from the relationship between the logarithmic value of the calibration curve and the count number.

In the present invention, the melting point of the release agent is DSC-7 (Perkin El
The endothermic peak of the DSC was measured using a differential scanning calorimeter (manufactured by a mer company), and the highest melting peak value was obtained.

Resin composition in the toner of the present invention, styrenes,
Those obtained by polymerizing one or more monomers selected from acrylic acids, methacrylic acids and derivatives thereof are preferable from the viewpoint of developing characteristics and charging characteristics.

Examples of usable monomers include styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene.

Examples of acrylic acids, methacrylic acids and derivatives thereof include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n-tetradecyl acrylate, and n-acrylate. Acrylates such as hexadecyl, lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate, and the like can be mentioned. Similarly, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate can be used. , Amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate, cyclic methacrylate Hexyl, phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, glycidyl methacrylate, methacrylic acid esters such as stearyl methacrylate.

In addition to the above-mentioned monomers, small amounts of other monomers as long as the object of the present invention can be achieved, for example, acrylonitrile,
2-vinylpyridine, 4-vinylpyridine, vinylcarbazole, vinylmethylether, butadiene, isoprene, maleic anhydride, maleic acid, maleic monoesters, maleic diesters, vinyl acetate, and the like may be used.

As the crosslinking agent used in the toner of the present invention, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 4-butanediol diacrylate, 1,5
-Pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 20
0, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type diacrylate (MAND
A, Nippon Kayaku) and those obtained by changing the above acrylate to methacrylate.

Examples of polyfunctional crosslinking agents include pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4
-Methacryloxy, polyethoxyphenyl) propane,
Diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, triallyl isocyanurate,
Triallyl trimellitate, diarylchlorendate and the like.

These crosslinking agents are preferably not contained at all in order to make the THF-insoluble content less than 10% by weight, but when they are contained, less than 1% by weight, preferably 0.1% by weight, based on the binder resin.
The content is 5% by weight or less, more preferably 0.2% by weight or less.

In the toner used in the present invention, the number average molecular weight _Mn is
1.0 × 10 ³ or less, weight average molecular weight M _w of 2.5 × 10 ³ or less, M _w /
At least one release agent having M _n = 3.0 or less and a melting point (mp) in the range of 60 to 120 ° C. is used in an amount of 0.1 to 20% by weight based on the toner.

Examples of the release agent preferably used in the toner of the present invention include paraffin wax, low molecular weight polyethylene wax, and polyolefin wax graft-modified with unsaturated fatty acid, styrene derivative or unsaturated fatty acid ester. Among them, a graft-modified polyolefin wax is particularly preferred from the viewpoint of prolonging the life of a developer and a machine such as a copying machine using the developer, and free of maintenance.

As the unsaturated fatty acid or unsaturated fatty acid ester used for synthesizing the graft-modified polyolefin,
Methacrylic acid and methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, dodecyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate Methacrylates such as 2-hydroxyethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, glycidyl methacrylate, acrylic acid and methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n- Octyl acrylate, lauryl acrylate, steer Acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, 2-chloroethyl acrylate, 2-hydroxyethyl acrylate, cyclohexyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dibutylaminoethyl acrylate, 2-ethoxy acrylate, Acrylates such as 1,4-butanediol diacrylate, maleic acid, fumaric acid, itaconic acid, citraconic acid and monoethylmalate, diethylmalate, monopropylmalate, dipropylmalate, monobutylmalate, dibutyl Malate, di-2-ethylhexyl fumarate, monoethyl fumarate, diethyl fumarate, dibutyl fumarate, di-2-ethylhexyl fumarate, monoe Examples thereof include unsaturated dibasic acid esters such as tilitaconate, diethylitaconate, monoethylcitraconate and diethylcitraconate, and one or more of these can be used simultaneously.

Moreover, styrene, o-
Methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene,
p-ethylstyrene, pn-butylstyrene, p-te
rt-butylstyrene, pn-dodecylstyrene, p-
Examples thereof include phenylstyrene and p-chlorostyrene, and one or more of these can be used simultaneously.

As a method for graft modification, a conventionally known method can be used. For example, a graft-modified polyolefin is obtained by heating and reacting the polyolefin with an aromatic vinyl monomer and an unsaturated fatty acid or an unsaturated fatty acid ester in the molten state or in the molten state in the presence of a radical initiator under air or under pressure. can get. Grafting with an aromatic vinyl monomer and an unsaturated fatty acid or unsaturated fatty acid ester may be performed at the same time,
It may be performed individually.

Examples of the initiator used for the grafting reaction include benzoyl peroxide, dichlorobenzoyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, tert-butyl perphenyl acetate, cumin perpivalate, and azobis-isobutyi. Ronitrile, dimethylazoisobutyrate, dichromyl peroxide and the like can be mentioned.

The toner used in the present invention is composed of the above constituent materials, has a number average molecular weight _Mn of 1.0 × 10 ³ or less, and a weight average molecular weight M _w
Is 2.5 × 10 ³ or less, M _w / M _n 3.0 or less, melting point (mp) 60 to 120
In addition to the release agent in the range of ° C., one or more release agents similar to the above-mentioned constituent materials having a melting point of more than 120 ° C. may be mixed and used.

As the charge control agent used in the toner of the present invention, a conventionally known positive or negative charge control agent is used. Today, charge control agents known in the art include:

(1) The following substances control the toner to be positively charged.

Nigrosine, an azine dye having an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), a basic dye, for example, CIBasic Yellow 2 (CI41000), CIBasic Yellow 3, CIBasic Red 1 (CI45160), CIBasic Red 9 (CI42500), CIBasic Violet 1 (CI42535), CIBasic Violet 3 (CI42555), CIBasic Violet 10 (CI45170), CIBasic Violet 14 (CI42510), CIBasic Blue 1 (CI42025), CIBasic Blue 3 (CI51005), CIBasic Blue 5 (CI42140), CIBasic Blue 7 (CI42595), CIBasic Blue 9 (CI52015), CIBasic Blue 24 (CI52030), CIBasic Blue 25 (CI52025), CIBasic Blue 26 (CI44025), CIBasic Green 1 (CI42040), CIBasic Green 4 (CI42000) and the like, lake pigments of these basic dyes (as the lacking agent, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide,
Ferrocyanide), CISovent Black 3 (CI2615
0), Hansa Yellow G (CI11680), CIMordant Bl
ack 11, CIpiment Black 1, etc.

Or, for example, benzolmethyl-hexadecyl ammonium chloride, decyl-trimethylammonium chloraroid or dialkyltin compounds such as dibutyl and dioctyl, metal salts of higher fatty acids, glass, mica, inorganic fine powder such as zinc oxide, EDTA, metal of acetylacetone Polyamine resins such as amino group-containing vinyl polymers, amino group-containing condensation polymers, and the like, such as complexes, particularly nigrosine, metal salts of higher fatty acids, and vinyl polymers having amino groups, in terms of dispersibility and the like. preferable.

(2) The following substances control the toner to be negatively charged. JP-B-41-20153, JP-B-42-27596,
Examples thereof include metal complex salts of monoazo dyes described in JP-A-44-6397 and JP-A-45-26478.

Nitrohumic acid and its salts or dyes and pigments such as CI14645 described in JP-A-50-133338,
-42752, JP-B-58-41508, JP-B-58-73
No. 84 and JP-B-59-7384, etc., salicylic acid, naphthoic acid and dicarboxylic acid Zn, Al, C
Metal complexes of o, Cr, Fe, etc., sulfonated copper phthalocyanine pigments, nitrile groups, styrene oligomers having halogens introduced, chlorinated paraffins, etc. , Naphthoic acid and dicarboxylic acid are preferred.

The toner of the present invention can provide good results even when additives are mixed as necessary. As an additive, for example,
Lubricants such as Teflon, zinc stearate and polyvinylidene fluoride, among which polyvinylidene fluoride are preferred. Alternatively, abrasives such as cerium oxide, silicon carbide and strontium titanate, among which strontium titanate are preferred. Alternatively, for example, a fluidity-imparting agent such as colloidal silica and aluminum oxide, particularly hydrophobic colloidal silica is preferable. Anti-caking agent, or, for example, a conductivity-imparting agent such as carbon black, zinc oxide, antimony oxide, and tin oxide; or a fixing aid such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, and various waxes; or an anti-offset agent There is. In addition, a small amount of white fine particles and black fine particles of opposite polarity can be used as a developing property improver.

Further, a coloring agent may be added to the toner of the present invention as needed.

Any appropriate pigment or dye is used as the colorant used in the toner of the present invention. Toner colorants are well known and include, for example, pigments such as carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, bengara, phthalocyanine blue, and indanthrene blue. These are used in an amount necessary and sufficient to maintain the optical density of the fixed image, and 0.1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the resin are good. A dye is further used for the same purpose. For example, azo dyes, anthraquinone dyes, xanthene dyes, methine dyes and the like, 0.1 to 100 parts by weight of the resin.
The addition amount is preferably 20 to 20 parts by weight, preferably 0.3 to 3 parts by weight.

To prepare the electrostatic image developing toner according to the present invention,
After sufficiently mixing the resin composition and the charge control agent according to the present invention, a pigment or dye as a colorant as needed, additives, etc. by a ball mill or other mixer, a heating roll, a kneader, an extruder, etc. The pigment or dye is dispersed or dissolved in a resin kneaded by melting, kneading and kneading with a heat kneading machine, and after cooling and solidifying, pulverized and classified to obtain a toner having an average particle diameter of 3 to 20 μm. Can be obtained.

(Examples) Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. In the following formulations, parts are parts by weight.

(Production Example of Magnetic Powder) Production Example 1 0.8M FeSO ₄ aqueous solution 1 in a 4-liter three-necked flask
Steam is oxidized at about 70 ° C. while blowing oxygen into a system in which liter, 1 liter of 0.03M aluminum sulfate aqueous solution and 1 liter of 0.90M caustic soda aqueous solution are mixed.

The obtained black powder was filtered, washed with water and dried to obtain a magnetic iron oxide powder containing 1% by weight of an aluminum element. (Magnetic Powder A) Production Example 2 0.8 M FeSO ₄ aqueous solution 1 in a 4-liter three-necked flask
The mixture is oxidized at about 70 ° C. while blowing steam and oxygen into a mixture of 1 liter and 1 liter of a 0.90 M aqueous sodium hydroxide solution. When the oxidation is completed, 1 liter of a 0.01 M aluminum sulfate aqueous solution is added to the system, and the reaction is further performed.

The obtained black powder was filtered, washed with water, and dried to obtain a magnetic iron oxide powder containing 0.4% by weight of an aluminum element (magnetic powder B) (Synthesis example of binder resin) Synthesis example 1 200 parts of cumene was put into a reactor. The temperature was raised to the reflux temperature.
A mixture of 100 parts of styrene monomer and 6 parts of di-tert-butyl peroxide was added dropwise at 135 ° C. over 4 hours. Furthermore, the solution polymerization was completed under cumene reflux (146 ° C. to 156 ° C.) to remove cumene. The obtained polystyrene is THF
And had a weight average molecular weight of 7,800, a peak molecular weight (M _A ) of 7,200, and Tg = 67 ° C. This is designated as a binder resin polymer A-1 according to the toner of the present invention.

Synthesis Examples 2 to 5 Solution polymerization was carried out in the same manner as in Synthesis Example 1 using the monomer composition, polymerization initiator and solvent shown in Table 1 below, and a polymer A-2 of a binder resin according to the toner of the present invention was obtained. To A-5 were obtained.

Synthesis Example 6 200 parts of degassed water in which 0.1 part of partially saponified polyvinyl alcohol was dissolved was added to the reactor, and the monomer composition shown in Table 2 was added to obtain a suspension dispersion. The suspension and dispersion are heated to 80 ° C. in a nitrogen atmosphere. The temperature was maintained for 24 hours to complete the polymerization reaction. After cooling to room temperature, the spherical polymer particles produced by the polymerization reaction were separated by filtration, sufficiently washed with water, dehydrated and dried to obtain a binder resin polymer B-1 according to the toner of the present invention. The weight average molecular weight was 452,000, the peak molecular weight was 433,000, and Tg was 57 ° C.

Synthesis Examples 7 to 10 Using the monomer composition and the polymerization initiator shown in Table 3 below, suspension polymerization was carried out in the same manner as in Synthesis Example 2, and the binder resin polymers B-2 to B-2 of the present invention were used. B-5 was obtained.

Next, a production example of the binder resin according to the toner of the present invention will be described.

Production Example 1 68 parts of polymer A-1 and 32 parts of polymer B-4 were converted to xylene 20
Add to 0 parts with stirring. Next, the mixture is heated to about 60 ° C. to completely dissolve the added polymers A-1 and B-4. After stirring was continued for about 2 hours, xylene was removed. This is designated as binder resin 1 according to the toner of the present invention.

Production Examples 2 to 10 Binder resins 2 to 10 according to the toner of the present invention were obtained in the same manner as in Production Example 1 except that the polymers shown in Table 4 below were used.

Example 1 Binder resin 1 100 parts Magnetic powder A 60 parts Negative charge control agent 2 parts Low molecular weight polyethylene 3 parts After premixing the above materials with a Henschel mixer, 150 parts
The mixture was kneaded with a two-roll mill heated to 20 ° C for 20 minutes. After allowing the kneaded material to cool, coarsely pulverized with a cutter mill, pulverized using a fine pulverizer using a jet stream, and further classified using an air classifier, a black fine powder having a volume average particle size of 11.2 μm was obtained. Obtained.

Colloidal silica fine powder for 100 parts of the black fine powder
0.4 part was dry-mixed to obtain a developer (toner). This is designated as Toner 1 of the present invention.

The pulverizability of the toner can be represented by the processing amount of the pulverizable toner per unit time. In the case of this toner, the air pressure was 5.6 Kg / cm ^2, which was 16 kg / hr, which was very good. or,
No fusion or the like occurred in the crusher.

The blocking property was examined by a change in the degree of aggregation when about 10 g of the toner was placed in a 100 cc polycup and allowed to stand at 50 ° C. for one day. The degree of aggregation was measured with a powder tester manufactured by Hosokawa Micron. 10% by weight and 13% by weight showed almost the same value between the room temperature storage product and the 50 ° C one day storage product, and the difference (ΔG) was 3%.
, It was confirmed that substantially no blocking occurred.

Fixing properties, offset properties, wrapping properties, image properties, and durability were examined using a modified NP-6650 copy machine manufactured by Canon.

In particular, with respect to the offset property, the cleaning mechanism of the fixing roller was removed, and the number of copies of the image or the contamination of the roller was evaluated by the number of copies to be resisted.

The test was conducted by lowering the set temperature of the fixing device by 5 ° C. The fixability was determined by rubbing the image with Silbon C paper 10 times in a reciprocating manner 10 times with a load of about 100 g, and the peeling of the image was represented by a reduction rate (%) of the reflection density. The evaluation image was viewed at the 200th sheet when 200 sheets were continuously taken.

The wrapping property was determined by taking out three black images on the entire surface, and then checking how much the nails depended on the traces of the nails for releasing the fixing roller on the images.

The high-temperature offset property is based on removing the cleaning mechanism of the fixing roller, making 100 copies of A4 size paper in a vertical feed, copying immediately with A3 size paper, and checking whether there is any dirt on the image. evaluated.

As a result, the fixing property was very good with a reduction rate of 3%, the offset property was good without dirt on the roller even at 50,000 sheets, and the wrapping property was slightly traced by the nail on the image, Very good.

A durability test was performed on about 10,000 sheets using an image having an image area ratio of about 5%. The image was good, and there was little fusion or filming to a photoconductor or the like. There was no effect. Also, no hot offset occurred at all.

The low molecular weight polyethylene used in this example had a number average molecular weight of 880, a weight average molecular weight of 1,900, a weight average molecular weight / number average molecular weight of 2.2, and a melting point of 95 ° C.

The THF-insoluble content of the toner is 4% by weight, and the weight-average molecular weight / number-average molecular weight of the THF-soluble component by GPC = 38.2.
Molecular weight peak M _A = 7,700, molecular weight peak M _B = 765,000, M _A
/ M _B = 99, area of the molecular weight distribution curve S _A : S _B : S _d = 1: 0.36:
It was 0.60.

Example 2 Binder resin 2 100 parts Magnetic powder A 80 parts Positive charge control agent 2 parts Graft modified wax 4 parts After premixing the above materials with a Henschel mixer, 150
The mixture was kneaded with a two-roll mill heated to 20 ° C for 20 minutes. After allowing the kneaded material to cool, coarsely pulverized with a cutter mill, pulverized using a fine pulverizer using a jet stream, and further classified using an air classifier, a black fine powder having a volume average particle size of 8.7 μm was obtained. Obtained.

Colloidal silica fine powder for 100 parts of the black fine powder
0.4 part was dry-mixed to obtain a developer (toner). This is designated as Toner 2 of the present invention.

The pulverizability of the toner can be represented by the processing amount of the pulverizable toner per unit time. In the case of this toner, the air pressure was 5.8 kg / hr at 5.6 kg / cm ^2, which was very good.
Also, no fusing or the like occurred in the pulverizer.

The blocking property was examined by a change in the degree of aggregation when about 10 g of the toner was placed in a 100 cc polycup and allowed to stand at 50 ° C. for one day. The degree of aggregation was measured with a powder tester manufactured by Hosokawa Micron. 15% and 19% by weight showed almost the same value between the room temperature storage product and the 50 ° C one-day storage product, and the difference (ΔG) was 4%.
, It was confirmed that substantially no blocking occurred.

The fixing property, the offset property, the winding property, the image property, and the durability were examined by using a modified copy machine of Canon NP-4835 (fixing set temperature: 200 ° C.).

In particular, with respect to the offset property, the cleaning mechanism of the fixing roller was removed, and the number of copies of the image or the contamination of the roller was evaluated by the number of copies to be resisted.

The test was conducted by lowering the set temperature of the fixing unit by 10 ° C. The fixing property was determined by rubbing the image with symbol C paper 10 times in a reciprocating manner at a load of about 100 g, and the peeling of the image was represented by a reduction rate (%) of the reflection density.

The wrapping property was determined based on the appearance of the nail for peeling off the fixing roller on the image at the time of taking out three black images on the entire surface, and how much the nail depended.

The high-temperature offset property is based on removing the cleaning mechanism of the fixing roller, making 100 copies of A4 size paper in a vertical feed, copying immediately with A3 size paper, and checking whether there is any dirt on the image. evaluated.

As a result, the fixing property was very good with a 6% reduction rate, the offset property was good without contamination of the rollers on the image even at 1,000 sheets, and the wrapping property was slightly traced by the nail on the image. Very good. Also, no high temperature offset occurred.

A durability test was performed on about 30,000 sheets using an image having an image area ratio of about 5%. The image was good, and there was no fusing to the photoreceptor or filming.

The graft-modified wax used in this example was a styrene-modified polyethylene wax having a number average molecular weight of 530, a weight average molecular weight of 820, a weight average molecular weight / number average molecular weight of 1.5, and a melting point of 91 ° C.

The THF-insoluble content of the toner was 2% by weight, and the weight-average molecular weight / number-average molecular weight by GPC of the THF-soluble component was 24.7%.
Molecular weight peak M _A = 14,000, molecular weight peak M _B = 680,000, M _A /
M _B = 48.6, area of molecular weight distribution curve S _A : S _B : S _d = 1: 0.40:
It was 0.59.

Example 3 An unfixed image was obtained by using the toner manufactured in Example 2 with a modified FC-5 machine of a copying machine manufactured by Canon Inc.

The fixing test of the unfixed image was performed by using an external fixing machine as shown in FIG. 2, which was composed of a pressing member which was brought into pressure contact with a heating body and brought a recording material into close contact with the heating body via a film. As the material of the fixing film 5, an endless film obtained by coating a release layer obtained by adding a fluorine resin and a conductive agent to a polyimide film to a thickness of 10 μm was used. Silicon rubber was used as the pressure roller 8, the nip was 3.5 mm, and the process speed was 50 mm / sec. Drive roller 6 for film drive
The roller 1 moves without wrinkles in the direction of the arrow due to the driving and tension of the driven roller 7 (the heating element 1 is a low-heat-capacity linear heating element, which is controlled by applying energy in a pulsed manner). The temperature control temperature was the same as that of the fixing device of the modified FC-5 (fixing temperature: 180 ° C), and the temperature was lowered by 15 ° C and tested. As a result, the fixability was 2% at a decreasing rate. Even after 3,000-sheet running, both the image and the fixing film were free of stains and excellent.

Further, as a high-temperature offset test, immediately after 100 sheets of postcard size paper were continuously passed, an unfixed image was passed through A4 size paper, and a test was performed to determine whether a stain was generated on the image.
As a result, there was no stain on the image.

Example 4 A toner 3 of the present invention was obtained in the same manner as in Example 2 except that the magnetic powder was changed to the magnetic powder B.

This toner was subjected to the same test as in Example 2. The results are shown in Table 6 below.

Examples 5-8 Toners 4-7 of the present invention in the same manner as in Example 1 except that the binder resin and the release agent were changed to those shown in Table 5.
I got

Examples 9 to 11 The toner 8 of the present invention was prepared in the same manner as in Example 2 except that the binder resin and the release agent were changed to those shown in Table 5 below.
Got ~ 10.

Comparative Example 1 The binder resin 2 used in Example 2 was replaced with a polymer A-2 10
Comparative toner 1 was obtained in the same manner except that the amount was changed to 0 parts and the polymer B-50 was used.

In the case of this comparative toner, when pulverized at an air pressure of 5.6 kg / cm ² , a large amount of fine powder toner particles were generated, the particle size distribution was broad, and the productivity was clearly inferior.

In the same manner as in Example 2, the fixing property, the offset property, the winding property, the image property, and the durability were examined using an FC-5 modified machine.

As a result, stains occurred on both the image and the roller when the offset property was 20 sheets. Regarding the wrapping property, a trace of relying on the nail was clearly left on the image, and the paper was not discharged from the fixing machine in some cases.

The THF-insoluble content of this toner was 0% by weight, and the weight-average molecular weight / number-average molecular weight by GPC of the THF-soluble component was 2.1, and the molecular weight peak M _A was 8,900.

Comparative Examples 2 to 4 Comparative toners 2 to 4 were obtained in the same manner as in Example 2 except that the polymers and the release agents shown in Table 5 were used. The comparative toners were evaluated as Comparative Examples 2 to 4 of the present invention, and the results are shown in Table 6 below.

Comparative Example 5 Comparative toner 3 was obtained in the same manner as in Example 2 except that magnetic iron oxide containing no aluminum element was used as the magnetic powder.

 This toner was subjected to the same test as in Example 3.

(Effect of the Invention) The present invention pays particular attention to the amount of THF-insoluble component of the binder resin contained in the toner and the molecular weight distribution of the THF-soluble component in GPC. It is excellent in offset resistance in a wide temperature range, does not fuse to a photoreceptor or the like, is excellent in pulverizability, and can provide a stable and good developed image even when used for a long time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a molecular weight distribution curve by GPC, and FIG. 2 is an explanatory diagram of a fixing device used for a fixing test of an unfixed image. In Fig. 2: 3: Heating element 4: Temperature sensor 9: Image support 10: Toner 11: Transport guide

Continued on the front page (72) Inventor Masaji Fujiwara 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Shinji 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. Inside

Claims (8)

(57) [Claims] 1. An electrostatic image developing toner containing at least a binder resin and a magnetic powder, wherein the magnetic powder contains an iron element combined with an oxygen element and an aluminum element combined with an oxygen element. In the magnetic powder.
The binder resin has a THF-insoluble content of less than 10% by weight based on the binder resin, and the THF-soluble content of the binder resin is GPC (gel permeation). Chromatography) in the molecular weight distribution
Weight average molecular weight / number average molecular weight ( _Mw / _Mn ) is 18 or more, and one molecular weight peak value between 3,000 and 20,000
M _A , one molecular weight peak value between 380,000 and 1,000,000
M _B , each having a molecular weight minimum value M _d between 20,000 and 380,000, M _B / M _A is 30 to 150, and the area of a molecular weight distribution curve from a molecular weight of 400 to M _d is S _A , when the area of the S _B of the molecular weight distribution curve of the molecular weight M _d to 5,000,000, an area surrounded by straight lines and the molecular weight distribution curve connecting the vertex of the vertex and molecular weight peak value M _B having a molecular weight peak value M _a was S _d , S _A , S _B and S _d satisfy the following relationship: S _A : S _B : S _d = 1: 0.3 to 0.8: 0.35 to 0.8. 2. The magnetic powder has a magnetic iron oxide containing an aluminum element combined with an oxygen element, and the aluminum element is contained in the magnetic iron oxide in an amount of 0.05 to 10%.
The toner for developing an electrostatic image according to claim 1, wherein the toner is contained by weight%. (3) a number average molecular weight of 1,000 or less, a weight average molecular weight of 2,500 or less, a weight average molecular weight / number average molecular weight (M _w / M _n ) of 3.0 or less, and a melting point of 60 to 120 ° C. 3. The toner for developing an electrostatic image according to claim 1, wherein the toner contains a release agent in an amount of 0.1 to 20% by weight based on the binder resin. 4. The binder resin has a weight average molecular weight of 5,000.
The polymer according to any one of claims 1 to 3, which is produced by mixing 0 to 30,000 polymer A and polymer B having a weight average molecular weight of 400,000 to 1.5 million in a solvent and then removing the solvent. Charge image developing toner. 5. A fixing device for heating and fixing a visible image of toner to a recording material by a fixedly supported heating member and a pressing member which is in pressure contact with the heating member and closely contacts the recording material with the heating member via a film. Wherein the toner contains at least a binder resin and a magnetic powder, wherein the magnetic powder contains an iron element in a state of being bonded to an oxygen element and an aluminum element in a state of being bonded to an oxygen element. In the magnetic powder.
The binder resin has a THF-insoluble content of less than 10% by weight based on the binder resin, and the THF-soluble content of the binder resin is GPC (gel permeation). Chromatography) in the molecular weight distribution
Weight average molecular weight / number average molecular weight ( _Mw / _Mn ) is 18 or more, and one molecular weight peak value between 3,000 and 20,000
M _A , one molecular weight peak value between 380,000 and 1,000,000
M _B , each having a molecular weight minimum value M _d between 20,000 and 380,000, M _B / M _A is 30 to 150, and the area of a molecular weight distribution curve from a molecular weight of 400 to M _d is S _A , When the area of the molecular weight distribution curve from the molecular weight _Md to 5 million is S _B , and the area surrounded by the straight line connecting the peak of the molecular weight peak value M _{A and} the peak of the molecular weight peak value M _B and the area surrounded by the molecular weight distribution curve is S _d , S _A , S _B and S _d satisfy the following relationship: S _A : S _B : S _d = 1: 0.3 to 0.8: 0.35 to 0.8. 6. The magnetic powder has a magnetic iron oxide containing an aluminum element combined with an oxygen element, and the aluminum element is contained in the magnetic iron oxide in an amount of 0.05 to 10%.
The heat fixing method according to claim 5, wherein the heat fixing method is contained by weight%. 7. A compound having a number average molecular weight of 1,000 or less, a weight average molecular weight of 2,500 or less, a weight average molecular weight / number average molecular weight (M _w / M _n ) of 3.0 or less, and a melting point of 60 to 120 ° C. 7. The heat fixing method according to claim 5, wherein a certain release agent is contained in an amount of 0.1 to 20% by weight based on the binder resin. 8. The binder resin has a weight average molecular weight of 5,000.
0 to 30,000 polymer A and 400 to 1.5 million weight molecular weight polymer B
8. The heat fixing method according to any one of claims 5 to 7, which is produced by removing the solvent after mixing in a solvent.