JP2681784B2 - Binder resin for toner - Google Patents

Description

The present invention relates to a toner binder resin for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Prior Art] Conventionally, as an electrophotographic method, many methods are known as described in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electrical latent image on a photoconductor by various means, and then the latent image is developed with toner, and a transfer material such as paper is used as necessary. After the toner image is transferred onto, the toner image is fixed by heating, pressure, solvent vapor or the like to obtain a copy.

When a step of transferring a toner image is provided, a step for removing the residual toner is usually provided.

Development methods for visualizing an electric latent image using toner include, for example, a magnetic brush method described in U.S. Pat.No. 2,874,063, a cascade developing method described in U.S. Pat.No. 2,618,552, and a method described in U.S. Pat. And the method using a conductive magnetic toner described in U.S. Pat. No. 3,909,258.

Conventionally, fine powders in which dyes and pigments are dispersed in natural or synthetic resins have been used as toners applied to these developing methods. For example, particles obtained by finely pulverizing a dispersion of a colorant in a binder resin such as polystyrene to about 1 to 30 μm are used as toner. As the magnetic toner, toner containing magnetic particles such as magnetite is used. On the other hand, in the case of using a so-called two-component developer, the toner is usually used by being mixed with carrier particles such as glass beads and iron powder.

Nowadays, such a recording method is widely used not only for general copying machines but also for computer output, microfilm printing, and the like. As a result, the required performance becomes higher, and various performances such as smaller size, lighter weight, lower energy, higher speed, more maintenance-free, and more personality are required at the same time. Was. In order to satisfy these requirements, the demands on the toner have become more severe in various aspects. For example, if the size is made smaller, the heat source such as the fixing device and the exposure lamp can be pushed into a narrow space, so that the temperature inside the machine tends to rise. Therefore, the blocking property of the toner must be further improved. In order to reduce the weight, the fixing roller is designed to be thinner and thinner, and the cleaning mechanism of the fixing roller and the cleaning mechanism of the photoconductor are going to be simple and light.
The direction is not to attach a coating device such as oil for offset prevention to the fixing device. Therefore, it is necessary to improve the fixing property of the toner, the offset resistance, and the cleaning resistance of the photoconductor. Further, in order to achieve lower energy and higher speed, the fixing property of the toner must be naturally improved, and in order to be more personalized, it is necessary to improve the reliability and prevent jamming. Becomes important. Jam generally occurs when the copy paper is wound around the roller of the fixing device, and it is necessary to improve the winding property of the toner on the fixing roller. However, there are many contradictory characteristics required for toner production and various characteristics of the toner itself.

Even if the above examples are taken, the demands for toner are strict, but the demands cannot be met unless they are simultaneously improved. However, in order to realize these, it is meaningless to lower the development characteristics such as image quality and toner durability and the toner production efficiency.

Especially in today's copying machines, there is a strong demand for lower energy consumption and higher speeds, and the durability of the machines is also improving.
Long exposure to strong mechanical loads. For this reason, the toner is required to have a high durability which has never been obtained, and moreover, it is necessary to maintain high quality and high resolution for a long period of time.

These performances are largely due to the homogeneity of the toner. Particularly, the dispersion in these toners, such as a polyolefin used as a colorant or a fixing aid, and in the case of a magnetic toner, a magnetic substance containing 30 to 60% by weight of the toner is a point of high durability.

These are largely due to the performance of the binder resin of the toner. There are many proposals to improve these by using a release agent, a plasticizer, and other additives, but these are auxiliary. Therefore, various methods have been proposed for improving the binder resin.

For example, Japanese Patent Publication No. 51-23354 proposes a toner using a crosslinked polymer as a binder resin. According to the method, the offset resistance and the wrapping resistance are remarkably improved. However, if the degree of cross-linking is increased, the fixing point rises, the fixing temperature is sufficiently low, and the offset resistance and wrapping resistance are high. Good fixing properties and sufficient fixing characteristics have not been obtained.
In general, in order to improve the fixability, the binder resin must have a low molecular weight to lower the softening point, which is inconsistent with the offset resistance improvement treatment, and in order to reduce the softening point Inevitably, the undesired phenomenon that the glass transition point of the resin is lowered and the toner during storage is blocked. Therefore, as disclosed in JP-A-59-88948, a toner was proposed in which a polymer having a low molecular weight and a polymer having a gel crosslinked to 70% or more were blended in order to satisfy low-temperature fixing and offset resistance. The combined polymer has poor compatibility with other polymers, and no toner having satisfactory fixability and developability has been obtained. Further, in the crosslinked polymer, there is a problem that it is difficult to disperse pigments, charge control agents, release agents, and the like, which are components added to the toner, and it is difficult to obtain good developing characteristics as a toner. There is.

In addition, in order to improve pulverizability and fixability, Japanese Patent Publication No. 60-2041
The number average molecular weight as in JP-A-1 is 100,000 to 500,000 and a high polymer, and after mixing with other monomer components, a uniform polymer is obtained by polymerization, and it was proposed to use it as a binder resin. It is not possible to include a highly cross-linking component in the resin component to satisfy offset resistance and non-winding property on the fixing roller, and even if a part of it is formed, the compatibility between the polymers is poor, so that it is uniform. In the present situation, the toner cannot be contained and when used as a toner binder, the dispersibility of the additive is poor and a toner satisfying the developing property and fixing property is not obtained.

Furthermore, JP-A-56-158340 proposes a toner composed of a low molecular weight polymer and a high molecular weight polymer, but this binder resin is difficult to contain a crosslinking component in practice. In order to improve the offset resistance with higher performance, it is necessary to increase the molecular weight or increase the ratio of the high molecular weight polymer. This direction is a direction in which pulverizability is remarkably reduced, and it is difficult to obtain a practically satisfactory one. Further, with respect to a toner blended with a low molecular weight polymer and a crosslinked polymer, Japanese Patent Application Laid-Open No. 58-86558 proposes a toner containing a low molecular weight polymer and an insoluble infusible high molecular weight polymer as main resin components. ing. According to that method, it is thought that the fixability and the pulverizability are improved,
Weight average molecular weight / number average molecular weight of low molecular weight polymer (Mw / M
Since n) is as small as 3.5 or less, and the insoluble and infusible high molecular weight polymer is as large as 40 to 90% by weight, it is difficult to satisfy both offset resistance and pulverizability with high performance. It is extremely difficult to produce a toner that sufficiently satisfies the fixability, anti-offset property, and pulverizability unless it is a fixing device having a supply device for preventing liquid. Further, the insoluble and infusible high molecular weight polymer has a large melt viscosity due to the heat kneading at the time of toner preparation, and therefore, the heat kneading should be performed at a temperature much higher than usual, or the heat kneading should be performed with a high share. However, as a result, the former has a problem that the toner characteristics are deteriorated due to the thermal decomposition of other additives, and the latter has a problem in that the molecules of the binder resin are excessively cleaved and the initial offset resistance performance is difficult to be obtained.

Further, it is not easy to disperse the magnetic substance and the fixing aid such as polyolefins in such a state that the high-crosslinking component and the low-molecular weight component are mixed, and there may be no problem in the conventional copying apparatus. Considering higher durability, it can be said that it is quite severe.

[Problems to be Solved by the Invention] An object of the present invention is to provide a binder resin for a toner that simultaneously satisfies excellent performance in various items.

Another object of the present invention is to provide a binder resin for toner which is excellent in fixing property and at the same time excellent in offset property, winding property and blocking property.

Another object of the present invention is to provide a binder resin for toner, which has good pulverizability and good toner production efficiency.

Another object of the present invention is to provide a binder resin for toner which is excellent in fusion resistance into the apparatus at the time of pulverization or fusion resistance of a photoconductor or the like.

Another object of the present invention is to provide a binder resin for a toner having good dispersibility such as a colorant, a release agent, and particularly a magnetic material.

Another object of the present invention is to provide a binder resin for toner which is excellent in developability, particularly image quality and durability.

[Means and Actions for Solving the Problem] That is, according to the present invention, a first vinyl polymer is dissolved or mixed in a vinyl monomer component to prepare a monomer composition, and the monomer composition is used as a crosslinking agent. A binder resin for a toner containing a gel component and a tetrahydrofuran-soluble component obtained by polymerizing in the presence, wherein the binder resin for a toner is substantially spherical or an aggregate of spherical particles. It is a vinyl-based resin particle with an average particle size of 0.1 to 0.7 mm, and contains 0.1 to 60% by weight of gel component, and the main peak in the molecular weight range of 1000 to 25000 in the GPC chromatogram of the tetrahydrofuran soluble component. Has a value and is a region of molecular weight 3000 to 150,000,
And at least 1 on the high molecular weight side of the main peak value.
It has two sub-peaks or sub-shoulders, 0 to 20% by weight of components with a molecular weight of 500,000 or more, and a molecular weight of more than 30,000 to 50.
The present invention relates to a binder resin for toner, characterized by containing 10 to 60% by weight of components and 20 to 90% by weight of components having a molecular weight of 30,000 or less, each based on the weight of the tetrahydrofuran-soluble component.

 The configuration of the present invention will be described.

In order to simultaneously achieve the above-mentioned objects, various binder resins were used, and as a result of diligent examination of the constitution and performance from various angles, the ratio of the gel component of the binder resin and the molecular weight distribution of the THF-soluble component We have found that it can be achieved with certain configurations.

Especially in the gel component, it mainly affects offset resistance, pulverizability, winding property, dispersibility of additives, and fixability, while the position of the main peak and sub-peak or sub-shoulder in the molecular weight distribution of THF-soluble components is It was found that it mainly affects the pulverizability, dispersibility, blocking resistance, and fixability.

Therefore, as the components required for the toner resin, both a high molecular weight region containing a gel component which is a solvent insoluble component and a low molecular weight region which is a solvent soluble component are required, and they are mixed uniformly. Is important.

In the resin composition of the present invention, it is necessary that the high molecular weight polymer including the cross-linking region component and the low molecular weight polymer are uniformly mixed. Since the high molecular weight polymer containing the cross-linking region component is insoluble in the solvent, it is difficult to bring the high molecular weight polymer and the low molecular weight polymer into a solution-like mixed state between the polymers, and it is apparently mixed. However, it does not mean that the mixture is truly homogeneous. Further, in the method in which the high molecular weight polymer is heat-melted with the low molecular weight polymer and mechanically mixed, it cannot be said that the polymer is truly homogeneously mixed. Therefore, in order to uniformly mix the low molecular weight component effective for low temperature fixing and dispersibility of the additive, and the cross-linking region component effective for offset and winding, the low-molecular weight component and the cross-linking region component are mixed. The presence of a high-molecular-weight component is effective in the case where the components are not crosslinked. Furthermore, the medium and high molecular weight components not only serve as a link between the molecular weight and the ratio, but also at low temperature fixing,
It was found to be highly effective in terms of offset, pulverizability of toner, and the like. Therefore, in order to obtain a resin composition in which a high molecular weight polymer having a cross-linking region component and a low molecular weight polymer are uniformly mixed, a monomer component which gives a medium or high molecular weight polymer in advance with the low molecular weight polymer together with a crosslinking agent. A method of obtaining a high-molecular-weight polymer having a cross-linking region component by dissolving or mixing it in the above, polymerizing again, and polymerizing in the second stage is used.

Therefore, in the present invention, the first vinyl polymer is dissolved or mixed in the vinyl monomer component to prepare a monomer composition, and the monomer composition is polymerized in the presence of a cross-linking agent to obtain a gel component and A method for obtaining a binder resin for toner containing a tetrahydrofuran-soluble component is used.

The low molecular weight polymer in the resin composition of the present invention can be obtained by a commonly used polymerization method such as a bulk polymerization method or a solution polymerization method.

In the bulk polymerization method, a polymer having a low molecular weight can be obtained by polymerizing at a high temperature to reduce the termination reaction rate, but there is a problem that the reaction is difficult to control. In that respect, in the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in radical chain transfer depending on the solvent, and by adjusting the amount of the initiator and the reaction temperature.
It is preferable to obtain a low molecular weight compound in the resin composition used in the present invention. It is difficult to synthesize a resin containing a necessary amount of a gel component only by a solution polymerization method. This low molecular weight polymer does not re-polymerize with the monomer giving the high molecular weight polymer among the above-mentioned crosslinking agent and the components in the crosslinking region, but it does not dissolve the gel component in the crosslinking region until it becomes an insoluble component in the solvent. Examples of the polymerization method to be obtained include an emulsion polymerization method and a suspension polymerization method, and a suspension polymerization method is particularly preferable.

According to the suspension polymerization method, a monomer containing a low molecular weight polymer in a suspended state is polymerized together with a crosslinking agent, so that the resin composition has a pearl-like shape and is crosslinked from the low molecular weight polymer. It is possible to obtain even a high-molecular weight polymer in a preferable state in which it is uniformly mixed, including the range component.

The resin particles of the present invention are substantially spherical or an aggregate of spherical particles. This is naturally generated to some extent in a polymerization method using a dispersion medium and a dispersoid.
For this reason, the resin powder has the advantages of good fluidity and easy handling, and, unlike the solution polymerization method or the bulk polymerization method, it does not require a step of crushing and pulverizing the lumps into fine pieces, so that the production efficiency is good, but for toners There may be some problems with the material. That is, since the fluidity (specific gravity) is extremely different from the resin powder and other materials such as pigments, release agents, magnetic materials, etc.,
There is a problem that the powder is not sufficiently mixed at the time of powder mixing in the previous stage of heat kneading. The conventionally known binder resin can be supplemented in the subsequent heat kneading step to produce a toner that can withstand normal use. It has been found that the resin of the constitution of the present invention is good in normal use, but in view of high durability, the conventional idea is insufficient. That is, in the binder resin,
When the high-molecular weight component and the low-molecular weight component containing the cross-linking component are uniformly contained, it is considered that it is necessary to sufficiently mix and disperse the other material into the low-molecular weight portion existing in the cross-linking network. Therefore, it is considered necessary to homogenize sufficiently during powder mixing in the previous step of heat kneading.

As a result of examination, when the average particle diameter is smaller than 0.10 mm, the bulk becomes large and it becomes difficult to disperse, and in order to reduce the particle diameter, a large amount of polyvinyl alcohol or calcium phosphate, which is a dispersant, is contained, and the toner It tends to deteriorate electrostatic properties, especially environmental characteristics. On the other hand, if the average particle size is larger than 0.7 mm, dispersion with a magnetic material or the like is poor at the time of powder mixing, and long-term durability becomes a problem. Preferably, the average particle size is 0.15 to 0.4 mm.

The average particle size here is the cumulative 50% by weight value of the distribution obtained by sieving (hereinafter referred to as D50%), and in a more preferred embodiment, the cumulative 10% value (hereinafter referred to as D10%) is 0.09 to 0.4. mm, preferably 0.1 to 0.2 mm, and similarly expressed, D20% is 0.12 to 0.5 mm, preferably 0.13 to
0.25 mm, D30% ~ D50% 0.15 ~ 0.7 mm, preferably 0.15
~ 0.4 mm, D60% ~ D80% 0.15 ~ 0.8 mm, preferably 0.25 ~ 0.7 mm, D90% ~ D100% 0.2 ~ 0.8 mm, preferably 0.5 ~ 0.8 mm, above 20 mesh Of 10
It is not more than 5% by weight, preferably not more than 5% by weight.

 The measuring method of this particle distribution is shown below.

Low tap type vibration sieving machine, JIS standard sieve 20,4
2,60,80,100,200 mesh attached, frequency 290rpm,
The vibration time was 330 seconds, and the sample was 33 g.

Further, in the molecular weight distribution of GPC, the molecular weight is 3
Chromatogram is divided into three parts with 10,000 and 500,000 as boundaries, and from the high molecular weight side, A component (500,000 or more region), B component (more than 30,000 to less than 500,000 region), C component (30,000 or less) Area), and the composition ratio of each component to the entire chromatogram is calculated by the gravimetric method in which the integrated value of the chromatogram or the chromatogram is cut out and divided into three parts, and the ratio is calculated by each weight. A component is 0 to 20%, preferably 0 to 15%, more preferably 0 to 10%; B component is 10 to 60%, preferably 15 to 55%, more preferably 20 to 50%; C component is 20 to 90%, preferably 35-
It is preferably 80%, more preferably 40 to 70%.

The reason for these is that, when the gel component in the resin composition exceeds 60%, the melting temperature of the cross-linking component causes the fixing temperature to increase when used in a toner, and further the dispersion of the additive is caused. Becomes worse. Further, the components in the high cross-linking region are likely to be cut during the kneading of the resin, which causes a trouble in the design of the toner. If the gel component is less than 0.1%, offset and winding around the roller are likely to occur, and the gel component is
If it is less than 0.1% and the high molecular weight region is large, the pulverizability is remarkably deteriorated.

If the molecular weight of the solvent-soluble component is 1000 to 25000, there is no main peak value, and if the main peak value exceeds 25,000, the fixing temperature of the toner created will rise and the fixing temperature range will narrow.
The pulverizability also deteriorates, leading to a decrease in production efficiency. If the molecular weight of the main peak value is less than 1000, the toner produced will have significantly poor offset resistance and winding around the roller,
In addition, blocking may occur. When the molecular weight of the sub-peak or sub-shoulder value is not in the range of 3000 to 150,000 and the value exceeds 150,000, the dispersibility of the additive during toner preparation is poor, the fixing temperature is remarkably increased, and the pulverizability is remarkably deteriorated. When the molecular weight of the sub-peak or the sub-shoulder value is less than 3000, the prepared toner may have poor anti-offset property and winding around the roller, which may cause blocking problems. In the resin composition of the present invention and the toner using the same, the above problems are remarkably improved, offset resistance and roller wrapping are excellent, a fixing temperature range is wide, and toner having good crushing property having excellent developing characteristics is provided. Is obtained.

The reason for this is that in a resin composition in which a high molecular weight polymer component including a crosslinked region to a low molecular weight polymer component is uniformly mixed, high molecular weight and low molecular weight segments are mixed together in the crosslinked region. It is considered that the high molecular weight component containing cross-linking prevents the decrease of cohesive force and excessive fluidity as a matrix during heat melting, while the low molecular weight component exhibits heat melting property, resulting in heat melting at low temperature. However, it is considered that it exhibits excellent heat-melting properties such that the cohesive force is reduced and excessive flow is suppressed even at high temperatures. In the present invention, a polymer that is uniformly mixed from a low molecular weight component to a high cross-linking component is defined as an image density by repeated use that occurs in the case of a non-uniformly mixed polymer when a toner is prepared using the polymer. Means that fog does not actually occur.

Regarding the grindability, the components in the high molecular weight region other than the cross-linking region impart toughness to the composition, while the components in the cross-linking region impart brittleness, and the low-molecular weight component imparts easiness to be further pulverized, thereby improving the overall composition. It is considered that the pulverization characteristics necessary for improving the excellent production efficiency are generated.

The gel component in the present invention refers to the weight ratio of the polymer component crosslinked in the resin composition, which becomes insoluble in the solvent, and is used as a parameter indicating the degree of crosslinking of the resin composition containing the highly crosslinked component. be able to. What is a gel component?
It is defined by the values measured as follows.

That is, as a resin sample, a fixed amount of 0.5 to 1.0 g of resin is weighed (w ₁ g), put into a cylindrical filter paper (Toyo Roshi Kaisha No.86R), put on a Soxhlet extractor, and chloroform or THF 100 to 200 ml is used as a solvent. After extracting for 6 hours and evaporating the soluble components extracted by the solvent, 100
After vacuum drying at ℃ for several hours, weigh the soluble resin component (w
₂ g), and calculate according to the following formula. In addition, since the solubility or swelling property of chloroform or THF as the extraction solvent in the resin sample is almost unchanged, either one can be used depending on which one.

Gel component content = (w ₁ −w ₂ ) / W ₁ × 100 (%) The solvent-soluble component obtained by the above operation is TH
After dissolving in F (tetrahydrofuran) and passing through a sample processing filter, it is used as a GPC sample.

In the present invention, the molecular weight of the peak or / and shoulder of the chromatogram by GPC is measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40 ° C., and THF as a solvent was flowed through the column at this temperature at a flow rate of 1 ml / min to obtain a sample concentration of 0.05 to 0.1% by weight.
Inject 50 to 200 μl of the THF sample solution of the resin prepared in step 1, and measure. In the measurement of 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 creating a calibration curve, for example, Pressure Chemical Co (Breath Ure Chemical). Made or manufactured by Toyo Soda Kogyo Co., Ltd. has a molecular weight of 6 ×
10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.
It is suitable to use 9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ and at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

In order to properly measure the molecular weight region of 10 ³ to 4 × 10 ⁶ as the column, it is preferable to combine a plurality of commercially available polystyrene gel gel columns.
Styragel (Stiller gel) 500, 10 ^3, 10 ^4, 10 ⁵ of combinations and, Showa Denko KK of Shodex (Shodex) KF-80M
Or KF-802,803,804,805 combination, KA-802,803,804,8
Combination of 05 or TSK gel G1000H, G200 made by Toyo Soda
Any combination of 0H, G2500H, G3000H, G4000H, G5000H, G6000H, G7000H, GMH is desirable.

The resin composition in the present invention contains a high molecular weight polymer component containing a crosslinking component and a low molecular weight polymer component, both of which are one or more vinyls selected from styrenes, acrylic acids, methacrylic acids and their derivatives. It is a vinyl-based resin obtained by polymerizing a system-based monomer, and the vinyl-based resin preferably has developing characteristics and charging characteristics. Examples of vinyl monomers used in the present invention include styrenes such as styrene, α-methylstyrene, vinyltoluene,
Chlorostyrene and the like are listed, and acrylic acids, methacrylic acids and their derivatives include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate,
Butyl allylate, octyl acrylate, acrylic acid 2
-Acrylic acid esters such as ethylhexyl, n-tetradecyl acrylate, n-hexadecyl acrylate, lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate, and the like, as well as methacrylic acid and methacrylic acid. Methyl, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, methacrylic acid Phenyl, methacrylic acid 2-
Examples thereof include methacrylic acid esters such as hydroxyethyl, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, glycidyl methacrylate, and stearyl methacrylate. Further, the high molecular weight polymer component including a cross-linked region in the resin component of the present invention and the low molecular weight polymer component include, in addition to the vinyl-based monomer described above, a small amount of other vinyl-based polymer within the range in which the object of the present invention can be achieved. Monomers such as acrylonitrile, 2-vinyl pyridine, 4-vinyl pyridine, vinyl carbazole, vinyl methyl ether, butadiene, isoprene, maleic anhydride, maleic acid, maleic acid monoesters, maleic acid diesters and vinyl acetate are used. Is also good.

As the cross-linking agent used for forming the cross-linking component during the production of the resin of the present invention, as a bifunctional cross-linking agent,
Divinylbenzene, bis (4acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-brylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6 -Hexane glycol diacrylate,
Neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dibropyrene glycol diacrylate, polypropylene glycol diacrylate, polyester type Diacrylate (MANDA Nippon Kayaku) and all of the above acrylates converted to methacrylates, pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, as polyfunctional crosslinking agents. Oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, polyexiphenyl) Bread, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diaryl chlorendate, and the like.

The selection of the type of initiator, the type of solvent and the reaction conditions for producing the resin of the present invention are important factors for obtaining the resin of the present invention. Examples of the initiator include benzoyl peroxide, 1,1-di (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, n-butyl-4,4-di (t
-Butylperoxy) valerate, dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t
-Organic peroxides such as butyl peroxide, azo and azo compounds such as azobisisobutyronitrile and diazoaminobenzene can be used. The following specifically describes the solution polymerization and suspension polymerization according to the present invention.

As the solvent used in the solution polymerization, xylene, toluene, cumene, cellosolvic acid acid, isopropyl alcohol, benzene or the like is used. In the case of a styrene monomer, xylene, toluene or cumene is preferred. It is appropriately selected depending on the polymer to be polymerized. The initiator is di-tert-butyl peroxide, tert-butyl peroxybenzoate, benzoyl peroxide, 2,2
0.1 parts by weight or more (preferably 0.4 to 15 parts by weight) of 2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), etc. relative to 100 parts by weight of the monomer.
Used at a concentration of The reaction temperature varies depending on the solvent used, the initiator, and the polymer to be polymerized.
It is good to carry out at ~ 180 ℃. Solvent 1 in solution polymerization
It is preferable to use 30 parts by weight to 400 parts by weight of the monomer with respect to 100 parts by weight.

The suspension polymerization is preferably carried out with 100 parts by weight or less (preferably 10 to 90 parts by weight) of the monomer per 100 parts by weight of the aqueous solvent. As the dispersant that can be used, polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, etc. are used, and there is an appropriate amount such as the amount of the monomer in the aqueous solvent, but generally 0.01 to 1 part by weight relative to 100 parts by weight of the aqueous solvent. Used. The polymerization temperature is suitably 50 to 95 ° C, but it should be appropriately selected depending on the initiator used and the target polymer. Also, as the type of initiator,
If it is insoluble or slightly soluble in water, it can be used, for example, benzoyl peroxide, tert-
Butyl peroxyhexanoate or the like is used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the monomer.

In the toner using the resin of the present invention, in addition to the above-mentioned binder resin component, the following compound is contained in a proportion smaller than the content of the binder resin component, as long as the effect of the present invention is not adversely affected. You may.

For example, silicone resin, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aliphatic hydrocarbon hydride resin such as low molecular weight polyethylene or low molecular weight polypropylene, aromatic Examples include petroleum resin, chlorinated paraffin, and paraffin wax.

When a magnetic toner is prepared using the binder resin of the present invention, magnetic fine particles are contained in the toner. The magnetic fine particles may be any material that exhibits magnetism or is magnetizable,
For example, iron, manganese, nickel, cobalt, chromium and other metals, magnetite, hematite, various ferrites,
There are McGun alloy, other ferromagnetic alloys, etc., and these have an average particle size of about 0.05 to 5μ (more preferably 0.1 to 1μ)
Can be used. The amount of magnetic fine particles contained in the magnetic toner is 15 to 80% by weight of the total weight of the toner.
Is good.

In addition, various substances can be added to the toner according to the present invention for the purpose of controlling coloring and charge. For example, carbon black, iron black, graphite, nigrosine, a metal complex of a monoazo dye, ultramarine blue, phthalocyanine blue, haiza yellow, benzidine yellow, quinacridone, various lake pigments and the like.

The toner prepared from the above-described binder resin, magnetic fine particles, colorant, charge control agent, and the like has strong resistance to the load applied in the developing device, and was not crushed and deteriorated in the durability test.

An ethylene olefin polymer may be used as a fixing aid together with a binder resin.

Here, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyethylene There is an ionomer having a skeleton. In the above copolymer, 50 mol% or more (more preferably 60 mol%
Above) is preferred.

The method for producing a toner using the resin according to the present invention is
It comprises a step of mixing the toner material in powder form, a step of heat kneading, and a step of pulverizing, and a step of classifying is added as necessary.

Next, an electrophotographic method using a developer using the resin according to the present invention will be described.

The step of developing the electric latent image using toner includes the above-described magnetic brush method, cascade development method, powder cloud method, a method using a conductive magnetic toner described in U.S. Pat.No. 3,909,258, There is a method using a high-resistance magnetic toner described in JP-A-53-31136.
The developer using the resin according to the present invention is suitable for a developing method using a so-called one-component developer containing magnetic fine particles. In the step of transferring the developed image to the transfer-receiving member, an electrostatic transfer method such as a corona transfer method or a bias transfer method is used.

Further, in the toner using the binder resin of the present invention,
A blade cleaning method, a fur brush cleaning method, or the like is applied to the step of removing the residual toner on the photosensitive layer or the insulating layer, and is particularly suitable for the blade cleaning method.

The powder image on the member to be transferred needs to be fixed on the member. As a method for this, a heat fixing method, a solvent fixing method, a flash fixing method, a laminating fixing method, and the like can be used. Suitable for roller fixing system.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

 In addition, the part in an Example shows a weight part.

Synthesis Example-1 85 parts of styrene, n in 200 parts of toluene at a boiling point
-Butyl acrylate 10 parts, α-methyl styrene 5 parts,
A mixed solution of 8 parts of di-tert-butyl peroxide was added dropwise over 5 hours, and then polymerization was carried out while keeping the boiling point for another 3 hours. Excluding toluene under reduced pressure, a low molecular weight polymer-
1 was obtained. Next, low molecular weight polymer-150 parts, styrene 75 parts,
24 parts of n-butyl acrylate, 0.4 of divinylbenzene
Parts, benzoyl peroxide 1.0 part of a homogeneous mixed solution is suspended and dispersed in 400 parts of water in which 0.8 part of polyvinyl alcohol partially saponified with a degree of polymerization of 2000 is dissolved at a stirring speed of 200 rpm using a specific stirring blade, Polymerization was carried out for 15 hours at a polymerization temperature of 80 ° C. to obtain a pearl-like resin composition in which a high molecular weight polymer containing a gel component was uniformly mixed to a low molecular weight polymer, and dried under reduced pressure to obtain a resin composition-1. did. The obtained resin composition was spherical particles and aggregates thereof, and the particle size was 0.12 mm in cumulative 50% value. The resin powder on 20 mesh was 2.5% by weight of the whole.

About 0.5 g of resin composition-1 was precisely weighed and put in a cylindrical filter paper (N0.86R made by Toyo Roshi Kaisha, Ltd.), and 180 ml of chloroform as a solvent.
Soxhlet extraction for 6 hours, evaporate to remove the solvent in the extracted soluble components, then 100 ℃
For 12 hours under vacuum, and the amount of the soluble resin component was weighed. From the sample weight and this value, the gel component weight (degree of crosslinking) was determined according to the above equation. Further, this soluble resin component was dissolved in THF, and as a sample having a concentration of 0.1% by weight, it was passed through a non-aqueous sample pretreatment filter to obtain a GPC sample. GPC
A Shodex KF-80M double column is used as a sample for the measurement column, and it is installed in a 40 ° C heat chamber of a GPC measuring device (Waters 150C ALC / GPC) with a THF flow rate of 1 ml / min. 20 samples under conditions
GPC was measured by injecting 0 μl. As a calibration curve for molecular weight measurement, the molecular weight is 0.5 × 10 ³ , 2.35 × 10 ³ , 10.2 × 10 ³ , 35 × 1
0 ³ , 110 × 10 ³ , 200 × 10 ³ , 470 × 10 ³ , 1200 × 10 ³ , 2700 × 10 ³ ,
A THF solution of 10 points of 8420 × 10 ³ monodisperse polystyrene reference substances (manufactured by Waters) was used.

The resin composition-1 had a gel component weight of 38% by weight, and an eluting component had a molecular weight main peak value of 5,900 and a sub peak value of 53,00. The chromatogram by GPC is shown in FIG.

Synthesis Example-2 A low molecular weight polymer-2 was obtained in the same manner as in the synthesis of the low molecular weight polymer-1 except that 5 parts of 2 ethylhexyl acrylate and 95 parts of styrene were used as the monomers in the synthesis of the low molecular weight polymer. Next, except that 50 parts of the low molecular weight polymer-2 is used, it is compounded in the same manner as in Synthesis Example-1, and it is mixed with 400 parts of water in which 0.7 part of the polyvinyl alcohol partially saponified product having a polymerization degree of 2000 is dissolved, and a stirring speed is set. It was suspended and dispersed at 190 rpm by using a certain stirring blade, and polymerized in the same manner as in Synthesis Example-1 to obtain a resin composition-2. The resin composition is spherical particles and aggregates thereof, the particle size of which is cumulative 50
The value was 0.3 mm. The resin powder on 20 mesh was 2.9% by weight of the whole. Furthermore, the gel component amount of the resin composition-2 is 37% by weight, and the molecular weight main peak value of the eluted component is
It was 5200 and the sub-peak value was 48,000.

Synthesis Example-3 130 parts of low molecular weight polymer in suspension polymerization, 0.7 part of divinylbenzene, benzoyl peroxide as an initiator
A pearl-like resin composition-3 was obtained in the same manner as in Synthesis Example-1, except that 1.3 parts were used. The resin composition is spherical particles and aggregates thereof, and this particle size has a cumulative 50% of 0.15.
mm. The resin powder on 20 mesh was 2.7% by weight of the whole. The resin composition-3 had a gel component amount of 58% by weight, a molecular weight main peak value of the eluted component was 5,900, and a sub-shoulder value of 39,000.

Synthesis Example-4 Triethylene glycol-di-acrylate 0.5 instead of divinylbenzene as a crosslinking agent in suspension polymerization
Except that all parts are used in the same manner as in Synthesis Example-1,
It was stirred in 400 parts of water in which 0.3 part of partially saponified polyvinyl alcohol with a degree of polymerization of 2,000 was dissolved, stirring speed / 70 rpm.
Then, the mixture was suspended and dispersed using a specific stirring blade and polymerized in the same manner as in Synthesis Example-1 to obtain a resin composition-4.

The resin composition was spherical particles and aggregates thereof, and the particle size was 0.65 mm in cumulative 50% value. The resin powder of 20 mesh or more was 4.8% by weight of the whole. The resin composition-4 had a gel component weight of 40% by weight, and an eluting component had a molecular weight main peak value of 5,900 and a sub peak value of 55,000.

Synthesis Example-5 Synthesis Example-1 except that the amount of the partially saponified polyvinyl alcohol having a polymerization degree of 2,000 in Synthesis Example-1 was 1.2 parts and the suspension dispersion was adjusted by selecting a stirring speed and a certain stirring blade. Create a resin composition in the same manner as in D50% 0.07m
Resin composition-5 having a residue of 1% by weight on m, 20 mesh was obtained.
The weight of the gel component, the molecular weight peak value and the sub-peak value of the THF-soluble component of the resin composition-5 were almost the same as those of Synthesis example-1.

Synthesis Example-6 Amount of partially saponified polyvinyl alcohol of Synthesis Example-4.
Resin composition-6 was prepared in the same manner as in Synthesis Example-2 except that the mixing speed was 15 parts by weight and the stirring speed and a specific stirring blade were selected. The resin composition-6 had a D50% of 0.79 mm and a remaining 11% by weight on a 20 mesh. Further, the gel component weight of this resin composition, the molecular weight peak value and shoulder value of the THF-soluble component,
It was almost the same as that of Synthesis Example-4.

Component A, component B, C of the resin composition obtained in each synthesis example
The ratios of the components are shown in Table 1 below.

Example 1 Powder mixing was performed with the above formulation.

For powder mixing, use a Henschel mixer with a capacity of 10 l,
Weighed to a total weight of 1650 g and mixed at about 3000 rpm for 30 seconds. The obtained powder mixture was apparently uniform, and no aggregates such as magnetic substances and release agents were found.

This was kneaded with an extruder, but the surface of the kneaded product was smooth and homogeneous, and was sufficiently homogeneously mixed. This is roughly pulverized, finely pulverized, and further classified, and the particle size is about 11μ
Toner was manufactured.

The pulverizability of this toner raw material is very good, and the processing amount is
It was 14.0 kg / hr. There was no fusion in the crusher.

A developer prepared by mixing 0.4 part by weight of hydrophobic silica with 100 parts by weight of this toner was placed in a Canon copying machine NP-400RE, and the fixability and image quality were evaluated. As shown in Table 2, 100,000 sheets were durable, but a high density and high image was stably maintained. Furthermore, the fixability was very good, the offset winding property was good, and there was no filming or fusion on the photoreceptor.

Example 2 The same procedure as in Example 1 was carried out except that 2100 parts by weight of Resin Composition was used. As a result, as shown in Table 2, the same results as in Example 1 were obtained in almost all items.

Example 3 A toner having a particle diameter of about 11 μm was manufactured in the same manner as in Example 1 except that the powder was mixed in the above formulation. The pulverizability of this toner was good and the throughput was 11.0 kg / hr. There was no fusion in the crusher. A developer prepared by mixing 100 parts by weight of this toner with 0.5 part by weight of hydrophobic positively-charged silica was put in a copying machine NP-3525 manufactured by Canon to evaluate the fixability and image quality. As shown in Table 2, 100,000 sheets were durable, but a high-density image was stably maintained. Furthermore, it has good fixing properties, good offset wrapping properties, filming on the photoreceptor,
There was no fusion.

Example 4 The same procedure as in Example 3 was carried out except that 100 parts by weight of resin composition-4 was used, and Table-2 was obtained in all items.
As shown in FIG. 5, good results, which are almost equal to or higher than those of Production Example 3, were obtained.

Comparative Example 1 All materials were powder-mixed in the same manner as in Example 1 except that 5100 parts by weight of Resin Composition was used. Performances such as powder mixability and pulverizability were almost the same as those in Example 1, but in image evaluation, image quality was slightly unstable and durability was 80,000 sheets to 10 sheets.
The difference was noticed among the millions.

Comparative Example 2 A toner was prepared in the same manner as in Example 2 except that 6100 parts by weight of Resin Composition was used.

It was confirmed that the magnetic substance selectively adhered to the inner wall of the Henschel mixer during powder mixing, and that the release agent was not well dispersed.

In the following heat kneading step of the extruder, the surface of the kneaded product was slightly smoothed, but a feeling that it was considerably compensated in the heat kneading step was obtained.

Thereafter, the same steps as in Example 2 were carried out to obtain almost the same toner. The toner performance was almost the same, but in the same long-term durability test, after 70,000 sheets, the image density,
The image quality deteriorates, and at 100,000 sheets, it is practically usable, but it is a problem.

Synthesis Example 7 A uniform mixture of 75 parts of styrene, 24 parts of n-butyl acrylate, 0.4 part of divinylbenzene and 1.0 part of benzoyl peroxide was dissolved in 400 parts of water in which 0.8 part of a partially saponified polyvinyl alcohol having a polymerization degree of 2000 was dissolved. Agitation speed 200r.
Polymerization temperature 8
Polymerization was carried out at 0 ° C. for 15 hours to obtain a pearl-like resin composition containing a gel component, which was dried under reduced pressure to obtain a resin composition-7.
The resulting resin composition is spherical particles and aggregates thereof,
The particle size was 0.10 mm at a cumulative 50% value. The resin powder of 20 mesh or more was 2.3% by weight of the whole.

Further, the amount of gel component of the resin composition-7 was 41% by weight, the molecular weight main peak value of the eluted component was 49000, and no sub-peak or shoulder was observed.

Comparative Example 3 Resin composition-1 used in Example 1 Instead of 100 weight, low molecular weight polymer-1 pulverized to 0.1 to 0.7 mm 33
A toner was prepared in the same manner as in Example 1 except that 67 parts by weight of the resin composition and 67 parts by weight of the resin composition were used.

It was confirmed that the magnetic substance selectively adhered to the inner wall of the Henschel mixer during powder mixing, and that the release agent was not well dispersed.

In the subsequent heat kneading step of the extruder, the kneaded product was in a particle state without a part of the resin composition-7 being dissolved, and the dispersion of the magnetic material was not sufficient.

In the crushing process, many finely pulverized products which did not contain the magnetic substance or which seemed to have an extremely small content were observed. Therefore, they were removed as much as possible in the classification process.

After that, when the image was evaluated as a toner in the same manner as in Example 1, the image density was low from the initial stage and the image quality was poor.

Evaluation Method The pulverizability of the toner raw material was determined by using a fine pulverizer using a jet stream at an air pressure of 5.5 kg / cm ² and a throughput per unit time. At the same time, the inner wall of the pulverizer was observed, and the presence or absence of fusion was examined.

Regarding the fixing property, offset property, winding property, image property, and durability, Canon copiers NP-7550 and NP-55
It investigated using 40.

Especially for the offset property, lower the set temperature of the fixing device by 5 ° C,
The cleaning mechanism of the fixing roller was removed, and it was evaluated whether the image was soiled or the roller was soiled.

The fixability was determined by rubbing the image with Silbon C paper 10 times in a reciprocating manner and applying 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 the 200th sheet when 200 sheets were taken continuously.

The wrapping property was determined by the appearance of three black images on the entire surface and the marks of the peeling claws of the fixing roller on the image at that time, and how much the claws were dependent on.

[Advantages of the Invention] The toner using the binder resin of the present invention does not cause winding blocking around the offset roller, and a high quality image can be obtained for a long period of time.

[Brief description of the drawings]

FIG. 1 shows a chromatogram of Synthesis Example-1 in Examples of the present invention.

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Claims (1)

(57) [Claims] 1. A monomer composition is prepared by dissolving or mixing a first vinyl polymer in a vinyl monomer component,
A binder resin for toner containing a gel component and a tetrahydrofuran-soluble component obtained by polymerizing the monomer composition in the presence of a crosslinking agent, wherein the binder resin for toner is substantially Spherical particles or aggregates of spherical particles are vinyl resin particles with an average particle diameter of 0.1 to 0.7 mm, and contain 0.1 to 60% by weight of a gel component, and a molecular weight in a GPC chromatogram of a tetrahydrofuran-soluble component. It has a main peak value in the range of 1000 to 25,000, and has a molecular weight of 3000 to 150,000.
And at least 1 on the high molecular weight side of the main peak value.
It has two sub-peaks or sub-shoulders, 0 to 20% by weight of components with a molecular weight of 500,000 or more, and a molecular weight of over 30,000 to 50
A binder resin for a toner, which comprises less than 10,000 components by weight in the range of 10 to 60% by weight and components having a molecular weight of 30,000 or less in the range of 20 to 90% by weight based on the weight of the tetrahydrofuran-soluble component.