JP2004037651A - Electrophotographic toner and evaluation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for evaluating the fluidity of electrophotographic toner with high accuracy regardless of skill of a person who measures. <P>SOLUTION: The fluidity of toner comprising at least a resin and pigment is evaluated in such a manner that a rotary vane is caused to enter a toner powder phase in a vessel while rotated, and then torque or load generated when the rotary vane moves in the powder phase is measured. <P>COPYRIGHT: (C)2004,JPO

Description

上記原材料をミキサーで十分に混合した後、２軸押出し機によりバレル温度１００℃、回転数１００ｒｐｍで溶融混練した。混練物を圧延冷却後カッターミルで粗粉砕し、ジェット気流を用いた微粉砕機で粉砕後、旋回式風力分級装置を用いて、平均粒径が７μｍの粒度分布に分級した。さらに、母体着色粒子１００部に対して、以下の混合条件にて添加剤を混合し、トナーを作製した。
添加剤　シリカ微粉末　　　　　　　　　１部
混合回転数　　　　　　　　　　　　７００ｒｐｍ
混合時間　　　　　　　　　　　　　１２０ｓｅｃ
混合機　　　　　　　　　　　　　スーパーミキサー
本トナーを作製した後、本評価法により流動性を測定した結果、表１，２のようになった。
また、画像のドット再現性は５段階評価でランク５であった。
【００６１】
―実施例１１―
実施例１０と同様の原材料、作製方法で混練、粉砕、分級を行ない、平均粒径が７μｍの粒度分布に分級した。
さらに、母体着色粒子１００部に対して、以下の混合条件にて添加剤を混合し、トナーを作製した。
添加剤　シリカ微粉末　　　　　　　　０．９部
混合回転数　　　　　　　　　　　　７００ｒｐｍ
混合時間　　　　　　　　　　　　　１２０ｓｅｃ
混合機　　　　　　　　　　　　　スーパーミキサー
本トナーを作製した後、本評価法により流動性を測定した結果、表１，２のようになった。
また、画像のドット再現性は５段階評価でランク５であった。
【００６２】
―実施例１２―
実施例１０と同様の原材料、作製方法で混練、粉砕、分級を行ない、平均粒径が７μｍの粒度分布に分級した。
さらに、母体着色粒子１００部に対して、以下の混合条件にて添加剤を混合し、トナーを作製した。
添加剤　シリカ微粉末　　　　　　　　０部
混合回転数　　　　　　　　　　　　７００ｒｐｍ
混合時間　　　　　　　　　　　　　１２０ｓｅｃ
混合機　　　　　　　　　　　　　スーパーミキサー
本トナーを作製した後、本評価法により流動性を測定した結果、表１，２のようになった。
また、画像のドット再現性は５段階評価でランク１であった。
【００６３】
以上の実施例１〜１２の測定結果を表１，２に示す。
【００６４】
【表１】

【００６５】
【表２】

【００６６】
【発明の効果】
以上説明したように、本発明の評価方法によれば、定量的に、精度よく、測定者の個人差なく電子写真用トナーの流動性を評価することができる。また、この評価方法をトナーの製造ラインに適用して、ドット再現性のよいトナーを確実に得ることができる。
【００６７】
【図面の簡単な説明】
【図１】本発明の評価装置の一例を説明する図。
【図２】評価装置に使用した回転翼の形状の一例を示す説明図。
【図３】実施例１〜９の回転翼侵入時のトルクとドット再現性との関係を示すグラフ。
【図４】実施例１〜９の回転翼侵入時の荷重とドット再現性との関係を示すグラフ。
【図５】実施例１〜１２の回転翼引き抜き時のトルクとドット再現性との関係を示すグラフ。
【図６】実施例１〜１２の回転翼引き抜き時の荷重とドット再現性を示すグラフ。
【図７】本発明の評価装置を使用したトナー製造装置の一例を説明する図。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrophotographic toner, an evaluation thereof, and a developing method using the toner.
[0002]
[Prior art]
Conventionally, there is JP-A-01-203941 as an evaluation method of an electrophotographic toner.
This is a method for accurately evaluating the fluidity of the developer in a developing machine by measuring the time required for the magnetic field to fall through a narrow portion of the funnel to which a magnetic field is applied. In Japanese Patent Application Laid-Open No. H04-116449, toner is placed on a tiltable plate, the plate is gradually tilted, and the angles at which the flow starts and ends are measured. Further, there is JP-A-2000-292967. This is done by stacking several stages of sieves, feeding toner on top of them, giving horizontal and vertical vibrations to the sieve part, and setting a predetermined coefficient to the amount of toner remaining in each sieve after a certain period of time. Is calculated by multiplying However, these methods have a large variation in data, and there are differences depending on a measurer, and it was not possible to evaluate a fine difference in fluidity between toners.
[0003]
The image quality of copiers, printers, and the like has been increasing, and recently, the reproducibility of fine dots has become very important. The reproducibility of this dot is greatly affected by the fluidity in addition to the toner and developer charge amount, and it is necessary to stably supply a uniform toner layer or developer layer to a fine latent image portion. It is coming.
Further, as the image quality is improved, the size of the toner used for the toner and the function thereof are advanced. For this reason, the structure of the toner has become more complicated, and it is necessary to perform finer control at the time of production than before. In particular, since the fluidity of the toner affects various image qualities in addition to the dot reproducibility, a highly accurate evaluation method that does not differ between individuals in terms of evaluation is required.
Also, when the method of producing the toner changes from a pulverization method to another method such as a polymerization method, the change in the flow characteristics with respect to the production conditions is large, and compared with the case of the pulverization method, finer control during production and Evaluation is required.
[0004]
[Problems to be solved by the invention]
Under such circumstances, the present invention aims to provide an evaluation method capable of quantitatively, accurately, and without individual differences in the fluidity of an electrophotographic toner, and evaluated by the evaluation method. An object of the present invention is to provide an electrophotographic toner having good dot reproducibility, a developer containing the same, and a developing method.
[0005]
[Means for Solving the Problems]
The present inventors have assiduously studied and as a result, measure the torque or weight generated when the rotating blades move into the toner powder phase while rotating the rotating blades, or when the rotating blades are removed from the toner phase. Was found to be effective and led to the present invention.
That is, the present invention
(1) The torque or load generated when the rotating blades move into the powder phase by rotating the rotating blades into the toner powder phase in the container while causing the fluidity of the toner composed of at least the resin and the pigment to enter. The toner evaluation method for electrophotography, wherein the evaluation is performed by measuring the toner.
(2) The method described in (1) above, wherein the rotor or blades are penetrated into the powder phase while rotating, and then the torque or the load when the rotor is removed from the powder phase while rotating the rotor is measured to evaluate. The toner evaluation method for electrophotography described in the above.
(3) The electrophotographic device according to (1) or (2), wherein the smaller angle between the surface of the toner powder phase in the container and the rotor is 0 to 89 °. Toner evaluation method.
(4) The toner evaluation method for electrophotography according to any one of (1) to (3), wherein the number of rotations of the rotor is 10 to 150 rpm.
(5) The method for evaluating a toner for electrophotography according to any one of the above (1) to (4), wherein the penetration speed of the rotor is 20 to 200 mm / min.
(6) The toner evaluation method for electrophotography according to any one of (1) to (5), wherein the measurement is performed so that the porosity of the toner powder phase is 0.5 to 0.7. .
(7) The value of the torque at the time of penetration of the rotating blade into the rotating blade measured by the evaluation method according to any one of (1) to (6) above is 0.1. -80 mNm.
(8) The value of the load at the time of penetration of the rotating blade into the rotating blade measured by the evaluation method according to any one of (1) to (6) above the toner after the mixing step of mixing the additive is 0.01. -3N. An electrophotographic toner characterized in that:
(9) After the toner after the mixing step of mixing the additive is penetrated into the toner powder phase while rotating the rotating blade measured according to the evaluation method according to any one of (1) to (6) above. An electrophotographic toner, wherein the value of the torque when the rotating blade is rotated to remove the toner from the toner powder phase is 0.1 to 23 mNm.
(10) After infiltrating the toner powder phase while rotating the rotating blade of the toner after the mixing step of mixing the additives, which is measured according to the evaluation method described in (1) to (6) above, The toner for electrophotography, wherein the value of the load when removing from the toner powder phase while rotating is adjusted to be 0.01 to 0.6 N.
(11) The toner for electrophotography according to any one of (7) to (10), wherein the toner comprising at least a resin and a pigment contains a charge control agent and / or a release agent.
(12) The electrophotographic toner according to any one of (7) to (10), wherein the toner has an average particle diameter of 4 to 10 μm.
(13) The toner for electrophotography according to any one of the above (7) to (10), wherein the toner is produced by a method other than the pulverization method.
(14) A one-component developing method comprising performing contact or non-contact development using the electrophotographic toner according to any one of (7) to (13).
(15) The one-component developing method according to (14), wherein a doctor roller is used.
(16) A two-component developing method comprising developing using the toner for electrophotography according to any one of (7) to (13) and a carrier having a particle size of 20 to 100 μm.
(17) A method for producing a toner for electrophotography, comprising producing a toner in a production line by using the evaluation method of (1).
(18) It is characterized in that the fluidity of toner comprising a container for storing the toner powder, a torque meter provided with a rotary wing to be inserted into or removed from the container, and / or a load cell provided in the lower portion of the container is evaluated. And a toner evaluation device for electrophotography.
[0006]
According to the evaluation method of the present invention, the toner phase can be measured as it is in a short time, so that it can be introduced into a production line, and a high-quality toner can be stably produced.
In this evaluation method, the rotating blade is made to enter (down) or withdraw (up) while rotating in the powder phase. The load is measured, and the fluidity is evaluated based on the torque and the value of the load. The shape of the rotor may be any shape, but it is necessary that the blade does not stand perpendicular to the toner surface layer. This method evaluates the fluidity based on the difference between the torque and load at the time of penetration and the torque and load at the time of pulling out. Is not suitable. Therefore, a shape in which the rotor blade stands perpendicular to the toner surface layer is not suitable.
[0007]
The torque and load of the toner powder change depending on the number of revolutions of the rotor and the speed of penetration of the rotor. In this measurement, in order to reduce the dispersion of the measurement, the state of the toner powder phase was made uniform, and the rotation speed and the penetration speed of the rotor were increased. Therefore, the measurement conditions were as follows.
・ Rotation speed of rotor: 10 to 150 rpm
・ Rotating blade penetration speed: 20 to 200 mm / min
When the number of rotations of the rotor is less than 10 rpm, it is difficult to make the toner powder phase uniform, and when it is more than 150 rpm, toner scattering occurs, which is not suitable. When the penetration speed of the rotor is lower than 20 mm / min, it is difficult to make the toner phase uniform, and when it is higher than 200 mm / min, the toner powder phase is apt to cause caking.
[0008]
FIG. 1 shows an example of the toner evaluation device of the present invention. The rotor is attached to the tip of the shaft, and the shaft itself can be moved up and down by an elevator. The container containing the toner is placed at the center of the stage, and the rotating wings come down to the center of the container. The torque applied to the rotor is detected by a torque meter provided above, and the load applied to the container containing the toner is detected by a load cell provided below the container. The amount of movement of the rotor is determined by a position detector. This configuration is only an example.
Other configurations, such as raising and lowering the laser, may be used.
[0009]
The shape of the rotor may be any shape other than the vertically standing shape as described above. (See FIG. 2.) It may be changed depending on the sample. However, since the torque and load values may not be reproduced due to replacement of the rotor, it is preferable that the rotor has a simple shape and that the same thing can be made many times. Although the material of the container is not limited, a transparent material such as glass is suitable for observing the state during the measurement of the powder. In addition, since the measurement is performed while replacing the powder, it is preferable that the surface is close to a mirror surface to reduce dirt. The size of the vessel is important, and it is necessary to select a larger (diameter) size for the length of the impeller so that the walls of the vessel are not affected when the impeller rotates.
[0010]
A high-sensitivity type torque meter is preferable, and a non-contact type torque meter is suitable. Load cells with a wide load range and high resolution are suitable. The position detector includes a linear scale, a displacement sensor using light, and the like, and a specification of 0.1 mm or less is suitable for accuracy.
For the measurement, a certain amount of toner is put into a container, and the container is set. Thereafter, the rotating blade is made to penetrate into the toner powder phase while rotating. Before starting the actual measurement, an operation may be performed in which the inside of the toner powder phase is made uniform by moving the rotor up and down. You don't have to. When the torque or load measurement is started, the measurement is performed at the determined number of revolutions and penetration speed. The direction of rotation of the rotating blade is arbitrary, but when the rotating blade is to enter, it is preferable to perform the rotation in the direction of pressing down the toner powder phase, and to pull out the rotating blade in the opposite direction. If the penetration distance of the rotor is small, problems occur in data reproducibility and the like. Therefore, it is better to penetrate the rotor deeply into an area where data is reproducible. According to our experimental results, it was possible to perform almost stable measurement if the penetration was 30 mm or more. The measurement mode can be under any condition including the rotation direction. For example, the measurement mode is as follows.
[0011]
{Circle around (1)} The rotor is rotated in the consolidation direction to penetrate (down), and the torque and load at that time are measured.
{Circle around (2)} When the rotor enters (downs) by 40 mm from the toner surface layer, the intrusion operation is stopped and the rotation of the rotor is stopped.
{Circle around (3)} Immediately change the direction of rotation of the rotor to the opposite direction, start the operation of pulling out (up) the rotor, and measure the torque and load at that time.
{Circle around (4)} When the tip of the rotating blade comes off the toner phase surface and becomes completely free (first home position), the pulling operation of the rotating blade is stopped, and the rotation is stopped.
The above operations (1) to (4) may be repeated to perform the operations continuously.
[0012]
Further, as another measurement method, when the load when the rotor blades penetrate while rotating in the rotation direction to press down the toner powder phase reaches a preset value, the intrusion operation and the rotation operation are stopped, and then, Measure the penetration distance and raise the rotor to the initial position (home position). This measurement may be performed once, but it is also effective to repeat this operation and check the change in the penetration distance with respect to the number of repetitions.
[0013]
As another measurement method, the rotor blades enter the toner powder phase that has been pressed down using a rotor blade or pressed in another way in the direction of rotation (shear direction) opposite to the direction in which the rotor blades are pressed down. There is a method of measuring the torque and load at that time.
In this measurement, the porosity of the toner powder phase is important, and in our experimental results, stable measurement was possible when the porosity was 0.5 or more. If it is less than 0.5, slight differences in conditions affect the torque and the load, and it is difficult to perform stable measurement. The range of the porosity of the toner powder phase was 0.5 to 0.7 including various measurement methods. If it is larger than 0.7, the toner scatters and is not suitable for measurement. Here, the porosity of the toner indicates the proportion of air contained in the toner powder.
However, the measurement system, measurement conditions, and the like are not limited to this.
[0014]
The toner used in this evaluation method needs to have an average particle diameter of 4 to 10 μm in order to realize a high quality image. The weight average particle diameter of the toner is 4 to 10 μm, and more preferably 5 to 7 μm. If the weight average particle diameter is less than 4 μm, problems such as contamination inside the apparatus due to toner scattering during long-term use, a decrease in image density in a low-humidity environment, poor photoconductor cleaning, and the like are likely to occur, and there is a concern about the effect on the human body. When the weight average particle size exceeds 10 μm, the resolution of the fine spots of 100 μm or less is not sufficient, and the fine spots tend to be scattered to non-image portions, resulting in poor image quality.
[0015]
The developer using the present toner needs to have a carrier having an average particle diameter of 20 to 100 μm in order to realize a high quality image. When the average particle size of the carrier is in the range of 20 to 100 μm, the charge amount of the toner can be made more uniform when the toner concentration in the developing device is in the range of 2 to 10% by weight. If the thickness is less than 20 μm, carrier particles are likely to adhere to the photoreceptor, and the efficiency of stirring with the toner is deteriorated, making it difficult to obtain a uniform charge amount of the toner. Conversely, when the average particle size of the carrier exceeds 100 μm, fine image reproducibility deteriorates, and high image quality cannot be obtained.
[0016]
Details of the toner and the developer are shown below.
Examples of the resin include polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, polyethylene resin, silicone resin, butyral resin, and terpene. Resins and polyol resins.
[0017]
Examples of the vinyl resin include styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene, and homopolymers of substituted styrenes: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, and styrene-vinyltoluene copolymer. Polymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methacryl Methyl acrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer Coalescence, styrene-vinyl ethyl acetate Copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Styrene-based copolymers such as copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate and the like.
[0018]
The polyester resin is composed of a dihydric alcohol as shown in Group A below and a dibasic acid salt as shown in Group B, and a trivalent or higher alcohol as shown in Group C or A carboxylic acid may be added as a third component.
Group A: ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4 butanediol, neopentyl glycol, 1,4 butenediol, 1,4-bis (hydroxymethyl) cyclohexane , Bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylene (2,2) -2,2'-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2, 2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,0) -2,2′-bis (4 -Hydroxyphenyl) propane and the like.
[0019]
Group B: maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, linoleic acid, or Esters of these acid anhydrides or lower alcohols.
[0020]
Group C: trihydric or higher alcohol such as glycerin, trimethylolpropane, pentaerythritol and the like, and trivalent or higher carboxylic acid such as trimellitic acid and pyromellitic acid.
[0021]
As the polyol resin, an epoxy resin, a compound having one alkylene oxide adduct of dihydric phenol or its glycidyl ether and one active hydrogen in the molecule that reacts with the epoxy group, and an active hydrogen reacting with the epoxy resin in the molecule. There are compounds obtained by reacting two or more compounds.
[0022]
The following are used as the pigment used in the present invention.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
[0023]
Examples of the yellow pigment include cadmium yellow, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, Hanza yellow G, Hanza yellow 10G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake. .
[0024]
Examples of orange pigments include molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.
[0025]
Examples of the red pigment include bengara, cadmium red, permanent red 4R, lithol red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, and brilliant carmine 3B.
[0026]
Examples of purple pigments include Fast Violet B and Methyl Violet Lake.
Examples of the blue pigment include cobalt blue, alkali blue, Victoria Blue Lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, fast sky blue, and indanthrene blue BC.
Green pigments include chrome green, chromium oxide, pigment green B, malachite green lake, and the like.
[0027]
One or more of these can be used.
Particularly in the case of color toners, it is essential to disperse good pigments uniformly.Instead of directly charging pigments into a large amount of resin, a masterbatch in which pigments are once dispersed at a high concentration is prepared and diluted. Is used. In this case, a solvent is generally used to help dispersibility, but there are environmental problems and the like, and in the present invention, water is used to disperse. When water is used, temperature control is important so that residual moisture in the masterbatch does not matter.
[0028]
In the toner of the present invention, a charge control agent is blended (internally added) inside the toner particles. However, they may be mixed (externally added) with the toner particles. The charge control agent makes it possible to control the charge amount optimally according to the development system. In particular, in the present invention, the balance between the particle size distribution and the charge amount can be further stabilized.
Nigrosine and quaternary ammonium salts, triphenylmethane dyes, imidazole metal complexes and salts can be used alone or in combination of two or more to control the toner to have a positive charge. Further, a metal salicylate complex, salts, organic boron salts, calixarene-based compounds, and the like are used to control the toner to have a negative charge.
[0029]
Further, a release agent can be internally added to the toner of the present invention in order to prevent offset during fixing. Release agents include natural waxes such as candelilla wax, carnauba wax, and rice wax, montan wax and its derivatives, paraffin wax and its derivatives, polyolefin wax and its derivatives, sasol wax, low molecular weight polyethylene, and low molecular weight polypropylene. And alkyl phosphate esters. The melting point of these release agents is preferably from 65 to 90 ° C. If the temperature is lower than this range, blocking during storage of the toner tends to occur. If the temperature is higher than this range, offset may easily occur in a region where the temperature of the fixing roller is low.
[0030]
Examples of a method for producing the toner according to the present invention include a pulverization method and a polymerization method (suspension polymerization, emulsion polymerization, dispersion polymerization, emulsion aggregation, emulsion association, and the like), but are not limited thereto.
As an example of the pulverization method, first, the above-described resin, a pigment or dye as a colorant, a charge control agent, a release agent, other additives, and the like are sufficiently mixed by a mixer such as a Henschel mixer, and then a batch method is performed. The components are kneaded well using a hot roll kneader such as a two-roll mill, a Banbury mixer, a continuous twin screw extruder, or a continuous single screw kneader, followed by rolling, cooling and cutting. The kneaded toner after cutting is crushed, coarsely crushed using a hammer mill or the like, further finely crushed using a fine crusher or a mechanical crusher using a jet stream, and a classifier using a swirling air stream or a Coanda effect. Is classified to a predetermined particle size by a classifier using Thereafter, an additive composed of inorganic particles or the like is attached or fixed to the particle surface by a mixer. The fluidity of the toner particles after the mixing step is evaluated using the present evaluation method. In this case, in the sampling inspection, the sample is placed in a glass sample container, and the sample container is directly placed on the sample table of the evaluation apparatus shown in FIG. 1 for measurement. The rotation speed of the rotor was 10 to 150 rpm, and the penetration speed of the rotor was 20 to 200 mm / min. The measurement is performed with the number of rotations in the direction of pressing down the toner powder phase when the rotating blades are made to intrude. After a penetration distance of 30 mm or more, the intrusion is stopped, the rotation speed is changed to reverse rotation, and the rotating blades are raised ( Pull out) and return to the original initial position. The torque and the load when the rotor blades enter and withdraw from the toner powder phase are measured, and the fluidity of the toner is evaluated.
[0031]
When the toner fluidity is evaluated by the present evaluation method, the measured value (torque, load) and the toner fluidity have the following relationship.
When the torque is small, the fluidity is good.
If the torque is large, the fluidity is poor.
When the load is small, the fluidity is good.
When the load is large, the fluidity is poor.
[0032]
The characteristics of this evaluation method using a rotary wing are as follows and can be measured quickly and easily, so that highly accurate measurement without individual differences can be performed.
(1) Non-destructive inspection.
(2) The sample can be measured as it is.
(3) Measurement can be performed in a short time.
(4) Anyone can easily measure.
[0033]
Therefore, measurement on a production line is also possible, and it can be installed between each process in a production process, and quality evaluation can be performed in the middle of the process. For example, after the mixing step, a sample extraction / measurement zone is provided in the course of transporting the powder sample to the next step, and a shutter is opened and closed at a certain timing to transport a fixed amount of the sample to the measurement unit. The tip of the measuring part is a container made of glass or the like, and the measurement is directly performed by the present evaluation method. Alternatively, the container is brought to the present evaluation device in another nearby place, placed on a sample stage, and measured by the present evaluation method. The measured toner is returned to the original sample. As a result of the evaluation, if the numerical value is out of the predetermined setting range, the sample is not sent to the filling process but is sent to the toner reprocessing process. These mechanisms can be applied to inspection after the pulverizing / classifying step, which is a step before the mixing step, inspection after the air sieving step after the mixing step, inspection before filling, and the like.
[0034]
Further, the toner evaluation device having these functions can be used alone as an evaluation device in the development stage.
In the case of toner, the measured values of torque and load in this evaluation method indicate fluidity as described above, and quantitative evaluation is possible. The conventional evaluation method up to now has a problem that the difference between toners can be evaluated, but cannot be evaluated if the type of toner is different. However, the values measured by this evaluation method are torque values and load values as powder characteristics, and values that can be evaluated on the same ring even if the type of toner changes or the particle size changes. Evaluation value.
[0035]
The torque and load characteristics during the movement of the rotor blades in the toner powder phase are closely related to the fluidity of the powder. It is easy to move due to its small adhesive force. Even if the rotor is moved in that phase, the torque is small and the load change is small. However, conversely, when the fluidity of the powder is poor, it is difficult to move due to the large adhesive force between the individual powder particles. And the force (heavy) acting in the downward direction also increases.
[0036]
Therefore, according to the evaluation method of the present invention, the fluidity can be evaluated based on the following relationship.
When fluidity is good → The torque and load when moving in the powder phase are small.
When the fluidity is poor → The torque and load when moving in the powder phase are large.
The fluidity of the toner is largely determined by the mixing step in the toner production step. That is, the fluidity of the toner particles greatly changes depending on the state in which the additive composed of the inorganic particles or the like is attached or fixed to the surface of the toner particles.
[0037]
The mixing state of the toner varies depending on the mixing conditions (feed amount, rotation speed, mixing time, etc.) in the mixing step. Therefore, the mixing conditions play an important role in the fluidity, and the evaluation of the fluidity after the mixing step is important.
In a printer or a copying machine, in order to realize high image quality, it is necessary to enhance the reproducibility of very minute dots. To achieve this, toner development that is faithful to very small latent images is required. To enable this faithful development, it is necessary to supply a uniform toner brush to the development area. For this purpose, it is necessary that the toner charge amount is under the optimal condition, but the easiness of movement and transport of the toner is very important. That is, in order to increase the reproducibility of minute dots, it is necessary to increase the fluidity of the toner.
[0038]
Therefore, the fluidity of the toner was evaluated by this method using a rotating blade, and the relationship with the dot reproducibility was examined.As a result, there was a very strong correlation, and the dot reproducibility improved when the torque and load were small. Was.
From the results, it was found that the toner having good dot reproducibility exhibited the following torque and load characteristics.
{Circle around (1)} The value of the torque when the rotor blades enter (down) is 0.1 to 80 mNm.
{Circle around (2)} The load value when the rotor blades enter (down) is 0.01 to 3N.
{Circle around (3)} The value of the torque when the rotor is pulled out (up) is 0.1 to 23 mNm.
{Circle around (4)} The value of the load when the rotor is pulled out (up) is 0.01 to 0.6 N.
[0039]
Note that other methods can be used for the evaluation mode without any problem. In addition, the evaluation items other than the torque and the load may be an intrusion distance to a certain load, an intrusion distance to a certain torque, or the like, or the total torque value and the load value during the measurement may be evaluated. May be. Further, other evaluation items may be used.
[0040]
After the mixing step, the mixture is passed through a sieve of 250 mesh or more to remove coarse particles and aggregated particles to obtain the toner of the present invention.
As an example of the polymerization method, toner particles are obtained by suspending and polymerizing a monomer composition obtained by adding a colorant, a charge control agent, and the like to a monomer in an aqueous medium. The granulation method is not particularly limited.
Further, when used as a two-component developer, a two-component developer is obtained by mixing with a magnetic carrier described later at a predetermined mixing ratio.
[0041]
The present toner is used as a one-component developer used in a contact or non-contact developing system. Various known contact or non-contact development systems are used. For example, there are a contact developing method using an aluminum sleeve, a contact developing method using a conductive rubber belt, and a non-contact developing method using a developing sleeve in which a conductive resin layer containing carbon black or the like is formed on the surface of an aluminum tube. .
Further, in the one-component developing method, the present toner is used in a developing method in which a roller-shaped blade for uniforming a toner layer is provided at an outlet of a toner supply unit. In such a system, not only filming on the photosensitive member but also filming on the doctor roller occurs. For this reason, not only can the toner layer not be formed uniformly, but also the toner charging becomes non-uniform, and the toner charge becomes small. For this reason, defective development occurs.
However, when the toner of the present invention is used, filming to the doctor roller does not occur, stable development is performed, and a system having excellent durability characteristics is obtained.
[0042]
When a magnetic toner is used, fine particles of a magnetic substance may be internally added to the toner particles. As the magnetic material, a ferromagnetic material such as ferrite, magnetite, iron, nickel, cobalt, or an alloy thereof can be considered. The average particle size of the magnetic material is preferably 0.1 to 1 μm. The content of the magnetic substance is preferably from 10 to 70 parts by weight based on 100 parts by weight of the toner.
[0043]
As the carrier used for the two-component developer, known carriers can be used. For example, magnetic particles such as iron powder, ferrite powder, nickel powder, and magnetite powder, or the surface of these magnetic particles is coated with a fluororesin or vinyl resin. And those treated with a silicone resin or the like, or magnetic particle-dispersed resin particles in which magnetic particles are dispersed in a resin. The average particle size of these magnetic carriers is preferably 20 to 100 μm. Preferably, it is 20 to 70 μm.
[0044]
When the average particle diameter of the carrier is in this range, by combining with the toner of the present invention, the charge amount of the toner can be made more uniform when the toner concentration in the developing device is in the range of 2 to 10% by weight. . When the particle size is 20 μm or less, the carrier particles are likely to adhere to the photoreceptor, and the efficiency of stirring with the toner is reduced, so that it is difficult to obtain a uniform charge amount of the toner. If it exceeds 100 μm, fine image reproducibility deteriorates.
[0045]
Further, as described above, the toner of the present invention can be used by adding an inorganic fine powder to the toner as a fluidity improver.
Examples of the inorganic fine powder of the present invention include Si, Ti, Al, Mg, Ca, Sr, Ba, In, Ga, Ni, Mn, W, Fe, Co, Zn, Cr, Mo, Cu, Ag, V, and Zr. Oxides and composite oxides. Among them, fine particles of silicon dioxide (silica), titanium dioxide (titania), and alumina are preferably used. Further, it is effective to perform a surface modification treatment with a hydrophobizing agent or the like. The following are typical examples of the hydrophobizing agent.
[0046]
Dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, Chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, hexaphenyldisilazane, hexatolyldisilazane and the like.
[0047]
The inorganic fine powder is preferably used in an amount of 0.1 to 2% by weight based on the toner. If it is less than 0.1% by weight, the effect of improving toner aggregation is poor. If it exceeds 2% by weight, problems such as toner scattering between fine lines, contamination inside the machine, scratches and abrasion of the photoreceptor tend to occur. is there.
[0048]
The developer of the present invention may further contain other additives within a range that does not substantially adversely affect the lubricant, for example, lubricant powders such as Teflon (registered trademark) powder, zinc stearate powder, and polyvinylidene fluoride powder; Abrasives such as cerium powder, silicon carbide powder and strontium titanate powder; or a small amount of a conductivity-imparting agent such as carbon black powder, zinc oxide powder and tin oxide powder can also be used as a developability improver.
In addition, this evaluation method can be used for toners and capsule toners produced by a polymerization method or a spray drying method produced without using a kneading step or a pulverizing step.
[0049]
【Example】
Hereinafter, Examples will be described, but they do not limit the present invention in any way. In this case, a toner was prepared in which the mixing conditions were changed, and the fluidity of the toner was evaluated using the present evaluation method, and the dot reproducibility was evaluated on a 5-point scale as a grainy feeling of the image. The fluidity of the toner is defined as the torque and load when the rotor blades penetrate 55 mm from the surface of the toner powder phase at the time of penetration, and the torque and load values when the rotor blades are 55 mm from the surface of the toner powder phase when the rotor blades are pulled out. Was measured. The rotor used for the evaluation had the shape shown in FIG. 2. The length of the rotor was 25 mm on one side, the width was 10 mm, the thickness was 1 mm, the angle between the toner phase surface and the rotor was 30 °, and the rotor was used. Is 20 rpm, and the penetration speed of the rotor is 50 mm / min. Further, in the five-step evaluation, the best dot reproducibility as the roughness of the image is ranked 5, the next good is ranked 4 and the worst is ranked 1, and the interval between them is closer to the good one. Ranks 3 and 2 were given.
[0050]
All parts in the following formulations are parts by weight.
-Example 1-
100 parts of resin polyol resin
Pigment carbon black 10 parts
Charge control agent zinc salicylate 5 parts
Release agent Low molecular weight polyethylene 5 parts
After sufficiently mixing the above raw materials with a mixer, the mixture was melt-kneaded at a barrel temperature of 100 ° C. by a twin-screw extruder. The kneaded product was rolled and cooled, coarsely pulverized by a cutter mill, pulverized by a fine pulverizer using a jet stream, and then classified into a particle size distribution having an average particle size of 6 μm using a revolving air classifier. Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
[0051]
Additive Silica fine powder 1 part
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2. Further, the dot reproducibility of the image was ranked 5 on a five-point scale.
[0052]
-Example 2-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 1, and the particles were classified into a particle size distribution having an average particle diameter of 6 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 1 part
Mixing speed 950rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 5 on a five-point scale.
[0053]
-Example 3-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 1, and the particles were classified into a particle size distribution having an average particle size of 8 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 1 part
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
In addition, the dot reproducibility of the image was ranked 3 on a five-point scale.
[0054]
-Example 4-
100% polyester resin
Pigment carbon black 10 parts
Charge control agent zinc salicylate 5 parts
The above raw materials were kneaded, crushed and classified in the same manner as in Example 1, and classified into a particle size distribution having an average particle size of 6.5 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 1 part
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 4 on a 5-point scale.
[0055]
-Example 5-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 4, and the particles were classified into a particle size distribution having an average particle size of 6.5 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 0.8 parts
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 4 on a 5-point scale.
[0056]
-Example 6-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 4, and the particles were classified into a particle size distribution having an average particle size of 6.5 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 1.2 parts
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 4 on a 5-point scale.
[0057]
-Example 7-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 4, and the particles were classified into a particle size distribution having an average particle size of 6.5 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 1 part
Mixing speed 850rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2. Further, the dot reproducibility of the image was ranked 5 on a five-point scale.
[0058]
-Example 8-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 4, and the particles were classified into a particle size distribution having an average particle size of 6.5 μm.
Further, with respect to 100 parts of the base colored particles, an additive was mixed under the following mixing conditions,
A toner was prepared.
Additive Silica fine powder 0.8 parts
Mixing speed 850rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 4 on a 5-point scale.
[0059]
-Example 9-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 4, and the particles were classified into a particle size distribution having an average particle size of 6.5 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 1.2 parts
Mixing speed 850rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 5 on a five-point scale.
[0060]

After sufficiently mixing the above raw materials with a mixer, the mixture was melt-kneaded by a twin-screw extruder at a barrel temperature of 100 ° C. and a rotation speed of 100 rpm. The kneaded product was rolled and cooled, coarsely pulverized by a cutter mill, pulverized by a fine pulverizer using a jet stream, and then classified into a particle size distribution having an average particle size of 7 μm by using a revolving air classifier. Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 1 part
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 5 on a five-point scale.
[0061]
-Example 11-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 10, and the particles were classified into a particle size distribution having an average particle size of 7 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 0.9 part
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
Further, the dot reproducibility of the image was ranked 5 on a five-point scale.
[0062]
-Example 12-
Kneading, pulverization, and classification were performed using the same raw materials and production method as in Example 10, and the particles were classified into a particle size distribution having an average particle size of 7 μm.
Further, an additive was mixed with 100 parts of the base colored particles under the following mixing conditions to prepare a toner.
Additive Silica fine powder 0 parts
Mixing speed 700rpm
Mixing time 120 sec
Mixer Super Mixer
After the present toner was produced, the fluidity was measured by the present evaluation method, and the results are as shown in Tables 1 and 2.
The dot reproducibility of the image was ranked 1 on a five-point scale.
[0063]
Tables 1 and 2 show the measurement results of Examples 1 to 12 described above.
[0064]
[Table 1]

[0065]
[Table 2]

[0066]
【The invention's effect】
As described above, according to the evaluation method of the present invention, it is possible to quantitatively and accurately evaluate the fluidity of the electrophotographic toner without the individual difference of the measurer. Further, by applying this evaluation method to a toner production line, a toner having good dot reproducibility can be reliably obtained.
[0067]
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of an evaluation device according to the present invention.
FIG. 2 is an explanatory view showing an example of the shape of a rotor used in an evaluation device.
FIG. 3 is a graph showing the relationship between the torque and the dot reproducibility at the time of intrusion of the rotor blades in Examples 1 to 9;
FIG. 4 is a graph showing a relationship between a load at the time of intrusion of a rotor and dot reproducibility in Examples 1 to 9;
FIG. 5 is a graph showing the relationship between the torque and the dot reproducibility when pulling out the rotor blades in Examples 1 to 12.
FIG. 6 is a graph showing the load and the dot reproducibility when pulling out the rotor blades in Examples 1 to 12.
FIG. 7 is a diagram illustrating an example of a toner manufacturing apparatus using the evaluation device of the present invention.

Claims (18)

At least the fluidity of the toner composed of the resin and the pigment is caused to penetrate into the toner powder phase in the container while rotating the rotor, and the torque or load generated when the rotor moves in the powder phase is measured. And a method for evaluating toner for electrophotography. 2. The electrophotograph according to claim 1, wherein the evaluation is performed by measuring a torque or a load when removing the powder from the powder phase while rotating the rotor after the rotor penetrates into the powder phase while rotating the rotor. Toner evaluation method. 3. The method for evaluating toner for electrophotography according to claim 1, wherein the smaller angle between the surface of the toner powder phase in the container and the rotor as the rotor is 0 to 89 [deg.]. The method for evaluating toner for electrophotography according to any one of claims 1 to 3, wherein the number of rotations of the rotor is 10 to 150 rpm. The method for evaluating a toner for electrophotography according to any one of claims 1 to 4, wherein the penetration speed of the rotor is 20 to 200 mm / min. The toner evaluation method for electrophotography according to claim 1, wherein the measurement is performed so that the porosity of the toner powder phase is 0.5 to 0.7. The toner after the mixing step of mixing the additives, wherein the value of the torque at the time of rotating blade penetration while rotating measured according to the evaluation method according to claim 1 is set to 0.1 to 80 mNm. Characteristic electrophotographic toner. The toner after the mixing step of mixing the additives, wherein the value of the load at the time of rotating blade penetration while rotating measured according to the evaluation method according to claims 1 to 6 is 0.01 to 3 N. Characteristic electrophotographic toner. 7. The toner after the mixing step of mixing the additives, is made to penetrate into the toner powder phase while rotating the rotating blade measured according to the evaluation method according to claim 1, and then is rotated while rotating the rotating blade. A toner for electrophotography, wherein the value of the torque at the time of removal from the body phase is 0.1 to 23 mNm. 7. The toner after the mixing step of mixing the additives, is made to penetrate into the toner powder phase while rotating the rotating blade measured according to the evaluation method according to claim 1, and then is rotated while rotating the rotating blade. A toner for electrophotography, wherein a value of a load at the time of removal from a body phase is 0.01 to 0.6 N. The electrophotographic toner according to any one of claims 7 to 10, wherein a charge control agent and / or a release agent is contained in at least a toner comprising a resin and a pigment. The electrophotographic toner according to any one of claims 7 to 10, wherein the toner has an average particle diameter of 4 to 10 µm. The electrophotographic toner according to any one of claims 7 to 10, wherein the toner is produced by a method other than the pulverization method. A one-component developing method comprising performing contact or non-contact development using the electrophotographic toner according to any one of claims 7 to 13. 15. The method according to claim 14, wherein a doctor roller is used. A two-component developing method, comprising developing using the electrophotographic toner according to any one of claims 7 to 13 and a carrier having a particle size of 20 to 100 µm. A method for producing a toner for electrophotography, comprising producing a toner in a production line by using the evaluation method according to claim 1. An electronic device for evaluating fluidity of a toner comprising a container for storing toner powder, and a torque meter having a rotary wing for entering or extracting from the container and / or a load cell provided at a lower portion of the container. Photo toner evaluation device.

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