JP4065246B2 - Powder adhesion measuring method and powder adhesion measuring device - Google Patents

Description

  The present invention relates to a powder adhesion measuring method and a powder adhesion measuring apparatus, and more particularly to measuring adhesion of a toner or the like applicable to the field of handling powders such as electrophotography.

  In the field of handling powder, it is important to grasp various characteristic values of the powder. One characteristic value of the powder is the adhesion of the powder. As a method for measuring the adhesion force of the powder, a method for estimating the force necessary to separate the powder from the object to which the powder is adhered is generally used. As a method for separating powder, a method using centrifugal force, vibration, impact, air pressure, electric field, magnetic field or the like is known.

  For example, there is a method in which toner particles are attached to the tip of an AFM cantilever and the adhesion force to the surface of the photoreceptor is measured (for example, see Non-Patent Document 1). Further, there is a method of separating powder from a substrate by applying a centrifugal force (see, for example, Patent Document 1). Further, there is a method of separating the powder from the substrate by vibrating the substrate (see, for example, Patent Document 2). In addition, there is a method in which an electric field is applied between the substrate and the powder collecting member to separate the powder from the substrate (see, for example, Patent Document 3). In addition, there is a method of measuring the adhesion force between the substrate and the powder by a method of separating the powder from the substrate by applying an ultrasonic wave to the powder (see, for example, Patent Document 4).

  Further, there is a method of measuring the adhesion force between magnetic particles and fine particles by separating the fine particles adhering to the magnetic particles from the magnetic particles mechanically and by an electric field (see, for example, Patent Document 5).

  In addition, as a generally well-known method for measuring the adhesion between powders, a two-divided cell that fills powder into a separable container and measures the tensile strength when the container is divided There is a law (for example, see Non-Patent Document 2).

  In addition, there is a technique in which the adhesion force between powders is measured by a method in which centrifugal force is applied to a substrate on which a powder layer is formed in the adhesion force between powders (for example, see Patent Document 6).

In addition, there is a method for measuring the adhesion force between powders by bringing the powder particles attached to the tip of the needle into contact with the powder attached to the substrate and measuring the force at the time of peeling (for example, patent document) 7).
Japanese Patent Application Laid-Open No. 10-276772 JP-A-11-153538 JP 2001-228075 A JP 2002-71484 A JP 2003-98065 A Japanese Patent Laid-Open No. 11-258081 JP 2001-183289 A Mary L. Ott, et al. , “Atomic force microscopy adhesion measurements of surface-modified toners for xerographic applications”, Colloids and Surfaces. 245-256 Edited by Hayakawa Souhachiro, Method for Measuring Physical Properties of Powder, Asakura Shoten, 1955, p. 94

  In the electrophotographic image forming process, the toner, which is a charged powder for forming an image, is repeatedly attached and separated between image forming members such as a photoconductor, and the adhesion force between the toner and the image forming member. Is an important characteristic value. Further, the toner image formed on the image forming member has two or more layers of toner particles, and the adhesion between the toner particles has an important influence on the characteristics of the process. In particular, in the transfer process, the cause of the phenomenon of deteriorating the image quality such as transfer dust and hollow image is closely related to the adhesion force between toners, and the control of the adhesion force between toners is an important issue. .

  However, since the methods of Non-Patent Document 1 and Patent Documents 1 to 4 are methods for measuring the adhesion force between the powder and the object to which the powder is adhered, the adhesion force between the powders is measured. It becomes difficult to measure.

  Further, when the adhesion force between charged powders is measured as in Non-Patent Document 2, it is necessary to fill a container with powder once charged by some means. For this reason, it is not possible to measure the adhesion between powders in a state where the powder layer is adhered to an object like the toner layer formed on the image forming member in the electrophotographic process. Further, normal powder has a distribution in particle size and charge amount, and there is a distribution in the adhesion between powders, but this method cannot measure the adhesion distribution between powders.

  Further, the method of Patent Document 6 can measure in a state where the powder layer is attached to an object and has good quantitativeness, but has a problem that it takes many measurement procedures and takes a long measurement time. In addition, since the number of separated particles from the powder layer is very large, the separated particles are in contact with each other or stacked, and the particle size of each particle cannot be measured. There is a problem that can not be.

  Further, the method of Patent Document 7 can accurately measure the adhesion between powders, but in order to obtain the average value and distribution of the adhesion between powders, measurement is performed on a large number of powder particles. There is a problem that it is necessary and takes time and effort.

  The present invention has been made in view of the above circumstances, and provides a powder adhesion measuring method and a powder adhesion measuring apparatus capable of quantitatively and easily measuring the adhesion distribution between charged powders. It is the purpose.

  In order to achieve this object, the present invention has the following features.

In the method for measuring powder adhesion according to the present invention, two or more layers of charged powder particles are deposited on a first substrate having electrodes, a powder layer is formed on the first substrate, and a first electrode having electrodes is formed. The two substrates are placed so as not to contact the powder layer, an air layer is provided between the first substrate and the second substrate, and the first substrate and the second substrate. A potential difference is provided between them, and some of the particles adhering to the first substrate are moved onto the second substrate, the powder weight m ₁ on the first substrate and the powder on the second substrate The weight m ₂ is measured, the powder weight ratio η is obtained from the equation (1), the layer thickness of the powder layer is d _2, and the powder layer division position Z _s corresponding to the powder weight ratio η is represented by the equation From (2), the electric field E (Z _s ) at the powder layer dividing position Z _s is obtained, and the measured adhesion amount distribution of the powder and the electric field E (Z _s ) are used to determine the adhesive force distribution between the powders. Characterized by seeking Than is. As a result, it is possible to perform measurement in a state where the charged powder adheres to the substrate, so that it is possible to easily measure the adhesion force distribution between the powders.

  The powder adhesion measuring method according to the present invention is characterized in that the substrate on which the electrode is formed is a flat plate, and the first substrate and the second substrate face each other in parallel. As a result, the electric field becomes uniform in a plane parallel to the substrate, so that the amount of movement of the powder becomes uniform in the plane, and high-precision measurement is possible.

  Moreover, the powder adhesion measuring method according to the present invention is characterized in that an insulating layer is provided on the electrodes of the first substrate and the second substrate. As a result, the occurrence of leakage current due to discharge or contact between the two substrates is suppressed, the value of the adhesion between the powders is obtained, and stable measurement with high quantitativeness becomes possible.

In addition, the method for measuring the adhesion of powder according to the present invention uses the insulating layer on the first substrate as layer 1, the powder layer as layer 2, the air layer as layer 3, and the insulating layer of the second substrate as layer 4. , _I , d _i (i = 1 to 4 (1 to 4 is the number of each layer)), D _i = d _i / ε _i (i = 1 to 4), The sum of D _i is D, ε ₀ is the dielectric constant of vacuum, the charge amount Q / M per unit weight of powder, the true specific gravity δ of powder, the bulk density M / V of powder, the dielectric constant of powder particles Using ε _p , the charge density ρ of the powder layer is obtained from Equation (3), the dielectric constant ε ₂ of the powder layer is obtained from Equation (4), and the voltage V ₁ and the second voltage are applied to the electrodes of the first substrate. The electric field E (z _s ) when the voltage V ₂ is applied to the electrode of the substrate is obtained by the equation (5), and thus the powder obtained from the measured powder weight ratio Body layer division position, parameters related to powder, etc. By substituting in the formula, it is possible to obtain high values of quantitativity powder adherence between.

  The powder adhesion measuring method according to the present invention is characterized in that a measured value corresponding to a powder weight ratio η of 0.5 or less is used as a measured value of the adhesion between powders. . In this way, by using the measured value in the range where the powder does not separate from the substrate, it is possible to measure only the adhesion force between the powders without being affected by the adhesion force between the powder and the substrate.

  The powder adhesion measuring method according to the present invention is characterized in that the potential difference between the substrates and the distance between the substrates are set within a range where no discharge occurs between the substrates. As a result, the influence on the measurement due to the discharge is avoided, so that an accurate measurement is possible.

  The powder adhesion measuring method according to the present invention is characterized in that a toner is used as a powder and a developing method in an electrophotographic method is used as a method for forming a toner layer on a first substrate. is there. This makes it possible to measure the adhesion distribution between the toners in the toner layer formed by development, thereby contributing to the development of electrophotographic processes and toners.

Moreover, the powder adhesion measuring apparatus according to the present invention is a powder adhesion means for adhering two or more charged powder particles on a first substrate having electrodes and forming a powder layer on the first substrate. And the second substrate having electrodes facing the first substrate so as not to contact the powder layer formed on the first substrate, and between the first substrate and the second substrate. A powder moving means for providing a potential difference and moving a part of particles of the powder layer formed on the first substrate to the second substrate, a powder weight m ₁ on the first substrate, a second A weight measuring means for measuring the powder weight m ₂ on the substrate, a charge amount distribution measuring means for measuring the charge amount distribution of the powder, and determining the powder weight ratio η from the formula (1), the layer thickness of the layer and d _2, the powder layer split position Z _s corresponding to the powder weight ratio η determined from equation (2), determined the powder layer dividing position field in Z _s E a (Z _s) The measured value of the charge amount distribution of the powder, is characterized in that it has a field E (Z _s), and adhesion distribution calculating means which calculates the adhesion distribution between powder from the. As a result, it is possible to perform measurement in a state where the charged powder adheres to the substrate, so that it is possible to easily measure the adhesion force distribution between the powders.

  The powder adhesion measuring apparatus according to the present invention is characterized in that the substrate on which the electrode is formed is a flat plate, and the first substrate and the second substrate face each other in parallel. As a result, the electric field becomes uniform in a plane parallel to the substrate, so that the amount of movement of the powder becomes uniform in the plane, and high-precision measurement is possible.

  In addition, the powder adhesion measuring apparatus according to the present invention is characterized in that an insulating layer is provided on the electrodes of the first substrate and the second substrate. As a result, the occurrence of leakage current due to discharge or contact between the two substrates is suppressed, the value of the adhesion between the powders is obtained, and stable measurement with high quantitativeness becomes possible.

In the powder adhesion measuring apparatus according to the present invention, the insulating layer on the first substrate is layer 1, the powder layer is layer 2, the air layer is layer 3, and the insulating layer of the second substrate is layer 4. , _I , d _i (i = 1 to 4 (1 to 4 is the number of each layer)), D _i = d _i / ε _i (i = 1 to 4), The sum of D _i is D, ε ₀ is the dielectric constant of vacuum, the charge amount Q / M per unit weight of powder, the true specific gravity δ of powder, the bulk density M / V of powder, the dielectric constant of powder particles Using ε _p , the charge density ρ of the powder layer is obtained from Equation (3), the dielectric constant ε ₂ of the powder layer is obtained from Equation (4), and the voltage V ₁ and the second voltage are applied to the electrodes of the first substrate. It is characterized by having an electric field calculation means for obtaining an electric field E (z _s ) when the voltage V ₂ is applied to the electrode of the substrate according to the equation (5). Powder layer division position obtained from the ratio and powder By substituting the formula and parameters related, it is possible to obtain high values of powder adherence between quantitativeness.

  The powder adhesion measuring apparatus according to the present invention is characterized in that toner is used as powder and a developing means in an electrophotographic system is used as means for forming a toner layer on the first substrate. is there. This makes it possible to measure the adhesion distribution between the toners in the toner layer formed by development, thereby contributing to the development of electrophotographic processes and toners.

The powder adhesion measuring method and the powder adhesion measuring apparatus according to the present invention attach two or more layers of charged powder particles on a first substrate having electrodes, and the powder layer on the first substrate. The second substrate having electrodes is placed so as not to contact the powder layer, an air layer is provided between the first substrate and the second substrate, and the first substrate; A potential difference is provided between the substrate and the second substrate, and some particles attached on the first substrate are moved onto the second substrate, and the powder weight m ₁ on the first substrate; The powder weight m ₂ on the second substrate is measured, the powder weight ratio η is obtained from the formula (1), the layer thickness of the powder layer is d ₂ , and the powder corresponding to the powder weight ratio η The body layer division position Z _s is obtained from the equation (2), the electric field E (Z _s ) at the powder layer division position Z _s is obtained, the measured value of the charge amount distribution of the powder, the electric field E (Z _s ), Adhesion between powder and powder By determining, charged powder can be measured since it is possible to carry out measurements in a state of adhering to the substrate, the adhesive force distribution between easily powder.

  First, the features of the powder adhesion measuring method and powder adhesion measuring apparatus according to the present invention will be described with reference to FIGS.

The powder adhesion measuring method and the powder adhesion measuring device according to the present invention according to the present invention attach two or more charged powder particles on the first substrate (5, 1) having electrodes, The powder layer (2) is formed on the first substrate (5, 1), the second substrate (4, 6) having an electrode is placed so as not to contact the powder layer (2), An air layer (3) is provided between the first substrate (5, 1) and the second substrate (4, 6), and the first substrate (5, 1) and the second substrate (4, 6), a potential difference is provided between the first substrate (5, 1), and a part of the particles adhering to the first substrate (5, 1) is moved onto the second substrate (4, 6). 5, 1) The powder weight m ₁ on the second substrate (4, 6) and the powder weight m ₂ on the second substrate (4, 6) are measured, and the powder weight ratio η is obtained from the equation (1). The layer thickness of layer (2) is d ₂ and the powder layer corresponds to the powder weight ratio η The division position Z _s is obtained from equation (2), the electric field E (Z _s ) at the powder layer division position Z _s is obtained, and the measured value of the charge amount distribution of the powder and the electric field E (Z _s ) Find the adhesion distribution between the bodies. As a result, it is possible to perform measurement in a state where the charged powder adheres to the substrate, so that it is possible to easily measure the adhesion force distribution between the powders.

  Hereinafter, embodiments of a powder adhesion measuring method and a powder adhesion measuring apparatus according to the present invention will be described in detail with reference to the drawings.

  First, the powder moving means included in the powder adhesion measuring apparatus according to the present invention will be described with reference to FIG. FIG. 1 suggests an example of the powder moving means in the present invention.

  A powder layer (2) in which two or more charged powder particles are laminated is attached on a first substrate (5, 1) having an insulating film (1) formed on a flat metal plate (5). In this state, the first substrate (5, 1) and the second substrate (4, 6) in which the insulating film (4) is formed on the flat metal plate (6) are parallel to each other. Are installed in the substrate holding member (10).

  Note that a powder layer (2) stacked on the first substrate (5, 1) is between the first substrate (5, 1) and the second substrate (4, 6). Insulating spacers (7) are provided so as to maintain an interval so as not to contact the substrates (4, 6). By this spacer (7), an air layer (3) is provided between the powder layer (2) laminated on the first substrate (5, 1) and the second substrate (4, 6). It will be.

The metal plate (5) is connected to the constant voltage power source (8), the metal plate (6) is connected to the constant voltage power source (9), and the powder (2) is the first substrate (5). A potential difference that moves from 1) to the second substrate (4, 6) is applied between the substrates. Assuming that the voltage of the constant voltage power source (8) is V ₁ and the voltage of the constant voltage power source (9) is V ₂ , if the charged polarity of the charged powder (2) is positive, V ₁ > V ₂ , When the charging polarity is negative, the voltage is set so that V ₁ <V ₂ .

  In FIG. 1, two power sources are used. However, it is also possible to construct such that one of the metal plates (5, 6) is grounded and a voltage is applied by one power source. Moreover, although the metal plate (5, 6) is used as what comprises the 1st board | substrate (5, 1) and the 2nd board | substrate (4, 6), 1st is provided by providing an electrode surface in an insulator. It is also possible to construct a second substrate and a second substrate.

  Next, a state when a voltage is applied to the powder layer (2) in which two or more powder particles are attached to the first substrate (5, 1) will be described with reference to FIG. FIG. 2 suggests an enlarged view of the powder layer (2) before voltage is applied.

When a voltage is applied to the powder layer (2) suggested in FIG. 2, the powder layer (2) moves to the second substrate (4, 6) and the particles (2b) moving to the second substrate (4, 6). ) Will be separated into particles (2a) that do not move to. When the weight of the particles (2b) moving to the second substrate (4, 6) is m ₂ and the weight of the particles (2a) not moving to the second substrate (4, 6) is m ₁ , the powder layer ( The powder weight ratio η indicating the proportion of particles moved from 2) can be defined by the following equation (1), and a dividing plane is assumed that divides the powder layer (2) by the weight ratio represented by η. Will be able to.

As suggested in FIG. 2, when the distance from the surface of the insulating layer (1) to the dividing plane is Z _s , z _s can be expressed by the equation (2) using the powder weight ratio η determined by the equation (1). It will be expressed as follows. D ₂ indicates the layer thickness of the powder layer (2).

Note that, on the powder layer splitting surface, the Coulomb force: F due to the electric field acting as a force for moving the powder particles and the inter-powder adhesion force acting as a force for holding the powder particles in the powder layer (2). Will be balanced. Coulomb force by electric field: F is calculated from the product of the charge amount q of one powder particle and the electric field E (z _s ) at the powder layer dividing surface. The adhesion force distribution between the powders can be obtained from the distribution of the charge amount distribution of the powder and the Coulomb force calculated from the electric field E (z _s ): F = qE (z _s ).

The electric field E (z _s ) at the powder layer dividing surface can be obtained by the following expressions (3) to (5).

Since the electric field between the parallel plates as shown in FIG. 1 is constant in a plane parallel to the substrate, it can be calculated by solving a one-dimensional Poisson equation. The layer thickness d and relative dielectric constant ε of the insulating layer (1), the powder layer (2), the air layer (3), and the insulating layer (4) are d ₁ , ε ₁ , d ₂ , ε ₂ , d _{3, respectively.} , Ε ₃ , d ₄ , ε ₄ , D _i = d _i / ε _i (i = 1 to 4), the sum of D _i is D, the volume charge density of the powder layer (2) is ρ, and vacuum When the dielectric constant is ε ₀ , the electric field E (z _s ) at the powder layer dividing surface can be calculated by the equation (5). In addition, each number of 1-4 suggests the number of a layer.

In the powder layer (2), powder particles and air are mixed. The powder charge amount per unit weight is Q / M, the true specific gravity δ of the powder, and the bulk density of the powder is M / M. When V and the dielectric constant of the powder particles are ε _p , the volume charge density ρ and the relative dielectric constant ε ₂ of the powder layer (2) can be calculated from the equations (3) and (4), respectively. Become.

Thus, the adhesion distribution between the powders is based on the powder weight ratio η calculated from the equation (1), the powder division position z _s calculated from the equation (2), the applied voltage, By substituting parameters relating to powder and the like into the equation (5), the electric field E (z _s ) is calculated, and the coulomb force calculated from the calculated electric field E (z _s ) and the charge amount distribution: F = It can be obtained from the distribution of qE (z _s ).

  In the powder layer (2), two or more powder particles are laminated. However, when the powder particle is one layer, the powder particles are separated from the first substrate (5, 1). The adhesion force between the powder particles and the first substrate (5, 1) is measured, and the adhesion force between the powders cannot be measured. Also, in the powder layer (2) in which two or more powder particles are laminated, the powder particles are not separated from the first substrate (5, 1) in order to measure only the adhesion between powders. It is necessary to measure in the range.

  The closer the powder weight ratio η is to 1, the more powder particles are separated from the first substrate (5, 1). In the case of the powder layer (2) in which two powder particles are laminated, the powder weight ratio η is ½ or less. In the case of the powder layer (2) in which three layers are laminated, the powder weight ratio η is 2 The upper limit of the powder weight ratio η increases as the number of layers increases, but there is no particular problem if the powder weight ratio η is 0.5 or less. For this reason, it is preferable to use a measured value corresponding to a powder weight ratio η of 0.5 or less as a measured value of the adhesion between powders. Thereby, there is no influence of the adhesive force between the powder and the substrate, and only the adhesive force between the powders can be measured. In addition, it is preferable to set the potential difference between the substrates and the distance between the substrates within a range in which no discharge occurs between the substrates. Thereby, since the influence on the measurement by discharge can be avoided, an accurate measurement becomes possible.

  Next, with reference to FIG. 3, the powder adhering means included in the powder adhering force measuring apparatus of the present invention will be described. FIG. 3 suggests an example of the powder adhering means in the present invention, and shows a developing apparatus using an electrophotographic two-component developing system.

  As suggested in FIG. 3, in the developing device (21), magnetic particles having a particle size about 5 to 10 times that of the powder and the powder are held, and the stirring device (22) configured by a screw or the like. Will be mixed and stirred. The mixed and stirred powder is triboelectrically charged and supplied to the developing sleeve (23) in a state of adhering to the magnetic particles. A magnet is provided inside the developing sleeve (23), and the surface can be rotated. The developing sleeve (23) has a magnetic brush formed on the surface thereof with magnetic particles spiked in a chain shape. The height of the magnetic brush formed on the developing sleeve (23) is regulated by the regulating plate (24), and the magnetic brush is conveyed to an area close to the first substrate (5, 1). Note that the powder adhering means suggested in FIG. 3 is arranged such that the developing sleeve (23) and the first substrate (5, 1) are close to each other with a certain distance therebetween to form a developing region, When a voltage is applied from the power source (8) connected to the first substrate (5, 1) and the power source (25) connected to the developing sleeve (23), the powder particles are separated from the magnetic particles. Then, an electric field that moves to the first substrate (5, 1) is generated.

  Since the first substrate (5, 1) moves in parallel at a constant speed by the moving mechanism, the powder particles adhere to the surface of the first substrate (5, 1) that has passed through the development region, and the first substrate (5, 1) The powder layer (2) is formed on the substrate (5, 1). Note that the amount of powder adhering on the first substrate (5, 1) is the amount of powder or magnetic particles, the amount of charge of the powder, and between the first substrate (5, 1) and the developing sleeve (23). Can be controlled by the potential difference, interval, speed, and the like.

  As suggested in FIG. 3, the powder adhesion measuring apparatus according to the present invention uses a two-component developing system as a powder adhesion means. It is also possible to apply a developing device using a one-component developing system that is directly attached from the developing sleeve. Further, the powder adhering means is not limited to the electrophotographic method, and is not particularly limited as long as two or more powder particles can be uniformly adhered.

  Further, the powder adhesion measuring apparatus according to the present invention has an independent form of the powder moving means suggested in FIG. 1 and the powder adhesion means suggested in FIG. 3, but as suggested in FIG. In addition, the powder moving means and the powder adhering means are arranged in one apparatus, and the first substrate (5, 1) for forming the powder layer (2) is moved from the powder adhering means to the powder moving means. It is also possible to construct it so that it can be moved automatically to the means. In the case of FIG. 4, the stage (11) is used as means for controlling the distance between the first substrate (5, 1) and the second substrate (4, 6).

  Next, an example of the powder weight measuring means in the present invention will be described with reference to FIG. FIG. 5 suggests a part of an apparatus that can measure the powder charge amount as well as the powder weight.

  As suggested in FIG. 5, the powder weight measuring means in the present invention comprises a member (31) and a member (32), and the member (31) is a suction nozzle (33) for sucking powder. And a powder introduction part (34) for introducing powder and an electrode (35) for measuring the charge amount of the introduced powder. The member (32) includes a filter (36) for holding the sucked powder, a wire mesh (37) installed to hold the filter (36), and a suction port (38) connected to the suction pump. It consists of.

  The powder weight measuring means in the present invention is composed of a double metal container in FIG. 5 where the hatched portion is made of metal and the halftone dot portion is made of plastic. The inner container is connected to the charge measuring device through the electrode (35), and the outer container is grounded.

  As suggested in FIG. 5, the powder weight measuring means in the present invention combines the member (31) and the member (32), so that the sucked powder adheres to the filter (36) and the inner side. It will be held in the container and the charge amount of the powder can be measured. For this reason, the filter (36) needs to be replaced for each measurement. The weight of the powder adhering to the substrate can be measured by measuring the weight of the member (31) and the member (32) after powder suction with a balance and subtracting the weight before powder suction. Further, the powder charge amount Q / M per unit weight can be obtained from the powder charge amount Q and the powder weight M measured at the time of powder suction.

  In the example of FIG. 5, the powder weight is measured by sucking the powder on the substrate. However, the powder weight can be measured by attaching the powder on the substrate to an adhesive tape or the like. It is also possible to measure from the change in weight of the substrate by removing the powder from the substrate.

  Next, the charge amount distribution measuring means in the present invention will be described.

  There are various methods for measuring the charge amount distribution of powder, and examples thereof are shown below.

  First, there is a method for obtaining an amount of charge from a toner dropping position which has been affected by an electric field, as described in JP-A-63-263475. Further, the particle size and the charge amount are measured by measuring the phase lag and the deflection amount of the charged particles moving under the action of the vibration of the sound wave and the electric field described in JP-A-63-118634 by the laser Doppler method. There is a laser Doppler method for simultaneously obtaining. A measuring apparatus using this laser Doppler method is commercialized as an espert analyzer (Hosokawa Micron Corporation).

  Next, a method for measuring the adhesion force distribution between powders will be described with reference to FIGS.

  First, as suggested in FIG. 3, the powder and magnetic particles are mixed, introduced into the developing device (21), and sufficiently stirred by the stirring device (22). A voltage is applied from the power source (8) and the power source (25) to create a potential difference between the first substrate (5, 1) and the developing sleeve (23), and the rotation of the developing sleeve (23) and the first substrate ( 5 and 1), and a powder layer (2) is formed on the first substrate (5, 1) as suggested in FIG. The first substrate (5, 1) on which the powder layer (2) is formed is opposed to the second substrate (4, 6), voltage is applied from the power source (8) and the power source (9), A potential difference is provided between the first substrate (5, 1) and the second substrate (4, 6), and a part of the powder layer (2) is moved to the second substrate (4, 6). Then, the powder weights on the first substrate (5, 1) and the second substrate (4, 6) are measured. The weight ratio η is obtained by substituting the weight of the powder on the first substrate (5, 1) and the second substrate (4, 6) into the equation (1).

Next, the powder layer division position z _s is obtained by substituting the weight ratio η into the equation (2), and the electric field E (z _s ) is obtained by substituting each parameter into the equation (5).

Further, in the same manner as described above, the powder layer (2) is formed on the first substrate (5, 1), the first substrate (5, 1) is removed from the measuring apparatus, and the measured particles of the e-part analyzer are taken in. Install in the upper mouth. Then, by blowing air to the powder layer (2) formed on the first substrate (5, 1), the powder particles fly, the powder particles are introduced into the measurement particle intake, Measure the charge distribution. The distribution of the Coulomb force F = qE (z _s ), which is the product of each charge amount q and the electric field E (z _s ) in the charge amount distribution, is obtained and used as the adhesive force distribution between the powders.

  Next, a method for measuring each parameter to be substituted into Expression (5) will be described.

  The true specific gravity δ of the powder can be measured by a liquid immersion method (Pycnometer method) or a pressure comparison method (Beckman method). The volume charge density ρ of the powder layer (2) can be estimated by substituting Q / M and bulk density M / V into equation (3). Although the bulk density of the powder layer (2) formed on the first substrate (5, 1) cannot be directly measured, the bulk density of the powder is measured by a method defined by JIS standards. it can.

The relative dielectric constant ε ₂ of the powder layer (2) can be estimated by the formula (4) from M / V, δ, and the relative dielectric constant ε _{p of the} powder particles. The relative dielectric constant can be measured by a capacitance method using an LCR meter. Thickness d ₂ of the powder layer (2) is a high magnification which can three-dimensional shape measurement of the object surface in the apparatus, for example, be measured by Keyence Corporation ultradeep shape measuring microscope. The layer thickness of the insulating layer (1) or the insulating layer (4) can be measured using a mechanical or optical thickness measuring device. As the layer thickness of the air layer (3), a value obtained by subtracting the layer thickness of the powder layer (2) from the thickness of the spacer (7) can be used.

  Next, an example of measuring the adhesion force distribution between powders using the above measuring apparatus will be described.

Assuming correspondence with the transfer process in the electrophotographic process, a polycarbonate layer having a dielectric constant similar to that of the photosensitive member is formed on the first substrate (5, 1), and then on the second substrate (4, 6). The transfer belt was affixed with a conductive adhesive to perform measurement. The polycarbonate layer has a relative dielectric constant ε ₁ of 3.3 and a film thickness d ₁ of 6 μm, and the transfer belt has a relative dielectric constant ε ₄ of 11.1 and a film thickness d ₄ of 150 μm.

Using a Ricoh toner and carrier, a toner layer was formed on the first substrate (5, 1) using the apparatus suggested in FIG. The relative dielectric constant epsilon _p of the toner particles, 3.2, true specific gravity [delta], 1.25 g / cm ^3, a bulk density of M / V of the toner, at 0.455 g / cm ^3, the toner layer from the formula (4) The relative dielectric constant ε ₂ is 1.8. The Q / M of the toner layer is −28 μC / g, and the volume charge density ρ of the toner layer is −12.7 C / m ³ from the formula (3). The layer thickness d _{2 of the} toner layer is 12.2 μm.

The potential difference (V ₂ −V ₁ ) between the first substrate (5, 1) and the second substrate (4, 6) was 700 V, and the weight ratio η was measured when the inter-substrate distance Z was 150 μm, 100 μm, and 75 μm. . Suggesting a η at each Z, a division position z _s of the toner layer, an electric field E (z _s) of z _s, the Figure 6. From the table suggested in FIG. 6, the average value of E (z _s ) was 0.689 MV / m.

4 is used to measure the charge amount distribution of the toner layer formed on the first substrate (5, 1), and to determine the average value of each charge amount q and E (z _s ) in the charge amount distribution. The distribution of the product qE (z _s ) is obtained as the distribution of the adhesion F between the powders. The measurement result of the adhesion distribution is suggested in FIG. In this measurement, the inter-substrate distance Z was changed with the potential difference between the first substrate (5, 1) and the second substrate (4, 6) constant, but the potential difference was changed with Z constant. Will give similar results.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited only to the above-described embodiment, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

It is a schematic block diagram which shows an example of the powder moving means in this invention. It is a figure for demonstrating the powder adhesive force measuring method of this invention. It is a schematic block diagram which shows an example of the powder adhesion means of this invention. It is a schematic block diagram which shows an example of the powder moving means and powder adhesion means of this invention. It is a schematic block diagram which shows an example of the powder weight measurement means in this invention. Substrate distance Z is 150 [mu] m, 100 [mu] m, and the weight ratio η at 75 [mu] m, a division position z _s of the toner layer, the electric field in the z _s E (z _s), is indicative table of. It is a figure which shows an example of the adhesive force distribution between the powders measured using this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulating layer 2 Powder layer 3 Air layer 4 Insulating layer 5 Metal flat plate 6 Metal flat plate 7 Spacer 8 Power source 9 Power source 10 Substrate holding member 11 Stage 21 Developing device 22 Stirring device 23 Developing sleeve 24 Restriction plate 25 Power source 31 Powder suction device Member 32 Powder suction device member 33 Suction nozzle 34 Powder introduction part 35 Electrode 36 Filter 37 Wire mesh 38 Suction port (5, 1) First substrate (4, 6) Second substrate

Claims (12)

Two or more charged powder particles are deposited on a first substrate having an electrode, a powder layer is formed on the first substrate, and a second substrate having an electrode is in contact with the powder layer Facing each other, providing an air layer between the first substrate and the second substrate, providing a potential difference between the first substrate and the second substrate, A part of the particles adhering to the first substrate is moved onto the second substrate, the powder weight m ₁ on the first substrate, and the powder weight m on the second substrate. ₂ , the powder weight ratio η is obtained from the formula (1), the layer thickness of the powder layer is d _2, and the powder layer division position Z _s corresponding to the powder weight ratio η is represented by the formula ( 2) obtained from, obtains an electric field E (Z _s) of the powder layer split position Z _s, and the measured value of the charge amount distribution of the powder, the electric field E and (Z _s), adhesive force distribution between the powder from Seeking Powder adhesion measurement method characterized.

  2. The powder adhesion measuring method according to claim 1, wherein the substrate on which the electrode is formed is a flat plate, and the first substrate and the second substrate face each other in parallel.   2. The method for measuring the adhesion of powder according to claim 1, wherein an insulating layer is provided on the electrodes of the first substrate and the second substrate. The insulating layer on the first substrate is the layer 1, the powder layer is the layer 2, the air layer is the layer 3, the insulating layer of the second substrate is the layer 4, and the relative dielectric constant and the layer thickness of each layer are Ε _i , d _i (i = 1 to 4 (1 to 4 is the number of each layer)), D _i = d _i / ε _i (i = 1 to 4), D is the sum of D _i , and ε ₀ is Using the dielectric constant of vacuum, the charge amount Q / M per unit weight of powder, the true specific gravity δ of powder, the bulk density M / V of powder, and the dielectric constant ε _p of powder particles, the powder layer Is obtained from the equation (3), the dielectric constant ε ₂ of the powder layer is obtained from the equation (4), the voltage V ₁ is applied to the electrode of the first substrate, and the voltage is applied to the electrode of the second substrate. The method of measuring a powder adhesive force according to any one of claims 1 to 3, wherein the electric field E (z _s ) when V ₂ is applied is obtained by the equation (5).

  The method for measuring a powder adhesion force according to claim 1, wherein a measurement value corresponding to the powder weight ratio η of 0.5 or less is used as a measurement value of the adhesion force between the powders.   2. The method for measuring powder adhesion according to claim 1, wherein the potential difference between the substrates and the distance between the substrates are set within a range in which no discharge occurs between the substrates.   2. The powder adhesion measuring method according to claim 1, wherein a toner is used as the powder, and a developing method in an electrophotographic method is used as a method of forming a toner layer on the first substrate. Powder adhering means for adhering two or more charged powder particles on a first substrate having an electrode, and forming a powder layer on the first substrate;
A second substrate having an electrode is placed opposite to the first substrate so as not to contact the powder layer formed on the first substrate, and both the first substrate and the second substrate are disposed. A powder moving means for providing a potential difference therebetween and moving some particles of the powder layer formed on the first substrate to the second substrate;
The powder weight m ₁ on the first substrate, the powder weight m ₂ on the second substrate, and weight measuring means for measuring a,
A charge amount distribution measuring means for measuring the charge amount distribution of the powder;
The powder weight ratio η is obtained from the equation (1), the layer thickness of the powder layer is d _2, and the powder layer division position Z _s corresponding to the powder weight ratio η is obtained from the equation (2). Adhesive force distribution calculating means for obtaining an electric field E (Z _s ) at the layer division position Z _s and obtaining an adhesive force distribution between the powders from the measured value of the charge amount distribution of the powder and the electric field E (Z _s ). When,
A powder adhesion measuring device characterized by comprising:

  9. The powder adhesion measuring apparatus according to claim 8, wherein the substrate on which the electrode is formed is a flat plate, and the first substrate and the second substrate face each other in parallel.   9. The powder adhesion measuring apparatus according to claim 8, wherein an insulating layer is provided on the electrodes of the first substrate and the second substrate. The insulating layer on the first substrate is the layer 1, the powder layer is the layer 2, the air layer is the layer 3, the insulating layer of the second substrate is the layer 4, and the relative dielectric constant and the layer thickness of each layer are Ε _i , d _i (i = 1 to 4 (1 to 4 is the number of each layer)), D _i = d _i / ε _i (i = 1 to 4), D is the sum of D _i , and ε ₀ is Using the dielectric constant of vacuum, the charge amount Q / M per unit weight of powder, the true specific gravity δ of powder, the bulk density M / V of powder, and the dielectric constant ε _p of powder particles, the powder layer Is obtained from the equation (3), the dielectric constant ε ₂ of the powder layer is obtained from the equation (4), the voltage V ₁ is applied to the electrode of the first substrate, and the voltage is applied to the electrode of the second substrate. The powder adhesive force measuring apparatus according to any one of claims 8 to 10, further comprising an electric field calculating means for obtaining the electric field E (z _s ) when V ₂ is applied by the equation (5). .

  9. The powder adhesion measuring apparatus according to claim 8, wherein a toner is used as the powder, and an electrophotographic developing means is used as the means for forming a toner layer on the first substrate.

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