JP5573285B2 - Powder surface treatment apparatus and method for producing surface treatment powder - Google Patents

Description

  The present invention relates to a powder surface treatment apparatus capable of changing the shape of a powder or the surface roughness of the powder to a desired state, or by adhering different kinds of powder to the powder surface to form a composite. The present invention relates to a method for producing a treated powder.

  In order to obtain multi-functional and high-performance powder products, the desired function and performance can be achieved by controlling the shape and surface roughness of the powder, or by attaching and compounding different types of powder on the powder surface. It has become widely practiced to obtain powder products having As a means for producing such a powder product, a mixer, a surface treatment device, a powder compounding device, or the like is used. By using these devices, powder products having desired functions and performances have been created by using energy of collision and friction between powders or between powder and the inside of the device.

  For example, Patent Document 1 discloses a method for producing an electrophotographic toner in which the charge control agent particles are uniformly fixed at least near the surface of the toner base particles and are not easily detached. Further, Patent Document 2 discloses a toner manufacturing apparatus for efficiently and uniformly attaching externally added fine particles to the surface of a resin powder.

JP 2004-246334 A JP 2005-128149 A

  However, with conventional techniques such as those disclosed in Patent Document 1 and Patent Document 2, it is possible to change the shape of the powder or the surface roughness of the powder to a desired state, It was difficult to maintain the same level of reproducibility by adhering the powder to form a composite. For example, the energy of the impact when the powder collides and the frictional energy generated in the powder may vary depending on the lot difference of the raw material powder. Even when the treatment is performed, the degree of the surface treatment applied to the finished surface-treated powder often differs. In addition, even a slight individual difference in the powder surface treatment apparatus changes the energy given to the powder. The energy imparted to the powder gradually changes due to deterioration over time (such as wear) of the powder surface treatment device, the temperature and moisture content of the powder due to seasonal fluctuations, or the ambient temperature and humidity of the powder surface treatment device In many cases, the degree of the surface treatment applied to the finished surface-treated powder may be different.

  As a method to reduce the difference in the finish (state of surface-treated powder) due to the above fluctuation factors, the ambient temperature and humidity of the powder surface treatment equipment that stores the raw powder before treatment in a constant temperature and humidity environment Although there are methods such as keeping constant, these methods require enormous costs. Depending on the lot difference of the raw material powder, individual differences and deterioration of the powder surface treatment equipment, it is possible to reset the processing conditions, but in the case of recent multifunctional and high function products, the evaluation cost, time etc. for that Is increasing and often not realistic.

  When the raw material powder contains a thermoplastic substance or the like, it is difficult to control the degree of the surface treatment because the hardness of the powder surface changes as the temperature rises. In addition, when using three or more types of powder as the raw material powder, for example, when attaching two or more types of processed powder having a relatively small particle size to a mother powder having a relatively large particle size, Naturally, two or more kinds of powders to be treated have different particle sizes, shapes, specific gravity, etc., so that each of them can be adhered to the mother particles at a desired degree of burial or at a desired separation rate with good reproducibility. It was very difficult to keep making. For example, in the case of an electrophotographic dry toner, a plurality of types of treated particles such as hydrophobic silica are attached to mother particles mainly composed of a thermoplastic resin in which a colorant is dispersed and contained. Some of the treated particles are embedded in the mother particles to achieve triboelectric charging performance as an integrated composite particle. Also, some of the treated particles are released from the mother particles and function as separate bodies to ensure the desired powder fluidity, or to promote the charging of the mother particles by friction with the composite mother particles. I do. The term “some” means that a certain proportion of the same type of treated particles may be attached and the rest may be released, or different treated particles may be attached or released at different proportions for each addition purpose. is there. The performance varies depending on the degree of embedding of the treated particles in the mother particles.

  In order to change the degree of adhesion of a plurality of particles having different purposes and functions, the surface treatment may be performed in a plurality of times. In some cases, the surface treatment is first performed with a mixture of a plurality of powders to be integrated more strongly, and the powder to be weakly adhered is added later to continue the surface treatment. It is important to precisely control the surface treatment state even in such a multi-step surface treatment.

  Therefore, in the present invention, when the powder to be surface-treated has a difference in particle size, particle size distribution, shape, etc. before processing for each lot, or when there are individual differences in the powder surface treatment apparatus due to wear due to aging, etc. Even if the surface treatment environment (season, time, weather temperature and humidity, etc.) is different, it is possible to carry out the desired surface treatment with good reproducibility, An object is to provide a manufacturing method.

  The inventor of the present invention replaces energy by collision and friction, which is a substantial driving force for the surface treatment of the powder, with heat energy, so that the surface treated powder or the powder dispersion medium (the surface treated powder is in the air). In the following description of the present invention, it was noted that “powder” can be measured as a temperature change of “powder dispersion medium”. It was also noted that the progress of the surface treatment of the powder also depends on the temperature of the powder to be surface treated. From these facts, the present inventor can control that the time-temperature curve of the powder during the surface treatment always draws a constant trajectory. It was found that the same surface treatment was always performed in the region, and the present invention shown below was completed. Of course, the means to be controlled is not means for forcibly applying heat, but means for giving energy to the powder by collision or friction. For example, it is conceivable to control the rotational speed of the rotating blades in the mixer to which the powder to be surface-treated is charged, or to increase or decrease the impact given to the powder by a member that collides with the powder in the mixer. .

  The present invention will be described below. In addition, in order to make an understanding of this invention easy, the reference sign of an accompanying drawing is attached in brackets, However, This invention is not limited to the form of drawing.

  A first aspect of the present invention is a powder surface treatment apparatus for performing a surface treatment of a powder, the container (1, 21) containing the powder (5), and the mechanical action on the powder in the container One or a plurality of mechanical action imparting means (2a, 2b, 3, 22), a temperature measuring means (4) for measuring the temperature of the powder, and a transition of the measurement result by the temperature measuring means for a desired time Provided is a powder surface treatment apparatus (10, 20) comprising a control means (17) for determining an operation of at least one of one or a plurality of mechanical action imparting means so as to approach a temperature curve. The above-mentioned problem is solved.

  In the present invention, “surface treatment” means changing the surface shape or surface roughness of the powder to be treated, or attaching another powder to the powder to be treated and combining it. means. “Mechanical action” means mechanical energy, impact, compression, shearing, friction, and the like. “Applying a mechanical action” means applying at least one of the above-mentioned mechanical actions. “Mechanical energy” means the sum of kinetic energy and potential energy. The “mechanical action imparting means” is not particularly limited as long as it gives the mechanical action to the powder to be surface-treated. Specific examples of the mechanical action imparting means will be described in detail later. Further, the “time temperature curve” is a curve showing the temperature change of the powder with respect to the time for which the surface treatment is performed on the powder, and the “desired time temperature curve” is with respect to the time for which the surface treatment is performed on the powder. 2 is a curve showing a preferable temperature of the powder during the surface treatment (including a case near a monotonically increasing straight line).

  In the powder surface treatment apparatus (10) of the first aspect of the present invention, the one or more mechanical action imparting means includes means (2a, 2b) for imparting at least mechanical energy to the powder (5) to be treated. The control means (17) preferably determines the operation of the means for applying the mechanical energy. In the present invention, the “means for giving at least mechanical energy” means means for giving at least mechanical energy to the powder to be treated, and may give other mechanical action simultaneously with giving mechanical energy. It is meant to include possible means.

  In the powder surface treatment apparatus (10) of the first aspect of the present invention, one or a plurality of mechanical action imparting means includes means (3) for applying at least an impact to the powder (5) to be treated, and control means ( 17) preferably determines the operation of the means for applying the impact. In the present invention, “at least means for giving an impact” means means for giving at least an impact to the powder to be treated, and includes means capable of giving another mechanical action simultaneously with giving an impact. is there.

  The powder surface treatment apparatus (10, 20) of the first aspect of the present invention can be suitably used when the powder to be surface-treated consists of a plurality of types of powders.

  The powder surface treatment apparatus (10, 20) of the first aspect of the present invention can be suitably used even when the surface-treated powder is composed of three or more kinds of powders.

  The powder surface treatment apparatus (10, 20) of the first aspect of the present invention can be suitably used even when the powder to be surface treated contains a thermoplastic substance.

  In the powder surface treatment apparatus (10, 20) of the first aspect of the present invention, the control means (17) indicates that the measurement result by the temperature measurement means (4) is on a desired time-temperature curve at the same time as the measurement result. When the temperature is lower than the temperature, the operation of the mechanical action imparting means is determined so as to increase the degree of the mechanical action given to the powder (5) by the mechanical action imparting means (2a, 2b, 3, 22), When the measurement result by the temperature measurement means is higher than the temperature on the desired time-temperature curve at the same time as the measurement result, the mechanical action is reduced so as to reduce the degree of the mechanical action given to the powder by the mechanical action giving means. It is preferable that it is a means which determines operation of a manual action provision means.

  In the powder surface treatment apparatus (10, 20) of the first aspect of the present invention, the control means has a desired time-temperature curve at which the slope of the change in the measurement result by the temperature measurement means (4) is the same as the current measurement result. The operation of the mechanical action imparting means is determined so as to increase the degree of the mechanical action given to the powder (5) by the mechanical action imparting means (2a, 2b, 3, 22) when the inclination is smaller. When the slope of the change in the measurement result by the temperature measurement means is larger than the slope of the desired time-temperature curve at the same temperature as the current measurement result, the degree of mechanical action given to the powder by the mechanical action imparting means is reduced. It is also preferable to be means for determining the operation of the mechanical action imparting means. As will be described later, the “slope of change in the measurement result by the temperature measurement means” is obtained from the current (latest) measurement result and the past measurement result. The “current measurement result” means the latest measurement result among the measurement results used when obtaining the slope of the change in the measurement result by the temperature measurement means.

  The second aspect of the present invention is a method for producing a surface-treated powder for producing a surface-treated powder, the step of containing the powder (5) in the container (1, 21), A step of applying a mechanical action to the powder by one or a plurality of mechanical action applying means (2a, 2b, 3, 22), a step of measuring the temperature of the powder by the temperature measuring means (4), and a temperature Determining the operation of at least one of the one or more mechanical action imparting means by the control means (17) so that the transition of the measurement result by the measuring means approaches a desired time-temperature curve. The problem is solved by providing a method for producing the surface-treated powder.

  In the method for producing a surface-treated powder according to the second aspect of the present invention, the one or more mechanical action imparting means includes means (2a, 2b) for imparting at least mechanical energy to the powder (5), and the control means (17 The method preferably includes the step of determining the operation of the means for applying the mechanical energy.

  In the method for producing a surface-treated powder according to the second aspect of the present invention, the one or more mechanical action imparting means includes means (3) that applies at least an impact to the powder (5), and is controlled by the control means (17). Preferably, the method includes the step of determining the operation of the means for giving an impact.

  The method for producing a surface-treated powder of the second aspect of the present invention can be suitably used when the surface-treated powder (5) is composed of a plurality of types of powders.

  The method for producing a surface-treated powder of the second aspect of the present invention can be suitably used even when the surface-treated powder (5) is composed of three or more kinds of powders.

  The method for producing a surface-treated powder of the second aspect of the present invention can be suitably used even when the surface-treated powder (5) contains a thermoplastic substance.

  In the method for producing the surface-treated powder according to the second aspect of the present invention, the measurement result by the temperature measurement means (4) is lower than the temperature on the desired time-temperature curve at the same time as the measurement result by the control means (17). In this case, the operation of the mechanical action means is determined so as to increase the degree of the mechanical action given to the powder (5) by the mechanical action applying means (2a, 2b, 3, 22), and the temperature measurement means When the measurement result is higher than the temperature on the desired time-temperature curve at the same time as the measurement result, the mechanical action means is reduced so as to reduce the degree of the mechanical action given to the powder by the mechanical action application means. Preferably, the step of determining the operation is included.

  In the method for producing a surface-treated powder according to the second aspect of the present invention, the control means (17) causes the slope of the change in the measurement result by the temperature measurement means (4) to be a desired time-temperature curve at the same temperature as the current measurement result. The operation of the mechanical action means is determined so as to increase the degree of the mechanical action given to the powder (5) by the mechanical action applying means (2a, 2b, 3, 22), When the slope of the change in the measurement result by the temperature measurement means is larger than the slope of the desired time-temperature curve at the same temperature as the current measurement result, the degree of the mechanical action given to the powder by the mechanical action applying means is reduced. Thus, it is preferable to include the step of determining the operation of the mechanically acting means.

  According to the first aspect of the present invention, when the powder to be surface-treated has a difference in particle size, particle size distribution, shape, etc. before the surface treatment for each lot or due to wear due to aging, etc. Powder surface treatment equipment that can perform desired surface treatment on powder with good reproducibility even when there is a difference or when the surface treatment environment (season, time, temperature, humidity, etc.) is different. Can be provided.

  According to the second aspect of the present invention, there is a difference in the particle size, particle size distribution, shape, etc. before the surface treatment of the powder to be surface-treated, or in the powder surface treatment apparatus due to wear due to aging. Even when there are individual differences or when the surface treatment environment (season, time, temperature, humidity, etc.) is different, it is possible to obtain a surface-treated powder in which the desired surface treatment is performed with good reproducibility. A method for producing a surface-treated powder can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS (a) is a figure which shows schematically the cross section of a part of the powder surface treatment apparatus of this invention concerning one Embodiment. (B) is a figure which shows schematically the cross section in bb shown to (a). It is a figure which shows roughly the specific example of a structure of a control means. It is a flowchart which shows roughly an example of the manufacturing method of the surface treatment powder of this invention. It is a flowchart which shows schematically the other example of the manufacturing method of the surface treatment powder of this invention. It is a figure which shows the time temperature curve assumed when surface-treated powder is manufactured with the powder surface treatment apparatus of this invention. It is sectional drawing which shows schematically the powder surface treatment apparatus of other embodiment.

  The powder surface treatment apparatus of the present invention comprises a container for storing powder to be surface treated, one or a plurality of mechanical action imparting means for imparting a mechanical action to the powder in the container, Temperature measuring means for measuring temperature; and control means for determining at least one operation of one or a plurality of mechanical action applying means so that the transition of the measurement result by the temperature measuring means approaches a desired time-temperature curve; It has.

  Fig.1 (a) is a figure which shows schematically the one part cross section of the powder surface treatment apparatus 10 of this invention concerning one Embodiment. FIG. 1B is a diagram schematically showing a cross section taken along line bb shown in FIG.

  As shown in FIG. 1 (a), the powder surface treatment apparatus 10 is configured to adjust the temperature of the container 1, the mixing rotary blades 2a and 2b, the deflector 3, and the powder 5 containing the powder 5 to be surface-treated. Temperature measuring means 4 capable of measuring. Furthermore, although not shown, the powder surface treatment apparatus 10 includes control means for determining the rotation speed of the mixing rotary blades 2a and 2b and / or the installation angle of the deflector 3. As will be described later, in the powder surface treatment apparatus 10, the mixing rotary blades 2 a and 2 b and the deflector 3 are mechanical action imparting units.

  The container 1 is a container for storing the powder 5 to be surface-treated, and the container 1 can be used without any particular limitation to those provided in a conventional powder surface treatment apparatus.

  The mixing rotary blades 2a and 2b are means for transmitting mechanical power through the shaft 2 and applying mechanical energy to the powder 5 by rotating. The mixing rotary blades 2a and 2b are means for giving at least mechanical energy, and may give an impact or the like. The size, shape, number, material and the like of the mixing rotary blades 2a and 2b can be the same as those of the conventional powder surface treatment apparatus.

  The deflector 3 is a unit that gives mechanical energy to the powder 5 moving in the container 1 by being given mechanical energy by the mixing rotary blades 2 a and 2 b and gives an impact to the powder 5. The size, shape, number, material, and the like of the deflector 3 can be the same as those of the conventional powder surface treatment apparatus.

  The temperature measuring means 4 is a means for measuring the temperature of the powder 5. The temperature measuring means 4 is not particularly limited as long as it can measure the temperature of the powder 5 during the surface treatment. As the temperature measuring means 4, for example, a thermocouple can be used. When using a thermocouple, as shown in FIG. 1 (a), it is preferable that the tip of the deflector 3 protrudes from the lower end by several mm and the other part is accommodated in a shaft for fixing the deflector 3 and the deflector. Generally, the container 1 is made of metal, and the mass and heat capacity of the container 1 are larger than those of the powder 5. Therefore, the tip of the temperature measuring means 4 (thermocouple) protrudes from the wall surface of the container 1 into the powder 5. It is preferable to measure the temperature of the powder 5 in the state. Although only one temperature measuring means 4 is shown in FIG. 1, it is preferable to install a plurality of temperature measuring means 4 and measure the temperature at a plurality of locations in order to reduce measurement errors.

  In the case of a rotary mixer type powder surface treatment apparatus such as the powder surface treatment apparatus 10, the powder 5 is put into the container 1, and the mixing rotary blades 2 a and 2 b are rotated at a high speed, whereby the powder 5 Can be mixed. At this time, the mixing rotary blades 2 a and 2 b give at least mechanical energy to the powder 5. The powder 5 given mechanical energy by the mixing rotary blades 2 a and 2 b moves in the container 1, and the surface of the powder 5 is caused by friction or collision between the powders or between the powder and the wall surface of the container 1. Processing proceeds. Furthermore, the surface treatment of the powder 5 also proceeds when the powder 5 collides with the deflector 3 and is given an impact from the deflector 3. As described above, the mixing rotary blades 2a and 2b and the deflector 3 impart a mechanical action to the powder 5, whereby the surface treatment of the powder 5 proceeds. That is, in the powder surface treatment apparatus 10, the mixing rotary blades 2a and 2b and the deflector 3 are mechanical action imparting means.

  As described above, mechanical action such as impact and friction is a substantial driving force for the surface treatment of the powder 5. The energy from this mechanical action is replaced by thermal energy. Therefore, the degree of mechanical action given to the powder 5 can be measured as a temperature change of the powder 5. The progress of the surface treatment of the powder 5 also depends on the temperature of the powder 5 itself to be surface treated. As will be described later, the powder surface treatment apparatus 10 includes the mixing rotary blades 2a, 2b and / or the deflector 3 so that the time temperature curve of the powder 5 during the surface treatment follows the desired time temperature curve. The control means for determining the operation is provided, and the same surface treatment can always be performed on the powder 5 to be surface-treated in each temperature region during the surface treatment. Further, according to the method for producing surface-treated powder using the powder surface treatment apparatus 10, there is a difference in the particle size, particle size distribution, shape, and the like before the surface treatment for the powder 5 to be surface-treated for each lot. Even if there are individual differences in the powder surface treatment apparatus 10 due to wear due to aging, etc., or when the surface treatment environment (temperature, humidity, etc. depending on season, time, etc.) is different, the desired surface It is possible to obtain a surface-treated powder that has been treated with good reproducibility.

  Therefore, according to the powder surface treatment apparatus 10, when the powder 5 to be surface-treated has a difference in particle size, particle size distribution, shape, etc. before the surface treatment for each lot or due to wear due to aging, etc. Even when there are individual differences in the processing apparatus 10 or when the surface treatment environment (season, time, temperature, humidity, etc.) is different, the desired surface treatment can be applied to the powder 5 with high reproducibility. Can be implemented.

  The desired time-temperature curve is a curve showing a preferable temperature (Y-axis) of the powder during the surface treatment with respect to the surface treatment time (X-axis) (of course, including a case close to a monotonically increasing straight line). As a method for determining a desired time-temperature curve, it is conceivable to determine the time-temperature curve based on a time-temperature curve when performing powder processing that is more ideal. For example, a time-temperature curve when an existing surface-treated powder is obtained can be determined as a desired time-temperature curve of a surface-treated powder to be produced. Also, how much the temperature of the time-temperature curve when the existing surface-treated powder is obtained should be shifted up and down due to the difference in physical properties between the existing surface-treated powder and the raw material powder of the surface-treated powder to be produced in the future. Assuming that powder processing that is closer to ideal can be performed, and how much the time axis of the time-temperature curve can be extended or contracted, it is possible to perform powder processing that is closer to ideal. Alternatively, a desired time-temperature curve can be determined. In addition, as described later, the time temperature at which the surface-treated powder was produced a plurality of times while the powder temperature during the surface treatment followed the desired time-temperature curve, and the surface-treated powder was obtained. When the curve deviates from the desired time-temperature curve, the actual time-temperature curve when the surface-treated powder with the best performance can be obtained can be determined as a new desired time-temperature curve. Furthermore, based on the performance of the surface-treated powder obtained with a certain time-temperature curve, a time-temperature curve that is deliberately shifted based on the researcher's knowledge is set, and as described later, The production of the surface-treated powder was repeated while the body temperature followed the shifted time-temperature curve, and the time-temperature curve when the surface-treated powder with the best performance was finally obtained was obtained at the desired time. It can also be defined on a temperature curve. However, since the actual measurement value by the temperature measuring means includes an error, the actual time-temperature curve when the surface-treated powder is obtained may include irregularities due to the error. In that case, it is good also as a desired time-temperature curve with the curve which performed the smoothing process.

  Next, the control means will be described in detail. FIG. 2 schematically shows a specific example of the configuration of the control means. As shown in FIG. 2, the control unit 17 mixes the rotating blades 2 a and 2 b and / or the deflector 3 (mechanical action applying unit) so that the transition of the measurement result by the temperature measuring unit 4 approaches a desired time-temperature curve. CPU 11 for determining the operation of the CPU 11, and a storage device for the CPU 11. The CPU 11 is configured by combining a microprocessor unit and various peripheral circuits necessary for its operation, and a storage device for the CPU 11 is, for example, a control necessary to determine the operation of the mixing rotary blades 2a, 2b and / or the deflector 3. A ROM 12 that stores programs and various data (for example, data of a desired time-temperature curve) and a RAM 13 that functions as a work area of the CPU 11 are combined. In addition to the configuration, the control unit 17 functions by combining the CPU 11 with a control program stored in the ROM 12.

  When determining the operation of the mixing rotary blades 2 a and 2 b and / or the deflector 3, first, the measurement result by the temperature measuring means 4 is input to the control means 17. An input signal from the temperature measuring means 4 reaches the CPU 11 as an input signal via the input port 14. Based on the signal from the temperature measuring unit 4 and the control program stored in the ROM 12, the CPU 11 mixes the rotating blades 2a, 2b so that the transition of the measurement result by the temperature measuring unit 4 approaches a desired time-temperature curve. And / or the operation of the deflector 3 is determined, and a signal related to the result determined via the output port 15 is output to the output means (for example, a screen of a personal computer or the like) 16 to the mixing rotary blades 2a, 2b and / or the deflector 3 The operation to be performed on is displayed on the output means 17. The operations to be performed on the mixing rotary blades 2a and 2b and / or the deflector 3 include, for example, the rotation speed of the mixing rotary blades 2a and 2b, the installation angle of the deflector 3, and the like. Note that, instead of the output unit 16, the rotational speed of the mixing rotary blades 2a and 2b, the installation angle of the deflector 3, and the like may be automatically controlled based on the determination by the CPU 11.

  A method for producing the surface-treated powder of the present invention using the powder surface treatment apparatus 10 provided with such a control means 17 will be described below with reference to FIGS. FIG. 3 is a flowchart schematically showing an example of the method for producing the surface-treated powder of the present invention. FIG. 4 is a flowchart schematically showing another example of the method for producing the surface-treated powder of the present invention.

  The manufacturing method of the surface-treated powder of the present invention shown in FIG. 3 includes the step S10 of storing the powder 5 in the container 1, the surface treatment of the powder in the container 1, and the surface treatment. Step S11 for starting time measurement, Step S12 for starting the surface treatment by the temperature measuring means 4 and measuring the temperature Tr of the powder 5 after elapse of a predetermined time, and the powder by the temperature measuring means 4 in Step S12 Step S13 for determining whether the measurement result (temperature Tr) of the temperature of the body 5 is lower than the temperature Ti on the desired temperature curve at the same time as the measurement result, and if Ti> Tr in step S13, the mixing rotation The operation of the mixing rotary blades 2a, 2b and / or the deflector 3 is determined by the control means 17 so that the mechanical action of the blades 2a, 2b and / or the deflector 3 on the powder 5 during the surface treatment is increased. Step S16, and step S14 for determining whether the temperature measurement result (temperature Tr) of the powder 5 by the temperature measuring means 4 in step S12 is higher than the temperature Ti on the desired temperature curve at the same time as the measurement result. When Ti <Tr in step S14, the mixing rotary blades are controlled by the control means 17 so that the mechanical action of the mixing rotary blades 2a, 2b and / or the deflector 3 on the powder 5 during the surface treatment is reduced. 2a, 2b and / or a step S17 for determining the operation of the deflector 3, and a step S15 for determining whether or not the condition for finishing the surface treatment is satisfied.

  Since the temperature measurement by the temperature measuring means 4 in step S12 includes an error, when determining the operation for the mixing rotary blades 2a, 2b and / or the deflector 3 by the method shown in FIG. The temperature Tr may be determined based on the average of a plurality of measurement results instead of the measurement results.

  Step S13 is a step of determining Ti> Tr. Here, the temperature Ti may not be strictly a temperature on a desired temperature curve, but may be a temperature range having a predetermined width. That is, when the temperature on the desired temperature curve at the time when the temperature Tr is measured by the temperature measuring means 4 is strictly Ti ′, Ti ′ ± Ti ′ × 5% is set to Ti in step S13. You can also.

  Step S14 is a step of determining Ti <Tr. However, similarly to step S13, the temperature Ti may be a temperature range having a predetermined width without strictly setting the temperature Ti to a temperature on a desired temperature curve. . That is, when the temperature on the desired temperature curve at the time when the temperature Tr is measured by the temperature measuring means 4 is strictly Ti ′, Ti ′ ± Ti ′ × 5% is set to Ti in step S14. You can also.

  As described above, step S16 is performed by the control means 17 so that the mixing rotary blades 2a, 2b and / or the deflector 3 exerts a mechanical action on the powder 5 during the surface treatment. This is a step of determining the operation of the deflector 3. Further, the step S17 is performed by the control means 17 so that the dynamic action of the mixing rotary blades 2a, 2b and / or the deflector 3 on the powder 5 during the surface treatment is reduced by the control means 17. 3 is a step of determining the operation of 3.

  The mixing rotary blades 2a and 2b give mechanical energy (mechanical action) to the powder 5 by rotating. The higher the rotational speed of the mixing rotary blades 2a and 2b, the more mechanical the powder 5 has. Give energy. Therefore, as a specific method for increasing the degree of mechanical action of the mixing rotary blades 2a and 2b on the powder 5, it is conceivable to increase the rotational speed of the mixing rotary blades of the mixing rotary blades 2a and 2b. On the other hand, as a specific method for reducing the degree of mechanical action of the mixing rotary blades 2a and 2b on the powder 5, it is conceivable to reduce the rotational speed of the mixing rotary blades of the mixing rotary blades 2a and 2b. Thus, when adjusting the degree of the mechanical action given to the powder 5 with the rotational speed of the mixing rotary blades 2a and 2b, the rotational speed of the mixing rotary blades 2a and 2b is monitored, and the mixing rotary blade 2a is monitored by an inverter or the like. It is preferable to accurately control the rotational speed of 2b.

  Further, as a specific method for increasing the degree of mechanical action of the deflector 3 on the powder 5, the deflector 3 is nearly perpendicular to the wall surface of the container 1 as shown in FIG. It is conceivable to install at an angle (close to the wall of the container 1). The closer the powder 5 mixed in the container 1 is to the wall surface of the container 1, the higher the density and the faster the movement speed. Therefore, when the deflector 3 is moved closer to the wall surface of the container 1, the powder 5 and the deflector 3 are moved. The impact caused by the collision is increased. On the other hand, as a specific method for reducing the degree of mechanical action of the deflector 3 on the powder 5, the deflector 3 is rotated in the direction of the arrow x shown in FIG. It can be considered to install at an angle close to parallel to the wall surface. The deflector 3 may be fixed by manually adjusting the installation angle, but may be provided with a drive control mechanism (not shown) so that the installation angle can be automatically changed.

  In this way, the temperature of the powder 5 during the surface treatment is sequentially controlled so as to follow a desired time-temperature curve, and the temperature of the powder 5 reaches a predetermined temperature, or the time for which the surface treatment is performed reaches the time. Then, it is determined that the condition for finishing the surface treatment is satisfied (step S15 YES), and the surface treatment of the powder 5 is finished.

  In performing the surface treatment of the powder 5 by the powder surface treatment apparatus 10, it is preferable to keep the temperature of the entire container 1 constant. This is because the reproducibility of the surface treatment is improved by performing the surface treatment of the powder 5 while keeping the temperature of the entire container 1 constant. As a method of keeping the temperature of the entire container 1 constant, a heat medium whose temperature is adjusted is caused to flow through a jacket (not shown) provided so as to be in contact with the outer peripheral surface of the container 1 and through which a fluid can flow. It is possible. For example, when it is desired to warm, the temperature-adjusted hot water is flown, and when it is desired to perform the treatment for a long time while cooling as much as possible, the temperature-adjusted cooling water is flowed. Hereinafter, the case where the surface treatment of the powder 5 is performed while cooling the container 1 with the temperature-controlled cooling water will be further described. In the case where the heat generation of the powder 5 is not so intense, and the powder 5 is quickly heated to a high temperature and the surface treatment is to be performed quickly, the temperature-adjusted warm water may be supplied.

  FIG. 5 (a) shows a time-temperature curve assumed when the surface treatment of the powder 5 is performed by the method shown in FIG. In FIG. 5A, the curve indicated by the solid line is the “desired time-temperature curve”, and the curve indicated by the plot indicates the temperature of the powder 5 during the surface treatment. The desired time-temperature curve rises from 33 ° C. FIG. 5A shows a case where the surface treatment is started when the temperature of the powder 5 is 30.degree.

  Immediately after the start of the surface treatment, since the temperature of the powder 5 is lower than the temperature on the desired time-temperature curve at the same time as the measurement result, it is necessary to give a larger mechanical action to the powder 5. Therefore, if the rotational speed of the mixing rotary blades 2a and 2b is adjusted, the mixed rotary blades 2a and 2b are rotated at a higher speed. If the installation angle of the deflector 3 is adjusted, the installation angle of the deflector 3 is adjusted so as to be closer to a right angle with respect to the inner wall of the container 1. In this way, the mixing rotary blades 2a, 2b and / or the deflector 3 are operated to perform the surface treatment of the powder 5.

  By this operation, the temperature of the powder 5 rises more steeply than the desired time-temperature curve, and the temperature of the powder 5 becomes higher than the temperature on the desired time-temperature curve around 25 seconds after the surface treatment is started. Therefore, it is necessary to reduce the degree of mechanical action given to the powder 5 next. Specifically, if the rotational speed of the mixing rotary blades 2a and 2b is adjusted, the mixing rotary blades 2a and 2b are rotated at a lower speed. If the installation angle of the deflector 3 is adjusted, the installation angle of the deflector 3 is adjusted so as to be an angle closer to parallel to the wall surface of the container 1. By operating the mixing rotary blades 2a, 2b and / or the deflector 3 in this way, the temperature increase angle of the powder 5 begins to decrease little by little, and the temperature of the powder 5 starts around 50 seconds after the surface treatment is started. The decline has begun. This is because the cooling water cooled well flows through the jacket of the container 1, and the heat absorption from the inner wall of the jacket exceeds the temperature rise of the powder 5 due to the mechanical action given to the powder 5 being converted into thermal energy. Assuming that Actually, the contact area and the contact opportunity between the powder 5 and the wall surface of the container 1 are small, and it is considered that the temperature rise angle of the powder 5 is small.

  Around 70 seconds after the start of the surface treatment, the temperature of the powder 5 is now lower than the desired time-temperature curve, and as described above, the mixing rotary blade is applied so as to give a larger mechanical action to the powder 5. 2a, 2b and / or the deflector 3 are operated. In this manner, the surface treatment is finished 300 seconds after starting the surface treatment while going up and down the desired time-temperature curve. According to such a method, although it is slightly above and below the desired time-temperature curve, the desired mechanical action is applied to the powder 5 in each temperature range as viewed throughout the surface treatment process.

  Next, a method for producing the surface-treated powder of the present invention shown in FIG. 4 will be described. The manufacturing method of the surface-treated powder of the present invention shown in FIG. 4 is the same as the method shown in FIG. 3 except for step S22, step S23, and step S24. Therefore, the description of the steps already described is omitted. To do.

  Step S22 is a step of measuring the slope Ir of the change in the measurement result of the temperature of the powder 5 by the temperature measuring means 4. As a method of obtaining the slope Ir of the change in the measurement result by the temperature measurement means 4, it may be determined from the current measurement result and the measurement result at the previous measurement, but the temperature measurement by the temperature measurement means 4 includes an error. Therefore, it is preferable to measure the temperature of the powder 5 at regular time intervals, and perform approximation using the measurement data of the three most recent points including the present time to obtain the slope Ir. In approximation, the latest value may be emphasized, and the weighting of values far from the present time may be reduced.

  Step S23 is a step of determining whether the slope Ir of the change in the measurement result obtained by the temperature measuring means 4 obtained in Step S22 is smaller than the slope Ii of the desired time-temperature curve at the same temperature as the current measurement result. If Ii> Ir, the process proceeds to step S16. If it is determined in step S23 that Ii> Ir is not satisfied, the process proceeds to step S24. In step S23, Ii may have a predetermined width without strictly setting a desired temperature curve. That is, when the slope of the desired time-temperature curve at the same time as the measurement of the slope Ir obtained in step S22 is strictly Ii ′, about Ii ′ ± Ii ′ × 5% is set as Ii in step S23. You can also

  Step S24 is a step of determining whether the slope Ir of the change in the measurement result obtained by the temperature measuring means 4 obtained in Step S22 is larger than the slope Ii of the desired time-temperature curve at the same temperature as the current measurement result. If Ii <Ir, the process proceeds to step S17. If it is determined in step S24 that Ii> Ir is not satisfied, the process proceeds to step S15. In step S24, like step S23, Ii may be given a predetermined width without strictly setting the desired temperature curve. That is, when the slope of the desired time-temperature curve at the same time as the measurement of the slope Ir obtained in step S22 is strictly Ii ′, about Ii ′ ± Ii ′ × 5% is set as Ii in step S24. You can also

  In this way, the temperature of the powder 5 during the surface treatment is sequentially controlled so as to follow a desired time-temperature curve, and the temperature of the powder 5 reaches a predetermined temperature or the time when the surface treatment is performed is a predetermined time. If it is reached, it is determined that the condition for finishing the surface treatment is satisfied (YES in step S15), and the surface treatment of the powder 5 is finished.

  FIG. 5B shows a time-temperature curve assumed when the surface treatment of the powder 5 is performed by the method shown in FIG. In FIG. 5B, the curve indicated by the solid line is the “desired time-temperature curve”, and the curve indicated by the plot indicates the temperature of the powder 5 during the surface treatment. At the start of the surface treatment, the temperature of the powder 5 is lower than the start temperature of the desired time temperature curve, so the surface treatment is performed at a predetermined rotational speed of the mixing rotary blades 2a, 2b and an average installation angle of the deflector 3. Start. Of course, a desired time-temperature curve subtracted from a lower temperature may be set and the control described later may be performed.

  10 seconds after the surface treatment is started, the temperature of the powder 5 reaches 33 ° C., and further several seconds later, the control means 17 calculates the temperature gradient of the powder 5 (° C./second), It is judged that the gradient is smaller than (0 seconds, 33 ° C.) and (4 seconds, 35.5 ° C.) of the time-temperature curve, and the rotational speed of the mixing rotary blades 2a, 2b is increased, or the deflector 3 is brought closer to the wall surface. Make operational decisions.

  In the case of FIG. 5 (b), the calculation by the control means 17 is continued thereafter, but the slope of the desired temperature curve cannot be caught up for a while and the surface treatment is started for 75 to 85 seconds. Around 30 ° C., after 30 seconds of the desired time-temperature curve, the slope around 42 ° C. has been caught up. Thereafter, the desired time-temperature curve is adjusted while adjusting the rotational speed of the mixing rotary blades 2a, 2b and the installation angle of the deflector 3 while comparing with the gradient of the desired time-temperature curve about 50 seconds ago. A similar history is drawn with a delay of about 50 seconds from the start of the surface treatment, and after 350 seconds from the start of the surface treatment, a predetermined temperature is reached and the surface treatment is terminated.

  FIG. 5B shows that the curve after 80 seconds from the start of the surface treatment is slightly different from the desired time-temperature curve, but thereafter the temperature change of the powder 5 is the desired time-temperature curve. This is an example that matches well. For example, when the powder 5 contains a thermoplastic component, the surface becomes softer as the temperature increases, and the process proceeds more easily, it is more important that the temperature of the powder 5 follows a desired time-temperature curve in a high temperature range. . The temperature measured by the temperature measuring means 4 such as a thermocouple is different from the instantaneous temperature at the location where the powder 5 collides when viewed microscopically, which is higher than estimated by the temperature measured by the temperature measuring means 4. The surface treatment of the powder 5 containing a plastic component may easily proceed. According to the present invention, since the temperature of the powder 5 can follow the desired time-temperature curve in the high temperature region as described above, even if the powder 5 to be surface-treated contains a thermoplastic substance. The desired surface treatment can be performed on the powder 5 with good reproducibility.

  The method shown in FIG. 3 has an advantage that the control program is relatively simple. On the other hand, in the method shown in FIG. 4, although the control program is complicated, the temperature of the powder during the surface treatment can be made to follow the desired time-temperature curve with higher accuracy. For example, when the actual temperature of the powder changes lower than the desired time-temperature curve, in the case of the method shown in FIG. 3, a large mechanical action is given to the powder so as to approach the desired temperature. Thus, the gradient of the temperature rise until the desired temperature is reached becomes steep. That is, the mechanical action applied to the powder while passing through the temperature region is larger than when the temperature of the powder to be surface-treated follows a desired time-temperature curve. On the other hand, in the case of the method shown in FIG. 4, since the degree of mechanical action given to the powder is determined based on the temperature at the time of temperature measurement and the inclination thereof, when viewed through the entire surface treatment process, In each temperature range, a mechanical action close to a desired mechanical action (mechanical action necessary for the temperature of the powder to follow a desired time-temperature curve) was given to the powder. When the surface-treated powder contains a thermoplastic material, the hardness of the powder changes depending on the temperature. Therefore, the mechanical action applied to the powder in each temperature range can be made closer to the desired mechanical action. Of particular importance.

  Of course, it is also possible to perform control such that the control is intermediate between both the method shown in FIG. 3 and the method shown in FIG. For example, due to lot differences in raw material powders and individual differences in powder surface treatment equipment, at the time of starting the powder surface, just a good mechanical action to make the temperature of the powder during surface treatment follow the desired time-temperature curve. The degree of may deviate from expectations. In such a case, the surface treatment is first started while controlling by the method shown in FIG. 4, and when the gradient of the change in the measured value by the temperature measuring means approaches the gradient of the desired time-temperature curve, it is shown in FIG. There is also a method of controlling by switching to another method. In this case, if the actual surface treatment start time is advanced or delayed with respect to the time axis of the desired time-temperature curve, the actual surface treatment time is shifted and read, and the method shown in FIG. 3 is executed. good.

  Further, in order to avoid the application of excessive mechanical action or to operate within the capability range of the powder surface treatment apparatus, the rotational speed of the mixing rotary blade, the upper and lower limits of the angle of the deflector, etc. may be set.

  Note that performing surface treatment with a small mechanical action over time is not the same as performing a surface treatment with a large mechanical action in a short time. At the moment when the powder collides, thermal energy is generated by plastic deformation or the like, and in the micro region, the temperature rises rapidly and diffuses to the whole temperature. The surface treatment of the powder proceeds while the temperature is rapidly rising in a microscopic region. The small mechanical action reduces the temperature rise in the micro area, so the degree of mechanical action applied to the powder is the same as when the surface treatment is performed in a short time with the large mechanical action. Even if it is, the finish of the surface treatment of the actual powder will be different.

  For example, when two or more types of processing particles having a relatively small particle size are fixed to the mother particles having a relatively large particle size, each particle has a different particle size, shape, and true specific gravity. When it is desired to control the degree of fixation (embedding depth) of each of the two types of treated particles to the mother particle and the ratio between the fixed treated particles and the treated particles that are still in the free state, if the number of particle types increases, it will collide when viewed microscopically. Since the number of combinations to be increased increases, the actual processing progress becomes complicated, and if the temperature history is different, it is difficult to say that the same processing can be performed. According to the present invention, since the temperature of the powder during the surface treatment follows the desired time-temperature curve, the surface-treated powder is composed of three or more kinds of powder as described above. However, the desired surface treatment can be performed on the powder with good reproducibility.

  In some cases, the surface treatment is performed in a plurality of stages. In some cases, the processing is performed with the base particles and the first type of processing particles, the processing proceeds to some extent, and when the temperature of the powder rises to some extent, the second type of processing particles are added and further surface treatment is performed. Even in such a case, the present invention is effective in order to implement a precise surface treatment with good reproducibility.

  Again, the idea of the present invention is that the degree of mechanical action given to the powder to be surface treated is roughly proportional to the temperature rise gradient (° C./sec) of the powder during the surface treatment. By adjusting the degree of mechanical action applied to the powder in each temperature range, and ensuring that the temperature of the powder during the surface treatment follows the desired temperature curve, a constant surface treatment is always possible with good reproducibility. There is to do.

  The powder surface treatment apparatus 10 having the configuration shown in FIG. 1 described so far is a so-called rotary mixer type powder surface treatment apparatus. As a powder surface treatment apparatus of such a form, it is the same as FM mixer manufactured by Nippon Coke Kogyo Co., Ltd. Device) and mechano-hybrid. By providing these with the above control means, etc., the powder surface treatment apparatus of the present invention can be obtained.

  In addition, the powder surface treatment apparatus of this invention is not limited to this form. The powder surface treatment of the present invention can also be achieved by providing the above-mentioned control means in a powder surface treatment apparatus such as AMS and a hybrid system (NHS) produced by Nara Machinery Co., Ltd., manufactured by Hosokawa Micron. It can be a device.

  For example, the mechano-fusion (powder surface treatment apparatus) 20 shown in FIG. 6 includes a container 21 that rotates by power from a motor (not shown), an inner piece 22 and a scraper 23 that are fixed in position. . In the powder surface treatment apparatus 20, the powder 5 is subjected to a mechanical action such as compression, shearing, and friction between the inner piece 22 and the inner piece 22 between the container 21 rotating in the direction of arrow Y with respect to the inner piece 22 and the scraper 23. . At this time, the powder 5 compacted between the container 21 and the inner piece 22 is scraped off from the inner wall of the container 21 by the scraper 23 and pressed against the wall surface of the container 21 by the centrifugal force generated by the rotation of the container 21. A mechanical action is received between 21 and the inner piece 22. In this way, the powder 5 is subjected to a mechanical action and subjected to a surface treatment. If the powder surface treatment apparatus is a type of powder surface treatment apparatus that uses a mechanical action to which the powder 5 is applied when the powder 5 passes through a predetermined gap i, such as the powder surface treatment apparatus 20, the inner piece 22 is used. Is the mechanical action imparting means, the position of the inner piece 22 is determined by the control means, and the width of the gap i is increased or decreased to adjust the degree of the mechanical action applied to the powder 5 and the powder during the surface treatment. The temperature of the body 5 can be made to follow a desired time temperature curve.

  In a powder surface treatment apparatus of a type that blows out powder from a nozzle or the like and uses energy generated by collision between the powders or collision of the powder with a collision plate, the nozzle and the collision plate for blowing out the powder are mechanical By applying the control means, the pressure applied to the powder blown out from the nozzle, the installation position of the collision plate, etc. are determined, and the degree of the mechanical action applied to the powder is adjusted and surface treatment is in progress. The temperature of the powder can be made to follow the desired temperature curve.

  Although the present invention has been described with reference to embodiments that are presently considered to be practical and preferred, the present invention is not limited to the embodiments disclosed herein, The present invention can be changed as appropriate without departing from the gist or concept of the invention that can be read from the entire specification, and a powder surface treatment apparatus and a method for producing the surface-treated powder accompanying such changes are also included in the technical scope of the present invention. Must be understood as being.

1 container 2 shaft 2a mixing rotary blade (mechanical action imparting means)
2b Mixing rotary blade (Mechanical action imparting means)
3 Deflector (Mechanical action imparting means)
4 Thermocouple (temperature measurement means)
5 Powder 10 Powder surface treatment device 11 CPU
12 ROM
13 RAM
14 input port 15 output port 16 output means 17 control means 20 mechanofusion (powder surface treatment apparatus)
21 Container 22 Inner piece 23 Scraper

Claims (10)

A powder surface treatment apparatus for performing surface treatment of powder,
A container containing the powder;
One or a plurality of mechanical action imparting means for imparting a mechanical action to the powder in the container;
Temperature measuring means for measuring the temperature of the powder;
The degree of mechanical action applied to the powder by at least one of the one or more mechanical action applying means is adjusted so that the transition of the measurement result by the temperature measuring means approaches a desired time-temperature curve. Control means;
With
The control means is
When the slope of the change in the measurement result by the temperature measurement means is smaller than the slope of the desired time temperature curve at the same temperature as the current measurement result, the mechanical action imparted to the powder by the mechanical action imparting means Determine the operation of the mechanical action imparting means to increase the degree,
When the slope of the change in the measurement result by the temperature measurement means is larger than the slope of the desired time temperature curve at the same temperature as the current measurement result, the mechanical action given to the powder by the mechanical action imparting means A powder surface treatment apparatus which is means for determining the operation of the mechanical action imparting means so as to reduce the degree. The one or more mechanical action applying means includes means for applying at least mechanical energy to the powder, and the control means adjusts the degree of mechanical action applied to the powder by the mechanical energy applying means. The powder surface treatment apparatus according to claim 1 . The one or more mechanical action imparting means includes means for applying at least an impact to the powder, and the control means adjusts the degree of the mechanical action applied to the powder by the impact applying means. The powder surface treatment apparatus according to 1 or 2 . The powder surface treatment apparatus according to any one of claims 1 to 3 , wherein the powder includes mother particles having a relatively large particle size and two or more kinds of processing particles having a relatively small particle size. . The powder surface treatment apparatus according to claim 4 , wherein the mother particles having a relatively large particle diameter include a thermoplastic substance. A method for producing a surface-treated powder for producing a surface-treated powder,
Containing the powder in a container;
In the container, the step of imparting a mechanical action to the powder by one or more mechanical action imparting means;
Measuring the temperature of the powder by means of temperature measuring means;
The control means causes the mechanical action applied to the powder by at least one of the one or more mechanical action imparting means so that the transition of the measurement result by the temperature measuring means approaches a desired time-temperature curve. Adjusting the degree,
Including
By the control means,
When the slope of the change in the measurement result by the temperature measuring means is smaller than the slope of the desired time-temperature curve at the same temperature as the current measurement result, the mechanical action imparting means gives the mechanical action to the powder. Determine the operation of the mechanical action imparting means to increase the degree,
When the slope of the change in the measurement result by the temperature measurement means is larger than the slope of the desired time temperature curve at the same temperature as the current measurement result, the mechanical action imparting means gives the mechanical action to the powder. A method for producing a surface-treated powder, comprising a step of determining an operation of the mechanical action imparting means so as to reduce the degree. The one or more mechanical action applying means includes means for applying at least mechanical energy to the powder, and the control means determines the degree of the mechanical action given to the powder by the mechanical energy applying means. The manufacturing method of the surface treatment powder of Claim 6 including the process to adjust. The one or more mechanical action applying means includes means for applying an impact to the powder, and the control means adjusts the degree of the mechanical action applied to the powder by the impact applying means; The manufacturing method of the surface treatment powder of Claim 6 or 7 containing. The surface-treated powder according to any one of claims 6 to 8 , wherein the powder includes mother particles having a relatively large particle size and two or more kinds of treated particles having a relatively small particle size. Production method. The method for producing a surface-treated powder according to claim 9 , wherein the mother particle having a relatively large particle size contains a thermoplastic substance.

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