JP2014167402A - Method for evaluating sedimentation state and sedimentation state evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for evaluating a sedimentation state, capable of evaluating the sedimentation state inexpensively and with a high precision even if a solid dispersion is sedimented where the specific gravity difference between solid particles and a solvent is small.SOLUTION: In an evaluation device 1, a sedimentation state of solid particles is evaluated on the basis of secular change of the measurement result of viscosity of a specific part. In this case, a solid dispersion which is a measuring object is measured while it is retained to be in a resting state. Even if the solid dispersion is sedimented where the specific gravity difference between the solid particles and a solvent is small, a small viscosity change thereof can be measured and the evaluation accuracy becomes high by performing an accurate viscosity measurement which is not influenced by a flow in the solid dispersion in the above-described manner. As the sedimentation state can be accurately evaluated, it is not necessary to adopt a sedimentation forming method for preparing a constant amount of solid dispersion as a centrifugal separation method or an acceleration test, and even when sedimentation evaluation of an expensive solid dispersion is performed, the cost thereof can be minimized.

Description

  The present invention relates to a method for evaluating the sedimentation state of a substance in which solid particles are dispersed in a liquid, and an apparatus therefor.

  When solid particles dispersed in a substance in which solid particles are dispersed in a liquid (hereinafter referred to as “solid dispersion”) have a specific gravity greater than that of the liquid (solvent), the passage of time in a stationary state As the solid particles settle in the liquid, the local dispersion density of the solid particles in the solid dispersion also changes with time.

  Conventionally, as a method for evaluating the sedimentation state of a solid dispersion, solid particle sedimentation is formed in the solid dispersion by a centrifugal method or an acceleration test, and the local dispersion characteristics (viscosity of the solid dispersion before and after the sedimentation are formed). A method for evaluating the sedimentation state based on concentration, etc.) is known.

  For example, in Patent Document 1, the ink containing the pigment in a dispersed state is centrifuged, and the ink concentration before centrifugation and the ink concentration of the supernatant liquid after centrifugation are measured to evaluate the sedimentation state of the ink. doing. Further, in Patent Document 2, an ink containing a pigment in a dispersed state is allowed to stand at room temperature for one month, and then the sedimentation state of the pigment after the ink is left is evaluated.

JP 2006-270431 A JP 2008-308692 A

  However, for solid dispersions in which the specific gravity difference between the solid particles and the solvent is small, the degree of sedimentation formed is not limited even when subjected to centrifugation (or standing for a long time) in an accelerated test. It is small and the sedimentation state cannot be fully evaluated. For this reason, there is a need for a method capable of evaluating the sedimentation state with high accuracy even for a dispersion having a small specific gravity difference.

  In general, the local dispersion density of solid particles (an index indicating the state of sedimentation) correlates with the viscosity at that site, and the greater the local dispersion density of solid particles, the greater the viscosity at that site. It has been known. For this reason, in addition to the sedimentation state evaluation method used in Patent Documents 1 and 2 described above, it is possible to evaluate the sedimentation state of solid particles by knowing the temporal change in the viscosity of the solid dispersion.

  However, when measuring the viscosity of a solid dispersion using a viscometer having a macro movable part such as a vibration type viscometer or a cone plate viscometer, the viscosity of the solid dispersion in a state where a dynamic flow has occurred is measured. Since it will be measured, a sedimentation state (stationary state) cannot be evaluated with high accuracy.

  In addition, in sedimentation evaluation methods using centrifugation and accelerated tests, it is necessary to prepare a certain amount of solid dispersion in a beaker or sample container, so these methods are applied to expensive solid dispersions (for example, drugs). Applying it leads to increased costs.

  The present invention has been made in view of the above problems, and the sedimentation state evaluation method and evaluation are capable of evaluating the sedimentation state at low cost and high accuracy even with a solid dispersion having a small specific gravity difference between the solid particles and the solvent. An object is to provide an apparatus.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a method for evaluating a sedimentation state of a solid dispersion as a substance in which solid particles are dispersed in a liquid, the solid held by a holding body. For the dispersion, based on the measurement step of measuring the viscosity at a specific site in the solid dispersion over time in a stationary state to obtain viscosity data at a plurality of time points, and the viscosity data at the plurality of time points Based on the change tendency specifying step for obtaining change tendency data for specifying the change tendency of the viscosity data over time, and the change tendency data and a predetermined evaluation criterion, the settling state of the solid particles in the solid dispersion And an evaluation step for evaluating.

  Invention of Claim 2 is a sedimentation state evaluation method of Claim 1, Comprising: It has further the stirring process of stirring the said solid dispersion prior to the said viscosity measurement process, It is characterized by the above-mentioned.

  The invention according to claim 3 is the sedimentation state evaluation method according to claim 1 or 2, wherein the solid dispersion is an ink jet ink in which solid particles of pigment are dispersed. And

  Invention of Claim 4 is a sedimentation state evaluation method in any one of Claim 1 thru | or 3, Comprising: The said at least 1 specific site | part is the said fixed dispersion | distribution in the state hold | maintained by the said holding body. It is set near the upper surface of the body.

  Invention of Claim 5 is the sedimentation state evaluation method in any one of Claim 1 thru | or 3, Comprising: The said at least 1 specific site | part is the said fixed dispersion | distribution in the state hold | maintained by the said holding body. It is set near the lower surface of the body.

  A sixth aspect of the present invention is the sedimentation state evaluation method according to any one of the first to third aspects, wherein a plurality of portions are set as the at least one specific portion, and the plurality of portions are retained. The first region set in the upper region as the height range of the upper half and the lower region as the height range of the lower half of the vertical height range occupied by the fixed dispersion in the state held by the body A second portion set in the interior, and in the evaluation step, the sedimentation state is evaluated based on the temporal change tendency of both the first portion and the second portion. To do.

  A seventh aspect of the present invention is the sedimentation state evaluation method according to any one of the first to sixth aspects, wherein the measuring step holds the detection unit of the viscosity sensor using surface acoustic waves with the holding body. Viscosity is measured by contacting the solid dispersion.

  The invention according to claim 8 is an apparatus for evaluating a sedimentation state of a solid dispersion as a substance in which solid particles are dispersed in a liquid, the holding body holding the solid dispersion, and the holding body. A viscosity sensor for measuring the viscosity of at least one specific site in the solid dispersion over time in a stationary state to generate viscosity data at a plurality of time points, and the plurality of time points Based on the viscosity data, change tendency specifying means for obtaining change tendency data for specifying the change tendency of the viscosity data with time, and information obtained from the change tendency data as an index for evaluating the sedimentation state of the solid particles Display means for displaying.

  Invention of Claim 9 is a sedimentation state evaluation apparatus of Claim 8, Comprising: Based on the said change tendency data and predetermined | prescribed evaluation reference | standard data, the sedimentation state of the said solid particle in the said solid dispersion A sedimentation state evaluating means for generating evaluation data for evaluating the evaluation data, wherein the display means displays the evaluation data.

  A tenth aspect of the present invention is the sedimentation state evaluating apparatus according to the ninth aspect, further comprising stirring means for stirring the solid dispersion held by the holding body.

  An eleventh aspect of the present invention is the sedimentation state evaluation apparatus according to any one of the eighth to tenth aspects, wherein the solid dispersion is an ink jet ink in which solid particles of pigment are dispersed. It is characterized by that.

  The invention according to claim 12 is the sedimentation state evaluation apparatus according to any one of claims 8 to 11, wherein the at least one specific part is the fixed dispersion in a state of being held by the holding body. It is set near the upper surface of the body.

  A thirteenth aspect of the present invention is the sedimentation state evaluation apparatus according to any one of the eighth to eleventh aspects, wherein the at least one specific portion is held in the state of being held by the holding body. It is set near the lower surface of the body.

  The invention according to claim 14 is the sedimentation state evaluation apparatus according to any one of claims 8 to 11, wherein a plurality of parts are set as the at least one specific part, and the plurality of parts are held in the holding state. The first region set in the upper region as the height range of the upper half and the lower region as the height range of the lower half of the vertical height range occupied by the fixed dispersion in the state held by the body The sedimentation state evaluation means evaluates the sedimentation state based on the temporal change tendency of both the first region and the second region. Features.

  A fifteenth aspect of the present invention is the sedimentation state evaluation apparatus according to any one of the eighth to fourteenth aspects, wherein the viscosity sensor is a viscosity sensor using a surface acoustic wave, and a detection unit of the viscosity sensor. In contact with the solid dispersion held by the holding body to measure the viscosity.

  When the specific gravity of the solid particles dispersed in the stationary solid dispersion is larger than the specific gravity of the liquid, the solid particles settle in the liquid over time, so that the local dispersion of the solid particles in the solid dispersion is performed. The density also changes over time. On the other hand, the local dispersion density of solid particles correlates with the viscosity at that site, and the greater the local dispersion density of solid particles, the greater the viscosity at that site. Therefore, the sedimentation state of the solid particles can be known by knowing the temporal change in viscosity.

  The inventions according to claims 1 to 15 use the above principle to evaluate the sedimentation state of solid particles based on the temporal change of the local viscosity measurement result. The viscosity is measured while the solid dispersion is kept stationary. In this way, the local viscosity measurement in a solid dispersion in a stationary state is precise because it is not affected by the flow, unlike the viscosity measurement in a solid dispersion in a state where dynamic flow occurs. . As a result, according to the present invention, the sedimentation state of the solid dispersion can be precisely evaluated.

  And since the sedimentation of the slight solid particle in a natural state can be evaluated in this way, it is not necessary to form a sedimentation state by a centrifugal separation method or an acceleration test. Therefore, there is no need to prepare a certain amount of solid dispersion in a beaker or a sample container as in the case of a centrifugal separation method or an accelerated test, and the required minimum sample amount is a few drops of a solid dispersion, and an expensive solid dispersion (for example, The cost can be kept to a minimum even when the sedimentation evaluation is performed.

  In particular, in the invention according to claim 2 or claim 10, the solid dispersion is stirred prior to the viscosity measurement. For this reason, it is possible to form a state in which the solid particles are dispersed almost uniformly in the solid dispersion at the start of viscosity measurement. The sedimentation curve of the solid particles in the solid dispersion is an exponential function with respect to time because it is one of the thermodynamic transient curves, and the density change per unit time becomes smaller as the sedimentation progresses. Therefore, by stirring before starting the viscosity measurement, a time region in which the density change per unit time becomes the largest can be used for the viscosity measurement, and the accuracy of evaluating the sedimentation state becomes particularly high.

  Even when the sedimentation state evaluation of the present invention is applied to a plurality of solid dispersions having different dispersion states, the dispersion state for each solid dispersion at the start of viscosity measurement, that is, in the initial state, is the same condition. The stability of sedimentation state evaluation can be improved.

  In the invention according to claim 4 or claim 12, a specific site for viscosity measurement is set near the upper surface of the fixed dispersion in a state of being held by the holding body. In the vicinity of the upper surface of the fixed dispersion, the time drop of the viscosity due to the sedimentation of the solid particles is the largest, so that the accuracy of the sedimentation state evaluation is increased.

  In the invention according to claim 5 or claim 13, a specific part for viscosity measurement is set in the vicinity of the lower surface of the fixed dispersion in a state of being held by the holding body. In the vicinity of the lower surface of the fixed dispersion, the increase in viscosity with time due to sedimentation of the solid particles is the largest, so that the accuracy of the sedimentation state evaluation is improved.

  In the invention according to claim 6 or claim 14, the first set in the upper region as the upper half height range of the upper and lower height ranges occupied by the fixed dispersion in the state of being held by the holding body. The sedimentation state is evaluated based on the tendency of the viscosity to change with time for both the part and the second part set in the lower region as the height range of the lower half.

  In the upper region, the viscosity decreases as the solid particles settle, and in the lower region, the viscosity increases as the solid particles settle. Compared to the case where the sedimentation state is evaluated based on the measurement result of only one region by evaluating the sedimentation state of the solid particles by using the viscosity measurement results at a plurality of parts having a reverse sign change tendency. The reliability of evaluation increases.

It is a side view which shows roughly the structure of the evaluation apparatus 1 concerning 1st Embodiment. It is a functional block diagram which shows the structure of 4 A of measurement parts concerning 1st Embodiment. It is a functional block diagram which shows the structure of the measurement part 4B concerning 1st Embodiment. It is a block diagram which shows the electric constitution of the control part 6 concerning 1st Embodiment. It is a flowchart which shows the operation | movement of sedimentation state evaluation concerning 1st Embodiment. In the evaluation apparatus 1 concerning 1st Embodiment, it is the figure which plotted the viscosity-elapsed time at the time of measuring a viscosity of white ink with time. As a comparative example of white ink, it is a graph plotting viscosity-elapsed time when the viscosity of magenta ink is measured over time. As a comparative example of white ink, it is a graph plotting viscosity-elapsed time when viscosity of cyan ink is measured over time. It is a side view which shows roughly the structure of 1 A of evaluation apparatuses concerning 2nd Embodiment. It is a functional block diagram which shows the structure of the viscosity sensor 4 of 1 A of evaluation apparatuses concerning 2nd Embodiment. It is a block diagram which shows the electric constitution of 6 A of control parts concerning 2nd Embodiment. It is a flowchart which shows the operation | movement of sedimentation state evaluation concerning 2nd Embodiment. It is a schematic side view of evaluation apparatus 1A in the operation process of sedimentation state evaluation concerning 2nd Embodiment. It is a side view which shows roughly the structure of the evaluation apparatus 1B concerning the modification of 1st Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<1 First Embodiment>
<1.1 Configuration of Evaluation Apparatus 1 of First Embodiment>
FIG. 1 is a side view schematically showing a configuration example of the sedimentation state evaluation apparatus of the first embodiment. Moreover, in FIG. 1 and each subsequent figure, the dimension and number of each part are exaggerated or simplified as needed for the purpose of easy understanding. Moreover, the arrow Z in the figure indicates upward in the vertical direction.

  As shown in FIG. 1, the evaluation device 1 of the first embodiment generally includes a measurement unit 4A that measures the viscosity of a solid dispersion to be subjected to sedimentation evaluation in a stationary state with respect to the upper surface portion thereof, and sedimentation evaluation. A measuring unit 4B that measures the viscosity of the target solid dispersion in a stationary state with respect to the lower surface portion thereof, and a control unit that controls the measuring units 4A and 4B and evaluates the sedimentation state of the solid dispersion based on the measurement results 6 and a sedimentation state evaluation apparatus including display means 7 for displaying an output result (evaluation result) in the control unit 6.

  The evaluation apparatus 1 can employ various solid dispersions (typically suspensions) such as paints, color resists for liquid crystals, and inkjet inks as solid dispersions to be evaluated. . In the present embodiment, a white ink for ink jet in which solid particles of a white pigment are dispersed in a liquid serving as a solvent. More specifically, the pigment is 20 wt%, the dispersant is 1 wt%, the photocurable resin is 73 wt%, A case will be described in which a white ink WI containing 6 wt% of a photopolymerization initiator and 0.1 wt% of an additive is used as a solid dispersion to be evaluated.

  Further, as the viscosity sensor 4 (upper viscosity sensor 43, lower viscosity sensor 41) used in the measurement units 4A and 4B, for example, a ViSmart sensor manufactured by Vectron (ViSmart is a registered trademark) can be used.

  Hereinafter, the structure of each part of the evaluation apparatus 1 will be described in detail.

<Measurement unit 4A>
First, the measurement unit 4A will be described.

  The measurement unit 4A has a holding body 2A that holds a solid dispersion (a white ink WI in the present embodiment) to be subjected to sedimentation evaluation, and the viscosity near the upper surface of the white ink WI held by the holding body 2A in a stationary state. It is comprised by the viscosity sensor 4 (upper viscosity sensor 43) to measure.

  In this embodiment, the holding body 2A is constituted by a container that opens to the top, and the white ink WI is stored therein.

  The upper viscosity sensor 43 is inserted from the upper opening of the holding body 2A, and the detection unit 44 is provided in contact with the upper surface of the white ink WI held by the holding body 2A. For this reason, the viscosity of at least one specific portion (near the upper surface) of the white ink WI that is allowed to stand in the holding body 2A for a certain period of time is measured over time in a stationary state by the upper viscosity sensor 43 at a plurality of time points. Viscosity data can be generated.

  FIG. 2 is a block diagram illustrating a configuration related to the function of the measurement unit 4A. In the following description, the space in which the white ink WI ink is held by the holding body 2A (hereinafter referred to as “measurement space L1a”) is a vertical height range occupied by the white ink WI in the state stored in the measurement space L1a. With the virtual horizontal plane IPa defined as the center height as a boundary, the height range of the upper half is called “upper region L3a” and the height range of the lower half is called “lower region L2a” (FIG. 2).

  The upper viscosity sensor 43 has a configuration related to the detection unit 44. The transmitting unit 441 emits an acoustic wave toward the white ink WI stored in the measurement space L1a, and the above-described propagating through the white ink WI emitted from the transmitting unit 441. Receiving means 442 for receiving an acoustic wave. The upper viscosity sensor 43 further includes a measurement control unit 431 that controls the viscosity measurement by the detection unit 44 and a viscosity data generation unit 432 that generates viscosity data based on the detection result by the detection unit 44.

  The transmitting means 441 is an acoustic wave (hereinafter referred to as “surface acoustic wave”) in a horizontal direction (a direction along the contact surface between the upper viscosity sensor 43 and the white ink WI) with respect to a portion near the upper surface in the upper region L3a. ). On the other hand, the receiving unit 442 is a unit that is provided at a position spaced apart from the transmitting unit 441 in the horizontal direction and receives the acoustic wave emitted from the transmitting unit 441 and propagated in the white ink WI.

  The measurement control unit 431 is a unit that sets the characteristics (amplitude, frequency, etc.) of the surface acoustic wave emitted from the transmission unit 441 and the measurement period, and controls the viscosity measurement by the detection unit 44.

Viscosity data generation means 432 is configured to apply the white ink WI, which is a medium for propagation of surface acoustic waves, based on the characteristics of the surface acoustic waves emitted by transmission means 441 and the characteristics of surface acoustic waves received by reception means 442. It is a means for measuring the acoustic impedance (unit: (ω × η × ρ) ^1/2 ) at the measurement location to determine the acoustic viscosity (unit: AV) and generating viscosity data indicating the acoustic viscosity. Where ω is the frequency expressed in radians, ρ is the density of the medium, and η is the intrinsic viscosity of the medium. Here, since ω is a value that can be set by the measurement control means 431, η × ρ can be obtained by acquiring acoustic impedance (unit: (ω × η × ρ) ^1/2 ). Further, since the acoustic viscosity (unit is AV) can be converted by a conversion formula AV = η × ρ = cSt × ρ ² , the acoustic viscosity can be calculated by measuring the acoustic impedance. . CSt represents the kinematic viscosity of the medium.

  As described above, the part (specific part) that is the target of viscosity measurement by the upper viscosity sensor 43 is the section (hereinafter referred to as “upper measurement part L30” from the transmitting unit 441 to the receiving unit 442 near the upper surface in the upper region L3a. "). Since the upper measurement site L30 is the site where the temporal decrease in viscosity due to the precipitation of the white pigment (solid particles) is the largest in the white ink WI, the accuracy of sedimentation state evaluation is increased by using this site as the measurement target.

  Further, since the upper viscosity sensor 43 is a measuring device that measures the viscosity of the upper measurement site L30 by applying micro vibrations to the upper measurement site L30, the viscosity having a macro movable part such as a vibration viscometer or a cone plate viscometer. Unlike the case where the viscosity is measured using a meter, the viscosity can be measured for the upper measurement portion L30 of the white ink WI in a very static state. As a result, highly accurate viscosity measurement is possible. In the present invention, `` measured in a stationary state '' does not mean strictly measuring without any dynamic processing, as in the viscosity measurement using the surface acoustic wave in the present embodiment, It means “measurement in a very static state that does not substantially affect the viscosity of the object”.

  In summary, the upper viscosity sensor 43 acquires the viscosity (acoustic viscosity) of the white ink WI in the upper measurement site L30 at a plurality of time points during the measurement period in an extremely static state, thereby obtaining white at the plurality of time points. It is possible to generate highly accurate viscosity data (hereinafter referred to as “upper viscosity data”) for the viscosity change of the ink WI. Then, the upper viscosity data is sent to the control unit 6.

<Measurement unit 4B>
Next, the measurement unit 4B will be described. FIG. 3 is a block diagram showing a configuration relating to the function of the lower viscosity sensor 41.

  The measurement unit 4B is configured by the viscosity sensor 4 (lower viscosity sensor 41) in a state where the detection unit 42 (detection surface) faces upward, and contacts the detection unit 42 (detection surface) and is allowed to stand for a certain period. The viscosity in the vicinity of the lower surface of the white ink WI is measured by the lower viscosity sensor 41 at a plurality of time points during the stationary period, and the measurement result is transmitted to the control unit 6. Thus, in the measurement unit 4B, the upper surface of the lower viscosity sensor 41 functions as a holding body that holds the white ink WI.

  In the following description, corresponding to the terms in the measurement unit 4A, a state where the white ink WI ink is held in the lower viscosity sensor 41 (hereinafter referred to as “measurement space L1b”) is stored in the measurement space L1b. With the virtual horizontal plane IPb defined as the center height of the vertical height range occupied by the white ink WI as the boundary, the upper half height range is “upper region L3b” and the lower half height range is “lower region L2b”. Call it (Figure 3).

  The lower viscosity sensor 41 is installed upside down with the upper viscosity sensor 43, and the region (specific portion) to be measured by the detection unit 42 is a section from the transmitting unit 421 near the lower surface to the receiving unit 422 in the lower region L2b. The configuration is the same as that of the upper viscosity sensor 43 except for the point (hereinafter referred to as “lower measurement site L20”).

  That is, the lower viscosity sensor 41 includes a transmission unit 421, a reception unit 422, and a configuration corresponding to each of the transmission unit 441, the reception unit 442, the measurement control unit 431, and the viscosity data generation unit 432 in the upper viscosity sensor 43. A measurement control unit 411 and a viscosity data generation unit 412 are provided.

  The lower measurement site L20 is the site where the viscosity increase due to sedimentation of the white pigment (solid particles) is the largest in the white ink WI. Therefore, the accuracy of sedimentation state evaluation is enhanced by using this site as the measurement target.

  The lower viscosity sensor 41 is a measuring device that measures the viscosity of the part by applying micro vibrations (surface acoustic waves) to the measurement part, like the upper viscosity sensor 43. The viscosity can be measured for the lower measurement portion L20 of the white ink WI. As a result, highly accurate viscosity data (hereinafter referred to as “lower viscosity data”) at a plurality of time points during the measurement period can be generated. Then, the lower viscosity data is sent to the control unit 6.

  In summary, in the measurement units 4A and 4B of the present embodiment, the upper viscosity sensor 43 for the upper measurement site L30 (first site) set in the upper region L3a for the white ink WI to be measured, For the lower measurement site L20 (second site) set in the lower region L2b, the lower viscosity sensor 41 measures the viscosity, and generates upper viscosity data and lower viscosity data based on these measurement results.

  In the evaluation process described later, the sedimentation state of the white ink WI is evaluated based on the tendency of the viscosity to change with time obtained from both the upper viscosity data and the lower viscosity data. Further, it is generally known that in a solid dispersion, the viscosity decreases as the solid particles settle on the upper side, and the viscosity increases as the solid particles settle on the lower side. In this embodiment, in order to evaluate the sedimentation state of the solid particles using the upper viscosity data and the lower viscosity data having a change tendency of the reverse sign, when evaluating the sedimentation state based on the measurement result for only one side The reliability of evaluation is increased compared to.

<Control unit 6>
The control unit 6 illustrated in FIG. 4 is a control unit that controls each unit of the evaluation apparatus 1 and applies the white ink WI to the white ink WI based on the viscosity measurement result of the white ink WI obtained from the upper viscosity sensor 43 and the lower viscosity sensor 41. The sedimentation state of the dispersed solid particles is evaluated, and the evaluation result is transmitted to the display means 7.

  The configuration of the control unit 6 as hardware is the same as that of a general computer. That is, the control unit 6 stores a CPU 61 that performs various arithmetic processes, a ROM 62 that is a read-only memory that stores basic programs, a RAM 63 that is a readable / writable memory that stores various information, and processing programs and data. The fixed disk 64 to be placed is connected to the bus line 69.

  The viscosity sensor 4 (upper viscosity sensor 43, lower viscosity sensor 41) and display means 7 are connected to the bus line 69. The CPU 61 of the control unit 6 executes the processing program stored in the fixed disk 64 to control each unit related to the evaluation device 1 and perform the sedimentation state evaluation of the white ink WI.

  The display unit 7 is configured by using, for example, a liquid crystal display and displays various information such as processing results (evaluation results) and messages.

  An input means 65 is electrically connected to the bus line 69. The input unit 65 is configured using, for example, a keyboard, a mouse, and the like, and receives input of commands, parameters, and the like.

  The user of the evaluation apparatus 1 can input commands, parameters, and the like from the input unit 65 while confirming the contents displayed on the display unit 7. The display unit 7 and the input unit 65 may be integrated to form a touch panel.

  Further, a reading device 66 that reads recorded contents from a recording medium RM such as a DVD or a CD-ROM is connected to the bus line 69. The processing program may be read from the recording medium RM by the reading device 66 and stored in the fixed disk 64. Further, it may be downloaded from an external information processing apparatus via a network.

  As shown in FIG. 4, the fixed disk 64 has a tendency of the viscosity data to change over time based on the viscosity data (upper viscosity data and lower viscosity data) generated by the viscosity sensor 4 as a processing program of the evaluation device 1. A change trend specifying program PR1, which is a program for obtaining change trend data to be specified, and evaluation data for evaluating the sedimentation state of the white pigment in the white ink WI based on the change trend data and a predetermined evaluation standard. A sedimentation state evaluation program PR2, which is a program, is stored.

  Accordingly, after the upper viscosity data and the lower viscosity data are generated in the measurement process described later, the change tendency specifying process (step ST3 in FIG. 5) described later is executed by the CPU 61 by executing the change tendency specifying program PR1. By executing PR2, an evaluation step (step ST4 in FIG. 5) described later is realized.

<1.2 Evaluation of sedimentation state in evaluation device 1>
FIG. 5 is a flowchart showing an operation of sedimentation state evaluation in the evaluation apparatus 1 of the present embodiment. Hereinafter, an operation flow for evaluating the sedimentation state of the white ink WI by the evaluation apparatus 1 will be described with reference to FIG.

  First, white ink WI, which is a solid dispersion to be evaluated for sedimentation, is supplied to the measurement units 4A and 4B, and preparation for starting viscosity measurement in the viscosity sensor 4 (upper viscosity sensor 43 and lower viscosity sensor 41) is performed. (Step ST1).

  Specifically, the user of the evaluation apparatus 1 supplies a predetermined amount of the white ink WI to the holding body 2A using an instrument such as a dropper, and the upper surface of the white ink WI and the lower surface (detection of the upper viscosity sensor 43) Part 44). Similarly, the user of the apparatus supplies a predetermined amount of white ink WI onto the detection unit 42 using an instrument such as a dropper. The supplied white ink WI is held on the upper surface of the lower viscosity sensor 41 where the detection unit 42 exists by the surface tension. As a result, the measurement units 4A and 4B are ready to start the measurement process of step ST2 (FIG. 1).

  In step ST2 (measurement step), the control unit 6 causes the upper viscosity sensor 43 to be lowered for the white ink WI that is stationary in the measurement space L1a, and downward for the white ink WI that is stationary in the measurement space L1b. The viscosity sensor 41 is activated. As a result, the viscosity measurement is performed at a plurality of points in time on the upper measurement site L30 and the lower measurement site L20 of the white ink WI.

  In the present embodiment, both the measurement units 4A and 4B generate viscosity data every 30 seconds during the measurement period of 30 minutes for the white ink WI at 25 ° C. that is room temperature. FIG. 6 shows an orthogonal coordinate system in which the horizontal viscosity is time (unit is minutes) and the vertical axis is viscosity (unit is AV). Is plotted in

  According to the downward viscosity data indicated by “□” (open square) in FIG. 6, the viscosity of the white ink WI at the lower measurement portion L20 is from 12.9 AV (elapsed time 0 minutes: at the start of measurement) to 15. The viscosity increased by 2.5 AV up to 4 AV (elapsed time 30 minutes: at the end of measurement).

  Further, according to the upper viscosity data indicated by “◇” (open diamonds) in FIG. 6, the viscosity of the white ink WI at the upper measurement site L30 is from 15.4 AV (at the start of measurement) to 14.2 AV (measurement). 1.2AV until the end).

  When the measurement process in step ST2 ends (the measurement operations of the upper viscosity sensor 43 and the lower viscosity sensor 41 are stopped), steps ST3 to ST3 are processes for evaluating and displaying the sedimentation state of the white ink WI. Step ST5 and steps ST6 and ST7, which are steps of discharging the white ink WI after the viscosity measurement and cleaning the measuring units 4A and 4B, are executed in parallel.

  First, the process concerning step ST3-step ST5 is demonstrated.

  When the controller 6 receives the downward viscosity data and the upward viscosity data, the CPU 61 executes the change tendency specifying program PR1. As a result, the upward change tendency data specifying the change tendency of the viscosity with time for the upper viscosity data and the downward change tendency data specifying the change tendency of the viscosity with time for the lower viscosity data are generated (step ST3). : Change tendency identifying step).

  The change tendency identification program PR1 of the present embodiment measures the amount of change in the viscosity of the white ink WI from the start of measurement to the end of measurement (unit is AV) based on viscosity data at a plurality of time points measured in the measurement process. It is a program specified for each.

  Accordingly, if the amount of change in viscosity from the start of measurement to the end of measurement in the lower measurement region L20 is ΔS2, and the amount of change in viscosity from the start of measurement to the end of measurement in the upper measurement region L30 is ΔS3, ΔS2 = + 2 as downward change tendency data. .5AV is generated as upward change tendency data ΔS3 = −1.2AV. Here, the sign of the change tendency data means thickening and thinning, respectively.

  When the downward change tendency data and the upward change tendency data are generated, the control unit 6 causes the CPU 61 to execute the sedimentation state evaluation program PR2. As a result, the lower evaluation data for evaluating the sedimentation state of the white ink WI based on the lower viscosity data and the predetermined first evaluation criterion, and the white ink WI based on the upper viscosity data and the predetermined second evaluation criterion. Upward evaluation data for evaluating the sedimentation state of is generated. Further, comprehensive evaluation data for evaluating the sedimentation state of the white ink WI is generated based on the lower evaluation data and the upper evaluation data (step ST4: evaluation step).

  As said evaluation criteria, the aspect which sets a predetermined threshold value is mentioned, for example. The first evaluation standard and the second evaluation standard in the present embodiment are as follows.

  Two threshold values of “0.5AV” and “1AV” are set as evaluation criteria, and when the absolute value of the viscosity change amount indicated by the change tendency data is 0.5 AV or less, “0 point: low sedimentation property” "If it is greater than 0.5 AV and less than or equal to 1 AV, the evaluation data is generated in three stages as" 1 point: a slight sedimentation is observed "and if it is greater than 1 AV," 2 points: a high sedimentation property ". The

  Accordingly, for the white ink WI of the present embodiment, the absolute value of the viscosity change amount indicated by the downward change tendency data (ΔS2 = + 2.5AV) is larger than 1, and therefore the downward evaluation data is “2 points”. Further, since the absolute value of the viscosity change amount indicated by the upward change tendency data (ΔS3 = −1.2AV) is larger than 1, the upward evaluation data is “2 points”.

  In the evaluation process of this embodiment, comprehensive evaluation data (4 points) for evaluating the sedimentation state of the entire white ink WI is generated by the sum of the lower evaluation data (2 points) and the upper evaluation data (2 points). Is done.

  Table 1 below shows each data generated in the steps ST1 to ST4.

  In step ST5, evaluation data (upper, lower, overall) is displayed on the display means 7. The user of the evaluation device 1 can grasp the sedimentation state of the white ink WI that is the measurement target by viewing the evaluation result. The display means 7 may display various information other than the evaluation data such as the substance name, viscosity data, change tendency data, or processing conditions (temperature and measurement period) of the solid dispersion.

  As described above, in the evaluation data of the present embodiment, a high score is set corresponding to the high sedimentation property. For the upper evaluation data and the lower evaluation data, one of 0 to 2 points, and 0 for the comprehensive evaluation data. Any one of ~ 4 points is output.

  For the white ink WI that is the object of evaluation in this embodiment, the highest score is displayed on the display means 7 for all of the evaluation data (upper, lower, and overall). It can be easily grasped that it is a solid dispersion that easily settles. The above evaluation criteria (typically, comparison with a threshold value) are values that are appropriately set depending on the type of solid dispersion to be evaluated and the processing conditions (temperature, measurement time, etc.).

  Next, step ST6 and step ST7, which are steps of discharging the white ink WI after the viscosity measurement and cleaning the measurement units 4A and 4B, will be described (FIG. 4).

  When the measurement of the viscosity of the white ink WI is completed in step ST2 (measurement step), the user of the apparatus discharges the white ink WI from the measurement units 4A and 4B (step ST6), and the measurement units 4A and 4B are cleaned (step ST6). Step ST7). By the operations of step ST6 and step ST7, the measurement unit 4A and 4B can measure the solid dispersion to be the next measurement / evaluation target.

<1.3 Sedimentation with other inks>
The case where the sedimentation state of the white ink WI is evaluated has been described so far. Hereinafter, the case where the sedimentation state of the magenta ink and the cyan ink is evaluated by the evaluation apparatus 1 will be described as a comparative example with the white ink WI. The processing conditions other than the type of ink, such as the measurement time, the temperature at the fixed time, and the control of the stirring means 3, are the same as those for the white ink WI described above.

  FIG. 7 shows the upper viscosity data and the lower viscosity data when magenta ink is subjected to sedimentation evaluation by the evaluation device 1, with the horizontal axis representing time (unit: minutes) and the vertical axis representing viscosity (unit: AV). It is plotted in the Cartesian coordinate system. FIG. 8 is the same as FIG. 7 and plots the upper viscosity data and the lower viscosity data in the orthogonal coordinate system when the cyan ink is evaluated. In FIGS. 7 and 8, points indicated by “□” (open squares) correspond to the lower viscosity data, and points indicated by “◇” (open diamonds) correspond to the upper viscosity data.

  From FIG. 7, it can be seen that the viscosity of the magenta ink at the lower measurement site L20 is increased by 0.1 AV from 12.6 AV (at the start of measurement) to 12.7 AV (at the end of measurement). It can also be seen that the viscosity of magenta ink at the upper measurement site L30 is reduced by 0.6 AV from 12.5 AV (at the start of measurement) to 11.9 AV (at the end of measurement).

  Based on the measurement result, the change tendency of the viscosity is specified (step ST3), and the sedimentation state is evaluated (step ST4), whereby each data shown in Table 2 is obtained for the magenta ink.

  Further, it can be seen from FIG. 8 that the viscosity of the cyan ink at the lower measurement site L20 changes from 11.6AV (at the start of measurement) to 11.6AV (at the end of measurement). It can also be seen that the viscosity of cyan ink at the upper measurement site L30 is increased by 0.1 AV from 12.6 AV (at the start of measurement) to 12.6 AV (at the end of measurement).

  Based on the measurement result, the change tendency of the viscosity is specified (step ST3), and the sedimentation state is evaluated (step ST4), whereby each data shown in Table 3 is obtained for the cyan ink.

  As can be seen from Tables 2 and 3, when the sedimentation state evaluation of this embodiment is performed for magenta ink and cyan ink, comprehensive evaluation data (1 point) for magenta ink and comprehensive evaluation data (0 point) for cyan ink. ) Is obtained.

  Since these evaluation data are displayed on the display means 7, the user of the evaluation apparatus 1 can grasp the settling state of magenta ink and cyan ink by looking at the display. That is, it is understood that magenta ink has a slight sedimentation property and cyan ink hardly settles.

  Note that the white ink WI was higher than the other inks by 4 points in the comprehensive evaluation data (easily forming a sedimented state). The white ink WI contains titanium, so that the white ink WI is liquid (solvent). This is because the specific gravity of the pigment is larger than that of magenta ink or cyan ink.

<1.4 Effect of Evaluation Device 1 of the Present Embodiment>
(1) As described above, in the evaluation apparatus 1 according to the present embodiment, the sedimentation state of solid particles is evaluated based on changes over time in the measurement results of local viscosity such as the lower measurement site L20 and the upper measurement site L30. To do. In that case, the measurement is performed while the solid dispersion to be measured is kept stationary. In this way, the local viscosity measurement in a solid dispersion in a stationary state is precise because it is not affected by the flow, unlike the viscosity measurement in a solid dispersion in a state where dynamic flow occurs. .

  Because of this high measurement accuracy, it is possible to measure changes in viscosity even for solid dispersions where the specific gravity difference between the solid particles and the solvent is small, and the sedimentation state of the solid dispersion is evaluated based on the measurement results. Therefore, the evaluation accuracy is increased.

  In addition, since the evaluation accuracy is high and the sedimentation of a small amount of solid particles can be evaluated after standing for a short time (natural state), it is not necessary to form a sedimentation state by a centrifugation method or an acceleration test. Therefore, sedimentation can be evaluated in a shorter measurement period (for example, 30 minutes) than the measurement period (for example, several hours) required for the centrifugal separation method or the acceleration test. Compared to centrifugation and accelerated tests where a certain amount of solid dispersion needs to be prepared in a beaker or sample container, the required minimum sample volume can be reduced and expensive solid dispersions (eg drugs) Even when the sedimentation evaluation is performed, the cost can be minimized.

  (2) The ink-jet ink in which the solid particles of the pigment are dispersed is a solid dispersion particularly suitable as an object of measurement / evaluation by the evaluation apparatus 1 of the present embodiment.

  In the ink jet method, the ink in a stationary state is suddenly pressurized, transited from a low shear region to a high shear region, and ejected from a nozzle. In this way, since the ink for ink jet is stored in a stationary state until immediately before ejection, precipitation of the pigment may occur in the ink during the stationary period. The sedimentation of the pigment leads to the collapse of the color balance due to the density difference in the ink and the clogging of the nozzle. As described above, since the sedimentation state evaluation of this embodiment measures the viscosity of the solid dispersion in the stationary state over time and evaluates the sedimentation state, the ink-jet ink evaluation (color balance evaluation, clogging) And the like.

  (3) In the measurement unit 4B of the present embodiment, a measurement site for viscosity measurement (lower measurement site L20) is set near the lower surface of the fixed dispersion in a state held by the lower viscosity sensor 41 (holding body). In the vicinity of the lower surface of the fixed dispersion, the time increase of the viscosity due to the sedimentation of the solid particles is the largest, so that the accuracy of the sedimentation state evaluation is improved.

  In the measurement unit 4A of the present embodiment, a measurement site (upper measurement site L30) for viscosity measurement is set near the upper surface of the fixed dispersion in a state of being held by the holding body 2A. In the vicinity of the upper surface of the fixed dispersion, the time drop of the viscosity due to the sedimentation of the solid particles is the largest, so that the accuracy of the sedimentation state evaluation is increased.

  Further, comprehensive evaluation data is generated based on the tendency of the viscosity with time for both the upper measurement site L30 and the lower measurement site L20 to evaluate the sedimentation state. In this way, by evaluating the sedimentation state of the solid particles using the measurement results at a plurality of sites having a viscosity change tendency with opposite signs, the sedimentation state is evaluated based on the measurement result for only one region. The reliability of the evaluation is increased compared to the case.

<2 Second Embodiment>
<2.1 Evaluation Device 1A according to Second Embodiment>
Next, a second embodiment of the present invention will be described. FIG. 9 is a cross-sectional view schematically showing a configuration example of the evaluation apparatus 1A according to the second embodiment. In FIG. 9 and the subsequent drawings, the same elements as those in the evaluation apparatus 1 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 9, the evaluation apparatus 1A of the second embodiment generally includes a pipe part 2 for feeding a solid dispersion to be subjected to sedimentation evaluation, and a solid dispersion flowing in the pipe part 2. Stirring means 3 that forms a state in which solid particles are dispersed almost uniformly in the solid dispersion by stirring, and a viscosity sensor 4 that measures the viscosity of the solid dispersion stirred by the stirring means 3 at a specific position in a stationary state. And a control unit 6A that controls each part of the evaluation device 1A to evaluate the sedimentation state of the solid dispersion, and a display means 7 that displays an evaluation result output from the control unit 6A. It is a sedimentation state evaluation apparatus.

  In addition to the above-described parts, the evaluation apparatus 1A is a valve that controls the opening and closing of the flow path of the pipe section 2 and is provided with an open / close valve 51 that is positioned upstream of the viscosity sensor 4 and on the downstream side. 52 located. Therefore, by controlling the opening and closing of the on-off valves 51 and 52, the solid dispersion supplied into the evaluation apparatus 1A is opposed to the viscosity sensor 4 and is a space in which the viscosity is measured by the viscosity sensor 4 (hereinafter, “ (Referred to as measurement space L1 ”) (FIG. 13 (b)).

  Since the entire configuration is as described above, the evaluation apparatus 1A stirs the solid dispersion to be evaluated to form a substantially uniform dispersion state, and then stores the solid dispersion in the measurement space L1 for a certain period ( Can be left standing). And the sedimentation state of the solid particle disperse | distributed in a solid dispersion can be evaluated based on this measurement result by measuring the viscosity in the specific site | part of a solid dispersion at several time points in the said period. Hereinafter, as in the first embodiment, a case where the white ink WI is a solid dispersion to be evaluated will be described.

  The configuration of each part of the evaluation apparatus 1A will be described in detail.

  The piping unit 2 is a piping system for feeding the white ink WI that is a solid dispersion to be subjected to sedimentation evaluation, and a supply port 21 that is an opening for supplying the white ink WI into the evaluation apparatus 1A. A pipe 20 that feeds the white ink WI supplied from the supply port 21 via the measurement space L1, and a white ink WI that has flowed through the pipe 20 and finished the viscosity measurement in the measurement space L1, is external to the evaluation apparatus 1A. And a discharge port 22 for discharging.

  The pipe 20 is provided with an on-off valve 51 on the upstream side of the viscosity sensor 4 and an on-off valve 52 on the downstream side of the viscosity sensor 4. For this reason, when the white ink WI is being supplied from the supply port 21, the opening / closing valve 52 is first closed, and then the opening / closing valve 51 is closed after a predetermined time has elapsed, thereby partitioning the opening / closing valves 51, 52 of the pipe 20. The measured section (measurement space L1) can be filled with the white ink WI. In the measurement step, the change in viscosity over time is measured for the specific portion of the white ink WI stored in the measurement space L1 in this way (FIG. 13B).

  Thus, in the evaluation apparatus 1A of the second embodiment, the pipe 20 and the on-off valves 51 and 52 function as a holding body that holds the white ink WI (solid dispersion). Then, the white ink WI stored (or left standing) in the measurement space L1 corresponds to the “solid dispersion held by the holding body” in the present invention.

  The stirring unit 3 is a unit that is attached to the upstream side of the viscosity sensor 4 along the flow path of the pipe 20 and stirs the white ink WI flowing in the pipe 20. Therefore, the white ink WI is stirred by the stirring means 3 prior to the viscosity measurement in the measurement space L1, and the white pigment (solid particles) is dispersed almost uniformly in the white ink WI at the start of the viscosity measurement. Can be formed.

  The stirring means 3 of the second embodiment is an apparatus that generates ultrasonic vibrations that can be switched ON / OFF, and stirs the white ink WI that flows in a position facing the stirring means 3 in the pipe 20 by the ultrasonic vibrations. It is means to do. In addition, the agitation unit 3 is not limited to this. For example, the agitation unit 3 having a macro movable part that agitates the white ink WI by rotating a propeller may be employed.

  Since the sedimentation curve of solid particles in a solid dispersion is one of thermodynamic transient curves, it is exponential with respect to time, and the density change per unit time becomes smaller as sedimentation progresses. Therefore, by stirring the white ink WI before the start of the viscosity measurement as described above, a time range in which the density change per unit time is the largest in the white ink WI can be used for the measurement period. The evaluation accuracy of the sedimentation state is increased.

  Further, even when the sedimentation state is evaluated for a plurality of types of solid dispersions having different dispersion states, for example, the white ink WI, the magenta ink, and the cyan ink, as described in the first embodiment, The dispersion state of each solid dispersion at the start, that is, in the initial state can be made the same condition by stirring, and the stability of the sedimentation state evaluation is improved.

  As in the first embodiment, the viscosity sensor 4 includes a lower viscosity sensor 41 provided with its detection unit 42 in contact with the lower surface of the measurement space L1, and a detection unit 44 provided in contact with the upper surface of the measurement space L1. And an upper viscosity sensor 43 provided.

  FIG. 10 is a block diagram showing a configuration related to the functions of the lower viscosity sensor 41 and the upper viscosity sensor 43. In the following description, as in the first embodiment, with respect to the measurement space L1, the virtual horizontal plane IP defined as the center height of the vertical height range occupied by the white ink WI in the state stored in the measurement space L1 is used as the boundary. The height range of the half is called “upper region L3”, and the height range of the lower half is called “lower region L2”.

  In the viscosity sensor 4 according to the second embodiment, as in the first embodiment, with respect to the white ink WI stored in the measurement space L1, the lower measurement site L20 (second site) set in the lower region L2 is used. The lower viscosity sensor 41 measures the viscosity of the upper measurement site L30 (first site) set in the upper region L3 by the upper viscosity sensor 43, and based on these measurement results, the lower viscosity data and Upper viscosity data.

  The control unit 6A shown in FIG. 11 controls the various operation mechanisms provided in the evaluation apparatus 1A. The control unit 6A is similar to the control unit 6 of the first embodiment in its schematic configuration, but differs from the control unit 6 in that the stirring means 3 and the on-off valves 51 and 52 are connected to the bus line 69. . As a result, the CPU 61 of the control unit 6A executes the processing program stored in the fixed disk 64, thereby controlling each unit related to the evaluation device 1A and executing the sedimentation state evaluation of the white ink WI.

<2.2 Evaluation of sedimentation state in evaluation apparatus 1A>
FIG. 12 is a flowchart showing an operation of sedimentation state evaluation in the evaluation apparatus 1A of the second embodiment. FIG. 13 is a schematic side view of the evaluation apparatus 1A in the operation process of the sedimentation state evaluation. Hereinafter, an operation flow for evaluating the sedimentation state of the white ink WI by the evaluation apparatus 1A will be described with reference to FIGS.

  First, the white ink WI that is a solid dispersion to be evaluated for the sedimentation state is supplied into the evaluation apparatus 1A. Specifically, the user of the evaluation apparatus 1A supplies a predetermined amount of white ink WI to the supply port 21 using an instrument such as a dropper (step ST11).

  The white ink WI supplied to the supply port 21 flows in the pipe 20 and flows toward the measurement space L1 via a position facing the stirring unit 3 (FIG. 13A). At this time, the stirring means 3 is controlled by the control unit 6A so as to be in an ON state in which ultrasonic vibration is generated. As a result, the white ink WI flowing through the position facing the stirring means 3 in the pipe 20 is stirred by the ultrasonic vibration (step ST12: stirring process).

  As shown in FIG. 13A, the on-off valve 51 is open and the on-off valve 52 is in a period from the start of the supply of the white ink WI through the supply port 21 until the measurement space L1 is filled with the white ink WI. Is closed. For this reason, the white ink WI flowing in the pipe 20 is blocked by the on-off valve 52 located downstream, and as a result, the measurement space L1 (a space sandwiched between the on-off valve 51 and the on-off valve 52 in the space in the pipe 20). ) Is filled with the white ink WI. When the measurement space L1 is filled with the white ink WI, the on-off valve 51 is also closed as shown in FIG. 13B (step ST13). Note that the opening / closing control of the opening / closing valves 51, 52 in the second embodiment is a fully automatic type performed by the control unit 6A (FIG. 9), but a semi-automatic type in which the user of the apparatus presses a button corresponding to the opening / closing, Alternatively, it may be a manual type that is manually opened and closed by the user of the apparatus.

  In step ST14 (measurement process), the upper viscosity sensor 43 and the lower viscosity sensor 41 are activated by the control unit 6A, and the viscosity measurement is performed at a plurality of times with respect to the white ink WI that is filled in the measurement space L1 and is allowed to stand. Is called.

  When the measurement process in step ST14 is completed, steps ST15 to ST17, which are processes for evaluating and displaying the sedimentation state of the white ink WI, and the white ink WI after the viscosity measurement are discharged to clean the pipe section 2. Steps ST18 and ST19, which are processes to be performed, are executed in parallel.

  First, the process concerning step ST15-step ST17 is demonstrated. Since these steps are the same as steps ST3 to ST5 in the evaluation apparatus 1 of the first embodiment, they will be described while being omitted as appropriate.

  When the controller 6A receives the downward viscosity data and the upward viscosity data, the CPU 61 executes the change tendency specifying program PR1. As a result, upward change tendency data specifying the change tendency of the viscosity with time for the upward viscosity data and downward change tendency data specifying the change tendency of the viscosity with time for the lower viscosity data are generated (step ST15). : Change tendency identifying step).

  When the downward change tendency data and the upward change tendency data are generated, the control unit 6A executes the sedimentation state evaluation program PR2 by the CPU 61. As a result, the lower evaluation data for evaluating the sedimentation state of the white ink WI based on the lower viscosity data and the predetermined first evaluation criterion, and the white ink WI based on the upper viscosity data and the predetermined second evaluation criterion. Upward evaluation data for evaluating the sedimentation state of is generated. Further, comprehensive evaluation data for evaluating the sedimentation state of the white ink WI is generated based on the lower evaluation data and the upper evaluation data (step ST16: evaluation step).

  In step ST17, evaluation data (upper, lower, overall) is displayed on the display means 7. The user of the evaluation apparatus 1A can grasp the sedimentation state of the white ink WI that is the measurement target by viewing the evaluation result. The display means 7 may display various information other than the evaluation data such as the substance name, viscosity data, change tendency data, or processing conditions (temperature and measurement period) of the solid dispersion.

  Next, step ST18 and step ST19, which are steps of discharging the white ink WI after the viscosity measurement and cleaning the piping part 2, will be described (FIG. 12).

  When the viscosity measurement of the white ink WI is completed in step ST14 (measurement step), the on-off valves 51 and 52 are opened by the control unit 6A (FIG. 13C). As a result, the white ink WI flows in the pipe 20 and is discharged to the outside of the evaluation apparatus 1A from the discharge port 22 (step ST18).

  Then, the cleaning liquid is supplied from the supply port 21 with the on-off valves 51 and 52 being opened. For example, the user of the apparatus supplies this cleaning liquid using a dropper or the like. As a result, the cleaning liquid flows in the pipe 20 and is discharged from the discharge port 22, whereby the inside of the pipe 20 is cleaned, and the solid dispersion to be measured and evaluated subsequently can be measured (step ST19). ).

<2.3 Effects of Evaluation Device 1A of Second Embodiment>
In the evaluation apparatus 1A of the second embodiment, since the solid dispersion stirring step is performed prior to the viscosity measurement step, a state in which the solid particles are dispersed almost uniformly in the solid dispersion at the start of the viscosity measurement is formed. be able to. As a result, a time region in which the density change per unit time is the largest can be used for viscosity measurement, and the evaluation accuracy of the sedimentation state is particularly high.

  Further, as shown in the first embodiment, even when the sedimentation state evaluation method is applied to a plurality of solid dispersions (white ink, magenta ink, cyan ink) having different dispersion states, In the evaluation apparatus 1A, the dispersion state of each solid dispersion at the start of measurement, that is, in the initial state can be set to the same condition, and the stability of the sedimentation state evaluation is improved.

  In addition, it cannot be overemphasized that the same effect is acquired about the part which is the same structure in the evaluation apparatus 1 of 1st Embodiment, and the evaluation apparatus 1A of 2nd Embodiment.

<3 Modification>
While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention.

  In 1st Embodiment and 2nd Embodiment, although the two viscosity sensors 4 of the upper viscosity sensor 43 and the lower viscosity sensor 41 were utilized, it is not restricted to this. That is, an aspect in which only one of the upper viscosity sensor 43 and the lower viscosity sensor 41 is used as the viscosity sensor 4 (typically, an aspect in which only one of the measurement units 4A and 4B of the first embodiment is employed. ), Viscosity data, change tendency data, and evaluation data for the one are generated.

  For this reason, the user of an apparatus can grasp | ascertain the sedimentation state of the solid dispersion by seeing the said evaluation data displayed on the display means 7. FIG. In addition, when only one of the upper viscosity sensor 43 and the lower viscosity sensor 41 is used as the viscosity sensor 4 as in this modification, the solid state is simpler than that of the evaluation devices 1 and 1A. The sedimentation state of the dispersion can be evaluated.

  In particular, as a modification of the evaluation device 1 of the first embodiment, in the case of using only the measurement unit 4B among the measurement units 4A and 4B, the upper surface of the lower viscosity sensor 41 (the surface on the side where the detection unit 42 is present). The solid dispersion to be measured is retained. For this reason, it is possible to evaluate the sedimentation state of the solid dispersion with an extremely simple configuration. Moreover, since a solid dispersion is hold | maintained on the upper surface of the downward viscosity sensor 41, a sedimentation state can be evaluated about a very small amount of solid dispersion. For this reason, even if it is a case where sedimentation evaluation of an expensive solid dispersion (for example, chemical | medical agent etc.) is performed, cost can be suppressed to the minimum.

  FIG. 14 is a side view showing an evaluation apparatus 1B that is a modification of the evaluation apparatus 1A of the second embodiment. The evaluation device 1B is different from the evaluation device 1A of the second embodiment in the arrangement positions of the upper viscosity sensor 43 and the lower viscosity sensor 41.

  In the evaluation apparatus 1A of the second embodiment, the viscosity measurement position of the lower viscosity sensor 41 is the lower measurement site L20 (near the lower surface of the white ink WI), and the viscosity measurement position of the upper viscosity sensor 43 is the upper measurement site L30 (white). It is set near the upper surface of the ink WI (FIG. 2). On the other hand, in the evaluation apparatus 1B, the viscosity measurement position at the lower viscosity sensor 41 is set in the second region L21 in the lower region L2, and the viscosity measurement position at the upper viscosity sensor 43 is set in the upper region L3. Although it is set to the part L31, it is not necessarily set near the lower surface and near the upper surface in the region (FIG. 14).

  Even if the first part and the second part do not correspond to the upper measurement part L30 and the lower measurement part L20 as in the present modification, the first part L31 and the lower region set in the upper region L3 If the sedimentation state is evaluated based on the time-dependent change tendency of the viscosity with respect to the second part L21 set in L2, the measurement results at a plurality of parts having the viscosity change tendency of opposite signs are used. Thus, the sedimentation state of the solid particles can be evaluated, and the reliability of the evaluation is increased as compared with the case where the sedimentation state is evaluated based on the measurement result of only one region.

  When the measurement site is set near the upper surface (or near the lower surface) as in the above embodiments, the time increase (or decrease) in viscosity due to sedimentation of solid particles is greatest near the upper surface (or near the lower surface). Therefore, it is desirable in that the effect of increasing the accuracy of the sedimentation state evaluation can be obtained.

  In each of the above embodiments, the control units 6 and 6A execute the change tendency specifying program PR1 by the CPU 61, thereby functioning as a change tendency specifying means for specifying the change tendency of the viscosity data with time. As this change tendency specifying program PR1, for example, a program for specifying the rate of change in viscosity with time can be employed in addition to the above-described program for specifying the amount of change in viscosity.

  In each of the above embodiments, the control units 6 and 6A execute the sedimentation state evaluation program PR2 by the CPU 61, thereby functioning as sedimentation state evaluation means for generating evaluation data based on the change tendency data and a predetermined evaluation standard. To do. Also in the sedimentation state evaluation program PR2, a program different from the sedimentation state evaluation program described above can be adopted. For example, the first evaluation standard (evaluation standard in the lower measurement) and the second evaluation standard (evaluation standard in the upper measurement) may be different thresholds. Further, the number of thresholds (two in the above embodiment) may be one or three or more. In the first embodiment, the comprehensive evaluation data is generated by the sum of the scores of the lower evaluation data and the upper evaluation data. However, the present invention is not limited to this. The method can be used.

  In each of the above-described embodiments, the display unit 7 displays the evaluation data (upper, lower, and overall) generated by the control units 6 and 6A. However, the present invention is not limited to this. The display means 7 may display at least change trend data as an evaluation index value. In this case, the user of the apparatus can grasp the sedimentation state of the solid dispersion by looking at the change tendency data. In addition, if evaluation data is displayed like said each embodiment, the user of an apparatus will be easier to grasp | ascertain the sedimentation state of a solid dispersion.

1, 1A, 1B Evaluation device 2 Piping section 2A Holding body 3 Stirring means 4 Viscosity sensor 4A, 4B Measuring section 6, 6A Control section 7 Display means 20 Piping 41 Lower viscosity sensor 42 Detection section 43 Upper viscosity sensor 44 Detection section IP, IPa, IPb Virtual horizontal plane L1, L1a, L1b Measurement space L2, L2a, L2b Lower region L3, L3a, L3b Upper region L20 Lower measurement site L21 Second site L30 Upper measurement site L31 First site

Claims (15)

A method for evaluating the sedimentation state of a solid dispersion as a substance in which solid particles are dispersed in a liquid,
For the solid dispersion held by the holding body, measuring the viscosity at least at one specific site in the solid dispersion over time in a stationary state to obtain viscosity data at a plurality of time points;
Based on the viscosity data at the plurality of time points, a change tendency specifying step for obtaining change tendency data for specifying a change tendency of the viscosity data with time, and
Based on the change tendency data and a predetermined evaluation standard, an evaluation step for evaluating the sedimentation state of the solid particles in the solid dispersion,
A sedimentation state evaluation method characterized by comprising: A sedimentation state evaluation method according to claim 1,
A sedimentation state evaluation method, further comprising a stirring step of stirring the solid dispersion prior to the viscosity measuring step. A sedimentation state evaluation method according to claim 1 or claim 2,
A sedimentation state evaluation method, wherein the solid dispersion is an ink jet ink in which solid particles of pigment are dispersed. A sedimentation state evaluation method according to any one of claims 1 to 3,
The at least one specific part is set near the upper surface of the fixed dispersion in a state of being held by the holding body. A sedimentation state evaluation method according to any one of claims 1 to 3,
The at least one specific part is set near the lower surface of the fixed dispersion in a state of being held by the holding body. A sedimentation state evaluation method according to any one of claims 1 to 3,
A plurality of sites are set as the at least one specific site,
The plurality of portions are a first portion set in an upper region as a height range of an upper half of a vertical height range occupied by the fixed dispersion in a state of being held by the holding body, and a lower half Including a second part set in the lower region as a height range,
In the evaluation step, the sedimentation state evaluation method is characterized in that the sedimentation state is evaluated based on the temporal change tendency of both the first part and the second part. In the sedimentation state evaluation method according to any one of claims 1 to 6,
The measurement step includes
A sedimentation state evaluation method comprising: measuring a viscosity by bringing a detection unit of a viscosity sensor using a surface acoustic wave into contact with the solid dispersion held by the holding body. An apparatus for evaluating the sedimentation state of a solid dispersion as a substance in which solid particles are dispersed in a liquid,
A holding body for holding the solid dispersion;
A viscosity sensor for measuring the viscosity of at least one specific part in the solid dispersion over time with respect to the solid dispersion held by the holder, and generating viscosity data at a plurality of time points; ,
Based on the viscosity data at the plurality of time points, a change tendency specifying means for obtaining change tendency data for specifying a change tendency with time of the viscosity data;
Display means for displaying information obtained from the change tendency data as an index for evaluating the sedimentation state of the solid particles;
A sedimentation state evaluation apparatus comprising: It is a sedimentation state evaluation apparatus according to claim 8,
A sedimentation state evaluation means for generating evaluation data for evaluating a sedimentation state of the solid particles in the solid dispersion based on the change tendency data and predetermined evaluation reference data;
Further comprising
The said display means displays the said evaluation data, The sedimentation state evaluation apparatus characterized by the above-mentioned. It is a sedimentation state evaluation apparatus according to claim 9,
Stirring means for stirring the solid dispersion held by the holding body;
A sedimentation state evaluation apparatus further comprising: A sedimentation state evaluation apparatus according to any one of claims 8 to 10,
A sedimentation state evaluation apparatus, wherein the solid dispersion is an ink-jet ink in which solid particles of pigment are dispersed. It is a sedimentation state evaluation apparatus in any one of Claims 8 thru | or 11, Comprising:
The at least one specific part is set near the upper surface of the fixed dispersion in a state of being held by the holding body. It is a sedimentation state evaluation apparatus in any one of Claims 8 thru | or 11, Comprising:
The at least one specific part is set near the lower surface of the fixed dispersion in a state of being held by the holding body. It is a sedimentation state evaluation apparatus in any one of Claims 8 thru | or 11, Comprising:
A plurality of sites are set as the at least one specific site,
The plurality of portions are a first portion set in an upper region as a height range of an upper half of a vertical height range occupied by the fixed dispersion in a state of being held by the holding body, and a lower half Including a second part set in the lower region as a height range,
The sedimentation state evaluation device evaluates the sedimentation state based on the temporal change tendency of both the first part and the second part. In the sedimentation state evaluation apparatus according to any one of claims 8 to 14,
The viscosity sensor is a viscosity sensor using a surface acoustic wave, and the viscosity measurement is performed by bringing the detection unit of the viscosity sensor into contact with the solid dispersion held by the holding body. apparatus.

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