JP2007024744A - Rotational viscosimeter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize advancement (accuracy improvement of shear rate dependence measurement) of a device having the so-called "circular cone-flat plate" shape inside a rotational viscosimeter. <P>SOLUTION: In this viscosimeter, having a disk 2 with a circular cone face on the driving side and a disk 3 with a flat face on the driven side arranged mutually concentrically, a guard 4 is arranged on the outer circumference of the disk 3 with the flat face on the driven side. The guard 4 has a cylindrical part 8, an annular plate 9 and an annular body 10 having a rectangular section, and the annular body 10 is arranged on the outer circumference of the disk 3, with the flat facing across a gap. A measuring sample is filled between the disk 2 with the circular cone face and the disk 3 with the flat face, and the disk 2 with the circular cone face on the driving side is driven and rotated, and the torque of the disk 3 with the flat face driven by viscosity of the measuring sample and receiving a driving force is measured, and the influence on viscosity measurement due to stress of the measuring sample from the outside of the disk 2 with the circular cone face on the driving side is blocked. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotational viscometer or a rotational viscometer type rheometer (hereinafter simply referred to as “rheometer”), and more particularly to a disc type rotational viscometer or rheometer with a conical surface with a guard.

  A rotational viscometer and a rheometer are devices that measure the viscosity and viscoelasticity of a sample to be measured by measuring the generation of rotation and the generated torque, or vice versa. An important feature of rotational viscometers and rheometers is that they can measure physical properties such as viscosity and viscoelasticity that change depending on the deformation or deformation speed (shear speed) of the measured object by controlling and measuring the rotational speed. is there.

  A rotational viscometer and a rheometer are measuring devices based on two components: a rotating element and a torque generated on a rotating shaft from resistance determined by the property of the object to be measured (sample) with respect to the rotation. Sample characteristics such as viscosity can be obtained from these two relationships.

  There are two types of rotational viscometers: a coaxial double cylindrical type and a two-disc type. The coaxial double cylindrical shape is a configuration in which a sample is placed in a gap between two cylinders having slightly different radii sharing a rotation axis (see Patent Document 1). The two-disc type is further divided into a cone-plate type and a parallel plate type.

  The cone-plate shape is configured such that the sample is placed in a gap between a very obtuse cone whose apex angle is close to 180 degrees and a plane whose apex is on the surface and whose rotation axis also coincides (patent) References 2 and 3). The parallel plate shape has a configuration in which a sample is placed in a gap between disk planes that are arranged in a narrow gap and whose two rotation axes coincide with each other.

  Both types of rotational viscometers have the feature that the deformation speed (shearing speed) of the sample can be obtained according to the rotational speed. However, the cone-plate type has been considered to be theoretically uniform.

Measurements using concentrated dispersions and polymer materials as samples often show nonlinearity whose properties change depending on the deformation rate, and a measurement method that can control the deformation rate, especially a cone-plate that can obtain a uniform sample deformation rate. The form of rotational viscometer is a very important measuring means.
Japanese Patent Publication No. 8-1415 JP-A-6-347392 JP-A-9-61333

  By the way, the cone-plate type rotational viscometer is supposed to obtain a uniform deformation rate of the sample, but this is accurate only when the conical disk has an infinitely large area. is there. In practice, end faces are always present because finite size cones and plates are used. As one method to make it as close as possible to the ideal, there is also used a means for measuring with a cone, a flat plate, and a sample inserted between them cut into the same radius.

  However, in addition to the fact that the end face effect is not eliminated even by such means, the dripping of the sample becomes a serious problem. In reality, the effect of the end face is usually neglected as not significant. The effect of this end face is the effect from the outer periphery of the cone. Considering that the torque is proportional to the cube of the radius in the cone-plate shape, it is impossible to think that it is small as it is, and this can be eliminated. This is an important issue.

  An object of the present invention is to solve the above-described conventional problems, and to realize an advancement of a device called a cone-plate type in a rotational viscometer (high accuracy of shear rate dependency measurement). Is. And this invention implement | achieves sophistication (high accuracy of a shear rate dependence measurement) also about a parallel plate type rotational viscometer.

  Furthermore, the present invention also realizes the sophistication (high accuracy of shear rate dependency measurement) for a cone-plate type rheometer or a parallel plate type rheometer (a disk type rheometer with a flat surface).

  In order to solve the above-mentioned problems, the present invention fills a sample to be measured between a drive-side disk and a driven-side disk, which are arranged concentrically with each other, and drives and rotates the drive-side disk. A rotational viscometer for measuring the viscosity of the sample to be measured by measuring the torque of the disk on the driven side that receives the driving force driven by the viscosity of the sample to be measured, and comprises a disk on the driven side A guard having an annular body disposed in a radial direction of the disk with a certain gap in the outer periphery of the disk, a surface of the driven disk that contacts the sample to be measured, and the annular Provided is a rotational viscometer characterized in that the surfaces of the body that are in contact with the sample to be measured are arranged in the same plane. In the description of the invention and the specification according to the present application, the “disc” includes a disc with a conical surface and a disc with a flat surface.

  The driven-side disc is fixed to the lower end of the rotating shaft, and the guard includes a cylindrical portion, an annular plate, and the annular body, and the cylindrical portion is concentrically disposed on the outer periphery of the rotating shaft. It is good also as a structure.

  In order to solve the above-described problems, the present invention fills a sample to be measured between a drive-side disk and a fixed-side disk, which are arranged concentrically with each other, and drives the drive-side disk with a drive torque. A rotational viscometer that measures the viscosity of the sample to be measured by measuring the rotational speed determined by the viscosity of the sample to be measured, and is arranged around the outer circumference of the disk on the drive side. A guard having an annular body disposed in a radial direction of the disc with a certain gap, a surface of the driving-side disc in contact with the sample to be measured, and the sample to be measured of the annular body Provided is a rotational viscometer characterized in that surfaces in contact with each other are arranged in the same plane.

  The drive-side disc is fixed to the lower end of the rotating shaft, and the guard includes a cylindrical portion, an annular plate, and the annular body, and the cylindrical portion is disposed concentrically on the outer periphery of the rotating shaft. It is good also as a structure.

  In order to solve the above-mentioned problems, the present invention fills a sample to be measured between a drive-side disk and a driven-side disk, which are arranged concentrically with each other, and drives and rotates the drive-side disk. A rheometer for measuring viscoelasticity of the sample to be measured by measuring the torque of the disk on the driven side that receives the driving force driven by the viscosity of the sample to be measured, A guard having an annular body disposed in a radial direction of the disk with a certain gap around the outer periphery of the disk, a surface of the driven disk that contacts the sample to be measured, and the annular The rheometer is characterized in that the surfaces of the body that are in contact with the sample to be measured are arranged in the same plane.

  The driven-side disc is fixed to the lower end of the rotating shaft, and the guard includes a cylindrical portion, an annular plate, and the annular body, and the cylindrical portion is concentrically disposed on the outer periphery of the rotating shaft. It is good also as a structure.

  In order to solve the above-described problems, the present invention fills a sample to be measured between a drive-side disk and a fixed-side disk, which are arranged concentrically with each other, and drives the drive-side disk with a drive torque. A rheometer that measures the viscoelasticity of the sample to be measured by measuring the rotational speed determined by the viscosity of the sample to be measured, and is arranged around the outer circumference of the disk on the driving side. A guard having an annular body arranged with a certain gap in the radial direction, and a surface of the drive side disk in contact with the sample to be measured, and a surface of the annular body in contact with the sample to be measured The rheometers are characterized in that the side surfaces are arranged in the same plane.

  The drive-side disc is fixed to the lower end of the rotating shaft, and the guard includes a cylindrical portion, an annular plate, and the annular body, and the cylindrical portion is disposed concentrically on the outer periphery of the rotating shaft. It is good also as a structure.

According to the present invention having the above configuration, the following effects are produced.
Since the space outside the part between the cone or the flat plate and the flat plate is more unconstrained, the deformation rate (shear rate or shear rate) of the sample becomes small. If it is non-linear, the stress generated thereby is different from that assumed from the number of rotations of the apparatus, resulting in a measurement error. Since the rotational viscometer is a torque measurement, the influence is larger as it is farther from the central axis, and the end face effect coming from the outer peripheral portion tends to cause this error. According to the present invention, this measurement error can be eliminated, and the deformation speed dependency with a small error can be measured.

  Further, in the conventional conical plate type, since the influence of the outside of the portion sandwiched between the cone and the flat plate is large, an error is still caused unless the amount of the sample is accurately entered. If the influence of the end face is eliminated by the present invention, the influence of the sample protruding outside is eliminated, so that the measurement error due to the sample amount can be greatly reduced. This also applies to the thermal expansion of the sample, so that the measurement of changing the temperature also has an effect of reducing errors. For the same reason, even if the solvent or the like in the sample is dried to cause a volume change, errors other than the influence of the normal drying due to the concentration change can be reduced.

  Embodiments of a rotational viscometer according to the present invention will be described below with reference to the drawings based on examples. The following description will focus on a rotational viscometer that measures viscosity, but the rheometer that measures viscoelasticity has exactly the same configuration and action.

(principle)
FIG. 4 shows a conventional conical plate type rotational viscometer 12. This rotational viscometer 12 is arranged concentrically on the flat surfaced disk 14 provided at the upper end of the rotational drive shaft 13 and on the flat surfaced disk 14, and the apex angle is close to 180 degrees on the lower surface. It is comprised from the disc 15 with a conical surface which has a very obtuse conical surface. The disc 15 with a conical surface is provided at the lower end of the rotary driven shaft 16.

  It arrange | positions so that the vertex part of the disc 15 with a conical surface may contact | connect the center of the disc 14 with a flat surface, and the rotational drive shaft 13 and the rotation driven shaft 16 are arrange | positioned concentrically. A liquid 17 which is a sample whose viscosity is to be measured is filled in a tapered gap between the flat surface and the conical surface between the flat surfaced disc 14 and the conical surface disc 15.

  When the disk 15 with a flat surface is rotated by the rotation drive shaft 13, the disk 15 with a conical surface rotates together with the viscosity of the sample to generate torque. By measuring this torque at the rotation driven shaft 16, the sample is measured. Can be measured.

  However, the outside of the portion sandwiched between the conical-surfaced disk 15 and the flat-surfaced disk 14 is a more unrestricted space, so the deformation rate (shear rate or shear rate) of the sample is reduced. If the property depending on the deformation speed of the sample is non-linear, the stress generated thereby differs from that assumed from the number of rotations of the apparatus, resulting in measurement errors. Since the rotational viscometer is a torque measurement, the influence is larger as it is farther from the central axis, and the end face effect coming from the outer peripheral portion tends to cause this error.

  In order to eliminate the effect of the end face of the circular plate 15 with the conical surface, the portion that receives the effect of the end face may be separated from the measurement system. That is, of the conical disk 15 or the flat disk 14, the method of measuring (generating) the torque is divided into an inner side and an outer side so that no stress is transmitted between them. The effect of the end face is hardly transmitted to the inner part, and if this part is used for measurement, the measurement without the end face effect is possible.

  In the present invention, a guard is disposed as an outer portion, and the surface of the guard is disposed with continuity (same conical surface / same plane) as if it were one object on the inner cone or flat plate. Since the guard moves together with the inside, no stress is generated in this part. A gap is required between the inner side and the inner side, but by reducing this, disturbance of the deformation speed of the sample due to rotation can be reduced. With such a configuration, the inner portion can be measured with high accuracy by eliminating the influence on the end face of the outer portion.

  FIG. 1 is a view showing a configuration of an embodiment of a conical plate type rotational viscometer according to the present invention, and FIGS. 2 and 3 show a main part of the rotational viscometer 1 of the embodiment specifically manufactured. It is a photograph. The rotational viscometer 1 will be described with reference to FIGS.

  The rotational viscometer 1 includes a drive-side conical disk 2 disposed below, and a driven-side flat-plate driven concentrically disposed on the conical-surface disk 2 where torque measurement is performed. The disc 3 with the flat surface on the side and the guard 4 arranged outside the disc 3 with the flat surface are provided.

  The disc 2 with a conical surface on the drive side is fixed concentrically (with the center of the disc 2 with a conical surface and the center of the rotary drive shaft 5 coincided) to the upper end of the rotary drive shaft 5. It is structured to rotate together with the rotary drive shaft 5 by a motor (not shown) for driving the motor. The disc 2 with a conical surface has a top surface formed in a conical shape, and an annular wall 7 is formed on the periphery thereof, and the disc 2 with a conical surface receives a sample whose viscosity is to be measured together with the annular wall 7. Functions as a sample container.

  The flat surfaced disc 3 has a flat bottom surface and is concentrically and horizontally fixed to the lower end of the rotary driven shaft 6, and its center is located at the apex of the cone of the conical surface disc 2. Are arranged concentrically. The rotation driven shaft 6 is measured by a torque measuring device (not shown).

  The guard 4 includes a cylindrical portion 8 concentrically arranged with the rotary driven shaft 6, a horizontal annular plate 9 provided at the lower end of the cylindrical portion 8, and an annular ring having a rectangular cross section provided on the lower surface of the horizontal annular plate 9. From the body 10, it is comprised integrally or separately.

  The annular body 10 is arranged so as to be positioned on the outer peripheral side of the flat plate 3 with a flat surface through an annular gap. The lower surface (surface in contact with the sample) of the disc 3 with the flat surface and the lower surface (surface in contact with the sample) of the annular body 10 are located on the same surface (same plane, with a gap in the radial direction (radial direction) of the disk 3. If the lower surface of the flat surfaced disk 3 is a conical surface, it is disposed within the same conical surface). In short, continuity as if it is one object is necessary.

  In this embodiment, the disc 2 with a conical surface is rotated, the guard 4 is arranged on the disc 3 side with a flat surface, and the torque is measured by the rotary driven shaft 6. It is good also as a structure opposite to a surface. That is, the rotational drive side may be replaced with the conical surface of the conical surface-equipped disc 2 to form a flat plate-like disc with a flat surface, and the conical surface may be provided on the lower surface of the flat surface-equipped disc 3. Good.

  Moreover, it is good also as a structure of what is called a parallel plate type | formula rotational viscometer which does not have a conical surface and is both flat surfaces. That is, the rotation drive side may be replaced with the conical surface of the conical surface-equipped disc 2 to form a flat plate-like disc with a flat surface, and the flat surface-equipped disc 3 may be left as it is. In this sense, the “disk” in the present invention includes not only a disk with a conical surface but also a disk with a flat surface having a flat surface.

  In the above embodiment, the rotation drive side disk and the rotation driven side disk are provided, but the rotation drive side disk and the fixed disk (fixed side disk) are combined to form both circles. A configuration may be adopted in which the sample to be measured is filled between the plates, the disc on the rotational drive side is rotated, and the torque of the disc on the rotational drive side itself is measured.

  Although the rotational viscometer 1 has been described above, it can be applied as a rheometer for measuring the viscoelasticity of a fluid material with exactly the same configuration.

(Function)
The operation of the rotational viscometer 1 having the above configuration will be described. When the viscosity of the sample 11 is measured by the rotational viscometer 1, the sample 11 is placed on the disc 2 with a conical surface functioning as a sample container and the lower surface of the disc 3 with a flat surface as shown in FIG. It is put to the extent that it is immersed. Then, the sample 11 is filled in a gap between the conical surface and the flat surface between the circular plate 2 with a conical surface and the circular plate 3 with a flat surface.

  The rotary drive shaft 5 is rotated by a motor (not shown) to rotate the disc 2 with a conical surface. Then, the torque of the disc 2 with a conical surface is transmitted to the disc 3 with a flat surface and the rotary driven shaft 6 due to the viscosity of the sample 11. The viscosity of the sample 11 can be measured by measuring the torque transmitted to the rotary driven shaft 6 with a torque measuring device (not shown).

  Since the outside of the portion sandwiched between the conical-surfaced disk 15 and the flat-surfaced disk 14 is a space that is not more restricted, the deformation rate (shear rate or shear rate) of the sample is reduced. If the property depending on the deformation speed of the sample is non-linear, the stress generated thereby differs from that assumed from the number of rotations of the apparatus, resulting in measurement errors. Since the rotational viscometer is a torque measurement, the influence is larger as it is farther from the central axis, and the end face effect coming from the outer peripheral portion tends to cause this error.

  In order to eliminate the effect of the end face of the circular plate 15 with the conical surface, the portion that receives the effect of the end face may be separated from the measurement system. That is, of the conical disk 15 or the flat disk 14, the method of measuring (generating) the torque is divided into an inner side and an outer side so that no stress is transmitted between them. The effect of the end face is hardly transmitted to the inner part, and if this part is used for measurement, the measurement without the end face effect is possible.

  However, in this rotational viscometer 1, the annular body 10 of the guard 4 is provided, and the lower surface of the annular body 10 is arranged with continuity in the same plane as the lower surface of the disk 3 through a gap. Yes. Therefore, between the lower surface of the annular body 10 and the lower surface of the disk 3, stress (shear stress) generated on the lower surface of the annular body 10 is blocked by the gap and is not transmitted. The influence on torque measurement is eliminated, and highly accurate measurement is possible.

  In short, stress acts on the outer peripheral surface of the guard 4 with respect to the disc 2 with the conical surface, but no stress is generated because the outer peripheral surface of the disc 3 with the flat surface does not move relative to the annular body 10. Thus, the measurement of the ideal conical disk 2 type viscometer 1 is possible.

  In addition, although a clearance gap is required between the annular body 10 of the guard 4 and the disc 3 with the flat surface on the inner side, the sample 11 is likely to be generated at the periphery of the disc 3 with the flat surface by rotation by reducing this. The deviation from the ideal flow can be reduced.

(Modification)
FIG. 5 is a view for explaining a modification of the embodiment of the rotational viscometer according to the present invention. The configuration of the rotational viscometer 1 of this modification is the same as that of the embodiment, but the torque measuring unit in the conventional coaxial double cylindrical rotational viscometer as shown in FIG. 6 can be shared. It is characterized by.

  That is, in the conventional coaxial double cylindrical rotational viscometer 18 shown in FIG. 6, the outer cylinder 19 is made to coincide with the axis of the inner cylinder 21 with high accuracy by using the wedge-shaped fastening auxiliary member 20. The cylinder 22 is configured to be held.

  Therefore, in this modification, by replacing the inner cylinder 21 with the disc 3 and the outer cylinder 19 with the guard 4, it is possible to use both the coaxial double cylinder rotational viscometer 18 and the rotational viscometer 1 of the present invention. I made it possible.

  Thus, in this modified example, the rotational viscometer 1 of the present invention can be used for fixing and holding the guard 4 so that the measuring system of the coaxial double cylindrical rotational viscometer 18 and the torque measuring unit can be shared. The wedge-shaped fastening auxiliary member 20 that holds the outer cylinder 19 of the coaxial double cylinder rotational viscometer 18 is designed to be used.

  As described above, the best mode for carrying out the rotational viscometer according to the present invention has been described by way of examples, but the present invention is not limited to the above examples, and is within the technical scope of the claims. Needless to say, there are various aspects.

  Since the rotational viscometer according to the present invention has the above configuration, it is suitable for viscosity measurement and viscoelasticity measurement for viscous materials and viscoelastic materials used for various purposes.

It is a figure explaining the Example of this invention. It is a photograph explaining the Example of this invention. It is a photograph explaining the Example of this invention. It is a figure explaining a prior art example. It is a figure explaining the modification of the Example of this invention. It is a figure explaining the conventional coaxial double cylinder rotational viscometer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,12 Rotational viscometer 2,15 Disc with conical surface 3 Disc with flat surface 4 Guard 5, 13 Rotation drive shaft
6, 16 Rotating driven shaft
Reference Signs List 7 annular wall 8 cylindrical portion 9 horizontal annular plate 10 annular body 11 sample liquid 14 disk with flat surface 17 sample liquid 18 coaxial double cylinder rotational viscometer 19 outer cylinder 20 wedge-shaped fastening auxiliary member 21 inner cylinder

Claims (8)

A sample to be measured is filled between a disk on the driving side and a disk on the driven side that are arranged concentrically with each other, the disk on the driving side is driven to rotate, and driven by the viscosity of the sample to be measured. A rotational viscometer that measures the viscosity of the sample to be measured by measuring the torque of the driven disk that receives the driving force,
On the outer periphery of the disk on the driven side, it has a guard having an annular body arranged with a certain gap in the radial direction of the disk,
The rotational viscosity, wherein the surface of the driven disk that contacts the sample to be measured and the surface of the annular body that contacts the sample to be measured are arranged in the same plane. Total. The driven disk is fixed to the lower end of the rotating shaft,
The guard is composed of a cylindrical portion, an annular plate and the annular body,
The rotational viscometer according to claim 1, wherein the cylindrical portion is concentrically arranged on an outer periphery of the rotating shaft. A sample to be measured is filled between a drive-side disc and a fixed-side disc that are arranged concentrically with each other, and the drive-side disc is driven with a drive torque determined to drive the sample to be measured. A rotational viscometer that measures the viscosity of the sample to be measured by measuring the rotational speed determined by the viscosity of
Around the outer periphery of the drive-side disk, there is a guard having an annular body that is arranged with a certain gap in the radial direction of the disk and controlled to rotate the same as the drive-side disk. And
The rotational viscosity, wherein a surface of the drive-side disc in contact with the sample to be measured and a surface of the annular body in contact with the sample to be measured are arranged in the same plane. Total. The disk on the driving side is fixed to the lower end of the rotating shaft,
The guard is composed of a cylindrical portion, an annular plate and the annular body,
The rotational viscometer according to claim 3, wherein the cylindrical portion is concentrically arranged on an outer periphery of the rotating shaft. A sample to be measured is filled between a disk on the driving side and a disk on the driven side that are arranged concentrically with each other, the disk on the driving side is driven to rotate, and driven by the viscosity of the sample to be measured. A rheometer that measures the viscoelasticity of the sample to be measured by measuring the torque of the driven disk that receives the driving force,
On the outer periphery of the driven-side disc, there is a guard having an annular body arranged with a certain gap in the radial direction of the disc,
The rheometer, wherein a surface of the driven disk that contacts the sample to be measured and a surface of the annular body that contacts the sample to be measured are arranged in the same plane. The driven disk is fixed to the lower end of the rotating shaft,
The guard is composed of a cylindrical portion, an annular plate and the annular body,
The rheometer according to claim 5, wherein the cylindrical portion is configured to be concentrically arranged on an outer periphery of the rotating shaft. A sample to be measured is filled between a drive-side disc and a fixed-side disc that are arranged concentrically with each other, and the drive-side disc is driven with a drive torque determined to drive the sample to be measured. A rheometer for measuring the viscoelasticity of the sample to be measured by measuring the rotational speed determined by the viscosity of
Around the outer periphery of the drive-side disk, there is a guard having an annular body that is arranged with a certain gap in the radial direction of the disk and controlled to rotate the same as the drive-side disk. And
The rheometer characterized in that a surface of the drive-side disk that contacts the sample to be measured and a surface of the annular body that contacts the sample to be measured are arranged in the same plane. The disk on the driving side is fixed to the lower end of the rotating shaft,
The guard is composed of a cylindrical portion, an annular plate and the annular body,
The rheometer according to claim 7, wherein the cylindrical portion is concentrically arranged on an outer periphery of the rotation shaft.