JPH0311725Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a rigid pendulum for measuring viscoelasticity, especially for paints,
The present invention relates to a rigid pendulum type viscoelasticity measuring device suitable for measuring the process of drying and forming films on solid surfaces of substances such as adhesives, polymeric materials, foods, and building materials.

[Conventional technology]

A measuring instrument has been proposed that measures the viscoelasticity of samples such as paints, adhesives, and polymeric materials using a rigid pendulum that vibrates on a knife-edge fulcrum (Seiji Ushiani: Shikizai, 51, p. 403 (1978)). FIG. 4 is a conceptual diagram thereof, FIG. 5 is a sectional view of a part thereof, and FIG. 6 is a block diagram.

In the figure, reference numeral 1 denotes a rigid pendulum, which has a knife-edge-shaped fulcrum 3 projecting downward from the upper side of the frame portion 2 and leg portions 4 extending downward from the lower side of the frame portion 2 . Reference numeral 5 denotes a support section, which has a sample holder 6 and a heater 7 on its upper part, on which a sample 8 is placed, and on which the fulcrum 3 of the pendulum 1 is placed. The test piece 8 has a structure in which a sample 10 of paint or the like is applied onto a support plate 9 such as a metal plate. 11 is an electromagnet for vibrating the pendulum 1, 12 is a driving timer, 13 is a detection probe, 14 is a displacement meter, 15 is a recorder (oscilloscope), 16 is a thermostat for controlling the heater 7, and 17 is a It is a recorder (balanced type).

The method for measuring viscoelasticity is to place a sample 8 on a support plate 9 coated with the sample 10 on the sample holder 6, lower the knife edge-shaped fulcrum 3 of the rigid pendulum 1 perpendicularly to the coated surface of the sample 10, and Set the state as shown in the figure. Then, according to the timing signal of the timer 12, the electromagnet 1
1 is energized, the magnetic material attached to the leg 4 of the pendulum 1 is attracted and vibrated, and the amplitude and frequency are detected by the probe 13 and the displacement meter 14 and recorded on the recorder 15. When heating the sample 10 for measurement, the heater 7 is energized by a signal from the thermostat 16 to heat the sample 8 through the sample holder 6.

In the case of viscoelasticity measurement during the entire process of film formation, the sample may be a liquid substance such as liquid paint, a powder substance such as powder coating, or a gel substance such as butter. Specifically, after the pendulum 1 is installed, the sample 10 is left at room temperature for a certain period of time to force the solvent in the sample 10 to evaporate. Thereafter, heating of the specimen 8 is started by the heater 7, and changes in the vibration period T and logarithmic damping rate Δ of the pendulum 1 as the specimen 10 hardens are measured over time. Vibration measurement is almost the same as described above, and the displacement of the lower end of the pendulum 1 is detected by the probe 13 and the displacement meter 14 and recorded on the recorder 15. The pendulum 1 is vibrated by energizing the electromagnet 11. The timer 12 automatically controls the excitation of the pendulum 1 and the recording of vibrations, and also controls the recording of the recorder 1.
Input the timing signal to 5. The temperature of the sample holder 6 is recorded on the recorder 17.

In such a measurement method, the fulcrum 3 of a rigid pendulum 1 having a shape as shown in Fig. 5 is placed on a horizontal base surface, the pendulum 1 is allowed to vibrate freely with this fulcrum 3 as a contact point, and the support in this vibration system is When a sample 10 of paint, adhesive, etc. is interposed between the plate 9 and the fulcrum 3, the pendulum 1 changes due to changes in its mechanical properties.
The amplitude and frequency of vibrations change. This change is measured over time to evaluate the curing process of coatings such as paints and adhesives.

Conventionally, the rigid pendulum 1 used in such a viscoelasticity measuring instrument is a plate-shaped pendulum that is thin in the vibration direction and has a wide surface perpendicular to the vibration direction, as shown in Figure 4. ing.

[Problem that the invention attempts to solve]

However, in the measurement of the film formation process described above, the sample 10 at the start of the measurement is in the form of a solution, powder, or gel and has low viscosity, so the damping effect on the rigid pendulum 1 is small, and therefore the magnetic material at the tip of the pendulum 1 is When the body is vibrated by the electromagnet 11, the pendulum 1 tilts linearly, but when the film becomes hard due to the formation of a film, the pendulum 1 tilts at the 3 knife-edge-shaped fulcrums contained in the film. Since it is firmly fixed, the magnetic body at the tip of pendulum 1 is connected to electromagnet 1.
1, the pendulum 1 does not tilt linearly but curves, and the leg portion 4 of the pendulum 1 is bent as shown in FIG. 7, 1a. Since the center of the rigid pendulum 1 continuously moves during measurement due to the bending of the pendulum 1, data abnormalities are not noticeable, but there is a problem of lack of reliability.

This idea was developed to solve the above problems, and is a rigid pendulum for viscoelasticity measurement in which the legs of the rigid pendulum used in a rigid pendulum type viscoelasticity measuring instrument do not bend even if the sample hardens during measurement. The purpose is to obtain.

[Means for solving problems]

This device has a frame part having a fulcrum that is placed on the sample, and legs protruding from the frame part, and the dimensions of the legs in the vibration direction are larger than the dimensions of the frame part in the vibration direction. This is a rigid pendulum for measuring viscoelasticity.

[Effect]

The rigid pendulum for measuring viscoelasticity of this invention is vibrated by placing the fulcrum on the sample like the conventional one, but the dimensions of the legs in the vibration direction are larger than the dimensions of the frame in the vibration direction. The legs are less deformed and do not bend even when the sample hardens, thus providing highly reliable data.

〔Example〕

1 and 2 show another embodiment of the invention, A is a front view, B is a sectional view thereof, C is a plan view, and FIG. 3 is a second embodiment of the invention. 7 is a plan view of FIG. A, and the same reference numerals as in FIGS. 4 to 7 indicate the same or corresponding parts. FIG.

1 to 3, the rigid pendulum 1 has a knife edge-shaped fulcrum 3 projecting downward from the upper side of the frame part 2, and legs extending downward from the lower side of the frame part 2, as in the conventional one. has 4,
It is made of rigid materials such as stainless steel, steel, ceramics, iron, plastic, and aluminum. The dimension of the leg portion 4 in the vibration direction is larger than the dimension of the frame portion 2 in the vibration direction. 2
1 is embedded in the leg 4 facing the electromagnet 11, or
Alternatively, the attached magnetic pieces 22 are metal sensor parts embedded or attached to the leg 4 facing the probe 13, and are attached to both sides of the leg 4 so as to maintain balance.

In Fig. 1, the leg portion 4 is a plate-like member,
In this example, a stainless steel leg part 4 with a thickness of 2 mm, a width of 10 mm, and a length of 150 mm is attached to a frame part 2 with a thickness of 3 mm and a width of 5 mm on one side in the vertical direction. ing.

In Fig. 2, a cylindrical leg part 4 is attached to the frame part 2, and in the embodiment, a cylindrical stainless steel leg part 4 with a diameter of 10 mm is attached to the frame part 2 with a thickness of 3 mm and a width of 5 mm on one side in the vertical direction. Section 4 is attached.

In Fig. 3, a prismatic leg portion 4 is attached to the frame portion 2, and in the embodiment, a prismatic stainless steel leg portion 4 with a side length of 10 mm is attached to the frame portion 2 with a thickness of 3 mm and a width of 5 mm on one side in the vertical direction. Legs 4 are attached.

The rigid pendulum 1 configured as described above has a specimen 8 placed on a specimen holder 6, similar to the conventional one.
The fulcrum 3 is placed on the sample 10 of
Vibrate around fulcrum 3. Even if the sample 10 hardens at this time, since the dimension of the leg portion 4 in the vibration direction is larger than the dimension of the frame portion 2 in the vibration direction, elastic deformation or plastic deformation of the leg portion 4 is small.
Since it does not curve, highly reliable data can be obtained. In the measurements using each of the pendulums 1 of the above embodiments, there was no deformation of the leg 4 in any case, but the conventional pendulum 1
It was curved as shown in Figure 7.

In this way, when using the rigid pendulum 1 to measure the viscoelasticity in the process of forming a film of paint, etc., it is possible to do the measurement without bending the pendulum 1 due to the force of the magnet used to give initial vibration during the measurement. .

In the above description, the shape of the pendulum 1 is not limited to that shown in the drawings, and the shape of the leg portion 4 may be any shape as long as the dimension in the vibration direction is larger than the dimension in the vibration direction of the frame portion 2. Can be changed arbitrarily.

[Effect of idea]

According to the present invention, the dimensions of the legs of the pendulum in the vibration direction are increased, resulting in the following effects.

There is no need to correct the curvature of the pendulum each time a measurement is made.

Since there is no deformation of the device, data reliability is ensured.

[Brief explanation of the drawing]

1 and 2 show another embodiment, A is a front view, B is a cross-sectional view thereof, C is a top view, and FIG. 3 is a diagram showing another embodiment of FIG. 4 is a conceptual diagram of a conventional viscoelasticity measuring instrument, FIG. 5 is a sectional view of a part thereof, FIG. 6 is a block diagram, and FIG. 7 is a perspective view showing the state of use. In each figure, the same reference numerals indicate the same or equivalent parts, 1 is a rigid pendulum, 2 is a frame part, 3 is a fulcrum,
4 is a leg part, 21 is a magnetic piece, and 22 is a sensor part.

Claims (1)

[Claims for Utility Model Registration] (1) It has a frame part having a fulcrum to be placed on a sample, and a leg part protruding from this frame part, and the dimension of the leg part in the vibration direction is equal to the vibration of the frame part. A rigid pendulum for measuring viscoelasticity, characterized in that the dimension is larger than the dimension in the direction. (2) The rigid pendulum for measuring viscoelasticity according to claim 1, wherein the leg portion is plate-shaped, cylindrical, or prismatic.