JPH0663963B2 - Method and device for measuring peeling force or rewinding force of adhesive tape - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for measuring the peeling force or rewinding force of an adhesive tape.

[Conventional technology and its problems]

As for the peeling force or the rewinding force of the adhesive tape, there are a method of measuring the peeling load at a constant speed and a method of measuring the peeling speed at a constant load.

The former is a constant speed peeling method, and the latter is a constant load peeling method.
The former is more common and is specified in JIS,
Probably because it is easier to measure the load than to measure the speed, most of the adhesive force, ie, the peel force data is measured by the constant load peeling method.

For constant speed peeling, the lowest peeling rate reported is 10 ^{- 4}
cm / sec. This is because if the speed is lower than this, a stable speed cannot be obtained due to the elongation of the substrate.

The low-speed peeling property of the pressure-sensitive adhesive tape is one of the extremely important properties for practical use. This is because it is often considered that peeling, which is a practical problem of the adhesive tape, is gradually caused by a restoring force of the bent base material or a minute stress due to shrinkage.

Regarding the peeling force, 90 ° peeling force and 180 ° peeling force are usually tested, but the test methods are roughly classified into two types as described above.

Next, a conventional 90 ° peel test method will be described with reference to the drawings.

1) Constant-speed peeling test method As shown in FIG. 2, a test piece 1 having a constant width is attached to the surface of an adherend 2 made of stainless steel, for example, for a constant length, and one end is subjected to a load such as a load cell. After fixing to the clamp 4 of the detector 3, the adherend 2 is moved downward at a constant speed, the load at that speed is measured, and the load for a predetermined width of the tape (for example, 1 cm) is obtained as a peeling force. is there. In this case, it is necessary to move the adherend 2 downward so that the non-adhesive part of the tape 1 becomes 90 ° with respect to the adherend. The corresponding peel force was difficult to measure.

The load cell shown in Fig. 2 is pendulum type.
It is a Shipper type tensile tester shown in the figure.

In the peeling test by the test, a test piece 1 having a predetermined width is adhered to the surface of a cylindrical adherend 2 on the right side of the rotation at an arbitrary length,
After fixing the non-adhesive end to a clamp 4 suspended on a pulley with a pendulum fixed in the center, the adherend 2 was moved at a constant speed (v) by a motor, and the pendulum 5 became vertical to the balanced portion. Is measured, and the peeling force is calculated by the following equation.

In this case, the angle θ changes from θ ₁ to θ between the times t ₁ and t _2.
If it reaches ₂ , the clamp position is r (θ ₁ −θ ₂ ).
Therefore, the true velocity V is V = v−r (θ ₁ −θ ₂ ) / (t ₂ −t ₁ ) ...
(2)

2) Constant load peeling test method In the constant load peeling test method, as shown in FIG. 4, the test piece 1 is adhered to the surface of the adherend 2 for an arbitrary length, and the non-bonded end is weighed with a constant weight 6 Then, the amount of displacement of the weight 6 is measured, the displacement speed is obtained from the amount of displacement at a constant time, and the load (g) (for a constant width) at that speed is obtained as the peeling force.

FIG. 5 shows the displacement amount with respect to time when a peeling test of a certain tape was performed.

In the figure, the velocity v is calculated as y / x. When this method is used, in order to obtain the peeling force for various speeds, it is necessary to measure the peeling force a plurality of times using different weights, which is troublesome.

In addition, in the device shown in FIG. 3 or FIG.
The unwinding force of the adhesive tape can be measured by rotatably mounting the wound adhesive tape instead of No. 1 and connecting one end of the unwound tape to the weight 6 by the clamp 4.

[Object of the Invention]

As a result of various studies on the peeling test method of the adhesive tape, the present inventor has found a method for obtaining data on the peeling force from the low speed region to the high speed region. No, it is not a constant load peeling test, and the peeling force or rewinding force of the adhesive tape from the low speed region to the high speed region can be easily measured by obtaining the change of the peeling speed or the rewinding speed due to the change of the peeling load. Methods and apparatus are provided.

[Structure of Invention]

The present invention is: 1. One end of the peeling force test piece of the adhesive tape is attached to the surface of the adherend, and the other end is connected to a rotatable pulley in which a pendulum having a weight is fixed to the center part, The pendulum is moved from immediately near the top of the pulley to the bottom of the pulley by the weight of the pendulum against the adhesive force of the test piece to the adherend. As a method of measuring the peeling force of the adhesive tape.

2. Set the adhesive tape rotatably on the frame, connect the rewinding end of the adhesive tape to a rotatable pulley with a pendulum with a weight fixed to the center, and place the pendulum directly above the pulley. The pendulum weight causes the pendulum weight to rotate to a position directly below the pulley against the unwinding force of the adhesive force from the vicinity, and the rewinding force of the adhesive tape as a function of that speed is measured from the change in the rotating speed of the pulley during this period. how to.

3. Peeling force of adhesive tape The adherend for adhering one end of a test piece and a pendulum having a weight independent of the adherend are attached to the center of the rotary shaft to the right, and the test is performed. An apparatus for measuring the peeling force of an adhesive tape, comprising a pulley for connecting the other end of one piece, and a rotation speed measuring machine for the pulley.

4. A pedestal capable of rotatably setting an adhesive tape, and a pendulum having a pendulum having a weight independent of the pedestal fixed to a central portion and being rotatable, and a pulley for connecting a rewinding end of the adhesive tape. And a rewinding force measuring device for an adhesive tape, wherein the pulley is provided with a rotational speed measuring machine.

Is.

The peeling force is measured in addition to the so-called pressure-sensitive adhesive tape, which is also used for a so-called adhesive tape having no tackiness at room temperature, and when the adhesive force of the adhesive, that is, the peeling force is tested,
Since this is applied to a base material to prepare a tape-shaped or sheet-shaped test piece, the measurement of the peeling force of the adhesive tape in the present invention includes the measurement of the peeling force of the adhesive tape or the adhesive. is there.

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the device of the present invention. Reference numeral 1 is a test piece of an adhesive tape whose peeling force is to be measured, 2 is a cylindrical adherend to which the adhesive tape 1 is attached, and 7 is a pulley. 4 is a clamp, 5 is a pendulum, 6 is a weight, 8 is a constant temperature bath, and 9 is a potentiometer.

First, the test piece 1 is attached to the adherend 2, and the end of the non-adhesive portion of the test piece is connected to the pulley 7 with a tape clamp 4
Then, the weight 6 of the pendulum 5 is fixed while being held at a position in the vicinity of an upper portion of the pulley 7. Then, when the weight 6 is released, the pendulum rotates in the direction of the arrow by the weight of the weight while resisting the adhesive force of the adhesive tape, and the weight reaches the portion immediately below the pulley 7 and stops.

The peeling load is transmitted to a pulley connected to the pendulum shaft.
At the same time, this shaft is also connected to a potentiometer to take out the displacement amount of the pendulum as an electric signal, and this signal is A / D converted and then input to the calculator.

The relationship between the position (angle θ) of the pendulum (angle θ) and the load after the pendulum weight 6 is released and immediately below the pulley is shown in FIG.

That is, when the weight position is just above (0 rad) and just below (π rad), the load is 0, and when it is just beside (π / 2 rad), the sine curve becomes maximum.

That is, since the weight starts right above, the load peels off while gradually increasing. Then, after the maximum load is exceeded, the adhesive tape peels off while the load gradually decreases. When subjected to a certain load, the test sample peels at a speed commensurate with the load due to its peeling characteristics. With this device, the peeling rate cannot be determined spontaneously, but the load with respect to the peeling rate can be easily calculated.

In the apparatus shown in FIG. 1, the adherend 2 is rotatably supported so that the peeling angle is always 90 °. Further, it is preferable that the adherend is held in a constant temperature and constant humidity tank so that it can be kept at a predetermined temperature and humidity.

Although FIG. 1 shows an example in which the adherend 2 is provided on the pulley 7, the adherend may be located at any position such as a side or a position directly below the pulley.

In the apparatus shown in FIG. 1, the adherend has a cylindrical shape, but it can be 90 ° or
It can also be used as a 180 ° peel tester. Also,
A rotary encoder may be used instead of the potentiometer.

The relationship between the peeling load and the position of the pendulum is as follows.

The peeling rate can be calculated as follows.

L: Distance from the center of rotation of the pendulum (cm) m: Pendulum mass (g) θ: Pendulum displacement angle r: Pulley radius (cm) g: Gravity velocity I: Pendulum inertia moment Potentiometer is green Ware made GPP45 (linearity: 1/1000
Torque: 15 g · cm) was used.

In practice, the elapsed time t was calculated with a resolution of 0.01 each time θ changed by 1 ° with a computer, and the angular velocity was obtained from θ = 1 / t. When r = 1.5 cm, if θ changes by 1 °, peeling proceeds by about 0.026 cm.

The peeling force of a pressure-sensitive adhesive tape obtained by applying a rubber-based pressure-sensitive adhesive to a thickness of 30 μm on a PET having a thickness of 25 μm was measured using the apparatus shown in FIG. 1 using a glass cylinder as an adherend. The measurement is made by pressing the adhesive tape with a 2 kg rubber roller and applying 2 at 50 ° C.
After standing for a time, the temperature was measured at 30 ° C.

The results obtained in the above test are shown in FIG. In FIG. 7, the horizontal axis shows the peeling speed in logarithm, and the vertical axis shows the peeling load.

When the weight is released at point A (near θ = 0) shown in FIG. 7,
While reaching cohesive failure, point B is reached, where the speed rapidly increases to point C (θ = π / 2), and then deceleration begins.
It can be seen that this time, the interface fractures, but does not pass through the point B, merges with the outward path at the point D, and again undergoes cohesive failure and returns to the point A.

The size of the device used for the test is 11.5 mm in diameter of the adherend.
cm, the diameter of the pulley was 3 cm, the length of the pendulum (up to the center point of the weight) was 8 cm, and the weight of the weight was 50 g.

Further, in place of the adherend 2 of FIG. 1, a wound adhesive tape is rotatably mounted, and the end portion of the unwound adhesive tape is connected to the clamp 4, whereby the unwinding force of the adhesive tape is increased. Can be measured.

Note that a plate-shaped adherend is used instead of the cylindrical adherend 2.
When performing the ° peel test, it is necessary to adjust the position of the plate so that the peel angle of the adhesive tape is kept at 90 ° during the test.

According to the present invention, the peeling load over a wide peeling speed region can be easily measured as shown in FIG. 7, and the composition of the pressure-sensitive adhesive, the coating thickness, etc. can be designed using these measurement results as an index. It is possible.

Similarly, based on the result of measuring the rewinding force of the adhesive tape, the composition of the adhesive, the coating thickness, the type of the release agent, and the like, particularly for the carrier tape, can be easily designed.

[Brief description of drawings]

FIG. 1 is a drawing for explaining the method and apparatus of the present invention,
2, 3 and 4 are drawings for explaining different conventional methods, FIG. 5 shows the relationship between time and displacement amount of weight in a constant load peeling tester, and FIG. FIG. 7 shows the relationship between the position of the pendulum and the load in the inventive method, and FIG. 7 shows the relationship between the peeling speed and the peeling load when measured according to the present invention. 1 ... test piece, 2 ... adherend, 3 ... load detector, 4 ...
… Clamp, 5 …… Pendulum, 6 …… Weight, 7 …… Pulley, 9 …… Potentiometer

Claims (4)

[Claims] 1. A peeling force test piece of an adhesive tape having one end adhered to the surface of an adherend and the other end connected to a rotatable pulley having a pendulum having a weight fixed to the center thereof,
The pendulum is moved from immediately near the top of the pulley to the bottom of the pulley by the weight of the pendulum against the adhesive force of the test piece to the adherend. Method for measuring the peeling force of adhesive tape. 2. An adhesive tape is rotatably set on a frame, and the rewinding end of the adhesive tape is connected to a rotatable pulley having a pendulum having a weight fixed to the center thereof, and the pendulum is attached directly to the pulley. The unwinding force of the pendulum is rotated from the vicinity of the upper part to the lower part of the pulley by the self-weight of the pendulum, and the unwinding force of the adhesive tape as a function of that speed is determined from the change in the rotating speed of the pulley during this period. How to measure. 3. An adhesive tape for adhering one end of a peeling force test piece and a pendulum having a weight independent of the adherend, which is fixed to a central portion and is rotatable.
Provide a pulley for connecting the other end of the test piece,
An apparatus for measuring the peeling force of an adhesive tape, wherein the pulley is provided with a rotation speed measuring device. 4. A pedestal capable of rotatably setting an adhesive tape, and a pendulum having a weight independent of the pedestal fixed to a central portion, which is rotatable, and is connected to a rewinding end portion of the adhesive tape. A rewinding force measuring device for an adhesive tape, which is provided with a pulley for the rotation of the pulley and is provided with a rotating speed measuring device for the pulley.