JP2012202878A - Adhesion strength evaluation method of laminates and adhesion strength evaluation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesion strength evaluation method of laminates with which a strength of adhesion between coating of laminates having different compositions or thickness of coating and a substrate is evaluated quantitatively within a short time.SOLUTION: A blade 21 is pressed on a surface A which is tilted with respect to an end face D or an advancing direction of the blade 21 in a laminate 1 applying coating 11 uniformly to a surface of a substrate 12, the blade 21 is then moved and a peel load value between the coating 11 and the substrate 12 and a cut load value of the coating 12 are determined. A load value required for tearing the coating 11 in a thickness direction and deforming a tester is determined from the cut load value, an inclination of a primary function of a moving distance of the blade 21, an angle formed from the surface A and a cut surface and thickness of the coating 11. Such a load value is subtracted from the peel load value, thereby determining an adhesion load value between the coating 11 and the substrate 12.

Description

  The present invention relates to a method for evaluating adhesion strength between a coating film and a substrate, and an apparatus for evaluating adhesion strength of a laminate in which a coating film is uniformly applied to the surface of the substrate.

  A peel test method (JIS K6854-1) is known as a method for quantitatively evaluating the adhesion strength between a coating film and a substrate. The peel test method is an evaluation method in which the coating film and the substrate are peeled off, and the load value necessary for peeling is used as the adhesion strength between the coating film and the substrate. This method has a drawback that when the adhesion strength between the coating film and the substrate is strong, one of the coating film and the substrate breaks, and the adhesion strength cannot be evaluated.

  In order to solve the above drawbacks, a method is used in which the coating film is peeled by moving the blade applied to the coating film, and the adhesion strength is obtained from the load value applied to the blade at this time. This method is disclosed in Japanese Patent Application Laid-Open No. 61-169745 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2005-283215 (Patent Document 2). These methods have a problem that the adhesion strength of laminates having different coating composition and coating film thickness cannot be compared. This is because the measured value includes a load value for cutting the side surface of the blade in the thickness direction of the coating film and a load value for deforming the peeled test piece.

  The above problem can be solved by subtracting the load value required for tearing the coating film and deforming the peeled test piece from the load value when peeling the coating film from the substrate. The load value required for the tearing of the coating film and the deformation of the peeled test piece is determined by moving the blade applied to the coating film to cut the coating film, and the cutting load value applied to the blade and the depth from the surface to the cutting surface. It can be obtained from the product of the slope of the linear function and the film thickness of the coating film. This method is disclosed in Japanese Patent Application No. 2010-218422 (Patent Document 3).

JP-A 61-169745 JP 2005-283215 A Japanese Patent Application No. 2010-218422

  In the method of Patent Document 3, in order to obtain the cutting load value and the slope of the linear function of the depth from the surface to the cutting surface, it is necessary to repeatedly perform cutting while changing the depth from the coating film surface. For this reason, many operations are required to perform the adhesion strength evaluation, and it takes a long time to measure.

  The present invention is intended to solve the above-described problems, and an object of the present invention is to provide a method for evaluating the adhesion strength of a laminate that is simpler and has a shorter measurement time than the method of Patent Document 3.

  In order to solve the above problems, the invention of claim 1 is a method for evaluating the adhesion strength between a coating film of a laminate in which a coating film is uniformly applied to the surface of the substrate and the substrate, and After the blade is pressed against the end face, the blade is moved in parallel with the surface of the coating film to peel the coating film from the substrate, and the first step of measuring the peeling load value between the coating film and the substrate, After pressing the blade against the surface of the coating film inclined with respect to the traveling direction, the blade is moved to cut the surface of the coating film, and the inclination of a linear function of the blade moving distance and the cutting load value of the coating film is measured. From the term consisting of the second step, the inclination in the second step, the angle formed by the surface of the coating film and the cutting surface, and the thickness of the coating film, From the third step for obtaining the load value required for deformation, and the peel load value in the first step, the load value in the third step is calculated. By then pulling, characterized in that it comprises a fourth step of obtaining the adhesion force value between the coating film and the substrate.

  According to a second aspect of the present invention, in the adhesion strength evaluation method according to the first aspect, an angle θ1 formed between the end surface of the laminated body against which the blade is pressed and the back surface of the laminated body is 20 ° or more and 70 ° or less. It is a range.

  According to a third aspect of the present invention, in the method for evaluating the adhesion strength of the laminate according to the first or second aspect, an angle θ2 formed by an end surface that presses the blade and the blade is 35 on a plane viewed from above the coating film. It is in the range of not less than 70 ° and not more than 70 °.

  Invention of Claim 4 is an apparatus which evaluates the adhesive strength between the coating film of a laminated body which apply | coated the coating film uniformly on the surface of the base material, and a base material, Comprising: The mounting direction was faced to the perpendicular direction The base material of the laminate is fixed, a stage that can be tilted with respect to the horizontal direction of movement of the blade, a blade that can move relative to the stage in the horizontal and vertical directions, and a blade that pushes the blade against the end face of the coating film When the blade is moved parallel to the surface of the paint film after application and the paint film is peeled off the substrate, the blade is pressed against the end face of the paint film and then moved to parallel to the surface of the paint film. And a load detector for detecting a horizontal load applied to the blade when the surface of the film is cut.

  According to the adhesion strength evaluation method and adhesion strength evaluation apparatus of the laminate according to the present invention, the adhesion strength between the coating film and the substrate of the laminate is quantitatively evaluated in a short time compared with the method of Patent Document 3. can do.

  Moreover, according to this invention of Claim 2 and Claim 3, it can peel easily in the interface between the coating film of a laminated body, and a base material.

It is a schematic cross section of the laminated body used as the object of evaluation according to the present invention. It is a model top view for demonstrating the 1st process and the 2nd process in the adhesion strength evaluation method of the laminated body which concerns on this invention. It is a model side view for demonstrating the 1st process in the adhesion strength evaluation method of the laminated body which concerns on this invention. It is an example of the graph of the load value with respect to the moving distance of the blade obtained when performing the 1st process of this invention with respect to the laminated body. It is a schematic diagram of the laminated body after performing the 1st process or the 2nd process of this invention with respect to a laminated body. It is a model side view for demonstrating the 2nd process in the adhesion strength evaluation method of the laminated body which concerns on this invention. It is an example of the graph of the cutting load value with respect to the moving distance of the blade obtained when performing the 2nd process of this invention with respect to the laminated body.

  Hereinafter, the form of the method and apparatus for evaluating the adhesion strength of a laminate according to the present invention will be described with reference to FIGS.

  First, the laminate to be evaluated in the present invention will be described with reference to FIG.

  The laminate 1 has a configuration in which a coating film 11 is provided in the upper layer and a base material 12 is provided in the lower layer. The coating film 11 is a film having a uniform component and film thickness. The surface in contact with the coating film 11 of the substrate 12 is smooth. The uppermost surface of the laminate 1 is referred to as the front surface A, the lowermost surface of the laminate 1 is referred to as the rear surface C, and the interface between the coating film 11 and the substrate 12 is referred to as the interface B. Moreover, the surface except the surface A and the back surface B among the surfaces of the laminated body 1 is defined as an end surface D.

  Hereinafter, the adhesion strength evaluation method of the present invention will be described.

  In the present invention, the blade 21 (see FIG. 2) is pressed against the end surface D of the coating film 11 and moved to peel the coating film 11 from the substrate 12, and the peeling load value between the coating film 11 and the substrate 12 is determined. The first process to be measured and the blade 21 is pressed against the surface A inclined with respect to the traveling direction of the blade 21 and then moved to cut the coating film 11, and the cutting load value of the coating film 11 and the cutting from the surface A are cut. A second step of obtaining a slope of a linear function of the depth to the surface.

  Hereinafter, the first step will be described with reference to FIGS.

  First, as shown in FIG. 3, the laminate 1 with the back surface C facing the stage 22 is fixed on the stage 22 using an adhesive or the like. Next, the blade 21 is pressed against the end surface D so that the tip of the blade 21 touches the vicinity of the interface B. At this time, the width direction of the blade 21 (the front and back direction in FIG. 3) is set to be parallel to the extending direction of the interface B on the end surface D. Thereafter, the blade 21 is moved in a straight line parallel to the interface B relative to the laminated body 1, and the coating film 11 is peeled off from the substrate 12. In this case, the blade 21 is moved in the arrow X1 direction parallel to the interface B, or the stage 22 is moved in the arrow X2 direction parallel to the interface B. At this time, as shown in FIG. 3, the load detector 23 such as a load cell connected to the blade 21 moves in the X2 direction while the blade 21 moves and peels the coating film 11 from the substrate 12. The load value is recorded with respect to the moving distance of the blade 21.

An example of the load value recorded by the load detector 23 in the first step is shown in FIG. FIG. 4 shows the moving distance of the blade 21 on the horizontal axis and the load value in the X2 direction applied to the blade 21 on the vertical axis. The load value continues to show a constant value after moving a certain distance. In FIG. 4 and Table 1, the constant value continues to be shown after moving about 0.4 mm. The load value that continues to show this constant value is defined as a peel load value F1.

  The shape of the laminated body 1 after the first step is shown in FIG. As shown in FIG. 5, after the operation of the first step, the coating film 11 is peeled off from the base material 12 to be rolled up as the test piece 31, and the test surface 32 is revealed. This test surface 32 becomes the interface B in the first step.

  In peeling by the first step, since the width of the coating film 11 is larger than the width of the blade 21 in the left-right direction in FIG. 5, the side surface portion of the blade 21 is positioned inside the width of the blade 21. And the coating film 11 located on the outer side are cut in the thickness direction of the coating film 11. The cut portion becomes the cut portion 33 in FIG. Further, as a result of peeling in the first step, the test piece 31 is deformed such as warpage or compression.

  The load value necessary for the tearing of the coating film 11 and the deformation of the test piece 31 is included in the peeling load value F1. When the load value representing the adhesion strength between the coating film 11 and the substrate 12 is F0 and the load value necessary for tearing the coating film 11 and deforming the test piece 31 is f, the following equation (1) is established.

F1 = F0 + f (1)
Since the load value f varies depending on the film thickness of the coating film 11 and the composition of the coating film 11, when comparing the adhesion strength of the laminates 1 having different film thicknesses of the coating film 11 and compositions of the coating film 11, the peeling load value F <b> 1. Cannot be used. Therefore, the load value f is obtained in the second step, and the adhesion load value F0 between the coating film 11 and the substrate 12 is taken out by subtracting from the peel load value F1 obtained in the first step.

  Next, a 2nd process is demonstrated based on FIG.2 and FIG.6.

  First, as shown in FIG. 6, the laminate 1 with the back surface C facing the stage 22 is fixed on the stage 22 using an adhesive or the like. At this time, as shown in FIG. 6, the stage 22 is tilted so that the traveling direction of the blade 21 and the surface A are not parallel. Next, the blade 21 is pressed against the surface A. At this time, the width direction of the blade 21 (the front and back direction in FIG. 6) is made parallel to the front and back direction in FIG. Thereafter, the blade 21 is moved in a straight line relative to the laminate 1 to cut the surface A of the coating film 11. In this case, the blade 21 is moved in the direction of the arrow X1, or the stage 22 is moved in the direction of the arrow X2. At this time, as shown in FIG. 6, the load in the X2 direction applied to the blade 21 while the blade 21 moves and cuts the surface A of the coating film 11 by the load detector 23 such as a load cell connected to the blade 21. The value is recorded against the distance traveled by the blade 21. Here, the moving distance of the blade 21 is x, and the load value in the X2 direction applied to the blade 21 in the second step is a cutting load value F2.

  An example of the cutting load value F2 recorded in the second step is shown in FIG. FIG. 7 shows the moving distance x of the blade 21 on the horizontal axis and the cutting load value F2 on the vertical axis. While the coating film 11 is being cut after moving a certain distance, the cutting load value F2 and the moving distance x show a linear function relationship. In FIG. 7, the cutting load value F2 and the movement distance x after a movement of about 0.15 mm show a linear function relationship.

  The laminate 1 after the operation in the second step has the shape shown in FIG. 5 in the same manner as after the operation in the first step. As shown in FIG. 5, after the operation of the second step, the upper portion of the coating film 11 is cut to be rolled up as the test piece 31, and the test surface 32 is dewed. The test surface 32 becomes a cross section of the coating film 11 non-parallel to the surface A in the second step.

  Also in the second step, as in the first step, deformation of the coating film 11 by the side portion of the blade 21 and warping or compression of the test piece 31 occurs.

  As shown in FIG. 7, while the coating film 11 is being cut, a linear function relationship is established between the moving distance x of the blade 21 and the cutting load value F2. When the slope of this linear function is a and the intercept is b, the following equation (2) is established.

F2 = a × x + b (2)
Further, in the second step, when the angle between the surface A and the test surface 32 is θ and the depth from the surface A to the test surface 32 is d, the following equation (3) between the movement distance x and the depth d: Holds.

d = tan θ × x (3)
From the equations (2) and (3), the following equation (4) is established between the cutting load value F2 and the depth d.

F2 = a / tan θ × d + b (4)
As in the equation (4), a linear function relationship is established between the cutting load value F2 and the depth d, with the inclination being a / tan θ.

  The term a / tan θ × d in Equation (4) represents a load value that depends on the depth d in the cutting load value F2. Of the factors included in the cutting load value F <b> 2, the factor depending on the depth d is a load value necessary for the tearing of the coating film 11 and the deformation of the test piece 31. That is, the term a / tan θ × d represents a load value necessary for the tearing of the coating film 11 and the deformation of the test piece 31.

  In the term a / tan θ × d, a / tan θ × d0 in which the depth d is replaced with the film thickness d0 of the coating film 11 is a load value necessary for the tearing of the coating film 11 and the deformation of the test piece 31 in the first step. Since f is expressed, the following equation (5) is established.

f = a / tan θ × d0 (5)
From the equations (1) and (5), the following equation (6) is established.

F0 = F1-a / tan θ × d0 (6)
That is, the third step for obtaining the slope a obtained from the result of the second step, the angle θ formed by the surface A and the test surface 32, and the term a / tan θ × d0 consisting of the film thickness d0 of the coating film 11 is performed. Furthermore, the adhesion load value F0 can be obtained by performing the fourth step of subtracting the term a / tan θ × d0 from the peel load value F1 of the first step.

That is, in the adhesion strength evaluation method of this embodiment,
In evaluating the adhesion strength between the coating film 11 and the substrate 12 of the laminate 1 in which the coating film 11 is uniformly applied to the surface of the substrate 12,
After pressing the blade 21 against the end face D of the coating film 11, the blade 21 is moved in parallel with the interface B of the coating film 11 to peel the coating film 11 from the substrate 12, and peeling between the coating film 11 and the substrate 12 is performed. A first step of measuring the load value F1,
After pressing the blade 21 against the surface A of the coating film 11 inclined with respect to the traveling direction of the blade 21, the blade 21 is moved to cut the surface A of the coating film 11, and the cutting load value F2 of the coating film 11 and the blade A second step of measuring a slope a of a linear function of a moving distance x of 21;
The term a / tan θ × d0 consisting of the inclination a in the second step, the angle θ between the surface A of the coating film 11 and the test surface 32, and the film thickness d0 of the coating film 11 is expressed in the thickness direction of the coating film 11 A third step for setting the load value required for the tearing and deformation of the test piece 31;
A fourth step of obtaining the adhesion load value F0 between the coating film 11 and the substrate 12 by subtracting the load value a / tan θ × d0 in the third step from the peel load value F1 in the first step; I do.

  The method of the present invention differs from the method of Patent Document 3 in that a value corresponding to the gradient a / tan θ of the linear function of the cutting load value F2 and the depth d is obtained. In the method of Patent Document 3, it is necessary to perform a test similar to the first step a plurality of times in order to obtain a value corresponding to a / tan θ. However, according to the adhesion strength evaluation method of the present invention, a / tan θ can be obtained by a single measurement, and the test can be performed in a simpler and shorter time than the method of Patent Document 3.

  When the blade 21 is pressed against the end surface D in the first step, the blade 21 can be easily pressed against the end surface D by using the following method.

  First, the blade 21 is applied to the surface A. Thereafter, the blade 21 is moved in the X2 direction or the stage 22 is moved in the X1 direction, and the blade 21 and the laminate 1 are sufficiently separated. Next, the blade 21 is moved in the Z direction by the thickness of the coating film 11. The blade 21 can be pressed against the end surface D by moving the blade 21 in the X1 direction or the stage 22 in the X2 direction.

  In the first step, it is necessary to confirm whether the test surface 32 coincides with the interface B by observing the test surface 32 with an optical microscope or measuring the depth from the surface A to the test surface 32.

  In the equations (3) to (6), the angle θ formed by the surface A and the test surface 32 is used, but the angle formed by the traveling direction of the blade 21 and the surface A in the second step may not coincide with the angle θ. is there. For this reason, it is better to measure the angle θ between the surface A and the test surface 32 by performing shape measurement after the second step.

  The laminated body 1 fixed on the stage 22 is desirably in the following shape.

  The end face D of the laminate 1 preferably has an angle θ1 formed between the end face D against which the blade 21 is pressed and the back face C in a range of 20 ° to 70 °. By setting θ1 to a range from 20 ° to 70 °, not 90 °, the success rate of peeling at the interface B when the coating film 11 is peeled can be improved. In particular, when the coating film 11 is thick, the peeling success rate at the interface B can be improved by setting θ1 in the range of 20 ° to 70 °. In addition, when θ1 is 0 ° to less than 20 °, it is disadvantageous in that it is necessary to increase the area of the laminated body 1 and the test time becomes long. When θ1 is more than 70 to 90 °, the interface It is disadvantageous in that the peeling of B2 tends to fail.

  The end surface D is preferably in a range where the angle θ2 formed by the end surface D against which the blade 21 is pressed and the blade 21 in a plane viewed from above the surface A is in the range of 35 ° to 70 °. By making θ2 in the range of 35 ° or more and 70 ° or less, the separation success rate at the interface B can be improved. If θ2 is 0 ° to less than 35 °, it is disadvantageous in that peeling at the interface B tends to fail, and if θ2 is more than 70 ° to 90 °, the area of the laminate 1 is increased. It is disadvantageous in that it requires and the test time is long.

  The adhesion strength evaluation apparatus of the present invention includes a stage 22 that fixes the laminate 1 and a blade 21 that includes a load detector 23, and the blade 21 is in a horizontal direction relative to the stage 22 relative to the stage 22. An apparatus that can move in the vertical direction and can tilt the stage 22 with respect to the horizontal traveling direction of the blade 21 can be used.

  Examples of the thin film adhesion strength evaluation method of the present invention will be described below.

  As the laminated body 1, a laminated body in which a urethane resin having a film thickness d0 of 24.8 μm was applied to one surface of a base film made of transparent polyethylene terephthalate and having a thickness of 250 μm was prepared.

  The adhesion strength evaluation method of the present invention was performed using a blade 21 having a width of 0.5 mm and a universal bond tester (manufactured by Daisy Corporation: series 4000). The urethane resin was used as the coating film 11 and the base film was used as the base material 12 and fixed on the stage 22 via a glass plate. At this time, the laminate was bonded to a glass plate using an epoxy adhesive, and the glass plate was screwed onto the stage 22. The size of the laminate is about 5 cm wide and 1 cm long, and after being bonded to a glass plate, it is processed with a razor blade so that θ1 is 20 ° to 70 ° and θ2 is 20 ° to 55 °. went. The first step and the second step of the present invention were performed by changing the location with respect to the same side in the width direction of the laminate. In the second step, the angle formed by the traveling direction of the blade 21 and the surface A was about 3 °. After the second step, the shape was measured with a stylus type surface roughness meter, and the angle θ formed by the surface A and the test surface 32 was determined.

  From the above method, the peel load value F1 was 1.450 N, the inclination a was 3.00 N / mm, and the angle θ was 3.21 °. When these and the film thickness d0 were used, the adhesion load value F0 was 0.123N from the equation (6). On the other hand, the adhesion load value obtained by the method of Patent Document 3 is 0.125 N, which is in good agreement with the adhesion load value F0 obtained by the method of the present invention.

  In the method of Patent Document 3, in order to obtain a value corresponding to the cutting load value F2 and the slope a / tan θ of the linear function of the depth d, it is necessary to cut the coating film a plurality of times. In the method of the present invention, the term a / tan θ can be obtained by performing the second step only once, and the obtained adhesion load value F0 is in good agreement with the value obtained by the method of Patent Document 3. . Thus, by using the adhesion strength evaluation method of the present invention, it was possible to easily and quantitatively obtain adhesion strength in a short time for laminates having different coating film thicknesses and coating film compositions.

  The adhesion strength evaluation method of the present invention can be used as a measurement method for quantitatively evaluating the adhesion strength between a coating film of a laminate and a substrate having different coating film thicknesses and coating film compositions.

  DESCRIPTION OF SYMBOLS 1 ... Laminated body, 11 ... Coating film, 12 ... Base material, 21 ... Blade, 22 ... Stage, 23 ... Load detector, 31 ... Test piece, 32 ... Test surface, 33 ... Ripped part, A ... Surface of laminated body B: Interface between coating film and substrate, C: Back surface of laminate, D: End face of laminate.

Claims (4)

A method for evaluating the adhesion strength between a coating film and a substrate of a laminate in which the coating film is uniformly applied to the surface of the substrate,
The first step of measuring the peel load value between the coating film and the substrate by moving the blade parallel to the surface of the coating film after pressing the blade against the end surface of the coating film and peeling the coating film from the substrate When,
After pressing the blade against the surface of the coating film tilted with respect to the blade traveling direction, the blade is moved to cut the surface of the coating film, and the inclination of the linear function of the blade movement distance and the cutting load value of the coating film is determined. A second step to measure,
From the term consisting of the inclination in the second step, the angle between the surface of the coating film and the cutting surface, and the film thickness of the coating film, the load value required for the tearing of the coating film in the thickness direction and the deformation of the test piece A third step to seek,
A fourth step of obtaining a contact load value between the coating film and the substrate by subtracting the load value in the third step from the peel load value in the first step. A method for evaluating the adhesion strength of a laminate.   2. The adhesion strength of the laminate according to claim 1, wherein an angle θ <b> 1 formed between an end face of the laminate to which the blade is pressed and a back surface of the laminate is in a range of 20 ° to 70 °. Evaluation methods.   3. The laminate according to claim 1, wherein an angle θ2 formed between the end face pressing the blade and the blade in a plane viewed from above the coating film is in a range of 35 ° to 70 °. Body adhesion strength evaluation method. An apparatus for evaluating the adhesion strength between a coating film and a substrate of a laminate in which the coating film is uniformly applied to the surface of the substrate,
A stage in which the base material of the laminated body placed with the laminating direction facing the vertical direction is fixed, and can be tilted with respect to the horizontal traveling direction of the blade;
A blade movable relative to the stage in the horizontal and vertical directions;
After pressing the blade against the end face of the coating film, the blade is moved in parallel with the surface of the coating film to peel the coating film from the substrate, and after pressing the blade against the end face of the coating film, the surface of the coating film And a load detector for detecting a horizontal load applied to the blade when the surface of the coating film is cut by moving the blade in parallel with the blade.

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