How to prepare a specimen for tensile testing

Abstract

To enable adhering together a columnar attachment (300) and an adhesion-objective test piece (200) while surely preventing a tilt of the columnar attachment in a simple manner when fabricating a tensile test sample where the columnar attachment is adhered vertically to an adhesion face of the adhesion-objective test piece via adhesive.SOLUTION: A guide implement (100) is a cylindrical body that has a hollow with both ends opened, in which an end face of one end is plane vertical to a height direction, and allows for standing erect when placed on a horizontal plane with the end face of the one end placed down. The hollow has a shape in which a part including at least one end face of a columnar attachment is movable freely back and forth inside the hollow while being regulated so that a longitudinal direction of a columnar attachment is aligned with a height direction of the cylindrical body. The guide implement is placed in a prescribed position on an adhesion face of an adhesion-objective test piece, and the columnar attachment is inserted into the hollow to perform adhesion.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a guide device that is preferably used when preparing a sample for a tensile test to measure the tensile strength of an adhesive. Ingredients This relates to the method of preparing the tensile test samples used. [Background technology]

[0002] One method for evaluating the adhesiveness of an adhesive is a tensile bond strength test method in which a tensile load perpendicular to the adhesive surface is applied to measure the load at break. In this tensile bond strength test method, a tensile test sample, in which the adhesive surfaces of two adherends, each of which has a flat adhesive surface, are adhesively bonded together, is attached to a tensile tester so that its axial direction (perpendicular to the adhesive surface) coincides with the tensile load direction, and the evaluation is performed by applying a load as described above and measuring the maximum load at which the adhesive breaks. Specifically, the above measurement is performed on at least five tensile test samples, and the tensile bond strength is calculated by dividing the measured maximum load by the measured adhesive area, and the average value is used for evaluation (see Non-Patent Document 1).

[0003] Depending on the application of the adhesive, the adhesiveness to the adherend made of a specific material is often important. In such cases, the adherend test piece made of the material to be evaluated for adhesiveness is often used as one adherend of the tensile test sample, and a columnar attachment (sometimes called a molded bar) made of a specific material such as metal or synthetic resin is often used as the other adherend. This columnar attachment also functions as a fixing member for fixing the tensile test sample to a tensile tester, with one end face being the adhesive surface and the other end being structured so that it can be fixed to the tensile tester (for example, having a hole for holding the test piece). Then, the other end of the columnar attachment in the tensile test sample is fixed to the lower (or upper) part of the tensile tester, and the adherend test piece is fixed in a holder fixed to the upper (or lower) part of the tensile tester, and a tensile test is performed.

[0004] For example, when measuring the adhesive strength (tensile bond strength) of a dental adhesive such as a dental resin cement to a tooth, a tensile test sample is prepared and measured as follows. That is, as shown in Fig. 1, a tensile test sample is prepared by preparing an adherend test piece with a planar adhesive surface exposed by polishing a tooth, attaching an adhesive film having a "hole with a diameter of 3 to 5 mm" (to define the adhesive area) to the adhesive surface, and then applying a dental adhesive to the inside of the hole and / or the adhesive surface of a columnar attachment, and bonding the adhesive surface of the adherend test piece exposed from the hole to the adhesive surface of the columnar attachment via the dental adhesive. Then, the prepared tensile test sample is fixed to a tensile tester, and a load is applied so as to pull the attachment perpendicularly to the adhesive surface of the adherend test piece, and the adhesive strength is measured (see Non-Patent Document 2 and Patent Document 1).

[0005] In addition, the JIS standard states that a tooth is fixed in a holder using an embedding material, then polished so that the polished surface is exposed horizontally, and used as an adherend test piece; the adherend test piece and columnar attachment are set in a special tool, after which an adhesive film is applied and adhesive is applied; and then the special tool is used to adhere the columnar attachment to a specified load for a specified period of time to prepare a sample for a tensile test (see non-patent document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-027913 A [Non-patent literature]

[0007] [Non-Patent Document 1] Satoru Ohtsubo, 1989, "Methods for expressing and measuring adhesive strength", Surface Technology, vol. 40, p1161-1169 [Non-Patent Document 2] Japanese Standards Association, "JIS T6611 Dental Resin Cement" issued on July 1, 2009 Summary of the Invention [Problem to be solved by the invention]

[0008] When measuring the tensile bond strength of dental adhesives such as dental resin cements to teeth, it is important to attach the columnar attachment perpendicular to the adhesive surface of the adherend test piece when preparing the tensile test sample. That is, as shown in Figure 3, if a tensile test sample in which the columnar attachment is attached at an angle to the adhesive surface of the adherend test piece is used and the tilted columnar attachment is pulled in a direction perpendicular to the adhesive surface of the adherend test piece, a peeling force will be applied, resulting in a low adhesive strength value. As a result, the adhesive strength cannot be measured accurately.

[0009] It is believed that the columnar attachment can be bonded perpendicularly to the adhesive surface of the adherend test piece by using the dedicated jig as disclosed in Non-Patent Document 2. Although Non-Patent Document 2 only shows the dedicated jig as a reference diagram and does not disclose any details, it is judged that the dedicated jig is something like that shown in Figure 2. That is, the jig 10 shown in FIG. 2 comprises a stand 20 having a support 21; a piston member 30 having a holding mechanism 32 capable of removably holding a columnar attachment 300 at one end of a relatively long cylindrical rod-shaped member 31 so that the axes of the two are aligned and having a load platform 33 connected to the other end; a sample stage 40 having a bottom 41 and a ceiling 42 on which an adherend test piece 200 can be placed and held in a predetermined position and having a U-shaped vertical cross section with three sides open, and in which a hole 43 through which the rod-shaped member 31 of the piston member 30 passes is provided in the ceiling 42 directly above the adherend test piece 200 held by the bottom 41; a stopper arm 50 having a stopper mechanism (not shown) for removably holding the piston member 30 and held by the support of the stand; and a lifting device (jack) 50 for moving the sample stage 40 up and down, all of which are arranged as shown in FIG. 2. Therefore, if the adherend test piece 200 and the columnar attachment 300 are set up, the adhesive film is applied and the adhesive is applied, and the lifting device 50 is used to bring the adhesive surface of the adherend test piece 200 and the adhesive surface of the columnar attachment 300 close together, a predetermined weight is then placed on the load platform and the stopper mechanism is released, the columnar attachment 300 will hang down, and it is believed that the columnar attachment 300 can be adhered perpendicular to the adhesive surface of the adherend test piece 200.

[0010] However, the above-mentioned dedicated tool is a relatively large-scale device, which limits the work space. In addition, the columnar attachment member must be attached to and detached from the piston member each time bonding is performed, making the operation complicated.

[0011] In addition, when making a relative comparison of the adhesiveness of different adhesives to the same material, or when making a relative comparison of the adhesiveness of the same adhesive to different materials, it is not necessary to perform the bonding under strict conditions as specified by the JIS standard, and the purpose can be achieved if the attachment can be prevented from tilting under unified bonding conditions and reliable bonding can be performed. For this reason, it is common to perform bonding manually (by manual operation) without using a jig, select a good sample, and perform measurement, but the probability of producing a good sample is not necessarily high, and waste occurs. In particular, when reusing a columnar attachment that has been used once to prepare a sample, it is necessary to polish and remove the hardened adhesive attached to the adhesive surface of the columnar attachment, and at that time, the adhesive surface may not be perpendicular to the longitudinal direction of the columnar attachment but may be slightly tilted (to a state of being approximately perpendicular), in which case the above probability is further reduced.

[0012] In view of these circumstances, the present invention aims to provide a technology that enables a substrate test piece to be bonded to a columnar attachment in a simpler manner without using the dedicated tool described above, while reliably preventing tilting of the attachment even when the columnar attachment is reused. [Means for solving the problem]

[0013] The present invention is to solve the above-mentioned problems, and an embodiment of the present invention is a method for preparing a tensile test sample for evaluating the adhesion of a curable adhesive to an adherend by a tensile test, comprising an adherend test piece having a flat surface that serves as an adherend bonding surface, and a columnar attachment having a flat surface at one end that is perpendicular or approximately perpendicular to the longitudinal direction and using the end surface as an attachment bonding surface, the columnar attachment being bonded together such that the longitudinal direction of the columnar attachment is perpendicular to the adherend bonding surface via a layer of a cured product of the curable adhesive formed between the adherend bonding surface and the attachment bonding surface, A. A preparation step of preparing (1) the adherend test piece, (2) the columnar attachment, (3) an adhesive film having an adhesive area determining hole formed therein, the hole having an area smaller than the area of ​​the adhesive surface of the attachment and determining the adhesive area, and (4) a guide device for guiding the columnar attachment to a predetermined position while moving it along its longitudinal direction; B. A film application step of applying the pressure-sensitive adhesive film onto the adhesive surface of the adherend; C. An adhesive application step of applying the curable adhesive in an uncured state to the adherend adhesive surface and / or the attachment adhesive surface exposed through the adhesive area defining hole; and D. A bonding step of bonding the adherend test piece and the columnar attachment by bringing the adherend surface and the attachment adhesive surface into close contact with each other via the uncured curable adhesive applied in the above step, and positioning the columnar attachment so that the longitudinal direction of the columnar attachment is perpendicular to the adherend adhesive surface, and then curing the curable adhesive to bond the adherend test piece and the columnar attachment; The guide instrument is a cylindrical body having a cavity with both ends open, an end face of one end being a plane perpendicular to a height direction, and being capable of standing on its own when placed on a horizontal surface with the end face of the one end facing down, and the cavity is The above columnar attachment The longitudinal direction of the cylindrical body is regulated to coincide with the height direction of the cylindrical body, and the columnar body is inserted into the cavity. attachment a guide device having a shape that allows at least a portion including an end face of said one end to move freely forward and backward, and while maintaining a state in which the longitudinal direction of said columnar attachment is perpendicular to the bonding surface of said adherend, said guide device moves along said longitudinal direction to guide said bonding surface of said attachment to a predetermined position on said bonding surface of said adherend, and while maintaining said state at said predetermined position, said guide device can bring said bonding surface of said adherend into close contact with said bonding surface of said attachment via a layer of said curable adhesive in an uncured state (hereinafter, said guide device that satisfies such conditions is also referred to as "the guide device of the present invention"); In the bonding step D, the end face of the one end of the guide device is placed on the adhesive film of the adherend test piece to which the adhesive film is attached or on the adherend adhesive surface, in a position such that the hole for determining the adhesive area is located inside the opening at the one end, and the guide device is held so that its height direction is perpendicular to the adherend adhesive surface, and then the columnar attachment is inserted from the attachment adhesive surface side through the opening at the other end of the guide device to perform the adhesion and positioning. The present invention relates to a method for preparing a sample for a tensile test.

[0014] Books Guide of the invention Ingredients In this case, it is preferable that the cylindrical body be capable of standing on its own when placed with the end face of the one end facing down on an inclined plane inclined within a range of at least ±2° from the horizontal, with the height direction of the cylindrical body perpendicular to the inclined plane.

[0015] It is also preferable that the shape of the cavity is similar to the shape of the pillar and has a similarity ratio such that a gap having a width of 0.05 to 0.20 mm is generated when the pillar moves inside the cavity.

[0016] Furthermore, it is preferable that the guide device is used to produce a bonded structure in which an adherend test piece having a flat surface that serves as the adherend adhesive surface, and a columnar attachment having an end face at one end that is perpendicular or approximately perpendicular to the longitudinal direction and uses the end face as the attachment adhesive surface, are bonded so that the longitudinal direction of the columnar attachment is perpendicular to the adherend adhesive surface via a layer of hardened curable adhesive formed between the adherend adhesive surface and the attachment adhesive surface, and the guide device moves the columnar attachment along its longitudinal direction while maintaining the longitudinal direction of the columnar attachment perpendicular to the adherend adhesive surface, guiding the attachment adhesive surface to a predetermined position on the adherend adhesive surface, and enabling the adherend adhesive surface and the attachment adhesive surface to be closely attached to each other via the layer of uncured curable adhesive while maintaining the state at the predetermined position.

[0017] Furthermore, in the above preferred aspect, it is preferable that a space is provided in the cavity near the periphery of the opening at the one end for accommodating excess uncured curable adhesive which protrudes from the adhesive surface of the attachment during the tight contact, and it is also preferable that the bonded body is a tensile test sample for evaluating the adhesion of the curable adhesive to an adherend by a tensile test.

[0019] In the above-mentioned embodiment of the preparation method (hereinafter also referred to as "the preparation method of the tensile test sample of the present invention" or "the preparation method of the present invention"), it is preferable that an adhesive film having adhesive layers on both sides is used as the adhesive film, and in the bonding step D, the end face of the one end of the guide instrument is placed on the adhesive film. It is also preferable that the curable adhesive is a dental resin cement, and the adherend is an animal's tooth. Effect of the Invention

[0020] According to the guide device of the present invention, it is possible to adhere a test piece to a columnar attachment while reliably preventing the attachment from tilting, even when the columnar attachment is reused, in a simpler manner without using a dedicated jig as shown in Fig. 2. In addition, according to the method for preparing a sample for a tensile test of the present invention using the guide device of the present invention, it is possible to efficiently prepare a sample for a tensile test that can suppress a decrease in adhesive strength derived from the sample in a tensile adhesion test and can accurately measure adhesive strength. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a schematic diagram showing the preparation and pretreatment steps of a sample for a tensile test used in a tensile bond strength test method. [Diagram 2] FIG. 1 is a schematic diagram of a conventional jig used to bond an adherend test piece to a columnar attachment when preparing a tensile test sample for use in a tensile bond strength test method. [Diagram 3] FIG. 2 is a schematic diagram showing the adhesive state between an adherend test piece and a columnar attachment in a tensile test sample, and how a load is applied during a tensile test. [Figure 4] 1A is a front view (I) of a representative guide device of the present invention, and FIG. 1B is a plan view (II) of an end face side of one end thereof. [Diagram 5] FIG. 5 is a perspective view showing a state in which an adherend test piece and a columnar attachment have been bonded using the guide instrument of the present invention shown in FIG. [Figure 6] FIG. 6 is a (longitudinal) cross-sectional view of the state shown in FIG. [Figure 7] This is a plan view of the state in which the guide device of the present invention is placed on the adhesive application surface of an adherend test piece (before the columnar attachment is inserted) when using the guide device of the present invention to bond the adherend test piece to a columnar attachment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The guide device of the present invention is a guide device for guiding a columnar member to a predetermined position while moving it along its longitudinal direction. Here, the member is not particularly limited as long as it is a columnar member whose longitudinal section has an aspect ratio (ratio of the columnar member's height to the maximum width of its transverse section) exceeding 1 and whose height direction is the longitudinal direction, and may be a truncated cone or a truncated polygonal pyramid, but it is preferable that the main part including at least one end face is a right columnar member such as a cylinder or a polygonal column whose generatrix is ​​perpendicular to the bottom surface.

[0023] The guide instrument of the present invention comprises a cylindrical body having a cavity with both ends open, with the end face of one end being a plane perpendicular to the height direction, and capable of standing on its own when placed on a horizontal surface with the end face of the one end facing down, and the cavity has a shape that allows the portion of the cylindrical body including at least the end face of the one end to move freely back and forth within the cavity while restricting the longitudinal direction of the cylindrical body to coincide with the height direction of the cylindrical body.

[0024] Here, the fact that the cylindrical body constituting the guide device of the present invention is self-supporting when placed on a horizontal surface with the end face of one end facing down means that the cylindrical body can be self-supporting in a state where the height direction (axial direction) of the cylindrical body is perpendicular to the horizontal surface. In order to make the cylindrical body self-supporting in this way, the ratio of the wall thickness (distance between the outer surface and the inner surface) at the end face of one end of the cylindrical body to the height may be increased so that the cylindrical body does not tilt or fall over or tilt due to a slight stimulus when placed. In this case, the wall thickness of the cylindrical body may be made thick overall, or only the wall thickness of the end face of one end and its vicinity may be made thick. It is preferable that the cylindrical body is self-supporting when placed on an inclined plane inclined at least within a range of ±2°, particularly ±5° from the horizontal, with the end face of one end facing down, so that the height direction of the cylindrical body is perpendicular to the inclined plane.

[0025] In addition, the fact that at least the part of the columnar body including the end face of the one end can move freely in the cavity means that when the columnar body is inserted into the opening of the other end side of the cylindrical body from its one end side, the columnar body can move freely in the cavity to at least a depth where the end face of the one end of the columnar body coincides with the end face of the one end of the cylindrical body. Therefore, when the length of the columnar body is longer than the height of the cylindrical body, there may be a part of the region of the other end side of the columnar body that is not inserted into the cavity, and the end face of the other end and its vicinity may be wider than the opening of the other end side of the cylindrical body. In the guide instrument of the present invention, from the viewpoint of ease of processing and ease of handling, it is preferable that the columnar body is made of a straight column and that the entire columnar body can pass through the cavity and move freely in the cavity.

[0026] In the guide device of the present invention, the shape inside the cavity is controlled so that the longitudinal direction of the columnar body coincides with the height direction of the tubular body during the above-mentioned movement. That is, the above-mentioned regulation is performed so as to satisfy a predetermined relationship in the relative relationship with the shape of the columnar body. Specific examples of methods for satisfying the predetermined relationship in such relative relationship include a method of making the gap (clearance) width between the columnar body and the tubular body extremely small when the columnar body is inserted into the cavity, and a method of using a columnar body having a structure in which a rail member extending in the longitudinal direction is attached to its side surface, and providing a groove that engages with the rail member on its inner surface, and a structure in which the rail member can slide while engaging with the groove, etc. In the former method, the gap (clearance) width may be narrowed in the entire region, or may be narrowed partially.

[0027] The guide device of the present invention is preferably used to produce a bonded structure in which an adherend test piece having a flat surface that serves as the adhesive surface of the adherend, and a columnar attachment having an end face at one end that is perpendicular or approximately perpendicular to the longitudinal direction and uses the end face as the attachment adhesive surface, are bonded so that the longitudinal direction of the columnar attachment is perpendicular to the adherend adhesive surface via a layer of hardened curable adhesive formed between the adherend adhesive surface and the attachment adhesive surface, and the guide device is preferably used to produce a bonded structure in which the longitudinal direction of the columnar attachment is perpendicular to the adherend adhesive surface, and the guide device moves along the longitudinal direction while maintaining the longitudinal direction of the columnar attachment perpendicular to the adherend adhesive surface, thereby guiding the attachment adhesive surface to a predetermined position on the adherend adhesive surface, and while maintaining the state at the predetermined position, allows the adherend adhesive surface and the attachment adhesive surface to be closely attached to each other via the layer of uncured curable adhesive. Such a guide instrument can be suitably used as a jig for attaching a columnar attachment perpendicularly to the adhesive surface of an adherend test piece when preparing a tensile test sample to be used when measuring the tensile bond strength of a dental adhesive, such as a dental resin cement, to a tooth.

[0028] The columnar attachment is often a cylindrical one having a diameter of about 5 to 10 mm and an aspect ratio of about 1.2 to 6.0. Hereinafter, the guide device of the present invention and the method for preparing a tensile test sample of the present invention will be described in detail with reference to the drawings, taking as an example a case where a tensile test sample is prepared using such a columnar attachment.

[0029] FIG. 5 shows a perspective view of the state where the adherend test piece 200 and the columnar attachment 300 are bonded using the guide instrument 100 of the present invention, and FIG. 6 shows a longitudinal cross-sectional view of the adherend test piece 200. First, the adherend test piece 200, which is one of the objects to be bonded (adherend), will be described. The adherend test piece 200 has a flat surface that becomes the adherend bonding surface 210. When preparing a tensile test sample for measuring the tensile adhesive strength of a dental adhesive such as a dental resin cement to a tooth, the adherend test piece 200 is made of a material that is the subject of adhesiveness evaluation. Examples of such materials include metals, ceramics, resins, teeth, bones, etc., and are not particularly limited, but animal teeth are preferable. When using teeth such as bovine teeth, the teeth are often fixed in a holder using an embedding material made of gypsum or a resin material, and then polished so that the polished surface is horizontally exposed, and used as the adherend test piece, but teeth directly polished can also be used as they are.

[0030] The other adherend, the columnar attachment 300, is made of a cylindrical columnar body 301 having a central axis 320. The size of the columnar body is usually determined by the outer diameter: OD 300 The diameter is about 5.0 to 10.0 mm, preferably about 6.0 to 9.0 mm, and the length: L is about 12.0 to 30.0 mm, preferably about 15.0 to 25.0 mm. The material used may be metal, acrylic resin, hybrid resin, or hardened dental cement, but metal materials such as stainless steel (SUS) are often used.

[0031] The end surface 302a of one end 301a of the columnar body 301 is to be the attachment bonding surface 310 and must be flat. In addition, the area must be larger than the area of ​​the bonding area determination hole described later, and the shape of the bonding area determination hole must be included in the flat surface. If such conditions are met, the vicinity of the outer periphery may be chamfered. In addition, the end surface 302a (attachment bonding surface 310) must be perpendicular or approximately perpendicular to the longitudinal direction of the columnar body 301 (the direction of the central axis 320 in the figure). Here, approximately perpendicular means that the deviation (inclination) from the perpendicular is extremely small, specifically, the inclination from the perpendicular in all directions is within 5°, particularly within 1°. The end surface 302a is usually finished by precision machining so that the end surface 302a is a flat surface perpendicular to the direction of the central axis 320. However, as described above, when removing the attached adhesive hardened body by manual polishing for reuse, the end surface 302a may be inclined. Even in such a case, so long as the inclination is within the above-mentioned range, the guide device of the present invention can be used to easily adhere the columnar attachment 300 perpendicularly to the adherend bonding surface 210. The other end 301b of the columnar body 301 is often structured so that it can be fixed to a tensile testing machine. In the embodiment shown in the figure, such a structure is formed with a test piece holding hole 303 parallel to the attachment bonding surface 310.

[0032] Next, the guide instrument 100 of the present invention will be described with reference to Figures 4 and 6. The guide instrument 100 is composed of a cylindrical tubular body 110 having a central axis 120, and one end 111a and the other end 111b have circular openings 113a and 113b, respectively, and the internal cavity 130 of the tubular body 110 is opened to the outside at these openings. The end face 112a of the one end 111a, i.e., the ring-shaped end face 112a at one end 111a of the cylindrical wall of the tubular body 110, is formed as a plane perpendicular to the height direction of the tubular body 110 (the direction of the central axis 120 of the cylinder). The thickness T of the cylindrical wall shown in the figure is constant T0 from one end 111a to the other end 111b along the central axis direction except for one end 111a and its vicinity, and gradually becomes thinner near one end 111a. Specifically, the thickness at end surface 112a gradually decreases from the height h, and becomes T0-w. This is because a space 131 for storing uncured curable adhesive (hereinafter, also referred to as "excess adhesive storage space") is provided, but the thickness may be constant in all regions without providing such a space.

[0033] In the embodiment shown in the figure, the area of ​​the end face 112a (which is the contact area with the mounting surface) is the outer diameter of the cylinder: OD 100 From the area of ​​the surface with diameter: ID 100 The area is calculated by subtracting the area of ​​a circle whose diameter is the length of the hole plus 2w. In the case where no space is provided, the OD 100 From the area of ​​the surface with diameter, ID 100 The area is obtained by subtracting the area of ​​a circle having a diameter of T0. The length of T0 and w, which is set as necessary, may be appropriately determined so that the area of ​​the end face 112a, which is the contact area with the placement surface, can stand on its own when placed on a horizontal surface with the end face 112a facing down, but it is preferable that the area is such that the central axis 120 can stand on its own when placed on an inclined surface inclined at least within a range of ±2° from the horizontal with the central axis 120 in a perpendicular direction to the inclined surface, and it is more preferable that the area is such that the central axis 120 can stand on its own when placed on an inclined surface inclined within a range of ±5° with the central axis 120 in a perpendicular direction to the inclined surface. The specific thickness is determined by the height: H and outer diameter: OD of the cylindrical body 110.100 Depending on the product, the height (H) is 4.0 to 20.0 mm and the outer diameter (OD) is 100 is 9.0 to 15.0 mm, the thickness T at the contact surface (T0-w in the figure) is preferably 0.3 to 5.0 mm, particularly preferably 1.0 to 4.0 mm.

[0034] In the guide device 100 of the present invention, the width of the gap (clearance) between the columnar attachment 300 and the cavity 130 when the columnar attachment 300 is inserted into the cavity 130 is made extremely small, specifically, the inner radius of the cylindrical body 110: r 100 =ID 100 / 2 and the radius of the column attachment 300: r 300 =OD 300 By setting Δr, which is the difference from L / 2, to 0.05 to 0.20 mm, preferably 0.05 to 0.15 mm, the direction of the central axis 320 of the columnar attachment 300 and the direction of the central axis 120 of the cylindrical body 110 are always regulated to coincide with each other when the attachment 300 moves within the cavity 130. Note that the height H of the cylindrical body 110 is preferably 2 / 10 to 9 / 10 of the length L of the columnar attachment 300, and more preferably 4 / 10 to 8 / 10, for the reasons that the columnar attachment 300 can be easily inserted and the movement direction can be reliably regulated during insertion.

[0035] The material of the guide device of the present invention is not particularly limited, but is preferably made of an acrylic resin such as PMMA because of ease of molding.

[0036] As described above, the guide instrument 100 of the present invention shown in the drawings is provided with an excess adhesive storage space 131 in the vicinity of the periphery of the opening 113a of the one end 111a. This makes it possible to reduce adverse effects of excess uncured curable adhesive that protrudes from the attachment bonding surface 310 during bonding in the manufacturing method of the present invention. The manufacturing method of the present invention will be described below, including this point.

[0037] The production method of the invention includes the following steps A to D. A. A preparation step of preparing (1) the adherend test piece, (2) the columnar attachment, (3) an adhesive film having an adhesion area determining hole formed therein, the hole having an area smaller than the area of ​​the adhesive surface of the attachment and determining the adhesion area, and (4) a guide device of the present invention; B. A film application step of applying the pressure-sensitive adhesive film onto the adhesive surface of the adherend; C. An adhesive application step of applying the curable adhesive in an uncured state to the adherend adhesive surface and / or the attachment adhesive surface exposed through the adhesive area defining hole; and D. A bonding process in which the adhesive surface of the adherend and the adhesive surface of the attachment are brought into close contact with each other via the uncured curable adhesive applied in the previous process, and the columnar attachment is positioned so that its longitudinal direction is perpendicular to the adhesive surface of the adherend, and then the curable adhesive is cured to bond the adherend test piece and the columnar attachment.

[0038] Since (1), (2) and (4) prepared in step A have already been explained, the adhesive film 400 in (3) will be explained. The adhesive film 400 is used to determine the adhesion area (the adhesion area measured to subtract the measured maximum load) when determining the tensile adhesion strength. That is, as shown in steps B to D, the adhesive film 400 is attached onto the adherend adhesion surface 210, and then the uncured curable adhesive 500 is applied to the adherend adhesion surface 210 and / or the attachment adhesion surface 310 exposed from the adhesion area determination hole 410, and then adhesion is performed. Therefore, as shown in FIG. 6, the adherend adhesion surface 210 and the attachment adhesion surface 310 are directly bonded via the adhesive only within the adhesion area determination hole 410 (without being blocked by the adhesive film 400), and the (opening) area of ​​the adhesion area determination hole 410 is the above-mentioned adhesion area. The adhesive strength of the adhesive film is much weaker than that of the adhesive (usually it rarely exceeds 2 MPa, and if necessary, a film with a weaker adhesive strength can be selected and used), so the presence of the adhesive on the adhesive film does not affect the maximum load measured. The adhesive film 400 is not particularly limited as long as it does not inhibit adhesion, and a commercially available adhesive tape with a resin film or the like as a base material and an adhesive layer formed on one or both sides and provided with a hole 410 for determining the adhesive area of ​​a predetermined shape can be used without any particular limitation. The hole 410 for determining the adhesive area is generally a circular hole with a diameter of 3 to 5 mm and a predetermined length, and an adhesive tape having such a hole is also used in the present invention.

[0039] The curable adhesive to be evaluated may be appropriately determined according to the purpose, and examples of dental curable adhesives include dental resin cements, dental resin cores, dental composite resins, dental self-polymerizing resins, dental primers, dental bonding materials, etc. Among them, the preparation method of the present invention is particularly suitable as a method for preparing samples for tensile tests of dental resin cements. Examples of dental resin cements include glass ionomer cements, self-adhesive adhesive resin cements, adhesive resin cements with pretreatment materials, etc. Depending on the curable adhesive used, some require pretreatment with a pretreatment agent such as a primer, and when using such an adhesive, it is sufficient to appropriately pretreat the adherend bonding surface 210 before applying the adhesive.

[0040] In the manufacturing method of the present invention, in the adhesion step D, the end face 112a of one end 111a of the guide instrument 100 is positioned on the adhesive film 400 or on the adherend adhesive surface 210 of the adherend test piece 200 to which the adhesive film 400 is attached, in a position such that the adhesive area determining hole 410 is present inside the opening 113a at the one end 111a, and the guide instrument 100 is held so that its height direction (direction of the central axis 120) is perpendicular to the adherend adhesive surface 210, and then the columnar attachment 300 is inserted from the attachment adhesive surface 310 side through the opening 113b at the other end 111b of the guide instrument to perform the above-mentioned adhesion and positioning.

[0041] When arranging the guide device 100, it is preferable to arrange it so that the center of the opening 113a of one end 111a coincides with the center of the hole 410 for determining the adhesion area when visually observed, as shown in FIG. 7. This makes it possible to perform more reliable and accurate measurement of the adhesive strength. In addition, since the guide device 100 stands on a flat surface, if the adherend adhesion surface 210 is placed while keeping the adherend adhesion surface 210 horizontal, the guide device 100 can be held so that the direction of the central axis 120 is perpendicular to the adherend adhesion surface 210. In this case, even if the guide device 100 is placed on an inclined plane inclined within a range of ±2°, particularly ±5° from the horizontal, if the guide device 100 stands on its own so that the direction of the central axis 120 is perpendicular to the adherend adhesion surface 210, the adherend adhesion surface 210 may be inclined within this range. Furthermore, if a double-sided (adhesive) film (tape) is used as the adhesive film 400 and the guide device is placed on it, the guide device can be held so that the direction of the central axis 120 is perpendicular to the adherend adhesion surface 210 even if the adherend adhesion surface 210 is greatly inclined. Furthermore, the insertion, adhesion and positioning of the columnar attachment 300 can be performed manually (by manual operation). That is, by pushing the attachment adhesive surface 310 into the opening 113b of the other end 111b of the guide instrument, the columnar attachment 300 moves while being regulated so that the direction of its central axis 320 coincides with the direction of the central axis 120 of the guide instrument 100, so that the insertion, adhesion and positioning can be performed automatically.

[0042] During the above-mentioned adhesion, depending on the amount of adhesive applied, excess uncured curable adhesive may overflow from the attachment adhesive surface 310, and the excess adhesive that has nowhere to go may occasionally flow between the end surface 112a of the guide device 100 and the placement surface, causing the guide device 100 to tilt. In order to prevent such a phenomenon from occurring, an excess adhesive storage space 131 is provided near the periphery of the opening 113a of one end 111a. In the figure, the excess adhesive storage space 131 is formed by chamfering the inner surface at one end 111a of the cylindrical body 110 at a predetermined chamfering angle, but the excess adhesive storage space 131 may also be formed by methods such as R chamfering or providing a step. The excess adhesive storage space may be of any size as long as it is large enough to store the excess adhesive, and a specific volume is 10 mm. 3 ~60mm 3 It is preferable that the height h and width w of the surplus adhesive storage space are appropriately determined within the range that satisfies the above-mentioned volume, but it is preferable that the width w is set so that the thickness at the contact surface: T(T0-w) is 0.3 mm or more. By providing such a space, the surplus adhesive flows into this space, making it possible to prevent the occurrence of the above-mentioned phenomenon. EXAMPLES

[0043] The present invention will be described below with reference to examples, but the present invention is not limited to these examples in any way.

[0044] Examples 1 to 4 Using guide instruments A to C of the present invention having the shapes shown in Figure 4 and the dimensions shown in Table 1, tensile test samples were prepared by the tensile test sample preparation method of the present invention as described below, and the adhesion of the dental resin cement to bovine anterior teeth was evaluated.

[0045] 1. Preparation and pretreatment of adherend test pieces The extracted bovine front tooth was polished with water-resistant abrasive paper P600 under water and the morphological plane was scraped off to prepare an adherend test specimen. After that, a double-sided adhesive tape with a 3 mm diameter hole was attached to the adhesive application surface. Next, a pretreatment material (Bondmar Lightless, Tokuyama Dental) was applied with a microbrush to the bovine tooth surface exposed through the hole in the double-sided tape on the adhesive application surface, and the adherend test specimen was prepared by drying with an air blower for 5 seconds.

[0046] 2. Preparation of Specimens for Tensile Testing As shown in Figures 6 and 7, the guide instrument was placed on the double-sided adhesive tape of the adherend test piece pretreated by the above method so that its center coincided with the center of the hole for determining the adhesive area, and was adhesively fixed, so that the central axis of the guide instrument was held perpendicular to the adherend surface. After that, an appropriate amount of resin cement paste (Estecem II, Tokuyama Dental) as a dental hardening adhesive was applied to the pretreated bovine tooth surface exposed from the hole of the double-sided tape. The resin cement paste is a pretreatment material combined adhesive resin cement, which contains a photopolymerization initiator and a benzoyl peroxide-amine compound-based chemical polymerization initiator, and can be photopolymerized or chemically polymerized during polymerization and hardening. Next, a columnar attachment (made of SUS304, diameter 8.0 mm, height 18.0 mm) was manually inserted through the opening of the guide instrument, and the adhesive surfaces were brought into close contact with each other via an adhesive as shown in Figure 6, and the adhesive was hardened by chemical polymerization to bond the two. Note that the columnar attachments used were an attachment (vertical) precisely machined so that its adhesive surface was perpendicular (90°) to the axial direction, and an attachment (inclined) whose adhesive surface was polished to a flat surface inclined 3° from the perpendicular. After bonding as described above, the specimen was immersed in water at 37° C. for 24 hours to obtain a sample for a tensile test.

[0047] 3. Adhesion evaluation by tensile test measurement The tensile adhesive strength of the obtained tensile test samples was measured using an autograph (crosshead speed 2 mm / min) manufactured by Shimadzu Corporation. Measurements were performed on five samples for each example, and the average value was used as the measurement result. The results are shown in Table 2. Reference Example 1 in Table 2 shows the results when a tensile test sample was used that was prepared using the attachment (vertical) and the jig shown in Fig. 2. As shown in Table 2, Examples 1 to 4 all obtained results equivalent to those of the Reference Example.

[0048] [Table 1]

[0049] [Table 2] [Explanation of symbols]

[0050] 10. Conventional fixture 20. Stand 21...post 30... Piston member 31... Rod-shaped member 32...holding mechanism 33...Load platform 40... Sample stage 41...bottom 42 Ceiling 43...hole 50 Lifting device 100 Guide device of the present invention 110... Cylindrical body 111a: One end of a cylindrical body 111b... Other end of cylindrical body 112a: One end surface of a cylindrical body 113a,b...opening 120...Cylindrical central axis 130...Cavity 131: Space for storing excess adhesive 200...Adherend test piece 210...adherent surface 300 ··· Column attachment 301... Column body 301a One end of the column 302a: End surface of one end 310... Attachment adhesive surface 320...Central axis of column 400···Adhesive film 410...Gluing area regulation hole 500 ··· Curable adhesive

Claims

1. A method for preparing a tensile test sample for evaluating the adhesion of a curable adhesive to an adherend by a tensile test, comprising a joint consisting of an adherend test piece having a flat surface that serves as an adherend adhesive surface, and a columnar attachment having, as one end face, a flat surface perpendicular or approximately perpendicular to the longitudinal direction, with the end face being an attachment adhesive surface, the columnar attachment being joined together such that the longitudinal direction of the columnar attachment is perpendicular to the adherend adhesive surface via a layer of a cured product of the curable adhesive formed between the adherend adhesive surface and the attachment adhesive surface, the method comprising the steps of: A. A preparation step of preparing (1) the adherend test piece, (2) the columnar attachment, (3) an adhesive film having an adhesive area determining hole formed therein, the hole having an area smaller than the area of ​​the adhesive surface of the attachment and determining the adhesive area, and (4) a guide device for guiding the columnar attachment to a predetermined position while moving it along its longitudinal direction; B. A film attachment step of attaching the pressure-sensitive adhesive film to the adhesive surface of the adherend; C. An adhesive application step of applying the curable adhesive in an uncured state to the adherend adhesive surface and / or the attachment adhesive surface exposed through the adhesive area defining hole; and D. A bonding step of bonding the adherend test piece and the columnar attachment by bonding the adherend surface and the attachment surface to each other through the uncured curable adhesive applied in the step above, positioning the columnar attachment so that the longitudinal direction of the columnar attachment is perpendicular to the adherend surface, and then curing the curable adhesive to bond the adherend test piece and the columnar attachment; The guide device is a cylindrical body having a cavity with both ends open, with one end face being a plane perpendicular to the height direction, and capable of standing on its own when placed on a horizontal surface with the end face of the one end facing down, the cavity has a shape that allows a portion of the columnar attachment including at least the end face of the one end to move freely forward and backward within the cavity while restricting the longitudinal direction of the columnar attachment to coincide with the height direction of the cylindrical body, and the columnar attachment is moved along its longitudinal direction while maintaining a state in which the longitudinal direction of the columnar attachment is perpendicular to the adherend bonding surface, thereby guiding the attachment bonding surface to a predetermined position on the adherend bonding surface, and allowing the adherend bonding surface and the attachment bonding surface to be in close contact with each other via a layer made of the curable adhesive in an uncured state while maintaining the state at the predetermined position, In the adhesion step D, the end face of the one end of the guide device is placed on the adhesive film of the adherend test piece to which the adhesive film is attached or on the adherend adhesive surface, at a position where the adhesive area determination hole is present inside the opening at the one end, and the guide device is held so that its height direction is perpendicular to the adherend adhesive surface, and then the columnar attachment is inserted from the attachment adhesive surface side through the opening at the other end of the guide device to perform the adhesion and positioning.

1. A method for preparing a sample for a tensile test, comprising the steps of:

2. 2. The method for preparing a tensile test sample according to claim 1, wherein an adhesive film having adhesive layers on both sides is used as the adhesive film, and in the bonding step D, the end face of the one end of the guide instrument is placed on the adhesive film.

3. 3. The method for preparing a specimen for a tensile test according to claim 1, wherein the curable adhesive is a dental resin cement and the adherend is an animal's tooth.

Images