JP4314570B2 - Method for evaluating processability of adhesive sheet and method for producing adhesive label - Google Patents

Description

  The present invention relates to a method for evaluating the processability of a pressure-sensitive adhesive sheet laminated in the order of a substrate, a pressure-sensitive adhesive, and a release sheet, and a method for producing a pressure-sensitive adhesive label incorporating this processability evaluation method in a process.

  The pressure-sensitive adhesive sheet is used after being processed into a label, a sticker or the like in a wide range from commercial use to household use. An adhesive label is produced from this adhesive sheet, and this adhesive label is affixed to a product to be adhered and its container.

In the process, first, printing according to the purpose is performed on the surface of the base material of the pressure-sensitive adhesive sheet, and then the desired cutting is performed by the action of putting a die-cut blade into the layer composed of the base material and the pressure-sensitive adhesive, so-called “half-cut”. A label is punched into the shape (hereinafter referred to as “punching”).
Next, after unnecessary parts (the base material layer and the pressure-sensitive adhesive layer which are not printed on the base material and become a waste part) generated by the punching are peeled off (hereinafter referred to as “scrap removal”), once. This adhesive sheet is rewound into a roll.
And using the automatic sticking machine (auto labeler), the adhesive label remaining on the wound adhesive sheet is peeled off from the release sheet and attached to the adherend.

  Therefore, in the processing stage of the pressure-sensitive adhesive label, (1) the punching ability when punching the label, (2) the scraping ability when removing the waste part, and (3) when sticking the label to the adherend ) Three workability of auto labeler suitability is required. Here, these three processability are collectively referred to as process suitability.

Conventionally, a test method of JIS-Z0237 is known as a method for evaluating the physical properties of this pressure-sensitive adhesive sheet.
However, with this test method alone, it has been difficult to properly determine whether the pressure-sensitive adhesive sheet has good processability.

  Therefore, at the actual label manufacturing site, the prototype adhesive sheet is put into the above-mentioned adhesive label production line, processed, and the prototype label is attached to the adherend to judge whether the processing suitability is good or bad. It was.

  However, in the above-mentioned method for evaluating the processing suitability by putting a prototype sheet into an actual adhesive label production line, it is necessary to stop and test the operating line, and (1) it takes time and effort. (2) In addition, there was a problem that the loss of the sample for evaluation was large, and (3) it was difficult to evaluate and manage lot fluctuation of the adhesive sheet material in advance.

  In view of the above-described problems of the prior art, the present invention is a method for evaluating the suitability of a pressure-sensitive adhesive sheet capable of determining the suitability of the pressure-sensitive adhesive sheet without actually performing a processing test on the pressure-sensitive adhesive sheet on the pressure-sensitive adhesive label production line. The purpose is to provide.

  Moreover, this invention aims at providing the manufacturing method of the adhesive label which incorporated the evaluation method of the workability of this adhesive sheet in the process.

To solve this problem,
This invention peels the said peeling sheet from the adhesive sheet laminated | stacked in order of the base material, the adhesive, and the peeling sheet, By the magnitude | size of the stringing area of the said adhesive in the cross-section peeling part of this peeled adhesive sheet The present invention provides a method for evaluating processability of an adhesive sheet, characterized by evaluating processability.

  The present invention also includes a first step for producing a pressure-sensitive adhesive sheet laminated in the order of a base material, a pressure-sensitive adhesive, and a release sheet, a second step for printing on the base material of the pressure-sensitive adhesive sheet, and a pressure-sensitive adhesive subjected to this printing. A third step of punching out the pressure-sensitive adhesive label from the sheet, a fourth step of removing the base material layer and the pressure-sensitive adhesive layer of the residue from the release sheet from the pressure-sensitive adhesive sheet after punching out the pressure-sensitive adhesive label, and the pressure-sensitive adhesive after removing the waste A fifth step of winding the sheet in a roll shape, and the method for evaluating the processability of the pressure-sensitive adhesive sheet during or after any one of the first to fifth steps. The present invention provides a method for producing a pressure-sensitive adhesive label.

  According to the method for evaluating the processability of the pressure-sensitive adhesive sheet of the present invention, it is possible to appropriately determine the processability of the pressure-sensitive adhesive sheet without actually performing a process test of the pressure-sensitive adhesive sheet on the pressure-sensitive adhesive label production line.

  Further, according to the method for evaluating the processability of the pressure-sensitive adhesive sheet of the present invention, it is possible to reduce the time required for the evaluation of processability without taking time and to reduce the amount of sample necessary for the evaluation of processability from the conventional method. It is possible to reduce and reduce the lot fluctuation of the adhesive sheet material in advance.

  Furthermore, according to the method for evaluating the processability of the pressure-sensitive adhesive sheet of the present invention, a pressure-sensitive adhesive sheet material having good processability can be easily selected.

  And according to the manufacturing method of the adhesive label of this invention, the adhesive label can be manufactured by incorporating this evaluation method of the processability of an adhesive sheet into an adhesive label manufacturing process appropriately.

  In the method for evaluating the processability of the pressure-sensitive adhesive sheet of the present invention, the release sheet is peeled from the pressure-sensitive adhesive sheet, and the processability is evaluated based on the size of the threading area of the pressure-sensitive adhesive in the cross-section peeled portion of the peeled pressure-sensitive adhesive sheet. Is.

This pressure-sensitive adhesive sheet has a structure in which a substrate, a pressure-sensitive adhesive, and a release sheet are laminated in this order. Examples of the substrate include a film, a nonwoven fabric, and paper. Specifically, the material of the film includes polypropylene, polyethylene, polyester, polystyrene, polyvinyl chloride, nylon, cellophane and the like. Moreover, as a material of a nonwoven fabric, pulp, rayon, Manila hemp, acrylonitrile, nylon, polyester, etc. are mentioned. Examples of paper include high-quality paper and resin-coated paper.
Corona treatment or an anchor coating agent may be applied to the surface of the base material surface on which the adhesive is laminated.

Examples of the pressure-sensitive adhesive include rubber-based, acrylic-based, silicone-based, urethane-based, and vinyl ether-based types of polymers. In addition, as the form of the pressure-sensitive adhesive, a solvent system, an emulsion-type pressure-sensitive adhesive, a water-based pressure-sensitive adhesive, or the like, a hot-melt pressure-sensitive adhesive, a UV curable pressure-sensitive adhesive, an EB-curable pressure-sensitive adhesive, or the like should be used. Can do.
The thickness of the pressure-sensitive adhesive is preferably 5 to 200 μm, more preferably 10 to 50 μm, in terms of the thickness after drying.

  As release sheet, glassine paper, kraft paper, clay coated paper, paper laminated with polyolefin film such as polyethylene, paper coated with resin such as polyvinyl alcohol and acrylate copolymer, polyolefin synthetic such as polyester and polypropylene Examples include a resin film or the like coated with a release resin such as a fluororesin or a silicone resin.

  This pressure-sensitive adhesive sheet can be produced, for example, by applying a pressure-sensitive adhesive to a release sheet, performing a treatment such as drying, heat curing, ionizing radiation curing, etc., and bonding a substrate thereto. On the contrary, it can also be obtained by a method in which a pressure-sensitive adhesive is applied to a substrate, subjected to treatment such as drying, thermosetting, ionizing radiation curing, and a release sheet is bonded thereto. Moreover, in order to improve the adhesiveness of a base material layer and an adhesive layer, you may bond together under high temperature.

In order to evaluate the processability of the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet is cut or half-cut to expose the cross section of the pressure-sensitive adhesive sheet. And a peeling sheet is peeled from the adhesive sheet which this cross section exposed. The peeling part of the cross section of this peeled adhesive sheet is observed with an optical microscope, visual observation, etc., and the peeling process of the adhesive between a base material and a peeling sheet is observed.
This peeling may be performed immediately at room temperature after cutting the pressure-sensitive adhesive sheet, but is preferably performed after leaving at a temperature of 30 to 50 ° C. for 30 minutes to 3 hours, and in particular, for 1 hour in a temperature atmosphere of 40 ° C. It is more preferable to leave it as it is. After leaving in the atmosphere in the above temperature range for the above time, when peeling is performed, the flow of the adhesive proceeds, and the adhesion to the surface of the substrate and the release sheet is increased. The difference in stringing can be clearly observed.

FIG. 1 is a cross-sectional view schematically showing a cross-section peeling portion of the pressure-sensitive adhesive sheet in this peeling process. In this peeling process, the distance L from the pressure-sensitive adhesive sheet 1 to the peeling sheet 4 until the angle θ between the substrate 2 and the peeling sheet 4 is 3 to 45 degrees, preferably 10 to 30 degrees, and most preferably 15 degrees. 0.1 to 1.5 mm, preferably 0.2 to 0.4 mm, and most preferably 0.3 mm. Here, the angle θ formed by the base material 2 and the release sheet 4 is a tangent to the surface of the base material 2 at a position 0.15 mm away from the contact point R where the base material 2 and the release sheet 4 are about to start peeling. The angle formed by the tangent to the surface of the release sheet 4
The peeling speed is 5 to 1000 mm / min, preferably 50 to 500 mm / min, and most preferably 300 mm / min.

  At this time, when the peeling occurs at the interface between the pressure-sensitive adhesive 5 and the release sheet 4, the phenomenon of adhesive residue on the release sheet 4 does not occur, and the pressure-sensitive adhesive 5 is released along with the release sheet 4. If it peels from the surface of the adhesive immediately, stringing of the adhesive 5 hardly occurs. FIG. 2 is a cross-sectional view of a cross-section peeled portion of the pressure-sensitive adhesive sheet 1 where stringing hardly occurs. In this pressure-sensitive adhesive sheet 1, since the label can be easily peeled off from the release sheet 4 at the time of label processing, good processability can be achieved.

  However, when the peeling does not proceed promptly with the peeling of the release sheet 4 or when the peeling occurs in the bulk of the pressure-sensitive adhesive 5 and causes cohesive failure, large stringing is observed. FIG. 3 is a cross-sectional view of a cross-section peeled portion of the pressure-sensitive adhesive sheet 1 that has generated a large string. In this pressure-sensitive adhesive sheet 1, since the label cannot be easily peeled off from the release sheet 4 at the time of label processing, good processability cannot be achieved.

In the present invention, the quality of the adhesive label processing suitability is determined by the size of the threading area 3 of the adhesive shown in FIG. The stringing area 3 is calculated by the following method.
(1) Let R be the contact point at which the substrate 2 and release sheet 4 in FIG.
(2) Let P be the point where the adhesive 5 is the furthest part farthest from the contact R and is in contact with the substrate 2.
(3) Similarly, let Q be the point where the adhesive 5 is the furthest part farthest from the contact R and is in contact with the release sheet 4.
(4) The stringing area 3 is the area of the PQR surrounded by the point P, the point Q, and the point R (the portion surrounded by the two-dot chain line in FIG. 1).

Therefore, the stringing area 3 means a size including the part of the adhesive 5 in the PQR and the part of the space where the adhesive 5 does not exist. When the size of the threading area 3 of this adhesive is small, it is preferably within 0.06 mm ² , and particularly preferably within 0.04 mm ² . The processability is good.

  Naturally, even if the size of the threading area 3 of the pressure-sensitive adhesive is within the above range, the pressure-sensitive adhesive 5 causes cohesive failure, and the surface of the base material 2 and the release sheet 4 are respectively separated. Needless to say, when it remains or when it completely peels off from the substrate 2 and moves onto the release sheet 4, the processability of the pressure-sensitive adhesive label is poor.

  This method for evaluating the processability of the pressure-sensitive adhesive sheet may be carried out alone, or may be incorporated into one step of the method for producing a pressure-sensitive adhesive label.

  The manufacturing method of the pressure-sensitive adhesive label is the first step of manufacturing a pressure-sensitive adhesive sheet laminated in the order of the base material, the pressure-sensitive adhesive, and the release sheet, the second step of printing on the base material of the pressure-sensitive adhesive sheet, and the printing. A third step of punching out the pressure-sensitive adhesive label from the pressure-sensitive adhesive sheet, a fourth step of removing the base material layer and the pressure-sensitive adhesive layer of the residue from the release sheet from the pressure-sensitive adhesive sheet after punching out the pressure-sensitive adhesive label, and a pressure-sensitive adhesive after removing the waste And a fifth step of winding the sheet into a roll. The process for evaluating the processability of the pressure-sensitive adhesive sheet of the present invention can be performed during any of the first to fifth steps or after the fifth step.

  By using the pressure-sensitive adhesive sheet evaluated as good by using this method for evaluating the processability of the pressure-sensitive adhesive sheet, line troubles in the method for producing a pressure-sensitive adhesive label can be avoided in advance.

  Hereinafter, the present invention will be described in more detail by way of examples. The present invention is not limited to the following examples.

[Example 1]
<Creation of adhesive sheet>
A release sheet (OKB-105NC, manufactured by Oji Paper Co., Ltd.) is coated with an adhesive (SPS-1260, manufactured by Dainippon Ink & Chemicals, Inc.) whose main component is an acrylic copolymer so that the thickness after drying is 20 μm. And then dried for 3 minutes at 90 ° C. using a hot air dryer, bonded with a polyethylene terephthalate (PET) film 50 μm (Ester A-4100, manufactured by Toyobo Co., Ltd.), and aged for 14 days at 23 ° C. It was created.

<Evaluation test for processability of adhesive sheet>
The pressure-sensitive adhesive sheet was cut into a size of 45 mm × 45 mm with a die-cut blade to expose a cross-sectional portion of the pressure-sensitive adhesive sheet. The base material edge part (play part) of this adhesive sheet was fixed with the holder, and the peeling sheet was peeled off at a speed of 300 mm / min. In FIG. 1, when the angle θ between the base material and the release sheet is 15 degrees and the distance L between the base material and the release sheet is 0.3 mm, the release is stopped, and the cross-section release portion is observed with an optical microscope (KH-2700, (Hilox). The magnification of the optical microscope was 250 times. As shown in FIG. 1, the contact point at which the base material 2 and the release sheet 4 are about to start peeling is R, and the threading portion of the adhesive 5 that is farthest from the contact point R is The point that is in contact with the base material 2 is P, the point that is the furthest part from the contact point R and that is in contact with the release sheet 4 is Q, and is surrounded by the point P, the point Q, and the point R The threading area of the pressure-sensitive adhesive represented by PQR was measured.

The stringing area of this pressure-sensitive adhesive sheet was 0.004 mm ^{2 as} shown in FIG. This value corresponds to the size of the threading area 3 of the pressure-sensitive adhesive within 0.06 mm ^2, which is a standard for judging whether or not the processability of the pressure-sensitive adhesive label is good.

<Evaluation of processability of actual adhesive label production line>
This pressure-sensitive adhesive sheet was put into an actual pressure-sensitive adhesive label production line, and the pressure-sensitive adhesive label was punched out, the residue was removed from the punched-out pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive sheet was wound up after removal. Next, this winding sheet was put into an automatic sticking machine, and an adhesive label was stuck on the adherend container.

  This pressure-sensitive adhesive sheet had good punching suitability and residue picking suitability in the pressure-sensitive adhesive label processing step. Furthermore, the auto labeler suitability was also good in the adhesive labeling process.

[Example 2]
The pressure-sensitive adhesive sheet was the same as in Example 1 except that SK Dyne 701F-L (manufactured by Soken Chemical Co., Ltd.) was used as the pressure-sensitive adhesive and that the aging period at the time of preparation of the pressure-sensitive adhesive sheet was 1 day at 23 ° C. It was created. Evaluation of the processability of this pressure-sensitive adhesive sheet was performed in the same manner as in Example 1.
The stringing area of this pressure-sensitive adhesive sheet was 0.16 mm ^{2 as} shown in FIG. This value exceeds the size 0.06 mm ² of the threading area 3 of the pressure-sensitive adhesive, which is a criterion for judging whether or not the processability of the pressure-sensitive adhesive label is good.

Moreover, it carried out similarly to Example 1, and evaluated the punching aptitude of the adhesive sheet, the scrap removal aptitude, and the auto labeler aptitude of the adhesive label.
The punching suitability and scrap removal suitability of this pressure-sensitive adhesive sheet were poor. Furthermore, the auto labeler suitability was poor in the adhesive labeling process.

  From the above results, it was found that the pressure-sensitive adhesive sheet having a small stringing area has good processability even in the production of an actual pressure-sensitive adhesive label by the method for evaluating the processability of the pressure-sensitive adhesive sheet.

  Therefore, it was confirmed that if the method for evaluating the processability of the pressure-sensitive adhesive sheet of the present invention is used, the processability of the pressure-sensitive adhesive sheet can be appropriately determined without actually performing a process test of the pressure-sensitive adhesive sheet on the pressure-sensitive adhesive label production line.

It is sectional drawing which represented typically the cross-section peeling part of the adhesive sheet in a peeling process. It is sectional drawing of the cross-section peeling part of an adhesive sheet with favorable processability. It is sectional drawing of the cross-section peeling part of the adhesive sheet with a processability defect.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adhesive sheet 2 Base material 3 Stringing area 4 Release sheet 5 Adhesive

Claims (4)

  From the pressure-sensitive adhesive sheet laminated in the order of the base material, the pressure-sensitive adhesive, and the release sheet, the release sheet is peeled off, and the processability is determined by the size of the threading area of the pressure-sensitive adhesive in the cross-section peeled portion of the peeled pressure-sensitive adhesive sheet. A method for evaluating the processability of a pressure-sensitive adhesive sheet, characterized by evaluating. After the pressure-sensitive adhesive sheet is cut and left at a temperature of 40 ° C. for 1 hour, the release sheet is peeled from the pressure-sensitive adhesive sheet until the angle between the base material and the release sheet becomes 10 to 30 degrees, 50 to 500 mm / The method for evaluating the processability of the pressure-sensitive adhesive sheet according to claim 1, wherein 0.2 to 0.4 mm is peeled at a peeling speed of 1 minute. The method for evaluating the workability of a pressure-sensitive adhesive sheet according to claim 1, wherein the sheet is peeled by 0.3 mm at a peeling speed of 300 mm / min until the angle between the substrate and the release sheet reaches 15 degrees. . A first step of producing a pressure-sensitive adhesive sheet laminated in the order of a substrate, a pressure-sensitive adhesive, and a release sheet;
A second step of printing on the substrate of the adhesive sheet;
A third step of punching out an adhesive label from the printed adhesive sheet;
A fourth step of removing the base material layer and the pressure-sensitive adhesive layer of the residue from the release sheet from the pressure-sensitive adhesive sheet after punching the pressure-sensitive adhesive label;
A fifth step of winding the adhesive sheet after scrap removal into a roll,
During any of the first to fifth steps or after the fifth step,
The manufacturing method of the adhesive label characterized by performing the evaluation method of the workability of the adhesive sheet in any one of Claims 1-3 .

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