Label for marking defective portion of electrode for secondary battery and method for manufacturing the same

Abstract

The present invention relates to a label for marking a defective portion of an electrode for a secondary battery and a manufacturing method thereof, and particularly, a label for marking a defective portion of an electrode for a secondary battery, which can be simply attached to a defective portion of an electrode for a secondary battery produced by an automated process, is provided with a release paper coated with a color contrasting with a color of the label for marking, when the label for marking is supplied by a label automatic feeder, in order to allow a light sensor provided in the automatic feeder to correctly recognize the release paper and the label for marking and automatically supply the label for marking. The label for marking and the manufacturing method thereof of the present invention use a release paper coated with a color that can be clearly recognized by a light sensor in contrast with a color of the label for marking, and in contrast with a black electrode, when a label of a bright color such as white is used, a user can be provided with visual convenience and clear recognition, and the label automatic feeder can also clearly recognize the label and the release paper, and a problem of unsmooth automatic supply of the label due to recognition error of the sensor is solved.

Description

TECHNICAL FIELD

[0001] The present invention relates to a label for marking a defective portion of an electrode for a secondary battery and a manufacturing method thereof, and more particularly, to a label for marking a defective portion of an electrode for a secondary battery, which is formed by combining a release paper coated with a color contrasting with a color of the label for marking and the label for marking, thereby allowing a label for marking, which can be easily attached to a position of the electrode for a secondary battery, recognized as having a defect, produced through an automated process, to be supplied by a label automatic feeder, to be recognized by a light sensor provided in the automatic feeder without error and to be automatically supplied, when the label for marking is supplied to mark a defective portion of the electrode. BACKGROUND

[0002] Generally, an electrode for a secondary battery is manufactured by coating an active material, a conductive material, and a binder to a thin sheet-shaped current collector having a thin thickness, and drying the same. When the thin sheet-shaped electrode for a secondary battery is manufactured, a problem such as a self defect can occur due to an external impurity mixed in when the active material or the like is coated on the surface of the current collector, or the active material or the like is not uniformly coated on the surface of the current collector. Therefore, after the electrode for a secondary battery is manufactured, it is wound on a winding roller, unwound, and then it is confirmed whether or not a defect exists on the entire surface and marked, and then it is wound on another winding roller again to be packaged or transferred to a cutting process, thereby removing a defective portion marked on the surface and using only a normal electrode portion.

[0003] In addition, as the demand for the electrode for a secondary battery increases, an automated production process is introduced, and in order to easily mark a defective portion generated on the surface of the electrode for a secondary battery in the automated production process while preventing a new defect due to an adhesive, the applicant of the present invention has disclosed a label for marking a defective portion of an electrode for a secondary battery, which adjusts an amount of an adhesive and a position of an adhesive layer to be optimal, in the prior patent 1, thereby minimizing a possibility of causing a secondary damage or a defect on the front and rear surfaces of the thin sheet-shaped electrode for a secondary battery.

[0004] However, the manufacturing process of the label disclosed in the prior patent 1 is complicated, the manufacturing cost is high, and the thickness of the label itself is also thick, and thus, considering that the label is discarded after marking a defective portion of the electrode for a secondary battery once, it is necessary to develop a label for marking a defective portion of an electrode for a secondary battery, which can retain the advantages of the existing label for preventing an adhesive from leaking and is more convenient and less expensive.

[0005] In addition, recently, as the production process of the electrode for the secondary battery is automated, not only the production process of the electrode, but also the supply device of the label or the sticker for identifying the defective part of the electrode is also showing a trend of automation. When the inspector confirms the label or the sticker for identification which is automatically supplied after the part of the electrode which is identified as defective, the next label or sticker is automatically supplied, and a light sensor which can identify the label or the sticker and the release paper is generally used. In general, the electrode for the secondary battery is dark such as black, and thus it is preferable that the label or the sticker which is attached to the defective part of the electrode produced and identifies the defective part mainly uses a light color such as white. However, the label or the sticker is manufactured and supplied in a state where the adhesive layer is formed in a part on the release paper, and at this time, the release paper mainly has a sky blue or white base, and thus the light sensor installed in the supply device of the label cannot well distinguish the label and the release paper, and often causes a supply error or a sensor identification error.

[0006] Therefore, it is necessary to apply a color different from the label to the release paper, but the existing release paper has a silicon coating process on the surface, and thus it is difficult to apply a color by post-processing, and when the silicon coating process is performed immediately after applying a certain color to the base sheet used as the release paper, there is a problem that the silicon coating is not well performed or the color layer is separated or peeled off due to warping after the coating. Therefore, when the label or the sticker for identifying the defective part of the electrode for the secondary battery uses a light color such as white, it is necessary to develop a release paper to which a color which is easily identified by the light sensor of the label automatic supply device is applied, and it is also necessary to develop a label for marking the defective part of the electrode for the secondary battery and a manufacturing method thereof, in which the color of the label and the release paper is clearly different, so that the light sensor of the device which automatically supplies the label can clearly distinguish and identify the release paper and the label.

[0007] Prior Patent Documents

[0008] Prior Patent 1: Korean Patent No. 10-1330880 (issued on November 12, 2013) SUMMARY

[0009] Technical Problem to be Solved

[0010] The present application is proposed to solve the problems and limitations of the prior art, and the object thereof is to provide a label for marking a defective part of an electrode for a secondary battery and a manufacturing method thereof, in which when a label for identifying a defective part of an electrode for a secondary battery which is produced by an automated production process is automatically supplied, a light sensor provided in a label automatic supply device can clearly identify a release paper and a label which are supplied, and a problem that the automatic supply is not smooth due to a sensor identification error can be avoided.

[0011] And, another object of the present application is to provide a label for marking a defective portion of an electrode for a secondary battery, which is simple in structure compared to a conventional label for identification, easy to manufacture and convenient for a label user to use, and which is also cheaper than the conventional label for identification, and a method for manufacturing the same.

[0012] Means for solving the problem

[0013] The label for marking a defective portion of an electrode for a secondary battery according to the present application is characterized by comprising: a release paper formed by sequentially laminating a base paper for a release paper, a release paper color layer formed by applying a certain color to a surface of the base paper for a release paper, a release paper adhesive layer formed by applying an adhesive of a transparent material to a surface of the release paper color layer, a release paper PET film layer formed by pasting a transparent polyethylene terephthalate (PET) film to a surface of the release paper adhesive layer, and a silicone layer formed by applying silicone to a surface of the release paper PET film layer; an adhesive layer formed by partially applying an acrylic adhesive to a surface of the silicone layer of the release paper, having a thickness of 5 to 30 μm; and a film-shaped label film formed of a synthetic resin material having another color contrasting with the release paper color layer, one side portion of which corresponding to 25 to 50% of the entire area is integrally combined to the adhesive layer by being adhered to the adhesive layer.

[0014] Preferably, the material of the label film is polyethylene terephthalate (PET), and the thickness of the label film is 25 to 50 μm. After checking whether or not a defective portion exists in an electrode for a secondary battery, even if the electrode is stored by being wound in a state in which the label for marking is pasted to the defective portion, the label of the PET material having a relatively thin thickness of 25 to 50 μm is pressed together with the electrode in a state of being wound due to pressure and weight applied at the time of winding, and has the least influence on the electrode.

[0015] In addition, the color of the release paper color layer is red or yellow, and the color of the label film is white, because the recognition rate is the best when a color sensor or an optical sensor such as an infrared sensor is used as a sensor for distinguishing and recognizing the label and the release paper in an automatic label supply device, and an error in the automatic supply does not occur.

[0016] In addition, the release paper PET film is a transparent film, and in order for the sensor to more effectively recognize the release paper color layer applied to the base paper, the release paper adhesive layer applied to the surface of the release paper color layer also uses an adhesive of a transparent material.

[0017] In addition, preferably, among the elements constituting the release paper, the thickness of the release paper adhesive layer is 10 to 15 μm, and the thickness of the release paper PET film layer is 16 to 25 μm, in order to allow the sensor to effectively recognize the color and the thickness of the label for marking according to the present application to not become too thick when it is wound and supplied. Preferably, the base paper uses a 60 g / m 2 a thinner art paper of 60 g / m

[0018] Among the elements constituting the label for marking according to the present application, the material forming the adhesive layer, i.e., the adhesive, uses an acrylic resin. Among them, an acrylic resin can use a removable resin or a permanent resin. Because, the electrode to which the label for marking is attached as a defective portion is discarded together in the state in which the label for marking is attached, it is not necessary to use an acrylic removable resin. The acrylic resin is an adhesive formed by polymerization of an acrylic monomer, and is an adhesive in which an acrylic polymer is the main body. Preferably, an acrylic ester or a methacrylic ester is used. However, in order to prevent the electrode from being defective again due to adhesive leakage when adhering, and to have a high adhesion force to a wide range of surfaces, further preferably, an acrylic removable resin is used. In addition, regarding the adhesion force value of the adhesive required by the present application, preferably, when a measuring device removes the adhered product at an angle of 90 degrees, it is 100 to 800 gr / 25 mm, and when it removes the adhered product at an angle of 180 degrees, it is 100 to 1400 gr / 25 mm.

[0019] Among the elements constituting the label for marking according to the present application, in order to recognize the boundary of the portion in which the adhesive layer exists on the back, the surface of the label film further includes one or more adhesive guide lines marked in a solid line or a wavy line form.

[0020] The purpose of the adhesive guide line is to allow the inspector who checks whether the electrode has a defective portion to easily recognize which portion of the back of the label film the adhesive is adhered to when the label for marking is attached to the defective portion of the electrode, to provide user convenience, and to allow the sensor recognizing the label for marking to easily recognize the attached label.

[0021] In addition, according to the label for marking according to the present application, the portion in which the adhesive layer does not exist in the release paper further includes a vent line formed in a solid line or a wavy line form by being partially cut along the length direction. The vent line has air in the gap due to the absence of the adhesive layer, and when the label for marking to which the release paper is attached is wound and stored, the thickness thereof becomes different depending on the presence or absence of the adhesive layer, in order to make it uniform, the air present in the portion in which the adhesive layer does not exist is vented.

[0022] The manufacturing method of a label for defect marking of an electrode for a secondary battery according to another aspect of the present application is characterized by comprising the steps of: a base paper preparation step of preparing a base paper used for a release paper; a release paper color layer formation step of forming a release paper color layer by applying a certain color to the surface of the prepared base paper and drying it; a release paper adhesive application step of forming a release paper adhesive layer by applying a transparent acrylic permanent adhesive to the surface of the formed release paper color layer; a release paper PET film layer formation step of forming a release paper PET film layer by adhering a transparent film of polyethylene terephthalate material to the surface of the release paper adhesive layer; a silicone layer formation step of forming a silicone layer by applying a silicone having a release function to the surface of the release paper PET film layer and drying it; an adhesive layer formation step of forming an adhesive layer having a thickness of 5 to 30 μm by partially applying an acrylic removable adhesive to the surface of the formed silicone layer of the release paper; and a label film combining step of combining a label film in the form of a film formed of a synthetic resin material having another color contrasting with the release paper color layer formed on the formed adhesive layer by attaching the label film prepared in advance to the back surface of only a portion corresponding to 25 to 50% of one side of the entire area of the label film and combining it with the release paper. However, when the area of the adhesive layer 200 is formed from one side end of the label film 300 to be 25% or less of the entire area of the label film, there is a problem in that the label film 300 is easily separated from the release paper 100, and thus the minimum area of the adhesive layer 200 is limited to 25% of the entire area of the label film. In addition, when the area of the adhesive layer exceeds 50% of the entire area of the label film, if the back surface of the entire area is also formed with the adhesive layer when the label for marking is adhered to the surface of the electrode for a secondary battery, the electrode of another portion having no defect is damaged.

[0023] Preferably, the silicone layer formation step is followed by a vent line formation step of partially cutting along the length direction in a portion where the adhesive layer is not present in the release paper to form a solid line or a wavy line-shaped vent line.

[0024] Preferably, the label film combining step is followed by an adhesive guide line marking step of marking an adhesive guide line in the form of a solid line or a wavy line on the surface of the label film along the boundary of a portion where the adhesive layer is present on the back surface.

[0025] Effects of the Invention

[0026] The label for marking according to the present application has the effect that, by using a release paper coated with a color that can be accurately recognized by a light sensor of a contrasting white label color, and by using a white or light-colored label for a contrasting black electrode, the user can be provided with visual convenience and clear recognition, and the label automatic supply device can also clearly recognize the label and the release paper, thereby solving the problem of unsmooth label automatic supply caused by recognition error of the sensor.

[0027] Furthermore, the label for marking according to the present application has the effect that the user can easily recognize up to which point is the adhesive layer, and when the label is adhered to the defective part of the electrode, the user is provided with convenience.

[0028] In addition, the manufacturing method of the label according to the present application has the effect that, while retaining the advantages of the existing identification label, compared with the existing identification label, a label with a simpler and cheaper structure is provided, thereby improving user convenience and providing convenience in manufacturing cost and manufacturing process. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The front and back surfaces of the label for marking according to the present application are shown.

[0030] Figure 2 The cross section of the A-A' part of the label for marking according to the present application is shown.

[0031] Figure 3 The overall manufacturing process of the label for marking according to the present application is shown.

[0032] EXPLANATION OF REFERENCE NUMERALS

[0033] 100: release paper

[0034] 110: base paper

[0035] 120: release paper color layer

[0036] 130: release paper adhesive layer

[0037] 140: release paper PET film layer

[0038] 150: silicone layer

[0039] 200: adhesive layer

[0040] 300: label film

[0041] 400: adhesive guide line

[0042] 500: exhaust line. DETAILED DESCRIPTION

[0043] One embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0044] Figure 1 The front and back sides of the label for marking according to the present invention are shown. Figure 2 A cross-section of the A-A' portion of the label for marking according to the present invention is shown.

[0045] Figure 1 In the figure, the left side shows the surface of the label of the present invention, and the right side shows the back of the label of the present invention.

[0046] The basic structure of the label for marking according to the present invention includes release paper 100, adhesive layer 200 and label film 300. Figure 1 and Figure 2 The solid lines in the diagram indicate what is visible, while the dashed lines indicate what exists on the back.

[0047] As a component of release paper 100, the base paper is white 60 / m 2 The standard-sized, glossy, flat art paper minimizes the thickness of the release liner and achieves the minimum thickness required for its function. When forming the release liner by sequentially laminating a release liner PET film layer 140 and a release liner PET film layer 150 with a release liner PET film layer 140 and a silicone resin layer 150, respectively, to maximize color contrast with the label film, the thickness of the release liner itself must be prevented from becoming excessive. Preferably, the thickness of the release liner PET film layer is 16-19 μm, with the release liner adhesive layer thickness being 10-15 μm. If the release liner is too thick, it will be difficult to roll up the label film during assembly, requiring adjustments to ensure the sensor can clearly identify the release liner and the label film while maintaining a relatively thin thickness. The silicone resin layer 150, formed by coating the surface of the release liner PET film layer 140 with silicone resin, functions as a release liner.

[0048] The adhesive layer 200 is formed by locally applying an acrylic adhesive to the surface of the silicone layer of the release paper, and its thickness is preferably 5 to 30 μm. In this embodiment, an acrylic removable adhesive is used to form the adhesive layer 200. Figure 1 The diagram shows the adhesive layer 200 bonded to the back of one side portion of the label film 300, which occupies approximately 25-30% of the total area. Preferably, the label film is made of PET film with a thickness of approximately 25-36 μm. In this embodiment, a white PET film is used as the label film.

[0049] In addition, in order to give convenience to the user, at least one adhesive guide line 400 is printed in a solid or wavy line form on the surface of the label film 300, in the portion where the adhesive layer is present on the back or around the portion where the label is adhered, in order to inform how much space is required for the adhesive to be pasted or to be pasted properly. Figure 1 and Figure 2 The boundary surface of the adhesive layer is marked with a solid line along the boundary. Among them, although not specifically shown in the drawing, for the convenience of the user, more than two adhesive guide lines 400 can be marked.

[0050] In addition, the portion where the adhesive layer 200 is not present in the release paper 100 can also have an exhaust line 500 formed in a solid or wavy line form by being partially cut along the length direction of the release paper. Through this exhaust line 500, in the state of being combined with the release paper, the air present in the space between the label film and the release paper can be smoothly exhausted to the outside of the release paper, and the phenomenon of being unable to uniformly wind or the label film being raised when winding the label of the present application in advance can be prevented, and the problem of the thickness becoming thicker in the wound state can also be prevented.

[0051] Figure 3 The overall manufacturing process of the label of the present application is shown.

[0052] The base paper preparation step (S100) is a step of preparing the base paper used for the release paper. Among them, the base paper is white, has a thickness of 60 g / m 2 and is a glossy art paper.

[0053] The release paper color layer forming step (S200) is a step of forming a release paper color layer by applying a certain color to the surface of the prepared base paper and drying it, and mainly uses red or yellow as the color of the release paper color layer.

[0054] The release paper adhesive application step (S300) is a step of forming a release paper adhesive layer by applying a transparent acrylic permanent adhesive to the surface of the formed release paper color layer, and is a process for better forming a silicone layer and better pasting the release paper PET film layer when applying silicone to prevent the release paper color layer from being glassy or detached and to function as a release paper. The adhesive used in the release paper adhesive application step is transparent, and the release paper PET film that is combined with it is also transparent.

[0055] After applying the release paper adhesive, in the release paper PET film layer forming step (S400), the release paper PET film is adhered to the surface of the release paper adhesive layer.

[0056] After that, in the silicone layer forming step (S500), after applying silicone having a releasing function to the surface of the releasing paper PET film layer, it is dried to form a silicone layer.

[0057] Through this step, a releasing paper having a certain color as one of the elements of the present application is manufactured.

[0058] In addition, after the releasing paper is manufactured, in the adhesive layer forming step (S600), an acrylic removable adhesive is partially applied to the surface of the silicone layer of the manufactured releasing paper to form an adhesive layer having a thickness of 5 to 30 μm.

[0059] After the adhesive layer is formed, if necessary, in the vent line forming step (S700), the part where the adhesive layer is not present in the releasing paper is partially cut along the length direction of the releasing paper to form a solid line or a wavy line shape of a vent line.

[0060] After that, in the label film combining step (S800), a label film in the form of a film made of a synthetic resin material having another color contrasting with the color layer of the releasing paper is combined with the adhesive layer formed, and only the back surface of the side part corresponding to 25 to 50% of the entire area of the label film is combined with the releasing paper to manufacture a label for marking a defective part of an electrode for a secondary battery of the present application.

[0061] In addition, after the label film combining step (S800), in order to provide convenience for the user, an adhesive guide line marking step (S900) can be further performed to mark an adhesive guide line in the form of a solid line or a wavy line on the surface of the label film in order to identify the boundary of the part where the adhesive layer is present on the back surface.

Claims

1. A label for marking defective portions of electrodes used in secondary batteries, characterized in that, include: Release paper is formed by sequentially layering a release paper base paper, a release paper color layer formed by coating a certain color on the surface of the release paper base paper, a release paper adhesive layer formed by coating a transparent adhesive on the surface of the release paper color layer, a release paper PET film layer formed by pasting a transparent polyethylene terephthalate film on the surface of the release paper adhesive layer, and a silicone resin layer formed by coating a silicone resin on the surface of the release paper PET film layer. The adhesive layer is formed by locally applying an acrylic adhesive to the surface of the silicone resin layer of the release paper, and its thickness is 5 to 30 μm. The film for the label is integrally bonded to the back of one side portion, which is equivalent to 25 to 50% of the total area, by an adhesive layer. It is formed of a synthetic resin material with other colors that contrast with the color layer of the release paper.

2. The label for marking defective portions of electrodes for secondary batteries according to claim 1, characterized in that, The label film is made of polyethylene terephthalate.

3. The label for marking defective portions of electrodes for secondary batteries according to claim 1, characterized in that, The color of the release paper's colored layer is red or yellow. The film used for the label is white.

4. The label for marking defective portions of electrodes for secondary batteries according to claim 1, characterized in that, The release paper adhesive layer is composed of an acrylic permanent adhesive.

5. The label for marking defective portions of electrodes for secondary batteries according to claim 1, characterized in that, The thickness of the release paper adhesive layer is 10–15 μm, and the thickness of the release paper PET film layer is 16–25 μm. The thickness of the film used for the label is 25–50 μm.

6. The label for marking defective portions of electrodes for secondary batteries according to claim 1, characterized in that, Also includes: To identify the boundary of the adhesive layer on the back side of the surface of the label film, one or more adhesive guide lines are marked in the form of solid lines or wavy lines.

7. A label for marking defective portions of electrodes for secondary batteries according to any one of claims 1 to 6, characterized in that, The portion of the release paper without an adhesive layer also includes exhaust lines formed by partial cutting along the length of the release paper in the form of solid lines or wavy lines.

8. A method for manufacturing a label for marking defective portions of electrodes in a secondary battery, characterized in that, Includes the following steps: Base paper preparation steps: Prepare the base paper used for the release paper; The steps for forming the colored release paper layer are as follows: After applying a certain color to the surface of the prepared base paper, it is dried to form the colored release paper layer. The release paper adhesive coating step involves coating a transparent acrylic permanent adhesive onto the surface of the formed release paper colored layer to form a release paper adhesive layer. The release paper PET film layer forming step involves adhering a transparent film of polyethylene terephthalate material to the surface of the release paper adhesive layer to form a release paper PET film layer. The silicone resin layer formation step involves coating a release paper PET film layer with a silicone resin that has a release function, and then drying it to form a silicone resin layer. In the adhesive layer formation step, an acrylic adhesive that can be removed is locally applied to the surface of the silicone resin layer of the formed release paper to form an adhesive layer with a thickness of 5 to 30 μm. In the label film merging step, a pre-prepared label film made of synthetic resin material with a color contrasting to the color layer of the release paper is adhered to the formed adhesive layer and merged with the release paper by merging only the back side of one side portion, which is equivalent to 25 to 50% of the total area of ​​the label film.

9. The method for manufacturing a label for marking defective portions of electrodes for secondary batteries according to claim 8, characterized in that, After the adhesive layer forming step, the method further includes an exhaust line forming step, in which the portion of the release paper without an adhesive layer is partially cut along the length of the release paper to form an exhaust line in the form of a solid line or a wavy line.

10. A method for manufacturing a label for marking defective portions of electrodes for secondary batteries according to claim 8 or 9, characterized in that, Following the label film merging step, the method further includes an adhesive guide line marking step, in which adhesive guide lines are marked on the surface of the label film in the form of solid or wavy lines to identify the boundaries of the adhesive layer present on the back side.

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