KR20180092538A - Tape for removal of optically clear adhesive on panel, method for preparing the same and method for separation and removal method of optically clear adhesive on panel using the tape - Google Patents

Abstract

Provided are a tape for removing an optically transparent adhesive, a manufacturing method thereof and a method for removing an optically transparent adhesive using the same, wherein the tape for removing the optically transparent adhesive is composed of a first release film layer, an elastomer layer having the thickness of 5 to 50 μm, a pressure-sensitive adhesive layer containing a UV-curable photosensitive resin, and a second release film layer, which are sequentially laminated. It is an object of the present invention to provide the optically transparent adhesive and the tape for removing the optically transparent adhesive, which has an excellent effect of removing an optically transparent adhesive resin.

Description

TECHNICAL FIELD [0001] The present invention relates to a tape for removing an optical transparent adhesive, a method for manufacturing the same, and a method for removing a transparent adhesive for optical using the same. BACKGROUND ART USING THE TAPE}

The present invention relates to a tape for removing an optical transparent adhesive, a method for producing the tape, and a method for removing an optical transparent adhesive using the tape.

A touch screen is a type of input device that recognizes the position of a finger or a pen when a touch is made at a specific position on the screen without using an input device such as a keyboard or a mouse. Various types of touch screen panels exist depending on manufacturers, but resistive film type and capacitive type are typically used. The touch screen panel basically includes a front window, a transparent electrode pattern (ITO), and a circuit (FPCB: Flexible Printed Circuit (FPCB)) for processing a change in resistance value or capacitance value with respect to a position value when touched, Board) substrate. The parts are joined together using Optically Clear Adhesive (OCA) or Optically Clear Resin (OCR) to form a touch screen panel.

FIG. 1 is a view schematically showing an example of the adhesion process of the components of the touch screen panel and the occurrence of defects. 1, a touch screen panel includes an optical transparent adhesive 4 between a transparent electrode pattern 2 attached on one surface of a circuit board 3 to which a control chip 5 is connected and a front window 1 Followed by high vacuum fret bonding or rolling bonding.

However, various lap joint failures occur such that bubbles are formed, foreign substances are contained, or cohesion positions become poor during the cementation process. In order to reduce the adhesion defect, the manufacturers have performed vacuum bonding and roller bonding with expensive devices, but it is known that the adhesion failure of about 20% or more occurs depending on the products. Accordingly, touch screen panel manufacturers are interested in playing expensive front windows (eg, tempered glass), ITO, and FPCB components.

However, since the optical transparent adhesive for bonding the front window and the ITO pattern film is very strong, it is very difficult to separate after adhesion, and it is necessary to remove the optical transparent adhesive remaining on the window surface or the ITO film surface It is very difficult.

For example, when a bad touch screen panel is formed, the front window 1 is separated from the transparent electrode pattern using a physical method, and then the transparent adhesive 4 for optical use remaining in the separated front window 1 is subjected to a chemical treatment process There is a problem that damage to the front window 1 and damage to the silk film, the logo part, and the lens coating film coated on the surface occur in the chemical treatment process.

Korean Patent Laid-Open Publication No. 10-2011-0088772 discloses a touch screen panel including a heating unit for heating one surface of a touch screen panel; A cooling unit for cooling the other surface of the touch screen panel; And a control unit for controlling the temperature of the heating unit and the cooling unit so that the adhesive force of one surface of the adhesive layer is broken. However, this method has a disadvantage in that a complex apparatus is required and the effect of removing the transparent adhesive for optical is not sufficient.

Korean Patent No. 10-1560286 discloses a method of removing a transparent adhesive for optical use on a panel using a tape including a pressure-sensitive adhesive layer, but when used in an actual process, a transparent adhesive for optical use is not easily removed at once In particular, in the case of Optically Clear Resin (OCR), it is necessary to repeat the lapping and peeling a plurality of times with the technique of the above patent to completely separate the adhesive layer .

Korean Patent Publication No. 10-2011-0088772 Korean Patent No. 10-1560286

Disclosure of the Invention The present invention is conceived to solve the above-described problems of the prior art, and provides a method for efficiently removing a transparent adhesive for optical or transparent adhesive resin for optical use from a front window or a touch screen panel in a process of reproducing a touch screen panel .

Another object of the present invention is to provide a tape for removing transparent adhesive for optical, which is excellent in the effect of removing optical transparent adhesive or optical transparent adhesive resin.

To achieve the above object, the present invention provides a pressure-sensitive adhesive composition comprising a first release film layer, an elastomer layer having a thickness of 5 to 50 탆, a pressure-sensitive adhesive layer containing an ultraviolet-curable photosensitive resin in an amount of 1 to 25% 2 release film layers are laminated in this order on a transparent substrate.

According to the present invention,

(a) applying an elastomer on the first release film to form an elastomer layer having a thickness of 5 탆 to 50 탆;

(b) applying a pressure-sensitive adhesive composition containing a UV-curable photosensitive resin on the second release film to form a pressure-sensitive adhesive layer containing 1 to 25% by weight of the photosensitive resin based on the total weight of the pressure-sensitive adhesive layer; And

(c) bonding the elastomer layer and the pressure-sensitive adhesive layer to each other.

The present invention also relates to

Preparing a panel in which a transparent adhesive for optics is laminated,

Sensitive adhesive layer comprising a first release film layer, an elastomer layer having a thickness of 5 占 퐉 to 50 占 퐉, a pressure-sensitive adhesive layer containing an ultraviolet-curable photosensitive resin in an amount of 1 to 25% by weight based on the total weight of the pressure-sensitive adhesive layer, and a second release film layer Preparing a transparent adhesive removing tape for optical use,

Removing the second release film layer of the optical transparent adhesive removing tape,

Bonding a pressure-sensitive adhesive layer of the optical transparent adhesive removing tape to the surface of the optical transparent adhesive of the panel,

Irradiating ultraviolet rays in the direction of the tape by putting the panel in which the optical transparent adhesive removing tape is laminated in an ultraviolet curing device,

And removing the first release film layer of the optical transparent adhesive removing tape, and then stretching the tape to remove it together with the transparent adhesive for optical use.

Since the pressure-sensitive adhesive layer of the tape for removing an optical transparent adhesive of the present invention is prepared by mixing an ultraviolet curable photosensitive resin composition with a thermosetting pressure-sensitive adhesive resin composition, the tape is laminated on a protrusion window or a touch screen panel in which OCA or OCR remains, , The chemical bond between the photosensitive resin contained in the pressure-sensitive adhesive layer and the unreacted photosensitive resin in the OCA or OCR is made so that the pressure-sensitive adhesive layer and the OCA layer are united with each other, so that OCA or OCR can be easily removed .

In addition, since the tape for removing an optical transparent adhesive of the present invention includes an elastomer layer formed to a thickness of 50 탆 or less, it provides an excellent effect for removing a transparent adhesive for optical use.

Further, according to the method for producing a tape for removing an optical transparent adhesive of the present invention, since the elastomer layer is coated on the release film and bonded to the pressure-sensitive adhesive layer, the number of processes can be reduced and the elastomer layer can be formed to 50 탆 or less, You can also get benefits.

FIG. 1 is a view schematically showing an example of a process of attaching a component of a touch screen panel and generating a defect,
2 is a cross-sectional view showing an example of a tape for removing a transparent adhesive for optical use of the present invention,
3 is a photograph of a reproduction front window and a touch screen panel to which an optical transparent adhesive is attached,
4 is a diagram illustrating the reaction between a photosensitive resin of a tape for removing an optical transparent adhesive of the present invention and a photosensitive reactor in OCA of a touch screen panel,
Fig. 5 is a diagram illustrating a method for removing a transparent adhesive for optical use according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would unnecessarily obscure the gist of the present invention.

The following description and drawings illustrate specific embodiments in order that those skilled in the art can readily implement the described apparatus and method. Other embodiments may include other variations, both structurally and logically. Unless explicitly required, individual components and functions may be selected generally, and the order of the processes may vary. Portions and features of some embodiments may be included in other embodiments or may be replaced by other embodiments.

In the following description, a transparent adhesive for optical (OCA) is described as an example, but the same can be applied to an optical transparent adhesive resin (OCR).

A pressure-sensitive adhesive layer comprising a first release film layer, an elastomer layer having a thickness of 5 탆 to 50 탆, an ultraviolet curable photosensitive resin in an amount of 1 to 25% by weight based on the total weight of the pressure-sensitive adhesive layer, Wherein the transparent adhesive tape for optical tape is laminated in order.

The pressure-sensitive adhesive layer of the tape for removing an optical transparent adhesive of the present invention is prepared by mixing an ultraviolet curable photosensitive resin composition with a thermosetting pressure-sensitive adhesive resin composition. On the other hand, OCA is composed of various types of ultraviolet curable photosensitive resin. During the manufacturing process of OCA, about 3 to 5% of the photosensitive resin remains in the OCA adhesive layer without reacting.

Therefore, when the pressure-sensitive adhesive layer of the OCA removing tape containing the UV-curable photosensitive resin of the present invention is laminated on the OCA on the panel and then passed through an ultraviolet curing machine, the double bond of the photosensitive resin and the chemical bond A reaction occurs in which the pressure sensitive adhesive layer and the OCA layer are integrated. As a result, OCA of the panel is removed together with the optical transparent adhesive removing tape of the present invention.

The ultraviolet curable photosensitive resin is contained in an amount of 1 to 25% by weight based on the total weight of the pressure sensitive adhesive layer. When the ultraviolet curing photosensitive resin is contained in the pressure sensitive adhesive layer in the above content, And the elongation of the tape is in an appropriate range, resulting in excellent OCA removal characteristics.

The pressure-sensitive adhesive layer of the tape for removing an optical transparent adhesive of the present invention is produced by adding a certain amount of a UV-curable photosensitive resin to a thermosetting acrylic, silicone or rubber adhesive.

The ultraviolet curable photosensitive resin that can be introduced into the pressure-sensitive adhesive layer of the present invention may be in the form of a monomer or oligomer having a monofunctional group, a bifunctional group, and a polyfunctional group having various structures and molecular weights, , Methacrylate-based, epoxyacrylate-based, polyester acrylate-based, urethane acrylate-based, and the like, but the present invention is not limited thereto.

The present invention also

(a) applying an elastomer on the first release film to form an elastomer layer having a thickness of 5 탆 to 50 탆;

(b) applying a pressure-sensitive adhesive composition containing a UV-curable photosensitive resin on the second release film to form a pressure-sensitive adhesive layer containing 1 to 25% by weight of the photosensitive resin based on the total weight of the pressure-sensitive adhesive layer; And

(c) a step of laminating the elastomer layer and the pressure-sensitive adhesive layer to each other.

The conventional tape for removing a transparent adhesive for optical is produced by applying a pressure-sensitive adhesive on an elastomer film produced by an extrusion method or the like. However, such an elastomer film has a limitation that it is practically difficult to have a thickness of less than 50 탆.

Further, the inventors of the present invention have found that when the thickness of the elastomer layer included in the optical transparent adhesive removing tape exceeds 50 탆, the elongation rate of the tape becomes insufficient, Respectively. That is, the stretchability of the elastomer layer should be excellent so that the adhesive layer can be easily separated from the adhesive layer, and the transparent adhesive for optical use can be easily peeled off.

On the other hand, if it exceeds 50 탆, the amount of the elastomer used increases, which is economically undesirable.

The elastomer film of the present invention preferably has a thickness of from 5 탆 to less than 30 탆 in terms of elongation and economy.

In the manufacturing method of the present invention, the elastomer layer may be formed by applying an elastomer on a release film by using a method such as COMMA coating or slot die coating. According to the above-described method, unlike the prior art, it becomes possible to form the elastomer layer with a thickness of 5 占 퐉 to 50 占 퐉.

Further, according to the method of forming such an elastomer layer, it is also possible to omit the adhesion step required when the releasing film is adhered to the elastomer film prepared in the prior art.

In the method for producing a tape for removing an optical transparent adhesive of the present invention, in the step (c) of laminating the elastomer layer and the pressure-sensitive adhesive layer, the adhesive force of at least one of the elastomer layer and the pressure- . ≪ / RTI >

That is, any one of the layers of the elastomer layer or the pressure-sensitive adhesive layer formed in the step (a) and the step (b) can be bonded without a separate adhesive by bonding them in a state of having an adhesive force.

Fig. 2 shows an example of a tape for removing a transparent adhesive for optical of the present invention. That is, the first release film layer 10, the elastomer layer 20 having a thickness of 5 占 퐉 to 50 占 퐉, the pressure-sensitive adhesive layer 30 including the ultraviolet-curable photosensitive resin, and the second release film layer 40 And a transparent adhesive for removing optical adhesive tape 100 laminated in this order.

In the present invention, the OCA removal method using the optical transparent adhesive removal tape is as follows.

That is, a step of preparing a panel in which a transparent adhesive for optics is laminated,

Sensitive adhesive layer comprising a first release film layer, an elastomer layer having a thickness of 5 占 퐉 to 50 占 퐉, a pressure-sensitive adhesive layer containing an ultraviolet-curable photosensitive resin in an amount of 1 to 25% by weight based on the total weight of the pressure-sensitive adhesive layer, and a second release film layer Preparing a transparent adhesive removing tape for optical use,

Removing the second release film layer of the optical transparent adhesive removing tape,

Bonding a pressure-sensitive adhesive layer of the optical transparent adhesive removing tape to the surface of the optical transparent adhesive of the panel,

Irradiating ultraviolet rays in the direction of the tape by putting the panel in which the optical transparent adhesive removing tape is laminated in an ultraviolet curing device,

Removing the first release film layer of the optical transparent adhesive removing tape, and then stretching the tape to remove it together with the optical transparent adhesive.

The ultraviolet lamp may be selected from, for example, a high-pressure mercury lamp and a metal halide lamp, and the energy may be 800 to 1,200 mJ / cm 2.

FIG. 4 illustrates the reaction between the photosensitive resin of the tape for removing optical transparent adhesive of the present invention and the photosensitive reactor in OCA of the touch screen panel.

FIG. 5 shows a method of removing a transparent adhesive for optical use according to the present invention. First, the pressure-sensitive adhesive layer 30 from which the second release film layer has been peeled off is adhered to a front window or a transparent adhesive for optical use on a touch screen panel to be removed, and then ultraviolet light is applied to the pressure- Lt; / RTI > Then, hold it at one end and pull it in the direction of forming 5 to 60 degrees. At this time, the tape is stretched from the end of the attaching surface, and the force acting as the tape is stretched is transmitted to the transparent adhesive for optical on the front window or touch screen panel. At this time, the optical transparent adhesive attached to the separation removing tape is also continuously removed while being stretched together with the separation removing tape.

The touch screen panel in the present invention should be understood not only in itself but also as a concept including each of the window panel 1 and the electrode pattern panel 2 constituting the touch screen panel as shown in Figs. That is, after the touch screen panel is disassembled for reproduction, the optical transparent adhesive for the window panel 1 and the electrode pattern panel 2 can be easily removed by the present invention.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

Manufacturing example  1. Preparation of pressure-sensitive adhesive coating liquid

The thermosetting pressure-sensitive adhesive and the curing agent are weighed and mixed according to the tabular table shown in Table 1 below, and then mixed using a mechanical stirrer for 15 minutes.

Then, the ultraviolet curing type monomer or oligomer is metered in and introduced, and the photoinitiator is metered in.

A solution of methyl ethyl ketone (MEK): toluene (Toluene) in a weight ratio of 50:50 was added thereto so that the total solid content was 18% by weight, and the mixture was stirred for 45 minutes using a mechanical stirrer.

Manufacturing example  2. Manufacture of tapes

The first release film is coated with 20 占 퐉 of an elastomer and dried and cured at 90 for 3 minutes.

The pressure-sensitive adhesive composition is coated on the second release film in a thickness of 20 μm and dried and cured at 90 ° C. for 3 minutes.

The elastomer layer and the pressure-sensitive adhesive layer are laminated together.

(Unit weight) Comparative Example 1 Example 1 Example 2 Comparative Example 2 Thermosetting adhesive Acrylic adhesive
(Based on 100% solids) 100 90 80 70 Acrylic pressure-sensitive adhesive hardener
(Based on 100% solids) One 0.9 0.8 0.7 UV curable monomer / oligomer Satomer SR506NS 4 8 12 Satomer SR610NS 2 4 6 Satomer CN2203NS 2 4 6 Satomer CN9007 2 4 6 Photoinitiator Omnicure 754 3 3 3 Total 104 104 104 104

Satomer SR506NS / Isobomyl Acrylate / Mono-functional

Satomer SR610NS / Polyethylene (600) Di-acrylate / Di-functional

Satomer CN2203NS / Polyester Acrylate Oligomer / Di-functional

Satomer CN9007 / Aliphatic Urethane Acrylate / Di-functional

Manufacturing example  3. Test panel manufacture

Laminae of cu-13302 (50㎛) OCA film to the gorilla class using a hot-roll laminator at 100, 1m / min, 2.5kgf / ㎠ and aging for 120 to 24 hours to manufacture test panels.

Comparative Experimental Example  1 and 2. OCA Removal Test

The second release film layer of the tape prepared in Comparative Example 1 and Comparative Example 2 was removed and lapped on the OCA layer of the test panel. The first release film layer is removed and the tape is stretched at an angle of 25 degrees to remove the OCA. The results are shown in Table 2.

Experimental Example  1 and 2. OCA Removal Test

The second release film layer of the tape prepared in Example 1 and Example 2 was removed and laminated to the OCA layer of the test panel, and an energy of 1,000 mJ / cm 2 was irradiated from the tape direction using an ultraviolet curing machine. The first release film layer is removed and the tape is stretched at an angle of 25 degrees to remove the OCA. The results are shown in Table 2.

OCA removal effect Remarks Film layer thickness Film tensile strength Film elongation Comparative Example 1 Poor Removal by 3 treatment 20um 1.2kgf / mm < 2 & 580% Example 1 Great One time removal 20um 1.25kgf / mm < 2 & 550% Example 2 Great One time removal 20um 1.28 kgf / mm < 2 & 527% Comparative Example 2 Poor Removal by 2 treatment 20um 1.23 kgf / mm < 2 & 420%

In the case of Comparative Example 1, the OCA was peeled off, but the adhesive layer of OCA was not removed at a time, but was removed only after repeating the lamination and peeling process three times. On the other hand, in the case of Examples 1 and 2 using the tape of the present invention, OCA was removed at once.

In the case of Comparative Example 2, it was removed only by repeating the peeling process with two times of lamination. In the case of Comparative Example 2, the content of the ultraviolet curing type photosensitive resin of the pressure-sensitive adhesive layer was high and the degree of stretching of the tape was somewhat insufficient as compared with Examples 1 and 2, and the peeling force was judged to be lowered.

Experimental Example 6 Test by peeling angle

From the test results, the new Example 3 having the intermediate value among the contents of the ultraviolet curing type monomers and the oligomers was obtained from the compositions of Examples 1 and 2, which had the best results, and the film was coated and aged to produce a tape. )

Comparative Example 1 Example 3 Thermosetting adhesive Acrylic adhesive
(Based on 100% solids) 100 85 Acrylic pressure-sensitive adhesive hardener
(Based on 100% solids) One 0.85 UV curable monomer / oligomer Satomer SR506NS 6 Satomer SR610NS 3 Satomer CN2203NS 3 Satomer CN9007 3 Photoinitiator Omnicure 754 3 Total 100 100

OCA was peeled at various angles using this tape, and the results are shown in Table 4 below.

OCA removal effect film 15 ° 25 ° 35 ° 45 ° 55 ° 65 ° thickness The tensile strength Elongation Comparative Example 1 Bad Bad Bad Bad Bad Bad 20um 1.2kgf / mm < 2 & 580% Remove 1/3 area only Remove 1/3 area only Remove 1/3 area only Remove only 1/4 area Remove 1/5 area only Not removed Example 3 Good Good Good Good Good Good 20um 1.27 kgf / mm < 2 & 537% 100% removal 100% removal 100% removal 100% removal 100% removal 95% removal

In the case of Comparative Example 1, the OCA was removed only in about 1/3 of the area at an angle of 15 ° to 35 °. However, in the case of using the tape using the composition of Example 3, the OCA film was well removed at an angle of about 60 ° or less can see. That is, in the case of Comparative Example 1 using the conventional technique, when the operator can not adjust the peeling angle of the OCA removal film, the film may be broken or peeling may not be performed easily, It is judged that the OCA removal rate is considerably good even if the operator works fast and insensitive to the separation angle.

10: first release film layer 20: elastomer layer
30: pressure-sensitive adhesive layer 40: second release film layer
100: Optical adhesive tape for removing transparent adhesive

Claims (4)

Sensitive adhesive layer comprising a first release film layer, an elastomer layer having a thickness of 5 占 퐉 to 50 占 퐉, a pressure-sensitive adhesive layer containing an ultraviolet-curable photosensitive resin in an amount of 1 to 25% by weight based on the total weight of the pressure-sensitive adhesive layer, and a second release film layer And a transparent adhesive removing tape for optical The method according to claim 1,
Wherein the pressure-sensitive adhesive layer is produced by adding a predetermined amount of ultraviolet curable photosensitive resin to a thermosetting acrylic, silicone or rubber adhesive. (a) applying an elastomer to a first release film to form an elastomer layer having a thickness of from 5 占 퐉 to 50 占 퐉;
(b) applying a pressure-sensitive adhesive composition containing a UV-curable photosensitive resin on the second release film to form a pressure-sensitive adhesive layer containing 1 to 25% by weight of the photosensitive resin based on the total weight of the pressure-sensitive adhesive layer; And
(c) a step of laminating the elastomer layer and the pressure-sensitive adhesive layer to each other; and Preparing a panel in which a transparent adhesive for optics is laminated,
Sensitive adhesive layer comprising a first release film layer, an elastomer layer having a thickness of 5 占 퐉 to 50 占 퐉, a pressure-sensitive adhesive layer containing an ultraviolet-curable photosensitive resin in an amount of 1 to 25% by weight based on the total weight of the pressure-sensitive adhesive layer, and a second release film layer Preparing a transparent adhesive removing tape for optical use,
Removing the second release film layer of the optical transparent adhesive removing tape,
Bonding a pressure-sensitive adhesive layer of the optical transparent adhesive removing tape to the surface of the optical transparent adhesive of the panel,
Irradiating ultraviolet rays in the direction of the tape by putting the panel on which the optical transparent adhesive removing tape is laminated in an ultraviolet curing unit,
Removing the first release film layer of the optical transparent adhesive removing tape, and then stretching the tape to remove it together with the optical transparent adhesive,

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