TWI532813B - Double-sided adhesive tape having improved reworkability - Google Patents

Description

Double-sided tape with improved heavy workability

The present invention relates to a double-sided tape having improved reworkability. In particular, the present invention relates to a double-sided tape in which one of the layers of the double-sided tape formed of a plurality of layers is easily peeled off when a force is applied to a gluing surface in a parallel direction, This improvement uses double-sided tape to create a reworkability in one of the processes of a product.

Various types of glues or tapes are used in the manufacture of one of the products such as electronic devices. In the event that a defect occurs in the process of manufacturing the products, the products may be discarded or the products removed into separate components and the disassembled components reused.

As electronic devices have recently been developed to meet higher performance and quality standards, each configuration of components of an electronic device has also been developed to meet such higher performance and quality standards, and thus each configuration of components of the electronic device Become expensive. In such cases, in the case where a defect occurs in the manufacturing process of one of the electronic products, if the products are discarded, the economic loss in addition to resource consumption and environmental pollution will also be severe.

An example of a high cost configuration component of an electronic device is a touch panel. A touch panel is mounted on a surface of a display panel to convert a physical contact of a finger of a user, a stylus or other stylus into an electrical signal and output a device of the signal. The touch panel has been applied to a liquid crystal display, a plasma display panel, an EL (electroluminescence) device, an organic light emitting diode, and the like.

Touch panels have a complex configuration and are expensive. However, defects may occur during the process of attaching the touch panel to a display panel or attaching a protective cover window to a touch screen. Such defects may be caused by contamination of the dust or a misalignment during the attachment process. In the case of such defects, a loss of money will occur if the defective product is discarded. In order to reduce economic losses, it would be desirable to separate the touch panel from the display panel or from the cover window and reuse the touch panel. Other components besides the touch panel also need to be reused.

However, since the touch panel is firmly adhered to the display panel or the cover window as a counterpart in the manufacturing process of the product, the touch panel may not be easily separated or may be damaged during the separation process. If the touch panel is not separated or damaged during the separation process, the high-priced touch panel with no problem in performance cannot be reused. Even if the touch panel is separated without causing any damage, if there is a residue of the adhesive on the separated touch panel, it will be difficult to reuse the separated touch panel.

Currently, electronic devices and their configuration components are complex and expensive. In view of the reduced manufacturing cost and workability, it is desirable to re-use individual components of the electronic device in a safe and secure manner even if a defect occurs in the manufacturing process of one of the electronic devices.

An object of the present invention is to provide an adhesive tape capable of safely attaching electronic device components to each other, and if necessary, can easily peel off the tape, thereby improving reworkability.

Another object of the present invention is to provide an adhesive tape in which a specific layer of a tape formed of a plurality of layers is easily peeled off so that even if a defect occurs during use of one of the tape assembly members, the tape can be easily separated. And other components.

It is still another object of the present invention to provide a display device manufactured by using an adhesive tape.

The present invention provides a double-sided tape comprising a film-shaped sheet, a first adhesive layer disposed on one surface of the sheet, and a second adhesive layer disposed on the other surface of the sheet.

In the double-sided tape, a crosshead speed of 10 mm/min is obtained by attaching an aluminum strip to an SUS panel by using a double-sided tape at a temperature of 60 ° C and stripping the aluminum strip from the SUS panel. The shear strength of the second adhesive layer is in the range of from about 0.05 kg/in ² to about 16 kg/in ² . When a reverse force is applied between the aluminum strip and the SUS panel in a parallel direction, the stress and strain are measured, and the maximum strain is regarded as the shear strength (refer to FIGS. 7 and 8). For reference only, the SUS panel is a stainless steel panel.

If the shear strength of the second adhesive layer is less than about 0.05 kg/in ² , the second adhesive layer may be peeled off due to collision during normal use or other reasons, thereby causing inconvenience in use. If the shear strength of the second adhesive layer is less than about 16 kg/in ² , the separability is sufficient to allow sufficient reworkability to be obtained. However, if the shear strength exceeds about 16 kg/in ² , the second adhesive layer is not easily peeled off, so that sufficient reworkability cannot be obtained. Therefore, the shear strength of the second adhesive layer is limited as set forth above.

In accordance with an embodiment of the present invention, to increase selectivity, the shear strength can be narrowly limited to from about 0.08 kg/in ² to about 10 kg/in ² in accordance with the test methods set forth above. If the shear strength is less than about 10 kg/in ² , more excellent workability can be obtained. Preferably, the second adhesive layer has a shear strength of from about 0.08 kg/in ^{2 to} about 4 kg/in ² .

According to an embodiment of the invention, the shear strength of the first adhesive layer is greater than the shear strength of the second adhesive layer.

According to another embodiment of the present invention, in order to increase the reworkability, the second adhesive layer is preferably adjusted to have 20 seconds or more when the weight of 1 kg is applied to one area of 4.5 in ² at 60 ° C. A shedding time and a peeling time of 600 minutes or less when a weight of 3 kg is applied to the area of 4.5 in ² . Preferably, at 60 ° C, the detachment time of the second adhesive layer is from 30 seconds or more when one weight of 1 kg is applied to one area of 4.5 in ² to when one weight of 3 kg is applied to 300 minutes or less for 4.5 in ² of this area.

The shedding time was measured as shown in Fig. 9, in which a PMMA/PC board was glued to an SUS panel by using double-sided tape and one weight of 1 kg or more was applied to the PMMA/PC board and the measurement was dropped. time.

If the second adhesive layer has the shedding time as explained above, it will not be possible to strip the second adhesive layer due to external impact during normal use, thereby improving ease of use and obtaining sufficient reworkability.

In order to increase the selectivity, the second adhesive layer may also be adjusted to have a shedding time of 30 seconds or more when the weight of 1 kg is applied to one area of 4.5 in ² at 60 ° C and when the weight is 3 kg When applied to this area of 4.5 in ² , there is one off time of 300 minutes or less. If the second adhesive layer has the shedding time as explained above, a more excellent reworkability can be obtained.

According to an exemplary embodiment of the present invention, the second adhesive layer may be formed of a gel polymer. The type or molecular weight of the polymer forming the second adhesive layer is not limited as long as the second adhesive layer formed of the polymer has the shear strength or shedding time as explained above. For example, a polymer having one of molecular weights of from about 10,000 g/mol to about 300,000 g/mol can be used or a polymer having one of molecular weights beyond one of the ranges can be used. The material forming the second adhesive layer may have a relatively low molecular weight one of the adhesive polymers or one of the relatively higher molecular weight adhesive polymers as needed. Different materials can be selected according to the needs and selection of a user.

In the case where rework is required in a manufacturing process using one of the double-sided tapes of the present invention, if a reverse force is applied to a bonding surface in a parallel direction, the second adhesive layer is peeled off to make it easy The components that have been attached to each other by means of the double-sided tape of the present invention are separated. As a result, the reworkability can be increased.

According to an embodiment of the present invention, the film-shaped sheet is made of a transparent material selected from the group consisting of an acryl-based resin, a polyester resin, a polycarbonate resin, and a norbornene-based resin. A group of monoolefin polymers and TAC (triethyl fluorene cellulose). According to an embodiment of the present invention, polyethylene terephthalate (PET) which is one of a polyester resin and has high light transmittance can be preferably used.

According to an embodiment of the invention, the thickness of the film sheet can be adjusted to be from about 5 μm to about 100 μm. If the film sheet has a thickness in one of the above ranges, it can be easily applied to a small display electronic device and a large display electronic device.

According to an embodiment of the invention, the thickness of the first adhesive layer and the second adhesive layer may be adjusted to be in the range of from about 5 μm to about 500 μm. If the thickness is in the above range, sufficient adhesion for bonding a component to a product (for example, an electronic product) can be obtained.

According to an embodiment of the invention, the second adhesive layer may be formed from a gel polymer composition. The size polymer composition forming the second adhesive layer contains a plurality of monomers and a polymerization initiator. In addition to the monomers and polymerization initiators, the size polymer composition may comprise a chain transfer agent, a polymerization inhibitor, an additive having a low molecular weight (having an average molecular weight of less than about 5000 g/mol) and a At least one of the curing agents. The amount of curing agent can vary depending on the type of curing agent used.

In accordance with an embodiment of the present invention, an auxiliary membrane may be additionally disposed on a surface of the second adhesive layer opposite the surface on which the membrane sheet is disposed. A third adhesive layer is disposed on the auxiliary membrane. The shear strength of the third adhesive layer is adjusted to be greater than the shear strength of the second adhesive layer.

The double-sided tape of the present invention is a transparent tape having excellent light transmittance. According to an embodiment of the invention, the double-sided tape has a light transmittance greater than about 90%.

The present invention also provides a display device using a double-sided tape. A display device according to an embodiment of the present invention includes a display panel, a double-sided tape disposed on a display surface of the display panel, and a transparent plate disposed on an opposite surface of the double-sided tape. The double-sided tape is a double-sided tape having improved reworkability according to the present invention.

According to an embodiment of the invention, the transparent plate can be a cover window of an electronic device. The transparent plate can be a touch panel. According to an embodiment of the present invention, the transparent plate may be disposed on one of the front surfaces of the touch panel attached to the display panel.

The double-sided tape according to the present invention has a good wettability due to a gel, thereby exhibiting a satisfactory adhesive force. Thus, in the normal use state, there is no need to worry that the double-sided tape will be peeled off. However, if a shear force is applied to a glued surface in a parallel direction, the second adhesive layer can be easily separated from the glue. Further, after the separation, the residue of the adhesive layer material can be easily removed. Therefore, if double-sided tape is used, excellent reworkability can be obtained.

Since the double-sided tape according to the present invention is transparent, it can be effectively applied to a display surface of a display device. In particular, the double-sided tape can be effectively used to glue and fix a transparent plate such as a touch panel or a cover window to one of the display surfaces of a display panel. If a transparent plate is adhered to one of the display surfaces of a display panel by using the double-sided tape, the second adhesive layer of the double-sided tape can be easily peeled off so that excellent reworkability can be obtained. Therefore, even if a defect occurs in a manufacturing process, the configuration component can be reused.

The invention will be explained in detail below with reference to the drawings.

1 shows the structure of a double-sided tape (100) in accordance with an embodiment of the present invention.

A double-sided tape (100) according to an embodiment of the present invention includes a film-shaped sheet (101), a first adhesive layer (110) disposed on one surface of the sheet, and another surface disposed on the sheet One of the second adhesive layers (120).

For the film sheet (101), a film-shaped polymer material can be used. Examples of polymeric materials include, but are not limited to, an acrylonitrile-based resin (such as polymethyl methacrylate (PMMA)), polyester (such as polyethylene terephthalate (PET), polycarbonate), A resin based on norbornene, a monoolefin polymer, and TAC (triethyl fluorene cellulose). The polymeric materials may be used individually or in combination of two or more types thereof.

Among the polymer films, a PET film which is easily available and has high transparency can be used.

For the film sheet (101) according to an embodiment of the present invention, a film sheet having a light transmittance of more than about 90% can be used.

The thickness of the film sheet (101) is not limited. According to an embodiment of the invention, the thickness of the film sheet (101) may be selected to be in the range of from about 5 μm to about 100 μm. In particular, the thickness can range from about 10 μm to about 50 μm.

The first adhesive layer is disposed on one surface of the film sheet (101). According to an embodiment of the invention, the first adhesive layer (110) may be formed from a gel polymer.

For the adhesive polymer forming the first adhesive layer (110), any adhesive polymer can be used as long as the adhesive polymer is generally used to attach the display component and has sufficient transparency so as not to reduce a display. Visibility can be. Examples of the binder polymer include pressure sensitive adhesive polymers known or commonly used, such as acrylonitrile based adhesive polymers, enamel based adhesive polymers, polyester based adhesive polymers, rubber based A binder polymer, or a polyurethane based binder polymer. The binder polymers may be used singly or in combination of two or more types thereof. For example, the adhesive polymer forming the first adhesive layer (110) may comprise a propylene sulfhydryl group _{having a} C _1-18 methacrylate having a weight ratio of greater than 50% based on the total weight of the monomer components. The polymer.

In accordance with an embodiment of the present invention, the first adhesive layer (110) can be formed from a commercial optical adhesive (e.g., an optical clearing adhesive) currently commercially available in the market. The first adhesive layer (110) should be transparent at a transmittance of greater than about 90%. The adhesive strength of the first adhesive layer (110) is not limited as long as the first adhesive layer (110) has sufficient adhesive force to attach the transparent plate (310) to the display surface of the display panel (320). .

Although the size of the adhesive polymer forming the first adhesive layer may be the same or a similar type of the adhesive polymer forming the second adhesive layer, the composition ratio or molecular weight may be different.

The shear strength of the first adhesive layer can be greater than about 1 kg/in ² . For stronger adhesion, the first adhesive layer may have a shear strength greater than about 3 kg/in ² . The shear strength is a value measured by performing a test using a double-sided tape to attach an aluminum strip to an SUS panel as seen in FIG. The temperature is 60 ° C, and the crosshead speed of the tool for stripping the aluminum strip from the SUS panel is 10 mm/min while applying a reverse force between the aluminum strip and the SUS panel in a parallel direction. During the application of the opposing force, the stress and strain are measured, as seen in Figure 8, and the maximum stress is considered to be the shear strength. (Test conditions: between an aluminum strip and a SUS panel, and the crosshead speed was 10 mm/min).

The molecular weight of one of the polymers forming the first adhesive layer is not limited. The molecular weight can range from as small as about 10,000 g/mol to as much as about 1,000,000 g/mol or can be greater than about 1,000,000 g/mol.

The second adhesive layer (120) is formed on the other surface of the film sheet (101) on which the first adhesive (110) layer is not disposed. The second adhesive layer is a separable layer which is easily peeled off when a force is applied to a glued surface in a parallel direction, thereby improving one of the products manufactured by using the double-sided tape of the present invention. Heavy work.

According to an embodiment of the invention, the second adhesive layer (120) may be formed from a gel polymer. A binder polymer forming a second binder layer may be prepared from a binder polymer composition, the binder polymer composition comprising a plurality of monomers and a polymerization initiator and further comprising a chain transfer agent, a polymerization inhibitor, There is at least one of a low molecular weight one of the additives and a curing agent.

The adhesive polymer forming the second adhesive layer should have sufficient transparency to not significantly reduce the visibility of a display. Examples of the adhesive polymer for the second adhesive layer include known or commonly used pressure sensitive adhesives, such as acryl-based based adhesive polymers, enamel based adhesive polymers, polyester based adhesives Agent polymer, rubber based adhesive polymer and polyurethane based adhesive polymer. The binder polymers may be used singly or in combination of two or more types thereof. Although the adhesive polymer forming the second adhesive layer is of the same or similar type as the adhesive polymer forming the first adhesive layer, its composition ratio or molecular weight is different.

According to an embodiment of the present invention, an acrylonitrile-based adhesive polymer can be used as the adhesive polymer forming the second adhesive layer.

For the acrylonitrile-based adhesive polymer, for example, a C _1-18 alkyl methacrylate (that is, a C _1-18 acrylate-based compound) can be used as one of the monomers. One of the main components is based on a polymer based on acrylonitrile. A copolymer containing one or more monomers different from the C _1-18 acrylate-based compound may be used.

Examples of copolymerizable monomers that can be used with C _1-18 acrylate-based monomers include, but are not limited to, copolymerizable monomers having various functional groups, a styryl-based monomer, and an alpha-olefin-based monomer. a monomer, a vinyl ester, a cyano group-containing monomer, a guanamine-containing monomer, a hydroxyl group-containing monomer, an acid group-containing monomer, an epoxy group-containing monomer, an amino group-containing monomer, and a monomer Carboxyl containing monomer.

Meanwhile, various monomers which are monomers which modify a polymer based on an acrylonitrile-based adhesive can also be used. According to an embodiment of the invention, isobornyl acrylate known as IBXA can also be used.

For one method of preparing a acrylonitrile-based adhesive polymer, a known method can be applied. For example, a solution polymerization method, an emulsion polymerization method, a self-polymerization method, or a photopolymerization method using one photoinitiator may be used.

According to an embodiment of the present invention, a photopolymerization method using a photoinitiator as one of polymerization initiators can be applied. For the photopolymerization initiator, a commercially available Irgacure series can be used.

A crosslinking agent can be used if desired. A commercially known crosslinking agent can be used. Specifically, a polyfunctional acrylate or methyl acrylate, a polyfunctional melamine compound, a polyfunctional epoxy compound, a polyfunctional isocyanate compound or the like can be used. However, the type of crosslinking agent is not limited. These crosslinking agents may be used singly or in combination of two or more types thereof.

The binder polymer can contain various additives. For example, various known additives such as a commonly used adhesive-imparting resin, a plasticizer, a filler, a colorant, an ultraviolet absorber, and a surfactant can be used. However, even if an additive is added, the transparency of the adhesive polymer resin should not be affected.

Further, the composition of the adhesive polymer forming the second adhesive layer further comprises at least one of a chain transfer agent, a polymerization inhibitor, an additive having a low molecular weight, and a curing agent.

There is at least one weak chemical bond in the chain transfer agent to induce a chain transfer reaction. Due to the chain transfer reaction, the average molecular weight of one of the finally produced polymers is reduced. Therefore, the chain transfer agent is referred to as a molecular weight controller. In the present invention, a chain transfer agent is used to reduce the molecular weight of one of the binder polymers forming the second adhesive layer (120) to adjust the shear strength of the second adhesive layer. According to an embodiment of the present invention, IOTG (isooctyl thioglycolate) can be used as a chain transfer agent.

The polymerization inhibitor delays a polymerization reaction to reduce the molecular weight of one of the polymers. According to an embodiment of the present invention, examples of the polymerization inhibitor include AMS (α-methylstyrene).

An additive having a low molecular weight is added to a polymer composition to reduce the strength or shear strength of the adhesive. One of the additives having a low molecular weight has an average molecular weight of less than about 5000 g/mol. Even if the additive does not affect the average molecular weight, it has a portion having a low molecular weight partially present in a polymer to reduce the adhesion or shear strength. As an additive having a low molecular weight, a commercially available product can be used. According to an embodiment of the present invention, as an additive having a low molecular weight, a commercial product Joncyl series (BASF) can be used.

A curing agent is added to a polymer composition to advance or control the curing reaction. The curing agent can essentially provide cohesiveness to a polymer composition and prevent damage to the surface of the second adhesive layer formed by a curing reaction. As the curing agent, a commercially available product can be used. According to an embodiment of the present invention, a commercial product HDD (SK Cytec Specialty Chemicals) can be used as a curing agent.

According to the present invention, the shear strength of the second adhesive layer has been weakened to improve the reworkability of the double-sided tape. The shear strength can be weakened by a chain transfer agent, a polymerization inhibitor, and an additive having a low molecular weight. The chain transfer agent, the polymerization inhibitor, and the additive having a low molecular weight may be used singly or in the form of a mixture of one or two or more types thereof. According to an embodiment of the present invention, the chain transfer agent may be contained in an amount of from about 0.03 parts by weight to about 5 parts by weight based on 100 parts by weight of the monomer, and may be from about 0.01 part by weight to about 0.5 part by weight. One amount contains a polymerization inhibitor, and may contain an additive having a low molecular weight in an amount of from about 1 part by weight to about 50 parts by weight. The weight of the components can vary depending on the type of monomer used. According to an embodiment of the present invention, the curing agent may be contained in an amount of more than 0 parts by weight but less than about 0.07 parts by weight or less based on 100 parts by weight of the monomer.

According to an embodiment of the invention, the shear strength of the second adhesive layer (120) is less than the shear strength of the first adhesive layer (110). Thus, in the case where rework is required, if the shear force is applied to a gluing surface in a parallel direction, the second adhesive layer is stripped so that the double-sided tape of the present invention can be easily separated from each other by the double-sided tape of the present invention. Component.

The shear strength of the second adhesive layer (120) is in the range of from about 0.05 kg/in ^{2 to} about 16 kg/in ² . Specifically, the shear strength is in the condition of attaching an aluminum strip to an SUS panel, a temperature system of 60 ° C, and a crosshead speed of 10 mm/min (test condition: between an aluminum strip and an SUS panel and The crosshead speed is 10 mm/min).

The shear strength can be adjusted to less than about 16 kg/in ² and can vary depending on the utilization of the double sided tape of the present invention. For example, if the double-sided tape of the present invention is applied to a mobile device (which is a smaller device), the shear strength does not need to be in the case where the double-sided tape of the present invention is applied to a large display device. The shear strength is as great. Therefore, the shear strength of the double-sided tape can be adjusted to be less than about 10 kg/in ² at a temperature of 60 ° C, that is, from about 0.08 kg/in ^{2 to} about 10 kg/in ² . Mobile devices include commonly known devices such as portable phones, smart phones, PMPs, car navigators, MP3 players, tablet PCs, small notebooks, and notebook computers.

Meanwhile, in order to promote reworkability, in the case of using a PMMA/PC board and an SUS panel at 60 ° C, the second adhesive layer can be adjusted to have a peeling time of 20 seconds when a weight of 1 kg is applied to an area of 4.5 in ² And when the weight of 3 kg was applied to the area of 4.5 in ² , there was one off time of 600 minutes or less (test condition: see Fig. 9).

The shedding time can also vary depending on the utilization of the double-sided tape of the present invention. For example, if the double-sided tape of the present invention is applied to a mobile device (which is a relatively small device), the adhesive strength does not need to be glued in the case where the double-sided tape is applied to a large display device. The force is as strong. Therefore, at 60 ° C, the double-sided tape can have a shedding time of 30 seconds or more when a weight of 1 kg is applied to an area of 4.5 in ² , or when a weight of 3 kg is applied to an area of 4.5 in ² Has a shedding time of 300 minutes or less.

As shown in FIG. 2, a second adhesive layer (120) of a double-sided tape (100) in accordance with an embodiment of the present invention can be used to attach a transparent plate (310) to one of the display panels (320). Display on the surface. In the case where rework is required, as shown in Figure 3, the second adhesive layer (120) should be easily stripped.

In FIG. 2, a first adhesive layer (110) is attached to a transparent plate (310) and a second adhesive layer (120) is attached to one of the display surfaces of the display panel (320). Conversely, the first adhesive layer can be attached to the display surface of the display panel and the second adhesive layer can be attached to the transparent plate.

According to an embodiment of the present invention, when forming the second adhesive layer as set forth above, one of the relatively lower molecular weight adhesive polymers may be used to increase the reworkability or may be used although not having a low average Molecular weight but containing a binder polymer having one of a specific low molecular weight additive. A polymer having one of molecular weights of about 10,000 to about 300,000 g/mol may be used depending on the application and user's choice, or a polymer having a molecular weight exceeding one of the ranges may be used.

According to an embodiment of the present invention, there is provided a method for manufacturing the double-sided tape of the present invention, wherein the prepared first adhesive polymer in a syrup state is disposed on one surface of the film sheet (101) And photocuring to form a first adhesive layer (110), and the prepared second adhesive polymer in a syrup state is disposed on the other surface of the film sheet (101) and photocured to form a first Two adhesive layer (120). The order in which the first adhesive layer and the second adhesive layer are formed may be reversed. The first adhesive layer and the second adhesive layer can be formed simultaneously.

If desired, a release paper or liner can be placed over the exposed surface of the first adhesive layer or the exposed surface of the second adhesive layer.

The thickness of the first adhesive layer (110) and the second adhesive layer (120) is not limited as long as it imparts sufficient adhesion. For example, the thickness of the first adhesive layer (110) and the thickness of the second adhesive layer (120) may range from about 5 μm to about 500 μm. In particular, the thickness may range from about 100 μm to about 400 μm.

The double-sided tape according to an embodiment of the present invention has a light transmittance (JIS K7361) of more than about 90% in a wavelength region of the visible spectrum.

In the present invention, the double-sided tape may have an additional layer as long as the effects of the present invention are not impaired.

For example, the double-sided tape (200) illustrated in FIG. 4 has a structure in which an auxiliary film (102) is disposed on the second adhesive layer (120) of the double-sided tape of FIG. A third adhesive layer (130) is disposed on the auxiliary membrane (102).

The material, thickness and other aspects of the auxiliary membrane (102) may be the same as the material, thickness and other aspects of the membrane sheet (101). The third adhesive layer (130) can be the same as the first adhesive layer (110).

The present invention also provides a display device using a double-sided tape (100, 200). A display device according to an embodiment of the present invention includes a display panel (320), a double-sided tape (100, 200) disposed on a display surface of the display panel, and a transparent cover disposed on the double-sided tape Board (310) (Figures 2 and 5).

Specifically, an embodiment of the present invention illustrated in FIG. 2 relates to a structure in which a second adhesive layer (120) of a double-sided tape (100) is adhered to a display surface of the display panel (320). Upper, and the first adhesive layer (130) is glued to the transparent plate (310). Figure 5 shows a structure in which a third adhesive layer (130) of a double-sided tape (200) according to another embodiment of the present invention is adhered to the display surface of the display panel (320), and the first adhesive is applied. The layer (110) is glued to the transparent plate (310).

According to an embodiment of the invention, the transparent plate (310) can be a cover of an electronic device, or the plate can be a touch panel.

According to another embodiment of the present invention, the transparent plate may be disposed on a cover window attached to a front surface of the touch panel on the display panel. In other words, the double-sided tape of the present invention can be used even in the case where one of the cover windows is attached to the front surface of the touch panel.

The double-sided tape according to the present invention can be attached to the display surface before the display panel.

The double-sided tape (100, 200) according to the present invention can be effectively used to glue and fix a transparent plate (310) such as a touch panel or a cover window to the display surface of the display panel (320). Double-sided tape (100, 200) can be used even in the case where one of the cover windows is attached to the display surface before the touch panel.

As shown in FIG. 3 and FIG. 6, if a parallel force (ie, a shearing force) is applied between the transparent plate (310) and the display panel (320), the second adhesive of the double-sided tape is easily peeled off. The agent layer for excellent reworkability.

The second adhesive layer (120) of the double-sided tape (100, 200) according to the present invention has good wettability due to a glue, thereby exhibiting a satisfactory adhesive force. Thus, in the normal use state, there is no need to worry that the second adhesive layer (120) will be peeled off. However, if a force is applied to a glued surface in a parallel direction, the second adhesive layer (120) is easily separated. After the separation, the residue of the adhesive layer material can be easily removed. As a result, the separated display panel (320) and transparent panel (310) can be reused without being discarded. Therefore, unnecessary waste is reduced, so that manufacturing costs can be reduced.

The type of display panel according to the present invention is not limited. For example, there is a liquid crystal display device, a CRT, a plasma display, an organic light emitting device display, and the like.

real example

The invention will be explained in more detail below with reference to examples and comparative examples.

ratio Comparative Examples 1 to 4 and Examples 1 to 25

For the film sheet (101), a PET film having one of thicknesses of 25 μm was used. An optical clearing agent 8146 (available from St. Paul 3M Company, which is commonly used as an OCA (Optical Clearing Adhesive)) is laminated on one surface of the sheet (101) at a thickness of 100 μm, thereby forming a first Adhesive layer (110).

To provide a second adhesive layer, a comparative example and examples of the adhesive polymer were prepared according to a photopolymerization method and the composition ratios in Table 1 below. The content in the following Table 1 represents the relative weight when the total amount of the monomers is 100 parts by weight. For the monomers, a mixture of two types of monomers based on acrylonitrile groups is used.

The above material information is shown in Table 2 below.

In Table 3 below, the monomer including a photoinitiator was partially polymerized by exposure to RV radiation in a nitrogen-rich atmosphere, and as a result, a pre-polymerization formulation in a syrup state was obtained.

After the addition of the remaining additional additives, the pre-polymerization formulation of the syrup state obtained above was knife coated between two polyoxynitride coated PET liners.

The coated material was exposed to low intensity UV radiation through four separate zones (as shown in Table 4 below) to obtain a second adhesive layer (120) having one of 50 μm thickness.

The second adhesive layer prepared above was applied on the other surface of the film sheet (101) to produce a double-sided tape and the second adhesive layer prepared above was used as Comparative Examples 1 to 4 and Example 1, respectively. To 25 to mention.

Evaluation

The molecular weight of the adhesive polymer used to prepare the double-sided tapes of Comparative Examples 1 to 4 and Examples 1 to 25 was measured, and the peeling time and shear strength of the double-sided tape were measured at a temperature of 60 °C.

The shear strength was measured between an aluminum strip and an SUS panel and at a crosshead speed of 10 mm/min.

In detail, a double-sided tape sample was prepared in a size of 1" x 1" for a shear test at 60 °C.

As shown in Figure 7, the sample is laminated to the aluminum strip in the form of a second adhesive layer (120; low-adhesive side) facing the aluminum strip, wherein the aluminum strip has a thickness of 1.3 mm and a width of 28 mm And the other side of the sample was laminated to the SUS panel (SUS: 0.8 mm × 75 mm × 75 mm) in the form of the first adhesive layer (110) facing the SUS panel. The SUS panel is a rust-free panel.

The laminated samples were defoamed for 20 minutes at 60 ° C 1 Mpa.

The sample was placed in an air convection chamber (provided by Instron) at 60 ° C and a reverse force was applied between the aluminum strip and the SUS panel in a parallel direction at a crosshead speed of 10 mm/min. A stress-strain curve was measured in 10 minutes as shown in Figure 8, and the maximum stress was considered as the shear strength.

The shedding time was measured at 60 ° C as shown in FIG.

In detail, a double-sided tape was prepared in one of 47 mm × 62 mm (which is 4.5 inches ² ). The above sample was laminated to a PMMA/PC board in the form of a second adhesive layer (120; low-adhesive side) facing the PMMA/PC board. PMMA/PC board is the Luplion of Mgc Philsett Co., Ltd. MR58, and its size is 52 mm × 70 mm × 0.8 mm (thickness). The sample was also laminated to the SUS panel (SUS: 0.8 mm × 75 mm × 75 mm) in the form of the first adhesive layer (110) facing the SUS panel.

The laminated sample was placed in a defoaming machine at 60 ° C 1 Mpa for 20 minutes, and then placed in a 60 ° C in the case of applying 1 kg weight or 3 kg weight to the PMMA/PC board, respectively. In an air convection oven. Then, measure the shedding time. In the case where the second adhesive layer was not peeled off and separated by applying a weight of 1 kg, a weight of 3 kg was applied to measure the fall-off time. Tables 5 and 6 show the results.

As shown in Tables 5 and 6 above, if at least one of a chain transfer agent, a polymerization inhibitor, one of a low molecular weight additive, and a hardener is contained in an appropriate amount, the second is reduced. The shear strength and shedding time of the adhesive layer (120) is such that when a force is applied to a glued surface in a parallel direction, the second adhesive layer can be easily stripped and separated.

In particular, when the PMMA/PC board and the second adhesive layer were forcibly separated, the double-sided tapes of Examples 1 to 25 exhibited a cohesive failure, that is, the PMMA/PC board and the second adhesive layer were maintained in their original state. The structure is separated at the same time. On the other hand, the double-sided tapes of Comparative Examples 1 to 4 exhibited a catastrophic failure in which the separated PMMA/PC board and the second adhesive layer caused damage to each other.

Accordingly, the present invention provides an adhesive tape capable of safely attaching electronic device components to each other, and if necessary, can easily peel off the tape, thereby improving the reworkability.

100. . . double-sided tape

101. . . Membrane

102. . . Auxiliary diaphragm

110. . . First adhesive layer

120. . . Second adhesive layer

130. . . Third adhesive layer

310. . . cant see thing

320. . . Display panel

1 is a diagram showing one of the structures of a double-sided tape (100) according to an embodiment of the present invention.

2 is a diagram showing the attachment of a transparent plate (310) to one of the surfaces of a display panel (320) using the double-sided tape (100) of FIG.

Figure 3 shows the double adhesive tape (100) used in Figure 2, stripping the second adhesive layer by applying a force to a glued surface in a parallel direction.

4 is a diagram showing one of the structures of a double-sided tape (200) according to another embodiment of the present invention.

Figure 5 is a diagram showing one of the surfaces of a display panel (320) attached to a transparent panel (310) using the double-sided tape (200) used in Figure 4.

Figure 6 shows the stripping of the second adhesive layer by applying a force in a parallel direction to a glued surface in the double-sided tape (200) used in Figure 5.

Figure 7 shows a structure for measuring the shear strength of a double-sided tape.

Figure 8 shows a stress-strain curve when parallel forces are applied to the aluminum strip of Figure 7 and the SUS panel to measure shear strength.

Figure 9 shows a structure for measuring the shedding time of a double-sided tape.

101. . . Membrane

110. . . First adhesive layer

120. . . Second adhesive layer

310. . . cant see thing

320. . . Display panel

Claims (18)

A double-sided tape comprising: a film-shaped sheet; a first adhesive layer disposed on one surface of the sheet; and a second adhesive layer disposed on the other surface of the sheet; The shear strength of the second adhesive layer is from about 0.05 kg/in ² to about 16 kg/in at a temperature of 60 ° C using an aluminum strip and an SUS panel at a crosshead speed of 10 mm/min. ² . The double-sided tape of claim 1, wherein the shear strength of the first adhesive layer is the same as or greater than the shear strength of the second adhesive layer. The double-sided tape of claim 1, wherein the shear strength is less than about 1 kg/in under the condition that the temperature is 60 ° C, an aluminum strip and an SUS panel are used, and the crosshead speed is 10 mm/min. ² . The double-sided tape of claim 1, wherein in the case of using a PMMA/PC board and an SUS panel at 60 ° C, the second adhesive layer is detached from a time when a weight of 1 kg is applied to an area of 4.5 in ² 20 seconds or more in the range of 600 minutes or less when the weight of 3 kg is applied to the area of 4.5 in ² . The double-sided tape of claim 1, wherein in the case of using a PMMA/PC board and an SUS panel at 60 ° C, the peeling time of the second adhesive layer is between when a weight of 1 kg is applied to one of 4.5 in ² 30 seconds or more in area is in the range of 300 minutes or less when the weight of 3 kg is applied to the area of 4.5 in ² . The double-sided tape of claim 1, wherein the film-shaped sheet is selected from the group consisting of an acryl-based resin, a polyester resin, a polycarbonate resin, a norbornene-based resin, an olefin polymer, and a TAC ( A group of triacetin celluloses. The double-sided tape of claim 1, wherein the film-shaped sheet is polyethylene terephthalate (PET). The double-sided tape of claim 1, wherein the film-shaped sheet has a thickness of from about 5 μm to about 100 μm. The double-sided tape of claim 1, wherein the film-shaped sheet has a light transmittance of more than 90%. The double-sided tape of claim 1, wherein the thickness of each of the first adhesive layer and the second adhesive layer is in a range from about 5 μm to about 500 μm. The double-sided tape of claim 1, wherein the second adhesive layer is formed of a gel polymer composition, and the adhesive polymer composition contains a plurality of monomers, a polymerization initiator, and a chain transfer agent, a polymerization inhibitor, at least one of a low molecular weight additive and a curing agent. The double-sided tape of claim 11, wherein the chain transfer agent is contained in an amount of from about 0.03 part by weight to about 5 parts by weight, based on 100 parts by weight of the monomer, from about 0.01 part by weight to about 0.5 part by weight A polymerization inhibitor and at least one of from about 1 part by weight to about 50 parts by weight of the additive having a low molecular weight. The double-sided tape of claim 1, wherein an auxiliary film is additionally disposed on a surface of the second adhesive layer opposite to a surface on which the film-shaped sheet is disposed, and a third adhesive layer is disposed on the auxiliary film Chip. The double-sided tape of claim 1, wherein the third adhesive layer has a shear strength greater than the shear strength of the second adhesive layer. The double-sided tape of claim 1, wherein the light transmittance is greater than 90%. A display device comprising: a display panel, a double-sided tape disposed on a display surface of the display panel, and a transparent plate disposed on the double-sided tape, wherein the double-sided tape is as requested Double-sided tape of item 1. The display device of claim 16, wherein the transparent plate is a cover of an electronic device. The display device of claim 16, wherein the transparent plate is a touch panel.