KR20070105030A - Polarizer and manufacturing method thereof and liquid crystal display having the same - Google Patents

Abstract

A polarizing plate, a manufacturing method thereof and an LCD having the same are provided to prevent an LCD from being damaged from an electrostatic discharge by adhering an electrostatic prevention layer to a polarizing layer. A polarizing plate includes a polarizing layer(10), an ESD prevention layer(20), an adhering layer(30), first and second supporting layers(50,51), a compensation film(60), and a release film(70). The polarizing layer polarizes and transmits an incident light. The ESD prevention layer is adhered to the polarizing layer and prevents an electrostatic discharge. The adhering layer is adhered to the ESD prevention layer. A corona process for a bonding plane of the adhering layer is performed to increase an adhering intensity. The first and second supporting layers support to protect the polarizing layer. The compensation film is attached to the second supporting layer and lessen a phase difference. The release film which protects the adhering layer is formed on the other side of the contact plane with the ESD prevention layer.

Description

Polarizing plate and manufacturing method thereof and liquid crystal display having the same {POLARIZER AND MANUFACTURING METHOD THEREOF AND LIQUID CRYSTAL DISPLAY HAVING THE SAME}

1 is a perspective view showing the structure of a polarizing plate according to an embodiment of the present invention.

2 is a flowchart sequentially illustrating a method of manufacturing a polarizing plate according to an embodiment of the present invention.

3 is a cross-sectional view illustrating a liquid crystal display device having a polarizing plate according to a first embodiment of the present invention.

4 is a cross-sectional view of a liquid crystal display device having a polarizing plate according to a second embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

10: polarizing film 20: antistatic layer

30: first pressure sensitive adhesive layer 31: second pressure sensitive adhesive layer

50: first support layer 51: second support layer

60: compensation film 70: release film

80: low reflection layer 101: upper polarizing film

102: lower polarizing film 200: liquid crystal display panel

200a: upper substrate 200b: lower substrate

201: upper polarizer 202: lower polarizer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate, a method for manufacturing the same, and a liquid crystal display device having the same, and more particularly, to a polarizing plate prevented from static electricity, a manufacturing method thereof, and a liquid crystal display device having the same.

In liquid crystal displays, two substrates on which field generating electrodes are formed are disposed so that the surfaces on which the two electrodes are formed face each other, a liquid crystal material is injected between the two substrates, and a voltage is applied to the two electrodes to generate a magnetic field. By moving the liquid crystal molecules by means of the device to display an image according to the light transmittance that varies accordingly.

In the liquid crystal display, polarizers are attached to upper and lower substrates of the liquid crystal panel to control the polarization state of incident light.

A polarizing plate is formed by adhering an adhesive layer to a polarizing film, and attaching a release film on an adhesive layer to protect an adhesive layer. The polarizing plate is attached to the liquid crystal display panel through the adhesive layer after removing the release film.

Here, the release film causes static electricity when peeling, and the generated static electricity causes high voltages on signal lines of the liquid crystal display panel, causing panel failure.

In addition, static electricity due to contact between the polarizer and the optical films attached to the lower substrate of the liquid crystal display panel is induced to break down the insulation between the electrodes and the signal lines of the thin film transistor on the lower substrate, causing panel failure. .

On the other hand, when the polarizing plate is attached to the liquid crystal display panel, bubbles are formed or wrinkles occur. In this case, once a polarizing plate is peeled off and corrected, it is re-bonded again. At this time, when the pressure-sensitive adhesive of the peeled polarizing plate remains on the liquid crystal display panel, display defects are caused.

Accordingly, an object of the present invention is to provide an antistatic layer to prevent static electricity, to prevent defects in the liquid crystal display panel, and to increase the adhesive strength with the pressure-sensitive adhesive layer adhered to the polarizing plate through corona treatment of the pressure-sensitive adhesive layer, To provide a polarizing plate and a manufacturing method thereof and a liquid crystal display having the same to prevent the remaining phenomenon.

In order to achieve the above object, the present invention provides a polarizing film that polarizes and transmits incident light, an antistatic layer adhered to the polarizing film to prevent static electricity, and a bonding surface adhered to the antistatic layer to increase adhesion strength. The polarizing plate containing this corona treated adhesive layer is provided.

And a compensation film attached to the first and second support layers for protecting and supporting the polarizer and the second support layer, and alleviating the phase difference.

And a release film for protecting the pressure-sensitive adhesive layer on the other side of the surface adhered to the antistatic layer.

In order to achieve the above object, the present invention is a polarizing plate manufacturing method comprising the step of bonding the polarizing film and the antistatic layer, the step of corona treatment of one side of the adhesive layer bonded and the step of bonding the antistatic layer and the pressure-sensitive adhesive layer. To provide.

The method may further include adhering the first and second support layers to protect and support the polarizing film and adhering a compensation film to alleviate the phase difference on the upper surface of the second support layer before the antistatic layer bonding step.

In addition, before the corona treatment step of the pressure-sensitive adhesive layer further comprises a aging step for stabilizing the adhesive performance of the pressure-sensitive adhesive layer.

In order to achieve the above object, the present invention provides a liquid crystal display panel for displaying an image, a polarizing film that is attached to the upper and lower substrates of the liquid crystal display panel to polarize and transmit the incident light, and adheres to the polarizing film to electrostatic The present invention provides a liquid crystal display including an antistatic layer for preventing and an upper and a lower polarizer having a corona treatment to increase adhesive strength and an adhesive layer adhered to the antistatic layer and adhered to the upper and lower substrates.

The adhesive strength between the antistatic layer and the pressure sensitive adhesive layer is superior to the adhesive strength between the liquid crystal display panel and the pressure sensitive adhesive layer.

The upper polarizing plate further includes a low reflection layer that prevents light incident from the outside from being reflected.

In addition, the antistatic layer is bonded to the lower reflection layer.

Other objects and features of the present invention in addition to the above object will become apparent from the description with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing the structure of a polarizing plate according to an embodiment of the present invention.

Referring to FIG. 1, the polarizing plate according to the present invention includes a polarizing film 10 for polarizing and transmitting incident light, an antistatic layer 20 for adhering to the polarizing film 10 to prevent static electricity, and an antistatic layer 20 ), The bonding surface includes a corona-treated first pressure-sensitive adhesive layer 30 to increase the adhesive strength.

The polarizing film 10 is formed by stretching while heating a thin film of polyvinyl alcohol to deposit iodic acid in a dichroic dye solution. Such a polarizing film 10 has a stretching axis in the stretched direction and a transmission axis perpendicular to the stretch axis.

The polarizing film 10 is typically formed of a polymer film. Polymer films include PolyVinyl Alcohol (PVA), Polyethylene Terephthalate (PET), and PolyVinyl Butyral (PVB). As well as the polarizing film 10, it is excellent in dyeing affinity for iodine.

The polarizing film 10 further includes first and second supporting layers 50 and 51 for protecting and supporting the polarizing film 10 therebetween.

The first and second support layers 50 and 51 are formed of TriAcetyl Cellulose (TAC) and the like, and are bonded to each other with the polarizing film 10 interposed therebetween. The first and second support layers 50 and 51 prevent shrinkage of the stretched polarizing film 10 and protect the polarizing film 10.

A compensation film 60 is further attached on the second support layer 51 to alleviate the phase difference due to the refractive index anisotropy of the liquid crystal display panel and the liquid crystal cell gap.

The compensation film 60 is formed by biaxially stretching a polymer film having a high light transmittance such as polyvinyl alcohol or polycarbonate (PC). One surface of the compensation film 60 is adhered to the second support layer 51 through the second adhesive layer 30, and the other surface is bonded to the antistatic layer 20.

The antistatic layer 20 may block static electricity introduced from the outside, static electricity introduced during an electrostatic discharge (ESD) test, and static electricity introduced when the release film 70 is peeled from the first adhesive layer 30.

In addition, the antistatic layer 20 is attached to the lower substrate 200b of the liquid crystal display panel to block static electricity generated by contact between the polarizing plate and the optical film.

The antistatic layer 20 is coated on one surface of the compensation film 60 with a transparent conductive material.

One surface of the first adhesive layer 30 is adhered to the antistatic layer 20, and the release film 70 is attached to the other surface. The release film 70 is peeled off when the first adhesive layer 30 adheres to the liquid crystal display panel.

At this time, the first pressure-sensitive adhesive 30 layer is corona-treated to the adhesive surface in order to increase the adhesive strength to be bonded to the antistatic layer 20.

Corona treatment increases the wettability of the surface by using high frequency electrical discharge on the surface of the polymer material. The low surface energy of polymer materials causes adhesion problems in inks, adhesives and coatings, which is solved by increasing the surface energy of the workpiece more than the material. Therefore, the corona treatment increases the wettability of the antistatic layer 20 material on the surface of the first pressure-sensitive adhesive layer 30 to improve the adhesive strength. Therefore, the adhesive strength between the first pressure sensitive adhesive layer 30 and the antistatic layer 20 becomes relatively superior to the adhesive strength between the first pressure sensitive adhesive layer 30 and the liquid crystal display panel. The corona-treated first pressure-sensitive adhesive layer 30 prevents the adhesive from remaining on the liquid crystal display panel from the first pressure-sensitive adhesive layer 30 when reworking the bonding operation between the polarizing plate and the liquid crystal display panel.

2 is a flowchart sequentially illustrating a method of manufacturing a polarizing plate according to an embodiment of the present invention.

Referring to FIG. 2, in the method of manufacturing a polarizing plate according to an exemplary embodiment of the present invention, a step (S21) of bonding the polarizing film 10 and the antistatic layer 20 and a surface of the first adhesive layer 30 to be bonded are shown. Corona treatment step (S31), and the step of bonding the anti-static layer 20 and the first pressure-sensitive adhesive layer 30 (S41).

First, the antistatic layer 20 using the transparent conductive material is coated on the polarizing film 10 and bonded.

Next, a corona treatment for increasing the wettability of the surface by high frequency electric discharge is performed on one surface to be bonded to the first pressure sensitive adhesive layer 30. At this time, the first pressure-sensitive adhesive layer 30 is attached to the release film 70 on one surface and the other surface corona treatment.

Finally, the polarizing film 10 to which the antistatic layer 20 is bonded and the corona-treated first pressure-sensitive adhesive layer 30 are adhered to each other.

Here, the method may further include adhering the first and second support layers 50 and 51 to protect and support the polarizing film 10 before the adhering the antistatic layer 20 (S21). The first and second support layers 50 and 51 are bonded to each other with the polarizer 10 therebetween.

In addition, the step (S22) of adhering the compensation film 60 for alleviating the phase difference before the step (S21) of the antistatic layer 20 further includes.

The compensation film 60 adheres to the second support layer 51 through the second adhesive layer 31.

And, further comprising the step of aging the first pressure-sensitive adhesive layer 30 before the corona treatment step (S31) of the first pressure-sensitive adhesive layer 30. The first pressure-sensitive adhesive layer 30 is generally aged for about one week in order to stabilize the adhesive performance.

3 is a cross-sectional view illustrating a liquid crystal display device having a polarizing plate according to a first embodiment of the present invention.

Referring to FIG. 3, a liquid crystal display device having a polarizing plate according to the present invention is attached to a liquid crystal display panel 200 for displaying an image and to upper and lower substrates 200a and 200b of the liquid crystal display panel 200, respectively. Upper and lower polarizing films 101 and 102 for polarizing and transmitting incident light, an antistatic layer 20 for adhering to the upper and lower polarizing films 101 and 102 to prevent static electricity, and a corona treatment to increase adhesion strength and static electricity. The upper and lower polarizers 201 and 202, which are attached to the prevention layer 20 and adhere to the liquid crystal display panel 200, are formed on the upper and lower polarizers 201 and 202.

 The liquid crystal display panel 200 arranges two substrates on which two electrodes are formed, injects a liquid crystal material between the two substrates, and then moves the liquid crystal molecules by a magnetic field generated by applying a voltage to the two electrodes to display an image of light transmitted therethrough. Display.

The lower polarizer 202 is attached to the lower substrate 200b of the liquid crystal display panel 200 and is the same as the polarizer illustrated in FIG. 1. Therefore, duplicate descriptions of the same components will be omitted.

The antistatic layer 20 of the lower polarizer 202 is bonded to the lower polarizer 102 to prevent static electricity flowing from the outside and static electricity generated when the release film 70 is peeled off.

For example, the antistatic layer 20 prevents static electricity generated by contact between the optical film and the lower polarizer 202 in the liquid crystal display.

The upper polarizer 201 is formed on the upper substrate 200a of the liquid crystal display panel 200, the antistatic layer 20 adhered to the upper substrate 200a through the first adhesive layer 30, and the antistatic layer 20 The second support layer with the compensation film 60 adhered to the upper portion, the second support layer 51 adhered to the compensation film 60 through the second pressure sensitive adhesive layer 31, and the upper polarizing film 101 interposed therebetween. The first support layer 50 to be bonded to the 51 is provided.

Here, the upper polarizing plate 201 further includes a low reflection layer 80 to prevent the light incident from the outside is reflected. The low reflection layer 80 is formed on the uppermost layer of the upper polarizing plate, and improves the contrast of the liquid crystal display panel 200 through anti-glare (AG) treatment.

The lower polarizing film 102 of the lower polarizing plate 202 has a stretching axis orthogonal to each other and the upper polarizing film 101 of the upper polarizing plate 201.

The lower polarizer 202 and the upper polarizer 201 are attached to the liquid crystal display panel 200 through the first adhesive layer 30, respectively, to form a liquid crystal display device.

One surface of the first adhesive layer 30 is adhered to the antistatic layer 20, and the other surface of the first adhesive layer 30 is adhered to the liquid crystal display panel 200. If the adhesion state is not good due to foreign matter or bubbles on the surface, it may be necessary to rebond the upper and lower polarizers 201 and 202 and the liquid crystal display panel 200. At this time, the first pressure-sensitive adhesive layer 31 is subjected to a corona treatment to increase the adhesive strength to the antistatic layer 20 on one surface.

The first pressure sensitive adhesive layer 30 must be relatively superior in adhesive strength with the antistatic layer 20 than the adhesive strength with the liquid crystal display panel 200 so that the first pressure sensitive adhesive layer 30 can be peeled off from the liquid crystal display panel 200. When the adhesive remains, it can be prevented.

The light incident on the lower polarizing plate 202 is polarized through the lower polarizing film 102 and then the phase is delayed while passing through the compensation film 60, and the compensation film 60 is phase delayed to the liquid crystal display panel 200. Supply polarized light. The light incident on the liquid crystal display panel 200 is transmitted in a direction corresponding to the arrangement of the liquid crystal molecules, and is incident on the compensation film 60 of the upper polarizer 201 to delay the phase. Light transmitted through the compensation film 60 of the upper polarizing plate 201 is polarized in the upper polarizing film 101 to display an image.

4 is a cross-sectional view of a liquid crystal display device having a polarizing plate according to a second embodiment of the present invention.

Referring to FIG. 4, in the liquid crystal display device having the polarizing plate according to the second embodiment of the present invention, the anti-static layer 20 of the upper polarizing plate 201 is the upper polarizing film 101 in contrast to the liquid crystal display shown in FIG. 3. It is attached to the upper surface, and has the same components except that the first pressure-sensitive adhesive layer 30 is bonded to the upper polarizing film (101). Accordingly, detailed description of the same components will be omitted.

The antistatic layer 20 is coated with a transparent conductive material to the first support layer 50 and bonded. At this time, the antistatic layer 20 blocks the static electricity flowing from the outside.

One surface of the first adhesive layer 30 is adhered to the upper polarizing film 101, and the other surface of the first adhesive layer 30 is adhered to the liquid crystal display panel 200. The first pressure sensitive adhesive layer 30 adheres to the upper polarizing film 101 to have an adhesive strength relatively superior to that of the liquid crystal display panel 200. Thus, one surface of the first pressure sensitive adhesive layer 30 is not subjected to corona treatment.

As described above, the polarizing plate and the manufacturing method thereof and the liquid crystal display having the same according to the present invention can solve the problem of adhesive remaining while maintaining high transmittance and good antistatic property without changing chemical composition of the antistatic layer through corona treatment of the adhesive layer. have.

According to the present invention, a polarizing plate, a method of manufacturing the same, and a liquid crystal display having the same prevent adhesion of an antistatic layer to a polarizing layer to prevent damage to the liquid crystal display due to static electricity. In addition, the corona treatment of the pressure-sensitive adhesive layer may increase the adhesive strength to prevent a phenomenon in which the pressure-sensitive adhesive remains in the liquid crystal display panel during rework of the polarizing plate and the liquid crystal display panel, thereby preventing poor display of the panel and the like, thereby improving productivity.

The present invention described above will be capable of various substitutions, modifications, and changes by those skilled in the art to which the present invention pertains. Accordingly, the present invention should not be limited to the above-described embodiments and the accompanying drawings, and the rights thereof should be determined by the claims.

Claims (10)

A polarizing film for polarizing and transmitting incident light; An antistatic layer adhered to the polarizing film to prevent static electricity; And a pressure sensitive adhesive layer bonded to the antistatic layer and having a bonding surface corona treated to increase adhesive strength. The method of claim 1, First and second support layers for protecting and supporting the polarizing film; And And a compensation film attached to the second support layer and alleviating the retardation. The method of claim 1, Polarizing plate further comprises a release film to protect the pressure-sensitive adhesive layer on the other side of the surface bonded to the antistatic layer. Adhering a polarizing film and an antistatic layer; Corona treating one surface of the adhesive layer to be bonded; And Method of manufacturing a polarizing plate comprising the step of adhering the antistatic layer and the pressure-sensitive adhesive layer. The method of claim 4, wherein Before the antistatic layer bonding step Adhering first and second support layers to protect and support the polarizer; And Adhering a compensation film for alleviating the retardation to an upper surface of the second support layer. The method of claim 4, wherein Before the corona treatment step of the pressure-sensitive adhesive layer Method for producing a polarizing plate, characterized in that it further comprises a aging step to stabilize the adhesive performance of the pressure-sensitive adhesive layer. A liquid crystal display panel which displays an image; A polarizing film attached to upper and lower substrates of the liquid crystal display panel and configured to polarize and transmit incident light; An antistatic layer adhered to the polarizing film to prevent static electricity; And upper and lower polarizers having a corona treatment to increase adhesive strength and adhered to the antistatic layer, and a pressure-sensitive adhesive layer adhering to the upper and lower substrates. The method of claim 7, wherein The adhesive strength between the antistatic layer and the pressure-sensitive adhesive layer is superior to the adhesive strength between the liquid crystal display panel and the pressure-sensitive adhesive layer. The method of claim 7, wherein The upper polarizing plate further comprises a low reflection layer for preventing the light incident from the outside is reflected. The method of claim 9, And the antistatic layer is adhered to the lower reflection layer.

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