JP2003177241A - Optical laminate, pressure-sensitive adhesive transfer tape, and method for producing optical laminate - Google Patents

Abstract

(57) [Problem] Regardless of whether a polarizing plate laminate or a retardation plate laminate (abbreviated as an optical laminate) is manufactured using an adhesive transfer tape, the liquid crystal display body surface is Provided is a pressure-sensitive adhesive transfer tape for an optical laminate, in which the reworkability of the optical laminate is improved, and the pressure-sensitive adhesive does not easily remain on the surface of the liquid crystal display during rework; and such a pressure-sensitive adhesive transfer tape. And a method for producing the same, wherein the optical laminate is bonded to a liquid crystal display member such as a polarizing plate or a retardation plate. SOLUTION: This is an optical laminate in which a liquid crystal display member (4) is laminated with two or more pressure-sensitive adhesive layers (3) having different adhesive strengths. When the pressure-sensitive adhesive layers on both sides of the two or more pressure-sensitive adhesive layers (3) are pressure-sensitive adhesive layers (3A) and (3B), the pressure-sensitive adhesive layer (3B) having a relatively large pressure Two or more pressure-sensitive adhesive layers (3) are attached to the liquid crystal display member (4) in a laminated state so as to be on the liquid crystal display member (4) side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical laminate in which a pressure-sensitive adhesive layer is laminated on a liquid crystal display member such as a polarizing plate or a retardation plate. The present invention also relates to a pressure-sensitive adhesive transfer tape for producing the optical laminate, and further to a method for producing an optical laminate using the pressure-sensitive adhesive transfer tape.

[0002]

2. Description of the Related Art <Polarizing plate laminate, retardation plate laminate> In the manufacturing process of a polarizing plate or a retardation plate, (a) after attaching a protective film to the polarizing plate or the retardation plate, The opposite surface of the retardation plate is adhesively processed, and the release film is adhered and coated on the adhesively processed surface, or (b) the release film is adhesively processed, and the adhesively processed surface is covered with a protective film. By sticking the surface opposite to the surface protection film of the polarizing plate or the retardation plate that protected the
A polarizing plate laminate or a retardation plate laminate is manufactured.

<Inspection of Foreign Substances> Such a polarizing plate laminate (having a pressure-sensitive adhesive layer provided on one side of a polarizing plate and a release film provided on the pressure-sensitive adhesive layer) used for a liquid crystal display or a retardation plate laminate. In the case of a body (having a pressure-sensitive adhesive layer provided on one surface of a retardation plate and a release film provided on the pressure-sensitive adhesive layer), if the release film is peeled off and inspected, contamination of foreign matter becomes a big problem. Therefore, it is general to perform the foreign matter inspection in the state of the laminated body. When inspecting foreign matter, a visual inspection is carried out using the crossed Nicol method (a method in which two polarizing plates are arranged with their stretching axes orthogonal to each other, a sample film is placed between the polarizing plates, and the foreign matter is inspected by transmitted light). It is common to do.

[0004]

<Problems of the conventional method> In the case of producing a polarizing plate laminate or a retardation plate laminate by the above-mentioned methods (a) and (b), roll processing is carried out. It is common to do. At that time, it is usual to carry out the processing while adjusting the machine such as adjusting the tension of the polarizing plate, the retardation film or the release film and controlling the nip condition each time the processing is performed. Also, if there are variations in thickness or tarmi on the polarizing plate, retardation plate or release film,
It is necessary to adjust it accordingly.

However, depending on these methods,
Although processing loss will inevitably occur in the actual adhesive processing, although there is little influence when the processing lot is large,
When the processing lot is small, the ratio of this loss is large, and as a result, the yield is significantly reduced. Since the polarizing plate and the retardation plate are expensive, this reduction in yield has a great influence on the product cost. Further, in these processing methods, there is a problem that it is not possible to cope with products with a short delivery time because the adhesive needs to be matured after the adhesive processing. In recent years, there is an increasing number of types of polarizing plate laminates or retardation plate laminates, and the delivery time tends to be shortened.
That is, although the processing lots have become smaller and it has become necessary to deal with short delivery times, the fact is that such a situation cannot be dealt with by the above method.

<Concepts and Problems of Use of Adhesive Transfer Tape> The inventors of the present invention have used a pressure-sensitive adhesive transfer tape having a structure in which an adhesive is sandwiched between two release films to form a polarizing plate laminate or a layer. The idea was to produce a retarder laminate. That is, a polarizing plate or a retardation plate and a pressure-sensitive adhesive transfer tape are prepared in advance, and the polarizing plate or the retardation plate and the pressure-sensitive adhesive transfer tape are bonded together by a bonding machine to obtain a polarizing plate laminate of a required grade. Alternatively, the required number of retarder laminates are manufactured. In this method, since the pressure-sensitive adhesive transfer tape in which the pressure-sensitive adhesive has been matured is used, the product obtained by bonding the polarizing plate or the retardation plate and the pressure-sensitive adhesive transfer tape with a bonding machine is not matured. It can be shipped as it is, and it can be expected that it will be effective for short delivery items.

The first possible release film used for such a pressure-sensitive adhesive transfer tape is a biaxially stretched polyester film used as a substrate, the surface of which is subjected to release processing with a release agent. At the time of its use, one release film of the pressure-sensitive adhesive transfer tape is peeled off and removed, and the exposed adhesive layer side of the remaining layer is bonded to a polarizing plate or a retardation plate. It remains in the body or the retardation plate laminate.

The polarizing plate laminate or the retardation plate laminate produced as described above is attached to the surface of the liquid crystal display body (the surface of the glass substrate or the plastics substrate) after peeling off the remaining release film. However, air bubbles or foreign matter may enter during the attachment. At such times,
It is necessary to temporarily peel off the polarizing plate laminate or the retardation plate laminate and then reattach it (rework).

However, in this reworking, when the adhesive force of the pressure-sensitive adhesive layer laminated on the polarizing plate laminate / retardation plate laminate to the polarizing plate / retardation plate is smaller than the adhesive force to the liquid crystal display surface. When the polarizing plate laminate / retarder laminate is peeled off, the pressure-sensitive adhesive may remain on the surface of the liquid crystal display body, making rework impossible.

The method as described in the first part of the description of "Prior Art" above, that is, (a) after attaching a protective film to a polarizing plate or a retardation plate, A method for producing a polarizing plate laminate / phase difference plate laminate by applying adhesive treatment to the opposite surface and coating a release film on the adhesive-treated surface, or (b) applying an adhesive treatment to the release film Then, a polarizing plate laminate or a retardation plate laminate is produced by sticking the surface of the polarizing plate or the retardation plate opposite to the surface protection film of which the surface is protected by a protective film, to the adhesive processed surface. In this method, since the adhesive is aged after the adhesive is adhered to the polarizing plate / retarder, the adhesiveness of the adhesive to the polarizing plate / retarder is improved. If you use a good adhesive,
The problem that the above rework cannot be performed still remains.

When the pressure-sensitive adhesive transfer tape is used, the adhesive that has been matured is attached to the polarizing plate and the retardation plate, so that the adhesiveness to the polarizing plate and the retardation plate is large. As a result, the adhesiveness to the surface of the liquid crystal display is also large, and the problem that the pressure sensitive adhesive is likely to remain on the surface of the liquid crystal display during rework tends to occur. Therefore, we also considered applying an easy-adhesion treatment such as corona treatment or ozone treatment to the surface of the pressure-sensitive adhesive layer that is attached to the polarizing plate / retarder.
Although the adhesive strength to the polarizing plate and the retardation plate can be improved to some extent, it is still insufficient and could not be a basic solution.

<Purpose of the Invention> The present invention, under such a background, uses a pressure-sensitive adhesive transfer tape to form a polarizing plate laminate.
Despite the fact that a retardation plate laminate (abbreviated as optical laminate) is manufactured, the reworkability of the polarizing plate laminate / retarder laminate (optical laminate) on the surface of the liquid crystal display is improved. And a pressure-sensitive adhesive transfer tape for a polarizing plate laminate / retardation plate laminate in which the pressure-sensitive adhesive does not easily remain on the surface of the liquid crystal display during rework, and such a pressure-sensitive adhesive transfer tape is used as a polarizing plate. It is an object of the present invention to provide an optical laminate attached to a liquid crystal display member such as a retardation plate and a method for producing the same.

[0013]

The optical laminate of the present invention is a laminate in which a pressure-sensitive adhesive layer (3) is laminated on a liquid crystal display member (4), and (b) the pressure-sensitive adhesive layer ( 3) is composed of two or more pressure-sensitive adhesive layers having different adhesive strengths, and (b) the two or more pressure-sensitive adhesive layers (3), wherein the pressure-sensitive adhesive layers on both outer sides are the pressure-sensitive adhesive layers (3A), (3B), and the adhesive strength is relatively small when the adhesive strength to glass is viewed as the adhesive strength (3A), and the adhesive strength is relatively large. When the adhesive layer is the pressure-sensitive adhesive layer (3B), the latter pressure-sensitive adhesive layer (3B) having a relatively high adhesive force is more than two layers of adhesive so that the liquid crystal display member (4) side is closer. The agent layer (3) is laminated on the liquid crystal display member (4) in a laminated state.

The pressure-sensitive adhesive transfer tape of the present invention is a pressure-sensitive adhesive transfer tape for sticking the pressure-sensitive adhesive layer (3) to the liquid crystal display member (4) to prepare an optical laminate. The tape comprises an adhesive layer (3) and two release films (1), (2)
Having a structure sandwiched between, and the pressure-sensitive adhesive layer (3)
Is composed of two or more adhesive layers having different adhesive strengths.

In the method for producing an optical laminate of the present invention, the remaining laminate obtained by peeling off one release film from the above-mentioned pressure-sensitive adhesive transfer tape is adhered to the liquid crystal display member (4), and It is characterized by producing an optical laminate.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the development of the story, the adhesive transfer tape will be described first, and then the optical laminate and the manufacturing method thereof will be described.

<< Adhesive Transfer Tape >><Explanation of Terms> The “tape” of the “adhesive transfer tape” means not only a narrow strip but also a wide one, a roll wound, or a roll. It is a concept that also includes a single sheet that is not wound into a shape.

"Adhesive transfer tape" means interlining (core material)
The pressure-sensitive adhesive layer having no layer has a layer structure in which it is sandwiched between two release films, and can also be referred to as a non-support tape. By the way, a normal "double-sided adhesive tape" is one in which an adhesive layer is provided on both sides of an interlining (core material) to be a support, and an adhesive body composed of such "adhesive layer / interlining / adhesive layer" is used. Since it has a structure in which a release film is arranged on both sides, when attention is paid to the layers other than the release film, it is an adhesive layer with a support.

In addition, in a usual "double-sided pressure-sensitive adhesive tape", a pressure-sensitive adhesive layer is provided on one side of a release film whose both sides are release-treated and wound for aging. The wound state may be tightened (referred to as winding tightness), which causes waviness and the like, which tends to adversely affect the optical characteristics of the pressure-sensitive adhesive layer. On the other hand, even with the "adhesive transfer tape", winding tightness occurs, but since sliding is possible between adjacent winding layers, the optical characteristics are less likely to be adversely affected.

<Characteristic constitution of the pressure-sensitive adhesive transfer tape of the present invention> In the pressure-sensitive adhesive transfer tape of the present invention, the pressure-sensitive adhesive layer (3) is attached to the liquid crystal display member (4) to prepare an optical laminate. This is a tape for transferring an adhesive for carrying out. Here, a typical example of the liquid crystal display member (4) is a polarizing plate or a retardation plate.

The tape has a structure in which the pressure-sensitive adhesive layer (3) is sandwiched between two release films (1) and (2), and the pressure-sensitive adhesive layer (3) is a two-layer structure having different adhesive strengths. It consists of the above adhesive layer.

<Release film (1), (2)> In order to obtain releasability, each of the base materials constituting the release film (1), (2) is at least the adhesive layer (3) The surface on the side that contacts with is peeled off.

The two peel films (1) and (2) preferably have different peel strengths. Less than,
The release film having a relatively heavy release force will be referred to as a first release film (1), and the release film having a relatively light release force will be referred to as a second release film (2).

As the base material of the release films (1) and (2), a non-stretched or uniaxially or biaxially stretched polyester film is preferably used. Here, the polyester is polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, or the like. As the substrate, as long as it has the required strength and optical properties, in addition to the above polyester film, polyolefin film, polyamide film, cellulose derivative film, polycarbonate film, polyphenylene sulfide film, various liquid crystal polymer film, poly Various films such as a vinyl chloride film, a polyvinylidene chloride film, and various biodegradable films can also be used, and these films may be unstretched films or stretched films. The base material may be not only a single film but also a multi-layer film. The substrate may be an easily adhesive treatment, a matting treatment, printing, or coloring. The thickness of the base material is not particularly limited, but is 6 to 188 μm from the viewpoint of ease of handling during use and cost.
It is often about the same.

Among the above-mentioned substrates, a uniaxially stretched polyester film having a maximum strain of the orientation main axis of 10 degrees or less is particularly preferable. If the maximum strain of the orientation main axis exceeds 10 degrees, an optical interference color may occur at the time of appearance inspection by the crossed Nicols method when the polarizing plate laminate or the retardation plate laminate is formed, which may make the inspection difficult. . Therefore, it is recommended to use such a uniaxially stretched polyester film as the substrate (1a) constituting at least the first release film (1) on the heavy release surface side. In addition, the measurement of the strain of the orientation main axis,
If the film is a roll-shaped long product, cut the film out 1000 mm in the longitudinal direction and the entire width in the width direction (in the case of a sheet, draw a rectangle with the largest area inscribed in the sample shape).
A square of 100 mm square sharing two sides with the apex of the rectangle is cut out from the four apexes, the orientation main axis is obtained by microwave, and when the molecular orientation of the first measured point is 0 degree, the other three points are This is done by finding the maximum value from the ones with the largest difference in orientation angle.

Any release agent can be used as the release agent for performing the release process on the substrate, but a silicone-based release agent having excellent release characteristics is desirable. When a substrate having insufficient heat resistance is used, an addition reaction type silicone release agent which cures at a relatively low temperature is suitable. The photo-initiator added to the addition reaction type silicone release agent may be a “heat + ultraviolet” curing type silicone, or as a type that does not apply heat, acrylic silicone, mercapto group-containing silicone, epoxy group It may be of a type that is cured by irradiation with ultraviolet rays, such as contained silicone. Although a release agent other than the silicone-based release agent can be used, when the release is heavy, the pressure-sensitive adhesive surface is roughened when the release film is removed from the polarizing plate / retardation plate, and the polarizing plate / retardation plate is used. Since the external appearance is deteriorated when the is adhered to the glass substrate surface (or the plastics substrate surface) of the liquid crystal display, it is desirable to select one that is easily peeled off. Therefore, it is desirable to use, as the release agent, a type that is lightly peeled within a range in which the residual adhesiveness is not deteriorated.

Among the silicone-based release agents, there is a light release type silicone in which a transfer component is contained in the release agent to facilitate the release. A silicone containing such transfer component in the release agent was used. In that case, the residual adhesiveness tends to decrease, and considering that the use of the present invention is a polarizing plate laminate / retarder laminate, a silicone containing a transfer component in a release agent is not suitable for the present invention. Not not. This is because when a release film with poor residual adhesion is used in a polarizing plate laminate / retardation plate laminate, after the polarizing plate or retardation plate is attached to a glass substrate (or plastics substrate),・ An autoclave is applied to improve the adhesion with the retardation plate, but at this time the adhesive strength of the adhesive is lower than the original adhesive strength, so the pressure state suddenly changes to normal pressure after the autoclave treatment. This is because there is a possibility that floating and bubbles may occur in the polarizing plate / retarder when returning.
It is possible to add an adhesion improver such as a silane coupling agent for the purpose of improving the adhesion to the substrate.

The coating amount of the release agent is not particularly limited, but in consideration of the release performance, it is about 0.03 to ² g / m ² , and particularly, it is 0.
It is preferably about 05 to 0.4 g / m ² . Although it depends on the type of the base material, if it is less than 0.03 g / m ² , the release performance tends to be insufficient, while if it exceeds ² g / m ² , the release film becomes a silicone coated surface when wound in a roll shape. There is a risk of blocking with the back of the coating.

The release layer is formed with a release agent by applying a silicone release agent to a substrate by various methods such as gravure coating, Meyer bar coating, air knife coating and doctor knife coating,
It can be achieved by drying and curing by a method such as heat treatment or ultraviolet irradiation.

Two release films (1) and (2) having different release forces, that is, relatively heavy, are obtained by appropriately selecting and applying a release agent to be applied to a substrate and drying and curing. A first release film (1) having a peeling force (hereinafter sometimes referred to as "heavy peeling"), a second release film having a relatively light peeling force (hereinafter sometimes referred to as "light peeling") A release film (2) is obtained. The base materials of the release films (1) and (2) may be of the same type or of different types. The release agent may be the same type or different types.

The layer structure of the first release film (1) is based on the base material (1
a) / Peeling treatment layer (1b). The layer structure of the second release film (2) is a substrate (2a) / a release treatment layer (2b).

<Addition of Antistatic Layers (1c) and (2c)> The first release film (1) for heavy release is the antistatic layer (1c) if necessary.
May have. Similarly a light release second release film
(2) may also have an antistatic layer (2c) if necessary. By adding the antistatic layers (1c) and (2c), the peeling electrification at the time of peeling the first and second release films (1) and (2) is prevented, and the release film is treated with an adhesive. It is possible to prevent the generation of static electricity and charging.

The antistatic layers (1c) and (2c) are the base material (1a) of the first release film (1) and / or the second release film (2).
On the surface of the base material (2a) of, the method of depositing or coating an antistatic component composed of a metal or a metal oxide, the method of coating a silicate compound, the method of coating a π-electron conjugated conductive polymer, It is provided by a known method of coating an antistatic agent.

Examples of the metal or metal oxide include metals such as aluminum, silicon, copper, silver, gold and indium, and oxides or complex oxides of these metals. Since it is used for optical applications, it is preferable that it has good transparency. From this viewpoint, a vapor deposition layer of indium oxide or silica is preferable.

The silicate compound is also suitable for this purpose because the antistatic layers (1c) and (2c) formed have good transparency.

Examples of the π-electron conjugated conductive polymer include polyaniline, polypyrrole, polyacetylene, polythiophene, and their derivatives.

As the antistatic agent, any known one can be used as long as it does not inhibit the curing of the silicone-based releasing agent, and examples thereof include a cationic activator, a quaternary ammonium salt, a pyrinidium salt and a primary amine. , Tertiary amine, pyridine derivative, stearoamidopropyldimethyl-β-hydroxyethyl ammonium nitrate,
Stearoamidopropyldimethyl-β-hydroxyethyl ammonium dihydrogen phosphate, special amine compound, alkyl type phosphoric acid ester, sodium alkyl diphenyl ether disulfonate, modified aliphatic dimethylethylammonium ethosulfate, anionic activator , Polyoxyethylene alkylamine, polyhydric alcohol derivative, nonionic activator, alkylamine derivative, alkyl phosphate amine salt,
Fatty acid esters, alkyldiethanolamides, polyethylene glycol esters, amphoteric activators, organoboron compounds, polythiophenes, polyanilines, functional group-containing polymers and the like are examples of commercially available antistatic agents.

These antistatic agents are coated on the substrates (1a) and (2a) by a known method. Specifically, methods such as gravure coating, Mayer bar coating, air knife coating and doctor knife coating are adopted. The amount of the antistatic agent applied is not particularly limited and may be determined in consideration of the type of antistatic agent and the required antistatic performance.

The surface on which the antistatic layers (1c) and (2c) are provided may be the surface to which the release agent is applied in the subsequent step, or the surface opposite to the release agent application side.

<Adhesive Layer (3), (3A), (3B)> As the adhesive forming the adhesive layer (3) interposed between the two release films (1) and (2), It is possible to use various pressure-sensitive adhesives including acrylic one-component or two-component pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives. Examples include emulsion type. Since the pressure-sensitive adhesive is used for optical applications, it is preferable that the color tone does not change such as yellowing with time.

Among these, monomers serving as soft segments (ethyl acrylate, butyl acrylate,
2-Ethylhexyl acrylate, etc.) and a monomer that becomes a hard segment (methyl methacrylate, vinyl acetate, acrylonitrile, styrene, etc.), or acrylic acid, methacrylic acid, hydroxyethyl (meth) acrylate, glycidyl An acrylic pressure-sensitive adhesive in which a functional group-containing monomer such as methacrylate is also copolymerized is preferably used. A two-component type containing an isocyanate curing agent, etc., dried after coating,
It is also possible to cure and carry out a crosslinking reaction.

In the pressure-sensitive adhesive transfer tape of the present invention, the above-mentioned pressure-sensitive adhesive layer (3) is used in at least two layers having different adhesive strengths.
The pressure-sensitive adhesive layer (3A), (3B). Of the two or more pressure-sensitive adhesive layers (3), the pressure-sensitive adhesive layers on both sides are
A) and (3B), and the adhesive strength is relatively small when the adhesive strength to glass is viewed as the adhesive strength (3A) and the adhesive strength is relatively small. The adhesive layer having the largest size will be referred to as the adhesive layer (3B). The adhesive layer
The advantage of having three or more layers (3) is that the adhesive transfer tape can be manufactured at low cost by using an inexpensive adhesive as the intermediate adhesive layer, and the adhesive performance of the adhesive transfer tape is Since it depends largely on the characteristics of the adhesive on both surfaces, the intermediate adhesive layer may be somewhat inferior in adhesive property.Therefore, for example, an antistatic agent may be added to the intermediate adhesive layer. It is possible to modify the entire pressure-sensitive adhesive layer. In the following, in order to avoid complexity, the case where the pressure-sensitive adhesive layer (3) is mainly composed of the pressure-sensitive adhesive layers (3A) and (3B) will be described.

The pressure-sensitive adhesive layers (3A) and (3B) are formed by applying a pressure-sensitive adhesive to one of the release films (1) and (2), and then applying another pressure-sensitive adhesive onto it. After applying and drying, a method of laminating another release film on it, ・ Applying an adhesive on one release film, drying, then applying another adhesive on it, drying, and then another Method of laminating one release film, -Applying an adhesive to one release film, drying, and then attaching the release film on top of it, and then peeling off the release film, attach another adhesive to the adhesive surface. After coating and drying, a method of laminating the other release film to the adhesive surface, -Applying the adhesive on one release film, drying and applying another adhesive on the other release film, Laminate the dried one so that the adhesive surfaces face each other. Method of applying a two-layer adhesive to the release film at the same time, after drying,
A method of laminating a release film on the formed adhesive surface, an optional method such as a method of laminating two types of adhesive transfer tapes so that the adhesive films face each other while peeling off the release film on one side. Method. Similarly, three or more pressure-sensitive adhesive layers can be formed.

The adhesive can be applied using, for example, a die coater, a gravure roll coater, a comma coater, an air knife coater or the like. Adhesive layer
The thickness of (3) is 1 to 100 μm per layer (especially 3 to 30 μm).
It is often about μm). The total thickness of the multi-layer is often about 3 to 200 μm (particularly 5 to 50 μm).

The pressure-sensitive adhesive force of each pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer (3) is 0.98 to 19.6 N / 2 in terms of the pressure-sensitive adhesive force to the glass adherend.
It is often about 5 mm. Further, since the pressure-sensitive adhesive layer (3) is used for optical applications, it is preferable that the pressure-sensitive adhesive layer (3) has high transparency, and the total light transmittance of the pressure-sensitive adhesive layer (3) itself is preferably 95% or more. Here, the total light transmittance is obtained by peeling off the second release film (2) on the light release surface side of the pressure-sensitive adhesive transfer tape and bonding it to a quartz plate with a thickness of 3 mm, and then the first release film.
It is a value measured by a transmittance meter with (1) peeled off.

In the pressure-sensitive adhesive layers (3A) and (3B) formed in two layers, the pressure-sensitive adhesive force of one pressure-sensitive adhesive layer to the polarizing plate / retarder and the pressure-sensitive adhesive layer of the other pressure-sensitive adhesive layer Regarding the relationship with the adhesive strength to glass substrates and plastics substrates,
The former adhesive force should be stronger than the latter adhesive force. If the relationship of the adhesive strength is reversed or close, the adhesive will remain on the liquid crystal display when peeling the polarizing plate laminate / retarder from the liquid crystal display during rework, and rework will not work. There is a risk.

Therefore, although there is a difference in adhesiveness between the case of sticking to a glass substrate and the case of sticking to a plastics substrate, this difference is aside. Adhesive layer (3A), which has relatively small force, is the first release film with heavy release
The adhesive layer (3B), which is located on the (1) side and has a relatively large adhesive strength (adhesive force) to glass, has a positional relationship in which it is located on the second peeling film (2) side for light peeling. Preferably. That is, from the pressure-sensitive adhesive transfer tape having the layer structure of "(1) / (3A) / (3B) / (2)", a light release second release film
(2) is peeled off to form "(1) / (3A) / (3B)",
The (3B) side is affixed to a liquid crystal display member (4) such as a polarizing plate or retardation plate, and an optical laminated structure with a layer structure of "(1) / (3A) / (3B) / (4)" After removing the body, the first release film (1) for heavy release is peeled and removed to form "(3A) / (3B) / (4)" and is also attached to the substrate surface of the liquid crystal display. LCD display / (3
A) / (3B) / (4) ”.

The pressure-sensitive adhesive layer is subjected to a treatment such as an autoclave treatment for the purpose of improving the adhesiveness when it is used as a polarizing plate laminate / retarder laminate or when it is attached to a liquid crystal display. However, it is necessary to select a material that does not allow floating or bubbles under this processing condition.

<Difference in Peelability> As described above, in the pressure-sensitive adhesive transfer tape of the present invention, two peeling films are used.
It is preferable that the weights of the peeling forces of (1) and (2) are different from each other. At this time, the pressure-sensitive adhesive layer (3A) having a relatively low adhesive force is located on the side of the first release film (1) for heavy release, and the pressure-sensitive adhesive layer (3B) having a relatively high adhesive force is more preferable. It is arranged so that it is located on the side of the second release film (2) for light release, but the first release film (1) for heavy release and the adhesive layer (3A)
The peeling force between and is W ₁ , the second peeling film for light peeling (2)
When the peeling force between the adhesive and the adhesive layer (3B) is W ₂ , W ₁
/ W ₂ ratio is 1.5 / 1 to 5/1 (especially 2/1 to 3/1)
It is preferable to set to. When this ratio is less than 1.5, there is a possibility that when the second release film (2) is peeled off, the "peeling" phenomenon in which the adhesive is partially adhered to the second release film (2), on the other hand, When this ratio exceeds 5, the above-mentioned "crying and tearing" phenomenon does not occur, but the problem that peeling of the first release film (1) is too heavy may be difficult to use.

<Optical Laminate><Attachment to Liquid Crystal Display Member (4)> The above-mentioned pressure-sensitive adhesive transfer tape is applied to a liquid crystal display member (4) such as a polarizing plate and a retardation plate. . At this time, the residue obtained by peeling off the lightly peelable second peeling film (2) from the adhesive transfer tape is attached to the surface of the polarizing plate or the retardation plate. As a result, an optical laminate including a polarizing plate laminate (including a polarizing plate laminate that also serves as a retardation plate) and a retardation plate laminate is obtained. The heavy release first release film (1) is usually left as it is until it is attached to a liquid crystal display.

That is, the optical laminate of the present invention is a laminate in which the pressure-sensitive adhesive layer (3) is laminated on the liquid crystal display member (4), and the pressure-sensitive adhesive layer (3) has a different adhesive force. The pressure-sensitive adhesive layer (3B) having two or more pressure-sensitive adhesive layers and having a relatively large adhesive force is the member for liquid crystal display (4).
Two or more pressure-sensitive adhesive layers (3) are attached to the liquid crystal display member (4) in a laminated state, that is, "(1) / (3A) / (3B). / (4) "or a layer structure obtained by peeling and removing (1) from this.

[0052]

EXAMPLES The present invention will be further described with reference to examples. In addition, the basic peeling force of the release film referred to in Example 1 to be described later is that the polyester tape "No.
B] was pasted together using a 2 kg rubber roller, and then the pasted sample was applied with a load of 20 g / cm ² at 70 ° C.
Aging was performed for 20 hours under the temperature condition of 30 ° C., and the peeling force of the sample after the aging was measured by a peeling tester using a peeling tester.
It was obtained by measuring the resistance value (unit: "N / 50 mm") when the tape was peeled off at a peeling speed of 0 mm / min and 180 ° peeling.

<Production of Release Film> Example 1 FIG. 1 is a sectional view showing an example of a process for producing an optical laminate using the pressure-sensitive adhesive transfer tape of the present invention.

A uniaxially stretched polyester film having a thickness of 38 μm and a maximum strain of the orientation main axis of 4 degrees (“Ester K1581” manufactured by Toyobo Co., Ltd., a lateral uniaxially stretched film of polyethylene terephthalate) (an example of the substrate (1a)). "SRX-21" manufactured by Toray Dow Corning Silicone Co., Ltd., which is an addition reaction type silicone release agent
1 "(catalyst" SRX-212 "to" SRX-211 "1
Add 2 parts by weight to 100 parts by weight) Add a heavy release additive to 100 parts by weight ("X92-1" manufactured by Shin-Etsu Chemical Co., Ltd.)
28 parts by weight of 28 "as a solid content of a release agent of 0.2 g
After coating so as to be / m ² , it was dried and hardened in a hot air circulation type oven at 120 ° C. for 30 seconds to form a hardened layer (1b). As a result, a heavy release (about 0.4 N / 50 mm) first release film (1) having a layer structure of (1a) / (1b) was obtained.

In the above, the heating condition for drying and curing is 120 ° C. × 30 seconds, which is, for example, 150 ° C. × 30 in a preliminary experiment in which various heating conditions are changed.
Under the high-temperature curing condition of 2 seconds, a slight waviness may occur, which may make it difficult to bond the sheets when the polarizing plate laminate is actually used. Therefore, optimum results were obtained.
This is because the condition of 30 seconds was adopted.

On the other hand, a biaxially stretched polyester film having a thickness of 38 μm (“Ester E51 manufactured by Toyobo Co., Ltd.
00 ") (an example of the base material (2a))," SRX-211 "(catalyst" SRX-2-2 "manufactured by Toray Dow Corning Silicone Co., Ltd.
After coated to a 0.2 g / m ² to 2 parts by weight added) as the solid content relative to 100 parts by weight of "SRX-211" and 12 ", 30 seconds drying and curing at 120 ° C. in a hot-air circulating oven Thus, a cured layer (2b) was formed. This allows
A light release (about 0.1 N / 50 mm) second release film (2) having a layer structure of (2a) / (2b) was obtained.

Heavy release first release film (1) obtained above
After applying an acrylic two-component solvent-type pressure-sensitive adhesive composition (using an isocyanate-based curing agent as a curing agent) to the release agent-treated surface of 15 μm on a dry basis,
It was dried in a hot air circulation oven at 0 ° C. for 2 minutes. The pressure-sensitive adhesive layer (3A) having a thickness of 15 μm formed had an adhesion of 3.9 N / 25 mm to the glass adherend.

Then, from the pressure-sensitive adhesive layer (3A), the release agent-treated surface side of the second release film (2) for light protection for temporary protection is attached, and (1) / (3A) A primary processed product having a layer structure of / (2) was produced.

On the other hand, on the release agent-treated surface of the lightly peelable second release film (2), an acrylic two-pack type different from the above in the type of the main agent, the curing agent and the addition amount of the curing agent was used. A solvent-type pressure-sensitive adhesive composition (using an isocyanate-based curing agent as a curing agent) was applied to a dry standard of 15 μm, and then dried in a hot air circulation oven at 90 ° C. for 2 minutes. As a result, an intermediate processed product having a layer structure of (2) / (3B) was obtained. The pressure-sensitive adhesive layer (3B) having a thickness of 15 μm formed on the glass adherend had an adhesive force of 8.8 N / 25 mm.

From the primary processed product of the layer structure of (1) / (3A) / (2) obtained above, a light release second release film for temporary protection
While peeling off (2), stick the surface of the adhesive layer (3B) of the intermediate processed product with the layer structure of (2) / (3B) obtained above to the exposed surface of the adhesive layer (3A). Then, add this under the condition of temperature 30 ℃.
The adhesive layer (3A) / (3B) was cured by aging for a day to prepare an adhesive transfer tape having a layer structure of (1) / (3A) / (3B) / (2).

Example 2 In Example 1, the release agent-treated surface of the first release film (1) for heavy release had a thickness of 15 μm due to an acrylic two-component solvent-type pressure-sensitive adhesive, and was applied to a glass adherend. After applying the adhesive for the adhesive layer (3A) with an adhesive force of 3.9 N / 25 mm, the thickness of the acrylic two-component solvent-type adhesive is 15 μm on the glass substrate. An adhesive for the adhesive layer (3B) having an adhesive force of 8.8 N / 25 mm was applied. Then, this was dried in a hot air circulation type oven at 90 ° C for 2 minutes, and then the second release film (2) with light release was attached, and then it was aged for 7 days at a temperature of 30 ° C. By promoting the curing of the pressure-sensitive adhesive layer (3A) / (3B), a pressure-sensitive adhesive transfer tape having a layer structure of (1) / (3A) / (3B) / (2) was produced.

Example 3 FIG. 2 is a sectional view showing another example of the pressure-sensitive adhesive transfer tape of the present invention.

In Example 1, the release-treated surface of the heavy release first release film (1) had a thickness of 10 μm due to an acrylic two-component solvent-type adhesive and had an adhesive force of 2.8 on a glass adherend. After applying the N / 25mm adhesive for the adhesive layer (3A), the thickness of the acrylic two-component solvent-type adhesive is 20μm, and the adhesive strength to the glass adherend is 4.5. A pressure-sensitive adhesive for the pressure-sensitive adhesive layer (3C) having N / 25 mm was applied. Then, this is dried in a hot air circulation type oven at 90 ° C for 2 minutes, and then the release agent treated surface of the second release film (2) for light release for temporary protection is placed on the adhesive layer (3C). The side was adhered to prepare a primary processed product having a layer structure of (1) / (3A) / (3C) / (2).

On the other hand, the light-peeling second release film (2) of Example 1 had a release agent-treated surface with a thickness of 10 μm due to an acrylic two-component solvent-type adhesive, and had an adhesive force to a glass adherend. Is 8.2 N / 25 mm for the adhesive layer (3B), then dried in a hot air circulation oven at 90 ° C for 2 minutes, and the layer composition of (2) / (3B) An intermediate processed product of

While peeling off the second release film (2) for light protection for temporary protection from the primary processed product of the layer structure of (1) / (3A) / (3C) / (2) obtained above, On the exposed adhesive layer (3C) surface,
The pressure-sensitive adhesive layer (3) of the intermediate product having the layer structure of (2) / (3B) obtained above
By laminating the surface on the (B) side, and then aging this for 7 days under the condition of a temperature of 30 ° C. to accelerate the curing of the adhesive layer (3A) / (3C) / (3B), (1 A pressure-sensitive adhesive transfer tape having a layer structure of) / (3A) / (3C) / (3B) / (2) was produced.

Comparative Example 1 In Example 1, the release agent-treated surface of the first release film (1) for heavy release had a thickness of 15 μm due to an acrylic two-component solvent-type pressure-sensitive adhesive. After applying the adhesive for the adhesive layer (3A) having an adhesive force of 3.9 N / 25 mm, it was dried in a hot air circulation type oven at 90 ° C. for 2 minutes. Then, from above the adhesive layer (3A), attach the release agent treated surface side of the light release second release film (2) for temporary protection, (1) / (3A) / (2) A primary processed product having a layer structure of was prepared.

On the other hand, the release agent-treated surface of the light release second release film (2) had a thickness of 15 μm due to the same adhesive as above,
After applying the adhesive for the adhesive layer (3A) that gives an adhesive strength of 3.9 N / 25 mm for the glass adherend, it is dried in a hot air circulation oven at 90 ° C for 2 minutes, and then (2) / (3A An intermediate processed product having a layer structure of (1) was obtained.

A second peeling film which is lightly peeled off for temporary protection from the primary processed product having the layer structure of (1) / (3A) / (2) obtained above.
While peeling off (2), (2) / (3
The adhesive layer (3A) side of the intermediate processed product having the layer constitution of (A) is pasted, and then this is aged for 7 days under the condition of a temperature of 30 ° C. to give an adhesive layer (3A) / (3A) By promoting the curing of (1) / (3A) / (3A) / (2), the layer structure (effectively 30μ thick
An adhesive transfer tape having a single composition of m (3A) was prepared.

Comparative Example 2 As a pressure-sensitive adhesive, the pressure-sensitive adhesive layer of Example 1 having an adhesive force of 8.8 N / 25 mm for a glass adherend when the thickness is 15 μm.
A pressure-sensitive adhesive transfer tape having a layer structure of (1) / (3B) / (2) was prepared in the same manner as in Example 2 except that the pressure-sensitive adhesive for (3B) was applied so as to have a dry standard of 30 μm. It was made.

Comparative Example 3 In Comparative Example 2, when laminated on a polarizing plate, the pressure-sensitive adhesive surface was subjected to corona treatment and then laminated on a polarizing plate to obtain a polarizing plate laminate.

Reference Example 1 In the same manner as in Example 1 except that the second release film (2) was used for both two release films,
An adhesive transfer tape having a layer structure of (2) / (3A) / (3B) / (2) was produced.

<Evaluation of pressure-sensitive adhesive transfer tape> Peeling of the light-peeling second release film (2) from the pressure-sensitive adhesive transfer tapes obtained in Examples 1 to 3, Comparative Examples 1 to 3 and Reference Example 1 above Force, heavy release first release film (1) release force, adhesive layer
The presence or absence of tear separation in (3) and the total light transmittance of the adhesive were measured or evaluated.

The light-peeling second release film (2) of the obtained pressure-sensitive adhesive transfer tape was peeled off and adhered to the polarizing plate (4) to prepare a polarizing plate laminate. The first release film (1) for heavy release remaining in the polarizing plate laminate was peeled off, adhered to a glass plate, and autoclaved for 20 minutes at 50 ° C. and 5 atm. The presence or absence of adhesive residue on the glass plate surface when the polarizing plate was peeled off was examined.

(Peeling Force of Lightly Peeling Second Peeling Film (2)) The pressure-sensitive adhesive transfer tape was cut into a width of 50 mm, and the light peeling second peeling film (2) was cut by 180 ° using a peeling tester.
The peel resistance was measured when peeled at a speed of 300 mm / min.

(Peeling force of the first peeling film (1) for heavy peeling) Second peeling film (2) for light peeling of the adhesive transfer tape
Was peeled off, and a 38 μm-thick polyester film was attached to the adhesive surface. This is cut into a width of 50 mm, and using a peeling tester, the first peeling film (1) for heavy peeling is 180 °
The peel resistance was measured when peeled at a speed of 300 mm / min.

(Presence / absence of tearing of the adhesive layer (3)) The second release film (2) for light release of the adhesive transfer tape was set at 180 °
When peeling was performed with a peel at a speed of 300 mm / min and a speed of 1 m / min, it was visually observed whether the pressure-sensitive adhesive remained on the light-peeling second release film (2). If the second release film (2) had a part of the adhesive remaining, it was determined that the adhesive did not separate, and if the adhesive did not separate, it was determined to be good.

(Appearance of glass-bonded product) The appearance of the sample after the autoclave treatment was observed. Those having no bubbles or floating between the polarizing plate and the pressure sensitive adhesive or between the glass and the pressure sensitive adhesive were judged to be good.

(Adhesiveness) The autoclaved sample was aged for 7 days at 23 ° C. and 50% RH, and a notch having a width of 25 mm was made on the polarizing plate (4) side (polarizing plate (4) Then, using a peeling tester, the resistance value when the polarizing plate was peeled from the glass plate at a peel angle of 180 ° and a speed of 300 mm / min was measured to obtain the adhesive strength.

(Presence or absence of adhesive residue on the surface of the glass plate) With respect to the sample for which the adhesive strength test was completed, the surface of the glass plate after peeling off the polarizing plate (4) was visually observed to see if there was adhesive residue. Examined. Those without adhesive residue were judged to be good.

(Total Light Transmittance of Adhesive Layer) The light release second release film (2) of the adhesive transfer tape was peeled off to obtain a thickness of 3
The total light transmittance was measured with a transmittance measuring device according to JIS K7105 in a state where it was bonded to a quartz plate having a size of mm and then the first peeling film (1) for heavy peeling was peeled off.

(Results) The results are shown in Tables 1 and 2. ○
Is good and x is bad. "MN" of peeling force unit
Is "millinewton", and "N" in the unit of adhesive force is newton.

[0082]

[Table 1]      Example 1 Example 2 Example 3   Peeling force W on the light peeling side₂        59 61 72   (mN / 50mm)   Peeling force W on heavy peeling side₁       135 127 140   (mN / 50mm)   W ₁ / W ₂ ratio 2.3 2.1 1.9   Presence or absence of tearing off of adhesive ○ None ○ None ○ None   Appearance of glass bonded product ○ No bubbles ○ No bubbles ○ No bubbles   Adhesive strength (N / 25mm) 5.2 5.4 3.9   Presence or absence of adhesive residue ○ None ○ None ○ None   Total light transmittance (%) 96 96 95

[0083]

[Table 2]      Comparative Example 1 Comparative Example 2 Comparative Example 3 Reference Example 1   Peeling force W on the light peeling side₂        66 44 44 57^#   (mN / 50mm)   Peeling force W on heavy peeling side₁       145 137 137 46^#   (mN / 50mm)   W ₁ / W ₂ ratio 2.2 3.1 3.1 0.8   Presence or absence of separation of adhesives ○ None ○ None ○ None × Yes   Appearance of glass bonded product ○ No bubbles ○ No bubbles ○ No bubbles −   Adhesive strength (N / 25mm) 4.9 5.4 8.0 −   Presence of adhesive residue × Partial × Almost all surface × Partial −   Yes yes yes yes   Total light transmittance (%) 96 95 95 −   (note)^# Partial tearing of the adhesive occurred when measuring the peeling force. Also, the adhesive       Heavy peeling Peeled off from the expected surface.   (Note) In Reference Example 1, because the adhesive broke up, a polarizing plate bonding test was conducted.       Could not be done.

(Analysis) As shown in Table 1, when the pressure-sensitive adhesive transfer tapes of Examples 1 to 3 having two or more pressure-sensitive adhesive layers having different pressure-sensitive adhesive strengths were used, the release film of the pressure-sensitive adhesive transfer tape itself was used. Has a good peeling property, has a good appearance when laminated on a glass plate after being laminated on a polarizing plate, and is also an adhesive when the polarizing plate is peeled off from the glass plate. Was not left on the glass surface and the reworkability was good.

On the other hand, in the pressure-sensitive adhesive transfer tapes of Comparative Examples 1 to 3 using one type of pressure-sensitive adhesive, the peelability of the release film of the pressure-sensitive adhesive transfer tape itself was good, but When it was laminated on a plate to form a polarizing plate laminate and then laminated on a glass plate, and then the polarizing plate was peeled off from the glass plate, the adhesive remained on the glass surface, resulting in poor reworkability. Also, in Comparative Example 3 in which adhesion of the pressure-sensitive adhesive transfer tape to the polarizing plate was improved by performing corona treatment on the pressure-sensitive adhesive surface when the pressure-sensitive adhesive transfer tape was attached to the polarizing plate.
When the polarizing plate was peeled from the glass plate, the pressure-sensitive adhesive remained on the glass surface, resulting in insufficient reworkability.

In the pressure-sensitive adhesive transfer tape of Reference Example 1 in which the same two release films were used,
The adhesive was weeping and could not be used as a normal tape.

Example 4 FIG. 3 is a sectional view showing still another example of the pressure-sensitive adhesive transfer tape of the present invention.

In Example 1, on one surface of the substrate (1a) for the first release film (1) for heavy release, a silicate compound type antistatic agent (“Colcoat Co. N-103X ") as solids.
After coating so as to be 05 g / m ² , it was dried for 30 seconds in a hot air circulation type oven at 120 ° C. to form an antistatic layer (1c). Thereafter, silicone was applied to the antistatic layer (1c) side in the same manner as in Example 1, dried and cured, and the release treatment layer was applied.
(1b) was formed to obtain a first release film (1).

Using this first release film (1), a pressure-sensitive adhesive transfer tape was produced in the same manner as in Example 1. The surface resistance of the release surface of the first release film (1) for heavy release of the obtained pressure-sensitive adhesive transfer tape was measured using "HIRESTA IP" manufactured by Mitsubishi Petrochemical Co., Ltd., and it was 5.6 × 10 ⁹ It was Ω.

[0090]

The pressure-sensitive adhesive transfer tape of the present invention comprises:
Since two or more adhesive layers (3A) and (3B) with different adhesive strengths are provided between the two release films (1) and (2), the release property of the release film of the adhesive transfer tape itself is improved. Is good, and the appearance when it is attached to a polarizing plate or retardation plate to form a polarizing plate laminate or a retardation plate laminate and then attached to a liquid crystal display substrate (glass substrate or plastics substrate) Further, the adhesive does not remain on the glass surface even when the polarizing plate or the retardation plate is peeled from the substrate, and the reworkability is good.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a process for producing an optical laminate using the pressure-sensitive adhesive transfer tape of the present invention.

FIG. 2 is a cross-sectional view showing another example of the pressure-sensitive adhesive transfer tape of the present invention.

FIG. 3 is a cross-sectional view showing still another example of the pressure-sensitive adhesive transfer tape of the present invention.

[Explanation of symbols]

(1) The first release film (of heavy release), (1a) ... Base material, (1b) ... Peeling treatment layer, (1c) ... antistatic layer, (2)… (light release) second release film, (2a) ... Base material, (2b) ... Peeling treatment layer (2c) ... Antistatic layer (not shown in the figure), (3) ... adhesive layer, (3A) ... adhesive layer, (3B) ... adhesive layer, (3C) ... adhesive layer, (4)… Liquid crystal display members (polarizing plate, retardation plate)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B32B 27/00 B32B 27/00 MF term (reference) 2H049 BA02 BA06 BB54 BB67 BC22 2H091 FA08X FA08Z FA11X FA11Z FB02 FB12 FB13 FC01 FC14 FC21 FD06 GA01 GA17 KA10 LA02 LA07 LA09 LA12 4F100 AH06 AK41D AK42 AR00D AR00E AT00A BA03 BA05 BA07 BA10A BA10C BA10E BA26B BA26C CA17 CB01 CB05B CB05C EJ37D GB41 JL14D JL14E YY00D YY00E 4J004 AA05 AA10 AA11 AB01 BA03 DA02 DA03 DB03 EA05 FA10 4J040 CA001 DF041 EK031 JA09 JB09 NA17 PA27

Claims (9)

[Claims] 1. An adhesive layer on a liquid crystal display member (4)
(3) A laminate in which (3) is laminated, (a) the pressure-sensitive adhesive layer (3) comprises two or more pressure-sensitive adhesive layers having different adhesive strengths, and (b) two or more pressure-sensitive adhesive layers. The adhesive layers on both sides of the adhesive layer (3) are referred to as adhesive layers (3A) and (3B), and when the magnitude of the adhesive strength is viewed as the adhesive strength to glass, the adhesive strength is relatively large. When the pressure-sensitive adhesive layer is a small adhesive layer (3A), and the pressure-sensitive adhesive layer having a relatively high adhesive strength is the pressure-sensitive adhesive layer (3B), the latter has a relatively high pressure-sensitive adhesive layer (3B). Two or more pressure-sensitive adhesive layers so that the side closer to the liquid crystal display member (4)
(3) The optical laminate, wherein (3) is attached to the liquid crystal display member (4) in a laminated state. 2. The optical laminate according to claim 1, wherein the first release film (1) is laminated on the adhesive layer (3A) having a relatively small adhesive force. 3. The optical laminate according to claim 1, wherein the liquid crystal display member (4) is a polarizing plate or a retardation plate. 4. An adhesive layer on a liquid crystal display member (4)
A tape for pressure-sensitive adhesive transfer for sticking (3) to produce an optical laminate, which comprises a release film (1) comprising two pressure-sensitive adhesive layers (3),
A pressure-sensitive adhesive transfer tape having a structure sandwiched between (2) and the pressure-sensitive adhesive layer (3) comprising two or more pressure-sensitive adhesive layers having different adhesive strengths. 5. The both outer of two or more layers of pressure-sensitive adhesive layer (3) Viscosity
When the pressure-sensitive adhesive layer is the pressure-sensitive adhesive layers (3A) and (3B), and the magnitude of the pressure-sensitive adhesive force is viewed by the magnitude of the adhesive strength to glass, the pressure-sensitive adhesive layer having a relatively low pressure-sensitive adhesive force is used. 3A), when the pressure-sensitive adhesive layer having a relatively high adhesive force is used as the pressure-sensitive adhesive layer (3B), the two release films (1) and (2) have different release force weights. , And the adhesive layer (3A) having a relatively small adhesive force is located on the side of the first release film (1) having a relatively heavy peeling force, while the adhesive force is relatively small. Large adhesive layer (3
The pressure-sensitive adhesive transfer tape according to claim 4, wherein B) is arranged on the side of the second release film (2) having a relatively light release force. 6. A peeling force between the first peeling film (1) having a relatively heavy peeling force and the pressure-sensitive adhesive layer (3A) is W ₁ , and a second peeling film having a relatively light peeling force ( 2) and adhesive layer
When the peeling force from (3B) is W ₂ , W ₁ / W ₂ =
The pressure-sensitive adhesive transfer tape according to claim 5, which is designed to have a thickness of 1.5 / 1 to 5/1. 7. The base material (1a) constituting the first release film (1) having a relatively heavy release force is composed of a uniaxially stretched polyester film having a maximum strain of the orientation main axis of 10 degrees or less. The pressure-sensitive adhesive transfer tape according to claim 5. 8. The optical laminate according to claim 1, wherein the remaining laminate obtained by peeling one release film from the pressure-sensitive adhesive transfer tape according to claim 4 is attached to a liquid crystal display member (4). A method for producing an optical laminate, which comprises: 9. The liquid crystal display member (4) is pasted with the remaining laminate obtained by peeling off the second release film (2) having a relatively light release force from the pressure-sensitive adhesive transfer tape according to claim 5. A method for producing an optical laminate, comprising producing the optical laminate according to claim 2.