JPWO2020085308A1 - Orientation film for transfer of liquid crystal compound alignment layer - Google Patents

Abstract

Provided is a transfer film for transferring a liquid crystal compound alignment layer, which can form a retardation layer or a polarizing layer (liquid crystal compound alignment layer) in which defects such as pinholes are reduced. do. An alignment film for transferring a liquid crystal compound alignment layer to an object, characterized in that the surface roughness (SRa) of the release surface of the alignment film is 1 nm or more and 30 nm or less, or the alignment film of the alignment film. The surface roughness (SRa) of the surface opposite to the release surface is 1 nm or more and 50 nm or less, and the 10-point surface roughness (SRz) of the surface opposite to the release surface of the alignment film is 10 nm or more. It is characterized in that it is 1500 nm or less.

Description

The present invention relates to a transfer film for transferring a liquid crystal compound oriented layer. More specifically, when manufacturing a polarizing plate such as a circular polarizing plate or a retardation plate in which a retardation layer composed of a liquid crystal compound alignment layer is laminated, or when manufacturing a polarizing plate having a polarizing layer composed of a liquid crystal compound alignment layer. The present invention relates to a transfer film for transferring a liquid crystal compound oriented layer, which is used in the above.

Conventionally, in an image display device, a circularly polarizing plate is arranged on the panel surface of the image display panel on the viewer side in order to reduce the reflection of external light. This circular polarizing plate is composed of a laminate of a linear polarizing plate and a retardation film such as λ / 4, and converts external light toward the panel surface of the image display panel into linearly polarized light by the linear polarizing plate, followed by λ /. It is converted to circularly polarized light by a retardation film of 4 mag. When the external light due to circularly polarized light is reflected on the surface of the image display panel, the rotation direction of the polarizing surface is reversed, and on the contrary, this reflected light is shielded by a linear polarizing plate by a retardation film such as λ / 4. Since it is converted to linearly polarized light in the direction of light and then shielded by a linear polarizing plate, emission to the outside is suppressed. As described above, as the circularly polarizing plate, one in which a retardation film such as λ / 4 is bonded to the polarizing plate is used.

As the retardation film, a single retardation film such as cyclic olefin (see Patent Document 1), polycarbonate (see Patent Document 2), and a stretched film of triacetyl cellulose (see Patent Document 3) is used. Further, as the retardation film, a retardation film of a laminate having a retardation layer made of a liquid crystal compound on a transparent film (see Patent Documents 4 and 5) is used. In the above, it is described that the liquid crystal compound may be transferred when the retardation layer (liquid crystal compound orientation layer) made of the liquid crystal compound is provided.

Further, a method of producing a retardation film by transferring a retardation layer made of a liquid crystal compound to a transparent film is known in Patent Document 6 and the like. A method is also known in which a retardation layer made of a liquid crystal compound such as λ / 4 is provided on a transparent film by such a transfer method to form a λ / 4 film (see Patent Documents 7 and 8).

In these transfer methods, various base materials for transfer have been introduced, and among them, transparent resin films such as polyester, triacetyl cellulose, and cyclic polyolefin are often exemplified.

However, when a retardation layer laminated polarizing plate (circular polarizing plate) manufactured by using these transparent resin films as a film base material for transfer is used for antireflection of an image display device, it has a pinhole shape or scratches. Light leakage may occur, which has been a problem.

Further, a method of manufacturing a polarizing plate by transferring a polarizing layer (liquid crystal compound alignment layer) containing a liquid crystal compound laminated on a transfer film and a dichroic dye to a protective film is also known. In the same manner as described above, light leakage may occur in the form of pinholes or on scratches, which has been a problem.

Japanese Unexamined Patent Publication No. 2012-56222 Japanese Unexamined Patent Publication No. 2004-144943 Japanese Unexamined Patent Publication No. 2004-46166 Japanese Unexamined Patent Publication No. 2006-243653 Japanese Unexamined Patent Publication No. 2001-4837 Japanese Unexamined Patent Publication No. 4-57017 Japanese Unexamined Patent Publication No. 2014-071381 Japanese Unexamined Patent Publication No. 2017-146616

The present invention has been made against the background of the problems of the prior art. That is, an object of the present invention is a transfer film for transferring a liquid crystal compound alignment layer, and forms a retardation layer or a polarizing layer (liquid crystal compound alignment layer) in which defects such as pinholes are reduced. It is intended to provide a transfer film capable of providing a transfer film.

In order to achieve such an object, the present inventor has provided a pinhole or the like on a retardation layer laminated polarizing plate (circular polarizing plate) manufactured by using a transparent resin film such as a polyester film as a film base material for transfer. We examined the causes of the defects. As a result, the microstructure on the surface of these film substrates has a great influence on the orientation state and retardation of the liquid crystal compounds in the retardation layer composed of the liquid crystal compounds formed on these film substrates, and the design It has been found that there are cases where the orientation state and phase difference are not obtained as they are, and as a result, defects such as pinholes occur. Then, the present inventor pays attention to the surface roughness of the film base material represented by a specific parameter among these microstructures, and uses the film base material in which the surface roughness is controlled within a specific range. As a result, it has been found that a retardation layer or a polarizing layer (liquid crystal compound orientation layer) can be formed in which the occurrence of defects such as pinholes is reduced without causing the above-mentioned conventional problems, and the first invention is completed. It came to.

Further, since the film base material is usually stored and supplied in a rolled state after production, the release surface of the film base material (from the liquid crystal compound among the two surfaces of the film base material) during that time is provided. The surface on which the retardation layer or polarizing layer is formed) and the surface on the opposite side (back surface) are in contact with each other under pressure, and the microstructure on the back surface may be transferred to the release surface. It was found that the influence of the microstructure on the back surface is also large. Then, the present inventor pays attention to the surface roughness of the film base material represented by a specific parameter among the microstructures on the back surface, and uses the film base material in which the surface roughness is controlled within a specific range. By doing so, it was found that a retardation layer or a polarizing layer (liquid crystal compound orientation layer) in which the occurrence of defects such as pinholes is reduced can be formed without causing the above-mentioned conventional problems, and the second invention is completed. It came to.

That is, the first invention has the following configurations (1) to (9).
(1) An alignment film for transferring a liquid crystal compound alignment layer to an object, characterized in that the surface roughness (SRa) of the release surface of the alignment film is 1 nm or more and 30 nm or less. Orientation film for layer transfer.
(2) The alignment film for liquid crystal compound alignment layer transfer according to (1), wherein the 10-point surface roughness (SRz) of the release surface of the alignment film is 5 nm or more and 200 nm or less.
(3) The alignment film for transferring a liquid crystal compound alignment layer according to (1) or (2), wherein the alignment film is a polyester film.
(4) A liquid crystal compound alignment layer in which a liquid crystal compound alignment layer and an alignment film are laminated, wherein the alignment film is the alignment film according to any one of (1) to (3). Laminate for transfer.
(5) It is characterized by including a step of laminating the polarizing plate and the liquid crystal compound alignment layer surface of the laminate according to (4) to form an intermediate laminate, and a step of peeling the alignment film from the intermediate laminate. A method for producing a liquid crystal compound oriented layer laminated polarizing plate.
(6) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film. The liquid crystal compound alignment layer comprises a step of irradiating linearly polarized light having an electric field vibration direction parallel to the flow direction or from the alignment film surface of the laminated body and receiving light on the liquid crystal compound alignment layer surface side. A method for inspecting a laminate for transfer.
(7) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), which is a step of irradiating elliptically polarized light from the liquid crystal compound alignment layer surface of the laminate and receiving light on the alignment film surface side. A method for inspecting a laminate for transferring a liquid crystal compound oriented layer, which comprises.
(8) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film. A step of irradiating linearly polarized light having an electric field vibration direction parallel to the flow direction from the alignment film surface of the laminate, and light transmitted through the laminate are provided on the liquid crystal compound alignment layer side of the laminate. A method for inspecting a laminated body for transferring a liquid crystal compound oriented layer, which comprises a step of reflecting the reflected light by a mirror-finished reflecting plate and a step of receiving the reflected light on the alignment film side.
(9) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), at least a step of irradiating the laminate with polarized light to allow the polarized light to pass through the laminate, and a laminate. Including the step of receiving the polarized light passing through the aligned body, the polarized light passing through the alignment film of the laminated body is in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film, or in the flow direction. Inspection of a laminated body for liquid crystal compound oriented layer transfer, characterized in that it is linearly polarized light having an electric field vibration direction parallel to the orthogonal direction, or the polarized light passing through the liquid crystal compound oriented layer surface of the laminated body is elliptically polarized light. Method.

The second invention has the following configurations (1) to (9).
(1) An alignment film for transferring a liquid crystal compound alignment layer to an object, in which the surface roughness (SRa) of the surface opposite to the release surface of the alignment film is 1 nm or more and 50 nm or less, and An alignment film for transferring a liquid crystal compound alignment layer, characterized in that the 10-point surface roughness (SRz) of the surface opposite to the release surface of the alignment film is 10 nm or more and 1500 nm or less.
(2) The alignment film for liquid crystal compound alignment layer transfer according to (1), wherein the maximum height (SRy) of the surface opposite to the release surface of the alignment film is 15 nm or more and 2000 nm or less.
(3) The alignment film for transferring a liquid crystal compound alignment layer according to (1) or (2), wherein the alignment film is a polyester film.
(4) A liquid crystal compound alignment layer in which a liquid crystal compound alignment layer and an alignment film are laminated, wherein the alignment film is the alignment film according to any one of (1) to (3). Laminate for transfer.
(5) It is characterized by including a step of laminating the polarizing plate and the liquid crystal compound alignment layer surface of the laminate according to (4) to form an intermediate laminate, and a step of peeling the alignment film from the intermediate laminate. A method for producing a liquid crystal compound oriented layer laminated polarizing plate.
(6) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film. The liquid crystal compound alignment layer comprises a step of irradiating linearly polarized light having an electric field vibration direction parallel to the flow direction or from the alignment film surface of the laminated body and receiving light on the liquid crystal compound alignment layer surface side. A method for inspecting a laminate for transfer.
(7) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), which is a step of irradiating elliptically polarized light from the liquid crystal compound alignment layer surface of the laminate and receiving light on the alignment film surface side. A method for inspecting a laminate for transferring a liquid crystal compound oriented layer, which comprises.
(8) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film. A step of irradiating linearly polarized light having an electric field vibration direction parallel to the flow direction from the alignment film surface of the laminate, and light transmitted through the laminate are provided on the liquid crystal compound alignment layer side of the laminate. A method for inspecting a laminated body for transferring a liquid crystal compound oriented layer, which comprises a step of reflecting the reflected light by a mirror-finished reflecting plate and a step of receiving the reflected light on the alignment film side.
(9) The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to (4), at least a step of irradiating the laminate with polarized light to allow the polarized light to pass through the laminate, and a laminate. Including the step of receiving the polarized light passing through the aligned body, the polarized light passing through the alignment film of the laminated body is in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film, or in the flow direction. Inspection of a laminated body for liquid crystal compound oriented layer transfer, characterized in that it is linearly polarized light having an electric field vibration direction parallel to the orthogonal direction, or the polarized light passing through the liquid crystal compound oriented layer surface of the laminated body is elliptically polarized light. Method.

According to the present invention, by using a film whose surface roughness is controlled within a specific range as an alignment film for transfer of a retardation layer or a polarizing layer, the surface of the surface opposite to the release surface is further formed. By using a film whose roughness is controlled within a specific range as an alignment film for transfer of the retardation layer and the polarizing layer, the orientation state and retardation of the liquid crystal compounds in the retardation layer and the polarizing layer can be adjusted as designed. Therefore, it is possible to form a retardation layer or a polarizing layer (liquid crystal compound orientation layer) in which the occurrence of defects such as pinholes is reduced.

The oriented polyester film of the present invention is for transferring a liquid crystal compound oriented layer to an object (another transparent resin film, a polarizing plate, etc.), and in the first invention, the surface roughness of the release surface of the oriented film (SRa) is 1 nm or more and 30 nm or less, and in the second invention, the surface roughness (SRa) of the surface opposite to the release surface of the alignment film is 1 nm or more and 50 nm or less. It is a feature. When an oligomer block coat layer, a release layer, a flattening coat layer, an easy-slip coat layer, an antistatic coat layer, etc., which will be described later, are provided, these layers may be referred to as an alignment film.

The resin constituting the film base material used for the alignment film is not particularly limited as long as it can maintain the strength of the alignment film as the base material, but among them, polyester, polycarbonate, polystyrene, polyamide, polypropylene, cyclic polyolefin, and triacetyl. Polystyrene is preferable, and polyethylene terephthalate, cyclic polyolefin, and triacetyl cellulose are particularly preferable.

The alignment film of the present invention may be composed of a single layer or a plurality of coextruded layers. In the case of multiple layers, the surface layer (release surface side layer A) / back surface side layer (B), A / intermediate layer (C) / A (the release surface side layer and the back surface side layer are the same), A / C A configuration such as / B, etc. can be mentioned.

When the film is stretched, it may be uniaxially stretched, weakly biaxially stretched (stretched in the biaxial direction but weak in one direction), or biaxially stretched, but the orientation direction is wide in the width direction. Uniaxial stretching or weak biaxial stretching is preferable in terms of being able to keep the amount constant. In the case of weak biaxial stretching, it is preferable that the main orientation direction is the stretching direction of the subsequent stage. In the case of uniaxial stretching, the stretching direction may be the flow direction of film production (longitudinal direction) or the direction orthogonal to the flow direction (horizontal direction).
In the case of biaxial stretching, simultaneous biaxial stretching or sequential biaxial stretching may be used. Stretching in the longitudinal direction is preferably stretched by roll groups having different speed differences, and stretching in the lateral direction is preferably tenter stretching.

The transfer alignment film is industrially supplied in a roll around which the film is wound. The lower limit of the roll width is preferably 30 cm, more preferably 50 cm, still more preferably 70 cm, particularly preferably 90 cm, and most preferably 100 cm. The upper limit of the roll width is preferably 5000 cm, more preferably 4000 cm, and even more preferably 3000 cm.

The lower limit of the roll length is preferably 100 m, more preferably 500 m, and even more preferably 1000 m. The upper limit of the roll length is preferably 100,000 m, more preferably 50,000 m, and even more preferably 30,000 m.

(Roughness of mold release surface)
The release surface (surface of layer A) of the alignment film for transfer of the present invention is preferably smooth. In the present invention, the "separation surface" of the alignment film means the surface of the alignment film intended to be provided with the liquid crystal compound alignment layer to which the alignment film is transferred. When an oligomer block coat layer, a flattening coat layer, a release layer, etc., which will be described later, are provided, if a liquid crystal compound orientation layer is provided on this, these oligomer block coat layers, a flattening layer, a release layer, etc. The surface (the surface in contact with the liquid crystal compound alignment layer) is the "separation surface" of the alignment film.

The lower limit of the three-dimensional arithmetic mean roughness (SRa) of the release surface of the alignment film for transfer of the present invention is preferably 1 nm, more preferably 2 nm. If it is less than the above, it may be difficult to achieve the numerical value in reality. The upper limit of SRa of the release surface of the alignment film for transfer of the present invention is preferably 30 nm, more preferably 25 nm, further preferably 20 nm, particularly preferably 15 nm, and most preferably 10 nm. be.

The lower limit of the three-dimensional ten-point average roughness (SRz) of the release surface of the alignment film for transfer of the present invention is preferably 5 nm, more preferably 10 nm, and further preferably 13 nm. The upper limit of SRz of the release surface of the alignment film for transfer of the present invention is preferably 200 nm, more preferably 150 nm, further preferably 120 nm, particularly preferably 100 nm, and most preferably 80 nm. be.

The lower limit of the maximum height of the release surface (SRy: maximum height of the release surface SRp + maximum depth of the release surface SRv) of the alignment film for transfer of the present invention is preferably 10 nm, more preferably 15 nm. More preferably, it is 20 nm. The upper limit of SRy of the release surface of the alignment film for transfer of the present invention is preferably 300 nm, more preferably 250 nm, further preferably 150 nm, particularly preferably 120 nm, and most preferably 100 nm. be.

The upper limit of the number of protrusions having a height difference of 0.5 μm or more on the release surface of the alignment film for transfer of the present invention is preferably 5 / m ² , more preferably 4 / m ² , and even more preferably 3. Pieces / m ² , particularly preferably 2 pieces / m ² , and most preferably 1 piece / m ² .

When the roughness of the release surface exceeds the above range, the minute portion of the liquid crystal compound alignment layer formed on the transfer orientation film of the present invention does not have the alignment state or phase difference as designed, and is pinhole-shaped or Scratch-like defects may occur. The reason for this is considered as follows. First, as will be described later, an orientation control layer such as a rubbing treatment orientation control layer or a photoalignment control layer can be provided between the transfer orientation film and the liquid crystal compound orientation layer, and this orientation control layer is a rubbing treatment. In the case of the orientation control layer, it is considered that the cause of the defect is that the orientation control layer of the convex portion is peeled off at the time of rubbing and the rubbing of the foot portion and the concave portion of the convex portion is insufficient. In addition, when the release surface layer contains particles, it is considered that the particles fall off during rubbing and damage the surface, which is also a cause of defects. Further, regardless of whether the rubbing treatment orientation control layer or the photoorientation control layer is provided, when the film is wound with the orientation control layer provided, the film is rubbed against the back surface layer, resulting in holes in the alignment control layer of the convex portion. It is also considered that the defect is caused by the fact that the film is vacant or the orientation is disturbed by the pressure. Due to these defects in the orientation control layer, when the liquid crystal compound alignment layer is provided on the orientation control layer, the orientation of the liquid crystal compound does not occur properly in the minute portion thereof, and the orientation state and phase difference as designed cannot be obtained, and as a result. It is considered that pinhole-like and scratch-like defects occur.

Further, even when the liquid crystal compound alignment layer is directly formed on the transfer alignment film without providing the alignment control layer, the thickness of the liquid crystal compound alignment layer is formed at the convex portion of the release surface of the alignment film when the liquid crystal compound is applied. It is also considered that the cause of the defect is that the phase difference as designed cannot be obtained because the thickness of the liquid crystal compound alignment layer becomes thicker at the concave portion of the release surface of the alignment film.

In order to make the roughness of the release surface (A) within the above range, the following method can be mentioned when the alignment film for transfer of the present invention is a stretched film.
-It is assumed that the release surface side layer (surface layer) of the original film does not contain particles.
-If the release surface side layer (surface layer) of the original film contains particles, use particles with a small particle size.
-If the release surface side layer (surface layer) of the original film contains particles, a flattening coat is provided.
In the present invention, the "release surface side layer" of the alignment film means a layer in which the release surface exists among each layer of the resin constituting the alignment film. Here, even when the film is a single layer, it may be referred to as a release surface side layer. In this case, the back surface side layer and the release surface side layer, which will be described later, are the same layer.

In addition to the above, it is also important to clean the raw materials and manufacturing process as follows.
-Filter the particle slurry during polymerization. Filter before chipping.
-Clean the chipped cooling water. Clean the environment from chip transfer to introduction of the film-forming machine.
-During film formation, filter the molten resin to remove aggregated particles and foreign matter.
-Filter the coating agent to remove foreign matter.
・ Perform in a clean environment during film formation, coating, and drying.

The surface layer is preferably substantially free of particles for smoothing. Substantially free of particles means that the particle content is less than 50 ppm, preferably less than 30 ppm.

The surface layer may contain particles in order to increase the slipperiness of the surface. When particles are included, the lower limit of the surface particle content is preferably 50 ppm, more preferably 100 ppm. The upper limit of the surface particle content is preferably 20000 ppm, more preferably 10000 ppm, still more preferably 8000 ppm, and particularly preferably 6000 ppm. If it exceeds the above, the roughness of the surface layer may not be within a preferable range.

The lower limit of the surface particle size is preferably 0.005 μm, more preferably 0.01 μm, and even more preferably 0.02 μm. The upper limit of the surface particle size is preferably 3 μm, more preferably 1 μm, still more preferably 0.5 μm, and particularly preferably 0.3 μm. If it exceeds the above, the roughness of the surface layer may not be within a preferable range.

Even when the surface layer does not contain particles or has particles having a small particle size, if the lower layer contains particles, the roughness of the release surface layer may increase due to the influence of the particles in the lower layer. In such a case, it is preferable to take a method such as increasing the thickness of the release surface layer or providing a lower layer (intermediate layer) containing no particles.

The lower limit of the surface layer thickness is preferably 0.1 μm, more preferably 0.5 μm, further preferably 1 μm, particularly preferably 3 μm, and most preferably 5 μm. The upper limit of the surface layer thickness is preferably 97%, more preferably 95%, and even more preferably 90% with respect to the total thickness of the alignment film for transfer.

The particle-free intermediate layer is substantially particle-free, and the particle content is less than 50 ppm, preferably less than 30 ppm. The lower limit of the thickness of the intermediate layer with respect to the total thickness of the transfer alignment film is preferably 10%, more preferably 20%, still more preferably 30% with respect to the total thickness of the transfer alignment film. The upper limit is preferably 95%, more preferably 90%.

If the surface layer of the alignment film for transfer has a high roughness, a flattening coat may be provided. Examples of the resin used for the flattening coat include those generally used as a resin for a coating agent such as polyester, acrylic, polyurethane, polystyrene, and polyamide. It is also preferable to use a cross-linking agent such as melamine, isocyanate, epoxy resin, or oxazoline compound. These are coated and dried as a coating agent dissolved or dispersed in an organic solvent or water. Alternatively, in the case of acrylic, it may be coated without a solvent and cured by radiation. The flattening coat may be an oligomer block coat. When the release layer is provided with a coat, the release layer itself may be thickened.

The lower limit of the thickness of the surface flattening coat layer is preferably 0.01 μm, more preferably 0.1 μm, still more preferably 0.2 μm, and particularly preferably 0.3 μm. If it is less than the above, the flattening effect may be insufficient. The upper limit of the thickness of the surface flattening coat layer is preferably 10 μm, more preferably 7 μm, further preferably 5 μm, and particularly preferably 3 μm. Even if it exceeds the above, a further flattening effect may not be obtained.

The flattening coat may be provided as an in-line coat during the film forming process, or may be separately provided offline.

(Roughness on the back side)
Further, even if the release surface of the transfer alignment film of the present invention is smoothed, a defect may occur in the liquid crystal compound alignment layer. This is because the alignment film for transfer is supplied in a rolled state, and the release surface and the back surface are in contact with each other, and the roughness of the back surface is transferred to the release surface (convex on the back surface to the release layer). It was found that this was because the portion was transferred to form a recess). The transfer alignment film provided with the liquid crystal compound alignment layer may be wound by laminating a masking film in order to protect the liquid crystal compound alignment layer, but is often wound as it is for cost reduction. When the liquid crystal compound alignment layer is wound in this way, it is considered that the liquid crystal compound alignment layer is dented, has holes, or the orientation is disturbed due to the convex portion on the back surface. Further, even when the liquid crystal compound alignment layer is provided later instead of being wound with the liquid crystal compound alignment layer provided, a phenomenon occurs in which a hole is formed in the liquid crystal compound alignment layer due to the convex portion on the back surface and the orientation is disturbed. It is thought that it is. In particular, the pressure is high in the winding core portion, and these phenomena are likely to occur. From the above findings, it was found that the above-mentioned drawbacks can be effectively prevented by keeping the roughness of the surface (back surface) opposite to the release surface within a specific range.

The lower limit of the three-dimensional arithmetic mean roughness (SRa) of the back surface of the alignment film for transfer of the present invention is preferably 1 nm, more preferably 2 nm, still more preferably 3 nm, particularly preferably 4 nm, and most preferably. It is 5 nm. The upper limit of SRa on the back surface of the alignment film for transfer of the present invention is preferably 50 nm, more preferably 45 nm, and even more preferably 40 nm. Beyond the above, there may be many drawbacks.

The lower limit of the three-dimensional ten-point average roughness (SRz) of the back surface of the alignment film for transfer of the present invention is preferably 10 nm, more preferably 15 nm, particularly preferably 20 nm, and most preferably 25 nm. .. The upper limit of SRz on the back surface of the alignment film for transfer of the present invention is preferably 1500 nm, more preferably 1200 nm, further preferably 1000 nm, particularly preferably 700 nm, and most preferably 500 nm. Beyond the above, there may be many drawbacks.

The lower limit of the maximum height (SRy: maximum backside peak height SRp + maximum backside valley depth SRv) of the back surface of the alignment film for transfer of the present invention is preferably 15 nm, more preferably 20 nm, and further preferably 25 nm. , Especially preferably 30 nm, most preferably 40 nm. The upper limit of the maximum height SRy of the back surface of the alignment film for transfer of the present invention is preferably 2000 nm, more preferably 1500 nm, further preferably 1200 nm, particularly preferably 1000 nm, and most preferably 700 nm. Is. Beyond the above, there may be many drawbacks.

The upper limit of the number of protrusions having a height difference of 2 μm or more on the back surface of the alignment film for transfer of the present invention is preferably 5 / m ² , more preferably 4 / m ² , and even more preferably 3 / m ^2. It is particularly preferably 2 pieces / m ² and most preferably 1 piece / m ² . Beyond the above, there may be many drawbacks.

If the roughness of the back surface of the alignment film for transfer of the present invention represented by the above parameters is less than the above range, the slipperiness of the film deteriorates, and it becomes difficult to slip when the film is conveyed by a roll or wound up. , May be easily scratched. In addition, when winding the film during manufacturing, the winding is not stable, wrinkles occur and the product becomes defective, and the unevenness of the end of the wound roll becomes large, so that the film is likely to meander in the next process. Or it becomes easy to break.
If the roughness of the back surface of the alignment film for transfer of the present invention exceeds the above, the above-mentioned drawbacks are likely to occur.

In order to make the roughness of the back surface within the above range, when the alignment film for transfer of the present invention is a stretched film, the following method can be mentioned.
-The back surface side layer (back surface layer) of the original film material contains specific particles.
-Use a film containing particles in the intermediate layer of the original film, and reduce the thickness by assuming that the back surface layer side (back surface layer) does not contain particles.
-If the back surface side layer (back surface layer) of the original film is rough, provide a flattening coat.
-If the back surface side layer (back surface layer) of the original film does not contain particles or the roughness is small, an easy-to-slip coat (particle-containing coat) is provided.

The lower limit of the particle size of the back surface layer is preferably 0.01 μm, more preferably 0.05 μm, and even more preferably 0.1 μm. If it is less than the above, the slipperiness is deteriorated and winding failure may occur. The upper limit of the particle size of the back surface layer is preferably 5 μm, more preferably 3 μm, and even more preferably 2 μm. If it exceeds the above, the back surface may become too rough.

When the back surface contains particles, the lower limit of the particle content in the back surface layer is preferably 50 ppm, more preferably 100 ppm. If it is less than the above, the slippery effect due to the addition of particles may not be obtained. The upper limit of the back layer particle content is preferably 10000 ppm, more preferably 7000 ppm, and even more preferably 5000 ppm. If it exceeds the above, the back surface may become too rough.

The lower limit of the back surface layer thickness is preferably 0.1 μm, more preferably 0.5 μm, further preferably 1 μm, particularly preferably 3 μm, and most preferably 5 μm. The upper limit of the back surface layer thickness is preferably 95%, more preferably 90%, and even more preferably 85% with respect to the total thickness of the alignment film for transfer.

It is also preferable to control the roughness of the back surface by including particles in the intermediate layer and thinning the back surface layer without containing particles. By taking such a form, it is possible to secure the roughness of the back surface while preventing the particles from falling off.

The particle size and the amount of particles added in the intermediate layer are the same as those in the back surface layer. In this case, the lower limit of the thickness of the back surface layer is preferably 0.5 μm, more preferably 1 μm, and even more preferably 2 μm. The upper limit of the thickness is preferably 30 μm, more preferably 25 μm, and even more preferably 20 μm.

When the back surface of the raw film is rough, it is also preferable to provide a flattening coat. As the flattening coat, those listed in the surface flattening coat can be used in the same manner.

The lower limit of the thickness of the back surface flattening coat layer is preferably 0.01 μm, more preferably 0.03 μm, and even more preferably 0.05 μm. If it is less than the above, the flattening effect may be reduced. The upper limit of the thickness of the back surface flattening coat layer is preferably 10 μm, more preferably 5 μm, and even more preferably 3 μm. Even if it exceeds the above, the effect of flattening will be saturated.

The back surface side of the raw film may not contain particles, and an easy-slip coat containing particles may be provided on the back surface side. Further, when the roughness of the back surface of the raw film is small, an easy-slip coat may be provided.

The lower limit of the particle size of the back surface slippery coat layer is preferably 0.01 μm, more preferably 0.05 μm. If it is less than the above, slipperiness may not be obtained. The upper limit of the particle size of the back surface slippery coat layer is preferably 5 μm, more preferably 3 μm, still more preferably 2 μm, and particularly preferably 1 μm. If it exceeds the above, the roughness of the back surface may be too high.

The lower limit of the particle content of the back surface slippery coat layer is preferably 0.1% by mass, more preferably 0.5% by mass, still more preferably 1% by mass, and particularly preferably 1.5% by mass. Most preferably, it is 2% by mass. If it is less than the above, slipperiness may not be obtained. The upper limit of the particle content of the back surface slippery coat layer is preferably 20% by mass, more preferably 15% by mass, and further preferably 10% by mass. If it exceeds the above, the roughness of the back surface may be too high.

The lower limit of the thickness of the back surface slippery coat layer is preferably 0.01 μm, more preferably 0.03 μm, and even more preferably 0.05 μm. The upper limit of the thickness of the back surface slippery coat layer is preferably 10 μm, more preferably 5 μm, further preferably 3 μm, particularly preferably 2 μm, and most preferably 1 μm.

In the above, the case where the alignment film for transfer of the present invention is a stretched film has been described, but the film is not formed by a casting method in which a dope obtained by dissolving triacetyl cellulose or the like in a solvent is developed on a metal belt or the like and the solvent is dried. Even in the case of a stretched film, by adding the particles, unevenness due to the particles is generated on the upper surface (opposite surface of the metal belt) as the solvent is removed, so that the roughness can be adjusted. In this case, it is preferable to reduce the surface roughness of the metal belt and use the metal belt surface as the release surface. In addition, when the dope contains particles, if it is peeled off from the metal belt in a state where the solvent content is high, unevenness due to the particles may appear on the metal belt surface. It is also preferable to peel off. Roughness can also be adjusted at the timing of these peelings. Further, when stretching and drying in a tenter with a small amount of solvent contained, the roughness can be adjusted by a stretching ratio or the like. When particles are not contained, the roughness of the metal belt may be adjusted so that the metal belt surface is the back surface. Further, the roughness may be transferred to the surface while being dried while being passed between rolls having different roughness.

Further, even in the case of an unstretched film formed by casting a molten resin such as COP, the roughness can be adjusted by adding particles. By using particles having a coefficient of thermal expansion different from that of the film resin, such as inorganic particles, it is possible to form irregularities on the surface due to the added particles due to heat shrinkage that occurs during cooling. In this case, it is preferable to reduce the surface roughness of the cooling roll that extrudes the molten resin into a sheet to form a mold release surface. Further, the cooling roll may be roughened to transfer the roughness, and the back surface may be used. Roughness may be transferred between rolls having different roughness at a temperature of Tg or more of the film resin.

As with the stretched film, the roughness of these unstretched films can be adjusted by a smooth coating or an easy-slip coating containing particles.

Next, additional features of the transfer orientation film of the present invention will be described.

(Orientation characteristics and physical properties of the alignment film for transfer)
When the transfer alignment film is an unstretched film and the retardation is almost zero, the alignment state of the liquid crystal compound alignment layer is inspected by irradiating linearly polarized light with the liquid crystal compound alignment layer laminated on the transfer alignment film. be able to. For example, when the liquid crystal compound alignment layer is a retardation layer, the sample is irradiated with linearly polarized light in an oblique direction (for example, 45 degrees) with respect to the slow axis of the retardation layer to be inspected, and the retardation layer becomes elliptically polarized light. Polarized light is passed through another retardation layer and returned to linearly polarized light, and this linearly polarized light is received through a polarizing plate that is in a dimmed state. As a result, when the retardation layer has a pinhole-like defect, the defect can be detected as a bright spot.

On the other hand, when a stretched film or the like has retardation, it may be difficult to inspect the orientation state of the liquid crystal compound orientation layer in a state where the liquid crystal compound orientation layer is laminated due to the influence of the retardation. In the past, it was possible to detect defects such as foreign matter by irradiating unpolarized light with respect to the defects of the retardation layer provided on the alignment film for transfer with retardation, but the drawback of the polarized state is the phase difference. It was necessary to peel off the layer and inspect it alone, or transfer it to a non-polarized material such as glass for inspection.

However, it was found that by using a film having a specific range of the slow phase axis of the film as the alignment film for transfer, the alignment state of the liquid crystal compound alignment layer can be inspected in a state where the liquid crystal compound alignment layer is laminated. ..

Generally, a polarizing element is used in which polyvinyl alcohol is stretched in the flow direction of the film and this is absorbed with a dichroic dye of iodine or an organic compound, and the quenching axis (absorption axis) of the polarizer is the film. It is in the flow direction. In the case of a circularly polarizing plate, the slow axis (orientation direction) of the λ / 4 layer is laminated at 45 degrees with respect to the extinction axis as the retardation layer, or the λ / 4 layer and the λ / 2 layer are obliquely oriented (10). ~ 80 degrees). Further, the optical compensation layer used for the liquid crystal display is also laminated in the oblique direction with respect to the quenching axis of the polarizer.

Therefore, the orientation state of the retardation layer is, for example, irradiating the retardation layer with linearly polarized light having a vibration direction parallel to or perpendicular to the flow direction of the film from the transfer orientation film side, and the retardation layer becomes elliptically polarized light. Inspection (evaluation) is performed by detecting with a light receiving element through a light receiving side retardation plate for returning the emitted light to linearly polarized light and a light receiving side polarizing plate installed in a direction that does not allow the linearly polarized light returned by the retardation plate to pass through. Can be done. On the contrary, the elliptically polarized light may be irradiated from the retardation layer side to detect the light linearly polarized by the retardation layer in the same manner. Specifically, when the retardation layer has a pinhole-like defect, the defect can be detected as a bright spot.

Therefore, when the alignment film for transfer has birefringence, if the orientation direction of the film deviates from the direction parallel to the flow direction of the film (MD direction) or the direction perpendicular to the flow direction (TD direction), the film The linearly polarized light that has passed through the light becomes elliptically polarized light, causing light leakage and making it difficult to accurately evaluate the retardation layer.

The lower limit of the angle (maximum location) between the MD or TD of the transfer orientation film of the present invention and the orientation direction is preferably 0 degrees. Further, the upper limit of the angle between the MD or TD of the transfer orientation film of the present invention and the orientation direction is preferably 14 degrees at the maximum value, more preferably 7 degrees, and further preferably 5 degrees. , Especially preferably 4 degrees, and most preferably 3 degrees. If it exceeds the above, it may be difficult to evaluate the orientation state of the retardation layer (liquid crystal compound alignment layer).

The lower limit of the angle difference of the orientation angle in the entire width (width direction) of the alignment film for transfer of the present invention is preferably 0 degrees. Further, the upper limit of the angle difference of the orientation angle over the entire width of the alignment film for transfer of the present invention is preferably 7 degrees, more preferably 5 degrees, further preferably 3 degrees, and particularly preferably 2 degrees. be. If it exceeds the above, it may be difficult to evaluate the orientation state of the retardation layer (liquid crystal compound alignment layer) in the width direction.

When stretching in the TD direction in the tenter, a force that causes the film to shrink in the MD direction acts in the stretching zone and the heat fixing zone. The edges of the film are fixed with clips, but the center is not fixed, so the Boeing phenomenon occurs at the exit of the tenter, which appears with a delay in the bow shape. This is the distortion in the orientation direction.

In order to reduce distortion in the orientation direction and achieve the above characteristics, the stretching temperature, stretching ratio, stretching speed, thermal fixation temperature, relaxation step temperature, relaxation step magnification, temperature distribution in the width direction of each temperature, etc. It may be adjusted as appropriate.

When the orientation direction does not fall within the specified range in the entire width of the formed film, it is preferable to adopt a portion within the above characteristic range, such as near the center of the stretched wide film. Further, since the distortion in the orientation direction tends to be reduced when the orientation in the uniaxial direction is strengthened, it is also preferable to use a weak biaxial or uniaxial stretched film. In particular, a weak biaxial or uniaxial stretched film in which the MD direction is the main orientation direction is preferable.

In the present invention, the angle difference between the orientation direction of the alignment film for transfer, the flow direction of the alignment film or the direction orthogonal to the flow direction, and the orientation angle in the width direction of the film is as follows. It is determined.
First, the film was pulled out from the roll, and the orientation direction was determined at five locations: both ends (points 5 cm inward from each end), the center, and the middle between the center and both ends. The intermediate portion between the central portion and both end portions is located at a position where the distance between the central portion and both end portions is divided into two equal parts. The orientation direction was the slow-phase axial direction of the film obtained using a molecular orientation meter. Next, it was examined whether the orientation direction of the entire film was close to the flow direction (MD) or the width direction (TD). Then, when the overall orientation direction of the film is close to the flow direction, the angle between the orientation direction and the flow direction of the film is obtained at each of the above five locations, and the value at the largest angle is set to ". It was adopted as the maximum value of "the angle between the orientation direction of the alignment film and the flow direction of the alignment film". On the other hand, when the overall orientation direction of the film is close to the width direction, the angle between the orientation direction and the direction orthogonal to the flow direction of the film is obtained at each of the above five locations, and the angle is the largest. Was adopted as the maximum value of "the angle between the orientation direction of the alignment film and the direction orthogonal to the flow direction of the alignment film".
Further, the difference between the maximum value and the minimum value among the angles obtained at the above five locations was defined as "angle difference in orientation angle in the width direction of the film".

The angle is a positive value when the orientation direction is on the same side as the maximum value with respect to the longitudinal direction or the width direction, and is negative when the orientation direction is on the opposite side of the longitudinal direction or the width direction. The minimum value is evaluated by distinguishing between positive and negative values.

The lower limit of the difference in heat shrinkage between the MD direction and the TD direction of the alignment film for transfer of the present invention at 150 ° C. for 30 minutes is preferably 0%. Further, the upper limit of the heat shrinkage difference between the MD direction and the TD direction of the alignment film for transfer of the present invention at 150 ° C. for 30 minutes is preferably 4%, more preferably 3%, and further preferably 2%. , Especially preferably 1.5%, and most preferably 1%. If it exceeds the above, the orientation direction of the liquid crystal compound deviates from the design when a high temperature is required for the alignment treatment of the liquid crystal compound, or when multiple liquid crystal compounds are laminated and the history of temperature increases, and the polarizing plate is used for the display. Light leakage may occur in the LCD.

The lower limit of the heat shrinkage rate of the alignment film for transfer of the present invention in the MD direction at 150 ° C. for 30 minutes is preferably -2%, more preferably -0.5%, still more preferably -0.1%. Yes, particularly preferably 0%, most preferably 0.01%. If it is less than the above, it may be difficult to achieve the numerical value in reality. Further, the upper limit of the heat shrinkage rate of the alignment film for transfer of the present invention in the MD direction at 150 ° C. for 30 minutes is preferably 4%, more preferably 3%, still more preferably 2.5%, and particularly. It is preferably 2%, most preferably 1.5%. If it exceeds the above, it may be difficult to adjust the difference in heat shrinkage. In addition, the flatness may be deteriorated and the workability may be deteriorated.

The lower limit of the heat shrinkage rate of the alignment film for transfer of the present invention in the TD direction at 150 ° C. for 30 minutes is preferably -2%, more preferably -0.5%, still more preferably -0.1%. Yes, particularly preferably 0%, most preferably 0.01%. If it is less than the above, it may be difficult to achieve the numerical value in reality. Further, the upper limit of the heat shrinkage rate of the alignment film for transfer of the present invention in the TD direction at 150 ° C. for 30 minutes is preferably 4%, more preferably 2.5%, still more preferably 2%, and particularly. It is preferably 1.5%, most preferably 1%. If it exceeds the above, it may be difficult to adjust the difference in heat shrinkage. In addition, the flatness may be deteriorated and the workability may be deteriorated.

The lower limit of the difference in heat shrinkage at 150 ° C. for 30 minutes in the direction of 45 degrees with respect to the MD direction and the direction of 135 degrees with respect to the MD direction of the alignment film for transfer of the present invention is preferably 0%. If it is less than the above, it may be difficult to achieve the numerical value in reality. Further, the upper limit of the difference in heat shrinkage at 150 ° C. for 30 minutes in the direction of 45 degrees with respect to the MD direction and the direction of 135 degrees with respect to the MD direction of the alignment film for transfer of the present invention is preferably 4%. It is preferably 3%, more preferably 2%, particularly preferably 1.5%, and most preferably 1%. If it deviates from the above range, the orientation direction of the liquid crystal compound deviates from the design, and light leakage may occur when the polarizing plate is used for the display.

The heat shrinkage characteristics of the film can be adjusted by the stretching temperature, the stretching ratio, the heat fixing temperature, the magnification of the relaxation step, the temperature of the relaxation step, and the like. It is also preferable that the film is released from the clip and wound at a surface temperature of 100 ° C. or higher during the cooling step. The release from the clip may be a method of opening the clip or a method of separating the end portion held by the clip with a knife or the like. In addition, offline heat treatment (annealing treatment) is also an effective method.

In order to obtain the above-mentioned heat shrinkage characteristics of the transfer orientation film of the present invention at 150 ° C. for 30 minutes, the material of the transfer orientation film is preferably polyester, particularly polyethylene terephthalate.

The lower limit of the maximum heat shrinkage rate at 95 ° C. of the alignment film for transfer of the present invention is preferably 0%, more preferably 0.01%. If it is less than the above, it may be difficult to achieve the numerical value in reality. Further, the upper limit of the maximum heat shrinkage rate at 95 ° C. of the alignment film for transfer of the present invention is preferably 2.5%, more preferably 2%, further preferably 1.2%, and particularly preferably 1. %, Most preferably 0.8%. If it exceeds the above, light leakage may occur when the polarizing plate is used for the display.

The lower limit of the angle between the maximum heat shrinkage direction and the MD or TD direction of the alignment film for transfer of the present invention is preferably 0 degrees. Further, the upper limit of the angle between the maximum heat shrinkage direction and the MD or TD direction of the alignment film for transfer of the present invention is preferably 20 degrees, more preferably 15 degrees, still more preferably 10 degrees, and in particular. It is preferably 7 degrees, most preferably 5 degrees. If it exceeds the above, the orientation direction of the liquid crystal compound deviates from the design, and light leakage may occur when the polarizing plate is used for the display.

The lower limit of the elastic modulus in the MD direction and the elastic modulus in the TD direction of the alignment film for transfer of the present invention is preferably 1 GPa, more preferably 2 GPa. If it is less than the above, it may be stretched in each process and the orientation direction may not be as designed. Further, the upper limit of the elastic modulus in the MD direction and the elastic modulus in the TD direction of the alignment film for transfer of the present invention is preferably 8 GPa, more preferably 7 GPa. If it exceeds the above, it may be difficult to achieve the numerical value in reality.

When the alignment film for transfer of the present invention is a polyester film, the amount of ester cyclic trimers precipitated on the surface of the release surface of the oriented polyester film after heating at 150 ° C. for 90 minutes (hereinafter, the amount of surface oligomer precipitation (150). The lower limit of (referred to as ° C. 90 min) is preferably 0 mg / m ² , and more preferably 0.01 mg / m ² . If it is less than the above, it may be difficult to achieve the numerical value in reality. The upper limit of the surface oligomer precipitation amount (150 ° C. 90 min) is preferably 1 mg / m ² , more preferably 0.7 mg / m ² , further preferably 0.5 mg / m ² , and particularly preferably 0. It is 3 mg / m ² . If it exceeds the above, haze rises or foreign matter is generated when multiple liquid crystal compound alignment layers are laminated or when alignment treatment at high temperature is required, and polarization is disturbed during orientation control by ultraviolet irradiation, as designed. A retardation layer or a polarizing layer may not be obtained. In the present invention, the "separation surface" of the alignment film means the surface of the alignment film intended to be provided with the liquid crystal compound alignment layer to which the alignment film is transferred. When the oligomer block coat layer, the flattening coat layer, the release layer, etc. are provided, if the liquid crystal compound orientation layer is provided on the oligomer block coat layer, the flattening layer, the release layer, etc., the surface of these oligomer block coat layers, the flattening layer, the release layer, etc. (The surface in contact with the liquid crystal compound alignment layer) is the "separation surface" of the alignment film.

In order to reduce the amount of surface oligomers precipitated, it is preferable to provide a coat layer (hereinafter referred to as an oligomer block coat layer) that blocks the precipitation of oligomers (ester cyclic trimers) on the surface of the transfer orientation film.

The oligomer block coat layer preferably contains 50% by weight or more of a resin having a Tg of 90 ° C. or higher. As such a resin, an amino resin such as melamine, an alkyd resin, polystyrene, an acrylic resin and the like are preferable. The upper limit of Tg of the resin is preferably 200 ° C.

The lower limit of the thickness of the oligomer block coat layer is preferably 0.01 μm, more preferably 0.03 μm, and even more preferably 0.05 μm. If it is less than the above, a sufficient blocking effect may not be obtained. The upper limit of the thickness of the oligomer block coat layer is preferably 10 μm, more preferably 5 μm, and even more preferably 2 μm. If it exceeds the above, the effect may be saturated.

Further, in order to reduce the amount of surface oligomer precipitated, the content of the oligomer (ester cyclic trimer) in the polyester resin constituting the release surface side layer of the alignment film for transfer (hereinafter referred to as the surface oligomer content). It is also preferable to lower. The lower limit of the surface oligomer content is preferably 0.3% by mass, more preferably 0.33% by mass, and even more preferably 0.35% by mass. If it is less than the above, it may be difficult to achieve the numerical value in reality. The upper limit of the surface oligomer content is preferably 0.7% by mass, more preferably 0.6% by mass, and even more preferably 0.5% by mass. In the present invention, the "release surface side layer" of the alignment film means a layer in which the release surface exists among each layer of polyester constituting the alignment film. Here, even when the film is a single layer, it may be referred to as a release surface side layer. In this case, the back surface side layer and the release surface side layer, which will be described later, are the same layer.

In order to reduce the surface oligomer content, it is preferable to reduce the oligomer content in the raw material polyester. The lower limit of the oligomer content in the raw material polyester is preferably 0.23% by mass, more preferably 0.25% by mass, and further preferably 0.27% by mass. The upper limit of the oligomer content in the raw material polyester is preferably 0.7% by mass, more preferably 0.6% by mass, and even more preferably 0.5% by mass. The oligomer content in the raw material polyester can be reduced by heat-treating the solid polyester at a temperature of 180 ° C. or higher and a melting point or lower, such as solid-phase polymerization. It is also preferable to inactivate the polyester catalyst.

Further, in order to reduce the amount of surface oligomer precipitates, it is also effective to shorten the melting time during film formation.

The lower limit of the haze of the alignment film for transfer of the present invention is preferably 0.01%, more preferably 0.1%. If it is less than the above, it may be difficult to achieve the numerical value in reality. The upper limit of the haze of the alignment film for transfer of the present invention is preferably 3%, more preferably 2.5%, further preferably 2%, and particularly preferably 1.7%. If it exceeds the above, the polarized light is disturbed during the irradiation with polarized UV, and the retardation layer and the polarizing layer as designed may not be obtained. Further, when inspecting the retardation layer or the polarizing layer, light leakage may occur due to diffused reflection, which may make the inspection difficult.

The lower and upper limits of the haze of the alignment film for transfer of the present invention after heating at 150 ° C. for 90 minutes are the same as above.

The lower limit of the amount of change in haze of the alignment film for transfer of the present invention before and after heating at 150 ° C. for 90 minutes is preferably 0%. The upper limit is preferably 0.5%, more preferably 0.4%, and even more preferably 0.3%.

The lower limit of the antistatic property (surface resistance) of the alignment film for transfer of the present invention is preferably 1 × 10 ⁵ Ω / □, and more preferably 1 × 10 ⁶ Ω / □. Even if it is less than the above, the effect may be saturated and no further effect may be obtained. Further, the upper limit of the antistatic property (surface resistance) of the alignment film for transfer of the present invention is preferably 1 × 10 ¹³ Ω / □, more preferably 1 × 10 ¹² Ω / □, and further preferably 1 ×. 10 ¹¹ Ω / □. If it exceeds the above, repelling due to static electricity may occur, or the orientation direction of the liquid crystal compound may be disturbed. For antistatic property (surface resistance), knead an antistatic agent into the alignment film for transfer, provide an antistatic coat layer on the lower layer or the opposite surface of the release layer, or add an antistatic agent to the release layer. By doing so, it can be within the above range.

Antistatic agents to be added to the antistatic coat layer, release layer and transfer orientation film include conductive polymers such as polyaniline and polythiophene, ionic polymers such as polystyrene sulfonate, tin-doped indium oxide, and antimony-doped oxidation. Examples include conductive fine particles such as tin.

A release layer may be provided on the transfer orientation film. However, if the film itself has low adhesion to a transferred material such as a retardation layer or an alignment layer and has sufficient releasability without providing a release layer, the release layer may not be provided. If the adhesion is too low, the adhesion may be adjusted by performing a corona treatment on the surface. The release layer can be formed by using a known release agent, and alkyd resin, amino resin, long-chain acrylic acrylate-based, silicone resin, and fluororesin are preferable examples. These can be appropriately selected according to the adhesion to the transcript.

Further, in the transfer orientation film of the present invention, an easy-adhesion layer may be provided as a lower layer of the oligomer block coat layer, the antistatic layer, and the release layer.

The lower limit of the ultimate viscosity (IVf) of the polyester constituting the transfer-oriented polyester film of the present invention is preferably 0.45 dl / g, more preferably 0.5 dl / g, and further preferably 0.53 dl / g. Is. If it is less than the above, the impact resistance of the film may be inferior. In addition, it may be difficult to form a film, or the uniformity of thickness may be inferior. The upper limit of IVf is preferably 0.9 dl / g, more preferably 0.8 dl / g, and even more preferably 0.7 dl / g. If it exceeds the above, the heat shrinkage rate may increase. In addition, it may be difficult to form a film.

The lower limit of the light transmittance of the alignment film for transfer of the present invention at a wavelength of 380 nm is preferably 0%. Further, the upper limit of the light transmittance of the alignment film for transfer at a wavelength of 380 nm of the present invention is preferably 20%, more preferably 15%, still more preferably 10%, and particularly preferably 5%. .. If it exceeds the above, the direction uniformity of the alignment layer and the liquid crystal compound alignment layer may deteriorate due to reflection from the back surface when the orientation is set to a specific orientation by irradiating with polarized ultraviolet rays. The light transmittance at a wavelength of 380 nm can be kept within the range by adding a UV absorber.

When the alignment film for transfer of the present invention is a polyethylene terephthalate film, the lower limit of the refractive index nx in the slow axis direction and the refractive index ny in the phase advance axis direction is preferably 0.005, more preferably 0.01. , More preferably 0.02, particularly preferably 0.03, and most preferably 0.04. If it is less than the above, it may be difficult to achieve the numerical value in reality. The upper limit of nx-ny is preferably 0.15, more preferably 0.13, and even more preferably 0.12. If it exceeds the above, it may be difficult to achieve the numerical value in reality.

In the case of biaxial stretching, the lower limit of nx-ny is preferably 0.005, more preferably 0.01. If it is less than the above, it may be difficult to achieve the numerical value in reality. In the case of biaxial stretching, the upper limit of nx-ny is preferably 0.05, more preferably 0.04, and even more preferably 0.03. If it exceeds the above, it may be difficult to achieve the numerical value in reality.

In the case of uniaxial stretching, the lower limit of nx-ny is preferably 0.05, more preferably 0.06. If it is less than the above, the merit of uniaxial stretching may be diminished. Further, in the case of uniaxial stretching, the upper limit of nx-ny is preferably 0.15, more preferably 0.13. If it exceeds the above, it may be difficult to achieve the numerical value in reality.

The lower limit of the refractive index (ny) in the phase-advancing axis direction of the alignment film for transfer of the present invention is preferably 1.55, more preferably 1.58, and even more preferably 1.57. Further, the upper limit of the refractive index (ny) in the phase-advancing axis direction of the alignment film for transfer of the present invention is preferably 1.64, more preferably 1.63, and further preferably 1.62.

The lower limit of the refractive index (nx) in the slow axis direction of the alignment film for transfer of the present invention is preferably 1.66, more preferably 1.67, and even more preferably 1.68. Further, the upper limit of the refractive index (nx) in the slow-phase axial direction of the alignment film for transfer of the present invention is preferably 1.75, more preferably 1.73, still more preferably 1.72, and in particular. It is preferably 1.71.

(Manufacturing method of alignment film for transfer)
Hereinafter, a method for producing the transfer alignment film when the transfer alignment film of the present invention is a stretched film will be described.
When MD stretching is performed, the lower limit of the MD magnification is preferably 1.5 times. The upper limit is preferably 6 times, more preferably 5.5 times, and even more preferably 5 times. Further, when TD stretching is performed, the lower limit of the TD magnification is preferably 1.5 times. The upper limit of the TD magnification is preferably 6 times, more preferably 5.5 times, and even more preferably 5 times.

The lower limit of the HS temperature is preferably 150 ° C, more preferably 170 ° C. If it is less than the above, the heat shrinkage rate may not decrease. The upper limit of the HS temperature is preferably 240 ° C, more preferably 230 ° C. If it exceeds the above, resin deterioration may occur.

The lower limit of the TD relaxation rate is preferably 0.1%, more preferably 0.5%. If it is less than the above, the heat shrinkage rate may not decrease. The upper limit of the TD relaxation rate is preferably 8%, more preferably 6%, and even more preferably 5%. If it exceeds the above, the flatness may deteriorate due to slack, or the thickness may become uneven.

The annealing treatment is preferably a method of unwinding the film, passing it through an oven, and winding it.

The lower limit of the annealing temperature is preferably 80 ° C., more preferably 90 ° C., and even more preferably 100 ° C. If it is less than the above, the annealing effect may not be obtained. The upper limit of the annealing temperature is preferably 200 ° C., more preferably 180 ° C., and even more preferably 160 ° C. If it exceeds the above, the flatness may decrease or the heat shrinkage may increase.

The lower limit of the annealing time is preferably 5 seconds, more preferably 10 seconds, and even more preferably 15 seconds. If it is less than the above, the annealing effect may not be obtained. The upper limit of the annealing time is preferably 10 minutes, more preferably 5 minutes, still more preferably 3 minutes, and particularly preferably 1 minute. Beyond the above, not only is the effect saturated, but a large oven may be required and productivity may be reduced.

In the annealing treatment, a method such as adjusting the relaxation rate by adjusting the peripheral speed difference between the unwinding speed and the winding speed, or adjusting the winding tension to adjust the relaxation rate is adopted. The lower limit of the relaxation rate is preferably 0.5%. If it is less than the above, the annealing effect may not be obtained. The upper limit of the relaxation rate is preferably 8%, more preferably 6%, and even more preferably 5%. If it exceeds the above, the flatness may decrease or winding failure may occur.

(Laminate for transfer of liquid crystal compound orientation layer)
Next, the laminate for transferring the liquid crystal compound oriented layer of the present invention will be described.
The liquid crystal compound alignment layer transfer laminate of the present invention has a structure in which the liquid crystal compound alignment layer and the transfer orientation film of the present invention are laminated. The liquid crystal compound alignment layer needs to be coated and oriented on the transfer alignment film. As a method of orientation, a method of giving an orientation control function by rubbing treatment or the like on the lower layer (separation surface) of the liquid crystal compound alignment layer, or a method of directly orienting the liquid crystal compound by irradiating polarized ultraviolet rays or the like after applying the liquid crystal compound. There is a way.

(Orientation control layer)
Further, a method in which an orientation control layer is provided on the transfer orientation film and a liquid crystal compound orientation layer is provided on the orientation control layer is also preferable. In the present invention, the liquid crystal compound alignment layer may be collectively referred to as a combination of the alignment control layer and the liquid crystal compound orientation layer instead of the liquid crystal compound alignment layer alone. The orientation control layer may be any orientation control layer as long as the liquid crystal compound orientation layer can be brought into a desired orientation state, such as a rubbing treatment orientation control layer in which a resin coating film is rubbed. A suitable example is a photo-orientation control layer that orients molecules by irradiation with polarized light to generate an orientation function.

(Rubbing treatment orientation control layer)
As the polymer material used for the orientation control layer formed by the rubbing treatment, polyvinyl alcohol and its derivatives, polyimide and its derivatives, acrylic resins, polysiloxane derivatives and the like are preferably used.

Hereinafter, a method for forming the rubbing treatment orientation control layer will be described. First, a rubbing treatment orientation control layer coating liquid containing the above polymer material is applied onto the release surface of the alignment film, and then heat-dried or the like to obtain an orientation control layer before the rubbing treatment. The orientation control layer coating liquid may have a cross-linking agent.

As the solvent of the rubbing treatment orientation control layer coating liquid, any solvent can be used as long as it dissolves the polymer material. Specific examples include alcohols such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol and cellosolve; ester solvents such as ethyl acetate, butyl acetate and gamma butyrolactone; acetone, methyl ethyl ketone, cyclopentanone and cyclohexanone. , And the like; aromatic hydrocarbon solvents such as toluene or xylene; and ether solvents such as tetrahydrofuran or dimethoxyethane. These solvents may be used alone or in combination.

The concentration of the rubbing treatment orientation control layer coating liquid can be appropriately adjusted depending on the type of polymer and the thickness of the orientation control layer to be produced, but it is preferably 0.2 to 20% by mass in terms of solid content concentration. The range of 0.3 to 10% by mass is particularly preferable. As the coating method, a known method such as a coating method such as a gravure coating method, a die coating method, a bar coating method and an applicator method, or a printing method such as a flexographic method is adopted.

The heating and drying temperature is preferably in the range of 30 ° C. to 170 ° C., more preferably 50 to 150 ° C., and even more preferably 70 to 130 ° C. in the case of PET, although it depends on the alignment film for transfer. When the drying temperature is low, it is necessary to take a long drying time, which may result in inferior productivity. If the drying temperature is too high, the alignment film for transfer may be stretched by heat, the heat shrinkage may be large, the optical function as designed may not be achieved, or the flatness may be deteriorated. The heating and drying time may be, for example, 0.5 to 30 minutes, more preferably 1 to 20 minutes, and even more preferably 2 to 10 minutes.

The thickness of the rubbing treatment orientation control layer is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and particularly preferably 0.1 μm to 1 μm.

Next, a rubbing process is performed. The rubbing treatment can generally be carried out by rubbing the surface of the polymer layer with paper or cloth in a certain direction. Generally, a rubbing roller of a brushed cloth made of fibers such as nylon, polyester, and acrylic is used to rub the surface of the orientation control layer. In order to provide the liquid crystal compound orientation control layer that is oriented in a predetermined direction diagonally with respect to the longitudinal direction of the elongated film, it is necessary to set the rubbing direction of the orientation control layer at an angle corresponding to the rubbing direction. The angle can be adjusted by adjusting the angle between the rubbing roller and the alignment film, and adjusting the transport speed of the alignment film and the rotation speed of the roller.

It is also possible to directly apply a rubbing treatment to the release surface of the transfer alignment film to give the transfer alignment film surface an orientation control function, which is also included in the technical scope of the present invention.

(Photo-orientation control layer)
The photo-alignment control layer is an alignment film in which a coating liquid containing a polymer or monomer having a photoreactive group and a solvent is applied to the alignment film and irradiated with polarized light, preferably polarized ultraviolet rays, to impart orientation-regulating power. It means that. The photoreactive group is a group that produces a liquid crystal alignment ability by irradiation with light. Specifically, it produces a photoreaction that is the origin of the liquid crystal orientation ability, such as a molecule orientation-inducing or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction that occurs when light is irradiated. be. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable in that they have excellent orientation and maintain the smectic liquid crystal state of the liquid crystal compound orientation layer. The photoreactive group capable of causing the above reaction is preferably an unsaturated bond, particularly a double bond, and is a group consisting of a C = C bond, a C = N bond, an N = N bond, and a C = O bond. A group having at least one selected from the above is particularly preferable.

Examples of the photoreactive group having a C = C bond include a vinyl group, a polyene group, a stilbene group, a stillbazol group, a stillvazolium group, a chalcone group and a cinnamoyl group. Examples of the photoreactive group having a C = N bond include a group having a structure such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and the like, and those having an azoxybenzene as a basic structure. Examples of the photoreactive group having a C = O bond include a benzophenone group, a coumarin group, an anthraquinone group and a maleimide group. These groups may have substituents such as an alkyl group, an alkoxy group, an allyl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group and an alkyl halide group.

Among them, a photoreactive group capable of causing a photodimerization reaction is preferable, and a photo-alignment layer in which a cinnamoyl group and a chalcone group require a relatively small amount of polarization for photo-orientation and is excellent in thermal stability and temporal stability is obtained. It is preferable because it is easy to obtain. Furthermore, as the polymer having a photoreactive group, a polymer having a cinnamoyl group such that the terminal portion of the side chain of the polymer has a cinnamic acid structure is particularly preferable. Examples of the structure of the main chain include polyimide, polyamide, (meth) acrylic, polyester, and the like.

Specific examples of the orientation control layer include JP-A-2006-285197, JP-A-2007-76839, JP-A-2007-138138, JP-A-2007-94071, and JP-A-2007-121721. , JP-A-2007-140465, JP-A-2007-156439, JP-A-2007-133184, JP-A-2009-109831, JP-A-2002-229039, JP-A-2002-265541, Orientation described in Kai 2002-317013, Japanese Patent Application Laid-Open No. 2003-520878, Japanese Patent Application Laid-Open No. 2004-522220, Japanese Patent Application Laid-Open No. 2013-33248, Japanese Patent Application Laid-Open No. 2015-7702, Japanese Patent Application Laid-Open No. 2015-129210. A control layer can be mentioned.

As the solvent of the coating liquid for forming the photo-orientation control layer, any solvent can be used as long as it dissolves a polymer and a monomer having a photoreactive group. As a specific example, the one mentioned in the method of forming the rubbing treatment orientation control layer can be exemplified. It is also preferable to add a photopolymerization initiator, a polymerization inhibitor, and various stabilizers to the coating liquid for forming the photoalignment control layer. Further, a polymer other than the polymer having a photoreactive group and the monomer, or a monomer having no photoreactive group copolymerizable with the monomer having a photoreactive group may be added.

Examples of the concentration of the coating liquid for forming the photo-orientation control layer, the coating method, and the drying conditions as described in the method for forming the rubbing treatment orientation control layer can be exemplified. The thickness is also the same as the preferable thickness of the rubbing treatment orientation control layer.

Polarization is preferably applied from the direction of the photo-alignment control layer surface before orientation. When the orientation direction of the photoalignment control layer is parallel or perpendicular to the orientation direction of the transfer orientation film, the transfer orientation film may be transmitted and irradiated.

The wavelength of polarization is preferably in the wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, ultraviolet rays having a wavelength in the range of 250 to 400 nm are preferable. Examples of the polarized light source include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, ultraviolet light lasers such as KrF and ArF, and high-pressure mercury lamps, ultra-high pressure mercury lamps, and metal halide lamps are preferable. ..

Polarization is obtained, for example, by passing light from the light source through a polarizer. By adjusting the polarization angle of the polarizer, the direction of polarization can be adjusted. Examples of the polarizer include a polarizing filter, a polarizing prism such as a Gran Thomson or a Granter, and a wire grid type polarizer. The polarized light is preferably substantially parallel light.

By adjusting the angle of the polarized light to be irradiated, the direction of the orientation regulating force of the optical orientation control layer can be arbitrarily adjusted.

The irradiation intensity varies depending on the type and amount of the polymerization initiator and the resin (monomer), but for example, it ^{is preferably 10 to 10000 mJ / cm 2 based on 365 nm, and more preferably 20} to 5000 mJ / cm 2.

(Liquid crystal compound orientation layer)
The liquid crystal compound orientation layer is not particularly limited as long as the liquid crystal compound is oriented. Specific examples include a polarizing film (polarizer) containing a liquid crystal compound and a dichroic dye, and a retardation layer containing a rod-shaped or discotic liquid crystal compound.

(Polarizing film)
The polarizing film has a function of passing polarized light in only one direction and contains a dichroic dye.

(Dichroic pigment)
The dichroic dye refers to a dye having a property in which the absorbance in the major axis direction and the absorbance in the minor axis direction of the molecule are different.

The dichroic dye preferably has an absorption maximum wavelength (λMAX) in the range of 300 to 700 nm. Examples of such a bicolor dye include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye and an anthraquinone dye, and among them, the azo dye is preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye and a stilbene azo dye, and preferably a bisazo dye and a trisazo dye. The dichroic dye may be used alone or in combination, but it is preferable to combine two or more kinds in order to adjust the color tone (achromatic color). In particular, it is preferable to combine three or more types. In particular, it is preferable to combine three or more kinds of azo compounds.

Preferred azo compounds include dyes described in JP-A-2007-126628, JP-A-2010-168570, JP-A-2013-101328, and JP-A-2013-210624.

The dichroic dye is also preferably a dichroic dye polymer introduced into the side chain of a polymer such as acrylic. Examples of these dichroic dye polymers include polymers listed in JP-A-2016-4055 and polymers obtained by polymerizing the compounds of JP-A-2014-206682 [Chemical formula 6] to [Chemical formula 12].

The content of the dichroic dye in the polarizing film is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass in the polarizing film from the viewpoint of improving the orientation of the dichroic dye. , 1.0 to 15% by mass is more preferable, and 2.0 to 10% by mass is particularly preferable.

The polarizing film preferably further contains a polymerizable liquid crystal compound in order to improve the film strength, the degree of polarization, and the film homogeneity. Here, the polymerizable liquid crystal compound also includes a film after polymerization.

(Polymerizable liquid crystal compound)
The polymerizable liquid crystal compound is a compound having a polymerizable group and exhibiting liquid crystallinity.
The polymerizable group means a group involved in the polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can undergo a polymerization reaction with an active radical, an acid, or the like generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxylanyl group, an oxetanyl group and the like. Of these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxylanyl group and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The liquid crystal compound may be a thermotropic liquid crystal or a riotropic liquid crystal, and may be a nematic liquid crystal or a smectic liquid crystal in the thermotropic liquid crystal.

The polymerizable liquid crystal compound is preferably a smectic liquid crystal compound, and more preferably a higher-order smectic liquid crystal compound, in that higher polarization characteristics can be obtained. When the liquid crystal phase formed by the polymerizable liquid crystal compound is a higher-order smectic phase, a polarizing film having a higher degree of orientation order can be produced.

Specific preferred polymerizable liquid crystal compounds include, for example, JP-A-2002-308832, JP-A-2007-16207, JP-A-2015-163596, JP-A-2007-510946, JP-A-2013-114131. No., WO2005 / 045485, Lub et al. Recl. Trav. Chim. Examples thereof include those described in Pays-Bas, 115, 321-328 (1996) and the like.

The content ratio of the polymerizable liquid crystal compound in the polarizing film is preferably 70 to 99.5% by mass, more preferably 75 to 99% by mass, and further preferably 75 to 99% by mass in the polarizing film from the viewpoint of increasing the orientation of the polymerizable liquid crystal compound. It is preferably 80 to 97% by mass, and particularly preferably 83 to 95% by mass.

The polarizing film can be provided by applying a polarizing film composition paint. The polarizing film composition coating material may contain a solvent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a leveling agent, a polymerizable non-liquid crystal compound, a cross-linking agent, and the like.

As the solvent, those listed as the solvent of the alignment layer coating liquid are preferably used.

The polymerization initiator is not limited as long as it polymerizes a polymerizable liquid crystal compound, but a photopolymerization initiator that generates active radicals by light is preferable. Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts.

The sensitizer is preferably a photosensitizer. For example, xanthone compounds, anthracene compounds, phenothiazines, rubrene and the like can be mentioned.

Examples of the polymerization inhibitor include hydroquinones, catechols, and thiophenols.

The polymerizable non-liquid crystal compound is preferably one that copolymerizes with the polymerizable liquid crystal compound, and examples thereof include (meth) crates when the polymerizable liquid crystal compound has a (meth) acryloyloxy group. The (meth) clearates may be monofunctional or polyfunctional. By using polyfunctional (meth) acrylates, the strength of the polarizing film can be improved. When a polymerizable non-liquid crystal compound is used, it is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, and particularly preferably 3 to 7% by mass in the polarizing film. If it exceeds 15% by mass, the degree of polarization may decrease.

Examples of the cross-linking agent include a polymerizable liquid crystal compound and a compound capable of reacting with a functional group of a polymerizable non-liquid crystal compound, and examples thereof include an isocyanate compound, a melamine, an epoxy resin, and an oxazoline compound.

The polarizing film composition coating film is applied directly onto the alignment film for transfer or the alignment control layer, and then dried, heated, and cured as necessary to provide the polarizing film.

As the coating method, as the coating method, a known method such as a coating method such as a gravure coating method, a die coating method, a bar coating method and an applicator method, or a printing method such as a flexographic method is adopted.

The alignment film for transfer after coating is guided to a warm air dryer, an infrared dryer, or the like, and is dried at 30 to 170 ° C., more preferably 50 to 150 ° C., and even more preferably 70 to 130 ° C. The drying time is preferably 0.5 to 30 minutes, more preferably 1 to 20 minutes, and even more preferably 2 to 10 minutes.

Heating can be performed to more strongly orient the dichroic dye and the polymerizable liquid crystal compound in the polarizing film. The heating temperature is preferably in the temperature range in which the polymerizable liquid crystal compound forms a liquid crystal phase.

When the polarizing film composition coating material contains a polymerizable liquid crystal compound, it is preferably cured. Examples of the curing method include heating and light irradiation, and light irradiation is preferable. By curing, the dichroic dye can be fixed in an oriented state. The curing is preferably carried out in a state where the liquid crystal phase is formed on the polymerizable liquid crystal compound, and may be cured by irradiating light at a temperature indicating the liquid crystal phase. Examples of the light in the light irradiation include visible light, ultraviolet light and laser light. Ultraviolet light is preferable because it is easy to handle.

The irradiation intensity is different in kind and amount of a polymerization initiator or a resin (monomer), for example, preferably 100~10000mJ / cm ² at 365nm reference, more preferably 200~5000mJ / cm ^2.

By applying the polarizing film composition coating on the alignment control layer, the polarizing film is oriented along the orientation direction of the alignment layer, and as a result, the polarizing film has a polarization transmission axis in a predetermined direction. When the film is directly applied to the alignment film for transfer without providing the control layer, the polarizing film can be oriented by irradiating the polarizing film with polarized light to cure the composition for forming the polarizing film. At this time, polarized light in a desired direction (for example, polarized light in an oblique direction) is irradiated with respect to the long direction of the alignment film for transfer. Further, it is preferable that the dichroic dye is firmly oriented along the orientation direction of the polymer liquid crystal by heat treatment thereafter.

The thickness of the polarizing film is 0.1 to 5 μm, preferably 0.3 to 3 μm, and more preferably 0.5 to 2 μm.

(Phase difference layer)
Typical examples of the retardation layer are those provided for optical compensation between the polarizer of the liquid crystal display device and the liquid crystal cell, and λ / 4 layer and λ / 2 layer of a circular polarizing plate. As the liquid crystal compound, a rod-shaped liquid crystal compound, a discotic liquid crystal compound, or the like can be used depending on the purpose, such as a raw or negative A plate, a positive or negative C plate, or an O plate.

When used as optical compensation for a liquid crystal display device, the degree of phase difference is appropriately set depending on the type of liquid crystal cell and the properties of the liquid crystal compound used in the cell. For example, in the case of the TN method, an O plate using a discotic liquid crystal is preferably used. In the case of the VA method or the IPS method, a C plate or an A plate using a rod-shaped liquid crystal compound or a discotic liquid crystal compound is preferably used. Further, in the case of the λ / 4 retardation layer and the λ / 2 retardation layer of the circularly polarizing plate, it is preferably used to form an A plate by using a rod-shaped compound. These retardation layers may be used not only as a single layer but also as a combination of a plurality of layers.

The liquid crystal compound used for these retardation layers is preferably a polymerizable liquid crystal compound having a polymerizable group such as a double bond in terms of being able to fix the orientation state.

Examples of the rod-shaped liquid crystal compound include JP-A-2002-030042, JP-A-2004-204190, JP-A-2005-263789, JP-A-2007-119415, JP-A-2007-186430, and special publications. Examples thereof include rod-shaped liquid crystal compounds having a polymerizable group described in Kaihei 11-513360.
Specific compounds include
CH ₂ = CHCOO- (CH ₂ ) m-O-Ph1-COO-Ph2-OCO-Ph1-O- (CH ₂ ) n-OCO-CH = CH ₂
CH ₂ = CHCOO- (CH ₂ ) m-O-Ph1-COO-NPh-OCO-Ph1-O- (CH ₂ ) n-OCO-CH = CH ₂
CH ₂ = CHCOO- (CH ₂ ) m-O-Ph1-COO-Ph2-OCH ₃
CH ₂ = CHCOO- (CH ₂ ) m-O-Ph1-COO-Ph1-Ph1-CH ₂ CH (CH ₃ ) C ₂ H ₅
In the formula, m and n are integers of 2 to 6 and
Ph1 and Ph2 are 1,4-phenyl groups (Ph2 may have a methyl group at the 2-position).
NPh is a 2,6-naphthyl group.
These rod-shaped liquid crystal compounds are commercially available from BASF as LC242 and the like, and they can be used.

A plurality of these rod-shaped liquid crystal compounds may be used in combination at any ratio.

式中、Ｒ_１〜Ｒ_６はそれぞれ独立して水素、ハロゲン、アルキル基、又は−Ｏ−Ｘで示される基（ここで、Ｘは、Ｘはアルキル基、アシル基、アルコキシベンジル基、エポキシ変性アルコキシベンジル基、アクリロイルオキシ変性アルコキシベンジル基、アクリロイルオキシ変性アルキル基である）である。Ｒ_１〜Ｒ_６は、下記一般式（２）で表されるアクリロイルオキシ変性アルコキシベンジル基（ここで、ｍは４〜１０）であることが好ましい。

Examples of the discotic liquid crystal compound include a benzene derivative, a tolucene derivative, a cyclohexane derivative, an aza-crown derivative, a phenylacetylene macrocycle, and the like, and various ones are described in JP-A-2001-155866. Is preferably used.
Among them, as the discotic compound, a compound having a triphenylene ring represented by the following general formula (1) is preferably used.

In the formula, R _{1 to} R ₆ are independently represented by hydrogen, halogen, alkyl group, or -OX (where X is X is an alkyl group, an acyl group, an alkoxybenzyl group, or an epoxy-modified group. It is an alkoxybenzyl group, an acryloyloxy-modified alkoxybenzyl group, and an acryloyloxy-modified alkyl group). R _{1 to} R ₆ are preferably acryloyloxy-modified alkoxybenzyl groups represented by the following general formula (2) (where m is 4 to 10).

The retardation layer can be provided by applying a composition coating material for a retardation layer. The composition coating material for a retardation layer may contain a solvent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a leveling agent, a polymerizable non-liquid crystal compound, a cross-linking agent and the like. As these, the ones described in the orientation control layer and the liquid crystal polarizer can be used.

The retardation layer is provided by applying the composition coating material for the retardation layer on the release surface of the alignment film or the alignment control layer, and then drying, heating, and curing.

As for these conditions, the conditions described in the orientation control layer and the liquid crystal polarizer are preferably used.

A plurality of retardation layers may be provided. In this case, a plurality of retardation layers may be provided on one transfer alignment film and transferred to an object, and the retardation layers may be transferred to an object. A plurality of types provided with a single retardation layer may be prepared and these may be transferred to an object in order.

Further, the polarizing layer and the retardation layer may be provided on one transfer alignment film, and this may be transferred to an object. Further, a protective layer may be provided between the polarizer and the retardation layer, or a protective layer may be provided on the retardation layer or between the retardation layers. These protective layers may also be provided on the transfer alignment film together with the retardation layer and the polarizing layer to transfer to the object.

Examples of the protective layer include a transparent resin coating layer. The transparent resin is not particularly limited to polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyester, polyurethane, polyamide, polystyrene, acrylic resin, epoxy resin and the like. A cross-linking agent may be added to these resins to form a cross-linked structure. Further, a photocurable composition such as a hard coat may be cured. Further, after the protective layer is provided on the alignment film, the protective layer may be subjected to a rubbing treatment, and the liquid crystal compound alignment layer may be provided on the protective layer without providing the alignment layer.

(Manufacturing method of liquid crystal compound oriented layer laminated polarizing plate)
Next, a method for producing the liquid crystal compound oriented layer laminated polarizing plate of the present invention will be described.
The method for producing a liquid crystal compound oriented layer laminated polarizing plate of the present invention includes a step of laminating the polarizing plate and the liquid crystal compound oriented layer surface of the liquid crystal compound oriented layer transfer laminate of the present invention to form an intermediate laminated body, and an intermediate laminated body. The step of peeling the alignment film from the body is included.
Hereinafter, a case where the liquid crystal compound alignment layer is a liquid crystal compound orientation layer used for a circularly polarizing plate will be described as an example. In the case of a circularly polarizing plate, a λ / 4 layer is used as the retardation layer (referred to as a liquid crystal compound orientation layer in the transfer laminate). The front retardation of the λ / 4 layer is preferably 100 to 180 nm. More preferably, it is 120 to 150 nm. When only the λ / 4 layer is used as the circular polarizing plate, the orientation axis (slow phase axis) of the λ / 4 layer and the transmission axis of the polarizer are preferably 35 to 55 degrees, more preferably 40 degrees to 50 degrees, still more preferably. Is 42-48 degrees. When used in combination with the polarizer of a stretched film of polyvinyl alcohol, the absorption axis of the polarizer is generally in the length direction of the long polarizing film, so λ is used for the long transfer orientation film. When the / 4 layer is provided, it is preferable to orient the liquid crystal compound so as to be within the above range with respect to the length direction of the long transfer orientation film. When the angle of the transmission axis of the polarizer is different from the above, the liquid crystal compound is oriented so as to have the above relationship in consideration of the angle of the transmission axis of the polarizer.

A circular polarizing plate is produced by transferring the λ / 4 layer in the transfer laminate in which the λ / 4 layer and the alignment film are laminated to a polarizing plate. Specifically, the polarizing plate and the λ / 4 layer surface of the transfer laminate are laminated to form an intermediate laminate, and the alignment film is peeled from the intermediate laminate. The polarizing plate may be provided with protective films on both sides of the polarizer, but those provided with protective films on only one side are preferable. In the case of a polarizing plate in which a protective film is provided on only one side, it is preferable to attach a retardation layer to the opposite side (polarizer surface) of the protective film. If protective films are provided on both sides, it is preferable that the retardation layer is attached to the intended surface on the image cell side. The surface assumed on the image cell side is a surface that is generally provided on the viewing side, such as a low reflection layer, an antireflection layer, and an antiglare layer, and is not surface-processed. The protective film on the side to which the retardation layer is bonded is preferably a protective film made of TAC, acrylic, COP or the like and having no retardation.

As the polarizer, a polarizer made by stretching a PVA-based film alone, or a polarizer made by applying PVA to an unstretched base material such as polyester or polypropylene and stretching the base material together to protect the polarizer. Examples thereof include those transferred to a film and those in which a polarizer composed of a liquid crystal compound and a dichroic dye is coated or transferred to a polarizer protective film, and all of them are preferably used.

As a method of sticking, conventionally known ones such as an adhesive and an adhesive can be used. As the adhesive, a polyvinyl alcohol-based adhesive, an ultraviolet curable adhesive such as acrylic or epoxy, and a heat-curable adhesive such as epoxy or isocyanate (urethane) are preferably used. Examples of the adhesive include acrylic, urethane, and rubber adhesives. It is also preferable to use an optical transparent adhesive sheet without an acrylic base material.

When a transfer type polarizing element is used, the polarizer is transferred onto the retardation layer (liquid crystal compound alignment layer) of the transfer laminate, and then the polarizer and the retardation layer are subjected to an object (polarizer protective film). May be transferred to.

As the polarizer protective film on the side opposite to the side where the retardation layer is provided, generally known films such as TAC, acrylic, COP, polycarbonate, and polyester can be used. Of these, TAC, acrylic, COP, and polyester are preferable. Polyethylene terephthalate is preferable as the polyester. In the case of polyester, an in-plane retardation of 100 nm or less, particularly a zero retardation film of 50 nm or less, or a high retardation film of 3000 nm to 30,000 nm is preferable.

When using a high retardation film, the angle between the transmission axis of the polarizer and the slow axis of the high retardation film is in the range of 30 to 60 degrees for the purpose of preventing blackout and coloring when viewing the image with polarized sunglasses. Is preferable, and further, the range of 35 to 55 degrees is preferable. In order to reduce rainbow spots when observed from a shallow oblique direction with the naked eye, the angle between the transmission axis of the polarizer and the slow axis of the high retardation film should be 10 degrees or less, or even 7 degrees or less. , Or 80 to 100 degrees, more preferably 83 to 97 degrees.

The polarizing element protective film on the opposite side may be provided with an antiglare layer, an antireflection layer, a low reflection layer, a hard coat layer, and the like.

(Composite retardation layer)
With the λ / 4 layer alone, coloring may occur without becoming λ / 4 over a wide range of the visible light region. Therefore, the λ / 4 layer may be used in combination with the λ / 2 layer. The front retardation of the λ / 2 layer is preferably 200 to 360 nm. More preferably, it is 240 to 300 nm.

In this case, it is preferable that the λ / 4 layer and the λ / 2 layer are arranged at an angle such that the total becomes λ / 4. Specifically, the angle (θ) between the orientation axis (slow phase axis) of the λ / 2 layer and the transmission axis of the polarizer is preferably 5 to 20 degrees, more preferably 7 to 17 degrees. The angle between the orientation axis (slow phase axis) of the λ / 2 layer and the orientation axis (slow phase axis) of λ / 4 is preferably in the range of 2θ + 45 degrees ± 10 degrees, more preferably in the range of 2θ + 45 degrees ± 5 degrees. Yes, more preferably in the range of 2θ + 45 degrees ± 3 degrees.

Also in this case, when used in combination with the polarizer of the stretched film of polyvinyl alcohol, the absorption axis of the polarizer is generally in the length direction of the long polarizing film, so that it is used for long transfer. When the alignment film is provided with the λ / 2 layer or the λ / 4 layer, it is preferable to align the liquid crystal compound so as to be within the above range with respect to the length direction or the vertical direction of the length of the long transfer alignment film. .. When the angle of the transmission axis of the polarizer is different from the above, the liquid crystal compound is oriented so as to have the above relationship in consideration of the angle of the transmission axis of the polarizer.

As examples of these methods and retardation layers, JP-A-2008-149757, JP-A-2002-303722, WO2006 / 100830, JP-A-2015-64418 and the like can be referred to. ..

Further, it is also a preferable form to provide a C plate layer on the λ / 4 layer in order to reduce a change in coloring when viewed from an angle. As the C plate layer, a positive or negative C plate layer is used according to the characteristics of the λ / 4 layer and the λ / 2 layer.

As a method of laminating these, for example, if it is a combination of λ / 4 layer and λ / 2 layer,
-A λ / 2 layer is provided on the polarizer by transfer, and a λ / 4 layer is further provided on the polarizer by transfer.
-A λ / 4 layer and a λ / 2 layer are provided in this order on the alignment film for transfer, and these are transferred onto the polarizer.
-A λ / 4 layer, a λ / 2 layer, and a polarizing layer are provided in this order on the alignment film for transfer, and these are transferred to the object.
-A λ / 2 layer and a polarizing layer are provided in this order on the alignment film for transfer, and this is transferred to an object, and the λ / 4 layer is further transferred on this.
Various methods such as can be adopted.

Also, when stacking C plates, a method of transferring the C plate layer onto the λ / 4 layer provided on the polarizer, or providing a C plate layer on the alignment film and further λ / 4 layer on the C plate layer. Various methods such as a method of providing a λ / 2 layer and a λ / 4 layer and transferring them can be adopted.

The thickness of the circularly polarizing plate thus obtained is preferably 120 μm or less. It is more preferably 100 μm or less, further 90 μm or less, particularly 80 μm or less, and most preferably 70 μm or less.

(Inspection Method 1 for Transfer of Liquid Crystal Compound Orientation Layer)
Next, a method for inspecting the laminate for transferring the liquid crystal compound oriented layer of the present invention will be described.
The method for inspecting a laminate for transferring a liquid crystal compound oriented layer of the present invention is parallel to the orientation direction of the alignment film, the direction orthogonal to the orientation direction, the flow direction of the alignment film, or the direction orthogonal to the flow direction. It includes a step of irradiating linearly polarized light having an electric field vibration direction from the alignment film surface of the laminate and receiving light on the liquid crystal compound alignment layer surface side, and a step of inspecting whether or not the received light is extinguished. As described above, in the present invention, the liquid crystal compound alignment layer transfer laminate is laminated on the transfer alignment film even if the transfer alignment film has birefringence and the liquid crystal compound orientation layer is a retardation layer. The optical characteristics can be inspected in the state.

In order to inspect the optical state of the retardation layer, linearly polarized light parallel or perpendicular to the orientation direction of the transfer orientation film is irradiated, and the change in the polarization state is measured by a receiver installed on the opposite surface of the laminate. To detect. Parallel to the orientation direction of the transfer orientation film is preferably -10 to +10 degrees, more preferably -7 to 7 degrees, still more preferably -5 to 5 degrees, and particularly preferably -3 to 3 degrees. Is -2 to 2 degrees. The direction perpendicular to the orientation direction of the transfer orientation film is preferably 80 to 100 degrees, more preferably 83 to 97 degrees, further preferably 85 to 95 degrees, particularly preferably 87 to 93 degrees, and most preferably 88 to 92 degrees. Degree. If it exceeds the above range, the polarized light that hits the retardation layer or the polarized light that has passed through may be disturbed by the influence of the retardation of the base material, and accurate evaluation may not be possible.

The angle of the linearly polarized light to be irradiated may be adjusted according to the orientation direction of the transfer orientation film, but the inspection becomes complicated. Therefore, it is also preferable to fix the linearly polarized light to be irradiated as parallel or perpendicular to the flow direction of the transfer orientation film for inspection. Here the parallel or vertical range is the same as above.

When the transfer alignment film does not have birefringence, it is preferable to irradiate the transfer alignment film with linearly polarized light parallel or perpendicular to the flow direction (MD direction) for inspection. Here, the parallel or vertical range is the same as above.

It is preferable to provide a polarizing filter between the light receiver and the liquid crystal compound alignment layer (phase difference layer) transfer laminate (inspection target film). Further, a light that is elliptically polarized by the retardation layer of the liquid crystal compound alignment layer (phase difference layer) transfer laminate is designed between the liquid crystal compound alignment layer (phase difference layer) transfer laminate and the polarizing filter. In the case of elliptically polarized light, it is preferable to provide a retardation plate for converting to linearly polarized light. For example, with such a configuration, if the retardation layer is as designed, the light detected by the receiver is quenched, but if there is light leakage, the retardation layer is designed. It can be seen that it deviates from. It is also possible to install multiple types of receivers with slightly different angles of the polarizing filter and the angle / phase difference of the retardation plate, and detect in which direction and how much the phase difference and orientation direction of the retardation layer are deviated. .. Further, if the retardation layer has a defect in a minute region due to pinholes or scratches, it can be detected as a bright spot.

(Inspection method 2 for transfer of liquid crystal compound oriented layer)
As for the method for inspecting the laminate for transferring the liquid crystal compound oriented layer of the present invention, there is still another method, and this inspection method will be described.
In another method, elliptically polarized light is irradiated from the retardation layer surface of the liquid crystal compound alignment layer (phase difference layer) transfer laminate, and light is received on the alignment film surface side. The elliptically polarized light to be irradiated is elliptically polarized light that is converted into linearly polarized light when the retardation layer of the laminated body is as designed. For such elliptically polarized light, it is preferable to emit linearly polarized light and convert it with a retardation plate.
The direction of the emitted linearly polarized light is the same as that described in the inspection method 1.

The linearly polarized light converted by the retardation layer of the laminated body passes through the alignment film as linearly polarized light without being disturbed by the retardation of the alignment film. It is preferable to provide a polarizing filter between the light receiver and the liquid crystal compound alignment layer (phase difference layer) transfer laminate (inspection target film). The polarizing filter is preferably in a direction in which the passing linearly polarized light cannot be transmitted.

For example, with the above configuration, defects and deviations of the retardation layer can be detected as in the inspection method 1.

(Inspection Method 3 for Transfer of Liquid Crystal Compound Orientation Layer)
In the above two inspection methods, a light source and a light receiver were provided on both sides of the liquid crystal compound alignment layer transfer laminate, but the light source and the light receiver were provided on the same side and mirror reflection on the opposite side. Since the inspection can also be performed by the method of providing a plate, this method will be described.
In this method, linearly polarized light is applied from the alignment film surface of the liquid crystal compound alignment layer transfer laminate. The direction of the linearly polarized light to be irradiated is the same as that described in the inspection method 1.

For example, the light converted to circularly polarized light by the liquid crystal compound alignment layer is reflected by a mirror surface reflector provided on the surface opposite to the light source, and returns to the laminated body in a circularly polarized state. Then, after being converted into linearly polarized light again by the liquid crystal compound alignment layer of the laminated body, it is transmitted through the alignment film and received light. All the light passing through the alignment film is linearly polarized light, and by setting the angle, the light passes through the alignment film as linearly polarized light without being disturbed by the phase difference of the alignment film.
It is preferable to provide a polarizing filter between the receiver and the film to be inspected. The polarizing filter is preferably in a direction in which the reflected linearly polarized light cannot be transmitted.

As the mirror surface reflecting plate, a metal plate, a metal-deposited glass, a metal-deposited resin plate, or the like used as an optical surface mirror can be used.

A retardation plate may be provided between the film to be inspected and the specular reflector. When the liquid crystal compound alignment layer is a λ / 4 retardation layer or a λ / 2 retardation layer, a retardation plate is not always necessary, but a retardation plate having a slight retardation is provided as in Method 1. , It may be possible to understand how the phase difference of the liquid crystal compound alignment layer deviates from the design.
When the liquid crystal compound alignment layer is not a λ / 4 retardation layer or a λ / 2 retardation layer, linearly polarized light passes through the liquid crystal compound alignment layer-phase difference plate-mirror surface reflector-phase difference plate-liquid crystal compound alignment layer. It is preferable to provide a retardation plate that returns to linearly polarized light in such a case.

(Inspection of polarizing layer)
When the liquid crystal compound alignment layer is a polarizing layer, the polarizing layer can be inspected by irradiating natural light (unpolarized light) and receiving the transmitted light through a polarizing filter. Further, the inspection can be performed by irradiating the transfer laminate with light converted to linearly polarized light through a polarizing filter and receiving the transmitted light. In these cases, the polarizing filter is set at an angle that quenches the polarizing layer provided on the transfer alignment film when it is as designed.

It is also possible to install a plurality of types of receivers having slightly different angles of the polarizing filters and detect in which direction and how much the orientation direction is deviated.

Further, in these cases, it is preferable to irradiate the natural light from the surface side of the alignment film for transfer, and to irradiate the latter linearly polarized light from the surface of the polarizing layer.

The above-mentioned inspection of the polarizing layer is a method of inspecting by transmitting light through the transfer laminate, but as another method, as in the inspection method 3 of the liquid crystal compound oriented layer transfer laminate, the opposite of the light source. A method in which a mirror surface reflector is provided on the side and light is received on the same side as the light source may be used. Whether the light to be irradiated is natural light or linearly polarized light is the same as described above. When irradiating natural light and receiving light through the polarizing filter, the polarizing filter may be arranged between the laminate and the specular reflector, or between the laminate and the receiver.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples, and may be carried out with appropriate modifications to the extent that it can be adapted to the gist of the present invention. It is possible, and they are all within the technical scope of the invention. The method for evaluating the physical properties in the examples is as follows.

(1) Three-dimensional surface roughness SRa, SRz, SRy
Using a stylus type three-dimensional roughness meter (SE-3AK, manufactured by Kosaka Research Institute Co., Ltd.), the cutoff value in the longitudinal direction of the film is 0.25 mm under the conditions of a needle radius of 2 μm and a load of 30 mg. The needle was measured at a needle feed rate of 0.1 mm / sec over a measurement length of 1 mm, divided into 500 points at a pitch of 2 μm, and the height of each point was incorporated into a three-dimensional roughness analyzer (SPA-11). The same operation was continuously performed 150 times in the width direction of the film at intervals of 2 μm, that is, over 0.3 mm in the width direction of the film, and the data was taken into the analyzer. Next, the central surface average roughness (SRa), the ten-point average roughness (SRz), and the maximum height (SRy) were determined using an analyzer.

(2) Number of protrusions with a height difference of 0.5 μm or more (quenching surface) and 2.0 μm (back surface) or more It was set in a state where the extinction position was maintained by scissors between the boards to make it a cross Nicole state. In this state, using the Nikon Universal Projector V-12 (measurement conditions: projection lens 50x, transmitted illumination luminous flux switching knob 50x, transmitted light inspection), the part where light is transmitted and appears to shine (scratches, foreign matter) The one having a major axis of 50 μm or more was detected. The portion detected in this way is cut out from the test piece to an appropriate size, and a three-dimensional shape measuring device (Micromap TYPE 550 manufactured by Ryoka System Co., Ltd .; measurement conditions: wavelength 550 nm, WAVE mode, objective lens 10 times) is used. It was used, observed from a direction perpendicular to the film surface, and measured. At this time, the unevenness that approaches within 50 μm when observed from the direction perpendicular to the film surface is assumed to be the same scratches and a rectangle that covers them as foreign matter, and the length and width of this rectangle are the scratches and the length of the foreign matter. The width and width. With respect to these scratches and foreign substances, the number of defects was quantified using a cross-sectional image (SURFACE PROFILE DISPLAY). The measurement was performed on 20 test pieces and converted into the number of defects per ^{1 m 2.} On the release surface, the number of defects with a height difference (difference between the highest and lowest points) of 0.5 μm or more was counted, and on the back surface, the number of defects with a height difference of 2.0 μm or more was counted.

(3) Inspection of Defects of Phase Difference Layer A rubbing treatment orientation control layer or a photoalignment control layer was arranged as an orientation control layer between the transfer alignment film and the liquid crystal compound alignment layer, and a sample for inspection was prepared. The specific creation procedure is as follows.

(When the orientation control layer is a rubbing treatment orientation control layer)
A transfer orientation film is cut out to a size of A4, a coating for a rubbing treatment orientation control layer having the following composition is applied to the release layer surface using a bar coater, and dried at 80 ° C. for 5 minutes to form a film having a thickness of 100 nm. bottom. The cutout was made so that the orientation principal axis of the transfer orientation film was parallel to the long side of A4. Subsequently, the surface of the obtained film was treated with a rubbing roll wrapped with a brushed nylon cloth to obtain a transfer orientation film in which a rubbing treatment orientation control layer was laminated. The rubbing was performed so as to be 45 degrees with respect to the long direction of the alignment film for transfer.

Completely saponified polyvinyl alcohol Molecular weight 800 2 parts by mass Ion-exchanged water 100 parts by mass Surfactant 0.1 parts by mass

Subsequently, a solution for forming a retardation layer having the following composition was applied to the surface subjected to the rubbing treatment by a bar coating method. It was dried at 110 ° C. for 3 minutes, irradiated with ultraviolet rays and cured to provide a 1/4 wavelength layer, and an inspection sample was obtained.
LC242 (manufactured by BASF) 95 parts by mass Trimethylolpropane triacrylate 5 parts by mass Irgacure 379 3 parts by mass Surfactant 0.1 parts by mass Methyl ethyl ketone 250 parts by mass

(When the orientation control layer is a photo-alignment control layer)
Based on the description of Example 1, Example 2, and Example 3 of JP2013-33248, a cyclopentanone 5% by mass solution of a polymer represented by the following formula was produced and used as a coating material for a photoalignment control layer. ..

Next, the transfer orientation film was cut out to a size of A4, the coating material for the photoalignment control layer having the above composition was applied to the release layer surface using a bar coater, and dried at 80 ° C. for 1 minute to form a film having a thickness of 80 nm. Was formed. Subsequently, polarized UV light was irradiated in a direction of 45 degrees with respect to the long direction of the film to obtain a transfer alignment film in which a photoalignment control layer was laminated. These paints were filtered through a membrane filter having a pore size of 0.2 μm, and coating and drying were performed in a clean room.

Subsequently, a solution for forming a retardation layer was applied to the surface on which the photoalignment control layers were laminated by the bar coating method. It was dried at 110 ° C. for 3 minutes, irradiated with ultraviolet rays and cured, and a 1/4 wavelength layer was provided to obtain a sample for inspection.

Next, using these inspection samples, defects of the retardation layer were inspected by the following procedure.
A lower polarizing plate is placed on a surface emitting light source using a white LED using a yellow phosphor as a light source, and an inspection sample prepared as described above is placed on the lower polarizing plate in the quenching axis direction (absorption axis) of the polarizing plate. The direction) was placed so as to be parallel to the long side direction of the inspection sample. Further, a λ / 4 film made of a stretched film of cyclic polyolefin is placed on it so that the main axis of orientation is 45 degrees with the extinction axis of the lower polarizing plate, and the upper polarizing plate is placed on the upper polarizing plate. The extinguishing axis of the lower polarizing plate was placed so as to be parallel to the extinguishing axis of the lower polarizing plate. In this state, the quenching state was observed with the naked eye (center portion 15 cm × 20 cm) and a 20-fold loupe (5 cm × 5 cm), and evaluated according to the following criteria.
⊚: No bright spots were observed with the naked eye, and almost no bright spots were observed by loupe observation (2 or less in 5 cm × 5 cm).
◯: No bright spots were observed with the naked eye, and a small number of bright spots were observed by loupe observation (3 or more and 20 or less in 5 cm × 5 cm).
Δ: No bright spots were observed with the naked eye, but bright spots were observed by loupe observation (more than 20 at 5 cm × 5 cm).
X: Bright spots were observed with the naked eye, or there was an overall light leakage that was not observed but was considered to be due to the presence of many bright spots observed by loupe observation.

(4) Inspection of defects after superimposition 1
Two inspection samples using the above rubbing treatment orientation control layer were prepared, and the respective retardation layer installation surfaces and opposite surfaces were overlapped and weighted at ^{1 kg / cm 2 for 10 minutes.} The defects of the retardation layer of this sample were inspected in the same manner as in (3) Inspection of the retardation layer defects.

(5) Inspection of defects after superimposition 2
In the inspection 1 of defects after superimposition, it is difficult to understand the influence of the roughness of the back surface when the roughness of the release surface is large, so the photoalignment control layer of Experimental Example 2A having a small roughness of the release surface was used. Using the inspection sample, the effect of the roughness of the back surface of the inspection sample using the photoalignment control layer of another experimental example was investigated.
Specifically, the retardation layer installation surface of the inspection sample provided with the 1/4 wavelength layer on the photo-orientation control layer of Experimental Example 2A and the opposite surface of the inspection sample using the photo-orientation control layer of each experimental example ^They were overlapped and weighted at 1 kg / cm 2 for 10 minutes. The defects of the retardation layer of this sample (inspection sample of Experimental Example 2A) were inspected in the same manner as in (3) Inspection of the retardation layer defects.

(6) Intrinsic Viscosity 0.2 g of a resin sample is dissolved in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (60/40 (weight ratio)), and an Ostwald viscometer is used at 30 ° C. Was measured. As the sample of the surface layer A, a film sample extruded by the layer A alone was prepared and used as a sample.

(7) Content of Ester Cyclic Trimer The polyester resin constituting the release surface side layer of the polyester film was scraped off with a cutter knife and finely frozen and pulverized. 0.1 g of this pulverized resin was dissolved in 3 ml of a mixed solvent of hexafluoroisopropanol (HFIP) / chloroform (2/3 (volume ratio)). 20 ml of chloroform was added to the obtained solution and mixed uniformly. 10 ml of methanol was added to the obtained mixed solution to reprecipitate the linear polyester. The mixture was then filtered and the precipitate washed with 30 ml of a mixed solvent of chloroform / methanol (2/1 (volume ratio)) and further filtered. The obtained filtrate was concentrated to dryness with a rotary evaporator. 10 ml of dimethylformamide was added to the concentrated dry matter to prepare an ester cyclic trimer measurement solution, and the content of the ester cyclic trimer was determined by liquid chromatography.
(Measurement condition)
Equipment: L-7000 (manufactured by Hitachi, Ltd.)
Column: μ-Bondasphere C18 5μ 100 angstrom 3.9 mm x 15 cm (manufactured by Waters)
Solvent: Eluent A: 2% acetic acid / water (v / v)
Eluent B: Acetonitrile Gradient B%: 10 → 100% (0 → 55 minutes)
Flow velocity: 0.8 ml / min Temperature: 30 ° C
Detector: UV-258nm

(8) Precipitation amount of ester cyclic trimer on the surface of the release surface of the film The polyester film was cut into 15 cm × 15 cm and heated in an oven at 150 ° C. for 90 minutes. After that, the heat-treated film was placed on a 15 cm x 15 cm stainless steel plate with the release surface facing up, and a 15 cm x 15 cm silicone sheet (thickness 5 mm) with a 10 cm x 10 cm hole in the center was placed on it. A stainless steel plate having the same shape as the silicone sheet (thickness 2 mm) was placed on top of each other, and the peripheral portion was clipped. Then, 4 ml of DMF (dimethylsulfoamide) was placed in the central hole and left for 3 minutes, and then DMF was recovered. The amount of ester cyclic trimer in the recovered DMF was determined by liquid chromatography. This value was divided by the area of the film in contact with the DMF to obtain the precipitation amount (mg / m ² ) of the ester cyclic trimer on the surface of the release surface of the film.
(Measurement condition)
Equipment: ACQUITY UPLC (manufactured by Waters)
Column: BEH-C18 2.1 x 150 mm (manufactured by Waters)
Mobile phase: Eluent A: 0.1% formic acid (v / v)
Eluent B: Acetonitrile Gradient B%: 10 → 98 → 98% (0 → 25 → 30 minutes)
Flow rate: 0.2 ml / min Column temperature: 40 ° C
Detector: UV-258nm

(9) Winding stability The winding state of the film having a width of 1800 cm prepared in the experimental example was visually evaluated.
◯: The end of the roll was uniform without wrinkles, and stable winding was possible.
Δ: Wrinkles were observed in a part, but the end of the roll was almost uniform, and stable winding was possible.
X: Wrinkles were formed irregularly, and the unevenness at the end of the roll was large, so that stable winding could not be performed.

<Manufacturing of polyester resin for transfer orientation film>
(Manufacture of particle-free polyester resin (PET (X-m)))
When the temperature of the esterification reaction can was raised to 200 ° C., 86.4 parts by mass of terephthalic acid and 64.6 parts by mass of ethylene glycol were charged, and 0.017 parts by mass of antimony trioxide was used as a catalyst while stirring. 0.064 parts by mass of magnesium acetate tetrahydrate and 0.16 parts by mass of triethylamine were charged. Then, the pressure was raised, the pressure esterification reaction was carried out under the conditions of a gauge pressure of 0.34 MPa and 240 ° C., the esterification reaction can was returned to normal pressure, and 0.014 parts by mass of phosphoric acid was added. .. Further, the temperature was raised to 260 ° C. over 15 minutes, and 0.012 parts by mass of trimethyl phosphate was added. Then, after 15 minutes, dispersion treatment was carried out with a high-pressure disperser, and after 15 minutes, the obtained esterification reaction product was transferred to a polycondensation reaction can, and a polycondensation reaction was carried out under reduced pressure at 280 ° C.

After completion of the polycondensation reaction, filtration is performed with a Naslon filter having a 95% cut diameter of 5 μm, extruded into a strand shape from a nozzle, and cooled and solidified using cooling water that has been previously filtered (pore diameter: 1 μm or less). , It was cut into pellets to obtain a polyethylene terephthalate resin (PET (Xm)). The intrinsic viscosity of PET (X-m) was 0.62 dl / g, the content of the ester cyclic trimer was 1.05% by mass, and virtually no inert particles and internally precipitated particles were contained. ..

(Silica particle-containing polyester resin (manufacture of PET (Z-Si1)))
In the manufacture of PET (X-m)
15 minutes after the temperature was raised to 260 ° C. and trimethyl phosphate was added, the ethylene glycol slurry of the silica particles was added to the produced polyester so as to be 10000 ppm.
-A silica particle-containing polyethylene terephthalate resin having an intrinsic viscosity of 0.63 dl / g was obtained in the same manner except that the filtration treatment was performed with a Naslon filter (manufactured by Nippon Seisen Co., Ltd.) having a 95% cut diameter of 20 μm. rice field.
For the ethylene glycol slurry of silica particles, silica particles (manufactured by Fuji Silysia Chemical Ltd.) having an average particle diameter of 2.5 μm are charged in ethylene glycol, and further filtered with a viscose rayon filter having a 95% cut diameter of 30 μm. Manufactured by doing.

(Silica particle-containing polyester resin (manufacture of PET (Z-Si2)))
In the production of PET (Z-Si1), the same procedure was carried out except that porous colloidal silica having an average particle size of 0.9 μm was used as the silica particles, and a polyethylene terephthalate resin containing silica particles having an intrinsic viscosity of 0.63 dl / g was obtained. Obtained.

(Silica particle-containing polyester resin (manufacture of PET (Z-Si3)))
In the production of PET (Z-Si1), the same procedure was carried out except that porous colloidal silica having an average particle size of 0.2 μm was used as the silica particles, and a polyethylene terephthalate resin containing silica particles having an intrinsic viscosity of 0.63 dl / g was obtained. Obtained.

(Silica particle-containing polyester resin (manufacture of PET (Z-Si4)))
In the production of PET (Z-Si1), the same procedure was carried out except that porous colloidal silica having an average particle size of 0.06 μm was used as the silica particles, and a polyethylene terephthalate resin containing silica particles having an intrinsic viscosity of 0.63 dl / g was obtained. Obtained.

(Polyester resin containing calcium carbonate particles (manufacturing of PET (Z-Ca)))
In the production of PET (Z-Si1), the same procedure was carried out except that the ethylene glycol slurry of calcium carbonate particles was used instead of the ethylene glycol slurry of silica particles, and the polyethylene terephthalate containing calcium carbonate particles having an intrinsic viscosity of 0.63 dl / g was used. Obtained resin.
The ethylene glycol slurry of calcium carbonate particles was produced by using calcium carbonate particles (manufactured by Maruo Calcium Co., Ltd.) having an average particle diameter of 0.6 μm instead of silica particles.

(Production of Crosslinked Polystyrene Particle-Containing Polyester Resin (PET (Z-St)) A 10% by mass aqueous dispersion of PET (Xm) and crosslinked polystyrene particles having an average particle size of 0.30 μm is supplied to a twin-screw extruder with a vent. The resin was heated and melted at 280 ° C., and the vent holes were reduced to a reduced pressure of 1 kPa or less to remove water. The melted polyester was filtered with a 95% cut diameter 20 μm Naslon filter and extruded into strands from a nozzle. , It was cooled and solidified using cooling water that had been previously filtered (pore size: 1 μm or less), and cut into pellets. The obtained crosslinked polystyrene particle-containing polyester resin (PET (Z-St)) had an intrinsic viscosity of 0. It was .62 dl / g and the crosslinked polystyrene particle content was 10000 ppm.

Experimental Examples 1A-4A
As a raw material for the release layer side of the alignment film for transfer, PET (X-m) resin pellets containing no particles are dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours, and then supplied to the extruder 1 to be supplied to the contralateral layer. As a raw material for (back surface layer), PET (X-m) resin pellets and polyester (PET (Z-Si1)) resin pellets containing particles are shown in Table 1, and the particle content of the opposite surface layer (back surface layer) is shown in Table 1. The blended material was dried and supplied to the extruder 2 and melted at 285 ° C. These two types of molten polymers are each filtered through a filter medium of a stainless sintered body (nominal filtration accuracy of 10 μm particles 95% cut), laminated in a two-type two-layer confluence block, and extruded into a sheet from a mouthpiece. Using the electrostatic application casting method, the film was wound around a casting drum having a surface temperature of 30 ° C. and cooled and solidified to prepare an unstretched film. At this time, the discharge amount of each extruder was adjusted so that the thickness of the release layer and the back surface layer became the predetermined values shown in Table 1.

This unstretched film was guided to a tenter stretching machine, and while gripping the end of the film with a clip, it was guided to a hot air zone having a temperature of 125 ° C. and stretched 4.0 times in the width direction. Next, while maintaining the width stretched in the width direction, heat fixing treatment was performed at a temperature of 210 ° C. for 10 seconds, and further relaxation treatment of 3.0% was performed. Then, both ends of the film cooled to 130 ° C. were cut with a shear blade ^{, the ears were cut off with a tension of 0.5 kg / mm 2} , and then wound up to obtain a uniaxially oriented PET film (width 1800 cm) having a film thickness of 50 μm. rice field. The central portion of the obtained film was slit to a width of 50 cm to obtain a film roll (alignment film for transfer) having a length of about 500 m.

Experimental Examples 5A, 6A
Of the raw materials for the opposite surface layer (back surface layer), the film roll (alignment film for transfer) is the same as in Experimental Examples 1A to 4A except that the PET (Z-Si1) resin pellet is changed to PET (Z-Ca). ) Was obtained.

Experimental Example 7A
The unstretched film produced by the same method as in Experimental Example 1A is heated to 105 ° C. using a heated roll group and an infrared heater, and then stretched 3.3 times in the traveling direction in the roll group having a peripheral speed difference. After that, the film was guided to a hot air zone having a temperature of 135 ° C. and stretched 3.5 times in the width direction to set the heat fixing temperature to 225 ° C. An oriented PET film was obtained. The central portion of the obtained film was slit to a width of 50 cm to form a film roll having a length of about 500 m. The film thickness was adjusted by changing the extrusion amount to increase the thickness of the unstretched film.

Experimental Example 8A
A film roll (alignment film for transfer) was obtained in the same manner as in Experimental Example 7A, except that an unstretched film prepared by the same method as in Experimental Example 5A was used.

Experimental Example 9A
Among the raw materials for the opposite surface layer (back surface layer), the same as in Experimental Examples 1A to 4A except that the PET (Z-Si1) resin pellets were changed to a combination of PET (Z-Si2) and PET (Z-Ca). A film roll (alignment film for transfer) was obtained.

Experimental Example 10A
PET (X-m) resin pellets and PET (Z-Si4) resin pellets are used as raw materials for the release layer side of the alignment film for transfer, and the particle content of the release layer has a predetermined value shown in Table 1. The blended product at such a ratio is dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours, and then supplied to the extruder 1 to use PET (X-m) resin pellets and particles as a raw material for the opposite surface layer (back surface layer). (PET (Z-Si3) and PET (Z-St)) resin pellets containing the above were blended at a ratio such that the particle content of the opposite surface layer (back surface layer) became a predetermined value shown in Table 1. The product was dried and supplied to the extruder 2, and PET (X-m) resin pellets as a raw material for the intermediate layer were dried and supplied to the extruder 3 and melted at 285 ° C. These three types of molten polymers are filtered through a filter medium of a stainless sintered body (nominal filtration accuracy of 10 μm particles 95% cut), laminated in a three-layer three-layer confluence block, and extruded into a sheet from the base. Using the electrostatic application casting method, the film was wound around a casting drum having a surface temperature of 30 ° C. and cooled and solidified to prepare an unstretched film. At this time, the discharge amount of each extruder was adjusted so that the thickness of the release layer and the back surface layer became the predetermined values shown in Table 1. After that, uniaxial stretching was carried out in the same manner as in Experimental Examples 1A to 4A to obtain a film roll (alignment film for transfer).

Experimental Example 11A
A film roll (alignment film for transfer) was obtained in the same manner as in Experimental Example 10A, except that biaxial stretching was carried out in the same manner as in Experimental Example 7A instead of uniaxial stretching.

Experimental Example 12A
A coating agent having the following composition was applied to the release layer surface of the film of Experimental Example 1A and dried in a heating oven at 150 ° C. for 3 minutes to form a flattening and oligomer block coat layer. The thickness of the coat layer was 2 μm.
・ Melamine cross-linked alkyl-modified alkyd resin (Hitachi Kasei Polymer Co., Ltd .: Tessfine 322: solid content 40%) 10 parts by mass ・ P-toluenesulfonic acid (Hitachi Kasei Polymer Co., Ltd .: dryer 900)
0.1 part by mass / solvent (toluene / methyl ethyl ketone = 1/1 part by mass) 40 parts by mass The coating agent was filtered through a 2 μm filter, and the air during drying was filtered through a HEPA filter with a 95% cut diameter of 1 μm. After that, a HEPA filter having a 99.9% cut diameter of 0.3 μm was used for high-precision filtration. Further, the coating agent was applied to the film in a class 1,000 environment. Hereinafter, the coating and drying steps were carried out in the same environment.

Experimental Example 13A
In Experimental Example 12A, a film roll (alignment film for transfer) was obtained in the same manner as in Experimental Example 12A, except that the thickness of the surface layer was changed from 10 μm to 25 μm and the thickness of the back surface layer was changed from 40 μm to 25 μm.

Experimental Example 14A
On the opposite surface of the release surface of Experimental Example 9A, a coating solution prepared by diluting Byron RV220 (manufactured by Toyobo) with a toluene / methyl ethyl ketone (= 1: 1) solution so as to have a solid content of 7% by mass is applied to a gravure coater. And dried at 120 ° C. for 30 seconds to form a flattening coat layer on the back surface.

Experimental Example 15A
Particle-free PET (Xm) resin pellets were supplied to neither of the extruders 1 and 2 to prepare an unstretched film. Next, a coating liquid having the following composition was applied to one side of this unstretched film ^{so that the coating amount after drying was 0.1 g / m 2} , followed by a dryer, and dried at 80 ° C. for 20 seconds. An easy-to-slip coat layer was formed on the back surface. An easy-slip coat layer was provided with the casting drum contact surface as the back surface.

(Coating liquid 1)
Water 50.00 parts by mass Isopropyl alcohol 36.10 parts by mass Polyester aqueous dispersion 13.00 parts by mass (Toyobo MD-1200 solid content concentration 34% by mass)
Colloidal silica 0.60 parts by mass (Nissan Chemical Industries, Ltd., MP2040, average particle size 200 nm, solid content concentration 40% by mass)
Surfactant (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

Next, the unstretched film was guided to a tenter stretching machine, and while gripping the end portion of the film with a clip, the unstretched film was guided to a hot air zone having a temperature of 125 ° C. and stretched 4.0 times in the width direction. Next, while maintaining the width stretched in the width direction, heat fixing treatment was performed at a temperature of 210 ° C. for 10 seconds, and further relaxation treatment of 3.0% was performed. Then, both ends of the film cooled to 130 ° C. were cut with a shear blade ^{, the ears were cut off with a tension of 0.5 kg / mm 2} , and then wound up to obtain a uniaxially oriented PET film (width 1800 cm) having a film thickness of 50 μm. rice field. The central portion of the obtained film was slit to a width of 50 cm to obtain a film roll (alignment film for transfer) having a length of about 500 m.

Experimental Example 16A
A film roll (alignment film for transfer) having an easy-slip coat layer formed on the back surface was obtained in the same manner as in Experimental Example 15A except that the coating liquid was changed to a coating liquid having the following composition.

Water 55.62% by mass
Isopropanol 30.00% by mass
Polyurethane resin (D-1) 11.29% by mass
Oxazoline-based cross-linking agent (E-1) 2.26% by mass
Particle 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
Particle 0.07% by mass
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicone type, solid content concentration 100% by mass)
(Solid content concentration 10% by mass)

The polyurethane resin (D-1) and the oxazoline-based cross-linking agent (E-1) in the above composition were produced by the following procedure.
(Manufacturing of polyurethane resin (D-1))
A polyurethane resin D-1 containing an aliphatic polycarbonate polyol as a constituent was produced by the following procedure. In a four-necked flask equipped with a stirrer, Dimroth condenser, nitrogen introduction tube, silica gel drying tube, and thermometer, 43.75 parts by mass of 4,4-diphenylmethane diisocyanate, 12.85 parts by mass of dimethylolbutanoic acid, number. 153.41 parts by mass of polyhexamethylene carbonate diol with an average molecular weight of 2000, 0.03 parts by mass of dibutyltin dilaurate, and 84.00 parts by mass of acetone as a solvent were added, and the mixture was stirred at 75 ° C. for 3 hours under a nitrogen atmosphere to prepare a reaction solution. Was confirmed to have reached the prescribed amine equivalent. Next, the reaction solution was cooled to 40 ° C., and then 8.77 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Next, 450 g of water was added to a reaction vessel equipped with a homodisper capable of high-speed stirring, the temperature was adjusted to 25 ° C., and the polyurethane prepolymer solution was added and water-dispersed while stirring and mixing at 2000 min-1. .. Then, a water-soluble polyurethane resin (D-1) having a solid content concentration of 35% by mass was prepared by removing a part of acetone and water under reduced pressure. The glass transition temperature of the obtained polyurethane resin (D-1) was −30 ° C.

(Production of Oxazoline-based Crosslinking Agent (E-1))
A flask equipped with a thermometer, a nitrogen gas introduction tube, a reflux condenser, a dropping funnel, and a stirrer, a mixture of 58 parts by mass of ion-exchanged water as an aqueous medium and 58 parts by mass of isopropanol, and a polymerization initiator (2,2). '-Azobis (2-amidinopropane), dihydrochloride) 4 parts by mass was added. On the other hand, in the dropping funnel, 16 parts by mass of 2-isopropenyl-2-oxazoline as a polymerizable unsaturated monomer having an oxazoline group, methoxypolyethylene glycol acrylate (average number of moles of ethylene glycol added: 9 mol, Shin-Nakamura Chemical Co., Ltd.) A mixture of 32 parts by mass and 32 parts by mass of methyl methacrylate was added and added dropwise at 70 ° C. for 1 hour under a nitrogen atmosphere. After completion of the dropping, the reaction solution was stirred for 9 hours and cooled to obtain a water-soluble resin (E-1) having an oxazoline group having a solid content concentration of 40% by mass.

Experimental Example 17A
In Experimental Example 1A, the particle content in the back surface layer was changed from 300 ppm to 2000 ppm, the ratio of the thickness of the release layer to the back surface layer was changed from 10/40 to 25/25, and the release layer surface was changed to Experimental Example. A film roll (alignment film for transfer) was obtained in the same manner as in Experimental Example 1A except that a flattening and oligomer block coat layer was added in the same manner as in 12A.

Experimental Example 18A
As a raw material for the release layer side of the alignment film for transfer, PET (Xm) resin pellets are dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours and then supplied to the extruder 1 to supply the opposite surface layer (back surface layer). PET (X-m) resin pellets are dried and supplied to the extruder 2 as raw materials for the intermediate layer, and PET (X-m) resin pellets and PET (Z-Si1) resin pellets are used as raw materials for the intermediate layer. The blended material in which the particle content of the intermediate layer had a predetermined value shown in Table 1 was dried and supplied to the extruder 3 and dissolved at 285 ° C. These three types of molten polymers are filtered through a filter medium of a stainless sintered body (nominal filtration accuracy of 10 μm particles 95% cut), laminated in a three-layer three-layer confluence block, and extruded into a sheet from the base. Using the electrostatic application casting method, the film was wound around a casting drum having a surface temperature of 30 ° C. and cooled and solidified to prepare an unstretched film. At this time, the discharge amount of each extruder was adjusted so that the thicknesses of the release layer, the intermediate layer, and the back surface layer became the predetermined values shown in Table 1. After that, uniaxial stretching was carried out in the same manner as in Experimental Examples 1A to 4A to obtain a film roll (alignment film for transfer).

Experimental Example 1B
As a raw material for the release layer side of the alignment film for transfer, PET (X-m) resin pellets containing no particles are dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours, and then supplied to the extruder 1 to be supplied to the contralateral layer. As a raw material for (back surface layer), PET (X-m) resin pellets and polyester (PET (Z-Si1)) resin pellets containing particles are shown in Table 1, and the particle content of the opposite surface layer (back surface layer) is shown in Table 1. The blended material was dried and supplied to the extruder 2 and melted at 285 ° C. These two types of molten polymers are each filtered through a filter medium of a stainless sintered body (nominal filtration accuracy of 10 μm particles 95% cut), laminated in a two-type two-layer confluence block, and extruded into a sheet from a mouthpiece. Using the electrostatic application casting method, the film was wound around a casting drum having a surface temperature of 30 ° C. and cooled and solidified to prepare an unstretched film. At this time, the discharge amount of each extruder was adjusted so that the thickness of the release layer and the back surface layer became the predetermined values shown in Table 1.

This unstretched film was guided to a tenter stretching machine, and while gripping the end of the film with a clip, it was guided to a hot air zone having a temperature of 125 ° C. and stretched 4.0 times in the width direction. Next, while maintaining the width stretched in the width direction, heat fixing treatment was performed at a temperature of 210 ° C. for 10 seconds, and further relaxation treatment of 3.0% was performed. Then, both ends of the film cooled to 130 ° C. were cut with a shear blade ^{, the ears were cut off with a tension of 0.5 kg / mm 2} , and then wound up to obtain a uniaxially oriented PET film (width 1800 cm) having a film thickness of 50 μm. rice field. The central portion of the obtained film was slit to a width of 50 cm to obtain a film roll (alignment film for transfer) having a length of about 500 m.

Experimental Example 2B
A commercially available biaxially stretched polyester film (Toyobo Co., Ltd., Toyobo Ester (R) film, E5100) was used as the alignment film for transfer. The non-corona surface was used as the release surface.

Experimental Example 3B
A film roll (alignment film for transfer) was obtained in the same manner as in Experimental Example 16A except that the slippery coat layer was not provided. Since the winding was wrinkled and stable winding was not possible, the transfer orientation film was not evaluated. In the roughness measurement, the non-contact surface of the casting drum was evaluated as the mold release surface, and the contact surface of the casting drum was evaluated as the back surface.

Table 1 shows the production conditions and characteristics of the transfer orientation films of Experimental Examples 1A to 18A and Experimental Examples 1B to 3B, and the evaluation results.

As is clear from Table 1, in each of Experimental Examples 1A to 18A in which the surface roughness of the release surface satisfies the requirements of the first invention, among the defect evaluations, the defects and the photo-orientation when the rubbing treatment orientation control layer is provided. The drawbacks of having a control layer were remarkably small, and the occurrence of pinhole-shaped or scratch-shaped light leakage was sufficiently suppressed. On the other hand, in Experimental Example 1B, in which the particle content of the back surface layer is too large and the surface roughness of the release surface is too large, among the defect evaluations, the defects and the photo-orientation especially when the rubbing treatment orientation control layer is provided. There are many drawbacks when the control layer is provided, and it is not possible to suppress the occurrence of pinhole-shaped or scratch-shaped light leakage. Similarly, in Experimental Example 2B, which does not have a slippery coating layer on the back surface as compared with Experimental Examples 15A and 16A and the surface roughness of the release surface is too large, among the defect evaluations, the rubbing treatment orientation control layer was particularly used. The drawbacks of having a photo-alignment control layer and the defects of having a photo-alignment control layer were remarkably large, and it was not possible to suppress the occurrence of pinhole-shaped or scratch-shaped light leakage.

Further, as is clear from Table 1, all of Experimental Examples 1A to 3A, 5A to 16A, and 18A in which the surface roughness of the surface (back surface) opposite to the release surface satisfies the requirements of the second invention are drawbacks. In the evaluation, there were remarkably few defects, and the occurrence of pinhole-shaped or scratch-shaped light leakage was sufficiently suppressed. On the other hand, in Experimental Example 3B, in which the surface roughness of the back surface is too small because the particles are not contained and the slippery coat layer is not provided on the back surface, the winding stability is inferior and stable winding cannot be performed. There was a problem. Further, in Experimental Examples 4A and 1B in which the particle content of the particles in the back surface layer is too large and the surface roughness on the back surface is too large, defects 1 and 2 after superimposition are remarkably large, and pinhole-like or scratch-like. The occurrence of light leakage could not be suppressed.

The liquid crystal compound alignment layer transfer alignment film of the present invention uses a film whose surface roughness is controlled within a specific range as an alignment film for transfer of a retardation layer or a polarizing layer, and is opposite to the release surface. Since a film in which the surface roughness of the side surface is controlled within a specific range is used as an alignment film for transfer of the retardation layer and the polarizing layer, the alignment state of the liquid crystal compound in the retardation layer and the polarizing layer And the retardation can be as designed, and a retardation layer or a polarizing layer (liquid crystal compound alignment layer) can be formed in which the occurrence of defects such as pinholes is reduced. Therefore, according to the present invention, a retardation layer laminated polarizing plate such as a circular polarizing plate can be stably manufactured with high quality.

Claims (18)

An alignment film for transferring a liquid crystal compound alignment layer to an object, wherein the surface roughness (SRa) of the release surface of the alignment film is 1 nm or more and 30 nm or less. Orientation film. The alignment film for transferring a liquid crystal compound alignment layer according to claim 1, wherein the 10-point surface roughness (SRz) of the release surface of the alignment film is 5 nm or more and 200 nm or less. The alignment film for transferring a liquid crystal compound alignment layer according to claim 1 or 2, wherein the alignment film is a polyester film. A laminate for transferring a liquid crystal compound alignment layer, which is a laminate in which a liquid crystal compound alignment layer and an alignment film are laminated, wherein the alignment film is the alignment film according to any one of claims 1 to 3. A liquid crystal compound orientation comprising a step of laminating a polarizing plate and a liquid crystal compound orientation layer surface of the laminate according to claim 4 to form an intermediate laminate, and a step of peeling an alignment film from the intermediate laminate. A method for manufacturing a layer-laminated polarizing plate. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 4, wherein the orientation state of the alignment film, the direction orthogonal to the orientation direction, or the flow direction of the alignment film, or Lamination for transfer of liquid crystal compound alignment layer, which comprises a step of irradiating linearly polarized light having an electric field vibration direction parallel to a direction orthogonal to the flow direction from the alignment film surface of the laminate and receiving light on the liquid crystal compound alignment layer surface side. How to inspect the body. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 4, comprising a step of irradiating elliptically polarized light from the liquid crystal compound alignment layer surface of the laminate and receiving light on the alignment film surface side. A method for inspecting a laminate for transferring a liquid crystal compound oriented layer. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 4, wherein the orientation state of the alignment film, the direction orthogonal to the orientation direction, or the flow direction of the alignment film, or A step of irradiating linearly polarized light having an electric field vibration direction parallel to the flow direction from the alignment film surface of the laminate, and a mirror surface provided on the liquid crystal compound alignment layer side of the laminate with light transmitted through the laminate. A method for inspecting a laminate for transferring a liquid crystal compound alignment layer, which comprises a step of reflecting the reflected light by a reflecting plate and a step of receiving the reflected light on the alignment film side. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 4, wherein at least the step of irradiating the laminate with polarized light to pass the polarized light through the laminate and passing through the laminate. Including the step of receiving polarized light, the direction in which the polarized light passing through the alignment film of the laminated body is in the orientation direction of the alignment film, in the direction orthogonal to the alignment direction, in the flow direction of the alignment film, or in the direction orthogonal to the flow direction. A method for inspecting a laminated body for transferring a liquid crystal compound oriented layer, characterized in that it is linearly polarized light having an electric field vibration direction parallel to the polarized light or the polarized light passing through the liquid crystal compound oriented layer surface of the laminated body is elliptically polarized light. An alignment film for transferring a liquid crystal compound alignment layer to an object, in which the surface roughness (SRa) of the surface opposite to the release surface of the alignment film is 1 nm or more and 50 nm or less, and the alignment film has a surface roughness (SRa) of 1 nm or more and 50 nm or less. A liquid crystal compound alignment layer transfer alignment film, characterized in that the 10-point surface roughness (SRz) of the surface opposite to the release surface is 10 nm or more and 1500 nm or less. The alignment film for transfer of a liquid crystal compound alignment layer according to claim 10, wherein the maximum height (SRy) of the surface opposite to the release surface of the alignment film is 15 nm or more and 2000 nm or less. The alignment film for transferring a liquid crystal compound alignment layer according to claim 10 or 11, wherein the alignment film is a polyester film. A laminate for transferring a liquid crystal compound alignment layer, which is a laminate in which a liquid crystal compound alignment layer and an alignment film are laminated, wherein the alignment film is the alignment film according to any one of claims 10 to 12. A liquid crystal compound orientation comprising a step of laminating a polarizing plate and a liquid crystal compound orientation layer surface of the laminate according to claim 13 to form an intermediate laminate, and a step of peeling an alignment film from the intermediate laminate. A method for manufacturing a layer-laminated polarizing plate. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 13, which is in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film, or Lamination for transfer of liquid crystal compound alignment layer, which comprises a step of irradiating linearly polarized light having an electric field vibration direction parallel to a direction orthogonal to the flow direction from the alignment film surface of the laminate and receiving light on the liquid crystal compound alignment layer surface side. How to inspect the body. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 13, which comprises a step of irradiating the liquid crystal compound alignment layer surface of the laminate with elliptically polarized light and receiving light on the alignment film surface side. A method for inspecting a laminate for transferring a liquid crystal compound oriented layer. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 13, which is in the orientation direction of the alignment film, in the direction orthogonal to the orientation direction, or in the flow direction of the alignment film. A step of irradiating linearly polarized light having an electric field vibration direction parallel to the flow direction from the alignment film surface of the laminate, and a mirror surface provided on the liquid crystal compound alignment layer side of the laminate with light transmitted through the laminate. A method for inspecting a laminate for transferring a liquid crystal compound alignment layer, which comprises a step of reflecting the reflected light by a reflecting plate and a step of receiving the reflected light on the alignment film side. The method for inspecting the orientation state of the liquid crystal compound alignment layer in the laminate according to claim 13, at least a step of irradiating the laminate with polarized light to pass the polarized light through the laminate, and passing through the laminate. Including the step of receiving polarized light, the direction in which the polarized light passing through the alignment film of the laminated body is in the orientation direction of the alignment film, in the direction orthogonal to the alignment direction, in the flow direction of the alignment film, or in the direction orthogonal to the flow direction. A method for inspecting a laminated body for transferring a liquid crystal compound oriented layer, which is linearly polarized light having an electric field vibration direction parallel to the polarized light, or polarized light passing through a liquid crystal compound oriented layer surface of the laminated body is elliptically polarized light.