WO2020085310A1

WO2020085310A1 - Liquid crystal compound alignment layer transfer film

Info

Publication number: WO2020085310A1
Application number: PCT/JP2019/041326
Authority: WO
Inventors: 佐々木　靖; 村田　浩一
Original assignee: 東洋紡株式会社
Priority date: 2018-10-26
Filing date: 2019-10-21
Publication date: 2020-04-30
Also published as: KR20210082159A; CN112771422A; KR20210079273A; CN112771423A; TW202033632A; JPWO2020085308A1; WO2020085308A1; CN112771423B; JPWO2020085310A1; TW202033339A; CN116804778A; CN112805136A; KR20210079272A; CN112805136B; CN112771422B; JPWO2020085307A1; TWI824046B; WO2020085307A1; CN112789531B; KR20210082163A

Abstract

Provided is a cyclic polyolefin-based transfer film for transferring a liquid crystal compound alignment layer, which is capable of forming a retardation layer or a polarizing layer (liquid crystal compound alignment layer) with reduced occurrence of defects such as pinholes. This liquid crystal compound alignment layer transfer film is the cyclic polyolefin-based film for transferring a liquid crystal compound alignment layer to an object, and is characterized in that a surface roughness (SRa) of a release surface of the film is 1-30 nm (inclusive).

Description

Liquid crystal compound alignment layer transfer film

The present invention relates to a transfer film for transferring a liquid crystal compound alignment layer. More specifically, when manufacturing a polarizing plate or a retardation plate such as a circularly polarizing 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. For example, the present invention relates to a transfer film for transferring a liquid crystal compound alignment layer.

Conventionally, in image display devices, a circularly polarizing plate is arranged on the viewer-side panel surface of the image display panel in order to reduce reflection of extraneous light. This circularly polarizing plate is composed of a laminated body of a linearly polarizing plate and a retardation film such as λ / 4, and converts external light traveling toward the panel surface of the image display panel into linearly polarized light by the linearly polarizing plate, and then λ / It is converted into circularly polarized light by a retardation film such as 4. Circularly polarized extraneous light reverses the direction of rotation of the polarization plane when reflected on the surface of the image display panel, and this reflected light is conversely shielded by a linear polarizing plate by a retardation film such as λ / 4. Since the light is converted into linearly polarized light in the direction indicated by the arrow and is then shielded by the linearly polarizing plate, it is possible to suppress the emission to the outside. As described above, the circularly polarizing plate is formed by laminating a retardation film such as λ / 4 on the polarizing plate.

As the retardation film, a single retardation film such as a cyclic olefin (see Patent Document 1), polycarbonate (see Patent Document 2), or a stretched film of triacetyl cellulose (see Patent Document 3) is used. 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. It is described above that the liquid crystal compound may be transferred when the retardation layer (liquid crystal compound alignment layer) made of the liquid crystal compound is provided.

Also, a method for producing a retardation film by transferring a retardation layer made of a liquid crystal compound to a transparent film is known from Patent Document 6 and the like. There is also known a method of forming a λ / 4 film by providing a retardation layer made of a liquid crystal compound such as λ / 4 on a transparent film by such a transfer method (see Patent Documents 7 and 8).

Various materials have been introduced as transfer base materials in these transfer methods, and transparent resin films such as polyester, triacetyl cellulose, and cyclic polyolefin are often exemplified. Among these, the cyclic polyolefin film is preferable because it has no refractive index anisotropy, and thus the state of the retardation layer can be inspected (evaluated) in the state where the retardation layer is provided on the film substrate.

However, when a retardation layer laminated polarizing plate (circular polarizing plate) manufactured by using a cyclic polyolefin film as a film substrate for transfer is used for antireflection of an image display device, it has a pinhole shape or a scratch shape. However, there was a problem that light leakage occurred.

A method for producing a polarizing plate by transferring a polarizing layer (liquid crystal compound alignment layer) containing a liquid crystal compound and a dichroic dye laminated on a transfer film to a protective film is also known. However, similar to the above, there is a problem that light leakage may occur in the form of pinholes or scratches.

Japanese Patent Laid-Open No. 2012-56322 JP, 2004-144943, A JP-A-2004-46166 JP, 2006-243653, A JP 2001-4837 A JP-A-4-57017 JP, 2014-071381, A JP, 2017-146616, A

The present invention has been made against the background of such problems of the conventional technology. That is, the object of the present invention is a cyclic polyolefin-based transfer film for transferring a liquid crystal compound alignment layer, in which the occurrence of defects such as pinholes is reduced and a retardation layer or a polarizing layer (liquid crystal compound alignment layer). It is intended to provide a transfer film capable of forming a film.

In order to achieve such an object, the present inventor has a drawback such as a pinhole in a retardation layer laminated polarizing plate (circular polarizing plate) manufactured by using a cyclic polyolefin film as a film substrate for transfer. I examined the cause. As a result, the microstructure on the surface of the film substrate greatly affects the alignment state and the retardation of the liquid crystal compound in the retardation layer made of the liquid crystal compound formed on the film substrate, and the alignment state as designed. It has been found that, in some cases, a phase difference cannot be obtained, which causes defects such as pinholes. Then, the present inventor pays attention to the surface roughness of the film base material represented by specific parameters among these microstructures, and uses the film base material whose surface roughness is controlled within a specific range. As a result, it has been found that it is possible to form a retardation layer or a polarizing layer (liquid crystal compound alignment layer) in which the occurrence of defects such as pinholes is reduced without causing the above-mentioned conventional problems, and to complete the present invention. I arrived.

That is, the present invention has the following configurations (1) to (4).
(1) A cyclic polyolefin-based transfer film for transferring an alignment layer of a liquid crystal compound onto an object, wherein the release film has a surface roughness (SRa) of 1 nm or more and 30 nm or less. A film for transferring a liquid crystal compound alignment layer.
(2) The film for transferring a liquid crystal compound alignment layer according to (1), wherein the release surface of the transfer film has a 10-point surface roughness (SRz) of 5 nm or more and 200 nm or less.
(3) A liquid crystal compound alignment layer comprising a laminate of a liquid crystal compound alignment layer and a transfer film, wherein the transfer film is the transfer film according to (1) or (2). Transfer laminate.
(4) a step of adhering the polarizing plate and the liquid crystal compound alignment layer surface of the laminate described in (3) to form an intermediate laminate, and a step of peeling the transfer film from the intermediate laminate. A method for manufacturing a polarizing plate laminated with a liquid crystal compound alignment layer.

According to the present invention, by using a cyclic polyolefin film whose surface roughness is controlled within a specific range as a transfer film for a retardation layer or a polarizing layer, the liquid crystal compound in the retardation layer or the polarizing layer is It is possible to form the retardation layer and the polarizing layer (liquid crystal compound orientation layer) in which the orientation state and the retardation can be made as designed and the occurrence of defects such as pinholes is reduced.

The transfer film of the present invention is for transferring the liquid crystal compound alignment layer to an object (other transparent resin film, polarizing plate, etc.), and has a surface roughness (SRa) of the release surface of the transfer film. It is characterized by being 1 nm or more and 30 nm or less. The transfer film may be a single film, or a release film may be provided on the film serving as a base material by coating or the like. Further, an antistatic layer, a slipping layer or the like may be provided on the back surface. Incidentally, in the present invention, those used as a transfer film alone without using a layer such as a release coat, and those used as a transfer film by providing a release coat or a back coat are collectively referred to as a transfer film. The film in the state before the coating is provided is called the base film.

The resin constituting the film substrate used in the transfer film of the present invention is a cyclic polyolefin type resin. The cyclic polyolefin is a compound containing an alicyclic structure in the repeating unit of the polymer. Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure, and the cycloalkane structure is preferable from the viewpoint of transparency. The proportion of repeating units having an alicyclic structure in the cyclic polyolefin may be appropriately selected according to the purpose of use, but is usually 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. . Preferred cyclic polyolefins include norbornene-based polymers, and hydrogenated norbornene-based polymers are particularly preferred. As these, those used as an optical film can be used as a suitable example.

The transfer film of the present invention may have a single-layer structure or a multi-layer structure by co-extrusion. In the case of a plurality of layers, surface layer (release surface side layer A) / back surface side layer (B), A / intermediate layer (C) / A (release surface layer and back surface layer are the same), A / C / B, and the like. Further, it may have a multilayer structure of four or more layers.

Transfer film is industrially supplied by a roll that winds the film. The lower limit of the roll width is preferably 30 cm, more preferably 50 cm, further 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 further preferably 3000 cm.

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

(Release surface roughness)
The release surface (A layer surface) of the transfer film of the present invention is preferably smooth. In the present invention, the “release surface” of the transfer film means the surface of the transfer film intended to be provided with the liquid crystal compound alignment layer to be transferred by the transfer film. In the case where a flattening coat layer or a release layer described later is provided, if a liquid crystal compound alignment layer is provided thereon, the surface of these flattening layer or release layer (contact with the liquid crystal compound alignment layer) Surface) is the "release surface" of the transfer film.

The lower limit of the three-dimensional arithmetic mean roughness (SRa) of the release surface of the transfer film 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. The upper limit of SRa of the release surface of the transfer film of the present invention is preferably 30 nm, more preferably 25 nm, further preferably 20 nm, particularly preferably 15 nm, most preferably 10 nm. . If it exceeds the above range, the alignment of the liquid crystal compound may be disturbed.

The lower limit of the three-dimensional ten-point average roughness (SRz) of the release surface of the transfer film of the present invention is preferably 5 nm, more preferably 10 nm, and further preferably 13 nm. If it is less than the above, it may be difficult to achieve the numerical value. The upper limit of SRz of the release surface of the transfer film 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. . If it exceeds the above range, the alignment of the liquid crystal compound may be disturbed.

The lower limit of the maximum height of the release surface (SRy: maximum release surface peak height SRp + release surface maximum valley depth SRv) of the transfer film of the present invention is preferably 10 nm, more preferably 15 nm, and It is preferably 20 nm. If it is less than the above, it may be difficult to achieve the numerical value. The upper limit of SRy of the release surface of the transfer film of the present invention is preferably 300 nm, more preferably 250 nm, further preferably 150 nm, particularly preferably 120 nm, most preferably 100 nm. . If it exceeds the above range, the alignment of the liquid crystal compound may be disturbed.

The upper limit of the number of projections having a height difference of 0.5 μm or more on the release surface of the transfer film of the present invention is preferably 5 / m ² , more preferably 4 / m ² , and further preferably 3 / M ² , particularly preferably 2 / m ² , and most preferably 1 / m ² . If it exceeds the above range, the alignment of the liquid crystal compound may be disturbed.

When the release surface roughness exceeds the above range, the alignment state and the retardation as designed do not occur in the minute portion of the liquid crystal compound alignment layer formed on the transfer film of the present invention, and pinholes or scratches are generated. -Like defects may occur. The reason for this is considered as follows. First, as described below, an alignment control layer such as a rubbing alignment control layer or a photo alignment control layer can be provided between the transfer film and the liquid crystal compound alignment layer. In the case of the control layer, it is considered that the orientation control layer of the convex portion is peeled off during rubbing, and the rubbing of the foot portion and the concave portion of the convex portion is insufficient, which causes the defects. Further, when particles are contained in the release surface layer, it is considered that particles fall off during rubbing and the surface is damaged, which is a cause of defects. In addition, when the film is wound with the orientation control layer provided, whether it is a rubbing-treated orientation control layer or a photo-orientation control layer, by rubbing against the back surface layer, holes are formed in the orientation control layer at the convex portion. It is considered that the defects are caused by the voids and the disordered orientation due to the pressure. Due to these defects in the alignment control layer, when the alignment layer for the liquid crystal compound is provided on the alignment control layer, the alignment of the liquid crystal compound does not occur properly in the minute portion, and the alignment state and phase difference as designed cannot be obtained. As a result, defects such as pinholes and scratches are considered to occur.

Even when the liquid crystal compound alignment layer is directly formed on the transfer film without providing the alignment control layer, the thickness of the liquid crystal compound alignment layer may be formed at the convex portion of the release surface of the transfer film when the liquid crystal compound is applied. It is also a cause of the defect that the retardation as designed cannot be obtained because the thickness of the liquid crystal compound alignment layer becomes thicker in the concave portion of the release surface of the transfer film. Conceivable.

The following methods may be mentioned for controlling the roughness of the release surface (A) within the above range.
-The release surface side layer (surface layer) of the base film does not contain particles.
-If the release surface side layer (surface layer) of the base film contains particles, the particles have a small particle size.
・ Smooth the surface of the roll (casting roll or touch roll) on the side that becomes the release surface.
-Provide a flattening coat on the release surface side of the base film.
In the present invention, the “release surface side layer” of the base film means a layer having a release surface among the layers of the resin constituting the base film. Here, even when the substrate 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 described later are the same layer.

In addition to the above, it is important to clean the raw materials and manufacturing process as follows.
-Filter the molten cyclic polyolefin resin.
・ Apply a filter to the coating agent to remove foreign matter.
・ Perform in a clean environment during film formation, coating and drying.

The surface layer preferably contains substantially no particles for smoothing. By substantially free of particles is meant that the particle content is less than 50 ppm, preferably less than 30 ppm.

The surface layer may contain particles to improve the slipperiness of the surface. When particles are included, the lower limit of the surface layer particle content is preferably 30 ppm, more preferably 50 ppm, and further preferably 100 ppm. The upper limit of the surface layer particle content is preferably 20000 ppm, more preferably 10000 ppm, further preferably 8000 ppm, and particularly preferably 6000 ppm. If it exceeds the above range, the roughness of the surface layer may not be within the preferred range.

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

Even if the surface layer does not contain particles or the particles have a small particle size, if the lower layer contains particles, the release surface layer may have a higher roughness due to the effect of the particles in the lower layer. In such a case, it is preferable to increase the thickness of the release surface layer or to provide 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 further preferably 90% based on the total thickness of the transfer film.

The content of particles is less than 50 ppm, preferably less than 30 ppm, in the sense that the intermediate layer containing no particles contains substantially no particles. The lower limit of the thickness of the intermediate layer with respect to the total thickness of the transfer film is preferably 10%, more preferably 20%, and further preferably 30% with respect to the total thickness of the transfer film. The upper limit is preferably 95%, more preferably 90%.

If the surface roughness of the transfer film (base film) is high, a flattening coat may be provided. Examples of the resin used for the flattening coat include those generally used as the resin for the coating agent such as polyester, acryl, polyurethane, polystyrene and polyamide. It is also preferable to use a crosslinking agent such as melamine, isocyanate, epoxy resin, or oxazoline compound. These are applied as a coating agent dissolved or dispersed in an organic solvent or water and dried. Alternatively, in the case of acrylic, it may be coated without a solvent and cured by radiation. The planarization coat may be an oligomer block coat. When the release layer is provided as 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, further 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 range, no further flattening effect may be obtained.

The flattening coat may be provided as an in-line coat during the film formation process, or may be provided as a separate offline coat.

(Release layer)
The obtained substrate film can be used as it is as a transfer film as long as it has a releasability from the transferred product (liquid crystal compound alignment layer). The film may be surface-treated in order to adjust the releasability. Examples of the surface treatment include corona treatment and plasma treatment.

Alternatively, a release layer may be provided. As the release layer, a known release agent can be used, and alkyd resins, amino resins, long-chain acrylic acrylates, silicone resins, and fluororesins are preferred examples. These can be appropriately selected according to the adhesion to the transfer material. In order to improve the adhesiveness between the base film and the release layer, the base film may be surface-treated. Examples of the surface treatment include the above treatments. Further, an easy adhesion coat may be applied.

(Roughness on the back side)
Further, even if the release surface of the transfer film of the present invention is made smooth, defects may occur in the liquid crystal compound alignment layer. This is because the transfer film is supplied in a rolled-up state, the front surface and the back surface are in contact with each other, and the roughness of the back surface is transferred to the surface (the convex portion of the back surface is transferred to the release layer). It was found that this is due to the formation of recesses. A transfer film provided with a liquid crystal compound alignment layer may be wound with a masking film attached to protect the liquid crystal compound alignment layer, but it is often wound as it is for cost reduction. When the liquid crystal compound alignment layer is wound in this manner, it is considered that the liquid crystal compound alignment layer has a phenomenon in which the projections on the back surface cause depressions, holes, or disordered alignment. Even when the liquid crystal compound alignment layer is not wound in the state of being provided, but the liquid crystal compound alignment layer is provided later, a phenomenon such that holes are formed in the liquid crystal compound alignment layer due to the convex portion on the back surface and the alignment is disturbed occurs. It is thought that In particular, the pressure is high at the core portion, and these phenomena are likely to occur. From the above findings, it was found that the above-mentioned defects can be prevented by setting 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 transfer film of the present invention is preferably 3 nm, more preferably 4 nm, and further preferably 5 nm. If it is less than the above range, the slipperiness may be deteriorated, and the roll may not be slipped smoothly during roll conveyance or winding, and may be easily scratched. The upper limit of SRa on the back surface of the transfer film of the present invention is preferably 50 nm, more preferably 45 nm, and further preferably 40 nm. If it exceeds the above, there may be many defects.

The lower limit of the three-dimensional ten-point average roughness (SRz) of the back surface of the transfer film of the present invention is preferably 15 nm, more preferably 20 nm, further preferably 25 nm. The upper limit of SRz on the back surface of the transfer film 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. If it exceeds the above, there may be many defects.

The lower limit of the maximum height of the back surface of the transfer film of the present invention (SRy: maximum back surface peak height SRp + back surface maximum valley depth SRv) is preferably 20 nm, more preferably 30 nm, further preferably 40 nm, Particularly preferably, it is 50 nm. The upper limit of the maximum height SRy of the back surface of the transfer film of the present invention is preferably 2000 nm, more preferably 1500 nm, further preferably 1200 nm, particularly preferably 1000 nm, most preferably 700 nm. is there. If it exceeds the above, there may be many defects.

The upper limit of the number of protrusions having a height difference of 2 μm or more on the back surface of the transfer film of the present invention is preferably 5 / m ² , more preferably 4 / m ² , and further preferably 3 / m ² . Yes, particularly preferably 2 / m ² , and most preferably 1 / m ² . If it exceeds the above, there may be many defects.

When the roughness of the back surface of the transfer film of the present invention represented by the above parameters is less than the above range, the slipperiness of the film is deteriorated, and when the film is conveyed by a roll, it is less likely to slip during winding, etc., It may be easily scratched. Further, during winding during film production, the winding is not stable and wrinkles occur, resulting in defective products, and the irregularities at the ends of the wound roll become large, and the film tends to meander in the next step. Or it is easy to break.
If the roughness of the back surface of the transfer film of the present invention exceeds the above, the above-mentioned defects are likely to occur.

The following method can be used to set the roughness of the back surface within the above range.
-The surface roughness of the roll (casting roll or touch roll) on the back side is set within a specific range.
-The backside layer (backside layer) of the base film contains specific particles.
-Use a substrate film containing particles as the intermediate layer, and reduce the thickness by making the back surface layer side (back surface layer) free of particles.
-If the back surface layer (back surface layer) of the base film has a large roughness, a flattening coat is provided.
-If the backside layer (backside layer) of the substrate film is too smooth, a slippery coat (particle-containing coat) is provided.

The lower limit of the particle diameter of the back surface layer is preferably 0.005 μm, more preferably 0.01 μm, further preferably 0.05 μm, and particularly preferably 0.1 μm. If it is less than the above range, slipperiness may be deteriorated and winding failure may occur. The upper limit of the particle diameter of the back surface layer is preferably 5 μm, more preferably 3 μm, and further preferably 2 μm. If it exceeds the above range, the back surface may be too rough.

When the back surface contains particles, the lower limit of the back surface layer particle content is preferably 50 ppm, more preferably 100 ppm. If it is less than the above range, the effect of slipperiness due to addition of particles may not be obtained. The upper limit of the content of the back surface layer particles is preferably 10,000 ppm, more preferably 7,000 ppm, and further preferably 5000 ppm. If it exceeds the above range, the back surface may be too rough.

The lower limit of the thickness of the back surface layer 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 thickness of the back surface layer is preferably 95%, more preferably 90%, and further preferably 85% based on the total thickness of the transfer film.

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 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 amount of particles in the middle layer are the same as those in the back 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 further preferably 2 μm. The upper limit of the thickness is preferably 30 μm, more preferably 25 μm, further preferably 20 μm.

If the back surface of the base film is rough, it is also preferable to provide a flattening coat. As the flattening coat, those mentioned for the surface flattening coat can be similarly used.

The lower limit of the thickness of the back surface flattening coat layer is preferably 0.01 μm, more preferably 0.03 μm, and further 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 further preferably 3 μm. Even if it exceeds the above, the flattening effect will be saturated.

A slippery coat containing particles may be provided on the back surface. The easy-sliding coat is effective when the back surface side of the base film does not contain particles or when the roughness is insufficient.

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

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

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

When providing these coats, it is preferable to subject the base film to the above-mentioned surface treatment or easy-adhesion coat.

The cyclic polyolefin film can be generally manufactured by a melt extrusion method. Hereinafter, this method will be briefly described.

In the melt extrusion method, the cyclic polyolefin resin is a single-screw or twin-screw extruder and is usually (Tg + 30) to (Tg + 180) ° C., preferably (Tg + 50) to (Tg + 150) ° C., particularly preferably (Tg + 60) to (Tg + 140). It is heated and melted at ℃ and extruded from a die onto a cast roll. Here, Tg is the glass transition temperature of the cyclic polyolefin resin.

In order to achieve proper surface roughness, it is preferable to filter the molten resin with a filter between the extruder and the die to remove coarse particles. The lower limit of the filtration accuracy of the filter used is preferably 0.5 μm, more preferably 1 μm. The upper limit of the filtration accuracy of the filter is preferably 100 μm, more preferably 50 μm, further preferably 25 μm, particularly preferably 20 μm, and most preferably 10 μm. This value is appropriately determined depending on the particle size of the particles to be added.

(Roll roughness)
By adjusting the roughness of the roll, the roughness of the surface of the formed film can be adjusted. For example, in the case where the casting roll is the release surface and the touch roll is the back surface, preferable roughness of the roll will be described below.

The lower limit of the three-dimensional arithmetic mean surface roughness (SRa) of the casting roll when the casting roll is used as the release surface is preferably 1 nm, more preferably 1.3 nm, and further preferably 1.5 nm. The upper limit of the three-dimensional arithmetic mean surface roughness (SRa) of the casting roll when the casting roll is used as the release surface is preferably 250 nm, more preferably 200 nm, further preferably 150 nm, and particularly preferably 100 nm. And most preferably 50 nm.

The lower limit of the three-dimensional 10-point average roughness (SRz) of the casting roll when the casting roll is used as the release surface is preferably 3 nm, more preferably 5 nm, and further preferably 7 nm. The upper limit of the three-dimensional ten-point average roughness (SRz) of the casting roll when the casting roll is used as the release surface is preferably 1000 nm, more preferably 700 nm, further preferably 500 nm, and particularly preferably 300 nm. And most preferably 250 nm.

The lower limit of the maximum height (SRy) of the casting roll when the casting roll is used as the release surface is preferably 5 nm, more preferably 8 nm, further preferably 10 nm. The upper limit of the maximum height (SRy) of the casting roll when the casting roll is used as the release surface is preferably 1500 nm, more preferably 1000 nm, further preferably 800 nm, and particularly preferably 600 nm.

The lower limit of the three-dimensional arithmetic average surface roughness (SRa) of the touch roll when the touch roll is used as the back surface is preferably 5 nm, more preferably 10 nm, and further preferably 15 nm. The upper limit of the three-dimensional arithmetic mean surface roughness (SRa) of the touch roll when the touch roll is used as the back surface is preferably 500 nm, more preferably 400 nm, further preferably 300 nm, particularly preferably 250 nm. , And most preferably 200 nm.

The lower limit of the three-dimensional 10-point average roughness (SRz) of the touch roll when the touch roll is used as the back surface is preferably 20 nm, more preferably 30 nm, and further preferably 40 nm. The upper limit of the three-dimensional ten-point average roughness (SRz) of the touch roll when the touch roll is used as the back surface is preferably 2000 nm, more preferably 1500 nm, further preferably 1200 nm, and particularly preferably 1000 nm. , And most preferably 800 nm.

The lower limit of the maximum height (SRy) of the touch roll when the touch roll is used as the back surface is preferably 30 nm, more preferably 40 nm, and further preferably 50 nm. The upper limit of the maximum height (SRy) of the touch roll when the touch roll is used as the back surface is preferably 3000 nm, more preferably 2500 nm, further preferably 2000 nm, particularly preferably 1500 nm, and most preferably It is 1000 nm.

By setting each roughness parameter of the casting roll and / or the touch roll within the above range, it becomes easy to control the roughness of the base film within an appropriate range.

Generally, the film forming conditions and the roughness of the film surface have the following relationship, and the roughness of the roll is determined in consideration of these.
-If the casting roll and the touch roll have the same roughness, the casting roll surface of the film becomes rougher.
-The smaller the distance between the die and the casting roll, the greater the roughness of the casting roll surface of the film.
-The closer the position where the molten resin contacts the casting roll and the position where the touch roll presses, the greater the roughness of each surface.
-The lower the melt viscosity of the resin, the greater the roughness of each surface.
-The higher the temperature of the casting roll and the touch roll, the greater the roughness of each surface.
-The higher the pressing force of the touch roll, the greater the roughness of each surface.

The temperature of the casting roll is preferably (Tg-30) to (Tg + 30) ° C, more preferably (Tg-20) to (Tg + 20) ° C.

The temperature of the touch roll is preferably (Tg-100) to (Tg + 30) ° C, more preferably (Tg-90) to (Tg + 20) ° C. Further, it is preferable that the temperature is set to be 0 to 50 ° C., further 5 to 40 ° C. lower than the temperature of the casting roll.

The pressing pressure (line pressure) of the touch roll is preferably 10 to 250 kgf / cm, more preferably 20 to 200 kgf / cm.

After that, the film is peeled from the casting roll, cooled while passing through the roll, and wound on the core. At the time of winding, both ends may be thickened (knurled).

When performing coating, the wound film may be set in a coating device, unwound and coating dried. In the above film-forming step, the film may be coated and dried after being peeled off from the casting roll and wound up, and then wound up.

It is preferable that the air in these processes is passed through a HEPA filter or the like to be air of class 10000 or less, further class 1000 or less.

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

(In-plane retardation of transfer film)
The transfer film of the present invention preferably has a low in-plane retardation. Specifically, the in-plane retardation of the transfer film of the present invention is preferably 50 nm or less, more preferably 30 nm or less, further preferably 20 nm or less, and particularly preferably 10 nm or less. By setting the in-plane retardation of the transfer film within the above range, it is possible to inspect the alignment state of the liquid crystal compound alignment layer by irradiating linearly polarized light in the state where the liquid crystal compound alignment layer is laminated on the transfer film. 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, so that the retardation layer converts the light into elliptical polarization. The polarized light is returned to the linearly polarized light by passing through another retardation layer, and the linearly polarized light is received through the polarizing plate in the extinction state. Accordingly, when the retardation layer has a pinhole-like defect, the defect can be detected as a bright spot.

The retardation of the transfer film can be obtained by measuring the refractive index and the thickness in the biaxial direction, and can also be obtained using a commercially available automatic birefringence measuring device such as KOBRA-21ADH (Oji Scientific Instruments). .

In order to make the in-plane retardation of the transfer film within the above range, in the film forming process of the base film, stretching is not performed, or when stretching is performed, the stretching ratio in the flow direction and the width direction is adjusted. The method of is mentioned.

The lower limit of haze of the transfer film 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. The upper limit of haze of the transfer film of the present invention is preferably 3%, more preferably 2.5%, further preferably 2%, and particularly preferably 1.7%. If it exceeds the above range, polarized light may be disturbed during irradiation of polarized UV, and a retardation layer as designed may not be obtained. In addition, light leakage may occur due to irregular reflection during the inspection of the retardation layer, which makes it difficult to perform the inspection.

The lower limit of the antistatic property (surface resistance) of the transfer film of the present invention is preferably 1 × 10 ⁵ Ω / □, more preferably 1 × 10 ⁶ Ω / □. Even if it is less than the above, the effect may be saturated, and further effect may not be obtained. The upper limit of the antistatic property (surface resistance) of the transfer film of the present invention is preferably 1 × 10 ¹³ Ω / □, more preferably 1 × 10 ¹² Ω / □, and further preferably 1 × 10. ^{It is 11} Ω / □. If it exceeds the above range, cissing due to static electricity may occur or the alignment direction of the liquid crystal compound may be disturbed. For antistatic property (surface resistance), kneading an antistatic agent into a transfer film, providing an antistatic coating layer on the lower layer or the opposite surface of the release layer, or adding an antistatic agent to the release layer. It can be set within the above range by the above.

Antistatic agents added to antistatic coating layers, release layers, and transfer films include conductive polymers such as polyaniline and polythiophene, ionic polymers such as polystyrene sulfonate, tin-doped indium oxide, antimony-doped tin oxide. Conductive fine particles such as

A release layer may be provided on the transfer film. However, when the film itself has low adhesion to a transfer 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 surface may be corona treated to adjust the adhesion. The release layer can be formed using a known release agent, and alkyd resins, amino resins, long-chain acrylic acrylates, silicone resins, and fluororesins are preferred examples. These can be appropriately selected according to the adhesion to the transfer material.

(Laminate for transferring liquid crystal compound alignment layer)
Next, the liquid crystal compound alignment layer transfer laminate 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 film of the present invention are laminated. The liquid crystal compound alignment layer must be coated on the transfer film for alignment. As a method for orienting, a method for giving an orientation control function by rubbing a lower layer (release surface) of the liquid crystal compound orientation layer, or irradiating polarized ultraviolet rays after coating the liquid crystal compound to orient the liquid crystal compound directly There is a way.

(Alignment control layer)
Further, a method in which an alignment control layer is provided on the transfer film and a liquid crystal compound alignment layer is provided on the alignment control layer is also preferable. In the present invention, the alignment layer and the liquid crystal compound alignment layer may be collectively referred to as a liquid crystal compound alignment layer, instead of the liquid crystal compound alignment layer alone. As the orientation control layer, any orientation control layer may be used as long as it can bring the liquid crystal compound orientation layer into a desired orientation state, but a rubbing treatment orientation control layer obtained by rubbing a resin coating film or A preferable example is a photo-alignment control layer that orients molecules by polarized light irradiation to produce an alignment 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 derivative, polyimide and its derivative, acrylic resin, polysiloxane derivative and the like are preferably used.

Hereinafter, the method of forming the rubbing orientation control layer will be described. First, a rubbing treatment orientation control layer coating liquid containing the above-mentioned polymer material is applied onto the release surface of the film, and then dried by heating to obtain an orientation control layer before the rubbing treatment. The orientation control layer coating liquid may contain a crosslinking agent.

As the solvent for the rubbing orientation control layer coating liquid, any solvent that dissolves the polymer material can be used without limitation. Specific examples thereof 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, cyclohexanone. , And the like; ketone-based solvents such as; and aromatic hydrocarbon solvents such as toluene and xylene; and ether-based solvents such as tetrahydrofuran and dimethoxyethane. These solvents may be used alone or in combination.

The concentration of the coating solution for rubbing alignment control layer can be appropriately adjusted depending on the type of polymer and the thickness of the alignment 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 a coating method, known methods such as a gravure coating method, a die coating method, a bar coating method and an applicator method, and a printing method such as a flexo method are used.

The heating and drying temperature is preferably in the range of 30 ° C to 170 ° C, more preferably 50 to 150 ° C, and further preferably 70 to 130 ° C. When the drying temperature is low, it is necessary to take a long drying time, which may result in poor productivity. When the drying temperature is too high, the transfer film may be elongated by heat or the heat shrinkage may be large, the optical function as designed cannot 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 further preferably 2 to 10 minutes.

The thickness of the rubbing 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, perform rubbing treatment. The rubbing treatment can be generally performed by rubbing the surface of the polymer layer with paper or cloth in a certain direction. Generally, the surface of the orientation control layer is rubbed by using a rubbing roller made of a raised cloth of fibers such as nylon, polyester, and acrylic. In order to provide the liquid crystal compound alignment control layer that aligns in a predetermined direction oblique to the longitudinal direction of the long film, the rubbing direction of the alignment control layer also needs to be at an angle suitable for it. The angle can be adjusted by adjusting the angle between the rubbing roller and the film, and adjusting the transport speed of the film and the rotation speed of the roller.

Note that it is also possible to directly rub the release surface of the transfer film to give the surface of the transfer film an orientation control function, and this case is also included in the technical scope of the present invention.

(Photo-alignment control layer)
The photo-alignment control layer, a coating solution containing a polymer or monomer having a photoreactive group and a solvent is applied to the film, polarized, preferably of an alignment film that imparts an alignment regulating force by irradiating polarized ultraviolet light. Say that. The photoreactive group refers to a group that produces a liquid crystal aligning ability when irradiated with light. Specifically, it is one that causes a photoreaction that is the origin of the liquid crystal alignment ability, such as an orientation induction or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction of a molecule generated by irradiation with light. is there. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable because they have excellent alignment properties and maintain the smectic liquid crystal state of the liquid crystal compound alignment 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 vinyl group, polyene group, stilbene group, stilbazol group, stilbazolium group, chalcone group and cinnamoyl group. Examples of the photoreactive group having a C = N bond include groups 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 and a formazan group, 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 a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group and a halogenated alkyl group.

Among them, a photoreactive group capable of causing a photodimerization reaction is preferable, a cinnamoyl group and a chalcone group have a relatively small amount of polarized light irradiation necessary for photoalignment, and a photoalignment layer having excellent thermal stability and stability over time. It is preferable because it is easily obtained. Furthermore, as the polymer having a photoreactive group, a polymer having a cinnamoyl group such that the end portion of the polymer side chain has a cinnamic acid structure is particularly preferable. Examples of the main chain structure include polyimide, polyamide, (meth) acrylic, polyester, and the like.

Specific alignment control layers include, for example, 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, and Alignment described in Japanese Unexamined Patent Publication No. 2002-317013, Special Table 2003-520878, Special Table 2004-529220, JP2013-33248, JP2015-7702, and JP2015-129210. A control layer is included.

The solvent for the photo-alignment control layer forming coating liquid can be used without limitation as long as it dissolves the polymer and monomer having a photoreactive group. Specific examples include those mentioned in the method of forming the rubbing orientation control layer. It is also preferable to add a photopolymerization initiator, a polymerization inhibitor, and various stabilizers to the coating liquid for forming the photo-alignment control layer. Further, a polymer other than the polymer having the photoreactive group and the monomer, or a monomer having no photoreactive group which is copolymerizable with the monomer having the photoreactive group may be added.

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

The polarized light may be irradiated either from the direction of the photo-alignment control layer surface before alignment or from the direction of the transfer film surface through the transfer film.

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

Polarized light is obtained, for example, by passing light from the light source through a polarizer. The polarization direction can be adjusted by adjusting the polarization angle of the polarizer. Examples of the polarizer include a polarizing filter, a polarizing prism such as Glan-Thompson and Glan-Teller, and a wire grid type polarizer. The polarized light is preferably substantially collimated light.

By adjusting the angle of polarized light to be irradiated, the direction of the alignment control force of the photo-alignment control layer can be adjusted arbitrarily.

The irradiation intensity is different in kind and amount of a polymerization initiator or a resin (monomer), for example, preferably 10 ~ 10000mJ / cm ² at 365nm reference, and more preferably 20 ~ 5000mJ / cm ^2.

(Liquid crystal compound alignment layer)
The liquid crystal compound alignment layer is not particularly limited as long as the liquid crystal compound is aligned. 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 dye)
The dichroic dye is a dye having a property that the absorbance in the long axis direction of the molecule and the absorbance in the short 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 dichroic dye include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye and an anthraquinone dye, and among them, an azo dye is preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye and a stilbeneazo dye, and a bisazo dye and a trisazo dye are preferable. The dichroic dyes 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). Particularly, it is preferable to combine three or more kinds. 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, 2010-168570, 2013-101328, and 2013-210624.

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

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, from the viewpoint of improving the orientation of the dichroic dye. , 1.0 to 15 mass% is more preferable, and 2.0 to 10 mass% is particularly preferable.

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

(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 that participates in the polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group capable of undergoing a polymerization reaction with an active radical or an acid generated from a photopolymerization initiator described later. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The compound exhibiting liquid crystallinity may be a thermotropic liquid crystal or a lyotropic 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 high-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 orientational order can be manufactured.

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, and JP-A-2013-114131. Publication, WO 2005/045485, Lub et al. Recl. Trav. Chim. Examples 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, further 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 coating composition for the polarizing film. 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 crosslinking agent and the like.

As the solvent, those mentioned as the solvent for the alignment layer coating solution are preferably used.

The polymerization initiator is not limited as long as it polymerizes the polymerizable liquid crystal compound, but a photopolymerization initiator that generates an active radical 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 photosensitizer is preferable as the sensitizer. For example, a xanthone compound, an anthracene compound, phenothiazine, rubrene, etc. are mentioned.

Examples of polymerization inhibitors include hydroquinones, catechols, and thiophenols.

As the polymerizable non-liquid crystal compound, those which are copolymerizable with the polymerizable liquid crystal compound are preferable, and for example, when the polymerizable liquid crystal compound has a (meth) acryloyloxy group, (meth) crates can be mentioned. The (meth) acrylates 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 contained in the polarizing film in an amount of 1 to 15% by mass, more preferably 2 to 10% by mass, and particularly preferably 3 to 7% by mass. If it exceeds 15% by mass, the degree of polarization may decrease.

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

A polarizing film is provided by directly applying a coating composition for a polarizing film on a transfer film or an orientation control layer, and then drying, heating, and curing if necessary.

As the coating method, known methods such as a gravure coating method, a die coating method, a bar coating method and an applicator method, and a printing method such as a flexo method are used as the coating method.

The transfer film after coating is introduced into a warm air dryer, an infrared dryer or the like, and dried at 30 to 170 ° C, more preferably 50 to 150 ° C, further 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 align 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 coating composition for the polarizing film 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 the oriented state. The curing is preferably performed in a state where a liquid crystal phase is formed in the polymerizable liquid crystal compound, and may be cured by irradiation with light at a temperature showing the liquid crystal phase. Examples of the light in the light irradiation include visible light, ultraviolet light and laser light. From the viewpoint of easy handling, ultraviolet light is preferable.

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.

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

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

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

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

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 from the viewpoint that the alignment state can be fixed.

Examples of rod-shaped liquid crystal compounds include JP-A-2002-030042, JP-A-2004-204190, JP-A-2005-263789, JP-A-2007-119415, JP-A-2007-186430, and Examples thereof include rod-like 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,
Ph1 and Ph2 are 1,4-phenyl groups (Ph2 may be a methyl group at the 2-position),
Examples of NPh include 2,6-naphthyl group.
These rod-shaped liquid crystal compounds are commercially available from BASF Corporation 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 an arbitrary ratio.

Examples of the discotic liquid crystal compound include benzene derivatives, truxene derivatives, cyclohexane derivatives, azacrown-based and phenylacetylene-based macrocycles, and various compounds are described in JP-A-2001-155866. Is preferably used.
Among them, a compound having a triphenylene ring represented by the following general formula (1) is preferably used as the discotic compound.

In the formula, R ₁ to R ₆ are each independently hydrogen, halogen, an alkyl group, or a group represented by —O—X (where X is an alkyl group, an acyl group, an alkoxybenzyl group, an epoxy-modified group). An alkoxybenzyl group, an acryloyloxy-modified alkoxybenzyl group, and an acryloyloxy-modified alkyl group). R ₁ to R ₆ are preferably an acryloyloxy-modified alkoxybenzyl group represented by the following general formula (2) (where m is 4 to 10).

The retardation layer can be provided by applying the composition coating for the retardation layer. The retardation layer 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 crosslinking agent and the like. As these, those described in the alignment control layer and the liquid crystal polarizer can be used.

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

Regarding these conditions, the conditions explained in the orientation control layer and the liquid crystal polarizer are used as preferable conditions.

A plurality of retardation layers may be provided. In this case, a plurality of retardation layers may be provided on one transfer film and transferred onto an object, and a single retardation layer may be provided on one transfer film. It is also possible to prepare a plurality of types provided with the retardation layer and to transfer these in order to the object.

Alternatively, the polarizing layer and the retardation layer may be provided on a single transfer film and 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 film together with the retardation layer or the polarizing layer and transferred to the object.

A transparent resin coating layer may be used as the protective layer. The transparent resin is not particularly limited, such as polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyester, polyurethane, polyamide, polystyrene, acrylic resin and epoxy resin. A cross-linking structure may be formed by adding a cross-linking agent to these resins. Further, it may be one obtained by curing a photocurable composition such as acrylic as a hard coat. Further, after the protective layer is provided on the transfer film, the protective layer may be rubbed, and the liquid crystal compound alignment layer may be provided thereon without providing the alignment layer.

(Method for producing polarizing plate with laminated liquid crystal compound alignment layer)
Next, a method of manufacturing the liquid crystal compound alignment layer laminated polarizing plate of the present invention will be described.
The method for producing a liquid crystal compound alignment layer laminated polarizing plate of the present invention includes a step of laminating a liquid crystal compound alignment layer surface of the liquid crystal compound alignment layer transfer laminate of the present invention to form an intermediate laminate, and an intermediate laminate. The step of peeling the transfer film from the body is included.
Hereinafter, the case where the liquid crystal compound alignment layer is the liquid crystal compound alignment layer used for the 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 alignment 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 circularly polarizing plate, the orientation axis (slow 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, and further preferably Is 42 to 48 degrees. When used in combination with a polarizer of a stretched film of polyvinyl alcohol, since the absorption axis of the polarizer is generally in the length direction of the long polarizer film, λ / When four layers are provided, it is preferable to orient the liquid crystal compound within the above range with respect to the length direction of the long transfer 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 by taking the angle of the transmission axis of the polarizer into consideration.

Create a circularly polarizing plate by transferring the λ / 4 layer in the transfer laminate in which the λ / 4 layer and the transfer film are laminated to the polarizing plate. Specifically, the polarizing plate and the λ / 4 layer surface of the transfer laminate are bonded together to form an intermediate laminate, and the transfer film is peeled from the intermediate laminate. The polarizing plate may have a protective film provided on both sides of the polarizer, but preferably has a protective film provided on only one side. In the case of a polarizing plate in which a protective film is provided only on one surface, it is preferable to attach a retardation layer to the opposite surface (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 side that is supposed to be on the image cell side. The surface that is assumed to be on the image cell side is a surface that is not generally surface-treated such as a low reflection layer, an antireflection layer, and an antiglare layer, which is provided on the viewing side. The protective film on the side to which the retardation layer is attached is preferably a protective film such as TAC, acrylic, or COP having no retardation.

As the polarizer, a PVA-based film alone is stretched to form a polarizer, or an unstretched substrate such as polyester or polypropylene is coated with PVA, and the polarizer is stretched to protect the polarizer. Examples thereof include those transferred to a film and those obtained by coating or transferring a polarizer comprising a liquid crystal compound and a dichroic dye on a polarizer protective film, and any of them is preferably used.

As a method of pasting, a conventionally known one such as an adhesive or an adhesive can be used. As the adhesive, a polyvinyl alcohol adhesive, an ultraviolet curable adhesive such as acrylic or epoxy, or a thermosetting adhesive such as epoxy or isocyanate (urethane) is preferably used. Examples of the adhesive include acrylic, urethane-based and rubber-based adhesives. It is also preferable to use an acrylic baseless transparent optical pressure-sensitive adhesive sheet.

When a transfer type is used as the polarizer, 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 targeted (polarizer protective film). It may be transferred to.

As the polarizer protective film on the side opposite to the side where the retardation layer is provided, commonly known ones such as TAC, acrylic, COP, polycarbonate, polyester can be used. Among them, TAC, acrylic, COP and polyester are preferable. The polyester is preferably polyethylene terephthalate. In the case of polyester, a zero retardation film having an in-plane retardation of 100 nm or less, particularly 50 nm or less, or a high retardation film of 3000 nm to 30,000 nm is preferable.

When a polyester high retardation film is used, the angle between the transmission axis of the polarizer and the slow axis of the polyester high retardation film is 30 to 30 mm in order to prevent blackout and coloring when viewing the image with polarized sunglasses. The range of 60 degrees is preferable, and the range of 35 to 55 degrees is more preferable. The angle between the transmission axis of the polarizer and the slow axis of the polyester high retardation film should be 10 degrees or less, and even 7 degrees or less, in order to reduce rainbow spots when observed from a shallow angle with the naked eye. Alternatively, it is preferably 80 to 100 degrees, more preferably 83 to 97 degrees.

-The polarizer 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)
When the λ / 4 layer alone is used, coloring may occur over a wide range of the visible light region without being λ / 4. 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 to arrange the λ / 4 layer and the λ / 2 layer at an angle such that the λ / 4 layer is λ / 4. Specifically, the angle (θ) between the orientation axis (slow 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 axis) of the λ / 2 layer and the orientation axis of λ / 4 (slow axis) is preferably 2θ + 45 ° ± 10 °, more preferably 2θ + 45 ° ± 5 °. Yes, and more preferably within the range of 2θ + 45 ° ± 3 °.

Also in this case, when it is used in combination with a polarizer of a stretched film of polyvinyl alcohol, it is common that the absorption axis of the polarizer is in the length direction of the long polarizer film, and therefore, for transfer of a long film. When the film is provided with a λ / 2 layer or a λ / 4 layer, it is preferable to align the liquid crystal compound so as to be in the above range with respect to the lengthwise direction of the long transfer film or the direction perpendicular to the lengthwise direction. 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 by taking the angle of the transmission axis of the polarizer into consideration.

For these methods and examples of the retardation layer, reference may be made to JP-A-2008-149577, JP-A-2002-303722, WO2006 / 100830, JP-A-2015-64418 and the like. .

Furthermore, it is also a preferable mode to provide a C plate layer on the λ / 4 layer in order to reduce the 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 a combination of a λ / 4 layer and a λ / 2 layer is used,
A λ / 2 layer is provided on the polarizer by transfer, and a λ / 4 layer is further provided on it by transfer.
A λ / 4 layer and a λ / 2 layer are provided in this order on the transfer film, and this is transferred onto the polarizer.
A λ / 4 layer, a λ / 2 layer and a polarizing layer are provided in this order on the transfer film, and this is transferred to an object.
A λ / 2 layer and a polarizing layer are provided in this order on the transfer film, and this is transferred to an object, and further a λ / 4 layer is transferred onto this.
Various methods such as can be adopted.

Also, when laminating the 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 film, and further forming a λ / 4 layer on the film Various methods such as a method of providing a λ / 2 layer and a λ / 4 layer and transferring the layer 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, still more preferably 90 μm or less, particularly preferably 80 μm or less, and most preferably 70 μm or less.

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 implemented with appropriate modifications within a range compatible with the gist of the present invention. It is possible and they are all included in the technical scope of the present invention. The methods for evaluating the physical properties in the examples are as follows.

(1) Three-dimensional surface roughness SRa, SRz, SRy
Using a stylus type three-dimensional roughness meter (SE-3AK, manufactured by Kosaka Laboratory Ltd.), with a needle radius of 2 μm and a load of 30 mg, with a cutoff value of 0.25 mm in the longitudinal direction of the film, The measurement was performed at a needle feed speed 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 as above was continuously performed 150 times at intervals of 2 μm in the width direction of the film, that is, over 0.3 mm in the width direction of the film, and the data was captured by the analyzer. Next, the center plane average roughness (SRa), the ten-point average roughness (SRz), and the maximum height (SRy) were obtained using an analyzer.

(2) Number of protrusions having a release surface height difference of 0.5 μm or more (release surface), 2.0 μm (back surface) or more A test piece with a width of 100 mm and a length of 100 mm was cut out in the longitudinal direction of the film, and two pieces of this were polarized. Scissors were inserted between the plates to create a crossed Nicols state, and the extinction position was maintained. In this state, using Nikon Universal Projector V-12 (measurement condition: projection lens 50 times, transmitted illumination light flux switching knob 50 times, transmitted light inspection), the part through which light is transmitted and appears to shine (scratches, foreign matter) Those having a major axis of 50 μm or more were detected. The portion thus detected is cut into an appropriate size from the test piece, and a three-dimensional shape measuring device (Micromap TYPE550, manufactured by Ryoka Systems Inc .; measurement conditions: wavelength 550 nm, WAVE mode, objective lens 10 times) is used. It was used and observed from the direction perpendicular to the film surface and measured. At this time, the irregularities that are close to each other within 50 μm when observed from the direction perpendicular to the film surface are assumed to be the same scratch and a rectangle covering them as foreign matter, and the length and width of this rectangle are scratched, and the length of the foreign matter is long. And width. Regarding the scratches and foreign matters, 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 . The number of defects having a height difference (difference between the highest point and the lowest point) of 0.5 μm or more on the release surface and the number of defects having a height difference of 2.0 μm or more on the back surface were counted.

(3) Film thickness (thickness of each layer)
After embedding the film in an epoxy resin, a cross section was cut out and observed with an optical microscope to determine the thickness.

(4) Inspection of Defects of Retardation Layer A rubbing-treated alignment control layer or a photo-alignment control layer as an alignment control layer disposed between the transfer film and the liquid crystal compound alignment layer was prepared as an inspection sample. The specific creation procedure is as follows.

(When the orientation control layer is a rubbing orientation control layer)
The transfer film was cut into a size A4, the coating for the rubbing orientation control layer having the following composition was 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. . Subsequently, the surface of the obtained film was treated with a rubbing roll wound with a nylon raised cloth to obtain a transfer film having a rubbing-treated orientation control layer laminated thereon. The rubbing was performed at 45 degrees with respect to the lengthwise direction of the transfer film.

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 to be cured, and a ¼ wavelength layer was provided to obtain an inspection sample.
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 alignment control layer is a photo-alignment control layer)
Based on the description of Example 1, Example 2, and Example 3 of JP-A-2013-33248, a 5 mass% solution of cyclopentanone of a polymer represented by the following formula was produced to obtain a coating material for a photo-alignment control layer. .

Next, the transfer film was cut into a size of A4, the photo-alignment control layer coating composition 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. Formed. Subsequently, polarized UV light was irradiated in a direction of 45 degrees with respect to the lengthwise direction of the film to obtain a transfer film in which a photo-alignment control layer was laminated. These paints were filtered with a membrane filter having a pore size of 0.2 μm, and coating and drying were performed in a clean room.

Next, the retardation layer forming solution was applied to the surface on which the optical alignment control layer was laminated by the bar coating method. It was dried at 110 ° C. for 3 minutes, irradiated with ultraviolet rays to be cured, and a ¼ wavelength layer was provided to obtain an inspection sample.

Next, using these inspection samples, the 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 the inspection sample prepared as described above is placed on the lower polarizing plate. (Direction) was placed parallel to the long side direction of the test sample. Further, a λ / 4 film made of a stretched film of a cyclic polyolefin is placed thereon so that the orientation main axis is in the direction of 45 degrees with the extinction axis of the lower polarizing plate, and the upper polarizing plate is placed on the upper polarizing plate. The extinction axis of was placed parallel to the extinction axis of the lower polarizing plate. In this state, the extinction state was observed with the naked eye (central part 15 cm × 20 cm) and a 20-fold magnifying glass (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 at 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 to 20 in 5 cm × 5 cm).
B: No bright spots were observed with the naked eye, but bright spots were found by loupe observation (more than 20 at 5 cm × 5 cm).
X: Bright spots were observed with the naked eye, or no bright spots were found, but there was overall light leakage which was attributed to the presence of many bright spots observed by loupe observation.

(5) Inspection of defects after superposition 1
Two inspection samples using the above rubbing orientation control layer were prepared, and the phase difference layer installation surface of the first sample and the opposite surface of the second sample were overlapped for 10 minutes at 1 kg / cm ^2. Was multiplied by the weight. The defect of the retardation layer of this sample was inspected in the same manner as in (4) Inspecting the retardation layer defect.

(6) Inspection of defects after superposition 2
In Inspection 1 of defects after superposition, since the influence of the roughness of the back surface is difficult to understand when the roughness of the release surface is large, the photo-alignment control layer of Example 2 having a small release surface roughness was used. Using the inspection sample, the influence of the roughness of the back surface of the inspection sample using the photo-alignment control layers of other examples and comparative examples was examined.
Specifically, the retardation layer installation surface of the inspection sample in which the quarter-wavelength layer was provided on the optical alignment control layer of Example 2 and the inspection sample using the optical alignment control layer of each of the Examples and Comparative Examples The opposite surfaces were overlaid and a load of 1 kg / cm ² was applied for 10 minutes. The defect of the retardation layer of this sample (inspection sample of Example 2) was inspected in the same manner as (4) Inspecting the retardation layer defect.

Production of Films A1 to A7 A thermoplastic norbornene resin (ZEONOR1420R manufactured by Nippon Zeon Co., Ltd.) is dried, supplied to an extruder and melted at 215 ° C., and a stainless sintered body filter material (nominal filtration accuracy 10 μm particles 95% cut). And then extruded into a sheet on a casting roll. From the opposite side of the resin wrapped around the casting roll, the resin was pressed against the casting roll with a touch roll. The cooled film was peeled off from the casting roll and wound into a roll. The surface roughness of the casting roll and the touch roll is as shown in Table 1. The films A1 to A4 and A7 were manufactured at a touch linear pressure of 200 Kgf / cm, and the films A5 and A6 were manufactured at a touch linear pressure of 200 Kgf / cm.

Example 1
The film A1 was used, and the above-mentioned physical properties were evaluated using the casting roll surface as the release layer surface. The evaluation results are shown in Table 2.

Example 2
The film A2 was used, and the above-mentioned physical properties were evaluated using the casting roll surface as the release layer surface. The evaluation results are shown in Table 2.

Example 3
The film A3 was used, and the above-mentioned physical properties were evaluated using the casting roll surface as the release layer surface. The evaluation results are shown in Table 2.

Example 4
The film A2 was used, and the above-mentioned physical properties were evaluated using the touch roll surface as the release layer surface. The evaluation results are shown in Table 2.

Example 5
The film A4 was used, and the above-mentioned physical properties were evaluated using the casting roll surface as the release layer surface. The evaluation results are shown in Table 2.

Example 6
The film A5 was used, and the above-mentioned physical properties were evaluated using the casting roll surface as the release layer surface. The evaluation results are shown in Table 2.

Example 7
The film A6 was used, and the above-mentioned physical properties were evaluated using the casting roll surface as the release layer surface. The evaluation results are shown in Table 2.

Example 8
Using film A2, the casting roll surface was subjected to corona treatment, a coating agent having the following composition was applied as a release layer (surface flattening coating layer) thereon, and dried in a heating oven at 150 ° C. for 3 minutes. . The thickness of the coating layer was 2 μm.
(Coating agent)
Melamine crosslinked alkyl-modified alkyd resin (manufactured by Hitachi Chemical Polymer Co., Ltd .: Tesfine 322: solid content 40%) 10 parts by mass P-toluenesulfonic acid (manufactured by Hitachi Chemical Polymer Co., Ltd .: dryer 900)
0.1 parts by mass / solvent (toluene / methyl ethyl ketone = 1/1 parts by mass) 40 parts by mass The coating agent was used after being filtered with a 2 μm filter.
The above-mentioned physical properties were evaluated using the surface on which the surface-flattening coat layer was formed as the release layer surface. The evaluation results are shown in Table 2.

Example 9
Using film A7, the touch roll surface was subjected to corona treatment, and a coating solution having the following composition was applied as a back surface easy-sliding coat layer thereon so that the coating amount after drying would be 0.07 g / m ² . Then, it was introduced into a dryer and dried at 80 ° C. for 30 seconds.
(Coating liquid)
-Water 50.00 parts by mass-Isopropyl alcohol 36.10 parts by mass-Polyester water dispersion 13.00 parts by mass (TOYOBO MD-1200 solid content concentration 34% by mass)
-Colloidal silica 0.60 part by mass (manufactured by Nissan Kagaku, MP2040, average particle size 200 nm, solid content concentration 40% by mass)
-Surfactant (fluorine type, solid content concentration 10% by mass) 0.30 parts by mass The above-mentioned physical properties were evaluated using the casting roll surface of the obtained film as the release layer surface. The evaluation results are shown in Table 2.

Example 10
Corrosion treatment is applied to the touch roll surface of the film A4, and the antistatic layer Pertron C-4402 (antimony-doped tin oxide particles) with MEK having a solid concentration of 5% is applied and heated. It was dried in an oven at 80 ° C. for 3 minutes. The thickness of the coating layer was 200 nm. The surface resistance was 7.5 × 10 ⁷ Ω / □. The above-mentioned physical properties were evaluated using the casting roll surface of the obtained film as the release layer surface. The evaluation results are shown in Table 2.

Example 11
A twin screw extruder in which a dried thermoplastic norbornene resin (ZEONOR1420R manufactured by Nippon Zeon Co., Ltd.) and silica particles (KE-P250 manufactured by Nippon Shokubai Co., Ltd.) having a particle size of 2.5 μm are mixed so that the particle content is 1000 ppm in terms of solid content. And pellet 1 was obtained.
The dried pellets 1 were supplied to the extruder 1, and the dried thermoplastic norbornene resin (ZEONOR 1420R manufactured by Nippon Zeon Co., Ltd.) was supplied to the extruder 2, and the stainless steel sintered filter media (nominal filtration accuracy of 10 μm particles 95 % Cut), the mixture was laminated in a 2-kind 2-layer confluent block and extruded into a sheet shape on a casting roll in the same manner as the film A1 to obtain a film B1. At this time, the resin on the extruder 2 side was made to be the casting roll surface.
The above-mentioned physical properties were evaluated using the casting roll surface of the obtained film as the release layer surface. The evaluation results are shown in Table 2.

Example 12
Dried thermoplastic norbornene resin (ZEONOR 1420R manufactured by Nippon Zeon Co., Ltd.) and silica particles having a particle diameter of 100 nm (KE-P10 manufactured by Nippon Shokubai Co., Ltd.) were added to a twin-screw extruder so that the particle content was 600 ppm in terms of solid content. Then, pellet 2 was obtained.
A film B2 was obtained in the same manner as in Example 11 except that the pellet 2 was supplied to the extruder 2.
The above-mentioned physical properties were evaluated using the casting roll surface of the obtained film as the release layer surface. The evaluation results are shown in Table 2.

Comparative Example 1
The film A3 was used, and the above-mentioned physical properties were evaluated using the touch roll surface as the release layer surface. The evaluation results are shown in Table 2.

As is clear from Table 2, in Examples 1 to 12 in which the surface roughness of the release surface satisfies the requirements of the present invention, the defects were markedly small in the defect evaluation, and pinhole-like or scratch-like light leakage occurred. Was sufficiently suppressed. Further, in Examples 1 to 6 and 8 to 12, the surface roughness of the back surface was suppressed to a low level, and therefore, among the defect evaluations, defects 1 and 2 after overlaying were remarkably small, and pinholes and scratches were observed. The occurrence of light leakage was sufficiently suppressed. On the other hand, Comparative Example 1 in which the surface roughness of the release surface was too large had many defects in the defect evaluation, and it was not possible to sufficiently suppress the occurrence of pinhole-shaped or scratch-shaped light leakage.

Although not shown in Table 1, when the in-plane retardation (Re) of the base material films used in Examples and Comparative Examples was determined, all of the base material films were 10 nm or less, which was sufficiently low, The alignment state of the liquid crystal compound alignment layer was inspected by irradiating linearly polarized light in a state where the liquid crystal compound alignment layer was laminated on the film.

The specific measurement procedure of in-plane retardation is as follows. That is, a 4 cm × 2 cm rectangle was cut out from the base film used in Examples and Comparative Examples so that the long side was in the flow direction, and used as a measurement sample. The refractive index (flow direction nx, width direction ny) of this sample was measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., measurement wavelength 589 nm). The product was measured at 5 points in the width direction of the film (center portion, both end portions, intermediate portion between the center portion and the end portion), and the average was taken as the product ((nx-ny) × d) of the film thickness d (nm). Thus, the in-plane retardation (Re) was obtained.

The liquid crystal compound alignment layer transfer film of the present invention uses a film whose surface roughness is controlled within a specific range as a transfer film for a retardation layer or a polarizing layer. The orientation state and retardation of the liquid crystal compound therein can be made as designed, and a retardation layer or a polarizing layer (liquid crystal compound orientation layer) in which occurrence of defects such as pinholes is reduced can be formed. 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

A cyclic polyolefin film for transferring a liquid crystal compound alignment layer to an object, characterized in that the release surface of the film has a surface roughness (SRa) of 1 nm or more and 30 nm or less. Film.
The film for transferring a liquid crystal compound alignment layer according to claim 1, wherein the release surface of the film has a 10-point surface roughness (SRz) of 5 nm or more and 200 nm or less.
A laminate comprising a liquid crystal compound alignment layer and a film, wherein the film is the film according to claim 1 or 2, wherein the liquid crystal compound alignment layer transfer laminate.
A liquid crystal compound alignment layer comprising: a step of adhering a polarizing plate and a liquid crystal compound alignment layer surface of the laminate according to claim 3 to form an intermediate laminate; and a step of peeling a film from the intermediate laminate. Method for manufacturing laminated polarizing plate.