JP6924832B2 - Liquid crystal film manufacturing method and functional film manufacturing method - Google Patents

Description

The present invention relates to a method for producing a liquid crystal film and a method for producing a functional film.

The layer containing the cholesteric liquid crystal phase (cholesteric liquid crystal layer) is known as a layer having a property of selectively reflecting either right-handed circularly polarized light or left-handed circularly polarized light in a specific wavelength range (selective reflection wavelength band). .. Therefore, the cholesteric liquid crystal layer can display an image of a color corresponding to the light of the selective reflection wavelength by reflecting the light, and has been developed for various uses.
For example, Patent Document 1 describes a configuration in which a single-layer cholesteric liquid crystal layer is provided with at least one region in which the selective reflection wavelength band is different from other regions, and utilizes the characteristics of the cholesteric liquid crystal. It is stated that the authentication information is recorded.
In Patent Document 1, as a method for forming a cholesteric liquid crystal layer having regions having different selective reflection wavelength bands, a cholesteric liquid crystal layer having a patterned selective reflection wavelength is obtained by exposing to ultraviolet rays through a mask on which a pattern is formed. The method of forming is described.

Japanese Unexamined Patent Publication No. 2006-142699

However, in the method for forming a cholesteric liquid crystal layer described in Patent Document 1, when a coating liquid of cholesteric liquid crystal is applied to a substrate and dried, and then the coating film is irradiated with ultraviolet rays to be cured, it is exposed using a pattern mask. It is carried out. Further, as the pattern mask, only a binary pattern mask having a light-shielding portion and a transmissive portion is described.

According to the study by the present inventors, the cholesteric liquid crystal layer formed by such a method has a desired selective reflection wavelength, that is, a region in which a desired color cannot be obtained or the selective reflection wavelength band is different. It was found that the boundary between them was blurred and sufficient fineness could not be obtained. Further, when a binary pattern mask is used, it is necessary to change the pattern mask and perform multiple exposures when forming three or more regions having different selective reflection wavelengths on the cholesteric liquid crystal layer. Therefore, it has been found that in order to form a more multicolored cholesteric liquid crystal layer, many steps are required and there is a problem that the production efficiency is poor.

In view of the above circumstances, the present invention provides a method for producing a liquid crystal film having high productivity and a method for producing a functional film, which can obtain a cholesteric liquid crystal layer capable of displaying a fine and desired color gradation image. The task is to do.

As a result of diligent studies on the problems of the prior art, the present inventors have conducted a delivery step of delivering a long support in the longitudinal direction and a cholesteric liquid crystal compound and photosensitive while transporting the delivered support in the longitudinal direction. A coating step of applying a liquid crystal composition containing a chiral agent to the surface of a support, an irradiation step of irradiating a coating film of an undried liquid crystal composition with light having a wavelength that the chiral agent is exposed to, and heating the coating film. It has an alignment step for aligning the liquid crystal and a curing step for curing the oriented coating film in this order. In the irradiation step, the coating film is irradiated with light through a pattern mask arranged on the support side to form a pattern. The mask is a multi-gradation pattern mask having three or more regions having different transmittances for light of wavelengths to which the chiral agent is exposed, and in the irradiation step, the coating film is irradiated with light through the multi-gradation pattern mask. By doing so, it has been found that the above-mentioned problems can be solved by irradiating each region of the coating film with different irradiation amounts of light.
That is, it was found that the above object can be achieved by the following configuration.

(1) A delivery process that sends out a long support in the longitudinal direction,
A coating step of applying a liquid crystal composition containing a cholesteric liquid crystal compound and a photosensitive chiral agent to the surface of the support while transporting the delivered support in the longitudinal direction.
An irradiation step of irradiating the coating film of the undried liquid crystal composition with light having a wavelength that the chiral auxiliary is exposed to.
An orientation process that heats the coating film to orient the liquid crystal display,
It has a curing step of curing the oriented coating film in this order.
In the irradiation step, the coating film is irradiated with light through a pattern mask arranged on the support side, and the coating film is irradiated with light.
The pattern mask is a multi-gradation pattern mask having three or more regions having different transmittances for light having a wavelength to which the chiral auxiliary is exposed.
A method for producing a liquid crystal film that irradiates a coating film with light through a multi-gradation pattern mask in an irradiation step to irradiate each region of the coating film with a different irradiation amount of light.
(2) The method for manufacturing a liquid crystal film according to (1), wherein the pattern mask is formed on the back surface of the support.
(3) The pattern mask is formed on the surface of a long base film.
The method for producing a liquid crystal film according to (1), wherein in the irradiation step, light is irradiated while the base film on which the pattern mask is formed is attached to the back surface of the support.
(4) The method for producing a liquid crystal film according to any one of (1) to (3), wherein the pattern mask is formed by grayscale printing.
(5) The irradiation step includes a first irradiation step and a second irradiation step.
The method for producing a liquid crystal film according to any one of (1) to (4), wherein the irradiation amount of light in the first irradiation step is smaller than the irradiation amount of light in the second irradiation step.
(6) The method for producing a liquid crystal film according to (5), wherein the total irradiation amount of the first irradiation step and the second irradiation step is 200 mJ / cm ^{2 or less.}
(7) The irradiation step includes a first irradiation step and a second irradiation step.
The method for producing a liquid crystal film according to any one of (1) to (6), wherein the peak wavelength of the light irradiated in the first irradiation step and the peak wavelength of the light irradiated in the second irradiation step are different from each other.
(8) The curing step is a step of photocuring the coating film.
The method for producing a liquid crystal film according to any one of (1) to (7), wherein the wavelength of the light irradiated in the curing step is different from the wavelength of the light irradiated in the irradiation step.
(9) In the curing step, the pattern mask is integrally conveyed in a state of being arranged on the back surface side of the support.
The method for manufacturing a liquid crystal film according to (8), wherein the surface side opposite to the pattern mask is irradiated with light.
(10) The method for producing a liquid crystal film according to any one of (1) to (9), wherein the method for applying the liquid crystal composition in the coating step is bar coating.
(11) A method for producing a liquid crystal film, which forms two or more cholesteric liquid crystal layers by repeating a combination of a coating step, an irradiation step, an orientation step, and a curing step two or more times.
The liquid crystal film according to any one of (1) to (10), wherein light is irradiated through a pattern mask of the same pattern in two or more irradiation steps, and the irradiation amount of light in each irradiation step is different from each other. Manufacturing method.
(12) After the curing step of the method for producing a liquid crystal film according to any one of (1) to (11), there is a step of attaching a circularly polarizing plate to the front surface of the cured coating film or the back surface of the support. A method for manufacturing a functional film.

According to the present invention, it is possible to obtain a cholesteric liquid crystal layer capable of displaying a fine and desired color gradation image, and it is possible to provide a method for producing a liquid crystal film having high productivity and a method for producing a functional film. ..

It is a figure which shows typically the manufacturing apparatus which carries out an example of the manufacturing method of the liquid crystal film of this invention. It is a schematic diagram for demonstrating an example of the manufacturing method of the liquid crystal film carried out by the manufacturing apparatus of FIG. It is a figure which shows typically the manufacturing apparatus which carries out another example of the manufacturing method of the liquid crystal film of this invention. It is a schematic cross-sectional view for demonstrating an example of the manufacturing method of the liquid crystal film carried out by the manufacturing apparatus of FIG. It is a schematic cross-sectional view for demonstrating an example of the manufacturing method of the liquid crystal film carried out by the manufacturing apparatus of FIG. It is a figure which shows the pattern mask used in an Example. It is a figure which shows the liquid crystal film produced in an Example. It is a figure which shows another example of the pattern mask used in this invention. It is a figure which shows the binary pattern mask used in the comparative example. It is a figure which shows an example of the pattern mask used in the manufacturing method of this invention. It is a figure which shows the liquid crystal film produced using the pattern mask shown in FIG.

Hereinafter, the method for producing the liquid crystal film of the present invention will be described in detail. The numerical range represented by using "~" in the present specification means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
Further, in the present specification, "orthogonal" and "parallel" include a range of errors allowed in the technical field to which the present invention belongs. For example, "orthogonal" and "parallel" mean that the error is within ± 10 ° with respect to strict orthogonality or parallelism, and the error with respect to strict orthogonality or parallelism is 5 ° or less. It is preferably 3 ° or less, and more preferably 3 ° or less.
In addition, angles other than "orthogonal" and "parallel", for example, specific angles such as 15 ° and 45 °, shall also include a range of errors allowed in the technical field to which the present invention belongs. For example, in the present invention, the angle means that it is less than ± 5 ° with respect to the concretely indicated exact angle, and the error with respect to the indicated exact angle is ± 3 ° or less. It is preferably present, and preferably ± 1 ° or less.

As used herein, "(meth) acrylate" is used to mean "one or both of acrylate and methacrylate".
As used herein, "identical" shall include an error range generally tolerated in the art. Further, in the present specification, when the term "all", "all" or "whole surface" is used, it includes not only 100% but also an error range generally accepted in the technical field, for example, 99% or more. It shall include the case where it is 95% or more, or 90% or more.

Visible light is light having a wavelength that can be seen by the human eye among electromagnetic waves, and indicates light in the wavelength range of 380 nm to 780 nm. Invisible light is light in a wavelength region of less than 380 nm or in a wavelength region of more than 780 nm.
Although not limited to this, among the visible light, the light in the wavelength range of 420 nm to 490 nm is blue light, and the light in the wavelength range of 495 nm to 570 nm is green light, which is 620 nm to 750 nm. Light in the wavelength range is red light.
Of the infrared light, near-infrared light is an electromagnetic wave in the wavelength range of 780 nm to 2500 nm. Ultraviolet light is light having a wavelength in the range of 10 to 380 nm.
In the present specification, the selective reflection wavelength is a half-value transmittance expressed by the following formula: T1 / 2 (%), where Tmin (%) is the minimum value of the transmittance of the target object (member). It refers to the average value of two wavelengths indicating.
Formula for calculating half-value transmittance: T1 / 2 = 100- (100-Tmin) ÷ 2

In the present specification, "haze" means a value measured using a haze meter NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd.
In theory, haze means a value expressed by the following equation.
(Scattering transmittance of natural light from 380 to 780 nm) / (Scattering transmittance of natural light from 380 to 780 nm + direct transmittance of natural light) x 100%
The scattering transmittance is a value that can be calculated by subtracting the direct transmittance from the obtained omnidirectional transmittance using a spectrophotometer and an integrating sphere unit. The direct transmittance is the transmittance at 0 ° based on the value measured using the integrating sphere unit. That is, a low haze means that the amount of directly transmitted light is larger than the total amount of transmitted light.
The refractive index is the refractive index for light having a wavelength of 589.3 nm.

In the present specification, Re (λ) and Rth (λ) represent in-plane retardation at wavelength λ and retardation in the thickness direction, respectively. Unless otherwise specified, the wavelength λ is 550 nm.
In the present specification, Re (λ) and Rth (λ) are values measured at a wavelength λ in AxoScan OPMF-1 (manufactured by Optoscience). By inputting the average refractive index ((Nx + Ny + Nz) / 3) and film thickness (d (μm)) in AxoScan,
Slow phase axial direction (°)
Re (λ) = R0 (λ)
Rth (λ) = ((Nx + Ny) /2-Nz) × d
Is calculated.
Although R0 (λ) is displayed as a numerical value calculated by AxoScan, it means Re (λ).

In the present specification, the refractive indexes Nx, Ny, and Nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) and a sodium lamp (λ = 589 nm) as a light source. When measuring the wavelength dependence, it can be measured with a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) in combination with an interference filter.
In addition, the values in the Polymer Handbook (JOHN WILEY & SONS, INC) and the catalogs of various optical films can also be used. The average refractive index values of the main optical films are illustrated below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethylmethacrylate (1.49), It is polystyrene (1.59).

The method for producing a liquid crystal film of the present invention
A delivery process that sends out a long support in the longitudinal direction,
A coating step of applying a liquid crystal composition containing a cholesteric liquid crystal compound and a photosensitive chiral agent to the surface of the support while transporting the delivered support in the longitudinal direction.
An irradiation step of irradiating the coating film of the undried liquid crystal composition with light having a wavelength that the chiral auxiliary is exposed to.
An orientation process that heats the coating film to orient the liquid crystal display,
It has a curing step of curing the oriented coating film in this order.
In the irradiation step, the coating film is irradiated with light through a pattern mask arranged on the support side, and the coating film is irradiated with light.
The pattern mask is a multi-gradation pattern mask having three or more regions having different transmittances for light having a wavelength to which the chiral auxiliary is exposed.
This is a method for producing a liquid crystal film in which the amount of light irradiated varies depending on the region of the coating film by irradiating the coating film with light through a multi-gradation pattern mask in the irradiation step.

Further, the method for producing the functional film of the present invention is:
This is a method for producing a functional film, which comprises a step of attaching a circularly polarizing plate to the front surface of the cured coating film or the back surface of the support after the curing step of the method for producing a liquid crystal film.

<Manufacturing method of liquid crystal film>
Hereinafter, an example of a preferred embodiment of the method for producing a liquid crystal film of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of an example of a liquid crystal film manufacturing apparatus (hereinafter, also referred to as “manufacturing apparatus”) that implements the liquid crystal film manufacturing method of the present invention (hereinafter, also referred to as “the manufacturing method of the present invention”). Is shown. Further, FIG. 2 shows a schematic diagram for explaining an example of a method for manufacturing a liquid crystal film carried out by the manufacturing apparatus shown in FIG.
The figure in the present invention is a schematic view, and the size of each part, the relationship between the thicknesses of each layer, the positional relationship, and the like do not always match the actual ones. The same applies to the following figure.

The manufacturing apparatus 100a shown in FIG. 1 uses a long support 12a to manufacture a liquid crystal film by roll-to-roll (hereinafter, also referred to as “RtoR”). As is well known, RtoR refers to a processed object that has been processed by sending out the object to be processed from a roll formed by winding a long object to be processed and performing a process such as film formation while transporting the object to be processed in the longitudinal direction. , Again, it is a manufacturing method of winding in a roll shape.

As an example, the manufacturing apparatus 100a includes a delivery roller 102, a first transport unit 120, a coating unit 150, a second transport unit 122, an exposure unit 152, a heating unit 154, a curing unit 156, and a third transport unit. It has a portion 124 and a take-up roller 116. The first transport unit 120, the second transport unit 122, and the third transport unit 124 have rollers for transport and the like, and transport a long object to be processed by a predetermined route.
In addition to the members shown in the figure, the manufacturing apparatus 100a is provided in a known apparatus such as a transfer roller pair, a guide member of a support, various sensors, etc., which performs film formation by coating while conveying a long object to be processed. It may have various members to be used.

In the manufacturing apparatus 100a, the roll 130 formed by winding the long support 12a is loaded into the delivery roller 102.
The support 12a is pulled out from the roll 130, passes through the first transport section 120, the coating section 150, the second transport section 122, the exposure section 152, the heating section 154, the curing section 156, and the third transport section 124, and is a winding roller. It is inserted into a predetermined route to 116.
Further, the prepared liquid crystal composition to be the cholesteric liquid crystal layer is supplied to the coating nozzle 104 of the coating unit 150 to perform coating.

In the manufacturing apparatus 100a using RtoR, the feeding of the support 12a from the roll 130 and the winding of the support 12a (laminated film 23d) on which the cholesteric liquid crystal layer 18 is formed are performed in synchronization with each other. As a result, the liquid crystal composition prepared in the coating unit 150 is applied to the support 12a, the coating film is exposed in the exposure unit 152, and then the coating film is exposed in the exposure unit 152 while the long support 12a is conveyed in the longitudinal direction by a predetermined transfer path. The coating film is heated in the heating portion 154 to orient the liquid crystal display, and the cured portion 156 is further irradiated with ultraviolet rays and / or heated to cure the coating film to form the cholesteric liquid crystal layer 18. Further, in the take-up roller 116, the long laminated film 23d in which the cholesteric liquid crystal layer 18 is formed on the support 12a is wound in a roll shape to form a roll 132.
In the present invention, the liquid crystal film is a film-like material having a cholesteric liquid crystal layer, and in the examples shown in FIGS. 1 and 2, the laminated film 23d in which the cholesteric liquid crystal layer 18 is laminated on the surface of the support 12a. Is the liquid crystal film of the present invention. The cholesteric liquid crystal layer 18 may be used in a state of being laminated on the support 12a, or may be used after being peeled off from the support 12a.

In the delivery step shown in S1 of FIG. 2, the support 12a delivered from the roll 130 has a pattern mask formed on a resin film such as a PET film.

As the resin film forming the support 12a, various known transparent sheet-like materials used as a substrate (support) can be used.

Specifically, low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene naphthalate (PEN), polyamide (PA), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), Polyacrytonitrile (PAN), polyimide (PI), transparent polyimide, polymethyl methacrylate resin (PMMA), polycarbonate (PC), polyacrylate, polymethacrylate, polypropylene (PP), polystyrene (PS), ABS, cycloolefin. A film (resin film) made of various resin materials such as copolymer (COC), cycloolefin polymer (COP), and triacetyl cellulose (TAC) is preferably exemplified.

In the present invention, the surface of such a film has necessary functions such as a protective layer, an adhesive layer, a light reflection layer, an antireflection layer, a light shielding layer, a flattening layer, a buffer layer, a stress relaxation layer, and a release layer. The one on which the layer (film) expressing the above is formed may be used as the support 12a.

The pattern mask included in the support 12a is a multi-gradation pattern mask having three or more regions having different transmittances for light (light having a wavelength exposed to the chiral agent) irradiated by the exposure unit 152, which will be described later.
Such a pattern mask can be formed by printing, for example, and a mask having a desired pattern can be obtained by printing so that the light transmittance of the ink layer formed on the surface of the resin film differs depending on the region. be able to. Specifically, it can be formed by grayscale printing (see FIG. 6) or color printing (see FIG. 8).

If the thickness of the support 12a is too thin, the supportability will be lowered, and there is a possibility that bending or the like may occur during transportation. On the other hand, if it is too thick, the flexibility may decrease, making it difficult to transport, increasing the size when wound on a roll, or making it difficult to peel off the formed cholesteric liquid crystal layer from the support 12a. ..
From the above viewpoint, the thickness of the support 12a is preferably 20 μm to 100 μm, more preferably 60 μm to 100 μm.

As shown in FIG. 1, the support 12a sent out from the roll 130 passes through the first transport portion 120 and reaches the coating portion 150. The support 12a is coated with the coating portion 150. In the example shown in FIG. 1, the liquid crystal composition is applied by the application nozzle 104 in a state where the support 12a is wound around the backup roller 106 when the application is applied by the application unit 150. When coating is performed by a method capable of coating without the backup roller 106, such as bar coating, the backup roller 106 may be omitted.
As shown in FIG. 2 in S2, in the coating step, the coating portion 104 applies a liquid crystal composition containing a cholesteric liquid crystal compound and a photosensitive chiral agent to the surface of the support 12a to form a coating film 21a. The laminated body of the support 12a and the coating film 21a is referred to as a laminated film 23a.
The liquid crystal composition will be described in detail later.

As a coating method in the coating step, a known coating method such as extrusion coating, gravure coating, die coating, bar coating, applicator coating, or a printing method such as flexographic printing can be applied.
Above all, bar coating is preferable from the viewpoint that coating unevenness can be suppressed even if the surface of the support 12a has irregularities (unevenness due to an ink layer serving as a pattern mask, etc.).

The coating film 21a may be formed on the pattern mask side of the support 12a, but is preferably formed on the surface opposite to the pattern mask. That is, the pattern mask is preferably formed on the surface (back surface) of the support 12a opposite to the surface on which the coating film 21a is formed.

Next, as shown in FIG. 1, the laminated film 23a passes through the second transport unit 122 and reaches the exposed unit 152. The laminated film 23a is subjected to an irradiation step in the exposed portion 152.
As shown in S3 of FIG. 2, in the irradiation step, the exposure apparatus 108 irradiates the undried coating film 21a from the support 12a side, that is, through the pattern mask. The light emitted by the exposure apparatus 108 is light having a wavelength that the chiral agent in the coating film 21a (liquid crystal composition) is exposed to. Therefore, the coating film 21b exposed by the exposure process is formed. In the exposed coating film 21b, the photosensitive chiral agent is exposed to light, and its structure changes.
The laminated body of the support 12a and the exposed coating film 21b is referred to as a laminated film 23b.

Here, the pattern mask is a multi-gradation pattern mask having three or more regions having different transmittances for light having a wavelength to which the chiral agent is exposed. Therefore, the exposed coating film 21b is irradiated with a different irradiation amount of light for each region corresponding to the pattern of the pattern mask.
Here, the amount of change in the structural change due to the photosensitivity of the photosensitive chiral agent differs depending on the irradiation amount. Therefore, in the exposed coating film 21b, the amount of change in the structural change of the chiral agent differs for each region according to the pattern of the pattern mask.

The wavelength of the light used for the exposure may be set according to the type of the photosensitive chiral agent and the like.
Further, the amount of light irradiation may be set according to the type of the photosensitive chiral auxiliary, the light transmittance of the pattern mask, and the like.

Next, as shown in FIG. 1, the laminated film 23b is conveyed to reach the heating unit 154. In the heating device 110, the coating film of the laminated film 23b is dried and subjected to an orientation treatment.
As shown in S4 in FIG. 2, in the alignment step, the heating device 110 heats the exposed coating film 21b to align the liquid crystal compound in the coating film 21b. By the heat treatment, a coating film 21c in which the liquid crystal compound is oriented according to the structure of the chiral agent is formed.
Here, as described above, in the coating film 21c, there are three or more regions having different exposure amounts. Therefore, each region has a structure in which the length of the spiral pitch of the cholesteric liquid crystal phase differs depending on the exposure amount. As will be described in detail later, the selective reflection wavelength in the cholesteric liquid crystal phase depends on the pitch of the helical structure in the cholesteric liquid crystal phase. Therefore, by forming three or more regions having different spiral pitch lengths of the cholesteric liquid crystal phase, three or more regions having different selective reflection wavelengths are formed.
The laminated body of the support 12a and the oriented coating film 21c is referred to as a laminated film 23c.

Next, as shown in FIG. 1, the laminated film 23c is conveyed to reach the cured portion 156. The laminated film 23c is cured in the cured portion 156.
As shown in FIG. 2 in S5, in the curing step, the cured portion 112 cures the oriented coating film 21c to form the cholesteric liquid crystal layer 18. As a result, a liquid crystal film having a cholesteric liquid crystal layer 18 is produced. The laminated body of the support 12a and the cholesteric liquid crystal layer 18 is referred to as a laminated film 23d.
As a method for curing the coating film 21c, known curing methods such as photocuring by irradiation with light such as ultraviolet rays and thermosetting by heating can be used.
When curing is performed by light irradiation, it is preferable to irradiate the coating film 21c with light from the surface side opposite to the pattern mask.

Next, the produced liquid crystal film (laminated film 23d) passes through the third transport unit 124 and is wound into a roll by a take-up roller 116 to form a roll 132.
Since the cholesteric liquid crystal layer of the produced liquid crystal film has a structure in which three or more regions having different selective reflection wavelengths are formed in a pattern corresponding to the mask pattern, each region reflects light of the selective reflection wavelength. It is possible to display an image of a color and a pattern according to the above.

In the conventional configuration in which a coating liquid of cholesteric liquid crystal is applied to a substrate, dried, and then exposed by using a pattern mask when the coating film is irradiated with ultraviolet rays to be cured, the liquid crystal in the coating film is dried. Since the compound is difficult to move, the amount of change in the pitch of the spiral structure of the liquid crystal compound becomes smaller than the desired amount of change even after exposure. Therefore, there is a problem that a desired selective reflection wavelength cannot be obtained, that is, a desired color tone cannot be reproduced.
Even in such a case, the desired selective reflection wavelength can be obtained by increasing the exposure amount, but if the exposure amount is large, light leaks to the unexposed portion and the unexposed portion is also exposed, so that the exposed portion and the unexposed portion are exposed. It was found that there was a problem that the boundary with the part (between regions with different selective reflection wavelengths) was blurred and sufficient fineness could not be obtained.
Further, in a configuration in which a binary pattern mask having a light-shielding portion and a transmissive portion is used as the pattern mask, when the binary pattern mask is used, three or more regions having different selective reflection wavelengths are formed in the cholesteric liquid crystal layer. At that time, it is necessary to change the pattern mask and perform multiple exposures. Therefore, it has been found that in order to form a more multicolored cholesteric liquid crystal layer, many steps are required and there is a problem that the production efficiency is poor.

On the other hand, in the production method of the present invention, since the coating film in the undried state is exposed before the coating film of the liquid crystal composition is heated and dried, the liquid crystal compound in the coating film is easily moved. Even with a small exposure amount, the amount of change in the pitch of the spiral structure of the liquid crystal compound can be set as the desired amount of change. Therefore, the desired selective reflection wavelength can be easily set, that is, the desired color can be reproduced. Further, since the exposure amount is small, it is possible to suppress light leakage to adjacent regions (regions with different exposure amounts), and it is possible to obtain a fine image without blurring the boundaries between regions having different selective reflection wavelengths. ..
Further, as the pattern mask, a multi-gradation pattern mask having three or more regions having different transmittances for light having a wavelength to which the chiral auxiliary is exposed is used, so that the selective reflection wavelength differs from the cholesteric liquid crystal layer in one exposure3. The above region can be formed. Therefore, the multicolored cholesteric liquid crystal layer can be efficiently manufactured in a small number of steps.
As described above, the manufacturing method of the present invention can obtain a cholesteric liquid crystal layer capable of displaying a fine image with a desired color gradation, and has high productivity.

Here, the pattern mask may have three or more regions having different transmittances for light of the wavelength to which the chiral auxiliary is exposed, but from the viewpoint of being able to reproduce more colors and increase the gradation. The pattern mask preferably has 8 or more regions having different transmittances, and more preferably 256 or more regions.

Further, in the example shown in FIG. 1, the produced liquid crystal film is wound in a roll shape, but the present invention is not limited to this, and the produced liquid crystal film is provided with a cutting portion for cutting into a predetermined size. May be good.

When the curing method of the coating film in the curing step is photocuring, the wavelength of the light irradiated in the curing step is preferably a wavelength different from the wavelength of the light irradiated in the irradiation step, and in the irradiation step. It is preferable that the wavelength of the light to be irradiated is longer than the wavelength of the light to be irradiated in the curing step. Specifically, the wavelength of the light irradiated in the irradiation step is preferably the wavelength that the chiral agent is exposed to and the wavelength at which the polymerization initiator is not cleaved.
By making the wavelength of the light to be irradiated different between the curing step and the irradiation step, it is possible to prevent the coating film from being cured by the light irradiation in the irradiation step, and the amount of change in the pitch of the spiral structure of the liquid crystal compound can be changed as desired. Can be a quantity.

As the wavelength of the light to be irradiated in the irradiation step, the wavelength to which the chiral agent is exposed may be selected according to the type of the chiral auxiliary. Specifically, the wavelength of the light irradiated in the irradiation step is preferably 350 nm to 400 nm. That is, it is preferable to use a chiral agent that is sensitive in this wavelength range.
Further, the irradiation amount of the light to be irradiated in the irradiation step may be set to an irradiation amount having a desired selective reflection wavelength according to the type of the chiral auxiliary and the like.

The wavelength of the light to be irradiated in the curing step may be selected according to the type of the polymerization initiator and the like. Specifically, the wavelength of the light irradiated in the curing step is preferably 300 nm to 350 nm. That is, it is preferable to use a polymerization initiator capable of initiating the polymerization reaction in this wavelength range.
Further, the irradiation amount of light to be irradiated in the curing step may be set according to the type of the polymerization initiator and the like.

Further, in the example shown in FIG. 1, the light irradiation is performed once in the irradiation step, but the light irradiation may be performed twice or more. For example, the irradiation step may have a configuration including a first irradiation step and a second irradiation step.
By configuring the light irradiation in the irradiation step by dividing it into two or more times, the structural change of the chiral auxiliary due to exposure can be adjusted more preferably, and a desired selective reflection wavelength can be obtained.

At that time, it is preferable that the light irradiation amount in the first irradiation step is smaller than the light irradiation amount in the second irradiation step.
As for the structural change of the chiral auxiliary, when the total amount of light irradiation is small, the amount of change with respect to the amount of light irradiation is large, and as the total amount of light irradiation is large, the amount of change with respect to the amount of light irradiation is small. Therefore, by making the irradiation amount of light in the first irradiation step smaller than the irradiation amount of light in the second irradiation step, it is possible to more preferably adjust the structural change of the chiral auxiliary due to exposure.

Further, in the irradiation step, the total irradiation amount of the first irradiation step and the second irradiation step ^{is preferably 200 mJ / cm 2} or less.
It is preferable that the total irradiation amount is 200 mJ / cm ² or less because the exposure of the unexposed portion can be prevented.

Further, in the first irradiation step and the second irradiation step, the peak wavelengths of the irradiated light may be different.
By setting the peak wavelength of the light in the first irradiation step to a wavelength shifted from the peak wavelength of the light exposed by the chiral agent and matching the peak wavelength of the light in the second irradiation step with the peak wavelength of the light exposed by the chiral agent. Substantially, the amount of light irradiation can be adjusted.
Specifically, for example, if the light absorption peak of the chiral agent is 365 nm and the spectrum has a base in the range of 250 nm to 450 nm, in the first irradiation step, light of 265 nm near the base is irradiated and the second irradiation is performed. In the step, by irradiating the peak light of 365 nm, the amount of light irradiation can be substantially adjusted.

Further, in the example shown in FIG. 1, the configuration is such that the cholesteric liquid crystal layer 18 is wound on the roll 132 immediately after being formed, but before the cholesteric liquid crystal layer 18 is wound, a protective film or the like is attached to the surface of the cholesteric liquid crystal layer 18. It may have a step to do.

Further, as shown by S6 in FIG. 2, a functional film having a step of transferring the cholesteric liquid crystal layer 18 to the circularly polarizing plate 16 after producing the liquid crystal film, and having the cholesteric liquid crystal layer 18 and the circularly polarizing plate 16. May be configured to produce.
Specifically, after the cholesteric liquid crystal layer 18 is formed and before being wound around the roll 132, the circularly polarizing plate 16 may be attached to the surface of the cholesteric liquid crystal layer 18, or the cholesteric liquid crystal layer 18 may be attached. After forming, the roll 132 may be loaded on a general bonding device after being wound on the roll 132, and the circularly polarizing plate 16 may be attached to the surface of the cholesteric liquid crystal layer 18.
Further, after the circularly polarizing plate 16 is attached, there may be a step of peeling off the support 12a.

The circular polarizing plate 16 is not limited, and a circular polarizing plate having a structure in which a linear polarizing plate and a λ / 4 plate are laminated can be used. Further, the circularly polarizing plate 16 transmits circularly polarized light in the direction opposite to the turning direction of the circularly polarized light reflected by the cholesteric liquid crystal layer 18.

By stacking the cholesteric liquid crystal layer 18 and the circular polarizing plate 16, among the light incident from the cholesteric liquid crystal layer 18 side (hereinafter, also referred to as the surface side), the cholesteric liquid crystal layer 18 has one of the selective reflection wavelengths. The circularly polarized light is reflected, and the other light passes through the cholesteric liquid crystal layer 18 and is incident on the circularly polarizing plate 16. Of the light incident on the circularly polarizing plate 16, the other circularly polarized light passes through the circularly polarizing plate 16.
On the other hand, the light incident from the circularly polarizing plate 16 side (hereinafter, also referred to as the back surface side) is converted into the other circularly polarized light by the circularly polarizing plate 16, passes through the circularly polarizing plate 16, and is incident on the cholesteric liquid crystal layer 18.
The other circularly polarized light transmitted through the circular polarizing plate 16 is transmitted through the cholesteric liquid crystal layer 18 without being reflected by the cholesteric liquid crystal layer 18 because the turning direction is opposite to the spiral swirling direction of the cholesteric liquid crystal phase of the cholesteric liquid crystal layer 18. do.
Therefore, when observing the functional film in which the cholesteric liquid crystal layer 18 and the circularly polarizing plate 16 are laminated from the front surface side, the other circularly polarized light that is incident and transmitted from the back surface side gives a view of the other side of the functional film. In addition to being visually recognized, light having a selective reflection wavelength in the reflection region of the cholesteric liquid crystal layer 18 is visually recognized. That is, when viewed from the surface side, an image of a pattern corresponding to the pattern shape of the cholesteric liquid crystal layer 18 is visually recognized together with a scene on the other side of the functional film.
On the other hand, when the functional film is observed from the back surface side, the scene on the other side of the functional film is visually recognized by the left circularly polarized light that is incident and transmitted from the front surface side, but the cholesteric liquid crystal layer that can be observed from the front surface side. The image displayed by 18 is not visible.
The functional film in which the cholesteric liquid crystal layer 18 and the circularly polarizing plate 16 are laminated in this way has transparency, but the image viewed from one side (cholesteric liquid crystal layer side) and the other side (the other side (cholesteric liquid crystal layer side)). The film can be different from the image seen from the circularly polarizing plate side).

An adhesive layer may be provided between the cholesteric liquid crystal layer 18 and the circularly polarizing plate 16.
Further, the configuration is not limited to the configuration in which the circularly polarizing plate is attached to the front surface of the cholesteric liquid crystal layer, and the configuration may be such that the circularly polarizing plate is attached to the back surface of the support. That is, it may be a functional film having a cholesteric liquid crystal layer, a support, and a circularly polarizing plate.

Here, in the examples shown in FIGS. 1 and 2, the support 12a has a pattern mask, but the present invention is not limited to this, and a film having the pattern mask may be attached to the support. ..
FIG. 3 schematically shows a manufacturing apparatus for carrying out another example of the method for manufacturing a liquid crystal film of the present invention.

The manufacturing apparatus 100b shown in FIG. 3 manufactures a liquid crystal film by RtoR. The manufacturing apparatus 100b includes a delivery roller 102, a supply roller 140, a first transport unit 120, a coating unit 150, a second transport unit 122, an exposure unit 152, a heating unit 154, a curing unit 156, and a first unit. 3 It has a transport unit 124, a recovery roller 144, and a take-up roller 116.
The manufacturing apparatus 100b shown in FIG. 3 is the same as the manufacturing method by the manufacturing apparatus 100a shown in FIG. 1 except that it has a supply roller 140 and a recovery roller 144. Mainly performs different parts. Further, the manufacturing method by the manufacturing apparatus 100b shown in FIG. 3 is the same as the manufacturing method by the manufacturing apparatus 100a shown in FIG. 1 except that the mask film 14 is attached to the support 12b and the mask film 14 is peeled off. , The following description mainly involves different steps.

In the manufacturing apparatus 100b, the roll 130 formed by winding the long support 12b is loaded into the delivery roller 102. A pattern mask is not formed on the support 12b.
The support 12b is pulled out from the roll 130, passes through the first transport section 120, the coating section 150, the second transport section 122, the exposure section 152, the heating section 110, the curing section 154, and the third transport section 124, and is a winding roller. It is inserted into a predetermined route to 116.
Further, the prepared liquid crystal composition to be the cholesteric liquid crystal layer is filled in a predetermined position of the coating portion 104.

Further, the supply roller 140 is loaded with a roll 142 formed by winding a mask film 14 (see FIG. 4) having a base film 20 and an ink layer 22 formed as a pattern mask on the surface of the base film 20. , The mask film 14 is pulled out from the roll 142 and inserted into a predetermined transport path from the first transport unit 120 to the third transport unit 124. The supply roller 140 is arranged between the delivery roller and the first transport unit 120 in the transport direction of the support 12b.

Further, at the position of the transport roller of the third transport unit 124, the mask film 14 is peeled from the support 12b, and the mask film 14 peeled from the support 12b is inserted into the recovery roller 144. The recovery roller 144 is arranged between the third transport unit 124 and the take-up roller 116 in the transport direction of the support 12b, and recovers the mask film 14 on the roll 146.

In the manufacturing apparatus 100b, the feeding of the support 12b from the roll 130 and the winding of the support 12b (laminated film 23d) on which the cholesteric liquid crystal layer 18 is formed are performed in synchronization with each other.
First, the mask film 14 is attached to the back surface of the support 12b to form a laminated film 25a while the long support 12b is transported in the longitudinal direction by a predetermined transport path (see FIG. 4).
Next, the liquid crystal composition prepared in the coating unit 104 is applied to the surface of the support 12b to obtain a laminated film 25b (see FIG. 5).

Next, the coating film is exposed in the exposure unit 152. At that time, the coating film 21a is irradiated with light from the mask film 14 side attached to the support 12b.
Here, the pattern mask included in the mask film 14 is a multi-gradation pattern mask in which three or more regions having different transmittances for light having a wavelength to which the chiral agent is exposed are formed by the ink layer 22. Therefore, by irradiating the coating film 21a with light through the pattern mask, different irradiation amounts of light are irradiated for each region corresponding to the pattern of the pattern mask, and three or more regions having different selective reflection wavelengths are irradiated. Can be formed.

At that time, it is preferable to attach the pattern mask (ink layer 22) side to the support 12b.
In the manufacturing method of the present invention, since the light is irradiated while transporting the support 12b by RtoR, the light is incident on the coating film from various directions, so that the light leaks and the region is affected. The boundary may be blurred. Therefore, by attaching the pattern mask to the support 12b and shortening the distance between the pattern mask and the coating film, light leakage can be suppressed and a finer image can be formed.

Next, the coating film is heated in the heating unit 110 to orient the liquid crystal display, and the cured portion 112 is further irradiated with ultraviolet rays and / or heated to cure the coating film to form the cholesteric liquid crystal layer 18, and the mask film is formed. 14. The laminated film 25e having the support 12b and the cholesteric liquid crystal layer 18.
Then, the mask film 14 is peeled off from the support 12b. The peeled mask film 14 is wound in a roll shape on the recovery roller 144 to form a roll 146.
Further, in the take-up roller 116, the long laminated film 23d in which the cholesteric liquid crystal layer 18 is formed on the support 12b is wound in a roll shape to form a roll 132.

In this way, the base film (mask film 14) on which the pattern mask is formed may be attached to the back surface of the support to perform the irradiation step (exposure).
In the example shown in FIG. 3, the coating step, the irradiation step, the alignment step, and the curing step are performed in a state where the mask film 14 is attached to the support 12b, but at least the irradiation step is performed on the mask film. The process may be performed with the 14 attached to the support 12b, and the other steps may be performed without the mask film 14 attached.
For example, the mask film 14 may be attached to the support 12b after the coating step. Alternatively, the roll 130 obtained by winding the laminate with the mask film 14 attached to the support 12b in a roll shape is loaded onto the delivery roller 102, and the laminate with the mask film 14 attached to the support 12b is covered. It may be configured to be sent out as a processed product.
Further, for example, the mask film 14 may be peeled off between the irradiation step and the alignment step, or the mask film 14 may be peeled off between the alignment step and the curing step. Alternatively, the roll 132 may be formed by winding the mask film 14 in a rolled state on the take-up roller 116 without peeling the mask film 14.

In the curing step, when the mask film 14 is attached to the support 12b, it is preferable to irradiate the surface side opposite to the mask film 14 with light.

Here, in the examples shown in FIGS. 1 and 2, one layer of the cholesteric liquid crystal layer 18 is formed on the support 12a, but the present invention is not limited to this, and the coating step, the irradiation step, the orientation step, and the alignment step are performed. The curing steps may be combined twice or more to form two or more cholesteric liquid crystal layers.
For example, the support on which the cholesteric liquid crystal layer is formed may be supplied to the manufacturing apparatus again as an object to be processed to form the cholesteric liquid crystal layer on the cholesteric liquid crystal layer. Alternatively, the manufacturing apparatus may have two or more combinations of a coating portion, an exposure portion, a heating portion, and a curing portion between the feeding roller and the winding roller in the transport direction of the support.

When performing the irradiation steps two or more times, it is preferable that the light is irradiated through the pattern mask of the same pattern and the irradiation amounts of the light in each irradiation step are different from each other.
As a result, when viewed from a direction perpendicular to the surface of the cholesteric liquid crystal layer, the selective reflection wavelength at the same position is different for each cholesteric liquid crystal layer. With this configuration, a color in which light having a selective reflection wavelength of a plurality of cholesteric liquid crystal layers is mixed is visually recognized. That is, various colors can be reproduced. For example, white can be reproduced by forming the cholesteric liquid crystal layer into a three-layer structure and assuming that each cholesteric liquid crystal layer reflects red, green, and blue, respectively.

(Cholesteric liquid crystal layer)
Next, the cholesteric liquid crystal layer will be described.
The cholesteric liquid crystal layer is a layer containing a cholesteric liquid crystal phase. The cholesteric liquid crystal layer is a layer formed by fixing the cholesteric liquid crystal phase.
The cholesteric liquid crystal layer reflects the right-handed or left-handed circularly polarized light of the light of the selective reflection wavelength, and transmits the other circularly polarized light of the selective reflection wavelength and the light of the other wavelength range.

The structure in which the cholesteric liquid crystal phase is fixed may be a structure in which the orientation of the liquid crystal compound that is the cholesteric liquid crystal phase is maintained, and typically, the polymerizable liquid crystal compound is placed in the orientation state of the cholesteric liquid crystal phase. The structure may be such that the structure is polymerized and cured by irradiation with ultraviolet rays, heating, etc. to form a non-fluid layer, and at the same time, the structure is changed to a state in which the orientation form is not changed by an external field or an external force. In the structure in which the cholesteric liquid crystal phase is fixed, it is sufficient that the optical properties of the cholesteric liquid crystal phase are maintained, and the liquid crystal compound does not have to exhibit liquid crystal properties anymore. For example, the polymerizable liquid crystal compound may have a high molecular weight due to a curing reaction and no longer have liquid crystal properties.

The selective reflection wavelength λ of the cholesteric liquid crystal phase depends on the pitch P (= spiral period) of the spiral structure in the cholesteric liquid crystal phase, and follows the relationship between the average refractive index n and λ = n × P of the cholesteric liquid crystal phase. Therefore, the selective reflection wavelength can be adjusted by adjusting the pitch of this spiral structure. Since the pitch of the cholesteric liquid crystal phase depends on the type of chiral auxiliary used together with the polymerizable liquid crystal compound or the concentration thereof added, a desired pitch can be obtained by adjusting these.
The full width at half maximum Δλ (nm) of the selective reflection band (circularly polarized light reflection band) indicating selective reflection depends on the refractive index anisotropy Δn of the cholesteric liquid crystal phase and the pitch P of the spiral, and Δλ = Δn × P. Follow the relationship. Therefore, the width of the selective reflection band can be controlled by adjusting Δn. Δn can be adjusted by the type of the liquid crystal compound forming the cholesteric liquid crystal layer, the mixing ratio thereof, and the temperature at the time of orientation. It is also known that the reflectance in the cholesteric liquid crystal phase depends on Δn, and when the same degree of reflectance is obtained, the larger the Δn, the smaller the number of spiral pitches, that is, the thinner the film thickness. Can be done.
For the measurement method of spiral sense and pitch, the method described in "Introduction to Liquid Crystal Chemistry Experiment", edited by Liquid Crystal Society of Japan, Sigma Publishing, 2007, p. 46, and "Liquid Crystal Handbook", LCD Handbook Editorial Committee, Maruzen, p. 196 can be used. can.

The reflected light of the cholesteric liquid crystal phase is circularly polarized light. Whether the reflected light is right-handed or left-handed depends on the twisting direction of the spiral in the cholesteric liquid crystal phase. The selective reflection of circularly polarized light by the cholesteric liquid crystal phase reflects the right circularly polarized light when the spiral twisting direction of the cholesteric liquid crystal phase is right, and the left circularly polarized light when the spiral twisting direction is left.
The direction of rotation of the cholesteric liquid crystal phase can be adjusted by the type of the liquid crystal compound forming the cholesteric liquid crystal layer or the type of the chiral auxiliary added.

In order to widen the wavelength region of the reflected light, it can be realized by sequentially stacking layers in which the selective reflection wavelengths λ are shifted. Further, a technique for expanding the wavelength range by a method called a pitch gradient method in which the spiral pitch in the layer is changed stepwise is also known. Specifically, Nature 378, 467-469 (1995), JP-A-6- Examples thereof include the methods described in Japanese Patent No. 281814 and Japanese Patent No. 4990426.

In the present invention, the selective reflection wavelength in the region of the cholesteric liquid crystal layer can be set in any range of visible light (about 380 to 780 nm) and near infrared light (about 780 to 2000 nm), and the setting thereof. The method is as described above.

Here, as described above, in the liquid crystal film produced by the production method of the present invention, the cholesteric liquid crystal layer has three or more regions having different selective reflection wavelengths.
For example, the cholesteric liquid crystal layer has a region in which red light (light in the wavelength range of 620 nm to 750 nm) is the selective reflection wavelength, a region in which green light (light in the wavelength range of 495 nm to 570 nm) is the selective reflection wavelength, and blue. The configuration may have a region in which light (light in the wavelength range of 420 nm to 490 nm) is used as the selective reflection wavelength.
Further, it may have a reflection region having infrared rays as the selective reflection wavelength. The infrared region is light having a wavelength region of more than 780 nm and 1 mm or less, and the near infrared region is light having a wavelength region of more than 780 nm and 2000 nm or less.

(Liquid crystal composition)
Examples of the material used for forming the cholesteric liquid crystal layer include a liquid crystal composition containing a liquid crystal compound and a photosensitive chiral agent. The liquid crystal compound is preferably a polymerizable liquid crystal compound.
The liquid crystal composition containing the polymerizable liquid crystal compound may further contain a surfactant, a polymerization initiator and the like.

--Polymerized liquid crystal compound ---
The polymerizable liquid crystal compound may be a rod-shaped liquid crystal compound or a disk-shaped liquid crystal compound, but is preferably a rod-shaped liquid crystal compound.
Examples of the rod-shaped polymerizable liquid crystal compound forming the cholesteric liquid crystal layer include a rod-shaped nematic liquid crystal compound. Examples of rod-shaped nematic liquid crystal compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, and alkoxy-substituted phenylpyrimidines. , Phenyldioxans, trans and alkenylcyclohexylbenzonitriles are preferably used. Not only low molecular weight liquid crystal compounds but also high molecular weight liquid crystal compounds can be used.

The polymerizable liquid crystal compound is obtained by introducing a polymerizable group into the liquid crystal compound. Examples of the polymerizable group include an unsaturated polymerizable group, an epoxy group, and an aziridinyl group, and an unsaturated polymerizable group is preferable, and an ethylenically unsaturated polymerizable group is particularly preferable. The polymerizable group can be introduced into the molecule of the liquid crystal compound by various methods. The number of polymerizable groups contained in the polymerizable liquid crystal compound is preferably 1 to 6, more preferably 1 to 3. Examples of polymerizable liquid crystal compounds include Makromol. Chem. , 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. No. 4,683,327, 5,622,648, 5,770,107, International Publication WO95 / 22586. , 95/24455, 97/00600, 98/23580, 98/52905, 1-272551, 6-16616, 7-110469. , 11-80081, JP-A-2001-328973, and the like. Two or more kinds of polymerizable liquid crystal compounds may be used in combination. When two or more kinds of polymerizable liquid crystal compounds are used in combination, the orientation temperature can be lowered.

Specific examples of the polymerizable liquid crystal compound include compounds represented by the following formulas (1) to (11).

［化合物（１１）において、Ｘ¹は２〜５(整数）である。］

[In compound (11), X ¹ is 2-5 (integer). ]

Further, as the polymerizable liquid crystal compound other than the above, a cyclic organopolysiloxane compound having a cholesteric phase as disclosed in Japanese Patent Application Laid-Open No. 57-165480 can be used. Further, as the above-mentioned polymer liquid crystal compound, a polymer having a mesogen group exhibiting a liquid crystal introduced at the main chain, a side chain, or both the main chain and the side chain, and a polymer cholesteric having a cholesteryl group introduced into the side chain. A liquid crystal, a liquid crystal polymer as disclosed in JP-A-9-133810, a liquid crystal polymer as disclosed in JP-A-11-293252, and the like can be used.

The amount of the polymerizable liquid crystal compound added to the liquid crystal composition is preferably 75 to 99.9% by mass, preferably 80 to 99% by mass, based on the solid content mass (mass excluding the solvent) of the liquid crystal composition. It is more preferably mass%, and particularly preferably 85-90 mass%.

--Chiral agent (optically active compound) ---
The chiral agent has the function of inducing the helical structure of the cholesteric liquid crystal phase. Since the chiral compound has a different twisting direction or spiral pitch of the spiral induced by the compound, it may be selected according to the purpose.
The chiral agent is not particularly limited, and is a known compound (for example, Liquid Crystal Device Handbook, Chapter 3, Section 4-3, TN (twisted nematic), STN (Super-twisted nematic) chiral agent, p. 199, Japan Society for the Promotion of Science. (Described in 1989, edited by the 142nd Committee of the Promotion Association), isosorbide, isomannide derivatives can be used.
The chiral agent generally contains an asymmetric carbon atom, but an axial asymmetric compound or a surface asymmetric compound that does not contain an asymmetric carbon atom can also be used as the chiral agent. Examples of axial or surface asymmetric compounds include binaphthyl, helicene, paracyclophane and derivatives thereof. The chiral agent may have a polymerizable group. When both the chiral agent and the liquid crystal compound have a polymerizable group, the repeating unit derived from the polymerizable liquid crystal compound and the repeating unit derived from the chiral agent are derived by the polymerization reaction between the polymerizable chiral agent and the polymerizable liquid crystal compound. Polymers with repeating units can be formed. In this aspect, the polymerizable group of the polymerizable chiral agent is preferably a group of the same type as the polymerizable group of the polymerizable liquid crystal compound. Therefore, the polymerizable group of the chiral agent is preferably an unsaturated polymerizable group, an epoxy group or an aziridinyl group, more preferably an unsaturated polymerizable group, and preferably an ethylenically unsaturated polymerizable group. Especially preferable.
Moreover, the chiral agent may be a liquid crystal compound.

As described above, when the cholesteric liquid crystal layer is manufactured, the magnitude of the spiral pitch of the cholesteric liquid crystal phase is controlled by light irradiation. Therefore, a chiral agent (also referred to as a photosensitive chiral agent) that can change the spiral pitch of the cholesteric liquid crystal phase in response to light is used.
The photosensitive chiral agent is a compound that can change the structure by absorbing light and change the spiral pitch of the cholesteric liquid crystal phase. As such a compound, a compound that causes at least one of a photoisomerization reaction, a photodimerization reaction, and a photodegradation reaction is preferable.
A compound that causes a photoisomerization reaction is a compound that causes stereoisomerization or structural isomerization by the action of light. Examples of the photoisomerized compound include an azobenzene compound and a spiropyran compound.
Further, the compound that causes a photodimerization reaction means a compound that causes an addition reaction between two groups and cyclizes by irradiation with light. Examples of the photodimerized compound include a cinnamic acid derivative, a coumarin derivative, a chalcone derivative, and a benzophenone derivative.

As the photosensitive chiral agent, a chiral agent represented by the following general formula (I) is preferably mentioned. This chiral agent can change the orientation structure such as the spiral pitch (twisting force, spiral twisting angle) of the cholesteric liquid crystal phase according to the amount of light at the time of light irradiation.

In the general formula (I), Ar ¹ and Ar ² represent an aryl group or a heteroaromatic ring group.
The ^{aryl group represented by Ar 1} and Ar ² may have a substituent, and has a total carbon number of 6 to 40, more preferably a total carbon number of 6 to 30. Examples of the substituent include a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a carboxyl group, a cyano group, or a heterocycle. The group is preferable, and a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, a hydroxyl group, an acyloxy group, an alkoxycarbonyl group, or an aryloxycarbonyl group is more preferable.

Among such aryl groups, the aryl group represented by the following general formula (III) or (IV) is preferable.

^{R 1} in the general formula (III) ^{and R 2} in the general formula (IV) are independently hydrogen atom, halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, alkoxy group, respectively. Represents a hydroxyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a carboxyl group, or a cyano group. Of these, a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, a hydroxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, or an acyloxy group is preferable, and an alkoxy group, a hydroxyl group, or an acyloxy group. Is more preferable.
^{L 1} in the general formula (III) ^{and L 2} in the general formula (IV) independently represent a halogen atom, an alkyl group, an alkoxy group, or a hydroxyl group, and have an alkoxy group having 1 to 10 carbon atoms. Alternatively, a hydroxyl group is preferred.
l represents an integer of 0, 1 to 4, and 0 and 1 are preferable. m represents an integer of 0, 1 to 6, and 0 and 1 are preferable. When l and m are 2 or more, L ¹ and L ² may represent different groups.

The ^{heteroaromatic ring group represented by Ar 1} and Ar ² may have a substituent, and has a total carbon number of 4 to 40, more preferably a total carbon number of 4 to 30. As the substituent, for example, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, a hydroxyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, or a cyano group is preferable. A halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, or an acyloxy group is more preferable.
Examples of the heteroaromatic ring group include a pyridyl group, a pyrimidinyl group, a frill group, a benzofuranyl group and the like, and among these, a pyridyl group or a pyrimidinyl group is preferable.

The content of the chiral agent in the liquid crystal composition is preferably 0.01 mol% to 200 mol%, more preferably 1 mol% to 30 mol%, based on the amount of the polymerizable liquid crystal compound.

--Polymer initiator ---
When the liquid crystal composition contains a polymerizable compound, it preferably contains a polymerization initiator. In the embodiment in which the polymerization reaction is allowed to proceed by irradiation with ultraviolet rays, the polymerization initiator used is preferably a photopolymerization initiator capable of initiating the polymerization reaction by irradiation with ultraviolet rays. Examples of photopolymerization initiators include α-carbonyl compounds (described in US Pat. Nos. 2,376,661 and 236,670), acidoin ethers (described in US Pat. No. 2,448,828), and α-hydrogen-substituted fragrances. Group acidoine compounds (described in US Pat. No. 2722512), polynuclear quinone compounds (described in US Pat. Nos. 3,043127 and 2951758), combinations of triarylimidazole dimers and p-aminophenyl ketone (US Pat. 35493667 (described in US Pat. No. 3,549,67), aclysine and phenazine compounds (Japanese Patent Laid-Open No. 60-105667, US Pat. No. 4,239,850), oxadiazole compounds (described in US Pat. ..
The content of the photopolymerization initiator in the liquid crystal composition is preferably 0.1 to 20% by mass, preferably 0.5% by mass to 12% by mass, based on the content of the polymerizable liquid crystal compound. More preferred.

--Crosslinking agent ---
The liquid crystal composition may optionally contain a cross-linking agent in order to improve the film strength and durability after curing. As the cross-linking agent, one that cures with ultraviolet rays, heat, humidity or the like can be preferably used.
The cross-linking agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a polyfunctional acrylate compound such as trimethylolpropane tri (meth) acrylate or pentaerythritol tri (meth) acrylate; glycidyl (meth) acrylate. , Epoxy compounds such as ethylene glycol diglycidyl ether; 2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], azilysin compounds such as 4,4-bis (ethyleneiminocarbonylamino) diphenylmethane; hexa Isocyanate compounds such as methylenediisocyanate and biuret-type isocyanate; polyoxazoline compounds having an oxazoline group in the side chain; alkoxysilane compounds such as vinyltrimethoxysilane and N- (2-aminoethyl) 3-aminopropyltrimethoxysilane. Be done. Further, a known catalyst can be used depending on the reactivity of the cross-linking agent, and the productivity can be improved in addition to the improvement of the film strength and the durability. These may be used alone or in combination of two or more.
The content of the cross-linking agent is preferably 3% by mass to 20% by mass, more preferably 5% by mass to 15% by mass. If the content of the cross-linking agent is less than 3% by mass, the effect of improving the cross-linking density may not be obtained, and if it exceeds 20% by mass, the stability of the cholesteric liquid crystal layer may be lowered.

--Other additives ---
In the liquid crystal composition, if necessary, a surfactant, a polymerization inhibitor, an antioxidant, a horizontal alignment agent, an ultraviolet absorber, a light stabilizer, a coloring material, metal oxide fine particles, etc. are optically added. It can be added within a range that does not deteriorate the performance or the like.

The liquid crystal composition may contain a solvent. The solvent is not particularly limited and may be appropriately selected depending on the intended purpose, but an organic solvent is preferably used.
The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, ketones such as methyl ethyl ketone and methyl isobutyl ketone, alkyl halides, amides, sulfoxides, heterocyclic compounds and hydrocarbons. , Esters, ethers and the like. These may be used alone or in combination of two or more. Among these, ketones are particularly preferable in consideration of the burden on the environment. The above-mentioned components such as the above-mentioned monofunctional polymerizable monomer may function as a solvent.

(Λ / 4 plate)
The λ / 4 plate constituting the circularly polarizing plate is a conventionally known λ / 4 plate, and when the light incident on the λ / 4 plate is linearly polarized light, it is emitted as circularly polarized light and is incident on the λ / 4 plate. When the light to be emitted is circularly polarized light, it is emitted as linearly polarized light.

The λ / 4 plate is a plate having a function of converting linearly polarized light having a specific wavelength into circularly polarized light or converting circularly polarized light into linearly polarized light. More specifically, it is a plate showing an in-plane retardation value at a predetermined wavelength λ nm of Re (λ) = λ / 4 (or an odd multiple of this). This equation may be achieved at any wavelength in the visible light range (eg, 550 nm).
The λ / 4 plate may have a configuration consisting of only an optically anisotropic layer or a configuration in which an optically anisotropic layer is formed on a support, but the λ / 4 plate has a support. In some cases, the combination of the support and the optically anisotropic layer is intended to be a λ / 4 plate.
As the λ / 4 plate, a known λ / 4 plate can be used.

Further, in the liquid crystal film of the present invention, it is preferable that the λ / 4 plate has a small amount of Rth (550), which is a retardation in the thickness direction.
Specifically, Rth (550) is preferably -50 nm to 50 nm, more preferably -30 nm to 30 nm, and even more preferably zero Rth (λ). This gives a favorable result in that the circularly polarized light obliquely incident on the λ / 4 plate can be converted into linearly polarized light.

Here, the λ / 4 plate is arranged so that the slow phase axis is aligned so that the other circularly polarized light (circularly polarized light in the turning direction transmitted through the cholesteric liquid crystal layer) transmitted through the cholesteric liquid crystal layer 18 becomes linearly polarized light. NS.

(Linear polarizing plate)
The linear polarizing plate constituting the circular polarizing plate has a polarization axis in one direction and has a function of transmitting specific linearly polarized light.
As the linear polarizing plate, a general linear polarizing plate such as an absorption type polarizing plate containing an iodine compound or a reflective polarizing plate such as a wire grid can be used. The polarization axis is synonymous with the transmission axis.
As the absorption type polarizing plate, for example, an iodine-based polarizing plate, a dye-based polarizing plate using a dichroic dye, and a polyene-based polarizing plate can be used. Iodine-based polarizing plates and dye-based polarizing plates are generally produced by adsorbing iodine or a dichroic dye on polyvinyl alcohol and stretching the polarizing plate.

Here, the linear polarizing plate is arranged so that the polarization axes are aligned so that the linearly polarized light that is incident through the λ / 4 plate is transmitted. As a result, the combination of the linear polarizing plate and the λ / 4 plate functions as a circular polarizing plate that transmits the light incident from the λ / 4 plate side by converting the other circularly polarized light into linearly polarized light. That is, the combination of the λ / 4 plate and the linear polarizing plate transmits circularly polarized light whose turning direction is opposite to that of the circularly polarized light reflected by the cholesteric liquid crystal layer 18.

(Adhesive layer)
The adhesive layer is formed by laminating a cholesteric liquid crystal layer 18 and a λ / 4 plate (circular polarizing plate).
As the adhesive layer, a material made of various known materials can be used as long as the target layer (sheet-like material) can be bonded, and the adhesive layer has fluidity when bonded, and then is solid. It may be a layer made of an adhesive, or a layer made of an adhesive that is a soft solid gel-like (rubber-like) that does not change in the gel-like state after that, or is adhesive to the adhesive. It may be a layer made of a material having both characteristics of the agent. Therefore, as the adhesive layer, a known material such as an optical transparent adhesive (OCA (Optical Clear Adhesive)), an optically transparent double-sided tape, an ultraviolet curable resin, or the like, which is used for bonding sheet-like materials, may be used.

[Use]
The use of the liquid crystal film of the present invention is not particularly limited, but for example, an advertising medium attached to a window glass as a window advertisement of a building, an advertising medium attached to a window glass of a car, a taxi, a bus, a train, or a light portion. Design decoration, road signs, windows for houses and stores, aquariums, zoos, botanical halls, museums, toys and stationery such as amusement machines, amusement cards, underlays, stage equipment, theater equipment, elevators, escalator , Transparent materials such as stairs, fashion materials such as bags and clothes, goggles and sunglasses, materials for interior fabrics such as covers, curtains and floors, POP advertisements (Point of purchase advertising), business cards, stickers, postcards, photographs, coasters, etc. Tickets, uchiwa, sensu, tents, blinds, shutters, protective shields, separations such as thrusters, home appliances (cameras, instant cameras, PCs (personal computers), smartphones, TVs, recorders, ranges, audio players, game machines, VR (Virtual reality) headsets, vacuum cleaners, washing machines), smartphone covers, stuffed animals, cups, plates, plates, vases and vases, desks, chairs, CDs (compact discs), DVD cases, books, calendars, pet bottles, Food packaging, instruments such as guitars and pianos, sports equipment such as rackets, bats, clubs, balls, attractions such as mazes, ferris wheels, jet coasters, haunted houses, artificial flowers, educational toys, board games, caps, canes, watches It can be used as clothing materials such as music boxes and necklaces, containers for cosmetics, solar panels, electric lights and lamp covers.

Although the liquid crystal film of the present invention has been described in detail above, the present invention is not limited to the above-mentioned examples, and it goes without saying that various improvements and changes may be made without departing from the gist of the present invention. Is.

The features of the present invention will be described in more detail with reference to Examples below. The materials, reagents, amounts of substances used, amounts of substances, proportions, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limited by the specific examples shown below.

[Example 1]
As Example 1, a liquid crystal film was produced using the manufacturing apparatus 100a having the configuration shown in FIG.

(Preparation of liquid crystal composition)
The composition shown below was stirred and dissolved in a container kept at 25 ° C. to prepare a cholesteric liquid crystal ink liquid A (liquid crystal composition).
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
Cholesteric liquid crystal ink liquid A
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
The following liquid crystal compound 1 1 g
Chiral auxiliary with the following structure 1 107 mg
Horizontal alignment agent with the following structure 1 1 mg
Initiator: IRGACURE 907 (manufactured by BASF) 40 mg
IRGANOX1010 10mg
MEK (Methyl Ethyl Ketone) 1.6g
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–

(Formation of cholesteric liquid crystal layer)
As the support 12a, a PET film having a thickness of 50 μm manufactured by FUJIFILM Corporation was used. A predetermined pattern was printed in color on the back surface of the support 12a to form a pattern mask.

As a coating step, the cholesteric liquid crystal ink liquid A prepared above was coated on the surface of the support using a die coater. The coating was adjusted so that the thickness of the coating layer after drying was about 2 to 5 μm, and the coating was performed at room temperature to form a coating film.
Next, as an irradiation step, the coating film was irradiated with UV (ultraviolet rays, wavelength 365 nm) at room temperature via a pattern mask at 50 mJ / cm ² . As a light source for UV irradiation, LEDUVHLDL-200X180-U6PSC (manufactured by CCS Co., Ltd.) was used.

Next, as a heating step, the support on which the coating film was laminated after the irradiation step was heated in a hot air drying zone at 90 ° C. for 1 minute.
Next, as a curing step, the coating film after heat treatment is irradiated with UV (wavelength 300 to 350 nm, 200 mJ / cm ² ) from the surface under a nitrogen atmosphere (oxygen concentration of 500 ppm or less) at room temperature to cure the coating film. A cholesteric liquid crystal layer was formed.
As a light source for UV irradiation, UE0961-426-05CQT (manufactured by Iwasaki Electric Co., Ltd.) was used.
After that, it was wound up by a winding roller.

[Example 2]
As Example 2, a liquid crystal film was produced using the manufacturing apparatus 100b having the configuration shown in FIG.
Specifically, a PET film manufactured by FUJIFILM Corporation with a thickness of 50 μm is used as the support 12b, and a predetermined pattern is used as the mask film 14 on the base film 20 (PET film manufactured by Toyo Boseki Co., Ltd. with a thickness of 100 μm). Is printed in color to form a pattern mask (ink layer 22), the mask film 14 is attached to the support 12b before the coating step, and the mask film 14 is peeled off after the curing step. Made a liquid crystal film in the same manner as in Example 1.
The mask film 14 was attached to the support 12b on the pattern mask side.

[Example 3]
A liquid crystal film was produced in the same manner as in Example 2 except that the base film 20 side of the mask film 14 was attached to the support 12b.

[Example 4]
In the irradiation step, the irradiation is performed twice, the irradiation amount in the first irradiation step is 20 mJ / cm ^2, and the irradiation amount in the second irradiation step is 40 mJ / cm ^2. , A liquid crystal film was produced.

[Example 5]
A liquid crystal film was produced in the same manner as in Example 4 except that the irradiation amount in the first irradiation step was 50 mJ / cm ² and the irradiation amount in the second irradiation step was 100 mJ / cm ^2.

[Example 6]
The liquid crystal display was the same as in Example 4 except that the wavelength of the light in the first irradiation step was 385 nm and the irradiation amount was 50 mJ / cm ^2, and the wavelength of the second irradiation step was 365 nm and the irradiation amount was 50 mJ / cm ^2. A film was made.

[Example 7]
A liquid crystal film was produced in the same manner as in Example 4 except that the irradiation amount in the first irradiation step was 125 mJ / cm ² and the irradiation amount in the second irradiation step was 125 mJ / cm ^2.

[Example 8]
As an initiator contained in the liquid crystal composition (cholesteric liquid crystal ink liquid A), IRGACURE 369 (manufactured by BASF), 40 mg was used, and the same as in Example 1 except that the wavelength of light in the curing step was 365 nm. A liquid crystal film was produced.

[Comparative Example 1]
A liquid crystal film was produced in the same manner as in Example 1 except that the irradiation step was performed after the alignment step.

[Comparative Example 2]
A liquid crystal film was produced in the same manner as in Example 1 except that a black-and-white binary pattern mask was formed on the support by printing as the pattern mask.

[Comparative Example 3]
A liquid crystal film was produced in the same manner as in Example 2 except that a monochrome binary pattern mask was formed on the support by printing as the pattern mask.

<Evaluation>
The liquid crystal film produced in each example was visually observed from the cholesteric liquid crystal layer side to evaluate the fineness of the pattern and the gradation of the color display, and evaluated according to the following criteria.

Evaluation of pattern definition AA: Very good A: Good B: Somewhat good C: The pattern is blurred.

Evaluation of gradation of color display A: High gradation B: Slightly high gradation C: Binary value or color blurring.
The results are shown in Table 1.
Further, an image obtained by photographing the pattern mask of Example 1 is shown in FIG. 8, and an image obtained by photographing the liquid crystal film produced in Example 1 is shown in FIG. In the present invention, the same effect can be obtained even with the grayscale pattern mask shown in FIG. Further, a part of the liquid crystal film shown in FIG. 7 is cut out for evaluation.
Further, the images of the binary masks used in Comparative Examples 2 and 3 are shown in FIG.

As shown in Table 1, it can be seen that the liquid crystal films of Examples 1 to 8 produced by the production method of the present invention have better definition and gradation as compared with Comparative Examples.
Further, from the comparison between Example 2 and Example 3, when the pattern mask is formed on a film different from the support and attached to the support to perform the irradiation step, the pattern mask side is set. It can be seen that it is preferable to attach it to the support.
Further, from the comparison between Example 1 and Examples 5 and 6, it can be seen that the fineness is further improved by irradiating the light in two steps in the irradiation step.
Further, from the comparison between Examples 5 and 6 and Example 7, it can be seen that ^{the total irradiation amount is preferably 200 mJ / cm 2 or less.}
Further, from the comparison between Example 1 and Example 8, it can be seen that it is preferable to make the wavelength of the light in the irradiation step different from the wavelength of the light in the curing step.

[Example 9]
As Example 9, a liquid crystal film was produced in the same manner as in Example 1 except that the pattern mask shown in FIG. 10 was used. An image of the produced liquid crystal film is shown in FIG.
As can be seen from FIGS. 10 and 11, it can be seen that regions in which the color of the cholesteric liquid crystal layer, that is, the selective reflection wavelength is different, are formed depending on the pattern and shading of the pattern mask.
From the above results, the effect of the present invention is clear.

12a, 12b Support 14 Mask film 16 Circular polarizing plate 18 Cholesteric liquid crystal layer 20 Base film 21a Coating film 21b Exposed coating film 21c Oriented coating film 22 Ink layer 23a to 23d, 25a to 25b Laminated film 100a, 100b Liquid crystal film Manufacturing equipment 102 Feeding roller 104 Coating nozzle 106, 114 Backup roller 108 Exposure device 110 Heating device 112 UV irradiation device 116 Winding roller 120 1st transport unit 122 2nd transport unit 124 3rd transport unit 130, 132, 142, 146 rolls 140 Supply roller 144 Recovery roller 150 Coating part 152 Exposure part 154 Heating part 156 Hardening part

Claims (12)

A delivery process that sends out a long support in the longitudinal direction,
A coating step of applying a liquid crystal composition containing a cholesteric liquid crystal compound and a photosensitive chiral agent to the surface of the support while transporting the delivered support in the longitudinal direction.
An irradiation step of irradiating the coating film of the liquid crystal composition in an undried state with light having a wavelength that the chiral agent is exposed to.
An orientation step in which the coating film is heated to orient the liquid crystal display, and
It has a curing step of curing the oriented coating film in this order.
In the irradiation step, the coating film is irradiated with light through a pattern mask arranged on the support side.
The pattern mask is a multi-gradation pattern mask having three or more regions having different transmittances for light having a wavelength to which the chiral agent is exposed.
In the irradiation step, by irradiating the coating film with light through the multi-wavelength pattern mask, different irradiation amounts of light are irradiated to each region of the coating film, and the above-mentioned in each region. By setting the amount of change in the structural change of the chiral auxiliary to be different and heating the coating film in the orientation step, the liquid crystal compound in each of the regions according to the amount of change in the structural change of the chiral auxiliary in each region. A method for producing a liquid crystal film in which the selective reflection wavelength is different for each of the regions. The method for manufacturing a liquid crystal film according to claim 1, wherein the pattern mask is formed on the back surface of the support. The pattern mask is formed on the surface of a long base film, and is formed on the surface of a long base film.
The method for producing a liquid crystal film according to claim 1, wherein in the irradiation step, light is irradiated while the base film on which the pattern mask is formed is attached to the back surface of the support. The method for producing a liquid crystal film according to any one of claims 1 to 3, wherein the pattern mask is formed by grayscale printing. The irradiation step includes a first irradiation step and a second irradiation step.
The method for producing a liquid crystal film according to any one of claims 1 to 4, wherein the irradiation amount of light in the first irradiation step is smaller than the irradiation amount of light in the second irradiation step. The method for producing a liquid crystal film according to claim 5, wherein the total irradiation amount of the first irradiation step and the second irradiation step is 200 mJ / cm ^{2 or less.} The irradiation step includes a first irradiation step and a second irradiation step.
The method for producing a liquid crystal film according to any one of claims 1 to 6, wherein the peak wavelength of the light irradiated in the first irradiation step and the peak wavelength of the light irradiated in the second irradiation step are different from each other. The curing step is a step of photocuring the coating film.
The method for producing a liquid crystal film according to any one of claims 1 to 7, wherein the wavelength of the light irradiated in the curing step is different from the wavelength of the light irradiated in the irradiation step. In the curing step, the pattern mask is integrally conveyed in a state of being arranged on the back surface side of the support.
The method for producing a liquid crystal film according to claim 8, wherein the surface side opposite to the pattern mask is irradiated with light. The method for producing a liquid crystal film according to any one of claims 1 to 9, wherein the method for applying the liquid crystal composition in the coating step is bar coating. A method for producing a liquid crystal film, which forms two or more cholesteric liquid crystal layers by repeating the combination of the coating step, the irradiation step, the alignment step, and the curing step two or more times.
6. Liquid crystal film manufacturing method. A function having a step of attaching a circularly polarizing plate to the front surface of the cured coating film or the back surface of the support after the curing step of the method for producing a liquid crystal film according to any one of claims 1 to 11. A method for producing a sex film.

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