JP2010282153A - Forgery preventing medium and method of manufacturing forgery preventing medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forgery preventing medium where the flexibility of pattern designing is improved and an optional birefringence pattern is formed efficiently. <P>SOLUTION: The forgery preventing medium includes a patterning optically anisotropic layer formed by discharging an ink composition containing a liquid crystal compound to an alignment layer by an inkjet method. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an anti-counterfeit medium using optical anisotropy and a method for manufacturing the same.

The means for preventing counterfeiting can be broadly classified into means for making the product itself unreplicatable, or means for making a product non-replicatable by attaching a non-replicatable mark to the product to determine that it is a genuine product (genuine product). In particular, the latter case is often used because it is more versatile than the former, which requires individual handling.
The latter means is further divided into two. One is that anyone can always recognize the presence of anti-counterfeiting means, and a well-known technique is hologram. The other is that the anti-counterfeiting means is normally undetectable, and only those who know the existence of the anti-counterfeiting means detect the anti-counterfeiting means by a special means and identify whether it is genuine or not. There is known a technique capable of discriminating by revealing a latent image or color shift. For example, Patent Documents 1 and 2 propose a retardation film for security using a polymerizable liquid crystal.

  These form a latent image by patterning an optically anisotropic layer containing liquid crystal. These retardation films have a problem that the patterning method is complicated because the optically anisotropic layer is formed by uniformly coating the entire film surface.

US Patent Publication No. 2008/0143926 JP 2008-70807 A

  Accordingly, an object of the present invention is to provide an anti-counterfeit medium in which an arbitrary birefringence pattern is efficiently formed with an increased degree of freedom in pattern design, and a method for manufacturing the same.

The problems of the present invention have been solved by the following means.
(1) An anti-counterfeit medium comprising a patterned optically anisotropic layer formed by discharging an ink composition containing a liquid crystal compound onto an alignment layer by an inkjet method.
(2) The forgery prevention medium according to (1), wherein an ink diffusion prevention barrier is provided on the alignment layer or the alignment layer.
(3) The anti-counterfeit medium according to (1) or (2), having an alignment layer on which irregularities are formed.
(4) The anti-counterfeit medium according to (1) or (2), which has an alignment layer that has been rubbed.
(5) The forgery prevention medium according to (1) or (2), which has an alignment layer subjected to photo-alignment.
(6) The anti-counterfeit medium according to any one of (1) to (5), which includes a reflective layer.
(7) A method for producing an anti-counterfeit medium, wherein an ink composition containing a liquid crystal compound is discharged onto an alignment layer by an ink jet method.
(8) The method for producing a forgery prevention medium according to (7), wherein an ink diffusion prevention barrier is provided on the alignment layer or the alignment layer.
(9) The method for producing a forgery prevention medium according to (7) or (8), wherein the ink composition contains a solvent having a boiling point of 160 ° C. or higher.
(10) A forgery prevention method comprising using the forgery prevention medium according to any one of (1) to (6) and a polarizing plate to visually recognize a latent image that has been made visible.

  The anti-counterfeit medium of the present invention has a high degree of freedom in birefringence patterns, can form any birefringence pattern efficiently, and has high productivity. According to the manufacturing method of the present invention, the forgery prevention medium having an arbitrary birefringence pattern having a high degree of freedom as described above can be efficiently manufactured by using the inkjet method.

(A)-(c) is sectional drawing which shows typically the layer structure in one Embodiment of the forgery prevention medium of this invention, respectively. It is a figure which shows the example of a birefringence pattern, (a) is explanatory drawing of the example patterned about the optical axis direction, (b) is explanatory drawing of the example patterned about retardation. It is a figure which shows the simplest voltage waveform which drives a piezoelectric element. It is a figure which shows the structure for observing the shape of the ink droplet which is flying. It is a figure which shows the pattern which the orientation layer formed in the sample of the PVA in the Example. It is a figure which shows the pattern which the orientation layer formed in the sample of an uneven | corrugated type or a photo-alignment film in the Example.

Hereinafter, preferred embodiments of the present invention will be described.
In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

  In the present specification, the “counterfeit prevention medium” refers to a laminated structure having an optically anisotropic layer for preventing forgery. The method of application is not particularly limited, but it can be formed on or attached to an article to prevent impersonation of the article or to prove the manufacturer of the article, or the shape of a wrapping paper, etc. Any medium can be used as long as it can prove the manufacturer.

The anti-counterfeit medium has at least one patterned optically anisotropic layer.
In the present specification, the patterning optically anisotropic layer means a layer that includes a plurality of regions having different birefringence and thereby can form a certain pattern. The regions having different birefringence may be regions having different retardation and / or optical axis directions, and are preferably regions having different retardations. A plurality of regions having different birefringence in the patterned optically anisotropic layer in the anti-counterfeit medium of the present invention are formed by the presence or absence of a layer forming material (ink composition) or by adjusting the film thickness. , There may be a portion formed from the same layer forming composition. The difference in birefringence may be derived from the presence or absence of the layer forming material, the film thickness, or the orientation of molecules in the composition, as will be described later. In other words, the patterned optically anisotropic layer of the present invention is patterned by changing the orientation direction or degree of orientation of the layer forming composition after the presence or absence of the composition for forming a layer is adjusted by ink jetting or by adjusting the film thickness. Can be obtained. In this specification, a layer including a plurality of regions having different birefringence, including a patterned optically anisotropic layer, and a laminate thereof may be referred to as a birefringence pattern.
Since the region having different birefringence is recognized when observed from the direction of the normal line of the anti-counterfeit medium, it should be a region divided by a plane parallel to the normal line of the anti-counterfeit medium. . “Different birefringence” means that when retardation is patterned, the retardation is preferably 20 nm or more, more preferably 30 nm or more, and further preferably 50 nm or more. When the optical axis is patterned, the direction of the optical axis is preferably 5 degrees or more, more preferably 10 degrees or more, and still more preferably 15 degrees or more.

In the present specification, retardation or Re represents in-plane retardation. In-plane retardation (Re (λ)) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (trade name, manufactured by Oji Scientific Instruments). Retardation or Re in this specification means those measured at wavelengths of 611 ± 5 nm, 545 ± 5 nm, and 435 ± 5 nm for R, G, and B, respectively. It means that measured at a wavelength of 5 nm or 590 ± 5 nm.
In this specification, “optical axis” means “slow axis” or “transmission axis”.

  In this specification, “substantially” for the angle means that the error from the exact angle is within a range of less than ± 5 °. Furthermore, the error from the exact angle is preferably less than 4 °, more preferably less than 3 °. With regard to retardation, “substantially” means that the retardation is within ± 5%. Furthermore, Re is not substantially 0 means that Re is 5 nm or more. In addition, the measurement wavelength of the refractive index indicates an arbitrary wavelength in the visible light region unless otherwise specified. In the present specification, “visible light” refers to light having a wavelength of 400 to 700 nm.

  In the present specification, the “retardation disappearance temperature” means the retardation of the optically anisotropic layer at a certain temperature when the temperature of the optically anisotropic layer is increased from 20 ° C. at a rate of 20 ° C. per minute. Means a temperature at which the retardation of the optically anisotropic layer at 20 ° C. is 30% or less.

  In the present specification, “the retardation disappearance temperature is not in a temperature range of 250 ° C. or lower” means that the letter of the optical anisotropic layer is not increased even when the temperature of the optical anisotropic layer is raised to 250 ° C. It means that the foundation does not become 30% or less of the retardation at 20 ° C.

A. Anti-Counterfeit Medium The anti-counterfeit medium of the present invention is obtained by laminating components of an anti-counterfeit medium on a support, and has at least a patterned optically anisotropic layer.
An example of the anti-counterfeit medium of the present invention and an example of a manufacturing method thereof will be described below with reference to the drawings. In addition, the anti-counterfeit medium of the present invention can be provided with a functional layer other than those described below, if necessary, as long as the function is not inhibited.

FIGS. 1A to 1C are cross-sectional views schematically showing a layer structure in an embodiment of the forgery prevention medium of the present invention. FIG. 1A shows an embodiment in which an alignment layer 14 having an ink diffusion prevention barrier 13 and a patterned optically anisotropic layer 12 are provided on a support 11. As shown in FIGS. 1B and 1C, layers other than the support 11 and the patterned optically anisotropic layer 12 can be provided depending on the application. In FIG. 1B, the reflective layer 15 can be provided as necessary to improve the visibility of the latent image. The protective layer 16 is a layer serving as the uppermost layer of the forgery prevention medium, and has a function of protecting the patterning optically anisotropic layer 12 from contamination and damage. FIG. 1C shows an embodiment having a metal layer 17 between the support 11 and the alignment layer 14.
1A to 1C, each layer is one layer. However, the present invention is not limited to this. For example, a plurality of patterned optically anisotropic layers may be provided.

Examples of the birefringence pattern include those in which the retardation and / or the optical axis direction is patterned in the plane. An example of a birefringence pattern is shown in FIG.
FIG. 2A is an explanatory diagram of an example of patterning in the optical axis direction. In FIG. 2A, the arrow indicates the optical axis direction. FIG. 2B is an explanatory diagram of an example in which the retardation is patterned. In the example shown in FIG. 2B, the retardations are different from each other at 0 nm, 66 nm, and 100 nm.
In patterning by ejection by ink jet, it is possible to change the amount of retardation by changing the film thickness by changing the amount of ink ejection. The structure described below can be taken. Moreover, axial patterning is also possible by combining with alignment film axial patterning. The optically anisotropic layer whose optical axis direction is patterned in the plane can be obtained by, for example, the method described in JP-T-2001-52580.

1. Support The anti-counterfeit medium uses a substrate that has not been subjected to retardation as a support. The retardation of the substrate is 2000 nm or less, preferably 1000 nm or less, more preferably 500 nm or less. The lower limit is preferably 0 nm, but is not limited thereto. This substrate includes the following supports.
The anti-counterfeit medium preferably has a light reflective support. The support is not particularly limited, but in the case where the latent image is made visible using reflected light, a support having a light reflecting layer described later or a support having a reflecting function may be used. As an example of a support having a reflection function, in addition to aluminum foil and stainless steel, a reflection function may be provided by providing glossy printing on an arbitrary support. A support subjected to hologram processing can also be used. Other examples of the support include cellulose ester (eg, cellulose acetate, cellulose propionate, cellulose butyrate), polyolefin (eg, norbornene polymer), poly (meth) acrylic acid ester (eg, polymethyl methacrylate), Examples thereof include plastic films such as polycarbonate, polyester and polysulfone, norbornene-based polymers, polyethylene terephthalate, and polyimide, paper, and cloth. The thickness of the support is preferably from 3 to 500 μm, more preferably from 10 to 200 μm when used for continuous production such as roll-to-roll. The support preferably has heat resistance sufficient not to be colored or deformed by baking to be described later. The anti-counterfeit medium may include a colored support. In other words, the anti-counterfeit medium may have a pattern that can be visually recognized without using the authentication device. When a birefringence pattern is read with a specific color, it is not affected by other colors, so that a colored support can be used with other colors.

2. Preparation of Patterning Optical Anisotropic Layer The patterning optical anisotropic layer can be prepared by discharging an ink composition containing a liquid crystal compound using an ink jet method.
Hereinafter, the ejection of the optically anisotropic layer, the ink composition containing the liquid crystal compound, and the ink composition by the inkjet method will be described in detail. However, the present invention is not limited to this embodiment, and other embodiments can be carried out with reference to the following description and conventionally known methods, and the present invention is limited to the embodiments described below. It is not something.

(1) Optically anisotropic layer The optically anisotropic layer is a layer having optical characteristics that are not isotropic in that there is at least one incident direction in which Re is not substantially 0 when the phase difference is measured. The optically anisotropic layer preferably has a retardation disappearance temperature. When the optically anisotropic layer has a retardation disappearance temperature, it is possible to eliminate the retardation of a part of the optically anisotropic layer by, for example, pattern heating. The retardation disappearance temperature is preferably greater than 20 ° C. and 250 ° C. or less, more preferably 40 ° C. to 245 ° C., further preferably 50 ° C. to 245 ° C., and 80 ° C. to 240 ° C. Is most preferred.

  The retardation value of the region provided with retardation in the optically anisotropic layer may be 5 nm or more at 20 ° C., preferably 10 nm or more and 2000 nm or less, particularly preferably 20 nm or more and 1000 nm or less, Most preferably, a desired value can be selected within the above range. If the retardation is too small, it may be difficult to form a birefringence pattern. If the retardation is too large, it may be difficult to recognize the color change of the latent image due to the retardation.

(2) Ink composition containing liquid crystal compound The patterning optically anisotropic layer in the invention can be formed by discharging an ink composition containing the following components including a liquid crystal compound using an inkjet method.

(I) Liquid crystalline compounds Generally, liquid crystalline compounds can be classified into rod-shaped types and disc-shaped types based on their shapes. In addition, there are low and high molecular types, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystalline compound can be used, but a rod-like liquid crystalline compound is preferably used. A mixture of two or more liquid crystal compounds may be used. Since the change in temperature and humidity can be reduced, it is more preferable to use a liquid crystalline compound having a reactive group, and it is also preferable to use a liquid crystalline compound having two or more reactive groups in one liquid crystal molecule.

  It is also preferable that the liquid crystal compound has two or more reactive groups having different polymerization conditions. In this case, it is possible to produce an optically anisotropic layer including a polymer having an unreacted reactive group by selecting conditions and polymerizing only a part of plural types of reactive groups. . The polymerization conditions used may be the wavelength range of ionizing radiation used for polymerization immobilization, or may be different in the polymerization mechanism used, but preferably controllable by the type of initiator used, a radical reactive group and a cationic reaction A combination of groups is good. A combination in which the radical reactive group is an acrylic group and / or a methacryl group and the cationic group is a vinyl ether group, an oxetane group and / or an epoxy group is particularly preferable because the reactivity can be easily controlled.

Examples of rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used. The polymer liquid crystalline compound is a polymer compound obtained by polymerizing a rod-like liquid crystalline compound having a low molecular reactive group. The rod-like liquid crystal compound having a low-molecular reactive group that is particularly preferably used is a rod-like liquid crystal compound represented by the following general formula (I).
General formula ^{(I): Q 1 -L 1} -A 1 -L 3 -M-L 4 -A 2 -L 2 -Q 2
In the formula, Q ¹ and Q ² are each independently a reactive group, and L ¹ , L ² , L ³ and L ⁴ each independently represent a single bond or a divalent linking group. A ¹ and A ² each independently represent a spacer group having 2 to 20 carbon atoms. M represents a mesogenic group.
Hereinafter, the rod-like liquid crystal compound having a reactive group represented by the general formula (I) will be described in more detail. In the formula, Q ¹ and Q ² are each independently a reactive group. The polymerization reaction of the reactive group is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. In other words, the reactive group is preferably a reactive group capable of addition polymerization reaction or condensation polymerization reaction. Examples of reactive groups are shown below.

Examples of the divalent linking group represented by L ¹ , L ² , L ³ and L ⁴ include —O—, —S—, —CO—, —NR ² —, —CO—O—, and —O—CO. —O—, —CO—NR ² —, —NR ² —CO—, —O—CO—, —O—CO—NR ² —, —NR ² —CO—O—, and NR ² —CO—NR ^2. A divalent linking group selected from the group consisting of-is preferred. R ² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. In the formula ^(I), Q ¹ -L 1 and ^Q 2 -L ² - _{is, CH 2 = CH-CO-} O-, CH 2 = C (CH 3) -CO-O- and _CH 2 = C ( Cl) -CO-O-CO- O- are _{preferable, CH 2 = CH-CO-} O- is most preferable.

A ¹ and A ² represent spacer groups having 2 to 20 carbon atoms. An alkylene group having 2 to 12 carbon atoms, an alkenylene group, and an alkynylene group are preferable, and an alkylene group is particularly preferable. The spacer group is preferably a chain and may contain oxygen atoms or sulfur atoms that are not adjacent to each other. The spacer group may have a substituent and may be substituted with a halogen atom (fluorine, chlorine, bromine), a cyano group, a methyl group, or an ethyl group.
Examples of the mesogenic group represented by M include all known mesogenic groups. In particular, a group represented by the following general formula (II) is preferable.
Formula ^{(II): - (- W} 1 -L 5) n -W 2 -
In the formula, each of W ¹ and W ² independently represents a divalent cyclic alkylene group or a cyclic alkenylene group, a divalent aryl group or a divalent heterocyclic group, and L ⁵ represents a single bond or a linking group. Specific examples of the linking group include specific examples of groups represented by L ^{1 to} L ⁴ in the formula (I), —CH ₂ —O—, and —O—CH ₂ —. n represents 1, 2 or 3.

W ¹ and W ² include 1,4-cyclohexanediyl, 1,4-phenylene, pyrimidine-2,5-diyl, pyridine-2,5diyl, 1,3,4-thiadiazole-2,5-diyl, 1,3,4-oxadiazole-2,5-diyl, naphthalene-2,6-diyl, naphthalene-1,5-diyl, thiophene-2,5-diyl, pyridazine-3,6-diyl . In the case of 1,4-cyclohexanediyl, there are trans isomers and cis isomers, but either isomer may be used, and a mixture in any proportion may be used. More preferably, it is a trans form. W ¹ and W ² may each have a substituent. Examples of the substituent include a halogen atom (fluorine, chlorine, bromine, iodine), a cyano group, an alkyl group having 1 to 10 carbon atoms (methyl group, ethyl group, propyl group, etc.), and an alkoxy group having 1 to 10 carbon atoms. (Methoxy group, ethoxy group, etc.), C1-10 acyl group (formyl group, acetyl group, etc.), C1-10 alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, etc.), carbon atom Examples thereof include an acyloxy group having 1 to 10 (acetyloxy group, propionyloxy group, etc.), nitro group, trifluoromethyl group, difluoromethyl group and the like.
Preferred examples of the basic skeleton of the mesogenic group represented by the general formula (II) are shown below. These may be substituted with the above substituents.

  Examples of the compound represented by the general formula (I) are shown below, but the present invention is not limited thereto. In addition, the compound represented by general formula (I) is compoundable by the method as described in Japanese National Patent Publication No. 11-513019 (WO97 / 00600).

(Ii) Solvent The ink composition used in the present invention may further contain a solvent.
As an example of the solvent, a solvent composed of a compound having a boiling point of 160 ° C. or higher at 760 mmHg (101.3 kPa) can be preferably exemplified. Examples of the organic solvent having a boiling point of 160 ° C. or higher at room temperature include high-boiling solvents, alkylene glycol acetates, and alkylene glycol diacetates described in paragraphs [0031] to [0037] of JP-A No. 2000-310706. Among them, dipropylene glycol monomethyl ether, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, propylene glycol-n-butyl ether acetate, dipropylene glycol mono-n-butyl ether, tripropylene glycol methyl ether acetate, diethylene glycol monobutyl ether, 1, 3-butanediol diacetate, dipropylene glycol-n-propyl ether acetate, propylene carbonate, diethylene glycol Particularly preferred examples include rumonobutyl ether acetate and dipropylene glycol-n-butyl ether acetate.

(Iii) Other additives The ink composition used in the present invention may contain a polymerization initiator for the polymerization reaction of the reactive group introduced into the liquid crystal compound. The polymerization reaction of the reactive group introduced into the liquid crystal compound is mainly performed in order to maintain and fix the alignment state of the liquid crystal compound. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator, and a photopolymerization reaction is more preferable. The photopolymerization reaction may be either radical polymerization or cationic polymerization. Examples of radical photopolymerization initiators include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatics. Aciloin compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US Pat. No. 3,549,367) Acridine and phenazine compounds (JP-A-60-105667, US Pat. No. 4,239,850) and oxadiazole compounds (US Pat. No. 4,212,970). Examples of the cationic photopolymerization initiator include organic sulfonium salt systems, iodonium salt systems, phosphonium salt systems, and the like. Organic sulfonium salt systems are preferable, and triphenylsulfonium salts are particularly preferable. As counter ions of these compounds, hexafluoroantimonate, hexafluorophosphate, and the like are preferably used.

The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the ink composition used in the present invention. In addition, it is preferable to use ultraviolet rays for light irradiation for polymerization of the liquid crystalline compound. Irradiation energy ^is preferably ^{10mJ / cm 2 ~10J / cm 2} , further preferably 25~800mJ / cm ^2. Illuminance is preferably 10 to 1,000 / cm ^2, more preferably 20 to 500 mW / cm ^2, further preferably 40~350mW / cm ^2. The irradiation wavelength preferably has a peak at 250 to 450 nm, and more preferably has a peak at 300 to 410 nm. In order to accelerate the photopolymerization reaction, light irradiation may be performed under an inert gas atmosphere such as nitrogen or under heating conditions.

(Iv) Horizontal alignment agent In the composition for forming the optically anisotropic layer, it is represented by the general formulas (1) to (3) described in [0068] to [0072] of JP-A-2007-121986. By containing at least one of a fluorine-containing homopolymer or copolymer using the above-mentioned compound and the monomer of the following general formula (4), the molecules of the liquid crystal compound can be substantially horizontally aligned.

In the formula, R represents a hydrogen atom or a methyl group, X represents an oxygen atom or a sulfur atom, Z represents a hydrogen atom or a fluorine atom, m is an integer of 1 to 6 and n ₂ is 1 to 12 Represents an integer. In addition to the fluorine-containing polymer containing the general formula (4), the compounds described in JP-A-2005-206638 and JP-A-2006-91205 can be used as the unevenness improving polymer in coating as a horizontal alignment agent. Are also described in the specification.
The addition amount of the horizontal alignment agent is preferably 0.01 to 20% by mass, more preferably 0.01 to 10% by mass, and particularly preferably 0.02 to 1% by mass of the mass of the liquid crystal compound. In addition, the compounds represented by the general formulas (1) to (4) may be used alone or in combination of two or more.

(V) Physical property value of ink composition As the physical property value of the ink composition, the viscosity at 25 ° C is preferably 20 to 100 mPa · s, and the ink temperature is in the range of 20 to 90 ° C when ejected by the apparatus. It is preferable to maintain the temperature at a substantially constant temperature, and the viscosity at that time is preferably 2 to 20 mPa · s. Further, the surface tension at 25 ° C. is preferably 10 to 50 mN / m, and when ejected by the apparatus, the ink temperature is preferably maintained at a substantially constant temperature in the range of 20 to 90 ° C., and the surface tension at that time is 20 It is preferable to set it to -30mN / m. In order to keep the ink temperature constant with a predetermined accuracy, it is preferable to have an ink temperature detecting means, an ink heating or cooling means, and a control means for controlling the heating or cooling according to the detected ink temperature. In addition, it is also preferable to have means for reducing the influence on the change in ink physical properties by controlling the energy applied to the means for ejecting ink according to the ink temperature.

(3) Ink composition ejection by inkjet method As inkjet method, charged inkjet ink is continuously ejected and controlled by electric field, ink is ejected intermittently using piezoelectric elements, and ink is heated. Various methods such as a method of intermittently spraying using the foam can be adopted. Details of the inkjet method are described below. In addition, about the inkjet method which can be used by this invention, the method as described in Unexamined-Japanese-Patent No. 2008-76690 can be referred.

(I) System Configuration A system for creating a patterned optically anisotropic layer using the ink composition has an inkjet head that ejects the ink composition onto an alignment layer. As the configuration of the head, as disclosed in, for example, Japanese Patent Laid-Open No. 5-193140, the head has a portion for applying ejection energy to the ink and a nozzle portion for ejecting the ink. The ejection and driving of the head are controlled by the control unit, and an arbitrary pattern is formed.

(Ii) Head drive method As a method for imparting ejection energy to the ink composition, as disclosed in JP-A-7-81090, so-called continuous method, ink droplets are continuously ejected and landed. A method of deflecting and selectively controlling droplets depending on whether or not they are to be performed, or a so-called on-demand method that ejects ink droplets only at necessary portions may be used. As disclosed in JP-A-5-16349, the on-demand system may be a system that generates and discharges ink pressure by deformation of a structure using a piezoelectric element or the like. As disclosed in Japanese Patent No. 234255, a method of discharging at a pressure generated by expansion accompanying vaporization by thermal energy may be used. Further, as disclosed in Japanese Patent Application Laid-Open No. 2001-277466, a method of controlling ejection to a medium by an electric field may be used.

(Iii) Ink landing diameter, nozzle diameter The ink landing diameter on the alignment layer is preferably between 10 and 500 μm, and the landing diameter is determined by the size of the ink droplet and the wettability of the ink to the alignment layer. Is done. The contact angle of the ink droplet to the alignment layer is preferably 0 to 80 degrees, and the diameter of the flying ink droplet is preferably 5 to 250 μm, and the nozzle diameter at this time is preferably 15 to 100 μm. Here, the contact angle of the ink droplet to the alignment layer was determined by dropping about 2 μl of ink on the plasma treated glass surface where no BM was formed using DropMaster700 (trade name, manufactured by Kyowa Interface Science Co., Ltd.). , The droplet shape image after 500 msec can be processed and measured by the θ / 2 method.

(Iv) Formation of birefringence pattern In order to create an optically anisotropic layer having an arbitrary birefringence pattern, it is preferable to determine and control drive conditions in the following procedure.
Hereinafter, an example of an on-demand method using a piezo will be described. However, the inkjet method is not limited, and the same method can be applied regardless of whether it is a thermal drive method or an electrostatic method.
The stability of the meniscus shape and the ejection shape determines the driving conditions for observing the shape of the flying droplet and obtaining a stable shape. FIG. 3 shows the simplest voltage waveform for driving the piezo element. Vp is the piezo voltage, tp is the drive time width, tf and tr are the rise and fall times of the drive waveform, respectively. These four may be controlled, or simply Vp and tp or tr + tp. Two may be controlled. While changing these parameters, observe the shape of the flying droplets and evaluate the stability. Here, a simple trapezoidal drive waveform is shown. However, as disclosed in, for example, Japanese Patent Laid-Open Nos. 10-235859 and 2003-34148, the waveform is further changed to improve the discharge amount and the like. It is also possible to control it.

The shape of the flying droplet can be observed with the configuration shown in FIG. The timing control unit 600 generates a piezo drive waveform according to the input ejection frequency f604, piezo voltage Vp602, and piezo drive time width tp603, and the head 640 is driven by the piezo waveform generation circuit 610.
Ink droplets are ejected from the head, but the portion where the ink flies is illuminated by the LED 650. Here, the timing at which the LED is turned on is determined by the delay amount 621 input to the variable delay circuit 620 after the piezo waveform is generated. The LED 650 is turned on by the LED lighting circuit 630 after a predetermined time delay from the piezo drive waveform according to the delay amount. The shape of the ink droplet in flight ejected from the nozzle can be photographed by a CCD camera 661 equipped with a microscope lens 660 and observed by a monitor 670. Vp and tp can be determined while looking at the monitor 670 so that the droplet shape thus observed is stable even at high frequencies. Here, “stable as a droplet shape” refers to a state in which images when a plurality of droplets are sequentially imaged on the monitor 670 are stable without being shaken, and minute droplets of ink called satellites are not generated. Furthermore, the closer the shape after the time to reach the substrate after ejection is closer to a sphere, the closer the landing shape on the substrate is to a circle, and the better the ink amount distribution in the pixel can be controlled.

Next, in order to confirm that the discharge amount is stable, the discharge amount is measured by the following method. In the configuration of FIG. 4, ink is ejected from a predetermined nozzle of the head 640 for a predetermined time, and the ejected ink is captured and the mass is measured. By dividing this by ejection time × frequency × number of nozzles, the amount of ink ejected at one time from one nozzle can be determined. It is determined whether or not the ejection ink amount thus obtained is within a specified range.
Here, in the case of a head having a plurality of nozzles and the discharge amount for each nozzle is not uniform, the energy of the discharge energy driving means can be individually controlled to make the discharge amount uniform for each nozzle. preferable.
Pattern formation using this ink jet method makes it possible to adjust the amount of retardation for each position by adjusting the amount and type of ink discharge depending on the location, and it can be used for any character, number, figure, photograph, picture, etc. A birefringence pattern can be created.

(V) Amount of ink The amount of ink to be landed on the alignment layer is determined from the desired retardation amount. The ink landing amount in the pixel is preferably ¹ to 30 g / m ² .

In the present invention, baking after ink discharge may be performed. The time from the ink ejection to the baking process described later is preferably 1 minute or longer. More preferably, it is 1.5 minutes or more, and most preferably 2 minutes or more.
When the time until the baking process after ink ejection is within this range, the flatness of the patterned optically anisotropic layer is good.

3. Fixing the alignment state of the liquid crystalline compound The optically anisotropic layer has an alignment state in which an ink composition containing a liquid crystalline compound is ejected onto the surface of the alignment layer described later by an ink jet recording method and exhibits a desired liquid crystal phase. Then, the layer is preferably prepared by fixing the alignment state by irradiation with heat or ionizing radiation.
When a discotic liquid crystalline compound having a reactive group is used as the liquid crystalline compound, it may be fixed in any alignment state of horizontal alignment, vertical alignment, tilt alignment, and twist alignment. In the present specification, “horizontal alignment” means that in the case of a rod-like liquid crystal, the molecular long axis is parallel to the horizontal plane of the support. In the case of a disc-like liquid crystal, the disc surface of the core of the disc-like liquid crystal compound. The horizontal plane of the support is parallel, but it is not required to be strictly parallel, and in this specification, it means an orientation with an inclination angle of less than 10 degrees with the horizontal plane. . The inclination angle is preferably 0 to 5 degrees, more preferably 0 to 3 degrees, further preferably 0 to 2 degrees, and most preferably 0 to 1 degree.

  When two or more optically anisotropic layers comprising a composition containing a liquid crystalline compound are laminated, the combination of the liquid crystalline compounds is not particularly limited, and a laminate of all layers made of a discotic liquid crystalline compound, all having rod-like properties. It may be a laminate of a layer made of a liquid crystal compound, a laminate of a layer made of a composition containing a discotic liquid crystal compound and a layer made of a composition containing a rod-like liquid crystal compound. The combination of the alignment states of the layers is not particularly limited, and optically anisotropic layers having the same alignment state may be stacked, or optically anisotropic layers having different alignment states may be stacked.

4). Fixing the alignment state of a liquid crystal compound having a radical reactive group and a cationic reactive group As described above, it is also preferable that the liquid crystal compound has two or more reactive groups having different polymerization conditions. In this case, it is possible to produce an optically anisotropic layer including a polymer having an unreacted reactive group by selecting conditions and polymerizing only a part of plural types of reactive groups. . Polymerization particularly suitable when a liquid crystalline compound having a radical reactive group and a cationic reactive group (for example, the aforementioned I-22 to I-25) is used as such a liquid crystalline compound. The immobilization conditions will be described below.

  First, as the polymerization initiator, it is preferable to use only a photopolymerization initiator that acts on a reactive group intended to be polymerized. That is, it is preferable to use only a radical photopolymerization initiator when selectively polymerizing radical reactive groups and only a cationic photopolymerization initiator when selectively polymerizing cationic reactive groups. The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.1 to 8% by mass, and 0.5 to 4% by mass of the solid content of the coating solution. It is particularly preferred.

Next, it is preferable to use ultraviolet rays for light irradiation for polymerization. At this time, if the irradiation energy and / or illuminance is too strong, both the radical reactive group and the cationic reactive group may react non-selectively. Accordingly, the irradiation energy ^is preferably ^{5mJ / cm 2 ~500mJ / cm 2} , more preferably 10 to 400 mJ / cm ^2, and particularly preferably ^{20mJ / cm 2 ~200mJ / cm 2} . The illuminance is preferably 5 to 500 mW / cm ^2, more preferably 10 to 300 mW / cm ^2, and particularly preferably 20 to 100 mW / cm ^2. The irradiation wavelength preferably has a peak at 250 to 450 nm, and more preferably has a peak at 300 to 410 nm.

  Of the photopolymerization reactions, reactions using radical photopolymerization initiators are inhibited by oxygen, and reactions using cationic photopolymerization initiators are not inhibited by oxygen. Therefore, when a liquid crystal compound having a radical reactive group and a cationic reactive group is used as the liquid crystalline compound and one kind of the reactive group is selectively polymerized, the radical reactive group is selectively polymerized. In some cases, it is preferable to perform light irradiation in an inert gas atmosphere such as nitrogen, and in the case of selectively polymerizing a cationic reactive group, light irradiation is performed under an oxygen-containing atmosphere (for example, in the air). It is preferable.

  In addition to the above-described method for fixing the alignment state of a liquid crystal compound having a radical reactive group and a cationic reactive group, as a method for fixing the alignment state of a liquid crystal compound, polarized light irradiation of US 2008-143926 of US Patent Publication The immobilization method can also be applied.

5). Post-treatment of optically anisotropic layer In order to modify the produced optically anisotropic layer, various post-treatments may be performed. Examples of post-treatment include corona treatment for improving adhesion, addition of a plasticizer for improving flexibility, addition of a thermal polymerization inhibitor for improving storage stability, and a coupling treatment for improving reactivity. It is done. In addition, when the polymer in the optically anisotropic layer has an unreacted reactive group, it is also an effective modifying means to add a polymerization initiator corresponding to the reactive group. For example, adding a radical photopolymerization initiator to an optically anisotropic layer obtained by polymerizing and fixing a liquid crystalline compound having a cationic reactive group and a radical reactive group using a cationic photopolymerization initiator Thus, the reaction of an unreacted radical reactive group when pattern exposure is performed later can be promoted. Examples of the means for adding the plasticizer and the photopolymerization initiator include a means for immersing the optically anisotropic layer in a solution of the corresponding additive and a solution of the corresponding additive on the optically anisotropic layer. And means for infiltration. In addition, when another layer is applied on the optically anisotropic layer, an additive may be added to the coating solution of the layer and immersed in the optically anisotropic layer.

6. Two or more optically anisotropic layers The anti-counterfeit medium of the present invention may have two or more optically anisotropic layers. Two or more optically anisotropic layers may be adjacent to each other in the normal direction, or another functional layer such as an alignment layer may be sandwiched therebetween. Two or more optically anisotropic layers may have almost the same retardation or different retardations. Further, the slow axis directions may be in substantially the same direction, or may be in different directions.

7). Alignment layer As described above, an alignment layer may be used to form the optically anisotropic layer. The alignment layer functions so as to define the alignment direction of the liquid crystal compound provided thereon. The orientation layer may be any layer as long as it can impart orientation to the optically anisotropic layer. Preferred examples of the alignment layer include a rubbing-treated layer of an organic compound (preferably a polymer), an oblique deposition layer of an inorganic compound, and a layer having a microgroove, ω-tricosanoic acid, dioctadecylmethylammonium chloride, and stearyl. Examples thereof include a cumulative film formed by Langmuir-Blodgett method (LB film) such as methyl acid, or a layer in which a dielectric is oriented by applying an electric field or a magnetic field.

  Examples of organic compounds for the alignment layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleimide copolymer, polyvinyl alcohol, poly (N-methylolacrylamide), polyvinylpyrrolidone, styrene / vinyltoluene. Copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, carboxymethyl cellulose, polyethylene, polypropylene, polycarbonate, etc. And polymers such as silane coupling agents. Examples of preferable polymers include polyimide, polystyrene, polymers of styrene derivatives, gelatin, polyvinyl alcohol, and alkyl-modified polyvinyl alcohol having an alkyl group (preferably having 6 or more carbon atoms).

(1) Polymer orientation layer For the formation of the orientation layer, it is preferable to use a polymer. The type of polymer that can be used can be determined according to the orientation (particularly the average tilt angle) of the liquid crystal compound. For example, in order to align the liquid crystalline compound horizontally, a polymer that does not decrease the surface energy of the alignment layer (ordinary alignment polymer) is used. Specific types of polymers are described in various documents about liquid crystal cells or optical compensation sheets. For example, polyvinyl alcohol or modified polyvinyl alcohol, a copolymer with polyacrylic acid or polyacrylate, polyvinyl pyrrolidone, cellulose, or modified cellulose are preferably used. When the alignment layer is used as a protective layer, the alignment layer material may have a functional group capable of reacting with the reactive group of the liquid crystalline compound. The reactive group can be introduced by introducing a repeating unit having a reactive group in the side chain or as a substituent of a cyclic group. In this case, it is more preferable to use an alignment layer that forms a chemical bond with the liquid crystal compound at the interface. Such an alignment layer is described in Japanese Patent Application Laid-Open No. 9-152509, and acid chloride or Karenz MOI (product) A modified polyvinyl alcohol in which an acrylic group is introduced into the side chain using a name, manufactured by Showa Denko KK is particularly preferable. When such an alignment layer is used, the interface adhesion between the patterning optically anisotropic layer and the alignment layer is strengthened, so that the alignment layer is also transferred together with the patterning optically anisotropic layer. The thickness of the alignment layer is preferably 0.01 to 5 μm, and more preferably 0.05 to 2 μm.

  A polyimide film (preferably fluorine atom-containing polyimide) widely used as an alignment layer for LCD is also preferable as the organic alignment layer. This is done by applying polyamic acid (for example, LQ / LX series (trade name, manufactured by Hitachi Chemical Co., Ltd.), SE series (trade name, manufactured by Nissan Chemical Co., Ltd.), etc.) to the support surface and 100 to 300 ° C. After baking for 0.5 to 1 hour, it is obtained by rubbing.

  Moreover, the rubbing process can utilize a processing method widely adopted as a liquid crystal alignment process of LCD. That is, a method of obtaining the orientation by rubbing the surface of the orientation layer in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. Generally, it is carried out by rubbing several times using a cloth or the like in which fibers having a uniform length and thickness are planted on average.

Moreover, as a vapor deposition material of the inorganic oblique vapor deposition film, SiO ₂ is representative, metal oxides such as TiO ₂ and ZnO ₂ , fluorides such as MgF ₂ , and metals such as Au and Al. The metal oxide can be used as an oblique deposition material as long as it has a high dielectric constant, and is not limited to the above. The inorganic oblique deposition film can be formed using a deposition apparatus. An inorganic oblique vapor deposition film can be formed by fixing the film (support) and performing vapor deposition, or moving the long film and performing continuous vapor deposition.

(2) Photo-alignment layer The photo-alignment film described below can also be used as the alignment layer.

  The photo-alignment film is anisotropic to the film obtained by irradiating the substrate coated with the constituent material of the photo-alignment film, which will be described later, with light whose polarization is controlled to cause a photoexcitation reaction (decomposition, isomerization, dimerization). Is used to align the liquid crystal molecules on the film.

  The constituent material of the photo-alignment film used in the present invention is not particularly limited as long as it has an effect of aligning liquid crystals (photoalignment) by irradiating light to cause a photoexcitation reaction. . As such materials, there are large photoreactive materials that impart anisotropy to the photoalignment film by causing a photoreaction, and anisotropy is imparted to the photoalignment film by causing a photoisomerization reaction. It can be divided into photoisomerization type materials.

The wavelength region of light that causes the photoexcitation reaction of the constituent material of the photo-alignment film is preferably in the ultraviolet light range, that is, in the range of 10 nm to 400 nm, and more preferably in the range of 250 nm to 380 nm.
Hereinafter, the photoreactive material and the photoisomerization type material will be described.

(I) Photoreactive type The photoreactive type material is a material that imparts anisotropy to the photo-alignment film by causing a photoreaction. The photoreactive material used in the present invention is not particularly limited as long as it has such characteristics. Among these, the photo-alignment is caused by causing a photodimerization reaction or a photodecomposition reaction. A material that imparts anisotropy to the film is preferred.

  Here, the photodimerization reaction refers to a reaction in which a reaction site oriented in the polarization direction by light irradiation undergoes radical polymerization and two molecules are polymerized. This reaction stabilizes the orientation in the polarization direction and makes the photo-alignment film different. It is possible to impart directionality. The photolysis reaction is a reaction that decomposes molecular chains such as polyimide oriented in the polarization direction by light irradiation. This reaction leaves a molecular chain oriented in the direction perpendicular to the polarization direction, and is different from the photo-alignment film. It is possible to impart directionality. In the present invention, among these photoreactive materials, it is more preferable to use a material that imparts anisotropy to the photoalignment film by a photodimerization reaction because of high exposure sensitivity and a wide range of material selection. .

  The photoreactive material utilizing the photodimerization reaction is not particularly limited as long as it is a material that can impart anisotropy to the photoalignment film by the photodimerization reaction, but it is a radical polymerizable functional group. It is preferable to include a photodimerization reactive compound having dichroism that has different absorption depending on the polarization direction. This is because by radical polymerization of the reaction site oriented in the polarization direction, the orientation of the photodimerization reactive compound is stabilized and anisotropy can be easily imparted to the photo-alignment film.

  Examples of the photodimerization reactive compound having such characteristics include a dimerization reactive polymer having at least one reactive site selected from cinnamate ester, coumarin, quinoline, chalcone group and cinnamoyl group as a side chain. Can do.

  Among these, the photodimerization reactive compound is preferably a dimerization reactive polymer containing cinnamate, coumarin or quinoline as a side chain. This is because anisotropy can be easily imparted to the photo-alignment film by radical polymerization of α and β unsaturated ketone double bonds aligned in the polarization direction as reaction sites.

  The main chain of the dimerization reactive polymer is not particularly limited as long as it is generally known as a polymer main chain, but the reaction sites of the side chains such as aromatic hydrocarbon groups are not limited. It is preferable that it does not have a substituent containing a lot of π electrons that hinders the interaction.

  The weight average molecular weight of the dimerization reactive polymer is not particularly limited, but is preferably in the range of 5,000 to 40,000, and is preferably in the range of 10,000 to 20,000. Is more preferable. The weight average molecular weight can be measured by a gel permeation chromatography (GPC) method. If the weight average molecular weight of the dimerization reactive polymer is too small, it may not be possible to impart appropriate anisotropy to the photo-alignment film. On the other hand, if it is too large, the viscosity of the coating liquid at the time of forming the photo-alignment film becomes high and it may be difficult to form a uniform coating film.

  As a dimerization reactive polymer, the compound represented by following formula (1) can be illustrated.

In the above formula, M ¹¹ and M ¹² each independently represent a monomer unit of a monopolymer or a copolymer. Examples thereof include ethylene, acrylate, methacrylate, 2-chloroacrylate, acrylamide, methacrylamide, 2-chloroacrylamide, styrene derivatives, maleic acid derivatives, and siloxane. M ¹² may be acrylonitrile, methacrylonitrile, methacrylate, methyl methacrylate, hydroxyalkyl acrylate or hydroxyalkyl methacrylate. x and y represent the molar ratio of each monomer unit in the case of a copolymer, and 0 <= x <= 1, 0 <= y <= 1, and x + y = It is a number satisfying 1. n represents an integer of 4 to 30,000. D ¹ and D ² represent a linking group unit.

R ¹ is a group represented by -A ^1- (Z ¹ -B ¹ ) _z -Z ^2- , and R ² is represented by -A ^1- (Z ¹ -B ¹ ) _z -Z ^3-. It is a group. Here, A ¹ and B ¹ are each independently a covalent single bond, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,4-cyclohexylene, 1,3-dioxane-2, It represents 5-diyl or 1,4-phenylene which may have a substituent. Z ¹ and Z ² are each independently a covalent single bond, —CH ₂ —CH ₂ —, —CH ₂ O—, —OCH ₂ —, —CONR—, —RNCO—, —COO— or — Represents OOC-. R is a hydrogen atom or a lower alkyl group, and Z ³ is a hydrogen atom or an alkyl or alkoxy having 1 to 12 carbon atoms, which may have a substituent, cyano, nitro, or halogen. z is an integer of 0-4. E ¹ represents a photodimerization reaction site, and examples thereof include cinnamic acid ester, coumarin, quinoline, chalcone group, cinnamoyl group and the like. j and k are each independently 0 or 1.

  Specific examples of such a dimerization reactive polymer include compounds represented by the following formulas (1-1) to (1-4).

  More specific examples of the dimerization reactive polymer include compounds represented by the following formulas (1-5) to (1-8).

Moreover, the dimerization reactive polymer which has a repeating unit represented by the following general formula (A) can also be mention | raise | lifted as an example.
Formula (A)

(In the formula, R ₁ represents a hydrogen atom or a substituent, and Y ₁ is formed by combining a divalent linking group selected from the following linking group group or two or more selected from the following linking group group. Represents a valent linking group, Ar ₁ and Ar ₂ each independently represents an aromatic ring having 1 to 10 carbon atoms, Ar ₁ and Ar ₂ may each have a substituent, and n is 1. Represents an integer of ~ 3.
(Linked group group)
—O—, —CO—, —NR ₂ — (R ₂ represents a hydrogen atom or an alkyl group), —S—, an alkylene group, or an arylene group. )

When R ₁ represents a substituent, an alkyl group and a halogen group can be mentioned as preferred examples. R ¹ is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a chloro group, more preferably a hydrogen atom, a methyl group, an ethyl group, or a chloro group, and even more preferably a hydrogen atom or a methyl group.

The _{Y 1, -O -, - CO} -, - NR 2 -, an alkylene group or an arylene group,, -CO -, - O - , - NR 2 -, that it contains an alkylene group Are particularly preferable, and most preferably include —CO—, —O—, and an alkylene group. If Y ₁ comprises an alkylene group, the number of carbon atoms in the alkylene group is preferably 1 to 10, more preferably 1 to 8, particularly preferably 1 to 6. Specific examples of particularly preferred alkylene groups include methylene, ethylene, trimethylene, tetrabutylene, hexamethylene groups and the like. When Y ₁ contains an arylene group, the carbon number of the arylene group is preferably 6 to 24, more preferably 6 to 18, and particularly preferably 6 to 12. Specific examples of particularly preferred arylene groups include phenylene and naphthalene groups. When Y ₁ contains a divalent linking group (that is, an aralkylene group) obtained by combining an alkylene group and an arylene group, the carbon number of the aralkylene group is preferably 7 to 34, more preferably 7 to 26, and particularly preferably. Is 7-16. Specific examples of particularly preferred aralkylene groups include a phenylenemethylene group, a phenyleneethylene group, and a methylenephenylene group. The group listed as Y ₁ may have a suitable substituent.

Ar ₁ is preferably a benzene ring, a thiophene ring, a furan ring, or a naphthalene ring, and more preferably a benzene ring.

When Ar ₁ has a substituent, examples of the substituent include an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, and an alkylcarbonyl having 1 to 6 carbon atoms. Groups, C1-C6 alkylcarbonyloxy groups, C1-C6 alkylcarbonylthio groups, C1-C6 alkylcarbonylamino groups, halogen groups, cyano groups, nitro groups, cyano groups, etc. More preferred substituents include methyl, ethyl, methoxy, fluorine, chloro, bromo, and cyano groups.

  These substituents may be substituted with other substituents, and preferred substituents in this case are also as defined above. Moreover, when it has two or more substituents, each substituent may be the same or different. If possible, the substituents may be bonded to each other to form a ring.

Ar ₂ is preferably a benzene ring, a furan ring, or a naphthalene ring, and more preferably a benzene ring. When Ar ₂ has a substituent, examples of the substituent include alkyl group, alkenyl group, alkynyl group, alkoxyl group, alkylthio group, alkylcarbonyl group, alkylcarbonyloxy group, alkylcarbonylthio group, alkylcarbonylamino group, alkyloxy group Examples include carbonyloxy group, alkyloxycarbonylthio group, alkyloxycarbonylamino group, alkylthiocarbonyloxy group, alkylaminocarbonylamino group, alkylaminocarbonyloxy group, halogen group, cyano group, nitro group, and aryl group. More preferable substituents include an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, an alkylcarbonyl group having 1 to 20 carbon atoms, and an alkyl group having 1 to 20 carbon atoms. Alkylca Rubonyloxy group, alkylcarbonylamino group having 1 to 20 carbon atoms, alkyloxycarbonyloxy group having 1 to 20 carbon atoms, alkyloxycarbonylthio group having 1 to 20 carbon atoms, alkyloxycarbonylamino group having 1 to 20 carbon atoms And an alkylaminocarbonyloxy group having 1 to 20 carbon atoms, a fluorine group, a chloro group, a bromo group, a cyano group, a nitro group, and an aryl group having 6 to 30 carbon atoms.
These substituents may be substituted with other substituents, and preferred substituents in this case are also as defined above. Moreover, when it has two or more substituents, each substituent may be the same or different. If possible, the substituents may be bonded to each other to form a ring.

  n represents an integer of 1 to 3, and is preferably 1 or 2.

  The polymer having a repeating unit represented by the general formula (A) may contain one type of repeating unit represented by the general formula (A) or may contain two or more types. . Moreover, the high molecular polymer which has a repeating unit represented by the said general formula (A) may have 1 type (s) or 2 or more types of repeating units other than said each repeating unit. The other repeating units are not particularly limited, and preferred examples thereof include repeating units derived from ordinary radical polymerizable monomers. Hereinafter, specific examples of monomers for deriving other repeating units will be given.

Monomer group 1) Alkenes ethylene, propylene, 1-butene, isobutene, 1-hexene, 1-dodecene, 1-octadecene, 1-eicosene, hexafluoropropene, vinylidene fluoride, chlorotrifluoroethylene, 3, 3, 3 -Trifluoropropylene, tetrafluoroethylene, vinyl chloride, vinylidene chloride, etc .;
2) Dienes 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-n-propyl-1,3-butadiene, 2,3-dimethyl-1,3- Butadiene, 2-methyl-1,3-pentadiene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, 2-chloro- 1,3-butadiene, 1-bromo-1,3-butadiene, 1-chlorobutadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, 1,1,2-trichloro -1,3-butadiene and 2-cyano-1,3-butadiene, 1,4-divinylcyclohexane and the like;

3) Derivatives of α, β-unsaturated carboxylic acid 3a) Alkyl acrylates Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl Acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, tert-octyl acrylate, dodecyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, 2-bromoethyl acrylate, 4- Chlorobutyl acrylate, 2-cyanoethyl acrylate, 2-acetoxyethyl acrylate, methoxybenzyl acetate Rate, 2-chlorocyclohexyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, 2-methoxyethyl acrylate, ω-methoxypolyethylene glycol acrylate (polyoxyethylene added moles: n = 2 to 100), 3-methoxy Butyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2- (2-butoxyethoxy) ethyl acrylate, 1-bromo-2-methoxyethyl acrylate, 1,1-dichloro-2-ethoxyethyl acrylate, glycidyl acrylate Such);

3b) Alkyl methacrylates Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2- Ethylhexyl methacrylate, n-octyl methacrylate, stearyl methacrylate, benzyl methacrylate, phenyl methacrylate, allyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, cresyl methacrylate, naphthyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, ω- Toxipolyethylene glycol methacrylate (number of added polyoxyethylene: n = 2 to 100), 2-acetoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2- (2-butoxyethoxy) ethyl methacrylate Glycidyl methacrylate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc .;

3c) Diesters of unsaturated polyvalent carboxylic acids Dimethyl maleate, dibutyl maleate, dimethyl itaconate, dibutyl taconate, dibutyl crotonate, dihexyl crotonate, diethyl fumarate, dimethyl fumarate, etc .;

3d) Amides of α, β-unsaturated carboxylic acids N, N-dimethylacrylamide, N, N-diethylacrylamide, Nn-propylacrylamide, N-tertbutylacrylamide, N-tertoctylmethacrylamide, N-cyclohexyl Acrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-benzylacrylamide, N-acryloylmorpholine, diacetone acrylamide, N-methylmaleimide and the like;

4) Unsaturated nitriles Acrylonitrile, methacrylonitrile, etc .;
5) Styrene and its derivatives Styrene, vinyl toluene, ethyl styrene, p-tert butyl styrene, methyl p-vinyl benzoate, α-methyl styrene, p-chloromethyl styrene, vinyl naphthalene, p-methoxy styrene, p-hydroxymethyl Styrene, p-acetoxystyrene, etc .;
6) Vinyl esters Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl salicylate, vinyl chloroacetate, vinyl methoxyacetate, vinyl phenylacetate, etc .;

7) Vinyl ethers Methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n-dodecyl vinyl ether N-eicosyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, fluorobutyl vinyl ether, fluorobutoxyethyl vinyl ether, etc .; and 8) other polymerizable monomers N-vinyl pyrrolidone, methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl Vinyl ketone, 2-vinyl oxazoline, 2-isopropenyl oxazoline and the like.

  More specifically, there are the following polymers. In addition, x, y, z in a formula shows the mole percentage of each repeating unit.

  In the dimerization reactive polymer used in the present invention, the repeating unit represented by the general formula (A) is preferably 5 mol% or more, and more preferably 10 mol% or more.

  In the composition comprising the dimerization reactive polymer used in the present invention, various additives can be used in combination with the polymer as necessary. For example, by using a polymerization initiator, a plasticizer, a surfactant and the like in combination, the uniformity of the coating film, the strength of the film, the orientation of the polymer compound having a photoreactive group, and the like can be improved. 30 mass% or less is preferable with respect to the high molecular compound which has a photoreactive group, and, as for the total amount of these addition amounts, 10 mass% or less is more preferable.

The aligned liquid crystal aligning agent is preferably fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred. Examples of the photopolymerization initiator or photopolymerization initiator system include vicinal polyketaldonyl compounds disclosed in US Pat. No. 2,367,660, acyloin ether compounds described in US Pat. No. 2,448,828, An aromatic acyloin compound substituted with an α-hydrocarbon described in US Pat. No. 2,722,512, a polynuclear quinone compound described in US Pat. Nos. 3,046,127 and 2,951,758, US Pat. No. 3,549,367 A combination of a triarylimidazole dimer and a p-aminoketone described in the document, a benzothiazole compound and a trihalomethyl-s-triazine compound described in JP-B-51-48516, and U.S. Pat. No. 4,239,850 Trihalomethyl-triazine compounds, US Pat. No. 42 And the like trihalomethyl oxadiazole compounds described in 2976 Pat. In particular, trihalomethyl-s-triazine, trihalomethyloxadiazole, and triarylimidazole dimer are preferable.
In addition, “polymerization initiator C” described in JP-A-11-133600 can also be mentioned as a preferable example. The content of the photopolymerization initiator or photopolymerization initiator system with respect to the total solid content of the liquid crystal aligning agent composition is generally 0.5 to 20% by mass, and preferably 0.5 to 5% by mass.

  Cationic polymerization initiators include Lewis salts such as aryl diazonium salts, diaryl iodonium salts, triaryl sulfonium salts such as etrafluoroborate and hexafluorophosphenol, benzyl silyl ether, o-nitrobenzyl silyl ether, triphenyl ( Examples thereof include a mixed system of a silanol-generating silane compound such as (t-butyl) peroxysilane and an aluminum complex such as tris (ethylacetoacetate) aluminum. Specifically, diazodisulfone photoacid generators such as WPAG-145, WPAG-170, WPAG-199 (all trade names, manufactured by Wako Pure Chemical Industries), WPAG-281, WPAG-336, WPAG-367 (any Product name, manufactured by Wako Pure Chemical Industries, Ltd.), SB 1A, SB 2B, SB 2B F, SB 3C (all are trade names, manufactured by Nippon Siebel Hegner), UVI-6974, UVI-6990 (trade name, manufactured by Union Carbide), FX512 (Trade name, manufactured by 3M), triarylsulfonium photoacid generators such as KI-85 (trade name, manufactured by Degussa), WPI-113 (trade name, manufactured by Wako Pure Chemical Industries), MC AA, MC BB, MC CC Commercially available photocationic initiators such as diaryliodonium salts such as MC CC PF and MC CC F (both trade names, manufactured by Nippon Siebel Hegner) can be used. The content of the cationic polymerization initiator based on the total solid content of the liquid crystal aligning agent composition is generally 0.5 to 20% by mass, and preferably 0.5 to 5% by mass.

  In the present invention, these photopolymerization initiators may be used in combination with two or more different photoreaction mechanisms.

  A conventionally well-known plasticizer is mentioned as a plasticizer. Specifically, phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diaryl phthalate, dimethyl glycol phthalate , Ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, glycol esters such as triethylene glycol dicaprylate, phosphate esters such as tricresyl phosphate, triphenyl phosphate, diisobutyl adipate , Dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioct Ruazereto, aliphatic dibasic acid esters such as dibutyl maleate, triethyl citrate, glycerin triacetyl ester, and the like butyl laurate.

  Examples of the surfactant include conventionally known anionic, cationic, nonionic and amphoteric surfactants. Fluorine compounds are particularly preferred, and examples thereof include perfluoroalkylamine oxides, perfluoroalkylethylene oxide adducts, perfluoroalkyl group and hydrophilic group-containing polymers, perfluoroalkyl groups, hydrophilic groups, and lipophilic group-containing polymers.

  Examples of the photoreactive material using photolysis reaction include polyimide “RN1199” (trade name) manufactured by Nissan Chemical Industries, Ltd. Examples of the photoreactive material using photodimerization reaction include “ROP102” and “ROP103” (both trade names) manufactured by Rolic technologies.

(Ii) Photoisomerization type Next, a photoisomerization type material will be described. The photoisomerization type material here is a material that imparts anisotropy to the photo-alignment film by causing a photoisomerization reaction as described above, and is particularly limited as long as it has such characteristics. However, it is preferable to include a photoisomerization reactive compound that imparts anisotropy to the photoalignment film by causing a photoisomerization reaction. By including such a photoisomerization-reactive compound, a stable isomer among a plurality of isomers is increased by light irradiation, so that anisotropy can be easily imparted to the photo-alignment film. It is.

  The photoisomerization reactive compound is not particularly limited as long as it is a material having the above-mentioned characteristics, but has a dichroism that makes absorption different depending on the polarization direction, and can be irradiated by light irradiation. It is preferable that it causes an isomerization reaction. This is because anisotropy can be easily imparted to the photo-alignment film by causing isomerization of the reaction site oriented in the polarization direction of the photoisomerization-reactive compound having such characteristics.

  Further, the photoisomerization reaction in which the photoisomerization reactive compound is generated is preferably a cis-trans isomerization reaction. This is because either the cis isomer or the trans isomer is increased by light irradiation, whereby anisotropy can be imparted to the photo-alignment film.

  Examples of the photoisomerization-reactive compound include a monomolecular compound and a polymerizable monomer that is polymerized by light or heat. These may be appropriately selected according to the type of liquid crystal used, but the anisotropy can be stabilized by polymerizing after imparting anisotropy to the photo-alignment film by light irradiation. It is preferable to use a polymerizable monomer. Among such polymerizable monomers, an acrylate monomer and a methacrylate monomer are preferable because anisotropy is imparted to the photo-alignment film and the polymer can be easily polymerized while maintaining the anisotropy in a good state. .

  The polymerizable monomer may be a monofunctional monomer or a polyfunctional monomer. However, since the anisotropy of the photo-alignment film due to polymerization becomes more stable, the bifunctional monomer It is preferable that

  Specific examples of such a photoisomerization-reactive compound include compounds having a cis-trans isomerization-reactive skeleton such as an azobenzene skeleton or a stilbene skeleton.

  In this case, the number of cis-trans isomerization reactive skeletons contained in the molecule may be one or two or more, but the alignment control of the ferroelectric liquid crystal becomes easy. Two are preferable.

  The cis-trans isomerization reactive skeleton may have a substituent in order to further enhance the interaction with the liquid crystal molecules. The substituent is not particularly limited as long as it can enhance the interaction with the liquid crystal molecules and does not interfere with the orientation of the cis-trans isomerization reactive skeleton, and examples thereof include a carboxyl group and a sulfonic acid. A sodium group, a hydroxyl group, etc. are mentioned. These structures can be appropriately selected depending on the type of ferroelectric liquid crystal used.

In addition to the cis-trans isomerization reactive skeleton, the photoisomerization reactive compound contains many π electrons such as aromatic hydrocarbon groups so that the interaction with the liquid crystal molecules can be further enhanced. It may have an included group, and the cis-trans isomerization reactive skeleton and the aromatic hydrocarbon group may be bonded via a bonding group. The bonding group is not particularly limited as long as it can enhance the interaction with the liquid crystal molecule. For example, —COO—, —OCO—, —O—, —C≡C—, —CH ₂ —CH _2- , —CH ₂ O—, —OCH ₂ — and the like can be mentioned.

  In addition, when using a polymerizable monomer as a photoisomerization reactive compound, it is preferable to have the said cis-trans isomerization reactive skeleton as a side chain. By having the cis-trans isomerization reactive skeleton as a side chain, the effect of anisotropy imparted to the photo-alignment film becomes larger, and is particularly suitable for controlling the alignment of ferroelectric liquid crystals Because it becomes. In this case, the aromatic hydrocarbon group or bonding group contained in the molecule is contained in the side chain together with the cis-trans isomerization reactive skeleton so that the interaction with the liquid crystal molecule is enhanced. It is preferable.

  Further, the side chain of the polymerizable monomer may have an aliphatic hydrocarbon group such as an alkylene group as a linking group so that the cis-trans isomerization reactive skeleton can be easily oriented.

  Among the photoisomerization reactive compounds of the monomolecular compound or polymerizable monomer as described above, the photoisomerization reactive compound used in the present invention is preferably a compound having an azobenzene skeleton in the molecule. This is because the azobenzene skeleton contains a lot of π electrons and thus has a high interaction with liquid crystal molecules and is particularly suitable for controlling the alignment of liquid crystals.

  Hereinafter, the reason why an anisotropy can be imparted to the photo-alignment film by causing the azobenzene skeleton to undergo a photoisomerization reaction will be described. First, when the azobenzene skeleton is irradiated with linearly polarized ultraviolet light, the trans azobenzene skeleton having the molecular long axis oriented in the polarization direction is changed to a cis isomer as shown in the following formula.

  Since the cis isomer of the azobenzene skeleton is chemically unstable compared to the trans isomer, it thermally or absorbs visible light and returns to the trans isomer. Whether to become the right transformer body occurs with the same probability. Therefore, if the ultraviolet light is continuously absorbed, the ratio of the right-side trans isomer increases, and the average orientation direction of the azobenzene skeleton becomes perpendicular to the polarization direction of the ultraviolet light. In the present invention, by utilizing this phenomenon, the alignment direction of the azobenzene skeleton is aligned, anisotropy is imparted to the photo-alignment film, and the alignment of liquid crystal molecules on the film can be controlled.

  Among such compounds having an azobenzene skeleton in the molecule, examples of the monomolecular compound include compounds represented by the following formula (2).

In the above formula, R ⁴¹ each independently represents a hydroxy group. R ⁴² is ^{- (A 41 -B 41 -A 41} ) m- (D 41) represents a linking group represented by ^{n-, R 43} is ^{(D 41) n- (A 41} -B 41 -A 41) Represents a linking group represented by m-. Here, A ⁴¹ represents a divalent hydrocarbon group, B ⁴¹ represents —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— or —OCONH—, and m represents Represents an integer of 0 to 3; D ⁴¹ represents a divalent hydrocarbon group when m is 0, and —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— when m is an integer of 1 to 3. Alternatively, -OCONH- is represented, and n represents 0 or 1. R ⁴⁴ each independently represents a halogen atom, a carboxy group, a halogenated methyl group, a halogenated methoxy group, a cyano group, a nitro group, a methoxy group or a methoxycarbonyl group. However, the carboxy group may form a salt with an alkali metal. R ⁴⁵ each independently represents a carboxy group, a sulfo group, a nitro group, an amino group or a hydroxy group. However, the carboxy group or the sulfo group may form a salt with the alkali metal.

  Specific examples of the compound represented by the above formula include compounds represented by the following formulas (2-1) to (2-4).

  Moreover, as a polymerizable monomer which has the said azobenzene skeleton as a side chain, the compound represented by following formula (3) can be mentioned, for example.

In the above formula, each R ⁵¹ is independently (meth) acryloyloxy group, (meth) acrylamide group, vinyloxy group, vinyloxycarbonyl group, vinyliminocarbonyl group, vinyliminocarbonyloxy group, vinyl group, isopropenyloxy. Represents a group, isopropenyloxycarbonyl group, isopropenyliminocarbonyl group, isopropenyliminocarbonyloxy group, isopropenyl group or epoxy group. R ⁵² is ^{- (A 51 -B 51 -A 51} ) m- (D 51) represents a linking group represented by ^{n-, R 53} is ^{(D 51) n- (A 51} -B 51 -A 51) Represents a linking group represented by m-. Here, A ⁵¹ represents a divalent hydrocarbon group, B ⁵¹ represents —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— or —OCONH—, and m represents Represents an integer of 0 to 3; D ⁵¹ represents a divalent hydrocarbon group when m is 0, and when m is an integer of 1 to 3, —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— Alternatively, -OCONH- is represented, and n represents 0 or 1. R ⁵⁴ each independently represents a halogen atom, a carboxy group, a halogenated methyl group, a halogenated methoxy group, a cyano group, a nitro group, a methoxy group or a methoxycarbonyl group. However, the carboxy group may form a salt with an alkali metal. R ⁵⁵ each independently represents a carboxy group, a sulfo group, a nitro group, an amino group or a hydroxy group. However, the carboxy group or the sulfo group may form a salt with the alkali metal.

  Specific examples of the compound represented by the above formula include compounds represented by the following formulas (3-1) to (3-4).

  In the present invention, various cis-trans isomerization reactive skeletons and substituents can be selected from such photoisomerization reactive compounds according to required characteristics. In addition, these photoisomerization reactive compounds can also be used individually by 1 type or in combination of 2 or more types.

  The photoisomerization type material used in the present invention may contain additives in addition to the above-mentioned photoisomerization reactive compound as long as the photoalignment property of the photoalignment film is not hindered. When a polymerizable monomer is used as the photoisomerization reactive compound, examples of the additive include a polymerization initiator and a polymerization inhibitor.

  The polymerization initiator or polymerization inhibitor may be appropriately selected from generally known compounds according to the type of photoisomerization reactive compound. The addition amount of the polymerization initiator or polymerization inhibitor is preferably in the range of 0.001% by mass to 20% by mass, and in the range of 0.1% by mass to 5% by mass with respect to the photoisomerization reactive compound. More preferably, it is within. This is because if the addition amount of the polymerization initiator or polymerization inhibitor is too small, the polymerization may not be started (prohibited), whereas if too large, the reaction may be inhibited.

(Iii) Forming method of photo-alignment film In order to form a photo-alignment film in the present invention, first, a photo-alignment film-forming coating solution obtained by diluting the constituent material of the photo-alignment film with an organic solvent is applied and dried. In this case, the content of the photodimerization reactive compound or photoisomerization reactive compound in the photoalignment film-forming coating solution is preferably in the range of 0.05% by mass to 10% by mass. More preferably, it is in the range of 2% by mass to 2% by mass. If the content is less than the above range, it will be difficult to impart appropriate anisotropy to the alignment film. Conversely, if the content is more than the above range, the viscosity of the photo-alignment film forming coating solution will increase. This is because it becomes difficult to form a uniform coating film.

  The method for applying the photo-alignment film forming coating solution is not particularly limited as long as it is a method capable of applying the photo-alignment film forming coating solution onto the lyophilic region. Coating method, roll coating method, rod bar coating method, spray coating method, air knife coating method, slot die coating method, wire bar coating method, dip coating method, blade coating method, micro gravure coating method, gravure coating method, casting method, inkjet Method, LB method, flexographic printing method, offset printing method, screen printing method and the like can be used.

  The thickness of the film obtained by applying the coating liquid for forming a photo-alignment film is preferably in the range of 1 nm to 2000 nm, more preferably in the range of 3 nm to 100 nm. This is because if the thickness of the film is thinner than the above range, sufficient optical alignment may not be obtained, and conversely, if the thickness is thicker than the above range, it may be disadvantageous in cost.

  Anisotropy is imparted to the obtained film by performing a photo-alignment treatment. Specifically, by irradiating light with controlled polarization, an anisotropy can be imparted by causing a photoexcitation reaction. The wavelength range of the light to be irradiated may be appropriately selected according to the constituent material of the photo-alignment film to be used, but is preferably in the ultraviolet light range, that is, in the range of 100 nm to 400 nm, more preferably 250 nm. Within the range of ˜380 nm. The polarization direction is not particularly limited as long as it can cause the photoexcitation reaction.

  Further, when a polymerizable monomer is used as a constituent material of the photo-alignment film, among the photoisomerization-reactive compounds, after photo-alignment treatment, it is polymerized by heating and applied to the photo-alignment film. Anisotropy can be stabilized.

(3) Concave and convex alignment layer As a liquid crystal alignment layer, not only a film subjected to rubbing or photo-alignment but also a film with small concavities and convexities can be used.
Various structures can be employed for the recess forming region. For example, a structure in which a plurality of grooves are arranged in parallel in the width direction at equal intervals can be employed in the recess forming region.

  These grooves may not be parallel to each other, but the longer the grooves are, the easier the long axes of the liquid crystal molecules or their mesogenic groups are aligned. The angle formed by these grooves is, for example, 5 ° or less, and typically 3 ° or less.

  These grooves may be arranged vertically and horizontally. The lengths of the grooves may be equal to each other or different from each other. Further, the distance between adjacent grooves in the length direction may be uniform or non-uniform. Furthermore, the distance between the grooves adjacent in the width direction may be uniform or non-uniform. Further, grooves having the same length may be arranged vertically and horizontally in each of the recess forming regions. Or you may arrange the groove | channel of various length at random.

  By making the grooves substantially parallel and appropriately setting the pitch, the diffraction grating can be constituted by these grooves.

  The recess formation layer (unevenness alignment layer) can be formed, for example, by a method of recording a hologram pattern using a two-beam interference method on a photosensitive resin material or a method of drawing a pattern by an electron beam. Alternatively, as is done in the manufacture of surface relief holograms, it can be formed by pressing a mold provided with fine linear projections onto the resin. For example, the concave portion forming layer is obtained by a method of pressing a master having a linear convex portion against a thermoplastic resin layer formed on a substrate while applying heat, that is, a hot embossing method. . Alternatively, the recess forming layer is formed by applying an ultraviolet curable resin on the substrate, irradiating the substrate with ultraviolet rays while curing the ultraviolet curable resin while pressing the original, and then removing the original. It is also possible.

  According to these methods, it is possible to form a plurality of recess formation regions having different groove length directions in one plane. In addition, according to these methods, a plurality of recess formation regions having different groove depths, widths, and / or grooves can be formed in one plane.

  The original plate can be obtained, for example, by performing electroforming of a mother die obtained by a method of recording a hologram pattern using a two-beam interference method, a method of drawing a pattern by an electron beam, or a method of cutting by a cutting tool. It is done. When the above-described diversity is not given to the recess forming layer, the groove may be formed by rubbing.

  The depth of these grooves is, for example, in the range of 0.05 μm to 1 μm. The length of the groove is, for example, 0.5 μm or more. The pitch of the grooves is, for example, 0.1 μm or more, and typically 0.75 μm or more. The pitch of the grooves is, for example, 10 μm or less, and typically 2 μm or less. In order to align the liquid crystal molecules or their mesogenic groups with a high degree of order, it is advantageous that the pitch of the grooves is small.

8). Ink Diffusion Prevention Barrier In the present invention, an ink diffusion prevention barrier can be provided on the alignment layer or the alignment layer as necessary. The ink diffusion prevention barrier has an action of suppressing unintentional movement and deformation of the ink after ink landing and adhering the ink to an intended position when discharging an ink composition containing a liquid crystal compound by an inkjet method. By forming the ink diffusion prevention barrier, a finer pattern can be formed.
The ink diffusion prevention barrier is formed as follows.
(1) When forming in an alignment layer When forming in an alignment layer, an unevenness | corrugation can be given to an alignment layer. The unevenness may be imparted before the alignment treatment or may be imparted after the alignment treatment. Examples of the method for forming the unevenness include embossing, photoresist processing, and machining.
The layer with the unevenness may be transferred.
(2) When forming as another layer on alignment layer When forming as another layer on alignment layer, it can carry out by discharge by a photoresist or an inkjet. It is preferable to perform photocuring using a photosensitive resin.
The layer with the unevenness may be transferred.

9. Functional layer laminated on birefringence pattern The birefringence pattern may be further laminated with functional layers having various functions. Examples of the functional layer include a reflective layer and a protective layer. Further, although not particularly limited, for example, a hologram layer, a reflective layer, a protective layer, and the like described below can be given.

(1) Hologram layer The anti-counterfeit medium of the present invention may have a hologram layer. Although a hologram is used alone as a forgery-preventing label, the anti-counterfeiting property is improved by combining it with a birefringence pattern that forms a latent image.

The type of hologram is not particularly limited, and may be a relief hologram or a volume hologram. The former is superior in terms of productivity, but the latter is superior in terms of anti-counterfeiting.
For various hologram materials, reference can be made to “Holographic Materials and Application Handbook” (supervised by Junpei Takiuchi, 2007). Regarding the formation of the relief hologram layer, the descriptions in JP-A-2004-177636 and JP-A-2005-91786 can be referred to. A typical method will be described below.

  The hologram resin used as the material for forming the hologram layer may be any of a thermoplastic resin, a thermosetting resin, a UV or an electron beam curable resin that can be molded by a press plate. Polyurethane added as a cross-linking agent to thermoplastic resins such as acrylic resins, epoxy resins, cellulose resins, vinyl resins, acrylic polyols and polyester polyols having reactive hydroxyl groups, and crosslinked melamine resins Resins, thermosetting resins such as phenolic resins, and ultraviolet or electron beam curable resins such as epoxy (meth) acryl and urethane (meth) acrylate can be used alone or in combination.

As a method for producing a hologram layer, (1) a UV curable resin or an electron beam curable resin is applied to a support, which is sent between a plate cylinder and an impression cylinder, and irradiated with ultraviolet rays or an electron beam. Method of curing, (2) As disclosed in JP-A-5-2322853, ultraviolet or electron beam curable resin composition and the concavo-convex surface of an existing hologram film are pressure-bonded, and ultraviolet or electron beam is applied. A method of transferring a hologram image by curing the resin by irradiation and then peeling off the hologram film, and (3) a synthetic resin in a molten state extruded from an extrusion die on one surface of the support. Examples include a method of laminating between a plate cylinder made of a cooling roll having a stamper on which a relief hologram is formed, and an impression cylinder, and any method is preferably used. Rukoto can.
In addition, when providing a fine uneven | corrugated shape by embossing on the surface in a resin layer, Comprising: When providing a reflection layer in a hologram layer so that it may mention later, embossing may be before or after formation of a reflection layer.

  The hologram layer is preferably formed on the birefringence pattern manufactured as described above. A commercially available hologram foil may be transferred onto the patterned optically anisotropic layer.

(2) Reflective layer When the birefringence pattern is visually recognized by reflection and the adherend is non-reflective, it is preferable to provide a reflective layer in order to improve the visibility of the birefringence pattern.

As the reflective layer, a reflective metal thin film or a layer containing reflective metal particles can be used.
Examples of the metal used for the metal thin film include Al, Cr, Ni, Ag, and Au. The metal thin film can be formed by vacuum film formation. The metal thin film may be a single layer film or a multilayer film, and can be manufactured by, for example, either physical vapor deposition or chemical vapor deposition.
Examples of the layer containing reflective metal particles include a layer printed with an ink such as gold or silver.
The reflective layer does not need to be a complete mirror surface, and the surface may be matted.
In the case of a transparent anti-counterfeit transfer foil, the reflection layer as described above is unnecessary, but in the case of having a hologram layer, in order to improve the visibility of the hologram, a transparent having a refractive index different from that of the hologram A reflective layer is preferably provided adjacent to the hologram layer.
As the transparent reflection layer, a thin film produced using a material having a large refractive index difference from the resin forming the hologram layer is preferable. Examples of the high refractive index material include titanium oxide, zirconium oxide, zinc sulfide, and indium oxide. Conversely, examples of the low refractive index material include silicon dioxide, magnesium fluoride, calcium fluoride, and aluminum fluoride.

  The thickness of the metal thin film or the transparent reflective layer varies depending on the material used, but can be arbitrarily selected within a range of, for example, 5 nm to 400 nm, preferably 10 nm to 100 nm.

(3) Protective layer The protective layer is a layer that becomes the outermost layer of the anti-counterfeit medium, and is a layer that protects the patterned optically anisotropic layer from contamination and damage during storage. The alignment layer may have a function as a protective layer.
As the material for the protective layer, for example, a fluoropolymer such as polyolefin or polytetrafluoroethylene or a polyfunctional acrylate is suitable.

10. Layer formation method Each layer such as an alignment layer formed as desired is formed by a dip coating method, an air knife coating method, a spin coating method, a slit coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, It can be formed by coating by an extrusion coating method (US Pat. No. 2,681,294). Two or more layers may be applied simultaneously. The method of simultaneous application is described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973).

11. Full surface heat treatment (bake)
You may bake with respect to the birefringence pattern produced as mentioned above. In this case, heating is preferably performed at 50 ° C. or higher and 400 ° C. or lower, more preferably 80 ° C. or higher and 400 ° C. or lower.

  Further, a liquid crystal compound-containing ink composition may be newly ejected by an ink jet method onto a birefringence pattern material that has been baked as necessary, and then further baked as necessary. This technique is useful when it is desired to independently control the retardation value imparted to each optically anisotropic layer.

12 Finish heat treatment If you want to further improve the stability of the birefringence pattern produced in the steps up to the previous section, further react with the unreacted reactive groups that remain after the immobilization, or increase the durability. A finish heat treatment may be performed for the purpose of vaporizing or removing unnecessary components therein. The finishing heat treatment may be performed at a temperature of about 180 to 300 ° C, more preferably 190 to 260 ° C, and even more preferably 200 to 240 ° C. The time for the heat treatment is not particularly limited, but is preferably 30 seconds or more and 5 hours or less, more preferably 1 minute or more and 2 hours or less, and particularly preferably 2 minutes or more and 1 hour or less.

B. Anti-Counterfeit System The birefringence pattern in the anti-counterfeit medium of the present invention is usually almost colorless and transparent, and is sandwiched between two polarizing plates (when the support is transparent, such as glass, PET, etc.) Or, when sandwiched between the reflective layer and the polarizing plate (when the support is paper, aluminum, paper printed with silver ink, etc.), it shows a characteristic brightness or color or can be easily recognized visually. That is, the birefringence pattern is usually almost invisible by visual observation, but a multicolor image can be easily identified through the polarizing plate. When the birefringence pattern is copied without passing through the polarizing plate, nothing is reflected. Conversely, when the birefringence pattern is copied through the polarizing plate, it remains as a permanent pattern, that is, a visible pattern without the polarizing plate. Therefore, it is difficult to duplicate a birefringence pattern. Since a method for producing such a birefringence pattern is not widespread and the material is also special, it is considered suitable for use as a forgery prevention means. The anti-counterfeit method of the present invention can be performed by using the anti-counterfeit medium of the present invention and a polarizing plate and visually recognizing a birefringence pattern (latent image) when confirming the authenticity.
In the present invention, the pattern visually recognized through the polarizing plate is not particularly limited, but preferably has three or more colors from the viewpoint of preventing forgery. A pattern having three or more colors can be formed by adjusting the retardation to three or more stages by changing the film thickness in the discharge of the liquid crystal compound-containing ink by the ink jet method. It is also preferable that the axial directions are different.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following examples.

Examples 1-7, Comparative Example 1
As shown in Table 1, an orientation layer and an ink diffusion barrier were formed on a reflective support, and a patterned optically anisotropic layer was formed thereon using an ink jet method to obtain a forgery prevention medium.
(Support)
A polyethylene terephthalate film deposited with aluminum having a thickness of 50 μm was used as a reflective support.

[1] Preparation of alignment film-In the case of PVA alignment film (Preparation of coating liquid AL-1 for alignment layer)
The following composition was prepared, filtered through a polypropylene filter having a pore size of 30 μm, and used as an alignment layer coating liquid AL-1.
---------------------------------------
Coating liquid composition for alignment layer (% by mass)
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Polyvinyl alcohol (PVA205 (trade name), manufactured by Kuraray Co., Ltd.)
3.21
Polyvinylpyrrolidone (Luvitec K30 (trade name), manufactured by BASF)
1.48
Distilled water 52.10
Methanol 43.21
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On the said support body, the coating liquid AL-1 for alignment layers was apply | coated and dried using the wire bar. The dry film thickness was 3.0 μm.
-In the case of uneven | corrugated alignment film On the said support body, the coating liquid AL-1 for alignment layers was apply | coated and dried using the wire bar. The dry film thickness was 3.0 μm.

In the case of a photo-alignment film 3% by mass of the following polymerization initiator was added to the compound (P-40) and the compound (P-40) to prepare a 1% by mass tetrahydrofuran solution. This solution was applied on the support by spin coating (3500 rpm, 20 seconds) so that the thickness after drying was about 0.05 to 0.15 μm, and an organic film was formed.

[2] Creation of an ink diffusion prevention barrier (also serving as an alignment layer (Example 2))
The surface of the quartz chrome mask (light-opening part pattern: φ200 μm, pitch 500 μm) is coated with a titanium oxide coating agent for photocatalyst (trade name: TKC301, manufactured by Teika Co., Ltd.) and dried at 350 ° C. for 3 hours. A substrate was prepared.
The film on which the alignment film was formed was used as a substrate to be exposed, the photocatalyst-containing layer side substrate was brought into soft contact with the exposed substrate, and exposed to ultraviolet light at normal temperature and normal pressure. As a result, it was possible to produce a film in which the alignment film in the exposed portion was etched to form a concave portion, and the unexposed portion became a convex portion.

(Created separately from the alignment layer (Examples 1, 3, 4))
[Preparation of a composition for forming an ink diffusion barrier (partition)]
A composition liquid K1 having the following composition was prepared.
---------------------------------------
Composition liquid K1 composition (mass%)
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Polymer (Random copolymer of benzyl methacrylate / methacrylic acid = 78/22 molar ratio, molecular weight 38,000) 5
Dipentaerythritol hexaacrylate (polymerization inhibitor MEHQ
500ppm, Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA) 5
The following compound 1 0.017
Phenothiazine 0.006
Methyl ethyl ketone 89.977
---------------------------------------

(Formation of partition walls)
The composition liquid K1 prepared as described above was applied and dried to obtain a dark color composition layer K1 having a film thickness of 2.3 μm.

In a proximity type exposure machine (manufactured by Hitachi High-Tech Electronics Engineering Co., Ltd.) with an ultra-high pressure mercury lamp, the exposure mask surface and dark color composition with the substrate and mask (quartz exposure mask with image pattern) standing vertically The distance between the physical layers K1 was set to 200 μm, and pattern exposure was performed in a nitrogen atmosphere with an exposure amount of 300 mJ / cm ² to a partition wall width of 20 μm and a space width of 100 μm.

Next, pure water is sprayed with a shower nozzle to uniformly wet the surface of the dark color composition layer K1, and then a KOH developer (containing a nonionic surfactant, trade names: CDK-1, Fuji Film). Electronics Materials Co., Ltd. 100-fold diluted) was subjected to shower development at 23 ° C. for 80 seconds and a flat nozzle pressure of 0.04 MPa to obtain a patterning image. Subsequently, ultrapure water was sprayed at a pressure of 9.8 MPa with an ultra-high pressure cleaning nozzle to remove the residue, and post exposure was performed from the upper surface with an exposure amount of 2500 mJ / cm ^{2 in} the atmosphere. A partition wall of 0.0 μm was obtained.

[Ink repellent plasma treatment]
The substrate on which the barrier ribs were formed was subjected to ink repellent plasma treatment under the following conditions using a cathode coupling parallel plate type plasma treatment apparatus.
(conditions)
Gas used: CF ₄
Gas flow rate: 80sccm
Pressure: 40Pa
RF power: 50W
Processing time: 30 sec

[3] In case of alignment treatment / PVA alignment film The alignment layer was rubbed in the MD direction.
-In the case of uneven alignment film A Si mold for thermal imprinting was produced.
The silicon substrate is coated with an electron beam resist (trade name: ZEP520 / manufactured by Nippon Zeon Co., Ltd.) to a thickness of 500 nm, and then a 100-400 nm line pattern is drawn with an electron beam drawing apparatus, and a resist pattern is formed by organic development. did. The conditions at this time were a drawing dose of 100 μC / cm ² and a development time of 2 minutes.
Next, a Si pattern having a depth of 1000 nm was formed by anisotropic dry etching of Si using an ICP dry etching apparatus. The conditions for Si anisotropic etching were C ₄ F ₈ flow rate 30 sccm, O ₂ flow rate 30 sccm, Ar flow rate 50 sccm, pressure 2 Pa, ICP power 500 W, and RIE power 130 W.
Next, the resist was peeled off by O ₂ plasma ashing (conditions: O ₂ flow rate 500 sccm, pressure 30 Pa, RF power 1000 W) to form a mold.

  Before heat imprinting, the surface of the Si mold was dipped with a fluorine-based surface treatment agent EGC-1720 (trade name, manufactured by Sumitomo 3M Limited) as a release agent. The Si mold was thermally imprinted on the support, and then the mold was released. The thermal imprinting conditions at this time were a substrate and mold temperature of 110 ° C., a press pressure of 15 MPa, and a holding time of 1 minute.

-In the case of a photo-alignment film The light emitted from the ultraviolet light emitted from the ultraviolet irradiator (made by HOYA CANDEO OPTRONICS, EXECURE 3000 (trade name)) is linearly applied to the obtained organic film through the polarizing plate. The film was converted to polarized light, and irradiated with an intensity of 100 mW / cm ² (365 nm) from a direction perpendicular to the support for 1 second to obtain an alignment film. The irradiation energy was 0.1 J / cm ² .

Furthermore, with respect to the obtained alignment film, light emitted from ultraviolet light emitted from an ultraviolet irradiator (manufactured by HOYA CANDEO OPTRONICS, EXECURE3000 (trade name)) is 100 mW from a direction perpendicular to the support. Irradiation was performed for 15 seconds at an intensity of / cm ² (365 nm), the alignment film was polymerized, and the alignment film was fixed. The irradiation energy was 1.5 J / cm ² .

[4] Coating (Preparation of liquid crystal compound-containing ink composition LC-1)
After preparing the following composition, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a liquid crystal compound-containing ink composition LC-1.
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Liquid crystal compound-containing ink composition composition (mass ratio)
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Bar-shaped liquid crystal (LC-1-1) 25.00
Horizontal alignment agent (LC-1-2) 0.02
Cationic photopolymerization initiator (CPI100-P (trade name), manufactured by San Apro Co., Ltd.) 0.66
Polymerization control agent (IRGANOX 1076 (trade name), manufactured by Ciba Specialty Chemicals Co., Ltd.)
0.07
Radical photopolymerization initiator (2-trichloromethyl-5- (p-styrylstyryl)
1,3,4-oxadiazole) 0.44
Hydroquinone monomethyl ether 0.002
N-methyl-2-pyrrolidone 73.808
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In the case of inkjet coating (Examples 1 to 7)
The liquid crystal compound-containing ink composition LC-1 was discharged using SX-3 (trade name, manufactured by Diamatix) as an inkjet head having a dedicated discharge control device. This ink-jet head is an on-demand type piezo-driven head, and 128 nozzles are arranged at intervals of 508 μm in one head.
The discharge was performed so that the pattern shown in FIG. 5 was formed for the sample with the alignment layer being PVA, and the pattern shown in FIG.

After drying at a film surface temperature of 105 ° C. for 2 minutes to form a liquid crystal phase, the alignment state is obtained by irradiating with ultraviolet rays using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 mW / cm ^{2 in} the air Was fixed to form an optically anisotropic layer having a thickness of 0 μm, 1.7 μm, and 3.5 μm. The illuminance of ultraviolet rays used at this time was 100 mW / cm ² in the UV-A region (integration of wavelengths from 320 nm to 400 nm), and the irradiation amount was 80 mJ / cm ² in the UV-A region.

  As shown in FIGS. 5 and 6, the retardation of each region of the anti-counterfeit medium was 0 nm, 140 nm, and 290 nm, respectively. The slow axis in these regions was substantially constant (the slow axis direction of each region is indicated by an arrow in FIGS. 5 and 6).

  It was confirmed whether the pattern could be observed by holding the polarizing plate over the obtained anti-counterfeit medium. As shown in Table 1, all of the patterns could be visually recognized well. The region where the retardation was 0 nm was observed as gray, the 140 nm region was amber, and the 290 nm region was observed as yellow.

・ In the case of bar coating (Comparative Example 1)
The ink composition LC-1 containing a liquid crystal compound was applied using a wire bar, dried at a film surface temperature of 105 ° C. for 2 minutes to form a liquid crystal phase, and then an air-cooled metal halide lamp (eye graphics) having an air atmosphere of 160 mW / cm ² . The optically anisotropic layer having a thickness of 3.5 μm was formed by fixing the alignment state by irradiating with ultraviolet rays using the product manufactured by Co., Ltd. The illuminance of ultraviolet rays used at this time was 100 mW / cm ² in the UV-A region (integration of wavelengths from 320 nm to 400 nm), and the irradiation amount was 80 mJ / cm ² in the UV-A region. Next, a photosensitive layer coating solution AD-1 was prepared as follows, and coated and dried to form a 1.0 μm photosensitive layer.

(Preparation of photosensitive layer coating liquid AD-1)
After preparing the following composition, it filtered with the filter made from a polypropylene with the hole diameter of 0.2 micrometer, and used as coating liquid AD-1.
───────────────────────────────────
Coating liquid AD-1 composition (mass%)
───────────────────────────────────
Random copolymer of benzyl methacrylate / methacrylic acid / methyl methacrylate = 35.9 / 22.4 / 41.7 molar ratio (mass average molecular weight 38,000) 8.05
KAYARAD DPHA (trade name, manufactured by Nippon Kayaku Co., Ltd.) 4.83
Radical photopolymerization initiator (2-trichloromethyl-5- (p-styrylstyryl)
1,3,4-oxadiazole) 0.12
Hydroquinone monomethyl ether 0.002
Megafuck F-176PF (trade name, manufactured by Dainippon Ink & Chemicals, Inc.)
0.05
Propylene glycol monomethyl ether acetate 34.80
Methyl ethyl ketone 50.538
Methanol 1.61
───────────────────────────────────

This sheet was subjected to UV pattern exposure as follows.
Exposure was performed for 8.2 seconds at an exposure illuminance of 6.25 mW / cm ² using Mikasa M-3L mask aligner and Photomask I (both trade names). The photomask I consists of three regions (Re = 0 nm, Re = 140 nm, Re = 290 nm) having different retardations as shown in FIG. The transmittance of each region (each region of the photomask I) with respect to ultraviolet light of λ = 365 nm is shown below.

――――――――――――――――――――――――――――――――――――
Area Transmittance ――――――――――――――――――――――――――――――――――――
Re = 0nm 0%
Re = 140nm 20%
Re = 290nm 96%
――――――――――――――――――――――――――――――――――――

  Thereafter, baking was further performed in a clean oven at 200 ° C. for 10 minutes to produce the forgery prevention medium of Comparative Example 1.

It was confirmed whether the pattern could be observed by holding the polarizing plate over the obtained anti-counterfeit medium. As shown in Table 1, fine cracks were formed on the aluminum surface, and it looked cloudy. When heated to 200 ° C. by heat development, the PET film as the support contracts, and the aluminum surface cannot follow and cracks occur.
In addition, there is another organic solvent development method as a method of phase difference patterning using a polymerizable liquid crystal. However, in this method, there is a concern about dissolution of a support or other layers. Further, patterning with two types of retardation values (eg, 0 nm, 200 nm) can be performed, but three or more types (eg, 0 nm, 100 nm, 200 nm) are difficult.

DESCRIPTION OF SYMBOLS 11 Support body 12 Patterning optical anisotropic layer 13 Ink diffusion prevention barrier 14 Orientation layer 15 Reflection layer 16 Protection layer 17 Metal layer 600 Timing control part 602 Piezo voltage 603 Piezo drive time width 604 Discharge frequency 610 Piezo waveform generation circuit 620 Variable delay Circuit 621 Delay 630 LED lighting circuit 640 Head 650 LED
660 Microscope lens 661 CCD camera 670 Monitor

Claims (10)

  An anti-counterfeit medium comprising a patterned optically anisotropic layer formed by discharging an ink composition containing a liquid crystal compound onto an alignment layer by an inkjet method.   The forgery prevention medium according to claim 1, wherein an ink diffusion prevention barrier is provided on the alignment layer or the alignment layer.   The anti-counterfeit medium according to claim 1, comprising an alignment layer having irregularities formed thereon.   The medium for preventing forgery according to claim 1 or 2, further comprising a rubbing alignment layer.   The medium for preventing forgery according to claim 1 or 2, further comprising an alignment layer subjected to photo-alignment.   The forgery prevention medium according to any one of claims 1 to 5, further comprising a reflective layer.   A method for producing an anti-counterfeit medium, which comprises discharging an ink composition containing a liquid crystal compound onto an alignment layer by an inkjet method.   The method for producing an anti-counterfeit medium according to claim 7, wherein an ink diffusion prevention barrier is provided on the alignment layer or the alignment layer.   The method for producing an anti-counterfeit medium according to claim 7 or 8, wherein the ink composition contains a solvent having a boiling point of 160 ° C or higher.   An anti-counterfeit method comprising using the anti-counterfeit medium according to any one of claims 1 to 6 and a polarizing plate to visually recognize a latent image that has been made visible.

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