JP5442370B2 - Tape-shaped recording medium and tape having birefringence pattern - Google Patents

Description

  The present invention relates to a tape-shaped recording medium, a tape having a birefringence pattern produced from the tape-shaped recording medium, and a tape writing apparatus for easily manufacturing a tape having a birefringence pattern.

  In recent years, tape printers for printing on tape-like recording media and tape printers called label word processors have been used. The tape-like recording medium that can be printed by this printing device has an adhesive surface covered with release paper on the back side, and can be attached as a label at a desired location by peeling the release paper after printing. it can.

  Such a tape printer is provided with a cartridge mounting part for detachably mounting a tape cartridge containing a tape-like recording medium. As the tape cartridge, a cartridge containing tape-like recording media having different widths and colors is prepared, and printing can be performed on recording media having different widths or colors by mounting desired cartridges (for example, Patent Document 1).

  On the other hand, as a countermeasure against counterfeits, it has been proposed to apply to a security article for preventing counterfeiting by forming an image using a birefringence pattern (for example, Patent Document 2). The birefringence pattern is a latent image that is invisible with a light source having no polarization property, and information such as an image can be visualized by a polarization filter. If it is possible to form an image using a birefringence pattern on the label as described above, a label sticker including a latent image that can be visually recognized only by using a special instrument can be obtained. Such a label sticker can identify the owner of the article to which the sticker is attached, but it cannot be visually recognized without a device, so that personal information can be prevented from being known to an unintended person.

Japanese Patent Laid-Open No. 8-267881 JP 2009-69793 A

  The present invention relates to a tape-like recording medium capable of easily producing a tape such as a label tape having a birefringence pattern, a tape cartridge including the tape-like recording medium, and a tape having a birefringence pattern produced from the tape-like recording medium. It is another object of the present invention to provide a tape writing device capable of easily manufacturing a tape having a birefringence pattern.

In order to solve the above problems, the present inventors have conducted intensive research. As a result, it has been found that a tape having a birefringence pattern can be easily produced by forming the birefringence pattern using heat. It has also been found that printing with ink can be synchronized with the formation of a birefringence pattern by forming a birefringence pattern using heat. The present invention has been completed based on the above findings.
That is, the present invention relates to the following (1) to (14).

(1) A tape-shaped recording medium for use in a tape writing apparatus having a thermal head, which can form a birefringence pattern by thermal writing with a thermal head.
(2) The tape-shaped recording medium according to (1), wherein the optically anisotropic layer contains a polymer having an unreacted reactive group.
(3) The optically anisotropic layer is prepared by applying and drying a solution containing a liquid crystalline compound having at least one reactive group to form a liquid crystal phase, and then heating or irradiating with light. The tape-shaped recording medium according to (1) or (2).
(4) The tape-shaped recording medium according to (3), wherein the liquid crystalline compound has at least a radical reactive group and a cationic reactive group.
(5) The tape-shaped recording medium according to (4), wherein the radical reactive group is an acryl group and / or a methacryl group, and the cationic group is a vinyl ether group, an oxetane group and / or an epoxy group.

(6) The tape-shaped recording medium according to any one of (1) to (5), wherein the tape-shaped recording medium includes a release layer, an adhesive layer, and the optically anisotropic layer in this order. .
(7) The tape-shaped recording medium according to (6), including a reflective layer between the adhesive layer and the optically anisotropic layer.
(8) The tape-shaped recording medium according to any one of (1) to (7), wherein a printing release layer capable of printing using heat on the surface is included on the outermost surface.
(9) A tape cartridge which has the tape-like recording medium according to any one of (1) to (8) and can be detachably attached to a tape writing device.
(10) The tape cartridge according to (9), including a writing ink supply material.
(11) A tape formed from the tape-shaped recording medium according to any one of (1) to (8),
A tape comprising a patterned optically anisotropic layer having two or more regions having different birefringence in a pattern.

(12) A tape formed from the tape-shaped recording medium according to (8),
A patterned optically anisotropic layer having two or more regions having different birefringence in a pattern, and a tape on which printing having the same boundary line as the boundary line of the region is performed.
(13) A tape writing apparatus having a tape-shaped recording medium supply unit, a driving unit for feeding the tape-shaped recording medium from the supply unit, and a thermal head unit for applying heat to a part of the fed-out recording medium. A tape writing apparatus having a light source capable of exposing a portion of the tape-shaped recording medium after passing through the thermal head.
(14) In the tape-shaped recording medium supply unit, the drive unit for feeding the tape-shaped recording medium from the supply unit, the thermal head unit for applying heat to a part of the fed tape-shaped recording medium, and the thermal head unit A tape writing apparatus having an ink supply material supply section for supplying ink to a tape-shaped recording medium supply section, wherein a portion of the tape-shaped recording medium after passing through the thermal head can be exposed. A tape writing device having a light source.

Tape-like recording medium capable of easily producing a tape such as a label tape having a birefringence pattern according to the present invention, a tape cartridge containing the tape-like recording medium, a tape having a birefringence pattern produced from the tape-like recording medium, A tape writing device that can easily manufacture a tape having a birefringence pattern is provided.
By using the tape-shaped recording medium of the present invention and simultaneously printing with ink and writing a birefringence pattern, it is possible to produce a label tape that can confirm a latent image until it is attached to an article. It is.

It is a figure which shows typically the structure of a basic tape-shaped recording medium. It is a figure which shows typically the structure of the tape-shaped recording medium which has an optically anisotropic layer on a support body. It is a figure which shows typically the structure of the tape-shaped recording medium which has an orientation layer. It is a figure which shows typically the structure of the tape-shaped recording medium which has an additive layer. It is a figure which shows typically the structure of the tape-shaped recording medium which has a mold release layer. It is a figure which shows typically the structure of the tape-shaped recording medium which has a printing peeling layer. It is a figure which shows an example of the structure of the whole control at the time of performing thermal pattern writing using a tape writing device. It is a figure which shows an example of the structure of the whole control at the time of performing thermal pattern writing using a tape writing device. It is a figure which shows the state which has pinched | interposed the recording material with the roller and the thermal head in the tape writing apparatus. It is a figure which shows the state in which the roller and the thermal head have pinched | interposed the recording material and the writing ink supply material in the tape writing apparatus. It is a schematic diagram of the tape cartridge which has a supply part for writing ink supply materials. It is a schematic diagram of a tape writing apparatus having an ultraviolet light source. 2 is a diagram schematically showing an image obtained in Example 1. FIG. 6 is a diagram schematically showing an image obtained in Example 2. FIG. 6 is a diagram schematically showing an image obtained in Example 3. FIG.

Hereinafter, the present invention will be described in detail.
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, retardation or Re represents in-plane retardation. In-plane retardation (Reθ) is determined from the transmission or reflection spectrum, Journal of Optical Society of America, vol. 39, p. 791-794 (1949) and Japanese Patent Application Laid-Open No. 2008-256590 can be measured using a spectral phase difference method that converts the phase difference. Although the above document is a measurement method using a transmission spectrum, particularly in the case of reflection, since light passes through the optically anisotropic layer twice, half of the phase difference converted from the reflection spectrum is applied to the optically anisotropic layer. Phase difference. Re0 is the front retardation. Re (λ) uses light having a wavelength of λ nm as measurement light. 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, “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, the retardation being substantially 0 means that the retardation is 5 nm or less. 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.

[Definition of birefringence pattern]
The birefringence pattern is a pattern in which two or more domains having different birefringence are patterned in a two-dimensional plane or three-dimensionally in a broad sense. In particular, in a two-dimensional plane, birefringence is defined by two parameters: the direction of the slow axis where the refractive index is maximum in the plane and the size of retardation in the domain. For example, an in-plane alignment defect in a retardation film made of a liquid crystal compound or a tilt distribution of liquid crystal in the thickness direction can be said to be a birefringence pattern in a broad sense, but in a narrow sense it is intentionally complex based on a predetermined design. It is desirable to define a pattern formed by controlling refraction properties as a birefringence pattern. In particular, the birefringence pattern in the present invention may be a pattern formed by domains having a constant slow axis direction and different retardation sizes.

[Tape with birefringence pattern]
A tape having a birefringence pattern is a tape having two or more regions having different birefringence. Individual regions having the same birefringence may be continuous or discontinuous.
The tape having a birefringence pattern may be transmissive or reflective (or transflective or semi-reflective). In the case of a tape attached to an opaque article, it is usually necessary to be a reflective type (or a transflective type).
In the case of the transmissive type, the light source and the observation point are on the opposite side across the tape, i.e., the patterned optically anisotropic layer, and the light emitted from the polarized light source produced using a polarizing filter or the like has a birefringence pattern. Different elliptically polarized light is emitted in the plane through the article, and information is visualized by passing through a polarizing filter on the observation point side. Here, the polarizing filter may be a linear polarizing filter, a circular polarizing filter, or an elliptical polarizing filter, and the polarizing filter itself may have a birefringence pattern or a dichroic pattern.

  In the case of the reflective type, both the light source and the observation point are on one side as viewed from the patterned optically anisotropic layer, and the reflective layer is on the opposite side of the tape as viewed from the patterned optically anisotropic layer. . Light emitted from a polarized light source manufactured using a polarizing filter, etc. passes through the tape, is reflected by the reflective layer, passes through the tape again, and different elliptically polarized light is emitted in the plane. Visualize the information by passing it through. Here, the polarizing filter may be a linear polarizing filter, a circular polarizing filter, or an elliptical polarizing filter, and the polarizing filter itself may have a birefringence pattern or a dichroic pattern. The same polarizing filter may be used for the light source and the observation. The reflective layer may also serve as a highly reflective hologram layer or electrode layer.

  Further, the reflective layer may be a semi-transmissive semi-reflective layer that partially reflects light and partially transmits light, in which case the tape can not only visualize both transmissive and reflective images, General information such as characters and images on the lower side of the transmissive semi-reflective layer can be visually recognized without a filter from the upper side of the optically anisotropic layer. The reflective layer may be on the optically anisotropic layer side or the opposite side of the support, but is preferably on the optically anisotropic layer side because there are few restrictions on the support.

  The tape having a birefringence pattern may have a printed layer (a layer having a printed surface). The printing layer generally provides a visible image superimposed on an invisible birefringence pattern, but can be combined with invisible security printing using, for example, a UV fluorescent dye or an IR dye. The printed layer may be above or below the optically anisotropic layer, or may be on the opposite side of the support from the optically anisotropic layer. When performing pattern writing by heat using the tape-shaped recording medium of the present invention, the ink is simultaneously supplied to synchronize the birefringence pattern and the printing by the ink, that is, the boundary line between the regions having different birefringence properties. It is also possible to produce a printed tape with the same borderline.

[Tape-shaped recording medium]
The tape-shaped recording medium of the present invention can be used in the production of a tape having a birefringence pattern by mounting it in a tape writing device. The tape-like recording medium is preferably long. In particular, it is preferable that the tape-shaped recording medium has a long shape that can be stored in a roll shape in a tape cartridge that is detachable from the tape writing device.
A tape-shaped recording medium is a material capable of producing a birefringence pattern. Moreover, it is preferable that it is a material which can produce the tape which has a birefringence pattern using a tape writing device.

  The tape-shaped recording medium may usually be a film or a sheet shape. In addition to the optically anisotropic layer, the tape-shaped recording medium may have a functional layer capable of imparting various secondary functions. Examples of the functional layer include a support, an alignment layer, a reflective layer, an adhesive layer, an additive layer (surface layer), and a release layer.

The tape-shaped recording medium shown in FIG. 1A is an example of a tape-shaped recording medium composed only of the optically anisotropic layer 12 having self-supporting properties.
An optically anisotropic layer is a layer having birefringence and is formed of a uniaxial or biaxially stretched polymer layer, a layer in which an aligned liquid crystal compound is fixed, an aligned organic or inorganic single crystal layer, etc. It only has to be. As the optically anisotropic layer, a layer capable of arbitrarily controlling the optical anisotropy by pattern heating such as hot stamping, thermal head, and infrared laser exposure is preferable. This is because an optically anisotropic layer having such a function can easily obtain a patterned optically anisotropic layer by a method described later. In addition to the patterning step, a pattern can be formed by combining with bleaching or developing with heat or a chemical solution as necessary. In this case, the bleaching and development by heat is preferable because there are few restrictions on the support. The tape-shaped recording medium shown in FIG. 1B is an example in which a reflective layer 13 is attached to an optically anisotropic layer 12 having self-supporting properties.

FIGS. 2A and 2B are examples in which an optically anisotropic layer 12 is provided on a support support 11.
The tape-shaped recording medium shown in FIGS. 3A to 3C is an example having an alignment layer 14. In the case of using a layer formed by applying and drying a solution containing a liquid crystalline compound as an optically anisotropic layer to form a liquid crystal phase and then fixing by polymerization by heating or light irradiation, the alignment layer 14 is a liquid crystalline compound. Functions as a layer to help the orientation of the film.

  4A to 4D are examples of tape-shaped recording media having an additive layer. As described later, the additive layer includes a layer for post-adding a plasticizer and a polymerization initiator to the optically anisotropic layer, a layer for imparting printing (preferably for printing with ink using heat. Layer), hard coat layer for surface protection, water-repellent layer to prevent graffiti from fingerprint attachment and magic pen, conductive layer to provide touch panel properties, shielding layer to be invisible by infrared camera by not transmitting infrared rays, left and right circle A circularly polarized light selective reflection layer that makes an image invisible with a circular polarizing filter by not allowing any polarized light to pass through, a photosensitive layer that imparts photosensitivity to the optically anisotropic layer, an antenna layer that acts as an RFID antenna, and when submerged Submergence detection layer that detects submersion by changing its color, etc., a thermotropic layer that changes color depending on temperature, a colored filter layer that controls the color of the latent image, and a transmissive type light source side polarized / non-polarized light In addition to a polarizing layer that makes a latent image visible when switched, a magnetic layer that imparts magnetic recording properties, and the like, a layer that functions as a mat layer, scattering layer, lubricating layer, photosensitive layer, antistatic layer, resist layer, etc. .

The tape-shaped recording medium according to the present invention may take a form in which a tape having a birefringence pattern formed therefrom can be used as an adhesive tape as it is. FIGS. 5A and 5B show examples in which an adhesive layer and a release layer are added to the tape-shaped recording medium having the structure of FIGS. 2A and 2B, respectively. The adhesive layer may be a layer formed from an adhesive or an adhesive. The release layer only needs to have a function of protecting the adhesive layer until the tape of the present invention is adhered to a desired article. A commercial product in which an adhesive and release paper or a release film are integrated may be used as the adhesive layer and the release layer.
The pressure-sensitive adhesive layer may be a special pressure-sensitive adhesive layer in which the pressure-sensitive adhesive remains on the object in a specific pattern when it is peeled after being once bonded to the object.

  Furthermore, the tape-shaped recording medium according to the present invention may be provided with a separate print release layer capable of printing using heat, preferably printing using ink using heat. FIGS. 6A and 6B show examples in which a print release layer is added to the tape-shaped recording medium having the structure of FIGS. 2A and 2B, respectively. By performing thermal pattern writing using the tape-shaped recording medium in such a form, the patterned optically anisotropic layer is formed from the optically anisotropic layer, and at the same time, the same pattern is printed on the print release layer. Is possible. Since the print release layer can be removed at the time of use (for example, when a tape is applied to an article to which a latent image is to be applied), the latent image can be confirmed without using a polarizing plate until the time of use. . FIG. 6C schematically shows an example having an adhesive layer and a release layer for application to an article together with a print release layer. FIG. 6D shows an example in which the print release layer is an adhesive layer and is bonded to another layer. In this case, the pressure-sensitive adhesive layer is preferably a pressure-sensitive adhesive layer that can be easily peeled off from other layers after pattern formation (in the figure, an optically anisotropic layer, ie, a patterned optically anisotropic layer). 6 (c) and 6 (d) show an example of a reflective type, a transmissive type without a reflective layer may be used in each figure.

  Hereinafter, a tape-shaped recording medium, a method for producing a tape using the recording medium, a tape material, a production method, and the like 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.

[Optically anisotropic layer]
The optically anisotropic layer in the tape-shaped recording medium is a layer having optical characteristics that are not isotropic in that there is at least one incident direction in which retardation is not substantially zero when the retardation is measured.

Examples of the optically anisotropic layer in the tape-shaped recording medium include a layer containing at least one monomer or oligomer and a cured product thereof, a layer containing at least one polymer, a layer containing at least one organic or inorganic single crystal, etc. Can be given.
The optically anisotropic layer containing a polymer is preferable in that it can satisfy different types of requirements such as birefringence, transparency, solvent resistance, toughness, and flexibility. The polymer in the optically anisotropic layer preferably has an unreacted reactive group. This is because it is considered that the unreacted reactive group reacts with heat to cause cross-linking of the polymer chain, whereby the retardation value is changed and the birefringence pattern is easily formed.

The optically anisotropic layer is preferably solid at 20 ° C., more preferably at 30 ° C., and even more preferably at 40 ° C. This is because if it is solid at 20 ° C., it is easy to apply other functional layers, and to transfer and paste onto a support.
In order to apply another functional layer, the optically anisotropic layer preferably has solvent resistance. In this specification, “having solvent resistance” means that the retardation after immersion for 2 minutes in the target solvent is within the range of 30% to 170% of the retardation before immersion, more preferably 50% to 150%. %, Most preferably in the range of 80% to 120%. The target solvent is water, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, N-methylpyrrolidone, hexane, chloroform, ethyl acetate, preferably acetone, methyl ethyl ketone, cyclohexanone, propylene glycol. Among monomethyl ether acetate and N-methylpyrrolidone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, or a mixed solvent thereof is most preferable.

  The optically anisotropic layer may have a retardation of 5 nm or more at 20 ° C., preferably 10 nm or more and 10,000 nm or less, and most preferably 20 nm or more and 2000 nm or less. If the retardation is 5 nm or less, it may be difficult to form a birefringence pattern. If the retardation exceeds 10,000 nm, the error may increase and it may be difficult to achieve practical accuracy.

  The method for producing the optically anisotropic layer is not particularly limited, but a solution containing a liquid crystalline compound having at least one reactive group is applied and dried to form a liquid crystal phase, and then heated or irradiated to polymerize and fix. A method of stretching a layer in which a monomer having at least two reactive groups is polymerized and fixed; a method of stretching a layer made of a polymer having a reactive group in a side chain; or a layer made of a polymer And a method of introducing a reactive group using a coupling agent or the like after stretching. As will be described later, the optically anisotropic layer may be formed by transfer. The thickness of the optically anisotropic layer is preferably 0.1 to 20 μm, and more preferably 0.5 to 10 μm.

[Optically anisotropic layer formed by aligning and fixing a composition containing a liquid crystal compound]
As a method for producing an optically anisotropic layer, a solution containing a liquid crystal compound having at least one reactive group is applied and dried to form a liquid crystal phase, and then heated or irradiated with light to polymerize and fix. This will be described below. This production method is preferable because it is easy to obtain an optically anisotropic layer having a thin film thickness and an equivalent retardation as compared with a production method for obtaining an optically anisotropic layer by stretching a polymer described later.

[Liquid crystal compounds]
In general, liquid crystal compounds can be classified into a rod-shaped type and a disk-shaped type 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.
Note that in this specification, when a layer formed from a composition including a liquid crystal compound is described, the formed layer does not need to include a compound having liquid crystallinity. For example, the low molecular liquid crystalline compound has a group that reacts with heat, light, etc., and as a result, is polymerized or cross-linked by reaction with heat, light, etc., and has a high molecular weight and loses liquid crystallinity. It may be a layer. Further, as the liquid crystal compound, two or more kinds of rod-like liquid crystal compounds, two or more kinds of disc-like liquid crystal compounds, or a mixture of a rod-like liquid crystal compound and a disk-like liquid crystal compound may be used. It is more preferable to use a rod-like liquid crystal compound or a disk-like liquid crystal compound having a reactive group because temperature change and humidity change can be reduced, and at least one of the reactive groups in one liquid crystal molecule is 2 or more. More preferably it is. In the case of a mixture of two or more liquid crystal compounds, at least one preferably has two or more reactive groups.

  Preferably, an unreacted reaction is obtained by using a liquid crystalline compound having two or more reactive groups having different crosslinking mechanisms and polymerizing only a part of the two or more reactive groups by selecting conditions. An optically anisotropic layer containing a polymer having a functional group may be prepared. The crosslinking mechanism is not particularly limited, such as a condensation reaction, hydrogen bonding, or polymerization, but at least one of two or more types is preferably polymerization, and two or more different types of polymerization are more preferably used. In general, in the crosslinking reaction, not only a vinyl group, (meth) acryl group, epoxy group, oxetanyl group, and vinyl ether group used for polymerization, but also a hydroxyl group, a carboxylic acid group, an amino group, and the like can be used.

  In the present specification, a compound having two or more types of reactive groups having different crosslinking mechanisms is a compound that is crosslinked by using stepwise different crosslinking reaction steps. The reactive group according to the above reacts as a functional group. In addition, for example, in the case of a polymer such as polyvinyl alcohol having a hydroxyl group in the side chain, after performing a polymerization reaction for polymerizing the polymer, if the hydroxyl group in the side chain is crosslinked with an aldehyde, two or more different crosslinking mechanisms In the present specification, when a compound having two or more different reactive groups is used, it is preferable that two or more types in the layer are formed at the time when the layer is formed on the support or the like. What is necessary is just a compound which is a compound which has a different reactive group, Comprising: The reactive group can be bridge | crosslinked in steps after that. As a particularly preferred embodiment, it is preferable to use a liquid crystalline compound having two or more polymerizable groups. The reaction conditions for the stepwise crosslinking may be any of a temperature difference, a light (irradiation) wavelength difference, or a polymerization mechanism difference, but it is preferable to use a difference in polymerization mechanism from the viewpoint of easy separation of the reaction, More preferably, it is controlled by the type of initiator used. As a polymerization mechanism, a combination of a radical polymerizable group and a cationic polymerizable group is preferable. A combination in which the radical polymerizable group is a vinyl group or a (meth) acryl group, and the cationic polymerizable group is an epoxy group, an oxetanyl group or a vinyl ether group is particularly preferable because the reactivity can be easily controlled. Examples of reactive groups are shown below.

  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. Examples of the rod-like liquid crystalline compound include those described in JP-A-2008-281989.

  Although the specific example of a rod-shaped liquid crystalline compound is shown below, this invention is not limited to these. 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).

As another aspect of the present invention, there is an aspect in which a discotic liquid crystal is used for the optically anisotropic layer. The optically anisotropic layer is preferably a layer of a low molecular weight discotic liquid crystalline compound such as a monomer or a polymer layer obtained by polymerization (curing) of a polymerizable discotic liquid crystalline compound. Examples of the discotic liquid crystalline compound include C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physicslett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and the cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. , 1794 (1985), J. Am. Zhang et al., J. Am. Chem. Soc. 116, page 2655 (1994), and azacrown-based and phenylacetylene-based macrocycles. The above discotic liquid crystalline compounds generally have a discotic mother nucleus with a molecular center, and a structure in which a linear alkyl group, alkoxy group, substituted benzoyloxy group or the like (L) is substituted in a radial manner In other words, it includes liquid crystallinity and is generally called disc-shaped liquid crystal. However, when such an aggregate of molecules is uniformly oriented, it exhibits negative uniaxiality, but is not limited to this description. Examples of the discotic liquid crystalline compound include those described in JP-A-2008-281989.
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.

  When two or more optically anisotropic layers made of a composition containing a liquid crystalline compound are laminated, the combination of the liquid crystalline compounds is not particularly limited, and a laminate of layers made of a rod-like liquid crystalline compound, a disk-like liquid crystal Any of a laminate composed of a layer comprising a composition containing a crystalline compound and a layer comprising a composition comprising a rod-like liquid crystalline compound or a laminate comprising all layers comprising a discotic liquid crystalline compound may be used. 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.

[solvent]
An organic solvent is preferably used as a solvent used for preparing a coating liquid when a composition containing a liquid crystalline compound is applied as a coating liquid to, for example, the surface of a support or an alignment layer described later. Examples of organic solvents include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.

[Fixed orientation]
The alignment of the liquid crystalline compound is preferably fixed by a crosslinking reaction of a reactive group introduced into the liquid crystalline compound, and more preferably by a polymerization reaction of the reactive group. 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 coating solution. Light irradiation for the polymerization of the liquid crystalline compound is preferably performed using ultraviolet rays. 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.

[Optical alignment by polarized irradiation]
The optically anisotropic layer may be a layer that exhibits or increases in-plane retardation due to photo-alignment by irradiation with polarized light. The polarized light irradiation can be performed with reference to the descriptions in paragraphs “0091” to “0092” of Japanese Patent Application Laid-Open No. 2009-69793, the description of Japanese Translation of PCT International Publication No. 2005-513241 (International Publication WO2003 / 054111), and the like.

[Fixing of alignment state of liquid crystal compound having radical reactive group and cationic reactive group]
As described above, it is also preferable that the liquid crystalline compound has two or more kinds of reactive groups having different polymerization conditions. In this case, it is possible to produce an optically anisotropic layer containing a polymer having an unreacted reactive group by selecting conditions and polymerizing only a part of the 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.

[Horizontal alignment agent]
In the composition for forming the optically anisotropic layer, compounds represented by the general formulas (1) to (3) described in paragraphs “0098” to “0105” of JP2009-69793A and general By containing at least one fluorine-containing homopolymer or copolymer using the monomer of formula (4), the molecules of the liquid crystal compound can be substantially horizontally aligned. In the present specification, “horizontal alignment” means that, in the case of a rod-like liquid crystal, the molecular long axis and the horizontal plane of the transparent support are parallel, and in the case of a disc-like liquid crystal, the circle of the core of the disc-like liquid crystal compound. The horizontal plane of the board and the transparent support is said to be parallel, but it is not required to be strictly parallel. In the present specification, an orientation with an inclination angle of less than 10 degrees with the horizontal plane is meant. And 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.
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) described in paragraphs “0098” to “0105” of JP-A-2009-69793 may be used alone or in combination of two or more. You may use together.

[Optically anisotropic layer produced by stretching]
The optically anisotropic layer may be prepared by stretching a polymer. The optically anisotropic layer preferably has at least one unreacted reactive group, but when preparing such a polymer, the polymer having a reactive group may be stretched in advance, A reactive group may be introduced into the optically anisotropic layer using a coupling agent or the like. Features of the optically anisotropic layer obtained by the stretching method include low cost and self-supporting property (no support is required for forming and maintaining the optically anisotropic layer).

[Two or more optically anisotropic layers]
As described above, the tape-shaped recording medium 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 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. A pattern having a large retardation can be produced by using two or more optically anisotropic layers whose slow axes are directed in substantially the same direction.

  As a method for producing a tape-shaped recording medium including two or more optically anisotropic layers, a tape is formed by using another tape-shaped recording medium as a transfer material, in which the optically anisotropic layer is directly formed on the tape-shaped recording medium. And a method such as transferring an optically anisotropic layer onto the recording medium. Of these, the method of transferring the optically anisotropic layer onto the tape-shaped recording medium using the tape-shaped recording medium as a transfer material is more preferable.

[Post-treatment of optically anisotropic layer]
Various post-treatments may be performed to modify the produced optically anisotropic layer. 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. Further, 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. 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 layer is added to the coating solution of the layer and the additive layer is immersed in the optically anisotropic layer.

  The additive layer formed on the optically anisotropic layer includes a photosensitive resin layer such as a photoresist, a scattering layer for controlling reflection gloss, a hard coat layer for preventing scratches on the surface, fingerprint adhesion, magic, etc. It may be shared with a surface layer such as a water / oil repellent layer for preventing graffiti and an antistatic layer for preventing dust from being charged. The photosensitive resin layer preferably contains at least one polymer and at least one photopolymerization initiator. Although there is no limitation in particular as a polymer, in order to give hard-coat property, the material with high Tg is preferable.

[Support]
Each tape-shaped recording medium may have a support for the purpose of maintaining mechanical stability. The support in the tape-shaped recording medium may be the support in the tape as it is, and the support in the tape is separate from the support in the tape-shaped recording medium (in or after the birefringence pattern is formed, It may be provided instead of or in addition to the support. The support is not particularly limited and may be rigid or flexible. However, when the support in the tape-shaped recording medium is directly used as the support in the tape, the support is usually flexible.
The rigid support is not particularly limited, but is a known glass plate such as a soda glass plate having a silicon oxide film on its surface, a low expansion glass, a non-alkali glass, a quartz glass plate, a metal such as an aluminum plate, an iron plate, or a SUS plate. A board, a resin board, a ceramic board, a stone board, etc. are mentioned. There are no particular limitations on the flexible support, but cellulose esters (eg, cellulose acetate, cellulose propionate, cellulose butyrate), polyolefins (eg, norbornene polymers), poly (meth) acrylic acid esters (eg, polymethyl) Methacrylate), polycarbonate, polyester and polysulfone, norbornene-based plastic films, paper, aluminum foil, cloth, and the like. In view of ease of handling, the thickness of the rigid support is preferably 100 to 3000 μm, and more preferably 300 to 1500 μm. As a film thickness of a flexible support body, 3-500 micrometers is preferable and 10-200 micrometers is more preferable. The support preferably has heat resistance sufficient not to be colored or deformed by baking to be described later. It is also preferable that the support itself has a reflecting function instead of the reflecting layer described later.
Further, the support itself may have a function as a release layer.

[Alignment layer]
As already described, an alignment layer may be used to form the optically anisotropic layer. The alignment layer is generally provided on a support or temporary support or an undercoat layer coated on the support or temporary support. 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 layer subjected to a rubbing treatment of an organic compound (preferably a polymer), a photo-alignment layer that exhibits liquid crystal alignment by polarized irradiation represented by azobenzene polymer and polyvinyl cinnamate, and an oblique layer of an inorganic compound. A vapor deposition layer, a layer having a microgroove, and a cumulative film formed by Langmuir-Blodgett method (LB film) such as ω-tricosanoic acid, dioctadecylmethylammonium chloride and methyl stearylate, or application of an electric or magnetic field Thus, a layer in which the dielectric is oriented can be exemplified. In the rubbing mode, the alignment layer preferably contains polyvinyl alcohol, and it is particularly preferable that the alignment layer can be cross-linked with at least one of the upper and lower alignment layers. As a method for controlling the orientation direction, a photo-alignment layer and a microgroove are preferable. The photo-alignment layer is particularly preferably a material that exhibits orientation by dimerization, such as polyvinyl cinnamate, and the microgroove is particularly preferably an embossing treatment of a master roll prepared in advance by machining or laser processing.

[Reflective layer]
The tape-shaped recording medium may have a reflective layer for producing a birefringent pattern that can be more easily identified. Although it does not specifically limit as a reflection layer, A thing without depolarizing property is preferable, for example, metal layers, such as aluminum and silver, the reflection layer by a dielectric multilayer film, and the printing layer which has glossiness are mentioned. A transflective layer having a transmittance of 30 to 95% and a reflectance of 30 to 95% can also be used. The transflective layer is preferable because the method of reducing the thickness of the metal layer can be manufactured at low cost. On the other hand, since the transflective layer made of metal has absorption, a dielectric multilayer film that can control transmittance and reflectance without absorption is preferable from the viewpoint of light utilization efficiency.

[Adhesive layer]
The tape-like recording medium is also preferably in the form of an adhesive tape having an adhesive layer. The material of the adhesive layer is not particularly limited, but is preferably a material having adhesiveness even after undergoing a heating step for producing a birefringence pattern. The adhesive layer may be formed on the tape after the birefringence pattern is formed.

[Release layer]
In order to protect the adhesive layer until the tape of the present invention is adhered to a desired article, it is preferable to have the release layer. Moreover, as a method for forming the adhesive layer and the release layer, a method in which the adhesive layer formed on a release layer made of release paper or a release film is bonded to the tape-shaped recording medium is preferable.

[Print release layer]
In order to obtain a form in which the latent image can be confirmed without a polarizing plate, a print release layer capable of printing using heat may be separately provided on the tape-like recording medium. The print peeling layer should just be provided as a layer for printing. After the tape of the present invention is adhered to an object, the printed release layer is preferably a layer that can be easily released from other layers so that the provided printing can be removed from the tape. A weak adhesive layer may be formed between the release layer and the tape-shaped recording medium.

[Surface layer]
The surface layer includes a scattering layer that controls reflection gloss, a hard coat layer that prevents scratches on the surface, a water and oil repellent layer that prevents graffiti such as fingerprint attachment and magic, and an antistatic layer that prevents dust from being charged. Can be mentioned. As the scattering layer, an embossed surface irregularity layer and a mat layer containing a mat agent such as particles are preferable. The hard coat layer is preferably a layer obtained by polymerizing a layer containing at least one bifunctional or higher polymerizable monomer by light irradiation or heat. The surface layer may be provided as the additive layer, for example.

[Coating method]
Each layer such as an optically anisotropic layer and an orientation 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, or a gravure. It can be formed by coating by a coating method or an extrusion coating method (US Pat. No. 2,681,294). Two or more layers may be applied simultaneously. The methods of simultaneous application are 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).

[Preparation of birefringence pattern]
A tape having a birefringence pattern can be produced by performing at least heating (thermal pattern writing) on the tape-shaped recording medium.
[Partial heating (thermal pattern writing)]
The heating temperature at the time of heating the partial region is not particularly limited as long as it is a temperature that causes a difference in the retardation between the heated portion and the non-heated portion. In particular, when it is desired to set the retardation of the heating part to substantially 0 nm, it is preferable to heat at a temperature equal to or higher than the temperature at which the retardation of the optically anisotropic layer of the birefringence pattern builder used disappears. On the other hand, the heating temperature is preferably less than the temperature at which the optically anisotropic layer is burned or colored. In general, heating at about 180 ° C. to 260 ° C. may be performed, 190 ° C. to 250 ° C. is more preferable, and 200 ° C. to 230 ° C. is more preferable.
On the other hand, when the above-mentioned optically anisotropic layer is produced by heating, it is preferably heated at a temperature not higher than the temperature at which the letter does not disappear. On the other hand, the heating temperature is preferably higher in order to facilitate the reaction. In general, heating at about 60 ° C. to 180 ° C. may be performed, and 80 ° C. to 140 ° C. is more preferable.

  Heating can be performed using a tape writing device, particularly a tape writing device having a thermal head. For example, thermal heads are described in Japanese Patent Application Laid-Open Nos. 2004-9327 and 2004-25771. As the apparatus, in addition to the tape printing apparatus described in JP-A-8-267881, any of a commercially available tape writing apparatus having a thermal head or similar heating means may be used.

[Anti-adhesion layer]
When heating is performed by bringing the heating means into contact, it is also preferable that the birefringence pattern builder has an adhesion preventing layer for preventing adhesion to these heat sources. As the adhesion preventing layer, a layer composed of a binder, inorganic fine particles, a lubricant, a surfactant, a crosslinking agent and the like can be used.
Examples of the binder include water-soluble polymers such as polyvinyl alcohol, vinyl acetate-acrylamide copolymer, methyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, gelatins, polyvinyl pyrrolidone, polyacrylamide derivatives, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber. It can be formed using a water-insoluble polymer such as latex or methyl acrylate-rubber latex.
Examples of the inorganic fine particles include colloidal silica, barium sulfate, zinc oxide, magnesium oxide, zirconium oxide, and alumina. The average particle size of the inorganic fine particles is preferably 0.01 μm to 0.25 μm.

Examples of the lubricant include zinc stearate, calcium stearate, paraffin wax, and polyethylene wax.
Examples of the surfactant include sulfosuccinic acid-based alkali metal salts and fluorine-containing surfactants. Specifically, sodium salts such as di (2-ethylhexyl) sulfosuccinic acid and di (n-hexyl) sulfosuccinic acid. And ammonium salts.
Examples of the crosslinking agent include epoxy compounds, blocked isocyanates, vinyl sulfone compounds, aldehyde compounds, methylol compounds, boric acid, carboxylic acid anhydrides, silane compounds, and the like.

[Treatment of reacting at least part of unreacted reactive groups]
The treatment for reacting at least a part of the unreacted reactive group is a treatment for reacting at least a part of the unreacted reactive group in the optically anisotropic layer after performing the above-mentioned partial heating step. Say. As an effect of the treatment, it is expected that the crosslinking in the optically anisotropic layer proceeds and the durability and heat resistance of the birefringence pattern are improved. The treatment may be performed on the entire area of the birefringence pattern builder.
Although it does not specifically limit as a process which reacts at least one part of an unreacted reactive group, For example, whole surface exposure, whole surface heating, etc. are mentioned. In the case of using the whole surface heating, it is preferably performed at a lower temperature than the partial heating.

[Reaction treatment by full exposure]
The irradiation wavelength of the light source in the reaction treatment by the entire exposure preferably has a peak at 250 to 450 nm, and more preferably has a peak at 300 to 410 nm. In the case where a step is simultaneously formed by the photosensitive resin layer, it is also preferable to irradiate light in a wavelength region that can cure the resin layer (eg, 365 nm, 405 nm, etc.). Specifically, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a blue laser, and the like can be given. Usually 3~2000mJ / cm ² about the preferred amount of exposure, and more preferably 5~1000mJ / cm ² or so, more preferably 10 to 500 mJ / cm ² or so, and most preferably at about 10 to 300 mJ / cm ² .

[Reaction treatment by heating the entire surface]
The reaction treatment by heating the entire surface may be performed at a temperature lower than the retardation disappearance temperature of the optically anisotropic layer of the birefringence pattern builder used. Generally, heating at about 120 to 180 ° C. may be performed, 130 to 170 ° C. is more preferable, and 140 to 160 ° C. is more preferable, but the required birefringence (retardation) and the optically anisotropic layer to be used What is necessary is just to determine suitably according to the thermosetting reactivity of these.

[Finish heat treatment]
In the present invention, after the pattern is fixed by the treatment of reacting at least a part of the unreacted reactive groups, the remaining unreacted reactive groups are further reacted to increase 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.

[Thermal pattern writing using a tape writing device]
An example of the overall control configuration when performing thermal pattern writing using a tape writing apparatus is shown in FIGS.
The system controller is provided with an operation unit provided with a keyboard and other control buttons. You can specify the character string to be written on the label directly with the keyboard and its size. The display unit can display the input content or the status of the tape writing device. The external interface exchanges data through the interface and enables external control. If the contents to be written are determined, the data is sent to the print controller. The print controller sends data to the thermal head controller and generates heat based on this data. At the same time, a drive signal is sent from the print controller to the drive unit, and a recording material (tape-shaped recording medium) is sent. As a result, a two-dimensional thermal pattern is recorded on the recording material. In addition to conveying the recording material, the drive unit may have an operation such as cutting of the recording material and a function of sending a monitor signal of the state of the recording material to the print controller, although not shown.

  Next, an example of the thermal head portion will be described. A thermal head is usually a wafer on which a heating resistor is formed, a driver IC that drives the heating resistor, an external wiring board for inputting drive signals from a printer, and a heat sink that functions as a heat sink and support. It consists of When the electrode is energized, the resistor generates heat, and the heat is transmitted to the thermal recording medium through the protective film and recorded. (Ceramics 42 (2007) No. 1 p.54) Various thermal heads are available depending on the application, and any of them may be used in the present invention. A preferable example for the tape is KSH128EA-STD manufactured by Kyocera Corporation. A thermal head is generally a head in which heating resistors are arranged in a one-dimensional array. The density of KSH128EA-STD manufactured by Kyocera Corporation is 203 dpi. For higher quality images, a head with a higher density may be selected.

  In order for the heat of the thermal head to be transferred to the recording material, the thermal head and the recording material need to be closely adhered. It is desirable to dispose a roller at a position facing the heat generating portion of the thermal head and sandwich the recording material between the roller and the thermal head as shown in FIG.

When a tape-like recording medium having a printing layer is used as the recording material, the writing ink supply material is sandwiched between the recording material and a roller and a thermal head as shown in FIG. Ink can be transferred.
For the driving of the thermal head and the conveyance of the recording material, for example, a known technique described in JP-A-7-290800 can be referred to.

The recording material is preferably supplied in the form of a roll wound in a tape writing device. In the tape writing apparatus, it is preferable that the recording material (tape-shaped recording medium) is detachably mounted in the form of a recording material cassette, that is, a tape cartridge.
In the tape writing device, it is only necessary that the recording material is drawn from the recording material supply unit, passed through the roller portion at the position facing the thermal head, and led to the driving roller. The opposing roller and / or the driving roller unit may be provided in the tape writing device so as not to be detachable, but may be included in the recording material cassette. When the recording material cassette includes an opposing roller and / or a driving roller unit, the driving roller is applied with a driving force by engaging with a driving mechanism outside the cassette.
The cassette may comprise a supply for writing ink supply material. In this case, a tape-like form is desirable. At the position of the thermal head, it is held so as to overlap the recording material (FIG. 11). As for the drive mechanism of the tape that supplies ink, it is desirable to supply the tape by the rotation of the drive roller, as with the recording material.

Further, after drawing with a thermal head, the pattern can be fixed by irradiating purple to ultraviolet light (wavelength 250 to 450 nm is preferable, wavelength 300 to 410 nm is more preferable) (FIG. 12). ). In this case, although not shown, it is possible to control the light of the light source by receiving the signal from the light source control unit that has received the signal from the printer controller. Various light sources can be used as the light source, and it is particularly preferable to use an LED including the aforementioned light.

[Tape with birefringence pattern]
The tape-shaped recording medium on which the thermal pattern is written has a birefringence pattern and is sandwiched between two polarizing plates, or only when a polarizing plate or a transflective layer is passed through a polarizing plate. It has a visible latent image. Taking advantage of this property, the tape obtained as described above can be used, for example, as a forgery prevention means. That is, when the birefringence pattern is copied without passing through the polarizing plate, nothing appears, and conversely, when 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.
In particular, a tape including a semi-transmissive / semi-reflective layer can be visually recognized even if it is attached from above a print or photograph printed on paper.

  The birefringence pattern is not only a security effect due to the latent image, but can be linked with digital information by encoding the pattern, for example, as a barcode or QR code, and can also be digitally encrypted. Become. Security can be enhanced even in combination with printing with invisible ink such as UV fluorescent ink and IR ink. Further, when peeled off, a combination with an unsealing prevention label function in which a part of the adhesive remains as a pattern on the object is also possible.

  Tape with birefringence pattern is not only security but also combined with other functions, such as product information display label function such as price tag and expiration date, submerged label function by printing ink that changes color when put on water, It can also be combined with a security insurance policy or ballot.

  When a tape having a birefringence pattern is used as an adhesive label, the label may be peeled off from the object and reused, which may reduce security. Therefore, it is preferable. The brittle processing method is not particularly limited, and examples thereof include a method of embrittlement of the support itself and a method of cutting a label.

The present invention will be described more specifically with reference to the following 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 specific examples.

(Preparation of optically anisotropic medium 1)
(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 (%)
──────────────────────────────────――
Polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.) 3.21
Polyvinylpyrrolidone (Luvitec K30, manufactured by BASF) 1.48
Distilled water 52.10
Methanol 43.21
──────────────────────────────────――

(Preparation of coating liquid LC-1 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid LC-1 for an optically anisotropic layer. LC-1-1 is a liquid crystal compound having two reactive groups. One of the two reactive groups is an acrylic group which is a radical reactive group, and the other is an oxetane group which is a cationic reactive group. is there. LC-1-2 is a discotic compound added for the purpose of orientation control. Tetrahedron Lett. It was synthesized according to the method described in Journal, Vol. 43, page 6793 (2002).
──────────────────────────────────――
Coating composition for optically anisotropic layer (%)
──────────────────────────────────――
Bar-shaped liquid crystal (LC-1-1) 32.59
Horizontal alignment agent (LC-1-2) 0.02
CPI100-P (manufactured by Sun Apro Co., Ltd.) 0.66
IRGANOX 1076 (Ciba Specialty Chemicals Co., Ltd.)
0.07
Methyl ethyl ketone 66.67
──────────────────────────────────――

(Preparation of surface layer coating liquid AD-1)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid AD-1 for a surface layer (surface protective layer).
────────────────────────────────── ――――――
Surface layer coating solution composition (% by mass)
────────────────────────────────── ――――――
MH-101-5 (manufactured by Fujikura Kasei Co., Ltd.) 7.51
2-Trichloromethyl-5- (p-styrylstyryl) 1,3,4-oxadiazole 0.48
Megafuck F-176PF (manufactured by DIC Corporation) 0.01
Methyl ethyl ketone 92.00
────────────────────────────────── ――――――

Aluminum is deposited to a thickness of 60 nm on a support of a polyethylene naphthalate film (Teonex Q83, manufactured by Teijin DuPont Films Co., Ltd.) having a thickness of 50 μm, and an alignment layer coating solution AL-1 is sequentially formed thereon using a wire bar. Was applied and dried. The dry film thickness was 0.5 μm. Next, rubbing in the MD direction, the coating liquid LC-1 for optically anisotropic layer was applied using a wire bar, dried at a film surface temperature of 90 ° C. for 2 minutes to form a liquid crystal phase, and then 160 mW under air. / Cm ² air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) is irradiated with ultraviolet rays to fix its orientation state and form an optically anisotropic layer having a thickness of 5 μm. Sample TRC-1 was produced. 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. Further, the surface layer coating liquid AD-1 was applied and dried to form a 1.2 μm surface layer, whereby an optically anisotropic medium 1 was produced.

(Production of tape-shaped recording medium 1 and tape cartridge 1)
Acrylic water-soluble adhesive liquidine AR-2090 (manufactured by Big Technos Co., Ltd.) is applied onto a release paper binder sheet 75S-518T (manufactured by Fujimori Kogyo Co., Ltd.), dried at 100 ° C. and separated with a 35 μm adhesive layer. A mold sheet 1 was formed. Next, the surface of the optically anisotropic medium 1 on the polyethylene naphthalate film side is bonded to the surface of the release layer with adhesive layer 1 on the adhesive layer side, and this is slit into a width of 12 mm. Was made. Furthermore, a tape cartridge 1 was produced using this tape-shaped recording medium 1. At this time, the ink ribbon that was normally attached to the tape cartridge was prepared without being attached.

(Production of tape-shaped recording medium 2 and tape cartridge 2)
A polypropylene film having a thickness of 12 μm was pressure-bonded to the surface layer side surface of the optically anisotropic medium 1, and the release sheet 1 with an adhesive layer was bonded to the surface of the polyethylene naphthalate film side. The tape-like recording medium 2 was produced by slitting this to a width of 12 mm. Further, a tape cartridge 2 was produced using this tape-shaped recording medium 2 and a black ink ribbon R4911-90 (J) (manufactured by Nippon Brady Co., Ltd.).

(Example 1: Production of birefringence patterning tape 1A)
A thermal head and a driving circuit thereof according to an embodiment of Japanese Patent Laid-Open No. 7-81123 were prepared. The control unit 16 described in the embodiment has substantially the same function as the drive control unit in FIG. 7 of the present application, and performs the control for tape conveyance described in FIG. The drive current was set such that the tape transport speed was 2 μm / sec and the applied power was 200 mJ / mm ² . Under this condition, the temperature of the heated portion by the thermal head becomes 200 ° C. Further, the tape cartridge 1 was attached to a tape writing device, and a 7 mm square pattern was thermally written under these conditions to obtain the phase difference patterning tape 1A of Example 1. When a polarizing plate HLC2-2518 (manufactured by Sanritz Co., Ltd.) was held over and observed, it was confirmed that a 7 mm square silver image was drawn on a reddish purple background. The obtained image is shown in FIG.

(Example 2: Production of birefringence patterning tape 1B)
Immediately after being discharged from the tape writing device, the birefringent patterning tape 1A is irradiated with ultraviolet rays using a mask aligner M-3L (manufactured by Mikasa Co., Ltd.), and the birefringent patterning tape 1B of Example 2 is used. Got. The illuminance of ultraviolet rays used at this time was 20 mW / cm ² in the UV-A region (integration of wavelengths from 320 nm to 400 nm), and the irradiation amount was 100 mJ / cm ² in the UV-A region. Furthermore, using a clean oven DES82 (manufactured by Yamato Scientific Co., Ltd.), the birefringent patterning tape 1A and the birefringent patterning tape 1B were simultaneously baked at 200 ° C. for 60 minutes. When observed while holding the polarizing plate HLC2-2518 (manufactured by Sanritz Co., Ltd.), the birefringent patterning tape 1B did not change with a 7 mm square silver image on the reddish purple background. 1A became entirely silver. That is, it was found that heat resistance was imparted to the birefringence patterning tape 1B by exposure. The obtained image is shown in FIG.

(Example 3: Production of birefringence patterning tape 2)
Using the tape writing device set to the same conditions as in Example 1, the tape cartridge 2 is further attached to the tape writing device, and a 7 mm square pattern is thermally written under these conditions to obtain the birefringent patterning tape 2 of Example 3. Obtained. The birefringent patterning tape 2 was printed with a black square of 7 mm square that can be visually confirmed, and the print could be peeled off by peeling off the polypropylene film on the surface. Furthermore, when observing the polarizing plate HLC2-2518 (manufactured by Sanritz Co., Ltd.), it was confirmed that a 7 mm square silver image was drawn on a reddish purple background. The obtained image is shown in FIG.

DESCRIPTION OF SYMBOLS 11 Support body 12 Optically anisotropic layer 13 Reflective layer or transflective layer 14 Orientation layer 15 Adhesive layer 19 Additive layer or surface layer 21 Release layer 22 Print release layer

Claims (15)

A tape-like recording medium for use in a tape writing device having a thermal head,
Birefringence pattern can be formed by thermal writing with a thermal head .
An optically anisotropic layer prepared by applying a solution containing a liquid crystalline compound having at least one reactive group and drying to form a liquid crystal phase, followed by heating or light irradiation;
A tape-shaped recording medium in which the liquid crystalline compound has at least a radical reactive group and a cationic reactive group. 2. The tape-shaped recording medium according to claim 1 , wherein 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. The tape-shaped recording medium according to claim 1 or 2, wherein the tape-shaped recording medium includes a release layer, an adhesive layer, and the optically anisotropic layer in this order . The tape-shaped recording medium according to claim 3, comprising a reflective layer between the adhesive layer and the optically anisotropic layer. The tape-shaped recording medium according to any one of claims 1 to 4, further comprising an adhesion preventing layer for preventing adhesion to the thermal head, wherein the adhesion preventing layer includes a binder and a lubricant. The tape-shaped recording medium according to any one of claims 1 to 5 , wherein a printing release layer capable of printing with ink utilizing heat on the surface is included on an outermost surface. A tape-like recording medium for use in a tape writing device having a thermal head,
Birefringence pattern can be formed by thermal writing with a thermal head.
A tape-like recording medium comprising a print release layer on the outermost surface, which can be printed with ink utilizing heat on the surface. The tape writer is
A tape writing apparatus comprising: a tape-shaped recording medium supply unit; a drive unit for feeding the tape-shaped recording medium from the supply unit; and a thermal head unit for applying heat to a part of the fed tape-shaped recording medium, The tape-shaped recording medium according to any one of claims 1 to 7, which is a tape writing device having a light source capable of exposing a portion of the tape-shaped recording medium after passing through the thermal head. The tape writer is
Tape-shaped recording medium supply unit, drive unit for feeding out the tape-shaped recording medium from the supply unit, thermal head unit for applying heat to a part of the fed-out tape-shaped recording medium, and tape-like recording in the thermal head unit A tape writing apparatus having an ink supply material supply unit for supplying ink to a medium supply unit, comprising a light source capable of exposing a portion of the tape-shaped recording medium after passing through the thermal head It is a tape writing device, The tape-shaped recording medium as described in any one of Claims 1-7. The tape-shaped recording medium according to claim 8 or 9, wherein the heat applied by the thermal head unit is 180 ° C to 260 ° C. A tape cartridge having the tape-like recording medium according to claim 1 and capable of being detachably attached to a tape writing device. 12. A tape cartridge according to claim 11, comprising a writing ink supply material. A tape formed from the tape-shaped recording medium according to claim 6 or 7 ,
A patterned optically anisotropic layer having two or more regions having different birefringence in a pattern, and a tape printed with ink having the same boundary line as the boundary line of the region. A tape writing apparatus comprising: a tape-shaped recording medium supply unit; a drive unit for feeding the tape-shaped recording medium from the supply unit; and a thermal head unit for applying heat to a part of the fed tape-shaped recording medium, A tape writing apparatus having a light source capable of exposing a portion of a tape-shaped recording medium after passing through the thermal head. Tape-shaped recording medium supply unit, drive unit for feeding out the tape-shaped recording medium from the supply unit, thermal head unit for applying heat to a part of the fed-out tape-shaped recording medium, and tape-like recording in the thermal head unit A tape writing apparatus having an ink supply material supply unit for supplying ink to a medium supply unit, comprising a light source capable of exposing a portion of the tape-shaped recording medium after passing through the thermal head Tape writing device.

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