JPH04361084A - Optical record sheet coated with agent containing color-changing microcapsule and optical recording method using it - Google Patents

Abstract

PURPOSE:To form excellent colored record image having high resolution and density gradating property easily and at low cost by using an optical record sheet coated with agent containing light responsive micro capsule and a simple device. CONSTITUTION:A base material paper 1 is coated with an agent CC containing microcapsule made by dispersing and mixing a microcapsule MC and a developer 3 in a binding resin 2 so as to form a monocolor optical record paper P. A dye precursor 8 is housed in the microcapsule MC. A graft polymer 7 having optical undissociative group is grafted on the inner periphery of a wall material 5 consisting of porous material as a base of a capsule film Cf. The monocolor optical record paper P is irradiated, being heated, with light having specific wavelength in accordance with record data and material permeability of the capsule film Cf is increased so as to diffuse the dye precursor 8 and the developer 3 reciprocally.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD OF THE INVENTION This invention relates to an optical recording sheet using microcapsules made of a photoresponsive composite film whose diffuse permeability of substance molecules can be controlled by optical stimulation, and an optical recording method thereof.

0002

[Prior art and its problems] Conventionally, various methods have been proposed as recording methods capable of full-color recording, such as an electrophotographic method, a thermal transfer method, an inkjet method, a photoresponsive microcapsule method, and a heat-developable silver salt method. It is also put into practical use.

By the way, the main qualities required for a full-color recorded image include resolution, density gradation, color purity, and degree of color overlap. In addition, the performance of the recording device must be high recording speed, quiet, low running costs, small and lightweight, be able to use plain paper and recycled paper, and be maintenance-free. has been done.

However, a full-color recording device that substantially satisfies the above-mentioned requirements has not yet been realized. For example, in the thermal transfer method, in addition to the recording paper, it is necessary to separately prepare a film that carries a developer such as toner or ink, which increases the size of the device and is inferior in terms of maintenance workability and running cost. Furthermore, the system using pressure fixing type capsule toner has the problem that the apparatus becomes large because it is necessary to apply extremely large pressure.

[0005]

OBJECTS OF THE INVENTION The present invention has been made in view of the problems of the prior art described above, and it is possible to produce high-quality full-color recorded images with high resolution and density gradation using a simple device in a maintenance-free and inexpensive manner. An object of the present invention is to provide an optical recording sheet that can be obtained and an optical recording method using the same.

[0006]

[Summary of the Invention] There are two main points of this invention, one of which is that the above-mentioned purpose is to provide microcapsules in a binder resin with a capsule membrane that changes material permeability upon irradiation with light. A microcapsule-containing agent formed by dispersing and mixing
An optical recording sheet formed by adhering to the surface of a support sheet, wherein the capsule membrane is grafted with a polymeric substance having a site that dissociates and ionizes when irradiated with light on the peripheral surface of a wall material made of a porous material. One of the reactive substances that are formed by polymerization and mixed with each other to cause a coloring reaction is dispersed and mixed in the binder resin, and the other reactive substance is incorporated in the microcapsule, and light of a specific wavelength is emitted. Provided is an optical recording sheet coated with a color-changing microcapsule-containing agent, characterized in that the material permeability of the capsule film is increased by irradiation with the reactive material to cause a coloring reaction by diffusing and mixing the reactive material with each other. This is achieved by doing so.

Another point of the main point of the present invention is that the above-mentioned object is to absorb light of a specific wavelength onto the peripheral surface of a wall material made of a porous material and a reactive substance that causes a coloring reaction when mixed with each other. A microcapsule-containing agent is prepared by dispersing and mixing in a binder resin microcapsules that are made of a capsule membrane graft-polymerized with a polymeric substance that has a site that dissociates and ionizes and contains the other of the reactive substances; An optical recording method using an optical recording sheet adhered to the surface of a support sheet, the method comprising: irradiating the microcapsule-containing agent on the optical recording sheet with image light containing light of the specific wavelength according to recording information; A color-changing microcapsule-containing agent is applied, which increases the substance permeability of the capsule membrane to cause a coloring reaction by mutual diffusion of the reactive substance, thereby forming a recorded image on the optical recording sheet. This point is achieved by providing an optical recording method using an optical recording sheet made of

[0008]

[Embodiments of the Invention] This invention will be described below in the first to fourth embodiments.
This will be explained in detail based on examples. <First Embodiment> FIG. 1 is a schematic cross-sectional view showing the structure of a monochrome optical recording paper as a first embodiment. A microcapsule-containing agent CC is placed on the surface of the base paper 1 as a support sheet.
It has been painted. In addition to paper, various films can be used as the support sheet. Microcapsule-containing agent CC
is formed by dispersing and mixing, in a binder resin 2, microcapsules MC, a color developer 3, which is a reactive substance that causes a color reaction when mixed with each other, and its auxiliary substance 4.

The binder resin 2 is a material for holding the microcapsules MC, the color developer 3, and the auxiliary substance 4 on the base paper 1, and therefore undergoes a phase transition so that it becomes a gel state at room temperature. A material with a high temperature (Tc) is used. As such a binder resin, for example, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, styrene-butadiene latex, etc. can be suitably used.

[0010] Microcapsule MC is constructed as follows. As shown in FIG. 2, the capsule membrane Cf of the microcapsule MC is based on a wall material 5 of a porous material and has a large number of micropores 6. In this example, a synthetic polymer material is used as the material for the wall material 5, and the porous sponge-like wall material 5 is formed. The thickness of the wall material 5 is set to approximately several tens of microns (μm) to several tens of nanometers (nm). As the polymer material forming the wall material 5, general polymer materials such as polyamide, polyester, polyurethane, polymethyl methacrylate, polyurea, polystyrene, polyvinyl alcohol, etc. can be suitably used.

The inner peripheral surface of the wall material 5 is coated with a photoresponsive polymer 7.
has been graft polymerized. This photoresponsive graft polymer 7 is a linear polymer having a sensitive group in its side chain that dissociates and ionizes when irradiated with light of a specific wavelength. By the way, many compounds are known that ionically dissociate when exposed to light, but in many cases the dissociated ions immediately recombine. As the material for the photoresponsive graft polymer 7 implanted on the inner circumferential surface of the capsule membrane Cf, a compound in which the lifetime of dissociated ions is sufficiently long is suitable. Examples of such materials include:

0012

[Chemical formula 1]

[0013]

[Chemical 2]

There are triphenylmethane derivatives such as: FIG. 3 shows the dissociation changes of a graft polymer in which a triphenylmethane derivative was introduced into the side chain as a sensitive group.

Since the above-mentioned graft polymer 7 is hydrophobic, in a stable state, it does not fit into the inner phase, which is an aqueous phase, and therefore adheres to the inner circumferential surface of the wall material 5 in a contracted conformation. (See (ST1) in FIG. 4). In this state, the pores 6 (see FIG. 2) of the wall material 5 are blocked by the graft polymer 7, and the capsule membrane Cf
The material permeability is lowered, and it can have sufficient permeation barrier properties even for substances with a small molecular weight.

In FIG. 1, a dye precursor 8 as the other reactive substance which is mixed with each other to cause a coloring reaction is contained in the microcapsule MC. Dye precursor 8
is a pigment that is normally colorless, but has the property of developing color when it reacts with acidic substances. As such substances, leuco dyes are widely known, and among them, common phthalide dyes, fluoran dyes, triphenylmethane dyes, phenothiazine dyes, and spiropyran dyes can be suitably used. Specifically, crystal violet lactone, carbazolyl blue, indolyl red, pyridine blue, rhodamine B lactam, malachite green, and 3-dialkylamino-7, which are widely used in general pressure-sensitive paper and thermal paper, etc. -dialkylaminofluorane, benzoylleucomethylene blue, and the like.

Various auxiliary substances 9 for adjusting the chemical properties of the dye precursor 8 are also mixed in the capsule internal phase. For example, when the dye precursor 8 is a leuco dye, the auxiliary substance 9 may be distilled water or an organic solvent such as benzene, toluene, alkylnaphthalene, biphenyls, or paraffins, which is a solvent for dissolving and dispersing the leuco dye. Can be used. Furthermore, various commercially available waxes and resin polymers are mixed in to impart appropriate viscosity to the capsule internal phase solution.

As described above, the microcapsule MC of this example
is a capsule membrane C in which a polymer 7 having a photosensitive group that dissociates upon irradiation with light of a specific wavelength is graft-polymerized on the inner peripheral surface.
The dye precursor 8, its auxiliary substance 9, and other substances are mixed and dispersed and sealed in the internal phase of f.

[0019] Here, a method for manufacturing microcapsules MC having the above-mentioned structure will be explained. First, a microcapsule intermediate is produced in which a capsule inner phase material containing a dye precursor is encapsulated in a shell-like wall material. As a method for producing this intermediate, an interfacial polymerization method, an in-situ polymerization method, a coacervation method, etc. can be used.

Next, ethylene glycol dimethacrylate is dissolved in a water and ethanol solution, and the above-mentioned microcapsule intermediate is introduced into this solution. A polymerization initiator is added to this and heated to introduce vinyl groups into the inner peripheral surface of the polymeric substance that makes up the capsule wall.

Next, in a heated aqueous solution, a vinyl derivative containing a leuco form of triphenylmethane, other vinyl monomers, and ethylene are polymerized onto the inner peripheral surface of the above-mentioned microcapsule intermediate using a radical initiator. As a result, a graft polymer is formed extending from the vinyl groups introduced into the inner peripheral surface of the capsule wall. Thereafter, by extracting and washing the microcapsules, the graft polymerized microcapsules of this example are completed.

Returning to FIG. 1, the color developer 3 dispersed and mixed in the binder resin 2 which becomes the outer phase of the microcapsules MC is one of the reactive substances that cause a color reaction, and the other reactive substance It is mixed with the dye precursor 8 of the capsule inner phase to develop color. When the dye precursor 8 is a leuco dye, the color developer 3 may include phenols such as α-naphthol, β-naphthol, and bisphenol A, zinc salicylate derivatives,
Acidic substances such as aromatic carboxylic acid metal salts can be used.

Further, the auxiliary substances 4 are various substances for adjusting the physical properties of the color developer 3, like the auxiliary substances 9 of the capsule internal phase, such as substances for dissolving and dispersing the color developer 3. Examples of such solvents include distilled water and organic solvents such as benzene and toluene. In this example, the color developer 3 and the auxiliary substance 4 are dispersed in the binder resin 2 which is gelatinized at room temperature as described above.

An optical recording method using the monochrome optical recording paper constructed as described above will be explained below. Figure 4 shows
Microcapsule-containing agent C in monocolor optical recording paper
FIG. 5 is a schematic explanatory diagram showing the substance diffusion operation in C, and FIG. 5 is a configuration explanatory diagram showing the schematic configuration of an optical recording apparatus for carrying out the optical recording method of this example. In FIG. 4, in the initial state (ST1) at room temperature, the microcapsule-containing agent CC deposited on the base paper 1 is in a thermally stable state. That is, the graft polymer (not shown) polymerized and implanted on the inner circumferential surface of the capsule membrane Cf is in a stable state exhibiting hydrophobicity, and has a conformation in which it adheres to the inner circumferential surface of the capsule membrane Cf. Therefore, the pores of the wall material (see FIG. 2) are blocked by the graft polymer, and the substance permeability of the capsule membrane Cf is low. Therefore, in this initial state, the dye precursor 8 in the inner phase of the capsule and the outer phase (in the binder resin 2)
The color developer 3 is isolated by the capsule membrane Cf and no color reaction occurs, and the entire microcapsule-containing agent CC is colorless and stable. In addition, the binder resin 2 is gelled at room temperature in its initial state, and the entire outer phase of the capsule is held in a non-fluid state by the binder resin 2, so that the capsule film of the dye precursor 8 and the color developer 3 is Mutual diffusion via Cf is more reliably prevented, and no color reaction occurs due to "leak" transmission between the two.

The monochrome optical recording paper P, on which the microcapsule-containing agent CC is in the above-mentioned initial state, is fed along the recording paper conveyance path 10 of the optical recording apparatus shown in FIG. The fed optical recording paper P is first heated by the heater 11 . As a result, the binder resin 2 of the microcapsule-containing agent CC is turned into a sol, the color developer 3 is melted, and the viscosity of the capsule outer phase is reduced (ST2). The heating temperature in this case is preferably set to 80° C. or higher, taking into account the usage environment and so that the molten state of the color developer 3 can be maintained during the next optical recording process. As the heater 11, a thin film/thick film line heater similar to a heat roller or a thermal head can be suitably used.

Next, optical recording is performed on the heated optical recording paper P by the optical recording head 12 (ST3). The optical recording head 12 includes a light source 12a, and irradiates light R containing component light having a wavelength ν to which the graft polymer is sensitive, in accordance with recording information. As in this example, when a triphenylmethane derivative is introduced as a photosensitive group of the graft polymer,
The wavelength ν that can excite it is light in the ultraviolet region. Therefore, when a laser recording head consisting of a laser light source, a light modulator, a scanning device, a focusing optical system, etc. is used as the optical writing head 11 shown in FIG.

Microcapsule MC irradiated with light R
In this case, the photosensitive group of the graft polymer absorbs component light having a wavelength of ν, becomes excited, dissociates, and becomes ionized. Among the generated ions, the ion dissociated from the polymer, for example, when the graft polymer is a triphenylmethane derivative (see Chemical Formula 1 or Chemical Formula 2), OH(-) or CN(-
) and other anions are dispersed in the solvent (internal phase liquid). As a result, triphenylmethane cations remain in the graft polymer, and due to the electrostatic repulsion between these cations, the graft polymer adopts a conformation that extends toward the center of the capsule as shown in FIG. 2. As a result, there are no obstacles blocking the pores 2 of the capsule membrane Cf, and the dye precursor 8 and the color developer 3 in the capsule and the outer phase easily permeate the capsule membrane Cf through the pores 2. That is, the substance permeability of the capsule membrane Cf increases.

By controlling the irradiation intensity of the light R, it is possible to adjust the amount of molecules actually excited and dissociated among all the photosensitive groups in the graft polymer. That is, by controlling the intensity of light irradiation, the substance permeability of the capsule membrane Cf can be freely controlled. As a result, it is possible to easily obtain not only a single-density recorded image by simple blinking control of light, but also a monochrome recorded image with density gradation, as described below. Note that even if light other than light having a wavelength of ν is irradiated, the above-mentioned conformational change due to photodissociation does not occur. Therefore, under the illumination of light that does not include component light having a wavelength of ν, the above-mentioned material transmission control by light irradiation, that is, optical recording, can be easily and accurately performed.

In the optical recording stage (ST3) shown in FIG.
It shows a state in which four dots corresponding to 4 bits of recording data are formed, and one microcapsule MC1 to MC4 is schematically associated with each dot. In this case, the intensity of the dot-forming light (dot light) R is the highest for the dot light R1 corresponding to the microcapsule MC1, and the intensity of the dot light R1 corresponding to the microcapsules MC2 and MC3 is the highest.
2 and R3, each irradiation intensity (indicated by the length of the white arrow in the drawing) gradually decreases. The dot corresponding to microcapsule MC4 is a white dot, and therefore the corresponding dot light is not irradiated. From now on, the microcapsule M corresponding to the dot light R1 with the highest irradiation intensity
The degree of dissociation (degree of extension in the radial direction) of the graft polymer 7 of C1 is the largest, and therefore the substance permeability increases the most, and as the irradiation intensity of the dot light R decreases, the substance permeability of the microcapsules MC2 and MC3 increases. It can be seen that the degree is also decreasing. Since the microcapsule MC4 is not irradiated with the dot light R, it is in the initial state (ST1
), it remains in a state with almost no substance permeability.

[0030] As time passes, the color developer 3 in the outer phase of the capsule
The amount of diffused into the internal phase of the capsule increases, and the color developer 3 diffused into this internal phase causes a color-forming chemical reaction with the existing dye precursor 8, and the microcapsules MC1 to MC3 begin to develop color (ST4). In addition, the dye precursor 8 present in the inner phase of the capsule
However, since the viscosity of the binder resin 2 is high, the diffusion distance is limited to the vicinity of the microcapsules from which it diffuses. Pigment 13 is produced when a color-forming chemical reaction occurs. As a result, the microcapsules MC1 to MC3 and their surroundings begin to develop color.

Here, the amount of diffusion of each material molecule in the capsule and the outer phase, such as the dye precursor 8 and the color developer 3, is determined by the capsule membrane Cf.
Although it varies depending on the size of the molecules that permeate and the pressure value inside and outside the capsule, it also varies greatly depending on the degree of dissociation of the graft polymer 7. Therefore, as mentioned above, the degree of dissociation of the graft polymer 7 is the highest in the microcapsules MC1 corresponding to the dots irradiated with the light R most intensely.
Therefore, the mutual diffusion of substances related to the microcapsules MC1 occurs most actively, and the coloring density becomes the highest. Then, the color density of the microcapsules MC2 and MC3 decreases in stages as the irradiation intensity of the light R decreases. In this way, a monochrome recorded image with density gradation is obtained.

The above coloring reaction stops when the light R is no longer irradiated. That is, when the light R is not irradiated, the photo-dissociated ions recombine and stabilize, and the graft polymer 7 loses its electrostatic repulsive force and returns to the conformation in which it is attached to the inner peripheral surface of the wall material. As a result, the pores of the capsule membrane Cf are blocked by the graft polymer, reducing substance permeability.
Mutual diffusion of dye precursor 8 and color developer 3 is prevented (ST
5). In this case, the dye 13 generated in the outer phase of the capsule is
Since the binder resin 2 restricts the diffusion movement and exists around the microcapsules that are the source of diffusion, each dot is clearly formed and the resolution of the recorded image is improved. In Figure 5,
When the monochrome optical recording paper P passes the position where the optical recording head 12 is disposed, the light R is no longer irradiated to the microcapsule-containing agent, so the coloring reaction stops, thereby finalizing the recorded image. The monochrome optical recording paper P on which the recorded image has been completed is then discharged outside the machine.

As described above, according to the optical recording method of this example,
The optical recording device has an extremely simple structure, requiring only the heater 11 and the optical recording head 12 as the main image forming process devices.
High-resolution monochrome recorded images can be obtained at low cost.

<Second Embodiment> In this example, optical recording is performed using a full-color optical recording paper coated with a microcapsule-containing agent that causes full-color color change. Therefore, as shown in FIG. 6, three types of microcapsules MCy, MCm, and MCc are used corresponding to the three primary colors. These three types of microcapsules MCy, MCm, and MCc have different configurations regarding the photoresponsiveness of each capsule film Cf. That is, graft polymers that respond to different wavelengths of light are polymerized and implanted on the inner peripheral surface of the wall material of each capsule membrane Cf. And microcapsules MCy, MCm,
Each internal phase of the MCc is provided with dye precursors 14a, 14b, 14c having different color-forming abilities and the same auxiliary substance (not shown). That is, the dye precursor 14a has the ability to develop yellow, the dye precursor 14b has the ability to develop magenta, and the dye precursor 14c has the ability to develop cyan. Then, these microcapsules MCy, MCm, MCc and a color developer (
) and auxiliary substances, etc. are dispersed and mixed in the binder resin 2 to form the full-color recording microcapsule-containing agent CC of this example.
f is configured. As the color developer, one is selected that has uniformly good coloring ability for all three types of dye precursors 14a, 14b, and 14c arranged in the inner phase of each capsule. Incidentally, as the materials for each element constituting the microcapsules MCy, MCm, and MCc, suitable materials can be selected from among the substances mentioned in the first embodiment.

The microcapsule-containing agent CCf having the above-mentioned structure is deposited on the base paper 1 to form a full-color optical recording paper Pf.
has been formed. Using this full-color optical recording paper Pf, a full-color recorded image is obtained by a full-color optical recording apparatus shown in FIG. This full-color optical recording device includes a heater 1.
A full-color recording head 16 equipped with three light sources 16a, 16b, and 16c is installed downstream of the recording head 5. These light sources 16a, 16b, and 16c emit recording lights Ra, Rb, and Rc containing component lights of wavelengths νa, νb, and νc to which the graft polymers of the three types of microcapsules MCy, MCm, and MCc are sensitive, respectively, for full-color recording. Each irradiation is performed according to the data. In this example, recording light Ra is associated with a yellow pixel, Rb with a magenta pixel, and Rc with a cyan pixel, respectively.

Next, an optical recording method using the full-color optical recording paper and recording apparatus constructed as described above will be explained. The method of this example, like the first example (see FIG. 4), consists of five steps: a thermally stable initial stage, a heating stage, an optical recording stage by light irradiation, a coloring reaction start stage, and a light irradiation stop stage. . FIG. 6 is a schematic explanatory diagram showing the state change of the microcapsule-containing agent CCf from the optical recording stage to the light irradiation stop stage. Further, FIG. 7 is a schematic explanatory diagram showing a schematic configuration of a full-color optical recording device.

[0037] The state of the microcapsule-containing agent at the initial stage is the same as that in the first example, and each graft polymer of the three types of microcapsules MCy, MCm, and MCc is coated on the inner peripheral surface of the capsule wall material. It has an attached conformation.

In FIG. 7, the full-color optical recording paper Pf fed along the recording paper conveyance path 17 is first heated by a heater 1 configured similarly to the recording apparatus of the first embodiment (see FIG. 5).
5. As a result, the binder resin 2 of the microcapsule-containing agent CCf shown in FIG. 6 is turned into a sol, the color developer 3 is melted, and the viscosity of the capsule outer phase is reduced.

Next, as shown in [a] of FIG.
Optical recording is performed by irradiating the microcapsule-containing agent CCf. As a result, microcapsules MCy, MCm,
Each graft polymer of MCc has three types of recording light Ra,
It selectively dissociates in response to irradiation of Rb and Rc. At this time, since the outer phase of the capsule has already been heated and is in a sol state, interdiffusion of the dye precursors 14a, 14b, 14c and the color developer (not shown) immediately starts. As shown in [b] of FIG. 6, in one dot area irradiated with the recording light Ra, the graft polymer of the microcapsule MCy is selectively dissociated, the substance permeability of the capsule membrane increases, and the capsule internal phase The dye precursor 14a and the color developer in the outer phase pass through the capsule membrane and begin to diffuse into each other. As a result, the dye precursor 14a and the color developer cause a coloring reaction, and a yellow dye 18a is produced. Similarly, magenta dye 18b is generated in one dot area irradiated with recording light Rb, and cyan dye 18c is generated in one dot area irradiated with recording light Rc. In this case, these three types of dyes are also generated in the outer phase of the capsule, but as in the case of the first embodiment, the diffusion of each dye precursor 14a, 14b, 14c is restricted by the binder resin 2. The dyes 18a, 18b, and 18c are generated only in the vicinity of the microcapsules from which the dye precursors 14a, 14b, and 14c are diffused.

[0040] FIG. 6C shows a state in which one dot area is irradiated with three types of recording beams Ra to Rc in a superimposed manner.
The graft polymers of all the microcapsules MCy, MCm, and MCc are dissociated to form dye precursors 14a,
Mutual diffusion of color developer 14b and 14c progresses, and three types of pigments (three primary colors) 18a, 18b, and 18c are generated, forming a black dot as a whole. In this way, by selectively controlling the types and intensities of the three types of recording light Ra to Rc according to the full-color recorded image data and multiple irradiating one dot area, a full-color recorded image with desired color and color density can be obtained. is obtained. In FIG. 7, the full-color recording paper Pf is carried out from the position where the optical recording head 16 is disposed, and the light R
When the microcapsule-containing agent CCf is no longer irradiated, the coloring reaction stops as in the first example. As a result, a full-color recorded image is determined, and then the full-color optical recording paper Pf is discharged outside the machine.

As described above, according to the optical recording method of this example,
A full-color optical recording device having a simple structure in which the main image forming process members are only the heater 15 and the optical recording head 16 can provide a good full-color image at a low cost.

<Third Example> In this example, a viscosity adjusting substance whose viscosity rapidly decreases as the temperature rises is mixed into the microcapsule inner phase of the microcapsule-containing agent as an auxiliary substance. As the viscosity adjusting substance, a polymer resin or wax whose viscosity decreases rapidly as the environmental temperature rises is used. As a result, under normal environmental temperature,
Due to the high viscosity of the internal phase substance of the capsule, the dye precursor contained therein is difficult to diffuse, and the binder resin of the external phase substance is also in a gel state, so the dye precursor and developer are difficult to diffuse. The isolation is more secure than in the first and second embodiments. Therefore, it is possible to more completely prevent a coloring reaction caused by "leakage" in which a small amount of substance molecules permeate through the capsule membrane at an early stage when no light is irradiated. The other configurations are the same as in the first embodiment.

In the optical recording method of this example, when the monochrome optical recording paper is heated before optical recording, the binder resin becomes a sol and the color developer melts, reducing the viscosity of the outer phase of the capsule. The viscosity of the above-mentioned viscosity adjusting substance contained in the internal phase decreases rapidly as the temperature rises. Therefore, in the next optical recording step, the dye precursor and the color developer smoothly interdiffuse to cause an active coloring reaction as in the first embodiment.

In FIG. 5, when the optical recording is completed, the monochrome recording paper P is carried out from the portion where the optical recording head 12 is provided. As a result, the light R is no longer irradiated onto the microcapsule-containing agent and its temperature is lowered. This results in
The graft polymer returns to its initial state conformation, the substance permeability of the capsule membrane decreases, and the viscosity of the microcapsule internal phase increases to the same level as the initial state. Therefore, the dye precursor in the inner phase of the capsule becomes difficult to diffuse and move, and the mutual diffusion of the dye precursor and the color developer is more reliably prevented than in the first embodiment, and the color development reaction is stopped.

As described above, according to this example, the coloring reaction can be precisely controlled not only by light but also by temperature, and the coloring reaction due to "leakage" and transmission of material molecules in the initial stage can be more completely prevented. Benefits can be obtained. Note that a viscosity adjusting substance whose viscosity rapidly decreases as the temperature rises may be mixed into the binder resin of the outer phase of the capsule.

Although the present invention has been described in detail based on three embodiments, the present invention is not limited to these specific embodiments, and various modifications can be made within the technical scope of the invention. Of course, it is possible. For example, the graft polymer may be polymerized and implanted not only on the inner peripheral surface of the microcapsule membrane wall material but also on the outer peripheral surface. In addition, in the first embodiment, the dye precursor was placed in the capsule inner phase and the color developer was placed in the capsule outer phase, but conversely, the color developer and color developer were placed in the capsule inner phase.
A dye precursor may be provided in the outer phase of the capsule. In this case as well, it is possible to obtain a similar monochrome optical recording paper that allows precise control of the density of the recorded image. Furthermore, the reactive substance is not limited to the dye precursor and the color developer, but various other reactive substances that cause a color reaction can be used.

[0047]

Effects of the Invention As described above in detail, according to the present invention, one of the reactive substances that are mixed with each other to cause a coloring reaction, and the capsule whose substance permeability changes in response to light irradiation of a specific wavelength. The membrane is formed by polymerizing and implanting a graft polymer with photo-dissociable groups on the peripheral surface of a wall material made of a porous material,
The microcapsules containing the other reactive substance in the capsule membrane are dispersed and mixed in a binder resin to prepare a microcapsule-containing agent, and this microcapsule-containing agent is applied to the surface of the support sheet. As a result, it is possible to provide an optical recording sheet on which high-resolution color recording images can be accurately optically recorded using a device with an extremely simple structure. In this case, by dispersing and containing a plurality of types of microcapsules that respond to different wavelengths of light in the binder resin, an optical recording sheet capable of optically recording high-resolution, full-color recorded images with a simple device can be obtained. By using such an optical recording sheet and controlling the light irradiation intensity according to the recorded data, it is possible to obtain high-resolution, full-color recorded images with density gradation at low cost using a simple device. It becomes possible. Furthermore, since the substance permeability of the capsule membrane does not change with light other than light having the above-mentioned specific wavelength, the coloring reaction can be precisely controlled even under normal light illumination, and the structure of the optical recording device becomes simpler.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a monochrome optical recording paper as an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the detailed structure of microcapsules coated on the monochrome optical recording paper.

FIG. 3 is an explanatory diagram showing photodissociation changes of the graft polymer of the microcapsules.

FIG. 4 is a schematic cross-sectional view showing step-by-step the coloring reaction operation based on the substance diffusion of the microcapsule-containing agent in the optical recording method using the monocolor optical recording paper.

FIG. 5 is a schematic explanatory diagram showing a schematic configuration of an optical recording apparatus that implements the above optical recording method.

FIG. 6 is a schematic cross-sectional view showing a coloring reaction operation based on substance diffusion of a microcapsule-containing agent in an optical recording method using a full-color optical recording paper as another embodiment of the present invention.

FIG. 7 is a schematic explanatory diagram showing a schematic configuration of an optical recording apparatus that implements the full-color recording method.

[Explanation of symbols]

1 Base paper 2 Binder resin 3 Color developer 4 Auxiliary substance (outer phase) 5 Wall material 6 Micropores 7 Graft polymer 8, 14a, 14b, 14c Dye precursor 9 Auxiliary substance (inner phase) 10, 17 Record Paper transport paths 11, 15 Heaters 12, 16 Optical recording head 13 Dye 18a Yellow dye 18b Magenta dye 18c Cyan dye CC Microcapsule-containing agent (monocolor) CCf
Microcapsule-containing agent (full color) Cf Capsule film MC1, MC2, MC3 Microcapsule (monocolor) MCy, MCm, MCc Microcapsule (full color) P Monocolor optical recording paper Pf Full color optical recording paper

Claims (14)

[Claims] Claim 1: A microcapsule-containing agent is formed by coating a support sheet surface with a microcapsule-containing agent, which is made by dispersing and mixing microcapsules equipped with a capsule membrane that changes substance permeability in response to light irradiation in a binder resin. In the optical recording sheet, the capsule membrane is formed by graft polymerizing a polymeric substance having a site that dissociates and ionizes when irradiated with light on the circumferential surface of a wall material made of a porous material, By dispersing and mixing one of the reactive substances that cause a color reaction in the binder resin, incorporating the other reactive substance in the microcapsules, and irradiating with light of a specific wavelength,
An optical recording sheet coated with a color-changing microcapsule-containing agent, characterized in that the substance permeability of the capsule membrane is increased to cause the reactive substance to diffuse and mix with each other to cause a color reaction. 2. The optical recording sheet according to claim 1, wherein one of the reactive substances is a color developer and the other of the reactive substances is a dye precursor. 3. The optical recording sheet according to claim 1, wherein one of said reactive substances is a dye precursor and the other of said reactive substances is a color developer. 4. The optical recording sheet according to claim 1, wherein the polymer substance is graft-polymerized on the inner peripheral surface of the wall material. 5. The optical recording sheet according to claim 1, wherein the polymer substance is graft-polymerized on the outer peripheral surface of the wall material. 6. The optical recording sheet according to claim 1, wherein the microcapsule-containing agent contains a plurality of types of microcapsules made of capsule films having different specific wavelengths. 7. The optical recording sheet according to claim 1, wherein the microcapsules contain a substance whose viscosity rapidly decreases as the temperature rises. 8. One of the reactive substances that causes a coloring reaction when mixed with each other, and a polymeric substance that has a part on the circumferential surface of a wall material made of a porous material that dissociates and ionizes when it receives light of a specific wavelength. A microcapsule-containing agent is prepared by dispersing and mixing microcapsules made of a graft-polymerized capsule membrane and containing the other reactive substance in a binder resin,
An optical recording method using an optical recording sheet adhered to the surface of a support sheet, the method comprising: irradiating the microcapsule-containing agent on the optical recording sheet with light of the specific wavelength according to recorded information; An optical recording sheet coated with a color-changing microcapsule-containing agent, which increases substance permeability and causes a coloring reaction by mutual diffusion of the reactive substance to form a recorded image on the optical recording sheet. An optical recording method using 9. The optical recording according to claim 8, wherein one of the reactive substances dispersed and mixed in the binder resin is a color developer, and the other of the reactive substances incorporated in the microcapsules is a dye precursor. Method. 10. The light source according to claim 8, wherein one of the reactive substances dispersed and mixed in the binder resin is a dye precursor, and the other of the reactive substances incorporated in the microcapsules is a color developer. Recording method. 11. The optical recording method according to claim 8, wherein an optical recording sheet is used in which an agent containing microcapsules formed by graft polymerization of the polymer substance is adhered to the inner peripheral surface of the wall material. 12. The optical recording method according to claim 8, wherein an optical recording sheet is used in which an agent containing microcapsules formed by graft polymerization of the polymer substance is adhered to the outer peripheral surface of the wall material. 13. The microcapsule-containing agent contains a plurality of types of microcapsules made of capsule films having different specific wavelengths, and is irradiated with a plurality of types of light, each of which has the specific wavelength, according to recorded information. The optical recording method according to item 8 or 9. 14. A recorded image is formed by incorporating a substance in the microcapsules, whose viscosity rapidly decreases as the temperature rises, and heating the microcapsules while irradiating the microcapsules with light of the specific wavelength. The optical recording method described.