JPH03291662A - Photosensitive and thermosensitive recording material - Google Patents

Abstract

PURPOSE:To record a high-quality multicolor image small in surface fogging and continuous in gradation by laminating a color developing agent layer, such as paper, and a layer containing porous microcapsules enclosing dye precursors, a polymerizable monomer, and a photopolymerization initiator on a substrate. CONSTITUTION:The color developing agent layer obtained by dispersing the color developing agent into a binder 7, and the porous microcapsules layer obtained by synthesizing the microcapsules 5a - 5c enclosing the photopolymerization initiators 3a - 3c and each having photosensitive wavelengths different from each other, the polymerizable monomer 4, the dye precursors 6a - 6c by in situ polymerization method or a combination of the in situ method and the coascelvation method, and dispersing the porous microcapsules 5a - 5c into a binder are laminated on the substrate 11, such as paper, thus permitting a multicolor image record small in surface fogging and continuous in gradation to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to light and heat sensitive recording materials, in particular 1 n situ
The present invention relates to a light and heat sensitive recording material capable of continuous tone recording using porous microcapsules synthesized by a polymerization method or a combination of an in 5 in situ polymerization method and a coacervation method.

[Summary of the invention]

In the present invention, a color developer layer in which a color developer that reacts with a dye precursor to form a color is dispersed in a binder is provided on one side of a support such as paper, and a dye precursor and a polymerizable layer are further disposed on the layer. Photosensitive and thermosensitive recording in which porous microcapsules containing monomers and photopolymerization initiators are synthesized using an in-5-itu polymerization method or a combination of an in-5-itu polymerization method and a coacervation method and are provided with a porous microcapsule layer dispersed in a binder. It is the material. 4 during photopolymerization with a photosensitive wavelength of λl
- In 5 in-itu polymerization method using a combination of an initiator and a dye precursor that develops a cyan color together with a polymerizable monomer or 1
It is encapsulated in porous microcapsules synthesized using a combination of n-situ polymerization method and coacervation method, and a photopolymerization initiator with a photosensitive wavelength of A2 and a dye precursor that develops magenta color are combined, and a photopolymerization initiator with a photosensitive wavelength of A3 is combined. By combining a photopolymerization initiator with
(separated by 0 nm or more) with polymerizable monomers using an in-5-itu polymerization method or an in-
At least two types of porous microcapsules synthesized using a combination of 5 itu polymerization method and coacervation method are dispersed in the porous microcapsule layer, and each type is irradiated with light corresponding to the photosensitive wavelength. The purpose is to create a high-quality, multicolor recorded image with continuous gradation by drawing a latent image using a heat roller or infrared rays, or by heating and developing the image.

[Conventional technology]

Conventional heat-sensitive recording materials are generally those in which thermochromic dyes are coated on a support such as paper, and the color is developed by heat from a thermal head or the like for recording. Furthermore, carbonless paper is a typical recording material to which microcapsules are applied, and the resolution depends on the pressurized area of a pressurized object such as a ballpoint pen.

In addition, as a recording material that applies light energy and microcapsules, Japanese Patent Application Laid-Open No. 58-88739 and Japanese Patent Application Laid-Open No. 58-17432 disclose a light- and heat-sensitive recording material recording sheet that uses light to create a latent image of an image. By destroying the microcapsules with pressure, the contents of the microcapsules are released, and the dye reacts with a color developer to develop color and produce an image.

Further, in Japanese Patent Application Laid-open No. 60-214990, after an image is formed by heat, the image is fixed and recorded by curing the photocurable resin inside the uncolored microcapsules using light energy.

Problems to be solved by the invention C] In conventional heat-sensitive and pressure-sensitive recording sheets, microcapsules are destroyed with high pressure, which causes image unevenness due to pressure unevenness in the pressurized area, and the device becomes larger. There was a problem that high-speed recording was not possible. Furthermore, in the fixing type using light energy, the resolution of the image depends on the heating element that is the thermal energy source, so there is a problem that a high-resolution image cannot be obtained.

[Means to solve the problem]

In order to solve the above problems, in the present invention, the following combinations of compounds are each included on a color developer layer formed by coating a support such as paper with a color developer dispersed in a binder. In 5itU polymerization method or in
A light- and heat-sensitive recording material was prepared by preparing a porous microcapsule layer in which at least two types of porous microcapsules synthesized using a combination of a 5-itu polymerization method and a coacervagedine method were mixed and dispersed in a binder.

・Cyan color dye precursor, photopolymerization initiator with photosensitive wavelength at λ1, polymerizable monomer ・Magenta color dye precursor, photopolymerization initiator with photosensitive wavelength at λ2, polymerizable monomer ・Yellow color dye precursor, λ3 The degree of polymerization of the polymerizable monomer in the porous microcapsules is increased by irradiating the photopolymerization initiator and polymerizable monomer with the photosensitive wavelength of the photopolymerization initiator and the polymerizable monomer in accordance with the image. During heat development, the amount of permeation of the dye precursor released from the porous microcapsules is controlled according to the degree of polymerization, making it possible to express continuous gradations and record multicolor images.

[For production]

The light and heat sensitive recording material of the present invention is irradiated with light corresponding to an image signal from a CRT, etc., to form a latent image on the polymerizable monomer in the porous microcapsules according to the image signal, and then a heat roller, a thermal head, or an infrared ray The amount of dye precursor that corresponds to the image signal passes through the porous microcapsules due to the heat generated by the heat source, and reacts with the color developer in the color developer layer to develop color, recording continuous gradation and high quality multicolor images. It is something that can be achieved.

7 [Example] The following will be described based on the drawings. FIG. 1 shows a schematic cross-sectional view of the porous microcapsule of the present invention.

The porous microcapsules 1 are formed using an in-5-itu polymerization method or a combination of an in-5-itu polymerization method and a coacervation method. Something that can be released by stimulating heat. The photopolymerization initiator 3 in the porous microcapsules 1 has its absorption wavelength as a photosensitive wavelength, and generates a photopolymerization initiation species by the light of the photosensitive wavelength to polymerize the polymerizable monomer 4. hardens. Furthermore, since the degree of polymerization can be controlled by the energy of the photosensitive wavelength, the amount of inclusions released from the porous microcapsules 1 can be controlled by heat depending on the degree of polymerization.

FIG. 2 is a schematic cross-sectional view showing a light and heat sensitive recording material using porous microcapsules containing dye precursors 6a, 6b and 6c that develop colors of cyan, magenta and yellow. A color developer layer in which a color developer is dispersed in a binder 7 is provided on a support 11 such as paper, and a photopolymerization initiator 3 having different photosensitive wavelengths is further provided on top of the developer layer.
a, 3b, 3c, a polymerizable monomer 4, and dye precursors 6a, 6b, and 6c, respectively, are incorporated into the porous microstructure using the in 5itU polymerization method or the combination of the tn 5itU polymerization method and the coacervation method. capsule 5a
, 5b, and 5c are dispersed in a binder to form porous microcapsules N8.

FIG. 3 is a schematic view showing the exposure state of the light and heat sensitive recording material of FIG. λ1, λ depending on the image signal from CRT etc.
2. When the light 13a, 13b, 13c with the wavelength of λ3 is irradiated, the polymerizable monomer 4 in the porous microcapsules 5a, 5b, 5c is cured according to the energy of the light with the respective wavelength, and the image is A latent image can be formed.

FIG. 4 is a schematic diagram showing the thermal development state of the light- and heat-sensitive recording material. By applying heat from a heating element 15 such as a thermal head to the porous microcapsule layer 10 side of the light and heat sensitive recording material 12 on which a latent image has been formed as shown in FIG. 3, it is uncured by light irradiation. Dye precursors 6a, 6b from the porous microcapsule membrane of the porous microcapsules
, 6c are transmitted and react with the color developer in the color developer layer 10 to obtain colored portions 14a, 14b, 14C of each color according to the image signal, and a multicolor image can be recorded.

In the present invention, melamine-
Examples include formalin resin, urea-formalin resin, and the like. In addition, examples of constituent materials of the porous microcapsule film using the core cell basis method include styrene-butadiene resin, styrene-maleic anhydride resin, and the like.

Leuco dyes used as pigments for expressing images include crystal violet lactone, rhodamine B lactam, malachite green, and 3-dialkyl ξ no 7.
-Dialkyl amyl fluorane, benzoyl leucomethylene blue, etc.

Color developers for coloring the leuco dye include aromatic carboxylic acid metal salts such as salicylic acid and its derivatives, clays such as acid clay, activated clay, and bentonite;
Phenol compounds such as α-naphthol, β-naphthol, bisphenol A, etc. can be used.

As the binder, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, styrene-butadiene latex, etc. can be used.

Polymerizable monomer is the main component in porous microcapsules and is also used as a solvent to dissolve dye precursors and photopolymerization initiators. It is necessary to have the ability to smoothly release the dye precursor from the porous microcapsules when the dye precursor is applied. Furthermore, since the size of porous microcapsules is determined by emulsifying the capsule liquid in water, it is important that the polymerizable monomer used as the solvent for the capsule liquid is insoluble in water. This is one of the factors. If an effective polymerizable monomer is solid at room temperature, it can be used in combination with other polymerizable monomers that are liquid at room temperature. It is also possible to use a polymerizable monomer that does not exhibit polymerizability but is solid at room temperature dissolved in a water-insoluble oil (such as diisopropylnaphthalene), but in this case, it is not completely polymerized. However, there is a problem in that the dye precursor oozes out from the porous microcapsules without being completely cured. As effective polymerizable monomers, monomers having two or more ethylenically unsaturated groups and polymers having ethylenically unsaturated ends or side chains can be used. Compounds included in these include polyesters having acrylate or methacrylate terminals, epoxy resins having acrylate or methacrylate terminals, and acrylic esters or methacrylic esters of polyhydric alcohols. Specifically, the compounds included in these include diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, polyethylene glycol diacrylate, and polyethylene glycol. Dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol In addition to hexaacrylate, dipentaerythritol hexamethacrylate, ethylcarpitol acrylate, ethylcarpitol methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, and the like, the following acrylates can be mentioned.

A A A-eM-N+-11M-A, Agox-yteiX-
A where, A: Niacrylic acid, M: dihydric alcohol, N:
Dibasic acid, X: polyhydric alcohol, Y: polybasic acid.

As the photopolymerization initiator, quinone, acyloin, diazoanthrone, diazonium salt, diazophenanthrone, disulfide, aromatic azide, aromatic ketone, aromatic azosulfonate, aromatic carbazide, etc. can be used.

Examples of the present invention are shown below, but the present invention is not limited thereto.

(Prepolymer preparation) Add 1 part of melamine to 30 parts by weight of 37% formaldehyde aqueous solution.
0 parts by weight was added, reacted at 60°C for 15 minutes, and then
1 part by weight of glycine was added and reacted for 1 minute to obtain an aqueous prepolymer solution. Even if this prepolymer aqueous solution is left to stand, polymerization may proceed naturally and it may harden, so it is necessary to encapsulate it immediately after preparation.

(Bottom of magenta colored capsule) 2 parts by weight of a leuco dye that develops a magenta color is added to trimethylolpropane triacrylate (a polymerizable monomer) (
After heating and melting 25 parts by weight of TMPTA) and cooling to room temperature, a complex compound of safranin and triphenyl-n-butylboron (photosensitive wavelength: 5
1 part by weight of N,N-dimethylformamide (DMF) was mixed with 1 part by weight of N,N-dimethylformamide (DMF) and thoroughly stirred to obtain a capsule encapsulating liquid. Water adjusted to pH 4 20
This capsule liquid was mixed with 0 parts by weight and emulsified and dispersed at 5000 rpm for about 5 minutes using a homogenizer. This dispersion was stirred with a mechanical stirrer and heated to 60°C in a hot water bath, and the previously prepared melamine-formalin resin prepolymer was added dropwise to the dispersion for about 30 minutes while keeping the temperature at 60°C.
Stirring was continued for an hour. At this time, if the prepolymer is not dropped immediately after preparation, the prepolymer may become polymerized and encapsulation may not be possible.

15- From the porous microcapsule dispersion thus obtained,
Porous microcapsules were separated by a centrifugal separator.

(Synthesis of cyan capsule) In Example 1, the same amount of leuco dye that develops cyan color was used, and the photopolymerization initiator was a complex compound of methylene blue and tripel-n-butyl boron (sensitivity wavelength: 650 nm). Using 1 part by weight, cyan capsules were prepared in the same manner.

(Bottom of yellow capsule) In Example 1, 2 parts by weight of a leuco dye that develops a yellow color was used, and as photopolymerization initiators, 1.0 parts by weight of benzophenone and 0.4 parts by weight of hydrarketone were used. A combination of parts (sensitivity wavelength: 400 nm) was used. Yellow capsules were then synthesized using the same method.

The same amount of the porous microcapsules of each color and the same amount of 5% (W/W) styrene-maleic anhydride copolymer 16 as the total amount of capsules are dispersed in an aqueous solution to form a capsule dispersion. .

As a color developer, 20 parts by weight each of bisphenol A and silica powders were dispersed in a 5% (W/W) polyvinyl alcohol (Wako Pure Chemical Industries, Ltd.) aqueous solution using a ball mill. A bar coater (Yoshitantsu Seiki Co., Ltd.: Bar Coater@20) was used to coat the top layer.Furthermore, the previously prepared capsule dispersion was coated on top of this developer layer using a bar coater. A photosensitive and thermosensitive recording paper according to the invention was prepared.

A 300W xenon short arc lamp (manufactured by Ushio Inc.: UYX-300) was used as a light source to evaluate the characteristics of the produced light and heat sensitive recording paper, and an interference filter (MELLES GRIO) was used to limit the wavelength of the light.
A latent image of the image is formed by irradiating each photosensitive wavelength of the photopolymerization initiator onto the light- and heat-sensitive recording paper using a printer (manufactured by T.T.), and a latent image is formed using a thermal head printing device (manufactured by Daii Denki: TH-Ml). The image was used.

As a result, the light and heat sensitive recording paper produced images that corresponded to the light irradiation time and was also capable of continuous gradation recording. In addition, selective color development using light was possible, and a multicolor image could be formed.

In areas where no color development is required, the polymerizable monomer is cured by light irradiation and the dye does not develop color, so it was possible to obtain a good image without background fog.

〔Effect of the invention〕

As described above, the present invention provides a color developer layer on a support such as paper, and further provides a porous microcapsule layer containing a dye precursor, a polymerizable monomer, and a photopolymerization initiator thereon. By adopting this structure, it is possible to provide a light and heat sensitive recording material that has little background fog, enables continuous gradation recording, and provides high quality multicolor image recording.

[Brief explanation of the drawing]

FIG. 1 shows a schematic diagram of a porous microcapsule used in the light and heat sensitive recording material of the present invention, FIG. 2 is a sectional view showing the light and heat sensitive recording material of the present invention, and FIG. 3 shows the light and heat sensitive recording material. FIG. 4 is a cross-sectional view not showing the exposure state, and FIG. 4 is a schematic diagram showing the heat development state of the light- and heat-sensitive recording material. 1...Porous microcapsules 2...Dye precursor 3...Photopolymerization initiator 3a...Photopolymerization initiator 3b sensitive to λ1...λ2
Photopolymerization initiator 3c sensitive to λ3...Photopolymerization initiator 4 sensitive to λ3...Polymerizable monomer 5a...Porous microcapsules 5b sensitive to λ1...
- λ2-sensitive porous microcapsules 5C...λ3-sensitive porous microcapsules 6a...Cyan dye precursor 6b...Magenta dye precursor 6C...Yellow dye precursor 7...・Binder 8... Porous microcapsule layer 9... Color developer 10... Color developer layer 11... Support 19 0-12 ・ ・ 13a ・ 13 b ・ 13c ・ 14a・ 14b ・ ・ 14c ・ ・ 15a ・ 15b ・ 15c ・ 16 ・ ・ Photosensitive and thermosensitive recording material irradiation light λ1 irradiation light λ2 irradiation light λ3 Porous microcapsules hardened by λ1 Porous microcapsules hardened by λ2 Porous hardened by λ3 Quality Microcapsule Cyan Coloring Area Magenta Coloring Area Yellow Coloring Area Heating Element or More

Claims (1)

[Scope of Claims] (1) A color developer layer that reacts with a dye precursor to form a color is provided on one surface of the support, and furthermore, a color developer layer is provided on one side of the support, and a color developer layer that reacts with a dye precursor and a polymerizable monomer and a light-sensitive wavelength is further provided on the developer layer. Porous microcapsules containing a photopolymerization initiator as a main component that can initiate polymerization of the polymerizable monomer by irradiation with light are prepared using an in situ polymerization method or a combination of an in situ polymerization method and a coacervation method. 1. A light- and heat-sensitive recording material characterized in that a porous microcapsule layer synthesized and dispersed in a binder is provided, and a multicolor image is recorded by heat development. (2) The capsule membrane that forms the outer shape of porous microcapsules is a porous membrane with many pores, and when heat is applied from the outside, the pores of the porous membrane of the porous microcapsules can be 2. The light and heat sensitive recording material according to claim 1, having a function of allowing the inclusions to pass through the porous microcapsules and be released to the outside of the porous microcapsules. (3) The light and heat sensitive recording material according to claim 1, wherein the capsule membrane material of the porous microcapsules in the in situ polymerization method is selected from among the combinations of compounds shown below. [1] melamine-formalin [2] urea-formalin (4) The light and heat sensitive recording material according to claim 1, characterized in that in the coacervation method, the porous microcapsule membrane material is selected from the following compounds. [1] Styrene-butadiene copolymer [2] Styrene-maleic anhydride copolymer [3] Gelatin [4] Gelatin-gum arabic system (5) The photopolymerization initiator itself is chemically changed by light energy. A compound that causes a chemical change and generates a polymerization initiating species, or a sensitizer that causes a chemical change due to light energy, and a polymerization initiating species generator that reacts with the chemically changed sensitizer to generate a polymerization initiating species. The light and heat sensitive recording material according to claim 1, characterized in that: (6) The porous microcapsule layer has different photosensitive wavelengths (at least each photopolymerization initiator has a photosensitive wavelength of 50 nm).
2. The photosensitive and thermosensitive recording material according to claim 1, comprising at least two different types of porous microcapsules each separately containing photopolymerization initiators separated by m or more. (7) The light and heat sensitive recording material according to claim 1, wherein the dye precursor is a leuco dye. (8) The light and heat sensitive recording material according to claim 1, wherein the polymerizable monomer is a compound that is crosslinked and cured by light energy. (9) The binder has the function of fixing the porous microcapsules in the porous microcapsule layer and preventing them from separating from the developer layer or support, and when heat is applied, 2. The light and heat sensitive recording material according to claim 1, wherein the viscosity is reduced so that the inclusions released from the porous microcapsules can be transferred to the color developer layer.