JPH08123069A - Microcapsule toner and photosensitive recording medium - Google Patents

Abstract

PURPOSE: To provide a microcapsule toner and photosensitive recording medium so that an image of high resolution with little pixel defect can be formed. CONSTITUTION: In this capsule toner, the number of photosensitive capsules having <=3μm particle diameter is controlled to <=0.1% of the number of whole photosensitive capsules. Since almost no capsule having too small particle diameter is present in the toner, the photosensitive capsules are surely broken in an area not exposed to light, namely, in the area where the material included in the capsules is not hardened. Further, the volume of capsules having >=4μm particle diameter is constrolled to <=0.1vol.% of the volume of whole photosensitive capsules. Blotting is thereby avoided, and light can reach to the bottoms of photosensitive capsules in an exposed area so that the material included in the capsules can be completely hardened. As a result, an image of high resolution having no pixel defect can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcapsule toner and a photosensitive recording medium used in an image forming apparatus such as a printer.

[0002]

2. Description of the Related Art Conventionally, an image forming method using a photosensitive capsule has been studied. For example, Japanese Patent Application Laid-Open Nos. 5-66559, 5-68871, and 5-297552 by the applicant of the present application have been studied. The publications and the like disclose microcapsule toners composed of photosensitive capsules whose mechanical strength changes in response to light. Further, it is also practiced to prepare a photosensitive recording medium in which such a photosensitive capsule is preliminarily carried on a film and utilize this for image formation.

When an image is formed using such a microcapsule toner or a photosensitive recording medium, the photosensitive capsule is exposed to light, the photosensitive material contained in the capsule is cured, and then pressure is applied. An image is formed by destroying only the weakly sensitive photosensitive capsule, causing the image forming material such as dye contained in the capsule to flow out, and transferring this to an image receiving paper.

[0004]

By the way, in recent years, in the field of image formation as described above, much research has been conducted to obtain higher quality images, and in particular, bleeding, spots and the like that occur in images are eliminated. There is a demand for development of a microcapsule toner and a photosensitive recording medium capable of obtaining a high-resolution image with few pixel defects.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a microcapsule toner and a photosensitive recording medium capable of forming an image having a high resolution with few pixel defects. And

[0006]

MEANS FOR SOLVING THE PROBLEMS, ACTIONS AND EFFECTS OF THE INVENTION The inventor of the present invention has made earnest studies to solve the above problems, and as a result, a photosensitive capsule having a particle diameter of 3 μm or less and a particle diameter of 40 have been obtained.
The inventors have found that the photosensitive capsule of μm causes the image defect and the deterioration of resolution, and completed the invention of the present application.

That is, the photosensitive capsules having a particle size of 3 μm or less are small in particle size, and are therefore less likely to be broken by the pressurization regardless of whether the capsule contents are hardened or not. Therefore, it hardly contributes to image formation, resulting in deterioration of resolution and pixel defects.

Further, in the case of capsules having a size of 40 μm or more, since the volume of the inclusions is large, bleeding occurs when the inclusions flow out, which causes a decrease in resolution. Further, as shown in FIG.
In (1), since the particle size is large, the light from the exposure light source 103 does not reach the capsule bottom portion 105 farthest from the light source 103 sufficiently, and the photosensitive capsule 101 is not completely cured, so that a pixel defect occurs.

The present invention thus completed has a microcapsule containing a photosensitive capsule containing at least an image forming material such as a dye or a pigment and a photosensitive material which is cured in response to light, as described in claim 1. The number of photosensitive capsules having a particle size of 3 μm or less is 0.1% or less with respect to the total number of photosensitive capsules, and the particle size is 40%.
The volume of the photosensitive capsules of μm or more is 0.1% or less with respect to the volume of all the photosensitive capsules.

Further, as described in claim 2, a photosensitive capsule containing at least an image forming material such as a dye or a pigment and a photosensitive material which is cured in response to light is provided on a support such as a film. In the carried photosensitive recording medium, the number of photosensitive capsules having a particle size of 3 μm or less is 0.1% or less with respect to the total number of photosensitive capsules, and the particle size is 40 μm.
It is characterized in that the photosensitive capsules are carried on the support so that the volume of the photosensitive capsules of m or more is 0.1% or less with respect to the total volume of the photosensitive capsules.

In the microcapsule toner and photosensitive recording medium of the present invention, the number of photosensitive capsules having a particle diameter of 3 μm or less is 0.1 with respect to the total number of photosensitive capsules.
When the content is not more than%, there are almost no capsules having a too small particle size, so that the photosensitive capsules are surely destroyed in the unexposed portion, that is, in the place where the inclusions are not cured. Therefore, pixel defects are eliminated and an image having high resolution is obtained. Further, by making the volume of the capsule having a particle diameter of 40 μm or more 0.1% or less with respect to the volume of all the photosensitive capsules, bleeding is eliminated, and in the exposed portion, the light is sufficiently exposed to the bottom of the photosensitive capsule. As a result, the capsule encapsulation is completely cured. As a result, an image having high resolution can be obtained without pixel defects.

Here, as the image forming material, for example, a dye, an inorganic pigment, an organic pigment, and a dye precursor that changes color by reacting with a color developer can be used. As the dye, xanthene dye, coumarin dye, merocyanine dye, thiazine dye, azine dye, methine dye, oxazine dye, phenylmethane dye, cyanine dye, azo dye, anthraquinone dye, pyrazoline Series dyes, stilbene series dyes, quinoline series dyes, leuco dyes and the like are preferably used. As an organic pigment,
Monoazo pigments, disazo pigments, azo lake pigments, quinacridone pigments, perylene pigments, anthrapyrimidine pigments, isoindolinone pigments, slene pigments, phthalocyanine pigments and the like are preferable. As an inorganic pigment,
Carbon black, yellow lead, red iron oxide, titanium oxide, molybdenum red, cadmium red, cobalt blue, chrome green and the like are preferable. Desirable dye precursors are diphenylmethane compounds, triphenylmethane compounds, bisphenylmethane compounds, xanthene compounds, thiazine compounds, fluorane compounds, spiropyran compounds, and the like, and mixtures thereof.

The photosensitive material is a substance which is sensitive to light and hardens, and a mixture of a polymerizable substance and a photopolymerization initiator is usually used. As the polymerizable substance, for example, an unsaturated compound can be used, and examples thereof include a compound having an ethylenically unsaturated group and a compound having an epoxy group. Among them, a compound having an ethylenically unsaturated group is preferable. Examples of the compound having an ethylenically unsaturated group include acrylic acid and salts thereof, acrylic acid esters, acrylamides, methacrylic acid and salts thereof, methacrylic acid esters, methacrylamides, maleic anhydride, maleic acid esters, and itacone. Acid esters, styrenes, vinyl ethers, vinyl esters, N-vinyl heterocycles,
Examples include allyl ethers, allyl esters, and derivatives thereof. Among these, it is desirable to use acrylic acid esters or methacrylic acid esters.

Specific examples of acrylic acid esters include:
Butyl acrylate, cyclohexyl acrylate, ethylhexyl acrylate, benzyl acrylate, furfuryl acrylate, ethoxyethyl acrylate,
Tricyclodecanyloxy acrylate, noniphenyloxyethyl acrylate, hexanediol acrylate, 1,3-dioxolane acrylate, hexanediol diacrylate, butanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, tricyclodecane dimethylol Diacrylate, tripropylene glycol diacrylate, bisphenol A diacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, hexaacrylate of caprolactone adduct of dipentaerythritol, trimethylolpropane triacrylate, propylene oxide adduct of trimethylolpropane Triacrylate, polyoxyethylene Diacrylate of bisphenol A, polyester acrylate, polyurethane acrylate.

Specific examples of methacrylic acid esters include butyl methacrylate, cyclohexyl methacrylate, ethylhexyl methacrylate, benzyl methacrylate, furfuryl methacrylate, ethoxyethyl methacrylate, tricyclodecanyloxy methacrylate, noniphenyloxyethyl methacrylate,
Hexanediol methacrylate, 1,3-dioxolane methacrylate, hexanediol dimethacrylate, butanediol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol dimethacrylate, tricyclodecane dimethylol dimethacrylate, tripropylene glycol dimethacrylate, bisphenol A dimethacrylate , Pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, hexamethacrylate of dipentaerythritol caprolactone adduct, trimethylolpropane trimethacrylate, trimethacrylate of propylene oxide adduct of trimethylolpropane, dimethacrylate of polyoxyethylenated bisphenol A , Polies Methacrylate, polyurethane methacrylate.

These polymerizable substances may be used alone or as a mixture of two or more. The photopolymerization initiator is one that is sensitive to light and initiates polymerization of the resin, and a direct cleavage type, hydrogen abstraction type, two-molecule type initiator or the like can be used. Specific examples of these initiators include aromatic carbonyl compounds, acetophenones, organic peroxides, diphenylhalonium salts, organic halides, 2,4,6-substituted-S-triazines,
2,4,5-triarylimidazole dimer, azo compound, dye borate complex, iron arene complex, titanocene compound and the like can be mentioned. Among them, benzophenone, benzyl, xanthone, thioxanthone, anthraquinone,
Acetophenone, 2,2-dimethyl-2-morpholino-4′-methylthioacetophenone, benzoyl peroxide, 3,3 ′, 4,4′-tetra (tertiarybutylbenzophenone), diphenyliodonium bromide, diphenyliodonium chloride, tetrachloride Carbon, carbon tetrabromide, 2,4,6-tristrichloromethyl-S-triazine, (η ⁵ -2,4-cyclopentadien-1-yl) [(1,2,3,4,5,6- η)-
(1-Methylethyl) benzene] iron (1+) hexafluorophosphate (1-) and the like are preferably used.
Further, these photopolymerization initiators may be used alone or as a mixture of two or more kinds.

Further, in the above-mentioned photosensitive capsule, an inorganic material or an organic material may be used as a material for forming an outer peripheral portion surrounding the image forming material, the photosensitive material and the like. Preferably,
It is more preferable to use a material that is an organic substance and that allows sufficient light transmission. Specific examples include gelatin, gum arabic, starch, sodium alginate, polyvinyl alcohol, polyethylene, polyamide, polyester, polyurethane, polyurea, polyurethane, polystyrene, nitrocellulose, ethyl cellulose, methyl cellulose, melamine-formaldehyde resin, urea-formaldehyde resin, and the like. And copolymers thereof.

The photosensitive capsule can be manufactured by a method already known in the art. Examples of such a production method include a phase separation method from an aqueous solution as disclosed in US Pat. Nos. 2,800,457 and 2,800,458, etc.
1974, 42-446, 42-771 and the like, the interfacial polymerization method, JP-B-36-91.
68, JP-A-51-9079, etc., in-situ method by polymerization of monomers, British Patent No. 952.
No. 807 and No. 965074, there are melt dispersion cooling methods and the like, but not limited thereto.
However, in the present invention, since the particle size of the photosensitive capsule is limited, a manufacturing method that falls within this range is more preferable. If the particle size does not fall within the limit range, operations such as filtering and centrifugation may be performed after the capsule is manufactured to remove the photosensitive capsules having a particle size of 3 μm or less and a particle size of 40 μm or more.

Regarding the average particle diameter of the photosensitive capsules, in order to further improve the image resolution,
20 μm is preferable, and 8 to 15 μm is even more preferable. Further, the support in the photosensitive recording medium of claim 2 is preferably a film having a thickness of several tens of μm to 100 μm, but is not particularly limited thereto.

[0020]

EXAMPLES Examples embodying the present invention will be described below. Example 1 In Example 1, the following (1) to (9)
By the procedure of, to create a photosensitive recording medium carrying a photosensitive capsule on the film, using this to form an image,
The resolution of the obtained image was examined.

(1) 100 parts by weight of a mixture of polyethylene glycol diacrylate and dipentaerythritol hexaacrylate as a polymerizable substance in a ratio of 3: 4, 100 parts by weight of high molecular polyurethane as a dispersant, and an azobarium lake pigment. Disperse 3 parts by weight. 0.5 parts by weight of a coumarin dye, 2 parts by weight of N, N-dimethylaniline, and a photopolymerization initiator (η ⁵ -2,4-cyclopentadien-1-yl) [(1,2,3,3) 4,5
6-η)-(1-methylethyl) benzene] iron (1+)
Add 3 parts by weight of hexafluorophosphate (1-),
A hydrophobic liquid component was obtained by heating at 100 ° C. for 10 minutes.

(2) 100 cc of a 1: 1 aqueous solution of a 5% polystyrene sulfonic acid partial sodium salt aqueous solution as an emulsifier and a 5% styrene-maleic anhydride copolymer aqueous solution.
Add the hydrophobic liquid component prepared in (1) above,
This was stirred with a homogenizer at 6000 rpm for 5 minutes. As a result, a so-called O / W emulsion in which the liquid component was present as droplets having a size of 5 to 20 μm in the aqueous solution was obtained.

(3) Separately from the emulsion of (2) above, a commercially available melamine powder was added to a 37% aqueous formaldehyde solution and adjusted to pH 9.0 with a sodium hydroxide solution, and this was heated at a water temperature of 60 ° C. for 30 minutes. A melamine formaldehyde prepolymer was obtained.

(4) To the O / W emulsion prepared in (2) above, the melamine-formaldehyde prepolymer prepared in (3) was added, and the mixture was stirred at 100 to 300 revolutions with an Ajihomomixer or the like while keeping the water temperature. The temperature was maintained at 80 ° C. for 5 hours, then adjusted to pH 7 and cooled to room temperature. As a result, a melamine-formaldehyde resin wall material was deposited around the droplets of the O / W emulsion, and a yellow image-recording photosensitive capsule (photosensitivity near 450 nm) was obtained.

(5) In the operation of (1) above, 3 parts by weight of a quinacridone pigment and 0.5 part by weight of an isoindolinone dye are used as magenta pigments instead of the azobarium lake pigment and the coumarin dye. Was used to prepare a photosensitive capsule in the same manner as in (1) to (4) above. As a result, a magenta image-recording photosensitive capsule (photosensitivity near 550 nm) was obtained.

(6) In the above (1), 3 parts by weight of a phthalocyanine pigment and 0.3 part by weight of a squarylium dye are used as a cyan pigment in place of the azobarium lake pigment and the coumarin dye. 1) ~
Photosensitive capsules were prepared in the same manner as in (4). As a result, a cyan image recording photosensitive capsule (photosensitive sensitivity of 65
(Near 0 nm) was obtained.

(7) An appropriate amount of the three types of photosensitive capsule emulsions obtained in (4), (5) and (6) above is mixed, sieved to remove capsules of 40 μm or more, and then centrifuged. It was washed using a machine and capsules with a size of 3 μm or less were removed. In this operation, the number of photosensitive capsules having a particle size of 3 μm or less becomes 0.1% or less with respect to the total number of photosensitive capsules, and the volume of capsules having a particle size of 40 μm or more becomes the volume of all photosensitive capsules. To 0.1%
Repeatedly until the following. Whether a capsule having a desired particle size was obtained was evaluated by a Coulter counter. The average particle size of the photosensitive capsules is 8.7.
μm.

(8) The yellow obtained in (7) above,
Magenta / Cyan mixed photosensitive capsule emulsion 20
10 g of a 10% polyvinyl alcohol (PVA) solution was added to 0 cc, coated on a polyethylene terephthalate (PET) film having a thickness of 38 μm, and dried to obtain a photosensitive recording medium.

As schematically shown in FIG. 1, the photosensitive recording medium 1 comprises a film 2 and a photosensitive capsule 3 carried on the film 2. The photosensitive capsule 3 is composed of an outer shell 4 and a liquid component 5 inside the outer shell 4, and in the liquid component 5,
It contains the above-mentioned pigment, dye, polymerizable substance, photopolymerization initiator, and the like.

(9) Using the obtained photosensitive recording medium,
Image recording was performed. As an image recording method, first, reflection exposure is performed using an exposure apparatus similar to that used in a normal copying machine, and this is overlapped with a transfer sheet coated with an absorption layer, and a pressure roller, etc. The pressure development is performed by the pressure means. Then, the uncured photosensitive capsules are destroyed by the pressure, the contained pigments and dyes flow out, and are transferred to the transfer sheet, whereby a full-color image is formed on the transfer sheet.

When the obtained image was observed,
No bleeding or spots were found in the image, and it was found that an image having high resolution without pixel defects was obtained. [Example 2] In Example 2 as well, a photosensitive recording medium was prepared in substantially the same manner as in Example 1 and image recording was performed using the same. Are partly different.

That is, in the second embodiment, when preparing the photosensitive capsule, first, 1% of a 5% polystyrenesulfonic acid partial sodium salt aqueous solution as an emulsifier and a 5% styrene-maleic anhydride copolymer aqueous solution were prepared. An aqueous solution mixed with 1: was prepared, and a hydrophobic liquid component prepared in the same manner as in (1) above was dropped into 100 cc of this emulsion through a glass filter having a hole of about 5 μm. As a result, an O / W emulsion in which the liquid component was present as droplets having a size of about 10 μm in the aqueous solution was obtained. Then, using this O / W emulsion, (4) of Example 1
An emulsion containing a yellow image-recording photosensitive capsule was prepared in the same manner as in.

Further, (5) and (6) of the above-mentioned Embodiment 1
An emulsion containing a photosensitive capsule for recording a magenta image and an emulsion containing a photosensitive capsule for recording a cyan image were prepared by changing the dye in the same manner as in. The three types of photosensitive capsule emulsions obtained as described above were mixed in appropriate amounts, and the particle size was measured with a Coulter counter. The number distribution of 3 μm or less was 0.1% or less, and the volume distribution of 40 μm or more was 0. 0.1% or less, and the average particle size was 9.3 μm. That is, by preparing an O / W emulsion using a glass filter, a photosensitive capsule satisfying the particle size condition of the present invention is obtained without performing filtering as in (7) of Example 1 above. I was able to.

Then, this mixed emulsion was applied to a PET film in the same manner as in (8) above to prepare a photosensitive recording medium, and using this, image recording was carried out in the same manner as in Example 1 above. As a result of observing the image, it was found that as in Example 1, no bleeding or spots were found in the image, and an image having high resolution without pixel defects was obtained.

Next, Comparative Examples 1 to 3 carried out for comparison with the above Examples 1 and 2 will be described. [Comparative Example 1] In the same manner as in Example 1 above, a yellow, magenta, and cyan mixed photosensitive capsule was coated on a PET film to prepare a photosensitive recording medium.

However, in the photosensitive capsules of Comparative Example 1, the number of photosensitive capsules having a particle size of 3 μm or less was 3.1% of the total number of the photosensitive capsules, and the volume of capsules having a particle size of 40 μm or more. Was 2.6% based on the total volume of the photosensitive capsules. Using this photosensitive recording medium, image recording was carried out in the same manner as in Example 1 above, and the obtained image was observed. As a result, there were many blurs and spots, and there were more pixel defects and resolution than in Examples 1 and 2 above. It turned out to be inferior.

Comparative Example 2 The photosensitive capsules of Comparative Example 1 (before being coated on a PET film) were subjected to a centrifugal separator to remove photosensitive capsules having a particle size of 3 μm or less. As a result, the number of photosensitive capsules having a particle size of 3 μm or less was 0.08% with respect to the total number of photosensitive capsules, and the volume of photosensitive capsules having a particle size of 40 μm or more relative to the volume of all photosensitive capsules. Was 2.8%. This was applied onto a PET film in the same manner as in the above example to prepare a photosensitive recording medium.

Using this, image formation was performed in the same manner as in Example 1, and the obtained image was observed. As a result, there were many bleeds and spots, and in terms of pixel defects and resolution compared to Examples 1 and 2 above. Turned out to be inferior. [Comparative Example 3] The photosensitive capsule used in Comparative Example 1 was
It was passed through a sieve of 440 mesh (aperture diameter 32 μm) to remove the photosensitive capsules having a particle diameter of 40 μm or more. As a result, the volume of photosensitive capsules having a particle size of 40 μm or more was 0% with respect to the volume of all photosensitive capsules, and the number of photosensitive capsules having a particle size of 3 μm or less was 3 with respect to the total number of photosensitive capsules. It became 2%. This was applied onto a PET film in the same manner as in the above example to prepare a photosensitive recording medium.

When an image was formed using this using the same method as in Example 1, the bleeding was eliminated, but the spots were not eliminated. Although the spots in Comparative Examples 1 and 2 were spots in which the color appeared darker than the surroundings,
The spots in this case are spots that appear lighter than the surrounding color, and it is considered that this is because the photosensitive capsules having a particle size of 3 μm or less are less likely to be broken.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to these and can be implemented in various modes. For example, the emulsion containing the photosensitive capsules prepared as in the above-mentioned examples is dried by a drying method such as a spray drying method, a vacuum drying method, a freeze drying method, etc., as described in JP-A-5-66559. By doing so, the microcapsule toner of the present invention can be obtained. When an image is formed using this microcapsule toner, an image having high resolution without pixel defects can be obtained as in the first and second embodiments.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a photosensitive recording medium of an example.

FIG. 2 is an explanatory diagram for explaining the operation of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photosensitive recording medium 2 ... Film 3 ... Photosensitive capsule 4 ... Outer shell part 5 ... Liquid component

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B01J 13/14 9342-4D B01J 13/02 B

Claims (2)

[Claims] 1. A microcapsule toner containing a photosensitive capsule containing at least an image forming material such as a dye or a pigment and a photosensitive material which is cured in response to light, wherein the photosensitive capsule has a particle diameter of 3 μm or less. Is 0.1% or less with respect to the total number of photosensitive capsules, and the particle size is 4
A microcapsule toner, wherein the volume of the photosensitive capsules of 0 μm or more is 0.1% or less with respect to the volume of all the photosensitive capsules. 2. A photosensitive recording medium in which a photosensitive capsule containing at least an image forming material such as a dye or a pigment and a photosensitive material which is cured in response to light is carried on a support such as a film. The number of photosensitive capsules having a particle size of 3 μm or less is 0.1% or less with respect to the total number of photosensitive capsules, and the particle size is 4
A photosensitive recording medium, wherein the photosensitive capsules are carried on a support so that the volume of the photosensitive capsules of 0 μm or more is 0.1% or less with respect to the volume of all the photosensitive capsules.