JPH01319045A - Color image forming method - Google Patents

Abstract

PURPOSE:To obtain bright colors by superposing a color transfer sheet formed with the specular image of an original picture with a white or transparent toner on a color transfer sheet to a transfer member and heating the same. CONSTITUTION:The specular image of the original picture is formed of the white or transparent toner on the color transfer sheet formed with a coloring agent-dispersed resin layer 13 via a release layer 12 and this color transfer sheet is superposed on the transfer member 6 and is heated. The specular image is formed by turning over an OHP sheet formed with the positive image of the original picture with, for example, a black toner and forming the image with the white or transparent toner from said sheet as an original. The resulted toner image 7 is brought into tight contact with the transfer member 6 and is heated, by which the color image is formed on the transfer member 6. The desired color image is thus obtd. without impairing the brightness thereon.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color image forming method that uses l/ner images obtained by electrophotography etc., and more specifically, the present invention relates to a color image forming method that uses l/ner images obtained by electrophotography etc. The present invention relates to a color image forming method.

[Conventional technology]

Conventionally, an image forming method using electrophotography involves forming an electrical latent image corresponding to the original image on a photoreceptor using a photoconductive substance, and developing the latent image with black toner. Then, the visualized toner image is transferred onto a transfer material and fixed by heating to obtain an image. In recent years, color transfer sheets for creating color images corresponding to original documents using the above-mentioned images have been developed and put into practical use.

FIG. 2 is an example of a conventional method of forming a color image using a color transfer sheet. In the color transfer sheet 1 used in this conventional method, as shown in FIG. 2(a), a release layer 12 and a colorant-dispersed resin layer 13 are sequentially formed on a heat-resistant film 11. To form a color image using this color transfer sheet, first, an image forming apparatus forms a black toner image 3 that is a mirror image of the original on this color transfer sheet 1 (FIG. 2(b)). Next, the release layer 12 is superimposed on the member 2 to be transferred and heated by a heating means such as a pressure heat roller, thereby melting the release layer 12 and making it easier to peel off from the heat-resistant resin film 11.
On the other hand, in the toner layer 3, the binder resin forming the toner is softened and fused to the transfer member 2. Therefore, when the transfer member 2 is peeled off from the color transfer sheet 1 in this state, a color image corresponding to the original is formed on the transfer member (second
Figure (C)).

FIG. 3 shows another example of forming a color image using the color transfer sheet described above.

First, a black toner image 5 corresponding to a document is formed on a member 4 to be transferred using an image forming apparatus. Next, as shown in FIG. 3(b), the above-mentioned color transfer sheet 1 is superimposed on the transfer member 4 on which the black toner image has been formed, and heated by a heating means such as a pressure heat roller, thereby forming a release layer 1.
2 is melted and easily peeled off from the heat-resistant resin film 11, and the binder resin forming the toner in the negative toner layer 5 is softened and fused to the colorant resin layer 13.

[Problems to be Solved by the Invention] However, as can be seen from FIGS. 2 and 3, the color image obtained by the color transfer sheet produced by the above-mentioned conventional method is layer(
Since the base of the chromatic color component is a black toner layer, the sharpness of the chromatic color is impaired, resulting in a dull color (chromatic) image.Especially when the colorant-dispersed resin layer is a light color such as yellow, In this case, the image is more influenced by the base, resulting in a dark image.Furthermore, it is not possible to form a color image with translucency, so it has not been possible to color, for example, an OHP sheet.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a method for forming a color image without impairing the vividness of the colors (chromatic colors).

Another object of the present invention is to provide a method for forming a translucent color image using a color transfer sheet.

[Means for solving the problem] A mirror image of the original image is formed using white or transparent toner on a color transfer sheet in which a colorant-dispersed resin layer is formed on a heat-resistant resin film via a release layer. , the color transfer sheet is superimposed on a transfer member and heated, or an image corresponding to the original image is formed on the transfer member using white or transparent toner, and the colorant-dispersed resin of the color transfer sheet is applied onto the toner image. The objects of the invention are achieved by stacking and heating the layers to form a color image.

[Operation] To obtain the color image of the present invention, first, a mirror image of the original image is converted to white toner or transparent toner onto a color transfer sheet by an image forming apparatus equipped with a developing device containing white toner or transparent toner. to form. Here, the mirror image is formed by, for example, turning over an OHP sheet on which a normal image of the original image is formed using black toner to form an original image, and forming an image using white toner or transparent toner. In particular, it is preferable to use an image forming apparatus having an optical system that can vary the number of reflection mirrors, since a mirror image can be easily obtained. Next, the obtained toner image is brought into close contact with a transfer member and heated by a heating roller or other heating means, thereby forming a color image on the transfer member.

Another method of obtaining a color image according to the present invention is to first form an image corresponding to a document using an image forming apparatus in which a developing device containing white toner or transparent toner is attached to a transfer member. Next, a color transfer sheet is polymerized on the obtained toner image, and a color image is formed on the transfer member by passing the resulting toner image through a heating roller or the like.

FIG. 1 is a schematic cross-sectional view of a color image formed using a color transfer sheet obtained by the method of the present invention.

When a white toner is used for the toner layer 7, the surface of the white toner image 7 is coated with the chromatic colorant-dispersed resin layer 13 in this way.
Because of the coating, the formed color (chromatic color) image is not affected by the hue of the underlying toner layer, and a desired color image can be obtained without loss of vividness. On the other hand, when a transparent toner is used for the toner layer 7, the color image formed will be affected by the base if the transfer member is colored, but if it is used on a white or transparent member, can obtain the desired vivid color image. Particularly when transparent toner is used for the toner layer 7, it is suitable for creating OHP originals, and when creating on glass, beautiful colors can be enjoyed even from the back side.

The invention will be explained in detail below.

The white toner used in the present invention includes a binder resin, a white colorant, and other additives such as a charge control agent and a release agent, and the composition is not particularly limited as long as it does not adversely affect the color tone of the toner. It's not something you can do. The weight ratio of the white colorant to the binder resin is preferably from 2:100 to 50:100.

As the binder resin used in this toner, various resin materials conventionally known as toner binder resins for electrophotography are used. For example, polystyrene, polystyrene
Styrenic copolymers such as butadiene copolymers, styrene/acrylic copolymers, polyethylene, ethylene copolymers such as polyethylene/vinyl hydrochloride copolymers, polyethylene/vinyl alcohol copolymers, phenolic resins, epoxy resins, allyl phthalate resins, polyamide resins, polyester resins, maleic acid resins, etc.

The white coloring agents used in this toner include zinc white,
Examples include titanium oxide, tin oxide, antimony white, zinc sulfide, zinc oxide, barium carbonate, clay, silica, white carbon, talc, alumina 1, and pallite.

As the charge control agent used in this toner, a known colorless or white one is used as it does not adversely affect the color tone of the white toner. Positive charge control
For purposes of use, organic compounds having a basic nitrogen atom, such as basic dyes, aminohyrine, pyrimidine compounds,
Polynuclear polyamine compounds, aminosilanes, or fillers surface-treated with these are used, and for negative charge control, carboxy group-containing compounds such as metal chelates of alkyl salicylic acids are used. . These charge control agents are preferably used in an amount of 1 to 10% by weight per toner.

Further, examples of the release agent used in this toner include silicone oil, low molecular weight olefin resins, and various waxes.

The white toner is obtained by melting and kneading the above components, cooling them, and then crushing and classifying them. It can also be obtained by dispersing toner ingredients in a resin solution and then spray granulating the resultant.

Further, a transparent toner can be produced by removing the white colorant component from the above-described white toner composition.

These white toner and transparent toner can be suitably selected and used depending on the color tone of the transfer material, but the transparent toner is preferably used when the transfer material is white or close to white. If the transfer material is colored, the white toner is preferably used with increased hiding power depending on the refractive index of the binder resin and the particle size and content of the white colorant.

Furthermore, the color transfer sheet used in the present invention is
The heat-resistant resin film can be appropriately selected based on its thermal conductivity, and polyethylene terephthalate (hereinafter referred to as P-T) is used because of its thermal conductivity.

) is preferred, and those rolled to a thickness of 40 μm to 120 μm, particularly 50 to 100 μm are used.

Various waxes are used for the release layer, including animal waxes such as beeswax, selanka wax, and beef tallow, vegetable waxes such as carnauba wax, petroleum waxes such as paraffin wax and microcrystalline wax, polyethylene wax, and other synthetic waxes. Waxes, such as polyhydric alcohol esters of higher fatty acids, higher ketones, higher amines, higher amides, condensates of higher fatty acids and amines, synthetic paraffins and chlorinated paraffins, silicone oils, etc.
It is formed to have a thickness of 2 μm to 0.3 μm.

In addition, the resin used in the colorant-dispersed resin layer is preferably one that is compatible with the binder resin of white toner (transparent toner). Known alcohol-soluble resins such as Blueul, polyvinyl butyral, polyvinylpyrrolidone, and polyacrylic acid may also be used. Examples of colorants to be dispersed in these resins include the following. Blue pigments: cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrenblue-1 (R3, BC), indigo purple pigment Cobalt purple, manganese purple, Faust violet B1 Methyl violet lake Green pigments...Chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B1 naphthol green B, green gold, acid green lake, malachite green Lake, Phthalocyanine Green Red Pigment... Red Garla, Red Red, Red Red, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Phise Red, Para Chlororthonitroaniline Red, Lysol Fast Scarlet G1 Brilliant Fast Scarlet, Vermilion, Brilliant Carmine BS, Permanent Red (F 2R, F 4R, FRL, FRLL,
F4RH), Fast Scarle Sotho VD, Belkan Fast Rupine B1 Risor Rend, Roukire Ndo (C
1D), Anfusian B1 Brilliant Scarlet C
1 Risor Rubin GK, Permanent Red F 5R
, Brilliant Carmine 6B.

Pigment Scarlet 3B, Bordeaux 5B1 Toluidine Maroon, Permanent Bordeaux F2 and 2 Helio Bordeaux BL, Bordeaux 10B1 Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y1 Alizarin Lake, Thioin Dico Red B, Thio Indigo maroon yellow pigment... Naphthol Yellow S, Hansa Yellow (1
'OG, 5G, G), cadmium yellow, yellow iron oxide, yellow ocher, yellow ocher, lead cyanamide, calcium leadate, Hansa yellow (GR, A, RN, R), pigment yellow,
Benzine Yellow (GSGR), Permanent Yellow (N
CC;), Palcan Fast Yellow (50, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow GL or C,1,5olvent Yellow 6
0, C, l.

5olvent Red 27, C, 1, 5olven
Examples include various oil-soluble dyes such as T Blue 35. These colorants vary depending on the desired image tone.
They may be used alone or in combination of two or more, and dispersed in the resin in an amount that provides sufficient image density, for example, 1 to 30% by weight, preferably 1 to 10% by weight.

Then, the mixture of resin and colorant mentioned above is dissolved in a solvent, and silicone oil is applied using an air knife coater, a roll coater, a bar coater, a blade coater, a slide hopper coater, a gravure coater, or a combination thereof, followed by linear tunnel drying. Baking drying is performed using various drying devices such as a hot air dryer such as a dryer, an arch dryer, an air loop dryer, a sine curve air float dryer, a dryer using infrared rays, a heated dryer, a microwave, etc. 40μm1
A base material for a color transfer sheet is formed by coating and drying preferably to a thickness of about 10 μm to 30 μm. Further, the colorant-dispersed resin layer is molded to have a softening point of 100 to 150°C, a volume resistivity of 109 to 1013 Ω'cm, and a surface resistivity of 109 to 101'' Ω·cm.

Examples are shown below.

(Example) After carbonization on the back ■ Creation of color transfer sheet Apply silicone oil to a thickness of 0.05 μm on a 50 μm PET film using an air knife coater,
It was dried at 0°C for 1 hour. Next, from above the silicone oil layer, an 80% resin solution prepared by dissolving polyvinyl butyral resin with a melting point of 160'C and 30 parts by weight of cobalt blue per 100 parts by weight of resin in methanol was coated with a roll coater to a thickness of 20 μm. was applied evenly. and,
This was dried at 120°C for 3 hours to create a blue color transfer sheet. The surface resistance of this transfer sheet is 8゜5×lO''′Ω, and the volume resistivity is 4.6×10′Ω・c
■Preparation of white toner Styrene-acrylic copolymer 100 parts by weight Titanium oxide pigment: CR-EL (manufactured by Ishihara Sangyo Co., Ltd.) 10 parts by weight Charge control agent: Bontron E-80 (Orient Chemical Co., Ltd.) 1 weight Low molecular weight IT polypropylene: 1.5 parts by weight of Viscol 550P (manufactured by Sanyo Chemical Co., Ltd.) A mixture of the above formulation was melt-kneaded, cooled, pulverized and classified to obtain a white toner.

The respective developing devices containing the white toner and ordinary black toner obtained above were installed in an electrophotographic copying machine DC-2055 (
(manufactured by Sanda Kogyo Co., Ltd.), and first, a normal image of the original image was formed on an OHP sheet using black toner. Then, this OHP sheet was turned over, and a white toner image having a mirror image white toner image was formed on the color transfer sheet obtained above as a document.

Next, the toner image on the obtained transfer sheet was transferred to a thickness of 2
When it was superimposed on a nn plate and passed through a heating roller, a blue image corresponding to the original original image was obtained on the plate. The resulting image was completely beautiful, with no dullness and a vivid blue color.

1 month λ ■ Creation of color transfer sheet Apply silicone oil to a thickness of 0.05 μm on a 50 μm PET film using an air knife coater.
It was dried at 100°C for 1 hour. Next, from above the silicone oil layer, a polystyrene-acrylic copolymer resin with a melting point of 160°C and 30 parts by weight of Naphthol Yellow S per 1 part by weight of resin were dissolved in tetrahydrofuran.
% resin solution was uniformly applied to a thickness of 20 μm using a roll coater. This was then dried at 120°C for 3 hours to produce a yellow color transfer sheet. This transfer sheet had a surface resistance of 8.9×10”Ω and a volume resistivity of 4.8×10”Ω·cm.

■Preparation of transparent toner Polymethyl methacrylate 100 parts by weight Charge control j
n-agent Nibontron E-80 (Orient Chemical Co., Ltd.) 1 part by weight Low molecular weight polypropylene: Viscol 550P (manufactured by Sanyo Chemical Co., Ltd.) 1.5 parts by weight A mixture consisting of the above formulation was melt-kneaded, cooled, pulverized, and classified. A clear toner was obtained.

The developing device containing the transparent toner obtained above was installed in an electrophotographic copying machine DC-2055 (manufactured by Sanda Kogyo Co., Ltd.), and first,
A normal image corresponding to the original image was formed on an OHr-' sheet using transparent toner. Then, when the color transfer sheet obtained above was superimposed on this OHP sheet and passed through a heated roller, a yellow image corresponding to the original image was obtained on the OHP sheet. It was a beautiful thing with a bright yellow color that was not overpowering.Also,
Even when viewed from the back side of this OHP sheet, it was a beautiful yellow color.

■Preparation of color transfer sheet Silicone oil was applied to a thickness of 0.05 μm on a 50 μm PE'T film using an air knife coater, and dried at 100'C for 1 hour. Next, from above the silicone oil layer, a polyvinyl butyral resin with a melting point of 160°C and an 80% resin solution prepared by dissolving 30 parts by weight of cadmium red per 100 parts by weight of resin in TeI-Rahi-Lonlan were rolled. It was applied uniformly to a thickness of 20 μm using a coater.Then, this was dried at 120'C for 3 hours to create a red color transfer sheet.The surface resistance of this transfer sheet was 8°6 x 109Ω, and the volume resistivity was is 4
, 7×10 9 Ω·cm.

■Preparation of transparent toner Polymethyl methacrylate 100 parts by weight Charge control agent: Bontron E-80 (Orient Chemical Co., Ltd.) 1 part by weight Low molecular weight 1 Polypropylene: Viscole 550P (manufactured by Sanyo Chemical Co., Ltd.) 1.5 parts by weight Mixture consisting of the above formulation After melt-kneading, the mixture was cooled, pulverized, and classified to obtain a transparent toner.

A developing device containing the transparent toner obtained above was installed in an electrophotographic copying machine DC-2055 (manufactured by Sanda Kogyo Co., Ltd.), and a transparent toner image having a transparent toner image was formed on the color transfer sheet obtained above. .

Next, the toner image on the obtained transfer sheet was superimposed on a glass plate, and the transfer sheet was heated from above with a heating roller, so that a red image that was a mirror image of the original original image was obtained on the glass plate. The resulting image was beautiful without dullness and without loss of vivid red color. When viewed from the back of the glass plate, a bright red color image corresponding to the original could be seen.

(Effects of the Invention) According to the present invention, a toner image of a copy obtained by an image forming apparatus such as a copying machine can be easily transferred to another transfer material in color (
It is possible to create a color transfer sheet that can be transferred as an image (chromatic color), and the resulting color image does not lose its vividness, and there is no color mixing within the image or at the edges of the image, making it possible to make the color image look more beautiful. . Further, a color image can be easily formed even on a transparent member, and a desired color image can be enjoyed even from the back side.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a schematic cross-sectional view of a color image formed using a color transfer sheet obtained by the method of the present invention, and FIG. FIG. 3 is a schematic cross-sectional view showing the process of creating a transfer sheet. FIG. 3 is a schematic cross-sectional view showing another process of creating a color transfer sheet using a conventional method. The river fish numbers in the figure each represent the following contents. 1.--Light color transfer sheet, 11-Heat resistant resin film, 12.. Peeling layer, 13.
- Colorant-dispersed resin layer, 2.4.6- Transfer member, 3.5... Toner layer, 7-...
- white or transparent toner layer;

Claims (2)

[Claims] (1) A mirror image of the original image is formed using white or transparent toner on a color transfer sheet in which a colorant-dispersed resin layer is formed on a heat-resistant resin film via a release layer, and color transfer having the mirror image is performed. A color image forming method comprising heating a sheet overlapping a transfer member. (2) Color transfer in which an image corresponding to the original image is formed using white or transparent toner on a transfer member, and a colorant-dispersed resin layer is formed on the toner image and a heat-resistant resin film via a release layer. A method for forming a color image, which comprises superimposing sheets so that the colorant-dispersed layer of the color transfer sheet and the toner image are in contact with each other, and heating the sheets.