JPH06100846B2 - Color liquid developer for electrostatic photography - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid developer for electrostatic photography, and more specifically, an electrostatic photography using a colorant obtained by flushing a mixed pigment of a coloring dye / pigment and mica or a mica-treated pigment. The present invention relates to a color liquid developer.

[Prior art]

Color liquid developers for electrostatic photography use colorants as resins (binders)
It is prepared by uniformly dispersing a toner coated with (1) in a carrier liquid having a high insulating property and a low dielectric constant. Since such color liquid developers generally have high transparency, they have the property of being easily influenced by the base color. For this reason,
For example, when an image is formed on a dark red background with green toner, the image does not become green but appears black due to the influence of the background color (red).

By the way, as one of means for obtaining a clear image, a toner image having a specific color is formed by hiding the background color on a color transfer paper without forming the toner image in a natural color by a subtractive color method. Often it is desired to form, but in such cases the use of conventional color liquid developers is not suitable.

〔Purpose〕

The present invention provides a color liquid developer for electrostatic photography containing a colorant having excellent opacity (hiding power) as a toner component.

Structure The present invention provides a color liquid developer for electrostatic photography, comprising a toner liquid containing a colorant and a binder as main components in a carrier liquid having a high insulating property and a low dielectric constant. Pigment
It is characterized in that a mixed pigment of 20 to 80 parts by weight and mica or a mica-treated pigment of 80 to 20 parts by weight is subjected to a flushing treatment.

By the way, the inventor of the present invention mixes a coloring dye and a mica or a mixed pigment of a mica-treated mixture with a flushing agent and mixes them in the toner as a colorant (pigment), so that the color tone of each toner becomes uniform and there is no color variation. It has been found that the toner layer can be opaque well,
The present invention has been completed based on such findings.

Examples of the mica used in the present invention and the mica-treated pigment include natural mica such as muscovite, phlogopite, biotite and soda mica, and fluorophlogopite, fluorotetrasilicon mica, artificial mica such as teniolite. Of these, muscovite is particularly suitable for use in the invention. Further, mica titanium obtained by processing muscovite may be used. Mica titanium is titanium dioxide coated on the surface of mica, and is generally called "pearl pigment". Table 1 shows commercially available products of such mica and processed mica.

In addition, Table 2 shows an example of the recently announced production of colored mica titanium.

In the present invention, these dyes and pigments to be coexisted with mica and mica-treated pigments include phthalocyanine blue, phthalocyanine green, sky blue, rhodamine lake, malachite green lake, methyl violet lake, peacock blue lake, naphthol green B, naphthol green. Y, Naphthol Yellow S, Resor Fast Yellow 2G, Permanent Red 4R,
Brilliant Fast Scarlet, Hansa Yellow,
Examples include Benzidine Yellow, Resole Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Permanent Red F5R, Vimento Scarlet 3B and Bordeaux 10B.

The mixing ratio of the mica-based pigment and the colored dye / pigment is in the range of 80 to 20 parts by weight for the former and 80 to 20 parts by weight for the latter.

If the amount of mica-based pigment in the pigment is small, the hiding power will be small, and if it is too large, the coloring power will be poor.
About parts by weight is suitable.

Next, the flushing process will be described. The water-containing paste of the mica type and the coloring dyes and pigments is put in a kneader called a flasher and mixed well together with the resin, the wax or a solution thereof. In this process, the water present in the surroundings of the pigment is replaced by the resin solution and / or wax.
This is taken out from the kneader, the aqueous phase is discarded, the resin solution and / or the pigment in which the pigment is dispersed is dried to remove the solvent, and the obtained lump is crushed. In the present invention, this is referred to as a "flushing-treated colorant". A means for removing water and solvent by reducing pressure while kneading with a kneader may be adopted.

The flushing treatment is known to have very good dispersion, because a water-containing paste can be used as a material and the treatment can be performed while kneading with a kneader. Also,
Resins used in the flushing treatment include natural resin-modified coal resin, natural resin-modified maleic acid resin, dammar, copearl, shellac, gum rosin, cured rosin, ester gum, glycerin ester-modified maleic acid resin, styrene-butadiene copolymer. Resins such as and the like, specifically, for example, the resins and waxes shown below can be used. These resins and waxes may be used alone or as a mixture of several kinds.

(Example of resin) Natural resin modified maleic acid resin MRG, MRG-411, MRG-S, MRG-H, MRP, MRA-L, MRM-42, MRM
−53 (above, Tokushima essential oil), Becca Site 1110, 111,
F231, J811, P120, P720, J-896 (manufactured by Dainippon Ink and Chemicals) Natural resin modified phenolic resin PRG, PRP, SPR-N, SPR-A, SPR-H (above Tokushima Essential oils) Beccasite 1100, 1123, 1126, F-171 (manufactured by Dainippon Ink and Chemicals) Natural resin modified pentaerythritol resin Pentasite P-406, P-423 (manufactured by Dainippon Ink and Chemicals) ) Natural resin modified polyester resin RM-1000, RM-1300, RM-4090, RM-4100 (Made by Tokushima essential oil) ESTEM GUM EG-8000, EG-9000, HG-H, PE, PE-H (Made by Tokushima Hardened rosin TLR-21, TLR-57 (above, Tokushima essential oil) (wax example) Besides the above, sun wax as polyethylene resin
E200, E250P (above, Sanyo Kasei Co.), 2000, 2500, 3000, 40
00,4100,8000B, 5000,6000,7000 (above, made by Chubu Polyethylene Co., Ltd.), Viscose 500P, 6 as polypropylene resin
60P (above, Sanyo Chemical Co., Ltd.), as vinyl chloride resin Dengavinyl SS-100, SS-130, DSS-130, SS-140, SS-8
0, SS-70, SS-Y, SH-250, SH-170, M-70, M-120, MM-9
0, EM-140, VP-30, SE-130, ME-120, ME-180, MHE-100,
PA-100, P-80 (all manufactured by Ki Kagaku Kogyo Co., Ltd.), paraffin wax (softening point 50 to 90 ° C), beeswax (softening point about 60)
℃), natural wax (softening point about 51 ℃) and the like.

Pigment and resin in such flushing treatment and /
Alternatively, the ratio with the wax is 0.1 to 6.0 parts by weight of resin or wax, preferably 0.1 to 0.6 parts by weight, relative to 1 part by weight of the dye or pigment.

In order to prepare a liquid developer using the "flashing-treated colorant" thus obtained, the colorant and the binder are mixed with a small amount of carrier liquid in an attritor, a ball mill,
A concentrated toner may be obtained by kneading and dispersing with a Kitty mill or the like, and if necessary, this may be diluted with a similar carrier liquid to about 5 to 10 times. The ratio of the colorant to the binder is appropriately 1: 1 to 10 (weight). Needless to say, it is advantageous that the general pigment and the mica-based pigment (mica, treated product of mica) in the colorant are of the same system because the image becomes clear.

As the binder here, alkyd resin, rosin-modified phenol formaldehyde resin, polyhydric alcohol ester of hydrogenated rosin, polyacryl or polymethacryl ester resin, styrene resin, chlorinated rubber and the like are used, but especially the following general formula (I) [However, R ¹ is hydrogen or a methyl group, and R ² is —COOC _m H _{2m + 1} or —OCOC _m H _{2m + 1} (m is an integer of 6 to 20). ] A monomer represented by and acrylic acid, methacrylic acid, vinyl pyridine, the following general formula (II) [However, R ³ is hydrogen or methyl, R ⁴ is -COOC _m H _{2m + 1} or -OCOC _m H _{2m + 1 (m} is an integer of from 1 to 5). ] The monomer represented by the following general formula (III) [However, R ⁵ is hydrogen or a methyl group, R ⁶ is -N (CH ₃ ) ₂ , -N (C
₂ H _{5) 2} or -OH. ] It is effective to use a copolymer (including a block copolymer) with a monomer represented by the following and one or more monomers selected from ethylene glycol dimethacrylate. The appropriate proportion of the vinyl monomer component represented by the general formula (II) in the copolymer is about 30 to 95 parts by weight.

As a binder, if necessary, a natural resin such as ester gum or softened rosin, a natural resin-modified maleic acid resin, a natural resin-modified phenol resin, a natural resin-modified polyester resin, a natural resin-modified pentaerythritol resin, or an epoxy resin is used. A natural resin-modified thermosetting resin, such as, may be added.

The carrier liquid is a liquid having a high insulating property and a low dielectric constant, and is a paraffinic or isoparaffinic hydrocarbon (Esso H, Isopar G, Isopar L, Isopar K,
Naphtha No. 6 Solvesso 100 etc.), ligroin, n-hexane, n-heptane, iso-octane, n-octane, carbon tetrachloride, trichlorotrifluoroethane, cyclohexane, etc. are used alone or in combination of two or more. To be done.

Examples are shown above. All parts here are parts by weight.

Example 1 Copper phthalocyanine blue (manufactured by Dainichiseika Co., Ltd.) 70 parts (solid content conversion) Muscovite (wet pulverized with a ball mill, cake-like) 30 parts (solid content conversion) Wax (Mitsui Petrochemical Co., Ltd.) 110P) 100 parts Pigment A is prepared by kneading and mixing 100 parts of rosin modified resin (MRP manufactured by Arakawa Chemical Co., Ltd.). Pigment A 100 parts Isolar H 20% dispersion of uralyl methacrylate-methyl methacrylic acid-methacrylic acid copolymer (copolymerization ratio 10: 2: 0.5) 220 parts Isopar G (manufactured by Exxon) 1000 parts in a ball mill After 20 hours of dispersion, 2000 parts of Isopar G is added and dispersed for 30 minutes. 20 as concentrated toner
A liquid developer (invention product 1) was prepared by diluting 0 parts of the product with 1000 parts of Isopar G.

For comparison, a liquid developer (Comparative Product 1) was produced in exactly the same manner except that muscovite was omitted.

Example 2 Copper phthalocyanine blue (manufactured by Dainichiseika Co., Ltd.) 70 parts (solid content conversion) Peer Grays ML100 (manufactured by Nihon Koken Co., Ltd.) 50 parts Wax (manufactured by Sanyo Kasei Co., Ltd. 161P) 100 parts Rosin modified resin (manufactured by Tokushima Seiyu Co., Ltd. RM1000) A kneaded material consisting of 100 parts was subjected to a flushing treatment, and then a liquid developer (Invention product 2) was prepared in the same procedure as in the example.

For comparison, a liquid developer (Comparative Product 2) was produced in exactly the same manner except that mica (Pia Glaze ML100) was omitted.

Example 3 Seika Fast Red 8040 (manufactured by Dainichiseika Co., Ltd.) 50 parts Pier Glaze MBR100 (manufactured by Nippon Koken Co., Ltd.) 70 parts OA wax (manufactured by BASF) 120 parts Polyethylene (PE6351 manufactured by Arakawa Chemical Co., Ltd.) 80 parts Kneading After flushing the product, a liquid developer (Invention product 3) was prepared in the same procedure as in Example 1.

For comparison, take a look at the mica (Pia Glaze MBR100),
50 to 70 parts of general pigment (Seika Fast Red 8040)
A liquid developer (Comparative Product 3) was produced in exactly the same manner except that the parts were replaced.

Commercially available electrophotographic copying machines (DT57 manufactured by Ricoh Co., Ltd.
The image was displayed at 00). As a result, both of the product 1 of the present invention and the comparative product 1 gave good blue images on white and light color transfer papers, but when a darker red transfer paper was used, the comparative product 1 showed a black image. In contrast, the product 1 of the present invention obtained an image that can be distinguished from blue.

Good green images were obtained for both the product 2 of the present invention and the comparative product 2, but a black image was also obtained for the comparative product 2 on the dark red transfer paper.

Good red images were obtained for both the product 3 of the present invention and the comparative product 3, but a dark image was obtained for the comparative product 3 on the dark green transfer paper.

Further, when the overprinting is performed with the comparative products 1, 2 and 3, the portion where the two colors overlap is almost blackish, whereas in the case of the inventive products 1, 2 and 3, the color copied later is more comparable. It was confirmed that it was vividly copied compared to the copy in.

〔effect〕

As is clear from the description of the examples, by using the liquid developer of the present invention, the image of overprinting becomes clear, and a clear image can be obtained especially on color transfer paper.

Claims (1)

[Claims] 1. A liquid developer comprising a toner having a colorant and a binder as a main component dispersed in a carrier liquid having a high insulating property and a low dielectric constant, the colorant being 20 to 80% by weight of a colored dye or pigment. And a mica or a mixed pigment of 80 to 20 parts by weight of mica-treated pigment is subjected to a flushing treatment, and a color liquid developer for electrostatic photography.