JPS62160465A - Liquid color developer for electrostatic photography - Google Patents

Abstract

PURPOSE:To obtain a developer superior in gradation reproductivity, storage stability, transparency, dryability, and the like by subjecting a dye or pigment represented by a specified formula to flashing treatment with a resin having a specified softening point. CONSTITUTION:The pigment represented by formula I (R is methoxypropyl, phenyl, or phenyl substituted by lower alkyl) subjected to the flashing treatment is used for the toner component. In said treatment, not only the pigment but the dye is kneaded together with water into a slurry, and the dye can obtain an effect similar to the pigment, and accordingly, the dye can be used for the toner component. This colorant and a binder resin are kneaded and dispersed together with a small amount of carrier fluid to make a concentrated toner. Since the obtained blue liquid developer has the pigment or the dye is dispersed in a state near primary particles, they are not liable to coagulate, and since these primary particles are coated with a resin having a softening point of 50-120 deg.C, the colorant can be well fixed to a transfer paper by heat fixing a toner image in a copying machine, gradation reproductivity can be enhanced, and color reproductivity can be improved with an OHP.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a liquid developer for electrostatic photography, and more specifically, a color liquid developer for electrostatic photography in which a toner component is a colorant obtained by flashing a specific dye or pigment. Regarding.

Toner made of inorganic or organic pigments coated with resin (binder) has high insulation properties and low vIf! Liquid developers for electrostatic photography, which are uniformly dispersed in a carrier liquid of 30% or less, are well known (Japanese Patent Laid-open Nos. 50-151528, 53-109633, 5
5-144252 etc.). This stuff in general.

The pigment is obtained by crushing and dispersing the pigment together with a resin and a carrier liquid using a ball mill, etc. However, with this method, the toner is not dispersed down to the primary particles, resulting in poor transparency, rough images, and sedimentation. There is a problem that the sedimentation causes caking.

Also, it is being considered to dye latex with a dye and apply this to 1 to 3 (Japanese Patent Application Laid-Open No. 45-2587
No. 8, No. 56-10619, etc.). However, this method has a problem in that the absolute density is low and, in addition, if the dye that has not penetrated into the latex is not completely removed, background fogging may occur.

However, as a means of manufacturing a liquid developer that improves these, (i) JP-A-57-34720, JP-A-57-193;
As seen in publications such as No. 73, wax and pigment are dispersed in a heated carrier liquid and rapidly cooled to perform a wax treatment on the pigment, and then dispersed together with a resin in the carrier liquid; As seen in Japanese Patent Publication No. 57-201248, it has been proposed to knead wax and pigment, spray granulate the mixture with a spray dryer, and disperse this together with a resin in a carrier liquid. However, in all of these cases, the compatibility between the wax and the pigment is poor, so the toner is still not dispersed down to the primary particles, resulting in poor transparency and poor drying properties, especially in overhead projectors (OHP). When projected, it appears blackish and has the disadvantage of insufficient color reproducibility.

The first object of the present invention is to provide a blue electrostatic photographic color liquid developer containing a toner component that is a colorant that is insoluble in a carrier liquid and has excellent dispersion stability and drying properties. .

A second object of the present invention is to provide a color liquid developer for electrostatic photography that has excellent gradation reproducibility, drying properties, transparency, etc., and exhibits good color reproducibility especially when used in 0IIP. It is.

In addition, the present invention provides a color liquid developer for electrophotography comprising toner particles containing a colorant and a binder as main components dispersed in an aliphatic hydrocarbon carrier liquid, wherein the colorant has the following general formula: (I) [However, R is a methoxypropyl group, a phenyl group, or a lower alkyl-substituted phenyl group. ] The dye and pigment represented by the following are flushed with a resin having a softening point of 50 to 120°C.

By the way, it has not been considered that inorganic or organic pigments such as carbon black and phthalocyanine blue can be used as colorants for toners by flashing treatment. When a soluble resin is applied, the resin dissolves in the carrier liquid used for toner dispersion, so depending on the type of resin, it may lower the electrical resistance of the carrier liquid or make the polarity of the toner particles unstable.

Further, in some cases, as a result of reversing, one image source density may be lowered or background smear may occur, making it impossible to form a clear image. Therefore, as a coloring agent resin, one that is insoluble in the carrier liquid and only slightly soluble is generally used. However, in the past, unless measures were taken such as taking into consideration the compatibility formulation balance between pigment and resin during colorant production or dispersing for a long time during toner production, the toner deteriorated in the developer over time. Dispersion stability is reduced due to sedimentation and aggregation, and the resulting copies have disadvantages such as poor drying properties, poor subsequent fixing properties, and easy set-off.

The present invention achieves the intended purpose by specifying and combining dyes and pigments and resins.

As mentioned above, the liquid developer according to the present invention has the general formula (
A flushed pigment (dye) expressed in summer) is used as a toner component. Therefore, we will proceed with the explanation of the "flushing process".

In the flashing process, first, a pigment or a water-containing paste of the pigment is placed in a kneader called a flasher together with a resin or a resin solution and mixed well. During this process, the water present around the pigment is replaced by the resin solution. This is taken out from the kneader, the aqueous phase is discarded, the pigment dispersed in the resin solution is dried, the solvent is removed, and the resulting lump is pulverized. In the present invention, this material is referred to as a "brushing-treated colorant." Note that it is also possible to use a method of removing water and solvent under reduced pressure while kneading with a kneader.

Flushing treatment is known to be very good in one dispersion because it can use a water-containing paste as a material and can be treated while kneading with a kneader. Also,
In the flushing process, by mixing not only the pigment but also the dye with water in the form of a slurry, almost the same effect as the pigment can be obtained. Therefore, in the present invention, dyes that are subjected to flushing treatment can also be employed as toner components.

Representative examples of dyes and pigments used in the present invention include the following.

(&1) (Nα2) (Nα3) Examples of resins used when flushing these dyes and pigments are as follows.

Eastman Chemical N-10111N-1110
8 N-12113 N-14106 N-34103 N-45118 C-10104 C-13110 C-15102 C-16106 E-10106 E-11106 E-12112 E-14104 E-15100 5 well petrochemical tiop to.

220P 113 220M P 113 320MP 114 210M P 120 4202E 108 4053E 111 Ni Mori Table 1 JLiiL 41 inverted point fqL
BASF OA wax 93-9
6 Petrolite BARECO50086BARE
CO655102 [IARECO1000113 E 730 93 E2018 117 E2020 117 E1040 105 PETRONABA C90,5 PETRONABA C-3690,5PETRONA
BA C-400104,5PETRONA [IA C
-750097,8 Hoechst PE520 1
18-120PED121 113-118 PED136 107-112 PED153 115-120 PED521 103-108PED5
22 100~105PED534 98
~105 Allied Chemical AC-Polyethylene 6&6A
102AC-Polyethylene 615 105 Sanyo Chemical Sunwax 131-P 108 Sunwax 151-P 107 Sunwax 161-P Ill Sunwax 165-P 107 Sunwax 171-P 105 Manufacturer name Product name - Choi ζ Shinko yυ -
Union Carbide DYNI 102D
Y N F 102 D Y N H102 D Y N J 102 D Y N K 102 Monsanto 0RLIZON 805 1160RLI
ZON 705 116 Fu Knob
MARLEX 1005 92 duyu small
ALATHON 3 103ALAT)ION
10 96ALATHON 12
84 ALATHON 14 80 ALATI(ON 16 95A
LAT)ION 20 86ALATION
22 84ALAT■ON 25
96 In addition to the above, Sunwax E200. E250P (manufactured by Sanyo Chemical Co., Ltd., 20
00.2500.3000.4000.4100.80
00 B, 5ooo, 6000.7000 (manufactured by Chubu Polyethylene Co., Ltd.), Viscol 500P, 660P (manufactured by Goyo Kasei Co., Ltd.) as polypropylene resin, Denga Vinyl 5S-100, 5S as vinyl chloride resin
-130, DSS-130, 5S-140, 5S-80
,5S-70,SS-Y,5H-250゜5ll
-1'70, M-70, M-120, MM-90, EM
-140, VP-30, 3E-130, ME-120,
ME-180, MIIE-100, PA-100, p-
ao (hereinafter Denki Kagaku Kogyo Co., Ltd. 12), Teflon K, Teflon FEP (as fluororesin (polytetrafluoroethylene))
(manufactured by Gotsui Fluorochemical Co., Ltd.), paraffin wax (softening point 50-98°C), beeswax (softening point approximately 60°C),
Examples include natural wax (softening point: about 51°C).

The appropriate ratio of the dye and pigment to the resin in such flushing treatment is 0.1 to 6.0 parts by weight, preferably 0.1 to 0.6 parts by weight, of the resin per 1 part by weight of the dye and pigment.

To prepare a liquid developer using the thus obtained [flushing-treated colorant].

The colorant and binder are cross-dispersed with a small amount of carrier liquid using an attritor, ball mill, kitty mill, etc. to make a concentrated toner.
It can be diluted approximately twice as much. The ratio of colorant and binder is 1
:l~10 (weight) is suitable.

As a binder in Niko, alkyd resin, rosin-modified phenol formaldehyde resin, polyhydric alcohol ester of hydrogenated rosin, polyacrylic or polymethacrylic ester resin, styrene resin, chlorinated rubber, etc. are used, but in particular, the following general Formula (II) [However, R1 is hydrogen or a methyl group, R2 is a hexamer represented by acrylic acid, methacrylic acid, vinylpyridine, the following general formula (m) [However, R3 is hydrogen or a methyl group, R4 is COOCm Ht m + x or -O
COC-H2m +1 (m is an integer from 1 to 5). ] Represented by the following general formula (IV) [where R
5 is hydrogen or methyl group, RG is -N (CH,), -
N (Cz Hs)z or -○H. ] It is effective to use a copolymer (including a block copolymer) with a monomer represented by the following and one or more heptamers selected from ethylene glycol dimethacrylate. The proportion of the vinyl monomer component represented by the general formula (n) in the copolymer is suitably from 30 to 95% by weight.

As a binder, natural resins such as ester gum and softened rosin, natural resin-modified maleic acid resin, natural resin-modified phenol resin, natural resin-modified polyester resin, natural resin-modified pentaerythritol resin, and epoxy resin can be used as binders. Natural resin-modified thermosetting resins, such as, may be added).

As the carrier liquid, paraffinic or isoparaffinic hydrocarbons (Aituno (-H, Isopar G, Aituno <-I, Aituno (-K, naphtha Nα6, manufactured by Esso),
Solbetsuso 100, etc.), ligroin, n-hexane, n-heptane, 1so-octane, n-octane, carbon tetrachloride, trichlorotrifluoroethane, cyclohexane, etc. are used alone or in combination of two or more. .

The thus obtained blue liquid developer of the present invention is characterized in that (i) the dye and pigment are dispersed in a state close to primary particles, so that they are difficult to aggregate, and (n) the primary particles of the dye and pigment have a softening point of 50 to 120.
Because it is coated with resin at ℃, the colorant is well fixed on the transfer paper by heating and fixing the copy using a copying machine.Furthermore, (iii) the toner particle size is small, so it has particularly excellent gradation reproducibility, and can be used on OHP. This ensures good color reproducibility.

Here, an example of producing a colorant in which the dye and pigment represented by the general formula (I>) is flushed with a resin having a softening point of 50 to 120 DEG C. is as follows.

Production Example 1 A mixture of soo grams of water and 300 g of the above Nal dye and pigment was thoroughly stirred in a flasher, then 150 g of polyethylene (Sunwax 161P manufactured by Kochu Kasei Co., Ltd.) was added thereto and heated to 130°C for 2 hours. After a semi-mixed building.

210 g of carbon tetrachloride was added and kneaded for an additional 2 hours.

Thereafter, water and carbon tetrachloride were removed under reduced pressure, and the mixture was ground in a ball mill.

Production Example 2 200 g of Union Carbide's DYNK and 100 g of chlorobenzene were heated to 150° C. and thoroughly stirred in a flasher. Thereafter, 200 g of a wet cake (water content 50%) of the Nα3 dye and pigment was added, and flushing was performed at 130° C. for 3 hours. Then, the pressure was reduced to obtain powder with a particle size of 3 to 15 μm.

Production Example 3 100 g of beeswax and 60 g of toluene were heated to 100°C and thoroughly stirred in a flasher. 100 g of the wet cake (moisture content 30%) of the Nα2 dye and pigment example was added to this, heated to 150° C., dispersed for 3 hours, and then decompressed to remove volatile components. Then, it is crushed to have a particle size of 5 to 10μ and a moisture content of 0.
A 75% powder was obtained.

Production Example 4 After thoroughly stirring soo g of water and 200 g of the Nα1 dye and pigment in a flasher, Sunwax 171P was added to the mixture.
Add 100 g and 110 g of toluene to 150'c1
'Heat and stir. After kneading for about 4 hours, the pressure was reduced to remove volatile components, and the mixture was pulverized.

Production Example 5 After thoroughly stirring 500 g of water and 120 g of the Nα3 dye and pigment in a flasher, 300 g of polyvinyl chloride (manufactured by Denki Kagaku Co., Ltd.) was added thereto, and the mixture was heated and kneaded at 120°C. Next, perchlorethylene was removed to obtain a powder of 30 to 50 microns.

Examples using these colorants are as follows. Again, all parts represent parts by weight.

Example I I2 Coloring agent obtained in Preparation Example 1 soo
2000 parts of Isopar H were placed in a ball mill and dispersed for 30 hours, and 4000 parts of Isopar H was added thereto and dispersed for 2 hours to obtain a concentrated toner. 150 parts of this concentrated toner was diluted with 1000 parts of Isopar H to prepare a liquid amulet for electrophotography.

Next, this developer is applied to a commercially available electrophotographic copying machine (manufactured by Ricoh Co., Ltd.,
DT-5700) for copying, a blue image with excellent drying properties was obtained with a one-image concentration of 1.15. When the image was copied onto 0IIP film, an image with good color reproduction was obtained.

Example 2 Using the colorants of Production Examples 2 to 5 and the resin and dispersion medium of Example 1, a liquid developer was prepared according to the same dispersion method as in Example 1, and evaluated. Got the results.

(Margin below) Table-1 Note 1) O represents good condition.

Note 2) Image density was measured using a Macbeth thermometer.

Note 3) Tone reproducibility is Kodak gray scale (20 steps)
The evaluation was based on how many levels the original was reproduced.

As is clear from the description of Examples, the liquid developer of the present invention has excellent gradation reproducibility, storage stability (dispersion stability), transparency, drying property (fixing property), etc., especially 011P. This improves color reproducibility when used.

Claims (1)

[Claims] 1. A liquid developer comprising a toner mainly composed of a colorant and a binder dispersed in an aliphatic hydrocarbon carrier liquid, wherein the colorant has the following general formula (I) ▲Math. , chemical formulas, tables, etc.▼(I) [However, R is a methoxypropyl group, a phenyl group, or a lower alkyl-substituted phenyl group. ] A color liquid developer for electrostatic photography, characterized in that the dye and pigment represented by the following are flushed with a resin having a softening point of 50 to 120°C.