JPS6227752A - Color liquid developer for electrostatic photography - Google Patents

Abstract

PURPOSE:To obtain a color liquid developer for electrostatic photography contg. a coloring agent which is insoluble in a carrier liquid and has excellent dispersion stability and drying characteristic as a toner component by subjecting a dye pigment consisting of a specific thioindigo deriv. to a flushing treatment with a resin having 50-120 deg.C softening point. CONSTITUTION:The coloring agent is prepd. by subjecting the dye pigment expressed by the formula to the flushing treatment with the resin having 50-120 deg.C softening point. The ratio between the dye pigment consisting of the thioindigo deriv. and the resin in the flushing treatment is adequately 10-60 pts.wt. dye pigment with respect to 100pts.wt. resin. The liquid developer is prepd. simply by kneading and dispersing 10-100pts.wt. such coloring agent, 5-40pts.wt. binder and 300-1,000pts.wt. carrier liquid to prepare the concd. toner and diluting such toner about 5-10 times with the similar carrier liquid as necessary.

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.

A liquid developer for electrostatic photography is well known, which is made by uniformly dispersing a toner containing an inorganic or organic pigment coated with a resin (binder) in a highly insulating and low dielectric constant carrier liquid. Yes (Unexamined Japanese Patent Publication 1973-
No. 151528, No. 53-109633, No. 55-1
44252 etc.). This product generally uses pigment as resin,
It is obtained by crushing and dispersing the toner together with 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 high sedimentation. There is a problem that the sediment causes caking.

In addition, dyeing latex with dye and applying this to toner is also being considered (Japanese Patent Laid-Open No. 45-258
No. 78, No. 56-10619, etc.), but this product has a low absolute density, and in addition, there is a problem that background fogging occurs if the dye that has not penetrated into the latex is not completely removed.

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, wax and pigment are kneaded, sprayed and granulated using a spray dryer, and then dispersed together with a resin in a carrier liquid.

etc. have been proposed. 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.

OBJECTIVES The first object of the present invention is to provide a color liquid developer for electrostatography, which contains a toner component that is a colorant that is insoluble in a carrier liquid and has excellent dispersion stability and drying properties.

The second objective of the present invention is gradation reproducibility and drying properties.

The object of the present invention is to provide a color liquid developer for electrostatic photography that has excellent transparency and exhibits good color reproducibility especially when used in OHP.

The present invention provides a color liquid developer for electrostatography, which comprises toner particles containing a colorant and a binder as main components dispersed in an aliphatic hydrocarbon carrier liquid, wherein the coloring agent has the following general formula: (1) [In the formula, R1 to R" are respectively -H5-Br, -NH2,
-Cl, -QC, H-5C2H2, -〇CH3, -C
It is either uN of H2 or -NHCOCH3. ] The dye and pigment represented by the following are flushed with a resin having a softening point of 50 to 120°C.

Incidentally, it has not been thought to use inorganic or organic pigments such as carbon black and phthalocyanine blue as colorants for toners by flashing treatment.

However, when a resin that is soluble in a carrier liquid is used as a resin for flushing processing, 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 destabilizes the polarity of

Further, in some cases, as a result of inversion, the image density may decrease or background smear may occur, making it impossible to form a clear image. Therefore, colorant resins that are insoluble or easily soluble in carrier liquids are 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 unsatisfactory drying properties, lack of subsequent fixing properties, and are prone to set-off.

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

As mentioned above, the liquid developer according to the present invention has the general formula (
The pigment (dye) represented by 1) is used as a toner component after being subjected to flushing treatment. Therefore, I will start by explaining the "brushing process".

In the flashing process, the pigment or water-containing paste of the pigment is first put into a kneader called a flasher together with a resin solution.
and mix 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 "flushing-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 provide 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,
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.

The dye and pigment used in the present invention are thioindigo derivatives represented by the above general formula (I). Representative examples of such thioindigo derivatives include the following.

(Left below) (1) C.I. Pigment Red 87 (Red) (2
) Sea Eye Butt Red 47 (Red) (3) Pat Lett 41 (Red) (4) 73340 Sea Eye Butt Red 26 (yellowish red) O○ (5) 73345 Sea Eye Butt Red (bright yellowish red) O○ ( 7) 73355'-7'''C is a leucosulfate ester of C,1,73355.

This is a leucosulfate ester of C,1,73360.

(11) 73325 butt dye (red) (12) 73330 butt dye (plain reddish orendo color) ○ ○ This is a leucosulfate ester of C, 1,73335.

(15) 73375 CI Pigment Red 86 (bright red) (16) 73380 Hatsutodai (bluish red) ○ ○ H2OCH.

This is a leucosulfate ester of C,1,73380.

H, CCH3 (19) 73386 Sea Isolbilized Butt Violet 2 (bright reddish violet) This is C0
It is the leucosulfate ester of I, 73385.

(20) 73390 Buttdai (blueish red) (2
1) 73395 Sea Butt Violet 3 (bright reddish violet) H,CCH3 This is the leucosulfate ester of C,1,73395.

The following resins can be exemplified as the resins used when flushing these dyes and pigments.

9 Shihijishi - face - j arrangement - name one Softening point ('C)
-Stoman Chemical N-10111N-11,10
8 N-12113 N-14106 N-341,03 N-45118 C-10104 C-13110 C-15102 C-16106 E-10106 E-11106 E-12112 E-14104 E-15100 Mitsui Petrochemical 110P 1002 20P
113 220MP 113 320MP 114 210MP 120 4202E 108 4053E 01 Ni Natahiji L lΔL ” Iris LBASF
OA wax 93-96 petrolite BARECO50086BARECO655
102 BARECO1000113 E 730 93 E2018 117 E2020 117 E 1040 105 PETRONABA C90,5 PETRONABA C-3690,5PETRONA
BA C-400104,5PETRONABA C-
750097,8 Hoechst PE520 11
8～123P E D 121 113～118
P E D 1.36 107~112 P E
D153 115-120P E D521
103~108P E D522 100~
105PED534 98-105 Allied Chemical AC-Polyethylene 6&6A
102AC-Polyethylene 615 105 Sanyo Kasei Sunwax 131-P 10g Sunwax 151-P 107 Sunwax 161-P 111 Sunwax 165-P 107 Sunwax 171-P 105 Manufacturer name Product name - Our local shop 1 Union Carbide DYNI 102D
Y N F 102 DYNH102 DYNJ 1.02 DY N K 102 Monsanto 0RLIZON 805 1160R
LIZON 705 116 PHILLIPS MAR
LEX 1005 92 Dupont ALA
THON 3- 103ALATHON 10
96 ALA D)ION 12' 8
4ALATHON 14 80 ALATHON 16 95 ALATHON 20 86 ALATHON 22 84 ALATHON 25 96 In addition to the above, polyethylene resins include Sunwax E200 (Sanyo Chemical Co., Ltd. 1!5), 2000.2500
．． 3000.4000.4100.8000B, 50
00.6000.7000 (from Chubu Polyethylene Co., Ltd., Viscol 500P as polypropylene resin,
660P (manufactured by Sanyo Chemical Co., Ltd.), Dengabi as vinyl chloride resin: -/L/ 5S-100, 5S-13
0,DSS-130,SS-140,5S-80,5
S-70, SS-Y, 5H-250, 511-17
0, M-70, M-120, MM-90, EM-140
, vP-30, 5E-130, ME-120, ME-1
80, MHE-100, PA-1oo, P-80 (manufactured by Denki Kagaku Kogyo Co., Ltd.), Teflon K as a fluororesin, Teflon FEP (manufactured by Mitsui Fluorochemical Co., Ltd.), paraffin wax (softening point 50-98°C) ), beeswax (
(softening point: about 60°C), natural wax (softening point: about 51°C), and the like.

The appropriate ratio of dye and pigment to resin in such flushing treatment is 10 to 60 parts by weight of dye and pigment to 100 parts by weight of resin.

In order to prepare a liquid developer using the "flushing-treated colorant" obtained in this way, 10 to 1
00 parts by weight, 5 to 40 parts by weight of binder, and 300 to 1 part of carrier liquid.
000 heavy image part is cross-dispersed using an attograph, ball mill, kitty mill, etc. to make a concentrated toner, and if necessary, this can be diluted about 5 to 10 times with a similar carrier liquid.As a binder here, 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) S [However, Rg is hydrogen or methyl group, R10 is -CO
OC,H2, , or -〇COCnH,n, (n is an integer from 6 to 20). ] A monomer represented by acrylic acid, methacrylic acid, vinylpyridine, the following general formula (III) [However, R11
is hydrogen or methyl group, R12 is COOCn HZ n
+x or -○COC, H, n, □ (n is an integer from 1 to 5)
It is. ] A monomer represented by the following general formula (IV) [However, R
13 is hydrogen or methyl group, Rl 4 is N(cH3)z,
N (C2HS)2 or -OH. ] It is effective to use a copolymer (including a block copolymer) of 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 formula (II) in the copolymer is about 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.

The carrier liquid may be paraffinic or isoparaffinic hydrocarbon (Isopar H, Isopar G manufactured by Esso).
, Isopar L, Isopar, naphtha Ha 6 Solbetsuso 100, etc.), ligroin, n-hexane, n-hebutane, 1so-octane, n-octane, carbon tetrachloride, trichlorotrifluoroethane, cyclohexane, etc. alone or in combination. More than one species is used in combination.

In the thus obtained red liquid developer of the present invention, (i) the dye and pigment are dispersed in a state close to primary particles, so that they do not aggregate, and (ii) the primary particles of the dye and pigment have a softening point of 50 to 12.
Because it is coated with resin at 0°C, the colorant is well fixed on the transfer paper by heating and fixing the copy with a copying machine, and (iii) the toner particle size is small, so the toner has excellent gradation reproducibility. , which improves color reproducibility on OHP.

Here, an example of producing a colorant is shown in which a dye and pigment represented by the general formula (1) is subjected to a flushing treatment with a resin having a softening point of 50 to 120°C.

Production example 1 Sea Eye Bat Red 2 (C-1,73365)
100g of cake-like material (50g of pigment bone) was heated to 130℃, and polyethylene (AC-polyethylene 170g) was heated to 130℃.
2) xylene solution (solid content 50 da; liquid temperature 130°C) 2
00g was added and kneaded for 1 hour. Next, after separating and removing water, the solvent was removed under vacuum, cooled, and then ground in a stone mill.

Production example 2 C.I. Bat Violet 2 (C, 1,73
200 g of cake-like material (50 g of pigment bone) of No. 385) was taken in a kneader, and 500 g of a toluene solution (solid content 30%) of exposed beeswax was added thereto and 1 liter was kneaded at 00° C. for 3 hours. Thereafter, a pulverized colorant was obtained in the same manner as in Production Example 1.

Production example 3 To Sea Ibara 1 Red 1 (C, ■, 73360
) (50 g of pigment bones) in a kneader.
Polyethylene (Sunwax 131-P)
) of xylene solution (30% solids) was added,
The mixture was kneaded at 130°C for 2 hours. Thereafter, a pulverized colorant was obtained in the same manner as in Production Example 1.

Comparative Production Examples 1 to 3 Production Examples 1 to 3, respectively, except that no flushing treatment was performed.
A pulverized colorant was obtained in the same manner as in 3.

Next, examples using the above coloring agent will be shown.

Example '1 A mixture consisting of 20 parts of the colorant obtained in Production Example 1 was placed in a ball mill and dispersed at 30°C for 60 hours to obtain a red toner. 15o-G (manufactured by Exxon) was added to this to prepare a liquid developer.

Next, using this liquid developer, a commercially available electrophotographic copying machine (
When copying was performed using Ricoh DT-1200), a good quality image was obtained.

Examples 2 and 3 A liquid was prepared in the same manner as in Example 1, except that the colorant obtained in Production Examples 2 and 3, the copolymer (50% dispersion of isooctane) and the dispersion medium of Example 1 were used. A developer was prepared and good quality images were obtained.

Comparative Examples 1 to 3 A liquid developer was prepared in the same manner as in Example 1, except that the colorant obtained in Comparative Production Examples 1 to 3 was used, except that a liquid developer was used. prepared and imaged.

When the characteristics of these six types of liquid developers and the image characteristics using these developers were investigated, the results shown in Table 1 were obtained.

In the table, ◯ means good, △ means fair, and × means poor.

(The following is a blank space) □□□---As is clear from the comparison of the following examples and comparative examples, the liquid developer of the present invention has excellent gradation reproducibility, dispersion stability, transparency, drying properties, etc. ○It improves color reproducibility when using HP.

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) [In the formula, R^1 to R^8 are -H, -Br, and -NH, respectively.
_2, -Cl, -OC_2H_5, -SC_2H_5,
-OCH_3, -CH_3, -NHCOCH_3. ] 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.