JPS6238478A - Color liquid developer for electrostatic photography - Google Patents

Abstract

PURPOSE:To obtain the titled liquid developer which is insoluble in a carrier liquid and to improve the dispersion stability and drying characteristic by subjecting a specific dye pigment to a flushing treatment with a resin having 50-120 deg.C softening point to form a coloring agent. CONSTITUTION:The coloring agent of the color liquid developer for electrostatic photography formed by dispersing toner particles essentially consisting of the coloring agent and binder into the aliphat. hydrocarbon carrier liquid is formed by subjecting the dye pigment expressed by the formula to the flushing treatment with the resin having 50-120 deg.C softening point. First the pigment or hydrous paste of the pigment is put together with the resin or resin soln. into a kneader and is thoroughly mixed to replace the water existing around the pigment by the resin soln. in the flushing treatment. The water phase is then discarded and the mixture is dried to removed the solvent. The resultant lump matter is pulverized. The ratio of the dye pigment and resin in the flushing treatment is 0.1-6.0pts.wt. by 1pt.wt. dye pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Tobunran The present invention relates to a liquid developer for electrostatic photography, and more specifically, a color liquid for electrostatic photography that uses a coloring agent obtained by flashing a specific dye and pigment as a toner component. Regarding developer.

A well-known liquid developer for electrostatic photography is a toner coated with an inorganic or organic pigment coated with a resin (binder) and uniformly dispersed 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 a pigment as a resin,
It is obtained by pulverizing 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.

Furthermore, dyeing latex with dye and applying this to toner is also being considered (Japanese Patent Laid-Open No. 45-25878
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 single-color reproducibility.

The first object of the present invention is to provide a color liquid developer for electrostatic photography that contains 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 OHP. It is.

Structure The present invention provides a color liquid developer for electrostatic photography, which is formed by dispersing toner particles containing a colorant and a binder as main components in an aliphatic hydrocarbon carrier liquid, wherein the colorant has the following general formula N) [ However, R1-R111' are hydrogen, halogen, and O, respectively.
CnHzn+1- 'nH2n+, or -〇〇NH-
@ (n is an integer from 1 to 4). ] 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 thought that inorganic or organic pigments such as carbon black and phthalocyanine blue may be subjected to flashing treatment to be used as colorants for toners).

However, if a resin that is soluble in a carrier liquid is used as a resin for flushing, the resin will dissolve in the carrier liquid used for toner dispersion.

Depending on the type of resin, it may lower the electrical resistance of the carrier liquid or make the polarity of toner particles unstable.

Further, in some cases, as a result of inversion, the density of one image may decrease or background smear may occur, making it impossible to form a clear image. Therefore, colorant resins that are insoluble or poorly soluble in the carrier liquid 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 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 (
The pigment (dye) represented by I) subjected to flashing treatment is used as a toner component. Therefore, I will start by explaining 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 "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 carbazole derivatives represented by the above general formula (I). Representative examples of such dyes and pigments include the following.

C, 1,12810 pigment m-chloroaniline → 4'-chloro-2-hydroxy-
1-Carbazolecarboxanide C,1,12815
Pigment 2.4-dichloroaniline → 4'-chloro-2-hydroxy-1-carbazole carboxanide C,1,12
820 Pigment C 1-Carbazole Carboxanide C. 1. 1
2825 Pigment Xanide The following resins can be exemplified as resins used in flashing treatment of these dyes and pigments.

Manufacturer name Product name -Kenko Wataru 4'C)-
Eastman Chemical N-10 111N
-11 108 N-12 113 N-14 106 N-34 103 N-45 118 C-10 104 C-13 110 C-15 102 C-16 106 E-10 106 E-11 106 E-12 112 E-14 104 E-15 100 Mitsui Petrochemicals 110P! 00220P
113 220M P 113 320M P 114 210M P 120 4202E 108 4053E 111 Vetrolite BARECO50086BARE
CO655102 BARECO1000113 E 730 93 E2018 117 E 2020 117 E 1040 105 PETRONABA C90,5 PETRONABA C-3690,5PETRONA
BA C-400104,5PETRONABA C-
750097,8 Hoechst PE520 11
8~123P E D121 ti3~118
PED136 107~112 PED153 115~120PED5
21 103~108P E D522
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 111 Sunwax 165-P 107 Sunwax 171-P 105 Koken Shipi J10 Episode 2 and Union Carbide D Y N I 102
D Y N F 102 D Y N H102 D Y N J 102 D Y N K 102 -t-n+nt0RIJZON 805 1160
RLIZON 705 116 Philips X
MARLEX 1005 92 Dupont ALATHON 3 103ALATHON
10 96 ALATHON 12 84 ALATHON 14 80 ALATHON 16 95 ALATHON 20 86 ALATHON 22 84 ALAT)ION 25 96 In addition to the above, Sunwax E200, E2 as polyethylene resin
50P (manufactured by Sanyo Chemical Co., Ltd.), 2000, 2500.3
000.4000.4100.8000B, 5000
．． 6000.7000 (manufactured by Chubu Polyethylene Co., Ltd.), Viscoel 500P, 6 as polypropylene resin
60P (manufactured by Sanyo Chemical Co., Ltd.), Denga vinyl 5S-100, 5S-130, DSS- as vinyl chloride resin
130゜5S-140,5S-80,SS-70,5
S-Y, 5H-250, 5H-170, M-70, M-
120, MM-90, EM-140-VP-30,5
E-130, ME-120, ME-180, MHE -
100, PA-100, P-80 (manufactured by Denki Kagaku Kogyo Co., Ltd.), paraffin wax (softening point 50 to 98°C).

Beeswax (softening point approx. 60℃), natural wax (softening point approx. 51℃)
) are examples.

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.

Using the "brushed colorant" thus obtained, a liquid developer is made into i! To l1m.

The colorant and binder are cross-dispersed with a small amount of carrier liquid using an attritor, ball mill, kitei mill, etc. to make a concentrated toner.
The ratio of coloring agent and binder is 1.
:1 to 10 (weight) is appropriate.

As the 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 (■) [However, R11 is hydrogen or methyl group, R12 is -C
O○C, H, □1 or -○COCH21m+4 (m is an integer from 6 to 20). ] Seven-termer represented by acrylic acid, methacrylic acid, vinylpyridine, the following general formula (+111) [However, R''
is hydrogen or methyl group, R14 is -COOC, H, C+
1 or -〇 〇 〇 〇, H,,. □ (m is an integer of 1 to 5)] A monomer represented by the following general formula (IV) [However,
R" is hydrogen or methyl group, R" is -N(CH,)2,
N(CzHs)z 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 (n) in the copolymer is 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 K, naphtha Na 6 sorbetsol 1OO, 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.

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

Here, an example of producing a colorant in which a dye or 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 1000 g of a 10% toluene solution of polyethylene wax (manufactured by Mitsui Petrochemical Co., Ltd., Hiwax 210MP) and a 10% aqueous solution of the above compound (m-chloroaniline) 1
000 g were well stirred with a flasher and kneaded for 4 hours while maintaining the temperature at 150°C. Then, water and solvent were removed by heating under reduced pressure, and the mixture was pulverized to obtain about 150 g of pigment.

Production example 2 Polyethylene wax (manufactured by Sanyo Chemical Co., Ltd., Sunwax 1
1000 g of a 10% toluene solution of 31-P) and 10% aqueous solution of the above compound (2,4-dichloroaniline)
About 15 g was prepared in the same manner as in Production Example 1, except that
0 g of pigment was obtained.

Production example 3 Wax (manufactured by Allied Chemical Co., Ltd., AC polyethylene 4
About 150 g of pigment was obtained in the same manner as in Production Example 1, except that 1000 g of a 10% toluene solution of No. 30) and 1000 g of a 10% aqueous solution of the compound (o-toluidine) were used.

Comparative Production Example 10% toluene solution of polyethylene wax (manufactured by Mitsui Petrochemical Co., Ltd., Hiwax 410P; softening point 122°C) 1
000g and 10 of the above compound (m-chloroaniline)
About 150 g of a comparative colorant was obtained in the same manner as in Production Example 1 except that 1000 g of % aqueous solution was used.

Next, Examples 1 to 3 and a comparative example using the colorant (resin-coated colorant) will be shown.

Table 1 shows 35 g of the colorant obtained in the above production example or comparative example.
170 g of the resin shown in (binder) and 80 g of carrier liquid
0g and cross-dispersed in a ball mill for 40 hours to obtain a concentrated toner, then diluted 100g with the same carrier liquid IQ to obtain 4
I made a seed liquid developer.

(The following is a margin.) Subsequently, when copying was performed using a commercially available electrophotographic copying machine (DT-5700 manufactured by Ricoh Co., Ltd.) using these four types of liquid developers, the results shown in Table 1-2 were obtained. In Table 2, O means good and Δ means fair.

Table-2 111) Measured with a Macbeth densitometer.

$2) Evaluation was based on the time it took for the image to dry.

Umbrella 3) The caking state and sedimentation separation state after being left for 7 days were evaluated.

As is clear from the description of Examples, the liquid developer of the present invention has excellent gradation reproducibility and storage stability (dispersion stability).

It improves transparency, drying properties (fixing properties), and especially 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) [However, R^1 to R^1^0 are hydrogen, halogen,
-OC_nH_2_n_+_1, -C_nH_2_n_
＋＿１ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (n is 1
~4 integer). ] 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.