JPS6227753A - 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 the dye pigment expressed by the formula as the coloring agent to a flushing treatment with a resin having 50-120 deg.C softening point. CONSTITUTION:The coloring agent prepd. by subjecting the dye pigment expressed by the formula to the flushing treatment with the resin having 50-120 deg.C softening point is used. The pigment or hydrous paste of the pigment is first put together with a resin soln. into a kneader known as a flusher and is thoroughly mixed in the flushing treatment. The water existing around the pigment is replaced by the resin soln. during this process. Such mixture is taken out of the kneader and the water phase is discarded. The mixture consisting of the resin soln. dispersed therein with the pigment is dried to remove the solvent; thereafter the resultant lumped material is pulverized. The ratio of the dye pigment and resin in such flushing treatment is adequately 0.1-0.6pts.wt. resin with respect 1 to pt.wt. dye pigment.

Description

[Detailed Description of the Invention] Technical Division 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.

Liquid developers for electrostatic photography are well known, in which a toner coated with an inorganic or organic pigment and a resin (binder) is 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
-144252 etc.). This product is generally 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 and poor image quality. There is a problem in that it has a large sedimentation property and the sedimentation 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.). but.

This product has a low absolute density, and in addition, there is a problem in that it causes background fogging 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;
No. 73 and other publications, 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 Application 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.

OBJECTIVE 1 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.

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 electrostatography, 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 is represented by the following general formula (I). [However, R', R2 and R3 are hydrogen atoms, halogen atoms, CnHzn+x or -○CnHzn+z (n is 1
~4 integer), and x', x2 . x3 and X4 are hydrogen atoms, halogen atoms, -No2. -CffiH2□ and □
or -o CJ'lzm+t (m is an integer from 1 to 4). ] It is characterized in that it is a dye & 1 dye represented by the following which has been flashed with a resin having a softening point of 50 to 120°C.

Incidentally, it has not been previously considered that inorganic or organic pigments such as carbon black and phthalocyanine blue are subjected to Francinc treatment to be used as a coloring agent for toner.

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 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 when manufacturing the colorant, or taking measures such as performing dispersion for a long time when manufacturing the toner, 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 pigment (dye) represented by r) subjected to flashing treatment is used as a toner component. Therefore, I will proceed with the explanation after getting the hang of the ``flushing process II.''

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." In addition.

A method of removing water and solvent under reduced pressure while kneading with a kneader may be used.

Flushing treatment is known to have very good dispersion because it can use a water-containing paste as a material and can be treated with a kneader while mixing. 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 is an acetoacetanilide-based disazo dye and pigment represented by the general formula (I) and commonly referred to as benzidine yellow.

Representative examples of such dyes and pigments include the following.

(Nα1) C01,21090 Pigment Yellow 12 (yellow) CNa2) C,1,2]100
Pigment Yellow 13 (Yellow) (NQ 3)
C,1,21095 Pigment Yellow 14 (yellow)
(Nα4) C01,21220 Pigment Yellow 15 (Nα5) C01,20040 Pigment Yellow 16 (Yellow) (NQG) C,1,21105
Pigment Yellow 17 (Vivid greenish yellow) (N (I7) C, 1,21096 Pigment Yellow 55 (Na8) Pigment Yellow 83 (Reddish yellow) (Nα9) C, 1,20045 Permanent
Gold Yellow (Nα10) C, 1, 21135
Palkan Firth Yellow (Mail) C, 1,
21165 Pigment Orange 14 (yellowish orange) (Nn12) C, 1, 21130 Pigment Orange 15 (Nα 1.3) C, 1, 21160 Pigment Orange 16 (&14) Nirasin Yellow 331
6 (yellow) (Nα15) described in Japanese Patent Publication No. 36-10478 (bright greenish yellow) Examples of resins used in flushing these dyes and pigments include the following.

Manufacturer name Product name Softening point ('C) Eastman Chemical N-10111N-11108 N-12113 N-14106 N-34103 N -45118 C-10104 C-13110 G-15102 C-16106 E-10106 E-11106 E -12112 E-14104 E-15100 Mitsui Petrochemical 110P 100220P
113 220MP 113 320MP 114 210MP 120 4202E 108 4053E 111 Manufacturer name - Sasa L-j distribution - Yoru - - Temperature 1℃
” 穎(工υ-B A S F OA WAX 93~96 PETROLITE BARECO
50086BARECO655102 BARECO1000113 E 730 93 E2018 117 E2020 1.17 E 1040 105 PETRONABA C90,5 PETRONABA C-3690,5PETRONA
BA C-400104,5PETRONABA C-
750097,8 Hoechst PE520 11
8～123P E D121 113～118P
ED136 107-112 P E D153 115-120 P E D5
21 103~108P E D522
1.00~105PED534 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 Manufacturer name - Dish-jV-Tai Softening point ("C)
Union Carbide DYNI 102D
Y N F '102 DYNH102 DY N J 102 DY N K 102 Monsanto 0RLIZON 805 1160RLI
ZON 705 116 Phillips
MARLEX 1005 92 Dupont A
LATHON 3 103LATHON 10
96 ALATION 12 84ALATION
14 80 ALAT)ION +6 95ALATHON
20 86 ALATHON 22 84 ALATHON 25 96 In addition to the above, polyethylene resins include Sunwax E200 (manufactured by Kochu Kasei Co., Ltd.), 2000.2500.3
000.4000.4100.8000B, 5000
．． 6000.7000 (manufactured by Chubu Polyethylene Co., Ltd.)
, Viscol soop, 6 as polypropylene resin
60P (manufactured by Kochu Kasei Co., Ltd.), Denga Vinyl 5S-100, 5S-130-DSS- as vinyl chloride resin
130, 5Sf-140, 5S-80, SS-70,
SS-Y, 511-250, sll-170, M-
70, M-120, MM-90, EM-140, vp
-30, 5E-130, ME-120, ME-180,
MICE-100, PA-100, P-80 (and above,'
(Manufactured by Ichiki Kagaku Kogyo Co., Ltd.), Teflon K, Teflon FEP (Mitsui Fluorochemical Co., Ltd.!0) as fluororesin, paraffin wax (softening point 50-98°C), beeswax (
Examples include natural wax (softening point: about 60°C), and natural wax (softening point: about 51°C).

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

To prepare a liquid developer using the thus obtained [brushed colorant], 10 to 1
00 parts by weight, 5 to 40 parts by weight of binder, and 300 to 1 part of carrier liquid.
000 parts by weight is cross-dispersed using an attritor, ball mill, kitty mill, etc. to make a concentrated 1-ner, and if necessary, this can be diluted to about 5 to IO 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 polymethalyl ester resin, styrene resin, chlorinated rubber, etc. are used, but in particular, the following general formula (I1) [However, R4 is hydrogen or methyl group, R5 is -CO
OC, H, n, or -〇〇〇nH2n+, (n is 6
~20 integer). ] A monomer represented by acrylic acid, methacrylic acid, vinylpyridine, the following general formula (III) [However, R' is hydrogen or a methyl group, R7 is -C○○CoH2n+1 or -○C0CnH2rl+□ (n is 1 to 5 is an integer). ] A monomer represented by the following general formula (rV) [However,
R3 is hydrogen or methyl group, R' is 'N (CH3)
z, N (c2Hs)2 or -○H. ] 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 about 30 to 95% by weight.

As a binder, natural resins such as ester gum, softened rosin, natural resin-modified maleic acid resin, and natural resin-modified phenol resin are used as binders.

Natural resin-modified thermosetting resins such as natural resin-modified polyester resins, natural resin-modified pentaerythritol resins, and epoxy resins 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 Solbetso 100, etc.), ligroin, [l-hexane, n-
Hebutane, 1so-octane, n-octane, carbon tetrachloride, trichlorotrifluoroethane, cyclohexane, etc. may be used alone or in combination of two or more.

The thus obtained liquid developer of the present invention has (i) dye and pigments that are dispersed in a state close to primary particles, which makes them difficult to aggregate, and (ii) primary particles of dye and pigments that have a softening point of 50 to 120°C.
Because it is coated with a resin, the colorant is well fixed on the transfer paper by heating and fixing it with a copying machine.
Furthermore, (iii) since the toner particle size is small, gradation reproducibility is particularly excellent, and color reproducibility at ◯ HP is improved.

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

First, 600 g of a paste pigment (water content 40%) was thoroughly stirred in a flasher, and then 000 g of a flashing resin (I0% toluene solution) was mixed therewith and kneaded for 1 hour. Next, this was heated under reduced pressure to remove volatile components such as water and solvent, thereby obtaining a colorant mass. Furthermore, this lump was crushed to a particle size of 3 μm or less. The pigments and flushing resins used here are shown in Table 1.

Table-1 Next, Examples and Comparative Examples using the above coloring agent will be shown.

Examples 1 to 6 Colorants obtained in the above production examples 30g lauryl methacrylate - methacrylate glycidyl methacrylate 50g taacrylate (50/], /5) Isopar 8
A concentrated toner was prepared by dispersing 150 g of the mixture in a ball mill for 6 hours.

A liquid developer was prepared by diluting 100 parts of this concentrated toner with Isopar H1,5Q.

Comparative Example 1 The flushing resin used in Production Example 3 was ○RLIZ.
I made a coloring agent by changing it to ON50 (softening point 126℃),
A liquid developer was prepared in the same manner as in Example 1 using this colorant.

Comparative Example 2 A liquid developer was prepared in exactly the same manner as in Example 6 except that a pigment that was not subjected to flushing treatment was used.

Subsequently, when copies were made using a commercially available electrophotographic copying machine (DT-5700 manufactured by Ricoh Co., Ltd.) using these eight types of liquid developers, the results shown in Table 2 were obtained.

Table-2 Umbrella 1) The image was evaluated by rubbing it with a finger behind the discharged paper surface.

Book 2) Evaluation was based on how many steps G, S, (Kodasoku gray scale) were reproduced from the original in 20 steps.

ψ3) Dispersion stability is evaluated as the sedimentation property of concentrated toner after being left for a week.As is clear from the description of the examples, the liquid developer of the present invention has excellent gradation reproducibility, dispersion stability, and transparency. .

It improves drying properties, especially color reproducibility when using HP.

Claims (1)

[Scope of Claims] 1. A liquid developer comprising a toner 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) ▲Math. , chemical formulas, tables, etc.▼…(I) [However, R^1, R^2 and R^3 are hydrogen atoms, halogen atoms, -C_nH_2_n_+_1 or -OC_nH_
2_n_+_1 (n is an integer from 1 to 4), X^1,
X^2, X^3 and X^4 are hydrogen atoms, halogen atoms,
-NO_2, -C_mH_2_m_+_1 or -OC_
mH_2_m_+_1 (m is an integer from 1 to 4). ] 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.