JPS6238477A - Color liquid developer for electrostatic photography - Google Patents

Abstract

PURPOSE:To obtain the titled toner which is insoluble in a carrier liquid and to improve the dispersion stability and drying characteristic thereof by subjecting a specific dye pigment to a flushing treatment with a resin having 50-120 deg.C softening point. 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. The pigment or the 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 with the resin soln. in the flushing treatment. The mixture is taken out of the kneader and the water phase is discarded. After the mixture is dried to remove the solvent, the lumped matter is ground to obtain the toner. The ratio of the dye pigment and resin in the flushing treatment is made 0.1-6.0pts. wt. more preferably 0.1-0.6pts.wt. resin by 1pt.wt. dye pigment.

Description

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

A well-known liquid developer for electrostatography 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.) are generally made by crushing and dispersing the pigment together with a resin and a carrier liquid using a ball mill or the like.
However, with these methods, the toner is not dispersed into primary particles, resulting in poor transparency and rough images, as well as high sedimentation, and the sedimentation causes caking. There is.

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 of the pigment, and this is 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 electrostatic photography, 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.

(2) The present invention provides a color liquid developer for electrophotography, which comprises 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: (1) [However, R1 to R'' are hydrogen, halogen, C@H2, respectively.
@41, -〇CnH2n+1, -OH, -CONH,,
-No2゜-3o2-@, -3o2CH2-@, -C
ONH-@-CONHCaH? p+>, -CONH-o
-C0NH,.

802 N(CnHznJa or -NHCOCnH, r
l.

(12, m and n are integers of 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.

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 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 1) is used as a toner component after being subjected to flushing treatment. 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 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.

The dye and pigment used in the present invention are thioindigo derivatives represented by the general formula (1). Representative examples of such dyes and pigments include the following 6 (Nα1) (NG2) (Nα3) br Br (Nα4) (Nα5) (Na 6 ) (Nα7) NHCOCH.

(&8) (&9) (Nα10) (&11) (&12) (&13) (&14) (NQ 15) a (&16) (翫17) (NQ 1g) (Na19) (Na20) (&21) (&22 ) (&23) CONHCH3 The following resins can be exemplified as resins used when flushing these dyes and pigments.

Manufacturer name - Shoichi "V - Taichi - Soft" 21] Sword -
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 Mitsui Petrochemical 110P 10022 0P
113 220MP 113 320MP 114 210MP 120 4202E 108 4053E 111 "Nikurumago LJNishibuki LJ Kitakabu Y BASF OA wax 93~9
6 Petrolite 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 P, E520 1
18~123PED121 113~118 PED136 107~112PED15
3 115-120 P E 0521 103-108 P E D5
22 100~105PED534 9g
~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 ≦ Finishing: l J Lighting Beast 2 and Union Carbide D Y N I 102
D Y N F 102 DYNH102゜D Y N J 102 DYNK 102 Monsanto 0RLIZON 805 1160R
LIZON 705 116 Philips X
MARLEX 1005 92 Dupont
ALATHON 3 103ALATHON 1
0 96 ALATHON 12 84 ALATHON 14 80 ALATHON 16 95 ALATHON
20 86 ALATHON 22 84 ALATHON 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 Sanyo Chemical Co., Ltd.) as polypropylene resin, Dengahinyl 5S-100, 5S- as vinyl chloride resin
130, DSS-130, 5S-140, SS-80
, 5S-70, 5S-Y, 5H-250, 5H-1
70, M-70, M-120, MM-90, EM-14
0, VP-30, 5E-130, ME-120, ME-
180,8HE-100, PA-100, P-80 (manufactured by Denki Kagaku Kogyo Co., Ltd.), paraffin wax (softening point 50-98℃), beeswax (softening point approx. 60℃), natural wax (softening point approx. 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 "flushed colorant" thus obtained, the colorant and binder are mixed with a small amount of carrier liquid in an attritor, a ball mill,
A concentrated toner may be prepared by cross-dispersing the toner using a kitty mill or the like, and if necessary, this may be diluted approximately 5 to 10 times with a similar carrier liquid. The ratio of colorant to binder is suitably 1:1 to 10 (by weight).

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 (n) [However, R" is hydrogen or methyl group, R" is -COO
CnH, n, or -0COcnH0+l (n is 6 to 2
an integer of 0), ] A monomer represented by acrylic acid, methacrylic acid, vinylpyridine, the following general formula (III) [However, R" is hydrogen or a methyl group, R" is -COOCnH1ll+1
or -〇cocnH21,+1 (n is an integer of 1 to 5), ] The following general formula (IV) [However,
R17 is hydrogen or methyl group, R” is N(CH3)2,
-N(c2HS)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 heptamer component represented by formula (II) 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, epoxy resins, etc. may be added.

The carrier liquid may be a paraffinic or isoparaffinic hydrocarbon (Isopar H, Isopar G manufactured by Esso).
, Isopar L, Isopar K, Naphtha & 6 Solvetsuso 100, etc.), ligroin, n-hexane, n-hebutane, 1so-octane, n-octane, carbon tetrachloride, trichlorotrifluoroethane, cyclohexane, etc. alone or in combination. The above are used in combination.

The thus obtained magenta to red 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. Because it is coated with a resin at ℃, the colorant is well fixed on the transfer paper by heating and fixing the copy with a copying machine.In addition, (i) the toner particle size is small, so it has particularly excellent gradation reproducibility; This ensures good color reproducibility.

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

Production Example 1 500 g (moisture content: 60%) of the pigment (compound &1) wet cake was thoroughly stirred with a flasher.

Polyethylene (AC-6 manufactured by Allied Chemical Company)
1,600 g of carbon tetrachloride was added and the mixture was heated to 150° C. and kneaded for 3 hours, then 230 g of carbon tetrachloride was added and kneaded for an additional 2 hours. Thereafter, the pressure was reduced to remove water and carbon tetrachloride, and the mixture was ground in a ball mill.

Production example 2 Polypropylene (Viscol 550P manufactured by Sanyo Chemical Co., Ltd.)
A mixture of 100 g and 60 g of toluene was heated to 100° C. and stirred well in a flasher. Pigment (Magic 3)
Wet cake (water content 50%) of 1000
After heating to 150° C. and dispersing for 3 hours, the pressure was reduced to remove volatile components.

It was then ground to obtain a powder with a particle size of 3 to 10 microns and a moisture content of 0.50%.

Production example 3 Polyethylene (Sunwax 131P manufactured by Sanyo Chemical Co., Ltd.)
150 g of a mixture of 200 g and 100 g of chlorobenzene
℃ and thoroughly stirred in a flasher. Add to this a wet cake of pigment (Nα5 compound) (water content 50%).
) 2000g was added and flushed at 150°C for 2 hours. Then, the pressure was reduced to remove volatile components, and the mixture was ground in a stone mill to obtain a powder with a particle size of 5 to 15 μm.

Production Example 4 After thoroughly stirring a mixture of 300 g of water and 1000 g of pigment (Nα7 compound) with a flasher, 800 g of Florado FC-721 (manufactured by 3M) and 100 g of toluene were added to the mixture.
0 g was added, and the mixture was heated and stirred at 150°C. After mixing for about 5 hours, the pressure was reduced to remove volatile components, and the mixture was pulverized.

Production Examples 5 to 10 Colorants were obtained in the same manner as Production Example 1, except that the pigment and flushing resin were changed to those shown in Table 1.

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

Example 1 Colorant obtained in Production Example 1 30g Copolymer (Isopaer (80% dispersion) 50g Isopaer H1
A mixture consisting of 50g was dispersed in a kedimir for 6 hours until the viscosity was 17.
．． A liquid developer was prepared by diluting this concentrated toner LOOG with Isopar H1,5Q.

Next, using this liquid developer, a commercially available electrophotographic copying machine (
When copying was performed using Ricoh DT-5700, an image with an image density of 1.22 and excellent drying properties was obtained. Also, when I copied it onto OHP film,
An image with good color reproduction was projected.

Examples 2 to 10 Liquid developers were prepared and evaluated in exactly the same manner as in Example 1, except that the colorants obtained in Production Examples 2 to 10 were used, and the results shown in Table 2 were obtained. Ta. In the table, 0 means good and Δ means fair.

Table-2 -1) Evaluation was made based on the time required for the toner image to dry.

Umbrella 2) Evaluation was made based on how many levels of G, S, (Kodak Grayscale) were reproduced from the original 20 levels.

As is clear from the description of Examples, the liquid developer of the present invention has excellent gradation reproducibility and fixing properties, and particularly improves color reproducibility when using an OHP.

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^1^2 are hydrogen, halogen,
-C_mH_2_m_+_1, -OC_nH_2_n_
+_1, -OH, -CONH_2, -NO_2, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, -CONHC_lH_2_l_+_1, ▲ Mathematical formulas, There are chemical formulas, tables, etc. ▼, -SO_2N(C_nH_2_n
___+_1)_2 or -NHCOC_nH_2_n_+_
1 (l, m and n are integers of 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.