JPS6244753A - Color liquid developer for electrostatic photography - Google Patents

Abstract

PURPOSE:To improve dispersion stability, transparency, dryness and color reproducibility when OHP is used by using a coloring agent obtd. by subjecting a specific dye pigment to a flushing treatment as a toner component. CONSTITUTION:A color liquid developer for electrostatic photography is formed by dispersing toner particles essentially consisting of the coloring agent and binder into an aliphat. hydrocarbon carrier liquid. The dye pigment which is expressed by any of formulas (I)-(IV) and is subjected to the flushing treatment with a resin having 50-120 deg.C softening point is used as the coloring agent. In the flushing treatment, the pigment or the hydrous paste of the pigment is first put into a kneader known as a flusher together with a resin or resin binder and is thoroughly mixed. The water existing around the pigment is replaced by the resin soln. during this process. The mixture is taken out of the kneader and the water phase is discarded. The pigment dispersed into the resin soln. is dried to remove the solvent and thereafter the resultant lump material is pulverized.

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.

BACKGROUND ART A liquid developer for electrostatic photography is well known, which is made by uniformly dispersing a toner coated with an inorganic or organic pigment with a resin (binder) in a highly insulating and low dielectric constant carrier liquid ( Japanese Patent Application Publication 1973-
No. 151528, No. 53-109633, No. 5'5-
144252 etc.). This thing is generally
If the pigment is powdered together with the resin and carrier liquid using a ball mill or other means, the toner will not be dispersed into primary particles, resulting in poor transparency and rough images, as well as high sedimentation, and the sedimentation will cause caking. There are problems such as causing

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 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.

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: (I)
, (II), (III) and (IV) (However, R1 to R' are -) (, -CQ, -Br, -CH3
Or -5o3Na. ) (However, R9 to R1@ are -H, -Cl, -Br, but R
At least one of 9 to R'' is -Cl, -Br
It is. ) xl -○ (However, R17 to R24 are -H, -Cl, -Br, X
1 and x2 are -CH3 or -S○, Na. )(
However, R''-'-R34 is -H or -Br, but the total number of Br in the formula is in the range of 0 to 3. It is characterized by being flushed.

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 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 (
Any of the pigments (dyes) represented by I), (■), (III) and (IV) subjected to flushing 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 brushing treatment can also be employed as toner components.

The dye and pigment used in the present invention have the general formula (I) (n),
It is an indigoid type represented by (m) or (IV). Representative examples of such indigoid dyes and pigments include the following.

(Nlkl) C, 1,73010 (Nα2) C, 1,73035 (Nα3) C, 1,73065 (Nα4) C, 1,73055 (&5) C, 1,73045 (Nα6) C, 1,73060 (翫Force C, 1,73040 (&8) C, 1,73050 (&9) C, 1,73030 (Nα10) C, 1,73025 (Nα11) C, 1,73075 Su (Nα12) C, 1,73066 (Nlkl3) C, 1,73080 (&14) C, 1,73085 (Nα15) C, 1,73090 (&16) C, 1,73015 (&17) C, I, 73020 (Nα20) C, 1,73001 Na (Na21) C ,1,73002 0S O,Na (Na22) C,1,73066 (翫23) C,1,73041 (&24) C,1,73110 The following resins are used when flushing these dyes and pigments. Can give examples.

-Ri2left: ``Self''LjL''L] Illusion point (``C)
Eastman Chemical N-1o 111N
-11108 N-12113 N-14106 N-34103 N-45118 C-10104 C-13110 G-15102 G-16106 E-10106 E-11106 E-12112 E -14104 E-15100 Mitsui Petrochemical 110P 1 00220P
113 220MP 113 320MP 114 210MP 120 4202 E 108 4053E 111 Manufacturer name Product name Softening point (”C)B
ASF OA wax 93-96 petrolite BARECO50086BARECO
655102 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 P E520 1
1g~123PED121 113~118 PED136 107~112 PED153 115~120 PED521 103~108PED5
22 100~105P E D534
98-105 Allied Chemical AC-Polyethylene 6
&6A 102AC-Polyethylene L/N615
105 Sanyo Chemical Sunwax 131-P 1
08 Sunwax 151-P 107 Sunwax 161-P 111 Sun+7x 165-P 107 Sunwax 1
71-P 105 Manufacturer name Product name Softening point (℃) Union carbide DYNI 102D Y
N F 102 DY N H102 DY N J 102 DY N K 102 Monsanto 0RLIZON 805 1160R
LIZON 705 116 PHILLIPS
MARLEX 1005 92 Dupont A
LATHON 3 103LATHON 10
96 ALATHON 12 84 ALATI(ON 14 80ALATHON
16 95 ALATHON 20 86A
LATHON 22 84 ALATHON 25 96 In addition to the above, polyethylene resins include Sunwax E200, E 250 P (manufactured by Sanyo Chemical Co., Ltd.),
2000.2500.3000.4000.4100.
8000B, 5000.6000.7000 (or more,
(manufactured by Chubu Polyethylene Co., Ltd.), Viscol 5o as polypropylene resin.

P, 660P (manufactured by Sanyo Chemical Co., Ltd.), Denga Vinyl 5S-100, 5S-130 as vinyl chloride resin,
I) SS-130, 5S-140, 5S-80, 5S-
70,5S-Y, 5t(-250,3H-170
, M-70, M-120, MM-90, EM-140,
VP-30, 5E-130, ME-120, ME-1
80, MHE-100, PA-100, P-80 (manufactured by Denki Kagaku Kogyo Co., Ltd.), paraffin wax (softening point 5
Examples include beeswax (softening point: about 60°C), natural wax (softening point: about 51°C).

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

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 and binder is 1:1 to 10 (by weight)
is appropriate.

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 (V) [However, Ro is hydrogen or a methyl group, R16 is COOC
n H2n + 1 or -0COCnH2n+□ (n is an integer from 6 to 20). ] A monomer represented by acrylic acid, methacrylic acid, vinylpyridine, the following general formula (VI) [However, R37 is hydrogen or a methyl group, R'' is -COOCnH2n+1 or -〇〇〇nH2rl+1 (n is 1 to 5) ] A monomer represented by the following general formula (■) [However, R''
is hydrogen or methyl group, R4' is -N(CH,)2, -N
(c2Hs)z or -OH. ] It is effective to use a copolymer (including a block copolymer) with one or more monomers selected from hetamine and ethylene glycol dimethacrylate represented by the following. The appropriate proportion of the vinyl heptamer component represented by formula (V) 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 Nα6 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 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 (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 using a copying machine. Furthermore, (■) the toner particle size is small, so it has particularly excellent gradation reproducibility; This improves the color reproducibility in HP.

Here, an example of producing a colorant will be shown in which the dye and pigment represented by the general formula (I) are flushed with a resin having a softening point of 50 to 120°C.

Production example 1 Polyethylene wax (Petrolite E 730) 1
1000g of 0% toluene solution and 4 of the above compound (&1)
The mixture with 1000 g of 0% aqueous solution was thoroughly stirred with a flasher and kneaded for 4 hours while keeping it at 150°C. 6 Then, after removing water and solvent by heating and reducing pressure, it was crushed to give 150 g of colorant (resin-coated colorant). I got it.

Production Example 2 Example 1 except that AC-polyethylene 6 & 6A (manufactured by Allied Chemical Co., Ltd.) was used instead of polyethylene wax (Petrolite E 730), and the compound (Nα9) was used instead of the above compound (Nα1). A coloring agent was obtained in the same manner as above.

Production Example 3 210MP (manufactured by Mitsui Petrochemicals) was used instead of polyethylene wax (Petrolite E 730), and
The compound (Nα18
) A coloring agent was obtained in the same manner as in Example 1 except that the following was used.

Production Example 4 Sunwax 151P (manufactured by Sanyo Chemical Co., Ltd.) was used instead of polyethylene wax (Petrolite E 730),
Also, the compound (Nα1) can be replaced with the compound (Nα1).
A coloring agent was obtained in the same manner as in Example 1 except that 20) was used.

Production Example 5 Same as Example 1 except that OA wax (manufactured by BASF) was used instead of polyethylene wax (Petrolite E 730) and the compound (Nα24) was used instead of the above compound (Nα1). A coloring agent was obtained.

Comparative Production Example A coloring agent was obtained in the same manner as in Example 1, except that polyethylene B-6 (manufactured by Allied Chemical Co., Ltd., softening point: 128°C) was used instead of polyethylene wax (Petrolite E 730).

Next, examples using the above coloring agent are as follows.

30g of the resin-coated colorant obtained as described above was added to the table.
Mix 170 g of the resin shown in 1 and 800 g of the carrier liquid,
A concentrated toner was obtained by cross-dispersing it in a ball mill for 40 hours, and 100 g of the concentrated toner was diluted with the same carrier liquid IQ to prepare six types of liquid developing/imaging sides.

Table 1 MMA: Methyl methacrylate MAA: GMA nigericidyl methacrylate Subsequently, using these liquid developers, copies were made using a commercially available electrophotographic copying machine (DT-1200 manufactured by Ricoh Co., Ltd.). Table 2 shows the results of copying. Shown below. In Table 2, ○ means good, Δ means normal, ×
means defective.

Table 2 111) Drying performance was evaluated by rubbing the image area with a finger immediately after copying paper.

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

Umbrella 3) Dispersion stability was evaluated in the caking state after being left for one week.

The effect is clear from the comparison between the inventive product and the comparative product.
The liquid developer of the present invention has excellent dispersion stability, transparency,
It improves drying properties, especially color reproducibility when using OHP.

Procedural amendment document 1985 Patent Application No. 184967 2 Title of the invention Color liquid developer for electrostatic photography 3 Relationship to the person making the amendment Patent applicant 1-3-6 Nakamagome, Ota-ku, Tokyo ( 674) Ricoh Co., Ltd. Representative Hama 1) Hiro 4, Agent 4-5 Kojimachi, Chiyoda-ku, Tokyo (102) 6 Contents of amendment (I) Page 14 of the specification, line 2 (Nα13) C, 1,7
The structural formula of 3080 is corrected as below.

(2) Formula (V) on page 21, line 5 of the circular is 3s fi’cH2=C R36” is corrected.

(3) The formula (VI) on page 21, line 11 of the same book is R” Ii′CH2=C Correct it to R”41.

(4) The formula (■) on the last line of page 21 of the same section is R” [rCH,=C Revised as C00CH2CH2R"j Correct.

(5) Replace “Table 1” on page 26 of the same book with the one on the attached sheet.

7. List of attached documents

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), ( II), (III) and (
IV) ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) (However, R^1 to R^8 are -H, -Cl, -Br, -CH
_3 or -SO_3Na. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (However, R^9 to R^1^6 are -H, -Cl or -Br, but among R^9 to R^1^6 At least one of these is -Cl or -Br.) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) (However, R^1^7 to R^2^4 are -H, -Cl or -B
r, X^1 and X^2 are -Na or -SO_3Na. )▲There are mathematical formulas, chemical formulas, tables, etc.▼...(IV) (However, R^2^5 to R^3^4 are -H or -Br, but the total number of Br in the formula is in the range of 0 to 3.) ) with a softening point of 50 to 120°C.
A color liquid developer for electrostatic photography, characterized in that it is flushed with a resin.