JPS5840740B2 - Liquid developer for electrophotography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid developer for electrophotography, and more specifically, the present invention relates to a liquid developer for electrophotography. This invention relates to a liquid developer for electrophotography which is uniformly dispersed in a carrier liquid.

Conventionally, it is well known to produce electrophotographic toner particles by kneading a colorant such as carbon black, phthalocyanine blue, phthalocyanine green, sky blue, etc., and a resin, and pulverizing the resulting mixture. It is also well known to produce an electrophotographic liquid developer by kneading the mixture in the presence of a liquid developer and dispersing it in an aliphatic carbon or arsenic carrier liquid having an electric resistance of 10<9 >Ω or more and a dielectric constant of 3 or less.

However, since the colorants used in the past were untreated, they caused strong secondary aggregation and could not be easily dispersed into primary particles even with ordinary equipment such as ball mills, attritors, or ultrasonic dispersers. It was something.

Therefore, when electrophotographic toner particles are formed, the colorant is exposed on the particle surface, and the polarity controllability of the toner particles varies among particles.

Furthermore, when the toner particles come into contact with an electrostatic latent image to be developed, charges are injected into the toner particles from the exposed colorant, resulting in a lack of polarity stability.

Furthermore, many colorants are electrically conductive, and when they are exposed on the surface of toner particles, a toner image is difficult to transfer when transferred by electrostatic transfer.

In addition, as a method for transferring a toner image obtained by developing an electrostatic latent image with a conventional liquid developer onto a transfer paper, an excess carrier liquid is squeezed from the developed image using a corona discharge, and then an excess of the carrier liquid is squeezed onto the transfer paper. The toner particles are stacked on top of each other and transferred by applying an electric charge using corona discharge or the like from the surface side of the transfer paper, but after squeezing, a considerable amount of carrier liquid is also present, and during transfer, the toner particles are transferred to the transfer paper by electrophoresis. It was meant to lead to.

Therefore, a large amount of the carrier liquid evaporates, and it takes a considerable amount of time for the toner image to be completely fixed on the transfer paper, making it impossible to copy at high speed.

It is an object of the present invention to solve the above-mentioned drawbacks, to provide excellent storage stability, to eliminate the need for a large amount of carrier liquid to be included in the toner image during transfer, and to reduce the amount of evaporation of the carrier liquid. It is an object of the present invention to provide an excellent liquid developer for electrophotography which can be quickly fixed.

Another object of the present invention is to provide a liquid developer for electrophotography that increases image density, improves the number of durable sheets in a copying machine, and has excellent not only dispersion stability but also redispersibility.

That is, the present invention has high insulation properties (electrical resistance 109Ω(1)
above) and a carrier liquid consisting of a non-aqueous solvent with a low dielectric constant (dielectric constant of 3 or less), in which a colorant and a resin component are mainly dispersed. A resin obtained by polymerizing at least one type of resin having an acetone tolerance value of 100 to 5000 and at least one type of monomer capable of dissolving this resin ( A component) and general formula (1) (R is -H or -CH3, X is C00CnH2n-h or -CnH2n+t (6≦
In a copolymer of a monomer represented by n≦20)) and a monomer having a glycidyl group or an unsaturated carboxylic acid or its anhydride, when the copolymer has a glycidyl group as a constituent unit, an unsaturated carboxylic acid or its anhydride When an anhydride or an unsaturated carboxylic acid or its anhydride is used as a constituent unit, a glycidyl group-containing hexamer is esterified, and the unsaturated portion of the ester is further represented by the general formula (2). This is a liquid developer for electrophotography, characterized in that it contains a non-aqueous thermoplastic resin B (component B) obtained by graft polymerization of at least one monomer of the following.

The present invention will be explained in more detail below.

The non-aqueous solvent used in the present invention is of the same type as the carrier liquid, i.e., petroleum-based aliphatic carbon with high insulation properties (electrical resistance of 109Ω or more) and low dielectric constant (dielectric constant of 3 or less), n- In addition to hexane, ligroin, n-heptane, n-pentane, isododecane, isooctane, etc., halogen derivatives thereof such as 4-carbon, perchlorethylene, etc. can be mentioned.

Incidentally, commercially available products of the petroleum fatty raw coal f arsenide include Isopar E, Isopar G, Isopar Shi, Isopar H, Isopar K, Naphtha A6, and Tsurpez 100 manufactured by Exxon.

These may be used alone or in combination.

The colorant to be dispersed in the nonaqueous solvent is one that has been subjected to a flashing process.

A colorant that has been subjected to a flushing process is one that is manufactured using a water-containing pigment cake, and is substantially insoluble (slightly soluble or insoluble) in the carrier liquid that makes up the final developer. A fine particulate pigment coated with a resin.

In fact 1 (in order to obtain a colorant with a desirable flashing process, a pigment paste made by adding water to an aqueous pigment or a non-aqueous pigment containing water immediately after generation and carbon black should be mixed in a weight ratio). The mixture is placed in a kneader called a flasher at a ratio of 0 to 200, mixed to some extent, and then a resin solution dissolved in a solvent is added thereto and kneaded well.

As a result, the water present around the pigment is replaced by the resin solution.

Water and solvent are removed from this in a kneader to form a mass, which is then ground.

Compared to pigments that are not subjected to flashing processing, this colorant can be easily separated into fine primary particles even if secondary aggregation occurs, and uniformly colored toner particles can be obtained. .

Furnace black, acetylene black, channel black, etc. can all be used as the above pigments, and commercially available products include Printex G, Special Black 15, Special Black 4, and Special Black 4.
-B (manufactured by Degussa), Mitsubishi #44, #30, MA-
11, MA-100 (manufactured by Mitsubishi Carbon Corporation), Ramen 30.40, and Conductex SC (manufactured by Cabot Corporation) are known.

Organic pigments include Phthalocyanine Blue, Phthalocyanino Green, Sky Blue Rhodamine Lake, Malachite Green Lake, Methyl Violet Lake, Peacock Blue Lake, Naphthol Green B1 Naphthol Green Y1 Naphthol Yellow S1 Lysol Fast Yellow 2G, Permanent Red 4R, Brilliant Fast Scarlet, Hansa Yellow Benzidine Yellow Resole Red, Lake Red C1 Lake Red D1 Brilliant Carmine 6B, Permanent Red F5R1 Pigment Scarlet 3B and Bordeaux 10B+! ]″-%-r:8.

The resin constituting component (A) used in the toner of the present invention is a resin having an acetone tolerance value of 100 to 5,000.

Here, the acetone tolerance value is a value indicating the solubility in an aliphatic hydrocarbon solvent as a carrier liquid, and its measurement method is as follows: 1. Prepare a 50% by weight toluene solution of the resin, and pour this solution 51 into a glass cylinder with an inner diameter of 60 mrn. into a container, then drip acetone into it, and measure the amount of acetone dropped (Vcc) until the solution becomes cloudy and the letters on a document placed under the container can no longer be read. , □oo, Aya, 7 □, 7 price 5'? It is calculated.

It can be said that the higher this value is, the more poorly soluble it is in aliphatic hydrocarbons.

The resins (resin A1) with an acetone tolerance value of 100 to 5000 include natural resin-modified maleic acid resin, tammal, copal, shellac, gum rosin, hard hyrodine, ester gum, glycerin ester-modified maleic acid resin, and styrene-butadiene copolymer. , natural resin-modified pentaerythritol resin, natural resin-modified polyester resin, vinyltoluene-butadiene resin, and water-added rosin.

These resins are difficult to dissolve in the aliphatic hydrocarbon that is the carrier liquid, and are preferably used in an amount of 1 to 4 parts by weight per 1 part of the total weight of carbon black and organic pigment.

Consists of a coloring agent that has been subjected to flashing processing, and (
A) Acetone tolerance value 100 of these components
-5000 commercially available resins include the following.

Examples of natural resin-modified maleic acid resins MRG, MRG-411, MRG-81MRG-HlM
RP, MRA-LlMRM-42, MRM-53 (manufactured by Tokushima Essential Oils), Veracasite 1110, Veracasite 1111, Veracasite F231゜Same J
811, 1120, P-720, J896 (manufactured by Inu Nippon Ink Fhigaku) Examples of natural resin-modified phenolic resins PRG, PRP, 5PR-N, 5PR-A, 5PR-H
(Made by Tokushima essential oils) Veracasite 1100. 1123, 1126, F
-171 (manufactured by Inu Nippon Ink Fhigaku) Example of natural resin modified pentaerythritol resin Pentacite P-406,
P-423 (manufactured by Inu Nippon Ink) Examples of natural resin-modified polyester resins RM-1000, RM-1300, RM 4090, RM-4100 (manufactured by Tokushima Seisei) Examples of ester gum EG-80001EG-9000 , H.G.-H.

PE, PE-H (manufactured by Tokushima Essential Oils) Example of Hard 1 Hyrodine TLR-2L TLR-57 (manufactured by Tokushima Essential Oils) The resin A used in the toner of the developer of the present invention has an acetone tolerance value of 100 to 5000 as described above. of resin (resin A1),
It is a polymer with a monomer (monomer A2) that can dissolve resin A1, and monomer A2 has the general formula (where R is H or CH3,6≦n≦20).

).

This product is substantially the same as the monomer represented by the general formula (1) as component (B).

Therefore, the monomer A2 here includes, for example, nisaryl, lauryl, 2-acrylic acid or methacrylic acid.
Examples include vinyl monomers such as ethylhexyl or hexyl ester: t-butyl methacrylate: cetyl methacrylate: octyl methacrylate: vinyl stearate.

As the monomer A2, one or more of glycidyl methacrylate, glycidyl acrylate, propylene glycol monoacrylate, propylene glycol methacrylate, hydroxyethyl methacrylate, acrylonitrile, methacrylonitrile, etc. (hereinafter referred to as monomer C) can be used as a mixture.

These monomers C are added to monomer A2 before polymerizing monomer A20, or added to the polymerization system after polymerizing monomer A2 and polymerized.

Monomer C is a resin substantially insoluble in non-aqueous solvents (resin A1
), but alone cannot be solvated in non-aqueous solvents when polymer f is dissolved.

In addition, the ratio of monomer A2 and monomer C is 70 to 99
:30 to 1 (weight ratio) is appropriate.

Furthermore, in the present invention, the mixture of monomer A2 and monomer C includes acrylic acid, methacrylic acid, or lower alkyl esters thereof (having 1 to 4 carbon atoms), styrene, methylstyrene, vinyltoluene, vinyl acetate, etc. (hereinafter referred to as monomer D). It is also possible to use a mixture of one or more of these.

These monomers D are added to the mixture of monomers A2 and C before polymerization, or added to the polymerization system after polymerization of monomer A2 and monomer C to polymerize.

Monomer D, like monomer C, dissolves resin A1, but alone cannot solvate the polymer f into a non-aqueous solvent.

In addition, when monomer D is used together, the ratio of monomer A2, monomer C and monomer D is 60 to 90:20 to 2.
Approximately 0 to 1 (weight ratio) is appropriate.

The ratio of resin A1 and monomer A2 (or a mixture of monomer A2 and monomer C and/or monomer D) is 5 to 5.
Approximately 50:95 to 50 (weight ratio) is appropriate.

The wax or polyolefin may be used in an amount of about 10 to 50 parts by weight per 100 parts by weight of the monomer, but may be varied depending on the use of the final product.

Therefore, to make resin A, to make a polymer of resin A1 and monomer A2, to make resin A1 to monomer A2,
It is advantageous to polymerize this monomer A2 after it has been dissolved in .

If such a method is adopted, other conditions can be changed f
It can cause a person to die.

For example, monomer A2 can be polymerized by dropping a monomer A2 solution in which resin A1 is dissolved into a nonaqueous solvent, or by adding an amount of nonaqueous solvent such that resin A1 does not precipitate to the monomer A2 solution. After polymerization with or without addition, the obtained polymer may be dispersed in a nonaqueous solvent.

Resin A is thus preferably formed as a resin dispersion, although this is convenient for subsequent addition of pigments or dyes.

Additionally, the dispersion may contain waxes or polyolefins with a softening point of about 60 DEG to 130 DEG C.

In this case, these substances can be added to the monomer solution before polymerization, during polymerization, or to the dispersion obtained after polymerization to further improve dispersibility.

Commercially available waxes or polyolefins include the following:

Example of polyethylene Polymerization conditions can be selected from various conditions, but in the case of thermal polymerization, for example, a common polymerization initiator such as peracid f-hibenzoyl or azobisisobutyronitrile is added to a monomer solution (monomer A2 solution in which resin A1 is dissolved). ) or in a non-aqueous solvent at about 70-110°C, preferably 80-100°C.
Heat it up.

Note that resin A1 (substantially insoluble in a non-aqueous solvent) and monomer A2, which are raw materials for resin A, may be used alone or in a mixture of two or more.

In this way, a dispersion containing a copolymer of resin A1 that is substantially insoluble in the non-aqueous solvent and monomer A2 that is solvated in the non-aqueous solvent is obtained.

The resin A1 portion of resin A contained in this dispersion acts as a dispersion stabilizer, while the polymer portion of Motsuma-A2 depends on the type and amount of materials used and polymerization conditions (temperature, stirring, cooling, etc.). is thought to act as a dispersion stabilizer, polarity control agent, and fixing agent.

The effect of this resin A in the developing solution is the wax or polyolefin as described above, or (B
) can be used in combination with the component (non-aqueous thermoplastic resin) to change the composition.

When wax or polyolefin is used in combination, the heated and melted polyolefin etc. precipitates in the polymerization system in the form of fine particles by rapid cooling, and during precipitation, it is dispersed in the polymer, and as a result,
The dispersion stability of the toner and the redispersibility of the dispersion liquid are further improved (the viscosity of the dispersed toner and the toner particle size can be controlled, and a stable toner that can form images with high contrast can be obtained). It becomes like this.

Here, an example of manufacturing resin A (resin dispersion) is as follows.

This production method is simple and can stably produce a uniform dispersion.

Production example 1 1, 61 capacity 3 equipped with a stirrer, thermometer, and reflux condenser
Isopar H3O0P was placed in a mouthful container and heated to 90°C.

On the other hand, 801 g of veracasite F-171 was dissolved in 200 g of 2-ethylhexyl methacrylate, and 2 g of azobisisobutyronitrile was further mixed therein.

This mixture was dropwise polymerized in the container for 4 hours, and then stirred for an additional 1 hour to prepare a resin dispersion having a solid content of 48.3%.

Production Example 2 Iso-octane 300S' was placed in the container used in Production Example 1 and heated to 90°C.

On the other hand, 50% of veracasite J8111 was added to stearyl methacrylate 2001 and glycidyl methacrylate 5f.
1 was dissolved, and further mixed with 2 g of lauryldimethylamine, 0.2 f of hydroquinone, and 2 fI of benzoyl peroxide.

Next, this mixed solution was dropwise polymerized into the container for 2.5 hours, and then heated at 90° C. for about 11 hours to reduce the solid content to 46.
An 8% resin dispersion was prepared.

Production Example 3 Isopar L400fI was placed in the container used in Production Example 1 and heated to 90°C.

On the other hand, 801 g of pentasite P-406 was dissolved in a mixed monomer of 18 S' glycidyl methacrylate and 100 f lauryl methacrylate, and 2 g of hibenzoyl peracid and 2.51 g of lauryl dimethylamine were further mixed therein.

Next, this mixed solution was dropwise polymerized into the container for 4 hours to prepare a resin dispersion having a solid content of 40%.

Production Example 4 In Production Example 1, 0RLIZO was added to Isopar H3O0f.
Dissolve 251 liters of N705 and add it to the container (90 liters) at the end of polymerization.
℃) was quenched with cooling water, but the solid content was 47.
．． A resin dispersion containing 1% polyethylene was prepared.

Production Example 5 In Production Example 3, at the end of polymerization, paraffin wax with a soft f point of 80°C was added to the polymerization system, heated and melted at 90°C,
After sufficient stirring, a paraffin wax-containing resin dispersion having a solid content of 35% was prepared in the same manner except that the container was quenched with tap water.

Production Example 6 Take isooctane 30 (1) in the container used in Production Example 1,
Heated to 90°C.

On the other hand, 100 S' of BETSUKASI J896 was dissolved in a monomer mixture of 200 P of 2-ethylhexyl methacrylate and 101 glycidyl methacrylate, and 2 g of hibenzoyl peracid was further mixed therein.

This mixed solution was dropwise polymerized into the container for 3 hours, and the temperature was maintained for 3 hours to complete the reaction.
1 l lauryl dimethylamine, 3 g methacrylic acid, and 0 g hydroquinone. IP was added and reacted at 90°C for 18 hours.

Next, after adding isooctane 500S' to this reaction thread,
Methyl methacrylate 50f? A mixture of F and hibenzoyl peracid 31 was added dropwise over 3 hours, and the reaction was continued for 5 hours to prepare a resin dispersion.

Production Example 7 In Production Example 6, 301 of Sunwax 131-P was further added to 5001 of isooctane, and after the reaction, the container (90
A polyethylene-containing resin dispersion was prepared in the same manner except that the sample was quenched with tap water.

Production Example 8 Take Isopar G30 (1) in the container used in Production Example 1,
Heated to 90°C.

On the other hand, a mixed monomer of 200 g of stearyl methacrylate and 51 g of glycidyl methacrylate was mixed with Pe/Tacite P.
501 of 423 was dissolved, and 0.11 of hydroquinone and 1 g of lauryl dimethylamine were further mixed.

This mixed solution was dropped into the container over 4 hours, and after further reacting at 90°C for 15 hours, Isopar 0500P
was added, and a mixture of 50'fI' methyl methacrylate and 41 azobisisobutyronitrile was added dropwise at 90°C over 3 hours to complete the reaction and create a resin dispersion with a solid content of 28.4%. .

Production Example 9 A polyethylene-containing resin dispersion was prepared in the same manner as in Production Example 8, except that 30 P of Sunwax 165-P was added to Isopar G301'.

Production Example 10 A resin dispersion was prepared in the same manner as in Production Example 8, except that methyl methacrylate 5 (1) was not reacted.

Production Example 11 Lauryl methacrylate) 70f in the container used in Production Example 1
, glycidyl methacrylate 10'iI was taken and the Peso force site (F-231) 2,0? was dissolved.

Heating to 90°C, adding peracid f Hibenzoyl 152 and polymerizing for 8 hours, then adding Isopar H100f to make the solid content 50%.
A resin dispersion was prepared.

Add 1.41 liters of pyridine to this dispersion and hold at 90°C for 20 hours.
It was heated to and then cooled.

Production Example 12 15g of methacrylic acid and 1.2' of pyridine were added to 20M' of the resin of Production Example 11. was added and polymerized at 90°C for 15 hours to prepare a resin dispersion with a solid content of 54%.

Production Example 13 Isopar H20M' was added to the resin 200P of Production Example 12 and heated to 90°C.

It contains low molecular weight polyethylene (Sunwax 171).
-P) 51' was added and dissolved, and then rapidly cooled with tap water, solid content 3.
A 1% resin dispersion was prepared.

Production Example 14 A resin dispersion having a solid content of 48% was prepared in the same manner as Production Example 12 except that methacrylic acid 121 was not used.

Next, to explain the manufacturing method of component B (nonaqueous thermoplastic resin, resin B, which constitutes the toner of the present invention), first, the general formula (1
) monomer and glycidyl (meth)acrylate, unsaturated carboxylic acid or unsaturated carboxylic acid anhydride (
The weight ratio of the mixture is 99.9 to 80:0.1 to 20) in an arsenic solvent and heated to 70 to 150'C under a polymerization catalyst such as azobisisobutyronitrile. Let's do it.

As mentioned above, examples of the monomer of general formula (1) include higher alkyl esters (having 6 to 20 carbon atoms) of acrylic acid or methacrylic acid such as lauryl, 2-ethylhexyl, stearyl, and vinylstearyl; Examples of unsaturated carboxylic acids that can be copolymerized with acrylic acid, methacrylic acid, fumaric acid, crotonic acid, itaconic acid, maleic acid, and the like.

Add glycidyl (meth)acrylate, unsaturated carboxylic acid or its anhydride (unsaturated carboxylic acid or its anhydride, unsaturated carboxylic acid or its anhydride when the copolymer has glycidyl (meth)acrylate as a constituent unit) to this reaction solution. When the structural unit is glycidyl (meth)acrylate, 01 to 20 parts by weight of glycidyl (meth)acrylate is added to 100 parts by weight of the copolymer, and the mixture is heated at 30 to 120°C in the presence of an ester catalyst.
react by heating.

As a result of this reaction, the copolymer is ester-fed, and the ester-1 moiety is grafted with active sites (one per polymer chain).
Because it is a single particle, it is difficult for gel formation to occur).

The ester-depleted copolymer serves as the backbone of the graft copolymer obtained in the final step, and is obtained in a state dissolved in the above-mentioned non-aqueous solution.

Furthermore, 5 to 100 parts by weight of the monomer represented by general formula (2), the monomer represented by general formula (3), or both monomers are added to this reaction solution based on 100 parts by weight of the ester-depleted copolymer. , in the presence of a polymerization catalyst such as hibenzoyl peracid, azobisisobutyronitrile,
The reaction is heated to 70 to 150°C.

This reaction yields a copolymer in which the monomer is grafted onto the ester-containing copolymer.

Among the monomers, C1 to C4, ie, methyl, ethyl, propyl, or butyl acrylate (or methacrylate) is used as the lower alkyl ester of acrylic acid (or methacrylic acid).

In this way, the graft copolymer (resin B) is obtained, but in the present invention, the soft f
It may be manufactured by adding wax or polyolefin having a hit point of 60 to 130°C, heating the nonaqueous solvent to completely dissolve it, and cooling it in the final step.

By cooling the reaction solution, if wax or polyolefin is dissolved, they are precipitated into fine particles.

Here, an example of manufacturing resin B (resin dispersion) is as follows.

This production method is simple and can stably produce a uniform dispersion.

Production Example 15 Isopar H (manufactured by Esso Standard) 300P was placed in a container equipped with a stirrer, a thermometer, and a reflux condenser, and 135
It was heated to around ℃.

A mixed solution of 160y' of lauryl methacrylate, 40 g of glycidyl methacrylate, and 21 g of hibenzoyl peracid was added dropwise over 2 hours, then heated and stirred for 1 hour, and then 1 g of paratoluenesulfonic acid and 5'f of acrylic acid were added. , hydroquinone 0. i was added and reacted at 90°C for 15 hours.

Isopar H3O0P was added to the reaction mixture, and a mixed solution of 55 g of isobutyl methacrylate and 2 g of asobisisobutyl nitrile was added dropwise at 90° C. over 1 hour, followed by further stirring for 1 hour to obtain a polymerized product.

The product was stable with a solids content of 28%.

Production Example 16 Place 300P of Isopar G (Esso Standard Co., Ltd. 1) in a container equipped with a stirrer, a thermometer, and a reflux condenser, and add 120
It was heated to around ℃.

A mixture of 150 g of stearyl methacrylate, 63 g of acrylic acid, and 3 g of azobisisobutyronitrile was added dropwise to the mixture at a constant rate over 3 hours, followed by further stirring for 1 hour to complete the reaction.

Add 5 g of glycidyl methacrylate, hydroquinone o, iy1, and 11 lauryl dimethylamine to this and add 90'
C. for 15 hours, and the copolymer obtained in the above reaction was subjected to esterification.

The ester f resistance was 48% based on the measurement of the decrease in acid value.

Next, Isopar G5001 was added to the esterification reaction solution at 90°C, and methyl methacrylate 50f? , anhis, 1 fufunalonitrile, and 3" f were added dropwise at an operating pressure of 3 hours, and the temperature of the solution was maintained at the above temperature for about 5 hours to complete the reaction.

Furthermore, Isopar G300 is added to this reaction product 3001.
After adding f, the mixture was heated to 90°C, polyethylene (Qrizon 805, manufactured by Monsanto Fhigaku Co., Ltd.) 501 was added, and the mixture was heated and dissolved for 1 hour until it became transparent.

The obtained product had a solid content of 17.4% and a particle size of 0.3-0.
It was a 5μ milky latex.

Next, an example will be shown in which the colorant is manufactured by flashing processing.

After stirring Production Example 17 well with a flasher, Veracasite P-7
600 g of 20 (10% toluene solution) was added to the flasher and further kneaded.

Next, water and solvent are removed by heating and reduced pressure to reduce the water content to 0.
A 92% colorant mass was obtained.

This was ground in a stone mill to obtain a powder of 1 to 50 microns.

After thoroughly stirring Production Example 18 in a flasher and then using shellac, a solution of Betsukasai) F231 (rosin-modified maleic acid resin manufactured by Inu Nippon Ink Chemical Co., Ltd.) was added to the flasher, and the mixture was heated to 150'C. The mixture was kneaded for 4 hours while maintaining the temperature.

Next, water and solvent are removed by heating and reduced pressure to reduce the water content to 0.
A mass of 80% was obtained.

This was ground in a hammer mill to obtain a coloring agent with a particle size of 1 to 10 microns.

Production Example 19 was washed with a flasher (after stirring, RM-1300 (manufactured by Tokushima Seyu Co., Ltd., natural resin-modified polyester resin) 1000 f
, 1000f of toluene was added and kneaded at 130°C for 3 hours.

Next, water and solvent are removed by heating and reduced pressure to create a water-containing valve with 0
．． A 92% colorant mass was obtained.

This was ground into powder using a stone mill.

Production example 20 Water 1200f Phthalocyanine green paste 200f-st
(30% paste) Carbon Mogul A
Stir well with a flasher at 600r.

Natural resin-modified maleic acid resin MRL <manufactured by Tokushima Seyu Co., Ltd.) 1
Add 20C1 and mix at 150℃ for 30 minutes, then add 100% xylene.
01 was added, and the mixture was further kneaded for 1 hour to remove water and xylene to obtain a colorant.

To prepare the liquid developer of the present invention, 1 part by weight of Resin A and Resin B obtained as described above is combined with 011 to 10 parts by weight of a coloring agent subjected to a flashing process and an appropriate amount of a carrier liquid (non-containing). (same as water solvent) is dispersed using a dispersing machine such as a three-roll mill, attritor, or ball mill to form a concentrated toner.
It may be diluted with a certain amount of carrier liquid.

In this case, a small amount of a polarity control agent may be added if necessary, but since the resin of the present invention has strong polarity and good dispersion stability, it is not necessary to add a polarity control agent.

Now, when we look into developers that use resin B without adding resin A, we find that resin B has good adsorption to pigment or dye particles, but tends to be inferior to polarity, and for this reason, high-speed development method However, there are disadvantages in that the image density is low and the number of durable sheets is small.

However, when transferring the toner image obtained by developing an electrostatic latent image to transfer paper, this developer has excellent transfer properties and excellent fixation properties on transfer paper. confirmed.

This is because Resin A generally has a lower molecular weight than Resin B (average molecular weight of about 1000 to 5000), and due to the structure of the resin, it fully functions as a polarity control agent, whereas Resin B
It has a high molecular weight (approximately 100,000) and has good adsorption to pigment or dye particles, so it is considered to have excellent transfer and fixing properties.

Therefore, when resin A and resin B are used alone,
Although it is possible to exhibit sufficient performance for low-speed development, it is not possible to obtain sufficient images with a high-speed machine that processes more than 20 sheets (A-4 size) per minute.

However, the developer of the present invention using both resin A and resin B has high image density, high fixability, and excellent durability and storage stability.

A suitable mixing ratio of resin A and resin B is 1 to 4:6 to 9 (by weight).

Example 1 Resin A obtained in Production Example 1 (solid content 3,5148
．． 3%) Resin B obtained in Production Example 15 (solid 38.5SF content 28%) Colorant (Fura lO'?lashing agent obtained in Production Example 20) Isooctane 200P A mixture was dispersed in a ball mill for 16 hours. A concentrated toner was obtained, and 251 was dispersed in isooctane 11 to prepare a liquid developer.

When this developer was copied using Newricy DT-1700 (manufactured by Ricoh, electronic copying machine), the transfer rate was 86%.
A copy with an image density of 1.30 and good fixability was obtained.

Further, when this developer was subjected to a forced inferiority test at 50° C. for two weeks and then subjected to development, a good quality copy with an image density of 1.28 was obtained.

Comparative Example 1 Resin A obtained in Production Example 1 (solid content 25.8?48
．． A mixture of 220 g of isooctane was dispersed in a ball mill for 16 hours to obtain a concentrated toner, and 25 g of the mixture was dispersed in isooctane 11 for comparison. A liquid developer was prepared.

Next, when copying was performed in the same manner as in Example 1 using this developer, a copy with an image density of 1.10 was obtained.

Furthermore, when this comparative liquid developer was subjected to a forced inferiority test at 50°C for two weeks and then subjected to development, the image density was 1.
A copy with a reduced quality of 0.08 was obtained.

Comparative Example Resin B obtained in Production Example 15 (solid 44.5P content 2
8%) Colorant (Fura 10 Bushing Pigment obtained in Production Example 20) A mixture consisting of isooctane 97z was dispersed in a ball mill for 16 hours to make a concentrated toner, and 25t? was dispersed in isooctane 11 to prepare a comparative liquid developer.

Next, when copying was carried out in the same manner as in Example 1 using this developer, a copy with an image density of 1.20 was obtained.

Furthermore, when this comparative liquid developer was subjected to a forced inferiority test at 50°C for two weeks and then subjected to development, the image density was 1.
A copy with a considerably lower grade of 10 was obtained.

Example 2 Resin A obtained in Production Example 3 (solid content 5.0140
%) Resin B obtained in Production Example 15 (solid 40.01 min2
8%) Colorant (Fura obtained in Production Example 17 10.0'f?
Thushing Pigment) A mixture consisting of 200 g of isooctane was dispersed for 20 hours using an attritor to obtain a concentrated toner, and 351 of the mixture was dispersed in 11 of isooctane to prepare a liquid developer.

When copies were made in the same manner as in Example 1 using this developer, the transfer rate was 83%, and the image density was 1.29.When actual copies were made using the same developer after storage for 30 days at 50°C, the transfer rate was 83%.
1.5%, image density 1.27, which has excellent storage stability, good transferability, and high image density.

In addition, toner half FJ'FZ Kozumi is 0.20 to 0.30μ
It didn't seem weird at all.

Example 3 Resin A obtained in Production Example 6 (solid content 30.0%) 01 Resin B obtained in Production Example 16 (solid content 60'?17
．． 4%) Colorant (Furano 101 Thing pigment obtained in Production Example 19) Carbon MA-11 (manufactured by Mitsubishi FHI Co., Ltd.) A mixture consisting of 5 gua Isopar G 101' was dispersed with an attritor for 18 hours to form a concentrated toner, That 50? was dispersed in Isopar G21 to prepare a liquid developer.

The average particle size of the toner was 0.32μ, and the transmittance was 35%.

After storing this developer at 50°C for 30 days, the average particle size and transmittance were measured in the same way.The average particle size was 033μ, the transmittance was 35.5%, and it was observed that there was little change in toner particles. Ta.

Example 4 Resin A obtained in Production Example 8 (solid content 2OS'28
．． 4%) Resin B obtained in Production Example 16 (solid content 80117.
4%) Colorant (flushing pigment obtained in Production Example 17) 3 (1) N Special Black (manufactured by Orient Figaku Co., Ltd.) A mixture consisting of 150 g of Isopar G was dispersed in a colloid mill for 10 hours to create a concentrated toner. did.

Place this concentrated toner on a glass 5 pin and seal it for 50'
When the toner was stored under forced conditions at C for 30 days, there was almost no change in viscosity, toner particle size, etc., as shown in the table below.

Further, when 50 grams of this concentrated toner was dispersed in Isopar G11 and copied using New Recopy 1) T-1700, the image density was 1.32 (after 30 days at 20°C) and 1.33 (
50°C - 30 days later) and 1.30 (initial).

Claims (1)

[Scope of Claims] 1 A coloring agent containing a coloring agent and a resin component dispersed in a carrier liquid consisting of a non-aqueous solvent having high insulation properties and a low dielectric constant, the coloring agent being flashed as the main component of the coloring agent. A liquid developer for electrophotography, characterized in that the resin component contains the following component (A) and a former component. (A) Natural resin-modified maleic acid resin, natural resin-modified phenol resin, natural resin-modified pentaerythritol resin, natural resin-modified polyester resin, ester gum, hard hyogen, water-added rosin, styrene-butadiene resin, and vinyltoluene-butadiene resin. At least one resin selected from the following with an acetone tolerance value of 100 to 5,000, and at least one resin capable of dissolving the resin represented by the following general formula (wherein R is H or CH3,6≦n≦20). Polymers with monomers. (B) General formula ■ (However, R is H or CH3, X is COOCnH2n+1 or -OCn H2n+t(
6≦n≦20). ) and a monomer having a glycidyl group or an unsaturated carboxylic acid or its anhydride, when the copolymer has a glycidyl group as a constituent unit, an unsaturated carboxylic acid or its anhydride, In addition, when unsaturated carboxylic acid or its anhydride is used as a constituent unit, a monomer having a glycidyl group is made into an ester gum, and the unsaturated part of the esterified product is added to the general formula (where R is H or CH3, Y is C00CnH2n+1 ( 1≦n≦4), OCOCmH2m+1 (1≦m≦6), A non-aqueous thermoplastic resin obtained by graft polymerizing at least one monomer represented by Soft f in the process of
The liquid developer for electrophotography according to claim 1, which is a resin obtained by heating and melting wax or polyolefin having a hit point of 60 to 130°C. 3 (B) component is soft f in any step during its manufacturing process.
The liquid developer for electrophotography according to claim 1, which is a resin obtained by heating and melting wax or polyolefin having a hit point of 60 to 130°C. 4. The electrophotographic liquid developer according to claim 1, wherein the ratio of component (A) to component (B) is 1 to 4 parts by weight - 6 to 9 parts by weight. 5 The coloring agent subjected to flashing processing is a water-containing paste of carbon black and/or organic pigment, natural resin-modified maleic acid resin, natural resin-modified phenol resin, natural resin-modified pentaerythritol resin, natural resin-modified polyester resin, ester gum, Acetone tolerance value 100~ selected from hard f-hyrosin, water-added rosin, styrene-butadiene resin, and vinyltoluene-butadiene resin
The liquid developer for electrophotography according to claim 1, which is obtained by flashing with No. 5000 resin. 6. The liquid developer for electrophotography according to claim 1 or 5, wherein the ratio of resin to pigment of the coloring agent subjected to the lashing process is 3 to 9 parts by weight - 1 to 7 parts. 7. Electrophotography according to claim 1, 5, or 6, wherein the ratio of the organic pigment to carbon black in the flashing colorant is 1 part by weight to 0 to 20 parts by weight. liquid developer.