JPH01216366A - Liquid developer for electrostatic charge image - Google Patents

Abstract

PURPOSE:To obtain a liquid developer to be used for an electrostatic charge image superior in transferability, and good in dispersibility and fixability by incorporating a specified ethylenic copolymer as a constituent in a carrier solution. CONSTITUTION:The carrier solution contains as the constituent at least one copolymer represented by formula I in which R1 is H or methyl; R2 is alkyl, aralkyl, or the like; and each of x and y is a molar fraction and x:y=0.995-0.80:0.005-0.20. The alkyl acrylate units and the like enhance dispersibility of the copolymer as the copolymerization component with the ethylene units, and the ethylene units exhibit superior transferability and fixability at the same time, thus permitting the obtained liquid developer for the electrostatic charge image to be enhanced in transferability and improved in dispersibility and fixability.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to transferability used for developing electrostatic latent images;
The present invention relates to a liquid developer with improved dispersibility and image properties.

"Prior Art" Generally, liquid developers used to develop electrostatic latent images are adsorbed or coated with colorants such as carbon black and various pigments to adjust the charge of toner particles and promote dispersion. Furthermore, there is a coating agent that imparts fixability after development, a dispersant that dissolves or swells in the carrier liquid and imparts dispersion stability to the toner particles, a charge control agent that adjusts the amount of charge on the toner particles, and a high electrical resistance (/ It consists of a carrier liquid with a resistance of 79 to 1015 Ω·α).

Coating materials include rubbers such as butadiene rubber, styrene-butadiene rubber, cyclized rubber, and natural rubber, styrene resins, vinyltoluene resins, acrylic resins, methacrylic resins, polyester resins, polycarbonates,
Synthetic resins such as polyvinyl acetate and ethylene copolymers,
Examples include rosin resins, hydrogenated rosin resins, alkyd resins containing modified alkyds such as linseed oil modified alkyds, and natural resins such as polytyl resins. Other phenolic resins, including modified phenolic resins such as Fe, nor-formalin resins, natural resin-modified maleic acid resins,
Phthalic acid R-ntaerythric, chroman-indenst
Fats, ester gum resins, vegetable oil bolyamides, etc. are known. Among these, ethylene copolymer can be cited as one that is excellent for transfer purposes.

JP-A-47-110 Jat shows an example of using ethylene/methacrylic acid copolymer as the ethylene copolymer, but since these copolymers have a large internal cohesive force due to carboxyl groups, Even if a plasticizing method using L is used and heated above the softening point, dispersion is insufficient and l) it is difficult to form fine particles. There are problems in that the dispersion stability is poor, the settling of the toner particles is significant, and when developed, the resolution is poor due to roughness of the image. Tokukai Sho t-ko λOri! -3 shows an example of using a polar solvent as a method of dispersing these copolymers, but this method is not necessarily preferable in terms of charging characteristics for liquid developers that use electrically insulating non-aqueous solvents as carrier liquids. It can not be said. Mama JP-A No. 1997/1999/CoflIJt describes a method for producing toner particles by heating and dissolving an ethylene copolymer such as ethylene/acetic acid or a vinyl copolymer in a solvent and then cooling it. However, this method has problems such as separation of the colorant from the colorant during dissolution of the polymer and non-uniform size of particles precipitated during cooling. As can be seen from these examples, conventional ethylene copolymers have a problem with dispersibility. Among other resins, few have been found that have good transferability and excellent dispersibility and fixing properties.

"Problems to be Solved by the Present Invention" When an ethylene copolymer is used as a coating material, the conversion efficiency is good, but dispersibility is difficult, so the dispersion stability is poor.
There were problems such as sedimentation of toner particles occurring in a short period of time, lack of disintegration properties, and poor image reproducibility.

A first object of the present invention is to provide a liquid developer for electrostatic images that has excellent transferability, dispersibility, and fixability.

A second object of the present invention is to provide a liquid developer for electrostatic images that provides high-resolution image quality with excellent image reproducibility.

A third object of the present invention is to provide a liquid developer for electrostatic images that provides high printing durability when used as a toner for planographic printing plates.

"Means for Solving the Problems" The present inventors have developed an electrostatic charge image product characterized in that a carrier liquid contains at least one kind of copolymer represented by the following general formula (I) as a constituent component. The liquid developer solves the problem and achieves the object of the present invention.

In the formula, s R1 represents a hydrogen atom or a methyl group.

R2 represents an alkyl group, an aralkyl group, an aryl group, or a cycloalkyl group.

X and y represent the number of moles t, z:y=0. Tata! ~0.
rO: 0.001 to 0.20.

In addition, an alkyl group, an aralkyl group, an aryl group of R2,
Cycloalkyl groups may be substituted with other substituents. (As a substituent, an alkyl group having up to 1-/2 carbon atoms, an alkyloxy group having 1-/2 carbon atoms, an aryloxy group, an alkyloxycarmenyl group having 7 to 2" carbon atoms, an aryloxycarbonyl group , represents a dialkylcarbonyl group, diarylcarbonyl group, alkyl/arylcarbonyl group, hydroxyl group, carboxyl group, cyano group, nitro group, sulfonic acid group, cycloalkyl group, aryl group, aralkyl group, halogen group, having a carbon number INlλ, Furthermore, the substituent may be substituted with the above substituent).

Next, the present invention will be described in detail.

The ethylene copolymer of the present invention is substantially insoluble in the carrier liquid and is swellable, and is used as a coating agent for colorants to form toner particles and provide fixing properties. When used as a toner for a lithographic printing plate, a colorant is not necessarily required and can be used alone to form toner particles.

Conventionally, ethylene copolymers such as ethylene/vinyl acetate copolymers, ethylene/methacrylic acid copolymers, and ethylene/ethyl acrylate copolymers have been mainly used in liquid developers.

When these ethylene copolymers were used for transfer, they often showed good transfer properties, but their dispersibility was poor, and when used as a developer, the toner particles tended to settle significantly, and when developed, they became fine particles. Since this was not possible, only images with noticeable roughness due to coarse particles could be obtained. When used as a liquid developer for transfer,
Of course, it is important to have excellent transferability, but dispersibility is equally important, and the degree of dispersion governs the image properties such as the resolution of the liquid developer.

The present invention has been accomplished in order to take advantage of the excellent transferability of ethylene copolymers and completely improve dispersibility.

In order to satisfy good surface dispersibility, K needs to be a component that has an affinity for the carrier liquid. The present inventors have discovered that in ethylene copolymers, compounds represented by general formula (I) such as alkyl (meth)acrylates are effective in improving dispersibility as copolymerization components for ethylene, and It has been found that it exhibits excellent transfer and fixing properties at the same time.

The ethylene copolymer represented by the general formula (I) of the present invention will be further explained below.

- In formula (I), when 2 is an unsubstituted or substituted alkyl group, specific examples of the alkyl group are n-propyl group, n-butyl group, n-amyl group, n-hexyl group, n-
These include octyl group, decyl group, dodecyl group, myristyl group, cetyl group, and stearyl group. The number of carbon atoms in the alkyl group is preferably 3 to 2λ.

In the case of an unsubstituted or substituted aralkyl group, specific examples of the aralkyl group include benzyl group, 7enethyl group, l-7termethyl group, λ-naphthylmethyl group, l-anthrylmethyl group, λ-anthrylmethyl group. , menshydryl group, etc.

In the case of an unsubstituted or substituted aryl group, specific examples of the aryl group include phenyl group, nonaphthyl group, nonaphthyl group, 1-anthryl group, 2-anthryl group.

In the case of an unsubstituted or substituted cycloalkyl group, specific examples of the cycloalkyl group include methyl group, cyclohexyl group, and cycloheptyl group.

When the substituent is an alkyl group, an alkyloxy group, an alkyloxycarbonyl group, a dialkylcarbonyl group, or an alkyl/arylcarbonyl group, specific examples of the alkyl group include a methyl group, an ethyl Iss n-propyl group,
Iso-propyl group, n-butyl group, isobutyl group, t-
They include linear or branched alkyl groups such as butyl group, n-amyl group, isoamyl group, n-hexyl Ms n-octyl group, 2-ethylhexyl group, decyl group, and dodecyl group.

When the substituent is an aryl group, an aryloxy group, an aryloxycarbonyl group, a diarylcarbonyl group, or an alkyl/arylcarbonyl group, specific examples of the aryl group include a phenyl group, l-naphthyl group, nonaphthyl group, and l-anthonyl group. , 2-anthonyl group, etc.

In the case of a cycloalkyl group or an aralkyl group as a substituent, the above-mentioned ones can be similarly mentioned as specific examples.

Other substituents include hydroxyl group, carbonyl group, cyano group, nitro group, sulfonic acid group, and continuous chain,
Halogen bases such as chlorine and bromine can be raised.

Preferred examples of R2 include a non-11-substituted or substituted alkyl group having 3 or more carbon atoms, a benzyl group, and an aryl group having an alkyl group having 2 or more carbon atoms as a substituent, an alkyloxy group, an alkyloxy group, an alkyloxycarbonyl group, and a dialkylcarbonyl group. Fund rate can be increased.

Further, preferred examples include those having a sulfonic acid group as a substituent.

The molecules t of these copolymers are io, o as values determined by GPC method.
oo~/,000,000 (weight average), preferably 20,000~zoo,000.

Melt flow rate is 0.0 according to JIS K-4730 method.
3~r00CfZlO min], preferably Ha0°! ~! 00
[t/10 minutes].

Next, specific examples of the compound represented by the general formula (I) of the present invention will be given.

/, CH3 Iris C00(CH2)7CHs z:y=0.2All', 0.034 Ko, CH3C00(
CH2)11CH3 z:y=O0ri64c:0.036 J, CH3C00(CH2)17CH3)(:y=(7, Taro4/L”, 0.020g・
CH3 ■ 2H5 z:y=0. ta:o, o3t t, CH3CH3 z:y=0. Taz: o, os J, CH3x: y=O
0ri! :0.0j 7・CHs r, CH3 ri, CHa
z: y-Q, ritu: 0. OJ6″・
CH3 These ethylene copolymers are manufactured by bulk, solution, suspension, or emulsion processes, and methods include high-pressure polymerization using a free radical initiator, medium-pressure polymerization using a transition metal compound, and halogenated transition metal and alkyl aluminum. There are medium and low pressure polymerization methods using compounds. Another method is to make the carboxyl group of a commercially available ethylene/methacrylic acid copolymer fully reacted with an acid chloride reagent to form an acid tetraride, and then reacted with an appropriate alcohol to esterify it. In this case, there are advantages in that a wide range of alcohols can be selected, the reaction is relatively easy, and equipment such as a high-pressure cooker is not required. Next, a specific example of the synthesis method will be shown.

Synthesis example (synthesis of specific compound) Toluene lt1 is placed in a three-necked container equipped with a reflux condenser with a moisture metering receiver, a stirring blade, a thermometer, and an adder.
Ethylene/methacrylic acid copolymer (copolymerization ratio of ethylene:methacrylic acid, weight ratio: r
y", 1i) iooft- was added, heated and refluxed under N2 atmosphere, and j0d was distilled off. ≦o ' After cooling at c-1, thionyl chloride/Jrft- was gradually added, and after 1 hour, dodecyl alcohol≠jft- The temperature was raised to 6!0C and the reaction was carried out for 10 hours. After the reaction, the reaction solution was precipitated in metal Jt, filtered and further washed with methanol. After drying, If%xd was measured. It was confirmed that the carboxyl group was completely esterified with dodecyl alcohol.

Specific examples 1 and 3 of the present invention. Hiroshi, Jl Ri is Nucrel N-J
Ethylene/methacrylic acid copolymer (ethylene:
Methacrylic acid copolymerization ratio 002444:0.034 molar ratio) It can be synthesized in the same manner as in the synthesis example using t-starting material. Another concrete example! , t, 7.10 is also Nucler N-
Ethylene methacrylic acid copolymer (ethylene: methacrylic acid copolymerization ratio 00!: 0
, Oj molar ratio) as a starting material in the same manner as in the synthesis example. The structure of both copolymers was confirmed by IR spectroscopy.

In the present invention, the carrier liquid has an electrical resistance of /X10
A non-aqueous solvent with a resistance of Ω·1 or more and 3 or less can be used. Examples of the non-aqueous solvent include solvents such as linear or branched aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and halogenated hydrocarbons.
Octane, in terms of volatility, safety, pollution, odor, etc.
Inoctane, decane, isodecane, dodecane, indodecane, nonane, isonoq Rough-in petroleum solvents Iso, RE, Aituno (Q, Isopar H% Isopar L (Iso, e-[l5oparj is a product name of Exxon Corporation) , Solbetsun 100, Shell Silua 1 (manufactured by Shell), and the like are suitable.

When a coloring agent is used in the developer of the present invention, known pigments and dyes, or both, which have been conventionally used for liquid developers can be used.

For example, Hansa Yellow (CI, //Ar0), Benzidine Yellow G (C, 1, Co10ri0), Benzidine Orange (C11,2/l10), Fast Red (C,
1,3701 Brilliant Carmine 3B (C,1
, / 60 / j-Lake), 7 thalocyanine blue (C, 1,7g/40), phthalocyanine green (C, 1,7 hiro 260), Victoria blue (C0
x, 4c2zyz-Lake), Spirit Plack (
C, 1, zo4ctz), tilb/l/-(C,
I, 7 # 3tO), alkali blue (C, 1, Hiroλ
770A), First Scarlet (C01,/Co3
1! t), Rhodamine AB (C, 1, Hiroj I60), First Sky Blue (C0I, 74! 200-L
ake), nigrosine (C, I, j)μ/j), carbon black, etc. Surface-treated pigments such as sitacasene black dyed with nigrosine, grafted carbon obtained by graft polymerization with polymers, etc. can also be used.

Although not necessarily required in the present invention, a known dispersant can be used to improve the dispersibility and stability of the liquid developer of the present invention. The dispersant is a resin that improves the dispersibility of the toner, and is a resin that improves the dispersibility of the toner by dissolving or swelling in the carrier liquid. For example, rubbers such as styrene-butadiene, vinyltoluene-butadiene, butadiene-isoprene, and acrylic monomers having long-chain alkyl groups such as coethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate. and copolymers of these with other monomers (styrene, (meth)acrylic acid and its methyl, ethyl, propyl esters, etc.), as well as graft copolymers and block copolymers. Can be done. Among these preferred dispersants, synthetic rubber dispersants are effective, and random or block copolymers of styrene-butadiene copolymers can be used as extremely effective dispersants.

When a charge control agent is used in the present invention, a conventionally known charge control agent can be used. For example, metal salts of fatty acids such as naphthenic acid, octenoic acid, oleic acid, stearic acid, metal salts of sulfosuccinic acid esters, Japanese Patent Publication No. 4 IJ-4
16, Japanese Patent Publication No. 37443jt, Japanese Patent Publication No. 72-47
Oil-soluble sulfonic acid metal salts shown in 042 etc., Special Showφj-ta! Metal salts of phosphoric acid esters shown in Rihiro, metal salts of abietic acid or hydrogenated abitic acid shown in Tokko Sho 4 At-kojJJj, Tokko Sho! j
Calcium alkynebenzenesulfonic acid hydrochloric acid shown in -2420, JP-A-Sho! t2-107137, Japanese Patent Application Publication No. 72-
JIr? J7, Japanese Patent Publication No. 77-ta ota3, Japanese Patent Publication No. 77-
Metal salts of aromatic carminic acids or sulfonic acids as shown in 7!3, nonionic surfactants such as polyoxyethylated alkylamines, lecithin, fats and oils such as linseed oil, polyvinylpyrrolidone , polyhydric alcohol organic acid ester, JP-A-17-21031/-II
The phosphoric acid ester surfactant shown in I-nee, Tokkosho! t-2≠24Ap, all of the sulfonic acid resins shown can be used. Also, Tokukai 1986-10!6
Amino acid derivatives described in JP-A-Sho, g/-J-0li xi can also be used. The amino acid derivative is a compound represented by the following formula (2) or (3),
Alternatively, it is a reaction mixture in which an amino acid is reacted with a titanium compound in an organic solvent, which is further mixed with water and reacted.

(In the formula, 3 and R4 are hydrogen atoms, alkyl groups with up to 7 to 22 carbon atoms, substituted alkyl groups (substituents include dialkylamino, alkyloxy, and alkylthio groups), and up to t-co≠ carbon atoms. Air group, substituted aryl group (substituents include dialkylamino group, alkyloxy group,
alkylthio group, chlorine group, bromine group, cyano group, nitro group, hydroxyl group), aralkyl group, carbon number l~,
It represents an acyl group, an alkylsulfonyl group, an alkylphosphonyl group having up to 2 carbon atoms, an arylsulfonyl group having up to 4 to 2 carbon atoms, and an arylphosphonyl group.

R3 and R4 may be the same or different, and may form a ring with 3-4, but they cannot become hydrogen atoms at the same time. A represents an alkylene group or substituted alkylene group having up to 10 carbon atoms.

X represents a hydrogen atom, a metal with a valence of 7 to 2, or a quaternary ammonium cation. n indicates a positive integer. ) Among these, preferred are metal salts of naphthenic acid, metal salts of dioctyl sulfosuccinic acid, basic barium sulfonate, lecithin, and the above-mentioned amino acid derivatives. More preferred are zirconium, cobalt, and manganese salts of naphthenic acid, calcium and sodium salts of dioctyl sulfosuccinate, and the above-mentioned salts.
Metal salts of the compound of formula 12) can be mentioned. −
As the metal salt of the compound of formula (2), titanium, cobalt, zirconium, and nickel salts are particularly preferred.

As these charge control agents, it is also possible to use one or more compounds in combination.

The liquid developer of the present invention can be manufactured by a conventionally known method.

When using a coloring agent, first heat the coating material made of a pigment or dye, or a coloring agent consisting of both of these and the copolymer of the present invention to a temperature above the softening temperature of the gold coating material, use a Banbury mixer, a coneater, a kneader, etc. A mixture is obtained by kneading using a mixing machine such as a planetary mixer or a three-roll mill, and cooling the mixture. Furthermore, various solvents and the like may be added during this kneading. In addition to the above methods, methods for obtaining the mixture include mixing the coloring agent and coating agent in their affinity solvents in a ball mill, planetary mixer, kneader, etc.
A mixture can be obtained by mixing the mixture with a mixer such as a paint shaker and drying the mixture or adding it to a non-solvent.

Also, as another method, JP-A-4/-/102 Ke! Also effective is the method of heating and plasticizing and kneading the coating agent and coloring agent in a solvent such as ASO, E L, etc., to obtain a spongy mixture upon cooling.

The mixture thus obtained is pulverized using a rotoplex, a bottle mill, etc., as required, and then ground using a sand grinder, along with a dispersant, as required.

Wet pulverize with a Dyno Mill, I-Lu Mill, etc. to make a developer concentrate. The solvent during wet pulverization may be a carrier liquid, or a solvent such as toluene or acetone may be added.

The toner concentrate thus obtained is dispersed in a non-aqueous solvent containing a charge control agent to prepare a liquid developer for electrophotography. The toner particle concentration in the developer is not particularly limited, but
Usually 0.0/f, 100? with respect to carrier liquid/l. , preferably O0/f~koO? It is. The amount of coating agent in the toner particles is 0.00 parts by weight per 7 parts by weight of colorant. /-20 parts by weight, preferably o, r to 10 parts by weight.

The concentration of the dispersant is usually 0°0/- with respect to the carrier liquid lt.
409, preferably 0. /-IO? It is.

Further, the charge control agent may be added by an addition method other than the above method. That is, it may be added during cross-mixing or wet pulverization, or they may be used in combination.

The amount of the charge control agent added is Q to the current charge control agent/lK.

DO/f, IO? It is desirable to adjust it so that it is included. It is preferably in the range of 0.019-/f.

The developer of the present invention can be used for photoreceptors using well-known organic photoconductors or inorganic photoconductors. The developer of the present invention can also be used to develop electrostatic latent images produced by means other than photosensitivity, such as by charging a dielectric material with a charging needle.

Organic photoconductors include a wide variety of well-known organic photoconductors. A specific example is [(researchDisclose
reJ magazine #10? There are substances described in JIr (Article titled "Electrophotographic Elements, Materials and Processes", 1973/J issue, page 4 onwards).

For example, electrophotographic photoreceptors made of poly-N-vinylcarbazole and co* ``* '-)!J nitrofluorene terone (US Patent J, u14A, 23F) are in practical use. , poly-N-vinylcarbazole was sensitized with a pyrylium salt dye (4!
Kosho at-artj B, electrophotographic photoreceptor containing organic pigment as main component (JP-A Sho Data-371173), electrophotographic photoreceptor containing eutectic complex consisting of dye and resin as main component (JP-A Sho-san 7- 10731), and a nine electrophotographic photoreceptor made by dispersing copper 7-thalocyanine in a resin (Special Publication Showa Co., Ltd. 7447).

Others, Electrophotography Society Journal No. 2! Volume, No. 3 (15'f4
) p, t2-7jlC.

The developer of the present invention can be used as disclosed in JP-A No. 37-/7/1, JP-A No. 197-/7-1, JP-A No. 7-7-1, JP-A No. 7-7-1, No. 7-7476, No. 7-7476. The durability of a method in which a printing plate is prepared by applying an organic photoconductor dispersed in an alkali-soluble resin such as a phenol resin to a conductive support such as aluminum, developing it with a developer, and etching it with an alkaline aqueous solution. It can also be used as a developer with excellent etching properties.

In addition, as an inorganic photoconductor, “Electrophotography J R,M.

5chaffert, Focal Press (L
Various inorganic compounds disclosed in pages 240 to 371, published by Ondon Publishing Co., Ltd. (Ill. 7/year), are representative. Specific examples include zinc oxide and zinc sulfide.

Examples include cadmium sulfide, selenium, selenium-tellurium alloy, selenium-arsenic alloy, selenium-tellurium-arsenic alloy, and the like. Other examples include amorphous silicon.

"Effects of the Invention" The liquid developer containing the ethylene copolymer of the present invention has good transferability, stable dispersibility and chargeability over a long period of time, and has excellent resolution and provides high-quality images. .

"Example" Examples of manufacturing a coating material and a liquid developer of the present invention are shown below, but the present invention is not limited by these K.

Example-1 TK Crossbull Planetary Mixer IJOLDM type (
Prepare the ingredients of the following composition in the Tokushu Kika ■).
The mixture was stirred at rotational speeds of z o r, p, and m for crosstalk.

Furthermore, under these conditions, parts by weight of Isopar L were added in portions over 2 hours to continue crosstalk.

Next, this mixture was discharged into a stainless steel vat and cooled to room temperature to obtain a sponge-like mixture.

This kneaded material is mixed with the following composition using glass beads with a diameter of approximately 4 m.
Preliminary dispersion was performed for 20 minutes.

This preliminary dispersion was wet-dispersed using a Dyno Mill KDL type (manufactured by Shinmaru Enterprises) using glass beads with a diameter of approximately 0.73~/W as the media, and wet-dispersed for 100 r, p, m, and fat times to form a thick dispersion. Obtained.

The solid content of this dispersion is Isopar Get pif, and as a charge control agent, basic Bauliu is tronate (manufactured by Kuitico Chemical) with a solid content of 0. A liquid developer-Ai was prepared by adding the liquid developer in an amount of If.

Next, ethylene/methacrylic acid copolymer sold as Niecler N-62 (manufactured by Mitsui DuPont Polychemicals) was added to the copolymer glue 9 of Compound Example-I of the present invention.
Ethylene:methacrylic acid copolymerization ratio O0ri 44 (:0,0
Comparative liquid developer-Bi was prepared in exactly the same manner except that 34 molar ratio) was used.

The particle size of these liquid developers was measured using a total centrifugal sedimentation type optical transmission method particle size measuring device (CAPA-jO0 manufactured by Horiba, Ltd.) and the charge amount measuring device described in JP-A-17-JR/76. Table 7 shows the amount of charge generated. Both polarities were negative.

Table 7 The charge flT is the value of the developer bulk, and the charge amount (■) is the value of the supernatant obtained by centrifuging the developer, that is, the value based on the ionic components in the carrier liquid. Here, the larger the value of (T-I), the larger the effective charge, and the smaller the value of (Product divided by T), the smaller the value of the ionic component in the amount of charge, which is advantageous as a developer.

Developer A has a smaller particle size and better dispersibility than BK. This is interpreted as an effect based on the long-chain alkyl group introduced into the ethylene copolymer that has an affinity for the carrier liquid.

Comparing the charge properties, Developer-B has a larger Bepulc charge f(T) than Developer-B, and the above-mentioned effective charge (
It can be seen that T-I) is also large and the charging property is excellent.

Next, polycarbonate (product name [Lexan lJ/J
G, E, Inc.) 10f, dialamine compound 11. shown below. The styryl dye tomy'2 methylene chloride redK shown below was dissolved as a sensitizer.

Next, this solution was coated on a polyethylene terephthalate film with a thickness of 10 microns having a palladium vapor-deposited layer using a wire bar, and then dried to remove the coating solvent and provide a photoconductive layer with a thickness of 6 microns.
The entire electrophotographic photoreceptor was manufactured. Surface 2+a of this film
The electrostatic latent image was stopped by applying an image exposure through the original manuscript of a positive maker.

(Diarylamine compound) (Styryl dye) This electrostatic latent image was developed using the developer-A and the comparative developer-B'lt. Comparing images A and B, it was found that in the image B, roughness Φ was noticeable on the edges and lines of the image, but compared to the human image, there was almost no roughness in the enlargement #1, and developer-A It is clear that this has excellent image reproducibility.

Next, a negative corona discharge (
-4 kV) t-, then layered on an aluminum plate used in the P8 version FFD-[ manufactured by Fuji Photo Film ■, and transferred by applying toner and polar opening (negative) corona discharge from the sensitive material side. However, we were able to transfer almost completely with a transfer rate close to that of Ktootsrc.

Note that the transfer rate was calculated using the following formula.

D8 = Image density DR before transfer on photosensitive material: 1 After transfer 1 Comparing the transferred F7Ii image, it was found that compared to A#iB, it gave a good transferred image with less image flow and thick 9 lines. .

Next, a printing test of the images transferred onto these aluminum plates was conducted according to the following procedure.

First, the image was transferred to an aluminum plate T-7'
After heating for a minute to fix the image, surface treatment was performed by gumming. Next, the printing machine (Davidson 200)
1-Done.

As a result of the printing durability test, both A and B had a printing durability of 30,000 sheets or more, confirming good printing durability.

Example 2 A compound having the general formula (2) in this specification was added to the dispersion obtained in Example 2 (-Gettf)/x10-'
Developer-0 and Comparative Developer-D1 were prepared in the same manner as in Example-1, with the moles contained. Table 1 shows the particle size and charge amount.

Table 2 Here, it can be seen that compared to Developer -0, Comparative Developer -2 has a smaller amount of charge, and its effective charge is almost zero, indicating that it is mostly composed of ionic components. It has been shown that the chargeability of an ethylene/methacrylic acid copolymer can be changed in a favorable direction by converting methacrylic acid into a carxyl group ester.

Next, development was carried out in the same manner as in Example 7, but with the comparative developer, image deletion and so-called double images, in which images appeared around the image lines, occurred. On the other hand, developer-C exhibited excellent image reproducibility with no image deletion or double images, and almost no roughness at the edges. Further, the transferability was also good, and the transfer force was close to 1001 g in the same manner as in Example-1.

Developers E to H were prepared by mixing and dispersing in the same manner as in Example 3 to Example 1, except that the copolymers shown in Table J were used. The particle size and charge amount are shown in Table-JIC.

It can be seen that all the developers have better dispersibility and chargeability than the comparative developer-BK of Example-1.

Next, development was performed in the same manner as in Example 1, and all showed excellent image reproducibility with little roughness at the edges. The transferability was tested in the same manner as in Example 7, and the transfer efficiency was 90-1004, indicating good transferability.

Example 7 Turprene/20 was used as a dispersion polymer when wet-dispersing the mixed material obtained in Example-//. (manufactured by Chuo Kasei,
Styrene-butadiene copolymer, copolymerization ratio of styrene and butadiene, o,'yr:o.

25 weight ratio) were allowed to coexist in the following composition.

A developer-① was prepared by dispersing in the same manner as in Example-7.

Table 1 shows the measurement results of particle size and charge amount.

Table 9: The dispersibility and chargeability of the specimens in which the μm dispersion polymer coexisted were improved compared to those without the coexistence. When developed in the same manner as in Example 7, it showed excellent image reproducibility with almost no image flow or edge roughness. Further, as a result of testing the transferability, it was found that the transfer efficiency was higher than that of j-IDO.

Example-t] t-TK loss double planetary mixer-130LDM
Pour into a mold (manufactured by Tokushu Kikaku ■) and boil for 1 hour at J'C.
The mixture was stirred and kneaded at rotational speeds R, P, and M. Furthermore, under these conditions, 37 parts by weight of Tsurupetz/00f was added and stirring was continued for 1 hour to obtain a mixture. Next, this mixture “2zo°C
After cooling to a temperature of 90%, it was added to 0 parts by weight of upper H2O to obtain a reprecipitate.

Thereafter, the mixture was dispersed in the same manner as in Example 1, and a charge control agent was added to prepare a developer -Jt-. Table of particle size and charge amount! Shown below. A developer having almost the same physical properties as in Example-I was obtained.

Table-! Next, as a result of developing, transferring, and printing in the same manner as in Example 7, it was confirmed that the developer of Example 7 had the same performance as that of humans.

Showa JJ July 2nd

Claims (1)

[Scope of Claims] A liquid developer for electrostatic images, characterized in that a carrier liquid contains at least one copolymer represented by the following general formula (I) as a constituent component. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) In the formula, R_1 represents a hydrogen atom or a methyl group. R_2 represents an alkyl group, an aralkyl group, an aryl group or a cycloalkyl group. x and y represent the number of moles, x:y=0.995-0.8
0:0.005 to 0.2.