JPS5983174A - Manufacture of wet developer for electrophotography - Google Patents

Abstract

PURPOSE:To obtain a stable polymer dispersed system by producing a polymer which has adsorbing power and becomes insoluble practically in a medium in the presence of a soluble polymer. CONSTITUTION:Resin particles to be dispersed are composed of a solvent-soluble polymer (the 1st polymer) and a solvent-insoluble polymer (the 2nd polymer). The polymers contain relatively polar functional groups, and by the interaction between the functional groups the 1st polymer is adsorbed on the surfaces of particles of the 2nd polymer to form adsorbed protective layers for preventing the coagulation and melt bonding of the particles. -COOH, -SO3H, -OCOCH3, N(CnH2n+1)2 (n=1-3), -NH3, -CH2-O-CH2-, etc. are arbitrarily combined and used as said functional groups.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing a liquid developer for developing electrostatic latent images, and particularly provides a method for easily obtaining toner particles having excellent dispersion stability.

An effective means for developing a one-polymer dispersion system that exhibits good dispersion stability is the use of a dispersion system using a graft polymer.

For example, Special Publication No. 53-54029, Special Publication No. 57 No. 129
As described in No. 85, there is a method in which a polymerizable vinyl group is introduced into a precursor polymer in advance by a polymer reaction, and monomers are polymerized in the presence of this group to form a graft copolymer. However, when polymerization is carried out by such a method, gel is often formed, and it may be difficult to form dispersed particles.

The present invention does not utilize the above-mentioned graft polymerization method, but rather shows a method for stabilizing the dispersion of an insoluble polymer through interaction between a soluble polymer and an insoluble polymer in a carrier liquid.

The present invention also shows a method for obtaining a polymer dispersion system having good dispersion stability without gel formation by polymerizing an insoluble polymer in the presence of a soluble polymer. .

Further, the method shown in the present invention has the advantage that stable dispersed particles can be formed without using a graft polymer, and is a simple and practically advantageous method for producing 5-dispersed particles.

Therefore, an object of the present invention is to obtain a polymer dispersion system with excellent dispersion stability without using a graft polymer, and furthermore, to obtain a polymer dispersion system which has an adsorption ability in the presence of a soluble polymer and is substantially insoluble in a medium. The goal is to obtain a stable polymer dispersion system without the formation of gel by producing a polymer that is The first objective is to control the particle size of the polymer and obtain polymer particles with a desired particle size.

The dispersed resin particles obtained in the present invention are basically composed of a solvent-soluble polymer (hereinafter referred to as a first polymer) and a solvent-insoluble polymer (hereinafter referred to as a second polymer). Both the solvent-soluble polymer and the solvent-insoluble polymer have relatively polar functional groups, and the interaction between these functional groups causes the first polymer to be adsorbed onto the surface of the second polymer particle. Forms an adsorption-retaining layer that prevents agglomeration and fusion between particles.

The polymer dispersion system shown in the present invention is composed of a first polymer and a second M polymer having functional groups that interact with each other, and the functional groups that interact with each other include 1, for example, -COOH and -8O3H.

OCOCH3+ N (Cn Hfa n + s
kJ (n=1~3) --CHz-o-CH2-
Indicates any combination of the following.

Comparisons can also be made by separately synthesizing the first and second polymers above, dissolving both polymers in a common solvent, and then dropping the above polymer solution into an isoparaffinic hydrocarbon solvent, etc. Polymer particles that exhibit good separation stability can be obtained, but keeping a relatively large amount of the common solvent used in this process in the separation system may be undesirable, such as reducing the insulation properties of the system. A lot.

Further, unless ultrasonic waves are used as a dispersion means, a large amount of aggregates may sometimes be produced. Therefore, from the system
This method is extremely disadvantageous in terms of the removal of the common solvent mentioned above and the removal of dispersion power.

On the other hand, according to the method according to the present invention, in the presence of the first polymer having adsorption ability, a monomer which is soluble in the solvent used in the monomer state but becomes insoluble in the solvent when formed into a polymer is carried out. When carried out, a common solvent for both of the above-mentioned polymers was not required, and polymer-dispersed particles having a particle size of at most 1 μm or less were always obtained as a product. At this time, the first polymer already present in the polymerization system merely has an adsorption effect on the precipitated second polymer.

Little or no grafting to the first polymer occurs, and it is the first that protects and stabilizes the resulting polymer particles.
The interaction is only between the functional groups present in the polymer and the second polymer.

This is clear from the fact that stable dispersed particles were not formed when neither of the two types of polymers had the above-mentioned functional groups.

Furthermore, the aforementioned Special Publication No. 53-54029 or Special Publication No. 5
No. 7-12985, etc., when similar polymerization was carried out in the presence of a soluble polymer having a 1M vinyl group, gel formation was often observed; however, the method shown in the present invention When polymerization was carried out, no grafting to the soluble polymer occurred, and therefore no gel formation was always observed. Furthermore, according to the overlapping method shown in the present invention, it was possible to produce an emulsion with a solid content concentration as high as about 50%.

The first if-form used in the present invention is, for example, a polymer that is soluble in the isoparaffinic hydrocarbon solvent used, and an initiator fragment or copolymer that serves as an adsorption site for the solvent-insoluble polymer. As a co-hybrid component.

For example, -COOH, 5OaH, -0COCH3, -N(
CnH8n+su2t (N=1~3), -NHL 0
8-NO2, -CN, -0H1-CHI-0-CHI-
However, in order to impart solubility to the polymer, it is preferable that the comonomer is obtained from a comonomer having a functional group such as .

The first polymer has the following general formula (a) X=H+ CH'*Y=CO2CrRH11
m+1 (6≦m≦22)CnH2n+t (2≦n≦2
0) OCpH2p+t (6≦p≦20) Particularly preferred is a soluble polymer obtained by copolymerizing a monomer selected from the following.

The compatible liquid here is an organic solvent with a low dielectric constant and high electrical insulation properties, such as normal paraffin hydrocarbons, isoparaffin hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and halogenated aliphatic hydrocarbons. Isoparaffinic hydrocarbons are preferred, such as Shell Silua 1 (manufactured by Shell Oil), Isopar G and Isopar H, and Isopar K and Isopar L (manufactured by Esso Oil),
Ipeen Luvent (manufactured by Idemitsu Oil Co., Ltd.) etc. can be used.

On the other hand, the monomer that provides the second polymer that is practically insoluble in the above-mentioned supporting liquid and that constitutes the dispersed particles is basically soluble in the above-mentioned supporting liquid in the monomer state, but when it forms a polymer, it becomes soluble in the supporting liquid. Any monomer can be used as long as it has the property of decreasing solubility and causing polymer precipitation. If the monomer itself used in this case provides a polymer that has adsorption ability for the first polymer described above, it is possible to polymerize as a single monomer to provide dispersed particles, but on the other hand, the monomer that provides the above-mentioned insoluble polymer When forming a polymer that does not have adsorption ability for the first polymer alone, it is possible to form a copolymer using, for example, a comonomer having the following functional groups as a copolymerization component to provide dispersed particles. I can do it. That is, the monomer that provides the polymer with adsorption ability for the polymer that is soluble in the above-mentioned compatible liquid has functional groups -COOH, -8O3H, OCOCH3 in the monomer.
, -N(Cn-NO2, -CN, -OH, -CHII
A monomer having -0-CR2 is preferred.

Examples of monomers forming the second polymer include styrene and its derivatives, C1-C4 alkyl esters of acrylic acid or methacrylic acid, maleic anhydride 1ls1
．． N-vinylpyrrolidone.

Maleic acid mono 2-ethylexyl, maleia M mo/
-n-octyl, mono-2-ethylexyl fumarate mono-n-octyl, acrylonitrile,
Methacrylonitrile, r-vinyl, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate.

hydroxyethyl methacrylate, vinylpyridine and its derivatives, vinylimidazole and its derivatives,
The second monomer can be formed from a single or copolymer of ethoxyethyl methacrylate, methoxyethyl methacrylate, vinyl sulfonic acid, p-vinylbenzenesulfonic acid, vinylamine, p-vinylnitrobenzene, and the like.

It is possible to control the particle size of the resulting dispersed particles by changing the ratio of the above-mentioned functional groups present in the first polymer and the second polymer. That is, particle formation is promoted, for example, by increasing the concentration of adsorption sites in the second polymer;
As a result, as the number of particles increases, the particle diameter tends to become smaller.

Furthermore, when a relatively highly polar monomer is used as a monomer to provide the second polymer, the solubility of the resulting polymer decreases, and the number of particles formed at the initial stage of polymerization increases, resulting in a decrease in particle size. On the other hand, when forming the second polymer, if a monomer as shown in the above general formula (a) is copolymerized as a copolymerization component to increase the solubility in the carrier liquid, the particle formation rate will be delayed. Particle size increases.

Furthermore, the particle size can also be controlled by changing the ratio of the first polymer and the second polymer. That is, as the concentration of the first polymer decreases during one polymerization, the concentration of adsorption sites for the generated second superposition body decreases, and as a result, the particle size increases.

Utilizing the above-mentioned properties, it has become possible to control the particle diameter of dispersed particles fairly freely according to the method shown in the present invention. Such a particle size control method is conventionally known, for example, as a reference document, 1-pispersion Powmeri
zafion in Organic Mediaje
difedby K.E.J.Barrett
+ John Wi 1ley and 5onS+
This method solves the practical difficulty of using a method of protecting and stabilizing dispersed particles using a block or graft copolymer as described in London 1974 and the like.

In order to use the polymer dispersion obtained according to the above description as a liquid developer for electrophotography, the dispersed particles may be colored and charged. As the coloring agent 7 for the dispersed particles, any coloring agent generally known as a coloring agent for wet type developers can be used.

For example, oil-soluble azo dyes such as Oil Blank 5 Oil Red, basic azo dyes such as Bismarck Brown and Chrysoidine, acidic azo dyes such as Wool Blank, Amide Blank Green, and Blue Bramek I-(F), Direct Dell Blank E, Bongo Red, etc. Direct dyes, anthraquinone dyes such as sootane violet and acid blue, carbonium dyes such as auramine, malachite green, Crystal Bay 1st/Tuto Victoria Blue, rhodamine dyes such as rhodamine B, quinoneimine dyes such as safranin, nigrosine 5 methylene blue, etc. Dyes include:

Examples of pigments include carbon blank, phthalocyanine blue, phthalocyanine green, washing red, and benzidine yellow. It is also possible to use surface-treated pigments such as carbon black dyed with nigrosine, kraft carbon, silicon oxide fine powder dyed with rhodamine B, microlith blue, and the like.

As for the method of coloring the dispersed polymer particles, there is a method in which the dye is previously dissolved in a solvent that dissolves the dye used, and this dye solution is added dropwise to the dispersed polymer liquid and stirred. In this case, the solvent for the dye is preferably mixed with, for example, an isoparaffinic hydrocarbon solvent used as the above-mentioned compatible liquid. Furthermore, it is desirable to use a solvent with relatively insulating properties and a high boiling point as a solvent for the dye. Showa 57-4873
As shown in No. 8, it is possible to produce a liquid developer that can be used satisfactorily as an electrophotographic wet developer without removing the solvent for the dye. Therefore, if a dye with relatively high solubility in organic solvents is used, such as an oil-soluble dye, and the amount of solvent relative to the dye is kept small, it is not necessary to remove the solvent after coloring the dispersed polymer particles.

Furthermore, in the polymer dispersion system, functional groups with an adsorption function contained in the dispersed particles can be used as adsorption points for dyes or pigments, and by introducing relatively highly polar functional groups into the polymer, dyes or pigments can be absorbed. This increases the dyeability (adsorption capacity) for dyes or pigments, making it difficult for dyes or pigments to be desorbed from the dispersed particles after coloring. If such a functional group having the above-mentioned adsorption ability is introduced into the dispersed particles, even when a dye is used for coloring, when the dye solution is added to the dispersed polymer liquid as described above, the amount of solvent for the dye will be reduced. Even if the amount of dye is small and the dye precipitates in the dispersed polymer liquid, the precipitated dye is molecularly adsorbed onto the polymer particles and the polymer dispersed particles can be successfully colored. Therefore, the solubility of the dye during coloring is not very important (and the amount of solvent for the dye can be extremely small).

The wet type developer of the present invention contains a charge control agent and a dye.

By selecting a pigment or the like, it is possible to freely produce a toner having a positive charge or a toner having a negative charge.

The charge control agent used in the wet developer of the present invention is 2
For example, copper oleate, cobalt naphthenate, zinc naphthenate, manganese naphthenate.

Examples include cobalt octylate, lecithin, sodium dioctyl sulfosuccinate, and aluminum salt of steverytrozin.

Further, toners produced by appropriately selecting monomers according to the method described in the present invention may be used, for example, in Japanese Patent Application No.
6-175048, 56-175049, 57-
4158. When used for a lithographic printing original plate such as that described in No. 57-4158, it is possible to provide a toner having etching resist properties when etched with an alkaline aqueous solution after development and fixation. Toner compositions used for such purposes include, for example, Japanese Patent Application No. 57-4
157, 57-40325, 57-21829
Toner particle compositions similar to those described in can also be used.

Example 1 Ivy Solvent (Idemitsu Petroleum Membrane) 500. F.

Add 170I of stearyl methacrylate and 30I of dimethylaminomethacrylate and heat to 75C under nitrogen introduction.
Stirring was performed for 30 minutes. Then, as a polymerization initiator, A
Add 1g of IBN (azobisisobutyronitrile) 7
Polymerization was carried out for 3 hours on a 5tZ' water bath to obtain a first polymer solution.

Thereafter, 100 g of the product solution was taken and transferred into a 1 t flask equipped with a stirrer, a thermometer, 1 dropping funnel, and a nitrogen inlet tube, and Ivytrubene 1-300.9 was added.
(90 g of monomers methyl methacrylate, 10 g of maleic anhydride mono-2-ethylhexyl ester and AIB
A mixture of NIg was added dropwise over 3 hours. after that,
After heating for an additional 3 hours under a nitrogen atmosphere, it was cooled to room temperature. The product was a white emulsion containing a composite resin dispersion with an average particle size of 012μ and excellent dispersion stability. Then, a solution of Oil Yellow GG-8 gM manufactured by Orient Chemical Co., Ltd. dissolved in xylene 20F was added to the emulsion under stirring. Furthermore, after adding aluminum stearate Ig as a charge control agent, it was diluted 50 times in ivy solvent to form a toner solution ().The obtained toner was a positively charged toner showing good dispersion stability. .

Example 2 In a 1.5 t flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, 500 y of IP Solvent, 100.9 y of lauryl methacrylate, and 5 g of methacrylic acid were placed, and BPO (benzoyl peroxide) was added as a polymerization initiator. II was added and polymerization was carried out for 5 hours on an 85r water bath to obtain a first polymer solution. Thereafter, a mixture containing 100 I of methyl methacrylate, 1.511 diethylamino methacrylate, 100 g of IP solvent, and 1 g of AIBN, which are monomers to give the second polymer, was added through the dropping funnel.
The mixture was added dropwise over a period of time and heating continued in a 75C water bath. After that, heating was continued for 3 hours at 85 U, and then 5 g of oil yellow was added to xylene 20 &
After adding a solution dissolved in the solution and 1 g of aluminum stearate, IP Solvent was added to dilute the solution 50 times. The product was a yellow emulsion with an average particle size of 02μ and excellent dispersion stability.

Example 3 Polymerization was carried out under various conditions shown in Table 1 below in the presence of a lauryl methacrylate-methacrylic acid copolymer solution, which is the first polymer synthesized as shown in Example 2. The results are shown below.

Example 4 200.9 ml of Ivy Solvent was added to 50 y of a 10% solution of lauryl methacrylate-methacrylic acid copolymer synthesized as shown in Example 2.

Styrene 100I as a monomer giving the second polymer
, 4-vinylpyridine 10I, methyl methacrylate-1
- 50g and 15g of polymerization initiator AIBN were added, and the mixture was heated and stirred at 75C for 5 hours under a nitrogen atmosphere. The product was a stable composite resin fractional emulsion with an average particle size of 0.20μ.

Example 5 A similarly stable emulsion was formed in a system containing 1-vinyl-2-methylimidazole in place of 4-vinylpyridine in Example 4.

Example 6 Example 2. Lauryl methacrylate-methacrylic acid copolymer lO% solution 500I synthesized as shown in
Vinyl acetate J, 00 g and A, I BNlg were added thereto and heated at 75C for 3 hours. The product is = F average particle size 0
．． It was a 21μ white emulsion.

Next, to 100 I of this emulsion liquid, 2 g of Victoria Blue was dissolved in 50 g of methanol, and saliva was added to the solution and heated and stirred. The product was a blue colored stable emulsion.

Example 7 Similarly to Example 6, a 10% solution of lauryl methacrylate-methacrylic acid copolymer 500. ! Vinyl acetate 100 in 7,? , dimethylaminoethyl methacrylate 2ON and AIBN 1.9 were added, and the mixture was heated and stirred at 75C for 4 hours. The product was a stable white emulsion with an average particle size of 0.09μ.

Example B Similarly to Example 6, 10% vinyl acetate was added to 500g of lauryl methacrylate-methacrylic acid copolymer lO% solution.
0. Ln-butyl acrylate 20.9, dimethylaminoethyl methacrylate 10g, Ivy Solvent 2
Add 00.9 and AIBNl, 5.9 and 6 at 575C.
heated for an hour. The product was a white emulsion with an average particle size of 025μ. Next, for this emulsion liquid,
Oil Yellow GG-85 manufactured by Orient Chemical Co., Ltd. xylene 20. ? The solution was poured under stirring.

Further, 1 g of ferric stearate was added as a charge control agent, and the mixture was diluted 50 times in ivy solvent to prepare a wet developer for electrophotography. The obtained developer exhibited good dispersion stability and excellent fixing properties.

Example 9 10% solution of lauryl methacrylate-methacrylic acid copolymer synthesized as shown in Example 2 500.9
200.9, methyl methacrylate) 50. Sl, Acrylonitrile #10.9.
1 g of AIBN was added, and the mixture was heated and stirred at SOC under nitrogen introduction. The product was an emulsion with an average particle size of 0.10μ.

Example 10 Stearyl methacrylate-+-1oo,v and methoxypolyethylene glycol methacrylate-F (CHz=
'5"C00fCH2CHzOf.CH3,N=9)
10& and AIBNl, l' were placed in a 1 t flask equipped with a stirrer, thermometer and nitrogen inlet tube, and AIBNl 500.9 was added and heated at 75U for 5 hours.

Stirring was performed. Next, take 100 g of the product solution and add 50 g of methyl methacrylate. L methylef 35g, hydroxyethyl methacrylate 10I and AIBN 1
．． Add 09 and heat and stir at 75C for 5 hours. The product was a stable emulsion with an average particle size of 0.15μ.

Next, oil blank HBB8 manufactured by Orient Chemical Co., Ltd. !
Dissolve i' in 60 g of xylene, drop it into the above-produced emulsion liquid F. After stirring, add 1.5 g of aluminum stearate as a charge control agent, add ivy solvent and dilute to a solid content concentration of 09% to form a toner. 1. When this toner was etched with an alkaline aqueous solution after development and fixing, it could be used as a wet developer having good etching resist properties, for example in Japanese Patent Applications No. 56-175048 and 1983.

Example 11 In 500 g of a 10% solution of lauryl methacrylate-methacrylic acid copolymer synthesized as shown in Example 2, Ivy Solvent 200I, methyl methacrylate 50&, 50 g of styrene, and N-vinylpyrrolidone IOg, AIBN l & was added, and the mixture was heated and stirred at 75 r. The product is a stable emulsion with an average particle size of OJ2μ.

Example 12 100 g of stearyl methacrylate and Ig of p-vinylbenzenesulfonic acid were added to Ivy Solvent 500I.
In addition, heat at 75C for 3 hours after adding AIBN 1#,
Stirring was performed. Thereafter, 100 y of product solution was taken, and 50 g of methyl methacrylate, 5 g of hydroxypropyl acrylate, Ivy Solvent 300.9 and 10 g of BPO (benzoyl peroxide) were added thereto and heated to 50 ml at 85 C.
Time polymerization was performed. The product was an emulsion with an average particle size of 0.09μ.

Example 13 2-ethylhexyl acrylate-t.50 & and p--
``-1-0 Styrene L/75 g was added with Ivy Solvent Loo& in the presence of AIBN O,519 and heated and stirred at 75C for 3 hours.Then, styrene 30& was added to the product solution.
, methyl methacrylate 6 (L9, 8 g of hydroxyethyl methacrylate and 5 g of BPOl were added to 9C
The mixture was heated and stirred at I' for 4 hours. The product has an average particle size of 0.3
It was an emulsion of 0μ.

Procedural amendment (spontaneous) 1.1 Table of contents Small Showa s7:1 Patent application number /94223
No. 2, Name of the invention, Probation 11 of the Electric Stingy Practical Warning Regulations 3, Relationship with the tenant making the amendment Patent Applicant Address Marunouchi, 111-ku, Chiyo, Tokyo-','iT
I No. 4 No. 2 Name (598) 2' I A *Paper paper company 4 Agent Address Address: 100 Tokyo, Chiyo Il1-ku Marunouchi-The] Official 4
No. 2 Mitsubishi Paper Mills Co., Ltd., page 5, date of amendment order, month, day, 6, 1939, number of inventions increased by amendment IJ' l.

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Claims (1)

[Claims] (1) In a method for producing an electrophotographic wet developer containing resin particles dispersed in a highly insulating hydrocarbon medium, the second polymer is soluble in the medium and has adsorption capacity (-). By polymerizing a monomer having a polar functional group capable of adsorbing to the first polymer under warm conditions in which the first polymer having a certain polar functional group is dissolved in the medium, A method for producing a composite resin dispersion f'ri! type developer for electrophotography, characterized in that it has low solubility in the medium and substantially forms a second polymer of particles.