DE3339662C2 - Process for the production of an electrophotographic suspension developer and its use for the production of electrophotographic printing plates - Google Patents

Abstract

A method for producing an electrophotographic liquid developer based on a resin dispersion containing resin particles in a carbon water medium which is highly insulating is described. In the process, in the presence of a first polymer which is dissolved in the medium and has a polar functional group which is adsorptive to a second polymer, a monomer having a polar group which is adsorptive to the first polymer is polymerized to form a second polymer which has low solubility in the medium and is essentially particulate.

Description

2. A method for producing a suspension developer according to claim 1, characterized in that that the polar functional groups are selected with an adsorptivity from the combination of Groups of the following classes (I) and (II):

Class (I):

-COOH -SO ₃ H and

Class (II):

-NH ₂ -N (C _n H _{2n + 1} J ₂ (η = Ibis 3) -CH ₂ -O-CH ₂ - -CONH- -COOCH ₃

/ V

-OH - <f N - <^ \ -NN -NO ₂ and -CN

3. A method for producing a suspension developer according to claim 2, characterized in that that the functional group of the first polymer is selected from class (I) and that the functional group

Group of the second polymer from class (II) is selected to obtain a positively charged Suspension developer.

4. A method for producing a suspension developer according to claim 2, characterized in that that the functional group of the first polymer is selected from class (II) and that the functional Group of the second polymer from class (I) is selected to obtain a negatively charged

35 Suspensiöiisentwiekiers.

5. A method for producing a suspension developer according to claim 1, characterized in that that the second, in the carrier liquid substantially insoluble polymer of vinyl acetate and one polymerizable heterocyclic compound is built up with at least one nitrogen atom in the ring, that the first polymer dissolved in the carrier liquid contains carboxyl groups and that from the first and particles formed from the second polymer contain a dye.

6. The method according to claim 5, characterized in that the size of the from the first polymer and resin particles formed and dispersed in the hydrocarbon carrier liquid by means of the concentration of the functional groups in the first and second polymers and the Adjusts the quantitative ratio between the first and the second polymer

7. Use of an electrophotographic suspension developer prepared according to claims 1 to 6 for the production of electrophotographic printing plates.

The invention relates to a method for producing an electrophotographic suspension developer according to the preamble of claim 1 and the use of the suspension developer produced by the process according to claim 7.

Generally, suspension developers consist of a high hydrocarbon carrier liquid

Insulation resistance, in which colored particles of a few μπι or smaller, with a positive or

negative electric charge are provided, are dispersed. To obtain a dispersion of such fine particles in one

Stabilizing non-aqueous medium is the application of Couiomb's repulsion, which results from the charge

originates on the surface of the individual particles, not a reliable measure to rely on can, in contrast to an aqueous emulsion; a generally effective way is that one

a protective adsorption layer of a polymer is formed around each particle, thereby protecting it from the steric

To make use of the repulsion effect between the particles coated in such a layer.

Suitable polymers that can form a protective adsorption layer are graft or block copolymers, the components that are both soluble and insoluble in their molecular skeleton in the carrier liquid contain. However, the ability to stabilize the dispersed particles is relatively delicate and on the composition, structure and molecular weight of such graft or block copolymers dependent, and it is very difficult in practice to obtain a copolymer with controlled structure and molecular weight to synthesize.

Another method is described, for example, in US-PS "0 81 391, in which one polymerisierba-

Re introduces vinyl group in a precursor polymer and a monomer in the presence of the obtained vinyl-containing Precursor polymer polymerized to form a graft copolymer Depending on the concentration of the precursor polymer, crosslinking reactions between the polymer molecules and give nondispersible particles. Another essential condition for making a stable dispersion is related to the particle size. So that a suspension developer keeps it can be without the toner particles settling during prolonged storage or use, the particle size must be a few μm or less, preferably 03 to 0.4 μm or less. For the Development properties is a narrow particle size distribution for a uniform reproduction of the Image advantageous. Therefore, it is an important problem in a suspension developer, the particle size and monitor their distribution.

In GB-PS 12 83 190 suspension developers are used to develop electrostatic latent images described from pigment particles (carbon black) with two differently soluble resins in a carrier liquid be coated. The toner particles there consist of carbon black and the desired dispersion stabilization is achieved by applying a practice ag made of the polymers mentioned there around the solid core a suspension developer with such polymer-coated pigment particles, the particle size becomes substantial is determined by the size of the pigment particles and, as a result, one has to ensure good dispersion to achieve very finely divided pigment particles, which according to the examples there by grinding in a Use a ball mill. Such mechanical crushing is technically complex, results in the free distribution of the pigment particles only to a limited extent and also does not produce a uniform one Particle sizes. Coarse particles cannot be completely avoided and must be sieved out. However, different particle sizes in a suspension developer result when they are used in the Electrophotography is poor due to agglomeration and the settling of particles over time Pictures.

The object of the invention is to show a process for the production of an electrophotographic suspension developer which has a high suspension stability, in which one does not have to use graft or block copolymers. This object is achieved by the method according to claim S.

The polar functional groups with an adsorptivity are preferably selected from the combination the groups of the following classes (I) and (I I)

Class I (acidic groups):

-COOH -SO ₃ H - / ~ \ -OH

Class Π (basic groups.):

-NH ₂ - N (C _n H _{2n +} 1), (n = 1,2 or 3) -CH ₂ -O-CH ₂ -

- C - NH— —C - O - CH ₃ —OH (alcoholic hydroxyl group)

- N N— —NO, —CN

45

Are monomers with a Class I functional group
Acrylic acid, methacrylic acid, 3-vinylpropionic acid, mono (Ci - Ce) -alkyl maleate,
Mono (Ci - Ce) alkyl fumarate, maleic acid, itaconic acid. Crotonic acid, sulfoethyl acrylate,

Sulfocthyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, 2-methyl-3-sulfopropyl acrylate, p-hydroxystyrene, p-hydroxybenzyl acrylate and p-hydroxybenzyl methacrylate.

Monomers with a functional group of class II are
Vinylamine, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl acrylate,
N ₁ N- diethylaminoethyl acrylate, Ν, Ν-diethylaminoethyl acrylate, N ₁ N- dipropylaminoethyl acrylate,
2- hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxy-3-chloropropyl acrylate, M-butylene glycol monoacrylate ^ -hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
3-hydroxypropyl methacrylate, 2-hydroxy-3-chloropropyl methacrylate, 1,4-butylene glycol monoethacrylate,
Carbitol acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate,
Methoxy polyethylene glycol acrylate,

I ^ = CH-COO- (C ₂ H ₄ OV-CH ₃ «= 2-25]

Tcirahydrofurfuryl acrylate, glycidyl acrylate, methoxyethyl methacrylate,

for methoxy polyethylene glycol methacrylate

IClI ₂ = C (CH ₃ ) -COO- (C ₂ H ₄ OV-CH ₃ η = 25]

Iu polypropylene glycol monomethacrylate

Γ 1

CH ₂ = C (CH ₃₎ -COO-V

H m = 1-25

Tetrahydrofurfuryl methacrylate, methacryloxypropyhrimethoxysilane, glycidyl methacrylate, vinyl acetate,
N-VinyI-2-pyrrolidone, acrylamide, methacrylamide, N-tert-butyl acrylamide, N-tert-octyl acrylamide,
N-butoxymethylacrylamide, diacetone acrylamide, N-vinylidazole, N-vinyl-2-methylimidazole,
4-vinylimidazole, 1-vinylpyrrole, 3,5-dimethylvinylpyrazole, 4-vinylpyridine, 2-methyl-5-vinylpyridine,
ίο 9-vinyl acridine, 4-vinyl quinoline, 2-vinyl quinoline and (Ci - d) alkyl vinyl ethers.

The first polymer used according to the invention is a polymer that is in a carrier liquid from a Hydrocarbon with high resistance to insulation, is soluble In order to impart solubility to the polymer, it is It is desirable to introduce a monomer as a comonomer which is selected from compounds of the general Formula (a), in addition to the monomer having a functional group of Class I or II.

CH ₂ = CY (a)

-

XH or CH ₃ and

Y means CO ₂ Q _n H _2n , ₊ , 6 </ n <22), C "H _{2 <n} + ι (2 </ 7 <20) or OCpH _2p +, (6 < pS 20).

The molar ratio of a monomer of the formula (a) to a monomer selected from class I or II is preferably more than 24 / 1.0.

Examples of hydrocarbons with high insulation resistance are n-paraffin hydrocarbons, isoparaffin hydrocarbons, cycloaliphatic hydrocarbons, aromatic hydrocarbons and halogenated aliphatic hydrocarbons. Of these hydrocarbons, isoparaffinic hydrocarbons are particularly preferred.

As a monomer for the preparation of the second polymer which is essentially insoluble in the carrier liquid and forms dispersible particles, any of those which are soluble in the carrier liquid can be used the solubility of which decreases with the progress of the polymerization and which ultimately in the carrier liquid precipitate, in this case one can use a monomer with the functional groups of class I or II dispersed particles obtained by polymerizing the monomer alone Monomer that does not contain such functional groups, you can get the desired αϊβμε ^ ίειίβπ Prepare particles by using as a comonomer a suitable monomer with functional groups of the class I or II admits. Examples of monomers that form the second polymer that differs from that which has functional groups of class I or II are styrene and its derivatives, the Cr bis Cs-alkyl acrylates or methacrylates, methyl vinyl ketone, ethyl vinyl ketone, vinyl propionate and vinyl pivalate.

In general, the ratio of the first polymer to the second polymer should preferably be 55 to 35% Weight basis.

You can this way? get dispersed polymer particles with a very good dispersion stability, by first preparing first and second polymers separately, the resulting polymers in one for both Polymers dissolve a suitable solvent and then add a hydrocarbon dropwise to the solution high insulation resistance. However, such a procedure is undesirable, and not just because that common solvent remains in relatively large amounts in the dispersion system and one exerts undesirable influence, e.g. B. a deterioration in the insulation resistance of the dispersion medium,

but because in some cases larger amounts of aggregates can be formed during the dropwise addition of the polymer solution, if not suitable countermeasures, e.g. B. an ultrasound can be taken.

In the inventive method in which the second polymer by polymerization in the presence of dissolved first polymer is formed by adding a monomer that is soluble in the carrier liquid, but that when polymerizing becomes insoluble, polymerizes, there is no need to use a solvent use that is common to both polymers.

The first polymer, which is present in a polymerization system, serves only as an adsorbent the precipitated second polymer and essentially or no grafting of the monomer occurs on the first polymer. Only through the interaction between the functional groups in the polymer particles formed are protected and stabilized in the first and in the second polymer. this emerges from the fact that polymer particles are not formed in the form of a stable suspension, when both polymers do not have any of the aforementioned functional groups.

A control of the size of the dispersed particles is possible inde.n one the concentration of the functional Groups in the first and second polymers selected from Class I or II are monitored.

For example, by increasing the concentration of adsorption sites in the second polymer, the Formation of polymer particles increases and there is a decrease in polymer size due to the increased number of the particles. One uses a monomer with a relatively high polarity in forming the second Polymer, then the solubility of the polymer formed decreases and results in a decrease in particle size

due to the increase in the number of particles formed in the initial stage of the polymerization. if on the other hand, a monomer of the general formula (a) is used in the preparation of the second polymer, so the rate of formation of the particles decreases and results in an increase in particle size. Control of the Particle size is also possible by having the ratio between the first and the second Polymer adjusts. When the concentration of the first polymer in the polymerization system decreases, then it decreases also decreases the number of adsorption sites for the second polymer and results in an increase in particle size.

Control of the size of the dispersed particles is made possible by taking advantage of the uses the aforementioned phenomena. These methods of controlling particle size have the difficulties overcome that in practice in the known method for protecting and stabilizing dispersed particles occurred by block or graft polymerization and as they are, for example, in K. E. J. Barret: "Dispersion Polymerization in Organic Media", John Willey + Sons, 1974.

In order to be suitable as a suspension developer in electrophotography, the in the aforementioned Art obtained dispersed particles in the polymer dispersion be colored and electrostatically charged. The color scheme of the dispersed particles can be done as is generally done with suspension developers. Suitable colorants are dyes, e.g. B. oil-soluble azo dyes, basic azo dyes, acidic azo dyes, Direct dyes, anthraquinone dyes, carbonium dyes, rhodamine dyes and quinoneimine dyes. Examples of colorants that are classified as pigments are carbon black, phthalocyanine blue, and phthalocyanine green and benzidine yellow.

You can also use surface treated pigments, e.g. B. Soot colored with nigrosine or finely powdered Use silicon dioxide colored with Rhodamine B (C. J. 45! 70).

The coloring of the dispersed polymer particles can be done by adding a dye in a Solvent, which dissolves the dye, dissolves and this dye solution drop by drop to the stirred one Polymer dispersion there. As a solvent for the dye is advantageously selected that with the Carrier liquid, e.g. B. an isoparaffinic hydrocarbon, is miscible. A preferred solvent has a relatively high insulation resistance and a high boiling point. For example, if you use an oil-soluble dye, as it is soluble in an aromatic hydrocarbon, so this is as a solution applied in a small amount of xylene, because this is not necessarily tapped from the suspension developer must be removed in order to obtain a product that can be used in electrophotography. Therefore, it is generally not necessary to use the solvent for the dye after the dyeing to remove dispersed polymer particles when the amount of solvent in relation to the dye is kept small by using a dye having a relatively high solubility in one organic solvent, for example an oil-soluble dye.

In the case of the suspension developers prepared according to the invention, one can have a functional group with Adsorption activity existing in the dispersed particles as an adsorption site for a dye or use a pigment. By adding a functional group with a relatively high polarity to a polymer (high dipole moment), it becomes possible to increase the color affinity (adsorptive power) for a dye or to increase pigment and to increase the desorption of the dye or pigment from the colored particles Reduce. There is also the possibility of converting a concentrated dye solution into a polymer dispersion the dye tends to precipitate in the dispersion medium. In such a case, if a functional group having an affinity for the dye is present in the polymer particles, the precipitated one Dye molecule as such can be adsorbed on the polymer particles and gives a sufficient one Coloring. As a result, the solubility of the dye is not so important and the amount of Reduce solvent for the dye to a considerable extent.

The suspension developer prepared according to the present invention can, if desired, be prepared so that it contains either positively charged or negatively charged toner particles, by adding suitable Manner selects a charge control agent and the dye or pigment. To someone positively charged Making suspension developer becomes the first polymer with Class I functional groups and that second polymer with functional groups of class II selected. If, on the other hand, you have a negatively charged one The first polymer with functional groups of class II and the second polymer with Class I functional groups is selected. If a basic group (class H, are present on the surface of the particles of the second polymer, then the cationic part of the through Dissociation of the charge control substance is generated, adsorbed onto the polymeric particles and yields positive charged particles, while if an acidic group (Class II) on the surface of the particles from the second polymer is present, the anionic part is adsorbed and thus negatively charged particles are formed.

Examples of charge control substances are copper oleate, cobalt naphthenate, zinc naphthenate, manganese naphthenate, Cobalt octylate, lecithin, sodium dioctyl sulfosuccinate and aluminum salts of rosin.

The suspension developer obtained by the process according to the invention should not only be an excellent one Have dispersion stability of the toner particles, but should also meet the other requirements z. B. excellent charge stability, high adsorption affinity for dyes and pigments, a Desired fixability, a slight change in the development properties on prolonged storage or have or enable application and easy handling in the developing device.

For example, in the preparation of a suspension developer for use in developing a conventional zinc oxide-based electrophotographic printing plate, an effective polymer combination can be used which satisfies the above requirements, the first polymer being a carboxyl group-containing liquid polymer and the second polymer being a polymer which is in is insoluble in the carrier liquid with high insulation resistance and which is derived from vinyl acetate and a polymerizable heterocyclic compound having at least one nitrogen atom in the ring.
Polyvinyl acetate is a suitable resin for use in electrophotographic suspension developers,

because it has a relatively low glass transition temperature, is easy to fix and a high one Has adsorption affinity for dyes and pigments. By having vinyl acetate as one of the ingredients When using the second polymer, one can overcome the problems of fixability and dyeability of the Loosen the toner particles. By having a polymerizable heterocyclic compound in the second polymer introduces at least one nitrogen atom in the nucleus, e.g. B. N-vinyl-2-pyrrolidone, 2-vinylpyrazine or N-vinylimidazole as a comonomer, the adsorption of a charge control substance is facilitated and, in addition, ad virorption sites are created for the first polymer provided with carboxyl groups, eliminating both the requirements the charge stability as well as the dispersion stability can be met. Even if the vinyl acetate monomer and the heterocyclic monomer are copolymerizable in any proportion, it is desirable that the proportion of vinyl poison units in the insoluble copolymer is 50% by weight or more and are preferably 70 wt .-% or more, and that the proportion of the units in the nitrogen-containing heterocyclic compound is 50% by weight or less, and preferably 1 to 30% by weight. That in the The carrier liquid-insoluble copolymer may, if necessary, contain other structural units of polymerizable Contain monomers, e.g. B. (meth) acrylic esters, acrylamide and dialkylaminoethyl (meth) acrylate. In such Cases the proportions of vinyl acetate and heterocyclic compound in the polymer are preferably in the ranges given above.

When using the suspension developer obtained according to the invention for the production of electrophotographic Printing forms as described in Japanese patent applications 1 75 048/8? and ! 75 049/81 one can use a suspension developer of a composition similar to that of theirs is described, for example, in Japanese Patent Application 4 157/82, obtained by adding styrene or adding a derivative thereof to the monomer composition to form the second polymer. Will the Preparation of the printing form carried out using the above suspension developer and then fixed, then a toner image is obtained which is resistant to an aqueous alkaline etching solution.

B e i s ρ i e 1 1

In a 1 -! - flask fitted with a stirrer, thermometer, and nitrogen inlet 500 grams of isoparaffinic hydrocarbon solvent (IP solvent), 190 grams of stearyl methacrylate, and 10 grams of methacrylic acid submitted. The mixture is stirred at 75 ° C. for 30 minutes under a stream of nitrogen. After adding ι g of azobisisobutyronitrile (AIBN) as a polymerization initiator, the mixture is on a water bath for 3 h Heated to 75 ° C., the polymerization taking place and a solution of the first polymer being obtained. A 100 g adapter the solution is placed in a 1-1 flask fitted with a stirrer, thermometer, and dropper funnel is provided with a nitrogen inlet, filled. After adding 300 g of the IP solvent, the flask is opened put a water bath at 70 ° C. To form the second polymer, a mixture of 90 g of methyl methacrylate, Pour 10 g of Ν, Ν-dimethylaminoethyl methacrylate and 1 g of AIBN into the flask through the dropping funnel added dropwise over a period of 3 hours. Then the mixture is further 3 h under a Heated nitrogen atmosphere and then cooled to room temperature. The reaction product is whiteness Suspension with an average particle size of 0.12 μm and excellent dispersion stability. A mixture of 5 g of yellow dye (CI. 11 020) in 20 g of xylene are added and then 1 g of aluminum stearate is added as a charge control substance. the Suspension is then diluted 50 times with the IP solvent using a suspension developer obtained, which carries a positive charge and has a very good dispersion stability.

Example 2

In a 1.5-1 flask fitted with a stirrer, thermometer and nitrogen inlet 500 g of IP solvent, 100 g of lauryl methacrylate and 5 g of methacrylic acid and 1 g of benzoyl peroxide are added (BPO) given. The mixture is formed on a water bath at 85 ° C for 5 h polymerized with a solution of the first polymer. To produce the second polymer, a mixture of

so 100 g of methyl acrylate, 5 g of diethylaminoehtyl methacrylate and 100 g of IP solvent and 1 g of AIBN through the Dropping funnel was added to the flask dropwise over 2 h, taking place on the water bath at 75 ° C warmed up. The mixture is then heated to 85 ° C. for a further 3 hours. As in Example 1 is obtained A solution of 5 g of yellow dye (C. 1.11 020) in 20 g of xylene and 1 g of aluminum stearate is added to the suspension. the Suspension is then diluted 50 times with IP solvent using a suspension developer obtained with excellent dispersion stability in the form of a yellow suspension, with an average Particle size of 0.2 μm.

Example 3

The first polymer, a lauryl methacrylate-methacrylic acid copolymer, was prepared as in Example 2 Formation of the second polymer was carried out in the presence of this copolymer under different conditions, as indicated in Table I, carried out. Table I also shows the test results.

Table I.

Change in the average particle size of polymer particles formed under various polymerization conditions
(Solvent: 5uO g IP solvent, temperature: 75 ° C; initiator: 1.0 g AIBN)

approach Lauryl methacrylate Methyl- Diethylaminoethyl Average Me'.hacrylic acid methacrylate methacrylate Particle size of the Copolymer (G) (G) Polymer particles (G) (μΐπ) 1 _ 50 10 Agglomeration 2 10 50 - > 1 3 10 60 10 0.21 4th 10 50 20th 0.11 5 20th 60 10 0.15 6th 20th 100 40 0.30 7th 20th iöö 20th 0.5 i 8th 20th 50 50 0.05 9 40 100 20th 0.31

Example 4

To 500 g of a 10% solution of a lauryl methacrylate-methacrylic acid copolymer, prepared according to Example 2, 200 g of IP solvent, a monomer mixture of 100 g of styrene, 10 g of 4-vinylpyridine and 50 g of methyl methacrylate were added to form the second polymer and 1, 5 g of AIBN were added as initiator. The mixture obtained was ^{stirred for 5 h at 75 °} C. under a nitrogen atmosphere. The reaction product was a stable suspension with an average particle size of 0.20 μm.

Example 5

A stable suspension is prepared by repeating the procedure of Example 4, wherein however, 1-vinyl-2-methylinriidazole was used instead of 4-vinylpyridine.

Example 6

To 500 g of a 10% solution of lauryl methacrylate-methacrylic acid copolymer, prepared according to the example 2, 100 g of vinyl acetate and 1 g of Al BN were added. The mixture was heated to 75 ° C. for 3 h, whereby received a white suspension with an average particle size of 0.21 μιτι. To 100 g of the suspension a solution of 2 g of Victoria Blue (C. 1.44 045) in 50 g of methanol was added. The mixture was <_ under Stir heated. A stable blue suspension was obtained as the reaction product.

Example 7

As in Example 6, 100 g of vinyl acetate, 20 g of dimethylaminoethyl acrylate and 1 g of AIBN were made into 500 g of one A 10% solution of a lauryl methacrylate-methacrylic acid copolymer was added, and the mixture was stirred for 4 hours stirred at 75 ° C. A stable white suspension was obtained with an average particle size of 0.09 μm.

Example 8

As in Example 6, there were 100 g of vinyl acetate, 20 g of n-butyl acrylate, 10 g of dimethylaminoethyl acrylate, 200 g of IP solvent and 1.5 g of AIBN to 500 g of a 10% solution of a lauryl methacrylate-methacrylic acid copolymer given. The mixture was heated to 75 ° C. for 6 hours. The reaction product was a white suspension with an average particle size of 0.25 μm. A solution was added dropwise to the suspension 5 g of yellow dye (C. 1.11 020) are added to 20 g of xylene. After adding 1 g of iron III stearate as charge control agent the mixture was diluted 50 times with IP solvent using an electrophotographic Suspension developer contained having good dispersion stability and excellent fixability.

Example 9

To 500 g of a 10% solution of a lauryl methacrylate-methacrylic acid copolymer, prepared according to Example 2, 200 g of IP solvent, 50 g of methyl methacrylate, 10 g of acrylonitrile and 1 g of AIBN were added. the Mixture was polymerized at 80 ° C under a Stiekstoffirorn. The reaction product was a suspension with an average particle size of 0.10 μm.

Example 10

In a 1-1 flask equipped with a stirrer, thermometer, and nitrogen inlet, were 100 g of stearyl methacrylate, 10 g of methoxy polyethylene glycol methacrylate

Γ '^H> 1

LCH ₂ -C-COO- (CH ₂ CH ₂ OVCh ₃ n = 9j

IO

6 g of monomethyl maleate and 1.8 g of AIBN were submitted. After adding 500 g of IP solvent, the mixture was ^{stirred at 75 °} C. for 5 h. 50 g of methyl methacrylate, 35 g of styrene, 10 g of hydroxyethyl methacrylate and 1.0 g of Al3N were added to a 100 g portion of the reaction mixture. The mixture was stirred for 5 h at 75 ° C., a stable suspension with an average particle size of 0.15 μm being obtained. A solution of 8 g of a black dye (CI 26 15G / in 60 g of xylene) was added dropwise to the suspension with stirring A printing plate as described, for example, in Japanese Patent Application Nos. i 75 048 / 8Ί, i 75 049 / 8Ί and 4158/8 was treated with the above suspension developer For fixing, the printing form was subjected to an etching treatment with an aqueous alkaline solution, and it was found that the present suspension developer is useful as a suspension developer having a desired etching resistance.

Example Π

To 500 g of a 10% solution of lauryl methacrylate-methacrylic acid copolymer, prepared according to the example 2, 200 g of IP solvent, 50 g of methyl methacrylate, 50 g of styrene, 10 g of N-vinylpyrrolidone and 1 g AIBN given. The mixture was stirred at 75 ° C., a stable suspension with an average Particle size of 0.12μπι received.

Example 12

100 g of stearyl methacrylate and 1 g of p-vinylbenzenesulfonic acid were added to 500 g of IP solvent. To

1 g of AIBN was added and the mixture was stirred at 75 ° C. for 3 h. To a 100 g portion of the reaction mixture

there were 50 g of methyl methacrylate, 5 g of hydroxypropyl acrylate, 300 g of IP solvent and 1.0 g of benzoyl peroxide (BPO) added. The mixture was polymerized for 5 h at 85 ° C., a suspension with a average particle size of 0.09 μπτι received.

Example 13

A mixture of 50 g of 2-ethylhexyl acrylate, 5 g of p-nitrostyrene, 0.5 g of AIBN and 100 g of IP solvent was stirred at 75 ° C. for 3 h. To the reaction mixture were added 30 g of styrene, 60 g of methyl methacrylate, 8 g of hydroxyethyl methacrylate and 1.5 g of BPO. The mixture was stirred for 4 h at 90 ⁰ C, to obtain a SusperMon having an average particle size of 030 μπι.

Example 14

A 1-1 flask equipped with a stirrer, thermometer and nitrogen inlet was charged with 500 g of IP solvent, 170 g of stearyl methacrylate and 30 g of dimethylaminoethyl methacrylate. The mixture was stirred for 30 min under a stream of nitrogen at 75 ° C. After addition of 1 g of AIBN as a polymerization initiator, the mixture was allowed to polymerize on a water bath at 75 ° C. for 3 hours to obtain a solution of a soluble polymer submitted -1-flask and with 300 g of IP solvent diluted to the diluted solution was added dropwise under heating on a water bath at 70 ⁰ C through the dropping funnel over the course of 3 hours a mixture of 90 g of methyl methacrylate, 10 g of acrylic acid (these are a monomer and a comonomer to form an insoluble polymer) and 1 g of AIBN are added. The polymerization mixture was heated for a further 3 h under a stream of nitrogen and then cooled to room temperature. The reaction mixture was a white suspension which contained a composite resin as a disperse phase with an average particle size of 0.2 μm and which had very good dispersion stability. A solution of 5 g of yellow dye (C. 1.11 020) in 20 g of xylene was added dropwise to the suspension with stirring. After adding 1 g of dioctyl sulfosuccinate as charge control agent, the suspension was diluted 50 times with IP solvent to give a suspension developer which was negatively charged and retained the desired dispersion stability and charge stability even after prolonged use.

Example 15

65

The procedure of Example 14 was repeated except that 40 g of styrene, 30 g of methyl methacrylate, 20 g n-Butyl acrylate and 10 g of methacrylic acid were used in making the second polymer. the Results are the same as those in Example 14.

Example 16

The procedure of Example 14 was repeated, except that 90 g of vinyl acetate, 5 g of methyl acrylate and 5 g were used Acrylic acid were used to make the second polymer. The results are the same as in Example 14.

Example 17

A solution of a soluble polymer was prepared as in Example 2, except that 100 g of lauryl methacrylate and 10 g of N-vinylpyrrolidone were used in the preparation of the; first polymers were used. The results are essentially the same as in Example 16. For comparison, a developer containing no N-vinylpyrrolidone was used The developer contained a large number of coarse particles with a particle size of 1 µm o-ier more and over time a large amount of sediment settled.

Example 18

The procedure of Example 15 was repeated except that 80 g of lauryl methacrylate, 10 g of N-vinyl pyrrolidone and 10 g of diethylaminoethyl methacrylate were used in the preparation of the first polymer.

Example IS

The procedure of Example 14 was repeated except that 60 g of ethyl methacrylate, 30 g of glycidyl methacrylate and 10 g of itaconic acid were used in the preparation of the second polymer.

Example 20

The procedure of Example 14 was repeated, but using the second polymer as in Example 19 and the first polymer was formed from 100 g of laui-yl methacrylate and 15 g of 4-vinylpyridine.

■ i Example 21 30 f |

The procedure of Example 15 was repeated except that the first polymer was composed of 10 g of methyl vinyl ether,> W

70 g of lauryl acrylate and 20 g of dimethylaminoethyl methacrylate was prepared. | ;;

Example! 22 35 fi

Into a 1-1 flask equipped with a stirrer, thermometer, and nitrogen inlet,? I;

100 g stearyl methacrylate 10 g methoxypolyethylene glycol methacrylate V,

Γ CHj Ί 40 ^:

10 g of dimethylaminoethyl methacrylate, 3 g of acrylamide and 1.8 g of AIBN were initially taken. 500 g of IP solvent were added and the mixture was stirred at 75 ° C. for 5 h. 50 g of methyl methacrylate, 35 g of styrene and 10 g of hydroxyethyl methacrylate were added to 100 g of the resulting solution , 10 g acrylic acid and 1.0 g AlBN added. The mixture was stirred for 5 h at 75 ° C., a stable suspension with an average particle size of 03 µm was obtained. A solution of 8 g of a black dye was added dropwise to the stirred suspension (C. 1.26 150) in 60 g of xylene. After adding 1.5 g of lecithin as a charge control agent, the suspension became like this diluted with IP solvent to a solids content of 0.9%, using a suspension developer received. This suspension developer was negatively charged and showed the desired dispersion stability.

Example 23

In a 1-1 flask equipped with a stirrer, thermometer and nitrogen inlet, 500 g of IP solvent, 100 g of lauryl methacrylate, 5 g of methacrylic acid and 1 g of BPO were initially charged as the polymerization initiator. The mixture was obtained by heating on a water bath at 85 ° C for 5 hours polymerized in a polymer solution. A 100 g portion of the polymer solution was placed in a 1-1 flask supplied with a stirrer, a thermometer, a dropping funnel and a nitrogen inlet was provided and diluted with 300 g of IP solvent. Add to the diluted solution kept on a water bath at 70 ° C was, liX) g of vinyl acetate, 10 g of N-vinylpyrrolidone were through the dropping funnel over a period of 3 h (An insoluble copolymer is formed from this monomer and comonomer) and I g of AIBN are added dropwise as a polymerization initiator. The mixture was heated for an additional 3 hours under a nitrogen atmosphere and then cooled to room temperature to obtain a white suspension excellent in dispersion stability. To the stirred suspension was added dropwise a solution of 5 g of a black Dye (C.I. 26 150) added to 20 g of xylene. After adding 1 g of aluminum stearate as a charge control agent the suspension was diluted 50 times with IP solvent, using a suspension developer,

which was positively charged and exhibited good dispersion stability was obtained as This suspension developer was for use in processing a zinc oxide coated electrophotographic offset plate suitable. It showed excellent fixability, high image density and no foaming even when long-term use as a developer. Of the nitrogen-containing heterocyclic compounds, N-vinyl pyrrolidone was a compound which gave particularly desirable results.

Comparative example 1

A suspension developer was prepared as in Example 23 except that N-vinylpyrrolidone was not used became. This suspension developer showed inferior dispersion stability and charge stability and image density than the suspension developer obtained in Example 23 and tended to stick to the rollers of the To adhere developing device.

Example 24

To 500 g of a 10% solution of a lauryl methacrylate-methacrylic acid copolymer, prepared as in Example 23, there were 200 g of IP solvent, 100 g of vinyl acetate, 10 g of acrylonitrile and 10 g of 4-vinylpyridine as well Given 1.5 g of AIBN. The mixture was then stirred at 75 ° C. in a nitrogen atmosphere for 5 h the mixture was treated as in Example 23. The same results as in Example 23 were obtained.

Example 25

The procedure of Example 24 was repeated, but using 1-vinyl-2-methylimidazole instead of 4-vinylpyridine was used. A stable suspension which was the same as that obtained in Example 24 was obtained.

Example 26

The procedure of Example 23 was repeated, but using 2-ethylhexyl methacrylate instead of lauryl methacrylate was used. The same results as in Example 23 were obtained.

Examples 27-30

In the same way as in Example 24, 100 g of vinyl acetate, 10 g of n-butyl acetate, 20 g of a nitrogen-containing heterocyclic compound shown in Table II below, 2iD0 g of IP solvent and 1.5 g AIBN added to 500 g of a 10% solution of a lauryl methacrylate-methacrylic acid copolymer, and the The resulting mixture was heated to 75 ° C. for 6 h. A suspension developer according to the invention was obtained by adding 2 g of Victoria blue (C 1.44 045), dissolved in methanol as a colorant, and 1 g of the aluminum salt of rosin as a charge control substance for the aforementioned suspension. The results obtained were the same as in Example 24.

Table II

Example No. Heterocyclic Compound

27 1-vinyl pyrrole

28 N-vinyl pyrrolidone

29 N-vinylimidazole

30 2-vinylquinoline

see Examples 31 to 33

The procedure of Example 23 was repeated, but instead of the lauryl methacrylate-methacrylic acid copolymer a lauryl methacrylate-acrylic acid (92: 8 by weight) copolymer, stearyl acrylate-acrylic acid (90:10 by weight) copolymer or lauryl methacrylate maleic acid (94: 6 by weight) Weight based) copolymer was used. The results were the same as in Example 23.

Example 34

The procedure of Example 23 was repeated, but using a vinyl acetate-N-vinylpyrrolidone-n-butyl acrylate-dimethylaminoethyl acrylate as the second polymer (60: 10: 20: 10 by weight) interpolymer was used. The results were the same as in Example 23.

Example 35

In a 1-liter flask equipped with a stirrer, thermometer, and nitrogen inlet, 500 g of IP solvent, 100 g of lauryl methacrylate and 5 g of methacrylic acid and 1 g of BPO were added given as a polymerization initiator. The mixture was left on a water bath at 85 ° C for 5 hours to give a ^

Polymer solution polymerizes. A 100 g portion of the Pol> .ner solution was in one with a stirrer, one

Thermometer, a dropping funnel and a nitrogen inlet equipped 1-iK.oIben and diluted with 300 g of IP solvent. To the diluted solution, which was kept at 70 ⁰ C on a water bath, were added dropwise through the dropping funnel over a period of 3 hours a mixture of 10 g of methyl methacrylate, 75 g of n-butyl methacrylate, 10 g of dimethylaminoethyl methacrylate, 3 g of N-vinylpyrrolidone ( these four monomers were used to obtain an insoluble interpolymer) and 1 g of AIBN was added as a polymerization initiator. The mixture was heated for a further 3 hours under a nitrogen atmosphere and then cooled to room temperature to obtain a white suspension which contained the composite resin as a disperse phase and was excellent in dispersion stability. A solution of 5 g of yellow dye (C. 1.11 020) in 20 g of xylene was added dropwise to the stirred suspension. After adding 1 g of aluminum stearate as a charge control substance, the suspension was diluted 50 times with IP solvent! diluted to give a suspension developer which was positively charged and had good dispersion stability. This suspension developer was suitable for processing an offset electrophotographic printing plate coated with zinc oxide

It had very good fixability and showed high image density even with long-term development no foaming occurred.

Comparative example 2

A suspension developer was prepared as in Example 35 except that no vinyl pyrridone was used Compared to the suspension developer prepared according to Example 35, the one thus obtained was Suspension developer inferior in both charge stability and image density.

Example 36

To 500 g of a 10% solution of a lauryl methacrylate-methacrylic acid copolymer, prepared according to Example 35, 200 g of IP solvent, 40 g of styrene, 30 g of methyl methacrylate, 25 g of n-butyl acrylate, 10 g Dimethylamineethyl methacrylate, 5 g of N-vinylpyrrolidone and 1.5 g of AIBN are added. The mixture was taking for 5 h stirred in a nitrogen atmosphere at 75 ° C. The mixture was then stirred in the same manner as in Example The obtained results were the same as in Example 35. The obtained suspension developer exhibited high etch resistance to alkali solutions, such as those used in the manufacture of lithographic Printing forms in the etching treatment of the photoconductive layer containing an organic photoconductive layer Material, used on.

Example 37

The procedure of Example 36 was repeated with the exception that instead of N-vinylpyrrolidop N-vinylpiperidone was used. The results were the same as in Example 36.

Example 38

The procedure of Example 35 was repeated, but instead of using dimethylaminoethyl methacrylate N-vinyl pyridine was used. The results were the same as in Example 35.

Example 39

The procedure of Example 35 was repeated, but using 2-ethylhexyl methacrylate instead of lauryl methacrylate was used. The results were the same as in Example 35.

Example 40

The procedure of Example 36 was repeated, but instead of Oil Yellow GG-S 2 g of Victoria Blue (methanolic solution) were used and instead of aluminum stearate 1 g of rosin aluminum salt. The results obtained were the same as in Example 36.

Examples 41 to 45

The procedure of Example 36 was repeated except that the following compounds were substituted of the basic nitrogen-containing compound were used. The results are the same as in Example 36.

Dimethylaminoethyl acrylate

Diethylaminoethyl methacrylate

N-vinyl pyrrole

N-vinylimidazole

N-vinyl pyridine

Claims (1)

Patent claims: 1. A method for producing an electrophotographic suspension developer contained in a Hydrocarbon carrier liquid with high insulation resistance dispersed resin particles composed of two are built up different polymers, characterized in that in the presence of a first polymer with polar functional groups dissolved in the carrier liquid with a monomer polar functional groups with the formation of a second in the carrier liquid essentially insoluble polymer polymerizes, being due to the interaction between the functional groups the first polymer is adsorbed on the surface of the second polymer and a protective adsorption 10 layer forms