DE3226175A1 - ELECTROSTATOGRAPHIC TONER MATERIAL - Google Patents

Description

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DESCRIPTION

The invention relates to an electrostatographic toner material, in particular an electrostatographic toner material which can be fixed by pressure and which contains encapsulated toner particles.
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In the known electrostatography, an electrostatic latent sound image, which is on a photoconductive or dielectric surface is present, with a toner material containing a dye and a fixing agent developed to form a visible tone image. The visible toner image becomes sluggish on the surface of a like on a sheet of paper, and fixed there.

The latent image is developed to form the visible toner image by means of a developing agent carried out containing a mixture of a toner material with carrier particles, or using a developing agent, which only contains the toner material. The development process, in which the mixture of toner material with Carrier material is used is called "two-component development process" designated. The development process in which only the toner material is used is called "one-component development process" designated.

The toner image formed on the latent image is then transferred to the surface of a carrier medium and fixed thereon. The method for fixing the toner image on the carrier medium can be according to one of three fixing methods be carried out, i.e. a heat setting process (melting process) , a solvent fixing method and a pressure fixing method.

In the pressure fixing method, the toner material is fixed on the surface of the support medium with the application of a pressure, and it is described, for example, in US Pat 3,269,626. In the pressure fixing method, neither a heating process nor solvents are used, and thus the difficulties that the Fixing method in the heat and the solvent fixing method are inherent. Furthermore, the pressure fixing method can be used in high speed copying and duplicating processes can be performed, and the start-up time is shortened in the pressure fixing process. Accordingly that is Pressure fixing method is a preferred fixing method because of it a number of preferred features are inherent.

However, the pressure fixing process also has some un-

desired features. For example, the pressure fixing method is obtained generally inferior fixation than the heat fixing method, whereby the toner image, which is fixed on a paper, can be rubbed off easily. The pressure fixing method requires a very high one Pressure for the fixation, and such a high pressure causes the cellulose fibers of the carrier medium, such as paper, to break. Furthermore, a gloss is generated on the surface of the carrier medium. In addition, the pressure rollers must have a, relative have a large size, since the rollers give the toner image on the carrier medium a very high pressure. Accordingly can reduce the size of the copier and duplicator do not exceed a certain limit, which is determined by the size of the pressure rollers.

One has already had an encapsulated toner material in the past proposed which contains toner particles enclosed in microcapsules. As a result, the * Disadvantages of the pressure fixing method described above eliminated will. The encapsulated toner material "is produced by removing core particles (which form the dye, such as soot,

hold) wrapped in wrappings that break when pressure is applied. The encapsulated toner material thus produced has several preferred features. For example, requires fixing the encapsulated toner material does not use high pressure, and fixation is excellent. Accordingly, the encapsulated toner material becomes as suitable for use in a pressure fixing process viewed. However, the encapsulated toner material proposed up to now appears in practical use not suitable as it does not have all the properties required for a smooth copying and duplicating process are required, and since there is not very good toner image fixation and quality results in *.

More specifically, it is a toner material which is used as a dry developing agent in electrostatography required that it had excellent powder properties (or powder flow properties) so that a high development quality is obtained, and that does not stain the surface of the photosensitive material on which the latent image is formed. The expression "Powder properties" means in particular the resistance to agglomeration and blocking of the toner particles. In the process for the manufacture of the encapsulated toner material, the toner material is generally from separated from the alumina dispersion and according to a spray drying process dried. The encapsulated toner material known to date either agglomerates during spray drying or when storing after spray drying. The thus agglomerated toner material deteriorates the resolution of the on the electrostatographic latent image formed visible toner image, whereby the sharpness of the visible toner image, which is fixed on the carrier medium is significantly deteriorated.

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It is also necessary that the toner material, which is used for the two-component development process, the surfaces of the carrier particles will not be stained. The toner material used as a developing agent in a Pressure fixing method used should continue to be satisfactory be under pressure during fixation and should not peel off the surface of the pressure roller, i.e. the Show the appearance of the toner on the roller surface sticks and stains them.

The encapsulated toner materials known to date are at least one of these requirements that for developing agents and those for the pressure fixing process used is not satisfactory.

It is therefore an object of the present invention to provide an electrostatographic toner material pose that does not have the disadvantages mentioned above.

According to the invention, an encapsulated toner material is to be made available which can be used in a pressure fixing process can be used and does not have the disadvantages described above.

According to the invention, an encapsulated toner material is intended for Are made available that in a pressure fusing process can be used and its powder properties are significantly improved.

According to the present invention, an encapsulated toner material having an improved pressure fixing ability in addition to the improved one is intended Powder properties are made available.

According to the invention, an encapsulated toner material is intended for Can be provided which have improved resistance to settling in addition to improved powder properties and has improved pressure fixability.

J-; rfandunr.qeinüß should be provided to cm (angckapnoltor, Tonorniator i al, which is resistant to breakage prior to the application of pressure in the pressure fixing process, while it is easily broken in the pressure fixing process.

According to the invention, a method for the production of the electrostatographic toner material, which the has the advantageous properties described above, to provide.

The invention relates to an electrostatographic toner material, which is encapsulated toner particles having an average particle size in the range of about 0.5 to about 1000 µm, wherein the toner particles comprise a pressure fixable adhesive core material containing a dye, and a pressure-destructible envelope, the envelope enclosing the core material and the envelope consists of a double layer that has a polyurethane, polyurea and / or polythiourethane layer and comprises a polyamide layer.

In the present invention, the term "polyurethane, polyurea and / or polythiourethane" means a polymer which has been produced by a polymerization reaction between a polyisocyanate and / or a polythioisocyanate and one or more of the counter compounds such as polyol, polythiol, water, polyamine and piperazine is. The term "polyurethane" therefore means either a simple polyurethane which essentially contains only urethane bonds, or a polymer which contains urethane bonds and a relatively small number of urea and / or thiourea bonds. The term "polyurea" means either a simple ^fc polyurea, containing substantially only urea bonds, or a polymer which urea bonds and a relatively small number of urethane and / or thio

contains urethane bonds. In the same way, the term "polythiourethane" means either a simple polythiourethane, which essentially only contains thiourethane bonds, or a polymer which contains thiourethane bonds and contains a relatively small number of urethane and / or urea bonds.

The electrostatographic toner material of the present invention is preferably made according to a process in which very small droplets of the pressure fixable adhesive Core material, which contains a dye dispersed in an aqueous medium, with the envelope which can be destroyed by pressure encapsulated with a double layer. The envelope contains a polyurethane, polyurea and / or polythiourethane layer and a polyamide layer. According to the invention, the encapsulated particles are produced in this way, and then the encapsulated particles are separated from the aqueous medium and dry toner materials are produced.

The encapsulation of the droplets from the core material with the The coating material is preferably made according to the interfacial polymerisation process, as in Japanese Patent Publications 38 (1963) r19 574, 42 (1967) -446 and 42 (1967) -771 and GB-PSs 989 '264, 95O 443, 867/797, I'd 069 140 and 1,046, although certain modifications can be made. For example, the encapsulation takes place preferably as follows:

In a hydrophobic liquid that contains the core materials, such as the dye, a pressure-fixable adhesive material (binder) and optionally magnetizable particles, contains, an acid chloride (substance A) and a polyisocyanate (substance B) are dissolved. This solution is then in one aqueous medium containing a polyamide or piperazine (substance C) and a dispersant, with formation

fine droplets of the core material with an average diameter in the range of
dispersed in the aqueous medium.

chen diameter in the range of about 0.5 to about 1000 µm in

The dispersion prepared as above is then neutralized or made weakly alkaline by adding an alkaline substance made what the formation of a polyamide resin envelope (the polyamide is essentially the reaction product of the acid chloride with the polyamine) around the hydrophobic droplets. The dispersion is then brought to a temperature heated between 40 and 90 C, with a coating made of the polyurea resin (the polyurea is essentially the reaction product of the polyisocyanate and the polyamine) on the inner surface of the polyamide resin envelope is formed. This gives a double layer around the hydrophobic droplets made of core material, the outer layer being in the consists essentially of polyamide and the inner layer consists essentially of polyurea. So are the encapsulated Particles made.

If a polyol (substance D) is further added to the above hydrophobic liquid, it becomes hydrophobic Droplets of core material create a double-layer envelope in which the outer layer is essentially made of polyamide and the inner layer consists essentially of polyurethane (the reaction product of a polyisocyanate with polyol).

Alternatively, if the polyisocyanate (substance B) is replaced by a polyisothiocyanate (substance E) and a polyol (Substance D) · is added to the hydrophobic liquid, a coating is formed around the droplets of hydrophobic core material produced from a double layer, the outer layer being essentially made of polyamide and the inner layer being made of consists essentially of polythiourethane (the reaction product of a polyisothiocyanate with polyol).

In the latter two methods, the inner layer, which consists of a mixture of polyurethane and polyurea or a mixture of polythiourethane and polyurea, can be prepared when adding the polyamine to the reaction system is added in an amount that exceeds the amount required to cope with the added Acid chloride to react.

The envelope of the particles thus formed is, as described above, a two-layer envelope. The term "double layer wrapping" is not intended comprise only one envelope in which the two layers are completely separated by a simple interface, but it also comprises a casing, one side of which, in particular the outside of the casing, mainly from one polyamide and the other side, especially the inside, of the envelope mainly from another Polymer or other polymers such as polyurethane, polyurea, polythiourethane or a mixture of two or three of these polymers.

Examples of substances A, B, C, D and E are as follows:

Examples of substance A (acid chloride) are adipoyl chloride, Sebacyl chloride, phthalyl chloride, isophthaloyl chloride, Terephthalyl chloride, fumaryl chloride, 1,4-cyclohexanedicarbony chloride, 4,4'-biphenyldicarbonychloride, 4,4'-sulfonyldibenzoyl chloride. Phosgene, polyesters that contain acid chloride groups, and polyamides that contain acid chloride groups contain.

The acid chloride of substance A can be replaced by a dicarboxylic acid or its acid anhydride. Examples of dicarboxylic acids are adipic acid, sebacic acid, phthalic acid, terephthalic acid, fumaric acid, 1,4-cyclohexanedicarboxylic acid and 4,4 '■ Biphenyl dicarboxylic acid. An example of acid anhydrides is Phthalic anhydride.

Examples of substance B (a polyisocyanate which contains at least two isocyanate groups) are m-phenylene diisocyanate, p-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene * - 1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylene-1,4-diisocyanate, Xylylene-1,3-diisocyanate, 4,4 ■ -diphenylpropane diisocyanate, Trimethylene diisocyanate, hexamethylene diisocyanate, Propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, Ethylidene diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, 4,4 ", 4" -triphenylmethane triisocyanate, toluene-2,4,6-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate, hexamethylene diisocyanate-hexanetriol adduct, 2,4-tolylene diisocyanate catechol adduct, tolylene diisocyanate trimethylolpropane adduct and xylylene diisocyanate trimethylol propane adduct.

Examples of substance C (polyamine or piperazine) are ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, Hexamethylenediamine, p-phenylenediamine, m-phenylenediamine, 2-hydroxytrimethylenediamine, diethylenetriamine, Triethylenetetraamine, diethylaminopropylamine, tetraethylene pentaamine, Epoxy compound-amino compound adduct, piperazine, 2-methylpiperazine and 2,5-dimethylpiperazine.

Examples of substance D (polyol) are water, ethylene glycol, 1,4-butanediol, catechol, resorcinol, hydroquinone, 1,2-dihydroxy-4-methylbenzene, 1,3-dihydroxy-5-methylbenzene, 3,4-dihydroxy-1-methylbenzene, 3,5-dihydroxy-i-methylbenzene, 2,4-dihydroxy-1-ethylbenzene, 1,3-naphthalenediol, 1,5-naphthalenediol, 2,3-naphthalenediol, 2,7-naphthalenediol, ο, ο'-biphenol, ρ, ρ'-biphenol, 1,1'-bi-2-naphthol, bisphenol A, 2,2'-bis (4-hydroxyphenyl) butane, 2,2'-bis (4-hydroxyphenyl) isopentane, 1,1'-bis (4-hydroxyphenyl) -cyclopentane, 1,1'-bis (4-hydroxyphenyl) -cyclohexane, 2,2'-bis (4-hydroxy-3-methy! phenyl) -pro-

pan, bis (2-hydroxyphenyl) methane, xylylene diol, ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-heptanediol, 1,7-heptanediol _f 1,8-octanediol , Trimethylolpropane, hexanetriol, pentaerythritol, glycerin and sorbitol. 5

Examples of substance E (polyisothiocyanate) are tetramethylene diisothiocyanate, Hexamethylene diisothiocyanate, p-phenylene diisothiocyanate, xylylene-1,4-diisothiocyanate and ethylidyne diisothiocyanate.

In the preparation of the dispersion from very small hydrophobic droplets, which are the substances for the formation of the Containing cladding and the core material is preferred as the hydrophobic liquid used for dispersion one used which contains a low-boiling solvent or a polar solvent. These solvents serve to accelerate the formation of the envelope.

Examples of these solvents are methyl alcohol, ethyl alcohol, Dietary ether, tetrahydrofuran, dioxane, methyl acetate, Ethyl acetate, acetone, methyla thy iceton, methyl isobutyl ketone, Cyclohexanone, n-pentane, η-hexane, benzene, petroleum ether, chloroform, Carbon tetrachloride, methylene chloride, ethylene chloride, Carbon disulfide and dimethylformamide.

Other features of the interfacial polymerization process and other methods for making microcapsules containing an oily liquid are disclosed in U.S. Patent 2 726 804, to which expressis verbis reference is made.

The core material of the present invention contains a dye for the formation of a visible image on the latent Image. The dye is generally a dye or pigment, but any other agent may be used does not give a direct visible image as a fluorescent substance may be used as a dye. 20th

The dye is generally selected from a variety of dyes, pigments and similar compounds, the general electrostatographic copying and

Diversification methods can be used. In general is the dye is a carbon toner or a chromatic one Toner. Examples of carbon toners include carbon black (carbon black). Examples of chromatic toners are blue dyes such as copper phthalocyanine and sulfonamide type dyes, yellow dyes, such as benzidine derivative dyes, e.g., diazo yellow, and red dyes, "such as Rhodamine B Lake, which is a double salt of a xanthine dye with phosphotungstate and molybdate, carmine 6B, which belongs to the azo pigments, and a quinacridone derivative.

The core material according to the invention also contains a binder, to keep the dye inside the core and fix the dye on the surface of the carrier term ™ diums like paper. The binder is generally selected from high-boiling liquids, the usually for the fine dispersion of oil-soluble photographic additives within an aqueous medium and are known to incorporate the additive in the silver halide color photosensitive material incorporate and / or selected from polymers suggested for use as binders .; for pressure fixable encapsulated toner materials can be used.

Examples of high-boiling liquids are the following compounds, which have a boiling point above 180 ° C:

(1) Phthalic acid ester

Dibutyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctyl phthalate, Dinonyl phthalate, dodecyl phthalate, butyl phthalyl butyl glycolate, dibutyl monofluorophthalate;

(2) phosphoric acid ester

Tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, tributy! phosphate, trlhexy! phosphate, trioctylphosphate

phate, trinonyl phosphate, tridecyl phosphate, trioleyl phosphate, Tris (butoxyethyl) phosphate, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate;

(3) citric acid ester

O-acetyl triethyl citrate, O-acetyl tributyl citrate, O-acetyl trihexyl citrate, O-Acetyltrioctylcitrate, O-Acetyltrinonyleitrat, O-Acetyltridecylcitrate, Triäthyleitrat, Tributyleitrat, Trihexylcitrat, Trioctyl citrate, trinonyl citrate, tridecyl citrate;

(4) benzoic acid ester

Butyl benzoate, hexyl benzoate, heptyl benzoate, octyl benzoate, nonyl benzoate, Decyl benzoate, dodecyl benzoate, tridecyl benzoate, te tradecyl benzoate, hexadecyl benzoate, octadecyl benzoate, oleyl benzoate, Pentyl o-itiethyl benzoate, decyl p-methyl ±> enzoate, octyl o-chlorobenzoate, Lauryl p-chlorobenzoate, propyl 2,4-dichlorobenzoate, Octyl 2,4-dichlorobenzoate, stearyl 2,4-dichlorobenzoate, Oley1-2,4-dichlorobenzoate, octyl p-methoxybenzoate;

(5) aliphatic acid esters

Hexadecyl myristate, dibutoxyethyl succinate, dioctyl adipate, dioctyl azelate, Decamethylene-1,10-diol diacetate, triacetin, tributin, Benzyl capirate, pentaerythritol tetracaproate, isosorbitol dicaprilate;

(6) Alkyinaphthalenes

Methylnaphthalene, dimethylnaphthalene, trimethylnaphthalene, Tetramethylnaphthalene, A'thy In aph thai in, Diethylnaphthalin, Triethylnaphthalene, monoisopropylnaphthalene, diisopropylnaphthalene, Tetraisopropylnaphthalene, monomethylethylnaphthalene, Isooctylnaphthalene;

(7) dialkyl phenyl ether

Di-o-methylphenyl ether, di-m-methyldiphenyl ether, di-p-methylphenyl ether;

(8) fatty acid and aromatic sulfonic acid amides Ν, Ν-dimethyllauroamide, Ν, Ν-diethylcaprylamide, N-butylbenzenesulfonamide ;.

(9) trimellitic acid ester
Trioctyl trimellitate; and

(10) diarylalkanes

Diarylmethanes, e.g. dimethylphenylphenylmethane, diarylethanes, e.g. 1-methylphenol-i-phenylethane, 1 -dimethy lph'eny 1-1 -phenylethane, 1-ethylphenyl-i-phenylethane.

The high boiling liquids given above and examples of other high boiling liquids used in the present Invention can be used are described in detail in the following publications:

Japanese Patent Publications 46 (1971) -23,233 and 49 (1974) -29,461, Japanese Unexamined Patent Publications 47 (1972) -1 031, 5O (1975) -62 632, 5O (1975) -82 078, 51 (1976) -26 035, 51 (1976) -26 036, 51 (1976) -26 037, 51 (1976) -27 921 and 51 (1976) -27 922, U.S. Patents 2,322,027, 2,353,262,

2,533,514, 2,835,579, 2,852,383, 3,287,134, 3,554,755,

3 676 137, 3 676 142, 3 700 454, 3 748 141, 3 837 863 and 3,936,303, British patents 958,441, 1,222,753,

1 346 364 and 1 389 674 and German Offenlegungsschrift

2,538,889.

For the purposes of the present invention, the high-boiling liquid is preferred among phthalic acid esters and phosphoric acid esters and alkyl naphthalenes.

Examples of polymers include the following polymers:

Polyolefins, olefin copolymers, polystyrene, styrene-butadiene copolymers, Epoxy resins, polyesters, natural and

synthetic rubbers, polyvinylpyrolidone, polyanude, coumarone indene copolymers, Methyl vinyl ether maleic anhydride copolymer, maleic acid modified phenolic resin, phenol modified Terpene resin, silicone resins, epoxy-modified phenolic resin, amino resins, polyurethane elastomers, polyurea elastomers, Homopolymers and copolymers of acrylic acid esters, homopolymers and copolymers of Methacrylic acid ester, acrylic acid long-chain alkyl methacrylate copolymer oligomers, Poly (vinyl acetate) and poly (vinyl chloride).

The polymers listed above and examples of others Polymers which can be used in the present invention are described in detail in the following publications described:

Japanese Patent Publication 48 (1973) -3O 499, 49 (1974) -1 588 and 54 (1979) -8 104, Japanese laid-open publications 48 (1973) -75 032, 48 (1973) -78 931, 49 (1973) -17 739, 51 (1976) -132 838, 52 (1977) -98 531, 52 (1977) -1O8 134, 52 (1977) -119 937, 53 (1978) -! 028, 53 (1978) -36 243, 53 (1978) -118 049, 55 (198O) -89,854 and 55 (198O) -166,655 and U.S. patents 3 788 994 and 3 893 933.

The core material can also contain other agents, such as mold release agents, and contain magnetizable particles.

The mold release agents or lubricants are used to avoid that becomes that the broken shell and the released core material adhere to the surface of the pressure roller. The Entfor-. Lubricant can be selected from those used in the known encapsulated toners in the past were proposed. Examples of mold release agents or lubricants are fluorine-containing resins, which are described in JA-OS'sen 55 (1980) -142 360 and 55 (1980) -142 362 are described will.

The magnetizable particles are contained in the core material, when a magnetizable toner material for the one-component development process should be produced. As magnetizable particles, one can use, for example, those in JA-OS's 53 (1978) -118 053, 53 (1978) -1 028 and 55 (198O) -166 655 are described. Examples of materials for magnetizable particles that are preferred for used in the present invention include metals such as cobalt, iron and nickel, metal alloys or metal composites, the aluminum, cobalt, copper, iron, lead, magnesium, nickel, tin, zinc, gold, silver, antimony, Beryllium, bismuth, cadmium, calcium, manganese, titanium, tungsten, Contains vanadium and / or zirconium. Examples of metal compounds are metal oxides, such as aluminum oxide, iron (III) oxide, Copper (II) oxide, nickel oxide, zinc oxide, zirconium oxide. Titanium oxide and magnesium oxide, refractory metal nitrides, such as chromium nitride, metal carbides such as tungsten carbide and silicon carbide, ferromagnetic ferrites, and their mixtures.

As mentioned above, the process for producing encapsulated toner particles includes the step of being very small Droplets of hydrophobic liquid containing the substance (A) and the core material dispersed in the aqueous medium or emulsified. For the production of a homogeneous dispersion (or emulsion) from the very small droplets of the hydrophobic liquid, it is preferred to use a hydrophilic protective colloid and / or in the reaction liquid incorporate a surface-active emulsifier, which allows the formation of the homogeneous dispersion (or emulsion) from the hydrophobic Facilitate droplets and prevent agglomeration of the hydrophobic droplets thus formed. The hydrophilic Protective colloid and the surface active agent can be used alone or together.

Examples of preferred hydrophilic protective colloids are proteins, such as gelatine, graft polymers of gelatine with other

their polymers, carboxylated gelatin, sulfonylated gelatin, Gelatin containing isocyanate groups, albumin and casein, cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose and cellulose sulfuric acid esters, saccharide derivatives such as sodium alginate and starch derivatives, and a A large number of synthetic hydrophilic homopolymers and copolymers, such as polyvinyl alcohol, some of which are acetalized Polyvinyl alcohol, poly-N-vinylpyrolidon, polyacrylic acid, polyacrylamide, Polyvinyl imidazole and polyvinyl pyrazole.

In the examples given above, the gelatin can be a lime-treated gelatin, an acid-treated gelatin, a hydrolyzed gelatin and an enzymatically decomposed gelatin. The graft polymers made from gelatin and other polymers can be gelatin which carries grafted chains made from homopolymers or copolymers of vinyl monomers such as acrylic acid, methacrylic acid, their derivatives, for example esters and amides, acrylonitrile and Is made of styrene. Examples of gelatin graft polymers are those which are miscible with gelatin, such as gelatin, the graft chains, which are made from polymers of acrylic acid, methacrylic acid, acrylamide, methacrylamide and hydroxyalkyl methacrylate exist, wear.

Details of these preferred gelatin graft polymers are disclosed in U.S. Patents 2,763,625, 2,831,767, and 2,956,884 described.

Representative examples of synthetic hydrophilic polymers are given, for example, in DE-OS 2,312,708, the US patents 3,620,751 and 3,879,205 and JA-PS 43 (1978) -7,561.

The surfactants for dispersion or emulsification the hydrophobic liquid in the hydrophilic liquid medium can either be in the hydrophobic liquid or be incorporated into the hydrophilic liquid medium or both.

Examples of surfactants are nonionic surfactants such as saponin (steroid type), Alkyl oxide derivatives, such as polyethylene glycol, polyethylene glycol / polypropylene glycol condensation products, Alky1- or alkylaryl ethers of polyethylene glycol, polyethylene glycol ester, Polyethylene glycol sorbitol esters, alkylamines or amides of polyalkylene glycol, polyethylene oxide adducts of silicone polymers, Glycidol derivatives such as polyglyceride kenyl succinate and alkylphenol polyglyceride, fatty acid esters of polyvalent ones Alcohols, alkyls of saccharide, urethanes and ethers; and anionic surfactants with acid groups, such as carboxy, sulfo, phospho, sulfate ester and phosphate ester groups, for example saponin of the triterpenoid type, alkylcarboxylic acid salts, alkylsulfonic acid salts, alkylbenzenesulfonic acid salt, Alkylnaphthalenesulfonic acid salts, alkyl sulfate esters, alkyl phosphate esters, N-acyl-W-alkyltaurines, sulfosuccinic acid esters, suI-foalkylpolyaxyethylene alkylphenyl ethers and polyoxyethylene alkyl phosphate esters.

Particularly preferred surfactants are anionic surfactants belonging to the sulfonic acid type and the sulfate ester type, namely compounds having in their molecular structure both hydrophobic groups containing 8 to 30 carbon atoms and hydrophilic groups of -SO ₃ M or .- OSO ₃ M (where M is Na or K). The preferred anionic surfactants are of the types mentioned above and are described in detail in "Surface Active Agents" (AW Perry, Interscience Publication Inc., New York).

Representative examples of preferred anionic surfactants Means are the following: sodium dodecyl sulfate, Sodium tetradecyl sulfate, Turkish red oil, Sodium dodecylcarboxyamidoethyl sulfate, sodium dodecyl sulfonate, sodium tefcradecyl sulfonate, sodium polyoxyethylene octylphenyl ether sulfonate, Sodium salt of dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium tetradecylamidophenylsulfonate and sodium triisopropyl naphthalene sulfonate.

The dispersion or emulsification of the reaction liquid can be carried out by a known homogenizing means such as one which belongs to the agitation type ,, the high pressure injection type, the ultrasonic vibration type and the kneading-type, "Particularly preferred homogenizers are a colloid mill, a known and conventional homogenising device, and a Electromagnetic distortion type ultrasonic homogenizer.

The encapsulated toner is then formed, for example, by subjecting the emulsified reaction liquid in the presence of a suitable catalyst as previously described Formation of shells around the core droplets is heated. Thereafter, the encapsulated toner is separated from the aqueous reaction medium and dried to form a dry encapsulated toner. The encapsulated toner is preferred washed with water after separation from the aqueous reaction medium and before drying. The drying process can by a process known per se, such as the spray drying process or the freeze-drying process. The spray-drying process is preferred.

The dry encapsulated toner thus formed can be mixed with a Insulating material and / or a charge control agent such as a metal-containing dye or a nigrosine dye, to be mixed »

The dry encapsulated toner can be mixed with a flow lubricant, such as a hydrophobic silica powder so that the flow lubricant spreads on the surface of the encapsulated toner. The encapsulated toner with the flow lubricant, such as a hydrophobic silica powder, on the toner surface shows a particularly improved powder quality and property. and is therefore at the very suitable for practical use.

The encapsulated toner obtained as described above can be used in the electrostatographic copying and duplicating machines are given to develop electrostatographically formed latent images so that a visible toner image is formed on the surface of the photoconductive material. The visible image will then fixed on a carrier medium such as paper by means of a suitable pressure fixing device. Regarding the pressure fixing device there is no particular limitation on fixing the encapsulated toner according to the invention, and any known device can be used in fixing the inventive encapsulated toner can be used. Examples of pressure fixing devices are described, for example, in Japanese Patent Publications 44 (1969) -9880, 44 (1969) -12797 and 46 (1971) -15876 and the JA-OS's 49 (1974) -62 143, 49 (1974) -77 641, 50 (1975) -51 333, 51 (1976) -31 235, 51 (1976) -4O 351, 52 (1977) -15 335, 52 (1977) -1O2 743, 54 (1979) -28,636, 54 (1979) -32,326, 54 (1979) -41,444 and 54 (1979) -48,251.

The electrostatographic toner material comprising the present invention contains encapsulated toner particles, has improved powder properties and is compared to mechanical Shock and abrasion in the developing device of the electrostatographic copier and duplicator resistant. The electrostatographic toner material of the present invention can easily be stored in the pressure fixing device Formation of a visible toner image, which is well fixed on the carrier medium, such as paper, can be broken. That Furthermore, toner material according to the invention hardly sets the pressure rollers, and hardly forms a film on the surfaces the carrier particles, the development loops and the photoconductive material.

The electrostatographic toner material with the double layer envelope, which has an inner polyurethane, polyurethane, fabric and / or polythiourethane layer and an outer polyamide layer according to a preferred embodiment of the invention comprises, shows significantly improved powder properties, i.e. it is practically free from agglomeration., The Powder properties of this toner material can be further improved when you have a flow lubricant such as hydrophobic silica (hydrophobic silica) on the surface separates even in small amounts. It is believed that these remarkable powder properties of the toner material caused by the outer polyamide surface, which easily absorbs water and Releases moisture, and that the flow lubricant is deposited on the surface more effectively and more evenly. The toner material according to the invention shows no "blocking" (sticking) even when it is at high temperature and high Humidity, such as 50 ° C and 90% relative humidity, during one day.

When used in the two-component development process the inventive toner material can be suitably charged so that it has an electrode charge in the area from 10 to 20, uc / g (plus or minus) along with an appropriate one Carrier or with a suitable charge control agent, so that a visible image which is on the The carrier medium is fixed, of high quality, such as high resolution and high sharpness, and with essentially none Veil, is generated. The development properties and the print fixability of the toner material according to the invention remain obtained at an excellent value even if the copying and duplicating process to some extent is repeated.

Even when developed in a one-component development process, the toner material of the present invention possesses

very good developing / pressure fixing properties and resistance to peeling. Will continue on the surfaces of the development loops and the photosensitive Material no film formed. 5

Other features of the electrostatographic copying and duplicating process, in which an encapsulated toner material is used are described in US Pat. No. 3,788,99 4, to which expressis verbis reference is made. 10

The following examples illustrate the invention. In the examples the term "part (s)" means "part (s) by weight".

example 1

Four parts of carbon black (soot) are made with 46 parts of castor oil mixed to form a primary liquid.

25 parts of tolylene diisocyanate-hexanetriol adduct are separated (a 3: 1 molar adduct) and 2 parts of terephthaloyl chloride in 25 parts of ethyl acetate to form mixed with a secondary liquid.

A mixture of the primary liquid and the secondary liquid is 200 parts of a previously cooled aqueous gum arabic solution (10% by weight solution) to form an oil-in-water emulsion which contains oil droplets with an average diameter of 10 to 15 µm contains, dispersed. Ten parts of an aqueous hexainethylene diamine solution. (10 wt% solution) are added to the emulsion. The mixture is stirred for 30 minutes and then the pH is adjusted to 9.0 by adding an aqueous 10% sodium carbonate solution. The mixture is then ^{heated to 70 °} C. for 2 hours with stirring so that the encapsulation reaction takes place completely.

The dispersion containing the encapsulated oily particles is subjected to centrifugal separation at 5000 r.p.m. subject, to separate the encapsulated particles from the aqueous gum arabic solution. The encapsulated so separated Particles are redispersed in 100 ml of water, and the dispersion is dried in a spray dryer, powdery encapsulated toner material being obtained.

The encapsulated toner material obtained as described above consists of a core material, which contains carbon black and castor oil, and a coating with a double Layer in which the outer layer consists essentially of a polyamide (reaction product of terephthaloyl chloride with hexamethylenediamine) and the inner layer essentially consists of polyurea / urethane (reaction product from tolylene diisocyanate-hexanetriol adduct with water). A microscopic examination of the encapsulated toner shows that the bulk of the toner particles are independent of one another is present and that no agglomerated particles, which are present as a mass, have formed.

The encapsulated toner is tested as described below.

The encapsulated toner is made fine with 0.5% by weight of hydrophobic Silica powder mixed well with the silica powder adhering to the surface of the toner. Five parts by weight of the toner treated in this way become more powdery with 95 parts by weight! Iron girders in a shaker mixed to prepare a developing agent. Microscopic examination ensures that the developing agent did not contain any broken toner particles.

A per se known electrostatographic copying and duplicating process is carried out using the above developing agent. The visible toner image formed on a latent image is then transferred to paper. The paper containing the toner image is treated with a press roller at a pressure of 350 kg / cm. A toner image with high sharpness is obtained which is well fixed on the paper. The toner comes off very little. '
10

Example 2

The procedures of Example 1 are repeated except that the aqueous hexamethylenediamine solution (10 wt .-% solution) is added in an amount of 20 parts instead of 10 parts. An encapsulated toner material is obtained, which consists of a core material, which contains carbon black and castor oil, and a coating with a double layer, the outer layer being essentially made of polyamide (reaction product of terephthaloyl chloride with hexamethylenediamine) and the inner layer consists essentially of polyurea (reaction product of tolylene diisocyanate hexanetriol with hexamethylenediamine and water). Microscopic examination of the encapsulated toner shows that the majority of the toner particles are independently present and that no agglomerated particles have formed in bulk.

The testing of the encapsulated toner as a developing agent takes place in the same way as described in Example 1. It was confirmed that there were essentially no destroyed toner particles were observed when mixed with the powdered iron carrier. It was further confirmed that a toner image with sharpness, which is well fixed on the paper, is obtained. The toner comes off a lot low value.

Example 3

The procedures of Example 1 are repeated except that the secondary fluid is replaced by a 25 part solution Tolylene diisocyanate hexanetriol adduct (adduct with a molar ratio of 3: 1), 2 parts of terephthaloyl chloride and 1 part of ethylenediamine-propylene oxide adduct (Adekakadorol, trademark from Asahi Denka Co., Ltd., Japan) in 25 parts of ethyl acetate. An encapsulated toner material is obtained, which consists of a core material, which contains carbon black and castor oil, and a coating with a double layer The outer layer consists essentially of polyamide (reaction product of terephthaloyl chloride with hexamethylenediamine) and the inner layer consists essentially of polyurethane (reaction product of ethylene diisocyanate-hexanetriol adduct with ethylenediamine-propylene oxide adduct). Microscopic examination of the encapsulated toner shows that the majority of the toner particles are independent of each other and that no agglomerated particles are formed in bulk became.

The testing of the encapsulated toner as a developing agent is carried out in the same manner as described in Example 1. It it was confirmed that there were essentially no broken toner particles when mixed with the powdery iron carrier. It was further confirmed that a toner image with sharpness well fixed on the paper was obtained will. There is very little toner leakage.

Example '4

The procedures described in Example 3 are repeated except that 25 parts of the tolylene diisocyanate-hexanetriol adduct be replaced by 22 parts of tolylene diisothiocyanate.

An encapsulated toner material is obtained, which consists of a

a core that contains carbon black and castor oil, and one Covering consists of a double layer, the outer layer being essentially made of polyamide (reaction product made of Terephthaloyl chloride with hexamethylenediamine) and the inner layer Essentially made of polythiourethane (reaction product of tolylene diisothiocyanate with ethylene diamine-propylene oxide adduct) consists. Microscopic examination of the encapsulated toner shows that the majority of the toner particles are independent of each other and that no agglomerated particles have been formed in bulk.

The testing of the encapsulated toner as a developing agent is carried out in the same manner as described in Example 1. It it was confirmed that substantially no destroyed toner particles were formed when mixed with the powdery iron carrier will. It was further confirmed that a toner image having a high sharpness and firmly adhered to the Paper is pinned. There is very little toner leakage.

Claims (12)

PATENT ADVOCATE! AND APPROVED REPRESENTATIVES BEFORE DTM EUROPEAN PATENT OFFICE DR. WALTER KRAUS DIPLOMA CHEMIKER. DR.-I N G. ANN EKÄTE WEISERT DIPL.-! N G. F-AC H Rl CHTUNG CHEMIE RMGARDSTRASSE 15 · D-8OOO MÜNCHEN 71 · TELEPHONE O 8 θ / 7 9 7O 77-7 θ 7O 78 · TELEX Ο5-212156 kpDtd TELEGRAM KRAUSPATENT 33 80 AW / to FUJI PHOTO FILM ., LTD. Minami-Ashigara-shi / Japan Electrostatographic Toner Material. PATENT CLAIMS 1. Electrostatographic toner material, characterized in that it is encapsulated toner particles having an average particle size in the range of about 0.5 to about 1000 µm, the toner particles a pressure-fixable adhesive core material containing a dye, and a pressure-destructible one Shell which encapsulates the core material, wherein the shell consists of a double layer, which is a Polyurethane, polythiourea and / or a polythiourethane layer and a polyamide layer. 2. Electrostatographic toner material according to claim 1, characterized in that the envelope with of the double layer an inner polyurethane, polyurea and / or polythiourea layer and an outer polyamide included. 3. Electrostatographic toner material according to claim 2, characterized in that the inner layer the casing consists essentially of the polymerization reaction product of a polyisocyanate, a polyol and water is made. 4. Electrostatographic toner material according to claim 2, characterized in that the inner layer the shell consists essentially of the polymerization reaction product of a polyisocyanate, a polyol and a Polyamine is made. 5. Electrostatographic toner material according to one of claims 1 to 4, characterized in that that the core material also has magnetizable particles contains. 6. Electrostatographic toner material according to one of claims 1 to 5, characterized in that that the pressure-fixable adhesive core material is a liquid medium which is at a temperature above 180 ° C boils. 7. Electrostatographic toner material according to one of claims 1 to 6, characterized in, that a flow lubricant is provided on the surface of the envelope. 8. Electrostatographic toner material according to claim 7, characterized in that the flow lubricant is a hydrophobic silica powder. 9. A method for making an electrostatographic toner material which encapsulated particles with a contains average particle size in the range from about 0.5 to about 1000 μm, characterized by net that you can get droplets with an average Droplet size ranging from about 0.5 to about 1000 µm one pressure-fixable adhesive core material containing a dye dispersed in an aqueous medium, with a pressure-destructible cover made of a double layer, which consists of a polyurethane, polyurea and / or comprises polythiourethane layer and a polyamide layer, encapsulated, forming the encapsulated particles, and the encapsulated particles from the aqueous medium separating to produce dry toner particles. 10. A method for producing an electrostatographic toner material according to claim 9, characterized in that the envelope with the double Layer comprises an inner polyurethane, polyurea and / or polythiourethane layer and an outer polyamide layer. 11. Method of making an electrostatographic device Toner material according to Claim 10, characterized in that the inner layer of the envelope is essentially from the polymerization reaction product of a polyisocyanate, a polyol and water. 12. A method for producing an electrostatographic toner material according to claim 10, characterized in that the inner layer of the envelope is substantially prepared from the polymerization reaction product of a polyisocyanate, a polyol and a polyamine has been.