DE3336411C2 - Electrostatographic toner material - Google Patents

Description

The invention relates to an electrostatographic toner mat rial and in particular an electrostatic fixable by pressure topographical toner material, which encapsulated toner part chen contains.

In electrostatography it is known to be an electrostat latent toner image on a photoconductive or dielectric surface is present with a toner mat rial, which contains a dye and a fixing agent Develop a visible toner image and that visible toner image on a surface of a carrier medium, like on a sheet of paper, to be transferred and fixed there.

The development of the latent image with the formation of the view The toner image can be created either by using a Developing agent, which is a toner material with a carrier contains particles, or a developing agent, which only contains a toner material. The development process in which the combination of a toner material with carrier particles is used as a "two-component development process ren referred to during the development process in which only one toner material is used as a "one-component Development process "is called.

The toner image formed on the latent image then becomes transfer the surface of a carrier medium and fi xiert. The process in which the toner image on the carrier dium can be fixed using one of three fixing methods done, d. H. a heat setting process (melting process), a solvent fixing method and a pressure fixing method drive.

The pressure fixing process in which the toner material on the Surface of a carrier medium using pressure is fixed on it, for example, in the US-PS  3,269,626. In the pressure fixing method in which neither heated nor a solvent is used no such difficulties that the heat-fixing ver drive or are inherent in the solvent fixation process. The Pressure fixation method can be used at a high speed Copying and duplication processes are used and the access time or dwell time is with the Druckfixierver drive short. Therefore, the pressure fixing method is considered an advantage considered fixing process, which a variety of be preferred properties is inherent.

However, the pressure fixing method also has some Disadvantage. For example, you get with the Druckfixierver generally have a worse fixation than that Heat fixing process, which causes the image fixed on the paper can be rubbed off more easily. The pressure fixing method still requires a very high pressure when fixing. On so high pressure breaks the cellulose fibers of the carrier medium, like paper, and you still get on the carrier medium a shiny surface. It is also necessary that the platen has a relatively large size because the platen the toner image on the carrier medium inevitably the very high Must give pressure. One can therefore reduce the The size of the copier and duplicator is not over reach a certain limit by the size of the Printing roller is defined.

An encapsulated toner material has already been pre-selected beat, which contains toner particles contained in microcapsules are included, eliminating the disadvantages described above of the pressure fixing process should be avoided. The one Encapsulated toner material is made by using a core material (which contains a dye such as carbon black) with an envelope which is broken by the application of pressure is enveloped. The encapsulated toner mat produced in this way rial has several advantages. For example it is not required to fix the encapsulated toner material  Lich to use a high pressure. The fixation is white very good. The encapsulated toner material is therefore very good for use in the pressure fixing method is suitable. The encapsulated toner mat proposed to date However, rial is not satisfied with its practical use because it does not meet the requirements that it need to be filled to ensure smooth copying and duplication to reach and result in toner images that are sufficient are appropriately fixed and of good quality.

More specifically, the toner material, which as a dry developing agent in electronics Statography should be used, very good powder properties properties (or powder flowability), so that a high Development quality is maintained and thus the surface of the photosensitive material on which the latent image is formed, is not stained.

A toner material which is used for two-component development is used, the surface may also chen of the carrier particles used in the combination will not pollute. The toner material, which as Developing agent used in the pressure fixing process is, must continue to be sufficient fixability or Have pressure and the roller surfaces must not soiling or it must not adhere to them, d. H. the Appearance that the toner adheres to the roller surface and it should be dirty. This issue is referred to below as "weaning".

DE-AS-25 42 374 describes pressure-fixable toner particles for the electrostatographic dry developer who as Binder a combination of at least two groups of Contains resins and is characterized in that it as Resin of the first group rosin, shellac, an alkyd resin, an epoxy resin, a polyester, a polyamide, a polyacrylic acid ester, a polymethacrylic acid ester, polystyrene Styrene / butadiene copolymer or a styrene / methacrylic  acid methyl ester copolymer and / or in the heat reactive petroleum resin and as a resin of the second group Ethylene / vinyl acetate copolymer, saponified ethylene / vinyl acetate copolymer and / or one of saponified Graft poly derived from ethylene / vinyl acetate copolymer contains merisat, the amount of resin of the second group pe, based on the resin of the first group, in the range of 5 to 40 wt .-% is.

In summary, the toner material, which in the Pressure fixation is used to a large extent all Properties such as powder properties (powder flowability), Fixability on the carrier medium (e.g. paper) as well as a preservability of the fixed image, a Resistance to settling and an electron chargeability and / or electrical conductivity, depending  of the system used. The pre to date encapsulated encapsulated toner materials have some of these properties not.

The present invention is based on the object electrostatographic encapsulated toner material for ver to provide a particularly improved fixation having. The term "fixation" as used in the present Application used includes the fixing property of a Image, which consists of the toner material on a carrier medium, like paper, as well as preservation and hold Availability of the toner image fixed on the carrier medium. How previously described, the procedure for fixing the Toner material in the pressure fixing process in general performed by using a carrier medium with the toner material then passes through pressure rollers made of hard metal, the encapsulated particles are destroyed on the carrier medium. Most of the previously known encapsulated toner material lien are not satisfied with their fixation lend and the fixed pictures can with your fingers and with other papers are easily rubbed off, taking this mate rialien be stained. The unsatisfactory fixie tion of the previously known toner materials is one of the facts toren, whereby the practical application of the Druckfixierver driving, using an encapsulated toner material is not possible.

The present invention also has the object grunde, an encapsulated toner material with improved Resistance to weaning as well as improving to provide the fixation or fixability.

The term "weaning" means the appearance that the Roll with part of the core material or the sheath of the encapsulated toner material is stained, which occurs if the carrier medium with the toner image applied thereon is passed through the metal rollers to the encapsulated  Destroy particles on the medium. The bad persistent speed compared to the discontinuation of the known toner materials another factor why the practical use of the Pressure fixing method in which an encapsulated toner mat used in real was not possible.

The invention is also based on the object encapsulated toner material with a satisfactory Zer Disturbability at the fusing level, but with durability versus a mechanical shock that occurs at other stages occurs, as well as with improvements in pressure fixation and resistance to weaning deliver.

The invention relates to an electrostatographic To nermaterial, which is characterized in that it is a core material and an envelope, wherein the core material a dye, a non-ferromagnetic inorganic Contains pigment and a binder, the binder Homopolymers and copolymers of acrylic acid esters, homopoly and copolymers of methacrylic acid esters and styrene Butadiene copolymers and a solvent with a Boiling point above 180 ° C, which the polymer dissolve or on can swell, contains.

The wrapping material is in the present invention from a polymer poses. Examples of polymers used as wrapping material can be used include a variety of resins, such as a polyurethane, polyamide, polyester, polysulfonamide, Polyurea, epoxy resin, polysulfonate and polycarbonate. A polyurethane resin and a polyurea resin are preferred.

In the present invention, the terms "poly urethane "and" polyurea "polymers made by polycondens reaction between a polyisocyanate and one or several of the counter compounds, such as a polyol, water, Po lyamine and piperazine. Dementia Accordingly, the terms "polyurethane" include either simple polyurethane, which is essentially only urethane  contains bonds, or a polymer which binds urethane conditions and a relatively small amount of urea bonds holds. The term "polyurea" means either one simple polyurea, which is essentially only urea contains bonds, or a polymer containing urea ent and a relatively small number of urethane bonds ent holds.

The envelope can essentially consist of a complex layer consist. For example, the wrapper can have two or more Polymers selected from the group consisting of a poly urethane resin, a polyurea resin and a polyamide resin, contain.

Encapsulation of the core material in the form of droplets with the wrapping material can by known methods for the production of so-called microcapsules, the one contain hydrophobic liquid, for example the border surface polymerization process, as in the US-PS's 3 577 515 and 3 429 827 and GB-PS's 950 443, 1 091 007 and 1 091 078, according to an internal polymer sationsverfahren, as it is in the US-PS'en 3 660 304, 3 726 804, 3,796,669 and 2,969,330, a phase separation proceed in aqueous medium, as in the US-PS's 2,800,457, 2,800,458, 3,041,289 and 3,205,175 is an external polymerization process, as in the US-PS'en 4 087 376, 4 089 802, 3 100 103 and 4 001 140 described ben, and a melt dispersion cooling process as it in U.S. Patent 3,167,602. Other known encapsulation methods and modifications and combinations of these encapsulation methods can if used.

Of these encapsulation processes, the interfacial poly merization process, in which the following process takes place, preferred for the production of the toner according to the invention terials used.  

First, the following two substances are selected:
Substance (A) which is a hydrophobic liquid or which is a substance which is soluble in a hydrophobic liquid, miscible with it or readily dispersible therein, and
Substance (B) which as such is a hydrophilic liquid or which is a substance which is soluble in, miscible with or readily dispersible in a hydrophilic liquid and which reacts with the substance (A) to form a polymerization reaction product which is either is insoluble in the hydrophobic liquid or in the hydrophilic liquid. Examples of polymerization reaction products are a polyurethane resin, a polyamide resin, a polyester resin, a polysulfonamine resin, a polyurea resin, an epoxy resin, a polysulfanate resin and a polycarbonate resin.

Second, very small droplets become hydrophobic Liquid containing substance (A) and the kernel rial, which is a dye, a non-ferromagnetic inorganic pigment and a binder that is a polymer consisting of homopolymers and copolymers of acrylic acid esters, homopolymers and copolymers of methacrylic acid esters and styrene-butadiene copolymers and a solvent with a boiling point above 180 ° C, which the polymer will dissolve or can swell, comprises, contains, in a hydrophilic Liquid, such as water, which contains substance (B), dispersed.

Substance (A) is suitable with substance (B) according to a methods, for example by heating the dispersion, implemented, an interfacial polymerization reaction takes place in the dispersion. The wrapping or Sheathing from the reaction product of substance (A) with the substance (B) (and / or water) around the hydrophobic droplet Chen created with the formation of microcapsules, which the core material and the wrapping that wraps around the core material  summarize, the core material a dye, a not ferromagnetic inorganic pigment and a binder  contains. The binder contains a mixture of a poly mers consisting of homopolymers and copolymers of acrylic acid esters, homopolymers and copolymers of methacrylic acid esters and styrene-butadiene copolymers and a solvent with a boiling point above 180 ° C, and can solve the polymer or swell.

Examples of the substance (A), which are preferred for the Her position of the casing according to the invention can be used are compounds with isocyanate groups, as follows to be discribed:

• (1) diisocyanate
  m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxy-4,4 ' - biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diiso cyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexa methylene diisocyanate, propylene-1, 2-diisocyanate, butylene-1,2-diisocyanate, ethylidene diisocyanate, cyclohexylene-1,2-diiso cyanate, cyclohexylene-1,4-diisocyanate, p-phenylene diisocyanate, triphenylmethane diisocyanate;
• (2) triisocyanate
  4,4 ′, 4 ′ ′ - triphenylmethane triisocyanate, polymethylene polyphenyl triisocyanate, toluene-2,4,6-triisocyanate;
• (3) tetraisocyanate
  4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate; and
• (4) polyisocyanate prepolymer
  an addition product from hexamethylene diisocyanate and hexanetriol, an addition product from 2,4-tolylene diisocyanate and catechol, an addition product from 2,4-tolylene diisocyanate and hexanetriol, an addition product from 2,4-tolylene diisocyanate and trimethylolpropane, an addition product from cyanopropylene trimethyl.

Examples of the substance (B), which are preferred in the manufacture development of the casing according to the invention are used the connections described below:

• (1) water;
  (2) polyol
  Ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-heptanediol, 1,7-heptanediol, 1,8-octanediol, trimethylol propane, hexanetriol, catechol, resorcinol, hydroquinone, 1,2-di hydroxy-4-methylbenzene, 1,3-dihydroxy-5-methylbenzene, 3,4-dihydroxy-1-methylbenzene, 3,5-dihydroxy-1-methylbenzene, 2,4-dihydroxy-1-ethylbenzene, 1,3- Naphthalenediol, 1,5-naphthalenediol, 2,3-naphthalenediol, 2,7-naphthalenediol, o, o'-biphenol, p, p'-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-methylphenyl) propane, bis (2-hydroxyphenyl) methane, xylylenediol, pentaerythritol, glycerol, sorbitol;
• (3) polyamine
  Ethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, p-phenylene diamine, m-phenylene diamine, 2-hydroxytrimethylene diamine, diethylene triamine, triethylene tetraamine, diethylaminopropylamine, tetraethylene pentaamine, an adduct of an epoxy compound and an amine compound; and
• (4) piperazine
  Piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine.

In the combinations described above, the substance (A) by an acid chloride, a sulfonyl chloride or a bis chloroformate to be replaced, with an envelope from a other resinous material, such as a polyamide resin, is formed.

Examples of these compounds are the following:

• (1) acid chloride
  Oxazoyl chloride, succinoyl chloride, adipoyl chloride, sebacoyl chloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, fumaroyl chloride, 1,4-cyclohexanedicarbonyl chloride, polyesters containing acid chloride groups, polyamides containing acid chloride groups;
• (2) sulfonyl chloride
  1,3-benzenedisulfonyl chloride, 1,4-benzenedisulfonyl chloride, 1,5-naphthalenedisulfonyl chloride, 2,7-naphthalenedisulfonyl chloride, 4,4'-biphenyldisulfonyl chloride, p, p'-oxybis- (benzenesulfonyl chloride), 1,6-hexanedisulfonyl chloride;
• (3) bishlor formate
  Ethylene bis (chloroformate), tetramethylene bis (chloroformate), hexamethylene bis (chloroformate), 2,2'-dimethyl-1,3-propane bis (chloroformate), p-phenylene bis (chloroformate).

When making the dispersion from very small hydropho ben droplets, which are the substance (A) and the core material contain the hydrophobic liquid that disperses is preferably a low-boiling solvent or a contain polar solvent. These solvents are used to this, the formation of the envelope, which is the reaction product between substance (A) and substance (B) accelerate. Examples of these solvents are methylal  alcohol, ethyl alcohol, diethyl ether, tetrahydrofuran, dioxane, Methyl acetate, ethyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, n-pentane, n-hexane, benzene, Pe trol ether, chloroform, carbon tetrachloride, methylene chloride, Ethylene chloride, disulfide carbon and dimethylformamide.

There is no limit to the wrapping material as long as the material can be destroyed or broken by pressure. Accordingly, other materials than those previously used described materials are used. Examples of that Materials are homopolymers and copolymers of styrene or substituted styrene such as polystyrene, poly (p-chlorosty rol), styrene-butadiene copolymer, styrene-acrylic acid copoly meres, styrene-acrylic acid ester copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid ester copolymer, Styrene-maleic anhydride copolymer, and styrene-vinyl acetate Copolymer; Polyvinyltoluene resin, acrylic ester homopolymer, Methacrylic ester homopolymer, xylene resin, methyl vinyl ether maleic anhydride resin, vinyl butyral resin, poly (vinyl alcohol) resin and poly (vinyl pyrrolidone).

The encapsulated toner material, the wrapping of which is essentially Lichen consists of a complex layer, the two or more rere polymers from the group polyurethane resin, polyurea Contains resin and polyamide resin can be made as follows the.

In a hydrophobic liquid which does the aforementioned Contains core material, an acid chloride and a poly dissolved isocyanate. This solution is then in an aqueous Medium containing a polyamine or piperazine and a disper contains sion agent, forming fine droplets the core material with an average diameter in Range from about 0.5 to about 1000 microns in the aqueous medium dispersed.  

The dispersion prepared as described above is then neutralized by adding an alkaline substance or made weakly alkaline and then to a temperature heated between 40 and 90 ° C. After completing this procedure Steps becomes a complex layer that essentially consists of a polyamide resin and a polyurea resin, wherein the polyamide resin is the reaction product which by Reaction generated between the acid chloride and the polyamine and the polyurea resin is the reaction product which by reaction between the polyisocyanate and the Polyamine has been created to form the droplet of core material educated. Thus, an encapsulated particle with a Envelope obtained from a complex layer.

If to the hydrophobic liquid in the above Process further a polyol is added to the droplet chen from the hydrophobic core material an envelope from a complex layer, which is essentially the polyamide contains resin and a polyurethane resin, the polyurethane resin is the reaction product of the polyisocyanate with the polyol.

In the latter method, a complex layer, which essentially from the polyamide, polyurea and poly urethane resins are produced when the polyamine too is added to the reaction system in an amount equal to Amount that is required to be added with the To react acid chloride.

The coating of the particles thus produced is as above wrote an encapsulation of a complex layer. Of the The expression "wrapping from a complex layer" includes one Envelope containing a polymer blend, as well as one Envelope containing a double layer. The expression "Wrapping with a double layer" is not meant to be just a wrapping include, in which the two layers by a simple Interface are completely separated, but it just includes if an enclosure where an interface is not in the um  envelope occurs clearly, however, the ratio of one Polymers to the other polymer (or other polymers) varies from the inner phase to the outer phase of the envelope.

The acid chloride can be by a dicarboxylic acid or its acid anhydride to be replaced. Examples of dicarboxylic acids are Adi pinic acid, sebacic acid, phthalic acid, terephthalic acid, fumar acid, 1,4-cyclohexanedicarboxylic acid and 4,4'-biphenyldicarbon acid. Examples of acid anhydrides are phthalic anhydride.

The internal polymerization process can be carried out in the following manner be performed.

In a hydrophobic liquid that is used to produce the Encapsulated toner particle core material is used become the substance (A) and one or more substances that are polymerizable with the substance (A) in the presence a low-boiling solvent or a polar solvent solvent dissolved. The hydrophobic liquid obtained is then in the aforementioned hydrophilic liquid, wel surface is not miscible with the hydrophobic liquid, dis pergiert and emulsified. The emulsion is then removed the low-boiling solvent or the polar solution by means of the outside of the hydrophobic liquid droplet chen and at the same time for the transport of the envelope-forming Substance heated to the surface of the droplets. The envelop Lung-forming substances are polymerized on the surface siert, whereby the desired envelope is generated. So who the desired encapsulated toner particles contained in the hydrophilic liquid are obtained.

As for the other features for the interfacial poly merisation process and other processes for the manu position of microcapsules containing a hydrophobic liquid is included, as described in U.S. Patent No. 3,726,804 Reference which express for the present application Lich to be considered revelation.  

The core material contains a dye for manufacturing a visible image from the latent image. The dye (or colorant) is generally a dye or a Pigment, but a certain agent, which directly no visible image reveals how a fluorescent agent can also optionally as a dye or coloring agent be applied.

The colorant or dye is generally from a variety of dyes, pigments and the like chooses that generally in the known electrostatogra phical copying and duplication processes used will. Generally the dye is a black toner or a chromatic toner. Examples of black toners are carbon black or carbon black. Examples of chromatic toners are blue dyes such as copper phthalocyanine and sulfone amide derivative dyes, yellow dyes such as benzidine derivative dyes, d. H. the one that is generally called diazo yellow and red dyes such as Rhodamine B Lake, d. H. a double salt of a xanthine dye with phosphorus wolf mat and molybdate, carbin 6B, which ge to the azo pigment listens, and a quinacridone derivative.

The core material contains a binder (adhesive material), so the dye stays inside the core, and which one the fixation of the dye on the surface of the support mediums such as paper.

It is an essential feature of the present invention that the binder with a polymer and a solvent contains a boiling point above 180 ° C, the solvent that can dissolve or swell polymers.

It is a binder that is present in a core material and which is a mixture of a polymer and a light contains volatile low-boiling solvent, known (see JP-OS 56 (1981) -144434). This state of the art is based  on the concept that an encapsulated toner material, which placed on a carrier medium, such as paper, broken with the mixture of the polymer and the volatile low-boiling solvent together with the dye adheres when pressure is applied and the polymer is easier it fixes both the dye and the lead wrapping material in the evaporation of the low boiling solvent.

The applicant has examined this method in more detail and has ge found that a binder which the polymer and contains volatile low-boiling solvents, not one satisfactory adhesion of the dye to the carrier medium and that the volatile low-boiling solvent the working conditions in the manufacture of the encapsulated toner material as well as the working conditions at the Copying deteriorates because of the low-boiling solvent spreads an unpleasant smell and is highly flammable is. Furthermore, the encapsulated deteriorates Toner material which contains the low-boiling solvent the core material contains the adhesion during storage; presumably this is due to volatilization of the low boiling solvent through the coating.

In contrast, the binder according to the invention contains composition of a polymer and a high-boiling solution medium, causing the dye to adhere to the support dium, like the paper, is improved compared to the bin detergent composition which is the polymer and a low contains boiling solvent. In addition, the visible Toner image, which is fixed on the carrier medium, better be stored. There are also no inconveniences such as the fire hazard and unpleasant smell, on.

The polymers used as binders are the following polymers:
Styrene-butadiene copolymer, homopolymer and copolymer of acrylic acid ester, homopolymer and copolymer of methacrylic acid ester.

The above polymers are described in detail in the following references:
JP-PS 48 (1973) -30 499, 49 (1974) -1588 and 54 (1979) -8104, JP-OS 48 (1973) -75 032, 48 (1973) -78 931, 49 (1974) -17 739, 51 (1976) - 132 838, 52 (1977) -98 531, 52 (1977) -108 134, 52 (1977) - 119 937, 53 (1978) -1028, 53 (1978) -36 243, 53 (1978) -118,049, 55 (1980) -89,854 and 55 (1980) -166,655, and U.S. Patents 3,788,994 and 3,893,933.

Examples of the solvent with a boiling point above 180 ° C, which dissolve or swell or swell the polymer are the following liquids:

• (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 esters
  Tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, tributyl phosphate, trihexyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, trioleyl phosphate, tris (butoxyethyl) phosphate, tris (chloroethyl) phosphate;
• (3) citric acid ester
  O-acetyltriethyl citrate, O-acetyltributyl citrate, O-acetyl tri hexyl citrate, O-acetyl trioctyl citrate, O-acetyltrinonyl citrate, O-acetyl tridecyl citrate, triethyl citrate, tributyl citrate, tri hexyl citrate citrate, tri hexyl citrate citrate
• (4) Benzoic acid ester
  Butyl benzoate, hexyl benzoate, heptyl benzoate, octyl benzoate, nonyl benzoate, decyl benzoate, dodecyl benzoate, tridecyl benzoate, tetradecyl benzoate, hexadecyl benzoate, octadecyl benzoate, oleyl benzoate, pentyl o-methyl benzoate, methyl benzoate, benzyl methyl benzoate, decyl benzoate, decyl benzoate, 2,4-dichloro benzoate, octyl 2,4-dichlorobenzoate, stearyl 2,4-dichlorobenzoate, oleyl 2,4-dichlorobenzoate, octyl p-methoxybenzoate;
• (5) Aliphatic acid esters
  Hexadecyl myristate, dibutoxyethyl succinate, dioctyl adipate, di octylazelate, decamethylene-1,10-diol diacetate, triacetin, tri butyne, benzyl caprate, pentaerythritol tetracaproate, isosorbitol dicaprilat;
• (6) alkylnaphthalenes
  Methylnaphthalene, dimethylnaphthalene, trimethylnaphthalene, tetramethylnaphthalene, ethylnaphthalene, diethylnaphthalene, triethylnaphthalene, monoisopropylnaphthalene, diisopropylnaphthalene, tetraisopropylnaphthalene, monomethylethylnaphthalene, isooctylnaphthalene;
• (7) dialkylphenyl ether
  Di-o-methylphenyl ether, di-m-methyldiphenyl ether, di-p-methylphenyl ether;
• (8) Amides of fatty acids and aromatic sulfonic acids
  N, N-dimethyllauroamide, N, N-diethylcaprylamide, N-butylbenzene sulfonamide;
• (9) Trimellitic acid ester
  Trioctyl trimellitate;
• (10) Diarylalkanes
  Diarylmethanes such as dimethylphenylphenylmethane, diarylethanes such as 1-methylphenyl-1-phenylethane, 1-dimethylphenyl-1-phenylethane and 1-ethylphenyl-1-phenylethane.

For the purposes of the present invention, this is high Ending solvents preferred among phthalic acid esters, Phos phosphoric esters, diarylalkanes and alkylnaphthalenes elects.

In the present invention, the polymer and the high-boiling solvent alone or in mixtures be used.

Regarding the ratio between the high-boiling Lö There is no limit to the solvent and the polymer. The However, ratio is preferred within a range  from 0.1 to 4 (high-boiling solvent / polymer) pressed as weight ratio, selected. The mixture of the polymer and the high-boiling solvent show some sometimes a very high viscosity, depending on the ratio between them. Such a viscous mixture can hardly be added Peaceful condition at the initial stage for the Her position of the fine droplets emulsified from the core material will. In such a case, a low-boiling solution solvent, which with the high-boiling solvent and is miscible with the polymer, but not miscible with the water bar, such as ethyl acetate or butyl acetate, is preferred to that Mixture added to lower the viscosity and the To facilitate formation of a satisfactory emulsion. The low-boiling solvent is used in the formation of Emulsion removed at reduced pressure.

The core material according to the present invention is characterized in that it contains a non-ferromagnetic inorganic pigment. The term "non-ferromagnetic inorganic pigment" means an inorganic pigment which has a magnetic susceptibility not exceeding 10 ^-4 (the value was determined when the magnetization was saturated in an external magnetic field). The nonferromagnetic inorganic pigment used in the present invention is preferably a nonferromagnetic metal oxide. Examples of non-ferromagnetic metal oxides are titanium dioxide, zinc oxide, manganese dioxide and magnesium oxide. Other non-ferromagnetic pigments that can be used in the present invention are carbonates such as calcium carbonate, sulfates such as calcium sulfate, and other metal compounds such as molybdenum disulfide.

The non-ferromagnetic pigment according to the invention can with other materials. Examples of Beschich processing materials are organic polymers, silicone polymers, surfactants and organic or inorganic solvents means. Preferred coating materials are more  valuable alcohols with 2 to 18 carbon atoms and 2 to 4 Hydroxyl groups in the molecule.

Examples of polyhydric alcohols with 2 to 4 hydroxyl groups are alcohols with 2 hydroxyl groups, such as ethylene glycol, Pro pylene glycol, 1,3-dihydroxypropane, 1,4-dihydroxybutane, penta methylene glycol, 2,5-dihydroxyhexane, 2,4-dihydroxy-2-methylpen tan, heptamethylene glycol and dodecamethylene glycol; Alcohols with 3 hydroxyl groups, such as trimethylolethane, trimethylolpro pan, glycerin, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6- Hexanetriol and 2,2-bis (hydroxymethyl) -3-butanol; and alcohols with 4 hydroxyl groups, such as pentaerythritol. Preferred alcohols are those with 2 to 6 carbon atoms and 3 hydroxyl groups pen in the molecule. Trimethylolethane is particularly preferred.

The coating material is generally not on that ferromagnetic inorganic pigment in an amount in the loading range from about 0.01 to 10% by weight, preferably from 0.1 to 1.5% by weight. The coating material will be preferably applied to the entire surface of the pigment. A non-uniform coating or coating that in portions, is still possible. Other examples for non-ferromagnetic inorganic pigments used in the present invention can be used in the following publications: Pigment Handbook, Volume 1, edited by Tempe C. Patton (A Wiley - Interscience Publication), Collective Edition of New Dyeing Process I: Dye and Pigment (in Japanese), published by Japan Socie ty for the promotion of Science, Dyeing Process No. 120 Committee (Kyoritsu Shuppan Co., Ltd., Japan), and Explana tory Industrial Chemistry (revised edition), shouted ben in Japanese by Yozabura Kohsaka (Maki shoten, Japan).

The non-ferromagnetic inorganic pigment is preferred in an amount of 5 to 70 wt .-%, based on the total amount of core material, available. A particularly preferred one Range is 10 to 50% by weight.  

As previously described, the core material of the invention contains encapsulated toner necessarily has a color substance, a non-ferromagnetic inorganic pigment Polymer and a high-boiling solvent. Other addition substances, such as a fluorine-containing resin, which are used in ver prevention of stopping can also be ver be applied.

As previously mentioned, the process includes manufacturing of the encapsulated toner particles a stage for the disperser sion or emulsification of the hydrophobic liquid that the Contains substance (A), and the core material in the aqueous medium in the form of very small droplets. For the production of the homogeneous dispersion (or emulsion) from the very small Droplets of the hydrophobic liquid are preferred in the reaction liquid einuar a hydrophilic polymer which the production of the homogeneous dispersion (or Emulsion) from the hydrophobic droplets and a Agglomeration of the hydrophobic droplets formed is prevented.

Examples of preferred hydrophilic polymers are proteins, such as gelatin, graft polymers from gelatin and other polymers ren, albumin and casein; Cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose and cellulose sulfuric acid ester; Saccharide derivatives such as sodium alginate and starch deri vate; and a variety of synthetic hydrophilic homopoly Merer and copolymers, such as poly (vinyl alcohol), partially ace Talized poly (vinyl alcohol), poly (N-vinyl pyrrolidone), Poly (acrylic acid), poly (acrylic acid amide), poly (vinyl imidazole) and poly (vinyl pyrazole).

In the above examples, the gelatin may be lime traded gelatin, an acid-treated gelatin, a hydrolyzed gelatin and an enzymatically decomposed gelatin his. The graft polymers of gelatin and other polymers can be gelatins, the graft polymers of gelatin and other polymers, or they can be copolymers of vinyl  monomers, such as acrylic acid, methacrylic acid, their derivatives, for example esters and amides, acrylonitrile and styrene, his. Examples of gelatin graft polymers are those that are miscible with gelatin, like gelatin which is grafted on Carries chains made from polymers of acrylic acid, acrylamide, Methacrylamide and hydroxyalkyl methacrylate exist.

Details of these preferred gelatin graft polymers be those in U.S. Patents 2,763,625, 2,831,767 and 2,956,884 wrote.

Representative examples of the synthetic hydrophilic Polymers are described, for example, in DE-OS 2 312 718 US-PS's 3 620 751 and 3 879 205 and JP-PS 43 (1968) -7561 described.

The dispersion or emulsion of the reaction liquid can by means of homogenization devices known per se, such as one that belongs to the agitation type, the high pressure injection type, belongs to the ultrasonic vibration type and the knuckle type leads. Particularly preferred homogenization device are a colloid mill, a common homogenization device and an ultrasonic homogenization device, which is induced by electromagnetic distortion.

The encapsulated toner is then, for example, by heating zen of the emulsified reaction liquid in the presence of a suitable catalyst, as previously described, with formation of shells around the core droplets. After that the encapsulated toner becomes from the aqueous reaction medium separated and dried, with a dried one encapsulated toner. The encapsulated toner will come before added with water after separation from the aqueous reaction medium and washed before the dry process.

Washing the encapsulated toner with water is special preferred in the case where a hydrophilic polymer  in the manufacture of the encapsulated toner is. The hydrophilic polymer present in the reaction mixture is adhered to the surface of the encapsulated toner and the encapsulated toner containing a hydrophilic polymer contains its surface, can easily agglomerate where deteriorate due to the powder properties of the toner material be tert. So that the toner material is not a disadvantage Having agglomeration, the hydrophilic polymer adheres to adheres to the surface of the encapsulated toner, preferably removed as far as possible by washing with water. Consequently exceeds the hydrophilic polymer on the surface of the encapsulated toner preferably not 5% by weight based on the total amount of toner. Particularly preferably exceeds it is not 1% by weight.

The drying process can be carried out according to processes known per se, such as after a spray drying process or freeze drying proceed, be carried out. The spray drying process is prefers.

The dried encapsulated toner particles are preferred heated to improve their powder properties. The tem temperature for heating the dried encapsulated toner Particle is preferably in the range of 50 to 300 ° C and be particularly preferably in the range from 80 to 150 ° C. The time that required for heating varies with heating temperature, the type of binder, etc. In general are times in the range from 10 min to 48 h and preferably 2 to Suitable for 24 hours.

With regard to the implementation of the heating process, there are no restrictions. Examples of possible heating options possibilities are an electric furnace, a muffle furnace, a Heating plate, an electric drying oven, a drying oven direction with a fluid bed and an infrared drying device tung.  

The dry encapsulated toner can then be insulated material and / or a charge control agent such as a Me tall containing dye or nigrosine dye, mixed will.

The dry encapsulated toner can be coated with a flow lubricant medium, such as with a hydrophobic silica powder the so that the lubricant is on the surface of the encapsulated toner distributed. The encapsulated toner that a flow lubricant, such as hydrophobic silica powder, on the Has toner surface, has particularly improved powder properties and therefore it is for practical use particularly suitable.

The encapsulated toner obtained as described above was, can in an electrostatographic copying and ver diversity machine for the development of an electrostato graphically generated latent image to form a view baren toner image on the surface of the photoconductive mate rials are used. The visible image is then on the Carrier medium, such as paper, by means of a suitable Pressure fixing device fixed. Regarding the pressure fixer device for fixing the invention encapsulated toner there is no limit and you can ir a known device for fixing the encapsulated rarely use toner according to the invention. examples for Pressure fixing devices are those in the JP-PS's 44 (1969) -9880, 44 (1969) -12 797 and 46 (1971) -15 876, and in JP-OS′en 49 (1974) -62 143, 49 (1974) -77 641, 50 (1975) -51 333, 51 (1976) -31 235, 51 (1976) -40 351, 52 (1977) -15 335, 52 (1977) - 102 743, 54 (1979) -28 636, 54 (1979) -32 326, 54 (1979) -41 444 and 54 (1979) -48,251.

Other features for electrostatographic copying and Duplication process in which encapsulated toner mat rialien are used in US Pat. No. 3,788,994 wrote, whose disclosure expressis verbis reference is taken.  

The following examples illustrate the invention. In the case of play mean the terms "part (s)" "part (s) by weight".

example 1

40 parts of triisopropylnaphthalene, 5 parts of carbon black and 45 parts Zinc oxide are sufficiently made in a mortar mixed with a primary liquid.

25 parts of polyisocyanate are separated with the following Formula:

and 2 parts terephthaloyl chloride in 45 parts ethyl acetate solves. The resulting solution is mixed with 66 parts of a solution of poly (isobutyl methacrylate) in ethyl acetate (30% by weight Solution) to produce a secondary liquid mixes.

A mixture of the primary liquid and the secondary Liquid becomes precooled aqueous rubber in 200 parts arabic solution (10 wt .-% solution) to produce a Oil-in-water emulsion, which oil droplets with a through contains average diameter of 10 microns, mixed. To 160 parts of an aqueous solution of hexa are added to the emulsion methylenediamine (10 wt .-% solution) and the mixture Stirred for 30 min. An aqueous sodium is added to the mixture carbonate solution (10 wt .-% solution) to adjust the pH of the Ge mix to set to 9.0. The resulting mixture is at 60 ° C for 2 h to carry out the reaction.

The aqueous microcapsule dispersion thus obtained is three times washed with water by centrifugal separation and by means of  a spray drying device to form a powder encapsulated toner material, which has a core (carbon black, zinc oxide, poly (isobutyl methacrylate) and triisopropylnaphthalene) and an envelope (a complex layer that essentially consists of Chen consists of polyamide resin and polyurea resin), which encapsulated, encased, spray dried the core.

The encapsulated toner material is at 100 ° C for 24 hours heated in an infrared drying oven and then the Powder properties checked. The heat-treated capsule The toner is very fluid. A microscopic examination of the encapsulated toner shows that the bulk of the toner portion Chen is independent of each other. It is confirmed that the encapsulated toner is free from caking and on their adverse phenomena after storage during one day at high temperature and high humidity conditions (50 ° C, relative humidity 90%).

The heat-treated toner is coated with 0.5% by weight of hydrophobic Si silicon dioxide to form an encapsulated toner material treated with improved fluidity. This toner shows no caking or other adverse phenomena, even after storage for several days at high temperature and high humidity conditions (50 ° C, relative humidity 90%).

The toner containing hydrophobic silica was tested as follows:
5 parts by weight of the toner are mixed with 95 parts by weight of powdered iron particles in a shaker to produce a developing agent. It was found through microscopic examination that the developing agent contains almost no broken toner particles.

A known electrostatographic copier and Duplication method was using the above Developing agent carried out. That in the latent picture The generated visible toner image was then transferred to paper. The paper that carries the toner image was cleaned with a Pressure roller treated at a pressure of 350 kg / cm². Man he holds a toner image with high sharpness, which is very good is fixed on the paper. The settling of the toner is very ge ring.

Example 2

A powdered, encapsulated toner material called titanium Contains dioxide instead of zinc oxide in the core, was after the process described in Example 1 for the preparation of the Microcapsules and spray drying the microcapsules, except that zinc oxide by titanium dioxide in the manufacture primary liquid was replaced.

The encapsulated toner was at 100 ° C for 24 hours in one Infrared drying oven heated and then the powder was added determined. The heat-treated encapsulated Toner is very fluid. A microscopic examination of the encapsulated toner shows that the bulk of the toner portion Chen exist independently of each other. It has been confirmed that the encapsulated toner is free from blocking or other adverse phenomena is after storage during a Day at very high temperature and high humidity conditions conditions (50 ° C, relative humidity 90%).

The heat treated toner becomes hydrophobic with 0.5% by weight with silicon dioxide to form an encapsulated toner mat rials mixed with improved flowability. This toner is free from blocks or other adverse phenomena, even after storing for several days at high temperature rature and high humidity conditions (50 ° C, relative Humidity 90%).  

Evaluation of the toner, which is hydrophobic silica contains, was described in the same manner as in Example 1 ben, performed by a developing agent, mixed was made with powdered iron carrier. By micros Copying observation confirmed that the development medium contains almost no broken toner particles.

A known electrostatographic copier and Duplication method was using the above Developing agent carried out. That in the latent picture The generated visible toner image was then transferred to paper. The paper that carried the toner image was printed roller treated at a pressure of 350 kg / cm². You get a high-definition toner image that works well on paper is fixed. The toner settling was very small.

Example 3

A powdered, encapsulated toner material that Ti tandioxide coated with trimethylolethane (coating amount: 0.5% by weight) instead of zinc oxide in the core, is made in the same way as in Example 1 for the preparation the microcapsules and spray drying the microcapsules except that the zinc oxide is replaced by titanium dioxide, which is coated with trimethylolethane, from Her position of the primary liquid has been replaced.

The encapsulated toner was at 100 ° C for 24 hours in one Infrared drying oven heated and then the powder was added determined. The heat-treated encapsulated Toner is very fluid. A microscopic examination of the encapsulated toner shows that the bulk of the toner particles are independent of each other. It has been confirmed, that the encapsulated toner is free from blocking or other adverse phenomena is after storage one day at high temperature and high humidity conditions (50 ° C, relative humidity 90%).  

The heat treated toner is with 0.5 wt .-% Sili calcium dioxide to form an encapsulated toner material, wel ches has an improved flowability, mixed. The This toner is free from blocking or other adverse effects Apparitions, even after storage for several days at high temperature and high humidity conditions (50 ° C, relative humidity 90%).

Testing the toner that contains hydrophobic silicon dioxide holds, is done in the same way as in Example 1, by produces a developing agent, which with a powder iron carrier is mixed. It was made by microscopy Testing confirmed that the developing agent was almost none contains broken toner particles.

A known electrostatographic copying and duplication methods using the above Developing agent carried out. The visible toner image, which was created on the latent image was then opened Transfer paper. The paper that carries the toner image is with a pressure roller at a pressure of 350 kg / cm² acts. A high-sharpness toner image is obtained, which is well fixed on paper. Furthermore, the weaning of the toner very low.

Claims (7)

1. Electrostatographic toner material, characterized in that it comprises a core material and an envelope, the core material containing a dye, a non-ferromagnetic inorganic pigment and a binder, the binder from homopolymers and copolymers of acrylic acid esters, homopolymers and copolymers of methacrylic acid esters and styrene-butadiene copolymers and contains a solvent with a boiling point above 180 ° C, which can dissolve or swell the polymer. 2. Toner material according to claim 1, characterized records that the non-ferromagnetic inorganic pigment with a polyhydric alcohol, the 2 to 4 Has hydroxyl groups, is coated. 3. Toner material according to claim 1 or 2, characterized ge indicates that the non-ferromagnetic inorganic pigment is a non-ferromagnetic metal oxide is. 4. Toner material according to claim 1, characterized records that the non-ferromagnetic inorganic cal pigment in an amount of 10 to 50 wt .-%, based on the total amount of core material. 5. Toner material according to claim 1, characterized records that the solvent which a Boiling point above 180 ° C and which the polymer  can dissolve or swell, from phthalic acid esters, phosphorus acid esters, alkylnaphthalene and diarylalkanes. 6. Toner material according to claim 1, characterized records that the envelope at least one poly contains urethane resin and polyurea resin. 7. Toner material according to claim 6, characterized records that the wrapping consists of a complex Layer consists of at least two resins, be made of polyurethane resin, polyurea resin and poly amide resin.