IL30116A - Xerographic developer material and imaging process in which it is used - Google Patents

Description

npnyn v^nrn »D*unoa nin»o lain Xerographic developer material and imaging process in which it is used RANK XEROX LIMITED C: 28433 .

This invention relates to imaging systems, and more particularly, to improved xerographic developing materials, their Tianufacture and use. ' The formation and development of images on the surface of photoconductor materials by electrostatic means is well known, rhe basic xerographic process, as taught by C. F. Carlson in U. S. Patent 2,297,691, involves placing a uniform electrostatic charge jn a photoconductive insulating layer, exposing the layer to a Light-and-shadow image to dissipate the charge on the areas of the Layer exposed, to the light and developing the resulting latent, ilectrostatic image by depositing on the image a finely divided ilectroscopic material referred to in the art as "toner". The :oner will normally be attracted to those areas of the layer which ■etain a charge, thereby forming a toner image corresponding to :he latent electrostatic image. This powder image may then be :ransferred to a support surface such as paper. The transferred .mage may subsequently be permanently affixed to the support lurface as by heat. Instead of latent image formation by uniformly :harging the photoconductive layer and then exposing the layer to light-and-shadow image, one may form the latent image by directly iharging the layer in image configuration. The powder image may infixed to .the photoconductive layer if elimination of the powder mage transfer step is desired. Other suitable fixing means such s solvent or overcoating treatment may be substituted for the ■ oregoing heat fixing steps.

Several methods are known for applying the electroscopic (articles to the latent electrostatic image to be developed. One evelopment method, as disclosed by E. N. Wise in U. S. Patent ,618,552, is known as "cascade" development. In this method, a eveloper material comprising relatively large carrier particles thereon is conveyed to and rolled or cascaded across the electrostatic latent image bearing surface. The composition of the carrier particles is so selected as to triboelectrically charge the toner particles to the desired polarity. As the mixture cascades or rolls across the image bearing surface, the toner particles are electrostatically deposited and secured to the charged portion of the latent image and are not deposited on the uncharged or background portions of the image. Most of the toner particles accidentally deposited in the background are removed by the rolling carrier, due apparently, to the greater electrostatic attraction between the toner and the carrier than between the tone] and the discharged background. The carrier, and excess toner are then recycled. This technique is extremely good for the development of line copy images.

Another method of developing electrostatic images is the "magnetic brush" process as disclosed, for example, in U. S. Patent 2,874,063. In this method, a developer material containing toner and magnetic carrier particles are carried by a magnet. The magnetic field of the magnet causes alignment of '''the magnetic carrier into a brush-like configuration. This "magnetic brush" is engaged with the electrostatic image-bearing surface and the toner particles are drawn from the brush to the latent image by electro-static attraction.

Still another technique for developing electrostatic latent images is the "powder cloud" process as disclosed, for , example, by C. F. Carlson in U. S. Patent 2,221,776. In this method, a developer material comprising electrically charged toner particles in a gaseous fluid is passed adjacent the surface bearing the latent electrostatic image. The toner particles are drawn by electrostatic attraction from the gas to the latent image This process is particularly useful in continuous tone development Other development methods such as "touchdown" develop- nent as disclosed by R. W. Gundlach in U. S. Patent 3,166,432 may e used where suitable.

Although some of the foregoing development techniques are employed commercially today, the most widely used1' commercial terographic development technique is the technique known as . . 'cascade" development. A general purpose office copying machine Incorporating this development process is described in U. S. .

Patent 3,099,943. The cascade technique is generally carried out Ln a commercial apparatus by cascading a developer mixture over :he upper surface of an electrostatic latent image-bearing drum laving a horizontal axis. The developer is transported from a :rough or sump to the upper portion of the drum by means of an jndless belt conveyor. The developer is cascaded downward along i portion of the surface of the drum into the sump and is subse-[uently recycled through the developing system to develop idditional electrostatic latent images. Small quantities of toner xe periodically added to the developing mixture to compensate for :he toner depleted by development. This process is then repeated ;or each copy produced by the machine and is ordinarily repeated lany thousands of times during the usable life of the developer.

Thus, it is apparent from the description presented bove as well as in other development techniques, that the toner s" subjected to mechanical attrition which tends to break down the larticles into undesirable dust fines. Toner fines are detrimenta]} o machine operation because they are extremely difficult to emove from reusable imaging surfaces and also because they tend o drift to other parts of the machine and deposit on critical lachine parts such as optical lenses. The formation of fines is etarded when the toner contains a tough, high molecular weight esin which is capable of withstanding the shear and impact orces imparted to the toner in the machine. Unfortunately, many igh molecular weight materials cannot be employed in high speed automatic machines because they cannot be rapidly fused during a powder image heat fixing step. Attempts to rapidly fuse a high melting point toner by means of oversized high capacity heating units have been confronted with the problems of preventing the charring of paper receiving sheets and of adequately dissipating the heat evolved from the fusing unit or units. Thus, in order to avoid charring or combustion, additional equipment such as complex and expensive cooling units are necessary to properly dispose of the large quantity of heat generated by the fuser . Incomplete removal of the heat evolve will result in. pera es discomfort . and damage to heat sensitive machine components. Further, the increased space occupied by and the high operating cost of the heating and cooling units, often outweigh the advantages achieved by the increased machine speed.' On the other hand, low molecular weight resins which are easily heat fused at relatively low temperatures are often undesirable because these materials tend to form thick films on reusable photoconductor surfaces. These films tend to cause image degradation and contribute to machine maintenance down time. In addition, low molecular' eight resins tend to form tacky images on the copy sheet which often offset to other adjacent sheets.. Further, toner particles containing low molecular weight resins tend to bridge, cake and block in the shipping container as well as in the xerographic machine. Also, the toner material must be capable of accepting a charge of the correct polarity when brought into rubbing contact with the surface of carrier materials in cascade, magnetic brush. or touchdow development systems. Some resinous materials which possess many properties which1 would be desirable in xerographic toners dispense poorly and cannot be used in automatic copying and duplicating machines. Other resins dispense well but form images which are characterized by low density, poor resolution, or high . background. Further, some resins are unsuitable for processes where electro- static transfer is employed; Since most thermoplastic materials are deficient in one or more of the above areas, there is a continuing need for improved toners and developers The present invention provides a xerographic developer material comprising particles, said particles including:- Finely-divided toner particles comprising colorant, a thermoplastic resin comprising a vinyl or vinylidene resin having a melting point of at least 110°P. and a solid additive which is an ester of o-phthalic or m!~phthalic acid or 4,5-epoxy - tetrahydrophthalic acid or a compound having a melting point between 115°1?. and 270°P. and having the general structure (1) wherein n represents a positive integer from 1 to 7 inclusive and R represents an esterifying radical having from 2 to 12 carbon atoms, (2) wherei R"' represents one or more of hydrogen, chlorine, bromine, an aryl rr.fiical or an alkyl radical having from 1 to 6 cnrbon atoms and R' and R" represent hydrogen, an aryl radical, a cycloalkyl radical a hydroxyalkyl radical, an alkenyl radical or an alkyl radical .having from 1 to 12 carbon atoms, or (3) wherein n* represents zero or a positive integer from 1 to 3 inclusive and m has an average value from 0.5 to 2.5 inclusive. For optimum operation in high speed xerographic machines employing paper receiving webs, the toner should have a melting range between about 110°F to about 300°F, and a melt viscosity of less than about 2,0 x 10"^ poise up to temperatures of about 300°F. Toner melting temperatures below about 300°F. are preferred because heat dissipation and paper degradation problems are avoided. The developers of this invention alBO contain a carrier for the toner particles and/or from 0.02 percent to 20 percent by weight, based on the weight of the toner in toner, of zinc stearate is available at the outer surfaces of the particles in the developing material. The developers of this invention containing zinc stearate are preferred because the resulting mixture is characterized by outstanding fusing rates, igh cleanability from electrostatic imaging surfaces ,. greater briboelectric stability, denser toner images and increased resistance to mechanical attrition. Unexpectedly, both the fire lazard and excessive power consumption problems encountered in ligh speed xerographic development processes are obviated when toners containing the above described polymeric esterification roduct and metal salt are employed. or vinylidene Any suitable vinyl/ resin naving a melting point of at o teast about 110 P. may be employed in the ^toners of this invention ?he vinyl resin may be a homopolymer or a copolymer of two or more rinyl monomers. Typical monomeric units which may be employed to :orm vinyl polymers include: styrene, p-chlorostyrene;/ vinyl laphthalene; ethylenically unsaturated mono-olefins such as ithylene, propylene, butylene, isobutylene inyl isters such as vinyl chloride, vinyl bromide, vinyl fluoride, .or inyl acetate, vinyl propionate, vinyl benzoate, /vinyl butyrate jK_L-the-lika; esters of alphamethylene aliphatic monocarboxylic cids such as methyl acrylate, ethyl aerylate, n-butylacrylate, sobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloro-thyl acrylate, phenyl acrylate, methyl-alpha-chloroacrylate, or lethyl methacrylate, ethyl methacrylate,/butyl methacrylate and-_hoi ike; acrylonitrile, methacrylonitrile, acrylamide, vinyl ethers or uch as vinyl methyl ether, vinyl isobutyl ether, /vinyl ethyl ther/^-and-thc like,; vinyl ketones such as vinyl methyl ketone, or inyl hexyl ketone,/methyl isopropenyl ketone amd 1ihe li-ko-; or inylidene halides such as vinylidene chloride/ vinylidene chloro-luoride a«*-the--3riH«et and N-vinyl compounds such as N-vinyl or rrole, N-vin l carbazole, N-vin l indole/ N-vin l rrolidine (or vinylidene) su t-tfee--1.4te and mixtures thereof. Generally, suitable vinyl/ resins employed in the toner have a weight average molecular weight between about 3,000 to about 500,000.

Toner resins containing a relatively high percentage of a styrene resin are preferred. The presence of a styrene resin is preferred because a greater degree of image definition is achieved with a given quantity of additive material. Further, denser images are obtained when at least ab<H_4i- 25 percent by weight, based on the total weight of resin in the toner,, of a styrene resin is present in the toner. The styrene- esin may be a homo- polymer of styrene or styrene homologues or copolymers of styrene with other monomeric groups containing a single methylene group attached to a carbon atom by a double bond. Thus, typical monomeric materials which may be copolymerized with styrene by addition polymerization include: p-chlorostyrene vinyl naphthalene; ethylenically unsaturated mono-olefins such as or ethylene, propylene, butylene isobutylene a»4— tfa«~ Aike; vinyl esters such as vinyl chloride, vinyl bromide, vinyl fluoride, or vinyl acetate, vinyl propionate, vinyl benzoa.te,/ inyl butyrate •aftd-tbe— like; esters of alpha-methylene aliphatic monocarboxylic acids such as methyl acrylate, ethyl acrylate, n-butylacrylate , the.-like; acrylonitrile, methacrylonitrile, acrylamide, vinyl or ethers such as vinyl methyl ether, vinyl isobutyl ether/ vmyl ethyl ether//a»4-*ke-l.i¼e.; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone/ methyl isopropenyl ketone afiel- ke or !-ifce; vinylidene halides such as vinylidene chloride vinylidene chlorofluoride emd-fche-.tiOe'e' and N-vinyl compounds such as N-vinyl| pyrrole, N-vinyl carbazole, N-vinyl indole/ N-vinyl pyrrolidine emjd the -i-i¾oy and mixtures thereof. The styrene resins may also be addition formed by the / olymerization of mixtures of two or more of these unsaturated monomeric materials with a styrene monomer. The expression "addition polymerization" is intended to include known polymerization techniques such as free radical, anionic and cationic polymerization processes.

The vinyl resins, including styrene type resins, may also be blended with one or more other resins if desired. When the vinyl resin is blended with another resin, the added resin is preferably another vinyl resin because the resulting blend is characterized by especially good triboelectric stability and uniform resistance against physical degradation. The vinyl resins employed for blending with the styrene type or other vinyl resin may be prepared by the addition polymerization of any suitable vinyl monomer such as the vinyl monomers described above. Other thermoplastic resins may also be blended with the vinyl resins of this invention. Typical non-vinyl type thermoplastic resins include: rosin modified phenol formaldehyde resins, oil modified e ester epoxy resins, polyurethane resins, cellulos/< resins, polyether resins and mixtures thereof. When the resin component of the toner contains styrene copolymerized with another unsaturated monomer or a blend of polystyrene and another resin, a styrene component of at least a&eu_ 25 percent, by weight, based on the total weight of the resin present in the toner is preferred because denser images are obtained and a greater degree of image definition is achieved with a given quantity of additive material.

The combination of the resin component, colorant and additive, whether the resin component is a homopolymer, copolymer . preferably has' or blend, /should -have a blocking temperature of at least a -H*½ o -4 110 F. and a melt viscosity of less than about 2.5 X 10 poise at o temperatures up to about 450 F. When the toner is characterized n o by a blocking temperature less tha a&eu½ 110 F. the toner particl may ■ -to a l m rat durin stora e a hin rati l form undesirable films on the surface of reusable, photo-constructors which adversely affect image quality. If the melt viscosity of the toner,, ,is greater than 2.5 x 10 ^ poise at temperatures above 450°F. , the toner material of this invention may not adhere properly to a receiving sheet even under conventional xerographic machine fusing conditions and may easily be removed by rubbing.

The solid toner additives of this invention may be selected from four different groups of organic compounds. In the first group the compounds are solid esters of o-phthalic or m-phthalic acid or tetrahydrophthalic acid* For maisimum resistance against . agglomeration, the toner should contain from 2 percent to 45 percent, by weight, based on the total weight of the toner resin, of a solid ester of o-phthalic or m-phthalic acid having a melting point between 110°F. to 175°F.

Any suitable solid ester of o-phthalic or m-phthalic . acid or 4,5-epoxy - tetrahydrophthalic acid may be employed in the toners of this invention. Typical solid esters of o-phthalic and m-phthalic acid and 4,5-expoxy - tetrahydrophthalic acid include diisodecyl 4,5-epoxy - tetrahydrophthalate, dicyclohexyl phthalate, diphenyl phthalate, dimethyl isophthalate, diethoxyethyl phthalate, and di-(dlhydroabletyl) phthalate. Esters having a melting point between 110°F. to 175°F. are preferred because the toners containing these additives possess greater storage stability. Maximum resistance against toner agglomeration is achieved when the toner contains from 2 percent to 45 percent by weight, based on the total weight of the toner resin, of the solid ester. As the relative quantity of additive in the toner is increased above 45 percent, the mechanical strength, creep image begins to decrease rapidly. Thus, when a toner consisting essentially of 100 percent ester material is employed in automatic copying and duplicating machines, extensive toner dust is formed and the fused toner images tend to crumble and flake off receiving sheets when the sheets are folded. VJhen less than 2 percent of the additive 1* employed in the toner, the toner fusing, flow and triboelectric properties are not very much better than those of a toner which does not contain the additives* If desired, mixtures of additives may be employed in the toner. An increase in the relative quantity of additive tends to reduce the melt viscosity of the ultimate toner.

Optimum results are obtained when the toner contains from 2 percent to 15 percent by weight, based on the total weight of the toner resin, of diphenyl phthalate because the resulting toner is characterized by excellent resistance to creep, high mechanical strength and improved Imaging properties. In the second group, the compounds have the general structure: wherein n represents a positive integer from 1 to 7 inclusive (preferably 3 to 7) and R represents an esterifying radical having from 2 to 12 (preferably 3 to 12) carbon atoms. Typical compounds represented by this fofmula include: pentaerythritol tetrabenzoate, sucrose benzoate, triethylene glycol dibenzoate, glyceryl tribenzoate, neopentylglycol dibenzoate or trimethylole-thane tribenzoate." -and- the litea . Outstanding results have been obtained when the additive is pentaerythritol tetrabenzoate. When the additive is pentaerythritol tetrabenzoate, the advantages obtained in blocking resistance, lower tendency to film and optimum fusing temperatures are supplemented by sharp, high-contrast copies having little or no background deposits. The negligible background deposits in the ultimate copy appear to be due to a markedly reduced tendency of the toner to adhere to the background areas of a photoconductor during development. Thus, toners containing pentaerythritol tetrabenzoate are the preferred toners in this invention. Compounds in the third group have the general structure: (b) " wherein R"' represents one or more of hydrogen, chlorine, bromine, an aryl radical, or analkyl radical having from 1 to 6 carbon atoms and R' and R" represent hydrogen, an aryl radical, a cycloalkyi radical, a hydroxyalkyl r adical, an alkenyl radical or an alkyl radical having from 1 to 12 carbon atoms. Typical compounds represented by this formula include: N-cyclohexyl p-toluene sulfonamide, N-ethyl p-toluene sulfonamide, o-toluene sulfonamide, p-toluene sulfonamide, N,N-di-P-hydroxyethyl p-toluene sulfonamide, Ν,Ν-dimethyl benzene sulfonamide, N-cyclohexyl benzene sulfonamide, JSi-cyclohexyl-3,4-dichlorobenzene sulfonamide and N-allyl p-toluene sulfonamide.

Compounds of the fourth group have the general structure: wherein n1 represents zero or a positive integer from 1 to 3 inclusive and m has an average value from 0,5 to 2,5 inclusive.

Typical polychlorinated polyphenyl compounds represented by this formula include: ρ,ρ'-diehloro biphenyl) 2,4,7,9-tetrachloro blphenyl; 1,4 bis (p-chlorophenyl)-2 chlorobenzene and 2,2· dichloro-4,4' (p-chlorophenyl) biphenyl. Some of these compounds are sold under the "Aroclor" trademark by the Monsanto Company, St. Louis, Missouri and under the "Halovax" trademark by the Koppers Company, Inc., Pittsburgh, Pennsylvania, for example, Aroclor 2565 , Aroclor 4465 , Aroclor 5442 , Aroclor 5460 and Halowax 0077. Preferably, the additive of the second, third and fourth groups is employed in an amount from 5.percent to 55 percent, by weight, based on the total weight of the resinous component of the toner. As the relative quantity of additive in the toner is increased above 65 percent, the mechanical strength, creep resistance and permanency of the ultimate fused toner image begins to decrease rapidly. Thus, when brittle, non-polymeric compounds such as the compounds disclosed in U.S. Patent 3 * 272 , 644 are employed as toners in automatic copying and duplicating machines, extensive toner dust is formed and the fused toner images tend to crumble and flake off receiving sheets when the sheets are folded. Further, some solid non-polymeric materials tend to vaporize or sublime and form toxic or flammable fumes. When less than 3 percent of the additive is employed in the toner, the toner fusing, flow and triboelectric properties are not very those of much better tha /a toner which does not contain the additives. If desired, mixtures of additives may be employed in the toner. An increase in the relative quantity of additive tends to reduce the melt viscosity of the ultimate toner.

It is to be understood that the specific formulas and names given to the additives and resins of this invention represent the vast majority of the material present, but do not exclude the presence of other materials thanthose specified. For example, some commercial materials such as polystyrenes, and polychlorinated polyphenyl compounds contain trace amounts of homologues or unreacted or partially reacted monomers. Any minor amount of such aubstituents may be present in the materials of this invention.

Any suitable solid hydrophobic metal salt of a fatty preferably one acid having melting point greater than 57 0. may be employed with the toner resin of this invention. The metal salt should be substantially insoluble in water. Water soluble metal salts lack the proper electrical properties and are adversely affected by humidity changes normally occurring in the ambient atmosphere. However, a large proportion of salts commonly regardec as insoluble, actually dissolve to a slight extent. To effective] carry out the purposes of this invention, the solubility of the salt should be negligible. The salts having the desired specific characteristics include many salts of linear saturated fatty acids, unsaturated fatty acids, partially hydrogena'ted fatty acids and substituted fatty acids and mixtures thereof. The metal salts may be tumbled or milled with the toner or carrier particles or intimately dispersed in each toner or carrier particle. However, the latter embodiment is less desirable than the tumbled or milled mixtures because a greater quantity of metal salt is required to provide a sufficient quantity of metal salt, exposed at the surface of the developer particles.' The metal salts are preferably mixed with toner material by tumbling . preformed finely divided metal salt particles with preformed finely divided toner par.ticles. The tumbling process is continued until the preformed metal salt particles are uniformly distributed throughout the mass of toner particles. Excellent toner mixtures are obtained when the preformed toner particles are tumbled with preformed metal salt particles having a size range between about- 0.5 to ■a¾o¾rt*- 50 microns. The tumbled mixtures are preferred because the resulting treated toners exhibit extremely stable imaging characteristics under widely fluctuating humidity conditions.

Typical fatty acids from which stable solid hydrophobic metal salts may be derived include: caproic acid, enanthylic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid lauric acid, tridecoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, nondecylic acid, arachidic acid, behenic acid, stillingic acid, palmitoleic acid, oleic acid, ricinoleic acid, petroselinic acid, vaccenic acid, linoleic acid, linolenic acid, eleostearic acid, licanic acid, parinaric acid, gadoleic acid, arachidonic acid, cetoleic acid and mixtures thereof. Typical stable solid metal salts of fatty acids include: cadmium stearate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, zinc oleate, manganese oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, magnesium oleate, zinc palmitate, cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, lead caprylate, lead caproate, zinc linoleate, cobalt linoleate, calcium linoleate, zinc ricinoleate, cadmium ricinoleate and mixtures thereof.

Where the solid hydrophobic metal salt of a higher fatty acid is to be physically mixed with or applied as a coating on toner or carrier particles, the metal salt is preferably present from in an amount ikienw-abou-t 0.02% to -afeeefe 10% based on the weight of the toner in the final developer mixture. Optimum results are obtained with efeoete 0.05 to abowb- 4% of the metal salt. Although the initial electrostatic imaging surface potential may be reduced and abrasion resistance improved when the proportion of metal sal present is increased .above afeew*- 10%, undesirable background deposits increase noticeably. If the charge voltage is reduced to compensate for the presence of metal salt in excess of about 10%, the images begin to acquire a "washed out" appearance. It ii not essential that the entire surface of each toner particle be coated with the metal salt, e.g., sufficient metal salt is presen when 10 to 16% of the toner particle surfaces are coated with a metal salt. When the metal salt is dispersed in rather than coated on a toner or carrier particle, proportionally more metal salt is necessary in order to maintain a sufficient quantity of exposed salt at the surface of the toner or carrier particle.

The additional amount of metal salt necessary depends to a large extent on the surface area of the particles, hence upon the particle diameter selected. The use of small quantities of calcium stearate as a pigment wetting agent in zinc oxide developing powders is known as disclosed by Greig in U. S. Patent 3,053,688 at column 5, line 41 and Greig et al in Canadian Patent 633,458 at column 9, line 8. However, the quantity of calcium stearate used by Greig and Greig et al to facilitate the wetting of pigments dispersed in zinc oxide developing powders is insufficient to provide an effective quantity of exposed calcium stearate at the surface of the toner particle for the purposes of the instant invention. When less than ab&fet--0.02% metal salt based on the weight of the toner is actually available at the surface of the toner particle, its triboelectric, flow, abrasion, transfer and image forming properties are -substantially the same as a toner or carrier which does not contain a metal salt of a fatty acid. Obviously, with a given quantity of metal salt based on the weight of the toner, a greater volume of the salt is available at' the surface of the toner or carrier when the metal salt is added to a mixture of preformed colored toner particles or carriers than when it is intimately dispersed within each toner particle or carrier. If the concentration of metal salt is increased to the point where the toner consists essentially of 100% metal salt, the metal salt will form slippery films on the electrostatic image-bearing surface and carrier particles which interfere with powder image transfer, background removal and cleaning. U. S. Patent 3,083,117 discloses a method of applying reactive toners containing 100% iron stearate to an electrostatic image and then transferring the developed image to a transfer sheet wet with an alcoholic solution of gallic acid. The iron stearate reacts with the gallic acid to form a black reaction product. In addition to the problems enqountered when toner containing 100% metal salt is employed, electrostatic development methods of the foregoing type require liquid pre- treatment of the receiving sheet with an attendant increase in cost and inconvenience. Further, curling, image bleeding, and offset, often occur when moistened receiving sheets are used.

Additional equipment to dispose of toxic and inflammable fumes may also be necessary.

Excellent results have been obtained with zinc stearate. When the toner and developer particles of this invention are treated with zinc stearate, particularly in the range of -abew-fc 0.05 to afees-fe- 4 percent by weight based on the total weight of toner, better flow, less background, higher density images at lower initial charging voltages, and higher machine speeds with less power are achieved. Drum wear is markedly reduced.

Any suitable pigment or dye may be employed as the colorant for. the toner particl.es. Toner colorants are well known and include, for example, carbon black, nigrosine dye, aniline blue, Calco Oil Blue, chrome yellow, ultra marine blue, duPont Oil Red, Quinoline Yellow, methylene blue chloride, phthalo-cyanine blue, Malachite Green Oxalate, lamp black, Rose Bengal and mixtures thereof. The pigment or dyes should be present in the toner in a sufficient quantity to render it highly colored so that it will form a clearly visible image on a recording member. Thus, for example, where conventional xerographic copies of typed documents are desired, the toner may comprise a black pigment such as carbon black or a black dye such as Amaplast Black dye, available from the National Aniline Products Inc.

Preferably, the pigment is employed in an amount from ahfflut 3 per cent to oboufe- 20 percent, by weight, based on the total weight of the colored toner. If the toner colorant employed is a dye, substantially smaller quantities of colorant may be used.

The toner compositions of the present invention may be prepared by any well known toner mixing and comminution technique. or exam le the in redients ma be thorou hl mixed b blendin mixing and milling the components and thereafter micropulverizing the resulting mixture. Another well known technique for forming toner particles is to spray-dry a ball-milled toner composition comprising a colorant, a resin and a solvent.

Generally, the degree of quality of toner fix at a given fuser temperature decreases with an increase in toner melt viscosity. As discussed above, if the melt viscosity of the -4 toners of this invention is greater than .afewte 2.5 X 10 poise o at temperatures above eboute 450 F., the toner materials do not adhere properly to a receiving sheet even under conventional xerographic machine fusing conditions. Thus, the melt viscosity value of the toners of this invention aids in the determination of the degree of flow and penetration . of the toner into the surface of a receiving substrate such as paper during the hea . fixing step. The expression "melt viscosity", as employed herein, is a measure of the ratio of shear stress to shear rate in poise at a given temperature. All viscosity measurements are determined with .(Registered Trade Mark) an Instron /Capillary Rheometer, Model TTC.

When the toner mixtures of this invention are to be employed in a cascade development process, the toner should have an average particle size by weight percent less than about 30 microns and preferably between about 4 and about 20 microns for optimum results. For use in powder cloud development methods, particle diameters of slightly less than 1 micron are preferred.

Suitable coated and uncoated carrier materials for cascade development are well known in the art. The carrier particles comprise any suitable solid material, provided that the carrier particles acquire a charge having an opposite polarity to that of the toner particles when brought in close contact with the toner particles so that the toner particles adhere to and surround the carrier particles. When a positive reproduction of the electrostatic images is desired, the carrier particle is selected so The toner images on 8 inch by 13 inch copy sheets are transported through the fuser at the rate of 11 sheets per minute which is twice the normal rate. Since the standard Xerox 813 copy machine drive motor stalls and overheats when the machine is operated at twice the normal operating speed, a motor having twice the power output is employed. After passage through the fuser, the copy sheets are fastened to a full page abrading cylinder having a diameter of about 4.75 inches. A conventional 813 cleaning web is pressed against the copy sheet by a spring loaded roller under a spring tension of about 40 pounds. By rotating the cylinder bearing the copy sheet, the entire toner image on the copy sheet is abraded by frictional contact with the web. A minimum fuser temperature is established when all the test characters are legible after an abrasion run of 5 'revolutions of the abrading cylinder. Xerox 813 carrier beads are employed with the toner during the development step. The minimum fuser temperature at which legible copies are obtained with the 813 toner is found to o be about 610 F. Many of the copies leaving the fuser contain glowing embers and in some instances live flames. ' Micrograph studies of the reusable imaging surface after 5,000 cycles reveals considerable wear and degradation of the surface.

EXAMPLE II A toner mixture is prepared comprising about 7.5 parts by weight of a copolymer of about 65 parts, by weight of styrene arid 35 parts by weight of butyl methacrylate; about 1.5 parts by weight of pentaerythritol tetrabenzoate; and about 1 part by weight of carbon black (Neo Spectra Mark II) . The additive is a hard, dry solid having a melting range of aboufc- 201 to obou-fe 204°F. The toner mixture has an Instron Capillary Rheometer melt viscosity of -4 o about .5 X 10 poise at 255 F. After melting and preliminary milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight percent of about 10 to abwb- 20 microns. About 1 part by weight of the pulverized toner particles are mixed with abmHs-0.01 parts by weight of zinc stearate particles having a size range from 0.5 to about; 35 microns and about 99 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and high resolution images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading o o cylinder is about 510 F. This is a reduction of about 100 F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser. No blocking is observed after a sample of this toner is stored in an air circulating oven maintained at a temperature of about 110°F. for 24 hours.

EXAMPLE III A toner mixture is prepared comprising about 8.5 parts by weight of a copolymer of about 65 parts, by weight of styrene and about 35 parts by weight of butyl methacrylate; about 0.5 parts by weight of a mixture of ortho and para toluene sulfonamide; and about 1 part by weight of carbon black (Regal 300) . The additive is available from the Monsanto Co. under the trademark SANTICIZER 9 and is a hard, dry solid having a melting point of about 221°F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight percent of about 7 to -about.12 microns. About 2 parts by weight of the pulverized toner particles are mixed with about 0.05 parts by weight of zinc stearate having a size range from afeett-fe 0.5 to -about. 35 microns and about 98 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and high resolution images substantially free from background are obtained. Under .substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and thafe the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 550°F.

This is a reduction of about 60°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser. Micrograph studies of the reusable imaging surface after 10,000 cycles reveals less wear and degradation of the surface than the imaging surface of Example I.

EXAMPLE IV A toner mixture is prepared comprising about 6.5 parts by weight of polystyrene; about 2 parts by weight of a poly-chlorinated polyphenyl and about 1.5 parts by weight of carbon black. The additive is available from the Monsanto Co. under the trademark Aroclor 5460 and is a hard, dry solid having a melting range of about- 208°F. to -aboufc_221°F. , a specific gravity (25°C./ 25°C.) of about 1.67 and a chlorine content of about 58.5 to 60.6 percent by weight. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight percent of atee-H-fe 10 to a&GUfe- 18 microns. About 1.5 parts by weight of about' the pulverized toner particles are mixed with a&ou - 0.015 parts by weight of iron oleate having a size range from about 5 to -ateetrt 40 microns and about 98.5 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and high resolution images substantially free from background are obtained. Under, substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be usee and that the minimum fuser temperature at which legible copies arc obtained after an abrasion run of 5 revolutions of the abrading o o cylinder is about 550 F. This is a reduction of 60 F. from the fuser temperature required for the control sample of Example I.

No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE V A toner mixture is prepared comprising about 7.5 parts \ by weight of a copolymer of about 70 parts by weight styrene and about 30 parts by weight of hexylmethacrylate; about 1.5 parts by weight of pentaerythritol tetrabenzoate and about 1 part by weight: of carbon black (Super Carbobar) . The additive is a hard, dry solid having a melting range of . After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight percent of -afeoufc- 10 to -atee«* 20 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.025 parts by weight of cobalt palmitate having a size range from -afeeu-fe 1 to ai>e*rt 30 microns and about 99 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and high resolution images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion o run of 5 revolutions of the abrading cylinder is about 490 F.

This is a reduction of 120°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE VI A toner mixture is prepared comprising about 7 parts by weight of a copolymer of 80 parts by weight of styrene and about 20 parts by weight of isobutyl methacrylate and about 2 parts by weight of pentaerythritol tetrabenzoate and about 1 part by weight of carbon black (Black Pearls L) . The additive is a hard, dry ^ o o solid having a melting range of -ebowfc-201 F. to a&eu-t. 204 F. The toner mixture has an Instron Capillary Rheometer melt viscosity -4 o of about .5 X 10 poise at 260 F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight percent of afeea*-10 to abe-H-fe- 20 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.01 parts by average particle size by weight percent of efcoefe 0.5 to~ek©wi~ 1 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.05 parts by weight of zinc linoleate. having a size range from -aixsw*-; 0.8 to about- 25 microns and about 99 parts by weight of uncoated glass carrier beads having an average particle size of about 500 microns and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and good images low in -background are obtained. Under substantially identical test conditions, it is found the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are . obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 570°F. This is a reduction of about 40°F. from the fuser temperature required for the control sample of Example I No live embers or flames are observed on copies emerging from the fuser. Micrograph studies of the reusable imaging surface after 10,000 cycles reveals less wear and degradation of the surface than the imaging surface of Example I.

EXAMPLE VIII A toner mixture is prepared comprising about 7 parts by weight of a copolymer of about 50 parts, by weight of propyl \ methacrylate and about 50 parts by weight of methacrylonitrile; about 2 parts by weight of a mixture of or.tho and para toluene sulfonamide; and about 1 part by weight of carbon black (Neo Spectra Mark II). The additive is available from the Monsanto Co. under the trademark SANTICIZER 9 and is a hard, dry solid having . o melting point of about 221 F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight percent of about 5 to about 16 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.06 parts by weight of zinc stearate having a size range from about 0.5 to about 20 microns and about 99 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and good resolution images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the o abrading cylinder is about 580 F. This is- a reduction of about 30°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser. Micrograph studies of the.. reusable imaging surface after 10,000 cycles reveals less wear and degradation of the surface than the imaging surface of Example I.

EXAMPLE IX .

A toner mixture is prepared comprising about 7.5 parts by weight of a copolymer of about 20 parts by weight of vinyl acetate and about 80 parts by weight of vinyl chloride; about 1.5 parts by weight of pentaerythritol tetrabenzoate ; and about 1 part by weight of carbon black. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a Szegvari attritor to yield toner particles having an average particle size by weight of abouj. 10 to about 20 microns. About 2 parts by weight of the pulverized toner particles are mixed with about 0.1 parts by weight of zinc | stearate having a size range from about 0.5 to abovtt 20 microns and about 98 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine describee in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 560°F. This is a reduction of about 50°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE X A toner mixture is prepared comprising about 9 parts by weight of an ethyl methacrylate polymer; about 1 part by weight of pentaerythritol tetrabenzoate and about 1 part by weight of carbon black. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight of about 5 to about 10 microns. About 1.5 parts by weight of the pulverized toner particles are mixed with about 0.01 parts by weight of zinc stearate having a size range from afeewt-0.5 to -about 40 microns and about 98.5 parts by weight of uncoated glass beads and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 o revolutions of the abrading cylinder is about 540 F. This is a o reduction of about 70 F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XI A toner mixture is prepared comprising about 8 parts by. weight of a copolymer of about 35 parts by weight vinyl acetate and about 65 parts by weight of acrylonitr le? about 1 part by weight of trimethylolethane tribenzoate and about 1 part by weight of carbon black. The additive is a hard, dry solid having a o melting point of about 163 F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight of about 7 to about 12 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.04 parts by weight of zinc stearate having a size range from abo t.0.5 to about 20 microns and about 99 parts by weight of glass beads having an average diameter of about 500 microns and coated with a silicone terpolyme reaction product of butyl methacrylate, styrene and vinyl tri-ethoxy silane and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 560°F. This is a reduction of about 50°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XII A toner mixture is prepared comprising 7.5 parts by weight of a copolymer of about 25 parts of n-butyl methacrylate resin and about 75 parts by weight of acrylonitrile resin; about 1.5 parts by weight of glyceryl tribenzoate; and about 1 part by weight of carbon black. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive and pigment in the thermoplastic resin body.. The resulting mixed composition is cooled and then finely subdivided in a high speed attritor to yield a toner particle size by weight of about 5 to about 10 microns. About 99 parts by weight of 813 Xerox carrier beads is mixed with about 1 part by weight of toner and about 0.05 parts by weight of zinc stearate having a size range from afeenfe 0.5 to _abo¾tfi-40 microns and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading o o cylinder is about 545 F. This is a reduction of about 65 F. from the fuser temperature required for the control example of Example 1. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XIII A toner mixture is prepared comprising about 5.5 parts by weight of a copolymer of about 90 parts by weight of styrene and parts by weight of isobutyl methacrylate, about 3.5 parts by weight of pentaerythritol tetrabenzoate and about 1 part by weight of carbon black. The additive is a hard, dry solid having a melting range of ebvvr 201 to -a e-Hk 204°F. After melting and preliminary mixing in a Banbury Mixer, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is copied and then finely subdivided in a jet pulverizer to yield toner particles having an average ar cle size by weig t ercent of about 10 to 20 microns, Afeout 1 part by weight of the pulverized toner particles is mixed with about 0.01 parts by weight of zinc stearate having a size range from adaou-t.0.5 to -afeosrt:- 20 microns and about 99 parts by weight of 500 microns uncoated glass carrier beads and substituted for the 813 developer in the testing machine described in Example I.

The treated toner dispenses well and high resolution images substan tially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion o run of 5 revolutions of the abrading cylinder is about 510 F. This is a reduction of about 100°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XIV A toner mixture is prepared comprising of about 5.5 parts by weight of copolymer of about 80 parts by weight styrene and about 20 parts by weight of ethyl acrylate, and about 3.5 parts by weight of a mixture of ortho and para toluene sulfonamide, and about 1.0 by weight of carbon black. The additive is available from the Monsanto Co. under the trademark SANTICIZER 9 and is a hard, dry solid having a melting point of 22l°F. After milling and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight of about 10 to about 20 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.02 parts by weight of lead stearate having a size range from about 10 to about 35 microns and about 99 parts by weight of 813 carrier in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be usedi and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 500°F. This is a reduction of about 110°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XV A toner mixture is prepared comprising about 7.5 parts of copolymer of about 80 parts by weight of styrene and about 20 parts by weight isobutyl methacrylate and about 1.5 parts glyceryl! tribenzoate and 1.0 parts by weight carbon black. Glyceryl tri-benzoate is a dry solid manufactured by Velsicol Chemical Corporation with a molecular weight of 404 and a melting point of about 160°F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight of about 8 to 22 microns. About 1 part by weight of the pulverized toner particles are mixed with aboul 0.01 parts by weight of zinc stearate having a size range from abo»* 0.4 to ateou.fc 40 microns and about 99 parts by weight of 813 Xerox carrier and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after abrasion of o revolutions of the abrading cylinder is about 540 F. This is a o reduction of 70 F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XVI A toner mixture is prepared comprising about 8.0 parts by weight of a copolymer of about 70 parts by weight styrene and 30 parts by weight of vinyl acetate, about 1.0 part by weight of trimethylolethane tribenzoate and about 1.0 parts by weight of carbon black. The additive is a hard, white crystalline solid having a melting point of about 163°F. and a molecular weight of 432. After melting and mixing in a Banbury mixer and thoroughly rubber milling to yield a uniformly dispersed composition of the additive in the thermoplastic resin body, the mixed composition is cooled and then pulverized in a Szegvari attritor to yield toner particles having an average particle size of about 10 to 20 microns. About 1 part by weight of the pulverized toner particlesj are mixed with about 0.03 parts by weight of zinc stearate havingj a size range from abottt-0.4 to atee« - 40 microns and about 99 parts by weight of 813 carrier in the test machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minumum fuser temperature at which legible copies are obtained after an abrasion run of 5 o revolutions of the abrading cylinder is about 550 F. This is a reduction of about 60°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser. .

EXAMPLE XVII A toner mixture is prepared comprising about 8.0 parts by weight of a copolymer of about.85 parts by weight styrene and about 15 parts by weight vinylidene chloride copolymer and about 1.0 part by weight of ethylene glycol dibenzoate and about 1.0 part by weight carbon black. The additive is available from the C. P. Hall Co. under the trademark Hallco 870 and is a hard, dry solid having a melting range of abe¾fe 156°F.. to -ebett-fe 164°F. Afti melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size by weight of about 8 to 14 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.01 parts by weight of zinc stearate having a. size range from about 0.4 to obout 40 microns and about 99 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 540°F. This is a reduction of 70°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XVIII A toner mixture is prepared comprising about 6.0 parts by weight of a copolymer of about 20 parts by weight styrene and about 80 parts by weight of vinyl alcohol; and about 3.0 parts N by weight of ]/-cyclohexyl p-toluene sulfonamide, and about 1.0 part by weight of carbon black; The additive is available from the Monsanto Co. under the trademark SANTICIZER 1-H and is a hard water insoluble crystalline solid, heat stable to about 300°F. with a crystalline melting point of 186°F. After melting and preliminary mixing, the composition is fed into a rubber mill and -thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle s \ size by weight percent of *b©«*-10 to 20 microns. About 2 parts by weight of the pulverized toner particles are mixed with about 0.02 parts by weight of zinc palmitate having a size range from ateowt 0.5 to k¾H*fe- 35 microns and about 98 parts by weight of a coated carrier comprising glass beads coated with ethyl cellulose coating and having an average diameter of about 600 microns and . substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantiall identical test conditions it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 560°F. This is a reduction of 50°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XIX A toner mixture is prepared comprising about 6.0 parts by weight of a copolymer of about 80 parts by weight styrene, about 2§ N ' parts by weight acrylonitrile and about 3.0 parts by weight of jfi-ethyl-p-toluene sulfonamide and about 1.0 part by weight of carbon black. The additive is available from the Monsanto Co. under the trademark SANTICIZER 3 and is a hard, white solid with a melting point of about 139°P. After melting and initial mixing, the compo sition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles hav-p an average particle size by weight of 10 to 20 microns. About 1 part by weight of the pulverized toner particles are mixed with about 0.04 parts by weight of zinc stearate having a size range from about 0.4 to about 40 microns and about 99 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in' Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 560°F. This is a reduction of 50°F. from the fuser temperature required for the control sample of Example I. No live embers or flame are observed on copies emerging from the fusL EXAMPLE XX A toner mixture is prepared comprising about 7.5 parts copolymer of about 80 parts by weight styrene and about 20 parts by weight of isobutyl methacrylate and about 1.5 parts by weight of pentaerythritol tetrabenzoate and about 1.0 parts by weight carbon black (Super Carbobar) . The toner has a melt viscosity as measured on the Instron Capillary Rhepmeter of .5 x 10 4 poise at a temperature of about 280°F. The additive is a dry solid having a melting range of about 201 to about 204°F. After melting and preliminary mixing, 'the com-position is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a Szegvari Attritor to yield toner particles having an average particle size of about 10 to 20 microns. About one part of the toner is mixed with about 0.03 parts by weight of zinc stearate having a size range from about 0.5 to about 40 microns and about 99 parts of a coated carrier comprising glass beads coated with an ethyl cellulose coating and having an average diameter of about 600 microns and is substituted for the 813 developer in the testing machine described in Example I. The treated toner dispenses well and images substantially free from background are obtained. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum . fuser temperature at which legible copies aire obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 550°F. This is a reduction of about 60°F. from the fuser temperature required for the control sample of Example I. No live embers or flames are observed on copies emerging from the fuser.

EXAMPLE XXI A sample of the treated toner and carrier described in Example V is employed in the 813 Xerox copying machine described in Example I to make copies of a standard test image. Although the 813 machine is again operated at 11 copies per minute, the fuser temperature is set at about 490°F. The quality of fix of the toner image is tested in a Taber Abraser, Model 174, available from the Welch Scientific Co. About 20 cycles of the abraser is required to obtain an image density reduction of about 20 percent as measured on a Densichrom reflection unit.

EXAMPLE XXII A sample of the control toner and carrier described in Example I is employed to form toner images. The imaging and testing procedure used is substantially identical to the procedure described in Example XXI. Less than about 2 cycles of the abraser is required to obtain an image density reduction of about 20 percent as measured on the Densichrom reflection unit. The deposited toner image is easily destroyed by rubbing the images with a finger or thumb.

EXAMPLE 3KIII A control toner mixture is prepared comprising about 9 parts by weight of a mixture of ortho and para toluene sulfonai and 1 part by weight of Nigrosine SSB dye. The sulfonamide mixture is available under the trademark Santicizer 9 and is a · hard, dry solid having a melting point of about 221°F. After melting and preliminary mixing, the composition is thoroughly milled to yield a uniform dispersion of dye and sulfonamide.

The resulting mixed composition is cooled and finely subdivided in a Szegvari Attritor to yield an average particle size by weight percent of about 8 to about 15 microns. The resulting across a negatively charged latent electrostatic image bearing surface. The deposited toner image is transferred to a paper sheet and fused at about 305°F. When the imaged paper sheet is folded, it is found that the toner images located along the crease tended to crack and crumble. When an imaged sheet formed by the processes described in Example III is folded, no cracking crumbling of the toner images located along the crease is observed.

EXAMPLE XXIV A control sample containing 1 part toner particles, containing Santicizer 9 dyed with Amplast Black a-nd having an average particle size of about 10 to about 20 microns and about 99 parts Xerox 813 carrier particles" is tumbled in a inches rotating cylindrical jar having, an inside diameter of about 2.25 / and a surface speed of about 140 feet per minute. An inspection of the developer mixture after about 50 hours after the test is initiated reveals a large quantity of undesirable fine powder.

EXAMPLE XXV A toner mixture containing about 7.5 parts by weight of a copolymer of about 80 parts by weight of styrene and about 20 parts by weight of isobutyl methacrylate and about 1.5 parts by weight Santicizer 9 and about 1 part by weight of carbon black, and having an average particle size of about 10 to about 20 microns is mixed with about 99 parts by weight of · Xerox 813 carrier particles. The resulting developer is tumbled, in the rotating cylindrical jar described in Example XXIV.

An inspection of the developer mixture 50 hours after the test is initiated reveals substantially no undesirable powder.

EXAMPLE XXVI A control toner mixture is prepared comprising about 7.5 parts by weight of a copolymer of about 65 parts by weight of styrene and 35 parts by weight of butylmethacrylate; about 1.5 parts by weight of polyethylene wax; and about 1 part by weight of carbon black (Neo Spectra Mark II) . The wax is available under the trademark Tenite 812A, sold by Eastman Kodak and is a dry solid having a melting range of about 220 to about 230°F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the wax in the thermoplastic resin body. The resulting mixed composition is cooled with liquid nitrogen and then finely sub-divided in a Szegvari Attritor to yield toner particles having an average particle size of about 10 to about 20 microns. Cooling below room temperature was necessary to avoid filming of the toner material on the attritor parts. About one part of the toner is mixed with about 99 parts of a coated carrier comprising glass- beads coated with an ethyl cellulose coating and having an average diameter of about 600 microns. The resulting developer is used to make 8,000 copies in an 813 Xerox copying machine. The copies, particularly the copies made near the termination of the test, are characterized by very low density images and high background. A examination of the xerographic drum after the termination of the test reveals a heavy film of toner over the surface of the drum.

EXAMPLE XXVI \ A control toner mixture is prepared comprising about 7 parts by weight of a copolymer of about 80 parts by weight styrene and about 20 parts by weight of isobutyl methacrylate · and about 2.0 parts by weight of poly-ethylene sebacate and about 1.0 parts by weight of carbon black. The additive is a dry solid having a melting point of about 167°F. After melting and preliminary mixing, the composition is fed into a rubbermLll and thoroughly milled to yield a uniformly dispersed composition of the additive in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet by sharp, high density images and low background deposits. An examination of the xerographic drum after the termination of the 3 test reveals substantially imperceptible film of the toner over 4 the surface of the drum. • 5 EXAMPLE XXIX 6 A control toner sample substantiall identical to the 7 toner described in Example VI is tested for its blocking tempera• 8 ture. The test procedure involves. the steps of initially heating o 9 the toner particles in an air circulating oven at about 100 F. for 10 a 24 hour period and, thereafter, increasing the temperature in o 11 5 increments every 24 hours. The blocking temperature is that 12 temperature at which a mild crushing action with a spatula is 13 required to restore any toner agglomerates' formed to the original 14 finely divided particulate form. The blocking temperature of the o control sample is about 125 F. 16 EXAMPLE XXX ■ 17 A control toner mixture is prepared comprising about 7 18 parts by weight of a copolymer of about 80 parts by weight of 19 styrene and 20 parts by weight of isobutyl methacrylate ; about 2 parts by weight of ethyl-phthalyl ethyl glycolate and about 1 21 part by weight of carbon black (Black Pearls L) . The ethyl phthaly 22 ethyl glycolate is available under the trademark SANTICIZER E-15 \ 23 and is a liquid. After melting and preliminary mixing, the com- i . ^ ■ 24 position is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the wax in the thermoplastic 26 resin body. The resulting mixed composition is cooled with liquid 27 nitrogen and then finely subdivided in a Szegvari Attritor to 28 yield toner particles having an average particle size of about 10 29 to about 20 microns. The toner particles are then tested according to the procedure described in Example XXIX. The toner particles 31 blocked at the initial test temperature of 100°F. 82 of the imaging surface reveals numerous scratches and the effects of erosive conditions.

EXAMPLE XXXIII About 0.1 parts of zinc stearate having a particle size distribution from about 0.75 microns to about 40 microns Ls gently folded into one part of a colored preformed toner particle of the type described in Example VI. The resulting developer mixture is then thoroughly milled in a Szegvari attritor for about 10 minutes. The developing procedure of Example XXXII Ls repeated with a new drum and with the foregoing milled mixture substituted for the toner of Example XXXII at a relative humidity 3f about 50 percent at 70°P. and at a relative humidity of 80 o jercent at 80 F. Copies prepared with the milled sample possess ligher density solid area coverage and cleaner background than :opies prepared with the control sample. Further, visual ixamination of the electrostatic image-bearing surface reveals .ess wear than on the scratched image-bearing surface of Example -XXII. Considerably less torque is necessary to drive the drum rhen the stearate additive is employed and a lower voltage is 'equired to transfer the toner images to a receiving sheet.

EXAMPLE XXXIV About 0.025 parts of zinc stearate having a particle size iistribution from about 0.75 microns to about 40 microns is ently folded into about 10 parts of a colored preformed toner 'article of the type described in Example VI. The resulting lixture is then tumbled in a sealed container for 15 minutes, bout one part of the tumbled mixture is mixed with 99 parts of thyl cellulose coated carrier beads having an average particle ize of about 400 microns. The resulting developer mixture is ployed in a cascade developing process as described in Example XXII at a relative humidity of 50 percent at 70°F. and at a 1 EXAMPLE XXXV 2 A toner mixture is prepared comprising about 10 parts 3 by weight of carbon black (Neo Spectra Mark II) about, 85 parts 4 by weight of a copolymer of 65 parts by weight of styrene and about 35 parts by weight of n-butylmethacrylate, and 5 parts by we:, 6 of dicyclohexyl phthalate. This phthalate has a melting point of '7 about 140°F. After melting and preliminary. mixing, the composition 8 is rubber milled to yield a uniformly dispersed composition of the 9 carbon black in the thermoplastic resin body. The resulting mixed ,10 composition is cooled and then finely subdivided in a jet 11 pulverizer to yield toner particles having a average particle 12 size of about 10 to about 15 microns. The toner has a melt 13 viscosity of about 0.5 x 10~4 poise at about 285°F. and a block14 ing temperature of about 135°F. About 1 part by weight of the 15 pulverized toner particles are mixed with about 0.01 parts by 16 weight of, zinc stearate particles having a particle size from 17 about 5 to about 40 microns, and about 99 parts by weight of 18 Xerox 813 carrier beads and substituted for the developer in the 19 testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard 21 Xerox 813 drive motor can be used and that the minimum fuser 22 temperature at which legible copies are obtained after an abrasion O 23 run of 5 revolutions of the abrading cylinder is about 570 F . 24 This is a reduction of about 40°F. from the fuser temperature required for the control sample of Example I. No glowing embers 26 are observed on the copy samples as they emerge from the. toner 27 fuser. Micrograph studies of the reusable imaging surface after 28 5,000 cycles reveals less wear and degradation of the imaging 29 surface than the imaging surface of Example I.

EXAMPLE XXXVI 31 A toner mixture is prepared comprising about 10 parts 32 by weight of carbon black (Super Carbobar) , about 80 parts by weight of a copolymer of 65 parts by weight of styrene and 35 part.5 by weight of n-butyl methacrylate, and about 10 parts by. weight of diphenyl phthalate. This phthalate has a melting point of about 156° F. After melting and preliminary mixing, the β composition is fed into a rubber mill and thoroughly milled to β yield a uniformly dispersed composition of the carbon black in the 7 thermoplastic resin body. The resulting mixed composition is 8 cooled and then finely subdivided in a jet pulverizer to yield 9 toner particles having an average particle size of about 6 to 0 about 12 microns. This toner has a melt viscosity of about 0.5 1 x 10~4 poise at 275° F. and a blocking temperature . of about 125° F. About 1.5 parts by weight of the pulverized toner particles are mixed with about 0.01 parts by weight of z-inc stearate particles having a particle size between about 5 to about 40 microns, and about 99 parts by weight of Xerox 813 carrier beads and substitute i for the 813 developer in the testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 545° F. This is a reduction of about. 65° F. from the fuser temperature required for the control sample of Example. I. No glowing embers are observed on the copy samples as they emerge from the fuser. Micrograph studies of the reusable imaging surface after 5,000 cycles reveals less wear and degradation of the imaging surface than the imaging surface of Example I.

EXAMPLE XXXVII •A toner mixture is prepared comprising about 10 parts by weight of Sudan Black BN dye, about 80 parts by weight of a copolymer of about 65 parts by weight of styrene and about 35 parts by weight of n-butyl methacrylate, and about 10 parts by 1 v weight of dihydroabietyl phthalate.' This phthalate has a melting point of about 149° F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the carbon black in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of -afeeu* 10. to abou- 15 microns. This toner has a melt viscosity of about 0.5 x 10~4 poise at about 275° F. and a blocking temperature of about 125° F. About 1 part by weight of the pulverized toner particles are mixed with about 0.05 parts by weight of zinc oleate having a particle size range between about 0.5 to about 35 microns and about 99 parts by weight of" 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revoluti ons of the abrading cylinder is about 550° F. This is" a reduction of 60° F. from the fuser temperature required for the control sample of Example I. No glowing embers are observed on the copy samples as they emerge from the fuser. Micrograph studies of the reusable \ imaging surface after 5,000 copies reveals less wear and degradation of the surface than the imaging surface of Example I.

EXAMPLE XXXVIII A toner mixture is prepared comprising about 10 parts by weight of carbon black, about 75 parts by weight of a copolymer of about 80 parts by weight of styrene and about 20 parts by weight of isobutylmethacrylate, and about 15 parts by weight of dicyclohexyl phthalate. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the dye in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of about 6 to about 9 microns. This toner has a melt viscosity of about 0.5 x 10~4 poise at about 275° F. and a blocking temperature of about 130. As in all the Examples, the blocking temperature is determined by initially heating the toner particles in an. air circulating oven at about 100° F. for a 24 hour period and, thereafter, increasing the temperature in 10° increments ever 24 hours. The blocking temperature is that temperature at which a m ld crushing action with a spatula is required to restore any r, toner agglomerates formed to the original finely divided particulate form. About 2 parts by weight of the pulverized toner particles are mixed with about 0.015 parts by weight of zinc stearate particles having a size range from about 5 to about 40 microns and about 99 parts by weight of 813 Xerox carriex beads and substituted for the 813 developer in the testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be employed and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 540° F. This is ^reduction of 60° F. from the fuser temperature required for the control sample of Example I. No glowing embers are observed on the copy samples as they emerge from the fuser. Micrograph' studies of the reusable imaging surface after 5,000 cycles reveals less wear and degradation of the surface than the imaging surface of Example I.

EXAMPLE XXXIX " A toner mixture is prepared comprising about 10 parts by weight of carbon black, about 75 parts by weight of a copolymer of about 80 parts by weight of styrene and about 20 parts by weight of isobutylmethacrylate, and about 15 parts by weight of dimethyl isophthalate. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of^the pigment and phthalate in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of about 6 to about 9 microns. This toner has a melt viscosity of about 0.5 x 10~4 poise at about 280° F. and a blocking temperature of about 130° F. About 1 part by weight of the pulverized toner particles are mixed with about 0.01 parts by weight of zinc stearate particles having a size range from about 0.5 to about 30 microns, and about 99 par;ts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be employed and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 560^ F. This is a reduction of 50° F. from the fuser temperature required for the control sample of Example I. No glowing embers are observed on the copy sheet samples as they emerge from the fuser. Micro-graph studies of the imaging surface after 5,000 cycles reveals less wear and degradation of the surface than the imaging surface of Example I.

EXAMPLE XL A toner mixture is prepared comprising about 10 parts by weight of carbon black, about 65 parts by weight of a copolymer of about 90 parts by weight polystyrene and about 10 parts by weight of isobutylmethacrylate, and about 25 parts by weight of dicyclohexyl phthalate. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the carbon black and phthalate in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average* particle size of about 10 to about 15 microns. This toner has a melt viscosity of about 0.5 x 10"4 poise at about 250° F. and a blocking temperature of about 110° F. About 1 part by weight of the pulverized toner particles are mixed with about 0.1 parts by weight of zinc oleate having a particle size from about 0.5 to about 25 microns, and about 99 parts by weight of 813 Xerox carrier beads and substituted for the 813 developer in the testing machine described in Example I. Under substantially identical tes conditions, it is found that the original ^standard Xerox 813 drive motor can be used and that the minimum fuser temperature . at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 500° F. This is a reduction of 110° F. from the fuser temperature required for the control sample of Example I. No glowing embers are observed on the copy sheet samples as they emerge from the'1 fuser.

Micrograph studies of the reusable imaging surface after 5,000 cycles reveals less wear and degradation of the surface than the imaging surface of Example I.

^ EXAMPLE XLI A toner mixture is prepared comprising about 10 parts by weight of carbon black (Neo Spectra Mark II) , about 65 parts by weight of polystyrene and 25 parts by weight of diphenyl phthalate. After melting and preliminary mixing, the composition is rubber milled to yield a uniformly dispersed composition of the carbon black in the thermoplastic resin body. The resulting mixed] composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of about 10 to about 15 microns. The toner has a melt viscosity of about 0.5 x 10 poise at about 255° F. and a blocking temperature of about 115° F. About 1 part by weight of the pulverized. toner particles are mixed with about 0.01 parts b weight of zinc stearate particles having a particle size from about 5 to about 40 microns, and about 99 parts by weight of Xerox 813 carrier beads and substituted for the developer in the testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 510° F. This is a reduction of about 100 F. from the fuser temperature . required for the control sample of Example' I. No glowing embers are observed on the copy samples as they emerge from the toner fuser. Micrograph studies of the reusable imaging surface after 5,000 cycles reveals less wear and degradation of the imaging surface than the imaging surface of Example I.

EXAMPLE XLII A toner mixture is prepared comprising! 'about 10 parts by weight of carbon black (Super Carobar) , about 70 parts by weight of polymethylmethacrylate and 20 parts by weight of di-(dihydroabietyl)phthalate. After melting and preliminary mixing, tne composition is rubber milled to yield a uniformly dispersed composition of the carbon black in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of about 6 to about 12 microns. The toner has a melt viscosity of about 0.5 x 10 poise at about 265° F. and a blocking temperature of about 120° F. About 1 part by weight of the pulverized toner particles are mixed with about 0.01 parts by weight of lead linoleate particles having a particle size from about 3 to about 35 microns, and about 99 parts by weigh of Xerox 813 carrier beads and substituted for the developer in the testing machine described in Example I. Under substantially identical test conditions/ it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 530° F. This is a reduction of about 80° F. from the fuser temperature required for the control sample of Example I. No glowing embers are observed on the copy samples as they emerge from the toner fuser. Micrograph studies of the reusable imaging surface after 5,000 cycles reveals less wear and degradation of the imaging surface than the imaging surface of Example^ I.

EXAMPLE XLIII ·.·'·'· A toner mixture is prepared comprising about 10 parts by weight of carbon black, about 75 parts by weight of a copolymer of 90 parts by weight of styrene and about 10 parts by weight of vinylidene chloride, and 15 parts by weight of diphenyl phthalate. After melting and preliminary mixing, the composition is rubber milled to yield a uniformly dispersed composition of the carbon black in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of about 7 to about 12 microns. The toner has a melt —4 o viscosity of about 0.5 x 10 poise at about 275 F. and a blocking temperature of about 125° F. About 1 part by weight of the pulverized toner particles are mixed with about 0.01 parts by weight of zinc stearate particles haying a particle size from about 5 to about 40 microns, and about 99 parts by weight of uncoated glass beads and substituted for the developer in the testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is about 565° F.

This is a reduction of about 65° F. from the fuser temperature required for the control sample of. Example I. No glo ing embers are observed on the copy samples as they emerge from the toner' fuser. Micrograph studies of the reusable imaging surface after 5,000 cycles reveals less wear and degradation of the imaging surface than the imaging surface of Example I.

EXAMPLE XLIV A toner mixture is prepared comprising about 10 parts by weight of carbon black (Neo Spectra Mark II) , .about 80 parts by weight of a copolymer of 70 parts by weight of styrene and about 30 parts by weight of vinyl acetate !"and 10 parts by weight of dicyclohexyl phthalate. After melting and preliminary mixing, the composition is rubber milled to yield a uniformly dispersed composition of the carbon black in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of about 10 to about 15 microns. The toner has a melt viscosity of about 0.5 x 10~4 poise at about 280° F. and a blocking temperature of about 135° F. About 1 part: by weight of the pulverized toner particles are mixed with about 0.01 parts by weight of zinc stearate particles having a particle size from about- 5 to about 40 microns, and about 99 parts by weight of coated carrier beads and substituted for the developer in the testing machine described in Example I. Under substantial!, identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum. fuser temperature at which legible copies are obtained after an abrasion run of 5. revolutions of the abrading cylinder is about 560° F.

This is a reduction of about 50° F. from the fuser temperature required for the control sample of Example I. No glowing embers fuser. Micrograph studies of the reusable imaging surface after. 5,000 cycles reveals less wear and degradation of the imaging surface than the imaging surface of Example I. ^ EXAMPLE XLV A toner mixture is prepared comprising about 10 parts by weight of carbon black, about 70 parts by weight of a copolymer! of 80 parts by weight of styrene and 20 parts by weight of acrylonitrile, and 20 parts by weight of dicyclohexyl phthalate. This phthalate has a melting point of about 140° F. After melting and preliminary mixing, the composition is rubber milled to yield a uniformly dispersed composition of the carbon black in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet" pulverizer to yield toner particles having an average particle size of about 5 to about 14 microns. The toner has a melt viscosity of about 0.5 x 10~4 poise at about 260° F. and a blocking temperature of about 120° F. About 1 part by weight of the pulverized toner particles are mixed with about 0.05 parts by weight of cobalt paImitate particles having a particle size from about 5 to about 40 microns, and about 99 parts by weight of uncoated glass carrier beads and substituted for the developer in the testing machine described in Example I. Under substantially identical test conditions, it is found that the original standard Xerox 813 drive motor can be used and that the minimum fuser temperature at which legible copies are obtained after an abrasion run of 5 revolutions of the abrading cylinder is. about 520° F. This is a reduction of about .90° F. from the fuser temperature required for the control sample of Example I. No glowing embers are observed on the copy samples as they emerge from the toner fuser. Micrograph studies of the reusable imaging surface after 5,000 cycles reveals less wear and degradation of the imaging surface than the imaging surface of Example I.

EXAMPLE XLVI A control toner mixture is prepared comprising about 5 parts by weight of carbon black and about 90 parts by weight of a polymeric esterification product of a linear alcohol, hexa- methylene glycol, and a dicarboxylic acid, sebacic acid. This polymer, hexamethylene sebacate, has a molecular weight of about 20,000 and a melting range of about 144 to 156° F. After melting and preliminary mixing, the composition is fed into a rubber mill and thoroughly milled to yield a uniformly dispersed composition of the carbon black in the thermoplastic resin body. The resulting mixed composition is cooled and then finely subdivided in a jet pulverizer to yield toner particles having an average particle size of about 7 to about 12 microns. About 1 part by weight of the pulverized toner particles are mixed with about 99 parts by weight of Xerox 813 carrier beads and substituted for the 813 developer in the testing machine described in Example I. The toner images after fusing are extremely faint, poorly defined and almost illegible. After about 70 imaging cycles, a heavy film of the toner is found on the surface of the modified Xerox 813 xerographic drum.

EXAMPLE XLVII A sample of toner particles of the type described in Example .HE- is tested for its imaging characteristics. About 1 part by weight of the pulverized oner particles are mixed with about 0.0025 parts by weight of zinc stearate particles having a particle size of about 0.5 to about 40 microns and about 99 parts by weight of uncoated glass carrier beads and substituted for the developer in the testing machine described in Example XLVI Under substantially identical test conditions, the resulting toner images are highly legible and very dense. A slight haze is found on the surface of the xerographic drum.

EXAMPLE XLVIII A control sam le containing one part colored preformed toner particles of the type described in Example XXXV having an average particle size of about 10 to about 15 microns is mixed with about 99 parts of coated glass beads having an average particle size of about 250 microns and then cascaded across an electrostatic image-bearing drum surface. The developed image is then transferred by electrostatic means to a sheet of paper whereon it is fused by heat. The residual powder is removed from the electrostatic imaging surface by a cleaning web of the type disclosed by W. P. Graff, Jr. et al in U.S. Patent 3,186,838.

After the copying process is repeated 25,000 times, the copies and electrostatic image-bearing surface are examined for quality and wear, respectively. The copies possess sharp line contrast and minimal background deposition. However, an examination of the imaging surface reveals the effects of considerable wear.

EXAMPLE XLIX About 0.01 parts of zinc stearate having a particle size distribution from about 5 microns to about 40 microns is gently folded into one part of a colored preformed toner particle of the type described in Example XLVIII. The resulting developer) mixture is cooled and then thoroughly milled in a Szegvari attritor for about 10 minutes. The developing procedure of XLVIII Example=£X¾=is repeated with a new drum and with the foregoing milled mixture substituted for the toner of Example XLVIII at a o relative humidity of about 50 percent of 70 F. and at a relative humidity of 80 percent at 80° F. Copies prepared with the milled sample possess higher density solid area coverage than copies prepared with the control sample. Further, micrograph studies of the electrostatic image-bearing surface reveals less wear than on the image-bearing surface of Example XLVIII, Considerably lee torque is necessary to drive the drum when the stearate additive is employed and a lower voltage is required to transfer the toner images to a receiving sheet.

I ' EXAMPLE XI -X- About 0.01 parts zinc stearate having a particle size distribution from about 5 microns to about ho microns is gently folded into about 10 parts of a colored preformed toner particle of the type described in Example -KfaVi-t. The resulting mixture is then tumbled in a sealed container for 15 minutes. About one part of the tumbled mixture is mixed with 9 parts of carrier beads having an average particle size of about 250 microns. The resulting developer mixture is employed ±n a cascade developing process as described in Example XfaVitrlat a relative humidity of 80 percent at 80°F.

The resulting fused toner images are denser under both humidity conditions than the images obtained in Example XLIX.

The expression "developer material" as employed herein plus metal salt is intended to include electro scopic toner material/ or combinations of toner material and carrier material.

Although specific materials and conditions are set forth in the foregoing examples, these are merely intended as illustrations of the present invention. Various other suitable thermoplastic toner resin components, additives, colorants, and development processes such as those listed above may be substituted for those in the examples with similar results. Other materials may also be added to the toner or carrier to sensitize, synergize or otherwise improve the fusing properties or other desirable properties of the system. 30116/2

Claims (2)

1. CLAIMS 1. A xerographic developer material comprising particles, said particles includin :- I: finely divided toner particles comprising i. a colorant, ii. a thermoplastic resin comprising a vinyl or vinylidene resin having a melting point of at least 110°F. and iii. a solid additive which is an ester of o-phthalic or m-phthalic acid or of 4,5- epoxy - tetrahydrophthalic acid or a compound having a melting point between 115°F. and 270°F. and selected from the organic compounds having the general otructuree wherein n represents a positive integer from 1 to 7 inclusive and R represents an esterifying radical having from 2 to 12 carbon atoms; (b) 0 R« wherein R'" represents one or more of hydrogen, ohlorine, bromine, an aryl radical, or an alkyl radical having from 1 to 6 carbon atoms and R' and R" represent 30116/2 hydrogen, an aryl radical, a cycloalkyl radical, a hydroxyalkyl radical, an alkenyl radical, or an alkyl radical having from 1 to 12 carbon atoms, and wherein n represents aero or a positive Integer from 1 to 3 inclusive and m has an average value from 0.5 to 2.5 inclusive, and mixtures thereof, and also including II: a carrier for said toner particles and/or from 0.0 per cent to 20 per cent by weight, based on the weight of said toner, of at least one solid, hydrophobic metal salt of a substituted or unsubstituted, saturated or having preferably one melting pint greater than 57°c. unsaturated fatty acid/at or immediately adjacent to external surfaces of said toner particles and/or said carrier.
2. 2. A xerographic develope material according to claim 1 wherein said finely divided toner has a blocking temperature of o °f -4 at least 110 F. and a melt viscosity less than 2.5 x 10 poise at temperatures up to 450°F. 3· A xerographic developer material according to claim 1 or 2 wherein said solid additive is an estor of o-phthalic or m-phthalio acid. 4. A xerographic developer material according to claim 3 wherein said ester has a melting point between 110°3? and 175°F» 5. A xerographic developer material according to claim 3 or 4 wherein said finely divided toner contains from 2 percent to 30116/2 15. ' Ά xerographic developer material according to any preceding claim wherein said metal salt of a fatty acid is zinc stearate. 16. A xerographic developer material .according to any .preceding claim wherein the particle size of said toner is less than 30 microns. 17. A. xerographic" developer material according to preceding claim wherein said.developer material include carrier, particles larger than said finely-divided tone particles. 18. A xerographic developer material according to claim 17 wherein said carrier particles have an average, particle diameter between 50 to 1,000 microns. 19. A xerographic developer material according to claim 17 or 18 wherein said developer material comprises 1. part by weight of said finely-divided toner particles and . from 10 to 200 parts by weight of said carrier particles. 20. A xerographic developer material according to . any of claims 1 to 16 wherein said developer material is free from carrier particles.- , 21. A process for the preparation of a xerographic y developer material according to any of claims 1 to 16 comprising forming said finely-divided" toner particles as particles having a size range up to 30 microns and thereafter tumbling said finely-divided toner material with said solid, . hydrophobic metal salt of a fatty acid until said metal sal is uniformly mixed with said finely-divided toner material. 22. An imaging process comprising establishing an electrostatic latent image on a surface and contacting said surface with a xerographic developer material according to , any of claims 1 to 20.. 30116/2 =» 66 - i 23. An imaging process according to Claim 22 further including the steps of transferring said toner to a receiving surface and fusing said tonor imag© on said receiving surfac©. 24. A xerographic developer material according to Claim 1 suTootantially as heroin described. For th® Applicants DR.RE iTiffiRS PCsBH