MXPA96000477A - Fusing or fusing element coated with fluoroelastomer, thermally conductor, thin and fusion system that includes it - Google Patents

Abstract

A long-lasting, thermally conductive, hard melt element is disclosed comprising a base member and a surface layer, wherein the surface layer includes a fluoroelastomer or fluorinated elastomer and an alumina filler having an average particle size of about 0.5 to about 15 microns, the alumina is present in an amount to provide a thermal conductivity of at least about 0.24 Watts / meterøKelvin in the surface layer

Description

* "FUSING OR FUSING ELEMENT COVERED WITH FLUOROELASTOMER, THERMAL CONDUCTOR, THIN AND FUSING SYSTEM INCLUDING IT" Inventor (s): CLIFFORD O. EDDY, North American, domiciled at 248 Shorewood Drive, Webster, New York 14580, E.U.A .; LOUIS D. FRANTANGELO, North American, domiciled at 14 Winchester Drive, Fairport, New York 14450, E.U.A .; GEORGE J. HEEKS, North American, domiciled at 72 Oakcrest Drive, Rochester, New York 14617, E.U.A .; ARNOLD W. HENRY, North American, domiciled at 43 Deer Creek Road, Pittsford, New York 14534, E.U.A .; ALAN R. KUNTZ, North American, domiciled at 427 Woodland Lane, Webster, New York 14580, E.U.A .; RABIN MOSER, North American, domiciled at 269 Hidden Brook Trail, Victor, New York 14564, E.U.A .; DAVID BATTAT, North American, domiciled at 85 Palmerston Road, Rochester, New York 14618, E.U.A .; SAMUEL KAPLAN, North American, domiciled in 1974 Finley Road, Walworth, New York 14568, E.U.A .; SANTOKH S. BADESHA, North American, domiciled at 48 Bromley Road,, Pittsford, New York 14534, E.U.A .; CHE CHUNG CHOW, North American, domiciled at 286 Valley Green Dr, Penfield, New York 14526, E.U.A .; DAVID H. PAN, North American, domiciled at 10 Westfield Commons, Rochester, New York 14625, E.U.A .; DAVID J.J. FRASER, North American, domiciled at 116-10 Deerhurst Lane, Webster, New York 14580, E.U.A. and YU-HSING CHIN, North American, domiciled at 116 Wexford Place, Webster, New York 14580, E.U.A ..

Causaire: XEROX CORPORATION, New York State Corporation, E.U.A., domiciled at Xerox Square - 020, Rochester, New York 14644, E.U.A.

FIELD OF THE INVENTION The present invention relates to a fusion element and to a fusion system for fusing organic pigment images into electrostatic printing apparatus. In particular, it relates to a thin, thermally conductive fluoroelastomer (or fluoroelastomer) melting element coating which, while it can be used as a pressure roller or oil-providing roller of release agent, is preferably used as a heated melting roller.

BACKGROUND OF THE INVENTION 15 In a typical electrostatic printing apparatus, a light image of an original to be copied is recorded in the form of a latent electrostatic image on a photosensitive element and the latent image is ? 20 turn subsequently visible by the application of electroscopic thermoplastic resin particles which are commonly referred to as organic pigment. The visible organic pigment image is then in a loose sprayed form and can be easily altered or destroyed. The organic pigment image is usually fixed or fused on a support, which may be a photosensitive element on its own or another support sheet such as plain paper.

The use of thermal energy to fix organic pigment images on a support element is well known. In order to fuse the organic electroscopic pigment material on a support surface permanently by heat, it is necessary to raise the temperature of the organic pigment material to a point at which the constituents of the organic pigment material undergo coalescence and become adherent. This heating causes the pigment The organic material flows to some extent to the fibers or pores of the support element. After this, as the material 'of the pigment. Organic cools, the solidification of the organic pigment material causes the organic pigment material to adhere firmly to the support. Typically, the thermoplastic resin particles are fused to the substrate by heating to a temperature of between about 90 C to about 160 C or at a further temperature. high, depending on the softening range of the particular resin used in the organic pigment. It is not desirable, however, to raise the temperature of the substrate to a temperature greater than about 200 ° C, due to the tendency of the substrate to discolour to Such high temperatures, particularly when the substrate consists of paper. Various methods for thermal fusion of electroscopic organic pigment images have been described in the prior art. These methods include providing the application of heat and pressure substantially concurrently by several means: a pair of rollers held in pressure contact; a band element in press contact with a roller; and the like. The heat can be applied by heating one or both of the rollers, plate elements or band elements. The fusion of the organic pigment particles is carried out when the appropriate combination of heat, pressure and contact time is provided. The balance of these parameters to cause the fusion of the organic pigment particles is well known in the art, and can be adjusted to suit particular machines or process conditions. During the operation of a fusion system in which heat is applied to cause thermal fusion of the organic pigment particles on a support, the organic pigment image and the support are passed through a contact point formed between the pair of rollers, or plate or band elements. The concurrent transfer of heat and the application of pressure at the point of contact effects the fusion of the organic pigment image on the support. It is important in the melting process that no displacement of the organic pigment particles 5 is carried from the support to the melting element during normal operations. The organic pigment particles displaced on the melting element can subsequently be transferred to other parts of the machine or on the support in subsequent copying cycles, to increase, well, the bottom or interfere with the "Material that is copied therein The so-called" hot displacement "occurs when the temperature of the organic pigment is elevated to a point where the organic pigment particles liquefy and A division of the molten organic pigment is carried out during the melting operation, with a portion remaining on the melting element. The temperature of hot displacement or degradation of the temperature of hot displacement is a measure of the melting roller release property, and therefore it is desired to provide a melting surface which has a low surface energy to provide the necessary release. To ensure and maintain good release properties of the fusing roll, it has been It has become customary to apply release agents to the fusion elements, to ensure that the organic pigment is completely released from the fusion roller w * during the fusion operation. Typically, these materials are applied as thin films of, for example, silicone oils to prevent the displacement of the organic pigment. In addition to preventing hot displacement, it is desirable to provide as much operational freedom as possible. Operational freedom means the difference in temperature between the minimum temperature required for J fix the organic pigment to the paper, the minimum fixing temperature, and the temperature at which the hot organic pigment will move to the melting roller, the temperature of hot displacement. 15 While the process of printing or electrostatic image formation described above has been used for many years in the production of copies of original documents and ßf prints of electronically generated images, a The recent development has been the use of such a process in the preparation and printing of checks, and in particular, personal checks with the use of magnetic dry organic pigment compositions. In these applications, the dried organic magnetic pigment is printed on the checks, to indicate the checking account and other appropriate identification information, which includes, for example, identification of the bank, etc. This information already on the check is subsequently read by means of a magnetic image character recognition device (referred to herein as "MICR") and the information obtained through it is processed for various accounting purposes. U.S. Patent No. 4,517,268 reissued as Reissue 33,172 to Gruber et al. Is an example of a basic magnetic image character recognition process, along with an organic pigment employed in such a process. In addition to the thermoplastic resinous materials in the organic pigment, the organic pigment contains a significant amount of magnitite particles to enable the magnetic image character recognition process. In addition, such organic pigment may contain additional additives used for various purposes which include, for example, materials for controlling the electrical properties of the organic pigment such as MR titanium dioxide.; surface additives such as "Kynar", a polyvinylidene fluoride available from Pennwalt Chemicals Corporation; the polyhydroxy wax, "Unilin", available from Petrolite, used to remove comet-shaped spots on the printing surface or image formation. The comet-shaped spots are ^^ a printing or imaging defect involving organic pigment, or portions thereof, which adhere to the surface of the printed or formed image, to cause a defect in the shape of a comet. During the process of recognition of magnetic character, the organic pigment image is passed through a contact reader several times (up to 20) through the recognition process complete. During the processing of checks by means of Of this process, and in addition to the normal wear and tear placed on the checks by the various mechanical blade handling devices, the individual contact readers provide a contact pressure on the side of the check, which has a tendency to deteriorate the image coverage of the organic pigment or break portions of the organic pigment image, which in addition to contaminating the reading head, can also 4Ff result in reading failure by the reader of contact and the subsequent rejection of the check in the process, together with the need to manually insert the number information to the check reading apparatus. In general, this results in poor performance of the character recognition device magnetic image, which results in increased bank charges from one bank to another. This difficulty is caused by a poor fixation of the organic pigment to the check substrate, which results in deterioration of the coverage of the organic pigment with flaking or breakage of the organic pigment image during various stages of processing. This poor adhesion of the organic pigment to the paper substrate or other check substrate results from the poor adhesion of the organic pigment image to the substrate itself, as well as the poor cohesion of the organic pigment material itself. In a specific mode, for example, in the "Duplicator 5090" apparatus of Xerox with an organic MICR (magnetic image character recognition) pigment similar to that described in US Pat. No. 4,517,268 and having a system of A fusion including a melting roller made of a hydrofluoroelastomer similar to that described in U.S. Patent No. 5,017,432, when operating under normal parameters, provides fixed organic pigment images on checks, for example, wherein the contact pressure placed on the check of the contact reader results in a deterioration of the organic pigment coverage, also as scale formation or breakage of the organic pigment particles. This poor adhesion of the MICR organic pigment together with the poor cohesion of the organic pigment material itself, results in poor binding to the check substrate under normal operating conditions. This deficiency in fixation or fusion may in part be due to the presence of certain additives for known purposes in the organic pigment. One solution to this poor fixation or fusion is to increase the temperature of the melting roller, which in so far as provides a minimum fixing temperature of up to -1 ° C (30 F), for example, beyond the normal minimum setting temperature for which the melting roller described in U.S. Patent No. 5,017,432 was designed, has the Negative aspect in that, due to the As the temperature increases, the decomposition of the adhesive or the polymer at the interface between the adhesive, the core of the melting roller and the hydrofluoroelastomer may take place, to result in the degradation of the material in the melting roller, as well with the pressure roller, with eventual catastrophic failure of the roller by breaking the surface layers. This is true since, to increase the temperature on the surface of the fusion element, it is necessary to increase the temperature of the The melting roller core, which results in a shorter life of the melting roller by degrading the adhesive between the core and the adjacent layer such as a hydrofluoroelastomer layer.

BRIEF DESCRIPTION OF THE INVENTION According to the present invention there is provided a melting element and a melting system, wherein the organic pigment, and in particular an organic MICR pigment (magnetic image character recognition), is sufficiently adequately fused to the substrate , - such as a check substrate, such that it will not deteriorate when contacted by a contact reader nor will scale or fragment during the reading operation, while at the same time the core temperature of the melting element does not need to be raised to a level which degrades the material of the melting element or no adhesive between it and an adjacent layer or element of pressure.

In addition, according to the present invention the organic pigment material will be much more completely absorbed in the paper substrate and the fusing element will be of sufficient hardness, also as it will have a surface temperature to provide penetration of the Organic pigment and formability of the organic pigment to allow the organic pigment to flow around the magnetic particles. iW. In a specific aspect of the present invention, there is provided a hard, long-lasting, thermally conductive melting element, wherein the melting element comprises a base element and a surface layer wherein the surface layer includes a fluoroelastomer or fluorinated elastomer and an alumina filler that has an average particle size of approximately 0.5 to approximately 15 microns, the * alumina is present in an amount to provide a thermal conductivity of at least about 0.24 Watts / meter Kelvin in the surface layer. The surface layer may comprise the body of the coating on the base member, since in one embodiment of the present invention, the only other layer is a layer of thin adhesive. In addition, in the embodiments of the present invention, a fusion system for a machine is provided. # 20 electrostatic printing, comprising a pressure element and a long-lasting, thermally conductive fusion element, comprising a base element and a surface layer wherein the surface layer includes a fluoroelastomer or fluorinated elastomer and a alumina filler having an average particle size of about 0.5 to about 15 microns, the alumina is present in an amount to provide a thermal conductivity of at least about 0.24 Watts / meter Kelvin in the surface layer. The pressure element in the melting system can be a soft, long-sleeve, non-jacketed roller comprising a cylindrical core and a non-oxidizing layer, which does not swell in silicone oil, of a thermally stable hydrofluoroelastomer, having 10 a Young's modulus of elasticity of less than • 2 about 35.15 Kg / cm (500 pounds / square inch), from about 0.635 cm (250 mils) to about 1.27 cm (500 mils) thick and a hardness of about 45 to approximately 60 Shore A, The pressure element alternatively in the fusion system may be a jacketed pressure element comprising for example a jacketed pressure element comprising "^^^ example a fluoroplastic sleeve such as resin Teflon perfluoroalkoxy (illustrative thickness of approximately 0.0508 cm (20 mils)) on a hydrocarbon rubber layer, such as ethylene propylene rubber (illustrative thickness of 1.27 cm (0.5 in.)) On a steel core (size illustrative of approximately 5.08 cm (2 inches)).

According to a further aspect of the present invention, the fluorinated elastomer or fluoroelastomer comprises a poly (vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene-curing monomer at the optional site) wherein the vinylidene fluoride is present in an amount " less than 40 percent by weight of the polymer In a further aspect of the present invention the fluoroelastomer or fluorinated elastomer has been cured from a solvent solution of the ## same with a nucleophilic curing agent and in the presence of less than 4 parts by weight of inorganic base per one hundred parts by weight of polymer, the inorganic base is effective to, at least partially, dehydrofluor the vinylidene fluoride. In a further aspect of the present invention, the alumina is present in the surface layer in an amount of about 30 parts Iß to about 100 parts by weight and preferably about 40 parts by weight to 70 parts by weight and more preferably about 55 parts by weight per 100 parts by weight of the fluoroelastomer or fluorinated slastomer. In a further aspect of the present invention, cupric oxide is present in the surface layer in an amount of up to about 30 parts by weight and preferably 2 to 18 parts by weight per 100 parts by step of the fluoroelastomer or fluorinated elastomer. In a further aspect of the present invention, the alumina has a particle size distribution of about 0.5 microns to about 8 microns. In a further aspect of the present invention, the surface layer of the fusion element has one. Hardness of approximately 75 to approximately 90 and preferably approximately 82 Shore A. In a further aspect of the present invention, the surface layer is approximately 0.01143 cm (4.5 mils) to approximately 0. 02286 cm (9 mils) in thickness, and preferably approximately 0.01524 cm (6 mils) in thickness. ~ f In a further aspect of this According to the invention, an adhesive layer is included between the core and the surface layer of the fluoroelastomer or fluorinated elastomer.

BRIEF DESCRIPTION OF THE DRAWINGS ff Figure 1 is a sectional view of a fusion system which may use the fusing element according to the present invention. Figure 2 is a graphical representation of the test of the fold area against the temperature of the melting roll, of a melting system having a melting roller similar to that described in the patent North American No. 5,017,432. Figure 3 is a similar graphical representation of the crease area test, together with a fusing system employing a fusing element according to the present invention. Figure 4 is a graphical representation of the increase in thermal conductivity with an increased percentage of the alumina filling volume calcined by volume of the elastomeric material. Figure 5 is a graphical comparison that illustrates the improvement in the temperature of the core and the surface of the melt roll, with a melt roll according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION While the following discussion of alumina filler is primarily in terms of calcined alumina, all other types of alumina filler, such as tabular alumina, sulfur alumina, and molten alumina may be used in addition or in place of the calcined alumina. As discussed in more detail herein, the alumina filler in the surface layer of the melt element may be of only one type or a mixture of two or more types of alumina selected from the group consisting of, for example, calcined alumina. , tabular alumina, sulfur alumina, and molten alumina. The particles of the alumina filler can be either alpha or gamma crystalline type. Unless otherwise indicated, fused alumina, sulfur alumina, tabular alumina, or a mixture of different types of alumina may be used in the same or similar amounts and particle sizes as calcined alumina, and provide the same or similar advantages as calcined alumina in the surface layer of the fusion element. While the following discussion is primarily in terms of a hydrofluoroelastomer, other suitable fluoroelastomers or fluorinated elastomers such as FFKM elastomers can be used.

As used herein, the phrase "average particle size," as used in connection with alumina filling, refers to the mean volume average, which is a point on a histogram that describes the volumetric distribution of particle size. . It is the point on the scale of observations which has equal area under the histogram either on one side or the other. A typical melting element of the present invention is described in conjunction with a melting assembly, as shown in Figure 1, where the number 1 designates a melting roller, comprising the surface 2 of the elastomer, on an element 4 of suitable base, which is a cylinder or hollow core made from any suitable metal, such as aluminum, anodized aluminum, steel, nickel, copper, and the like, having a suitable heating element 6, disposed in the hollow portion thereof, which is coextensive with the cylinder. The support roller 8 or pressure roller cooperates with the melting roller 1 to form a contact point or contact arc 10, through which a copying paper or other substrate 12 passes, in such a way that the images 14 of organic pigment thereon are brought into contact with the surface layer 2 of the elastomer of the melt roll 1.

As shown in Figure 1, the backing roller 8 has a rigid hollow steel core 16 with a soft surface layer 18 thereon. The reservoir 20 contains polymeric release agent 22, which may be solid or liquid at room temperature, but is fluid at operating temperatures. In the embodiment shown in figure 1, in order to apply the polymeric release agent 22 to the surface layer 2 of the elastomer, two delivery agent supply rollers 17 and 19, mounted rotatably in the indicated direction, are provided for transporting the release agent 22 from the reservoir 20 to the surface layer of the elastomer. As illustrated in Figure 1, the roller 17 is partially submerged in the reservoir 20 and carries on its surface release agent from the reservoir to the supply roller 19.

By using a regulating sheet 19, a layer of the polymeric release fluid can be initially applied to the supply roll 19 and subsequently to the surface layer 2 of the elastomer, in a controlled thickness ranging from a submicroscopic thickness to a thickness of several microns of the release fluid. Thus, by means of the regulating device 24 about 0.1 to 2 microns or greater in thickness of release fluid can be applied to the surface of the surface layer 2 of the elastomer. The fusion element can be a roller, strip, flat surface or other suitable shape, used in fixing the thermoplastic organic pigment images to a suitable substrate. Typically, the fusion element is made of a hollow cylindrical metal core, such as copper, aluminum, steel? the like, and has an outer layer of the fluoroelastomer or curable fluorinated elastomer selected. Alternatively, there may be one or more thermally conductive intermediate layers between the substrate and the outer layer of the cured elastomer if. HE. you want Typical materials having the appropriate thermal and mechanical properties for such intermediate layers include thermally conductive silicone elastomers (eg 0.59 Watts / meter / Kelvin) such as high temperature vulcanizable materials ("HTV") and liquid silicone rubber or rubbers ("LSR"), which Fr1 may include a filler alumina in the amounts described above. The silicone elastomer can have a thickness of about 2 mm (radius). An HTV is either a normal polydimethyl siloxane ("PDMS"), with only methyl substituents on the chain, (OSi- (CH,) _) or a similar material with some vinyl groups on the chain (OSi (CH = CH ") (CH_)). Either one material or another is cured by peroxide to create crosslinking. An LSR (rubber or liquid silicone rubber) usually consists of two types of chains PDMS (polydimetil siloxane normal), one with some 5 vinyl substituents and the other with some hydride substituents. They are kept separate until they are mixed just before molding. A catalyst in one of the components leads to the addition of the hydride group (OSiH (CHd) in one type of chain to the vinyl group in the other type of chain to cause cross-linking. According to the present invention, a melting system including a melting element is provided, wherein the saperficial layer of the melting element comprises a fluoroelastomer or fluorinated elastomer filled with an alumina filler having a size of average particle from about 0.5 to about 15 microns present in an amount to provide a thermal conductivity of at least 0.24 Watts / me-Ff tro ° Kelvin in the surface layer, together with a hardness from about 75 to about 90 and preferably about 82 Shore A. Typically, the surface layer of the melting element is from about 0.01016 cm (4 mils) to about 0.02286 cm (9 mils) and preferably 0.01524 cm (6 mils) thick, as a balance between conformability and cost and to provide freedom in thickness manufacturing. It has been found that such a melting system and melting element provide sufficient hardness to the melting element to allow the penetration of the magnetic particles in the organic pigment into the paper substrate, such as check material, while at the same time providing sufficient formability of the thermoplastic resin to allow the flow of the organic pigment material around the individual magnetic particles. The hardness of the surface layer of the melting element is greatly increased by increasing the amounts of the alumina filler, which allows to absorb as much organic pigment as possible to the paper substrate. In addition, the harder the coating surface of the melting element, the greater the penetration of the organic pigment into the paper. Suitable fluoroelastomers or fluorinated elastomers include FFKM elastomers and hydrofluoroelastomers. Illustrative FFKM elastomers are perfluorohules of the polymethylene type having all substituent groups on the polymer chain, either fluoro perfluoroalkyl groups, or perfluoroalkoxy groups. Hydrofluoroelastomers (also known as FKM elastomers), according to the present invention, are those defined in the designation of ASTM D1418-90 and are directed to fluorohules or fluorocarbons of the polymethylene type having fluoro and perfluoroalkyl or perfluoroalkoxy substituent groups on a polymer chain. Fluorinated elastomers or fluoroelastomers useful in the practice of the present invention are those described in detail in U.S. Patent No. 4,257,699 issued to Lentz, also as those described in commonly assigned U.S. Pat. Nos. 5,017,432 to Eddy et al., And 5,061,965 to Ferguson et al. As described therein, these fluoroelastomers, particularly of the class of copolymers, terpolymers, and tetrapolymers of vinylidene fluoride hexafluoropropylene, tetrafluoroethylene, and site curable monomer (believed to contain bromine) commercially known under various commercial designations such as "Viton A", "Viton E60C", "Viton E430", "Viton 910", "Viton GH", "Viton GF" and "Viton F601C". The designation "Viton" is a trademark of EI DuPont deNemours, Inc. Other commercially available materials include "Fluorel 2170", "Fluorel 2174", "Fluorel 2176", "Fluorel 2177" and "Fluorel LVS 76", "Fluorel" is a trademark of 3M Company. Additional materials commercially available include "Aflas" a copolymer of poly (propylene-tetrafluoroethylene), "Fluorel II" a terpolymer of poly (propylene-tetrafluoroethylene-vinylidene fluoride) both also available from 3M Company. Also the "Tecnoflons" identified as "FOR-60KIR", "FOR-LHF", "NM", FOR-THF, "FOR-TFS", "TH", "TN505" are available from Ausimont Chemical Co. Typically, these fluoroelastomers or fluorinated elastomers can be cured with a nucleophilic addition curing system, such as a bisphenol crosslinking agent with an organophosphonium salt accelerator, as described in more detail in the Lentz patent referred to above, and in the Eddy et al. patent, or with a peroxide , as described in the DuPont literature, in which case a curing monomer at the site, such as bromomethyl perfluorovinyl ether is also necessary. A particularly preferred embodiment of the hydrofluoroelastomer is that described in U.S. Patent No. 5,017,432 issued to Eddy et al., Which provides a surface layer of the melting element comprising poly (vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene-curing monomer). at the site, which is believed to contain bromine) wherein the vinylidene fluoride is present in an amount less than 40 percent by weight and which is cured from a solution of dry solvent thereof with a nucleophilic curing agent soluble in the solvent solution ^^? - and in the presence of less than 4 parts by weight of inorganic base per 100 parts of polymer, the inorganic base 5 is effective to, at least partially, dehydrofluor partially the vinylidene fluoride, which is described in greater detail in U.S. Patent No. 5,017,432 and the nucleophilic curing system is also described in greater detail in the patent North American No. 4,272,179 issued to Seanor and US Patent No. 4,264,181 issued to Lentz et al. According to the present invention, the fluoroelastomer or fluorinated elastomer is filled with alumina, such as calcined alumina to provide the desired hardness, thermal conductivity and formability of the melting element surface. Calcined alumina is alumina heated to a temperature below jk, 2038 ° C (3700 ° F) which prevents the melting from being carried out, but still allows the water to be expelled. This produces a highly surfactant filler which, in combination with an average particle size of about 0.5 to 15 microns and preferably 1 to 9 microns, provides the desired thermal conductivity, hardness and formability of the fusion layer. Whereas the sizes of 1 miera and 9 micras provide approximately the same results in the performance of the filling, in order to provide a more processable material and to minimize the problems with the size of the filling, it is preferred to use a filling that It has a nominal size of approximately 1 miera. The thermal conductivity of the surface layer is at least about 0.24 Watts / meter ° Kelvin to provide an acceptable fixation with good adhesion of the organic pigment to the substrate, which as seen from Figure 4 is achieved to approximately 11% by volume of ~ ß ^ Calcined alumina e.n the total volume of the surface layer. This corresponds to about 30 parts by weight of calcined alumina per 100 parts by weight of the fluoroelastomer or fluorinated elastomer. In a modality Particularly preferred is that it achieves a good balance between good adhesion and formability on the one hand and hardness on the other hand, the surface layer has approximately 20% by volume of the total volume of J éfcr calcined alumina or 55 parts e.n weight d * 2 alumina calcined by 100 parts by weight of the fluoroelastomer or fluorinated elastomer, to provide a thermal conductivity of about 0.31 Watts / meter K. In general, the calcined alumina filling may be present in the surface layer of FKM in an amount of about 0.50 Watts / meter K. 30 parts by weight to about 100 parts and preferably from about 40 to about 70 parts by weight per 100 parts by weight of the fluoroelastomer or fluorinated elastomer. A particularly preferred amount of calcined alumina to provide the best balance between thermal conductivity and hardness is about 55 parts by weight per 100 parts by weight of the fluoroelastomer or fluorinated elastomer. Such formulation with only calcined alumina present to provide thermal conductivity and no filling Additional 10 is typically employed in fusing systems with organic pigment release agents, which do not require the use of metal oxide particle securing sites. Such organic pigment release agents include the release agents aminofunctionals described in U.S. Patent Application Serial No. 08 / 314,759 (D / 93569I) filed on September 29, 1994. An option according to the present invention and a further preferred embodiment includes the use of metal oxide filler particles, as assurance sites for a functional organic pigment release agent. The preferred embodiment includes up to about 30 parts by weight, preferably about 12 to 18 parts and more preferably 15 parts. by weight gives copper oxide (cubic oxide) in the surface layer per 100 parts by weight of the fluoroelastomer or fluorinated elastomer which is useful in a system of • fusion in conjunction with a functional release agent and in particular a mercapto functional oil, as described in U.S. Patent No. 4,029,827 issued to Imperial et al. In this embodiment the cupric oxide particles that provide the assurance sites for the functional release agent are provided in the constituents of the total surface layer fill in approximately a volume-for-volume substitution of the cupric oxide. for alumina .. It is important that in all the modalities, the amount of total filler that includes alumina and any cupric oxide, also as additional filler material does not is present in such a large amount to make the surface layer so hard that acceptable conformity of the organic pigment particles around the magnetic particles is not obtained. Figure 4 illustrates that, over the range of Given the data provided, the increase in thermal conductivity with the increased volume percent of calcined alumina in the surface layer can be adjusted by a quadratic equation with excellent statistical certainty. Thus, predictions of thermal conductivity from the knowledge of the volume percent of alumina can easily be made about this range. Reverse prediction can also be done. The particle size described herein for alumina filling is an important factor that contributes to the improved release of the organic pigment from the melting element, thereby minimizing or eliminating the phenomenon of hot displacement wherein the organic pigment it adheres to the surface of the fusion element and such residual organic pigment is subsequently transferred to a copy sheet. The filling of ^ V alumina in the surface layer of the fusion element can be. of only one type of alumina or a mixture of two or more types of alumina selected for example from calcined alumina, sulfur alumina, molten alumina, and tabular alumina. Any suitable mixing ratio can be used, such as from about 95% to 5% of one type of alumina and from about 5% to about 95% for the second type of alumina for a mixture of two components. The various types of alumina can to be used individually or in any combination, wherein illustrative mixtures include calcined alumina / tabular alumina; tabular alumina / molten alumina; sulfur alumina / calcined alumina; and calcined alumina / tabular alumina / molten alumina. Mixtures of different types of alumina, fused alumina alone, sulfur-treated alumina alone, or tabular alumina alone, all can be as effective as the use of only calcined alumina in the alumina element.

"Present fusion, because the various types of alumina all have the same or similar thermal conductivity value of 25 Watts / meter Kelvin. Anhydrous alumina is preferred. The molten alumina is prepared by heating alumina to approximately 2300 C (4172 F) (above its melting point of 2071.7 C (3761 F)), cooling and then milling the alumina to the desired particle size. The sulfur alumina is manufactured by the oxidation at high temperature of the aluminum chloride, which results in submicroscopic particles of aluminum oxide. The calcined alumina according to the present invention will be distinguished from the tabular alumina, which is a sintered alumina that has been heated to a slightly lower temperature than 2037.8 C (3700 F), the melting point of aluminum oxide . The name "tabular" comes from the fact that the material is predominantly composed of table-like crystals. Tabular alumina having an average particle size of about 5 to 7 microns is available from Alcoa (designation of 20 micron alumina). Other adjuvants and fillers can be incorporated in the elastomer according to the present invention, as long as they do not affect the integrity of the The elastomer, the interaction between the metal oxide and the polymeric release agent or prevent the proper crosslinking of the elastomer. Such fillers normally found in the elastomer composition include coloring agents, reinforcing fillers, crosslinking agents, processing aids, accelerators and polymerization initiators. The system of nucleophilic curing with the agent Bisphenol crosslinking and organophosphonium salt accelerator is described in U.S. Patent No. 4,272,179. However, according to the present invention, the nucleophilic curing agent (crosslinking agent and accelerator) is soluble or can be is suspended in a solvent solution of the polymer (for example "VITON GF") and is used in the presence of less than 4 parts by weight of inorganic base (for example, Ca (OH) "and MgO) per 100 parts by weight of the polymer. Normally, the tetrapolymers of vinylidene fluoride Hexafluoropropylene and tetrafluoroethylene are cured by peroxide. However, as discussed «+ - previously the preferred manufacturing process for a melting element is to spray a solvent solution of the polymer onto a substrate, whereby the carado returns by peroxide in difficult air, since the peroxide reacts preferably with # oxygen in the air or residual solvent, instead of curing the polymer. The preferred alternate capping system is a nucleophilic curing system, such as a bisphenol crosslinking agent and an organophosphonium salt accelerator. Typically, the curing process is carried out in the presence of 8 to 10 parts by weight of inorganic base per 100 parts of polymer. The inorganic base dehydrofluorizes the vinylidene fluoride 10 in the polymer to create double bonds which f act as reactive sites for crosslinking.

However, the presence of excess base results in long-term degradation of the elastomers and if the excess base continues with the dehydrofluorination of the vinylidene fluoride, it generates double bonds, which causes the melting element to harden, Subsequent oxidation causes the surface energy to increase and the release performance to be degraded. Thus, it is preferred to cure the polymer at a level of relatively low base, to control the reactivity of vinylidene fluoride. Typical curing agents such as "Viton Curative No. 30" which consists of about 50 weight percent "bisphenol AF" and 50 weight percent poly (vinylidene fluoride-hexafluoropropylene) and "Viton" Curative No. 20"which consists of approximately one third of chloride ^^ triphenyl benzyl phosphonium and two thirds of poly (fluoride) vinylidene-hexafluoropropylene) both available from E. I. DuPont deNemours Company, will not work as curing agents at low base levels. While the ex cta reason for this is unclear, it is believed that it is at least in part due to the fact that the "Curative No. "is not soluble in the solvent solution of the polymer and therefore is not in close proximity to many of the smallest number of reactive sites for flp crosslinking carried out by the dehydrofluorination of vinylidene fluoride. While the curing agents "Curative" Nos. 20 and 30 do not work effectively at low base levels, it has been found surprisingly that another agent of carado "Viton Curative "," Curative No. 50", also available from E. I.

DuPont deNemours, which is normally used with high base levels, can be used to cure F poly (vinylidene-hexafluoropropylene-tetra-fluoroethylene fluoride) at less than one half of its normal base level or less than about 4 parts by weight per 100 parts of polymer. Since the curing agent "Curative No. 50" is soluble in the solvent solution of the polymer at low base levels, it is easily available in the reactive sites for cross-linking. The curing agent "Viton Curative No. 50" incorporates an accelerator (a salt or salts of quaternary phosphonium) and a crosslinking agent, "bisphenol AF" into a single curing system. The melting element of the present invention is preferably a roller, preferably one prepared by applying, either in one application or successively applying to the surface to be coated thereon, a thin coating or coatings of the elastomer with alumina filler. scattered in it. The coating is most conveniently carried out by spraying, immersing or the like, a homogeneous solution or suspension of the elastomer containing the filler. While the techniques of molding, extrusion and covering or wrapping are alternative means which can be used, it is preferred to spray successive applications of a solvent solution of the polymer, alumina and other metal oxide filler, if any, to the surface to be coated. Typical solvents that can be used for this purpose include methyl ethyl ketone, methyl isobutyl ketone and the like. When successive applications are made to the surface to be coated, it is generally necessary to heat the film coated surface to a temperature sufficient to instantaneously remove any solvent contained in the film. For example, when a melt roll is coated with an elastomer layer containing metal oxide, the elastomer having metal oxide dispersed therein is applied successively to the roll in thin coatings and between each application, the evaporation of the solvent in the film coated on the roller, at temperatures of at least 25 C to about 90 C or higher, for instantaneously remove most of the solvent contained in the film. When the desired thickness of coating is obtained, the coating is cured and by this adhered to the roller surface. Typically, the coating is cured by a step-by-step heating process of about 24 hours, such as 2 hours at 95 C, 2 hours at 150 C, 2 hours at 175 ° C, 2 hours at 200 ° C and 16 hours at 230 ° C, followed by cooling and polishing. A typical formulation for the surface layer of the merger element includes: 100 parts by weight of the available hydrofluoroelastomer of E.I. DuPont or 3M. 30 to 75 parts by weight of the calcined alumina available from K.C. Abrasives. 1 part by weight of CaiOHd available from J.T. Baker 2 parts by weight of MgO, "Maglite D" available from C.P., Hall 2 parts by weight of carbon black N990 available from R.T. Vanderbilt Co. 5 parts by weight of DuPont VC50 available from E.I. DuPont.

Optionally, up to 30 parts by weight of? C oxide, available from American Chemet as product number 13600 may be included. The hard, thermally conductive surface layer of the melting element containing the fluoroelastomer or fluorinated elastomer together with the alumina filling is present in a thickness of approximately 0.01016 cm. (4 mils) to approximately 0.02286 cm (9 thousandths of an inch) and preferably 0.01524 cm ijff (6 thousandths of an inch) which provides a balance suitable between conductivity and conformability. At a thickness less than 0.01016 cm (4 mils) the formability of the surface layer decreases to a point where it shows no more conformability than the metal core, while at a thickness above the optimal thickness of 0.01524 cm (6 mils) the caestration is not performance, but rather one relative to the cost of materials in the layer. The melting element according to the present invention, which in a specific embodiment is an internally heated melting roller, can be used in a melting system with or without a functional oil as an organic pigment release agent. In case you want to use a functional mercapto oil, the fusion surface must contain sites for securing proper fixing or fixing, such as metal oxide particles. In this regard, attention is directed to the Lentz et al., And Lentz and Seanor patents referred to above, which describe fusion elements and methods for fusing 15 images of thermoplastic resin organic pigment to a substrate, wherein the polymeric release agent having functional groups is applied to the surface of the fusion element. In a preferred embodiment of the J-present invention, a mercapto functional oil can be used as a release agent in conjunction with sites assuring or fixing cupric oxide on the fusion surface. On the other hand, and in another preferred embodiment of the present invention, an aminofunctional organic pigment release agent is used, which, because it has aminofunctional groups which react with the surface of the fluoroelastomer or fluorinated elastomer, can be used without assurance sites such as metal oxide particles or cupric oxide on the surface of the melting element. Such aminofunctional release agents include those described in U.S. Patent Application Serial No. 08 / 314,759 (D / 93569I) filed on September 29, 1994, the description of the caal is hereby incorporated by reference in its entirety. Amino-functional release agents are also described in the US Pat. No. Shoji et al., 5,157,445, the disclosure of which is hereby incorporated by reference in its entirety. Preferred mercapto functional silicone release agents are described in the North American patent of Imperial et al., 4,029,827, the disclosure of which is fully incorporated by reference. A typical basic mercapto functional polysiloxane chain is of the dialkyl type having the general formula: wherein R represents a "spacer" group pending the polymeric backbone and SH is the mercapto functional group. In preferred embodiments R is an alkyl portion having about 1-8 carbon atoms, typically a propyl group (-CEd-CH -CH "-). For a typical polymer that has a functional content of 1 percent mol, there is a portion for every 99 b. If the content of the mercapto funcioal group is 2 percent mol, there is an average of 2 servings a for each 98 portions b. In embodiments, a may range from about 2 to about 4, and preferably 3; b is at least about 65, preferably from about 65 to about 200, more preferably from about 135 to about 200, and especially more than about 200. The spacer groups R may all be similar, for example, methyl, ethyl or propyl, or they may be mixtures of alkyl groups, for example, mixtures of propyl and butyl or ethyl jF, and propyl, and the like. In addition, the spacer group R can be straight or branched chain. The typical molecule shown in the above general formula comprises substituted methyl groups on the Si atoms at non-spacer group sites. However, these non-spacer group sites can typically comprise alkyl groups in general of about 1 to 6 carbon atoms and mixtures thereof. Other groups may be substituted at those sites by those skilled in the art, so long as the substituted groups do not interfere with the mercapto functional groups designated in the general formula by -SH. The R-SH groups can be randomly positioned in the molecule, to provide the critical functional groups in the release agents, processes and devices of the present invention. Alternatively, or in addition, the 0 mercapto (-SH) functional groups can be located on spacer groups (R) at terminal sites on the molecule, that is, the molecule can be "capped at the end" by the mercapto functional groups. The polymeric release agent can also be applied in conjunction with a cutting agent or dilution agent with which it is miscible, that is, two or more miscible components. An example of this embodiment is a mixture of the polydimethylsiloxane having f mercapto functional groups attached to a propyl spacer group 0 mixed with the polydimethylsiloxane (silicone oil) with which it is miscible and which acts as a diluting agent. Typical mixtures include 50/50 and 25/75 of mercapto functional release material to silicone oil. In general, according to the objects of the present invention, the amount suffic to cover the surface must be that amount which will maintain a thickness of the fluid in the submicroscopic to microscopic range, and is preferably from about 0.5 microns to about 10 microns thick. The molecular weight of the polyalkyl siloxane fluids containing mercapto reactive chemically reactive groups must be sufficly high, so that the fluid is not too volatile. Molecular weights in the order of 5,000 have been found satisfactory, with preferred molecular weights they are approximately 10,000 to 15,000 and older. In certain embodiments, mercapto functional silicone release oils are Preferred over amino functional release oils. It has been observed that the MICR ink characters (the MICR ink may be a dry ink which may be on a ribbon) of the thermal coders may not Jff * adhere to the surface of copies previously fused with an amino-functional release agent. The problem has been investigated to the amine-cellulose interactions, which inhibit the diffusion of the oil to the body of the paper. The absence of cellulose interactions with non-functional silicone oils and mercapto functional allows the diffusion of these fluids to the body of the paper. The MICR ink can then adhere to the exposed paper fibers. In particular, the experiments indicate that the amine functionality, but not the mercapto functionality, for the release of oil, 5 adheres to the cellulose fibers of the paper. Surface measurements (ESC &) have detected high silicone content on the paper that has been passed through a fusing element that uses an amino fluid. The non-functional release fluids and mercapto functionalities show significantly less ff silicon on the surface of the paper since these fluids are able to undergo rapid diffusion to the paper.

NMR spectroscopy (nuclear magnetic resonance) has detected a specific interaction between the fibers of paper pulp and amine, but not with mercapto functionality. The measurements on functional amine oil filtered through a cellulose bed, shows a significant adsorption of groups Jff amina. This adsorption is manifested by a reduction significant in the content of amine in the filtrate. This finding suggests that there is either a hydrogen bond interaction between the basic amine groups and the cellulose hydroxy groups or, more likely, the amine groups react with cellulose. In contrast to amine-functional silicone fluency, the mercapto fluid does not show such interactions and passes through the cellulose column without any loss of functionality. Thus, the mercapto functional release oil can react with the alumina filler in the surface layer of the melting element and by this provides excellent surface coverage, which allows a long life of release and a long life of the melting element. Moreover, the mercapto functional oil reacts little or does not react with the components of the paper, in such a way that the paper surface is not covered with a layer of oil, which can prevent the adhesion of MICR ink. 'Mercapto functionality can be terminal, pending, or both. To promote adhesion between the core of the The melting element and the surface layer of the hydrofluoroelastomer, an adhesive, and in particular a silane adhesive, as described in U.S. Patent No. 5,049,444 issued to Bingham et al., J ^. entitled "Silane Adhesive System For Fusing Member" on Which includes a copolymer of vinylidene fluoride, hexafluoropropylene and at least 20 weight percent of a coupling agent, which comprises at least one organo functional silane and an activator can be used. In addition, for weight hydrofluoroelastomers With a higher molecular weight, such as, for example, "Viton GF", the adhesive can be formed from the hydrofluoro-elastomer FKM in a solvent solution, together with an amino silane represented by the formula as described in the U.S. Pat. No. 5,332,641. wherein R can be an alkyl group having 1 to 7 carbon atoms; R 'can be an alkyl group having 1 to 7 carbon atoms or a polyalkoxyalkyl group of less than 7 carbon atoms; Y is an amino group or an amino substituted alkyl, or a substituted polyamino alkyl, or an alkenylalkoxy amino, or an aryl amino of less than 15 carbon atoms, h is from 1 to 3, b is from 0 to 2, which is 2 and h + b = 3. As discussed previously, the outer surface layer of the fusing member according to the present invention can be from about 0.01016 cm (4 mils) to 0.02286 cm (9 mils) and preferably it is approximately 0.01524 cm (6 mils) thick, to provide the desired thermal conductivity and conformability. As previously indicated, a thickness of less than 0.01016 cm (4 mils) is experienced # difficulty in providing adequate formability to allow the flow of organic pigment around the magnetically attractable particle and the paper to fix the organic pigment, in addition to providing adequate formability, such a thickness of the surface layer of the melting element together with the loading of the alumina in the quantities previously indicated, provides a surface layer that has a hardness to allow penetration of the organic pigment particles to the surface of the paper. In addition, while providing acceptable formability and hardness, the presence of the alumina allows the surface layer of the melting element is more conductive and provides a lower minimum fixing temperature (approximately -1 C), also as a lower core temperature of the melting element, which results in less degradation of the surface layer of the fluoroelastomer or fluorinated elastomer and / or the interface and adhesive between the core and the surface layer of the fluoroelastomer. The attention now turns to figures 2 and 3 which illustrate an evaluation used to measure the fixation of an organic pigment to the substrate and in this Fixation is intended to define the penetration or absorption of the organic pigment as much as possible to the substrate such as paper. In tests, the crease area is a measure of fixation, the lower the crease area, the better the fixation. This is an organic pigment test fused to a substrate, to measure how much of the organic pigment material is flaked or fragmented at any paticular point, and is measured by folding a substrate sheet with a broad band of fixed organic pigment on it , and separating it to determine how much organic pigment can be dislodged from the leaf substrate that leaves white areas. The poorer the fixation of the organic pigment to the larger substrate is the white area and the larger the fold number. In the graphs of Figures 2 and 3 an acceptable fixation is one with a fold area less than about 40 on each of the graphs. As can be seen, the melting roller according to the invention provides an acceptable fixation at a surface temperature of just over 199 C (390 F), compared to the prior art of almost 215.5 C (420 F). The following examples further define and describe the fusion element according to the present invention, and illustrate a preferred embodiment of the present invention. In the examples which follow all parts and percentages are by weight, unless otherwise specified, and the tests were carried out under the same conditions, which include melting speed, width of the Contact and pressure of the roller, unless otherwise specified.

EXAMPLE I A melting roller prepared with the use of a _10 stainless steel melting roller core, Cylindrical, approximately 7.6 cm (3"inches) in diameter and 40.6 cm (16 inches) long, which was degreased, cleaned by blasting blasting, degreased and covered with a silane adhesive as described described in U.S. Patent No. 5,332,641. The melting layer was prepared from a solvent solution / dispersion, which contained 100 parts by weight of a hydrofluoroelastomer, "Viton GF", a *. 35 percent by weight fluoride polymer Vinylidene, 34 weight percent hexafluoropropylene and 29 weight percent tetrafluoroethylene and 2 weight percent of a curing monomer at the site, polymerized. 1 part by weight of Ca (0H) 2, 2 parts by weight of magnesium oxide, Maglite D, available from C.P.

Hall, Chicago, Illinois, 2 parts by weight of carbon black N990 available from R.T. Vanderbilt Co., and 5 parts by weight of "Curative No. 50" from DuPont, in a mixture of methyl ethyl ketone and methyl isobutyl ketone which was sprayed onto the cylindrical roll of 7.6 cm (3 inches-5 days) to a nominal thickness of approximately 0.01524 cm (6 mils) and the coated melting element was cured by step heating in air at 95 C for 2 hours, 175 C for 2 hours, 205 ° C for 2 hours and 230 ° C for 16 hours. The cured melting roller was tested in a F apparatus "Xerox 5090" where a pigment image was formed. large solid area organic, on a paper substrate and was evaluated for fixation according to the fold test described above for surface temperatures of the melting roller as indicated in Figure 2. As discussed previously, the lower the fold area, which is a measure of flaking or breaking-off; tion of the organic pigment particles and the area folded and therefore a measure of the level of fixation of the organic pigment by means of penetration or absorption to the surface of the paper substrate is taken at that temperature of the surface of the melting roller where the fold area is less than 40 in the orderly scale.

EXAMPLE II The procedure of Example I is repeated, except that the melting layer is prepared from a solution of methyl ethyl ketone and methyl isobutyl ketone of 100 parts by weight of "Viton GF", 55 parts by weight of calcined ana, in size nominal 1 miera, available from KC, Abrasives as "# 1 Calcined Ana" which provides approximately 20 percent by vo of ana in the melting roll melting coating, one part by weight of Ca (OH) ", 2 parts by weight of - Magnesium oxide, "Maglite D", 2 parts by weight of carbon black N990, 5 parts by weight of "Viton Curative" VC50". The area of image fold and pigment The organic solid area was evaluated in the same manner as in Example I and as shown in Figure 3, a melt layer surface temperature of more than 199 ° C (390 F) provides a crease area of 40 ° C. or less. ¡ÉF, in the graph of figure 3, which represents the ana calcined - according to the present invention, the conductivity of the roller die allows more heat to go to the roller surface, whereby more heat is supplied to the organic pigment / paper substrate interface. 25 EXAMPLE III The procedure of Example II is repeated, except that the filling consisted of 46 parts by weight of calcined ana and 15 parts by weight of cupric oxide, available from American Chemet Company. A melting roller prepared according to this procedure had a hardness and thermal conductivity similar to those obtained for the roller described in example II and can be used in a melting environment of the organic pigment, with a functional release agent such as a silicone oil having mercapto functionality. The cupric oxide will act as an assurance or fixation site for such a release agent.

Figure 5 is a graphical comparison of the melting surface layer according to the present invention, as described in Example II, with that obtained according to the melting layer described in Example L, where it is noted that the present invention provides a core temperature 30 degrees lower with a surface temperature 25 degrees lower, while reaching the same temperature at the organic pigment / paper interface.

EXAMPLE IV A fusion roller is stamped as described in Example III and installed in a Xerox "Duplicator 5090" apparatus, which uses organic MICR pigment. Xerox standard mercapto functional silicone oil (designated as "FUSER") is used AGENT MR ") having a formula as described herein, with a mercapto content of 0.2 mol percent as the release agent, the test was completed after approximately 1.8 million impressions were made with good adhesion from the MICR organic pigment to the paper, without failure of release, and without problems of paper clogging.In all this run, the pressure d release separation was maintained at 0.42-0.49 Kg / cm (6-7 pounds / square inch) ), which indicates that the surface layer containing the hydrofluoroelastomer and the ana filling was stable during the life of the melting roller.Excellent results were carried out although the MICR pigment-organic had a minimum fixing temperature of 11 C (20 F) higher than the organic pigment that did not include MICR, typically used with the "Xerox 5090 Duplicator" apparatus, which results in a harder fusion environment.

Thus, according to the present invention, new and improved fusion element and fusion system have been provided. In particular, a melting element having a higher thermal conductivity to allow adequate fixation of the organic pigment, a fixing or melting temperature that does not change, to the organic pigment / paper interface, lower core temperature has been provided. of the melting element, and lower surface temperature of the melting element. The present melting element also has sufficient hardness to compress or firmly fix the organic pigment image to the paper substrate, by absorbing the pigment or gyneum therein, and provide sufficient thermal energy to allow the organic pigment to penetrate the surface of the paper. the substrate sheet, while at the same time providing formability of the organic pigment image by allowing the organic pigment material to flow around the individual particles that can be attracted magnetically and to the paper to fix the organic pigment. In general, the higher the thermal conductivity, the lower the minimum fixing temperature and the core temperature, to obtain the same level of image fixation. In addition, the reduction of the thickness of the surface layer gradually reduces the minimum fixing temperature requirements, without changing the temperature through the organic pigment. That is, the fixation remains constant. Because the heat transfer of the thinner surface layer is carried out more rapidly, the enabling of a lower surface temperature while the interface temperature of the paper with organic pigment remains unaffected. However, too thin a coating thickness is not desirable for the formability of the elastomer. The fold is better with a higher filler content and higher thickness in the range of 0.01016 cm (4 mils) to 0.02286 cm (9 mils), it will be noted that a thinner layer would be desired for cost reasons and heat flow, but that the thickness within the proposed range is desired in order to obtain the formability of the roll to the organic pigment images on the substrate and that beyond approximately 0.02286 coi (9 thousandths of an inch), at cost of the surface layer becomes excessive without a commensurate improvement in fixing the organic pigment. For a constant thickness of the layer as the filler load of alumina increases, the hardness and thermal conductivity increase in a similar manner. As the hardness increases, however, the reduction in formability may limit the contents of the filler. According to # present invention, the core temperature of the melting roller and the interface of the elastomer is decreased, so that life is preserved and thermal conductivity is increased to conduct heat more rapidly to the surface. In addition, the organic pigment image is suitably fused and permanently affixed to the paper substrate and does not excessively fragment in _1 or contact readers. In addition, the use of mercapto functional release oil with the present melting element results in the absence of ink adhesion problems such as MICR ink to paper substrates such as checks and envelopes. All of the patents and applications referred to herein are hereby incorporated specifically and wholly by reference in their entirety in the present application. While the invention has been described in detail with reference to specific and preferred modalities, it will be appreciated that several modifications? and _ variations will be apparent to one skilled in the art. For example, while the invention has been illustrated with reference to a melting roller, it is will understand that it has the same application to other fusion elements, such as flat or curved plate elements in pressure contact with the roller, All of such # modifications and modalities as readily as can be presented to those skilled in the art are proposed to be within the scope of the appended claims.

It is noted that in relation to this date, the best method known by the applicant to bring to practice the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having described the invention as above, property is claimed as contained in the following 15 twenty

Claims (22)

1. A long-lasting, thermally conductive fusion element, characterized in that it comprises a base member and a surface layer, wherein the surface layer includes a fluoroelastomer or fluorinated elastomer and an alumina filler having an average particle size of about 0.5 to About 15 microns, the alumina is present in an amount to provide a thermal conductivity of at least about 0.24 Watts / meter Kelvin in the surface layer.

2. The melting element according to claim 1, characterized in that the alumina is calcined alumina.

3. The melting element according to claim 1, characterized in that the alumina is 20 selects from the group consisting of tabular alumina or fused alumina. ^

4. The fusion element according to claim 1, characterized in that the fluoroelastomer or fluorinated elastomer is a hydrofluoroelastomer.

5. The melting element according to claim 1, characterized in that the fluoroelastomer or fluorinated elastomer comprises a poly (vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene-curing monomer at the site) wherein the vinylidene fluoride is present in an amount less than 40 percent by weight of the polymer.

6. The fusion element according to claim 1, characterized in that the alumina is T? present in the surface layer in an amount of about 30 parts to about 100 parts by weight per 100 parts by weight of the fluoroelastomer or fluorinated elastomer.

The melting element according to claim 1, characterized in that the alumina has a particle size distribution of J L about 0.5 microns to about 8 microns.

8. The melting element according to claim 1, characterized in that the melting element is a roller.

9. The melting element according to claim 1, characterized in that it includes cupric oxide, present in the surface layer in an amount of up to about 30 parts by weight per 100 parts by weight of the fluoroelastomer or fluorinated elastomer.

10. A fusion system for an electrostatic printing machine, characterized in that it comprises a pressure element and a long-lasting, thermally conductive fusion element which comprises a 10 base element and a surface layer, wherein the layer > Surface W includes a fluoroelastomer or fluorinated elastomer and an alumina filler having an average particle size of from about 0.5 to about 15 microns, alumina is present in an amount 15 to provide a thermal conductivity of at least about 0.24 Watts / meter Kelvin in the surface layer.

11. The fusion system according to claim 10, characterized in that the alumina is calcined alumina.

12. The fusion system according to claim 10, characterized in that the alumina is 25 selected from the group consisting of tabular alumina, sulfur alumina, and fused alumina.

13. The fusion system according to claim 10, characterized in that the fluoroelastomer or fluorinated elastomer is a hydrofluoroelastomer.

14. The fusion system according to claim 10, characterized in that the fluoroelastomer or fluorinated elastomer comprises a poly (fluoride) Vinylidene-hexafluoropropylene-tetrafluoroethylene monomer-curing site) wherein the vinylidene fluoride is present in an amount of less than 40 percent by weight of the polymer.

15. The fusion system according to claim 10, characterized in that the alumina is present in the surface layer in an amount of about 30 parts to about 100 parts by weight per 100 parts by weight of the fluoroelastomer or 20 fluorinated elastomer.

16. The fusion system according to claim 10, characterized in that the alumina has a particle size distribution of about 0.5 microns to about 8 microns.

17. The fusion system conforms to claim 10, characterized in that the fusion element is a roller.

18. The fusion system according to claim 10, characterized in that the pressure element is a soft, long-lasting, non-jacketed roller, comprising a cylindrical core and a non-oxidizing layer, which does not swell in oil. silicone, of a thermally stable hydrofluoroelastomer having? ß a modulus of Young's elasticity of hands of about 35.15 Kg / cm (500 pounds / square inch), from about 0.635 cm (250 thousandths of an inch) to about 1.27 cm ( 500 thousandths of 15 inch) thick, and a hardness of about 45 to about 60 Shore A.

19. The fusion system according to claim 10, characterized in that it includes oxide 20 cubic, present in the surface layer in an amount of up to about 30 parts by weight per 100 parts by weight of the fluoroelastomer or fluorinated elastomer.

20. The fusion system according to claim 10, characterized in that it includes a supply of aminofunctional organic pigment release agent and an apparatus for delivering the release agent to the surface layer of the fusion element.

21. The fusion system according to claim 10, characterized in that it includes a supply of mercapto functional organic pigment release agent and an apparatus for delivering the release agent to the surface layer of the fusion element.

22. The fusion system conforms to claim 21, characterized in that the release agent of the organic pigment, mercapto functional, is: wherein R is an alkyl having 1 to 8 carbon atoms ffßf carbon, a fluctuates from about 2 to about 4, and b is at least about 65. In testimony of which I sign the present in this City of Mexico, D.F., on February 2, 1996. Attorney Fk