JP2003084482A - Printing member and/or method and device for heating toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately fix toner on a printing member or to perform preparation thereof by making a multicolor printing paper printing member compatible with a special state caused by using microwaves. SOLUTION: This method is to fix the toner on a base material or the printing member, and the printing member having the toner is irradiated and heated with the microwaves from at least one microwave transmitter so as to melt the toner, and the toner whose modulus of elasticity G' is remarkably lowered from the solid state of the toner to the liquid state of the toner at the time of heating is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing toner onto a substrate or a printing member, for example a paper-like or tape-like printing member, preferably for digital printers.

Furthermore, the present invention advantageously provides a toner-based or printing member, for example, a toner, for carrying out the aforementioned method.
It relates to a heating device for printing members and / or toners, preferably for fixing on paper-shaped or tape-shaped printing members for digital printers.

[0003]

BACKGROUND OF THE INVENTION In digital electrostatic or electrophotographic printing, an electrostatic latent image is formed and this electrostatic latent image is developed with charged toner particles, the toner particles being the printing member on which the image is recorded, For example, it moves and adheres to the paper. The image thus transferred onto the printing member is fixed by heating and softening the toner and / or heating the printing member.
By this process, and during this process, toner particles combine with the printing member and, in some cases, also with each other.

It is known in principle to use microwaves to fix the toner on the printing member. Since the absorption of microwave energy into the toner is usually at least one order of magnitude less than the absorption into the printing member,
Advantageously, the printing member is heated by microwaves, which heats the toner on the printing member to a temperature at which the toner is combined with the printing member. As is known, when microwaves are used for fixing toner, values that characterize the printing member used, such as the weight, humidity and composition of the printing member, are critical and need to be considered. .

It is known, for example, from US Pat. No. 4,511,778 to fix a toner image on a printing member, for example a sheet of paper, using high frequencies, for example microwaves. At that time, the aspect of the known device is that the microwave is transmitted depending on the size of the printing member, and as a value indicating the characteristics of the printing member, the toner is appropriately melted and fixed in consideration of this value. It is a means to be able to do.

[0006] This is a fairly crude approach, in which only the obvious amount, such as the size of the printing element, is taken into account, for example a relatively large element to be heated will have a relatively large heat capacity. On account of the fact that, on the basis of the fact that it requires more energy overall than the relatively small parts to be heated, it is a pre-made method for the operation of this device before fusing.

However, this crude, up-front approach does not take into account another critical condition when utilizing microwaves for toner fusing. Thus, for example, the cited method can only be used for monochromatic printing of paper weights with a small range of deformation, and for papers of different color toners, possibly different properties and possibly different water contents. Weight cannot be taken into account in this crude, sized manner of the printing member. In color printing, the toner image has, for example, four different toner layers. At that time, the maximum density of each toner layer is 100 on the image base or printing member.
%, Where the maximum total density of the toner layer is 400%
Toner image. Usually, the density of a single color toner image is in the range of 10% to 100% and the density of a color toner image is in the range of 10% to 290%.

Moreover, when the paper printing member is used, the edge area of the paper, which is irradiated with microwaves, is processed differently in energy from that in the intermediate area, resulting in a non-uniform printed product. May be.

Moreover, in the conventional toner fixing using only microwaves, in some cases, the melting of the toner becomes incomplete depending on the position density of the toner, or as a result, bubbles are formed in the toner area. It is heated and heated. Adhesion of toner on the printing member is also insufficient in some cases. The reason for this is, for example, that the adhesion between the toner and the printing member is
This is because they are not formed sufficiently. In particular, a problem arises when the printing member is printed on both sides of two printing processes, which are carried out successively in succession.

Due to this possible problem, as already mentioned, in the prior art and in the usual way microwave irradiation is not used during fusing, the toner is heated without microwave irradiation, The pair of rollers is used to apply pressure to bond with the printing member.

However, in principle, contactless fixing is desired in order to eliminate adverse effects on printed images.
Another advantage of contactless fusing is that wear is avoided, which improves the settling time of the device being used as well as the reliability of the device.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to use microwaves, advantageously also for multicolor printing paper printing members, advantageously adapted to the particular conditions occurring.
To properly fix the toner on the printing member, or to prepare it.

[0013]

SUMMARY OF THE INVENTION To solve the problem, the present invention is directed to irradiating a printing member having toner with microwaves from at least one microwave transmitter and heating to melt the toner, It is proposed to use a toner that undergoes a sharp transition from the solid state of the toner to the liquid state of the toner (indicating a strong decrease in elastic modulus G ′) during the heating.

[0014]

DETAILED DESCRIPTION OF THE INVENTION In the practice of the invention, it is possible to use a dry toner which is still quite stiff, for example at an average temperature of about 50 ° C. to 70 ° C., so that the toner is processed in the usual way, for example to about It can be crushed to a desired average toner size of 8-4 μm, is not tacky at development temperature, does not melt, and suddenly becomes a very thin liquid state with low viscosity at a relatively high temperature of about 90 ° C. As a result, in some cases, by utilizing the capillarity phenomenon, it is deposited without contact from the outside without contacting the inside of the printing member and adheres to it, and when cooled, it is cured and fixed very rapidly again. , That is,
The surface gloss is compatible with the printing component and is good (especially because no grain size limits are formed). In this case, a color toner for color saturation (improvement of saturation) is also meaningful.

In this connection, in the context of the toner of the present invention, the ratio of the values of the elastic modulus G ′ at the reference temperature value is calculated from the starting temperature at the time when the toner begins to become glassy plus 50 ° C. For the elastic module value at temperature itself,
1E-5, preferably <1E-7, where E
Is a base 10 exponential function.

The starting temperature at which the toner begins to become glassy is preferably determined as the temperature value at which the tangent line in the function characteristic of the elastic modulus G'crosses as a function of the temperature before and after the glassy transition. To be

Advantageously, the toner transitions from its solid state to its liquid state in a predetermined temperature interval or window of a size of approximately 30 ° K to 50 ° K. This region is above 60 ° C, preferably about 70 ° C to 130 ° C, more preferably 75 ° C to 125 ° C.

In an embodiment of the method according to the invention (independent claim), at least one physical method parameter is corrected with the energy supply into the printing member with the toner, in order to adapt it to a special situation. It is controlled and / or adjusted depending on the parameters.

According to the invention, it is not a crude and straightforward procedure, but advantageously a control can be carried out which is adapted to the actual, advantageously measured situation.

In this case, the above-mentioned energy supply amount corresponds approximately to the microwave power consumed by the entire system consisting of the printing member and the toner, and as a result, according to the invention, it corresponds to the actual situation. , The transmitted power and the consumed power are compared and adjusted. This corresponds substantially to efficiency control and / or regulation. Here, in general terms, the adjustment takes place on the side of the sender, which can be regarded as a microwave source in the broadest sense, and / or on the side of the receiving toner printing element system or operating part.

To this end, the invention advantageously proposes to adjust the power of the microwave transmitter and / or the speed of movement of the printing member and / or the frequency of the microwave, This adjustment of the microwave frequency can advantageously achieve a relatively high energy absorption directly in the toner itself, so that the effect on the toner fusing is indirectly a problem on the printing member. It enables more accurate detection than many methods.

As a measurable parameter for the parameter-dependent control, the invention advantageously proposes the temperature of the printing member or the microwave energy reflected by the toner-printing member-system, ie not absorbed. To do. Other measurable parameters may be, without limitation, the weight / thickness of the printing member or the water content or the thickness and gloss of the toner layer.

In principle, 100 MHz to 100 GHz
All frequencies in the microwave range can be used. As usual, ISM frequencies open to industrial, academic or medical uses, preferably 2.45 GH
z is used. However, with other frequencies within the other frequency ranges mentioned above, a greater than normal component of the radiant energy is advantageously absorbed not only by the printing member but also by the toner.

In an apparatus of the type described at the outset, the above-mentioned problem is to heat the toner by irradiating it with microwaves so as to rapidly transition from a solid state to a liquid state during heating, as described in the independent claim. Is provided with at least one microwave radiating transmitter.

Advantageously, furthermore, the one or more operating parameters are provided adjustable.

Regarding the effect achieved by the present invention,
Significantly as already mentioned in connection with the method according to the invention, the method parameters mentioned here correspond to the operating parameters of the device.

Another embodiment of the device according to the invention, which is also claimed as an independent claim, is characterized in that the at least one microwave conductor is configured in a meander or fold-like shape.

The advantage of the microwave conductor structure of the present invention is that because of the use of microwave energy, the relatively large length of the microwave conductor has a continuous wave region as an alternating length with the printing member. It can be used for. To that end, the microwave conductor is advantageously guided back and forth a plurality of times over the transport path for the printing member transverse to the transport direction. By doing so, it becomes possible to heat the printing member uniformly and uniformly with high efficiency.

The meander shape can be made relatively compact by allowing the meander portions to move closely relative to each other. Additionally, the microwave conductor width may be narrowed in order to correspondingly increase the electric field strength. A compact construction type is particularly desirable for front and back side printing of printing members and for fixing each toner image required therefor.

Depending on the microwave energy supplied, the field strength is up to 3 kV / mm, preferably around 0.2.
kV / mm to about 1.0 kV / mm.

Swept through each meander member, the electric field strength E is reduced based on the degree of absorption by the printing member or by the toner image. This absorption is not dependent on the electric field strength linearly (to E ^2), it can be partially compensated for by appropriately reducing continuously the width of the meander portion member successive. Compensation can advantageously be effected additionally or alternatively by converging the width of the microwave conductor or by a suitable conical shape. The purpose in each case is to keep the field strength substantially constant over the length of the microwave conductor, in particular also inside the meander sub-member, which is likewise achieved by the above-mentioned focusing geometry. can do. Furthermore, this measure makes it possible to reduce the size of the meander structure in the conveying or processing direction.

In addition, the converging shape can partially compensate for the drop in absorption in the meander submember. To that end, the focusing geometry is configured so that the electrolytic strength at the beginning of the meander part member is less than the electrolytic strength at the end of the meander part member. Since the absorption does not depend linearly on the electrolytic strength E (~ E ² ) and linearly on the width of each microwave conductor, an appropriate ratio between the microwave conductor width and the electric field strength can be determined by the meander part. There can be a substantially constant absorption over the length of the member.

The conveying direction of the printing member can be in both directions perpendicular to the extending direction of the meander part member, but in the case of loading and unloading the printing member,
It is necessary to properly consider and control the microwave power.

The number of meander sub-members depends on the required absorbed power, or on the temperature of the printing member and on the heating or drying uniformity of the printing member.

The device according to the invention can be used advantageously not only as a fixing device or fuser, but also as a residual heat device for a subsequent fixing device, as a conditioning device for conditioning printing members, in particular paper. Is also suitable. The printing member can be changed beforehand by applying heat before the start of the printing process.

The device according to the invention is advantageously for a digital multicolor printing press, so that also for a printing press so configured, patent protection is claimed in the scope of the invention. There is.

The apparatus of the present invention will be described in detail below with reference to the illustrated embodiment for a digital multi-color printing machine (thus, it is within the scope of the present invention even for a printing machine configured as such). Is claiming protection in).

Examples of the present invention will be described below with reference to FIGS.
However, the present invention is not limited to the described embodiments and drawings.

[0039]

EXAMPLES The G'ratio is the ratio of the elastic modulus G'of the glassy transition start temperature plus 50 ° C. to the glassy transition start temperature. The starting temperature of the glassy transition is specified according to FIG. 1 from the intersection of the tangents of G ′ before and after the glassy transition, which in the example shown is just 70 ° C.

FIG. 2 shows the scanned functional characteristics of G ′ according to FIG. 1 for the example of three toners.
The function value of G'is Bo with a parallel plate with a diameter of 40 mm.
Determined by rheological measurements with a lin rheometer. Frequency 1 rad / s corresponding to 0.16 Hz
The temperature is continuously changed at 50 ° C to 200 ° C. The measurement voltage (strain: strain) causes the sample to dilute due to shear stress (S
chubverduennung) No (Newton characteristic: Newtonische
s Verhalten).

Only the toner of the present invention rapidly transitions from the solid state to the liquid state, with a terminal G'value of about 1.00E-0.
It is 2. As a result, the G'ratio is
It is 5.0E-08.

FIG. 3 schematically shows a microwave conductor 1 having a meandering or zigzag shape. The microwave conductor 1 has a microwave generating system 2 at one end thereof.
, And the other end is connected to the system 3 for terminating the microwave conductor, through which the microwave propagates in the direction of the arrow 4. The meander-shaped part has mutually parallel meander sub-members 11 to 15 arranged transversely to the transport direction 5 of the printing member. In FIG. 3, the meander sub-members are each of the same width. However, among the successive meander sub-members 11 to 15, each succeeding meander sub-member in the transport direction 5 has a slight width with respect to the preceding meander sub-member, and / or each meander sub-member. The sub-members are converging or conically curved and narrowed so that the microwave conductor 1 and / or the microwave conductor 1 and / or Alternatively, the electric field strength can be made substantially constant over the entire length of the meander portion member.

FIG. 4 shows a side view of the apparatus configuration of FIG. The same components are likewise indicated in the subsequent FIG. 5 with the same reference numbers as in FIG.

It can be seen from FIG. 4 that the microwave conductor 1 is provided with through-hole slits 6 for printing members.

FIG. 5 shows a microwave conductor 1 which corresponds to the microwave conductor 1 of FIG. 3 but has been brought closer so that the meander part members 11 to 15 are in direct contact with each other.

The present invention relates to a method of fixing toner onto a substrate or a printing member, for example a paper-like printing member, preferably for a digital printer, wherein the toner-containing printing member is at least one microwave transmitter. By irradiating with microwaves from the above to heat the toner in order to melt the toner, and at the time of heating, a toner showing a strong decrease in elastic modulus G ′ from the solid state of the toner to the liquid state of the toner is used. Attached.

Advantageously, the value of the elastic modulus G'of the inventive toner at the reference temperature value calculated from the starting temperature at the start of the glassy transition of the inventive toner plus 50 ° C. and the starting temperature The ratio with the value of the elastic modulus G ′ is set to <10 ⁻⁵ .

Furthermore, the present invention advantageously relates to a device for fixing toner with at least one transmitter emitting microwaves for carrying out the method described above.

[Brief description of drawings]

FIG. 1 shows the functional properties of the toner modulus G ′ as a function of temperature for defining the starting temperature of the vitreous transition of the toner,

2 shows, for comparison, the functional properties of the inventive toner and two prior art toners scanned according to FIG. 1;

FIG. 3 is a schematic plan view of the microwave conductor of the present invention,

4 is a side view of the microwave conductor of FIG. 3,

FIG. 5 is a plan view of a second meandering microwave conductor having a particularly compact structure.

[Explanation of symbols]

1 microwave conductor 2 Microwave generation system 3 Microwave conductor termination system 5 Print member conveyance direction 6 Through-hole slits for printing members 11-15 Meander Part Member

Continued front page    (72) Inventor Hans-Otto Krause             Germany Eckernfelde             Pfeverdemarkt 27 (72) Inventor Frank Morgenweck             Federal Republic of Germany Kiel Muriusushi             Utrase 28 (72) Inventor Domingo Rode             Federal Republic of Germany Kiel Redderkan             93 (72) Inventor Detlef Schulze-Hagenest             Morphseedorff, Federal Republic of Germany             Uttde 51 (72) Inventor Gerhard Vulcher             Federal Republic of Germany Cologne Achener             Strasse 114 (72) Inventor Kai-Uwe Prassich             Federal Republic of Germany Dortmund             Selling Veg 11 (72) Inventor Dinesh Tiago             United States New York Fairpo             White White Alder Circle 18 F-term (reference) 2H005 EA03 FB04                 2H030 AD01 AD04 AD18 BB02                 2H033 AA02 AA11 AA23 BA25 BA58                       BA59 BE04 CA04 CA09 CA36                       CA44

Claims (22)

[Claims] 1. A method of fixing toner onto a substrate or a printing member, for example a paper-like printing member, preferably for a digital printer, wherein the printing member with toner is microwaved from at least one microwave transmitter. Irradiate with waves,
A method comprising heating the toner to melt it, and using a toner exhibiting a strong decrease in elastic modulus G ′ from the solid state of the toner to the liquid state of the toner during the heating. 2. The ratio of the value of the elastic modulus G ′ at the reference temperature value calculated from the starting temperature at the start of the glassy transition portion of the toner plus 50 ° C. and the value of the elastic modulus at the starting temperature is < 1
0 ^-5, advantageously, the method of claim 1 wherein the ^<10-7. 3. The method according to claim 1, wherein the transition from the solid state of the toner to the liquid state of the toner is performed in a temperature range of about 50 ° C. or lower. 4. The temperature range of the toner state change,
4. A process as claimed in any one of claims 1 to 3 which extends to 60 [deg.] C., preferably in the range of about 75 [deg.] C. to about 125 [deg.] C. 5. At least one method parameter is adjusted and / or adjusted in dependence on a parameter which correlates with the energy supply into the printing member with toner, in particular according to one of the claims 1 to 4. The method for fixing toner according to the item. 6. The microwave transmitter power is adjusted depending on the energy supply, at which time the power is increased when the energy supply is too low and the power is adjusted when the energy supply is too high. 6. The method of claim 5, wherein the method is low to maintain a suitable energy supply that is approximately constant on average. 7. The speed of movement of the printing member passing through the area irradiated by microwaves is adjusted depending on the energy supply, the adjustment being made such that when the energy supply is too low, the printing member is moved relatively. A method as claimed in claim 5, wherein the printing member is fixed at a low speed and the printing member is fixed at a relatively high speed if the energy supply is too high. 8. The method according to claim 5, wherein the microwave transmitter is tuned and / or tuned with respect to the frequency of the microwaves transmitted from the microwave transmitter, depending on the energy supply. 9. The method according to claim 5, wherein the temperature of the printing member is used as a correlation parameter with the energy supply. 10. The method according to claim 5, wherein the efficiency of energy supply is used as a correlation parameter with the energy supply. 11. A frequency is selected within a microwave frequency range of 100 MHz to 100 GHz outside of the vacated ISM frequency, and at the time of the selection, the absorption component of the measured microwave energy by the toner in the entire absorption is concerned. 2. Selection to favor higher toner absorption.
The method according to any one of 1 to 10. 12. The method according to claim 1, wherein a color toner is used. 13. A toner or a base material or a printing member, for example,
In a device for heating printing members and / or toners, preferably fixed on a paper-like printing member for a digital printer, preferably for carrying out the method according to any one of claims 1-12. And a transmitter for radiating at least one microwave is provided for irradiating and heating the toner exhibiting a strong decrease in elastic modulus G ′ from the solid state of the toner to the liquid state of the toner. apparatus. 14. The physical operating parameter for controlling the irradiation is adjustable depending on the correlation parameter with the toner-printing member-energy supply into the device arrangement.
The device according to 3. 15. The device according to claim 13 or 14, wherein the microwave conductor is configured in a meander or fold shape. 16. The apparatus according to claim 15, wherein the microwave conductor includes a meander-shaped coil or a partial member which is arranged so as to reciprocate substantially in the lateral direction with respect to the conveyance direction of the printing member. 17. A device according to claim 15, wherein the meander parts are arranged compactly in abutment with each other. 18. A microwave conductor for forming a field strength of up to about 3 kV / mm, preferably from about 0.2 kV / mm to about 1.0 kV / m, is provided.
7. The device according to any one of items 7 to 7. 19. A device according to claim 16, wherein successive meander-shaped members have different widths. 20. The apparatus of claim 19, wherein each subsequent meander-like member has a slight width relative to the preceding meander-like member. 21. Device according to claim 19 or 20, wherein the shape of the at least one meander-shaped part member is narrowed. 22. Provided for a multi-color printing machine,
22. An apparatus according to any one of claims 13 to 21, which operates according to an electrophotographic printing method.