JPS6015941B2 - Toner image fixing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of fixing a toner image by the action of heat or a solvent, and more particularly to a method of fixing a toner image that protects the toner image from being destroyed when the toner image is in a softened state. It is something.

Recently, it has been proposed to mark industrial products with information such as shipping destination, specifications, numbers, etc. using toner. In office copying machines, when the toner image is softened by heat or solvent, objects are prevented from coming into contact with the toner image. However, in industrial products, after marking is applied, the toner images are often directly sent to the next process without being protected. Therefore, since the toner image is sent in a softened state before being fixed, transportation equipment, machinery, etc. may come into contact with this surface and destroy the toner image. FIG. 1 shows a conventional fixing method.

First, an image of toner particles 20 is formed on a substrate 1 such as a steel plate {a'. Next, the toner particles 20' are sprayed with a volatile solvent to melt the thermoplastic resin contained in each toner particle and form an image 21. , the magnetic chuck 4 for conveying the substrate 1 descends and comes into contact with the image 21.
c'. When the magnetic chuck 4 moves upward after being transported, a portion 21a of the image 21 adheres to the magnetic chuck 4, and a remaining portion 21b remains on the substrate 1 [d}. This destroys the image 21 and makes the marked information difficult to read. When marking industrial products, objects often come into contact with images, and since there is no protection for images that are in a softened state, as mentioned above, objects may come into contact with images that are in a soft Q state. There was a risk of destroying it. Therefore, an object of the present invention is to provide a toner image fixing method that prevents the toner image from being destroyed even if an object comes into contact with the softened toner image.

The method of the present invention is characterized in that coarse particles, which are coarser than toner particles and do not soften with heat or solvent, are mixed into the toner image.

These coarse particles are larger than the toner particles, so when an object approaches the toner image, it comes into point contact with the coarse particles, thus preventing the object from directly contacting the toner image in the horizontal position. can do. This minimizes damage to the image when the object leaves. The present invention will be explained in more detail below.

FIG. 2 is an explanatory diagram showing an example of the fixing method of the present invention.
Toner particles 20 are attached to the substrate 1 [a'. A solvent containing coarse particles 5 is sprayed onto the toner particles 20 by a spray gun 3. The coarse particles 5 used are so strong that they will not be softened by a solvent or heat, and will not be crushed by the pressing force of an object. The size of the coarse particles 5 is selected to be sufficiently smaller than the picture elements of the marked information and sufficiently larger than the thickness of the toner image in the fixed state. The picture element is often about the size of a 1×1 willow, and the thickness of the fixed toner image does not exceed 50 μm, so hard particles with an average diameter of about 50 to 200 μm are selected as the coarse particles 5. . These include magnets, fused silica powders, calcined alumina powders, crosslinked polymer powders, and the like. Two toner particles are softened by the solvent to form an image 21.

When the image 21 is in a softened state, when the magnetic chuck 4 comes into contact with it, it makes point contact with the coarse particles 5 and does not directly touch the image 21 {d. Fixation of the image 21 progresses while the magnetic chuck 4 is in contact with it. When the conveyance of the substrate 1 is completed and the magnetic chuck 4 is moved upward, some of the coarse particles 5 are attached and peeled off, but image 2
1 is hardly peeled off. Experiments have shown that although image peeling could not be completely eliminated, the degree of damage was significantly reduced. FIG. 3 shows another embodiment of the invention.

A discharge recording needle 31 is disposed above the conductive roller 30 having an electrostatic recording layer, and a static haze latent image is formed on the conductive roller 30 by the discharge recording needle 31. This static latent image is visualized by a developing device 32 containing toner 20. This visualized toner image is transferred in contact with an intermediate belt 33 having an insulating surface. Since the coarse particles 5 are uniformly attached to the intermediate belt 33 by the coarse particle applicator 34 in advance, the toner image is transferred onto the coarse particles 5. The coarse particles 5 and the toner image are carried onto the base 1 and are blown onto the base 1 by vibrations such as ultrasonic waves.
indirectly transferred to the top. Since this substrate 1 is in a heated state like a steel plate sent out from a rolling process, the toner particles 20 are melted and fixing progresses. Since the toner image on the substrate 1 contains coarse particles 5, even if an object such as a magnetic chuck approaches the toner image during fixing, it is protected from directly contacting the toner image.

In addition to the above embodiments, methods for mixing coarse particles into a toner image include the following.

One method is to spray coarse particles together with air onto the softened toner image, since the toner image is fixed by the heat of the substrate when the substrate is hot, such as a steel plate sent out from a rolling process. There is a way to attach it to. Another method is to scatter coarse particles on a substrate in advance and transfer a toner image onto the coarse particles. Still another method is to spray coarse particles onto the toner image when the toner image is in a softened state by spraying a solvent. A method of using a mixture of toner particles and coarse particles during development may be considered, but this is not practical because the mass of each coarse particle is too large for the coarse particles to adhere to the latent image solely through electrical interaction.

Furthermore, the consumption rates of different substances in a mixture do not necessarily match.

Therefore, a monitoring mechanism for maintaining a constant composition is required, which complicates the apparatus, which is not preferable. Therefore, in such a case, it is preferable to carry out development in two stages. That is, first, toner development is carried out by cascade development, and then a certain amount of coarse particles are deposited on the toner image using a developing roll filled with coarse particles in the recesses of a gravure roll. Generally, in the case of heat fixing, unless the fluidity of the toner is sufficiently improved, fusing will not proceed smoothly.

In particular, if it contains a substance that does not dissolve in heat, kudzu mold often does not progress at all. However, since the coarse particles used in the present invention have a much larger particle size than the toner particles, they have almost no adverse effect on the fusion of the toner particles. This advantage occurs when the toner particles have a diameter of 20 to 50 peaks and the coarse particles have a diameter of 200 peaks or more. In the present invention, about 300 to 700 Buddhas is particularly desirable. More generally, in the case of heat fixing, it is necessary to ensure sufficient contact between toner particles of the same composition, and if coarse particles that do not dissolve in heat are present, all of the toner particles must be The question is what percentage of the surface area is occupied by non-fixing particles. The actual mixing volumes of toner particles and coarse particles are V, , V2, and the average particle diameters are r, , r, respectively.
If it is set to 2, the value of ratio/protection of each surface area needs to be above a certain range.

If r and r2 are extremely different, it is necessary to apply the filling rate of the powder layer to the toner particles. It has been experimentally found that fixing is successful when the above ratio is 0.3 to 0.4 or more. More preferably it is 0.5 or more. In addition, coarse particles that do not easily impair the contrast are those whose image is white or light-colored, and when the substrate is dark-colored, they are transparent or have the same color as the image;
Anything attached to the background area will be removed sooner or later, so it will have no effect. In the opposite case, it is transparent or has the same color as the image (oily color). Next, an example will be given and explained. Example 1 An image was formed on an electrostatic recording layer using a white toner consisting of a linear thermoplastic polyester and a white pigment with an average particle size of about 60 μm, and this was transferred onto a steel plate at room temperature to obtain a marking image.

The image was dissolved and fixed by spraying 40 tsp of trichloroethylene to this. After spraying, a magnetic chuck was brought into contact with the toner image at different time intervals under an atmosphere of 20:00. As a result of this experiment, the image was transferred to the magnetic chuck within 2 minutes, which not only stained the chuck surface but also made it difficult to read the image. On the other hand, using the method shown in FIG.
A fixing agent in which 100% of the calcined alumina powder of A was dispersed was sprayed, and a magnetic chuck was brought into contact with the toner image in the same manner as above, but there was almost no damage to the image immediately after spraying.

Example 0 Marking information consisting of dots of 1 row x 1 fence was electrostatically formed using thermosetting white powder paint Evaron 2000 (epoxy resin-based manufactured by Chugoku Paint Co., Ltd.) below the electrostatic recording layer. 18,000 black steel plates with a thickness of 40 were placed facing each other in parallel with a gap of 7, a necessary voltage difference was applied between them, and ultrasonic vibration was applied to the recording layer side to transfer the toner image.

The toner immediately melted and became fluid on the steel plate, but it took about 15 minutes to complete curing, by which time the image would stick to other objects if it came into contact with it. Therefore, after image transfer, 30% by volume of silica hardened with hardened epoxy resin was added.
Coarse particles with a particle size of 200 μm were dispersed onto a steel plate using an air stream.

With this operation, the contrast of the image did not deteriorate, and even when objects were brought into immediate contact, almost no adhesion occurred. Example M An image having coarse particles was transferred onto the surface of a substrate using the apparatus shown in FIG. 3, and fixed by the heat possessed by the substrate.

Even when an object came into contact with this image, the image did not break. Example W 3 side x 3 side dots (dot gap 0
．． 7 side) was formed in the same manner as in Example B.

This was transferred onto a 100 qo black steel plate with a thickness of 20 mm, and tetrachloroethane was sprayed and fixed with a solvent.
Since the solvent is still contained in the resin, the surface becomes soft and there is a diameter of 3
00 to 600 quartz glass bulbs were sprinkled all over and made to adhere to the soft toner. Even if the conveying rollers came into contact with it while the solvent was not volatilizing, no image was formed and it was unbearable. Note that the glass particles falling in the background gradually fall off the surface of the steel plate, and the image contrast is not impaired at all.
Example V This example is an example in which coarse particles are first dispersed onto a substrate.

Place one sail of Teflon-coated Ottaku Sand on the steel plate (
Natural cinnabar sand) was sprinkled. The density of scattering is 1, 20
~4 female litters. On top of this is a white toner of about 70 particles (75 particles of linear aromatic polyester resin and titanium oxide).
:25 mixture) was used to form a marking pattern in which 3 unit dots x 3 ribs were arranged. A 4:1 mixture of trichloroethylene and MIBK was used as a solvent for spraying and fixing. The toner splintered and filled the spaces between the Teflon-coated particles, and even when a magnetic roller was brought into contact with the toner in this state, the image was not damaged. As is clear from the above description, in the present invention, since coarse particles are mixed into a toner image, when an object approaches a softened toner image, the coarse particles prevent the object from coming into contact with the toner image. Therefore, there is no risk of image destruction.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a conventional fixing method, FIG. 2 is an explanatory diagram showing an example of the fixing method of the present invention, and FIG. 3 is an explanatory diagram showing another embodiment of the present invention. 1...Base, 20...Toner particles, 2
1...Image, 3...Subray gun, 4...Magnetic chuck, 5...Coarse particles, 30...Conductive lo-fu, 31...Discharge recording needle, 32...・
Developing machine, 34... Coarse particle applicator, 3
3...Intermediate belt. Figure - Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A method for fixing a toner image on a substrate by softening the toner particles by applying heat or a solvent to the toner image formed on the substrate, which Alternatively, coarse particles that do not soften with a solvent may be mixed into the toner image so as not to impair the image contrast, and when the toner particles are in a softened state, even if an object tries to contact the image, the object will come into contact with the coarse particles and the image will be imaged. A toner image fixing method characterized in that the toner image fixing method is characterized in that it does not destroy the toner image. 2. The toner image fixing method according to claim 1, wherein the coarse particles are mixed into the toner image by spraying the coarse particles together with a solvent. 3. Claim 1, characterized in that when the base is heated and the toner image is softened by the heat of the base, the coarse particles are blown onto the toner image together with air. The toner image fixing method described. 4. The coarse particles are uniformly adhered onto the intermediate belt, and the toner image formed on the electrostatic recording drum is transferred onto the coarse particles, and the coarse particles and the toner image formed on the intermediate belt are combined. A toner image fixing method according to claim 1, characterized in that the toner image is transferred onto a substrate. 5. The toner image fixing method according to claim 1, wherein the coarse particles are sprayed when the toner particles are in a softened state by spraying the solvent onto the toner image. 6. The toner image fixing method according to claim 1, wherein the coarse particles are dispersed on the substrate in advance, and the toner image is formed on the coarse particles. 7. The toner image fixing method according to any one of claims 1 to 6, wherein the coarse particles are silica. 8. The toner image fixing method according to any one of claims 1 to 6, wherein the coarse particles are quartz glass spheres. 9. The toner image fixing method according to any one of claims 1 to 6, wherein the coarse particles are fired aluminum powder. 10. The toner image fixing method according to any one of claims 1 to 6, wherein the coarse particles are crosslinked polymer powder. 11. The toner image fixing method according to claim 1, wherein the substrate is a heated steel plate. 12 When the steel plate has a dark color at room temperature, the toner particles are white or light-colored, and the coarse particles are the same color as the toner particles or transparent so as not to impair the image contrast. 12. The toner image fixing method according to claim 11. 13
When the toner image is thermally fixed, the toner particles have a particle size of 20 to 50 μm, and the coarse particles have a particle size of 3 μm.
The toner image fixing method according to claim 1, wherein the toner image fixing method is 00 to 700μ. 14 When the toner image is thermally fixed, let the mixed volumes of toner particles and coarse particles be V_1 and V_2, and the average particle diameters be r_1 and r_2, respectively. There are ▲mathematical formulas, chemical formulas, tables, etc.▼ 2. The toner image fixing method according to claim 1, wherein a relational expression holds true.