KR20120120637A - Recording medium for electrophotogrphy - Google Patents

Abstract

PURPOSE: A recording media for electric pictures is provided to perform toner fusion at low temperature and pressure by reducing the amount of fillers. CONSTITUTION: A recording media for electric pictures comprises a base material(10) and a toner fusing layer(20). The toner fusion layer is formed on one or more surfaces of the material. The toner fusing layer comprises 0.5-5 parts by weight of filler and 0.5-5 parts by weight of additive based on 100 parts by weight of binder. The binders are two or more selected from a group consisting of polyvinyl chloride copolymer, acrylic copolymer, polyester resin and ethylene-vinyl acetate copolymer. The glass transition temperature of the binder is -10-80 deg. Celsius.

Description

Recording medium for electrophotography {Recording medium for electrophotogrphy}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording medium, and more particularly to an electrophotographic recording medium having high glossiness using a binder having a low glass transition temperature.

With the recent spread of computer-aided technology, it has become common to create data on a computer and print out the data using a printer. The printer used in this case is a dot impact printer, a laser printer, a thermal printer, an inkjet printer, etc., for example. Among them, a printing output method (electrophotography) using a laser beam has been widely used by consumers in addition to inkjets because of the advantages of high output speed and high resolution images.

In general, the electrophotographic method applied to the printer or copier is usually subjected to five image processing steps. The first step is to apply a constant charge to the photoconductor drum or belt in the dark, the second step is to irradiate a laser beam to the photoconductive drum or belt to create an electrostatic latent image (latent image) In a third step, the latent image is exposed to the charged toner so that the toner is transferred onto the drum or the belt with an electrostatic force. In the fourth step, the toner is transferred to the recording medium while the recording medium passes between the photoconductive drum or belt and the corona. At this time, the recording medium must have a certain degree of conductivity so that the image of the toner is transferred by the electrostatic force. The final fifth step is to fix the toner transferred to the recording medium, mainly through hot fusing to apply heat and pressure by a roller.

A variety of recording media are used in such electrophotographic printers, such as plain paper. As the performance of the toner used in the transfer photo printer is improved and the transfer / settlement technology is developed, such as the high-gloss recording media commonly used in inkjet printers, Dedicated recording media have also been required for electrophotographic printers.

Dedicated paper used in conventional electrophotographic printers is generally formed by including a resin layer, an underlayer layer, and a receiving layer. This multilayer structure is complicated in processes and causes a large loss in energy and production yield for each process. There has been a problem.

On the other hand, many known recording media for electrophotographic printers (exclusive paper) contain a large amount of filler in the receiving layer to increase smoothness and glossiness. There has been a problem that requires it.

SUMMARY OF THE INVENTION The present invention provides an electrophotographic recording medium comprising a toner fusion layer having a simple and economical monolayer structure.

The present invention provides an electrophotographic recording medium capable of performing toner fusion at low temperature and low pressure by minimizing the content of the filler.

The present invention provides an electrophotographic recording medium having improved print gloss and print quality.

One aspect of the present invention includes a substrate and a toner fusion layer formed on at least one surface of the substrate, wherein the toner fusion layer comprises 0.5 to 5 parts by weight of filler and 0.5 to 5 parts by weight of additives relative to 100 parts by weight of the binder. An electrophotographic recording medium.

Another aspect of the present invention includes the steps of injecting the electrophotographic recording medium into an electrophotographic printer to first fuse the toner onto the recording medium; The toner is injected by injecting the recording medium between belts formed of at least one selected from the group consisting of polyimide, polyester or non-stretched polypropylene, polyvinyl alcohol film, polyurethane film, polycarbonate film, teflon film, silicone film and metal. And a method for printing an electrophotographic comprising a second fusion step.

The electrophotographic recording medium according to the present invention is formed on the substrate with only a toner fusion layer, so that the manufacturing process is simple and economical. In addition, the electrophotographic recording medium of the present invention is efficient because toner fusion can be performed at low temperature and low pressure by reducing the content of the filler. The electrophotographic printing method according to the present invention performs a two-step fusion to further increase the gloss of print and print quality.

1 is a schematic diagram showing the structure of an electrophotographic recording medium according to the present invention.
Fig. 2 is a schematic diagram showing still another structure of an electrophotographic recording medium according to the present invention.
Figure 3 is a schematic diagram of performing a second fusion step, an embodiment of the present invention.

The present invention relates to an electrophotographic recording medium having a toner fusion layer on a substrate.

1 and 2 are schematic diagrams showing the structure of an electrophotographic recording medium according to the present invention. 1 and 2, the recording medium of the present invention includes a toner fusion layer 20 on at least one surface of the substrate 10. As shown in FIG.

The substrate 10 may use a known electrophotographic substrate, but is not limited thereto. It is sufficient that the substrate must withstand the fusion temperature at the time of printer output and satisfy the requirements of smoothness, whiteness, friction, antistatic property, fixability, and the like. The base material is paper, polyester film, synthetic paper (stretched polypropylene) and the like and can be variously applied. The types of paper can be broadly divided into coated and non-coated paper. Non-coated paper includes woody paper and newspaper paper, and woody paper is called imitation paper and is widely used for copy paper and printer paper. Coated paper includes art paper, snow white paper, CCP, etc. Art paper has excellent gloss and smoothness, high whiteness, low oil absorption and absorbency, and is suitable as coated paper. CCP paper has high gloss on one side and looks like a glossy coating and is suitable for high quality cases and high quality prints. In addition, the oil-absorbing property and absorbency similar to the art paper is possible as a coated paper.

The thickness of the substrate varies depending on the intended use, but the substrate having a low thickness may generate curl after output. The paper used for the coating is double-sided art, and 150g, 180g, 200g and 180g and 200g paper can reduce the effect of curl. In addition, CCP paper has better luster than art paper and can be used when a high gloss base is required.

The toner fusion layer 20 is formed on at least one surface of the substrate.

The toner fusion layer of the present invention can perform the role of three layers of the conventional water-containing layer, the underlayer layer, and the resin layer as one layer. Since the toner fusion layer must be fused by heat and compression of the fuser roll of the printer, the toner fusion layer needs to be quickly fused and the surface glossiness is high. In addition, the toner fusion layer must be excellent in flexibility and elongation rate to prevent cracking of the output surface, and must also be excellent in water resistance, antistatic property, etc. in order to prevent warpage and wrinkles of the base paper.

The toner fusion layer 20 includes 0.5 to 5 parts by weight of a filler and 0.5 to 5 parts by weight of an additive with respect to 100 parts by weight of a binder to satisfy the properties.

The binder may be two or more selected from the group consisting of polyvinyl chloride copolymers, acrylic copolymers, polyester resins, and ethylene vinyl acetate copolymers. More preferably, the binder may be two or more selected from the group consisting of a polyvinyl chloride copolymer, an acrylic copolymer and an ethylene vinyl acetate copolymer. Most preferably, the binder comprises a polyvinyl chloride copolymer, and may be formed including at least one of an acrylic copolymer and ethylene vinyl acetate. The binder has excellent adhesion and color when toner is fused and it is easy to realize secondary gloss.

The polyvinyl chloride copolymer may be at least one selected from polyvinyl chloride acrylic copolymer, polyvinyl chloride vinyl acetate copolymer, polyvinyl chloride urethane copolymer, preferably polyvinyl chloride acrylic copolymer or polyvinyl chloride vinyl acetate Copolymer.

The acrylic copolymer may be at least one selected from acrylic vinyl acetate copolymer, acrylic silicone copolymer, acrylic urethane copolymer, acrylic modified polyester copolymer, preferably the acrylic copolymer is acrylvinyl acetate copolymer, acrylic silicone air It is coalescing.

The glass transition temperature of the polymer forming the binder may be -10 ~ 80 ℃, preferably -5 ~ 40 ℃. The low glass transition temperature of the polymer can easily implement gloss at low temperatures, and can further enhance the adhesion of the toner.

The weight average molecular weight of the polymer forming the binder is 2,000 to 100,000.

The polymer forming the binder may be used in the form of a water phase.

When the binder is present in the aqueous phase, the size of the dispersed particles may be 10 ~ 800nm, pH 3 ~ 9. The polymer forming the binder has transparency in coating, and can control the degree of whiteness when a white filler is used.

The filler is used to prevent blocking properties due to the use of a binder having a low glass transition temperature (Tg).

As the filler, a product having a high specific surface area, a low oil absorption amount, and a particle size of several nanometers may be used. As the filler, alumina, silica, calcium carbonate, titanium oxide, zinc oxide, and the like may be used, and preferably silica having a colloidal form, and the particle size is in the range of 5 to 40 nm, preferably 5 to 10 nm. .

The filler may be used 0.5 to 5 parts by weight based on 100 parts by weight of the binder. In the present invention, the amount of the filler may be used in a very small amount compared to the content of the binder. When the content of the filler exceeds 5 parts by weight, there is no output problem, but the gloss is produced by using a polisher. This is because the problem may not occur.

The toner fusion layer of the present invention contains an additive. Release agents, wetting agents, brighteners, antistatic agents can be used as the additive.

The release agent prevents jams from passing through the pressing roller after fusion of the toner of the printer. The mold releasing agent may be a silicone mold releasing agent, a wax mold releasing agent, a silicone acrylic mold releasing agent, an acrylic silicone mold releasing agent, or the like. The release agent may be used in an amount of 0.05 to 5 parts by weight based on 100 weights of the binder.

The antistatic agent is used to prevent static electricity that may occur when printing the printer. Static electricity generated at the time of printer output interferes with the fusion of the toner and causes haze around the image. Antistatic agents include nonionic antistatic agents and anionic antistatic agents, and anionic antistatic agents are more effective. The antistatic agent may be used in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the binder.

The brightener is used to improve whiteness, and a known brightener may be used. The brightener may be used 0.1 to 3 parts by weight based on 100 parts by weight of the binder.

The wetting agent is used to improve abnormalities such as streaks and craters by uniformly dispersing the coating liquid on the substrate by lowering the surface tension during the toner fusion layer coating. The humectant may use 0.05 to 0.5 parts by weight based on 100 parts by weight of the binder.

The toner fusion layer may further include a dispersant used to evenly disperse the filler in the coating liquid. The dispersant may vary from 0.05 to 0.5 parts by weight based on the amount of filler used, compared to 100 parts by weight of the binder.

The toner fusion layer may be coated on one or both surfaces of the substrate, and then dried to prepare an electrophotographic recording medium. The coating process is a comma coating, gravure coating, merbar coating, slot die coating, blade coating, roll coating, knife coating, the drying process is for 2 seconds to 5 minutes within the range of 50 ℃ to 130 ℃ It is preferable to make, and if a crosslinking agent is added at this stage, a thermal crosslinking reaction by the crosslinking agent occurs. Therefore, if the drying temperature is less than 50 ℃ cross-linking reactivity is lowered, if it exceeds 130 ℃ yellow phenomenon may occur is not preferred.

The coating thickness of the toner fusion layer is in the range of 1 to 40 µm, preferably 5 to 20 µm. If the coating thickness is higher than the above range, the economical efficiency is lowered, the color implementation is inferior, and if the coating thickness is low, the toner fusion is poor, the peeling phenomenon of the output image may occur, and the gloss may be degraded when passing through the polisher.

In another aspect, a method of printing an electrophotographic method includes the steps of: first injecting a toner onto a recording medium by injecting the recording medium for electrophotographic into an electrophotographic printer;

The toner is injected by injecting the recording medium between belts formed of at least one selected from the group consisting of polyimide, polyester or non-stretched polypropylene, polyvinyl alcohol film, polyurethane film, polycarbonate film, teflon film, silicone film and metal. A second fusion step.

The first fusion step is a hot fusing step of applying heat and pressure by a roller after undergoing several image processing steps as in the electrophotographic method applied to a conventional printer or copier. The toner transferred to the recording medium can be fixed by the above steps. The recording medium used in the first fusion step is the electrophotographic recording medium having the toner fusion layer 20 formed on at least one surface of the substrate 10. Since the electrophotographic recording medium has been described above, a description thereof will be omitted.

The second fusion step is a step of refusion of the recording medium that has undergone the first fusion step. The second fusion step may be performed continuously or discontinuously with the first fusion step in a printer or copier in which the first fusion step is performed. In addition, the second welding step may be performed through a separate second welding device. The second welding machine may be a gloss machine.

The second fusion step is the recording between the belt formed of one or more selected from the group of polyimide, polyester or unstretched polypropylene, polyvinyl alcohol film, polyurethane film, polycarbonate film, Teflon film, silicone film and metal. Injecting the medium to re-melt the toner.

The polymer film or the metal 10 is a calendering material for increasing the glossiness over the silver salt photograph quality of the image output to the printer, it is preferable to use a material without film deformation in high heat. In addition, it is suitable that the polymer film or the metal 10 has a surface roughness of 0.2 μm or less.

The polymer film may be formed of at least one of a polyimide film, a polyester film, an unstretched polypropylene film, a polyvinyl alcohol film, a polyurethane film, a polycarbonate film, a teflon film, and a silicon film.

The metal is at least one selected from the group consisting of SUS (stainless steel), carbon steel, titanium alloys and copper alloys, aluminum alloys, magnesium alloys, tungsten alloys, molybdenum alloys, zinc alloys, silver, gold, copper-nickel alloys, Thin film or foil shape.

      The metal may further be used by Teflon coating or silicone coating.

The polymer film thickness is 5 ~ 200㎛ is suitable and 20 ~ 100㎛ is more suitable considering the workability when passing through the polisher.

       The thickness of the metal is suitable 50 ~ 150㎛ and even more suitable 50 ~ 100㎛ considering the formation of the belt of the polisher.

Through the second fusion step, the glossiness of the output image and the non-output part may be increased at the same time as the complete toner fusion process, thereby preventing a decrease in output gloss and image floating, which are disadvantages of the laser printer. In addition, the second fusion step may improve the output photograph quality and at the same time increase the scratch resistance and at the same time obtain a laminating treatment effect, as if the quality is equal to or higher than the silver salt photograph quality.

Figure 3 is a schematic diagram of performing a second fusion step, an embodiment of the present invention. Referring to FIG. 3, a first fusion recording medium 100 from a printer or a copying machine is injected into a second fusion apparatus 200 and secondly fused. The second welding device 200 may include a film belt 210, a roller 220, and a heater 230. The second welding device may be implemented in any other form. For example, the second welding device may include a roller driving motor, a roller speed and heater temperature controller, a compression pressure controller, and the like.

The temperature applied to the recording medium by the heater is preferably 20 to 100 ° C, preferably 40 to 80 ° C. If the temperature is in the range of 40 ~ 80 ℃ it is advantageous in terms of fusion of the laser printer toner using a polisher and the gloss of the base surface more than the picture quality. In the present invention, the temperature applied by the heater is in the range of 40 ~ 80 ℃ relatively low temperature compared to the conventional electrophotographic device, so that it does not have to use a high heat-resistant film (for example, polyimide film), energy efficiency and durability of the device Is also advantageous.

The driving speed of the roller may be 1 ~ 20m / min. The compaction pressure of the roller may range from 200 to 800 psi, preferably 400 to 600 psi.

Table 1 below shows the component ratio (solid content) of the toner fusion layer composition. The substrate used was 200 g / m 2 double-sided art paper and the coating thickness was 15 μm. The coating was using a marbar and dried at 110 ° C. for 2 minutes. The second fusion step was performed using a second fusion machine equipped with a polyimide film belt.

[Table 1]

Table 2 below shows the optical density and glossiness before and after passing the second fusion step. Light density represents the color density and this value represents the ability to express color. The examples show much better optical density even before passing the second fusion step (only performing the first fusion in the printer) compared to the comparative example. In addition, it can be seen that the light density difference is more remarkable after the embodiments have passed through the second fusion step as compared with the comparative example.

Referring to Table 2, looking at the glossiness of the output recording medium, the glossiness of the comparative example was slightly higher than that of the embodiment before passing the second fusion step, but after passing through the second fusion machine, the examples were significantly higher than the comparative example. Shows the figure.

Table 2. Test Results According to Toner Fusion Layer Manufacturing Example]

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (6)

An electrophotographic recording comprising a substrate and a toner fusion layer formed on at least one surface of the substrate, wherein the toner fusion layer comprises 0.5 to 5 parts by weight of filler and 0.5 to 5 parts by weight of additives relative to 100 parts by weight of the binder. media. The recording medium of claim 1, wherein the binder is at least two selected from the group consisting of polyvinyl chloride copolymers, acrylic copolymers, polyester resins, and ethylene vinyl acetate copolymers. An electrophotographic recording medium according to claim 1, wherein the binder has a glass transition temperature of -10 ° C to 80 ° C. 3. The polyvinyl chloride copolymer according to claim 2, wherein the polyvinyl chloride copolymer is at least one selected from polyvinyl chloride acrylic copolymer, polyvinyl chloride vinyl acetate copolymer, polyvinyl chloride urethane copolymer, and
And the acrylic copolymer is at least one selected from acrylvinyl acetate copolymer, acrylic silicone copolymer, acrylic modified polyester copolymer, and acrylic urethane copolymer. The recording medium according to claim 1, wherein the size of the dispersed particles is 10 to 800 nm and the pH is 3 to 9 when the binder is present in the aqueous phase. Injecting an electrophotographic recording medium according to any one of claims 1 to 5 into an electrophotographic printer to first fuse the toner onto the recording medium;
The toner is injected by injecting the recording medium between belts formed of at least one selected from the group consisting of polyimide, polyester or non-stretched polypropylene, polyvinyl alcohol film, polyurethane film, polycarbonate film, teflon film, silicone film and metal. And a second fusing step.

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