JP2002225444A - Manufacturing device for thermal transfer image receiving sheet, and thermal transfer image receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device for a thermal transfer image receiving sheet, by which a favorable image quality wherein defects such as void are not generated while using a normal paper as a base material can be obtained. SOLUTION: This manufacturing device for the thermal transfer image receiving sheet is equipped with a powder coating section, and a fixing section. In this case, the powder coating section applies a power coating substance on the base material by an electrostatic adsorption method. The fixing section fixes the applied powder coating substance on the base material by a hot roll. The fixing section comprises at least two fixing units. Also, the powder coating section is equipped with first and second spray guns with an interval in the flowing direction of the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying a powder coating material on a substrate by an electrostatic adsorption method, and then passing the coated substrate between a pair of hot rolls to fix the powder coating material. Forming a thermal transfer image-receiving sheet having a powder coating unit for applying a powder coating material on a substrate by an electrostatic adsorption method and a fixing unit for fixing the applied powder coating material on the substrate by a heat roll; The present invention relates to a thermal transfer image-receiving sheet manufacturing apparatus and a thermal transfer image-receiving sheet that uses plain paper as a base material and that can provide good image quality without causing defects such as white spots.

[0002]

2. Description of the Related Art As a thermal transfer image-receiving sheet of a thermal transfer recording system using a sublimable dye, a composition containing a resin having a dye-dyeing property is coated on the surface of a base material such as synthetic paper, and dried to dry the dye. It is known to form a receiving layer. For example, JP-A-8-112974 discloses a method in which a coating composition containing a resin is applied on plain paper by a charge dispersion method, and then heated to melt the powder coating composition, cooled, fixed, and continuously. It is described that a receiving layer composed of a coating film is formed on plain paper.

[0003] Further, in JP-A-2000-44841, a continuous plain paper base material unwound from a roll is guided into a booth by a conveyor belt, where it is dry-coated by an electrostatic spray method, and then is subjected to two upper and lower parts. It is described that the sheet is guided between fixing rollers and is fixed by the fixing rollers.
One spray gun is installed in the booth,
A needle electrode is incorporated at the tip of the spray gun, and a negative high voltage is applied by a DC power supply, so that the powder mixture injected from the spray gun is negatively charged.

[0004]

However, in the conventional powder coating and fixing methods, the powder coating is not sufficiently performed on the plain paper substrate, and the powder fixing is not sufficient. Problems such as omission occurred, and only a thermal transfer image-receiving sheet from which good image quality could not be obtained could be obtained.

An object of the present invention is to provide an apparatus for manufacturing a thermal transfer image-receiving sheet which uses plain paper as a base material and provides good image quality without causing defects such as white spots, and causes defects such as white spots using plain paper as a base material. An object of the present invention is to provide a thermal transfer image receiving sheet capable of obtaining excellent image quality.

[0006]

According to the first aspect of the present invention, there is provided a powder coating unit for applying a powder coating material on a substrate by an electrostatic adsorption method. A thermal transfer image-receiving sheet manufacturing apparatus for forming a thermal transfer image-receiving sheet having a fixing unit for fixing an applied powder coating material on a substrate by a heat roll, wherein the fixing unit includes at least two fixing units. I do. Since the fixing is performed through at least two fixing units, sufficient fixing properties are obtained, and smoothness of the coated surface is also obtained.

According to the first aspect of the present invention, the heat roll of the first fixing unit is a roll made of a material having excellent heat resistance and releasability, and the heat roll of the second and subsequent fixing units is used as the heat roll. It is desirable to use a roll having good smoothness. With such a configuration, the smoothness of the coated surface is improved, and it is possible to manufacture a thermal transfer image-receiving sheet that can obtain good image quality without any defect such as white spots.

According to the first aspect of the present invention, a guide roll can be provided between the fixing units so that the path between the fixing units can be changed according to the physical properties of the powder coating material to be fixed. Further, the arrangement of the guide rolls between the fixing rolls can be changed, and by changing the arrangement of the guide rolls, the tying angle between the base material and the rolls can be changed from 0 ° to 150 °. . With such a configuration, it is possible to manufacture a thermal transfer image receiving sheet optimally fixed according to the physical properties of the powder coating material.

According to a fifth aspect of the present invention, there is provided a powder coating unit for applying a powder coating material on a substrate by an electrostatic adsorption method, and a coated powder coating material. A thermal transfer image receiving sheet manufacturing apparatus comprising a fixing unit for fixing the base material on a base material by a heat roll, comprising a preheating unit for heating the base material before the powder coating unit. Preheating the base material in front of the powder coating section can enhance the fixability of the powder coating.

According to a sixth aspect of the present invention, there is provided a powder coating unit for applying a powder coating material on a substrate by an electrostatic adsorption method, and a coated powder coating material. A thermal transfer image-receiving sheet manufacturing apparatus comprising a fixing unit for fixing the substrate on a heat roll with a heat roll, between the powder coating unit and the fixing unit,
It is characterized by having a preheating section for heating the base material immediately before the fixing section after applying the powder. By heating just before the fixing section, the fixability of the powder to the substrate can be improved.

A tenth aspect of the present invention achieves the object of the invention relating to the thermal transfer image receiving sheet, and is a thermal transfer image receiving sheet manufactured by using the thermal transfer image receiving sheet manufacturing apparatus according to the ninth aspect.

According to a seventh aspect of the present invention, there is provided a powder coating unit for applying a powder coating material on a substrate by an electrostatic adsorption method, and a coated powder coating material. A heat transfer image-receiving sheet manufacturing apparatus including a fixing unit for fixing an image onto a substrate by a heat roll, wherein the powder application unit includes first and second spray guns spaced from each other in a flow direction of the substrate. It is characterized by the following. By discharging powder from both the first and second spray guns, it is possible to apply a large amount of powder. The first and second spray guns also enable high-speed coating. In the first spray gun, idle shot is performed to increase the absolute amount of the negatively charged air under the coating atmosphere, and the negatively charged air is discharged to the second spray gun.
By increasing the rate of collision with the powder coating material discharged from the spray gun, it is possible to increase the adsorptivity to non-charged or positively charged substrates.

In the invention according to claim 8, the spray gun can be configured to be movable in the width direction of the base material. With such a configuration, uniform application can be performed.

According to a ninth aspect of the present invention, there is provided a powder coating unit for applying a powder coating material on a substrate by an electrostatic adsorption method, and a coated powder coating material. A thermal transfer image-receiving sheet manufacturing apparatus for forming a thermal transfer image-receiving sheet provided with a fixing device for fixing a sheet onto a substrate by a heat roll, wherein the powder coating unit is provided with a first and a second at intervals in a flow direction of the substrate. The fixing unit comprises at least two fixing units, comprises a first preheating unit for heating the base material before the powder coating unit, and between the powder coating unit and the fixing unit.
It is characterized in that it has a second preheating section for heating the base material immediately before the fixing section after applying the powder. This device has the advantages of the first, fifth, sixth, and seventh aspects of the invention.

According to a tenth aspect of the present invention, there is provided a thermal transfer image receiving sheet which is manufactured by using the apparatus according to the ninth aspect, and uses a plain paper as a base material and does not cause defects such as white spots. Good image quality can be obtained.

[0016]

FIG. 1 shows a typical example of a thermal transfer image-receiving sheet manufacturing apparatus of the present invention. The apparatus comprises first and second spray guns 2a, 2 spaced apart in the direction of flow of the substrate 1.
b, a first preheating unit 4 provided in front of the powder coating unit 3, a fixing unit 7 including a first fixing unit 5 and a second fixing unit 6, and a powder coating unit 3. A second preheating unit 8 is provided between the coating unit 3 and the fixing unit 7 and heats the base material immediately before the fixing unit after the application of the powder. Also, the first fixing unit 5
The second fixing unit 6 includes an upper heat roll 6a and a lower heat roll 6b. A guide roll 9 whose position can be changed is provided between the first and second fixing units 5 and 6. still,
In FIG. 1, reference numeral 10 denotes an unwinding roll of the substrate, and 11 denotes a winding roll.

As the heat roll of the fixing unit, a roll coated with a fluorine resin or silicone rubber is used. PFA (tetrafluoroethylene / perfluoroalkylvinyl ether copolymer), PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene / hexafluoropropylene), PCTFE (polychlorotrifluoroethylene), There are PVDF (polyvinylidene fluoride), polyvinyl fluoride, ETFE (ethylene / tetrafluoroethylene copolymer), and ECTFE (ethylene / chlorotrifluoro copolymer). Among the above fluororesins, PFA and PTFE resins excellent in heat resistance and peelability are preferable.

The upper heating roll 5a of the first fixing unit 5 includes PFA having excellent heat resistance (180 ° C. or higher) and excellent peelability.
A roll made of PFTE resin is used. As the upper heat roll 6a of the second fixing unit 6, a roll having high smoothness is used. The smoothness is determined by the roll surface roughness (R
a): 5.0 μm, roll specular gloss (Ga 45 °):
It is preferable that the roll is made of a material having a heat resistance of 8.0%.

The lower heat roll 5b of the first fixing unit 5 and the lower heat roll 6b of the second fixing unit 6 are preferably made of the above-mentioned resin, and have heat resistance and smoothness.

A similar fixing unit is provided after the second fixing unit to improve the fixing property and the smoothness.
More than one fixing unit may be provided.

The arrangement of the guide rolls 9 between the fixing rolls 5 and 6 can be changed. By changing the arrangement of the guide rolls 9, the tying angle between the base material 1 and the guide rolls 8 is changed from 0 ° to 150 °. be able to. In the present invention, the tying angle is, as shown in FIG. 2, the angle difference θ between the direction 12 of the base material entering the fixing roll (heat roll) and the direction 12 of the base material leaving the fixing roll.

The powder coating material is discharged by using one or both of the first and second spray guns 2a and 2b.
Due to the collision between the ionized air emitted from the spray gun and the powder coating material, the powder is charged negatively and directed along the line of electric force to the positive or uncharged substrate 1.
Form a powder layer.

By providing the spray gun in the flow direction of the base material so that the powder coating material can be discharged from both the first and second spray guns 2a and 2b, it is possible to apply a large amount of coating. . It also enables high-speed coating.

In the first spray gun, idle shot is performed to increase the absolute amount of negatively charged air under the coating atmosphere, and the negatively charged air is discharged from the second spray gun. By increasing the rate of collision with the body paint, the adsorptivity to non-charged or positively charged substrates can be increased.

The first and second spray guns 2a and 2b are provided in the flow direction of the base material, are movable in the width direction, and are configured so that the powder can be uniformly applied over the entire width of the base material. .

Next, the present invention will be specifically described with reference to examples. (Example 1) The following powder coating material was prepared. Composition of the substance paint: polyester resin 80 parts (manufactured by Mitsubishi Rayon Co., Ltd., Diacron FC-611) Styrene-acrylic copolymer resin 20 parts (manufactured by Mitsubishi Rayon Co., FB-208) Charge control agent 4 parts (Orient Chemical Co., Bontron P-51) Titanium oxide: 2 parts (Tochem Products, TCA888) Amino-modified silicone: 1 part (Shin-Etsu Chemical Co., Ltd. X22-349) Coating amount: 13 g / m ² After the raw materials were mixed by a mixer, they were heated and melted and kneaded by a melt kneader. After cooling and solidifying, the powder was classified to obtain a powder coating composition having an average particle size of 8 μm.

As a base material, a plain paper (Tokihyo 10 made by Mitsubishi Paper Mills)
4.7 g / m ² ), the powder coating material is discharged from a spray gun of a powder coating part to be adsorbed on a substrate surface, and then a PFA tube is attached to an upper heating roll composed of a PFA deposition roll and a roll body. Fixing unit consisting of a lower heat roll consisting of a roll wound with PFA and PFA on the roll body
From the upper and lower heat rolls consisting of rolls having high smoothness (roll surface roughness (Ra): 0.5 μm, roll specular gloss (Ga 45 °): 8.0%) consisting of a roll around which a tube is wound The powder was fixed on the surface of the base material through a fixing unit having a second fixing unit. The coating conditions at that time are shown in Table 1.

[0028]

[Table 1]

As described above, a thermal transfer image-receiving sheet having a high smoothness of 630 s was obtained. When sublimation transfer was performed on this thermal transfer image receiving sheet, there was no defect such as white spots, and good image quality was obtained.

As in Example 1, except that only the first fixing unit was used. As a result, a thermal transfer image-receiving sheet having a low smoothness of 60 s was obtained. When sublimation transfer was performed on this thermal transfer image-receiving sheet, ribbon removal occurred during the transfer. In addition, many white spots were generated due to low smoothness, and only poor image quality was obtained.

As in Example 1, except that only the second fixing unit was used. As a result, sufficient fixing was not performed, so that the substrate was rolled off after passing through the fixing section, and a thermal transfer image-receiving sheet could not be obtained. Table 2 shows the results of Example 1, Comparative Example 1, and Comparative Example 2. In addition, the evaluation method of an evaluation item is as follows.

Evaluation method: Smoothness: Smoothness was measured using an Oken type air permeability smoothness tester manufactured by Asahi Seiko. What are the evaluation criteria? 200s is excellent (○), 100
s to less than 200 s were evaluated as acceptable (△), and less than 100 s as unusable (x). Fixing: Fixing was evaluated by adhering a mending tape manufactured by Nichiban Co. to the coated surface after fixing, peeling the mending tape in the vertical direction, and visually observing the peeled surface. The evaluation criterion is that "there is no separation at the interface between the base material and the receiving layer inside the receiving layer, and cohesive failure inside the base paper occurs."
Excellent (○), “cohesive failure occurs inside the receiving layer” (可), “peeling at the interface between the substrate and the receiving layer” is not possible (×)
And Printing: The state after the image was transferred by the sublimation transfer apparatus IMATION 2740 was evaluated. The evaluation criterion is excellent (「),“ No ribbon removal occurs during transfer, no white spots, etc., and a good image can be formed ”(good),“ Ribbon removal occurs. Image quality is good. "Possible." Is acceptable (△), and "Ribbon is removed. Image quality is poor. Many white spots are generated."

[0033]

[Table 2]

Example 2 A dye-receiving layer was formed on a substrate by using only the first preheated portion, and the state of fixing was evaluated in the same manner as in Example 1, and the obtained thermal transfer was evaluated. Sublimation transfer was performed on the image receiving sheet, and the obtained image was evaluated. As a result, by heating the substrate in advance in the first preheating section before applying the powder, the fixation of the powder to the substrate was improved, and good image quality was obtained.

Example 3 A dye-receiving layer was formed on a substrate using only the second preheated portion in the same manner as in Example 1, and the state of fixing was evaluated. Sublimation transfer was performed on the sheet, and the obtained image was evaluated. As a result, even when the base material was heated just before fixing after the application of the powder, the fixation of the powder to the base material was improved, and good image quality was obtained.

Comparative Example 3 A dye-receiving layer was formed on a substrate in the same manner as in Example 1 except that the second preheating section was not used and the first preheating section was not used, and the state of fixing was performed. And sublimation transfer was performed on the obtained thermal transfer image-receiving sheet, and the obtained image was evaluated. As a result, stripping of the ribbon occurred, and white spots also occurred. (Comparative Example 4) In the same manner as in Comparative Example 3, the temperature of the heat roll of each fixing unit was raised by 10 ° C. to form a dye receiving layer on a substrate, and the state of fixing was evaluated. Sublimation transfer was performed on the image receiving sheet, and the obtained image was evaluated. As a result, the product was not rolled during production due to insufficient fixing, and the product could not be sold.

Table 3 shows Examples 2 and 3 and Comparative Example 3 listed above.
4 shows the results.

[0038]

[Table 3]

Example 4 As in Example 1, except that the temperature was 23 ° C. and 60% RH. H. In the coating environment, only the air is discharged from the first spray gun (punching), and the powder is discharged from the second spray gun to form a dye-receiving layer on the base material. Was evaluated. The degree of adsorption of the powder discharged from the spray gun onto the substrate was evaluated by visual inspection. The evaluation criteria at that time were: "The amount of powder that does not adsorb to the base material and flutter under the atmosphere of the application section is small.""A lot of fluttering powder." Further, sublimation transfer was performed on the obtained thermal transfer image-receiving sheet, and the obtained image was evaluated. As a result, by idling with the first spray gun and discharging the powder with the second spray gun,
The adsorbability of the powder to the substrate was enhanced, and the powder was well adsorbed to the substrate even in a high humidity environment.

(Comparative Example 5) In the same manner as in Example 4, except that the first spray gun was not used, and only the second spray gun was used, and the powder was adsorbed to the substrate in a high humidity environment. . As a result, the powder was poorly adsorbed on the substrate and the fixation was poor, and as a result of the test, cohesive failure was observed inside the receiving layer.
Sublimation transfer was performed on the obtained thermal transfer image-receiving sheet, and white spots occurred in a part of the obtained image.

(Comparative Example 6) In the same manner as in Comparative Example 5, except that the coating environment was set at 23 ° C and 30% RH. H. The powder was adsorbed on the substrate in a low humidity environment of i. As a result, good results were obtained for all of the adsorption, fixing, and printing.

Table 4 shows Example 4 and Comparative Examples 5 and 6.

[0043]

[Table 4]

[0044]

As described above in detail, the thermal transfer image-receiving sheet manufacturing apparatus according to the first aspect of the present invention is provided with a fixing section including at least two fixing units, so that sufficient fixing properties can be obtained. The smoothness of the coated surface is also obtained.

Further, since the thermal transfer image-receiving sheet manufacturing apparatus according to the present invention is provided with a pre-heating section for heating the substrate before the powder applying section, the first pre-heating section before applying the powder. By heating the substrate in advance in the section, the fixation of the powder to the substrate is improved, and good image quality is obtained.

According to a sixth aspect of the present invention, there is provided a thermal transfer image-receiving sheet manufacturing apparatus according to the present invention, wherein a preheating section heats a base material between a powder application section and a fixing section and immediately before the fixing section after applying the powder. Since the base material is provided, the base material is heated immediately before fixing to improve the fixing property.

Further, in the thermal transfer image-receiving sheet manufacturing apparatus according to the present invention, since the powder application section is provided with the first and second spray guns at intervals in the flow direction of the base material, a large amount of powder is applied. And a large amount of coating can be applied. In addition, the first spray gun performs an idle shot to increase the absolute amount of the negatively charged air in the coating atmosphere, and the negatively charged air
By increasing the rate of collision with the powder coating material discharged from the spray gun, it is possible to increase the adsorptivity to uncharged or charged equipment.

Further, in the thermal transfer image-receiving sheet manufacturing apparatus according to the present invention, the powder application section includes first and second spray guns spaced from each other in a flow direction of the base material, and a fixing section. Is composed of at least two fixing units, and has a first preheating section for heating the base material in front of the powder applying section, and between the powder applying section and the fixing section, after applying the powder and immediately before applying the fixing cloth. Since the second preheating portion for heating the base material is provided, the advantages of the first, fifth, sixth, and seventh aspects of the invention are obtained.

The thermal transfer image-receiving sheet of the present invention according to the tenth aspect is manufactured by using the thermal transfer image-receiving sheet manufacturing apparatus according to the ninth aspect. No good image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a typical example of a thermal transfer image-receiving sheet of the present invention.

FIG. 2 is an explanatory diagram of a tying angle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2a, 2b Spray gun 3 Powder coating part 4 First preheating part 5 First fixing unit 6 Second fixing unit 7 Fixing part 8 Second preheating part 9 Guide roll

Claims (10)

[Claims] 1. A thermal transfer image receiving apparatus comprising: a powder application section for applying a powder coating material on a substrate by an electrostatic adsorption method; and a fixing section for fixing the applied powder coating material on the substrate by a hot roll. A thermal transfer image receiving sheet manufacturing apparatus for forming a sheet, wherein the fixing unit comprises at least two fixing units. 2. The heat roll of the first fixing unit is a roll made of a material having excellent heat resistance and releasability, and the heat roll of the second and subsequent fixing units is a roll having good smoothness. The thermal transfer image receiving sheet manufacturing apparatus according to claim 1, wherein the apparatus is used. 3. The thermal transfer image receiving apparatus according to claim 1, wherein a guide roll is provided between the fixing units so that a path between the fixing units can be changed according to the physical properties of the powder coating material to be fixed. Sheet manufacturing equipment. 4. The arrangement of the guide rolls between the fixing rolls can be changed, and by changing the arrangement of the guide rolls, the tying angle between the base material and the rolls can be changed from 0 ° to 150 °. 4. The thermal transfer image receiving sheet manufacturing apparatus according to claim 3, wherein: 5. A thermal transfer image receiving apparatus comprising: a powder application section for applying a powder coating material on a substrate by an electrostatic adsorption method; and a fixing section for fixing the applied powder coating material on the substrate by a hot roll. A thermal transfer image-receiving sheet manufacturing apparatus, comprising: a sheet heating apparatus; and a preheating section for heating a substrate before the powder coating section. 6. A thermal transfer image receiving apparatus comprising: a powder application unit for applying a powder coating material on a substrate by an electrostatic adsorption method; and a fixing unit for fixing the applied powder coating material on the substrate by a hot roll. A thermal transfer image-receiving sheet manufacturing apparatus, comprising: a sheet manufacturing apparatus, comprising a preheating section between a powder application section and a fixing section, which heats a substrate immediately before the fixing section after applying the powder. 7. A thermal transfer image receiving apparatus comprising: a powder coating unit for applying a powder coating material on a substrate by an electrostatic adsorption method; and a fixing unit for fixing the applied powder coating material on the substrate by a hot roll. A thermal transfer image-receiving sheet manufacturing apparatus, wherein the powder application unit includes first and second spray guns at intervals in a flow direction of the base material. 8. The thermal transfer image-receiving sheet manufacturing apparatus according to claim 7, wherein the spray gun is configured to be movable in the width direction of the base material. 9. A thermal transfer image-receiving sheet having a powder application section for applying a powder coating material on a substrate by an electrostatic adsorption method, and a fixing for fixing the applied powder coating material on the substrate by a hot roll. Wherein the powder coating unit includes first and second spray guns spaced from each other in the flow direction of the base material, and the fixing unit includes at least two fixing units. A first preheating section for heating the base material in front of the powder application section, and a second preheating section for heating the base material immediately before applying the fixing cloth after applying the powder between the powder application section and the fixing section. A heat transfer image-receiving sheet manufacturing apparatus, comprising: 10. A thermal transfer image receiving sheet manufactured by using the thermal transfer image receiving sheet manufacturing apparatus according to claim 9.