JP4777632B2 - How to determine whether UV curable ink can be used - Google Patents

Description

The present invention relates to a method for determining whether or not to use ultraviolet curable ink used for a display board such as an automobile meter .

  2. Description of the Related Art Conventionally, for example, a meter arranged on an instrument panel of an automobile has been put into practical use in which various characters and the like are printed on the display board with solvent-type ink or ultraviolet curable ink. Such a meter has a display plate printed with solvent-type ink or ultraviolet curable ink disposed therein, and its front surface is closed with a transparent resin plate (for example, a transparent acrylic resin plate, trade name: Delpet 80N manufactured by Asahi Kasei). It is comprised by the sealed box body and assembled | attached to the predetermined location of an instrument panel. Also. Such a meter is generally subjected to multi-layer printing (generally 3 to 7 layers) and partial printing, and its functionality and design are satisfied.

  In the conventional meter in which the display plate is printed with ultraviolet curable ink, the display plate after the ultraviolet irradiation is disposed in a substantially sealed box, and the transparent resin plate is disposed in front of the display plate. Volatile components are generated from the ink layer of the display board. As a result, fogging and microcracks are generated on the transparent resin plate arranged on the front surface, and the visibility of the display board through the transparent resin plate is lowered.

  Therefore, in order to prevent such a decrease in visibility, after the ink layer of the display board is UV-cured, it is subjected to after-baking that is heated at a temperature equal to or higher than the maximum ambient temperature to be used, and a transparent resin plate disposed on the front surface. Volatile components that cause damage such as cloudiness and cracks are released from the ink layer, and then assembled into a meter made of a substantially sealed box to complete an automobile meter.

  However, after-baking inevitably reduces the line work efficiency in the automobile meter production line, and additionally requires additional heat energy for the after-baking.

In recent years, there is a high demand for reducing not only visible defects but also odors from parts in the vehicle, and reducing odor components as much as possible is an important need that contributes to the riding comfort of automobiles. The present invention has been made in view of such a conventional problem, and is disposed inside the meter without causing after-baking and without causing damage such as fogging or microcracks on the front transparent resin plate of the meter. It is an object of the present invention to provide a method for determining whether or not an ultraviolet curable ink can be used for determining whether or not it can be used for manufacturing a display panel.

In order to solve the above-mentioned problems, the UV curable ink use determination method according to the present invention is arranged in a substantially sealed environment in which a transparent PMMA resin plate is disposed on the front surface and a light emitter is disposed on at least a part of the rear surface. A method for determining whether or not to use the ultraviolet curable ink, which is used for a display plate on which a mold ink is printed on a translucent resin substrate and subjected to predetermined ultraviolet curing. A sample of the display panel is formed by printing ink and irradiating with ultraviolet rays, and without after baking. The sample is placed on the bottom of a glass beaker having a space volume of 50 to 300 with respect to the volume 1 of the sample. After being placed, the beaker opening is closed with a transparent acrylic resin plate, the bottom temperature of the beaker is heated in the range of 80 to 110 ° C., and left for at least 1 hour or more The transparent haze value of the acrylic resin plate is determined that usable for the display plate of the UV inks when it is 5.0 or less, in the case of more than 5.0 is judged to be unusable. Here, the “substantially sealed environment” refers to an environment in which the surroundings are covered by a case, but the circulation of outside air and air is not zero due to gaps, screw holes, etc. between the cases.

That is, the present inventors have results of the study, the sample, the test using the beaker and the transparent acrylic resin plate, the haze value of the transparent acrylic resin plate is formed a printed film with an ultraviolet curing ink is 5.0 or less According to the display board, it has been confirmed that the display can be placed inside the meter without causing damage such as fogging or microcracks on the transparent resin plate in front of the meter in a substantially sealed environment.

  Therefore, in the configuration in which the transparent acrylic cover is disposed in the display direction and the electronic circuit including the LED is disposed in the back direction, the transparent acrylic cover is not damaged such as fogging or microcracks. Moreover, the automobile meter which has such a display board can provide the automobile meter which does not cause damage, such as cloudiness and a micro crack, in the transparent acrylic cover of the meter front surface.

By the present invention lever, without after-baking, UV curing, which can be used for a display plate located inside the meter damage such as fogging and fine cracks on the front transparent resin plate of the meter without generating It can be determined whether or not it is ink.

Accordingly , the automobile meter can be prevented from being damaged such as fogging and minute cracks on the front transparent resin plate without accompanying after-baking.

Experimental example

Black 1 to Black 6 black ink shown in Table 1 below, Red 1 to Red 6 red ink shown in Table 2, White 1 to White 6 white ink shown in Table 3, Ku 1 to Ku 6 shown in Table 4 A matte clear ink was prepared.

  In Tables 1 to 4, the blending unit of each component is% by weight.

  And about the ink shown to this Table 1-Table 4, the cloudiness and the micro crack test were done using the experimental apparatus shown in FIG.

That is, the hot plate 2 (“Hot Plate HP-2L” manufactured by Seiei Inai Co., Ltd.) was placed on the base 1. On the hot plate 2, four beakers 31, 32, 33, 34 made of glass having an inner diameter of 31 mm and a height of 59 mm are arranged at a portion of 100 ° C., and the upper opening is a transparent acrylic plate 4 (Asahi Kasei Delpet 80N, size 40 × 40 mm, thickness 1.8 mm). And each said ink was repeatedly printed on the single side | surface of the polycarbonate resin sheet of thickness 0.5mm, and it hardened | cured with the thickness of 30 micrometers adhering to the said resin sheet by performing ultraviolet irradiation of 600 mJ / cm < ² > using a metal halide lamp. A printing sheet provided with an ink layer was obtained. Each multi-layer printing sheet using the inks of Examples 1 to 4 and Comparative Examples 1 and 2 was cut into a circular shape to prepare a test piece 5. Here, when the volume of the test piece 5 is “1”, the test piece 5 and the beakers 31 to 34 are such that the spatial volume of the beakers 31 to 34 is 50 to 300. Adjusted. Each test piece 5 is placed on the bottom in each of the beakers 31 to 34 with the ink layer facing upward, the bottom surfaces of the beakers 31 to 34 are set to 95 ± 15 ° C., and the top opening is formed on the transparent acrylic plate 4 ( Asahi Kasei Delpet 80N, size 40 × 40 mm, thickness 1.8 ± 0.2 mm) was covered and left for 1 hour.

  And the haze value of the transparent acrylic board 4 was measured, and what was 5.0 or less was set as "(circle)", and the thing exceeding 5.0 was set as "*", and the cloudiness of the 30-micrometer-thick printed matter of said Table 1-4 , Recorded in the column “Results of microcrack test”.

  As is clear from Tables 1 to 4, black 5, black 6, red 5, red 6, white 5, white 6, black 5, and black 6 have haze values exceeding 5.0, whereas 1-4 had a haze value of 5.0 or less.

  Meter display plates 1 and 2 having a cross-sectional structure shown in FIGS. The meter display board 1 is formed by sequentially forming a white ink layer W, a black ink layer B, and a matte clear ink layer C on one side of a printing sheet S. The meter display board 2 has a white ink layer W, two black ink layers B, a red ink layer R in the two black ink layers B, and a matte clear ink layer C in order on one surface of the printing sheet S. While printing, a white ink layer W and a partial black ink layer B are formed on the other surface.

  In these meter display plates 1 and 2, as shown in Table 5, each ink layer is formed using the ink of the experimental example, and the meter display plate 1 or 2 is arranged with a transparent acrylic cover in the display direction. In addition, Examples 1 to 4 and Comparative Examples 1 and 2 were assembled by assembling a car meter composed of a box body in a substantially sealed environment in which an electronic circuit including an LED is arranged on the back surface direction. Accordingly, each of the examples and comparative examples includes two types: an automobile meter in which the meter display board 1 is incorporated, and an automobile meter in which the meter display board 2 is incorporated.

  The automobile meters according to Examples 1 to 4 and Comparative Examples 1 and 2 were left in a room that was closed on the same day as the vehicle interior for one year.

Then, the transparent acrylic plate placed on the front surface of the automobile meter is visually observed, and the transparent acrylic plate is clouded and no microcrack is generated. The automobile meter on the display panel 1 was recorded in the column “cloudiness of the three-layer meter”, and the automobile meter on the meter display board 2 was recorded in the column “cloudiness of the meter on one side, five layers, and the other layer, two layers”.

  As is clear from Table 5, a meter for an automobile using the meter display board 1 and the meter display board 2 printed with black 5, black 6, red 5, red 6, white 5, white 6, black 5, and black 6. In (Comparative Example 1 and Comparative Example 2), cloudiness and microcracks occurred. On the other hand, the meter for vehicles using the meter display board 1 and the meter display board 2 printed in black 1 to black 4, red 1 to red 4, white 1 to white 4, and 1 to 4 (Example 1) -4) was cloudy and no microcracks occurred.

  Therefore, by the above

  A sample of the display plate is prepared, and the sample is arranged on the bottom surface of a glass beaker having a space volume of 50 to 300 with respect to the volume 1 of the sample, and the beaker opening is closed with a transparent PMMA resin plate. A display comprising heating at a bottom temperature of 80 to 110 ° C. and leaving it for at least 1 hour or more, and then forming a print film with an ultraviolet curable ink having a haze value of 5.0 or less on the transparent PMMA resin plate. In the case of a plate, it was confirmed that it could be placed inside the meter without causing after-baking and without causing damage such as fogging or minute cracks on the front transparent resin plate of the meter.

Further, it is a substantially hermetically sealed box having a transparent resin plate on the front surface, and a meter in which the display plate is arranged, so that the front transparent resin plate can be fogged without accompanying after-baking. It was confirmed that damage such as microcracks would not occur.
Furthermore, as a result of sensory evaluation of the strength of the odor of each completed meter display board with and without the conventional after-baking treatment, the results shown in Table 5 are obtained, which is significant against odor. We succeeded in raising the effect.

  Here, the sensory test of the odor intensity was conducted by performing sensory evaluation (5 persons: arbitrary extraction) by a human at a distance of 300 mm using each meter display board, and "O- ◎" “Slightly felt” was marked “◯”, and greatly felt “x”.

It is a schematic cross section which shows the experimental apparatus used in the experiment example of this invention. It is a schematic plan view which shows the experimental apparatus. It is a schematic diagram which shows the cross-sectional structure of the meter display board used in the Example of this invention.

Explanation of symbols

2 Hot plate 3 Beaker 4 Transparent acrylic plate 5 Test piece

Claims (3)

Transparent PMMA resin plate in front, is placed under substantially sealed environment arranging the light emitter to at least a portion of the back, the UV curable ink on the display panel performs a predetermined ultraviolet curing printed on translucent resin substrate A method for determining whether or not to use the ultraviolet curable ink to be used ,
A UV curable ink to be judged is printed on one side of a polycarbonate resin and irradiated with ultraviolet rays to prepare a sample of the display board without accompanying after-baking. Place the sample on the bottom of a glass beaker having 300, close the beaker opening with a transparent acrylic resin plate, heat the beaker at a bottom temperature of 80-110 ° C. and leave it for at least 1 hour After that, when the haze value of the transparent acrylic resin plate is 5.0 or less, it is determined that the ultraviolet curable ink can be used for the display plate. A method of determining whether or not to use an ultraviolet curable ink . 2. The determination as to whether or not the ultraviolet curable ink can be used according to claim 1 , wherein a transparent acrylic cover is disposed in the display direction, and an electronic circuit including an LED is disposed in the back direction. Way . The method for determining whether or not to use ultraviolet curable ink according to claim 1 or 2, wherein the display board is provided in an automobile meter.

Images