JP2501238B2 - Manufacturing method of design sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a plastic sheet having a color change, and, as an effect, a designing sheet in which the colors of reflected light and transmitted light have complementary colors. It is a thing.

[Prior Art] With respect to the color of conventional plastics, a method in which an inorganic or organic colorant is uniformly dispersed in a resin to give a color is the most basic and is widely used. With this method, the pigment absorbs a part of the irradiated white light, and that part is transmitted or reflected to obtain a color by selective absorption, so that the color of the plastic surface is artificial and dull. Flat color gives only a monotonous feel.

It is also common and common to use a technique such as printing, for example, gravure printing or offset printing, to give characters or photographs in multiple colors to the surface of a plastic to give a display or design. By using this printing technology, the design of the surface of the plastic can be freely attached, and the amount of information displayed is enormous. However, the design has no depth of color and has a poor three-dimensional effect.

Therefore, recently, in order to give this three-dimensional effect, a method of controlling the light to enhance the design is used, and for example, by making unevenness in the surface finely and in a certain direction, the part where the light is reflected and the part that becomes a shadow are conscious. It is created in and has an effect. Alternatively, metals such as aluminum, gold, silver, etc. are vapor-deposited on the surface, or they are made to have a partial gloss by printing as particles with an appropriate vehicle, or they appear three-dimensional by using light interference like holograms. Techniques are also becoming popular.

Among these, in the technology to give iris color or interference color by using particles (pearl pigment) coated with titanium dioxide on fine scale-like mica, and to give gloss and give a decorative effect such as metallic feeling or high-class feeling. In addition, in the method of coating and printing, there is a method of orienting the coating in a certain direction depending on the characteristics of the coating itself such as a lacquer for imitation pearls to sufficiently bring out the effect. In addition, although there are methods of orienting the molded product by a centrifugal casting method, a slide casting method, a vibration method, etc., there is no sufficient method in the sheet molding technique.

[Problems to be Solved by the Invention]

The object of the present invention is to disperse an amorphous and transparent plastic in which a titanium dioxide-coated mica pigment is dispersed, without crushing the pigment, to disperse the pigment uniformly, and to orient the orientation in one direction, A designing sheet is formed by a pressing method, in which the colors of the reflected light and the transmitted light have a complementary color relationship with each other, and further, the designing sheet capable of exhibiting the effect to the maximum with good contrast is formed.

[Means for solving the problem]

That is, the present invention is a thin flakes whose thickness is 0.05 to 2.0 μ.
The mica particles, which are m, are coated with titanium dioxide in a film thickness range of 30 to 500 mμ in an amorphous and transparent resin to disperse the particles evenly, and to orient the particles. it is a manufacturing method of the design sheet, wherein a film is formed by production conditions of the pressure 10kgf / cm ² ~200kgf / cm ² by law.

The amorphous and transparent resin in the present invention may be any thermoplastic resin as long as it can be processed into a film sheet by a pressing method. For example, polyvinyl chloride (PVC), amorphous polyester resin (PETG), polycarbonate (PC), acrylic resin such as polyacrylonitrile (PAN), polymethylmethacrylate (PMMA), and the like can be given. .

Using this resin as a vehicle, scaly mica coated with titanium dioxide in a thin film is dispersed. The titanium dioxide referred to herein may be rutile type or anatase type, and the thickness thereof is preferably 30 to 500 mμ. It is preferable that the scaly mica is obtained by a wet method in which muscovite, which is the most colorless and transparent, has a smooth surface. The thickness is preferably 0.05 to 2.0 μm, and the size is preferably 10 to 200 μm.

The thickness of the mica is preferably 0.05 to 2.0 μm, because the mica has a cleavability, and therefore, when the mica mass is crushed, the particles become scaly. Usually its thickness is 0.
If it is less than 0.05 μm, it is brittle and easily broken, and if it exceeds 2.0 μm, it may be cleaved into thinner particles during the pearl pigment manufacturing process. Therefore, the preferred thickness range is 0.05 to 2.0
μm.

The principle that the plastic sheet develops various hues is that among the light rays entering the sheet, the light reflected at the boundary between the titanium dioxide-coated mica vehicle and titanium dioxide and the light reflected at the boundary between titanium dioxide and mica The light interferes with each other and appears. Therefore, the color to be developed is determined by the thickness of the titanium dioxide and the thickness of the mica, and the light transmitted through the sheet is visible only for the light of the wavelength that is transmitted without being reflected by the titanium dioxide-coated mica. For this reason, the hue when the sheet is viewed with reflected light and the hue when the sheet is viewed with transmitted light are complementary to each other.

The thickness of titanium dioxide is preferably 30 to 500 mμ, although the film thickness of titanium dioxide can be arbitrarily formed, but with an extremely thin film of less than 30 mμ, the reflected light on the titanium dioxide layer surface among the incident white light, Since the wavelength shift from the light transmitted through the titanium dioxide layer and the reflected light on the surface of the mica is extremely small, interference hardly occurs and no interference color appears. Also, 50
In the case of an extremely thick film exceeding 0 mμ, the deviation of the reflected light in each layer becomes twice the wavelength or more. Therefore, the interference color that develops is 50
This means that it is the same as any of the interference colors that can be expressed with a film thickness of 0 mμ or less, and it does not make sense to make it thicker than 500 mμ. From the above, the desirable film thickness of titanium dioxide is 30 to 500 mμ.

With respect to the intensity of this color development, that is, the color density, the amount of the titanium dioxide-coated mica added to the vehicle is determined, and the arrangement of the titanium dioxide-coated mica in the vehicle is also changed. The addition amount can be variously changed depending on the thickness of the film and the use, but 0.5 to 10 parts by weight is preferable. Regarding the arrangement, it is important that the plate-like surface of the scale-like mica is arranged in a fixed direction in each particle as shown in FIG. Even if they are not arranged, the hue is shown, but the strength of the color is weak. Further, if the particles are finely crushed in the production, the color development becomes dull.

The pressing method is most suitable for obtaining the designable sheet as described above with such points in mind.

[Action]

The pressing method is a basic method for producing a thermoplastic resin film sheet and is a method generally used. This is a method in which a resin mixed in advance with a predetermined composition is sufficiently kneaded with two simple heating mixing rolls of three or three, and this is molded into a film or sheet by heat and pressure. In this case, the press is not specified as a single-wafer process, a continuous process or a continuous press using a roll.

It has been found that by applying pressure in the thickness direction of the film sheet during this pressing, the titanium dioxide-coated mica particles are aligned in the resin, and the plate-like surface of the particles is aligned in the direction parallel to the surface of the film sheet. The condition for this pressure is 10
Sufficient orientation of the particles can be obtained by carrying out in the range of up to 200 kgf / cm ² . That is, when the pressure is less than 10 kgf / cm ² , the orientation of the pigment is insufficient, the degree of color development is extremely weak, and a light ray of a complementary color is not particularly obtained when seen in transmitted light, and the sheet is simply whitish. I can't get a design. On the other hand, when the pressure exceeds 200 kgf / cm ² , the resin flows so strongly that color unevenness occurs, making good sheeting operation difficult. Therefore, the press molding pressure is particularly preferably 20 kgf / cm ² within the above range.
It is good to set it to about 100 kgf / cm ² .

Also, in order to finish the surface of the film sheet as a mirror surface, by pressing with a press plate having a mirror surface with an average surface roughness of 1 μm or less, the light reflected from the pearl pigment returns without being diffusely reflected, so that the color is It becomes more colorful and enhances its effect.

〔Example〕

Example 1 Composition: parts by weight Straight PVC having an average molecular weight of 700 (SX-7G manufactured by Sumitomo Chemical Co., Ltd.) 100 Sn stabilizer (S-2000GS manufactured by Kyodo Chemical Co., Ltd.) 1 Epoxidized soybean oil (Q-130P manufactured by ADEKA ARGUS) ) …… 2 Soluble agent (ATBC manufactured by Dainippon Ink and Chemicals) ………… 4 Lubricant (wax QP manufactured by Ciba-Geigy) …… 0.2 Lubricant (Kao wax # 200 manufactured by Kao) …… 0.4 Reinforcing agent (manufactured by Kanebuchi Chemical, Kaneace B-22) …… 7 Pearl pigment (Merck & Co., Iriodin 235)… 3 With the composition as above, 18 in a heating mixing roll
The mixture was sufficiently kneaded at 0 ° C. for about 10 minutes, and the resin kneaded product obtained here was pressed in a heating press machine at 170 ° C. and 50 kg / cm ² to prepare a sheet having a thickness of 0.3 m / m. This sheet produced a green PVC sheet in reflected light and a red PVC sheet in transmitted light.

〔The invention's effect〕

According to the present invention, a functional design in which reflected light has a pearly tone of hues of gold, red, purple, blue, and green, and transmitted light appears as a complementary color of each hue, that is, purple, green, yellow, orange, and red. And a so-called pastel color tone plastic sheet having a light color tone as a whole is obtained. By using the designable sheet of the present invention, films for laminating packaging, packaging materials for plastic cases, lamp shades, blinds, roll curtains, interior products such as wallpaper, cards, labels, malls, and other items in the field of daily sundries. , "Brightness vs. purple", "Red vs. green", "Purple vs. yellow", depending on factors such as ambient brightness, entering of transmitted light, color tone and form of contents,
The surface changes with the complementary color relationship of "blue vs. orange" and "green vs. red" and the surface can be shined in a pearly tone to give a high design property, and it can also bring added value such as anti-counterfeiting and display function.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the inventive design sheet, and FIG. 2 is a schematic view showing the shape of the pearl pigment.

Claims (2)

(57) [Claims] 1. Particles in which titanium dioxide is coated on the surface of a mica having a thickness of 0.05 to 2.0 μm and a thickness of 30 to 500 mμ are mixed with an amorphous and transparent resin. A method for producing a designable sheet, which comprises forming a film by a heating press method under a production condition of a pressure of 10 to 200 kgf / cm ² . 2. The method for producing a designable sheet according to claim 1, wherein press plates having a mirror surface with an average surface roughness of 1 μm or less are used for pressing.