Colored resin molding, colored film, coloring ink and printing film

Abstract

To provide a colored resin molding containing a coloring agent in a transparent resin which exhibits a dichromic effect of changing the color of a black substrate and the color of a white substrate without requiring a brilliant agent, a fluorescent dye and a pigment.SOLUTION: A colored resin molding has a transparent resin, a red coloring agent which is contained in the transparent resin and has high scattering property, and a blue coloring agent which is contained in the transparent resin and has low scattering property. A hue angle on the black substrate in a 10° visual field using a D65 light source is 0° to 70°, and the hue angle on the white substrate is 200° to 270° .SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a colored resin molding that appears approximately red to brown on a black background and approximately blue on a white background. [Background technology]

[0002] There is a known artificial gemstone made of glass called a "sapphirete." This artificial gemstone has a subtle dichroic effect that causes it to change color from brown to blue depending on the angle from which it is viewed. However, the knowledge of how to make sapphirete has now been lost.

[0003] On the other hand, as a method of reproducing the dichroic effect using resin molded products, a liquid crystal light control film that changes color by turning on and off a voltage using polarized light is known. In addition, a dichroic effect in which the hue changes depending on the viewing angle or the base color by using a glittering material such as pearl is also known. In addition, it is known that fluorescent dye pigments can also change the hue depending on the color change of the base, such as changing from yellow to green (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-107467 A [Patent Document 2] WO2021 / 095881 publication Summary of the Invention [Problem to be solved by the invention]

[0005] However, liquid crystal dimming using polarized light requires electronic devices for dimming. Also, resin moldings using lustrous materials such as pearls or fluorescent dyes and pigments have limitations in dimming and require special lustrous materials. For this reason, there is a demand for colored resin moldings that contain colorants in transparent resins and have a subtle dichroic effect like sapphirette by changing only the color of the base, without the need for lustrous materials, fluorescent dyes, or fluorescent pigments.

[0006] To provide a colored resin molding having a dichroic effect in which the color changes between a black background and a white background, without requiring any luminous agent or fluorescent dye or pigment, which is a resin molding having a coloring agent contained in a transparent resin. [Means for solving the problem]

[0007] The colored resin molding according to the present invention has a transparent resin, a highly scattering red colorant contained in the transparent resin, and a low scattering blue colorant contained in the transparent resin, and has a hue angle (h ab The color temperature is characterized in that the hue angle (CIE 1976a, b) is 0° to 70°, and the hue angle on a white background is 200° to 270°.

[0008] The present invention also relates to a colored film comprising the above-mentioned colored resin molding.

[0009] The present invention also relates to a colored ink containing the above-mentioned colored resin molding.

[0010] The present invention also relates to a printed film comprising the above-mentioned colored ink printed thereon. Effect of the Invention

[0011] In order to solve the above problems, the present inventors have succeeded in producing a colored resin molding that exhibits dichroism, appearing almost red to brown on a black background and almost blue on a white background, by mixing and adjusting a highly scattering red colorant such as red oxide and a low scattering blue colorant such as cyanine blue in a transparent resin. [Brief description of the drawings]

[0012] [Figure 1] 1 shows a color diagram for explaining the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a method for measuring the color of a colored resin molding. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (transparent resin) It is generally known that a "transparent resin" is a resin that has little reflection or absorption of visible light and allows visible light to pass through the resin without being diffused. The transparent resin is preferably a thermoplastic resin. As such a thermoplastic resin, a thermoplastic resin used for producing a general resin molded product can be used. As the thermoplastic resin, for example, polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polycarbonate; polystyrene; ABS; polyamide; polymethyl methacrylate; polyurethane; polyphenylene ether, etc. can be mentioned. As these thermoplastic resins, amorphous thermoplastic resins may be used, and one type alone or two or more types in combination can be used.

[0014] The transparent resin may be a thermosetting resin other than a thermoplastic resin. The thermosetting resin may be a conventionally known thermosetting resin such as a urethane resin, an epoxy resin, a phenol resin, an unsaturated polyester resin, a vinyl ester resin, an alkyd resin, a melamine resin, an imide resin, a styrene-based resin obtained by polymerizing a monomer having a vinyl polymerizable functional group having two or more functionalities, or a (meth)acrylate resin.

[0015] (Highly scattering red colorant and low scattering blue colorant) In the present invention, by incorporating a highly scattering red colorant and a low scattering blue colorant in the transparent resin, the hue angle on a black background and the hue angle on a white background can be adjusted to different colors.

[0016] Here, the red colorant is a color that has a hue angle (h ab It is more preferable that the hue angle of the red colorant is 20° or more, and more preferably 50° or less.

[0017] In addition, the blue colorant is the hue angle (h ab (CIE1976a,b hue angle) is 180° to 360°. The hue angle of the blue colorant is more preferably 225° or more, and even more preferably 315° or less. Each hue angle is measured in the same manner as the hue angle of a resin molded product described later, but a white or black base is not used during this measurement.

[0018] The red colorant used in the present invention is highly scattering, and the blue colorant is low scattering. Here, in the case of a blue colorant with low scattering properties, if the blue colorant is concentrated to the point where light does not pass through the resin molded product, the brightness of the resin molded product will be reduced. This is because the blue colorant has low scattering properties, so light rays are not scattered much. Therefore, in order to prevent light rays from passing through the resin molded product, it is necessary to increase the concentration of the blue colorant. As a result, the concentration of the blue colorant increases, and the brightness of the colored resin molded product at that point decreases. On the other hand, in the case of a red colorant with high scattering properties, even if the resin molded product is concentrated to the point where light rays do not pass through it, the brightness of the resin molded product remains relatively high. This is because if the scattering properties of the colorant are high, light rays do not pass through it easily even if the concentration of the colorant is relatively low. Therefore, the brightness remains relatively high even at the stage where light rays do not pass through the resin molded product.

[0019] Specifically, the scattering property of each colorant is measured as follows. First, each colorant is mixed into a transparent resin (transparent soft polyvinyl chloride resin) to create a test piece that is not completely transparent. The thickness of the test piece is 1 mm. Here, the total light transmittance of the "not completely transparent test piece" is 1% or less.

[0020] In this state, for each test piece, the lightness (L * ) and measure the lightness (L * A highly scattering red colorant is considered to have a lightness (L * From a practical standpoint, the lightness (L * A blue colorant with low scattering has a lightness (L * ) is often greater than or equal to 1 for practical purposes.

[0021] When measuring these lightness values, each colorant to be measured is mixed into a transparent soft polyvinyl chloride resin to prepare a test piece with a thickness of 1 mm. Then, as shown in Figure 2, each test piece (coloring composition) is placed on a Konica Minolta "CM-36dG." However, no white or black undercoat is provided. The specific color measurement conditions are a D65 light source, a viewing angle of 10°, LAV for the illumination diameter and measurement diameter size, and SCE method for the measurement method.

[0022] Examples of highly scattering red colorants include organic pigments such as red iron oxide such as yellowish red iron oxide and purple iron oxide, cadmium red, azo chelate pigments, insoluble azo pigments, condensed azo pigments, diketopyrrolopyrrole pigments, indigo pigments, perinone pigments, perylene pigments, quinacridone pigments, isoindolinone pigments, and metal complex pigments. Examples of low-scattering blue colorants include copper phthalocyanines such as α-type copper phthalocyanine blue and β-type copper phthalocyanine blue, ultramarine blues, cobalt blues, blue dyes, and the like.

[0023] (Hue angle of colored resin moldings) In the present invention, as shown in the schematic diagram of FIG. 1, the hue angle (h ab The hue angle (CIE 1976a, b) is 0° to 70°, and the hue angle on a white background is 200° to 270°. In other words, the resin molding of the present invention has a significant difference in hue angle between the black background and the white background, and exhibits dichroism. Furthermore, the resin molded product of the present invention can have a hue angle of 200° to 270° in transmitted color, just like on a white background.

[0024] The hue angle of a colored resin molding is measured as follows. That is, each colorant to be measured is mixed into a transparent soft polyvinyl chloride resin to prepare a test piece having a thickness of 1 mm. Then, as shown in FIG. 2, each test piece (coloring composition) is placed on a Konica Minolta "CM-36dG". Then, a white base (EVER's EVER-WHITE9582) or a black base (EVER-BLACK0005) is placed between each test piece and the measurement part, and color measurement is performed. The specific color measurement conditions are as follows: the illumination diameter and measurement diameter are LAV, and the measurement method is SCE method.

[0025] In a preferred embodiment, the saturation (C *ab :CIE1976 a,b chroma) must be greater than or equal to 3 and less than or equal to 150.

[0026] The common method of expressing color is the CIE L color space, which was established by the International Commission on Illumination (CIE) to express colors that can be seen by the human eye. * a * b * There is a color system (color space) called the CIE L*a*b* color system (see Figure 1). In this system, color is expressed by three coordinates: lightness is "L*", red (magenta) to green is "a*" (positive is magenta, negative is greenish), and yellow to blue is "b*" (positive is yellowish, negative is blueish).

[0027] In fact, by kneading various colorants into transparent resin, it was found that when a color was chromatic on a white background (i.e., when the saturation was relatively high), on a black background it often had a similar hue to that on the white background, or on a black background it often had a low saturation black color. In contrast, the resin molded product of the present invention was able to show a relatively high saturation on both a white background and a black background. Specifically, the saturation (C *ab The chroma (CIE 1976 a, b chroma) is preferably 3 or more and 150 or less. Each of these chroma is more preferably 3 or more and 20 or less.

[0028] These saturations are measured in the same manner as in the color measurement of each colored resin molding, as shown in FIG.

[0029] The preferred ratios of each component in the resin molded product are shown below. (1) If the mass of the highly scattering red colorant is 1.000: The mass of the low-scattering blue colorant is preferably 0.040 to 0.500, more preferably 0.045 to 0.400, and particularly preferably 0.050 to 0.320. The mass of the transparent resin is preferably 800 to 5,000, more preferably 900 to 4,500, and particularly preferably 1,000 to 4,000.

[0030] (2) The lightness of the red colorant (L * ) is 25 or more and the mass is 1.000 The mass of the low-scattering blue colorant is preferably 0.040 to 0.500, more preferably 0.045 to 0.400, and particularly preferably 0.100 to 0.320. The mass of the transparent resin is preferably 800 to 5,000, more preferably 900 to 4,500, and particularly preferably 1,000 to 4,000.

[0031] (3) The lightness of the red colorant (L * ) is 15 or more and less than 25 (especially 24.999 or less), and the mass is 1.000 The mass of the low-scattering blue colorant is preferably 0.040 to 0.500, more preferably 0.045 to 0.400, and particularly preferably 0.050 to 0.320. The mass of the transparent resin is preferably 800 to 5,000, more preferably 900 to 4,500, and particularly preferably 1,000 to 4,000.

[0032] (Other additives) The colored resin molding of the present invention may contain other additives within the scope of the present invention. For example, dispersants, antioxidants, stabilizers, ultraviolet absorbers, lubricants, processing aids, antistatic agents, impact resistance aids, fillers, matting agents, etc. may be contained. When the amount of resin contained in the colored resin molding is taken as 100 parts by mass, the content of other additives is preferably 5 parts by mass or less, and may be 0 parts by mass.

[0033] (Manufacturing of colored resin molded products) The colored resin molding of the present invention can generally be obtained by melt mixing and dispersing the resin and the colorant using a Banbury mixer, a Nauta mixer, a kneading roll, or a single-screw or twin-screw extruder, etc. Furthermore, for the purpose of uniformly dispersing the resin and the colorant before kneading, preliminary dispersion may be performed using a tumbler mixer, a blender, or a high-speed mixer.

[0034] The molding method of the obtained colored resin molded product is not limited, but it is molded into a predetermined shape by a known method such as injection molding, injection compression molding, compressed air molding, blow molding, vacuum molding, foam molding, extrusion molding, etc. At this time, additives such as heat stabilizers, weather stabilizers, lubricants, pigment dispersants, and antistatic agents can be added depending on the purpose. In addition, other pigments and dyes can be added depending on the purpose required for the molded product, such as high designability.

[0035] A film- or sheet-shaped molded product can be produced by molding a colored resin molded product using a molding machine by a general film molding method or sheet molding method. Examples of the molding machine that can be used include an extrusion molding machine, a blow molding machine, a vacuum molding machine, a pressure molding machine, a compression molding machine, and a calendar molding machine. The thickness of the film-shaped molded product and the sheet-shaped molded product may be appropriately adjusted depending on the application. Specifically, the thickness is preferably 0.1 to 500 μm, and more preferably 1 to 100 μm.

[0036] When a laminated film is co-extruded, the resins constituting each layer are heated and melted, and then fed to an extrusion die through respective flow paths from different extruders, pumps, etc., and bonded together after being extruded in multiple layers from the extrusion die. As the extrusion die, for example, a T-die such as a multi-manifold die or a feed block can be used.

[0037] In addition, a fibrous molded product can be produced by spinning a colored resin molding using a spinning machine. The fiber diameter of the fibrous molded product may be appropriately adjusted depending on the application. Specifically, it is preferably 1 to 1,000 μm, more preferably 1 to 500 μm, and particularly preferably 5 to 200 μm. The fibrous molded product may be cut to an appropriate length or bundled into a fiber bundle. Furthermore, it can be processed into a cloth or nonwoven fabric.

[0038] (Suitable uses of the colored resin molding of the present invention) The colored molded product of the present invention has dichroism, and therefore can be suitably used in a wide variety of applications that utilize dichroism. In other words, it can be widely used in applications that utilize dichroism as design or decoration, and can be formed on the outer surfaces of various parts and containers. In addition, because it has the special property of dichroism, it is expected to be used as an anti-counterfeiting material.

[0039] Specifically, for example, a colored film made of the colored resin molding of the present invention can be attached to various objects. In addition, the colored ink containing the colored resin molding of the present invention can be printed on various objects to form a printed film having dichroism. Such colored ink can contain various organic solvents and various known additives. EXAMPLES

[0040] (Each colorant) The colorants shown in Table 1 were prepared. However, the lightness (L * ) and hue angle were measured and are shown in Table 1.

[0041] [Table 1]

[0042] (Production of Colored Resin Moldings in Examples and Comparative Examples) Each resin molded product was manufactured by mixing each colorant in the formulation shown in Table 2 with transparent soft vinyl resin and roll molding it. However, in order to efficiently disperse each colorant, a pre-processed moisturizing powder colorant for polyvinyl chloride resin, Discol, was used. A colored resin molded product with a thickness of 1 mm was manufactured. However, the values ​​shown in Table 2 indicate the mass ratio of each component when the mass of the red colorant is taken as 1.000.

[0043] [Table 2]

[0044] (Color measurement results for each colored resin molded product) The color of each colored resin molding on a white and black background was measured as described above. The C* of the L*a*b* color space according to CIE1976 was measured with a D65 light source and a 10° field of view. ab , h ab was calculated, and the results are shown in Table 3.

[0045] [Table 3]

[0046] From Table 3, the color difference between the white and black backgrounds (ΔE * : CIE1976L*a*b*color diffrence), Δh ab , hue difference (ΔH * ab The hue-difference (CIE 1976 a,b) was calculated and the results are shown in Table 4.

[0047] [Table 4]

[0048] The colored resin moldings of Examples 1 to 4 have such high saturation (C * ab >>3.00), and its hue angle h ab Difference Δh ab In other words, by changing the color of the base, the hue of the colored resin molding changes significantly, and we have succeeded in demonstrating significant dichroism.

[0049] The colored resin moldings of Comparative Example 1 and Comparative Example 2 did not exhibit any significant dichroism.

[0050] Example 5 is an example in which the yellowish iron oxide of Examples 1 to 4 was changed to a purple iron oxide. In this case as well, significant dichroism was successfully achieved.

[0051] Example 6 is a colored resin molding in which yellowish red iron oxide and α-type copper phthalocyanine blue are mixed instead of the β-type copper phthalocyanine blue used in Examples 1 to 4. Example 7 is an example in which both the red colorant and the blue colorant used in Examples 1 to 4 are changed. All of the examples have been successful in achieving significant dichroism.

[0052] Comparative Example 3 is a colored resin molding containing only yellowish red iron oxide and no low-scattering blue colorant. In this case, the colored resin molding did not exhibit dichroism.

Claims

1. A colored resin molding comprising a transparent resin, a highly scattering red colorant contained in said transparent resin, and a low-scattering blue colorant contained in said transparent resin, the colored resin molding having a hue angle of 0° to 70° on a black background in a 10° field of view using a D65 light source and a hue angle of 200° to 270° on a white background.

2. 2. The colored resin molding according to claim 1, wherein the chroma on a black background and the chroma on a white background are 3 or more and 150 or less, respectively.

3. 3. The colored resin molding according to claim 1, wherein the red colorant is red iron oxide.

4. 3. The colored resin molding according to claim 1, wherein the blue colorant is a phthalocyanine colorant.

5. A colored film comprising the colored resin molding according to claim 1 or 2.

6. A colored ink comprising the colored resin molding according to claim 1 or 2.

7. A printed film comprising a print of the colored ink according to claim 6.

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