An oily structural color pigment ink and applications thereof

Abstract

The application discloses an oily structural color pigment ink and application thereof, and belongs to the technical field of photonic crystal material preparation. Components of the oily structural color pigment ink include at least one block polymer brush, at least one resin or at least one precursor of the resin, and at least one organic solvent. The oily structural color pigment ink provided by the application is a layered structural color material obtained by self-assembly based on the microphase separation principle of the block polymer brush. The provided oily structural color pigment ink can be compatible with most common pigment coloring methods, including but not limited to screen printing, spraying, inkjet printing and intaglio printing. The structural color of the oily structural color pigment ink is not limited to the visible light band, and covers ultraviolet spectrum, visible spectrum and infrared spectrum, and the wavelength range of the covered electromagnetic spectrum is 200 nm to 2000 nm.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photonic crystal material preparation, and particularly relates to an oily structural color pigment ink and application thereof. BACKGROUND

[0002] Pigment is a substance used for coloring, which can be uniformly dispersed in various media such as oil, resin, water, organic solvent, etc. to provide color and hiding power, and is widely used in industries such as coatings, inks, plastics, rubber, ceramics, papermaking, textile printing and dyeing, and cosmetics. In history, the pigment industry has always played an important role, providing rich and colorful colors for artistic creation, industrial manufacturing and daily life. However, with the passage of time, the development of this industry has gradually exposed some problems and limitations. First, the production process of traditional pigments often accompanies high energy consumption and high pollution. The production of many pigments needs to use toxic or harmful chemicals, which may pose a threat to the environment and human health during the production process. In addition, the extraction and processing process of pigments may also lead to waste of resources and ecological damage. Secondly, the performance of traditional pigments has limitations in some application fields. For example, they may not perform well in light resistance, heat resistance, chemical corrosion resistance, etc., and the dye or pigment itself will also slowly decompose and fade over time, which limits its use in high-end application fields. Thirdly, the sustainability problem of traditional pigments is increasingly prominent. With the global emphasis on environmental protection and sustainable development, the production and use of traditional pigments have been increasingly restricted. This requires the pigment industry to find new materials and technologies to reduce the impact on the environment.

[0003] Structural Color is an optical phenomenon produced by photonic crystals (PhCs), which is an artificial microstructure material with important application value in the field of optics, especially in the generation and regulation of color. Photonic crystals can modulate light waves through their periodic structure, producing achromatic colors. These colors are produced by the scattering, interference, and diffraction of light by the microstructure of the material's surface. There are many examples of structural color in nature, which exhibit color in a unique way in biological organisms. For example, butterfly wings, peacock feathers, beetle shells, and other biological colors often originate from the selective reflection of specific wavelengths by their special periodic nanostructure. The wings of the Morpho butterfly are a typical one-dimensional photonic crystal, whose structure can produce bright blue structural color. The feathers of the peacock exhibit the effect of two-dimensional photonic crystals, and their microscopic periodic stripe structure can reflect bright structural color. In addition, opal, a gemstone, exhibits a special color-changing effect due to the accumulation of SiO2 small balls inside, and is known as the color palette of gemstones. Even in daily life, such as the cut surface of beef jerky, the arrangement of muscle fibers forms a two-dimensional photonic crystal structure, reflecting a specific luster.

[0004] At present, the preparation of structural color materials is mainly through the following methods: (1) Electron beam lithography: using electron beam direct writing and reactive ion beam etching to prepare two-dimensional photonic crystal thin films on substrates. This method has high precision, but the processing time is long and the cost is high; (2) Colloidal particle self-assembly technology: using colloidal microspheres to self-assemble in solution to form three-dimensional photonic crystals. This method has a long preparation process and is sensitive to external perturbations, which may cause structural defects; (3) Nanoimprint technology: quickly replicating photonic crystal structures through imprinting, suitable for large-area preparation, but there may be challenges in controlling the depth and uniformity of the imprint; (4) Femtosecond laser direct writing: using femtosecond laser to directly write photonic crystal structures on the surface of materials, which can obtain high-precision three-dimensional structures, but the equipment cost is high and the production efficiency is relatively low; (5) Chemical vapor deposition: growing photonic crystals through chemical vapor deposition technology, which can obtain high-quality three-dimensional photonic crystals, but the preparation process is complex and requires high equipment and environmental requirements; (6) Sol-gel method: preparing photonic crystals through the sol-gel method, which has low cost, but it is difficult to accurately control the aperture and shape, which may affect the performance of photonic crystals; (7) Multi-beam coherent holographic technology: achieving rapid preparation of photonic crystals through multi-beam interference, suitable for various lattice types, but limited by the wavelength of the laser, it is difficult to prepare a complete photonic bandgap in the visible light region. SUMMARY

[0005] The application aims to provide an oily structural color pigment ink and application thereof. The oily structural color pigment ink provided by the application is a layered structural color material obtained by self-assembly based on the principle of microphase separation of block polymer brushes.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme.

[0007] One of the technical schemes of the application provides an oily structural color pigment ink, which comprises at least one block polymer brush (BBCP), at least one resin or a precursor of the resin, and at least one organic solvent.

[0008] The blocks in the block polymer brush can be microphase-separated to form layered domains.

[0009] The resin or the resin generated from the precursor is compatible with at least one block of the block polymer brush, and the light transmittance is not less than 50%.

[0010] The block polymer brush used in the application can be microphase-separated by self-assembly, heating to a specific temperature, solvent evaporation induced assembly, or through a printing process such as blade coating.

[0011] The block polymer brush (bottle brush-like block polymer) in the application refers to a special structure of polymer material, which is characterized by densely grafting side chain polymers on the polymer backbone to form a brush-like form. The design and synthesis of this structure usually rely on precise polymerization techniques, such as living radical polymerization, atom transfer radical polymerization (ATRP), and reversible addition fragmentation chain transfer polymerization (RAFT) methods, which also bring special physical and chemical properties to the block polymer brush. In particular, the densely grafted side chains make the self-assembly behavior of the block polymer brush different from that of general block polymers, and it is easier to form ordered nanostructures such as photonic crystals and nanowires through self-assembly. These structures have potential applications in the fields of optics and electronics. By changing the composition and degree of polymerization of the block polymer brush, its self-assembly behavior can be controlled, so as to prepare nanostructures with specific morphology and chemical composition.

[0012] Preferably, the block polymer brush comprises: poly poly-styrene-b-poly poly-ethylene glycol (PPS-b-PPEO), poly poly-tert-butyl acrylate-b-poly poly-ethylene glycol (PPtBA-b-PPEO), poly poly-dimethylsiloxane-b-poly poly-ethylene glycol (PPDMS-b-PPEO), poly poly-methyl methacrylate-b-poly poly-ethylene glycol (PPMMA-b-PPEO), poly poly-methyl acrylate-b-poly poly-ethylene glycol (PPMA-b-PPEO), poly poly-acrylonitrile-b-poly poly-ethylene glycol (PPAN-b-PPEO), poly poly-lactic acid-b-poly poly-ethylene glycol (PPLA-b-PPEO), poly poly-ε-caprolactone-b-poly poly-ethylene glycol (PPCL-b-PPEO), poly poly-ethylene-b-poly poly-ethylene glycol (PPE-b-PPEO), poly poly-propylene-b-poly poly-ethylene glycol (PPP-b-PPEO), poly poly-styrene-b-poly poly-acrylic acid (PPS-b-PPAA), poly poly-dimethylsiloxane-b-poly poly-methyl methacrylate (PPDMS-b-PPMAA), poly poly-dimethylsiloxane-b-poly poly-vinyl pyrrolidone (PPDMS-b-PPVP), poly poly-styrene-b-poly poly-4-vinyl pyridine (PPS-b-PP4VP), poly poly-styrene-b-poly poly-2-vinyl pyridine (PPS-b-PP2VP), poly poly-styrene-b-poly poly-dimethylsiloxane-b-poly poly-ethylene glycol (PPS-b-PPDMS-b-PPEO), poly poly-styrene-b-poly poly-tert-butyl acrylate-b-poly poly-ethylene glycol (PPS-b-PPtBA-b-PPEO), poly poly-tert-butyl acrylate-b-poly poly-dimethylsiloxane-b-poly poly-ethylene glycol (PPtBA-b-PPDMS-b-PPEO), or poly poly-methyl methacrylate-b-poly poly-styrene-b-poly poly-ethylene glycol (PPMMA-b-PPS-b-PPEO).

[0013] The synthesis process of the block polymer brush described in the present application refers to the patent US20210395463A1. Taking PPS-b-PPEO as an example: the first step obtains a norbornene-terminated PS macromonomer by anionic polymerization; the second step obtains a norbornene-terminated PEO macromonomer by esterification reaction; the third step carries out ring-opening metathesis polymerization according to the method of the patent US20210395463A1 to obtain the block polymer brush.

[0014] It should be noted that the synthesis method of different norbornene-terminated macromonomers is determined according to actual production needs, including but not limited to anionic polymerization, cationic polymerization, macromolecular esterification, Click reaction or DA addition.

[0015] Preferably, the mass of the block polymer brush accounts for 15-80% of the total mass of the oily structural color pigment ink after removing the organic solvent.

[0016] The micro-phase separation of the block polymer brush in the present application is the key to self-assembly into a layered photonic crystal structure, which determines the size of the layered structure domain of the photonic crystal and the maximum reflection wavelength.

[0017] Preferably, the resin or the resin generated by the precursor of the resin comprises polystyrene, polyester, polyvinyl ether, polyether, polyacrylate, polymethacrylate, polyacrylamide, polymethacrylamide, polyurethane, polysiloxane, polyamide, polyethylene terephthalate, phenolic resin, urea resin, alkyd resin, epoxy resin or silicone resin.

[0018] In the present application, the role of the resin is to swell the layered structure of the photonic crystal to adjust the domain size, and the selection of the resin should consider the used block polymer brush, the subsequent processing performance requirements and the subsequent use performance requirements and other factors.

[0019] Preferably, the organic solvent comprises acetone, methanol, ethanol, dimethylformamide, toluene, dichloromethane, n-heptane, cyclohexane, ethyl acetate, butyl acetate, chloroform, diethyl ether, anisole, toluene, xylene, benzene, tetrachloromethane, pyridine, hexane, isopropanol, tetrahydrofuran, 1,4-dioxane, styrene, methyl methacrylate or methyl acrylate.

[0020] In the present application, the organic solvent plays a role in adjusting the viscosity of the ink system and uniformly dispersing each component in the system. The primary requirement for the selection of the organic solvent is to be able to dissolve other components in the system, in addition, the volatility, polarity, viscosity and other characteristics of the organic solvent also affect the final performance of the structural color ink.

[0021] Preferably, the components of the oily structural color pigment ink further comprise an adjusting component.

[0022] More preferably, the adjusting component comprises one or more of a plasticizer, a stabilizer, an antioxidant, an anti-aging agent, an anti-UV agent, a degradation agent, a lubricant, a heat stabilizer, a foaming agent, an antistatic agent, a flame retardant, a filler, a coupling agent, a processing modifier, a nucleating agent, an impact modifier, a leveling agent and a defoaming agent.

[0023] In the present application, the addition of the adjusting component is to improve the processing performance and use performance of the oily structural color pigment ink, and the addition of part of the adjusting component is also used to adjust the color of the oily structural color pigment ink formula.

[0024] The second technical solution of the present application provides an application of the above-mentioned oily structural color pigment ink in screen printing, spraying, inkjet printing or gravure printing.

[0025] The use method of the oily structural color pigment ink provided by the present application is as follows:

[0026] The oil-based structural color pigment ink prepared by the present application can be used in combination with traditional pigment coloring methods. After printing the ink on a substrate, the photonic crystal structure covering the surface of the substrate can be obtained through solvent evaporation and post-processing, thereby producing structural color.

[0027] Solvent evaporation increases the viscosity of the structural color ink and improves the adhesion of the ink on the substrate. In addition, the evaporation of some solvents can induce the microphase separation process of the block polymer brush, thereby improving the order of the photonic crystal structure. The solvent evaporation process can be environmental drying or active drying of the printed product (for example, using infrared / heat lamps or ultraviolet lamps for active drying). Active drying of the printed product can quickly dry the ink solution to achieve efficient multiple printing or efficient implementation of other types of post-processing.

[0028] The processing method of the printed oil-based structural color pigment ink includes but is not limited to annealing, curing the printed product, or printing a protective varnish, transparent coating, or some other surface material on the printed product. The curing process of the printed product usually depends on the type of resin used in the formula and can be achieved by methods including but not limited to ultraviolet curing, thermal curing, air drying curing, or near-infrared curing to obtain a stable photonic crystal structure. The purpose of the annealing process is to promote the microphase separation process of the block polymer brush and obtain a more ordered photonic crystal structure.

[0029] The color regulation method of the oil-based structural color pigment ink provided by the present application is as follows:

[0030] The color regulation method of the structural color ink can be roughly divided into three types. One is to directly configure the structural color ink with the desired color by selecting appropriate block polymer brushes (a block polymer brush or a mixture of multiple block polymer brushes), appropriate resins, and appropriate adjusting components during the preparation process of the structural color ink, and the process is referred to the preparation method of the oil-based structural color pigment ink. Two is to pre-mix two structural color inks with different colors to obtain a new desired color with a reflection wavelength between the two, for example, mixing red and blue structural color inks at a ratio of 1:1 to obtain a green ink with a reflection wavelength between the two. Three is to obtain the desired color by the principle of additive / subtractive color, for example, printing multiple layers of photonic crystal structures with multiple domain sizes on the same substrate to obtain the desired color, for example, printing red, blue, and green structural color inks to cover the RGB color gamut.

[0031] The beneficial technical effects of the present application are as follows:

[0032] The structural color coating obtained by the oil-based structural color pigment ink provided by the present application can reflect ultraviolet-visible-infrared light with a wavelength range of 200nm-2000nm.

[0033] The photonic crystal in the oil-based structural color pigment ink can be combined with a traditional pigment coloring process to obtain a structural color coating through printing.

[0034] The structural color of the oil-based structural color pigment ink can provide a color effect that cannot be produced by current pigments and dyes, and can theoretically achieve arbitrary spectral design.

[0035] The oil-based structural color pigment ink can provide an enhancement effect through pigments and dyes, and can achieve a wider range of colors by combining the formed structural color coating with pigments and dyes, and produce a new color gamut through the mixing of subtractive and additive color mixing theories. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a LAB color model.

[0037] Figure 2 is a reflection characteristic curve diagram of the oil-based structural color pigment ink of Formulas 1-5 in Example 1 after printing and heat treatment.

[0038] Figure 3 is a reflection characteristic curve diagram of the oil-based structural color pigment ink of Formulas 6-10 in Example 2 after printing and light treatment.

[0039] Figure 4 is a reflection characteristic curve diagram of the oil-based structural color pigment ink of Formulas 11-15 in Example 3 after printing and natural drying. DETAILED DESCRIPTION

[0040] A number of exemplary embodiments of the present application are described herein; however, it is understood that the present application should not be limited to these particular embodiments. The terminology used herein is for the purpose of describing only the particular embodiments of the present application and is not intended to be limiting of the present application. It is understood that the use of certain specific language makes apparent to one of ordinary skill in the art that certain embodiments of the application are intended for use in connection with particular aspects, features and / or embodiments of the present application.

[0041] Further, with respect to numerical ranges, it is to be understood that every numerical value between the upper and lower limits of this range is also specifically disclosed. Each intermediate value literally and implicitly falls within the ambit of the application as claimed. The upper and lower limits of these smaller ranges can independently be included or excluded in the range.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described herein. It is to be understood that this application is not limited to particular methods or materials, unless otherwise specified, unless specific

[0043] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", "contains", "containing", or variations thereof, are intended to be open-ended terms that mean including, but not limited to.

[0044] In embodiments, the measurement of color values can be done using the L*a*b* color space. The LAB color model (see Figure 1 ), also known as CIELab color space, is a color space defined by the International Commission on Illumination (CIE) in 1976. It is a three-dimensional color space widely used for the computation, comparison and quantitative specification of color in various color spaces. The LAB color model is characterized by being device independent and uniformly reflecting human visual perception. The LAB color model consists of three components: L* - a lightness component, indicating the light-dark degree of a color, ranging from 0 (black) to 100 (white). a* - a chroma component, indicating the degree of color bias on the red-green axis, with negative values biasing towards green and positive values biasing towards red. b* - a chroma component, indicating the degree of color bias on the yellow-blue axis, with negative values biasing towards blue and positive values biasing towards yellow. The color gamut of the LAB color space is very wide, it not only contains all the colors that the human eye can perceive, but also includes some theoretical colors. This means that, compared to RGB and CMYK color spaces, LAB can more comprehensively describe colors. Color measurement should be performed using a spectrophotometer that meets the International Commission on Illumination (CIE) standard. The device should be calibrated regularly to ensure the accuracy of the measurement results.

[0045] Example 1

[0046] The oily structural color pigment ink was prepared according to the formulation in Table 1.

[0047] Table 1

[0048]

[0049] In Table 1, BBCP is specifically PPS-b-PPEO (total molecular weight about 110W); phenolic resin precursor is commercially available Inokem reagent (item number P832682-500g).

[0050] The oily structural color pigment ink in Formulations 1-5 was printed and heat treated (130°C, 4h), the color values were measured, and the chroma C was calculated using origin. The measurement and calculation results are shown in Table 2.

[0051] Table 2

[0052] Formulation L a b C 1 166.29 46.53 -140.42 147.93 2 164.05 76.57 -192.77 207.42 3 204.52 77.31 -235.79 248.14 4 209.69 52.26 -215.53 221.77 5 179.20 63.50 -200.26 210.08

[0053] The precise color values of Formulations 1-5 after heat treatment are shown in Table 2, and the obtained photonic crystals are blue.

[0054] The reflectance curves of the oily structural color pigment ink in Formulas 1-5 after printing and heat treatment are shown in Figure 2 .

[0055] Example 2

[0056] The oily structural color pigment ink was prepared according to the formula in Table 3.

[0057] Table 3

[0058]

[0059] In Table 3, the BBCP is specifically PPS-b-PPEO (total molecular weight about 130W); the epoxy resin precursor is a commercially available epoxy acrylate agisin 1030; and the triarylsulfonium salt is a photoinitiator.

[0060] The oily structural color pigment ink in Formulas 6-10 was printed and then subjected to light treatment (365 nm ultraviolet light irradiation for 30 min), and the color values were measured, and the chroma C was calculated using origin, and the measurement and calculation results are shown in Table 4.

[0061] Table 4

[0062] Formulation L a b C 6 158.19 9.88 -117.47 117.88 7 166.29 48.68 -143.46 151.49 8 204.52 75.86 -231.14 243.27 9 179.20 61.26 -204.33 213.31 10 237.37 26.73 -206.67 208.39

[0063] The accurate color values of Formulas 6-10 after light treatment are shown in Table 4, and the photonic crystal obtained is blue.

[0064] The reflectance curves of the oily structural color pigment ink in Formulas 6-10 after printing and light treatment are shown in Figure 3 .

[0065] Example 3

[0066] The oily structural color pigment ink was prepared according to the formula in Table 5.

[0067] Table 5

[0068]

[0069]

[0070] In Table 3, the BBCP is specifically PPS-b-PPEO (total molecular weight about 130W); the epoxy resin precursor is a commercially available epoxy acrylate agisin 1030; and the triarylsulfonium salt is a photoinitiator.

[0071] The oily structural color pigment ink in Formulas 11-15 was printed and naturally dried, and the color values were measured, and the chroma C was calculated using origin, and the measurement and calculation results are shown in Table 6.

[0072] Table 6

[0073] Formulation L a b C 11 252.41 -22.74 -49.77 54.72 12 278.09 -6.55 -86.40 86.65 13 271.64 -23.99 -61.72 66.22 14 255.86 -4.17 -75.37 75.48 15 295.83 -48.53 -12.15 50.03

[0074] The precise color values of the formulations 11-15 after printing and drying are shown in Table 6, and the photonic crystals obtained are blue.

[0075] The reflectance curves of the oily structural color pigment inks of the formulations 11-15 after printing and natural drying are shown in Figure 4 .

[0076] The above embodiments are only used to describe the preferred modes of the present application, and are not used to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by those skilled in the art shall fall within the protection scope of the present application.

Claims

1. An oily structural color pigment ink, characterized by, The components include at least one block polymer brush, at least one resin or at least one precursor of the resin, and at least one organic solvent; The blocks in the block polymer brush can undergo microphase separation to form lamellar domains; The resin or the resin generated by the precursor of the resin is compatible with at least one block of the block polymer brush, and the light transmittance is not less than 50%; The resin or the resin generated by the precursor of the resin is polystyrene, polyvinyl ether, polyacrylate, polymethacrylate, polyacrylamide, polymethacrylamide, polyurethane, polysiloxane, polyethylene terephthalate, phenolic resin, urea resin, alkyd resin, epoxy resin or silicone resin; The block polymer brush is poly polystyrene-b-poly polyethylene glycol or poly poly-ε-caprolactone-b-poly polyethylene glycol; The mass of the block polymer brush accounts for 15-80% of the total mass of the oily structural color pigment ink after removing the organic solvent.

2. The structural color pigment ink according to claim 1, wherein The organic solvent includes acetone, methanol, ethanol, dimethylformamide, dichloromethane, n-heptane, cyclohexane, ethyl acetate, butyl acetate, chloroform, diethyl ether, anisole, toluene, xylene, benzene, tetrachloromethane, pyridine, hexane, isopropanol, tetrahydrofuran, 1,4-dioxane, styrene, methyl methacrylate or methyl acrylate.

3. The structural color pigment ink of claim 1, wherein The components of the oily structural color pigment ink further include an adjusting component.

4. The structural color pigment ink of claim 3, wherein The adjusting component includes one or more of plasticizers, stabilizers, antioxidants, anti-aging agents, anti-UV agents, degrading agents, lubricants, foaming agents, antistatic agents, flame retardants, fillers, coupling agents, processing modifiers, nucleating agents, impact modifiers, leveling agents and defoaming agents.

5. Use of the oily structural color pigment ink according to any one of claims 1-4 in screen printing, spraying, inkjet printing or gravure printing.

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