Preparation method of high-performance 3D photonic crystal structural color paint

Abstract

The invention discloses a preparation method of a high-performance 3D photonic crystal structural color coating. The high-performance 3D photonic crystal structural color coating is composed of 1-30 parts by weight of hard 3D photonic crystal toner, 5-45 parts by weight of an active monomer diluent, 50-80 parts by weight of ultraviolet (UV) light-cured resin and 1-5 parts by weight of a photoinitiator. In the preparation process, the 3D photonic crystal toner, the active monomer diluent, the ultraviolet light-cured resin and the photoinitiator are fully mixed at room temperature, and the 3D photonic crystal toner is uniformly dispersed in the ultraviolet light-cured resin. The photonic crystal toner is obtained by crushing a hard photonic crystal film at room temperature, and the hard photonic crystal film is prepared by mediating a shell softener. The prepared 3D photonic crystal structural color paint can provide a durable, stable and bright color for a decorated material in various modes such as spray coating, brush coating, blade coating or dip coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and in particular, relates to a method for preparing a high-performance 3D photonic crystal structural color coating. Background Art

[0002] In recent years, with the continuous improvement of environmental protection standards and the in-depth research on functional materials, structural color materials have gradually become a research hotspot in the fields of coating, decoration and anti-counterfeiting due to their unique optical color rendering effect, light bleaching resistance and long-term stability. The colors of traditional dyes and pigments are easily affected by the environment and fade, which makes it difficult to meet the demand for high-end decorative materials for long-lasting bright colors. Structural color materials based on photonic crystal effects regulate the propagation of light through periodic structures at the micro-nano scale, thereby achieving high brightness, saturation and stable color display, which has obvious green and environmental advantages.

[0003] At present, the research on 3D photonic crystal structural color coatings mainly focuses on the exploration of synthesis mechanism, structural regulation and its optical properties (CN 110079171A). In the existing technologies, most of them first use high temperature, long-term curing or multi-step processing to prepare 3D photonic crystal materials with ideal photonic bandgap effect, and then freeze and break the photonic crystal materials under liquid nitrogen, which not only increases the process complexity and production cost, but also puts forward high requirements on the production environment. At the same time, in the preparation process of structural color coatings, how to achieve efficient and uniform dispersion of photonic crystal color powder pigments in the matrix material (UV light-curing resin) is the key to ensure the optical properties and application stability of the final product. However, the existing preparation process is difficult to take into account the uniform dispersion and structural stability of the pigment at room temperature. There are often problems such as pigment agglomeration, structural destruction, difficulty in controlling the mesh number and difficulty in achieving effective compounding with the resin matrix, which causes microcracks at the interface between the structural color pigment and the resin. Under long-term use or complex environmental conditions, the coating is prone to delamination, cracking and fading. In addition, in practical applications, 3D photonic crystal structural color coatings, especially in the processes of spraying, brushing and scraping, place higher requirements on the interface bonding between the coating and the substrate, the curing speed and the final film quality. Therefore, it is urgent to develop a photonic crystal structural color coating with a simpler preparation method and better comprehensive performance to meet the needs of large-scale industrial applications. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, such as the complicated preparation process of photonic crystal structural color coatings, the uneven distribution of pigments in the coatings, and the poor stability of the formed coatings, the purpose of the present invention is to provide a new preparation method for high-performance 3D photonic crystal structural color coatings; the present invention uses a shell softener to prepare a hard 3D photonic crystal film, which is then crushed at room temperature to form a photonic crystal color powder, and a suitable amount of active monomer diluent, ultraviolet (UV) light-curing resin and photoinitiator to achieve the preparation of 3D photonic crystal structural color coatings. The high-performance 3D photonic crystal structural color coating proposed in the present invention not only simplifies the preparation process, but also greatly improves the dispersibility of the color powder in the resin and the stability of the final coating. The prepared structural color coating can present a bright and stable structural color effect through application methods such as spraying, brushing and scraping, which greatly expands the application prospects of structural color coatings in the field of industrial decoration.

[0005] In the present invention, the high-performance photonic crystal structural color coating is mainly composed of hard 3D photonic crystal color powder, active monomer diluent, ultraviolet (UV) light-curing resin and photoinitiator. The hard 3D photonic crystal color powder is formed by crushing the photonic crystal hard film with excellent optical properties at room temperature. The photonic crystal hard film is based on hard core hard shell microspheres as building units, and is mediated by adding a shell softener, so that uniform film formation can be achieved at room temperature, and then prepared by continuous roller bending, shearing and curing processes. The crushed photonic crystal color powder is mixed with the active monomer diluent, so that it can be evenly dispersed in the light-curing resin, and the preparation of the structural color coating is completed by ultraviolet curing with the addition of an appropriate amount of photoinitiator.

[0006] The technical solution of the present invention is specifically described as follows.

[0007] The present invention provides a method for preparing a high-performance 3D photonic crystal structural color coating, and the specific steps are as follows: (1) Using hard core hard shell microspheres as building units, adding a shell softener to the hard core hard shell microsphere solid powder to make the solid form a uniform film at room temperature, and then subjecting the obtained film to continuous roller bending, shearing and UV curing to obtain a hard photonic crystal film; (2) crushing the hard photonic crystal film at room temperature to obtain photonic crystal color powder; (3) Mixing and stirring the photonic crystal color powder, the active monomer diluent, the ultraviolet light curing resin and the photoinitiator at room temperature to obtain the photonic crystal structural color coating.

[0008] Preferably, in step (1), the hard core hard shell microspheres are prepared by semi-continuous stepwise seed emulsion polymerization or reflux precipitation polymerization; the hard core and hard shell are seeds, hard core and hard shell from the inside to the outside in order; the seeds are selected from one or more of polystyrene, polymethyl methacrylate, silicon dioxide, titanium dioxide or ferroferric oxide; the hard core is composed of inorganic materials, organic polymers or inorganic-organic hybrid materials, wherein when the component is an organic polymer, its glass transition temperature is higher than 50°C; further preferably, the hard core material is selected from a mixture of one or more of polystyrene, polymethyl methacrylate, polyisobutyl methacrylate, polytert-butyl methacrylate, polyisobornyl methacrylate, polyacrylonitrile, silicon dioxide, titanium dioxide and ferroferric oxide; the crosslinking agent selected for the hard core microspheres is a mixture of one or more of divinylbenzene, 1,4-butanediol diacrylate, allyl methacrylate, dipropylene glycol diacrylate and diacetone acryloyl. The hard shell is mainly composed of an organic polymer, and its glass transition temperature is higher than 50°C; further preferably, the hard shell material is selected from one or more of polystyrene, polymethyl methacrylate, polyisobutyl methacrylate, polytert-butyl methacrylate, polyisobornyl methacrylate, polyacrylonitrile, polyacrylic acid, polymethyl acrylate, polytert-butyl methacrylate, polyisobutyl acrylate, polyisobutyl methacrylate, poly2-phenoxyethyl acrylate, poly2-phenoxyethyl methacrylate, polylauryl acrylate, polylauryl methacrylate, polyisodecyl acrylate, polyisodecyl methacrylate, polyisobornyl acrylate, polyhydroxyethyl acrylate, polyhydroxyethyl methacrylate, polyhydroxybutyl acrylate and polyhydroxybutyl methacrylate; more preferably, the hard shell material is selected from any one or more of polyisobutyl methacrylate, polyacrylic acid and polymethyl methacrylate.

[0009] Preferably, in step (1), the shell softener is a polymerizable acrylic acid, acrylic acid ester or methacrylic acid ester monomer; the difference in solubility parameter (δ) between the shell softener adapted to the shell polymer and the shell polymer is generally less than 2; the added shell softener will enter the network of the shell polymer and swell the polymer; after the addition of the shell softener, the glass transition temperature of the shell layer drops significantly, generally below -20 °C. Further preferably, the shell softener is selected from acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, n-octyl acrylate, n-octyl methacrylate, isooctyl acrylate, isooctyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, dicyclopentadiene acrylate, 4-tert-butylcyclohexyl acrylate, diethylene glycol diacrylate, caprolactone acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, ethoxylated trimethylolpropane The shell softener is selected from one or more of triacrylate, tetrahydrofuran acrylate, isoborneol acrylate, o-phenylphenoxyethyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, propylene glycol triacrylate, diethylene glycol phthalate diacrylate, triethylene glycol diacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, lauryl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and dipropylene glycol diacrylate; more preferably, the shell softener is selected from one or more of diethylene glycol diacrylate, diethylene glycol diacrylate and triethylene glycol diacrylate. Preferably, in step (1), firstly, a shell softener is added to the hard core hard shell microsphere solid powder in a mass ratio of 1:4 to 4:1, and the microsphere powder is repeatedly stirred at room temperature until the microsphere powder becomes a viscoelastic solid, and then the viscoelastic solid is calendered with a PET film to obtain a composite film of a "PET / viscoelastic solid / PET" structure, and then the composite film is continuously roller-bent, sheared and UV-cured, and finally the PET film is peeled off to obtain a hard photonic crystal film. Further preferably, the continuous roller bending is performed at room temperature.

[0010] In the above step (2), preferably, the mesh size of the photonic crystal toner is 5-250 mesh; more preferably, the mesh size is 50-150 mesh. The color of the photonic crystal toner is determined by the size of the hard core hard shell microspheres, and the color of the toner can be continuously adjusted between blue and red.

[0011] Preferably, in step (3), in terms of weight parts, the photonic crystal toner comprises 1 to 30 parts by weight, the reactive monomer diluent comprises 5 to 45 parts by weight, the UV curable resin comprises 50 to 80 parts by weight, and the photoinitiator comprises 1 to 5 parts by weight.

[0012] In the above step (3), the photonic crystal toner is first dispersed in a reactive monomer diluent, wherein the reactive monomer diluent is a polymerizable monomer, and the difference in solubility parameter between the monomer and the shell polymer and the UV-curable resin is less than 2. Preferably, the reactive monomer diluent is one or more of an acrylate monomer, a methacrylate monomer or a pyrrolidone monomer; further preferably, the reactive monomer diluent is selected from N-vinyl pyrrolidone, dicyclopentadiene acrylate, 4-tert-butyl cyclohexyl acrylate, diethylene glycol diacrylate, caprolactone acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, ethoxylated trimethylolpropane triacrylate, tetrahydrofuran acrylate, isoborneol acrylate, o-phenylphenoxyethyl acrylate, 2-phenoxyethyl acrylate, 1,6-hexanediol diacrylate, dimethacrylate, 1,6-hexanediol di ... The invention can be selected from the group consisting of tripropylene glycol diacrylate, trimethylolpropane triacrylate, glycerol triacrylate, diethylene glycol phthalate diacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, lauryl alcohol methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and dipropylene glycol diacrylate; more preferably, the active monomer diluent is selected from the group consisting of tetrahydrofuran acrylate, isobornyl acrylate, vinyl pyrrolidone and lauryl alcohol methacrylate.

[0013] In the above step (3), the active monomer diluent containing the photonic crystal color powder is added to the UV light-curing resin. Preferably, the light-curing resin is aliphatic polyurethane acrylate; further preferably, the UV light-curing resin is selected from one or more of 2423, 2421, 6200, 6201, 6205, 6206, 6210, 6211, 6280, 6298, 6300, 6310, 6350, 6370, 6380, 6390, 6410, 6411, 6460, 6600, 6601, 6606, 6901, 6902, 8400, 8402, 8403, 9678.

[0014] In the above step (3), a photoinitiator is added to the coating so as to achieve efficient photocuring by UV light; preferably, the photoinitiator is one or more of hydroxy ketone, phenylacetic acid aldehyde ester, benzyl dimethyl ketal, amino ketone and metallocene; more preferably, the photoinitiator is one or more of 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, benzophenone, 2-hydroxy-2-methyl-1-phenylpropanone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methylpropanone, methyl benzoylformate, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone and bis[2,6-difluoro-3-(1H-pyrrole)phenyl]titanium.

[0015] The present invention also provides a high-performance 3D photonic crystal structure color coating prepared by the above-mentioned preparation method; in terms of weight parts, it is composed of 1 to 30 parts by weight of photonic crystal color powder, 5 to 45 parts by weight of active monomer diluent, 50 to 80 parts by weight of ultraviolet light curing resin and 1 to 5 parts by weight of photoinitiator.

[0016] In the present invention, the high-performance 3D photonic crystal structural color effect coating can be applied to the substrate by spraying, brushing, scraping or dipping, and after UV light curing, a bright, uniform and weather-resistant structural color effect coating is formed on the decorated surface. The light curing time is 1 to 30 seconds.

[0017] As described above, the present invention can achieve uniform dispersion of structural color powder in resin at room temperature, thereby forming a bright and stable structural color effect on the surface of the decorated material; compared with the prior art, the present invention has the following beneficial effects: (1) Preparation at room temperature, simplified process and energy saving The present invention adopts a method of preparing a hard photonic crystal film at room temperature and directly crushing it to form a photonic crystal color powder, avoiding complex processes such as high-temperature curing, multi-step processing, and liquid nitrogen freezing in traditional processes, thereby greatly reducing production energy consumption and costs, while simplifying the production process and improving the environmental friendliness and industrial adaptability of the process.

[0018] (2) The dispersion of structural color pigments and the stability of the resulting coatings are significantly improved The hard photonic crystal film is prepared by the shell softener, and the mesh size of the photonic crystal color powder formed at room temperature is highly controllable. After being uniformly mixed with the active monomer diluent and UV curing resin, it not only effectively prevents the agglomeration and structural damage of the structural color pigment, but also enhances the interface bonding force between the coating and the substrate, ensuring a long-lasting and stable structural color effect, and avoiding the micro cracks, delamination and fading problems that are easy to occur in traditional technologies.

[0019] (3) Fast curing speed and wide application range By using an appropriate amount of photoinitiator and a photocurable resin system, the present invention realizes rapid UV curing of photonic crystal structural color coatings, significantly shortening the production cycle. At the same time, the structural color effect coating can be applied to different substrates by spraying, brushing, scraping and dipping. The formed coating is not only bright in color and has excellent optical properties, but also has good weather resistance and light bleaching resistance, meeting the requirements of high-end decoration and anti-counterfeiting and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Field emission scanning electron microscopy (FESEM) images of hard core-shell particles.

[0021] Figure 2 Application photos of high-performance 3D photonic crystal structural color effect coatings.

[0022] Figure 3 Stability test of coatings formed by high-performance 3D photonic crystal structural color effect coatings.

[0023] Figure 4 Differential scanning calorimetry (DSC) curves of hard core hard shell microsphere powder and after adding shell softener.

[0024] Figure 5 Macroscopic photograph of the coating formed by high-performance 3D photonic crystal structural color effect coating.

[0025] Figure 6 Structural color coating formed by coatings formulated with different shell softeners and active diluents. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solution of the present invention in conjunction with specific embodiments, so that relevant technical personnel in the field can have a more comprehensive understanding of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. It should be pointed out that the protection scope of the present invention cannot be limited by this. For professional and technical personnel, without departing from the implementation principle of the present invention, several improvements and changes can be made, and these improvements and changes should also be covered by the protection scope of the embodiments of the present invention.

[0027] Example 1

[0028] This embodiment provides a high-performance 3D photonic crystal structure color effect coating and a preparation method thereof, wherein the color of the synthesized photonic crystal toner is green, and the synthesis method of the hard core hard shell microspheres can adopt the semi-continuous stepwise seed emulsion polymerization method adopted in CN 115183900 B, and the monomer polymerized into the shell layer is selected as isobutyl methacrylate to obtain hard core hard shell microspheres with a particle size of about 200 nanometers ( Figure 1), the monodispersity index is less than 0.05. The prepared hard core hard shell microsphere emulsion is spray dried to obtain a solid powder, which is used as a raw material for preparing structural color effect coatings. The specific preparation process of high-performance 3D photonic crystal structural color effect coatings is as follows: Step 1: Add 50 parts by weight of shell softener diethylene glycol diacrylate to 50 parts by weight of hard-core hard-shell microsphere solid powder, and stir repeatedly until the microsphere powder becomes a viscoelastic solid; further, the viscoelastic solid and PET film are calendered to obtain a composite film (PET / viscoelastic solid / PET), and the obtained composite film is subjected to continuous roller bending, shearing and curing to obtain a photonic crystal film with excellent properties.

[0029] Step 2: Peel off the prepared photonic crystal film from the PET film, then put them into a blender and crush them at room temperature, and sieve the photonic crystal toner with sieves of different mesh sizes to obtain photonic crystal toners of different mesh sizes.

[0030] Step 3: Select 15 parts by weight of 100-mesh 3D photonic crystal color powder and add it to 20 parts by weight of tetrahydrofuran acrylate, and stir well; then add the tetrahydrofuran acrylate containing the color powder to 70 parts by weight of 9-functionality resin 2421, stir to make the color powder evenly dispersed, and finally add 1 part by weight of photoinitiator 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide to complete the preparation of 3D photonic crystal structural color effect coating.

[0031] Step 4: Apply the obtained structural color coating to the object by brushing, and use a 365 nm ultraviolet lamp to irradiate for 3 seconds to complete the photocuring ( Figure 2 ).

[0032] The obtained coating was subjected to performance tests, including solvent resistance and related stability performance tests. The test results showed that the obtained coating had good stability ( Figure 3 ).

[0033] Example 2

[0034] The implementation process of the 3D photonic crystal structural color coating provided in this embodiment is the same as that of Example 1, except that in the preparation of the hard core hard shell particles, the hard core is a silica microsphere synthesized by the Stöber method, and the hard shell is coated on the hard core by reflux precipitation, and the main component is polyisobutyl methacrylate. The synthesis method can be based on the reflux precipitation polymerization used in CN 118271895A and CN116376323A. The core-shell microsphere solid can be obtained by freeze drying.

[0035] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0036] Example 3

[0037] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that of embodiment 1, except that in the preparation of hard core hard shell particles, the diameter of the hard core hard shell particles obtained is 183 nanometers, and the monodispersity index is 0.02. The color of the toner prepared by using microspheres of this particle size is blue.

[0038] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0039] Example 4

[0040] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that of embodiment 1, except that in the preparation of hard core hard shell particles, the diameter of the hard core hard shell particles obtained is 233 nanometers, and the monodispersity index is 0.04. The color of the toner prepared by using microspheres of this particle size is red.

[0041] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0042] Example 5

[0043] The implementation process of the 3D photonic crystal structural color coating provided in this embodiment is the same as that of Example 1, except that in the preparation of hard core hard shell particles, the hard core hard shell particles obtained have a hard shell composed of a copolymer of polyisobutyl methacrylate, polyacrylic acid and polymethyl methacrylate.

[0044] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0045] Example 6

[0046] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that of Example 1, except that in step 1, 30 parts by weight of shell softener is mixed with 70 parts by weight of hard core hard shell microsphere powder.

[0047] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0048] Example 7

[0049] The implementation process of the 3D photonic crystal structural color coating provided in this embodiment is the same as that of Embodiment 1, except that in step 1, the shell softener added is a mixture of diethylene glycol phthalate diacrylate and triethylene glycol diacrylate.

[0050] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0051] Example 8

[0052] The implementation process of the 3D photonic crystal structural color coating provided in this embodiment is the same as that of Example 1, except that in step 3, 15 parts by weight of 50-mesh 3D photonic crystal color powder is added to 20 parts by weight of tetrahydrofuran acrylate and stirred evenly.

[0053] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0054] Example 9

[0055] The implementation process of the 3D photonic crystal structural color coating provided in this embodiment is the same as that of Example 1, except that in step 3, 15 parts by weight of 150 mesh 3D photonic crystal color powder is added to 20 parts by weight of tetrahydrofuran acrylate and stirred evenly.

[0056] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0057] Example 10

[0058] The implementation process of the 3D photonic crystal structural color coating provided in this embodiment is the same as that of Example 1, except that in step three, 15 parts by weight of 100-mesh 3D photonic crystal color powder is added to 20 parts by weight of isobornyl acrylate and stirred thoroughly.

[0059] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0060] Embodiment 11

[0061] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that of Example 1, except that in step three, 15 parts by weight of 100-mesh 3D photonic crystal color powder is added to 20 parts by weight of vinyl pyrrolidone and stirred evenly.

[0062] The stability of the prepared 3D photonic crystal structural color coating is the same as that in Example 1.

[0063] Example 12

[0064] The implementation process of the 3D photonic crystal structural color coating provided in this embodiment is the same as that of Embodiment 1, except that in step 3, 15 parts by weight of 100-mesh 3D photonic crystal color powder is added to 20 parts by weight of lauryl methacrylate and stirred evenly.

[0065] The stability of the prepared 3D photonic crystal structural color coating is the same as that in Example 1.

[0066] Example 13

[0067] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that of embodiment 1, except that in step 3, tetrahydrofuran acrylate containing photonic crystal color powder is added to 70 parts by weight of 2423 resin.

[0068] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0069] Embodiment 14

[0070] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that of Example 1, except that in step 3, tetrahydrofuran acrylate containing photonic crystal color powder is added to 50 parts by weight of 2423 resin and 20 parts by weight of 9678 resin.

[0071] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0072] Embodiment 15

[0073] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that of Example 1, except that in step three, 2.5 parts by weight of photoinitiator 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide is added to the prepared color powder coating.

[0074] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0075] Example 16

[0076] The implementation process of the 3D photonic crystal structure color coating provided in this embodiment is the same as that in Example 1, except that in step three, 1 part by weight of photoinitiator 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide and 1 part by weight of 1-hydroxycyclohexyl phenyl ketone are added to the prepared color powder coating.

[0077] The stability of the prepared 3D photonic crystal structure color coating is the same as that in Example 1.

[0078] Embodiment 17

[0079] The implementation process of the 3D photonic crystal structure color paint provided in this embodiment is the same as that of Embodiment 1, except that in step 4, the 3D photonic crystal structure color paint is sprayed on the decorated object by spraying.

[0080] The stability of the prepared 3D photonic crystal structure color coating is the same as that of Example 1.

[0081] Performance test of high-performance 3D photonic crystal structural color coatings: Coating stability test: The 3D photonic crystal coating obtained in Example 1 was placed in pH = 1, pH = 13, and organic solvents (tetrahydrofuran, acetone, dioxane, dimethylformamide) for 1 minute each, and then subjected to brushing, rubbing, and knocking continuity tests. The test results showed that the optical properties and dimensions of the coating did not change ( Figure 3 ).

[0082] Differential Scanning Calorimetry Test: The hard core hard shell microsphere solid powder obtained in Example 1 was used for differential scanning calorimetry test. The results showed that the glass transition temperature of the hard core was 110°C and the glass transition temperature of the hard shell was 62°C. Figure 4 a.

[0083] Furthermore, the glass transition temperature of the core-shell microsphere solid was tested after adding the shell softener diethylene glycol diacrylate. The results showed that the glass transition temperature of the hard shell was -25 °C. Figure 4 b.

[0084] Structural color coating appearance: Take photos to record the coating colors formed by the green / blue / red three-color photonic crystal coatings obtained in Example 1, Example 3 and Example 4 ( Figure 5 ).

[0085] Appearance of structural color coatings formed by different shell softeners and active diluents: Take photos to record the coating colors formed by the structural color photonic crystal coatings obtained in Example 7 and Example 11 ( Figure 6 ).

[0086] Comparative Example 1

[0087] The 3D photonic crystal structural color coating was prepared by a method substantially the same as that in Example 1, except that when synthesizing the core-shell microspheres, the shell layer was mainly composed of polybutyl acrylate having a glass transition temperature of -40°C.

[0088] The prepared photonic crystal film cannot be broken into powder well at room temperature.

[0089] Comparative Example 2

[0090] The 3D photonic crystal structural color coating was prepared by a method substantially the same as that in Example 1, except that the shell softener used was ethyl acetate.

[0091] The prepared photonic crystal film has poor optical properties and is whitish in overall color.

[0092] Comparative Example 3

[0093] The 3D photonic crystal structural color coating was prepared by a method substantially the same as that in Example 1, except that tetrahydrofuran was selected as the diluent.

[0094] Many bubbles appear in the prepared 3D photonic crystal structural color coating.

[0095] As mentioned above, the structural color coating of the present invention can be applied to the substrate by spraying, brushing, scraping or dipping, and after UV light curing, a bright, uniform and weather-resistant structural color coating is formed on the decorated surface. Compared with traditional coatings, the structural color coating not only avoids the problem of easy fading of dyes and pigments in traditional coatings, but also uses the photonic crystal structure to regulate the interference effect of light, so that the presented color has higher stability. In summary, the present invention realizes the efficient preparation of high-performance 3D photonic crystal structural color coatings.

Claims

1. A method for preparing a high-performance 3D photonic crystal structural color coating, characterized in that: The specific steps are as follows: (1) Using hard core hard shell microspheres as building units, adding a shell softener to the hard core hard shell microsphere solid powder to make the solid powder uniformly form a film at room temperature, and then bending, shearing and curing the obtained film through continuous rollers to obtain a hard photonic crystal film; (2) crushing the hard photonic crystal film at room temperature to obtain photonic crystal color powder; (3) Mixing and stirring the photonic crystal color powder, the active monomer diluent, the ultraviolet light curing resin and the photoinitiator at room temperature to obtain the photonic crystal structural color coating.

2. The preparation method according to claim 1, characterized in that: In step (1), the hard core hard shell microspheres are prepared by semi-continuous stepwise seed emulsion polymerization or reflux precipitation polymerization, with a monodispersity index of less than 0.05 and a size between 120 nanometers and 400 nanometers; the hard core and the hard shell are seeds, hard core and hard shell from the inside to the outside; the seeds are selected from one or more of polystyrene, polymethyl methacrylate, silicon dioxide, titanium dioxide or ferrosoferric oxide; the hard core is composed of inorganic materials, organic polymers or inorganic-organic hybrid materials, wherein when the component is an organic polymer, its glass transition temperature is higher than 50°C; the hard shell is mainly composed of organic polymers, and its glass transition temperature is higher than 50°C.

3. The preparation method according to claim 1, characterized in that: In step (1), the shell softener is an acrylate or methacrylate monomer.

4. The preparation method according to claim 1, characterized in that: In step (1), a shell softener is first added to the hard core hard shell microsphere solid powder in a mass ratio of 4:1 to 1:4, and the microsphere powder is repeatedly stirred at room temperature until the microsphere powder becomes a viscoelastic solid, and the difference in solubility parameter δ between the shell softener adapted to the shell polymer and the shell polymer is less than 2; then the viscoelastic solid and the PET film are calendered to obtain a composite film with a "PET / viscoelastic solid / PET" structure, and then the composite film is continuously roller bent, sheared and UV cured at room temperature, and finally the PET film is peeled off to obtain a hard photonic crystal film.

5. The preparation method according to claim 1, characterized in that: In step (2), the mesh size of the photonic crystal color powder is 5 mesh to 250 mesh.

6. The preparation method according to claim 1, characterized in that: In step (3), according to the weight parts, the photonic crystal color powder is 1 to 30 parts by weight, the active monomer diluent is 5 to 45 parts by weight, the ultraviolet light curing resin is 50 to 80 parts by weight, and the photoinitiator is 1 to 5 parts by weight.

7. The preparation method according to claim 1, characterized in that: The reactive monomer diluent is a polymerizable monomer, and the difference in solubility parameter between the monomer and the shell polymer and the UV curable resin is less than 2.

8. The preparation method according to claim 1, characterized in that: In step (3), the active monomer diluent is one or more of an acrylate monomer, a methacrylate monomer or a pyrrolidone monomer, the UV-curable resin is an aliphatic polyurethane acrylate, and the photoinitiator is one or more of a hydroxy ketone, a phenylacetic acid aldehyde ester, a benzyl dimethyl ketal, an amino ketone or a metallocene.

9. A high-performance 3D photonic crystal structural color coating prepared according to the preparation method of claim 1.

Images