阅读说明：本技术 一种可制备全息彩色图案的材料及其制备方法和应用 (Material capable of preparing holographic color pattern and preparation method and application thereof ) 是由 洪炜 于 2020-04-28 设计创作，主要内容包括：本发明公开了一种可制备全息彩色图案的材料及其制备方法和应用。所述材料由光敏性基团和聚合物接枝形成,其中光敏性基团占材料的质量分数为1～25％,所述光敏性基团的结构如式(Ⅰ)所示；其中所述聚合物的分子链上含有可与羟基反应的基团,选自聚氨酯、环氧树脂、聚丙烯酸、聚丙烯酸丁酯、聚苯乙烯、聚甲基丙烯酸甲酯、聚氨酯、聚酰胺酸或聚酰亚胺中的一种或多种。本发明所述材料可在多种基底材料表面形成带有图案、具有二维凹凸结构的薄膜,在透射光或者反射光下由于衍射效应,观察到明显的彩虹色图案,且图案颜色有强烈的角度依赖性,具有幻彩的效果；另外,所述材料的制备简单、基底适用性广,在防伪、装饰等领域具有广阔的应用前景。<Image he="386" wi="477" file="DDA0002472176460000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention discloses a material capable of preparing holographic colorful patterns and a preparation method and application thereof. The material is formed by grafting a photosensitive group and a polymer, wherein the photosensitive group accounts for 1-25% of the material by mass, and the structure of the photosensitive group is shown as a formula (I); wherein the molecular chain of the polymer contains a group capable of reacting with hydroxyl, and the group is selected from one or more of polyurethane, epoxy resin, polyacrylic acid, polybutyl acrylate, polystyrene, polymethyl methacrylate, polyurethane, polyamic acid or polyimide. The material of the invention can be used inThe film with patterns and a two-dimensional concave-convex structure is formed on the surfaces of various substrate materials, obvious rainbow color patterns are observed under transmitted light or reflected light due to the diffraction effect, and the pattern color has strong angle dependence and has the effect of magic color; in addition, the material is simple to prepare, the substrate has wide applicability, and the material has wide application prospect in the fields of anti-counterfeiting, decoration and the like.)

1. The material capable of preparing the holographic color pattern is characterized by being formed by grafting a photosensitive group and a polymer, wherein the photosensitive group accounts for 1-25% of the material by mass, and the structure of the photosensitive group is shown as the formula (I):

wherein R is₁、R₂、R₃、R₄、R₅Each independently is hydrogen, halogen, hydroxyl, aldehyde group, C_1～4Alkyl radical, C_1～2Amide, C_1～4Ether radical, C_1～4Ester group, C_1～4A keto or monocyclic aromatic substituent;

wherein the molecular chain of the polymer contains a group capable of reacting with hydroxyl, and the group is selected from one or more of polyurethane, epoxy resin, polyacrylic acid, polybutyl acrylate, polystyrene, polymethyl methacrylate, polyurethane, polyamic acid or polyimide.

2. The material for preparing holographic color pattern according to claim 1, wherein the photosensitive group accounts for 5-10% of the material by weight.

3. Holographic color pattern preparable material as claimed in claim 1, wherein R is₁、R₂、R₃、R₄、R₅Each independently hydrogen, halogen, hydroxyl, formaldehyde, methyl, ethyl, formamide, C_1～4Ether radical, C_1～4Ester group, C_1～4A keto or monocyclic aromatic substituent; the polymer is selected from one or more of polyurethane, epoxy resin or polyacrylate.

4. Use of a material as claimed in claims 1 to 3 for the production of holographic color images.

5. A method for preparing a holographic color image is characterized by comprising the following steps: the material capable of preparing holographic color pattern as claimed in any one of claims 1 to 3 is used as photosensitive paint, which is prepared into solution and coated on the base material to form a layer of photosensitive film, and then a layer of ultraviolet light-permeable mask plate with target image in raster shape is covered; then forming a pattern on the surface of the film by ultraviolet irradiation; and finally, soaking the film with the pattern in a solution containing metal ions to form a grating structure on the surface of the film, and cleaning to obtain the holographic color image.

6. The method for preparing the holographic color image according to claim 5, wherein the width of an exposure line in a grating structure of the target pattern in the mask is 50-5000 nm, and the grating period is 50-5000 nm.

7. The method for preparing a holographic color image according to claim 5, wherein the wavelength of the ultraviolet light is 100 to 400 nm.

8. The method of claim 5, wherein the metal ion is an ion capable of complexing with the photosensitive group of formula (I).

9. The method for preparing a holographic color image according to claim 8, wherein the interval of the grating structures formed on the surface of the film is 0.5 to 10 μm, and the height is 20 to 50 nm.

10. Use of the holographic color image produced according to any of claims 5 to 9 as a holographic security label.

Technical Field

The invention relates to the technical field of optical anti-counterfeiting, in particular to a material capable of preparing holographic colorful patterns and a preparation method and application thereof.

Background

The micron-scale grating structure can enable the material to show vivid rainbow color through transmitted light or reflected light, and the generated structural color has the advantages of difficulty in counterfeiting, fastness and the like compared with dye color. Holographic anti-counterfeiting labels based on grating structures are widely applied to outer packaging of daily consumer products such as medicines, cigarettes, wines and the like, but the traditional grating structures usually utilize preparation methods such as nano-imprinting and laser engraving, the substrate selectivity is low, the holographic anti-counterfeiting labels can only be basically suitable for plastic films plated with aluminum, and the products are also almost opaque due to the existence of metal coating films on the bottom layers.

Based on the limitation of the existing micron-scale grating structure in preparation, a material which has wide base adaptability and is easy to prepare into the micron-scale grating structure is provided, so that the popularization and the application of the holographic anti-counterfeiting label are facilitated.

Disclosure of Invention

Aiming at the problems of the traditional method in the manufacture of holographic color patterns (holographic anti-counterfeiting labels), the invention provides a material capable of preparing holographic color patterns. The base material of the material capable of preparing the holographic color pattern has high adaptability, can be suitable for all base materials adhered by the coating, is simple to prepare, can be quickly and simply prepared into the holographic color pattern, and can be applied as a holographic anti-counterfeiting label.

It is another object of the present invention to provide the use of said material for the preparation of holographic color patterns.

Still another object of the present invention is to provide a method for preparing a holographic color image.

The invention also aims to provide application of the holographic color image as a holographic anti-counterfeiting label.

The above object of the present invention is achieved by the following scheme:

a material capable of preparing holographic color patterns is formed by grafting photosensitive groups and polymers, wherein the photosensitive groups account for 1-25% of the material by mass, and the photosensitive groups have the structures shown in the formula (I):

wherein R is₁、R₂、R₃、R₄、R₅Each independently is hydrogen, halogen, hydroxyl, aldehyde group, C_1～4Alkyl radical, C_1～2Amide, C_1～4Ether radical, C_1～4Ester group, C_1～4A keto or monocyclic aromatic substituent; wherein the molecular chain of the polymer contains a group capable of reacting with hydroxyl, and the group is selected from one or more of polyurethane, epoxy resin, polyacrylic acid, polybutyl acrylate, polystyrene, polymethyl methacrylate, polyurethane, polyamic acid or polyimide.

In the material for preparing holographic color patterns, the structure of a grafted photosensitive group and a polymer is shown as a formula (II):

the formula (II) shows that the photosensitive group is grafted on the branched chain of the polymer, and the grafting ratio can be adjusted. Wherein, the grafting of the photosensitive group and the compound can be carried out by means of blending or chemical grafting. Taking a polymer as an example of polyamic acid, the preparation process of the holographic color pattern material is as follows:

wherein x: y is in the range of 10: 1 to 100: 1.

Adding 4, 4' -biphenyldiamine and biphenyldiamine containing photosensitive groups into equipment provided with a mechanical stirring and inert gas protection device, adding anhydrous N-methyl pyrrolidone, stirring and dissolving at 0-25 ℃, then adding pyromellitic dianhydride into the materials at one time, continuously stirring and reacting to obtain a photosensitive polyamic acid solution after the reaction is finished, and separating to obtain the photosensitive polyamic acid.

Wherein after the photosensitive group in the material is oxidized and reduced (after being irradiated by ultraviolet light), the structure of the material is shown as a formula (III):

preferably, the photosensitive group accounts for 5-10% of the material by mass.

Preferably, said R is₁、R₂、R₃、R₄、R₅Each independently hydrogen, halogen, hydroxyl, formaldehyde, methyl, ethyl, formamide, C_1～4Ether radical, C_1～4Ester group, C_1～4A keto group or a monocyclic aromatic substituent.

Preferably, said R is₁、R₂、R₃Each independently hydrogen, methyl ester (-COOCH)₃) An ethyl ester group, a formamide or a formaldehyde group; r₄Is hydrogen, methyl or methoxy; r₅Is hydrogen.

Preferably, the photosensitive group has a structure represented by any one of the following structural formulas:

preferably, the polymer is selected from one or more of polyurethane, epoxy resin or polyacrylate.

Preferably, the group capable of reacting with hydroxyl on the molecular chain of the polymer is one or more of carboxyl, amino, acyl halide, acid anhydride, aldehyde or alkyl halide group.

The invention also protects the application of the material capable of preparing the holographic color pattern in preparing the holographic color image.

The invention also provides a preparation method of the holographic color image, which comprises the following steps: the material capable of preparing the holographic color pattern is photosensitive coating, is prepared into solution and is coated on a base material to form a layer of photosensitive film, and then a layer of ultraviolet light-permeable mask plate with a target image in a grating shape is covered; then forming a pattern on the surface of the film by ultraviolet irradiation; and finally, soaking the film with the pattern in a solution containing metal ions to form a grating structure on the surface of the film, and cleaning to obtain the holographic color image.

Preferably, the thickness of the photosensitive film formed on the surface of the substrate material is 3-300 μm.

Preferably, after the photosensitive coating solution is coated on the base material, the solvent is removed, and a photosensitive film is formed on the surface of the base material. Wherein the solvent can be removed by a method conventional in the art, such as a blast heating treatment, etc.

Preferably, the width of an exposure line in a grating structure of a target pattern in the mask plate is 50-5000 nanometers, and the grating period is 50-5000 nanometers.

More preferably, the width of the exposure line in the grating structure is 1000-2000.

Preferably, the wavelength of the ultraviolet light is 100-400 nanometers.

More preferably, the wavelength of the ultraviolet light is 365 nm.

Preferably, the metal ion is an ion that can be complexed with a photosensitive group of formula (i).

Preferably, the metal ions are divalent palladium ions, silver ions, and divalent copper ions. More preferably, the metal ions are divalent copper ions.

After the photosensitive coating is irradiated by ultraviolet light, pyridine rings in photosensitive groups of the photosensitive coating undergo redox reaction and then are complexed with metal ions. Therefore, when the film is soaked in the metal ion solution, metal ions in the solution can be selectively adsorbed on the area irradiated by ultraviolet light on the film to cause the exposure area in the shape of the grating to form a concave-convex structure, so that an obvious rainbow color pattern is observed under transmitted light or reflected light due to the diffraction effect, and the pattern color has strong angle dependence and has the effect of fantasy color.

Preferably, the interval of the grating structures formed on the surface of the film is 0.5-10 μm, and the height is 20-50 nm. More preferably, the interval of the grating structure is 1-3 μm, and the height is 30 nm.

Variations in the spacing and height of the grating structures have an effect on the depth of the holographic color of the pattern produced, but within the above ranges, holographic color patterns can be obtained.

The spacing width in the grating structure on the surface of the holographic color pattern can be adjusted by adjusting the spacing distance in the grating on the mask plate, and the height can be adjusted by the ultraviolet irradiation time.

Preferably, the time of ultraviolet irradiation is 3 to 15 minutes.

Preferably, the soaking time in the metal ion solution is 15-60 seconds.

Preferably, after soaking in the metal ion solution, the cleaning process is performed by washing with an ethanol solution.

The holographic color image prepared by the method is applied as a holographic anti-counterfeiting label.

Compared with the prior art, the invention has the following beneficial effects:

the material capable of preparing the holographic color pattern is formed by grafting a photosensitive group and a polymer, and can be coated on the surfaces of various substrate materials, so that the substrate materials have wide applicability; after the photosensitive film is irradiated by ultraviolet light, pyridine rings in photosensitive groups of the photosensitive film undergo redox reaction, and the reacted groups can be complexed with metal ions, so that a grating-shaped concave-convex structure is formed on the surface of the photosensitive film, an obvious iridescent pattern is observed under transmitted light or reflected light due to diffraction effect, and the pattern color has strong angle dependence and has the effect of fantasy color.

When the materials capable of preparing the holographic color pattern adopt different polymers, a transparent photosensitive film can be prepared, so that the bottom film of the holographic color pattern is transparent. The transparent holographic substrate can be suitable for reflected light holography and transmitted light holography, and has the advantages which are not possessed by the common metal-coated holographic anti-counterfeiting label.

The holographic color image has clear patterns, bright and rich colors, presents rainbow colors, has simple preparation method and wide substrate applicability, and has wide application prospect in the fields of anti-counterfeiting, decoration and the like.

Drawings

FIG. 1 is a holographic color pattern prepared using photosensitive polyamic acid in example 1.

Fig. 2 is an atomic force microscope picture of a holographic color pattern surface grating structure prepared using photosensitive polyamic acid in example 1.

FIG. 3 is a holographic color pattern prepared using photosensitive polyamic acid in example 2.

FIG. 4 is a holographic color pattern prepared using photosensitive polyamic acid in example 3.

Detailed Description

The present invention is further described in detail below with reference to specific examples, which are provided for illustration only and are not intended to limit the scope of the present invention. The test methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are, unless otherwise specified, commercially available reagents and materials.