WO2022179358A1 - Color-changing crack paint film and preparation method therefor - Google Patents

Abstract

The present invention relates to a color-changing crack paint film attached to a substrate. The substrate has a first surface and a second surface. The paint film comprises a color-changing layer and a transparent crack layer. The first surface is provided with the color-changing layer which changes in various colors as the outside temperature changes and the transparent crack layer. The paint film combines the advantages of the transparent crack layer and the color-changing layer which changes colors as the outside temperature changes. The transparent crack layer can fully highlight various color changes of the bottom layer, and the space separated by the transparent crack layer will produce a dreamy three-dimensional feeling brought about by the color-changing effect. Further specifically provided is a method for preparing a color-changing crack paint formed by combining a UV transparent crack layer and a temperature-sensitive liquid crystal microcapsule. The color-changing crack paint prepared thereby has a low VOC content, is environmentally friendly, and has advantages such as a relatively high hardness, a relatively strong adhesive force, weather resistance, and acid-base resistance.

Description

A kind of discoloration crack paint film and preparation method thereof

This application claims the priority of the invention patent application whose filing date is February 23, 2021, the application number is CN202110204042.7, and the invention name is "a discolored cracked paint film and its preparation method", the entire contents of which are incorporated by reference in this application.

technical field

The invention relates to the technical field of decoration, in particular to a discolored cracked paint film and a preparation method thereof.

Background technique

With the development of modern coating technology, crack paint is widely favored by people for its natural and changeable texture, beautiful and unique, and good three-dimensional effect, and has gradually become a high-end decorative paint commonly used in the field of surface coating. The traditional crack paint usually uses nitrocellulose as the main resin, which makes the solvent volatilize quickly, and generates large internal stress to promote the cracking of the paint film. At the same time, fillers such as fumed silica are added as cracking agents to promote the shrinkage of the paint film and form uniform cracks. , thereby revealing the primer color at the cracks. This kind of cracked paint generally uses nitro paint as the primer, and also needs nitro varnish to overcoat. During the curing process of the paint film, the volatilization of the solvent is not environmentally friendly. In addition, the comprehensive performance of the nitro paint film is poor, it is easy to age, yellow, poor long-term adhesion, poor weather resistance, high temperature or exposure to the sun is likely to cause the paint to flour and fall off, which greatly limits the single-component nitrocellulose. The use of base crack paint.

And with the improvement of people's living standards, the majority of users will not only be satisfied with common cracked decorative products, but begin to pursue more colorful color changes. Color-changing coatings have entered the public's field of vision, especially the color-changing cracks with special cracks. Lacquer, this kind of crack paint not only has changeable cracks, but also full of three-dimensional artistic beauty. The traditional crack paint has a single color. It only has the base color of the crack and the color of the topcoat itself, but lacks the visual impact brought by the color. The paint surface is opaque and lacks 3D stereoscopic and mirror-like effects, and the traditional crack paint cannot change with the external temperature. A change in color occurs, and the color is monotonous. Therefore, a new type of color-changing crack paint is urgently needed to solve the problems of performance, environmental protection and color change performance.

SUMMARY OF THE INVENTION

In order to overcome the defects of traditional cracked paint, the technical problem to be solved by this application is how to provide a discolored cracked paint film that can significantly improve the sense of layering of color change and colorful discoloration, and a preparation method thereof.

As far as the color-changing cracked paint film is concerned, the method for solving the above-mentioned technical problems of the present application is to provide a color-changing cracked paint film, which is attached to a substrate, and the substrate has a first surface and a second surface; the paint film Including: a color-changing layer, the color-changing layer changes in color with the change of the external temperature, the color-changing layer includes a first macromolecule polymer and a plurality of liquid crystal microcapsules dispersed in the first macromolecule polymer, the The liquid crystal microcapsules include thermotropic liquid crystal; and a transparent crack layer, the transparent crack layer has a plurality of cracks arranged regularly or irregularly; the discoloration layer and the transparent crack layer are arranged on one side of the first surface .

As a further improvement of the present application, the liquid crystal microcapsule includes a core material and a wall material, and the core material is a thermotropic liquid crystal.

As a further improvement of the present application, the wall material is formed by interfacial polymerization of a polybasic acid chloride compound and a polyvalent amine compound.

As a further improvement of the present application, the first macromolecular polymer is water-based acrylic resin, water-based polyurethane, water-based epoxy resin, water-based UV light-curable resin, water-based polyester resin, water-based alkyd resin, water-based amino resin, water-based acrylic resin One or at least two of emulsion, water-based phenolic resin, water-based silicone resin, polyvinyl alcohol, polyester, polyacryl alcohol, polyethylene glycol, polyvinyl pyrrolidone, gelatin, sodium alginate, and chitosan are mutually modified. high molecular weight polymers.

As a further improvement of the present application, the transparent crack layer is a UV transparent crack layer.

As a further improvement of the present application, the pencil hardness range of the color changing layer after curing is H or more.

As a further improvement of the present application, the pencil hardness range of the UV transparent crack layer after curing is above 2H.

As a further improvement of the present application, the glossiness of the transparent crack layer at a test angle of 20 degrees is more than 90%.

As a further improvement of the present application, the components for preparing the UV transparent crack layer include UV resin and photoinitiator.

As a further improvement of the present application, the UV resin is an acrylic monomer or prepolymer and a derivative thereof.

As a further improvement of the present application, the acrylic monomer or prepolymer and its derivatives are epoxy-modified acrylic resin, polyester-modified acrylic resin, fluorine-modified acrylic resin, polyurethane-modified acrylic resin, polyether One or at least two compound products of modified acrylic resin and silicone modified acrylic resin.

As a further improvement of the present application, the substrate is a dark substrate.

As a further improvement of the present application, a dark bottom layer on the first surface and/or the second surface is also included.

As a further improvement of the present application, the components for preparing the dark bottom layer include a second high molecular polymer and a dark dye mixed in the second high molecular polymer, wherein: the second high molecular polymer For polyurethane, solvent-based acrylic resin, water-based acrylic resin, acrylic emulsion, UV light curing resin, epoxy resin, amino resin, saturated polyester resin, unsaturated polyester resin, phenolic resin, alkyd resin, silicone resin One or at least two mutually modified high molecular polymers.

As a further improvement of the present application, the thickness of the color changing layer is 30 μm˜200 μm.

As a further improvement of the present application, the thickness of the transparent crack layer is 30 μm˜200 μm.

As far as the preparation method of the color-changing cracked paint film is concerned, the method for solving the above-mentioned technical problems in the present application is to provide a preparation method of the color-changing cracked paint film, which includes the following steps: S1. After the high molecular polymer is mixed in proportion, fully stirred and uniformly mixed to obtain a color-changing layer coating; S2, preparation of a transparent crack layer coating: after mixing the UV resin and the photoinitiator in proportion, fully stirring and uniformly mixing to obtain a transparent crack layer coating ; S3, the color-changing layer coating is attached to the dark base layer formed on the base material or the base material with a layered structure, dried, and baked to obtain the discoloration formed on the base material or the dark base layer on the base material. layer; S4, the transparent crack layer coating is attached to the discoloration layer with a layered structure, and UV light is cured to obtain a transparent crack layer attached to the discoloration layer; S5, will pass through the base of steps S3, S4 The material is boiled and baked in sequence to obtain a discolored cracked paint film.

As a further improvement of the present application, an auxiliary agent is added to the color-changing layer coating and/or the transparent crack layer coating, and the auxiliary agent is a dispersing agent, a leveling agent, a thickening agent, a wetting agent, a One or at least two adjuvants in combination of foaming agent and deionized water.

As a further improvement of the present application, an adhesion promoter is added to the color-changing layer paint and/or the transparent crack layer paint.

As a further improvement of the present application, the adhesion promoter is one or more of siloxane coupling agent and derivatives thereof, sodium titanate coupling agent and derivatives thereof.

As a further improvement of the present application, the siloxane coupling agent and its derivatives are epoxy-modified siloxane coupling agent, amine-modified siloxane coupling agent, and fluorine-modified siloxane coupling agent At least one of the sodium titanate coupling agent and its derivatives is at least one of an epoxy-modified sodium titanate coupling agent and an amine-modified ammonium titanate coupling agent.

As a further improvement of the present application, before step S5, the step of using a sharp object to score lines on the transparent crack layer and/or the discoloration layer is also included.

As a further improvement of the present application, the substrate includes a first surface and a second surface, and the preparation method further includes forming the dark underlayer on the first surface and/or the second surface.

The beneficial effect of the present application is that the present application provides a discolored cracked paint film, which is attached to a substrate, and the substrate has a first surface and a second surface; the paint film includes: a discolored layer, the discolored The color-changing layer changes with the change of the external temperature, and the color-changing layer includes a first macromolecule polymer and a plurality of liquid crystal microcapsules dispersed in the first macromolecule polymer, and the liquid crystal microcapsules include thermal and a transparent crack layer, the transparent crack layer has a plurality of cracks arranged regularly or irregularly, the discoloration layer and the transparent crack layer are arranged on one side of the first surface. The paint film combines the advantages of a transparent crack layer and a color-changing layer that changes in color with changes in external temperature. The transparent crack layer can perfectly highlight the various color changes of the bottom layer, and the space separated by the transparent crack layer is in the color-changing effect. Under the blessing, it will produce a dreamy three-dimensional sense of space. It also specifically provides a method for preparing a color-changing crack paint composed of a UV transparent crack layer and a temperature-sensitive liquid crystal microcapsule. Excellent adhesion, weather resistance, solvent resistance, acid and alkali resistance, salt resistance, etc. The pencil hardness of the paint surface is as high as 4H.

Description of drawings

Fig. 1 is an embodiment structural representation of discoloration crack paint film;

2 is a schematic diagram of a temperature change state of an embodiment of a discolored cracked paint film;

3 is a schematic diagram of a temperature change state of another embodiment of a discolored cracked paint film;

4 is a schematic diagram of a temperature change state of another embodiment of a discolored cracked paint film;

In the figure: 1, the base material; 2, the dark bottom layer; 3, the discoloration layer; 4, the transparent crack layer, 11, the first surface; 12, the second surface.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the specific embodiments of the present application and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments, and are not intended to limit the scope of the present invention. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Aiming at the technical problem to be solved by this application, how to provide a color-changing cracked paint film that can significantly improve the layering of color changes, and provide a color-changing cracked paint film, as shown in FIG. 1, which is attached to the substrate 1, and the described The substrate 1 has a first surface 11 and a second surface 12; the paint film includes: a color-changing layer 3, and the color-changing layer 3 changes in colorful colors with the change of the external temperature, and the colorful colors include the following colors Variation: red, yellow, green, blue, purple, the color changing layer 3 includes a first macromolecule polymer and a plurality of liquid crystal microcapsules dispersed in the first macromolecule polymer, and the liquid crystal microcapsules include But not limited to thermotropic liquid crystal; and a transparent crack layer 4, the transparent crack layer 4 has a plurality of cracks arranged regularly or irregularly; the discoloration layer 3 and the transparent crack layer 4 are arranged on the first surface On one side of 11 , the discoloration layer 3 is attached to the first surface 11 , and the transparent crack layer 4 is attached to the discoloration layer 3 . As a further preferred embodiment, the liquid crystal microcapsules include a core material and a wall material, and the core material may be but not limited to thermotropic liquid crystal. As a further preferred embodiment, the wall material is formed by interfacial polymerization of a polybasic acid chloride compound and a polyvalent amine compound. Preferably, the polybasic acid chloride compound may be, but not limited to, one of terephthaloyl chloride, isophthaloyl chloride, 1,3,5-benzenetricarboxylic acid chloride, succinyl chloride, oxalyl chloride, and adipoyl chloride or multiple, the polyamine compound is selected from ethylenediamine, butanediamine, hexamethylenediamine, 2,2,4-trimethylhexanediamine, 2,4,4-trimethylhexanediamine, octanediamine One or more of amine, decanediamine, p-phenylenediamine, m-phenylenediamine, diethylenetriamine, and triethylenetetramine.

As a preferred embodiment of the present application, the components for preparing the color-changing layer 3 further include a first macromolecule polymer, and the first macromolecule polymer includes but is not limited to water-based acrylic resin, water-based polyurethane, and water-based epoxy resin , waterborne UV light-curable resin, waterborne polyester resin, waterborne alkyd resin, waterborne amino resin, waterborne acrylic emulsion, waterborne phenolic resin, waterborne silicone resin, polyvinyl alcohol, polyester, polyacryl alcohol, polyethylene glycol, One or at least two mutually modified high molecular polymers among polyvinylpyrrolidone, gelatin, sodium alginate and chitosan. As a preferred embodiment, the pencil hardness range of the color-changing layer 3 after curing is above H, and the pencil hardness range of the color-changing layer is set above H. The purpose is to facilitate the formation of cracks in the later transparent crack layer during boiling or baking. .

As a preferred embodiment of the present application, the transparent crack layer 4 may be, but not limited to, the UV transparent crack layer 4 . As a preferred embodiment, the pencil hardness range of the UV transparent crack layer after curing is above 2H. As a preferred embodiment, the glossiness of the transparent crack layer at a test angle of 20 degrees is more than 90%. The setting of the above preferred solution is conducive to the formation of cracks in the later transparent crack layer during boiling or baking, and is also conducive to discoloration and crack paint. The film exhibits a three-dimensional texture. As a further preferred embodiment, the components for preparing the UV transparent crack layer 4 include UV resin and photoinitiator. As a further preferred embodiment, the UV resin can be, but not limited to, acrylic monomers or prepolymers and derivatives thereof. Preferably, the acrylic monomers or prepolymers and derivatives thereof can be But not limited to one or at least two of epoxy-modified acrylic resin, polyester-modified acrylic resin, fluorine-modified acrylic resin, polyurethane-modified acrylic resin, polyether-modified acrylic resin, and silicone-modified acrylic resin a compound product.

As a preferred embodiment of the present application, the substrate 1 can be a dark-colored substrate, for example, a dark-colored substrate is prepared by mixing a dark-colored dye into the polymer material during the preparation of the substrate, or the paint film A dark base layer 2 on the first surface 11 and/or the second surface 12 may also be included to function as a substrate. Wherein, the dark color can be, but not limited to, black, dark color, dark cyan, dark blue, dark gray, and the like. As a further preferred embodiment, the components for preparing the dark bottom layer 2 include a second high molecular polymer and a dark dye mixed in the second high molecular polymer, wherein: the second high molecular polymer The material can be but not limited to polyurethane, solvent-based acrylic resin, water-based acrylic resin, acrylic emulsion, UV light curing resin, epoxy resin, amino resin, saturated polyester resin, unsaturated polyester resin, phenolic resin, alkyd One or at least two of resins and silicone resins are mutually modified high molecular polymers.

As a preferred embodiment of the present application, the thickness of the color changing layer 3 is 30 μm˜200 μm; the thickness of the transparent crack layer 4 is 30 μm˜200 μm.

The above-mentioned paint film combines the advantages of the transparent crack layer 4 and the discoloration layer 3 that changes in various colors with the change of the external temperature. The transparent crack layer 4 can perfectly highlight the various color changes of the bottom layer, and is separated by the transparent crack layer 4. Under the blessing of the discoloration effect, the open space will produce a dreamy three-dimensional sense of space.

Aiming at the technical problem to be solved by this application, a method for preparing a color-changing cracked paint film that can be combined with multi-colored discoloration effects and can significantly improve the layered sense of color change is provided, comprising the following steps: S1. After the liquid crystal microcapsules and the first macromolecular polymer are mixed in proportion, fully stirred and uniformly mixed to obtain a color-changing layer coating; S2, the preparation of the transparent crack layer coating: after mixing the UV resin and the photoinitiator in proportion, fully stirring and mixing Evenly, a transparent crack layer coating is obtained; S3, the color-changing layer coating is formed in a layered structure on the base material or the dark base layer on the base material, dried and baked to obtain the dark base layer formed on the base material or base material on the discoloration layer; S4, the transparent crack layer coating is attached to the discoloration layer 3 with a layered structure, and UV light is cured to obtain the transparent crack layer 4 attached to the discoloration layer 3; S5, will go through step S3 The substrate 1 of S4 is sequentially boiled and dried to obtain a discolored and cracked paint film. As a preferred embodiment, in step S3, the baking temperature is 40°C to 60°C; as a preferred embodiment, in step S4, the power of the light curing is 6kW; as a preferred embodiment, in step S5 , the boiling temperature is 100 °C, and the boiling time is 1h ~ 2h. After the boiling is completed, take it out immediately, wipe off the water marks, and bake at a temperature of 80 °C ~ 120 °C.

The above preparation method combines the multi-colored color-changing liquid crystal microcapsules with the transparent crack layer 4 with the color changing with the temperature change, which solves the problem of the single color tone of the traditional crack paint. The color-changing layer 3 with liquid crystal microcapsules can change 2-12 colors with temperature changes, and can be adjusted at will within the temperature change range. Transparent crack layer 4, the generation of straight cracks divides the complete coating into different areas, and the transparent crack layer 4 is a UV transparent crack layer 4, and the UV light-cured transparent crack layer 4 produces curved surfaces, and these areas will be due to this. The curved surface makes the whole paint film produce a sense of space like a broken mirror, which can perfectly highlight the various color changes of the bottom layer.

In this application, the reasons for the preferred UV transparent crack layer 4 are mainly as follows: the crack paint is mainly divided into two types: solvent-based and water-based. The traditional solvent-based crack paint is mostly nitro resin, which depends on increasing the amount of pigments and fillers, and controlling the amount of solvent. The volatilization rate, with the help of the self stress of the paint film, the surface of the paint film presents irregular cracks and gaps, so that the underlying color that is different from the color of the cracked paint surface is exposed from the cracks and cracks, thereby cracking into different patterns. However, this method has many defects, not only poor adhesion, but also intolerant of harsh environmental conditions, which will cause the paint surface to peel off in high temperature environment, easy to age under sunlight, and poor weather resistance. And due to the particularity of its solvent-based coatings, the VOC content is high. During the coating process, a lot of irritating odors will be generated with the volatilization of the solvent, which will endanger the environment and the health of construction workers. The application applies UV transparent crack layer 4, which is rapidly cured under UV irradiation, and the internal molecules shrink instantly, resulting in internal stress. Under the action of internal stress, boiling and baking the paint film will cause its molecular shrinkage rate to change. Cracks occur, and the VOC content is low, which is environmentally friendly.

In this application, as a preferred embodiment, an adhesion promoter is added to the color-changing layer coating and/or the transparent crack layer coating; as a further preferred embodiment, the adhesion promoter may be but not only Limited to one or more of siloxane coupling agent and its derivatives, sodium titanate coupling agent and its derivatives; as a further preferred embodiment, the siloxane coupling agent and its derivatives Can be but not limited to at least one of epoxy modified siloxane coupling agent, amine modified siloxane coupling agent, fluorine modified siloxane coupling agent, sodium titanate coupling agent and its The derivative can be, but not limited to, at least one of epoxy-modified sodium titanate coupling agent and amine-modified ammonium titanate coupling agent. The purpose of the adhesion promoter is to enhance the adhesion between the transparent crack layer 4 and the discoloration layer 3 and between the discoloration layer 3 and the substrate 1 .

In the present application, in the above step S1, the liquid crystal microcapsule is mainly composed of a wall material and a core material. The core material can be, but is not limited to, a thermotropic liquid crystal material. As a preferred embodiment, the core material is mainly a cholesteric phase. Liquid crystals mainly include cholesteryl ester liquid crystals and chiral nematic liquid crystals. By adjusting the proportion of liquid crystals and the content of chiral agents, liquid crystal formulations that change color at different temperatures can be prepared; the wall materials are mainly polymer materials, and the polymer materials are Conventional solvent evaporation method, interfacial polymerization method, complex coacervation method or in-situ polymerization method and other microcapsule preparation methods form a wall material on the surface of the core material, which plays the role of stabilizing the core material. In this application, as a preferred embodiment, the wall material is formed by interfacial polymerization of a polybasic acid chloride compound and a polyvalent amine compound. As a further preferred embodiment, the polybasic acid chloride compound may be, but not limited to, terephthalene. One or more of acid chloride, isophthaloyl chloride, 1,3,5-benzenetricarboxylic acid chloride, succinyl chloride, oxalyl chloride, adipoyl chloride, the polyamine compound is selected from ethylenediamine, butanediamine, Hexanediamine, 2,2,4-trimethylhexanediamine, 2,4,4-trimethylhexanediamine, octanediamine, decanediamine, p-phenylenediamine, m-phenylenediamine, diethylene One or more of triamine and triethylenetetramine. The wall material provided by the present application can withstand the processes such as boiling and baking in the preparation process of the transparent crack layer 4, and the wall material formed by the interfacial polymerization of the polybasic acid chloride compound and the polyvalent amine compound has good hardness and can improve the wall thickness. The solvent resistance of the material prevents the penetration of solvents into the core material.

In the present application, in the above step S1, the first polymer can be, but not limited to, water-based acrylic resin, water-based polyurethane, water-based epoxy resin, water-based UV light-curable resin, water-based polyester resin, and water-based alkyd resin. , water-based amino resin, water-based acrylic emulsion, water-based phenolic resin, water-based silicone resin, polyvinyl alcohol, polyester, polypropylene alcohol, polyethylene glycol, polyvinyl pyrrolidone, one or at least two of natural high molecular polymers kind of mutually modified macromolecular polymer, the natural macromolecule can be but not limited to gelatin, sodium alginate, chitosan, etc.; the color-changing layer coating can also include additives, which can be but It is not limited to one or at least two adjuvants in combination of dispersing agent, leveling agent, thickening agent, wetting agent, defoaming agent, deionized water.

In this application, the dispersing agent is mainly used to uniformly disperse the solid and liquid particles of inorganic and organic pigments that are difficult to dissolve in liquids, and at the same time, it can also prevent the particles from settling and agglomerating to form a stable suspension; the leveling agent It is mainly used to promote the coating to form a flat, smooth and uniform film during the drying and film-forming process, which can effectively reduce the surface tension of the coating liquid and improve its leveling and uniformity; the thickener is mainly used to improve The viscosity of the material system keeps the material system in a uniform and stable suspended state or opaque state; the wetting agent is mainly used to reduce the surface energy of the solid material and make it more easily wetted by water; the defoaming agent is mainly It is used to reduce the surface tension of water, solutions, suspensions, etc., to prevent the formation of foam, or to reduce or eliminate the original foam.

In this application, as a preferred embodiment, the color-changing layer coating mainly includes the following components by weight percentage: 10%-30% of liquid crystal microcapsules, 60%-85% of the first macromolecular polymer, auxiliary agent 1 %-5%, adhesion promoter 1%-5%. In the preparation process: preferably, after mixing the liquid crystal microcapsules, the first macromolecular polymer, the auxiliary agent and the adhesion promoter in proportion, use a disperser to disperse at a high speed for 20min-30min at a rotating speed of 400r/min～1000r/min, Stir evenly, and stand at room temperature for 1 h to 2 h to obtain a color-changing layer coating.

In this application, in the above step S2, as a preferred embodiment, the UV resin can be, but not limited to, acrylic monomers or prepolymers and derivatives thereof; as a further preferred embodiment, the acrylic monomers The polymer or prepolymer and its derivatives can be but not limited to epoxy modified acrylic resin, polyester modified acrylic resin, fluorine modified acrylic resin, polyurethane modified acrylic resin, polyether modified acrylic resin, silicone One or at least two compound products of modified acrylic resins. The photoinitiator is a substance that the initiator molecule has a certain light-absorbing ability in the ultraviolet light region (250ˉ400nm) or the visible light region (400ˉ800nm). As a further preferred embodiment of the application, the photoinitiator is a cationic polymerization photoinitiator and a free radical. Photoinitiators, of which cationic polymerization photoinitiators are divided into cracking photoinitiators and hydrogen abstraction photoinitiators. Cationic photoinitiators can be divided into salts, metal organics, and organosilanes, among which iodonium salts, sulfur salts and iron aromatic hydrocarbons are the most representative; cracking initiators absorb the ultraviolet quantum emitted by strong ultraviolet light, thereby triggering Polymerization, cross-linking and grafting reactions make the liquid form a solid film within a fraction of a second, such as 1173, 184, 907, 369, 1490, 1700, etc. Radical photoinitiators include thioxanthone-based photoinitiators, alkyl aryl ketone derivatives, benzophenone-based photoinitiators, benzil-based photoinitiators, and the like. In addition, fluorinated diphenyltitanocene and bis(pentafluorophenyl)titanocene have outstanding photoinitiated activity, storage stability and low toxicity, and their absorption wavelengths have been extended to 500 nm, with larger absorption in the visible region, Visible light initiated polymerization curing for acrylates is particularly effective.

In the present application, in the above-mentioned step S2, as a preferred embodiment, the transparent crack layer coating also includes an auxiliary agent, and the auxiliary agent can be, but not limited to, a dispersant, a leveling agent, a thickening agent, and a wetting agent. , a defoamer, and one or at least two adjuvants in deionized water. As a preferred embodiment, the transparent crack layer coating mainly includes the following components by weight: 70%-90% of UV resin, 2%-30% of photoinitiator, auxiliaries: 0.2%-1%, attached Stress accelerator 1%-4%. In the preparation process: preferably, after mixing the UV grease, photoinitiator, auxiliary agent and adhesion promoter in proportion, use a disperser to disperse at high speed for 20min-30min at a rotating speed of 400r/min～1000r/min, stir evenly, room temperature Standstill for 1h to 2h to obtain a transparent crack layer coating.

In this application, as a preferred embodiment, the substrate includes a first surface and a second surface, and the preparation method further includes forming the dark base layer on the first surface and/or the second surface , such as: before the color-changing layer paint in step S3 is attached to the substrate 1 in a layered structure, a layer of dark primer can also be attached on the first surface 11 of the substrate, and/or on the substrate A layer of dark primer is attached on the second surface 12 of the base material, and the step of attaching the dark primer on the second surface of the substrate layer is not limited by the order of attachment of other functional layers. As a further preferred embodiment, the components of the dark primer include dark paste and a second high molecular polymer; as a further preferred embodiment, the second high molecular polymer can be but not only Limited to polyurethanes, solvent-based acrylic resins, water-based acrylic resins, acrylic emulsions, UV-curable resins, epoxy resins, amino resins, saturated polyester resins, unsaturated polyester resins, phenolic resins, alkyd resins, and silicone resins One or at least two mutually modified high molecular polymers. As a preferred embodiment, the dark primer further includes a resin auxiliary, which can be, but is not limited to, one of a dispersing agent, a leveling agent, a thickening agent, a wetting agent, and a defoaming agent. one or a combination of at least two adjuvants. As a preferred embodiment, the dark primer includes the following components by weight: 60%-85% of the second high molecular polymer, 10%-30% of the dark color paste, and resin auxiliary: 1% -5%, the balance is deionized water. In the preparation process: preferably, after mixing the second high molecular polymer, the dark slurry, the third auxiliary agent and deionized water in proportion, use a disperser to disperse at a high speed for 20min-30min at a rotating speed of 400r/min～1000r/min. , stir evenly, and stand at room temperature for 1 h to 2 h to obtain a dark primer. As a preferred embodiment, the above-mentioned adhesion promoter may also be added to the dark primer.

In this application, as a preferred embodiment, before step S5, it also includes the step of using sharp objects to engrave lines on the transparent crack layer and/or the discoloration layer, and the sharp objects are engraving knives, etc., and the engraving lines The position, size, pattern and trend can be arbitrarily set according to the pattern to be prepared. As a preferred embodiment, in step S3, the thickness of the color changing layer 3 is 30 μm˜200 μm. As a preferred embodiment, in step S4, the thickness of the transparent crack layer 4 is 30 μm˜200 μm. Different from the traditional cracked paint, which needs to control the thickness of the paint film to adjust the crack density, the present invention can rely on the method of adding a score line for artificial control to achieve the expected effect.

In the present application, a color-changing cracked paint film can be prepared from the above-mentioned preparation method of a color-changing cracked paint film, including a color-changing layer 3 and a UV transparent cracked layer 4 that change in colorful colors with external temperature changes. The film is attached to the substrate 1, the substrate 1 includes a first surface 11 and a second surface 12, a discoloration layer 3 and a transparent crack layer 4 are arranged on the first surface 11, and the discoloration layer 3 is prepared. The components include liquid crystal microcapsules. As a preferred embodiment, the color-changing crack paint film may also include a dark-colored bottom layer 2, as shown in FIG. The preparation method of cracked paint film, the specific scheme is as follows:

First, a first layer of dark primer is attached to the first surface 11 of the substrate 1 by a suitable process. After the primer film is dried, the thickness of the primer film can be 10 μm-100 μm, preferably 30 μm. After drying, it is placed in an oven for baking at a temperature of 60°C-100°C and a baking time of 0.5h-2h to obtain a paint film material with a dark bottom layer 2 . Wherein, the substrate 1 is a glass/metal material substrate or resin, the substrate 1 is a transparent or colored substrate, and the attachment process includes but is not limited to coating, spraying, screen printing, and the like.

Next, a second layer of color-changing layer 3 is attached on top of the first layer of dark base layer 2 of the substrate 1 using a suitable process. After the color-changing layer paint film is dried, the color-changing layer paint film thickness may be 30 μm-200 μm, preferably 50 μm. After the surface of the color-changing layer paint film is dried, it is placed in an oven for baking at a temperature of 40°C-60°C and a baking time of 0.5h-2h to obtain a paint film material with a dark bottom layer 2 and a color-changing layer 3.

Thirdly, a third transparent crack layer 4 is attached on the second discoloration layer 3 of the base material 1 using a suitable process. After the paint film of the transparent crack layer is dried, the paint film thickness of the transparent discoloration layer may be 30 μm-200 μm, preferably 50 μm. Place the transparent color-changing layer paint film under the UV curing machine for light curing, the use band is full band, the power is 6kw, after curing, leave it at room temperature for 2-10 days to obtain a dark bottom layer 2, color changing layer 3 and transparent The paint film material of the crack layer 4.

Finally, Option 1: The above three-layer paint film material can be directly boiled in boiling water at 100°C for 1-2 hours. After boiling, take it out immediately, wipe off the water stains, and place it in an oven at 80-120°C for baking. After the baking is completed, the UV layer is cracked, and multiple continuous irregular crack curves appear randomly.

Option 2: The paint film material with the above three-layer paint film can be engraved on the surface of the UV layer with sharp objects such as a carving knife, and the paint film material after the engraving can be placed in boiling water at 100 °C for 1h. -2h. After boiling, take it out immediately, wipe off the water stains, and place it in an oven at 80-120°C for baking. After the baking is completed, the UV layer is cracked, and multiple continuous irregular crack curves appear randomly. Taking a random point on any artificial engraved line as the endpoint, there will be several short cracks 2-3cm long. The denser the scribe lines, the more cracks are produced.

The discolored cracked paint film and its preparation method described in the present application will be described in detail below with reference to specific embodiments.

Example 1

Choose transparent glass plate as base material, decorate discoloration crack paint on this base material, and its preparation steps are as follows:

1. Formulation of dark primer

The components in the dark primer in this example and the weight percentages of each component are shown in Table 1.1:

Table 1.1: Components of dark primer and their weight percentages

composition	name	weight percentage	Manufacturer
dark paste	207TK	10%	Marlboro Ink
Waterborne polyurethane resin	234B	85%	LANXESS Chemicals
lubricant	BYK-333	0.6%	BYK
leveling agent	BYK-381	1.4%	BYK
defoamer	BYK-024	0.50%	BYK
thickener	PS-166	2%	Yuanhe Chemical
Deionized water	Deionized water	0.50%

After mixing the dark slurry, water-based polyurethane resin, resin auxiliary and deionized water in proportion in Table 1.1, disperse at a high speed of 800r/min using a disperser for 20min, stir evenly and let stand for 1h at room temperature to obtain a dark bottom layer Coatings, the resin additives are wetting agent BYK-333, leveling agent BYK-381, defoamer BYK-024 and thickener PS-166 in Table 1.

2. Preparation of color-changing layer paint

Table 1.2 shows the components in the color-changing layer coating that changes in color with temperature changes and the weight percentages of each component:

Table 1.2: Components of the color-changing layer coating and the weight percentage of each component

The core material of the liquid crystal microcapsules described in Table 1.2 is a cholesteric liquid crystal, and the wall material is a gelatin gum arabic mixed wall material prepared by a complex coacervation method, and the temperature change range is 12°C to 35°C;

After mixing the liquid crystal microcapsules, water-based polyurethane resins, resin additives, adhesion promoters, and deionized water in proportions in Table 1.2, disperse them at high speed with a disperser at a speed of 800 r/min for 20 minutes, stir evenly, and place them at room temperature for 1 hour. A color-changing layer coating was obtained, and the resin additives were the wetting agent BYK-333, the leveling agent BYK-381, the defoaming agent BYK-024 and the thickening agent PS-166 in Table 2.

3. Preparation of transparent crack layer coating

The transparent crack layer of this embodiment is set as the UV transparent crack layer, and the components in the UV transparent crack layer coating and the weight percentage of each component are shown in Table 1.3:

Table 1.3: Components of UV transparent crack coating and their weight percentages

Dissolve the photoinitiator TPO and photoinitiator 819 in Table 1.3 in the polyester modified acrylic resin under heating conditions, add a wetting agent and an adhesion promoter and mix, and use a disperser at a speed of 400 r/min. Disperse at high speed for 20 min, stir evenly, and place at room temperature for 1 h to obtain UV transparent crack layer coating.

4. Use a 150μm wire rod to coat a layer of dark primer on the transparent glass. After the surface of the primer film is dry, place it in an oven at 60°C for 20 minutes to obtain a dark primer with a dry film thickness of 30μm.

5. Use a 150 μm wire rod to coat a layer of color-changing layer paint on the dark bottom layer. After the surface of the color-changing layer paint film is dried, place it in an oven at 60°C for 20 minutes to obtain a color-changing layer with a dry film thickness of 30 μm.

6. Use a 100μm wire rod to coat a layer of UV transparent crack layer paint on the discoloration layer, and place the crack layer paint film under a UV curing machine for light curing. The use band is the full band and the power is 6kw. Leave for 2 days.

7. Put the glass substrate coated and maintained in steps 4, 5, and 6 in sequence in boiling water at 100°C for 1 hour. After boiling, take it out immediately, wipe off the water marks, and place it in a Baking in an oven at 100° C., after the baking is completed, cracks appear on the surface of the glass substrate, and a glass plate whose surface is decorated with discoloration crack paint is obtained.

Fig. 2 is a schematic diagram of the surface state of a discolored cracked paint film prepared by the method of Example 1. It can be clearly observed from the figure that in the temperature change range of the liquid crystal microcapsules, because the liquid crystal microcapsules show a colorful state, so , the surface of the glass plate shows a three-dimensional structure state. In the non-temperature-variable range of the liquid crystal microcapsules, because the color of the liquid crystal microcapsules does not appear, the surface of the glass plate only shows a cracked state and a dark bottom color. And in the temperature change range of the liquid crystal microcapsules, the surface of the glass plate will show different color changes with the change of temperature.

Example 2

Choose iron plate as base material, decorate discoloration crack paint on this base material, and its preparation steps are as follows:

1. Formulation of primer

The bottom layer of this example is set to be a dark bottom layer, and the components in the dark primer paint and the weight percentages of each component are shown in Table 2.1:

Table 2.1: Components of dark primer and their weight percentages

composition	name	weight percentage	Manufacturer
dark paste	A8501	30%	Eastcom New Materials
water-based acrylic resin	C84	65%	Covestro
lubricant	BYK-333	0.5%	BYK
leveling agent	BYK-381	1.0%	BYK
defoamer	BYK-024	1.0%	BYK
thickener	PS-166	0.5%	Yuanhe Chemical
Deionized water	Deionized water	2%

After mixing the dark paste, water-based acrylic resin, resin auxiliary and deionized water in proportion in Table 2.1, disperse at high speed with a disperser at a speed of 800r/min for 20min, stir evenly and let stand for 1h at room temperature to obtain a primer. The resin additives are wetting agent BYK-333, leveling agent BYK-381, defoaming agent BYK-024 and thickening agent PS-166 in Table 1.

2. Preparation of color-changing layer paint

The components and the weight percentages of each component in the color-changing layer coating with colorful color changes with temperature changes of the present embodiment are shown in Table 2.2:

Table 2.2: Components of the color-changing layer coating and the weight percentage of each component

composition	name	weight percentage	Manufacturer
Liquid crystal microcapsules	27-37℃	10%
Waterborne polyurethane resin	3576	85%	Yuanhe Chemical
lubricant	BYK-333	0.6%	BYK
leveling agent	BYK-381	1.0%	BYK
defoamer	BYK-024	0.3%	BYK
thickener	PS-166	1.0%	Yuanhe Chemical
adhesion promoter	Addbond LTW	1.0%	Degussa
Deionized water	Deionized water	1.1%

The core material of the liquid crystal microcapsules described in Table 2.2 is a cholesteric liquid crystal, and the wall material is a gelatin gum arabic mixed wall material prepared by a complex coacervation method, and the temperature change range is 27°C to 37°C;

After mixing the liquid crystal microcapsules, water-based polyurethane resins, resin additives, adhesion promoters, and deionized water in proportions in Table 2.2, use a disperser at a speed of 800 r/min to disperse at high speed for 20 minutes, stir evenly, and place at room temperature for 1 hour. A color-changing layer coating was obtained, and the resin additives were the wetting agent BYK-333, the leveling agent BYK-381, the defoaming agent BYK-024 and the thickening agent PS-166 in Table 2.

3. Preparation of transparent crack layer coating

The transparent crack layer of the present embodiment is set as the UV transparent crack layer, and the components in the UV transparent crack layer coating and the weight percentage of each component are as shown in Table 2.3:

Table 2.3: Components of UV transparent crack coating and their weight percentages

composition	name	weight percentage	Manufacturer
Polyurethane Modified Acrylic Resin	YS-213	90%	allnex resin
photoinitiator	1176	3%	Guangyi Chemical
photoinitiator	UV-1130	3%	Jinheng Blue Ocean
adhesion promoter	KH-570	3%	Yangzhou Yizheng
lubricant	BYK-333	1%	BYK

After mixing the polyurethane-modified acrylic resin, photoinitiator 1176, photoinitiator UV-1130, adhesion promoter, and wetting agent BYK-333 in Table 2.3, use a disperser to disperse at high speed for 20min at a speed of 400r/min. After stirring evenly, it was placed at room temperature for 1 hour to obtain a UV transparent crack layer coating.

4. Use a spray gun to spray a layer of dark primer on the iron plate. After the surface of the primer film is dry, place it in an oven at 60°C for 20 minutes to obtain a dark primer with a dry film thickness of 50μm.

5. Use a spray gun to spray a layer of color-changing layer paint on the dark bottom layer. After the surface of the color-changing layer paint film is dry, place it in an oven at 60°C for 20 minutes to obtain a color-changing layer with a dry film thickness of 50 μm.

6. Use a spray gun to spray a layer of UV transparent crack layer paint on the discolored layer, and immediately place the paint film under the UV curing machine for light curing. sky.

7. Put the iron plate that has been coated and cured in steps 4, 5, and 6 in boiling water at 100°C for 1 hour. After the boiling is completed, take it out immediately, wipe off the water marks, and place it in a Baking in an oven at 100° C., after the baking is completed, cracks appear on the surface of the iron plate, and an iron plate whose surface is decorated with discoloration crack paint is obtained.

Example 3

The transparent glass plate is selected as the base material, and the discoloration crack paint is decorated on the base material, and the preparation steps are as follows:

1. Formulation of primer

The bottom layer of this example is set to be a dark bottom layer, and the components in the dark primer paint and the weight percentages of each component are shown in Table 3.1:

Table 3.1: Components of dark primer and their weight percentages

composition	name	weight percentage	Manufacturer
dark paste	8503	20%	Siou Krypton Chemical
Silicone Modified Polyurethane Resin	SIPU-8333	70%	Hengchenke
lubricant	BYK-333	0.6%	BYK
leveling agent	BYK-381	1.4%	BYK
defoamer	BYK-024	0.5%	BYK
thickener	PS-166	0.5%	Yuanhe Chemical
Deionized water	Deionized water	7%

After mixing the dark slurry, silicone modified polyurethane resin, resin auxiliary and deionized water in proportion in Table 3.1, disperse at a high speed of 800r/min using a disperser for 20min, stir evenly and let stand for 1h at room temperature to obtain Primer coating, the resin additives are wetting agent BYK-333, leveling agent BYK-381, defoaming agent BYK-024 and thickening agent PS-166 in Table 1.

2. Preparation of color-changing layer paint

Table 3.2 shows the components in the color-changing layer paint with colorful color changes of this embodiment and the weight percentages of each component:

Table 3.2: Components of the color-changing layer coating and the weight percentage of each component

composition	name	weight percentage	Manufacturer
Liquid crystal microcapsules	26-40℃	20%
polyvinyl alcohol	PVA1788	73%	Guangzhou Shenchuang
adhesion promoter	KH-550	2%	Yangzhou Yizheng
Deionized water	Deionized water	5%

The core material of the liquid crystal microcapsules described in Table 3.2 is a cholesteric liquid crystal, and the wall material is a gelatin acacia mixed wall material prepared by a complex coacervation method, and the temperature change range is 26°C to 40°C;

After mixing the liquid crystal microcapsules, polyvinyl alcohol, adhesion promoter, and deionized water in Table 3.2 in proportion, disperse at a high speed of 800r/min using a disperser for 15min, stir evenly, and place at room temperature for 1h to obtain a color-changing layer coating .

3. Preparation of transparent crack layer coating

The transparent crack layer of the present embodiment is set as the UV transparent crack layer, and the components in the UV transparent crack layer coating and the weight percentage of each component are shown in Table 3.3:

Table 3.3: Components of UV transparent crack coating and the weight percentage of each component

After mixing the silicone-modified acrylic resin, photoinitiator TPO, photoinitiator 1173, adhesion promoter and wetting agent in Table 3.3, use a disperser at a speed of 400r/min to disperse at high speed for 20min, stir evenly and then room temperature Placed for 1 hour to obtain UV transparent crack layer coating.

4. Use a 200μm wire rod to coat a layer of dark primer on the transparent glass. After the surface of the primer film is dried, bake it in a 60°C oven for 20 minutes to obtain a dark primer with a dry film thickness of 50μm.

5. Use a 200μm wire rod to coat a layer of color-changing layer paint on the dark bottom layer. After the surface of the color-changing layer paint film is dried, bake in a 60°C oven for 20 minutes to obtain a color-changing layer with a dry film thickness of 45 μm.

6. Use a 100μm wire rod to coat a layer of UV transparent crack layer paint on the discoloration layer, and place the crack layer paint film under a UV curing machine for light curing. The use band is the full band and the power is 6kw. Leave for 2 days.

7. Use an engraving knife to carve patterns of different thicknesses on the surface of the glass substrate that has been coated and maintained in steps 4, 5, and 6 in sequence.

8. Put the glass substrate after steps 4, 5, 6, 7 coating, curing and scribing are completed in boiling water at 100 °C for 2 hours. After the boiling is completed, take it out immediately and wipe the water dry. After the baking is completed, cracks of different shapes appear on the surface of the glass substrate, and a glass plate whose surface is decorated with discoloration crack paint is obtained.

3 is a schematic diagram of the surface state of a discolored cracked paint film prepared by the method of Example 3. It can be clearly observed from the figure that in the temperature change range of the liquid crystal microcapsules, because the liquid crystal microcapsules show a colorful state, so , the surface of the glass plate shows a three-dimensional structure. In the non-temperature-variable range of the liquid crystal microcapsules, because the color of the liquid crystal microcapsules does not appear, the surface of the glass plate only shows a cracked state and a dark bottom color. And in the temperature change range of the liquid crystal microcapsules, the surface of the glass plate will show different color changes with the change of temperature. In addition, because the crack layer is carved with patterns of different thickness and fine lines with a carving knife, the surface of the discolored crack paint film prepared in Example 3 shows a different crack state from that in Example 1, which proves that the method of adding engraving lines can be used. Carry out artificial control to achieve the desired effect.

Example 4

The transparent glass plate is selected as the base material, and the discoloration crack paint is decorated on the base material, and the preparation steps are as follows:

1. Formulation of primer

The bottom layer of this example is set to be a dark bottom layer, and the components in the dark primer paint and the weight percentages of each component are shown in Table 4.1:

Table 4.1: Components of dark primer and their weight percentages

composition	name	weight percentage	Manufacturer
dark paste	8503	28%	Siou Krypton Chemical
Silicone Modified Polyurethane Resin	SIPU-8333	62%	Hengchang Chemical Co., Ltd.
lubricant	BYK-333	0.6%	BYK
leveling agent	BYK-381	1.4%	BYK
defoamer	BYK-024	0.5%	BYK
thickener	PS-166	0.5%	Yuanhe Chemical
Deionized water	Deionized water	7%

After mixing the dark slurry, silicone modified polyurethane resin, resin auxiliary and deionized water in proportion in Table 4.1, disperse at a high speed of 800r/min using a disperser for 20min, stir evenly and let stand for 1h at room temperature to obtain Primer coating, the resin additives are wetting agent BYK-333, leveling agent BYK-381, defoaming agent BYK-024 and thickening agent PS-166 in Table 1.

2. Preparation of color-changing layer paint

The components and the weight percentages of each component in the color-changing layer paint with colorful color changes with temperature changes of the present embodiment are shown in Table 4.2:

Table 4.2: Components of the color-changing layer coating and the weight percentage of each component

composition	name	weight percentage	Manufacturer
Liquid crystal microcapsules	26-40℃	10%
natural polymer	gelatin	85%	Boyang Biology
Deionized water	Deionized water	5%

The core material of the liquid crystal microcapsules described in Table 4.2 is a cholesteric liquid crystal, and the wall material is a gelatin gum arabic mixed wall material prepared by a complex coacervation method, and the temperature change range is 26°C to 40°C;

Dissolve the natural polymer gelatin in Table 4.2 in deionized water under heating, and the ratio of gelatin to deionized water is 1:5; then mix liquid crystal microcapsules, gelatin solution, and deionized water The rotating speed of 400r/min is used for high-speed dispersion of dispersing machine for 15min, and after stirring evenly, it is placed at room temperature for 1h to obtain the color-changing layer coating.

3. Preparation of transparent crack layer coating

The transparent crack layer of the present embodiment is set as the UV transparent crack layer, and the components in the UV transparent crack layer coating and the weight percentage of each component are shown in Table 4.3:

Table 4.3: Components of UV transparent crack coating and their weight percentages

After mixing the photoinitiator TPO, photoinitiator 1173, adhesion promoter, polyester modified acrylic resin, and wetting agent in Table 4.3, disperse at a high speed of 400 r/min using a disperser for 20 minutes, and stir evenly at room temperature. Placed for 1 hour to obtain UV transparent crack layer coating.

4. Use a 200μm wire rod to coat a layer of dark primer on the transparent glass. After the surface of the primer film is dried, bake it in a 60°C oven for 20 minutes to obtain a dark primer with a dry film thickness of 50μm.

5. Use a 200μm wire rod to coat a layer of color-changing layer paint on the dark bottom layer. After the surface of the color-changing layer paint film is dried, bake in a 60°C oven for 20 minutes to obtain a color-changing layer with a dry film thickness of 45 μm.

6. Use a 100μm wire rod to coat a layer of UV transparent crack layer paint on the discoloration layer, and place the crack layer paint film under a UV curing machine for light curing. The use band is the full band and the power is 6kw. Leave for 2 days.

7. On the surface of the glass plate coated and maintained in steps 4, 5, and 6 in turn, use a 100-grid knife to carve intersecting lines.

8. Put the glass plate after steps 4, 5, 6, 7 coating, curing and scribing are completed in 100 ℃ boiling water for 2 hours. After the boiling is completed, take it out immediately and wipe the water dry. After the baking is completed, cracks of different shapes appear on the surface of the glass plate, and a glass plate decorated with discoloration crack paint is obtained.

Figure 4 is a schematic diagram of the surface state of a discolored cracked paint film prepared by the method of Example 4. It can be clearly observed from the figure that in the temperature change range of the liquid crystal microcapsules, because the liquid crystal microcapsules show a colorful state, so , the surface of the glass plate shows a three-dimensional structure. In the non-temperature-variable range of the liquid crystal microcapsules, because the color of the liquid crystal microcapsules does not appear, the surface of the glass plate only shows a cracked state and a dark bottom color. And in the temperature change range of the liquid crystal microcapsules, the surface of the glass substrate will show different color changes with the change of temperature. In addition, because the crack layer was carved with patterns of different thickness and fine lines with a carving knife, the surface of the discolored crack paint film prepared in Example 4 showed a different crack state from that in Example 1 and Example 3, which proved that it can be achieved by adding engraving. The line method is artificially controlled to achieve the desired effect.

To sum up, the present application provides a color-changing cracked paint film, which is attached to a base material, and the base material has a first surface and a second surface; the paint film includes a color-changing layer, and the color-changing layer changes with the external environment. Colorful color changes occur due to temperature changes, the color changing layer includes a first macromolecule polymer and a plurality of liquid crystal microcapsules dispersed in the first macromolecule polymer, and the liquid crystal microcapsules include thermotropic liquid crystals; and a transparent crack layer, the transparent crack layer has a plurality of cracks arranged regularly or irregularly; the discoloration layer and the transparent crack layer are arranged on one side of the first surface. The paint film combines the advantages of a transparent crack layer and a color-changing layer that changes in color with changes in external temperature. The transparent crack layer can perfectly highlight the various color changes of the bottom layer, and the space separated by the transparent crack layer is in the color-changing effect. Under the blessing, it will produce a dreamy three-dimensional sense of space. It also specifically provides a method for preparing a color-changing crack paint composed of a UV transparent crack layer and a temperature-sensitive liquid crystal microcapsule. Excellent adhesion, weather resistance, solvent resistance, acid and alkali resistance, salt resistance, etc. The pencil hardness of the paint surface is as high as 4H. The discolored cracked paint film of the present application can be applied to craft decorative articles, toys, cups, special paints, decorative building materials, furniture and the like.

The positional relationship between the discoloration layer and the transparent crack layer described in the present application is not limited to the above embodiments, and the discoloration layer may be located below the transparent crack layer or above the transparent crack layer, which is not specifically limited.

Although this specification is described in terms of embodiments, not every embodiment only includes an independent technical solution. This description in the specification is only for the sake of clarity. Those skilled in the art should take the specification as a whole. The technical solutions can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

The series of detailed descriptions listed above are only specific descriptions for the feasible embodiments of the present invention, and they are not used to limit the protection scope of the present invention. Changes should all be included within the protection scope of the present invention.

Claims (23)

1. A color-changing crack paint film, characterized in that it is attached to a base material, and the base material has a first surface and a second surface; the paint film comprises:

   A color-changing layer, the color-changing layer changes in color with the change of the external temperature, the color-changing layer includes a first high molecular polymer and a plurality of liquid crystal microcapsules dispersed in the first high molecular polymer, and the liquid crystal microcapsules are dispersed in the first high molecular polymer. Included in the capsule is a thermotropic liquid crystal; and

   a transparent crack layer, the transparent crack layer has a plurality of cracks arranged regularly or irregularly;

   The discoloration layer and the transparent crack layer are disposed on one side of the first surface.
2. The color-changing cracked paint film according to claim 1, wherein the liquid crystal microcapsules comprise a core material and a wall material, and the core material is a thermotropic liquid crystal.
3. The color-changing cracked paint film according to claim 2, wherein the wall material is formed by interfacial polymerization of a polybasic acid chloride compound and a polyvalent amine compound.
4. The color-changing cracked paint film according to claim 1, wherein the first macromolecular polymer is water-based acrylic resin, water-based polyurethane, water-based epoxy resin, water-based UV light-curable resin, water-based polyester resin, and water-based alcohol Acid resin, water-based amino resin, water-based acrylic emulsion, water-based phenolic resin, water-based silicone resin, polyvinyl alcohol, polyester, polyacryl alcohol, polyethylene glycol, polyvinylpyrrolidone, gelatin, sodium alginate, chitosan One or at least two mutually modified high molecular polymers.
5. The color-changing cracked paint film according to claim 1, wherein the transparent cracked layer is a UV transparent cracked layer.
6. The color-changing cracked paint film according to claim 1, wherein the pencil hardness range of the color-changing layer after curing is H or more.
7. The color-changing crack paint film according to claim 5, wherein the pencil hardness range of the UV transparent crack layer after curing is 2H or more.
8. The color-changing cracked paint film according to claim 7, wherein the transparent cracked layer has a glossiness of more than 90% at a test angle of 20 degrees.
9. The color-changing crack paint film according to claim 5, wherein the components for preparing the UV transparent crack layer comprise UV resin and photoinitiator.
10. The discolored and cracked paint film according to claim 9, wherein the UV resin is an acrylic monomer or prepolymer and a derivative thereof.
11. The color-changing cracked paint film according to claim 10, wherein the acrylic monomer or prepolymer and its derivatives are epoxy-modified acrylic resin, polyester-modified acrylic resin, and fluorine-modified acrylic resin , One or at least two compound products of polyurethane modified acrylic resin, polyether modified acrylic resin and silicone modified acrylic resin.
12. The discolored and cracked paint film according to claim 1, wherein the base material is a dark base material.
13. The discolored cracked paint film of claim 1, further comprising a dark base layer on the first surface and/or the second surface.
14. The color-changing cracked paint film according to claim 13, wherein the components for preparing the dark bottom layer comprise a second high molecular polymer and a dark dye mixed in the second high molecular polymer, wherein : The second high molecular polymer is polyurethane, solvent-based acrylic resin, water-based acrylic resin, acrylic emulsion, UV light curing resin, epoxy resin, amino resin, saturated polyester resin, unsaturated polyester resin, phenolic resin One or at least two mutually modified high molecular polymers among alkyd resin and silicone resin.
15. The color-changing cracked paint film according to any one of claims 1-14, wherein the thickness of the color-changing layer is 30 μm˜200 μm.
16. The color-changing crack paint film according to any one of claims 1-14, wherein the thickness of the transparent crack layer is 30 μm˜200 μm.
17. A method for preparing a discolored cracked paint film, comprising the steps of:

    S1. Preparation of the color-changing layer coating: after mixing the liquid crystal microcapsules and the first macromolecular polymer in proportion, fully stirring and uniformly mixing to obtain the color-changing layer coating;

    S2. Preparation of transparent crack layer coating: after mixing the UV resin and the photoinitiator in proportion, fully stir and mix evenly to obtain a transparent crack layer coating;

    S3, forming the color-changing layer coating on the base material or the dark bottom layer on the base material with a layered structure, drying, and baking to obtain the color-changing layer formed on the base material or the dark base layer on the base material;

    S4, attaching the transparent crack layer coating to the discoloration layer with a layered structure, and curing with UV light to obtain a transparent crack layer attached to the discoloration layer;

    S5. The base material subjected to steps S3 and S4 is sequentially boiled and baked to obtain a discolored and cracked paint film.
18. The method for preparing a color-changing cracked paint film according to claim 17, wherein an auxiliary agent is added to the color-changing layer coating and/or the transparent cracking layer coating, and the auxiliary agent is a dispersant, a flow One or at least two adjuvants in combination of leveling agent, thickening agent, wetting agent, defoaming agent and deionized water.
19. The method for preparing a color-changing cracked paint film according to claim 17, wherein an adhesion promoter is added to the color-changing layer coating and/or the transparent cracking layer coating.
20. The method for preparing a discolored cracked paint film according to claim 17, wherein the adhesion promoter is one of a siloxane coupling agent and its derivatives, a sodium titanate coupling agent and its derivatives one or more.
21. The method for preparing a discolored and cracked paint film according to claim 20, wherein the siloxane coupling agent and its derivatives are epoxy-modified siloxane coupling agent, amine-modified siloxane coupling agent At least one of a coupling agent and a fluorine-modified siloxane coupling agent, the sodium titanate coupling agent and its derivatives are epoxy-modified sodium titanate coupling agent, amine-modified ammonium titanate coupling agent at least one of the agents.
22. The method for preparing a discolored cracked paint film according to claim 17, characterized in that, before step S5, it further comprises the step of using a sharp object to score lines on the transparent crack layer and/or the discolored layer.
23. The method for preparing a discolored cracked paint film according to claim 17, wherein the substrate has a first surface and a second surface, and the preparation method further comprises: The dark bottom layer is formed on the two surfaces.

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