Photosensitive color-changing cloth bookmark and preparation method thereof

Abstract

The present invention relates to the technical field of photosensitive color-changing cloth bookmarks, and in particular to a photosensitive color-changing cloth bookmark and a preparation method thereof. The preparation steps of the photosensitive color-changing cloth bookmark include: spraying a photosensitive coating on a base cloth, the number of spraying is 3-4 times, and the total thickness of the coating is 0.3mm-0.5mm; drying the coated base cloth at a temperature of 50-60°C, and then curing and cutting it into bookmarks; wherein the photosensitive coating includes the following materials in parts by weight: 42-46 parts of base resin, 1-2 parts of dispersant, 0.5-1 parts of defoaming agent, 16-20 parts of filler, 1-1.2 parts of film-forming aid, 2-3 parts of photosensitive color-changing material and 0.4-0.6 parts of adhesive. The present invention combines the advantages of photosensitive color-changing material and cloth bookmark, not only has a unique color-changing effect, but also has the characteristics of durability, environmental protection and comfortable hand feel. The preparation method of the bookmark is simple and easy to implement, suitable for large-scale production, and can meet the market demand for new bookmark products.

Description

Technical Field

[0001] The invention relates to the technical field of photosensitive color-changing cloth bookmarks, and in particular to a photosensitive color-changing cloth bookmark and a preparation method thereof. Background Art

[0002] With technological advancements and people's pursuit of a higher quality of life, bookmarks, a common reading aid, are no longer limited to traditional paper or plastic materials. In recent years, photochromic materials have gradually attracted attention due to their unique visual effects and broad application prospects. Photochromic cloth bookmarks, a novel product that combines traditional bookmark functionality with modern technology, are not only practical but also aesthetically pleasing and entertaining.

[0003] Photochromic materials are materials that change color under specific lighting conditions. These materials typically contain photochromic dyes or photochromic microcapsules. They change color under exposure to light sources such as sunlight and ultraviolet light, returning to their original state when the light source disappears or changes. Due to their unique color-changing properties, photochromic materials are widely used in anti-counterfeiting, decoration, and entertainment applications.

[0004] There are already some photosensitive color-changing bookmarks on the market, but most of these products use plastic or paper as their substrates. While they can achieve color-changing effects, they lack durability, environmental friendliness, and hand feel. Furthermore, the color-changing effects of these bookmarks are often relatively simple, lacking layering and aesthetic appeal. Based on this, the present invention provides a photosensitive color-changing cloth bookmark and a method for preparing it. Summary of the Invention

[0005] The purpose of the present invention is to provide a photosensitive color-changing cloth bookmark and a preparation method thereof, which can achieve diversified color-changing effects, enhance the layering and ornamental value, and change quickly and reversibly when a small amount of organic color-changing material is added. The added filler can also reduce the release of organic matter, and when a small amount is added, almost no toxic substances are discharged. The bookmark also has certain anti-mildew properties.

[0006] In a first aspect, the present invention provides a method for preparing a photosensitive color-changing cloth bookmark, comprising: spraying a photosensitive coating on a base cloth, the spraying times being 3-4 times, and the total coating thickness being 0.3mm-0.5mm; drying the coated base cloth at a temperature of 50-60°C, and then curing and cutting it into bookmarks; wherein the photosensitive coating comprises the following materials in parts by weight: 42-46 parts of a base resin, 1-2 parts of a dispersant, 0.5-1 parts of a defoaming agent, 16-20 parts of a filler, 1-1.2 parts of a film-forming aid, 2-3 parts of a photosensitive color-changing material, and 0.4-0.6 parts of an adhesive.

[0007] Furthermore, the base fabric includes any one of cotton, linen and polyester.

[0008] Furthermore, the curing step includes curing at room temperature for 20-22 hours and then curing at 30-40°C for 30-34 hours.

[0009] Furthermore, the filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:(4-5).

[0010] Furthermore, the preparation method of the modified kaolin includes: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing kaolin and calcium carbonate in deionized water to form a suspension, mixing the suspension with the ethanol solution of the aforementioned silane coupling agent, stirring at a temperature of 50-60°C for 1.5-2h, filtering and drying to obtain the modified kaolin.

[0011] Furthermore, the weight ratio of the silane coupling agent, ethanol aqueous solution, kaolin, calcium carbonate and deionized water is (0.5-1): (5-7): (12-16): (6-8): (100-110).

[0012] Furthermore, the base resin is a modified acrylic ester emulsion, and the preparation method includes: adding 20-22 parts of butyl acrylate, 5-7 parts of methyl methacrylate, 6-7 parts of polyvinyl alcohol, 0.07-0.09 parts of sodium lauryl sulfate, 0.03-0.05 parts of ammonium persulfate, and 0.03-0.05 parts of trimethylolpropane to 70-74 parts by weight of deionized water at a temperature of 70-78°C, heating to 80-84°C, reacting for 40-60 minutes, then dropwise adding 4-6 parts of sodium bicarbonate, and filtering to obtain the product.

[0013] Furthermore, the dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; and the photochromic material is Runba GS5030.

[0014] Furthermore, the adhesive is NB-101.

[0015] In a second aspect, the present invention provides a photosensitive color-changing cloth bookmark prepared using the aforementioned preparation method.

[0016] The beneficial effects of the present invention are:

[0017] When calcium carbonate-modified kaolin is used as an inorganic filler in the preparation of a photochromic coating, the addition of calcium carbonate forms a composite structure with the kaolin. This composite structure effectively slows or prevents the release of organic matter in the presence of organic matter. When added as an inorganic filler, the interaction between calcium carbonate and kaolin enhances the interaction between the filler and the organic matter, reducing the migration and release of the organic matter. Furthermore, calcium carbonate itself has stable chemical properties and is not prone to reacting with organic matter, further reducing the generation and release of harmful substances.

[0018] The calcium carbonate-modified kaolin in the present invention has certain mildew resistance, which is mainly attributed to the change in its surface properties and the regulation of the microenvironment. The addition of the silane coupling agent not only enhances the binding force between the kaolin and the calcium carbonate, but also changes their surface properties. The change in the surface properties of the calcium carbonate-modified kaolin makes it difficult for microorganisms to attach to its surface. This is because microorganisms need to find suitable attachment sites during the attachment process, and the modified surface may no longer have these sites or the properties of these sites have changed, making it difficult for microorganisms to grow and reproduce on its surface.

[0019] The organic photochromic material in the present invention is a type of compound that can change color under illumination. Their color change principle generally involves that after the photosensitive substance absorbs light energy, the molecular structure changes, resulting in changes in the absorption and reflection properties of light, thereby producing a color change. This change can be reversible, that is, when the illumination stops or the light source is changed, the color can be restored to its original state. The color change principle of cobalt chloride is mainly based on the changes in its crystal structure and the influence of external environmental conditions (such as humidity and temperature). In anhydrous state, cobalt chloride appears blue, but when it absorbs water molecules, the crystal structure changes, causing the color to become pink or red. In addition, the color change of cobalt chloride is also affected by temperature, and reversible color change can occur at a specific temperature. When the organic photochromic material is compounded with cobalt chloride for color change, it can exhibit the characteristics of fast change speed and reversible change process.

[0020] In the present invention, when the organic photochromic material Runba GS5030 and cobalt chloride are used together as raw materials to prepare the coating, the two cooperate to achieve diversified color-changing effects while adding less organic color-changing materials, thereby enhancing the sense of hierarchy and ornamental value. Among them, the organic photochromic material changes color under light, while the cobalt chloride is mainly affected by humidity and temperature. Therefore, the two have a certain degree of complementarity in color-changing conditions, which can make the coating present a variety of color changes under different environments. Secondly, organic photochromic materials usually have brighter color changes, while the color changes of cobalt chloride are relatively soft, which enhances the sense of hierarchy of colors; since cobalt chloride itself has color-changing properties and can produce synergistic effects with organic photochromic materials, the amount of organic color-changing materials can be appropriately reduced when preparing the coating; this can not only reduce costs, but also reduce the impact on the environment. In addition, the synergistic effect of organic photochromic materials and cobalt chloride can also improve the color change sensitivity and reversibility of the coating; when external conditions such as light, humidity or temperature change, the coating can respond quickly and change color; when the external conditions return to their original state, the coating can also quickly return to its original color.

[0021] Furthermore, from the perspective of microenvironment regulation, cobalt chloride can also act as a drying agent, hardener and mildew inhibitor in coatings; cobalt chloride inhibits the growth of microorganisms by regulating the microenvironment and releasing antibacterial active ions. In addition, cobalt chloride, as a drying agent for coatings, can accelerate the drying process of coatings; after drying, a dense film layer is formed on the surface of the coating, which can block the invasion of external moisture and microorganisms, thereby improving the mildew resistance of the coating. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention. It should be noted that the silane coupling agent used in the present invention is γ-aminopropyltriethoxysilane and the polyvinyl alcohol model is RS-1717.

[0023] Example 1

[0024] This embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric three times to a total coating thickness of 0.4 mm; drying the coated base fabric at 55° C., then curing it at room temperature for 21 hours and then at 35° C. for 32 hours, and cutting it into bookmarks;

[0025] The photosensitive coating comprises the following materials in parts by weight: 44 parts of base resin, 1.5 parts of dispersant, 0.75 parts of defoaming agent, 18 parts of filler, 1.1 parts of film-forming aid, 2.5 parts of photosensitive color-changing material and 0.5 parts of adhesive.

[0026] The base fabric includes any one of cotton, linen and polyester. The embodiments and comparative examples of the present invention all use cotton base fabrics.

[0027] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 21 parts of butyl acrylate, 6 parts of methyl methacrylate, 6.5 parts of polyvinyl alcohol, 0.08 parts of sodium lauryl sulfate, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at 74°C, heating to 82°C, reacting for 50 minutes, then dropwise adding 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0028] The filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:4.5. The preparation method of the modified kaolin comprises: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing kaolin and calcium carbonate in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring at a temperature of 55° C. for 1.75 hours, filtering, and drying to obtain the filler. The weight ratio of the silane coupling agent, the ethanol aqueous solution, the kaolin, the calcium carbonate, and the deionized water is 0.75:6:14:7:105.

[0029] The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0030] Example 2

[0031] This embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric three times to a total coating thickness of 0.3 mm; drying the coated base fabric at 50° C., then curing it at room temperature for 20 hours and then at 30° C. for 30 hours, and cutting it into bookmarks;

[0032] The photosensitive coating comprises the following materials in parts by weight: 42 parts of base resin, 1 part of dispersant, 0.5 parts of defoaming agent, 16 parts of filler, 1 part of film-forming aid, 2 parts of photosensitive color-changing material and 0.4 parts of adhesive.

[0033] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 20 parts of butyl acrylate, 5 parts of methyl methacrylate, 6 parts of polyvinyl alcohol, 0.07 parts of sodium lauryl sulfate, 0.03 parts of ammonium persulfate, and 0.03 parts of trimethylolpropane to 70 parts by weight of deionized water at 70°C, heating to 80°C, reacting for 40 minutes, then dropwise adding 4 parts of sodium bicarbonate, and filtering to obtain the product;

[0034] The filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:4. The preparation method of the modified kaolin comprises: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing kaolin and calcium carbonate in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring at a temperature of 50° C. for 1.5 hours, filtering, and drying to obtain the filler. The weight ratio of the silane coupling agent, the ethanol aqueous solution, the kaolin, the calcium carbonate, and the deionized water is 0.5:5:12:6:100.

[0035] The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0036] Example 3

[0037] This embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating onto a base fabric four times to a total coating thickness of 0.5 mm; drying the coated base fabric at 60° C., curing the base fabric at room temperature for 22 hours and then at 40° C. for 34 hours, and cutting the base fabric into bookmarks;

[0038] The photosensitive coating comprises the following materials in parts by weight: 46 parts of base resin, 2 parts of dispersant, 1 part of defoamer, 20 parts of filler, 1.2 parts of film-forming aid, 3 parts of photosensitive color-changing material and 0.6 parts of adhesive.

[0039] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 22 parts of butyl acrylate, 7 parts of methyl methacrylate, 7 parts of polyvinyl alcohol, 0.09 parts of sodium lauryl sulfate, 0.05 parts of ammonium persulfate, and 0.05 parts of trimethylolpropane to 74 parts by weight of deionized water at 78°C, heating to 84°C, reacting for 60 minutes, then dropwise adding 6 parts of sodium bicarbonate, and filtering to obtain the product;

[0040] The filler includes cobalt chloride and modified kaolin in a weight ratio of 1:5. The preparation method of the modified kaolin includes: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing kaolin and calcium carbonate in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring at a temperature of 60°C for 2 hours, filtering and drying to obtain the filler. The weight ratio of the silane coupling agent, the ethanol aqueous solution, the kaolin, the calcium carbonate and the deionized water is 1:7:16:8:110.

[0041] The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0042] Example 4

[0043] This embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric three times to a total coating thickness of 0.5 mm; drying the coated base fabric at 50° C., then curing it at room temperature for 22 hours and then at 30° C. for 34 hours, and cutting it into bookmarks;

[0044] The photosensitive coating comprises the following materials in parts by weight: 42 parts of base resin, 2 parts of dispersant, 0.5 parts of defoaming agent, 20 parts of filler, 1 part of film-forming aid, 3 parts of photosensitive color-changing material and 0.4 parts of adhesive.

[0045] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 22 parts of butyl acrylate, 5 parts of methyl methacrylate, 7 parts of polyvinyl alcohol, 0.07 parts of sodium lauryl sulfate, 0.05 parts of ammonium persulfate, and 0.03 parts of trimethylolpropane to 74 parts by weight of deionized water at 70°C, heating to 84°C, reacting for 40 minutes, then dropwise adding 6 parts of sodium bicarbonate, and filtering to obtain the product;

[0046] The filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:4. The preparation method of the modified kaolin comprises: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing kaolin and calcium carbonate in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring at a temperature of 60° C. for 1.5 hours, filtering, and drying to obtain the filler. The weight ratio of the silane coupling agent, the ethanol aqueous solution, the kaolin, the calcium carbonate, and the deionized water is 0.5:7:12:8:100.

[0047] The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0048] Comparative Example 1

[0049] This comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric, spraying the coating three times, and achieving a total coating thickness of 0.4 mm; drying the coated base fabric at 55° C., then curing the base fabric at room temperature for 21 hours and then at 35° C. for 32 hours, and cutting the base fabric into bookmarks;

[0050] The photosensitive coating comprises the following materials in parts by weight: 44 parts of base resin, 1.5 parts of dispersant, 0.75 parts of defoaming agent, 18 parts of filler, 1.1 parts of film-forming aid, 2.5 parts of photosensitive color-changing material and 0.5 parts of adhesive.

[0051] The base fabric includes any one of cotton, linen and polyester. The embodiments and comparative examples of the present invention all use cotton base fabrics.

[0052] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 21 parts of butyl acrylate, 6 parts of methyl methacrylate, 6.5 parts of polyvinyl alcohol, 0.08 parts of sodium lauryl sulfate, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at 74°C, heating to 82°C, reacting for 50 minutes, then dropwise adding 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0053] The filler is modified kaolin. The preparation method of the modified kaolin includes: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing kaolin and calcium carbonate in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring at a temperature of 55° C. for 1.75 hours, filtering and drying to obtain the filler, wherein the weight ratio of the silane coupling agent, the ethanol aqueous solution, the kaolin, the calcium carbonate and the deionized water is 0.75:6:14:7:105;

[0054] The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0055] Comparative Example 2

[0056] This comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric, spraying the coating three times, and achieving a total coating thickness of 0.4 mm; drying the coated base fabric at 55° C., then curing the base fabric at room temperature for 21 hours and then at 35° C. for 32 hours, and cutting the base fabric into bookmarks;

[0057] The photosensitive coating comprises the following materials in parts by weight: 44 parts of base resin, 1.5 parts of dispersant, 0.75 parts of defoaming agent, 18 parts of filler, 1.1 parts of film-forming aid, 2.5 parts of photosensitive color-changing material and 0.5 parts of adhesive.

[0058] The base fabric includes any one of cotton, linen and polyester. The embodiments and comparative examples of the present invention all use cotton base fabrics.

[0059] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 21 parts of butyl acrylate, 6 parts of methyl methacrylate, 6.5 parts of polyvinyl alcohol, 0.08 parts of sodium lauryl sulfate, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at 74°C, heating to 82°C, reacting for 50 minutes, then dropwise adding 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0060] The filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:4.5. The preparation method of the modified kaolin comprises: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing kaolin in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring at a temperature of 55° C. for 1.75 hours, filtering, and drying to obtain the filler. The weight ratio of the silane coupling agent, the ethanol aqueous solution, the kaolin, and the deionized water is 0.75:6:21:105.

[0061] The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0062] Comparative Example 3

[0063] This comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric, spraying the coating three times, and achieving a total coating thickness of 0.4 mm; drying the coated base fabric at 55° C., then curing the base fabric at room temperature for 21 hours and then at 35° C. for 32 hours, and cutting the base fabric into bookmarks;

[0064] The photosensitive coating comprises the following materials in parts by weight: 44 parts of base resin, 1.5 parts of dispersant, 0.75 parts of defoaming agent, 18 parts of filler, 1.1 parts of film-forming aid, 2.5 parts of photosensitive color-changing material and 0.5 parts of adhesive.

[0065] The base fabric includes any one of cotton, linen and polyester. The embodiments and comparative examples of the present invention all use cotton base fabrics.

[0066] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 21 parts of butyl acrylate, 6 parts of methyl methacrylate, 6.5 parts of polyvinyl alcohol, 0.08 parts of sodium lauryl sulfate, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at 74°C, heating to 82°C, reacting for 50 minutes, then dropwise adding 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0067] The filler comprises cobalt chloride and kaolin in a weight ratio of 1:4.5; the dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0068] Comparative Example 4

[0069] This comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric, spraying the coating three times, and achieving a total coating thickness of 0.4 mm; drying the coated base fabric at 55° C., then curing the base fabric at room temperature for 21 hours and then at 35° C. for 32 hours, and cutting the base fabric into bookmarks;

[0070] The photosensitive coating comprises the following materials in parts by weight: 44 parts of base resin, 1.5 parts of dispersant, 0.75 parts of defoaming agent, 18 parts of filler, 1.1 parts of film-forming aid, 2.5 parts of photosensitive color-changing material and 0.5 parts of adhesive.

[0071] The base fabric includes any one of cotton, linen and polyester. The embodiments and comparative examples of the present invention all use cotton base fabrics.

[0072] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 21 parts of butyl acrylate, 6 parts of methyl methacrylate, 6.5 parts of polyvinyl alcohol, 0.08 parts of sodium lauryl sulfate, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at 74°C, heating to 82°C, reacting for 50 minutes, then dropwise adding 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0073] The filler comprises cobalt chloride and modified calcium carbonate in a weight ratio of 1:4.5. The preparation method of the modified calcium carbonate comprises: adding a silane coupling agent to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, dispersing the calcium carbonate in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring at a temperature of 55° C. for 1.75 hours, filtering, and drying to obtain the filler. The weight ratio of the silane coupling agent, the ethanol aqueous solution, the calcium carbonate, and the deionized water is 0.75:6:21:105.

[0074] The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0075] Comparative Example 5

[0076] This comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric, spraying the coating three times, and achieving a total coating thickness of 0.4 mm; drying the coated base fabric at 55° C., then curing the base fabric at room temperature for 21 hours and then at 35° C. for 32 hours, and cutting the base fabric into bookmarks;

[0077] The photosensitive coating comprises the following materials in parts by weight: 44 parts of base resin, 1.5 parts of dispersant, 0.75 parts of defoaming agent, 18 parts of filler, 1.1 parts of film-forming aid, 2.5 parts of photosensitive color-changing material and 0.5 parts of adhesive.

[0078] The base fabric includes any one of cotton, linen and polyester. The embodiments and comparative examples of the present invention all use cotton base fabrics.

[0079] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 21 parts of butyl acrylate, 6 parts of methyl methacrylate, 6.5 parts of polyvinyl alcohol, 0.08 parts of sodium lauryl sulfate, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at 74°C, heating to 82°C, reacting for 50 minutes, then dropwise adding 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0080] The filler includes cobalt chloride and calcium carbonate in a weight ratio of 1:4.5; the dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0081] Comparative Example 6

[0082] This comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the following steps: spraying a photosensitive coating on a base fabric, spraying the coating three times, and achieving a total coating thickness of 0.4 mm; drying the coated base fabric at 55° C., then curing the base fabric at room temperature for 21 hours and then at 35° C. for 32 hours, and cutting the base fabric into bookmarks;

[0083] The photosensitive coating comprises the following materials in parts by weight: 44 parts of base resin, 1.5 parts of dispersant, 0.75 parts of defoaming agent, 18 parts of filler, 1.1 parts of film-forming aid, 2.5 parts of photosensitive color-changing material and 0.5 parts of adhesive.

[0084] The base fabric includes any one of cotton, linen and polyester. The embodiments and comparative examples of the present invention all use cotton base fabrics.

[0085] The base resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 21 parts of butyl acrylate, 6 parts of methyl methacrylate, 6.5 parts of polyvinyl alcohol, 0.08 parts of sodium lauryl sulfate, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at 74°C, heating to 82°C, reacting for 50 minutes, then dropwise adding 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0086] The filler is cobalt chloride; the dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; the photochromic material is Runba GS5030; and the adhesive is NB-101.

[0087] The photosensitive color-changing cloth bookmarks prepared in Examples 1-4 and Comparative Examples 1-6 were tested, and the results are shown in Table 1 below:

[0088] 1. Anti-mildew test: HG / T 3950-2007 culture medium method, culture medium: MSA, inoculation: HG / T standard mold (1.0×10 6 spore / ml) and cultured in a 25°C incubator for 4 weeks.

[0089] Growth rating standard: Grade description (growth area): 0 no growth, i.e. no growth is observed under a microscope (magnification 50 times); 1 trace growth, i.e. growth is visible to the naked eye, but the growth coverage area is less than 10%; 2 growth coverage area is greater than 10%.

[0090] 2. Place the prepared bookmark in a room with normal light, observe the color change of the bookmark, and record the time; if the color needs to be restored, place the discolored bookmark in a dark room and record the color restoration time.

[0091] The test results are shown in Table 1.

[0092] Table 1 Test results

[0093]

[0094]

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. All technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a photosensitive color-changing cloth bookmark, characterized in that: include: The photosensitive coating is sprayed on a base fabric 3-4 times, with a total coating thickness of 0.3mm-0.5mm; the coated base fabric is dried at a temperature of 50-60°C, then cured and cut into bookmarks; wherein the photosensitive coating comprises the following materials in parts by weight: 42-46 parts of a base resin, 1-2 parts of a dispersant, 0.5-1 parts of a defoamer, 16-20 parts of a filler, 1-1.2 parts of a film-forming aid, 2-3 parts of a photochromic material and 0.4-0.6 parts of an adhesive; the filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:(4-5); when calcium carbonate-modified kaolin is used as an inorganic filler to prepare the photosensitive color-changing coating, the addition of calcium carbonate can form a certain composite structure with the kaolin, and this structure can effectively slow down or prevent the release of organic matter in the presence of organic matter; the preparation method of the modified kaolin comprises: A silane coupling agent is added to an ethanol aqueous solution with a pH value of 4 and a mass concentration of 95%, kaolin and calcium carbonate are dispersed in deionized water to prepare a suspension, the suspension is mixed with the ethanol solution of the silane coupling agent, and the mixture is stirred at a temperature of 50-60° C. for 1.5-2 hours, filtered, and dried to obtain the product. The matrix resin is a modified acrylic ester emulsion, and the preparation method comprises: adding 20-22 parts of butyl acrylate, 5-7 parts of methyl methacrylate, 6-7 parts of polyvinyl alcohol, 0.07-0.09 parts of sodium lauryl sulfate, 0.03-0.05 parts of ammonium persulfate, and 0.03-0.05 parts of trimethylolpropane to 70-74 parts by weight of deionized water at a temperature of 70-78° C. in sequence, heating to 80-84° C., reacting for 40-60 minutes, then dropwise adding 4-6 parts of sodium bicarbonate, and filtering to obtain the product.

2. The method for preparing a photosensitive color-changing cloth bookmark according to claim 1, characterized in that: The base fabric comprises any one of cotton, linen and polyester.

3. The method for preparing a photosensitive color-changing cloth bookmark according to claim 1, characterized in that: The curing comprises curing at room temperature for 20-22 hours and then curing at 30-40° C. for 30-34 hours.

4. The method for preparing a photosensitive color-changing cloth bookmark according to claim 1, characterized in that: The weight ratio of the silane coupling agent, ethanol aqueous solution, kaolin, calcium carbonate and deionized water is (0.5-1): (5-7): (12-16): (6-8): (100-110).

5. The method for preparing a photosensitive color-changing cloth bookmark according to claim 1, characterized in that: The dispersant is Dispersant 900; the defoaming agent is BYK-033; the film-forming aid is ethylene glycol monobutyl ether; and the photochromic material is Runba GS5030.

6. The method for preparing a photosensitive color-changing cloth bookmark according to claim 1, characterized in that: The adhesive is NB-101.

7. A photosensitive color-changing cloth bookmark prepared by the method for preparing a photosensitive color-changing cloth bookmark according to any one of claims 1 to 6.

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