Photochromic cloth bookmark and preparation method thereof

Abstract

The invention relates to the technical field of photochromic cloth bookmarks, in particular to a photochromic cloth bookmark and a preparation method thereof. The preparation method of the photochromic cloth bookmark comprises the steps that photosensitive paint is sprayed on base cloth for 3-4 times, and the total thickness of the coating is 0.3 mm-0. 5 mm; the coated base cloth is dried at the temperature of 50-60 DEG C, then cured and cut into the bookmark; wherein the photosensitive coating is prepared from the following materials in parts by weight: 42 to 46 parts of matrix resin, 1 to 2 parts of dispersing agent, 0.5 to 1 part of defoaming agent, 16 to 20 parts of filler, 1 to 1.2 parts of coalescing agent, 2 to 3 parts of photochromic material and 0.4 to 0.6 part of adhesive. The photochromic bookmark combines the advantages of a photochromic material and a cloth bookmark, not only has a unique color changing effect, but also has the characteristics of durability, environment friendliness, comfortable hand feeling and the like, and the preparation method of the bookmark is simple, easy to implement, suitable for large-scale production and capable of meeting the requirements of the market for novel 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 the advancement of science and technology and people's pursuit of quality of life, bookmarks, as a common reading aid, are no longer limited to traditional paper or plastic materials. In recent years, photosensitive color-changing materials have gradually attracted people's attention due to their unique visual effects and wide application prospects. As a new product that combines the functions of traditional bookmarks with modern technology, photosensitive color-changing cloth bookmarks are not only practical, but also ornamental and interesting.

[0003] Photochromic materials are materials that can change color under specific lighting conditions. Such materials usually contain photochromic dyes or photochromic microcapsules, which can change color under the irradiation of light sources such as sunlight and ultraviolet light. When the light source disappears or changes, the color can return to its original state. Photochromic materials are widely used in anti-counterfeiting, decoration, entertainment and other fields due to their unique color-changing effect.

[0004] At present, there are some photosensitive color-changing bookmark products on the market, but most of these products use plastic or paper as the substrate. Although they can achieve the color-changing effect, they are insufficient in durability, environmental protection and hand feel. In addition, the color-changing effect of these bookmarks is often relatively single, lacking in layering and ornamental properties. Based on this, the present invention proposes a photosensitive color-changing cloth bookmark and a preparation method thereof. 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 sense of hierarchy 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 number of spraying times is 3-4 times, and the total coating thickness 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 comprises 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.

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

[0008] Furthermore, the curing step includes first 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 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 acid, 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 dropping 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 by the aforementioned preparation method.

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

[0017] When the present invention uses calcium carbonate modified kaolin as an inorganic filler to prepare a photosensitive color-changing coating, the addition of calcium carbonate can form a certain composite structure with kaolin, and this structure can effectively slow down or prevent the release of organic matter when organic matter exists. When added as an inorganic filler, due to the interaction between calcium carbonate and kaolin, the interaction force between the filler and the organic matter is enhanced, reducing the migration and release of the organic matter. In addition, calcium carbonate itself has a stable chemical property and is not easy to react with organic matter, thereby 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 of its surface properties and the regulation of the microenvironment. The addition of the silane coupling agent not only enhances the binding force between kaolin and calcium carbonate, but also changes their surface properties. The change of 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, which makes it difficult for microorganisms to grow and reproduce on its surface.

[0019] The organic photochromic material in the present invention is a class of compounds that can change color under illumination. Their color change principle usually involves that after the photosensitive substance absorbs light energy, the molecular structure changes, causing the absorption and reflection properties of light to change, 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 change of 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 change to pink or red. In addition, the color change of cobalt chloride is also affected by temperature, and reversible color changes can occur at a specific temperature. When the organic photochromic material is used to compound the color change with cobalt chloride, the characteristics of fast change speed and reversible change process can be shown.

[0020] In the present invention, when the organic photochromic material Runba GS5030 and cobalt chloride are used as raw materials to prepare the coating, the two cooperate to achieve the diversification of the color-changing effect and enhance the sense of hierarchy and ornamental value when less organic photochromic material is added. 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 complementarity in the 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 coatings; 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 preventer in paint; 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 paint, can accelerate the drying process of paint; a dense film layer is formed on the surface of the dried paint, which can block the invasion of external moisture and microorganisms, thereby improving the mildew resistance of the paint. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field 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] The present embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, the steps comprising: spraying a photosensitive coating on a base cloth, the number of spraying times is 3 times, and the total thickness of the coating is 0.4 mm; drying the coated base cloth at a temperature of 55° C., then curing it at room temperature for 21 hours, and then curing it 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 defoamer, 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, and the embodiments and comparative examples of the present invention all use cotton base fabric.

[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 acid, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at a temperature of 74° C., heating to 82° C., reacting for 50 minutes, then dropping 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 defoamer 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] The present embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, the steps comprising: spraying a photosensitive coating on a base cloth, the number of spraying times is 3 times, and the total coating thickness is 0.3 mm; drying the coated base cloth at a temperature of 50° C., then curing it at room temperature for 20 hours, and then curing it 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 defoamer, 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 laurylate, 0.03 parts of ammonium persulfate, and 0.03 parts of trimethylolpropane to 70 parts by weight of deionized water at a temperature of 70° C., heating to 80° C., reacting for 40 minutes, then dropping 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 for 1.5 hours at a temperature of 50°C, 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 defoamer 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] The present embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, the steps comprising: spraying a photosensitive coating on a base cloth, the number of spraying is 4 times, and the total thickness of the coating is 0.5 mm; drying the coated base cloth at a temperature of 60° C., then curing it at room temperature for 22 hours, and then curing it at 40° C. for 34 hours, and cutting it 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 acid, 0.05 parts of ammonium persulfate, and 0.05 parts of trimethylolpropane to 74 parts of deionized water at a temperature of 78° C., heating to 84° C., reacting for 60 minutes, then dropping 6 parts of sodium bicarbonate, and filtering to obtain the product;

[0040] The filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:5. 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 for 2 hours at a temperature of 60°C, 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 defoamer 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] The present embodiment provides a method for preparing a photosensitive color-changing cloth bookmark, the steps comprising: spraying a photosensitive coating on a base cloth, the number of spraying times is 3 times, and the total thickness of the coating is 0.5 mm; drying the coated base cloth at a temperature of 50° C., then curing it at room temperature for 22 hours, and then curing it 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 defoamer, 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 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 laurylate, 0.05 parts of ammonium persulfate, and 0.03 parts of trimethylolpropane to 74 parts of deionized water at a temperature of 70° C., heating to 84° C., reacting for 40 minutes, then dropping 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 for 1.5 hours at a temperature of 60°C, 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 defoamer 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] The present comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the steps of: spraying a photosensitive coating on a base cloth, spraying for 3 times, and having a total coating thickness of 0.4 mm; drying the coated base cloth at a temperature of 55° C., then curing at room temperature for 21 hours, and then curing at 35° C. for 32 hours, and cutting 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 defoamer, 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, and the embodiments and comparative examples of the present invention all use cotton base fabric.

[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 acid, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at a temperature of 74° C., heating to 82° C., reacting for 50 minutes, then dropping 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0053] The filler is modified kaolin, and 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 defoamer 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] The present comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the steps of: spraying a photosensitive coating on a base cloth, spraying for 3 times, and having a total coating thickness of 0.4 mm; drying the coated base cloth at a temperature of 55° C., then curing at room temperature for 21 hours, and then curing at 35° C. for 32 hours, and cutting 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 defoamer, 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, and the embodiments and comparative examples of the present invention all use cotton base fabric.

[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 acid, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at a temperature of 74° C., heating to 82° C., reacting for 50 minutes, then dropping 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 for 1.75 hours at a temperature of 55°C, 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 defoamer 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] The present comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the steps of: spraying a photosensitive coating on a base cloth, spraying for 3 times, and having a total coating thickness of 0.4 mm; drying the coated base cloth at a temperature of 55° C., then curing at room temperature for 21 hours, and then curing at 35° C. for 32 hours, and cutting 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 defoamer, 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, and the embodiments and comparative examples of the present invention all use cotton base fabric.

[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 acid, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at a temperature of 74° C., heating to 82° C., reacting for 50 minutes, then dropping 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 Dispersant900; the defoamer 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] The present comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the steps of: spraying a photosensitive coating on a base cloth, spraying for 3 times, and having a total coating thickness of 0.4 mm; drying the coated base cloth at a temperature of 55° C., then curing at room temperature for 21 hours, and then curing at 35° C. for 32 hours, and cutting 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 defoamer, 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, and the embodiments and comparative examples of the present invention all use cotton base fabric.

[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 acid, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at a temperature of 74° C., heating to 82° C., reacting for 50 minutes, then dropping 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 calcium carbonate in deionized water to prepare a suspension, mixing the suspension with the ethanol solution of the silane coupling agent, stirring for 1.75 hours at a temperature of 55°C, 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 defoamer 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] The present comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the steps of: spraying a photosensitive coating on a base cloth, spraying for 3 times, and having a total coating thickness of 0.4 mm; drying the coated base cloth at a temperature of 55° C., then curing at room temperature for 21 hours, and then curing at 35° C. for 32 hours, and cutting 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 defoamer, 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, and the embodiments and comparative examples of the present invention all use cotton base fabric.

[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 acid, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at a temperature of 74° C., heating to 82° C., reacting for 50 minutes, then dropping 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0080] The filler comprises cobalt chloride and calcium carbonate in a weight ratio of 1:4.5; the dispersant is Dispersant900; the defoamer 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] The present comparative example provides a method for preparing a photosensitive color-changing cloth bookmark, comprising the steps of: spraying a photosensitive coating on a base cloth, spraying for 3 times, and having a total coating thickness of 0.4 mm; drying the coated base cloth at a temperature of 55° C., then curing at room temperature for 21 hours, and then curing at 35° C. for 32 hours, and cutting 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 defoamer, 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, and the embodiments and comparative examples of the present invention all use cotton base fabric.

[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 acid, 0.04 parts of ammonium persulfate, and 0.04 parts of trimethylolpropane to 72 parts by weight of deionized water at a temperature of 74° C., heating to 82° C., reacting for 50 minutes, then dropping 5 parts of sodium bicarbonate, and filtering to obtain the product;

[0086] The filler is cobalt chloride; the dispersant is Dispersant 900; the defoamer 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 an incubator at 25°C for 4 weeks.

[0089] Growth rating standards: 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; to restore the color, place the discolored bookmark in a dark room and record the color recovery 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 the base fabric 3-4 times, and the total coating thickness is 0.3mm-0.5mm; the coated base fabric is dried at a temperature of 50-60°C, and then cured and cut into bookmarks; wherein the photosensitive coating comprises 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.

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 filler comprises cobalt chloride and modified kaolin in a weight ratio of 1:(4-5).

5. The method for preparing a photosensitive color-changing cloth bookmark according to claim 4, characterized in that: 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 50-60° C. for 1.5-2 hours, filtering and drying to obtain the modified kaolin.

6. The method for preparing a photosensitive color-changing cloth bookmark according to claim 5, 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).

7. The method for preparing a photosensitive color-changing cloth bookmark according to claim 2, characterized in that: The base 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 acid, 0.03-0.05 parts of ammonium persulfate, and 0.03-0.05 parts of trimethylolpropane to 70-74 parts of deionized water at a temperature of 70-78°C, heating to 80-84°C, reacting for 40-60 minutes, then dripping 4-6 parts of sodium bicarbonate, and filtering to obtain the base resin.

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

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

10. 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 9.

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