Preparation method of gold mud powder and gold mud powder

Abstract

The invention provides a preparation method of gold mud powder and the gold mud powder, and relates to the technical field of preparation of precious metal powder colloidal particles. The preparation method comprises the following steps: by using spherical gold powder as a raw material, firstly, mixing and ball-milling the spherical gold powder with auxiliaries, namely polyvinyl alcohol and gelatin, washing with deionized water, and drying to obtain flaky gold powder; and uniformly mixing the flaky gold powder with an adhesive and a nonionic surfactant, and drying to obtain the gold mud powder. According to the method, two organic assistants are added during grinding to assist grinding, the two organic assistants synergistically adjust the dispersity of the gold powder in the ball-milling liquid, and the cold welding phenomenon caused by the soft texture of the gold powder in the grinding process and the gold powder adhesion and agglomeration phenomena caused by insufficient viscosity and lubricity of the ball-milling liquid are effectively avoided. Besides, the surface tension of water in the gold paste is reduced by adding the nonionic surfactant, so that the gold mud powder can be directly coated on the smooth surfaces of utensils after being mixed with water, the gold brushing process is simplified, and the application range of the gold mud powder is expanded.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of precious metal powder colloid particles, and in particular to a preparation method of gold mud powder for decoration and the gold mud powder. Background Art

[0002] Gold is one of the rarest and most precious metals in the world. It not only has the characteristics of high density, high chemical stability, soft texture, excellent ductility, non-oxidation and corrosion resistance, but also has a bright golden color. It can maintain good luster and performance in a variety of environments and is easy to process. It is widely used in jewelry making, Kintsugi restoration, gilding of Buddha statues, thangka, sutra writing, and Maki-e and other arts and crafts decoration fields.

[0003] In the aforementioned field of arts and crafts decoration, common processing methods include gilding, brushing gold, gilding, gold plating, and the like. Among them, brushing gold refers to brushing the surface of the Buddha statue with gold powder or gold paste to form a golden coating, and gold mud pigment (gold mud powder) is an important raw material for preparing gold paste. In traditional processes, gold mud powder is mainly prepared by manually kneading a mixture of gold foil and animal glue, washing with a large amount of water and drying. The labor and raw material costs of this preparation method are high, especially the gold foil raw material used in the preparation process needs to be repeatedly beaten manually, and the preparation process includes twelve steps, which is very complicated and lengthy. In addition, the traditional gold brushing process is also relatively complicated, and the water-soluble gold mud powder is difficult to directly apply on the smooth surface of the object. The object needs to be cleaned, polished, and other pre-treatments in advance before it can be evenly brushed.

[0004] In view of this, it is necessary to design a preparation method of gold mud powder and gold mud powder to solve the above problems. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides a method for preparing gold mud powder and gold mud powder, using spherical gold powder with a particle size of 2-4 μm and a purity greater than 99% as a raw material, firstly mixing the spherical gold powder with auxiliary agents polyvinyl alcohol and gelatin to prepare flaky gold powder by ball milling, and then mixing the flaky gold powder with a binder and a non-ionic surfactant to prepare gold mud powder. The gold mud powder prepared by the method can be directly applied to the smooth surface of an object after being mixed with water, without the need to polish the object in advance, and has a low cost of use, simple and convenient operation, a wide range of applications, and has achieved large-scale production.

[0006] In a first aspect, the present application provides a method for preparing gold mud powder, which is prepared using spherical gold powder, comprising the following steps: S1, mixing the spherical gold powder with a polyvinyl alcohol solution and a gelatin solution, adding zircon balls for ball milling, filtering, washing with deionized water until the gold powder solution is clear, and drying to obtain flaky gold powder; S2, uniformly mixing the flaky gold powder obtained in step S1 with a binder and a non-ionic surfactant, and drying the mixture to obtain gold mud powder.

[0007] Furthermore, the particle size of the spherical gold powder is 2-4 μm, and the purity is greater than 99%.

[0008] Furthermore, in step S2, the nonionic surfactant is polyethylene glycol monooctyl phenyl ether, and the amount of polyethylene glycol monooctyl phenyl ether used is 0.1-1% of the mass of the flaky gold powder.

[0009] Furthermore, in step S1, the concentration of the polyvinyl alcohol solution is 0.1-0.3 g / mL, and each gram of spherical gold powder is mixed with 8-20 mL of the polyvinyl alcohol solution.

[0010] Furthermore, in step S1, the concentration of the gelatin solution is 0.1-0.3 g / mL, and each gram of spherical gold powder is mixed with 8-20 mL of gelatin solution.

[0011] Furthermore, in step S1, the ratio of the spherical gold powder to the zircon ball is 1:(40-60); in step S1, the rotation speed of the ball mill is 150-200 r / min, and the ball milling time is 3-5 h.

[0012] Furthermore, in step S2, the adhesive is a gelatin solution, and the concentration of the gelatin is 0.1-0.3 g / mL; in step S2, each gram of flaky gold powder is mixed with 0.08-0.2 mL of the gelatin solution.

[0013] Furthermore, in step S1 and step S2, the drying temperature is 60-90°C.

[0014] Furthermore, step S2 also includes adding water to the mixture of flaky gold powder, adhesive and non-ionic surfactant to adjust the gold paste to a viscous state, dipping the viscous gold paste with a brush, allowing the gold paste to naturally drip onto the polyethylene plastic plate under the action of gravity to form small droplets, and then drying it.

[0015] In a second aspect, the embodiment of the present application provides a gold mud powder, which is prepared according to any one of the above technical solutions, and is used in the fields of gold painting of Buddha statues, thangka, scripture writing, and painting. When using the gold mud powder, there is no need to polish the object in advance, and the gold mud powder can be directly applied on the smooth surface of the object after adding water to make it viscous.

[0016] The beneficial effects of the present invention are: The present application provides a method for preparing gold mud powder and the gold mud powder. Spherical gold powder with a particle size of 2-4 μm and a purity greater than 99% is used as a raw material. The spherical gold powder is first mixed with auxiliary agents polyvinyl alcohol and gelatin for ball milling to prepare flaky gold powder, and then the flaky gold powder is mixed with an adhesive and a non-ionic surfactant to prepare the gold mud powder. The method has a high degree of mechanization and a short process. The prepared gold mud powder can be directly applied to the smooth surface of an object after being mixed with water, without the need to polish the object in advance. The use cost is low, the operation is simple and convenient, and the application range is wide. Large-scale production has been achieved.

[0017] (1) In the ball milling process of the present application, polyvinyl alcohol and gelatin are added simultaneously. The synergistic effect of the two helps to adjust the dispersibility of the gold powder in the ball milling liquid, thereby preparing flaky gold powder with regular shape and uniform dispersion. Among them, polyvinyl alcohol molecules contain a large number of hydroxyl groups, which can increase the hydrophilicity of the gold powder, make the gold powder fully dispersed, and avoid the cold welding phenomenon caused by the gold powder being too soft; adding organic additive gelatin can increase the viscosity of the ball milling liquid, improve the lubricity, and avoid uneven dispersion of the gold powder caused by adhesion or agglomeration of the gold powder.

[0018] (2) The adhesive of the present application is preferably gelatin, and the nonionic surfactant is preferably polyethylene glycol monooctylphenyl ether. Among them, one end of the polyethylene glycol monooctylphenyl ether molecule is a hydroxyl hydrophilic group, and the other end is an alkane hydrophobic group. The hydrophilic group can form hydrogen bonds with water molecules, so that a molecular film is formed on the surface of the liquid. The molecular film can reduce the surface tension of the water in the gold paste, so that the gold paste can be directly and evenly coated on the smooth surface of the object. This improvement not only simplifies the gold brushing process, but also broadens the application range of gold mud powder.

[0019] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a SEM image of the gold mud powder prepared in Example 1 of the present application; Figure 2 This is a SEM image of the gold mud powder prepared in Example 2 of the present application; Figure 3This is a SEM image of the gold mud powder prepared in Example 3 of the present application; Figure 4 This is a SEM image of the gold mud powder prepared in Comparative Example 1 of the present application; Figure 5 This is a SEM image of the gold mud powder prepared in Comparative Example 2 of the present application; Figure 6 The present invention is a comparison diagram of the effects of brushing the gold mud powders prepared in Example 1 and Comparative Example 3 of the present application onto the surface of a smooth copper object after being respectively prepared into gold slurries; wherein, a is a brushing effect diagram of the gold mud powder prepared in Comparative Example 3, and b is a brushing effect diagram of the gold mud powder prepared in Example 1. DETAILED DESCRIPTION

[0022] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0024] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0025] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0027] In traditional processes, gold mud powder is mainly prepared by manually kneading a mixture of gold foil and animal glue, washing it with a large amount of water and drying it. The labor and raw material costs of this preparation method are high, especially the gold foil raw materials used in the preparation process need to be repeatedly beaten manually. The preparation process includes twelve steps and is very complicated and lengthy. In addition, the traditional gold brushing process is also relatively complicated. The water-soluble gold mud powder is difficult to directly apply on the smooth surface of the object. The object needs to be cleaned, polished and other pre-treatments in advance before it can be evenly brushed.

[0028] In order to solve the technical problems that the preparation cost of traditional gold mud powder is high and the traditional water-soluble gold mud powder cannot be directly applied on the smooth surface of objects, resulting in a complicated gold-brushing process, the present application provides a preparation method of gold mud powder and gold mud powder, wherein two organic additives are added during grinding to assist grinding, and the two organic additives synergistically adjust the dispersibility of the gold powder in the ball-milling liquid, thereby effectively avoiding the cold welding phenomenon caused by the soft texture of the gold powder during the grinding process and the adhesion and agglomeration of the gold powder caused by the insufficient viscosity and lubricity of the ball-milling liquid; the surface tension of the water in the gold slurry is reduced by adding a non-ionic surfactant, so that the gold mud powder can be directly applied on the smooth surface of the object after being mixed with water, which not only simplifies the gold-brushing process, but also expands the application range of the gold mud powder.

[0029] In the first aspect, an embodiment of the present application provides a method for preparing gold mud powder, which is prepared by using spherical gold powder with a particle size of 2-4 μm and a purity greater than 99%. The preparation method of spherical gold powder can be found in Chinese patent publication number CN118682140B, which will not be repeated here.

[0030] The method for preparing the gold mud powder provided in the embodiment of the present application comprises the following steps: S1, mixing spherical gold powder with polyvinyl alcohol solution and gelatin solution, adding zircon balls for ball milling, filtering to remove the zircon balls, washing with deionized water until the gold powder solution is clear, drying at 60-90° C., and obtaining flaky gold powder.

[0031] The concentration of the polyvinyl alcohol solution is 0.1-0.3 g / mL, and each gram of spherical gold powder is mixed with 8-20 mL of the polyvinyl alcohol solution. The concentration of the gelatin solution is 0.1-0.3 g / mL, and each gram of spherical gold powder is mixed with 8-20 mL of the gelatin solution.

[0032] Adding polyvinyl alcohol and gelatin at the same time during the ball milling process, the synergistic effect of the two helps to adjust the dispersion of gold powder in the ball milling liquid, and then prepares gold powder with regular shape and uniform dispersion. Among them, polyvinyl alcohol molecules contain a large number of hydroxyl groups, which can increase the hydrophilicity of gold powder, make the gold powder fully dispersed, and avoid the cold welding phenomenon caused by the gold powder being too soft; adding organic additive gelatin can increase the viscosity of the ball milling liquid, improve lubricity, and avoid uneven dispersion of gold powder caused by adhesion or agglomeration of gold powder.

[0033] Preferably, the solvent of the polyvinyl alcohol solution and the gelatin solution is water.

[0034] In the embodiment of the present application, the ratio of spherical gold powder to zircon balls is 1:(40-60), the ball milling speed is 150-200 r / min, and the ball milling time is 3-5 h.

[0035] Preferably, the equipment used for ball milling is a planetary ball mill.

[0036] Preferably, the number of washings with deionized water is 6-10 times.

[0037] S2, mixing the flaky gold powder obtained in step S1 with a binder and a non-ionic surfactant, adding water to adjust the gold paste to a viscous state, and drying at 60-90° C. to obtain gold mud powder.

[0038] The binder is preferably a gelatin solution, the concentration of gelatin is 0.1-0.3 g / mL, and each gram of flaky gold powder is mixed with 0.08-0.2 mL of gelatin solution. The nonionic surfactant is polyethylene glycol monooctyl phenyl ether, and the amount of polyethylene glycol monooctyl phenyl ether is 0.1-1% of the mass of the flaky gold powder.

[0039] One end of the molecule of polyethylene glycol monooctylphenyl ether is a hydroxyl hydrophilic group, and the other end is an alkane hydrophobic group. The hydrophilic group can form hydrogen bonds with water molecules, forming a molecular film on the surface of the liquid. The molecular film can reduce the surface tension of the water in the gold paste, so that the gold paste can be directly and evenly coated on the smooth surface of the object. This improvement not only simplifies the gold brushing process, but also makes the application range of gold mud powder wider.

[0040] Preferably, the solvent of the gelatin solution is water.

[0041] In the embodiment of the present application, step S2 also includes using a brush to dip the viscous gold paste, allowing the gold paste to drip naturally onto the polyethylene plastic plate under the action of gravity to form small droplets, and then drying at 60-90° C. In this way, the shape of the prepared gold mud powder product is a round thin sheet with a spherical crown on the top, and the size of the round thin sheet is uniform and moderate, which is convenient for weighing and taking.

[0042] In the second aspect, the embodiment of the present application provides a gold mud powder, which is prepared by any of the technical solutions in the aforementioned solutions, and the gold mud powder is used in the fields of gold painting of Buddha statues, thangka, scripture writing, and maki-e. When using the gold mud powder, there is no need to polish the object in advance, and the gold mud powder can be directly applied on the smooth surface of the object after adding water to make it viscous.

[0043] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0044] Example 1 Embodiment 1 provides a method for preparing gold mud powder, comprising the following steps: S1. Mix 2 g of spherical gold powder with a particle size of 2-4 um with 20 mL of a polyvinyl alcohol solution with a concentration of 0.2 g / mL and 20 mL of a gelatin solution with a concentration of 0.2 g / mL in a ball mill, add 100 g of zircon balls, and place the ball mill in a planetary ball mill. Mill at a speed of 150 r / min for 4 h, then filter out the zircon balls, wash with deionized water for 8 times until the gold powder solution is clear, and dry at 80°C to obtain flaky gold powder.

[0045] S2, weigh 2g of flaky gold powder and mix it with 0.2mL of 0.2g / mL gelatin and 2mg of polyethylene glycol monooctylphenyl ether, then add 120uL of water to adjust the gold paste to a viscous state, dip a brush into the gold paste, and allow the gold paste to drip naturally onto a polyethylene plastic plate under the action of gravity to form small droplets, and dry at 80°C to obtain bright yellow gold mud powder.

[0046] The gold mud powder prepared in Example 1 was characterized by a scanning electron microscope (SEM). Figure 1 As shown, it can be seen that the flaky gold powder in the gold mud powder has a uniform morphology. After measurement, the average size of the flaky gold powder is 7-8μm.

[0047] Example 2 Example 2 provides a method for preparing gold mud powder (enlarged test), comprising the following steps: S1. Mix 10 g of spherical gold powder with a particle size of 2-4 um with 100 mL of a polyvinyl alcohol solution with a concentration of 0.2 g / mL and 100 mL of a gelatin solution with a concentration of 0.2 g / mL in a ball mill, add 500 g of zircon balls, and place the ball mill in a planetary ball mill. Mill for 4 h at a speed of 150 r / min, then filter to remove the zircon balls, wash with deionized water for 8 times until the gold powder solution is clear, and dry at 80°C to obtain flaky gold powder.

[0048] S2, weigh 10g of flaky gold powder and mix it with 1mL of 0.2g / mL gelatin and 10mg of polyethylene glycol monooctylphenyl ether, then add 600uL of water to make the gold paste viscous, dip the gold paste with a brush, and let it drip naturally on a polyethylene plastic plate under the action of gravity to form small droplets, and dry it at 80℃ to obtain bright yellow gold mud powder.

[0049] The gold mud powder prepared in Example 2 was characterized by scanning electron microscopy (SEM). Figure 2 As shown, it can be seen that the flaky gold powder in the gold mud powder has uniform morphology. After measurement, the average size of the flaky gold powder is 7-8μm.

[0050] Example 3 Example 3 provides a method for preparing gold mud powder (enlarged test), comprising the following steps: S1. Mix 25 g of spherical gold powder with a particle size of 2-4 um with 250 mL of a polyvinyl alcohol solution with a concentration of 0.2 g / mL and 250 mL of a gelatin solution with a concentration of 0.2 g / mL in a ball mill, add 1250 g of zircon balls, and place the ball mill in a planetary ball mill. Mill at a speed of 150 r / min for 4 h, then filter out the zircon balls, wash with deionized water for 8 times until the gold powder solution is clear, and dry at 80°C to obtain flaky gold powder.

[0051] S2, weigh 25g of flaky gold powder and mix it with 2.5mL of 0.2g / mL gelatin and 25mg of polyethylene glycol monooctylphenyl ether, then add 1.5mL of water to adjust the gold paste to a viscous state, use a brush to dip the gold paste, and allow the gold paste to drip naturally onto a polyethylene plastic plate under the action of gravity to form small droplets, and dry it at 80°C to obtain bright yellow gold mud powder.

[0052] The gold mud powder prepared in Example 3 was characterized by scanning electron microscopy (SEM). Figure 3 As shown, it can be seen that the flaky gold powder in the gold mud powder has a uniform morphology. After measurement, the average size of the flaky gold powder is 7-8μm.

[0053] Comparative Example 1 Comparative Example 1 provides a method for preparing gold mud powder, which is different from Example 1 in that only one grinding aid, namely gelatin, is used in step S1. Specifically, 2 g of spherical gold powder with a particle size of 2-4 um is mixed with 40 mL of a gelatin solution with a concentration of 0.2 g / mL in a ball mill, 100 g of zircon balls are added, and the ball mill is placed in a planetary ball mill, ball milled at a speed of 150 r / min for 4 hours, and then the zircon balls are filtered out, washed with deionized water 8 times until the gold powder solution is clear, and dried at 80°C to obtain flaky gold powder. The other contents are the same as those in Example 1 and will not be repeated here.

[0054] The gold mud powder prepared in Comparative Example 1 was characterized by scanning electron microscopy (SEM). Figure 4 As shown, it can be seen that the flaky gold powder in the gold mud powder has uneven morphology and obvious cold welding phenomenon, that is, most of it is pressed into large flakes. In subsequent applications, the size of the flaky gold powder is too large and the morphology is uneven, which may cause the surface of the gold layer obtained by brushing to have obvious granularity, affecting the use effect.

[0055] Comparative Example 2 Comparative Example 2 provides a method for preparing gold mud powder, which is different from Example 1 in that only one grinding aid, namely polyvinyl alcohol, is used in step S1. Specifically, 2 g of spherical gold powder with a particle size of 2-4 um is mixed with 40 mL of polyvinyl alcohol solution with a concentration of 0.2 g / mL in a ball mill, 100 g of zircon balls are added, and the ball mill is placed in a planetary ball mill, ball milled at a speed of 150 r / min for 4 hours, and then the zircon balls are filtered out, washed with deionized water 8 times until the gold powder solution is clear, and dried at 80°C to obtain flaky gold powder. The other contents are the same as those in Example 1 and will not be repeated here.

[0056] The gold mud powder prepared in Comparative Example 2 was characterized by scanning electron microscopy (SEM). Figure 5 As shown, it can be seen that the flaky gold powder in the gold mud powder does not show obvious cold welding phenomenon, but the flaky gold powder is unevenly distributed, and a small amount of flaky gold powder is bonded together, which may cause the surface of the gold layer obtained by brushing to be rough and have poor gloss during subsequent use.

[0057] Comparative Example 3 Comparative Example 3 provides a method for preparing gold mud powder, which is different from Example 1 in that: polyethylene glycol monooctylphenyl ether is not added in step S2. Specifically, 2g of flaky gold powder is weighed and mixed with 0.2mL of gelatin with a concentration of 0.2g / mL, and 120uL of water is added to adjust the gold paste to a viscous state, and the gold paste is dipped with a brush to allow the gold paste to drip naturally on a polyethylene plastic plate under the action of gravity and form small droplets, and then dried at 80°C to obtain bright yellow gold mud powder. The other contents are the same as those in Example 1 and will not be repeated here.

[0058] The gold mud powder prepared in Comparative Example 3 cannot be directly applied to the smooth surface of an object by brushing, and the object needs to be pre-treated by polishing in advance, which not only increases the use process but also has a narrow application range.

[0059] Comparative Example 4 Comparative Example 4 provides a method for preparing gold mud powder, which is different from Example 1 in that in step S2, the adhesive gelatin is replaced with gum arabic. Specifically, 2g of flaky gold powder is weighed and mixed with 0.2mL of 0.2g / mL gum arabic and 2mg of polyethylene glycol monooctylphenyl ether, and then 120uL of water is added to adjust the gold paste to a viscous state. The gold paste is dipped with a brush, and the gold paste is naturally dripped on a polyethylene plastic plate under the action of gravity to form small droplets, and dried at 80°C to obtain bright yellow gold mud powder. The other contents are the same as those in Example 1 and will not be repeated here.

[0060] The surface brightness and color of the gold mud powder prepared in Example 1 and Comparative Example 4 were characterized by using a spectrophotometer. The results are shown in the table below.

[0061] As shown in the table above, compared with Example 1, the gold mud powder prepared in Comparative Example 4 is darker and less yellow, which may be because the color of the gold mud powder is affected by the color of the gum arabic. Therefore, in the preparation method of the gold mud powder provided in the present application, gelatin is more suitable as a binder.

[0062] The gold mud powders prepared in Example 1 and Comparative Example 3 were used to prepare gold paste and brush-coated the copper objects (white copper) with smooth surfaces. 200uL of water was added to each gram of gold mud powder to make a thick gold paste. The brushing effect was shown in FIG. Figure 6As shown. It can be seen that the gold paste obtained by mixing the gold mud powder of Example 1 can be evenly brushed on the object, while the gold paste obtained by mixing the gold mud powder of Comparative Example 3 quickly shrinks into an irregular shape after being brushed on the object, and it is difficult to brush evenly. This is related to the excessive surface tension of the gold paste. In the molecular structure of the non-ionic surfactant polyethylene glycol monooctylphenyl ether, one end is a hydroxyl hydrophilic group and the other end is an alkane hydrophobic group. The hydrophilic group can form hydrogen bonds with water molecules to form a molecular film on the surface of the liquid. The molecular film can reduce the surface tension of water in the gold paste, so that the gold paste can be directly and evenly coated on the smooth surface of the object.

[0063] In summary, the present application provides a method for preparing gold mud powder and gold mud powder. Spherical gold powder with a particle size of 2-4 μm and a purity greater than 99% is used as a raw material. The spherical gold powder is first mixed with additives polyvinyl alcohol and gelatin for ball milling to prepare flaky gold powder. The flaky gold powder is then mixed with an adhesive and a non-ionic surfactant to prepare a bright yellow gold mud powder. The prepared gold mud powder can be directly applied to the smooth surface of an object after being mixed with water. The preparation method has been successfully scaled up and can process 25g of gold powder at a time. In the comparative example, when only the additive polyvinyl alcohol is used in the ball milling, the prepared flaky gold powder has obvious cold welding phenomenon; when only the additive gelatin is used in the ball milling, the prepared flaky gold powder has obvious adhesion and agglomeration phenomenon; when the adhesive gelatin is replaced with gum arabic, the color of the gold mud powder becomes darker and is not yellow enough; when the non-ionic surfactant is not added, the gold paste obtained by mixing the gold mud powder with water cannot be directly and evenly coated on the smooth surface of the object.

[0064] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing gold mud powder, characterized in that: The method is prepared by using spherical gold powder, comprising the following steps: S1, mixing the spherical gold powder with a polyvinyl alcohol solution and a gelatin solution, adding zircon balls for ball milling, filtering, washing with deionized water until the gold powder solution is clear, and drying to obtain flaky gold powder; S2, uniformly mixing the flaky gold powder obtained in step S1 with a binder and a non-ionic surfactant, and drying the mixture to obtain gold mud powder.

2. The method for preparing gold mud powder according to claim 1, characterized in that: The particle size of the spherical gold powder is 2-4 μm, and the purity is greater than 99%.

3. The method for preparing gold mud powder according to claim 1, characterized in that: In step S2, the nonionic surfactant is polyethylene glycol monooctyl phenyl ether, and the amount of polyethylene glycol monooctyl phenyl ether used is 0.1-1% of the mass of the flaky gold powder.

4. The method for preparing gold mud powder according to claim 1, characterized in that: In step S1, the concentration of the polyvinyl alcohol solution is 0.1-0.3 g / mL, and each gram of spherical gold powder is mixed with 8-20 mL of the polyvinyl alcohol solution.

5. The method for preparing gold mud powder according to claim 1, characterized in that: In step S1, the concentration of the gelatin solution is 0.1-0.3 g / mL, and each gram of spherical gold powder is mixed with 8-20 mL of the gelatin solution.

6. The method for preparing gold mud powder according to claim 2, characterized in that: In step S1, the ratio of the spherical gold powder to the zircon ball is 1:(40-60); in step S1, the rotation speed of the ball mill is 150-200 r / min, and the ball milling time is 3-5 h.

7. The method for preparing gold mud powder according to claim 1, characterized in that: In step S2, the adhesive is a gelatin solution, and the concentration of the gelatin is 0.1-0.3 g / mL; in step S2, each gram of flaky gold powder is mixed with 0.08-0.2 mL of the gelatin solution.

8. The method for preparing gold mud powder according to claim 1, characterized in that: In step S1 and step S2, the drying temperature is 60-90°C.

9. The method for preparing gold mud powder according to claim 1, characterized in that: Step S2 also includes adding water to the mixture of flaky gold powder, adhesive and non-ionic surfactant to adjust the gold paste to a viscous state, dipping the viscous gold paste with a brush, allowing the gold paste to naturally drip onto the polyethylene plastic plate under the action of gravity to form small droplets, and then drying.

10. A gold mud powder, characterized in that: The gold mud powder is prepared according to the preparation method of the gold mud powder according to any one of claims 1 to 9, and the gold mud powder is used in the fields of gilding Buddha statues, thangkas, sutra writing and maki-e; when using the gold mud powder, there is no need to polish the objects in advance, and water is added to adjust the gold mud powder to a viscous state and then it is directly applied on the smooth surface of the object.

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