Method for manufacturing anti-counterfeiting composite particles

Abstract

This invention provides a method for manufacturing composite particles for counterfeit prevention. [Solution] The method includes the steps of: obtaining multiple metal-modified composite particles by grafting multiple core-shell type composite particles with a treatment solution containing a metal precursor, an alkaline substance, and a reducing agent; and producing multiple anti-counterfeiting composite particles by performing a first polymerization treatment on a first mixture containing the metal-modified composite particles, a first monomer, a second monomer, and a first initiator aqueous solution containing a first initiator, wherein the type of the first monomer is different from that of the second monomer, the weight ratio of the first monomer to the second monomer is 2 to 5, and the weight ratio of the total amount of the first monomer and the second monomer to the first initiator is 120 to 180.

Description

Technical Field

[0001] The present invention relates to a technology for preventing the forgery of artworks, and particularly to a method for manufacturing composite particles for anti-forgery.

Background Art

[0002] Artworks represent the creativity and ingenuity of the author, and their value is immeasurable. However, in order for unscrupulous people to gain benefits, imitations of artworks flow into the market, which not only infringes on the rights of the creators but also damages the reliability of the art market. Therefore, a method that gives artworks an anti-forgery function without sacrificing their original value is one of the solutions to prevent the emergence of imitations.

[0003] Patent Document 1 provides a method for preventing painting forgery, in which an identification unit is installed on a painting medium. After the user completes a painting on the painting medium, identification information related to this painting is written into the identification unit using a writing device. When determining the authenticity of the painting, the identification information in the identification unit is read and identified using an identification device.

[0004] However, with the rapid progress of imitation technology, the identification unit itself is also easily imitated, and the anti-forgery function of the original design is gradually losing its effect.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, an object of the present invention is to provide a new method for manufacturing composite particles for anti-forgery.

Means for Solving the Problems

[0007] The present invention provides a step of obtaining a plurality of metal-modified composite particles by grafting a plurality of core-shell type composite particles with a treatment solution containing a metal precursor, an alkaline substance, and a reducing agent, wherein the grafting treatment is performed under conditions where the rotation speed is in the range of 200 rpm to 500 rpm and the temperature is in the range of 60°C to 80°C, and the metal precursor is reduced to a metal by the reducing agent, and then grafted onto the surface of the plurality of core-shell type composite particles to form the plurality of metal-modified composite particles. b. A step of producing a plurality of anti-counterfeiting composite particles by performing a first polymerization treatment on a first mixture containing a plurality of metal-modified composite particles, a first monomer, a second monomer, and a first initiator aqueous solution containing a first initiator, wherein the first polymerization treatment includes a step of copolymerizing the first monomer and the second monomer on the surface of the plurality of metal-modified composite particles to form the plurality of anti-counterfeiting composite particles under conditions where the rotation speed is in the range of 200 rpm to 500 rpm and the temperature is in the range of 60°C to 80°C, The present invention provides a method for producing anti-counterfeiting composite particles, wherein the type of the first monomer differs from that of the second monomer, the weight ratio of the first monomer to the second monomer is 2 to 5, and the weight ratio of the total amount of the first monomer and the second monomer to the first initiator is 120 to 180. [Effects of the Invention]

[0008] The effect of the present invention is that, by step a, the metal is grafted onto the surface of the core-shell type composite particle, so that each resulting metal-modified composite particle has a distinguishable distinguishing feature.

[0009] Furthermore, in step b, the first monomer and the second monomer are copolymerized on the surface of the metal-modified composite particle, so that each anti-counterfeiting composite particle produced has a stable multi-core-shell structure in addition to its distinctive features.

[0010] Therefore, when these anti-counterfeiting composite particles are added to art materials such as paints, drawing paper, wood, ceramics, and adhesives to create works of art, not only are the works of art given anti-counterfeiting properties, but these anti-counterfeiting composite particles do not interact with the art materials, and thus do not affect the inherent value of the works of art. [Brief explanation of the drawing]

[0011] [Figure 1] These are SEM images of multiple anti-counterfeiting composite particles from Example 1. [Modes for carrying out the invention]

[0012] In this description of the present invention, terms such as "first," "second," etc., are used solely for the purpose of distinction and do not imply or suggest relative importance.

[0013] The present invention will be described in detail below. The present invention provides a method for producing anti-counterfeiting composite particles, comprising steps a and b.

[0014] Step a is a step in which multiple core-shell type composite particles are grafted with a treatment solution containing a metal precursor, an alkaline substance, and a reducing agent to obtain multiple metal-modified composite particles.

[0015] Step b is a step of producing a plurality of anti-counterfeiting composite particles by performing a first polymerization treatment on a first mixture containing the plurality of metal-modified composite particles, a first monomer, and a second monomer, and a first initiator aqueous solution containing the first initiator.

[0016] Steps a and b will be explained in detail below.

[0017] <Step a> The grafting process includes forming a first product containing a plurality of metal-modified composite particles by grafting the metal-modified composite particles on the surface of the core-shell composite particles after the metal precursor is reduced to a metal by a reducing agent under the conditions that the rotation speed ranges from 200 rpm to 500 rpm and the temperature ranges from 60 °C to 80 °C.

[0018] By this metal, each of the obtained metal-modified composite particles has distinguishable identification characteristics. The type of the metal is selected from at least one of the metals from Group 3 to Group 10 elements of the periodic table, for example.

[0019] In some embodiments of the present invention, the metal is selected from at least one of erbium (Er), lanthanum (La), dysprosium (Dy), samarium (Sm), yttrium (Y), and praseodymium (Pr).

[0020] In some examples of the present invention, the metal is dysprosium, lanthanum, and erbium, and the molar ratio of dysprosium, lanthanum, and erbium is 1:2:7.

[0021] To generate the metal, a reducing agent is used to reduce the metal precursor to the metal. The type of the metal precursor is selected according to the type of the metal to be generated.

[0022] In some examples of the present invention, the metal is dysprosium, lanthanum, and erbium, and the metal precursor is selected from an aqueous solution of dysprosium nitrate, an aqueous solution of lanthanum nitrate, and an aqueous solution of erbium nitrate.

[0023] By an alkaline substance, the reducing agent reduces the metal precursor in an alkaline environment to generate a metal.

[0024] In some embodiments of the present invention, the reducing agent is selected from at least one of hydrazine, hypophosphite, and sulfite.

[0025] In some embodiments of the present invention, the reducing agent is hydrazine. In some embodiments of the present invention, the alkaline substance is sodium hydroxide.

[0026] In some embodiments of the present invention, the molar ratio of metal, alkaline substance, and reducing agent is in the range of 2-6:1-4:1-4.

[0027] Each core-shell composite particle is a particulate polymer having a core-shell structure. In some embodiments of the present invention, these core-shell composite particles are produced by steps P1 and P2.

[0028] Step P1: The second mixture and the second initiator aqueous solution are subjected to a second polymerization treatment to obtain a polymerization product containing multiple homopolymer particles.

[0029] In step P1, the second mixture contains a third monomer, the second initiator aqueous solution contains a second initiator, the second polymerization treatment includes polymerizing the third monomer to form homopolymer particles under conditions where the rotation speed is in the range of 200 rpm to 500 rpm and the temperature is in the range of 60°C to 80°C, the type of the third monomer is the same as the first monomer, and the weight ratio of the third monomer to the second initiator is in the range of 80 to 160.

[0030] Step P2: The third mixture and the third initiator aqueous solution are subjected to a third polymerization treatment to obtain core-shell type composite particles.

[0031] In step P2, the third mixture contains the polymerization product, the fourth monomer, and the fifth monomer, and the aqueous solution of the third initiator contains the third initiator. The third polymerization treatment is carried out under conditions where the rotation speed is in the range of 200 rpm to 500 rpm and the temperature is in the range of 60°C to 80°C, by copolymerizing the fourth monomer and the fifth monomer onto the surface of the plurality of homopolymer particles to form core-shell type composite particles, thereby obtaining a third product containing core-shell type composite particles. The type of the fourth monomer is the same as the third monomer but different from the fifth monomer. The weight ratio of the fourth monomer to the fifth monomer is in the range of 3 to 5, and the weight ratio of the total amount of the fourth monomer and the fifth monomer to the third initiator is in the range of 80 to 300.

[0032] In some embodiments of the present invention, the third polymerization treatment further includes mixing the third product with ethylene glycol and then filtering to separate core-shell composite particles from the third product.

[0033] The function of ethylene glycol is to disperse core-shell composite particles and to make them easily collectible.

[0034] In step P1, the third monomer polymerizes to form structurally stable homopolymer particles. Next, in step P2, the fourth monomer and the fifth monomer copolymerize on the surface of the homopolymer particles, so that each formed core-shell composite particle has a stable core-shell structure.

[0035] Any monomer that can be used in a homopolymerization reaction can be used as the third monomer. For example, the third monomer is selected from, but is not limited to, at least one of styrene, methacrylonitrile, acrylonitrile, methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, vinyl acetate, ketones having a vinyl group, and 1,4-divinylbenzene.

[0036] In some embodiments of the present invention, the third monomer is styrene, and the plurality of homopolymer particles are polystyrene particles. In some embodiments of the present invention, the particle size of the plurality of homopolymer particles can be further controlled by having the concentration of the third monomer in the second mixture be in the range of 0.7 wt% to 1.4 wt%.

[0037] Any initiator capable of initiating a homopolymerization reaction can be used as a second initiator. For example, the second initiator can be selected from radical initiators, ionic initiators, or halogens.

[0038] The radical initiator can be selected from organic peroxides or persulfates. The ion initiator can be selected from ammonium salts or metal amine complexes. The halogen can be selected from chlorine or bromine.

[0039] In some embodiments of the present invention, the second initiator is ammonium persulfate, chlorine, or bromine. In some embodiments of the present invention, the concentration of the second initiator in the aqueous solution of the second initiator is in the range of 0.19 wt% to 0.38 wt%, which allows for further control of the shape and size of the homopolymer particles.

[0040] Since the fourth monomer is the same type as the third monomer, we will omit the details here.

[0041] Any monomer that can be used in copolymerization reactions can be used as the fifth monomer, and can be selected from, but is not limited to, at least one of styrene, methacrylonitrile, acrylonitrile, methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, vinyl acetate, ketones having a vinyl group, and 1,4-divinylbenzene.

[0042] In some embodiments of the present invention, the third monomer and the fourth monomer are both styrene, and the fifth monomer is methyl methacrylate. Therefore, each core-shell composite particle has a core-shell structure in which polystyrene particles form the core and styrene-methyl methacrylate copolymer forms the shell.

[0043] Furthermore, because the fourth monomer and the third monomer are of the same type, the core and shell within each core-shell composite particle have good compatibility, forming a stable core-shell structure.

[0044] Each core-shell composite particle possesses complex properties because the core and shell are made of different polymers, particularly because the core is a homopolymer and the shell is a copolymer.

[0045] For example, a core-shell type composite particle, which has polystyrene particles as the core and styrene-methyl methacrylate copolymer as the shell, possesses the properties of both polystyrene and styrene-methyl methacrylate copolymer. In other words, each core-shell type composite particle has properties such as excellent melt flow index, low hygroscopicity, excellent weather resistance, and excellent optical properties.

[0046] Any initiator capable of initiating a copolymerization reaction can be used as a third initiator; for example, the third initiator can be selected from radical initiators, ionic initiators, or halogens.

[0047] The radical initiator can be selected from organic peroxides or persulfates. The ion initiator can be selected from ammonium salts or metal amine complexes. The halogen can be selected from chlorine or bromine.

[0048] In some embodiments of the present invention, the third initiator is ammonium persulfate, chlorine, or bromine. In some embodiments of the present invention, the concentration of the third initiator in the aqueous solution of the third initiator is in the range of 0.43 wt% to 0.85 wt%, which allows for further control of the shape and size of the core-shell composite particles.

[0049] In some embodiments of the present invention, the grafting process further includes mixing the first product with an aqueous ethylene glycol solution, followed by centrifugation to separate the metal-modified composite particles from the first product.

[0050] An aqueous solution of ethylene glycol is composed of ethylene glycol and water. The function of the aqueous solution of ethylene glycol is to disperse metal-modified composite particles and to make them easily collectible.

[0051] In this step a, the metal is grafted onto the surface of the core-shell composite particle, so that each resulting metal-modified composite particle has a distinguishable distinguishing feature.

[0052] <Step b> The first polymerization treatment involves copolymerizing a first monomer and a second monomer on the surface of multiple metal-modified composite particles under conditions of a rotation speed of 200 rpm to 500 rpm and a temperature of 60°C to 80°C to form multiple anti-counterfeiting composite particles, thereby obtaining a second product containing multiple anti-counterfeiting composite particles.

[0053] Here, the type of the first monomer differs from that of the second monomer, the weight ratio of the first monomer to the second monomer is 2 to 5, and the weight ratio of the total amount of the first and second monomers to the first initiator is 120 to 180.

[0054] Any monomer that can be used in copolymerization reactions can be used as the first monomer. For example, the first monomer is selected from at least one of styrene, methacrylonitrile, acrylonitrile, methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, vinyl acetate, ketones having a vinyl group, and 1,4-divinylbenzene.

[0055] Any monomer that can be used in copolymerization reactions can be used as the second monomer. For example, the second monomer is selected from at least one of styrene, methacrylonitrile, acrylonitrile, methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, vinyl acetate, ketones having a vinyl group, and 1,4-divinylbenzene. In some embodiments of the present invention, the second monomer is different from the fifth monomer.

[0056] In some embodiments of the present invention, the first monomer is styrene and the second monomer is 1,4-divinylbenzene, so each anti-counterfeiting composite particle has a core-shell structure in which a metal-modified composite particle forms the core and a styrene-1,4-divinylbenzene copolymer forms the shell.

[0057] Furthermore, since the first monomer and the third monomer are of the same type as the fourth monomer, these anti-counterfeiting composite particles have a stable multi-core-shell structure.

[0058] In some embodiments of the present invention, the concentration of the first monomer in the first mixture is 4 wt% to 8 wt%, and the concentration of the second monomer is 1 wt% to 3 wt%, thereby further controlling the size of the anti-counterfeiting composite particles.

[0059] Any initiator capable of initiating a copolymerization reaction can be used as the first initiator. For example, the first initiator can be selected from radical initiators, ionic initiators, or halogens.

[0060] The radical initiator can be selected from organic peroxides or persulfates. The ion initiator can be selected from ammonium salts or metal amine complexes. The halogen can be selected from chlorine or bromine. In some embodiments of the present invention, the first initiator is ammonium persulfate, chlorine, or bromine.

[0061] In some embodiments of the present invention, the concentration of the first initiator in the aqueous solution of the first initiator is 0.43 wt% to 0.85 wt%, thereby allowing for further control of the shape and size of the anti-counterfeiting composite particles.

[0062] In some embodiments of the present invention, the weight ratio of the first monomer to the third monomer is in the range of 3 to 5 in order to ensure that each anti-counterfeiting composite particle has a more stable multi-core shell structure, and at the same time has an appropriate shell thickness so that the metal-modified composite particle used as the core is easily detectable by an analytical instrument.

[0063] In some embodiments of the present invention, the first polymerization treatment further includes centrifuging and drying the second product to separate anti-counterfeiting composite particles from the second product. In some embodiments of the present invention, drying is carried out in a temperature range of 30°C to 40°C.

[0064] In step b, the first monomer and the second monomer copolymerize on the surface of multiple metal-modified composite particles, so that each resulting anti-counterfeiting composite particle has a stable multi-core-shell structure in addition to its distinctive properties. [Examples]

[0065] The present invention will be described in more detail by the following examples, but it should be understood that these examples are illustrative and not limiting the implementation of the present invention.

[0066] <Manufacturing Example 1> Core-shell type composite particles Step P1: 2.4 g of the third monomer (of type styrene) and 170 g of water were stirred for 1 hour at 70°C and 350 rpm to obtain the second mixture (concentration of the third monomer was 1.4 wt%).

[0067] A second aqueous solution containing 15 mg of a second initiator (ammonium persulfate) and 8 g of water (concentration of the second initiator: 0.19 wt%) was added to the second mixture, and the mixture was stirred at 70°C and 350 rpm for 0.5 hours to perform the second polymerization treatment.

[0068] Subsequently, stirring was stopped, and the mixture was allowed to stand for 3 hours to stably produce the polymerization product. The polymerization product contains multiple homopolymer particles and has a transparent gel-like appearance.

[0069] Step P2: 17.6 g of the fourth monomer (of type styrene) and 4 g of the fifth monomer (of type methyl methacrylate) were added to the polymerization product, and the mixture was stirred for 1 hour at a temperature of 70°C and a rotation speed of 350 rpm to obtain the third mixture.

[0070] A third aqueous solution containing 85 mg of a third initiator (ammonium persulfate) and 20 g of water (concentration of the third initiator: 0.43 wt%) was added to the third mixture, and the third polymerization treatment was carried out for 3 hours by continuously stirring at 70°C and a rotation speed of 350 rpm.

[0071] Subsequently, stirring was stopped, and a third product containing multiple core-shell type composite particles was obtained. The third product had the appearance of a clear gel. 150 mL of ethylene glycol was added to the third product and mixed thoroughly to obtain a colloidal dispersion containing the core-shell type composite particles. The colloidal dispersion was filtered, and a solid filtrate was collected, which consisted of multiple core-shell type composite particles (yield: 24 g).

[0072] <Example 1> Composite particles for counterfeit prevention Step a: 2.4 mL of 0.1 M aqueous solution of dysprosium nitrate (0.24 mmol of dysprosium), 4.8 mL of 0.1 M aqueous solution of lanthanum nitrate (0.48 mmol of lanthanum), 16 mL of 0.1 M aqueous solution of erbium nitrate (1.60 mmol of erbium), and 1 mL of 1 M aqueous solution of sodium hydroxide (1 mmol of sodium hydroxide) were added together to 24 g of core-shell type composite particles of Production Example 1. The mixture was stirred at 60°C and a rotation speed of 350 rpm for 0.5 hours, then 0.5 mL of 2 M aqueous solution of hydrazine (1 mmol of hydrazine) was added, and the mixture was stirred at 60°C and a rotation speed of 350 rpm for 0.5 hours to perform grafting, thereby obtaining a first product containing multiple metal-modified composite particles.

[0073] To the first product, 300 mL of an aqueous ethylene glycol solution (composed of ethylene glycol and water in a volume ratio of 1:1) was added and centrifugation was performed to collect the solid centrifugated product. Then, another 300 mL of the aqueous ethylene glycol solution was added and centrifugation was performed again to collect the solid recentrifugated product. This recentrifugated product was metal-modified composite particles (yield 24 g).

[0074] Step b: 10 g of the first monomer (of type styrene), 3 g of the second monomer (of type 1,4-divinylbenzene), and 170 g of water were added to 24 g of the metal-modified composite particles to obtain the first mixture (concentration of the first monomer: 5.9 wt%, concentration of the second monomer: 1.8 wt%).

[0075] An aqueous solution of the first initiator (concentration of the first initiator: 0.43 wt%) containing 85 mg of the first initiator (type: ammonium persulfate) and 20 g of water was added to the first mixture, and the first polymerization treatment was carried out for 3 hours at 70°C with stirring at a rotation speed of 350 rpm.

[0076] Subsequently, stirring was stopped to obtain a second product containing multiple anti-counterfeiting composite particles. The second product was centrifuged to collect the solid centrifugal, and the centrifugal was dried at 35±5°C to obtain a dried product. This dried product is the anti-counterfeiting composite particles (yield: 37 g).

[0077] <Evaluation Criteria> The shape and size of the anti-counterfeiting composite particles in Example 1 were analyzed using a scanning electron microscope (manufacturer: JEOL Ltd., model number: JSM-6360). The analysis results are shown in Figure 1. From Figure 1, it can be seen that the particle sizes of the multiple anti-counterfeiting composite particles in Example 1 are in the range of 367 nm to 459 nm.

[0078] <Application Example 1> The anti-counterfeiting composite particles of Example 1 and paint were mixed in a 1:1 weight ratio to form a mixed paint. This mixed paint was then applied to a canvas and allowed to dry to form a dried paint, thereby creating a painting.

[0079] Three samples were obtained by scraping off 4 mg, 8 mg, and 12 mg of dried paint from the painting. The molar ratios of dysprosium, lanthanum, and erbium in the three samples were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS, manufacturer: Agilent Technologies, model: Agilent 7890). The analysis results are shown in Table 1. [Table 1]

[0080] From step a of Example 1, it can be seen that the molar ratio of dysprosium, lanthanum, and erbium in the metal precursor used to produce the anti-counterfeiting composite particles of Example 1 is approximately 1:2:7. From Table 1, it can be seen that the range of molar ratios of dysprosium, lanthanum, and erbium obtained by analyzing samples acquired from the painting of Application Example 1 is 1:1.8 to 2.6:7.9 to 8.0.

[0081] These results indicate that the range of molar ratios of dysprosium, lanthanum, and erbium obtained from the analysis is similar to the molar ratios of dysprosium, lanthanum, and erbium in the metal precursor, and that the anti-counterfeiting composite particles of Example 1 impart identifiable features to the painting of Example 1 that can be identified by analytical instruments, and that the type and ratio of these identifiable features are designed according to the type and ratio of the metal precursor.

[0082] As described above, in the method for producing anti-counterfeiting composite particles of the present invention, in step a, a metal is grafted onto the surface of the core-shell type composite particle, so that each resulting metal-modified composite particle has identifiable distinguishing features.

[0083] Furthermore, in step b, the first monomer and the second monomer are copolymerized on the surface of the metal-modified composite particle, so that each anti-counterfeiting composite particle produced has a stable multi-core-shell structure in addition to its distinctive features.

[0084] Furthermore, in step P1, the third monomer polymerizes to form structurally stable homopolymer particles, and in step P2, the fourth monomer and the fifth monomer copolymerize on the surface of the homopolymer particles, so that each resulting core-shell composite particle has a stable core-shell structure.

[0085] When these anti-counterfeiting composite particles are added to art materials such as paints, drawing paper, wood, ceramics, and adhesives, and used to create works of art, each anti-counterfeiting composite particle possesses its own distinctive characteristics. As a result, the artwork also acquires its own unique distinguishing features, which can be identified by analytical instruments. Therefore, the artwork is difficult to counterfeit, and even if it is counterfeited, it can be identified as a fake. This effectively prevents counterfeit goods from entering the art market and being mistaken for genuine articles.

[0086] Furthermore, since each anti-counterfeiting composite particle has a stable multi-core-shell structure, these anti-counterfeiting composite particles are not only easy to store, but their identification features are less affected by factors such as the properties of the art material and the temperature and humidity during production. The art material is also not altered by the influence of these anti-counterfeiting composite particles, thus reliably achieving the objectives of the present invention.

[0087] The above embodiments are illustrative in illustrating the principles and effects of the present invention and do not limit it. Those skilled in the art can make some modifications and alterations to the above embodiments, provided they do not deviate from the spirit and scope of the invention. Therefore, all modifications and alterations made by those skilled in the art, provided they do not deviate from the spirit of the invention, should also be considered to fall within the scope of protection of the present invention. [Industrial applicability]

[0088] The present invention's method for producing anti-counterfeiting composite particles is suitable for producing anti-counterfeiting composite particles for works of art.

Claims

1. a. A step of obtaining a plurality of metal-modified composite particles by grafting a plurality of core-shell type composite particles with a treatment solution containing a metal precursor, an alkaline substance, and a reducing agent, wherein the grafting treatment is performed under conditions where the rotation speed is in the range of 200 rpm to 500 rpm and the temperature is in the range of 60°C to 80°C, and the metal precursor is reduced to a metal by the reducing agent, and then grafted onto the surface of the plurality of core-shell type composite particles to form the plurality of metal-modified composite particles. b. A step of producing a plurality of anti-counterfeiting composite particles by performing a first polymerization treatment on a first mixture containing the metal-modified composite particles, a first monomer, and a second monomer, and a first initiator aqueous solution containing a first initiator, wherein the first polymerization treatment includes a step of copolymerizing the first monomer and the second monomer on the surface of the plurality of metal-modified composite particles to form the plurality of anti-counterfeiting composite particles under conditions of a rotation speed in the range of 200 rpm to 500 rpm and a temperature in the range of 60°C to 80°C, A method for producing anti-counterfeiting composite particles, wherein the type of the first monomer is different from that of the second monomer, the weight ratio of the first monomer to the second monomer is 2 to 5, and the weight ratio of the total amount of the first monomer and the second monomer to the first initiator is 120 to 180.

2. In step a, the metal is selected from at least one of the metals from Group 3 to Group 10 of the periodic table, and the reducing agent is selected from at least one of hydrazine, hypophosphate, and sulfite. In step b, the first monomer and the second monomer are each independently selected from at least one of styrene, methacrylonitrile, acrylonitrile, methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, vinyl acetate, ketones having a vinyl group, and 1,4-divinylbenzene. A method for producing anti-counterfeiting composite particles according to claim 1, wherein the concentration of the first monomer in the first mixture is 4 wt% to 8 wt%, the concentration of the second monomer is 1 wt% to 3 wt%, and the concentration of the first initiator in the aqueous solution of the first initiator is 0.43 wt% to 0.85 wt%.

3. The method for producing anti-counterfeiting composite particles according to claim 2, wherein the metal is at least one selected from the group consisting of erbium, lanthanum, dysprosium, samarium, yttrium, and praseodymium.

4. The core-shell type composite particles are manufactured by the following steps P1 and P2: A step of performing a second polymerization treatment on a second mixture containing a third monomer and a second initiator aqueous solution containing a second initiator to obtain a polymerization product containing a plurality of homopolymer particles, wherein the second polymerization treatment includes polymerizing the third monomer to form the plurality of homopolymer particles under conditions where the rotation speed is in the range of 200 rpm to 500 rpm and the temperature is in the range of 60°C to 80°C. Step P2, a third polymerization treatment to obtain the plurality of core-shell type composite particles, wherein the third polymerization treatment includes copolymerizing the fourth monomer and the fifth monomer on the surface of the plurality of homopolymer particles under conditions where the rotation speed is in the range of 200 rpm to 500 rpm and the temperature is in the range of 60°C to 80°C. The type of the third monomer is the same as that of the first monomer, and the weight ratio of the third monomer to the second initiator is in the range of 80 to 160. The method for producing anti-counterfeiting composite particles according to claim 1, wherein the type of the fourth monomer is the same as that of the first monomer and different from that of the fifth monomer, the weight ratio of the fourth monomer to the fifth monomer is in the range of 3 to 5, and the weight ratio of the total amount of the fourth monomer and the fifth monomer to the third initiator is in the range of 80 to 300.

5. In step P1, the concentration of the third monomer in the second mixture is in the range of 0.7 wt% to 1.4 wt%, and the concentration of the second initiator in the second initiator aqueous solution is in the range of 0.19 wt% to 0.38 wt%. In step P2, the fifth monomer is selected from at least one of styrene, methacrylonitrile, acrylonitrile, methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, vinyl acetate, ketones having a vinyl group, and 1,4-divinylbenzene. The method for producing anti-counterfeiting composite particles according to claim 4, wherein the concentration of the third initiator in the aqueous solution of the third initiator is in the range of 0.43 wt% to 0.85 wt%, and the first initiator, the second initiator, and the third initiator are each independently a radical initiator, an ionic initiator, or a halogen.

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