Anti-counterfeiting leather and preparation method thereof

Abstract

The present invention relates to the field of leather technology, and in particular to an anti-counterfeiting leather and a preparation method thereof. The anti-counterfeiting leather comprises a substrate layer, a resin connecting layer and an anti-counterfeiting layer, wherein the resin connecting layer is arranged on the upper surface of the substrate layer, and the anti-counterfeiting layer is arranged on the upper surface of the resin connecting layer; the anti-counterfeiting layer is made of an anti-counterfeiting coating, and the anti-counterfeiting coating comprises the following raw materials in parts by weight: 100 parts of polyurethane resin, 4-8 parts of ultraviolet fluorescent anti-counterfeiting fiber, 4-8 parts of color powder, 30-40 parts of diluent, 7-10 parts of silicone acrylic emulsion, 5-8 parts of polyvinylidene fluoride, 3-6 parts of 2-hydroxyethyl ether cellulose, and 8-14 parts of filler. The anti-counterfeiting leather has good light fastness and wear resistance, and the leather surface can present a pattern visible to the naked eye under irradiation of an ultraviolet light source, and has good anti-counterfeiting function. The preparation method of the anti-counterfeiting leather is simple in process, easy to control in operation, and is conducive to large-scale industrial production. The obtained anti-counterfeiting leather has stable quality and excellent comprehensive performance.

Description

Technical Field

[0001] The present invention relates to the technical field of leather, and in particular to anti-counterfeiting leather and a preparation method thereof. Background Art

[0002] Leather fabrics have been widely used in the fields of luggage, clothing, shoes and furniture decoration due to their advantages such as high-grade texture, lightness, breathability and wear resistance. Manufacturers can design leather fabrics of different colors and patterns as needed to meet the needs of consumers. However, existing leather products usually have no anti-counterfeiting function and are often counterfeited by other manufacturers. It is difficult for ordinary consumers to distinguish the authenticity, which has an adverse impact on the brand and causes economic losses. Among the existing leather anti-counterfeiting methods, it is common to attach labels or anti-counterfeiting codes to the leather products when they are produced or shipped, but labels and anti-counterfeiting codes are easy to imitate. In addition, existing leather fabrics often have problems such as poor light fastness, easy fading, and poor wear resistance, which need to be further improved. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide an anti-counterfeiting leather, which has excellent light fastness and wear resistance, and the leather surface can present a pattern visible to the naked eye under ultraviolet light source, and has good anti-counterfeiting function.

[0004] Another object of the present invention is to provide a method for preparing anti-counterfeiting leather, which has a simple process, easy operation and control, is conducive to large-scale industrial production, and the anti-counterfeiting leather prepared has stable quality, excellent light fastness, wear resistance and anti-counterfeiting function, and has superior comprehensive performance.

[0005] The objectives of the present invention are achieved through the following technical solutions: an anti-counterfeiting leather, comprising a substrate layer, a resin connecting layer and an anti-counterfeiting layer, the resin connecting layer being arranged on the upper surface of the substrate layer, and the anti-counterfeiting layer being arranged on the upper surface of the resin connecting layer; the anti-counterfeiting layer is made of an anti-counterfeiting coating, and the anti-counterfeiting coating comprises the following raw materials in parts by weight: 100 parts of polyurethane resin, 4-8 parts of ultraviolet fluorescent anti-counterfeiting fiber, 4-8 parts of color powder, 30-40 parts of diluent, 7-10 parts of silicone acrylic emulsion, 5-8 parts of polyvinylidene fluoride, 3-6 parts of 2-hydroxyethyl ether cellulose, and 8-14 parts of filler.

[0006] The anti-counterfeiting leather of the present invention is provided with an anti-counterfeiting layer, a resin connecting layer and a substrate layer in sequence from top to bottom, wherein ultraviolet fluorescent anti-counterfeiting fibers are provided in the anti-counterfeiting layer. Under ordinary light, the ultraviolet fluorescent anti-counterfeiting fibers in the anti-counterfeiting layer are integrated with the resin connecting layer, thereby achieving a good invisible effect. What is observed by the naked eye is a visual effect identical to the apparent state of the resin connecting layer. However, under the irradiation of an ultraviolet light source, the ultraviolet fluorescent anti-counterfeiting fibers in the anti-counterfeiting layer can show a special pattern that can be observed by the naked eye, thereby playing an effective anti-counterfeiting role.

[0007] The anti-counterfeiting coating of the present invention is prepared by compounding raw materials such as polyurethane resin, silicone acrylic emulsion, polyvinylidene fluoride, 2-hydroxyethyl ether cellulose, filler, etc., so that the raw materials are well coordinated. The prepared anti-counterfeiting layer and the resin connecting layer have good adhesion and are not easy to fall off. In addition, the anti-counterfeiting coating has better light fastness and wear resistance, thereby improving the performance of the anti-counterfeiting leather.

[0008] Furthermore, a release film is provided on the upper surface of the anti-counterfeiting layer. The release film of the present invention can be used as a coating carrier during the preparation of anti-counterfeiting leather. During the preparation of anti-counterfeiting leather, an anti-counterfeiting coating is applied to the surface of the release film and dried to obtain an anti-counterfeiting layer. The release film also provides good protection for the anti-counterfeiting layer and can be removed for use. The release film can be a plastic release film or release paper as required. The ultraviolet fluorescent anti-counterfeiting fiber is an ultraviolet fluorescent anti-counterfeiting fiber as required, and the ultraviolet fluorescent anti-counterfeiting fiber can be dispersed in the anti-counterfeiting layer. The leather can be designed into different patterns and shapes as required.

[0009] Furthermore, the substrate layer is a cortex layer, a cloth layer or a paper layer. Furthermore, the cloth layer is a knitted cloth layer, a plain woven cloth layer, a raised cloth layer or a non-woven cloth layer.

[0010] Furthermore, the non-woven fabric is made of a mixture of polyurethane fibers and nylon fibers.

[0011] Furthermore, the thickness of the resin connection layer and the anti-counterfeiting layer are both 150-250 μm.

[0012] Furthermore, the diluent is at least one of fatty acid methyl ester and butanone.

[0013] Furthermore, the filler is at least one of nano-silicon dioxide, nano-calcium carbonate and nano-barium sulfate.

[0014] Furthermore, the preparation method of the silicone acrylic emulsion includes the following steps: (S1) taking 10-15 parts of butyl acrylate, 6-10 parts of styrene, 4-7 parts of methyl methacrylate, 3-6 parts of acrylic acid, 2-4 parts of emulsifier and 50-60 parts of deionized water in proportion, pre-emulsifying, then introducing nitrogen protection and heating to 75-85° C. for 10-20 minutes to obtain a mixture A;

[0015] (S2) adding 0.5-1.2 parts of initiator dropwise to mixture A over a period of 100-140 min; then adding 10-15 parts of butyl acrylate, 6-10 parts of styrene, 4-7 parts of methyl methacrylate, 3-6 parts of acrylic acid, and 2-3 parts of emulsifier dropwise over a period of 100-140 min; then adding 2-4 parts of tetramethyltetraethylenetetrasiloxane and 2-4 parts of vinyltriisopropoxysilane dropwise over a period of 100-140 min to obtain mixture B;

[0016] (S3) After the dropwise addition is completed, the temperature is kept at 20-30 minutes, then the temperature is raised to 80-87° C., and the temperature is kept at 30-40 minutes, and the temperature is cooled to room temperature; the pH value is then adjusted to 7.8-8.4 using a pH regulator, and the mixture is filtered to obtain a silicone acrylic emulsion.

[0017] Furthermore, in the step (S1), the pre-emulsification time is 20-40 min, and the stirring speed of the pre-emulsification is 800-1200 RPM.

[0018] Furthermore, in the step (S2), the initiator is at least one of potassium persulfate, ammonium persulfate or sodium persulfate.

[0019] Furthermore, in the steps (S1) and (S2), the emulsifier is at least one of fatty alcohol polyoxyethylene ether, sodium lauryl sulfate or alkylphenol polyoxyethylene ether.

[0020] The present invention prepares a silicone acrylic emulsion through the preparation method. The prepared emulsion has stable quality and is well compatible with raw materials such as polyurethane resin, silicone acrylic emulsion, polyvinylidene fluoride, 2-hydroxyethyl ether cellulose, filler, etc., so that the prepared anti-counterfeiting coating has good adhesion to the resin connecting layer, etc., and the anti-counterfeiting layer has high light fastness and wear resistance, and helps to improve the water resistance of the anti-counterfeiting leather.

[0021] Furthermore, the preparation method of the anti-counterfeiting coating includes the following steps: A1, mixing filler, 2-hydroxyethyl ether cellulose, polyvinylidene fluoride and diluent in proportion, stirring for 15-30 minutes at a stirring speed of 1500-2000RPM; A2, adding polyurethane resin, silicone acrylic emulsion, ultraviolet fluorescent anti-counterfeiting fiber, color powder and other remaining raw materials to the obtained mixture, stirring at a temperature of 50-60°C for 10-30 minutes at a stirring speed of 900-1400RPM to obtain the anti-counterfeiting coating.

[0022] Furthermore, the resin connecting layer is made of polyurethane resin coating, which includes the following raw materials in parts by weight: 100 parts of polyurethane resin, 4-8 parts of color powder, 30-40 parts of diluent, 7-10 parts of silicone acrylic emulsion, 5-8 parts of polyvinylidene fluoride, 3-6 parts of 2-hydroxyethyl ether cellulose, and 8-14 parts of filler. The polyurethane resin is preferably, but not limited to, the polyurethane resin HP-8050S produced by Fujian Huapu Resin Co., Ltd. Except for not adding ultraviolet fluorescent anti-counterfeiting fiber, the rest of the raw materials of the polyurethane resin coating are the same as those of the anti-counterfeiting coating. The resin connecting layer of the present invention is prepared by compounding raw materials such as polyurethane resin, silicone acrylic emulsion, polyvinylidene fluoride, 2-hydroxyethyl ether cellulose, and filler, so that each raw material is well matched. The obtained resin connecting layer has good adhesion to the substrate layer, is not easy to fall off, and has better light fastness and wear resistance, thereby improving the performance of the anti-counterfeiting leather.

[0023] Another object of the present invention is achieved by the following technical solution: The method for preparing the anti-counterfeiting leather comprises the following steps:

[0024] (1) taking a release film, applying an anti-counterfeiting coating on the surface of the release film, and forming an anti-counterfeiting layer after drying; and applying a polyurethane resin coating on the upper surface of the anti-counterfeiting layer;

[0025] (2) Laminating the base material layer on the upper surface of the resin connecting layer and drying the layer to obtain the anti-counterfeiting leather.

[0026] Furthermore, in step (1), the drying temperature is 150-180° C., and the drying time is 3-5 minutes.

[0027] Furthermore, in step (2), the drying temperature is 150-180° C., and the drying time is 5-10 minutes.

[0028] The preparation method of the anti-counterfeiting leather of the present invention has simple process, easy controllable operation, is conducive to large-scale industrial production, and the prepared anti-counterfeiting leather has stable quality, excellent light fastness, wear resistance and anti-counterfeiting function.

[0029] The present invention has the beneficial effects of exhibiting excellent light fastness and abrasion resistance, and the leather surface exhibits a pattern visible to the naked eye under ultraviolet light, demonstrating excellent anti-counterfeiting capabilities. The preparation method for the anti-counterfeiting leather is simple, easily controlled, and amenable to industrialized mass production. The resulting anti-counterfeiting leather exhibits stable quality and superior overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the anti-counterfeit leather picture of Example 1.

[0031] Figure 2 This is the anti-counterfeit leather diagram of Example 2.

[0032] Figure 3 The present invention provides an anti-counterfeit leather pattern with toners of different colors added thereto. DETAILED DESCRIPTION

[0033] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the embodiments. The contents mentioned in the embodiments are not intended to limit the present invention.

[0034] Example 1

[0035] In this embodiment, a type of anti-counterfeiting leather comprises a substrate layer, a resin connecting layer, and an anti-counterfeiting layer. The resin connecting layer is disposed on the upper surface of the substrate layer, and the anti-counterfeiting layer is disposed on the upper surface of the resin connecting layer. The anti-counterfeiting layer is made of an anti-counterfeiting coating. The anti-counterfeiting coating comprises the following raw materials in parts by weight: 100 parts polyurethane resin, 5 parts ultraviolet fluorescent anti-counterfeiting fiber, 4 parts color powder, 32 parts diluent, 8 parts silicone acrylic emulsion, 6 parts polyvinylidene fluoride, 4 parts 2-hydroxyethyl ether cellulose, and 10 parts filler. The polyurethane resin is HP-8050S polyurethane resin from Fujian Huapu Resin Co., Ltd. The color powder is phthalocyanine blue powder. The ultraviolet fluorescent anti-counterfeiting fiber is ultraviolet fluorescent anti-counterfeiting fiber used in the prior art. The substrate layer is a non-woven fabric layer composed of 50wt% polyurethane fiber and 50wt% nylon 6 fiber.

[0036] Furthermore, a plastic release film is provided on the upper surface of the anti-counterfeiting layer.

[0037] Furthermore, the thickness of the resin connecting layer and the anti-counterfeiting layer are both 200 μm.

[0038] Furthermore, the diluent is composed of fatty acid methyl ester and butanone in a weight ratio of 1:1. The filler is composed of nano-calcium carbonate and nano-barium sulfate in a weight ratio of 2:1.

[0039] Furthermore, the preparation method of the silicone acrylic emulsion includes the following steps: (S1) taking 12 parts by weight of butyl acrylate, 7 parts of styrene, 5 parts of methyl methacrylate, 4 parts of acrylic acid, 3 parts of emulsifier and 55 parts of deionized water in proportion, pre-emulsifying, then introducing nitrogen protection and heating to 80° C. for 14 minutes to obtain a mixture A;

[0040] (S2) 0.8 parts of initiator are added dropwise to the mixture A over a period of 120 min; 12 parts of butyl acrylate, 8 parts of styrene, 5 parts of methyl methacrylate, 4 parts of acrylic acid, and 2.5 parts of an emulsifier are then added dropwise over a period of 120 min; 3 parts of tetramethyltetraethylenetetrasiloxane and 2 parts of vinyltriisopropoxysilane are then added dropwise over a period of 120 min to obtain a mixture B;

[0041] (S3) After the dropwise addition is completed, the temperature is kept at 84° C. for 35 minutes, and then cooled to room temperature; the pH value is adjusted to 8.1 using a pH regulator, and the mixture is filtered to obtain a silicone acrylic emulsion.

[0042] Furthermore, in the step (S1), the pre-emulsification time is 30 minutes, and the stirring speed of the pre-emulsification is 900 RPM.

[0043] Furthermore, in the step (S2), the initiator is potassium persulfate.

[0044] Furthermore, in steps (S1) and (S2), the emulsifier is composed of fatty alcohol polyoxyethylene ether AEO-10 ​​and sodium lauryl sulfate in a weight ratio of 1:1.

[0045] The silicone acrylic emulsion prepared in the embodiment of the present invention has good stability. 2+ Stability can be found after 0.5% Ca 2+ , 2% Ca 2+ , 5% Ca 2+ Stability test shows that the silicone acrylic emulsion does not flocculate, delaminate, precipitate or break after 48 hours.

[0046] Furthermore, the preparation method of the anti-counterfeiting coating includes the following steps: A1, mixing filler, 2-hydroxyethyl ether cellulose, polyvinylidene fluoride and diluent in proportion, stirring for 20 minutes at a stirring speed of 1600RPM; A2, adding polyurethane resin, silicone acrylic emulsion, ultraviolet fluorescent anti-counterfeiting fiber, color powder and other remaining raw materials to the obtained mixture, stirring at a temperature of 55°C for 20 minutes at a stirring speed of 1100RPM to obtain the anti-counterfeiting coating.

[0047] Furthermore, the resin connecting layer is made of a polyurethane resin coating, which includes the following raw materials by weight: 100 parts polyurethane resin, 4 parts color powder, 32 parts diluent, 8 parts silicone acrylic emulsion, 6 parts polyvinylidene fluoride, 4 parts 2-hydroxyethyl ether cellulose, and 10 parts filler. The polyurethane resin coating is composed of the same raw materials as the anti-counterfeiting coating, except that the ultraviolet fluorescent anti-counterfeiting fiber is not added.

[0048] The method for preparing the anti-counterfeiting leather comprises the following steps:

[0049] (1) taking a release film, applying an anti-counterfeiting coating on the surface of the release film, and forming an anti-counterfeiting layer after drying; and applying a polyurethane resin coating on the upper surface of the anti-counterfeiting layer;

[0050] (2) Laminating the base material layer on the upper surface of the resin connecting layer and drying the layer to obtain the anti-counterfeiting leather.

[0051] Furthermore, in step (1), the drying temperature is 160° C. and the drying time is 4 minutes. In step (2), the drying temperature is 170° C. and the drying time is 6 minutes.

[0052] Example 2

[0053] In this embodiment, a security leather comprises a substrate layer, a resin connecting layer, and an anti-counterfeiting layer. The resin connecting layer is disposed on the upper surface of the substrate layer, and the anti-counterfeiting layer is disposed on the upper surface of the resin connecting layer. The anti-counterfeiting layer is made of an anti-counterfeiting coating. The anti-counterfeiting coating comprises the following raw materials in parts by weight: 100 parts polyurethane resin, 4 parts ultraviolet fluorescent anti-counterfeiting fiber, 4 parts toner, 30 parts diluent, 7 parts silicone acrylic emulsion, 5 parts polyvinylidene fluoride, 3 parts 2-hydroxyethyl ether cellulose, and 9 parts filler.

[0054] Furthermore, the diluent is composed of fatty acid methyl ester and butanone in a weight ratio of 1:1. The filler is composed of nano-calcium carbonate and nano-silicon dioxide in a weight ratio of 1.5:1.

[0055] Furthermore, the preparation method of the silicone acrylic emulsion includes the following steps: (S1) taking 10 parts by weight of butyl acrylate, 6 parts of styrene, 4 parts of methyl methacrylate, 3 parts of acrylic acid, 2 parts of emulsifier and 50 parts of deionized water and mixing them in proportion, performing pre-emulsification, and then introducing nitrogen protection and heating to 75° C. for 20 minutes to obtain a mixture A;

[0056] (S2) 0.5 parts of initiator were added dropwise to the mixture A over a period of 100 min; 10 parts of butyl acrylate, 6 parts of styrene, 4 parts of methyl methacrylate, 3 parts of acrylic acid, and 2 parts of an emulsifier were then added dropwise over a period of 100 min; 2 parts of tetramethyltetraethylenetetrasiloxane and 3 parts of vinyltriisopropoxysilane were then added dropwise over a period of 120 min to obtain a mixture B;

[0057] (S3) After the dropwise addition is completed, the temperature is kept at 87° C. for 30 minutes, and the temperature is cooled to room temperature. The pH value is then adjusted to 7.8 using a pH regulator, and the mixture is filtered to obtain a silicone acrylic emulsion.

[0058] Furthermore, in the step (S1), the pre-emulsification time is 20 min, and the stirring speed of the pre-emulsification is 1200 RPM.

[0059] Furthermore, in the step (S2), the initiator is potassium persulfate.

[0060] Furthermore, in the steps (S1) and (S2), the emulsifier is composed of sodium lauryl sulfate and alkylphenol polyoxyethylene ether TX-10 in a weight ratio of 2:1.

[0061] Furthermore, the preparation method of the anti-counterfeiting coating includes the following steps: A1, mixing filler, 2-hydroxyethyl ether cellulose, polyvinylidene fluoride and diluent in proportion, stirring for 15 minutes at a stirring speed of 2000RPM; A2, adding polyurethane resin, silicone acrylic emulsion, ultraviolet fluorescent anti-counterfeiting fiber, color powder and other remaining raw materials to the obtained mixture, stirring at 60°C for 15 minutes at a stirring speed of 1000RPM to obtain the anti-counterfeiting coating.

[0062] Furthermore, the resin connecting layer is made of polyurethane resin coating, which includes the following raw materials in parts by weight: 100 parts of polyurethane resin, 6 parts of color powder, 30 parts of diluent, 7 parts of silicone acrylic emulsion, 5 parts of polyvinylidene fluoride, 3 parts of 2-hydroxyethyl ether cellulose, and 9 parts of filler.

[0063] The method for preparing the anti-counterfeiting leather comprises the following steps:

[0064] (1) taking a release film, applying an anti-counterfeiting coating on the surface of the release film, and forming an anti-counterfeiting layer after drying; and applying a polyurethane resin coating on the upper surface of the anti-counterfeiting layer;

[0065] (2) Laminating the base material layer on the upper surface of the resin connecting layer and drying the layer to obtain the anti-counterfeiting leather.

[0066] Furthermore, in step (1), the drying temperature is 150° C. and the drying time is 5 minutes. In step (2), the drying temperature is 160° C. and the drying time is 8 minutes.

[0067] The rest of the content of this embodiment is the same as that of embodiment 1.

[0068] Example 3

[0069] In this embodiment, a security leather comprises a substrate layer, a resin connecting layer, and a security layer. The resin connecting layer is disposed on the upper surface of the substrate layer, and the security layer is disposed on the upper surface of the resin connecting layer. The security layer is made of an security coating. The security coating comprises the following raw materials in parts by weight: 100 parts polyurethane resin, 6 parts ultraviolet fluorescent security fiber, 6 parts color powder, 40 parts diluent, 10 parts silicone acrylic emulsion, 8 parts polyvinylidene fluoride, 6 parts 2-hydroxyethyl ether cellulose, and 14 parts filler.

[0070] Furthermore, a release film is provided on the upper surface of the anti-counterfeiting layer.

[0071] Furthermore, the filler is composed of nano-silicon dioxide and nano-calcium carbonate in a weight ratio of 1:1.

[0072] Furthermore, the preparation method of the silicone acrylic emulsion includes the following steps: (S1) taking 15 parts by weight of butyl acrylate, 8.5 parts of styrene, 6 parts of methyl methacrylate, 5.5 parts of acrylic acid, 3.5 parts of emulsifier and deionized water in proportion, mixing them for pre-emulsification, then introducing nitrogen protection and heating to 82° C. for 10 minutes to obtain a mixture A;

[0073] (S2) 1.2 parts of initiator are added dropwise to the mixture A over a period of 140 min; 13 parts of butyl acrylate, 8.5 parts of styrene, 5 parts of methyl methacrylate, 6 parts of acrylic acid, and 3 parts of an emulsifier are then added dropwise over a period of 140 min; 4 parts of tetramethyltetraethylenetetrasiloxane and 2 parts of vinyltriisopropoxysilane are then added dropwise over a period of 1140 min to obtain a mixture B;

[0074] (S3) After the dropwise addition is completed, the temperature is kept at 30 minutes, then the temperature is raised to 85° C., and the temperature is kept at 40 minutes, and the temperature is cooled to room temperature; the pH value is then adjusted to 8.4 using a pH regulator, and the mixture is filtered to obtain a silicone acrylic emulsion.

[0075] Furthermore, in the step (S1), the pre-emulsification time is 40 minutes, and the stirring speed of the pre-emulsification is 800 RPM.

[0076] Furthermore, in the step (S2), the initiator is sodium persulfate.

[0077] Furthermore, the preparation method of the anti-counterfeiting coating includes the following steps: A1, mixing filler, 2-hydroxyethyl ether cellulose, polyvinylidene fluoride and diluent in proportion, stirring for 30 minutes at a stirring speed of 1500RPM; A2, adding polyurethane resin, silicone acrylic emulsion, ultraviolet fluorescent anti-counterfeiting fiber, color powder and other remaining raw materials to the obtained mixture, stirring at 60°C for 10 minutes at a stirring speed of 1400RPM to obtain the anti-counterfeiting coating.

[0078] Furthermore, the resin connecting layer is made of polyurethane resin coating, which includes the following raw materials in parts by weight: 100 parts of polyurethane resin, 7 parts of color powder, 40 parts of diluent, 10 parts of silicone acrylic emulsion, 8 parts of polyvinylidene fluoride, 6 parts of 2-hydroxyethyl ether cellulose, and 14 parts of filler.

[0079] The method for preparing the anti-counterfeiting leather comprises the following steps:

[0080] (1) taking a release film, applying an anti-counterfeiting coating on the surface of the release film, and forming an anti-counterfeiting layer after drying; and applying a polyurethane resin coating on the upper surface of the anti-counterfeiting layer;

[0081] (2) Laminating the base material layer on the upper surface of the resin connecting layer and drying the layer to obtain the anti-counterfeiting leather.

[0082] Furthermore, in step (1), the drying temperature is 170° C. and the drying time is 3 minutes. In step (2), the drying temperature is 180° C. and the drying time is 5 minutes.

[0083] The rest of the content of this embodiment is the same as that of embodiment 1.

[0084] Example 4

[0085] In this embodiment, a security leather comprises a substrate layer, a resin connecting layer, and a security layer. The resin connecting layer is disposed on the upper surface of the substrate layer, and the security layer is disposed on the upper surface of the resin connecting layer. The security layer is made of an security coating. The security coating comprises the following raw materials in parts by weight: 100 parts polyurethane resin, 6 parts ultraviolet fluorescent security fiber, 6 parts color powder, 38 parts diluent, 9 parts silicone acrylic emulsion, 6 parts polyvinylidene fluoride, 4 parts 2-hydroxyethyl ether cellulose, and 10 parts filler.

[0086] Furthermore, the resin connecting layer is made of polyurethane resin coating, which includes the following raw materials in parts by weight: 100 parts of polyurethane resin, 6 parts of color powder, 38 parts of diluent, 9 parts of silicone acrylic emulsion, 6 parts of polyvinylidene fluoride, 4 parts of 2-hydroxyethyl ether cellulose, and 10 parts of filler.

[0087] The rest of the content of this embodiment is the same as that of embodiment 1.

[0088] Example 5

[0089] In this embodiment, a security leather comprises a substrate layer, a resin connecting layer, and an anti-counterfeiting layer. The resin connecting layer is disposed on the upper surface of the substrate layer, and the anti-counterfeiting layer is disposed on the upper surface of the resin connecting layer. The anti-counterfeiting layer is made of an anti-counterfeiting coating. The thickness of each of the resin connecting layer and the anti-counterfeiting layer is 250 μm.

[0090] The rest of the content of this embodiment is the same as that of embodiment 1.

[0091] Example 6

[0092] In this embodiment, a security leather comprises a substrate layer, a resin connecting layer, and an anti-counterfeiting layer. The resin connecting layer is disposed on the upper surface of the substrate layer, and the anti-counterfeiting layer is disposed on the upper surface of the resin connecting layer. The anti-counterfeiting layer is made of an anti-counterfeiting coating. The thickness of each of the resin connecting layer and the anti-counterfeiting layer is 150 μm.

[0093] The rest of the content of this embodiment is the same as that of embodiment 1.

[0094] Comparative Example 1

[0095] The difference between this comparative example and Example 1 is that the anti-counterfeiting coating used in the anti-counterfeiting layer and the polyurethane resin coating used in the resin connecting layer do not contain polyvinylidene fluoride, and are replaced by an equal amount of polyurethane resin.

[0096] Comparative Example 2

[0097] This comparative example differs from Example 1 in that the anti-counterfeiting coating used in the anti-counterfeiting layer and the polyurethane resin coating used in the resin connecting layer both utilize an equal amount of ETERSOL 1156S acrylic emulsion, replacing the silicone acrylic emulsion used in Example 1. Comparative Examples 1-2 utilize the same toner as Example 1, while the remaining examples utilize toners of different colors as needed.

[0098] The release layer attached to the anti-counterfeiting layer of the anti-counterfeiting leather of the present invention was torn off, and the anti-counterfeiting leathers of Examples 1-4 and Comparative Examples 1-2 were tested for light fastness and abrasion resistance. The test data are shown in Table 1 below:

[0099]

[0100] Color fastness to light was tested using ISO 105-B02:2014, Method 2, using a xenon arc lamp, exposure cycle A1, no flip-flop mode, against a blue wool sample (blue card). Abrasion resistance was tested using ISO 5470-1:2016, using a Taber grinder, H-18 wheel, load 10N.

[0101] The anti-counterfeiting coating and polyurethane resin coating of Comparative Example 1 both use an equal amount of polyurethane resin to replace polyvinylidene fluoride. By comparing Example 1 with Comparative Example 1, it can be seen that the light fastness and abrasion resistance of Example 1 are better than those of Comparative Example 1. Comparative Example 2 uses an acrylic emulsion in the prior art to replace the silicone acrylic emulsion of the present application. By comparing Example 1 with Comparative Example 2, it can be seen that the light fastness of Example 1 is better than that of Comparative Example 2.

[0102] The anti-counterfeiting leathers of Examples 1-4 and Comparative Examples 1-2 were subjected to an alkali solution immersion resistance test, and the test method was as follows: the anti-counterfeiting leathers were cut into 3 cm * 15 cm rectangular strips, placed in 10% by mass sodium hydroxide and soaked for 24 hours, and then taken out. It can be observed that there is no separation or peeling between the layers of Examples 1-4 and Comparative Example 1, and there is a slight separation phenomenon between the edges of the resin connecting layer and the substrate layer of Comparative Example 2, indicating that the anti-counterfeiting leather of the present invention has good alkali solution immersion resistance and water resistance.

[0103] The anti-counterfeiting leathers of Examples 1-4 and Comparative Examples 1-2 were tested for water resistance using the following method: The leathers were cut into 3 cm x 15 cm rectangular strips, immersed in water for 3 hours, and then removed. The water marks in Examples 1-4 and Comparative Examples 1-2 extended no longer than 1 cm. Furthermore, the water marks in Examples 1-4 extended no longer than 0.7 cm, demonstrating that the anti-counterfeiting leathers of the present invention possess excellent water resistance.

[0104] The anti-counterfeiting leathers of Examples 1-4 were tested for their bending resistance. The test method was as follows: the anti-counterfeiting leathers were cut into 3 cm*15 cm rectangular strips and tested using a leather folding tester at -20°C and room temperature, respectively. The anti-counterfeiting leathers of Examples 1-4 can withstand bending for more than 30,000 to 50,000 times at -20°C and more than 80,000 to 100,000 times at room temperature.

[0105] In summary, the anti-counterfeiting leather of the present invention has excellent light fastness and abrasion resistance, good resistance to alkali immersion and bending resistance, and the leather surface can present a pattern visible to the naked eye under ultraviolet light, thus having good anti-counterfeiting function. The preparation method of the anti-counterfeiting leather is simple in process, easy to operate, and is conducive to large-scale industrial production. The resulting anti-counterfeiting leather has stable quality and excellent overall performance.

[0106] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the scope of protection of the present invention.

Claims

1. Anti-counterfeiting leather, characterized by: The invention comprises a substrate layer, a resin connecting layer and an anti-counterfeiting layer, wherein the resin connecting layer is arranged on the upper surface of the substrate layer, and the anti-counterfeiting layer is arranged on the upper surface of the resin connecting layer; the anti-counterfeiting layer is made of anti-counterfeiting coating; The anti-counterfeiting coating comprises the following raw materials in parts by weight: 100 parts of polyurethane resin, 4-8 parts of ultraviolet fluorescent anti-counterfeiting fiber, 4-8 parts of color powder, 30-40 parts of diluent, 7-10 parts of silicone acrylic emulsion, 5-8 parts of polyvinylidene fluoride, 3-6 parts of 2-hydroxyethyl ether cellulose, and 8-14 parts of filler; The preparation method of the silicone acrylic emulsion comprises the following steps: (S1) Pre-emulsifying the mixture by mixing 10-15 parts by weight of butyl acrylate, 6-10 parts by weight of styrene, 4-7 parts by weight of methyl methacrylate, 3-6 parts by weight of acrylic acid, 2-4 parts by weight of an emulsifier, and 50-60 parts by weight of deionized water; then heating the mixture to 75-85° C. under nitrogen protection for 10-20 minutes to obtain a mixture A; (S2) adding 0.5-1.2 parts of an initiator dropwise to the mixture A over a period of 100-140 minutes; then adding 10-15 parts of butyl acrylate, 6-10 parts of styrene, 4-7 parts of methyl methacrylate, 3-6 parts of acrylic acid, and 2-3 parts of an emulsifier dropwise over a period of 100-140 minutes; and then adding 2-4 parts of tetramethyltetraethylenetetrasiloxane and 2-4 parts of vinyltriisopropoxysilane dropwise over a period of 100-140 minutes to obtain a mixture B; (S3) After the dropwise addition is completed, the temperature is kept at 20-30 minutes, then the temperature is raised to 80-87°C, the temperature is kept at 30-40 minutes, and the mixture is cooled to room temperature; the pH value is then adjusted to 7.8-8.4 using a pH regulator, and the mixture is filtered to obtain a silicone acrylic emulsion.

2. The anti-counterfeiting leather according to claim 1, characterized in that: A release film is provided on the upper surface of the anti-counterfeiting layer.

3. The anti-counterfeiting leather according to claim 1, characterized in that: The diluent is at least one of fatty acid methyl ester and butanone.

4. The anti-counterfeiting leather according to claim 1, characterized in that: The filler is at least one of nano silicon dioxide, nano calcium carbonate and nano barium sulfate.

5. The anti-counterfeiting leather according to claim 1, characterized in that: In the step (S2), the initiator is at least one of potassium persulfate, ammonium persulfate or sodium persulfate.

6. The anti-counterfeiting leather according to claim 1, characterized in that: In the steps (S1) and (S2), the emulsifier is at least one of fatty alcohol polyoxyethylene ether, sodium lauryl sulfate or alkylphenol polyoxyethylene ether.

7. A method for preparing the anti-counterfeiting leather according to any one of claims 1 to 6, characterized in that: The steps include: (1) Take a release film, apply an anti-counterfeiting coating on the surface of the release film, and form an anti-counterfeiting layer after drying; apply a polyurethane resin coating on the upper surface of the anti-counterfeiting layer; (2) Laminating the base material layer on the upper surface of the resin connecting layer and producing the anti-counterfeiting leather after drying.

8. The method for preparing anti-counterfeit leather according to claim 7, characterized in that: In the step (1), the drying temperature is 150-180°C and the drying time is 3-5 minutes.

9. The method for preparing anti-counterfeit leather according to claim 7, characterized in that: In the step (2), the drying temperature is 150-180° C. and the drying time is 5-10 minutes.

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