A thin offset cold laminating material and a preparation process thereof

Abstract

The application discloses a thin cold laminating material and a preparation process thereof, and belongs to the technical field of cold laminating materials. The thin cold laminating material comprises a base film layer, a release layer coated on the base film layer, an imaging layer coated on the release layer, an aluminum plating layer plated on the imaging layer, and a protective glue layer coated on the aluminum plating layer. The imaging layer raw material components comprise butanone, ethyl acetate, an imaging layer resin base, and color powder. The imaging layer resin base is obtained by copolymerization of methyl methacrylate, hydroxyethyl methacrylate, an unsaturated stabilizer tri (allylbenzene) imidazoline, and 2,4,6-tri (2-allylphenoxy) -1,3,5-triazine. The release layer raw material components comprise tetraethyl orthosilicate, octaphenylcyclo tetrasiloxane, tetra-vinyl tetramethyl cyclo tetrasiloxane, dimethyl siloxane mixed ring, n-heptane, and 3,5-di-tert-butyl salicylaldehyde. The protective glue layer comprises methyl methacrylate, hydroxyethyl methacrylate, butyl acrylate, dimethylbenzene, and glycidyl acrylate.

Description

Technical Field

[0001] This invention relates to the field of cold foil stamping materials, specifically to a thin offset cold foil stamping material and its preparation process. Background Technology

[0002] With the rapid development of the packaging and printing industry, the market demand for cold foil stamping materials is constantly increasing. Cold foil stamping materials are highly favored due to their unique decorative effects and wide range of applications.

[0003] However, traditional cold stamping materials suffer from insufficient adhesion between the release layer, imaging layer, and aluminum plating layer. This is mainly due to the significant differences in the interfacial properties of each layer, resulting in a lack of effective chemical bonding or physical interlocking. For example, while release layers made of silicon-based materials have good demolding properties, this also leads to weaker adhesion between them and other layers.

[0004] Furthermore, to achieve rich color effects, the toners added to the imaging layer alter its surface properties and internal structure, thus affecting its adhesion to the release layer and the aluminized layer. Toner particles may form defects at the interface, reducing the contact area and lowering the overall adhesion strength. The surface roughness of the imaging layer also directly affects the product's appearance quality. If the surface is not smooth enough, the aluminized layer cannot be evenly deposited, leading to a decrease in gloss. At the same time, these tiny bumps may also become stress concentration points during subsequent use, affecting the material's durability.

[0005] Therefore, the present invention solves the above problems by preparing a thin offset cold foil stamping material. Summary of the Invention

[0006] The purpose of this invention is to provide a thin offset cold foil stamping material and its preparation process to solve the technical problems mentioned in the background section.

[0007] The technical solution to achieve the objective of this invention is:

[0008] A thin offset cold foil stamping material includes a base film layer, a release layer coated on the base film layer, an imaging layer coated on the release layer, an aluminum plating layer vacuum-deposited on the imaging layer, and a protective adhesive layer coated on the aluminum plating layer; the base film layer is a 6U BOPET film.

[0009] Furthermore, the release layer raw material components include: tetraethyl orthosilicate, octaphenylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, dimethylsiloxane mixed cyclic, n-heptane, 3,5-di-tert-butylsalicylaldehyde, tris(trimethylsilyl)phosphate, and polydimethylsiloxane.

[0010] Further, the imaging layer comprises, by weight parts: 30-50 parts by weight of butanone, 5-10 parts by weight of ethyl acetate, 40-60 parts by weight of imaging layer resin base, and 1-3 parts by weight of pigment; the imaging layer resin base comprises, by weight parts: 2.5 parts by weight of methyl methacrylate, 2-3 parts by weight of hydroxyethyl methacrylate, 2 parts by weight of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 2-4 parts by weight of unsaturated stabilizer, 0.01-0.012 parts by weight of initiator, and 40 parts by weight of xylene.

[0011] Further, the raw material components of the protective adhesive layer, by weight, include: 60-80 parts by weight of protective layer resin base material and 20-40 parts by weight of xylene; the raw material components of the protective layer resin base material, by weight, include: 2.5 parts by weight of methyl methacrylate, 2-3 parts by weight of hydroxyethyl methacrylate, 2 parts by weight of butyl acrylate, 2-4 parts by weight of glycidyl acrylate, 0.01-0.012 parts by weight of initiator, and 40 parts by weight of xylene.

[0012] Furthermore, before vacuum aluminum plating, the imaging layer is ultrasonically impregnated in an aluminum acetate mixture and a hydrogen bromide aqueous solution in sequence; wherein, the aluminum acetate mixture comprises, by weight, 50 parts ethanol, 50 parts acetic anhydride, 2-4 parts aluminum acetate, and 1.6-1.7 parts sodium ethoxide.

[0013] This invention also provides a process for preparing a thin offset cold foil stamping material, comprising the following preparation steps:

[0014] (1) Preparation of release layer coating;

[0015] (2) Preparation of imaging layer coating: Add methyl ethyl ketone to the mixing tank according to the formula ratio, stir evenly at a constant temperature of 25-30℃ for 5-15 minutes, and then add ethyl acetate, imaging layer resin base and pigment to the mixing tank in sequence according to the ratio, while stirring. After adding, continue stirring for 23-25 ​​hours to obtain the imaging layer coating.

[0016] (3) Preparation of protective coating: Add xylene to the mixing tank according to the formula ratio, stir evenly at a constant temperature of 25-30℃ for 5-10 minutes, then add the protective layer resin base material to the mixing tank according to the ratio, stirring while adding, and continue stirring for 30-60 minutes after adding, to obtain the protective coating.

[0017] (4) First, apply a release coating to the base film layer and then dry it. Then, apply an imaging layer coating to the release coating and dry it. After that, immerse it in 100 parts by weight of aluminum acetate mixture and heat it to 135-145℃ for ultrasonic immersion for 7-9 hours. Then, add 11-12 parts by weight of 40% hydrogen bromide aqueous solution and continue ultrasonic immersion for 4 hours. After taking it out, put it in 10 parts by weight of methanol and continue ultrasonic immersion at room temperature for 24 hours. After taking it out and drying it, vacuum plate aluminum on the image layer after immersion. Finally, apply a protective coating to the aluminum layer and dry it to form a thin offset cold foil material.

[0018] Further, the preparation method of the release coating is as follows: 75-80 parts by weight of dimethylsiloxane mixed cyclic compound are placed in a reactor at 50°C and dehydrated under a nitrogen atmosphere and -0.095 MPa for 28-32 minutes. Then, 15 parts by weight of tetravinyltetramethylcyclotetrasiloxane, 5-15 parts by weight of octaphenylcyclotetrasiloxane, and 150 ppm of potassium methoxide alkali gel catalyst are added. Dehydration is continued under a nitrogen atmosphere and -0.095 MPa for 28-32 minutes. Then, the temperature is raised to 170°C and the reaction is carried out for 80-15 minutes. After naturally cooling to room temperature for 00 min, 0.0003 parts by weight of tris(trimethylsilyl)phosphate were added. After stirring at room temperature for 28-30 min, unreacted monomers were removed under reduced pressure at 200℃ under nitrogen atmosphere and -0.095 MPa. Then, the temperature was lowered to 90℃ and 20 ppm of chloroplatinic acid catalyst was added. After reacting at a constant temperature for 4 h, the mixture was cooled to room temperature, and 40-50 parts by weight of polydimethylsiloxane, 5-15 parts by weight of 3,5-di-tert-butylsalicylaldehyde, and 50-60 parts by weight of n-heptane were added to obtain the release coating.

[0019] Further, the preparation method of the catalyst potassium methoxide alkaline gel is as follows: 20 parts by mass of dimethylsiloxane mixed rings are placed in a reactor at 50°C and dehydrated under a nitrogen atmosphere and -0.095 MPa for 28-32 min. Then, 0.3 parts by mass of potassium methoxide are quickly added and dehydrated under a nitrogen atmosphere and -0.095 MPa for another 28-32 min. The temperature is then raised to 110°C and reacted at an appropriate stirring rate for 2 h to obtain potassium methoxide alkaline gel, which is then purged with nitrogen and stored at low temperature for later use.

[0020] Further, the preparation method of the imaging layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 84-86°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2-3 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 2-4 parts by mass of unsaturated stabilizer, and 0.01-0.012 parts by mass of initiator azobisisobutyronitrile is added dropwise. After 3 hours, the dropwise addition is stopped, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0021] Further, the preparation method of the unsaturated stabilizer tris(allylphenyl)imidazoline is as follows: 53 parts by mass of 4-allylbenzaldehyde, 160 parts by mass of water and 50 parts by mass of ice are placed in a reaction vessel and cooled to 0°C. 90 parts by mass of 25% ammonia solution are immediately injected while stirring at 600-1000 rpm. The mixture is naturally heated to 0°C and then heated to 40°C in a water bath and stirred at this temperature for 12 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with water, and dried in air. Subsequently, it is mixed with 110 parts by mass of DMF and 2.74 parts by mass of 80% sodium ethoxide, and heated to 60°C under nitrogen protection. This temperature is maintained for 10 hours, and then the temperature is increased until reflux is carried out for 6-8 hours. The mixture is then cooled to room temperature, water is added, a solid is precipitated, filtered, washed with water, and dried to obtain the unsaturated stabilizer tris(allylphenyl)imidazoline.

[0022] Further, the preparation method of the protective layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 84-86°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2-3 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of butyl acrylate, 2-4 parts by mass of glycidyl acrylate, and 0.01-0.012 parts by mass of azobisisobutyronitrile (AIB) initiator is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0023] By adopting the above technical solution, the present invention has the following beneficial effects:

[0024] The invented thin-film offset cold foil stamping material includes a base film layer, a release layer coated on the base film layer, an imaging layer coated on the release layer, an aluminum plating layer deposited on the imaging layer, and a protective adhesive layer coated on the aluminum plating layer. The raw material components of the imaging layer include: methyl ethyl ketone, ethyl acetate, imaging layer resin base material, and pigment. The imaging layer resin base material is obtained by copolymerizing methyl methacrylate, hydroxyethyl methacrylate, unsaturated stabilizer tris(allylphenyl)imidazoline, and 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine. The raw material components of the release layer include: tetraethyl orthosilicate, octaphenylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, dimethylsiloxane mixed cyclic, n-heptane, and 3,5-di-tert-butylsalicylaldehyde. The protective adhesive layer includes: methyl methacrylate, hydroxyethyl methacrylate, butyl acrylate, xylene, and glycidyl acrylate.

[0025] The base film layer uses 6U BOPET film, which makes the prepared thin offset cold stamping material thinner than traditional cold stamping materials.

[0026] The release layer material is composed of tetraethyl orthosilicate, octaphenylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, a mixed cyclic form of dimethylsiloxane, n-heptane, and 3,5-di-tert-butylsalicylaldehyde. This release layer utilizes a silicone-based release agent, which improves its abrasion resistance and transparency, thereby enhancing the abrasion resistance of thin offset cold stamping materials. Furthermore, the addition of the antioxidant 3,5-di-tert-butylsalicylaldehyde enhances the anti-aging properties of the release layer material.

[0027] The imaging layer material includes methyl methacrylate, hydroxyethyl methacrylate, an unsaturated stabilizer (tris(allylphenyl)imidazoline), and 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine. These components copolymerize through unsaturated bonds to form an acrylic copolymer with a hyperbranched structure, which enhances the mechanical properties of the imaging layer material. This copolymer is then dissolved in methyl ethyl ketone (MEK) and mixed with ethyl acetate and pigment. During this process, the unsaturated stabilizer tris(allylphenyl)imidazoline is dispersed on the hyperbranched acrylic copolymer molecular chains, acting as a free radical scavenger to capture and neutralize free radicals generated by heat, light, or oxidation reactions, preventing polymer chain breakage and decomposing peroxides, thus improving the antioxidant properties of the imaging layer material.

[0028] Subsequently, the coated imaging layer is immersed in an aluminum acetate mixture for ultrasonic impregnation. The aluminum acetate mixture penetrates into the cavities of the imaging layer, and the precipitate formed after the hydrolysis of aluminum acetate fills these cavities, making the imaging layer smoother. Simultaneously, under the action of acetic anhydride in the aluminum acetate mixture, tris(allylphenyl)imidazoline in the imaging layer is converted into 1,2-diphenyl-1,2-ethylenediamine. The amino groups on this compound undergo a cross-linking reaction with the aldehyde groups in the release layer, thereby firmly bonding the release layer and the imaging layer together.

[0029] Finally, vacuum aluminum plating is performed on the smooth imaging layer surface. During the vacuum aluminum plating process, aluminum atoms diffuse into the uniformly distributed alumina lattice in the imaging layer, or oxygen atoms in the alumina diffuse into the aluminum plating layer, forming a transition zone. The existence of this transition zone strengthens the interfacial bonding force between the two materials, making the aluminum plating layer more uniform. This not only enhances the adhesion between the imaging layer and the aluminum plating layer, but also improves the overall gloss of the thin offset cold foil stamping material. Detailed Implementation

[0030] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0031] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0032] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0033] The following are the sources of raw materials for the examples and comparative examples:

[0034] Dimethylsiloxane mixed cyclic compounds (DMC, with octamethylcyclotetrasiloxane as the main component), industrial grade, Momentive Advanced Materials (Nantong) Co., Ltd.

[0035] (Example 1)

[0036] A preparation process for a thin offset cold foil stamping material includes the following preparation steps:

[0037] (1) Preparation of release coating: 75 parts by mass of dimethylsiloxane mixed cyclic compound were placed in a reactor at 50°C and dehydrated for 28 min under nitrogen atmosphere and -0.095 MPa. Then, 15 parts by mass of tetravinyltetramethylcyclotetrasiloxane, 5 parts by mass of octaphenylcyclotetrasiloxane, and 150 ppm of potassium methoxide alkali gel catalyst were added. Dehydration was continued for 28 min under nitrogen atmosphere and -0.095 MPa. Then, the temperature was raised to 170°C and the reaction was carried out for 80 min. After naturally cooling to room temperature, 0.0003 parts by weight of tris(trimethylsilyl)phosphate were added. After stirring at room temperature for 28 min, unreacted monomers were removed under reduced pressure at 200℃ under nitrogen atmosphere and -0.095 MPa. Then, the temperature was lowered to 90℃ and 20 ppm of chloroplatinic acid catalyst was added. After reacting at a constant temperature for 4 h, the mixture was cooled to room temperature and 40 parts by weight of polydimethylsiloxane, 5 parts by weight of 3,5-di-tert-butylsalicylaldehyde, and 50 parts by weight of n-heptane were added to obtain the release coating.

[0038] (2) Preparation of imaging layer coating: Add 30 parts by mass of butanone to a mixing tank, stir evenly at a constant temperature of 25℃ for 5 minutes, then add 5 parts by mass of ethyl acetate, 40 parts by mass of imaging layer resin base material and 1 part by mass of color powder to the mixing tank while stirring, and continue stirring for 23 hours after the addition is complete to obtain the imaging coating.

[0039] (3) Preparation of protective coating: Add 20 parts by mass of xylene to a mixing tank, stir evenly at a constant temperature of 25℃ for 5 minutes, then add 60 parts by mass of protective layer resin base material to the mixing tank while stirring, and continue stirring for 30 minutes after the addition is complete to obtain the protective coating.

[0040] (4) First, a 0.3 μm thick release coating is applied to the base film layer and then dried. Then, a 0.3 μm thick imaging layer coating is applied to the release coating and then dried. After that, it is immersed in 100 parts by mass of aluminum acetate mixture and heated to 135°C for ultrasonic immersion for 7 hours. Then, 11 parts by mass of 40% hydrogen bromide aqueous solution is added and ultrasonic immersion is continued for 4 hours. After taking it out, it is placed in 10 parts by mass of methanol and ultrasonic immersion is continued at room temperature for 24 hours. After taking it out and drying it, a 380 Å thick aluminum plating layer is vacuum deposited on the immersed imaging layer. Finally, a 0.3 μm thick protective coating is applied to the aluminum plating layer and then dried to form a thin offset cold foil material.

[0041] The base film layer is a 6U BOPET film.

[0042] The preparation method of the catalyst potassium methoxide alkaline gel is as follows: 20 parts by mass of dimethylsiloxane mixed rings are placed in a reactor at 50°C and dehydrated for 28 min under nitrogen atmosphere and -0.095 MPa. Then, 0.3 parts by mass of potassium methoxide are quickly added and dehydrated for another 28 min under nitrogen atmosphere and -0.095 MPa. The temperature is then raised to 110°C and reacted for 2 h under an appropriate stirring rate to obtain potassium methoxide alkaline gel, which is then purged with nitrogen and stored at low temperature for later use.

[0043] The preparation method of the imaging layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 84°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 2 parts by mass of unsaturated stabilizer, and 0.01 parts by mass of initiator azobisisobutyronitrile is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0044] The preparation method of the unsaturated stabilizer tris(allylphenyl)imidazoline is as follows: 53 parts by mass of 4-allylbenzaldehyde, 160 parts by mass of water and 50 parts by mass of ice are placed in a reaction vessel and cooled to 0°C. 90 parts by mass of 25% ammonia solution are immediately injected while stirring at 600 rpm. The temperature is naturally raised to 0°C, and then heated to 40°C in a water bath and stirred at this temperature for 12 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with water, and dried in air. Subsequently, it is mixed with 110 parts by mass of DMF and 2.74 parts by mass of 80% sodium ethoxide, and heated to 60°C under nitrogen protection. This temperature is maintained for 10 hours, and then the temperature is raised until reflux for 6 hours. The mixture is then cooled to room temperature, water is added, a solid is precipitated, filtered, washed with water, and dried to obtain the unsaturated stabilizer tris(allylphenyl)imidazoline.

[0045] The preparation method of the protective layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 84°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of butyl acrylate, 2 parts by mass of glycidyl acrylate, and 0.01 parts by mass of initiator azobisisobutyronitrile is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0046] (Example 2)

[0047] A preparation process for a thin offset cold foil stamping material includes the following preparation steps:

[0048] (1) Preparation of release coating: 78 parts by mass of dimethylsiloxane mixed cyclic compound were placed in a reactor at 50°C and dehydrated for 30 min under nitrogen atmosphere and -0.095 MPa. Then, 15 parts by mass of tetravinyltetramethylcyclotetrasiloxane, 10 parts by mass of octaphenylcyclotetrasiloxane, and 150 ppm of potassium methoxide alkali gel catalyst were added. Dehydration was continued for 30 min under nitrogen atmosphere and -0.095 MPa. Then, the temperature was raised to 170°C and the reaction was carried out for 90 min. After naturally cooling to room temperature, 0.0003 parts by weight of tris(trimethylsilyl)phosphate were added. After stirring at room temperature for 29 min, unreacted monomers were removed under reduced pressure at 200℃ under nitrogen atmosphere and -0.095 MPa. Then, the temperature was lowered to 90℃ and 20 ppm of chloroplatinic acid catalyst was added. After reacting at a constant temperature for 4 h, the mixture was cooled to room temperature and 45 parts by weight of polydimethylsiloxane, 10 parts by weight of 3,5-di-tert-butylsalicylaldehyde, and 55 parts by weight of n-heptane were added to obtain the release coating.

[0049] (2) Preparation of imaging layer coating: Add 40 parts by mass of butanone to a mixing tank, stir evenly at a constant temperature of 28℃ for 10 min, then add 8 parts by mass of ethyl acetate, 50 parts by mass of imaging layer resin base material and 2 parts by mass of color powder to the mixing tank while stirring, and continue stirring for 24 h after the addition is complete to obtain the imaging coating.

[0050] (3) Preparation of protective coating: Add 30 parts by mass of xylene to a mixing tank and stir evenly at a constant temperature of 28℃ for 8 minutes. Then add 70 parts by mass of protective layer resin base material to the mixing tank while stirring. After adding, continue stirring for 45 minutes to obtain the protective coating.

[0051] (4) First, a 0.3 μm thick release coating is applied to the base film layer and then dried. Then, a 0.3 μm thick imaging layer coating is applied to the release coating and then dried. Afterward, it is immersed in 100 parts by weight of aluminum acetate mixture and heated to 140°C for ultrasonic immersion for 8 hours. Then, 11.5 parts by weight of 40% hydrogen bromide aqueous solution is added and ultrasonic immersion is continued for 4 hours. After taking it out, it is placed in 10 parts by weight of methanol and ultrasonic immersion is continued at room temperature for 24 hours. After taking it out and drying, a 300 angstrom thick aluminum plating layer is vacuum deposited on the immersed imaging layer. Finally, a 0.3 μm thick protective coating is applied to the aluminum plating layer and then dried to form a thin offset cold foil material.

[0052] The base film layer is a 6U BOPET film.

[0053] The preparation method of the catalyst potassium methoxide alkaline gel is as follows: 20 parts by mass of dimethylsiloxane mixed rings are placed in a reactor at 50°C and dehydrated for 30 min under nitrogen atmosphere and -0.095 MPa. Then, 0.3 parts by mass of potassium methoxide are quickly added and dehydrated for another 30 min under nitrogen atmosphere and -0.095 MPa. The temperature is then raised to 110°C and reacted for 2 h under an appropriate stirring rate to obtain potassium methoxide alkaline gel, which is then purged with nitrogen and stored at low temperature for later use.

[0054] The preparation method of the imaging layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 85°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2.5 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 3 parts by mass of unsaturated stabilizer, and 0.011 parts by mass of initiator azobisisobutyronitrile is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0055] The preparation method of the unsaturated stabilizer tris(allylphenyl)imidazoline is as follows: 53 parts by mass of 4-allylbenzaldehyde, 160 parts by mass of water and 50 parts by mass of ice are placed in a reaction vessel and cooled to 0°C. 90 parts by mass of 25% ammonia solution are immediately injected while stirring at 800 rpm. The temperature is naturally raised to 0°C, and then heated to 40°C in a water bath and stirred at this temperature for 12 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with water, and dried in air. Subsequently, it is mixed with 110 parts by mass of DMF and 2.74 parts by mass of 80% sodium ethoxide, and heated to 60°C under nitrogen protection. This temperature is maintained for 10 hours, and then the temperature is raised until reflux for 7 hours. The mixture is then cooled to room temperature, water is added, a solid is precipitated, filtered, washed with water, and dried to obtain the unsaturated stabilizer tris(allylphenyl)imidazoline.

[0056] The preparation method of the protective layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 85°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2.5 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of butyl acrylate, 3 parts by mass of glycidyl acrylate, and 0.011 parts by mass of azobisisobutyronitrile (azobisisobutyronitrile) initiator is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0057] (Example 3)

[0058] A preparation process for a thin offset cold foil stamping material includes the following preparation steps:

[0059] (1) Preparation of release coating: 80 parts by mass of dimethylsiloxane mixed cyclic compound were placed in a reactor at 50°C and dehydrated for 32 min under nitrogen atmosphere and -0.095 MPa. Then, 15 parts by mass of tetravinyltetramethylcyclotetrasiloxane, 15 parts by mass of octaphenylcyclotetrasiloxane, and 150 ppm of potassium methoxide alkali gel catalyst were added. Dehydration was continued for 32 min under nitrogen atmosphere and -0.095 MPa. Then, the temperature was raised to 170°C and the reaction was carried out for 100 min. After naturally cooling to room temperature, 0.0003 parts by weight of tris(trimethylsilyl)phosphate were added. After stirring at room temperature for 30 min, unreacted monomers were removed under reduced pressure at 200℃ under nitrogen atmosphere and -0.095 MPa. Then, the temperature was lowered to 90℃ and 20 ppm of chloroplatinic acid catalyst was added. After reacting at a constant temperature for 4 h, the mixture was cooled to room temperature and 50 parts by weight of polydimethylsiloxane, 15 parts by weight of 3,5-di-tert-butylsalicylaldehyde, and 60 parts by weight of n-heptane were added to obtain the release coating.

[0060] (2) Preparation of imaging layer coating: Add 50 parts by mass of butanone to a mixing tank, stir evenly at a constant temperature of 30℃ for 15 minutes, then add 10 parts by mass of ethyl acetate, 60 parts by mass of imaging layer resin base material and 3 parts by mass of color powder to the mixing tank while stirring, and continue stirring for 25 hours after the addition is complete to obtain the imaging coating.

[0061] (3) Preparation of protective coating: Add 40 parts by mass of xylene to a mixing tank, stir evenly at a constant temperature of 30℃ for 10 minutes, then add 80 parts by mass of protective layer resin base material to the mixing tank while stirring, and continue stirring for 60 minutes after the addition is complete to obtain the protective coating.

[0062] (4) First, a 0.3 μm thick release coating is applied to the base film layer and then dried. Then, a 0.3 μm thick imaging layer coating is applied to the release coating and then dried. After that, it is immersed in 100 parts by mass of aluminum acetate mixture and heated to 145°C for ultrasonic immersion for 9 hours. Then, 12 parts by mass of 40% hydrogen bromide aqueous solution is added and ultrasonic immersion is continued for 4 hours. After taking it out, it is placed in 10 parts by mass of methanol and ultrasonic immersion is continued at room temperature for 24 hours. After taking it out and drying, a 320 Å thick aluminum plating layer is vacuum deposited on the immersed imaging layer. Finally, a 0.3 μm thick protective coating is applied to the aluminum plating layer and then dried to form a thin offset cold foil material.

[0063] The base film layer is a 6U BOPET film.

[0064] The preparation method of the catalyst potassium methoxide alkaline gel is as follows: 20 parts by mass of dimethylsiloxane mixed rings are placed in a reactor at 50°C and dehydrated for 32 min under nitrogen atmosphere and -0.095 MPa. Then, 0.3 parts by mass of potassium methoxide are quickly added and dehydrated for another 32 min under nitrogen atmosphere and -0.095 MPa. The temperature is then raised to 110°C and reacted for 2 h at an appropriate stirring rate to obtain potassium methoxide alkaline gel, which is then purged with nitrogen and stored at low temperature for later use.

[0065] The preparation method of the imaging layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 86°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 3 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 4 parts by mass of unsaturated stabilizer, and 0.012 parts by mass of initiator azobisisobutyronitrile is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0066] The preparation method of the unsaturated stabilizer tris(allylphenyl)imidazoline is as follows: 53 parts by mass of 4-allylbenzaldehyde, 160 parts by mass of water and 50 parts by mass of ice are placed in a reaction vessel and cooled to 0°C. 90 parts by mass of 25% ammonia solution are immediately injected while stirring at 1000 rpm. The temperature is naturally raised to 0°C, and then heated to 40°C in a water bath and stirred at this temperature for 12 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with water, and dried in air. Subsequently, it is mixed with 110 parts by mass of DMF and 2.74 parts by mass of 80% sodium ethoxide, and heated to 60°C under nitrogen protection. This temperature is maintained for 10 hours, and then the temperature is raised until reflux for 8 hours. The mixture is then cooled to room temperature, water is added, a solid is precipitated, filtered, washed with water, and dried to obtain the unsaturated stabilizer tris(allylphenyl)imidazoline.

[0067] The preparation method of the protective layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 86°C while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 3 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of butyl acrylate, 4 parts by mass of glycidyl acrylate, and 0.012 parts by mass of azobisisobutyronitrile (azobisisobutyronitrile) initiator is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

[0068] Comparative Example 1

[0069] The only difference between Comparative Example 1 and Example 2 is that the raw material components of the release coating, by weight, include: 5-10 parts by weight of water-based oxidized polyethylene wax emulsion E-842N, 50-60 parts by weight of ethanol, and 30-40 parts by weight of water; the remaining steps and components are the same as in Example 2.

[0070] Comparative Example 2

[0071] The only difference between Comparative Example 2 and Example 2 is that the release layer raw material components include: tetraethyl orthosilicate, octaphenylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, dimethylsiloxane mixed cyclic, n-heptane, tris(trimethylsilyl)phosphate, polydimethylsiloxane, and antioxidant 1010; the remaining steps and components are the same as in Example 2.

[0072] Comparative Example 3

[0073] The only difference between Comparative Example 3 and Example 2 is that the raw material components of the imaging layer resin base material, by weight, include 2.5 parts by weight of methyl methacrylate, 2-3 parts by weight of hydroxyethyl methacrylate, 2 parts by weight of butyl methacrylate, 2-4 parts by weight of unsaturated stabilizer, 0.01-0.012 parts by weight of initiator, and 40 parts by weight of xylene; the remaining steps and components are the same as in Example 2.

[0074] Comparative Example 4

[0075] The only difference between Comparative Example 4 and Example 2 is that the raw material components of the imaging layer resin base, by weight, include 2.5 parts by weight of methyl methacrylate, 2-3 parts by weight of hydroxyethyl methacrylate, 2 parts by weight of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 2-4 parts by weight of antioxidant 1010, 0.01-0.012 parts by weight of initiator, and 40 parts by weight of xylene; the remaining steps and components are the same as in Example 2.

[0076] Comparative Example 5

[0077] The difference between Comparative Example 5 and Example 2 lies only in step (4). The specific steps of step (4) are as follows: First, a 0.3 μm thick release coating is applied to the base film layer and then dried. Then, a 0.3 μm thick imaging layer coating is applied to the release coating and then dried. Subsequently, a 240 angstrom thick aluminum plating layer is vacuum deposited on the imaging layer. Finally, a 0.3 μm thick protective coating is applied to the aluminum plating layer and then dried to form a thin offset cold foil material. The remaining steps and components are the same as in Example 2.

[0078] Example of results:

[0079] Tensile property test: The thin offset cold stamping materials prepared in the examples and comparative examples were tested for tensile properties according to GB / T228.1.

[0080] Gloss: The gloss of the thin offset cold foil materials prepared in the examples and comparative examples was tested under the condition of an incident angle of 60°.

[0081] Abrasion resistance: The thin-film offset cold foil materials prepared in the examples and comparative examples were tested using an LXD-A digital Shore hardness tester.

[0082] Peel test: The thin offset cold foil materials prepared in the examples and comparative examples were subjected to peel test. The peel test was conducted by peeling the thin offset cold foil materials by sticking tape to the protective layer.

[0083] Table 1

[0084]

[0085] Table 1 below shows the performance test results of the thin offset cold foil stamping materials prepared in the examples and comparative examples:

[0086] Referring to Table 1, compared with the comparative examples, the screen-printed cold foil prepared in the examples has better abrasion resistance, mechanical properties, and gloss, and better adhesion between the release layer, imaging layer, aluminum plating layer, and protective layer. Compared with Comparative Examples 1-2 and Example 2, the release layer prepared using tetraethyl orthosilicate, octaphenylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, dimethylsiloxane mixed cyclic compounds, n-heptane, 3,5-di-tert-butylsalicylaldehyde, tris(trimethylsilyl)phosphate, and polydimethylsiloxane resulted in screen-printed cold foil with better abrasion resistance, mechanical properties, and gloss, and better adhesion between the release layer, imaging layer, aluminum plating layer, and protective layer. Compared with Example 2, Examples 3-4 use methyl methacrylate, hydroxyethyl methacrylate, 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, unsaturated stabilizer, initiator, and xylene to obtain the imaging layer resin base material. The resulting screen-printed cold foil has better mechanical properties, higher gloss, and better adhesion between the release layer, imaging layer, aluminum plating layer, and protective layer. Compared with Example 2, Comparative Example 5 involves ultrasonically impregnating the imaging layer in an aluminum acetate mixture and a hydrogen bromide aqueous solution before vacuum aluminum plating. The resulting screen-printed cold foil has better mechanical properties, higher gloss, and better adhesion between the release layer, imaging layer, aluminum plating layer, and protective layer.

[0087] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A thin offset cold foil stamping material, characterized in that, It includes a base film layer, a release layer coated on the base film layer, an imaging layer coated on the release layer, an aluminum plating layer vacuum-deposited on the imaging layer, and a protective adhesive layer coated on the aluminum plating layer; the base film layer is a 6U BOPET film. The release layer raw material components include: tetraethyl orthosilicate, octaphenylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, dimethylsiloxane mixed cyclic, n-heptane, 3,5-di-tert-butylsalicylaldehyde, tris(trimethylsilyl)phosphate, and polydimethylsiloxane. The imaging layer comprises, by weight, the following raw material components: 30-50 parts by weight of butanone, 5-10 parts by weight of ethyl acetate, 40-60 parts by weight of imaging layer resin base, and 1-3 parts by weight of pigment; the imaging layer resin base comprises, by weight, 2.5 parts by weight of methyl methacrylate, 2-3 parts by weight of hydroxyethyl methacrylate, 2 parts by weight of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 2-4 parts by weight of unsaturated stabilizer, 0.01-0.012 parts by weight of initiator, and 40 parts by weight of xylene; the unsaturated stabilizer is tris(allylphenyl)imidazoline. Before vacuum aluminum plating, the imaging layer is ultrasonically impregnated in an aluminum acetate mixture and a hydrogen bromide aqueous solution in sequence; wherein, the aluminum acetate mixture comprises, by weight, 50 parts ethanol, 50 parts acetic anhydride, 2-4 parts aluminum acetate, and 1.6-1.7 parts sodium ethoxide.

2. The thin offset cold foil stamping material according to claim 1, characterized in that, The protective adhesive layer comprises, by weight, 60-80 parts of protective layer resin base material and 20-40 parts of xylene; the protective layer resin base material comprises, by weight, 2.5 parts of methyl methacrylate, 2-3 parts of hydroxyethyl methacrylate, 2 parts of butyl acrylate, 2-4 parts of glycidyl acrylate, 0.01-0.012 parts of initiator, and 40 parts of xylene.

3. A preparation process for a thin offset cold foil stamping material as described in any one of claims 1 to 2, characterized in that, The preparation steps include the following: (1) Preparation of release layer coating; (2) Preparation of imaging layer coating: Add methyl ethyl ketone to the mixing tank according to the formula ratio, stir evenly at 25~30°C for 5~15 minutes, and then add ethyl acetate, imaging layer resin base and pigment to the mixing tank in sequence according to the ratio, while stirring. After adding, continue stirring for 23~25 hours to obtain the imaging coating. (3) Preparation of protective coating: Add xylene to the mixing tank according to the formula ratio, stir evenly at a constant temperature of 25-30℃ for 5-10 minutes, then add the protective layer resin base to the mixing tank according to the ratio, stirring while adding, and continue stirring for 30-60 minutes after adding to obtain the protective coating. (4) First, apply a release coating to the base film layer and then dry it. Then, apply an imaging layer coating to the release coating and dry it. Then, immerse it in 100 parts by weight of aluminum acetate mixture and heat it to 135~145℃ for ultrasonic immersion for 7~9h. Then, add 11~12 parts by weight of 40% hydrogen bromide aqueous solution and continue ultrasonic immersion for 4h. After taking it out, put it in 10 parts by weight of methanol and continue ultrasonic immersion at room temperature for 24h. After taking it out and drying it, vacuum aluminum plating is applied to the imaging layer after immersion. Finally, a protective coating is applied to the aluminum plating layer and then dried to form a thin offset cold foil material.

4. The preparation process of the thin offset cold foil stamping material according to claim 3, characterized in that, The preparation method of the release coating is as follows: 75-80 parts by weight of dimethylsiloxane mixed cyclic compound are placed in a reactor at 50°C and dehydrated under a nitrogen atmosphere and -0.095 MPa for 28-32 min. Then, 15 parts by weight of tetravinyltetramethylcyclotetrasiloxane, 5-15 parts by weight of octaphenylcyclotetrasiloxane, and 150 ppm of potassium methoxide alkali catalyst are added. Dehydration is continued under a nitrogen atmosphere and -0.095 MPa for 28-32 min. The temperature is then raised to 170°C and reacted for 80-100 min. After natural cooling to room temperature, 0.0003 parts by weight of tris(trimethylsilyl)phosphate are added. The mixture is stirred at room temperature for 28-30 min. Unreacted monomers are then recovered under reduced pressure at 200°C under a nitrogen atmosphere and -0.095 MPa. The temperature is then lowered to 90°C and 20 ppm of chloroplatinic acid catalyst is added. The reaction is carried out at a constant temperature for 4 minutes. After cooling to room temperature, add 40-50 parts by weight of polydimethylsiloxane, 5-15 parts by weight of 3,5-di-tert-butylsalicylaldehyde, and 50-60 parts by weight of n-heptane to obtain the release coating.

5. The preparation process of the thin offset cold foil stamping material according to claim 3, characterized in that, The preparation method of the imaging layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 84~86℃ while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2~3 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of 2,4,6-tris(2-allylphenoxy)-1,3,5-triazine, 2~4 parts by mass of unsaturated stabilizer, and 0.01~0.012 parts by mass of initiator azobisisobutyronitrile is added dropwise. After 3 hours, the dropwise addition is stopped, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

6. The preparation process of the thin offset cold foil stamping material according to claim 5, characterized in that, The preparation method of the unsaturated stabilizer tris(allylphenyl)imidazoline is as follows: 53 parts by mass of 4-allylbenzaldehyde, 160 parts by mass of water and 50 parts by mass of ice are placed in a reaction vessel and cooled to 0°C. 90 parts by mass of 25% ammonia solution are immediately injected while stirring at 600~1000 rpm. The temperature is naturally raised to 0°C, and then heated to 40°C in a water bath and stirred at this temperature for 12 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with water, and dried in air. Subsequently, it is mixed with 110 parts by mass of DMF and 2.74 parts by mass of 80% sodium ethoxide, and heated to 60°C under nitrogen protection. This temperature is maintained for 10 hours, and then the temperature is raised until reflux is carried out for 6~8 hours. The mixture is then cooled to room temperature, water is added, a solid is precipitated, filtered, washed with water, and dried to obtain the unsaturated stabilizer tris(allylphenyl)imidazoline.

7. The preparation process of the thin offset cold foil stamping material according to claim 3, characterized in that, The preparation method of the protective layer resin base material is as follows: 40 parts by mass of xylene are placed in a reaction vessel, and the temperature is raised to 84~86℃ while stirring. Then, a mixture of 2.5 parts by mass of methyl methacrylate, 2~3 parts by mass of hydroxyethyl methacrylate, 2 parts by mass of butyl acrylate, 2~4 parts by mass of glycidyl acrylate, and 0.01~0.012 parts by mass of azobisisobutyronitrile (AIOnitrile) initiator is added dropwise. The dropwise addition is stopped after 3 hours, and the reaction is continued at the temperature for another 3 hours to obtain the imaging layer resin base material.

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