Halogen-containing polyurethane as well as preparation method and application thereof

Abstract

The invention discloses halogen-containing polyurethane as well as a preparation method and application thereof, belongs to the technical field of optical materials, and solves the problem that the fireproof performance is not ideal enough when a polyurethane material is used as an anti-counterfeiting packing material in the prior art. According to the halogen-containing polyurethane provided by the invention, the target product is obtained by selecting the halogen-containing preparation raw materials and carrying out reasonable molecular design on the halogen-containing preparation raw materials. The halogen-containing polyurethane provided by the invention not only inherits all the advantages of traditional polyurethane, but also has a remarkable flame-retardant characteristic by introducing halogen elements.

Description

Technical Field

[0001] The present invention relates to the technical field of optical materials, and more specifically to a halogen-containing polyurethane and a preparation method and application thereof. Background Art

[0002] With the advancement of science and technology and the development of the market, anti-counterfeiting technology has become an important means to protect product authenticity and brand reputation. Especially in the field of packaging, the application of anti-counterfeiting packaging materials is becoming more and more extensive. They can not only effectively prevent the circulation of counterfeit and inferior products, but also enhance the overall safety of products and the trust of consumers. Polyurethane materials are ideal for manufacturing various anti-counterfeiting packaging materials due to their unique chemical structure and physical properties such as excellent elasticity, wear resistance and processing flexibility.

[0003] However, with the increasing market demand for safety, traditional polyurethane materials can no longer meet the needs of modern packaging, especially in special occasions that require fire resistance and flame retardancy. Summary of the invention

[0004] The invention provides a halogen-containing polyurethane and a preparation method and application thereof, which are used to solve the problem that the fireproof performance of the polyurethane material in the prior art is not ideal when used as an anti-counterfeiting packaging material.

[0005] In a first aspect, the present invention provides a halogen-containing polyurethane, the chemical structure of which is shown in Formula I:

[0006]

[0007] Among them, x:y is 2:1-20; structural unit A is an alkyl or aryl structure, which contains at least one halogen element and at least two isocyanate groups; structural unit B is an alkyl or aryl structure, which contains at least one halogen element and at least two hydroxyl groups; structural unit C is an aryl structure, which contains at least one halogen element and at least two hydroxyl groups or at least two amino groups; structural unit D is a photosensitive group, which is connected to the structural unit C by an ether bond through an alkane chain, and its molar percentage in the halogen-containing polyurethane monomer is 1% to 50%.

[0008] As a possible implementation method, the structural formula of the structural unit A is any one of Formula II and Formula III,

[0009]

[0010] And / or, the structural formula of the structural unit B is any one of Formula IV, Formula V, Formula VI, Formula VII, Formula VIII, and Formula IX,

[0011]

[0012] and / or, the structural unit C has a structural formula of any one of formula X, formula XI, formula XII, formula XIII, formula XIV, and formula XV,

[0013]

[0014] Wherein, X is any one of fluorine, chlorine, bromine and iodine.

[0015] As a possible implementation method, the structural formula of the photosensitive group is shown in Formula XVI,

[0016]

[0017] Wherein, n is a positive integer from 1 to 50.

[0018] In a second aspect, the present invention provides a method for preparing a halogen-containing polyurethane as described in any possible implementation of the first aspect, comprising the following steps: in an inert gas environment, uniformly mixing the structural unit A and the structural unit C-structural unit D in an organic solvent at a temperature of 0 to 5°C, adding the structural unit B and a catalyst, stirring the reaction at a certain temperature program to obtain a halogen-containing polyurethane solution; coating the halogen-containing polyurethane solution on a base material, and drying at a temperature of 50 to 100°C to obtain the halogen-containing polyurethane.

[0019] As a possible implementation method, the reaction mixture is uniformly mixed in an organic solvent under ice-water bath conditions at 0 to 5°C, and the operation time is 1.5 to 2.5 hours; the certain temperature program includes: reacting at a temperature of 0 to 5°C for 1.5 to 2.5 hours; reacting at a temperature of 40°C for 1.5 to 2.5 hours; reacting at a temperature of 60°C for 1.5 to 2.5 hours; reacting at a temperature of 80°C for 10.5 to 13.5 hours; the mass concentration of the halogen-containing polyurethane solution is 10% to 50%; and / or the drying time is 30 to 120 minutes.

[0020] As a possible implementation manner, the temperature condition of 0-5°C is achieved by an ice-water bath; and / or, the temperature condition of 40°C, the temperature condition of 60°C and the temperature condition of 80°C are all achieved by an oil bath; and / or, the reaction is stirred under a certain temperature program, and the reaction time is 18 hours.

[0021] In a third aspect, the present invention provides an application of the halogen-containing polyurethane described in any possible implementation of the first aspect or the halogen-containing polyurethane prepared by the preparation method described in any possible implementation of the second aspect in holographic anti-counterfeiting technology.

[0022] As a possible implementation method, the halogen-containing polyurethane is fixed under the pattern of the mask and placed under a UV light source; the UV light is exposed through the mask for 3 to 30 seconds, and the exposure amount is 50 to 250 mJ / cm 2 , a holographic color pattern is obtained on the surface of the halogen-containing polyurethane.

[0023] As a possible implementation manner, the mask has a target image in a grating shape and is transparent to ultraviolet light.

[0024] As a possible implementation method, the wavelength of the ultraviolet light is 100 to 400 nm; and / or the exposure line width of the grating shape is 0.1 to 10 μm and the grating period is 0.1 to 10 μm; and / or the halogen-containing polyurethane surface obtains a holographic color pattern, and the grating structure has a spacing of 0.1 to 10 μm and a height of 0.05 to 1 μm.

[0025] The halogen-containing polyurethane material provided by the present invention is a new type of polyurethane material. It not only inherits all the advantages of traditional polyurethane, but also has significant flame retardant properties by introducing halogen elements. At the same time, the production cost of some traditional anti-counterfeiting packaging materials is high, which limits their large-scale production. However, the polyurethane material has a low cost, and the halogen-containing polyurethane material provided by the present invention also has good optical properties and processing properties; under specific lighting conditions, this material can undergo a photochemical reaction to form a stable pattern or text, thereby realizing the hiding and display of information, thereby providing an effective anti-counterfeiting function.

[0026] The present invention provides a method for preparing halogen-containing polyurethane. By selecting halogen-containing preparation raw materials and performing reasonable molecular design on them, an intrinsic halogen-containing polyurethane material is prepared by grafting a photosensitive group with a polymer, and the performance of the polyurethane material itself is maintained or slightly improved.

[0027] The present invention provides an application of halogen-containing polyurethane in holographic anti-counterfeiting technology, and a holographic color pattern with a grating structure is formed on its surface through selective exposure of a mask or direct exposure of a laser. The halogen-containing polyurethane can be coated on the surface of a variety of substrate materials for large-area preparation, and a photochemical reaction occurs in its photosensitive group, thereby forming a grating-shaped concave-convex structure. Due to the Bragg diffraction effect, these structures will produce obvious rainbow patterns, and the pattern colors have strong angle dependence. The flame retardancy and stability of the halogen-containing polyurethane can provide dual protection for the safety of the product. Whether it is an accidental fire during transportation or a risk of spontaneous combustion during storage, this material can effectively reduce losses and protect the product from damage. At the same time, its excellent anti-counterfeiting performance also provides strong technical support for combating counterfeit and shoddy products. This feature makes the halogen-containing photosensitive polyurethane material show great application potential in the field of packaging that requires high safety, such as electronic products, flammable and explosive items, etc.

[0028] The present invention discloses a halogen-containing polyurethane material that can be directly used for anti-counterfeiting packaging materials. When different halogen-containing monomers are used, transparent photosensitive films with good stability suitable for different environments can be prepared. The material has the advantages of good flame retardancy, excellent thermal stability, low production cost, wide adaptability and excellent mechanical properties, and can meet the anti-counterfeiting requirements in various complex scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is a graph of thermogravimetric analysis test analysis data of polyurethanes A to C provided in the embodiments of the present invention.

[0031] Figure 2 This is a low-temperature differential scanning calorimeter test data analysis chart of polyurethane A to polyurethane C provided in the embodiments of the present invention.

[0032] Figure 3 The images of polyurethane A provided in the embodiment of the present invention under different devices are, from left to right, digital images after development, optical microscope images, and atomic force microscope images.

[0033] Figure 4 Holographic color images of polyurethane A to polyurethane C provided in the embodiments of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to solve the problem that the fireproof performance of polyurethane materials in the prior art is not ideal when used as anti-counterfeiting packaging materials, the embodiment of the present invention provides a preparation experiment of halogen-containing polyurethane, and applies and characterizes it. It can be seen that the halogen-containing polyurethane provided by the embodiment of the present invention has a photochemical reaction in its photosensitive group, thereby forming a grating-shaped concave-convex structure. Due to the Bragg diffraction effect, these structures will produce obvious rainbow patterns, and the color of the pattern has a strong angle dependence.

[0036] Furthermore, the embodiment of the present invention provides a performance test experiment of halogen-containing polyurethane. It can be seen that due to the introduction of halogen elements, the thermal stability of polyurethane materials is improved.

[0037] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0038] Example 1

[0039] This embodiment provides an experiment for preparing halogen-containing polyurethane.

[0040] The preparation experiment provided in this embodiment is prepared by polycondensation of halogen-containing (the halogen in this embodiment is chlorine element) isocyanate, halogen-containing diol and photosensitive monomer, wherein the photosensitive group is grafted on the polymer.

[0041]

[0042] According to the synthetic route shown in the above formula, 11.78 kg of photosensitive group-containing diphenyl diamine (such as "structural unit C-structural unit D" shown in the above formula) and 32.04 g of halogen-containing 3,3'-dichloro-4,4'-diisocyanate biphenyl (such as "structural unit A" shown in the above formula) were added to a container containing 239.71 kg of N,N-dimethylformamide (DMF) under the conditions of anhydrous and inert gas protection, and stirred in an ice water bath at 0-5°C for 2 hours. Then, 16.11 kg of 4,6-dichlororesorcinol (such as "structural unit B" shown in the above formula) and 0.59 kg of catalyst dibutyltin dilaurate were added to the reaction system and stirred for 2 hours. The reaction system was moved into an oil bath pot and heated to 40°C for 2 hours, then continued to heat to 60°C for 2 hours, and finally heated to 80°C for 12 hours, and reacted for a total of 20 hours. The halogen-containing polyurethane solution A was prepared by a segmented heating method. The halogen-containing polyurethane solution A was defoamed at room temperature in the dark, coated on a cover glass treated with a 3-aminopropyltriethoxysilane solution by spin coating, and then transferred to a vacuum oven and baked at 100° C. for 90 minutes to obtain polyurethane A.

[0043] Example 2

[0044] This embodiment provides an experiment for preparing halogen-containing polyurethane.

[0045] The preparation experiment provided in this embodiment is prepared by polycondensation of halogen-containing (the halogen in this embodiment is chlorine element) isocyanate, halogen-containing diol, photosensitive monomer and chain extender, wherein the photosensitive group is grafted on the polymer.

[0046]

[0047] According to the synthesis route shown in the above formula, 11.78 g of photosensitive group-containing diphenyl diamine (as "structural unit C-structural unit D" shown in the above formula) and 21.90 g of halogen-containing 4-chloro-6-methyl-m-phenylene diisocyanate (as "structural unit A" shown in the above formula) were added to a container containing 170.44 kg of N,N-dimethylformamide (DMF) under anhydrous and inert gas protection conditions, and the reaction was stirred in an ice-water bath at 0-5°C for 2 hours. Then, 4.42 kg of 3-chloro-1,2-propanediol ("structural unit B" shown in the above formula), 4.51 kg of chain extender 1,4-butanediol and 0.42 kg of catalyst dibutyltin dilaurate were added to the reaction system and stirred for 2 hours. Then, the reaction system was moved into an oil bath pot and heated to 40°C for 2 hours, then continued to heat to 60°C for 2 hours, and finally heated to 80°C for 12 hours, and reacted for 20 hours in total. The halogen-containing polyurethane solution B was prepared by segmented heating. The halogen-containing polyurethane solution B was defoamed at room temperature and protected from light, and coated on a cover glass treated with 3-aminopropyltriethoxysilane solution by spin coating, and then transferred to a vacuum oven and baked at 100°C for 90 minutes to obtain polyurethane B.

[0048] Example 3

[0049] This embodiment provides a preparation experiment of polyurethane.

[0050] The preparation experiment provided in this embodiment is prepared by polycondensation of halogen-free isocyanate, halogen-free diol and photosensitive monomer, wherein the photosensitive group is grafted on the polymer.

[0051]

[0052] According to the synthetic route shown in the above formula, 11.78g of photosensitive group-containing benzyl diamine (as shown in the above formula "structural unit C'-structural unit D'") and 18.49g of toluene diisocyanate (as shown in the above formula "structural unit A'") were added to a container containing 148.48kg of N,N-dimethylformamide (DMF) under anhydrous and inert gas protection conditions, and stirred in an ice water bath at 0-5°C for 2h. Then, 6.85kg of 1,2-propylene glycol (as shown in the above formula "structural unit B'") and 0.37kg of catalyst dibutyltin dilaurate were added to the reaction system and stirred for 2h. The reaction system was moved into an oil bath pot and heated to 40°C for 2h, then continued to heat to 60°C for 2h, and finally heated to 80°C for 12h, and reacted for a total of 20h. Halogen-containing polyurethane solution C was prepared by segmented heating. The obtained polyurethane solution C was defoamed at room temperature in the dark, coated on a cover glass treated with a 3-aminopropyltriethoxysilane solution by spin coating, and then transferred to a vacuum oven and baked at 100° C. for 90 min to obtain polyurethane C.

[0053] Example 4

[0054] This embodiment provides an application experiment of halogen-containing polyurethane.

[0055] A holographic color image is prepared on a halogen-containing photosensitive polyurethane film, and the preparation method is as follows:

[0056] The polyurethane to be tested is placed close to the chrome surface of the UV-transmissive mask, fixed under the pattern of the mask, and placed under a UV light source with a wavelength of 365nm for selective exposure, thereby obtaining a holographic color pattern on the surface of the polyurethane to be tested. The exposure time is 3 to 30 seconds, and the exposure amount is 50 to 250mJ / cm 2 .

[0057] In this example, polyurethanes A to C prepared in Examples 1 to 3 were used as polyurethanes to be tested to prepare holographic color images, and the following were obtained: Figure 3 The images shown and Figure 4 The holographic color image shown. It can be observed that polyurethane B has obvious rainbow color under white light. The rainbow color comes from the Bragg diffraction effect of the grating structure on the surface of the film on the incident light. The microstructure of the film surface is as follows Figure 3 As shown in the optical microscope photos and atomic force microscope photos, it can be observed that there is a regular grating structure on the surface of the film, and the interval between the grating structures is 2μm and the height is 400nm. The grating structure depends on the pattern of the mask or the design of laser engraving.

[0058] Example 5

[0059] This embodiment provides a performance test experiment of halogen-containing polyurethane.

[0060] Thermogravimetric analysis was performed on the polyurethanes A to C prepared in Examples 1 to 3, and the following results were obtained: Figure 1 From the results shown, it can be seen that the decomposition temperature of the halogen-containing polyurethane is as high as 232.6°C when the weight loss is 5%, which indicates that the introduction of halogen elements improves the fire retardant properties of polyurethane materials.

[0061] Materials with high glass transition temperatures are less sensitive to temperature changes than materials with low glass transition temperatures, so materials with high glass transition temperatures have better thermal stability. Polyurethanes A to C prepared in Examples 1 to 3 were tested by low-temperature differential scanning calorimetry, and the following results were obtained: Figure 2 The results show that the glass transition temperature of polyurethane B is 118.6°C, which is higher than the glass transition temperature of traditional polyurethane (-20 to 70°C). Therefore, due to the introduction of halogen elements, the thermal stability of polyurethane materials is improved.

[0062] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0063] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A halogen-containing polyurethane, characterized in that: Its chemical structure is shown in Formula I. Among them, x:y is 2:1 to 20; The structural unit A is an alkyl or aryl structure, which contains at least one halogen element and at least two isocyanate groups; The structural unit B is an alkyl or aryl structure, which contains at least one halogen element and at least two hydroxyl groups; The structural unit C is an aromatic structure, which contains at least one halogen element and at least two hydroxyl groups or at least two amino groups; The structural unit D is a photosensitive group, which is connected to the structural unit C via an alkane chain with an ether bond, and its molar mass accounts for 1% to 50% in the halogen-containing polyurethane monomer.

2. The halogen-containing polyurethane according to claim 1, characterized in that The structural formula of the structural unit A is any one of Formula II and Formula III, And / or, the structural formula of the structural unit B is any one of Formula IV, Formula V, Formula VI, Formula VII, Formula VIII, and Formula IX, and / or, the structural unit C has a structural formula of any one of formula X, formula XI, formula XII, formula XIII, formula XIV, and formula XV, Wherein, X is any one of fluorine, chlorine, bromine and iodine.

3. The halogen-containing polyurethane according to claim 1, characterized in that The structural formula of the photosensitive group is shown in Formula XVI, Wherein, n is a positive integer from 1 to 50.

4. A method for preparing a halogen-containing polyurethane according to any one of claims 1 to 3, characterized in that: The following steps are involved: In an inert gas environment, the structural unit A and the structural unit C-structural unit D are uniformly mixed in an organic solvent at a temperature of 0 to 5° C., the structural unit B and a catalyst are added, and the mixture is stirred and reacted at a certain temperature program to obtain a halogen-containing polyurethane solution; The halogen-containing polyurethane solution is coated on a base material and dried at a temperature of 50-100° C. to obtain the halogen-containing polyurethane.

5. The preparation method according to claim 4, characterized in that: The step of uniformly mixing the mixture in an organic solvent under an ice-water bath at 0 to 5° C. is performed for 1.5 to 2.5 hours; The certain temperature program includes: reacting at a temperature of 0 to 5°C for 1.5 to 2.5 hours; reacting at a constant temperature of 35 to 45°C for 1.5 to 2.5 hours; reacting at a constant temperature of 55 to 65°C for 1.5 to 2.5 hours; reacting at a constant temperature of 75 to 85°C for 10.5 to 13.5 hours; The mass concentration of the halogen-containing polyurethane solution is 10% to 50%; And / or, the drying time is 30 to 120 minutes.

6. The preparation method according to claim 4, characterized in that: The temperature condition of 0 to 5°C is achieved by an ice water bath; And / or, the temperature condition of 35-45° C., the temperature condition of 55-65° C. and the temperature condition of 75-85° C. are all achieved by oil bath; And / or, the reaction is stirred under a certain temperature program, and the reaction time is 18 hours.

7. Use of the halogen-containing polyurethane according to any one of claims 1 to 3 or the halogen-containing polyurethane prepared by the preparation method according to any one of claims 4 to 6 in holographic anti-counterfeiting technology.

8. The use according to claim 7, characterized in that: Fixing the halogen-containing polyurethane below the pattern of the mask and placing it under an ultraviolet light source; UV light is exposed through the mask for 3 to 30 seconds, and the exposure amount is 50 to 250 mJ / cm 2 , a holographic color pattern is obtained on the surface of the halogen-containing polyurethane.

9. The use according to claim 8, characterized in that: The mask has a target image in a grating shape and is transparent to ultraviolet light.

10. The use according to claim 9, characterized in that: The wavelength of the ultraviolet light is 100 to 400 nm; And / or, the exposure line width of the grating shape is 0.1-10 μm, and the grating period is 0.1-10 μm; And / or, the halogen-containing polyurethane surface obtains a holographic color pattern, and the interval of the grating structure is 0.1-10 μm and the height is 0.05-1 μm.

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