Preparation method and application of reversible writing erasure and information encryption crystalline film
By adopting an interpenetrating network polymer system and dual decryption program in the crystalline film, the problem of poor response of the crystalline film is solved, rapid information implantation and safe hiding are achieved, and the security and stability of information storage are improved.
Patent Information
- Application Number
- CN202510418869.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-07-11
AI Technical Summary
The reversible erasing characteristics of existing crystallized films are poorly responsive to external stimuli and cannot effectively implant and protect specific information.
The interpenetrating network polymer system is adopted to control the mutual solubility difference between the polyurethane crystalline network and the non-crystalline confined domain network, and the island structure is formed at the micron level to achieve rapid crystallization of the pressed area, and to protect information security by combining a dual decryption program of specific temperature and time.
It realizes rapid implantation and safe hiding of specific information, and can only be read and written through specific conditions, improving the security and stability of information storage.
Smart Images
Figure CN120289838A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of the preparation of reversible crystalline polymer films, and particularly relates to a preparation method and application of a crystalline film for reversible writing, erasing and information encryption. Background Art
[0002] Since ancient times, the recording of information by humans has never stopped. From rock engraving to paper and ink writing, and then to modern online communication, the scope of information recording and knowledge transmission has increased exponentially, and information encryption and fixed-point transmission are crucial.
[0003] In recent years, materials with reversible writing and erasing functions have gradually attracted attention in the fields of information storage and encryption. Crystalline films, especially films made of different types of materials (such as organic substances, inorganic substances or organic-inorganic composites), have shown potential in information encryption, data storage and reverse processing due to their unique physical and chemical properties. The advantage of such crystalline films is that they can be reversibly written and erased by external stimuli (such as temperature, electric field or light). Information is stored in the crystalline film in different forms, and the original state can be restored by controlling the environmental conditions, thereby realizing the erasure and update of data. In addition, the chemical properties of different types of crystalline polymers are not the same. Combining appropriate encryption technologies, the crystalline film can also improve the security of information storage, enabling the data to be read only by authorized users.
[0004] Although conventional crystalline polymers have reversible erasure characteristics, due to their too fast crystallization rate, they often crystallize without difference and have poor responsiveness to external stimuli, making it impossible to implant specific information. Summary of the Invention
[0005] To solve the problems in the background art, the present invention provides a preparation method and application of a crystalline film for reversible writing, erasing and information encryption.
[0006] To achieve the above object, the present invention adopts the following technical solutions:
[0007] A preparation method of a crystalline film for reversible writing, erasing and information encryption, comprising the following steps:
[0008] Step 1: By mass, dissolve 20-80 parts of polyurethane crystalline network monomers, 20-80 parts of non-crystalline confinement network monomers, and 0.1-15 parts of photoinitiators in 0-80 parts of solvents, and add 0-20 parts of polyurethane catalysts and mix evenly;
[0009] Step 2: Transfer the mixture onto a mold, irradiate it with a light source to trigger the cross-linking reaction of the double bonds by the photoinitiator, transfer it to an oven at 40-150 °C after irradiation and heat for 0.5-8 h to cause the cross-linking reaction of the polyurethane network, and place it under vacuum conditions to remove the solvent, obtaining a crystalline film with reversible writing and erasing and information encryption properties.
[0010] Further, in Step 1, the polyurethane crystalline network monomer comprises an isocyanate and a polyol, and the molar ratio of the isocyanate group to the hydroxyl group in the polyol is 1:1 to 1.05:1. The non-crystalline confinement network monomer is an acrylate monomer. The isocyanate includes one or more combinations of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate. The polyol includes one or more combinations of polyethylene glycol, polycaprolactone diol, polycaprylic adipate diol, polyethylene terephthalate diol, polyethylene terephthalate diol, pentaerythritol, 1,4-butanediol, and glycerol. The acrylate monomer includes one or more combinations of butyl acrylate, methyl methacrylate, methyl acrylate, 2-hydroxyethyl acrylate, ethyl acrylate, ethyl methacrylate, isobornyl acrylate, 4-morpholino acrylate, dipropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol phthalate diacrylate, and trimethylolpropane triacrylate.
[0011] Further, the molecular weight range of the polyethylene glycol, polycaprylic adipate diol, polyethylene terephthalate diol, and polyethylene terephthalate diol is 2000-20000, and the molecular weight of the polycaprolactone diol is 640-4000. Among them, the large molecular weights of the polyethylene glycol and the polycaprolactone diol increase the probability of regular arrangement of the chain segments and provide excellent crystallization ability for the polyurethane network.
[0012] Preferably, the molecular weights of the polyethylene glycol, polycaprylic adipate diol, polyethylene terephthalate diol, and polyethylene terephthalate diol are independently selected as 2000, 3000, 4000, 8000, 10000, or 20000, and the molecular weight of the polycaprolactone diol is 640, 1000, 2000, 3000, or 4000.
[0013] Further, in step one, the polyurethane catalyst includes basic catalysts or organometallic polyurethane catalysts; the photoinitiator includes one or a combination of more than one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinobenzylphenyl)butanone, benzophenone, and 2-isopropylthioxanthone, and the solvent includes one or a combination of more than one of toluene, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, dichloromethane, and trichloromethane.
[0014] Further, in step two, the light irradiance of the light source is 0.5 - 150 mW / cm 2 .
[0015] Further, the temperature for removing the solvent under vacuum conditions is maintained at 80 - 150 °C.
[0016] Application of a crystalline film prepared by the described preparation method. Before use, heat the prepared crystalline film to above 80 °C for 1 - 60 min, take it out and let it cool to room temperature. Specific information is formed by writing or pressing and stored in the film. After being placed at room temperature for more than 3 h, the information in the film is hidden. Heat it to 40 - 80 °C for 1 - 60 min, and after placing it at room temperature for 10 s - 120 min, the information on the film can be redisplayed. If the heating temperature is higher than 80 °C for 1 - 60 min, the stored information in the film is erased.
[0017] Compared with the prior art, the beneficial effects of the present invention are:
[0018] The present invention prepares an interpenetrating polymer network system, including a crystalline network and a non-crystalline confinement network. Utilizing the difference in mutual solubility between the two networks, an island structure is formed at the micron level to achieve rapid crystallization in the pressed area, thereby realizing the implantation of specific information. After a longer time, the entire film is crystallized and the implanted information is hidden. Only through a specific double decryption process of temperature and time can the information be read and written again. An incorrect decryption process will cause the information not to be displayed or the information to self-destruct. Description of the Drawings
[0019] Figure 1 Among them, the left column of figures is the display diagram of the writing effect of traditional crystalline materials; the right column of figures is the display diagram of the writing effect of the crystalline film of the present invention;
[0020] Figure 2 Among them, the left figure is the crystalline film before pressing. After annealing and being placed at room temperature for 1 h, no crystalline characteristic peak appears in the XPS curve; the right figure is the crystalline film after pressing. After annealing and being placed at room temperature for 10 min, a crystalline characteristic peak can appear in the XPS curve.
[0021] Figure 3 It is a schematic diagram of the double decryption process of the crystalline film of the present invention. Specific embodiments
[0022] The technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.
[0023] Example 1:
[0024] A preparation method of a crystalline film for reversible writing erasure and information encryption, comprising the following steps:
[0025] Step 1: By mass, dissolve 50 parts of polyurethane crystalline network monomers, 50 parts of non-crystalline confinement network monomers, and 1 part of photoinitiator in 30 parts of solvent, and add 0.5 part of polyurethane catalyst and mix evenly; the polyurethane crystalline network monomers include hexamethylene diisocyanate, polycaprolactone diol with a molecular weight of 4000, and glycerol, where the molar ratio of isocyanate groups to hydroxyl groups is 1.05:1; the non-crystalline confinement network monomers are isobornyl acrylate and trimethylolpropane triacrylate, and the ratio between the two is 9:1; the polyurethane catalyst is dibutyltin dilaurate, the solvent is N, N-dimethylformamide, and the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone;
[0026] Step 2: Transfer the mixture onto a glass mold, and immediately irradiate it with a UV light source (365 nm, 50 mW / cm 2 ) for 20 min to trigger the double bond of the photoinitiator to undergo a crosslinking reaction. After irradiation, transfer it to an oven at 40 °C and heat for 8 h to cause the polyurethane network to undergo a crosslinking reaction. Place the sample under vacuum at 100 °C overnight to remove the solvent, and obtain a crystalline film for reversible writing erasure and information encryption. After cutting the sample, use a self-made writing pen to write on the film to test its writing crystallization ability, as shown in Figure 1 .
[0027] Example 2:
[0028] Prepare a crystalline film for reversible writing erasure and information encryption using the preparation method in Example 1. Before use, heat the prepared crystalline film at 100 °C for 10 min, then take it out and place it at room temperature. Use a special writing pen to press to form specific information. Utilize the difference in the mutual solubility of the two networks to form a sea-island structure at the micron level, which greatly increases the stress sensing ability and can preferentially form crystal nuclei, achieving rapid crystallization in the pressed area, thereby realizing the implantation of specific information. The information is stored in the film. The difference in the crystallization rate of the crystalline film before pressing and after pressing is shown in Figure 2 ... After being placed at room temperature for 48 h, the information in the film is hidden. Heat it to 50 °C for 30 min and then place it at room temperature for 10 min, and the information on the film can be redisplayed again. This process can be repeated multiple times. When the heating temperature is higher than 80 °C for 5 min, the information stored in the film is erased. The information security is protected through a dual security procedure of temperature and time. The process is shown in Figure 3 ...
[0029] Example 3
[0030] A preparation method of a crystalline film for reversible writing erasure and information encryption, comprising the following steps:
[0031] Step 1: By mass, dissolve 20 parts of polyurethane crystalline network monomers, 80 parts of non-crystalline confinement network monomers, 10 parts of photoinitiator in 80 parts of solvent, and add 1 part of polyurethane catalyst and mix evenly; the polyurethane crystalline network monomers include toluene diisocyanate, polycaprolactone diol with a molecular weight of 640, and glycerol, where the molar ratio of isocyanate groups to hydroxyl groups is 1:1; the non-crystalline confinement network monomers are methyl methacrylate and dipropylene glycol diacrylate, and the ratio of the two is 6:4; the polyurethane catalyst is 1,8-diazabicyclo[5.4.0]undec-7-ene, the solvent is dichloromethane, and the photoinitiator is 2-isopropylthioxanthone;
[0032] Step 2: Transfer the mixture onto a glass mold, immediately irradiate it with a UV light source (365 nm, 50 mW / cm 2 ) for 20 min to trigger the cross-linking reaction of the double bonds by the photoinitiator. After irradiation, transfer it to an oven at 150 °C and heat for 0.5 h to cause the cross-linking reaction of the polyurethane network. Place the sample under vacuum at 100 °C overnight to remove the solvent, obtaining a crystalline film for reversible writing erasure and information encryption. After cutting the sample, use a self-made writing pen to write on the film to test its writing and crystallization ability.
[0033] Example 4
[0034] A preparation method of a crystalline film for reversible writing erasure and information encryption, comprising the following steps:
[0035] Step 1: By mass, dissolve 80 parts of polyurethane crystalline network monomer, 20 parts of non-crystalline confinement network monomer, and 2 parts of photoinitiator in 80 parts of solvent, and add 1 part of polyurethane catalyst and mix evenly; the polyurethane crystalline network monomer includes isophorone diisocyanate, polyethylene glycol with a molecular weight of 2000, and glycerol, where the molar ratio of isocyanate groups to hydroxyl groups is 1.05:1; the non-crystalline confinement network monomer is methyl methacrylate and dipropylene glycol diacrylate, and the ratio between the two is 8:2; the polyurethane catalyst is 1,8-diazabicyclo[5.4.0]undec-7-ene, the solvent is N,N-dimethylacetamide, and the photoinitiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide;
[0036] Step 2: Transfer the mixture onto a glass mold, and immediately irradiate it with a UV light source (365 nm, 50 mW / cm 2 ) for 20 min to trigger the cross-linking reaction of the double bond by the photoinitiator. After irradiation, transfer it to an oven at 150 °C and heat for 0.5 h to cause the cross-linking reaction of the polyurethane network. Place the sample under vacuum at 100 °C overnight to remove the solvent, and obtain a crystalline film with reversible writing, erasing, and information encryption. After cutting the sample, use a self-made writing pen to write on the film to test its writing crystallization ability.
[0037] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for preparing a crystalline film for reversible writing, erasing, and information encryption, characterized in that, It includes the following steps: Step 1: Dissolve 20 - 80 parts by mass of polyurethane crystalline network monomer, 20 - 80 parts by mass of non-crystalline confinement network monomer, and 0.1 - 15 parts of photoinitiator in 0 - 80 parts of solvent, and add 0 - 20 parts of polyurethane catalyst and mix evenly; Step 2: Transfer the mixture onto a mold, irradiate with a light source to trigger the cross-linking reaction of the double bond by the photoinitiator, transfer it to an oven at 40 - 150 °C after irradiation and heat for 0.5 - 8 h to cause the cross-linking reaction of the polyurethane network, place it under vacuum conditions to remove the solvent, and obtain a crystalline film with reversible writing, erasing, and information encryption.
2. The preparation method according to claim 1, characterized in that: In Step 1, the polyurethane crystalline network monomer contains isocyanate and polyol, where the molar ratio of isocyanate group to hydroxyl group in polyol is 1:1 - 1.05:1, and the non-crystalline confinement network monomer is an acrylate monomer.
3. The preparation method according to claim 2, characterized in that: The isocyanate includes one or a combination of more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate; the polyol includes one or a combination of more of polyethylene glycol, polycaprolactone diol, polycaprylic adipate diol, polyethylene terephthalate glycol, polyethylene terephthalate glycol, pentaerythritol, 1,4-butanediol, and glycerol; the acrylate monomer includes one or a combination of more of butyl acrylate, methyl methacrylate, methyl acrylate, 2-hydroxyethyl acrylate, ethyl acrylate, ethyl methacrylate, isobornyl acrylate, 4-morpholino acrylate, dipropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol phthalate diacrylate, and trimethylolpropane triacrylate.
4. The preparation method according to claim 3, characterized in that: The molecular weight range of the polyethylene glycol, polycaprylic adipate diol, polyethylene terephthalate glycol, and polyethylene terephthalate glycol is 2000 - 20000, and the molecular weight of the polycaprolactone diol is 640 - 4000.
5. The preparation method according to claim 4, characterized in that: The molecular weights of the polyethylene glycol, polycaprylic adipate diol, polyethylene terephthalate glycol, and polyethylene terephthalate glycol are independently selected from 2000, 3000, 4000, 8000, 10000, or 20000, and the molecular weight of the polycaprolactone diol is 640, 1000, 2000, 3000, or 4000.
6. The preparation method according to claim 1, characterized in that: In Step 1, the polyurethane catalyst includes an alkali catalyst or an organometallic polyurethane catalyst; the photoinitiator includes one or a combination of more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinobenzylphenyl)butanone, benzophenone, and 2-isopropylthioxanthone; the solvent includes one or a combination of more of toluene, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, dichloromethane, and trichloromethane.
7. The preparation method according to claim 1, characterized in that: In step two, the light irradiance of the light source is 0.5 - 150 mW / cm 2 .
8. The preparation method according to claim 1, characterized in that: In Step 2, the temperature for solvent removal under vacuum conditions is maintained at 80 - 150 °C.
9. Use of a crystalline film prepared by the preparation method according to any one of claims 1-8, characterized in that: Before use, heat the prepared crystalline film to above 80 °C for 1 - 60 min, take it out and let it cool to room temperature. Specific information is formed by writing or pressing and stored in the film. After being placed at room temperature for more than 3 h, the information in the film is hidden. When heated to 40 - 80 °C for 1 - 60 min and then placed at room temperature for 10 s - 120 min, the information on the film can be redisplayed. If the heating temperature is higher than 80 °C for 1 - 60 min, the stored information in the film is erased.