Medical self-shedding water-based photocuring pressure-sensitive adhesive and preparation method thereof
The preparation of a medical pressure-sensitive adhesive that is easy to detach by water-based photocuring polyurethane solves the problem of skin damage during peeling of pressure-sensitive adhesives in the prior art, and provides a solution with good biocompatibility, low toxicity and low energy consumption.
Patent Information
- Application Number
- CN202510904770.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-01
- Publication Date
- 2025-10-31
AI Technical Summary
Existing medical pressure-sensitive adhesives are prone to causing mechanical damage when peeled off from the patient's skin, especially to the elderly, children and patients with poor skin conditions. There is a lack of medical pressure-sensitive adhesives on the market that are easy to remove and skin-friendly.
The medical self-removing pressure-sensitive adhesive, which uses water-based light-cured polyurethane as the main component, ensures that the adhesive's initial tack and holding power decrease over time by adjusting the proportion of raw material components and the preparation process, making it easy to detach on its own and avoiding mechanical damage.
It achieves the self-removal property of pressure-sensitive adhesive, reduces mechanical damage to the skin, has good biocompatibility and low toxicity, low odor, is environmentally friendly, has low cost, fast curing speed, low energy consumption, and is suitable for a variety of application fields.
Smart Images
Figure CN120865833A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of medical biomaterials technology, specifically relating to a self-detaching water-based photocurable pressure-sensitive adhesive for medical use and its preparation method. Background Technology
[0002] Pressure-sensitive adhesives (PSAs) are viscoelastic materials that adhere to substrate surfaces when pressure is applied. They are widely used in various packaging, electronics, labeling, and medical materials. Medical PSAs are a special branch of PSAs because they come into contact with the human body, and therefore have special or more stringent requirements regarding their wettability, toxicity, sensitization, and adhesion.
[0003] Medical pressure-sensitive adhesives can be classified according to their composition into acrylic, silicone, polyurethane, and hot-melt types, among others. Traditional solvent-based pressure-sensitive adhesives have seen their market share decline year by year due to their high toxicity, high energy consumption, and high VOC emissions. Solvent-free pressure-sensitive adhesives, with their environmental friendliness and low odor, are gradually replacing traditional pressure-sensitive adhesives in the market. Among these, photocurable pressure-sensitive adhesives are a typical example of a new type of pressure-sensitive adhesive.
[0004] UV-curable pressure-sensitive adhesives are in a viscous liquid state with good fluidity during construction. When used, they are applied to the substrate and cured into pressure-sensitive adhesive products with good adhesion after being irradiated by electron beam or ultraviolet light. They have the advantages of convenient construction, fast curing speed, low energy consumption, and low toxicity. According to their composition, UV-curable pressure-sensitive adhesives can be divided into rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives, polyurethane-based pressure-sensitive adhesives, etc.
[0005] Photocurable polyurethane pressure-sensitive adhesives are a type of polyurethane that can be cured by light. They have excellent mechanical properties, and their molecular weight and molecular structure can be flexibly adjusted. They also have good compatibility with other systems and have important applications in the medical field.
[0006] Currently, the requirements for medical pressure-sensitive adhesives are higher than those for other applications due to the specific nature of their use. For pressure-sensitive adhesives intended for use on the human body, which require direct or indirect contact with the skin, medical ISO-10993 certification is necessary. To prevent the adhesive layer from detaching from the affected area, medical pressure-sensitive adhesives have strong adhesion, which means that significant force is required to remove the adhesive layer from the patient, potentially damaging their skin. There are currently no medical pressure-sensitive adhesives on the market specifically designed for elderly people, children, or patients with poor skin conditions. Medical adhesive-associated skin injury (MARSI) is specifically used to describe chemical or mechanical damage to a patient's skin caused by medical pressure-sensitive adhesives. Mechanical damage occurs because when the pressure-sensitive adhesive is peeled off from the affected area, the stratum corneum and hair are also peeled off. This often happens when medical pressure-sensitive adhesives are used by special groups such as the elderly, children, and patients with poor skin. The patents and products of medical pressure-sensitive adhesives on the market mainly focus on low allergenicity, therapeutic function, antibacterial properties, etc. Therefore, there is an urgent need in the market for a pressure-sensitive adhesive that is easy to remove to solve this problem. Summary of the Invention
[0007] To address the shortcomings of the existing technology, this invention provides a medical self-removing water-based light-curing pressure-sensitive adhesive and its preparation method. The pressure-sensitive adhesive has good initial tack, and after being applied to the affected area for a period of time, the initial tack and holding tack will weaken until they basically disappear, making it easy to remove from the skin without damaging the skin.
[0008] The present invention is solved by the following technical solution.
[0009] A medical self-removing waterborne photocurable pressure-sensitive adhesive, comprising waterborne photocurable polyurethane, a photoinitiator, a neutralizing agent, an active diluent, and water; wherein the mass ratio of the waterborne photocurable polyurethane, photoinitiator, neutralizing agent, active diluent, and water is 20–50: 2–5: 0.2–1: 10–40: 50–300; wherein the neutralizing agent is one or more of dimethylethanolamine, triethylamine, triethanolamine, and ammonia; and wherein the active diluent is acryloylmorpholine, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate. The waterborne photocurable polyurethane comprises one or more of polyethylene glycol 400 dimethacrylate and polyethylene glycol 600 dimethacrylate; the raw material components of the waterborne photocurable polyurethane include diisocyanate, self-made polyol, catalyst 1, polymerization inhibitor, and end-capping agent; the mass ratio of the diisocyanate, self-made polyol, catalyst, polymerization inhibitor, and end-capping agent is 20-100:1000-12000:0.02-1:0.05-0.5:5-20; the photoinitiator is one or more of TPO, 184, TMO, 819, 1173, and ITX.
[0010] In a preferred embodiment, the diisocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate; the catalyst 1 is one or more of bismuth neodecanoate, dibutyltin dilaurate, and stannous octoate; the polymerization inhibitor is one or more of p-hydroxyanisole, tert-butylhydroquinone, phenothiazine, and hydroquinone; and the end-capping agent is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypropyl methacrylate, and pentaerythritol triacrylate.
[0011] In a preferred embodiment, the self-made polyol comprises the following raw material components: polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, and antioxidant; the mass ratio of the polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, and antioxidant is 600-4000: 150-1200: 150-600: 0.05-0.5: 0.05-1.
[0012] In a preferred embodiment, the polyol comprises one or more of the following: neopentyl glycol, 1,6-hexanediol, polyethylene glycol 600, polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, tetraethylene glycol, polypropylene glycol 1000, polypropylene glycol 2000, polypropylene glycol 3000, polytetrahydrofuran 1000, polytetrahydrofuran 2000, polycaprolactone diol 1000, and polycaprolactone diol 2000; the polycarboxylic acid... The acid includes one or more of adipic acid, sebacic acid, isophthalic acid, phthalic acid, and terephthalic acid; the aqueous chain extender is dimethylolpropionic acid; the catalyst 2 is one or more of tetrabutyl titanate, tetrapropyl titanate, and butylstannic acid; the antioxidant is one or more of 1010, 168, 1076, 1035, and triphenyl phosphite, and this antioxidant can also be used in polyester synthesis and polyurethane synthesis processes.
[0013] The preparation method of a medical self-removing water-based photocurable pressure-sensitive adhesive according to this application includes the following steps:
[0014] S10: Preparation of self-made polyol: Under nitrogen protection, polyol, polycarboxylic acid and antioxidant are added to the reaction vessel and heated to 150±10℃. After the reactants are completely dissolved, catalyst 2 is added and the temperature is increased by 10±5℃ per hour until it reaches 240±15℃. After the reaction is kept at a constant temperature, an aqueous chain extender is added. After the reaction is completed, the temperature is lowered to below 90℃ and the product is discharged to obtain the self-made polyol.
[0015] S20: Preparation of waterborne photocurable polyurethane: Self-made polyol and diisocyanate were added to a reaction vessel, stirred and heated to 60±8℃, catalyst 1 was added, and the exothermic temperature was controlled to be less than 90℃. After the exothermic reaction was completed, the temperature inside the vessel was maintained at 70±8℃. After the reaction was completed, polymerization inhibitor and end-capping agent were added, and the exothermic temperature was controlled to be less than 85℃. After the exothermic reaction was completed, the temperature inside the vessel was maintained at 80±5℃. After the reaction was completed, the temperature was cooled to below 65℃ to obtain waterborne photocurable polyurethane.
[0016] S30: Preparation of waterborne photocurable pressure-sensitive adhesive: Add waterborne photocurable polyurethane to a reaction vessel, heat to 60±8℃, add a neutralizing agent, stir, add solvent water, and after the waterborne photocurable polyurethane is completely dissolved, add a self-made photoinitiator and an active diluent, stir, filter and discharge to obtain the waterborne photocurable pressure-sensitive adhesive.
[0017] Compared with existing technologies, the present invention has the following beneficial effects: It provides a medical self-removing water-based light-curing pressure-sensitive adhesive and its preparation method. This pressure-sensitive adhesive has good biocompatibility, low toxicity, and the adhesive itself is non-irritating to the skin. It has strong initial tack, and the tack decreases with the duration of use until it can no longer adhere to the skin and detaches on its own, without requiring the patient to tear it off, and will not cause medical adhesive-associated skin injury (MARSI) or other harm.
[0018] Furthermore, compared to the monomers such as isooctyl acrylate used in light-curing acrylic pressure-sensitive adhesives, which have a pungent odor, strong skin irritation, and are prone to residue, this invention has advantages such as low odor, no skin irritation, water as a solvent and participation in curing to form a gel, environmental friendliness, lower cost, easy production, fast curing speed, low energy consumption, low heat release, and wide range of applications, thus possessing high economic value and application prospects. Attached Figure Description
[0019] Figure 1 This is a typical synthetic route diagram of the self-made polyols in the embodiments of the present invention.
[0020] Figure 2 for Figure 1 The structural formula of the product of a typical synthetic route.
[0021] Figure 3 This is a schematic diagram of the structure of R1.
[0022] Figure 4 Typical synthesis route diagram of waterborne photocurable polyurethane in the embodiments of the present invention.
[0023] Figure 5 The infrared spectrum of the waterborne photocurable polyurethane in the embodiments of the present invention is shown.
[0024] Figure 6 This is a typical TGA curve for waterborne UV-cured polyurethane.
[0025] Figure 7 This is a diagram of the light-cured pressure-sensitive adhesive in Example 8 of this application, showing its just-cured state.
[0026] Figure 8 for Figure 7 The state diagram of the light-cured pressure-sensitive adhesive after vacuum drying at 60℃ for 24 hours.
[0027] Figure 9 This diagram illustrates the application and storage methods for pressure-sensitive adhesives. Detailed Implementation
[0028] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0029] In the following embodiments, the same or similar reference numerals denote the same or similar originals or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0030] The medical self-detaching waterborne photocurable pressure-sensitive adhesive of this application is prepared through the following steps.
[0031] Step 1: Preparation of self-made polyol: Under nitrogen protection, add polyol, polycarboxylic acid, and antioxidant to a reactor, heat to 150±10℃ (temperature 1), and wait for the reactants to completely dissolve. Add catalyst 2, and heat approximately 10℃ per hour until reaching 240±15℃ (temperature 2). Maintain this temperature for 3 hours, measuring the acid value hourly until it reaches the theoretical value. Add water-based chain extender: dimethylolpropionic acid, measuring the acid value hourly until it reaches the theoretical value. Cool to below 90℃ (preferably 80℃) and discharge to obtain the self-made polyol.
[0032] Step 2: Preparation of waterborne photocurable polyurethane: The self-made polyol and diisocyanate from Step 1 are added to the reactor. While stirring, the temperature is raised to 60±8℃ (Temperature 3). Catalyst 1 is added, and the heat release is controlled to be less than 90℃. After the heat release is completed, the temperature inside the reactor is maintained at 70±8℃ (Temperature 4). After reacting for 4 hours, the NCO value is measured every hour until the NCO value reaches the theoretical value. The polymerization inhibitor and end-capping agent are added, and the heat release is controlled to be less than 85℃. After the heat release is completed, the temperature inside the reactor is maintained at 80±5℃ (Temperature 5). After reacting for 3 hours, the NCO value is measured every hour until the NCO value is lower than 0.05. The temperature is then lowered to below 65℃ (preferably 60℃) to obtain the waterborne photocurable polyurethane.
[0033] Step 3: Preparation of water-based photocurable pressure-sensitive adhesive: Add the water-based photocurable polyurethane from step 2 into the reactor, heat to 60±8℃ (temperature 6), add the neutralizing agent, stir for 15 minutes, slowly add solvent water, and after the water-based photocurable polyurethane is completely dissolved, add the self-made photoinitiator and reactive diluent, stir for 30 minutes, filter and discharge to obtain the water-based photocurable pressure-sensitive adhesive.
[0034] The following are the first steps of specific embodiments 1 to 15.
[0035]
[0036] The following are specific examples 1 to 15, step 2.
[0037]
[0038]
[0039] The following are specific examples 1 to 15, step 3.
[0040]
[0041] In Examples 1 to 15 above, the typical synthetic route for the self-made polyol in the first step is as follows: Figure 1 As shown, where n1 = 4–135, n2 = 13–40, n3 = 10–25, and the product can be denoted as... Figure 2 The structural formula in the text, where the structure of R1 is as follows: Figure 3 As shown.
[0042] The typical synthesis route diagram for waterborne photocurable polyurethane in the second step is as follows: Figure 4 As shown, the infrared spectrum of the photocurable polyurethane in the second step of Example 1 is as follows. Figure 5 As shown in the figure, 2280cm -1 The disappearance of the isocyanate peak at 1700 cm⁻¹ proves that the isocyanate has completely reacted. -1 The presence of a carboxyl peak at the point indicates that dimethylolpropionic acid has been successfully incorporated into the chain segment, signifying the successful synthesis of photocurable water-soluble polyurethane acrylate.
[0043] In the above embodiments, the mass ratios of the raw material components in the first step of preparing the self-made polyol are as follows:
[0044] In Examples 1 to 5: polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, antioxidant; the mass ratio of the polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, and antioxidant is 2000:150:150:0.05:0.05.
[0045] In Examples 6 to 10: polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, antioxidant; the mass ratio of the polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, and antioxidant is 4000:1200:600:0.5:1.
[0046] In Examples 11 to 15: polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, antioxidant; the mass ratio of the polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, and antioxidant is 600:600:300:0.2:0.5.
[0047] In the above embodiments, the mass ratios of the raw material components in the second step of preparing the waterborne photocurable polyurethane are as follows:
[0048] In Examples 1 to 5: diisocyanate, self-made polyol, catalyst 1, polymerization inhibitor, and end-capping agent; the mass ratio of the diisocyanate, self-made polyol, catalyst, polymerization inhibitor, and end-capping agent is 20:1000:0.02:0.05:5.
[0049] In Examples 6 to 10: diisocyanate, self-made polyol, catalyst 1, polymerization inhibitor, and end-capping agent; the mass ratio of the diisocyanate, self-made polyol, catalyst, polymerization inhibitor, and end-capping agent is 100:12000:1:0.5:20.
[0050] In Examples 11 to 15: diisocyanate, self-made polyol, catalyst 1, polymerization inhibitor, and end-capping agent; the mass ratio of the diisocyanate, self-made polyol, catalyst, polymerization inhibitor, and end-capping agent is 60:6000:0.5:0.2:13.
[0051] In the above embodiments, the overall mass ratio of the raw material components of the prepared water-based photocurable pressure-sensitive adhesive is as follows:
[0052] In Examples 1 to 5, the mass ratio of waterborne photocurable polyurethane, photoinitiator, neutralizer, reactive diluent, and water is 50:5:1:40:300.
[0053] In Examples 6 to 10, the mass ratio of waterborne photocurable polyurethane, photoinitiator, neutralizer, reactive diluent, and water was 20:2:0.2:10:50.
[0054] In Examples 11 to 15, the mass ratio of waterborne photocurable polyurethane, photoinitiator, neutralizer, reactive diluent, and water was 40:4:0.7:30:180.
[0055] The following is a description of the function and effect of the waterborne photocurable pressure-sensitive adhesive prepared in this application.
[0056] (1) Biocompatibility: The polyethylene glycol (PEG) introduced in this invention is a common carrier in pharmaceuticals. PEG is a strongly hydrophilic polyether, which allows it to be compatible with aqueous environments such as body fluids in vivo. Unlike some hydrophobic substances, it does not easily accumulate in biological tissues, thus avoiding potential toxicity or adverse reactions caused by aggregation. PEG has a relatively simple structure, mainly composed of methylene and etheroxy groups. These groups themselves are not significantly toxic, unlike some compounds containing halogens, nitro groups, etc., which may undergo redox reactions in vivo to produce harmful metabolites. The metabolic process of PEG in vivo is relatively mild, with a safe metabolic pathway, high excretion efficiency, and low immunogenicity. It generally does not produce toxic decomposition products.
[0057] Furthermore, in this application: bismuth neodecanoate, which has low toxicity, is preferably used in catalyst 1, and dibutyltin dilaurate, which has reproductive toxicity, is not used. Tetraisopropyl titanate or tetraisobutyl titanate, which has low toxicity, is preferably used in catalyst 2, and butyltin acid, which has reproductive toxicity, is not used.
[0058] In this application, the isocyanate used preferably isophorone diisocyanate or dicyclohexylmethane diisocyanate, which are low in toxicity; hexamethylene diisocyanate and toluene diisocyanate, which are highly toxic, are avoided. The neutralizing agent used preferably is dimethylethanolamine or triethanolamine, which are low in toxicity, odor, and skin irritation; triethylamine and ammonia are avoided. The reactive diluent used preferably is acryloylmorpholine, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, polyethylene glycol 400 dimethacrylate, or polyethylene glycol 600 dimethacrylate, which are low in odor and skin irritation; hydroxyethyl acrylate is avoided.
[0059] The selection of the above components ensures the excellent biocompatibility of the product in this application.
[0060] (2) Pressure sensitivity and elongation testing: The rolling ball ramp stop method was used for testing, according to the Chinese national standard GB / T4852-2002 "Test Method for Initial Tack of Pressure Sensitive Adhesive Tape (Rolling Ball Method)"; the elongation of the sample was also measured using the national standard GB / T1040.2-2022. The product performance will be further explained below with reference to the examples.
[0061] Example Finished product viscosity (25℃, cps) Elongation (%) Initial tack (steel ball number #) 1 110 130 4 2 150 170 4 3 240 80 3 4 190 110 4 5 130 140 3 6 1620 480 6 7 1260 540 5 8 2120 680 6 9 1380 390 5 10 2640 410 4 11 470 210 4 12 650 170 3 13 420 230 4 14 730 230 4 15 380 190 4
[0062] As shown in the table, the elongation and pressure sensitivity of the pressure-sensitive adhesive are related to the resin structure, the type and proportion of diluent, and the proportion of water. The result is the combined effect of all components. In Examples 1-5, the resin itself has a relatively small molecular weight, and the proportion of water is relatively large, so the cohesive force of the finished pressure-sensitive adhesive is weak, and the elongation and initial tack are low. In Examples 6-10, the resin itself has a relatively large molecular weight, a high proportion of soft segments, and a low proportion of water, which gives the pressure-sensitive adhesive better cohesive force and initial tack. The initial tack is basically above 5, and the elongation is basically over 400%. In Examples 11-15, the resin itself has a moderate molecular weight, and the proportion of water is lower than that of Examples 1-5. Therefore, the elongation and initial tack are better than those of Examples 1-5.
[0063] In pressure-sensitive adhesive (PSA) formulations, the number of monomers available is limited due to water solubility constraints. Acrylomorpholine provides cohesive strength, while low-Tg components such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxybutyl acrylate increase the flexibility and initial tack of the PSA. Polyethylene glycol 400 diacrylate and polyethylene glycol 600 diacrylate increase crosslinking density and water retention. At the same time, the polyethylene glycol structure in the chain segments increases the flexibility of the PSA.
[0064] (3) The principle of pressure sensitivity and self-detachment in this invention: The chemical structure of polyethylene glycol is HO(CH2CH2O). n H, containing numerous repeating units, significantly influences the crystallinity of PEG molecular chains due to their regularity. Regular molecular chains form crystalline structures. When the molecular weight is less than 600, PEG is in a liquid state; when the molecular weight is between 600 and 1000, it is in a paste state; and when the molecular weight is greater than 1000, it is in a sheet-like solid state. Simultaneously, the melting point increases with increasing molecular weight. By adjusting the proportion of PEG segments in the molecule and designing the regularity of the segments, the crystallinity and physical state of the molecule can be controlled. The introduction of hydrophilic reactive diluent monomers and solvent water molecules into the pressure-sensitive adhesive system causes the molecular chains to swell, disrupting the crystallinity of the molecules. This results in the pressure-sensitive properties brought by the low-Tg polyether segments in the molecule becoming prominent immediately after the pressure-sensitive adhesive has cured.
[0065] After the pressure-sensitive adhesive (PSA) cures, the water in the system exists in three forms: bound water, restricted water, and free water. Free water accounts for over 90% of the total. When the PSA is applied to the patient's skin, the water slowly evaporates due to body temperature and exposure to air. As the proportion of free water decreases, the loss of moisture causes the crystallinity of the molecular chain segments to dominate, resulting in the PSA losing its viscoelasticity and exhibiting a crystalline plastic state. The moisture loss time and pressure sensitivity can be designed through moisture content and formulation structure. For example, through formulation design, the initial tack can be 6#, and through a water loss process of 6–36 hours, the tack of the PSA can be reduced to below 2#, allowing it to be easily removed from the skin without causing pain to the patient.
[0066] Appendix Figure 6 The image shows a typical TGA curve for waterborne UV-cured polyurethane. The TGA curve shows an endothermic process between 25 and 50°C, indicating the breakdown of crystallinity and the occurrence of melting. Between 50 and 150°C, a fluctuating exothermic process occurs, representing the volatilization of small amounts of bound and restricted water in the system. Between 150°C and 225°C, a stable linear curve is observed. From 225°C, molecular decomposition and exothermic processes occur.
[0067] Appendix Figure 7 This is the freshly cured state of the photocurable pressure-sensitive adhesive in Example 8 of this application. Specifically, the photocurable pressure-sensitive adhesive is placed in a mold to form a 50mm*35mm*10mm sample. Figure 6 It can be seen that the freshly cured pressure-sensitive adhesive is gel-like, exhibiting both pressure sensitivity and viscoelastic properties.
[0068] Appendix Figure 8 for Figure 7 The image shows the state of the UV-cured pressure-sensitive adhesive after vacuum drying at 60℃ for 24 hours. As can be seen from the figure, when the UV-cured pressure-sensitive adhesive loses its free water, its volume shrinks, its weight decreases, and it loses its pressure sensitivity and viscoelastic state, exhibiting crystallinity and plasticity. In practical use, the pressure-sensitive adhesive does not need to lose all its free water before its initial tack decreases, allowing it to be easily peeled off.
[0069] Appendix Figure 9 For the application and storage of pressure-sensitive adhesives, the product of this invention is typically made into a thin sheet, covered with a film, cut into small pieces, and individually packaged during application. This ensures that moisture does not evaporate significantly, guaranteeing the storage stability of the pressure-sensitive adhesive. When using, peel off the film and apply it to the affected area.
[0070] As described above, this application provides a self-removing water-based photocurable pressure-sensitive adhesive for medical use and its preparation method. This pressure-sensitive adhesive exhibits good biocompatibility, low toxicity, and the adhesive itself is non-irritating to the skin. It has strong initial tack, but the adhesion decreases over time until it can no longer adhere to the skin and detaches on its own, eliminating the need for the patient to peel it off. Furthermore, compared to photocurable acrylic pressure-sensitive adhesives that use monomers such as isooctyl acrylate, which have pungent odors, strong skin irritation, and are prone to residue buildup, this invention has a low odor, is non-irritating to the skin, uses water as a solvent and participates in the curing process to form a gel, is environmentally friendly, has lower cost, is easy to produce, has a fast curing speed, low energy consumption, and low heat release.
[0071] The scope of protection of this invention includes, but is not limited to, the above embodiments. The scope of protection of this invention is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art fall within the scope of protection of this invention.
Claims
1. A medical self-removing water-based photocurable pressure-sensitive adhesive, characterized in that, The raw material components of this pressure-sensitive adhesive include water-based UV-curable polyurethane, photoinitiator, neutralizer, reactive diluent, and water; The mass ratio of the waterborne photocurable polyurethane, photoinitiator, neutralizer, reactive diluent, and water is 20-50: 2-5: 0.2-1: 10-40: 50-300. The neutralizing agent is one or more of dimethylethanolamine, triethylamine, triethanolamine, and ammonia. The active diluent is one or more of the following: acrylomorpholine, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, polyethylene glycol 400 dimethacrylate, and polyethylene glycol 600 dimethacrylate. The waterborne photocurable polyurethane comprises diisocyanate, self-made polyol, catalyst 1, polymerization inhibitor, and end-capping agent; the mass ratio of diisocyanate, self-made polyol, catalyst, polymerization inhibitor, and end-capping agent is 20-100: 1000-12000: 0.02-1: 0.05-0.5: 5-20. The photoinitiator is one or more of TPO, 184, TMO, 819, 1173, and ITX.
2. The medical self-removing water-based photocurable pressure-sensitive adhesive according to claim 1, characterized in that, The diisocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate; The catalyst 1 is one or more of bismuth neodecanoate, dibutyltin dilaurate, and stannous octoate; The polymerization inhibitor is one or more of p-hydroxyanisole, tert-butylhydroquinone, phenothiazine, and hydroquinone. The capping agent is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypropyl methacrylate, and pentaerythritol triacrylate.
3. The medical self-removing water-based photocurable pressure-sensitive adhesive according to claim 2, characterized in that, The self-made polyol comprises the following raw material components: polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, and antioxidant; the mass ratio of the polyol, polycarboxylic acid, aqueous chain extender, catalyst 2, and antioxidant is 2000~50000:150~1200:150~600:0.05~0.5:0.05~1.
4. The medical self-removing water-based photocurable pressure-sensitive adhesive according to claim 3, characterized in that, The polyols include one or more of the following: neopentyl glycol, 1,6-hexanediol, polyethylene glycol 600, polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 8000, tetraethylene glycol, polypropylene glycol 1000, polypropylene glycol 2000, polypropylene glycol 3000, polytetrahydrofuran 1000, polytetrahydrofuran 2000, polycaprolactone diol 1000, and polycaprolactone diol 2000; The polycarboxylic acids mentioned include one or more of the following: adipic acid, sebacic acid, isophthalic acid, phthalic acid, and terephthalic acid; The aqueous chain extender is: dimethylolpropionic acid; The catalyst 2 is one or more of tetrabutyl titanate, tetrapropyl titanate, and butylstannic acid. The antioxidant is one or more of the following: 1010, 168, 1076, 1035, and triphenyl phosphite.
5. A method for preparing a medical self-removing water-based photocurable pressure-sensitive adhesive according to any one of claims 1 to 4, characterized in that, Includes the following steps: S10: Preparation of self-made polyol: Under nitrogen protection, polyol, polycarboxylic acid and antioxidant are added to the reaction vessel and heated to 150±10℃. After the reactants are completely dissolved, catalyst 2 is added and the temperature is increased by 10±5℃ per hour until it reaches 240±15℃. After the reaction is kept at a constant temperature, an aqueous chain extender is added. After the reaction is completed, the temperature is lowered to below 90℃ and the product is discharged to obtain the self-made polyol. S20: Preparation of waterborne photocurable polyurethane: Self-made polyol and diisocyanate were added to a reaction vessel, stirred and heated to 60±8℃, catalyst 1 was added, and the exothermic temperature was controlled to be less than 90℃. After the exothermic reaction was completed, the temperature inside the vessel was kept at 70±8℃. After the reaction was completed, polymerization inhibitor and end-capping agent were added, and the exothermic temperature was controlled to be less than 85℃. After the exothermic reaction was completed, the temperature inside the vessel was kept at 80±5℃. After the reaction was completed, the temperature was cooled to below 65℃ to obtain waterborne photocurable polyurethane. S30: Preparation of waterborne photocurable pressure-sensitive adhesive: Add waterborne photocurable polyurethane to a reaction vessel, heat to 60±8℃, add a neutralizing agent, stir, add solvent water, and after the waterborne photocurable polyurethane is completely dissolved, add a self-made photoinitiator and an active diluent, stir, filter and discharge to obtain the waterborne photocurable pressure-sensitive adhesive.