High-moisture-penetrability solvent type medical acrylate pressure-sensitive adhesive and preparation method thereof

Abstract

The invention belongs to the technical field of adhesives, and particularly relates to a high-moisture-penetrability solvent type medical acrylate pressure-sensitive adhesive and a preparation method thereof.The high-moisture-penetrability solvent type medical acrylate pressure-sensitive adhesive is prepared by using an initiator to initiate free radical polymerization of soft monomers, hard monomers and the like and then mixing with a modifier and the like. The prepared modifier has an aerogel state and shows a rich pore structure, the pore structure can form a breathable and moisture-permeable passage in a pressure-sensitive adhesive film, the breathable and moisture-permeable performance of the pressure-sensitive adhesive is greatly enhanced, meanwhile, the modifier structure contains a large number of quaternary ammonium cation structures, the pressure-sensitive adhesive can be endowed with good antibacterial performance, and the pressure-sensitive adhesive has the advantages of being environmentally friendly and free of pollution. The functional improvement of the pressure-sensitive adhesive is realized.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, specifically relating to a highly moisture-permeable solvent-based medical acrylate pressure-sensitive adhesive and its preparation method. Background Technology

[0002] Medical pressure-sensitive adhesives, as key interface materials between medical devices and human skin or tissue, directly affect the safety, effectiveness, and patient comfort of medical products. Acrylic pressure-sensitive adhesives, with their excellent biocompatibility, stable chemical properties, and adjustable adhesion characteristics, have become the mainstream choice in the field of medical pressure-sensitive adhesives. Traditional medical acrylic pressure-sensitive adhesives are mainly divided into three categories: solvent-based, water-based, and hot-melt. Among them, solvent-based acrylic pressure-sensitive adhesives, due to their excellent film-forming properties and strong initial adhesion, occupy an important position in applications with stringent performance requirements, such as high-end medical dressings, transdermal drug delivery systems, and electrocardiogram electrodes.

[0003] However, with the development of modern medical technology and the increasing demands for patient experience, medical pressure-sensitive adhesives face new challenges: skin health issues during long-term application are receiving increasing attention. Problems such as skin overhydration, maceration, itching, and even infection caused by occlusive dressings, coupled with insufficient antibacterial properties that easily lead to infection, have prompted researchers to develop pressure-sensitive adhesive systems with higher moisture permeability and antibacterial properties. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a highly moisture-permeable solvent-based medical acrylate pressure-sensitive adhesive and its preparation method.

[0005] In a first aspect, the present invention provides a highly moisture-permeable solvent-based medical acrylate pressure-sensitive adhesive, comprising the following raw materials in parts by weight:

[0006] The composition includes 32-38 parts of soft monomer, 8-12 parts of hard monomer, 2-4 parts of functional monomer, 0.1-0.2 parts of initiator, 60-85 parts of organic solvent, 1-3.5 parts of modifier, and 0.3-0.5 parts of curing agent.

[0007] The modifier is tamarind gum aerogel containing quaternary ammonium cations.

[0008] As a preferred embodiment of the present invention, the soft monomer is at least one of ethyl acrylate, butyl acrylate, or isooctyl acrylate; the hard monomer is at least one of vinyl acetate, butyl methacrylate, or methyl acrylate; the functional monomer is at least one of hydroxyethyl methacrylate, glycidyl methacrylate, or methacrylic acid; the initiator is azobisisobutyronitrile or azobisisoheptanenitrile; and the organic solvent is ethyl acetate.

[0009] As a preferred embodiment of the present invention, the modifier is prepared by the following method:

[0010] Step 1: Add tamarind gum to a mixed solution of acetone and deionized water, stir until homogeneous, add functionalizing agent and accelerator to the resulting homogeneous mixture, raise the temperature to 30-40℃, keep it at that temperature for 4-8 hours, then stop heating, filter out the product, wash and vacuum dry to obtain modified tamarind gum.

[0011] Step 2: Add the modified tamarind gum to the deionized water mixture and start stirring. After a uniform mixture is formed, continue to add bis(2-hydroxyethyl)dimethylammonium chloride and catalyst. After the addition is complete, start heating and raise the temperature to 60-70℃. Keep it at this temperature for 8-12 hours, then stop heating. Pour the product into a mold and wait for it to gel. Transfer it to a freeze dryer for freeze drying. Finally, grind it through a 100-200 mesh sieve.

[0012] As a preferred embodiment of the present invention, the functionalizing agent is prepared by the following method:

[0013] Add succinyl chloride to acetone and stir until well mixed. Then, under ice bath conditions, continue to add glycidyl ester and accelerator. After the addition is complete, remove from the ice bath and stir continuously at 30-40℃ for 3-6 hours. Evaporate to remove the solvent, collect the crude product, and purify it.

[0014] As a preferred embodiment of the present invention, the molar ratio of succinyl chloride and glycidyl is 1:1.

[0015] As a preferred embodiment of the present invention, the accelerator is triethylamine or pyridine.

[0016] As a preferred embodiment of the present invention, the catalyst is a boron trifluoride diethyl ether complex.

[0017] As a preferred embodiment of the present invention, the mass ratio of the modified tamarind gum to bis(2-hydroxyethyl)dimethylammonium chloride is 1:0.15-0.3.

[0018] As a preferred embodiment of the present invention, the curing agent is an isocyanate-based curing agent.

[0019] A second aspect of the present invention provides a method for preparing a highly moisture-permeable solvent-based medical acrylate pressure-sensitive adhesive, comprising the following steps:

[0020] Step 1: Weigh and prepare all the raw materials according to their weight proportions;

[0021] The second step involves adding the soft monomer, hard monomer, functional monomer, and initiator to an organic solvent and mechanically stirring until a uniform mixture is formed. Nitrogen gas is then introduced for protection, and heating is started to raise the temperature to 72-76°C. The mixture is then kept at this temperature for 6-9 hours, after which heating is stopped, the material is cooled down, and the polymer is discharged to form an acrylate polymer solution.

[0022] The third step is to add the modifier to the acrylate polymerization solution, stir and mix evenly, then add the curing agent. After the addition is complete, stir and mix evenly at room temperature.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention uses succinyl chloride and glycidyl chloride as raw materials to carry out a condensation reaction between the acyl chloride groups and active hydroxyl substituents in their structures and controls the molar ratio of the two to obtain a glycidyl chloride derivative containing acyl chloride substituents in the structure, i.e. a functionalizing agent, which can continue to condense with the hydroxyl groups in the tamarind gum structure, thereby introducing active epoxy substituents into the tamarind gum structure to obtain modified tamarind gum. Then, by using bis(2-hydroxyethyl)dimethylammonium chloride as a crosslinking agent, a continuous ring-opening reaction is carried out with the epoxy substituents in the modified tamarind gum structure to obtain tamarind gum with a crosslinked structure. Then, by cold drying treatment, it is formed into an aerogel state to obtain the modifier.

[0025] (2) The modifier prepared by the present invention has an aerogel state and exhibits a rich pore structure. This pore structure can form a breathable and moisture-permeable channel inside the pressure-sensitive adhesive film, which greatly enhances the breathability and moisture permeability of the pressure-sensitive adhesive. At the same time, the modifier structure contains a large number of quaternary ammonium cation structures, which can give the pressure-sensitive adhesive good antibacterial properties and realize the functional improvement of the pressure-sensitive adhesive. Detailed Implementation

[0026] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0027] Example 1

[0028] This embodiment provides a highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive, which comprises the following raw materials by weight:

[0029] 32 parts ethyl acrylate, 8 parts vinyl acetate, 2 parts hydroxyethyl methacrylate, 0.1 parts azobisisobutyronitrile, 60 parts ethyl acetate, 1 part modifier, and 0.3 parts dicyclohexylmethane diisocyanate;

[0030] The preparation method of the acrylate pressure-sensitive adhesive includes the following steps:

[0031] Step 1: Weigh and prepare all the raw materials according to their weight proportions;

[0032] Step 2: Add ethyl acrylate, vinyl acetate, hydroxyethyl methacrylate and azobisisobutyronitrile to ethyl acetate, stir mechanically until a uniform mixture is formed, purge with nitrogen for protection, turn on heating, raise the temperature to 72°C, keep it at this temperature for 9 hours, then stop heating, cool down and discharge the material to form an acrylate polymer solution.

[0033] The third step is to add the modifier to the acrylate polymerization solution, stir and mix evenly, then add dicyclohexylmethane diisocyanate. After the addition is complete, stir and mix evenly at room temperature.

[0034] The modifier is prepared using the following method:

[0035] Step A: Add 1.2g succinyl chloride to acetone, stir and mix evenly, then add 0.57g glycidyl and 0.2g triethylamine under ice bath conditions. After the addition is complete, remove from the ice bath and stir continuously at 35℃ for 4 hours. Evaporate to remove the solvent, collect the crude product, and purify it to obtain the functionalized reagent.

[0036] Step B: Add 1.5g of tamarind gum to a mixed solution of acetone and deionized water, stir until homogeneous, then add 0.2g of functionalizing agent and 0.1g of triethylamine to the resulting homogeneous mixture. After the addition is complete, raise the temperature to 35℃ and keep it at that temperature for 6 hours. Then stop heating, filter out the product, wash and vacuum dry it to obtain modified tamarind gum.

[0037] Step C: Add 0.8g of modified tamarind gum to the mixed solution of deionized water, start stirring, and after a uniform mixture is formed, continue to add 0.2g of bis(2-hydroxyethyl)dimethylammonium chloride and 0.01g of boron trifluoride diethyl ether complex. After the addition is complete, start heating and raise the temperature to 65℃. After holding at this temperature for 92 hours, stop heating, pour the product into a mold, wait for it to gel, transfer it to a freeze dryer for freeze drying, and finally grind it through a 100-mesh sieve.

[0038] Example 2

[0039] This embodiment provides a highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive, which comprises the following raw materials by weight:

[0040] 35 parts butyl acrylate, 9 parts butyl methacrylate, 3 parts glycidyl methacrylate, 0.2 parts azobisisobutyronitrile, 75 parts ethyl acetate, 3 parts modifier, and 0.4 parts dicyclohexylmethane diisocyanate;

[0041] The preparation method of the acrylate pressure-sensitive adhesive includes the following steps:

[0042] Step 1: Weigh and prepare all the raw materials according to their weight proportions;

[0043] Step 2: Add butyl acrylate, butyl methacrylate, glycidyl methacrylate and azobisisobutyronitrile to ethyl acetate, stir mechanically until a uniform mixture is formed, purge with nitrogen for protection, turn on heating, raise the temperature to 75°C, keep it at this temperature for 8 hours, then stop heating, cool down and discharge the material to form an acrylate polymer solution.

[0044] The third step is to add the modifier to the acrylate polymerization solution, stir and mix evenly, then add dicyclohexylmethane diisocyanate. After the addition is complete, stir and mix evenly at room temperature.

[0045] The preparation method of the modifier is the same as that in Example 1.

[0046] Example 3

[0047] This embodiment provides a highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive, which comprises the following raw materials by weight:

[0048] 38 parts of isooctyl acrylate, 12 parts of methyl acrylate, 4 parts of methacrylic acid, 0.2 parts of azobisisobutyronitrile, 85 parts of ethyl acetate, 3.5 parts of modifier, and 0.5 parts of dicyclohexylmethane diisocyanate;

[0049] The preparation method of the acrylate pressure-sensitive adhesive includes the following steps:

[0050] Step 1: Weigh and prepare all the raw materials according to their weight proportions;

[0051] Step 2: Add isooctyl acrylate, methyl acrylate, methacrylic acid and azobisisobutyronitrile to ethyl acetate, stir mechanically until a uniform mixture is formed, purge with nitrogen for protection, turn on heating, raise the temperature to 76°C, keep it at this temperature for 6 hours, then stop heating, cool down and discharge the material to form an acrylate polymer solution.

[0052] The third step is to add the modifier to the acrylate polymerization solution, stir and mix evenly, then add dicyclohexylmethane diisocyanate. After the addition is complete, stir and mix evenly at room temperature.

[0053] The preparation method of the modifier is the same as that in Example 1.

[0054] Comparative Example 1

[0055] The difference between this comparative example and Example 2 is that the modifier is removed, but everything else is the same.

[0056] The acrylic pressure-sensitive adhesive provided in the above examples and comparative examples was uniformly coated on a clean glass plate surface. After it was completely cured at a temperature of 100°C, it was removed from the film and used as a test film.

[0057] (1) Cut out a circular test membrane with a diameter of 10 mm, take 1 mL of Staphylococcus aureus bacterial suspension, add it to beef broth, incubate at room temperature for 6 h, and then dilute the bacterial suspension to a concentration of 10. -5 CFU / mL, take 0.5mL and drop it onto the surface of a circular test film, continue to incubate at room temperature for 6h, then wash with sterile water, collect the washing solution, take another 0.5mL of the washing solution, incubate at room temperature for 8h, observe the colony count, and at the same time perform a blank test. Calculate the inhibition rate using the formula [(blank test colony count - sample colony count) / blank test colony count] × 100%;

[0058] (2) According to GB / T 1037-2021, under the conditions of (37±0.5)℃ and (90±5)% relative humidity, test the water vapor transmission rate of the film and evaluate the moisture permeability of the film;

[0059] The test results are recorded in Table 1:

[0060] Antibacterial rate (%) <![CDATA[Water vapor transmission rate (g / (m 2 •24h))]]> Example 1 98.9 204.8 Example 2 99.3 206.9 Example 3 99.0 206.1 Comparative Example 1 65.1 139.6

[0061] As can be seen from the above, the pressure-sensitive adhesive prepared in the embodiments of the present invention has good moisture permeability and antibacterial properties. After removing the modifier, on the one hand, the air permeability channels are reduced, resulting in poor moisture permeability of the pressure-sensitive adhesive; on the other hand, the quaternary ammonium cation is lost, resulting in a significant decrease in antibacterial properties.

[0062] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention, including the best mode, and also to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive, characterized in that, By weight, it includes the following ingredients: The composition includes 32-38 parts of soft monomer, 8-12 parts of hard monomer, 2-4 parts of functional monomer, 0.1-0.2 parts of initiator, 60-85 parts of organic solvent, 1-3.5 parts of modifier, and 0.3-0.5 parts of curing agent. The modifier is tamarind gum aerogel containing quaternary ammonium cations.

2. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 1, characterized in that, The soft monomer is at least one of ethyl acrylate, butyl acrylate, or isooctyl acrylate; the hard monomer is at least one of vinyl acetate, butyl methacrylate, or methyl acrylate; the functional monomer is at least one of hydroxyethyl methacrylate, glycidyl methacrylate, or methacrylic acid; the initiator is azobisisobutyronitrile or azobisisoheptanenitrile; and the organic solvent is ethyl acetate.

3. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 1, characterized in that, The modifier is prepared using the following method: Step 1: Add tamarind gum to a mixed solution of acetone and deionized water, stir until homogeneous, add functionalizing agent and accelerator to the resulting homogeneous mixture, raise the temperature to 30-40℃, keep it at that temperature for 4-8 hours, then stop heating, filter out the product, wash and vacuum dry to obtain modified tamarind gum. Step 2: Add the modified tamarind gum to the deionized water mixture and start stirring. After a uniform mixture is formed, continue to add bis(2-hydroxyethyl)dimethylammonium chloride and catalyst. After the addition is complete, start heating and raise the temperature to 60-70℃. Keep it at this temperature for 8-12 hours, then stop heating. Pour the product into a mold and wait for it to gel. Transfer it to a freeze dryer for freeze drying. Finally, grind it through a 100-200 mesh sieve.

4. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 3, characterized in that, The functionalizing agent is prepared using the following method: Add succinyl chloride to acetone and stir until well mixed. Then, under ice bath conditions, continue to add glycidyl ester and accelerator. After the addition is complete, remove from the ice bath and stir continuously at 30-40℃ for 3-6 hours. Evaporate to remove the solvent, collect the crude product, and purify it.

5. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 4, characterized in that, The molar ratio of succinyl chloride to glycidyl is 1:

1.

6. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 4, characterized in that, The accelerator is triethylamine or pyridine.

7. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 3, characterized in that, The catalyst is a boron trifluoride diethyl ether complex.

8. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 3, characterized in that, The mass ratio of the modified tamarind gum to bis(2-hydroxyethyl)dimethylammonium chloride is 1:0.15-0.

3.

9. The highly moisture-permeable solvent-based medical acrylic pressure-sensitive adhesive according to claim 1, characterized in that, The curing agent is an isocyanate-based curing agent.

10. A method for preparing a highly moisture-permeable solvent-based medical acrylate pressure-sensitive adhesive as described in claim 1, characterized in that, Includes the following steps: Step 1: Weigh and prepare all the raw materials according to their weight proportions; The second step involves adding the soft monomer, hard monomer, functional monomer, and initiator to an organic solvent and mechanically stirring until a uniform mixture is formed. Nitrogen gas is then introduced for protection, and heating is started to raise the temperature to 72-76°C. The mixture is then kept at this temperature for 6-9 hours, after which heating is stopped, the material is cooled down, and the polymer is discharged to form an acrylate polymer solution. The third step is to add the modifier to the acrylate polymerization solution, stir and mix evenly, then add the curing agent. After the addition is complete, stir and mix evenly at room temperature.