阅读说明：本技术 一种可降解压敏胶及一种可降解压敏胶带 (Degradable pressure-sensitive adhesive and degradable pressure-sensitive adhesive tape ) 是由 杨智童 于 2021-07-22 设计创作，主要内容包括：本发明提供一种可降解压敏胶,原料包括：丙烯酸酯共聚物30-50重量份、增粘树脂5-10重量份、改性壳聚糖20-30重量份、液体聚异丁烯橡胶5-10重量份、交联剂2-5重量份,苯乙烯-异戊二烯-苯乙烯嵌段共聚物5-15重量份。本发明的可降解压敏胶极大的降低了医疗粘结用品的污染问题,分解率高,环境友好。(The invention provides a degradable pressure-sensitive adhesive, which comprises the following raw materials: 30-50 parts of acrylate copolymer, 5-10 parts of tackifying resin, 20-30 parts of modified chitosan, 5-10 parts of liquid polyisobutylene rubber, 2-5 parts of cross-linking agent and 5-15 parts of styrene-isoprene-styrene block copolymer. The degradable pressure-sensitive adhesive disclosed by the invention greatly reduces the pollution problem of medical bonding articles, is high in decomposition rate and is environment-friendly.)

1. A degradable pressure-sensitive adhesive comprises the following raw materials: 30-50 parts of acrylate copolymer, 5-10 parts of tackifying resin, 20-30 parts of modified chitosan, 5-10 parts of liquid polyisobutylene rubber, 2-5 parts of cross-linking agent and 5-15 parts of styrene-isoprene-styrene block copolymer.

2. The degradable pressure sensitive adhesive of claim 1, wherein: the raw materials comprise: 40-50 parts of acrylate copolymer, 5-10 parts of tackifying resin, 26-30 parts of modified chitosan, 5-10 parts of liquid polyisobutylene rubber, 2-5 parts of cross-linking agent and 5-15 parts of styrene-isoprene-styrene block copolymer.

3. The degradable pressure sensitive adhesive of claim 1, wherein: the preparation method of the acrylate copolymer comprises the following steps: a) adding 5-9g of methacrylate into a 200mL flask at normal temperature, adding 5mL of tetrahydrofuran solution, adding magnetons, and stirring by magnetic force to obtain a uniform solution; b) 3g of hydroxypropyl acrylate is dispersed in 8mL of acrylic acid, magnetic stirring is carried out, the rapid temperature rise of a reaction system is prevented through an ice water bath, and the reaction is carried out for 10 minutes; c) and (2) dispersing 1-2g of methacrylate into 5mL of acrylic acid, adding the mixture into the reaction system, reacting for 5 minutes, and stirring uniformly to obtain the acrylate copolymer.

4. The degradable pressure sensitive adhesive of claim 1, wherein: the preparation method of the modified chitosan comprises the following steps: a. placing 8-15 parts of hinokitiol extracted from cypress in a first container, adding 5-20 parts by weight of ethanol, and stirring to obtain ethanol solution of hinokitiol; b. b, adding 1-5 parts by weight of sorbic acid into the solution prepared in the step a, and adding 3-5 parts by weight of deionized water for complete dissolution to prepare a modified solution of chitosan; c. and (b) adding 15-20 parts by weight of chitosan into the modified solution obtained in the step (b), adding 2-5 parts by weight of glycerol serving as a catalyst, heating to 90-100 ℃, stirring, obtaining a mixture for solid-liquid separation, filtering to obtain a solid, drying, and grinding to obtain the modified chitosan with the particle size of less than 20 micrometers.

5. The degradable pressure sensitive adhesive of claim 1, wherein: the cross-linking agent is ethoxylated nonylphenol acrylate and hydroxyl-terminated acrylic acid caprolactone, the weight portion ratio of which is 2: 1.

6. The degradable pressure sensitive adhesive of claim 1, wherein: the tackifying resin is modified rosin resin.

7. The degradable pressure sensitive adhesive of claim 1, wherein: the preparation method of the modified rosin comprises the following steps: adding 50 parts by weight of rosin resin, 3-5 parts by weight of zinc borate, 1-3 parts by weight of potassium hydrogen fluoride and 5-8 parts by weight of maleic anhydride into a reaction kettle, uniformly stirring, then carrying out programmed heating at a heating speed of 5-8 ℃/min to 220-280 ℃, keeping the temperature for 30-45 minutes, stopping heating for 3-5 minutes, rapidly cooling to room temperature at a speed of 8-15 ℃/min, and taking out from the reaction kettle to obtain the modified rosin resin.

8. The degradable pressure sensitive adhesive of claim 1, wherein: the preparation method of the degradable pressure-sensitive adhesive comprises the following steps: 1) adding modified chitosan, acrylate copolymer, styrene-isoprene-styrene block copolymer and cross-linking agent into a reaction kettle, keeping the temperature at 140 ℃ and stirring for reaction for 30-40 minutes; 2) then adding tackifying resin and liquid polyisobutylene rubber, continuously heating to the temperature of 160-; 4) all the raw materials are completely melted and no obvious bubbles are extracted, and the raw materials are filtered by a plurality of layers of metal filter screens and discharged; 5) and cooling, cutting and packaging after discharging to obtain the degradable pressure-sensitive adhesive.

9. A degradable pressure-sensitive adhesive tape comprises a base material and a degradable pressure-sensitive adhesive coated on one side or two sides of the base material, and is characterized in that: the preparation method comprises the following steps: and (3) placing the degradable pressure-sensitive adhesive into a coating machine, heating to 120-140 ℃, coating on the single surface or double surfaces of the substrate, attaching a release film, and rolling to obtain the degradable pressure-sensitive adhesive tape.

10. The degradable pressure sensitive tape of claim 9, wherein: the base material is any one of PLA modified film or modified non-woven fabric.

Technical Field

The invention belongs to the technical field of adhesives, and particularly relates to a degradable pressure-sensitive adhesive and a degradable pressure-sensitive adhesive tape.

Background

The pressure-sensitive adhesive is the product with the largest dosage and the widest application range in the adhesive, and products of the pressure-sensitive adhesive are almost spread in various fields of packaging, automobiles, transportation, communication, electric appliances, building materials, machinery, aviation, light industry, sanitation and the like.

The application of the adhesive in the medical and health field begins for a long time, for example, a plaster (commonly called a dogskin plaster) for external treatment of traumatic injuries and internal diseases has been developed thousands of years ago in Chinese medicine, and along with the progress of medical science, the application of the adhesive in the medical field is increased, for example, the production of adhesive plasters, rubberized teeth, artificial corneas, artificial organs, the adhesion of the artificial organs to surrounding tissues and the like. The medical and sanitary adhesive is suitable for human tissues, has no toxic or side effect on human bodies or has side effect, and the harmfulness of the adhesive is far less than the harmfulness of the adhesive, such as no foreign body reaction, anaphylactic reaction, pain reaction and inflammatory reaction, the adhesive for bonding cell tissues has good wettability to water, namely has certain hydrophilicity, and is convenient to use, and the mechanical properties, such as hardness, strength and elasticity, of the cured adhesive layer are suitable for the bonded tissues and are easy to sterilize. The percutaneous absorption preparation system utilizes a pressure-sensitive adhesive system to deliver medicine through the whole skin, so that the medicine is absorbed into the systemic circulation from the capillary vessels in the dermis through the epidermis to achieve the purpose of treating or preventing diseases, and is also called percutaneous administration. With the rapid development of numerous patch products such as percutaneous absorption preparations and the like, the requirements on adhesives are higher and higher, and the existing adhesives in the market have the following defects in terms of basic therapeutic effects at present: (1) the secondary infection of polar raw materials to patients cannot be avoided, and the adhesive has high polarity and can cause side effects such as infection, inflammation and the like to the patients. (2) Due to the influence of the adhesive, the medicine can not enter the body at a preset speed, the constant treatment concentration is maintained, the peak-valley phenomenon of the administration concentration occurs, and the probability of toxic and side effects is increased; (3) the adhesive has poor adhesiveness, is easy to fall off, or has obvious pain and tearing feeling when the patch is removed after treatment due to the adhesive, the medicament cannot enter the body at a constant speed for a long time due to the influence of the adhesive, the effect of prolonging the administration interval, reducing the administration times and increasing the compliance of a patient is influenced, and a general oral slow (controlled) release preparation can only maintain the effective action for 12 to 24 hours, so that the transdermal patch can maintain the effective blood concentration for a longer time; (4) due to the barrier effect of the adhesive, the absorption rate of the medicine through the skin is very slow, the medicine takes effect slowly, and most medicines with large molecular mass, poor fat solubility and low dosage cannot reach effective treatment concentration; (5) the adhesive has poor load performance, so that the controlled release membrane is broken or the medicine overflows, the medicine release rate is increased rapidly, and the treatment effect is influenced.

Pressure-sensitive adhesives are adhesive materials which can be easily peeled off while realizing one-time adhesion in industrial pharmacy under slight pressure (such as finger pressure), and play roles of ensuring close contact between a drug release surface and the skin, storing drugs, controlling release and the like in a percutaneous absorption preparation. The selection of the pressure-sensitive adhesive is very important for a percutaneous absorption preparation, and the ideal pressure-sensitive adhesive preferably has good biocompatibility, is nontoxic and nonirritating to skin and cannot cause anaphylactic reaction; has strong adhesion and cohesive strength, and can adapt to the characteristics of soft flexibility and multiple folds of the skin surface; has stable chemical properties, good resistance to temperature and moisture (such as sweat), and adaptability for adhering different types of skin, and can contain certain amount of medicine and percutaneous absorption promoter without affecting chemical stability and adhesion. The pressure-sensitive adhesive used in the percutaneous absorption preparation must have the performance of being sensitive to pressure after being added with the medicinal preparation, and can avoid the phenomena of wiredrawing or residual adhesive on the skin surface and the separation of the adhesive layer and a backing material caused by the damage of the adhesive layer when the percutaneous preparation is uncovered. Currently, pressure-sensitive adhesives on the market are roughly classified into three categories: polyisobutylenes, acrylates, polysiloxanes.

The polyisobutylene pressure-sensitive adhesive base material has weak viscosity, the acrylate pressure-sensitive adhesive has poor adhesive force and solvent resistance and is poorer at high temperature, and the polysiloxane pressure-sensitive adhesive is formed by linearly polymerizing silicone resin on the skin, becomes soft and is adhered to the skin, has good biocompatibility, air permeability and moisture permeability, is high in price and is not suitable for market popularization.

Chinese patent publication No.: "CN 104434542A" discloses a medical antibacterial adhesive and a preparation method thereof, the medical adhesive has good adhesive property, and can realize adhesive bonding rapidly at low temperature; the medical adhesive disclosed by the invention has excellent antibacterial property; the method is simple and easy to implement, convenient to implement and suitable for large-scale popularization and application. But the biocompatibility is poor, the air permeability and the moisture permeability are poor, the adhesive has an obvious barrier effect, the release of the effect of the medicine is influenced, and the requirement of actual use cannot be met.

Disclosure of Invention

The invention aims to provide a degradable pressure-sensitive adhesive and a degradable pressure-sensitive adhesive tape aiming at the problem that the pressure-sensitive adhesive is difficult to degrade or has low degradation rate in the prior art.

In order to achieve the purposes, the specific scheme is as follows:

a degradable pressure-sensitive adhesive comprises the following raw materials: 30-50 parts of acrylate copolymer, 5-10 parts of tackifying resin, 20-30 parts of modified chitosan, 5-10 parts of liquid polyisobutylene rubber, 2-5 parts of cross-linking agent and 5-15 parts of styrene-isoprene-styrene block copolymer.

Preferably, the starting materials comprise: 40-50 parts of acrylate copolymer, 5-10 parts of tackifying resin, 26-30 parts of modified chitosan, 5-10 parts of liquid polyisobutylene rubber, 2-5 parts of cross-linking agent and 5-15 parts of styrene-isoprene-styrene block copolymer.

The preparation method of the acrylate copolymer comprises the following steps: a) adding 5-9g of methacrylate into a 200mL flask at normal temperature, adding 5mL of tetrahydrofuran solution, adding magnetons, and stirring by magnetic force to obtain a uniform solution; b) 3g of hydroxypropyl acrylate is dispersed in 8mL of acrylic acid, magnetic stirring is carried out, the rapid temperature rise of a reaction system is prevented through an ice water bath, and the reaction is carried out for 10 minutes; c) and (2) dispersing 1-2g of methacrylate into 5mL of acrylic acid, adding the mixture into the reaction system, reacting for 5 minutes, and stirring uniformly to obtain the acrylate copolymer.

The preparation method of the modified chitosan comprises the following steps: a. placing 8-15 parts of hinokitiol extracted from cypress in a first container, adding 5-20 parts by weight of ethanol, and stirring to obtain ethanol solution of hinokitiol; b. b, adding 1-5 parts by weight of sorbic acid into the solution prepared in the step a, and adding 3-5 parts by weight of deionized water for complete dissolution to prepare a modified solution of chitosan; c. and (b) adding 15-20 parts by weight of chitosan into the modified solution obtained in the step (b), adding 2-5 parts by weight of glycerol serving as a catalyst, heating to 90-100 ℃, stirring, obtaining a mixture for solid-liquid separation, filtering to obtain a solid, drying, and grinding to obtain the modified chitosan with the particle size of less than 20 micrometers.

The cross-linking agent is ethoxylated nonylphenol acrylate and hydroxyl-terminated acrylic acid caprolactone, the weight portion ratio of which is 2: 1.

The tackifying resin is modified rosin resin.

The preparation method of the modified rosin resin comprises the following steps: adding 50 parts by weight of rosin resin, 3-5 parts by weight of zinc borate, 1-3 parts by weight of potassium hydrogen fluoride and 5-8 parts by weight of maleic anhydride into a reaction kettle, uniformly stirring, then carrying out programmed heating at a heating speed of 5-8 ℃/min to 220-280 ℃, keeping the temperature for 30-45 minutes, stopping heating for 3-5 minutes, rapidly cooling to room temperature at a speed of 8-15 ℃/min, and taking out from the reaction kettle to obtain the modified rosin resin.

The preparation method of the degradable pressure-sensitive adhesive comprises the following steps: 1) adding modified chitosan, acrylate copolymer, styrene-isoprene-styrene block copolymer and cross-linking agent into a reaction kettle, keeping the temperature at 140 ℃ and stirring for reaction for 30-40 minutes; 2) then adding tackifying resin and liquid polyisobutylene rubber, continuously heating to the temperature of 160-; 4) and (3) completely melting all the raw materials and cooling to obtain the degradable pressure-sensitive adhesive without obvious bubbles.

A degradable pressure-sensitive adhesive tape comprises a base material and a degradable pressure-sensitive adhesive coated on one side or two sides of the base material, and the preparation method comprises the following steps:

and (3) placing the degradable pressure-sensitive adhesive into a coating machine, heating to 120-140 ℃, coating on the single surface or double surfaces of the substrate, attaching a release film, and rolling to obtain the degradable pressure-sensitive adhesive tape.

The base material is any one of PLA modified film or modified non-woven fabric.

The preparation method of the PLA modified film comprises the following steps: soaking the existing PLA film in a modifying solution at a speed of 0.1-0.3m/s for 0.8-1.2s, inserting two electrodes with a voltage of 50-80V into the soaking solution, and taking the soaking solution as a 5-10% pullulan aqueous solution, and air-drying or air-drying and rolling to obtain the LLA modified film.

The preparation method of the modified non-woven fabric comprises the following steps: soaking PLLA nonwoven fabric in polylactic acid, and irradiating under 400-60nm wavelength 3000LEX intensity for 5-10 min.

Compared with the prior art, the invention has the following technical effects:

1. the degradable pressure-sensitive adhesive disclosed by the invention greatly reduces the pollution problem of medical bonding articles, is high in decomposition rate and is environment-friendly.

2. The degradable pressure-sensitive adhesive prepared by modifying chitosan and rosin resin and matching with the acrylate copolymer prepared by a special method has moderate viscosity and can have a higher bacteriostatic function.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A first part:

preparation of an acrylate copolymer: a) adding 5-9g of methacrylate into a 200mL flask at normal temperature, adding 5mL of tetrahydrofuran solution, adding magnetons, and stirring by magnetic force to obtain a uniform solution; b) 3g of hydroxypropyl acrylate is dispersed in 8mL of acrylic acid, magnetic stirring is carried out, the rapid temperature rise of a reaction system is prevented through an ice water bath, and the reaction is carried out for 10 minutes; c) and (2) dispersing 1-2g of methacrylate into 5mL of acrylic acid, adding the mixture into the reaction system, reacting for 5 minutes, and stirring uniformly to obtain the acrylate copolymer.

Preparing modified chitosan: a. placing 8-15 parts of hinokitiol extracted from cypress in a first container, adding 5-20 parts by weight of ethanol, and stirring to obtain ethanol solution of hinokitiol; b. b, adding 1-5 parts by weight of sorbic acid into the solution prepared in the step a, and adding 3-5 parts by weight of deionized water for complete dissolution to prepare a modified solution of chitosan; c. and (b) adding 15-20 parts by weight of chitosan into the modified solution obtained in the step (b), adding 2-5 parts by weight of glycerol serving as a catalyst, heating to 90-100 ℃, stirring, obtaining a mixture for solid-liquid separation, filtering to obtain a solid, drying, and grinding to obtain the modified chitosan with the particle size of less than 20 micrometers.

The preparation method of the modified rosin resin comprises the following steps: adding 50 parts by weight of rosin resin, 3-5 parts by weight of zinc borate, 1-3 parts by weight of potassium hydrogen fluoride and 5-8 parts by weight of maleic anhydride into a reaction kettle, uniformly stirring, then carrying out programmed heating at a heating speed of 5-8 ℃/min to 220-280 ℃, keeping the temperature for 30-45 minutes, stopping heating for 3-5 minutes, rapidly cooling to room temperature at a speed of 8-15 ℃/min, and taking out from the reaction kettle to obtain the modified rosin resin.

Example 1

Weighing the following raw materials in parts by weight:

22kg of acrylate copolymer;

5-10 parts of modified rosin resin;

20-30 parts of modified chitosan;

5-10 parts of liquid polyisobutylene rubber;

2-5 parts of a cross-linking agent;

5-15 parts of styrene-isoprene-styrene block copolymer.

Preparing degradable pressure-sensitive adhesive: 1) adding modified chitosan, acrylate copolymer, styrene-isoprene-styrene block copolymer and cross-linking agent into a reaction kettle, keeping the temperature at 140 ℃ and stirring for reaction for 30-40 minutes; 2) then adding the modified rosin resin and the liquid polyisobutylene rubber, continuing to heat to 160-; 4) all the raw materials were completely melted and no significant bubbles were blown out, and cooled to obtain the degradable pressure sensitive adhesive of example 1.

A degradable pressure-sensitive adhesive tape comprises a PLA modified film and a degradable pressure-sensitive adhesive coated on one side of the PLA modified film, and the preparation method comprises the following steps: and (3) putting the degradable pressure-sensitive adhesive in the embodiment 1 into a coating machine, heating to 120-.

The formulations of the degradable pressure sensitive adhesives of examples 2-6 are described in the following tables, and the degradable pressure sensitive adhesives and the methods for preparing the degradable pressure sensitive adhesive tapes are described in reference to example 1.

The degradable pressure-sensitive adhesive tapes of the 6 embodiments are tested by using a GB/T4851 pressure-sensitive adhesive tape adhesiveness test method, and the test results are as follows by taking an average value for three tests:

from the above test data of examples 1-6, it can be seen that examples 1-6 have a large adhesion to materials such as infusion tubes and stainless steel tubes, and a moderate adhesion to skin, and the adhesion to skin is greater than 2N/inch by the reaction of medical staff, resulting in a strong pain feeling, while the adhesive tape peels off by itself during use because the adhesion is insufficient if the adhesion to skin is less than 1.2N/inch. Therefore, the adhesive force of the degradable pressure-sensitive adhesive tapes of examples 1 to 6 to the skin was just moderate, and it can be seen from the degradation residual rate after 1 month, the degradation exceeded 2/3 after 1 month in the air, and the degradation rate after 3 months was as high as 95% or more. Antibacterial tests show that the inhibition rate of the degradable pressure-sensitive adhesive tapes of examples 1-6 on staphylococcus aureus is up to more than 99%.

A second part:

preparing modified chitosan: a. placing 8-15 parts of hinokitiol extracted from cypress in a first container, adding 5-20 parts by weight of ethanol, and stirring to obtain ethanol solution of hinokitiol; b. b, adding 1-5 parts by weight of sorbic acid into the solution prepared in the step a, and adding 3-5 parts by weight of deionized water for complete dissolution to prepare a modified solution of chitosan; c. and (b) adding 15-20 parts by weight of chitosan into the modified solution obtained in the step (b), adding 2-5 parts by weight of glycerol serving as a catalyst, heating to 90-100 ℃, stirring, obtaining a mixture for solid-liquid separation, filtering to obtain a solid, drying, and grinding to obtain the modified chitosan with the particle size of less than 20 micrometers.

The preparation method of the modified rosin resin comprises the following steps: adding 50 parts by weight of rosin resin, 3-5 parts by weight of zinc borate, 1-3 parts by weight of potassium hydrogen fluoride and 5-8 parts by weight of maleic anhydride into a reaction kettle, uniformly stirring, then carrying out programmed heating at a heating speed of 5-8 ℃/min to 220-280 ℃, keeping the temperature for 30-45 minutes, stopping heating for 3-5 minutes, rapidly cooling to room temperature at a speed of 8-15 ℃/min, and taking out from the reaction kettle to obtain the modified rosin resin.

Example 7:

weighing the following raw materials in parts by weight:

22kg of ethyl acrylate;

5-10 parts of modified rosin resin;

20-30 parts of modified chitosan;

5-10 parts of liquid polyisobutylene rubber;

2-5 parts of a cross-linking agent;

5-15 parts of styrene-isoprene-styrene block copolymer.

Preparing degradable pressure-sensitive adhesive: 1) adding modified chitosan, ethyl acrylate, styrene-isoprene-styrene block copolymer and cross-linking agent into a reaction kettle, keeping the temperature at 140 ℃ and stirring for reaction for 30-40 minutes; 2) then adding the modified rosin resin and the liquid polyisobutylene rubber, continuing to heat to 160-; 4) all the materials were completely melted and no significant bubbles were blown out, and cooled to obtain the degradable pressure sensitive adhesive of example 7.

A degradable pressure-sensitive adhesive tape comprises a PLA modified film and a degradable pressure-sensitive adhesive coated on one side of the PLA modified film, and the preparation method comprises the following steps: and (3) putting the degradable pressure-sensitive adhesive of the embodiment 7 into a coating machine, heating to 120-140 ℃, coating on one side or two sides of the substrate, attaching a release film, and rolling to obtain the degradable pressure-sensitive adhesive tape of the embodiment 7.

The formulations of the degradable pressure sensitive adhesives of examples 8-12 are described in the following table, and the methods for preparing the degradable pressure sensitive adhesives and the degradable pressure sensitive adhesive tapes are described in reference to example 7.

The degradable pressure-sensitive adhesive tapes of 6 examples 7-12 were tested by the adhesion test method of the pressure-sensitive adhesive tape of GB/T4851, and the test results were averaged three times and are as follows:

from the above test data of examples 7-12, it can be seen that the adhesive force of examples 7-12 to materials such as infusion tubes and stainless steel tubes is general, the adhesive force to skin is large, and the average adhesive force is larger than 2N/inch, and for the degradation residue rate after 1 month, it can be seen that the degradation is about 1/2 after 1 month in air, the degradation rate is about 2/3 after 3 months, and the degradation effect is obviously inferior to that of examples 1-6. Bacteriostasis tests show that the inhibition rate of the degradable pressure-sensitive adhesive tapes of examples 7-12 on staphylococcus aureus is up to more than 98%.

And a third part:

preparation of an acrylate copolymer: a) adding 5-9g of methacrylate into a 200mL flask at normal temperature, adding 5mL of tetrahydrofuran solution, adding magnetons, and stirring by magnetic force to obtain a uniform solution; b) 3g of hydroxypropyl acrylate is dispersed in 8mL of acrylic acid, magnetic stirring is carried out, the rapid temperature rise of a reaction system is prevented through an ice water bath, and the reaction is carried out for 10 minutes; c) and (2) dispersing 1-2g of methacrylate into 5mL of acrylic acid, adding the mixture into the reaction system, reacting for 5 minutes, and stirring uniformly to obtain the acrylate copolymer.

Preparing modified chitosan: a. placing 8-15 parts of hinokitiol extracted from cypress in a first container, adding 5-20 parts by weight of ethanol, and stirring to obtain ethanol solution of hinokitiol; b. b, adding 1-5 parts by weight of sorbic acid into the solution prepared in the step a, and adding 3-5 parts by weight of deionized water for complete dissolution to prepare a modified solution of chitosan; c. and (b) adding 15-20 parts by weight of chitosan into the modified solution obtained in the step (b), adding 2-5 parts by weight of glycerol serving as a catalyst, heating to 90-100 ℃, stirring, obtaining a mixture for solid-liquid separation, filtering to obtain a solid, drying, and grinding to obtain the modified chitosan with the particle size of less than 20 micrometers.

Example 13:

weighing the following raw materials in parts by weight:

22kg of acrylate copolymer;

5-10 parts of rosin resin;

20-30 parts of modified chitosan;

5-10 parts of liquid polyisobutylene rubber;

2-5 parts of a cross-linking agent;

5-15 parts of styrene-isoprene-styrene block copolymer.

Preparing degradable pressure-sensitive adhesive: 1) adding modified chitosan, acrylate copolymer, styrene-isoprene-styrene block copolymer and cross-linking agent into a reaction kettle, keeping the temperature at 140 ℃ and stirring for reaction for 30-40 minutes; 2) then adding rosin resin and liquid polyisobutylene rubber, continuing to heat to 160-; 4) all the materials were completely melted and no significant bubbles were blown out, and cooled to obtain the degradable pressure sensitive adhesive of example 13.

A degradable pressure-sensitive adhesive tape comprises a PLA modified film and a degradable pressure-sensitive adhesive coated on one side of the PLA modified film, and the preparation method comprises the following steps: the degradable pressure-sensitive adhesive of the embodiment 13 is placed in a coating machine, heated to 120-140 ℃, and coated on one side or two sides of a substrate, and then a release film is attached and wound to obtain the degradable pressure-sensitive adhesive tape of the embodiment 13.

The formulations of the degradable pressure sensitive adhesives of examples 14-18 are as described in the following table, and the degradable pressure sensitive adhesives and the methods of preparing the degradable pressure sensitive adhesive tapes are as described in reference to example 13.

The degradable pressure-sensitive adhesive tapes of 6 examples 13-18 were tested by the adhesion test method of GB/T4851 pressure-sensitive adhesive tape, and the test results were averaged three times and are as follows:

from the above test data of examples 13 to 18, it can be seen that the adhesive force of examples 13 to 18 to the materials such as the infusion tube, the skin and the stainless steel tube is large, so that the adhesive force of the degradable pressure sensitive adhesive tapes of examples 13 to 18 to the skin is too large to be applied to the medical adhesive tape, and it can be seen that the degradation rate is about 2/3 after 1 month in the air and reaches as high as 85% or more after 3 months. Bacteriostasis tests prove that the degradable pressure sensitive adhesive tapes of examples 13 to 18 have the inhibition rate of more than 99 percent on staphylococcus aureus.

The fourth part:

preparation of an acrylate copolymer: a) adding 5-9g of methacrylate into a 200mL flask at normal temperature, adding 5mL of tetrahydrofuran solution, adding magnetons, and stirring by magnetic force to obtain a uniform solution; b) 3g of hydroxypropyl acrylate is dispersed in 8mL of acrylic acid, magnetic stirring is carried out, the rapid temperature rise of a reaction system is prevented through an ice water bath, and the reaction is carried out for 10 minutes; c) and (2) dispersing 1-2g of methacrylate into 5mL of acrylic acid, adding the mixture into the reaction system, reacting for 5 minutes, and stirring uniformly to obtain the acrylate copolymer.

The preparation method of the modified rosin resin comprises the following steps: adding 50 parts by weight of rosin resin, 3-5 parts by weight of zinc borate, 1-3 parts by weight of potassium hydrogen fluoride and 5-8 parts by weight of maleic anhydride into a reaction kettle, uniformly stirring, then carrying out programmed heating at a heating speed of 5-8 ℃/min to 220-280 ℃, keeping the temperature for 30-45 minutes, stopping heating for 3-5 minutes, rapidly cooling to room temperature at a speed of 8-15 ℃/min, and taking out from the reaction kettle to obtain the modified rosin resin.

Example 19

Weighing the following raw materials in parts by weight:

22kg of acrylate copolymer;

5-10 parts of modified rosin resin;

20-30 parts of chitosan;

5-10 parts of liquid polyisobutylene rubber;

2-5 parts of a cross-linking agent;

5-15 parts of styrene-isoprene-styrene block copolymer.

Preparing degradable pressure-sensitive adhesive: 1) adding chitosan, acrylate copolymer, styrene-isoprene-styrene block copolymer and cross-linking agent into a reaction kettle, keeping the temperature at 140 ℃ and stirring for reaction for 30-40 minutes; 2) then adding the modified rosin resin and the liquid polyisobutylene rubber, continuing to heat to 160-; 4) all the materials were completely melted and no significant bubbles were blown out, and cooled to obtain the degradable pressure sensitive adhesive of example 19.

A degradable pressure-sensitive adhesive tape comprises a PLA modified film and a degradable pressure-sensitive adhesive coated on one side of the PLA modified film, and the preparation method comprises the following steps: and (3) putting the degradable pressure-sensitive adhesive of the embodiment 19 into a coating machine, heating to 120-140 ℃, coating on one side or two sides of the substrate, attaching a release film, and rolling to obtain the degradable pressure-sensitive adhesive tape of the embodiment 19.

The formulations of the degradable pressure sensitive adhesives of examples 20-24 are described in the following table, and the degradable pressure sensitive adhesives and the methods for preparing the degradable pressure sensitive adhesive tapes are described in reference to example 19.

The degradable pressure-sensitive adhesive tapes of the 6 embodiments are tested by using a GB/T4851 pressure-sensitive adhesive tape adhesiveness test method, and the test results are as follows by taking an average value for three tests:

from the above test data of examples 19-24, it can be seen that examples 19-24 have a large adhesion to materials such as infusion tubes and stainless steel tubes, and a large adhesion to skin, and that the adhesion to skin >2N/inch by the reaction of medical staff produces a strong pain sensation, while the adhesive tape, if less than 1.2N/inch, peels off by itself during use because of insufficient adhesion. Therefore, the degradable pressure-sensitive adhesive tapes of examples 19 to 24 had a large adhesive force to the skin and a strong pain feeling when used, and it was found that the degradation residue rate after 1 month was about 2/3 after 1 month in the air, and the degradation rate after 3 months was as high as 80% or more. Bacteriostasis tests show that the degradable pressure sensitive adhesive tapes of examples 19 to 24 have about 70 percent of inhibition rate to staphylococcus aureus.

Fifth part

Example 25, the crosslinker ratio employed was ethoxylated nonylphenol acrylate: hydroxyl-terminated dihexanolide acrylate 1: 2; otherwise prepared as in example 19.

Example 26, no styrene-isoprene-styrene block copolymer was added.

The degradable pressure sensitive adhesives of examples 25-26 were tested in three tests and averaged, and the test results were as follows:

the test results of examples 25 and 26 show that the degradable pressure sensitive adhesive tapes of examples 25 and 26 have high adhesion to materials such as infusion tubes, skin and stainless steel tubes, so the degradable pressure sensitive adhesive tapes of examples 13 to 18 have high adhesion to skin and are not suitable for medical tapes, and that the degradation residue rate after 1 month is about 1/3 after 1 month exposure to air, and the degradation rate after 3 months is about 50%. Bacteriostasis tests prove that the inhibition rate of the degradable pressure-sensitive adhesive tapes of examples 13 to 18 on staphylococcus aureus is up to more than 96%. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.