Isolated biochemical protective material and preparation method thereof

Abstract

The invention provides an isolated biochemical protection material and a preparation method thereof.The preparation method comprises the steps that EVOH is added into an isopropyl alcohol solution, heating and stirring are conducted, and an EVOH / isopropyl alcohol mixed solution is obtained; selecting a protective textile material, and performing plasma treatment; the obtained EVOH / isopropanol mixed solution is sprayed to the surface of a textile material through high-pressure airflow, high-temperature setting treatment is carried out, and the isolated biochemical protection material is obtained. The high-molecular solution of EVOH and isopropanol is adopted for spraying, excellent barrier property and good processability can be provided for the protective material, hydrogen bonds with relatively strong action can be formed among EVOH high molecules, a compact protective layer is formed on the surface of a base material, and the protective material has relatively high mechanical strength and adhesive force; the prepared protective material has good chemical and biological barrier property, keeps good fabric flexibility, and can be applied to the field of biochemical protection.

Description

Technical Field

[0001] The present invention relates to the technical field of protective materials, and in particular to an isolation type biochemical protective material and a preparation method thereof. Background Art

[0002] According to different protection mechanisms, biochemical protection materials can be divided into three categories: adsorption-type protective materials, detoxification-type protective materials and isolation-type protective materials. Among them, adsorption-type protective materials achieve protection against biochemical substances by adding high specific surface area activated carbon microporous materials. The material has good air permeability, but the performance is greatly affected by humidity and the protection time is short. After adsorption saturation, desorption treatment is required to remove harmful substances. Detoxification-type protective materials directly compound antidotes with protective materials and achieve protection functions with the help of special biochemical reactions. This type of material is convenient and effective, but the types of antidote protection are limited, the repeatability is poor, it is easy to fail, and it is seldom used. Isolation-type protective materials can directly block harmful substances outside the protective material. Its components are mainly rubber, polymer composite membrane or a composite material of the two.

[0003] my country's isolation protection materials are mainly rubber (butyl rubber, chloroprene rubber, fluororubber, etc.) and polyvinyl chloride (PVC) polymer coatings, which are reusable but have disadvantages such as high density, easy aging or poor air permeability. Compared with similar imported products, the protection level is low and can only meet the needs of industrial acid and alkali protection. In order to broaden the protection spectrum of biochemical protection materials and improve their wearing comfort, fiber-based advanced biochemical protection materials represented by non-woven fabrics and polymer multilayer composite films have attracted widespread attention.

[0004] A Chinese patent with publication number CN112959769A discloses an ultra-light high-barrier nuclear, biological and chemical protective material and a processing method thereof. The material comprises a first barrier layer, a bearing layer is adhered to the surface of the first barrier layer, a second barrier layer is adhered to the surface of the bearing layer, a functional layer is adhered to the surface of the second barrier layer, the first barrier layer and the second barrier layer have the same structure, the first barrier layer comprises a high-barrier ethylene-vinyl alcohol copolymer, the invention uses high-density polyethylene fiber as raw material for spinning and water-jet weaving, and achieves lightweight while improving the strength of the fabric by increasing the yarn count and strength, optimizing the tightness of the fabric, and improving the weaving process, thereby developing a lightweight and high-strength fabric as the bearing layer, with a high-barrier ethylene-vinyl alcohol copolymer as the core layer, sandwiched between two layers of nylon film, further improving the barrier properties and reducing the thickness of the film, and the outer layer is supplemented with ethylene polymer to form a barrier layer, thereby greatly reducing the weight of the protective material. The shortcoming of this invention is that it uses high-barrier ethylene-vinyl alcohol copolymer and nylon plastic film as the middle layer, which destroys the comfort function of the protective material to a certain extent. The Chinese patent with publication number CN101181661A discloses a multifunctional breathable protective material and its preparation method, which consists of a multifunctional protective fabric layer, a barrier layer and an adsorption layer. The protective material of this invention has multiple functions, and the functions are organically combined through membrane, composite and finishing, achieving the harmonious unity of multiple functions and durable use. The method of this invention is used to prepare a breathable nuclear, biological and chemical protective material with multiple protective functions, simple process and low cost, and has significant economic and social benefits. The shortcoming of this invention is that the protective performance against biochemical substances is not good.

[0005] In view of this, it is necessary to design an improved isolation type biochemical protective material and a preparation method thereof to solve the above problems. Summary of the invention

[0006] In view of the defects of the above-mentioned prior art, the purpose of the present invention is to provide an isolation type biochemical protective material and a preparation method thereof, which increases the barrier properties of the textiles by spraying a water / isopropanol solution containing ethylene-vinyl alcohol copolymer (EVOH) on the surface of the textiles without destroying the wearing comfort of the textiles.

[0007] To achieve the above object, the present invention provides a method for preparing an isolation type biochemical protective material, comprising the following steps:

[0008] S1, adding EVOH to an isopropanol solution, heating and stirring, to obtain an EVOH / isopropanol mixed solution;

[0009] S2, subjecting the protective textile material to plasma treatment to obtain a pretreated material;

[0010] S3. Use high-pressure airflow spraying technology to spray the EVOH / isopropyl alcohol mixed solution obtained in step S1 onto the surface of the pretreated material obtained in step S2, and perform shaping treatment to obtain an isolation type biochemical protective material.

[0011] As a further improvement of the present invention, in step S1, the mass ratio of water to isopropanol in the isopropanol solution is 1:(1-1.2), the heating and stirring temperature is 55-65° C., and the heating and stirring time is 30-40 min.

[0012] The vinyl content in the EVOH is 20 to 50%.

[0013] As a further improvement of the present invention, in step S2, the protective textile material is one of meltblown non-woven fabric, spunbond non-woven fabric, polyester knitted fabric, nylon knitted fabric, polyester woven fabric and nylon woven fabric.

[0014] As a further improvement of the present invention, in step S3, the coating thickness of the isolation type biochemical protection material obtained is 0.05 to 2 mm.

[0015] The temperature of the shaping treatment is 80-150° C. and the time is 1-30 minutes.

[0016] The present invention also provides an isolation type biochemical protective material, which is prepared by the preparation method of the isolation type biochemical protective material.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention provides an isolation type biochemical protective material and a preparation method thereof, wherein a mixed solution containing EVOH / isopropyl alcohol is prepared, sprayed on the surface of a protective textile material, and subjected to a high temperature setting treatment to obtain an isolation type biochemical protective material. The present invention uses a polymer solution of EVOH / isopropyl alcohol to provide the protective material with excellent barrier properties and good processability, so that the material has both good chemical and biological barrier properties and good fabric flexibility.

[0019] (2) Compared with EVOH composite protective film materials, the present invention can avoid unnecessary cutting and welding when preparing protective fabrics with complex structures, thereby avoiding damage to the integrity of the protective materials.

[0020] (3) Compared with protective materials that are sprayed with EVOH nanofiber membranes for protection, the present invention uses EVOH polymer for spraying, which has the advantages of strong adhesion and high protection level. Since the EVOH nanofiber suspension exists in the form of ultrafine short fibers in water / isopropanol, during spraying, the EVOH short fibers are repeatedly stacked on the surface of the fabric to form a nanofiber protective material. The interaction force between the EVOH short fibers in this material is very weak, and it does not have the mechanical properties required for protective clothing. However, the present invention sprays a polymer solution of EVOH, and strong hydrogen bonds are formed between the EVOH polymers to form a dense protective layer on the surface of the substrate. It has high mechanical strength and adhesion. Combined with the comprehensive properties of the substrate, it can be used for protection in the biochemical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an infrared spectrum of the isolation-type biochemical protection material provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0024] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0025] The present invention provides a method for preparing an isolation type biochemical protective material, comprising the following steps:

[0026] S1. Add EVOH into isopropanol solution, heat and stir to obtain EVOH / isopropanol mixed solution.

[0027] Specifically, the mass ratio of water to isopropanol in the isopropanol solution is preferably 1:(1-1.2), the heating temperature is preferably 55-65° C., and the stirring time is preferably 30-40 min. The vinyl content in EVOH is 20-50%.

[0028] Selecting EVOH with a vinyl content in the range of 20-50% can ensure that the material has a certain degree of flexibility while maintaining good barrier properties.

[0029] Isopropyl alcohol is an organic solvent that can dissolve EVOH, and the addition of water can adjust the polarity and volatility of the solution. The mass ratio of water to isopropyl alcohol is preferably 1: (1-1.2), which helps to evenly dissolve EVOH while maintaining the appropriate viscosity of the solution, reducing the rapid volatilization of isopropyl alcohol, improving the stability of the solution, and facilitating the subsequent spraying process.

[0030] The heating temperature can ensure that EVOH is fully dissolved, while avoiding excessive temperature that causes EVOH degradation or excessive volatilization of the solution, thereby obtaining a uniform, easy-to-spray solution. Stirring helps to mix EVOH and the solvent, increase the dissolution rate, and obtain a uniform mixed solution.

[0031] S2. Plasma-treating the protective textile material to obtain a pre-treated material.

[0032] Specifically, the protective textile material is preferably one of meltblown nonwoven fabric, spunbonded nonwoven fabric, polyester knitted fabric, nylon knitted fabric, polyester woven fabric and nylon woven fabric.

[0033] Plasma treatment can etch the surface of the material, introduce new functional groups, increase surface energy and hydrophilicity, make the surface of the protective textile material more active, and facilitate the adhesion of the coating. The plasma-treated material is more easily wetted by the EVOH / isopropyl alcohol mixed solution, thereby achieving better coating uniformity, enhancing the adhesion between the coating and the substrate, and improving the durability and protective performance of the material.

[0034] S3. Use high-pressure airflow spraying technology to spray the EVOH / isopropyl alcohol mixed solution obtained in step S1 onto the surface of the pretreated material obtained in step S2, and perform shaping treatment to obtain an isolation type biochemical protective material.

[0035] Specifically, the temperature of the shaping treatment is preferably 80 to 150° C., and the time is preferably 1 to 30 minutes. The coating thickness of the obtained isolation type biochemical protective material is 0.05 to 2 mm. The coating thickness can ensure that the material has good biochemical protection performance while maintaining appropriate air permeability and flexibility. The coating thickness within this range can balance protection and practicality. A coating that is too thin cannot provide sufficient protection, while a coating that is too thick will reduce the comfort and air permeability of the material.

[0036] High-pressure airflow spraying technology can produce fine droplets, so that the EVOH / isopropyl alcohol mixed solution is evenly distributed on the surface of the pre-treated material to form a uniform coating. The shaping treatment solidifies the EVOH coating by heating, which improves the durability and protective performance of the coating. By controlling the coating thickness, shaping treatment temperature and time, the comprehensive performance of the isolation type biochemical protective material can be optimized, including protection, comfort and durability.

[0037] The present application can form a dense protective film by spraying an EVOH / isopropanol mixed solution on a protective textile material that has been pretreated with plasma. EVOH has excellent barrier properties and can effectively prevent the penetration of biochemical agents (such as bacteria, viruses, and chemical harmful substances), thereby providing efficient biochemical protection. Plasma treatment can increase the activity of the textile surface and increase its surface energy, thereby enhancing the bonding force between the EVOH mixed solution and the textile material. This makes the protective layer less likely to fall off and improves the durability of the material. The shaping treatment can fix the morphology of the EVOH layer on the textile surface, increasing its stability and durability. After multiple uses and washings, the material can still maintain good protective properties. This method is applicable to a variety of different protective textile materials, and suitable base materials can be selected according to different application requirements to prepare isolated biochemical protective materials suitable for different occasions. Compared with some traditional methods for preparing protective materials, this technology can reduce the use of harmful chemicals and reduce the impact on the environment.

[0038] The preparation method of the isolation type biochemical protection material provided by the present invention is described below in conjunction with specific embodiments.

[0039] Example 1

[0040] Example 1 provides a method for preparing an isolation type biochemical protective material, comprising the following steps:

[0041] S1. Weigh EVOH and add it to an isopropanol solution with a mass ratio of water to isopropanol of 1:1. Heat to 60° C. and stir for 30 min to obtain an EVOH / isopropanol mixed solution, wherein the vinyl content in the EVOH is 27%.

[0042] S2. Select meltblown nonwoven fabric for plasma treatment.

[0043] S3, spraying the EVOH / isopropyl alcohol mixed solution onto the surface of the melt-blown nonwoven fabric with high-pressure airflow, and subjecting the melt-blown nonwoven fabric to a high-temperature setting treatment at 150°C for 10 minutes to obtain an isolation-type biochemical protective material. Figure 1 As shown, it can be seen that in the range of 3150-3500cm -1 There is a strong -OH stretching vibration peak near 3010-2850cm. This is because the EVOH molecular structure contains a large number of hydroxyl groups, and hydrogen bonds are formed between hydroxyl groups, which makes the absorption peak broaden and increase in intensity. -1 The absorption peaks between -CH2- and methylene -CH- are the stretching peaks; at 1050-1075cm -1 Nearby, the absorption peak of CO bond contained in the vinyl alcohol segment of EVOH; at 1350-1260cm -1 It is the bending vibration peak of hydroxyl -OH.

[0044] Embodiment 2-4

[0045] Examples 2-4 respectively provide a method for preparing an isolation-type biochemical protective material. Compared with Example 1, the only difference is that the protective textile materials are different, namely spunbond non-woven fabric, polyester woven fabric and nylon knitted fabric. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0046] Examples 5-7 and Comparative Examples 1-2

[0047] Examples 5-7 and Comparative Examples 1-2 respectively provide a method for preparing an isolation-type biochemical protective material. Compared with Example 1, the only difference is that the mass fraction of EVOH is different, as shown in Table 1. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0048] Examples 8-10 and Comparative Examples 3-4

[0049] Examples 8-10 and Comparative Examples 3-4 respectively provide a method for preparing an isolation-type biochemical protective material. Compared with Example 1, the only difference is that the coating thickness is different, as shown in Table 1. Other experimental parameters and conditions are basically the same as those in Example 1 and will not be repeated here.

[0050] Table 1 Experimental parameters

[0051]

[0052] The performance test of the materials obtained in the embodiments and comparative examples is carried out as follows:

[0053] The total bending length test method is based on GB / T18318.1-2009 "Determination of bending properties of textiles Part 1: Inclined plane method", and the sample is tested using the LLY-B01 electronic stiffness tester. The sample length is (250±1) mm, the width is (25±1) mm, the test angle is 41.5°, and the pressing plate advance speed is 4 mm / s. The warp bending strength CL and the weft bending length CH of the fabric are tested respectively, and the total bending length is calculated.

[0054] The water vapor transmission rate is tested using GB / T 1037-88 “Test method for water vapor permeability of plastic film and sheet - Cup method”.

[0055] The refrigerant permeability test was conducted in accordance with GB / T 7755-2003 “Determination of gas permeability of vulcanized rubber or thermoplastic rubber”, and the refrigerant used was R410A with good permeability.

[0056] The oxygen transmission rate test is conducted according to ASTM F3136-15 "Standard Test Method for Oxygen Transmission Rate of Plastic Film and Sheeting by Dynamic Accumulation Method".

[0057] The bacterial barrier rate test is conducted based on the content of the bacterial barrier rate section in the pharmaceutical industry standard YY 0469-2011 "Medical Surgical Masks".

[0058] The test results are as follows:

[0059] Table 2 Test results of material properties obtained in the examples and comparative examples

[0060]

[0061]

[0062] As can be seen from Table 2, the thicker the EVOH coating thickness of the fabric, the better the barrier effect to oxygen and refrigerant; the higher the vinyl content in EVOH, the better the barrier performance to water vapor; the lower the vinyl content, the higher the vinyl alcohol content, the better the barrier performance to oxygen and refrigerant. This is mainly due to the good hydrophobicity of the vinyl component, which has a good barrier effect on the infiltrating water vapor; the vinyl alcohol component has a high molecular polarity, which has a good barrier effect on the penetrating molecules with large molecular polarity. In Comparative Example 3, when the coating thickness is only 0.02 microns, the porosity of the non-woven fabric will decrease, but because the coating is too thin, the gaps between the non-woven fabrics cannot be completely blocked, resulting in bacterial leakage when doing bacterial barrier experiments.

[0063] During the spraying process of EVOH polymer solution, strong hydrogen bonds can be formed between polymer chains, and these hydrogen bonds can provide good adhesion during the curing process. Due to the formation of hydrogen bonds, the protective layer formed by EVOH polymer solution on the surface of the substrate has a stronger bonding force with the substrate and is not easy to fall off, thereby improving the durability and reliability of the material. EVOH polymer solution forms a dense protective layer on the surface of the substrate, which can effectively block the penetration of biochemical agents.

[0064] Compared with EVOH nanofiber membrane, the present application has the following advantages: the ultrafine short fibers in the EVOH nanofiber suspension will be repeatedly stacked on the fabric surface during spraying, but because the interaction between the short fibers is very weak, the formed nanofiber protective material is insufficient in mechanical properties and cannot meet the strength requirements of protective clothing; while the protective layer formed by spraying the EVOH polymer solution of the present application is not only dense, but also has higher mechanical strength due to the interaction between the polymer chains. This means that the material can not only provide efficient protection, but also withstand certain physical stresses, and is more suitable for practical applications. Therefore, the present application overcomes the deficiencies of nanofiber membranes in mechanical properties and protection levels by using EVOH polymer solution spraying to prepare protective materials. The prepared protective materials have both good chemical and biological barriers and good fabric flexibility, and are suitable for protection in the biochemical field.

[0065] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing an isolation type biochemical protective material, characterized in that: The following steps are involved: S1, adding EVOH to an isopropanol solution, heating and stirring, to obtain an EVOH / isopropanol mixed solution; S2, subjecting the protective textile material to plasma treatment to obtain a pretreated material; S3. Use high-pressure airflow spraying technology to spray the EVOH / isopropyl alcohol mixed solution obtained in step S1 onto the surface of the pretreated material obtained in step S2, and perform shaping treatment to obtain an isolation type biochemical protective material.

2. The method for preparing the isolation type biochemical protective material according to claim 1, characterized in that: In step S1, the mass ratio of water to isopropanol in the isopropanol solution is 1:(1-1.2).

3. The method for preparing the isolation type biochemical protective material according to claim 2, characterized in that: The temperature of the heating and stirring is 55-65°C.

4. The method for preparing the isolation type biochemical protective material according to claim 2, characterized in that: The heating and stirring time is 30 to 40 minutes.

5. The method for preparing the isolation type biochemical protective material according to claim 2, characterized in that: The vinyl content in the EVOH is 20 to 50%.

6. The method for preparing the isolation type biochemical protective material according to claim 1, characterized in that: In step S2, the protective textile material is one of meltblown nonwoven fabric, spunbonded nonwoven fabric, polyester knitted fabric, nylon knitted fabric, polyester woven fabric and nylon woven fabric.

7. The method for preparing the isolation type biochemical protective material according to claim 1, characterized in that: In step S3, the coating thickness of the obtained isolation type biochemical protection material is 0.05-2 mm.

8. The method for preparing the isolation type biochemical protective material according to claim 1, characterized in that: In step S3, the temperature of the shaping treatment is 80-150°C.

9. The method for preparing the isolation type biochemical protective material according to claim 8, characterized in that: The time of the shaping treatment is 1 to 30 minutes.

10. An isolation type biochemical protective material, characterized in that: The invention is prepared by the preparation method of the isolation type biochemical protection material according to any one of claims 1 to 9.

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