Preparation method of temperature-responsive color-changing nonwoven fabric

Abstract

The application discloses a preparation method of temperature-responsive color-changing non-woven fabric. After the non-woven fabric is impregnated by a polyvinylpyrrolidone solution and an oxidized sodium alginate solution, microcapsules are loaded on the surface of the non-woven fabric by using a spraying method, and the heat conduction efficiency between the interface and the microcapsules is enhanced in combination with the bonding components generated in the impregnation, so that the temperature-sensing color-changing sensitivity of the color-changing non-woven fabric is improved, and the temperature-sensing color-changing non-woven fabric has significant significance for temperature monitoring of sanitary products.

Description

Technical Field

[0001] The present invention relates to the field of sanitary products, and in particular to a method for preparing a temperature-responsive color-changing non-woven fabric. Background Art

[0002] Changes in human body temperature have a significant impact on the body's physiological functions. Furthermore, physiological disturbances can lead to impairments in the body's thermoregulatory mechanisms, resulting in significant temperature fluctuations. Therefore, real-time and efficient monitoring of body temperature not only provides insights into a person's health status but also guides disease treatment and enables effective health monitoring. However, current temperature monitoring requires sophisticated equipment and the use of multiple sensors, resulting in a cumbersome testing process and a waste of resources. With advances in technology, smart fabrics are gradually becoming part of our lives, with thermochromic fabrics being a key component.

[0003] Existing thermochromic fabrics are usually sprayed with thermochromic materials on non-woven fabrics. In order to achieve a higher load of color-changing material, adhesives are usually used to bond the thermochromic material to the non-woven surface. However, excessive adhesive components will lead to the defect of poor temperature sensitivity, limiting the application prospects of color-changing fabrics.

[0004] Therefore, a temperature-responsive color-changing non-woven fabric is developed for human body temperature monitoring to avoid the defect of poor temperature sensitivity of the existing color-changing non-woven fabric. Summary of the Invention

[0005] The present invention provides a method for preparing a temperature-responsive color-changing non-woven fabric, which overcomes the defect of poor sensitivity of the color-changing non-woven fabric in the prior art.

[0006] To achieve the above object, the scheme of the present invention is as follows:

[0007] In a first aspect of the present invention, a method for preparing a temperature-responsive color-changing nonwoven fabric is provided, comprising the following steps:

[0008] S1. The non-woven fabric is immersed in a polyvinyl pyrrolidone solution and an oxidized sodium alginate solution;

[0009] S2. After spraying the mixed solution onto the surface of the impregnated non-woven fabric, it is dried to obtain a temperature-responsive color-changing non-woven fabric; the mixed solution is obtained by dispersing color-changing microcapsules in an aqueous solution of polyvinyl pyrrolidone; the color-changing microcapsules are microcapsules with urea-formaldehyde resin as the wall layer and a thermochromic material coated inside.

[0010] Optionally, in step S1, the concentration of the polyvinyl pyrrolidone solution is 1-3 mg / mL, and the immersion time is 3-6 hours; and / or the concentration of the oxidized sodium alginate solution is 0.5-2 mg / mL, and the immersion time is 1-2 hours.

[0011] Optionally, in step S2, the mass ratio of the color-changing microcapsules to polyvinyl alkoxide in the mixed solution is 1:(1.3-1.5).

[0012] Optionally, in step S2, the concentration of the polyvinyl pyrrolidone solution is 2-5 mg / mL.

[0013] Optionally, in step S2, the spraying amount of the mixed solution on the non-woven fabric surface is 0.5-2 mL / cm 2 .

[0014] Optionally, the particle size of the color-changing microcapsules is 2-7 μm.

[0015] Optionally, the spraying process uses a spray gun, the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.4-0.6 MPa, and the moving speed is 20-30 cm / s.

[0016] Optionally, the drying process temperature is 20-40° C., and the vacuum drying is performed for 10-24 hours.

[0017] In a second aspect of the present invention, a temperature-responsive color-changing nonwoven fabric obtained by the preparation method described in the first aspect is provided. The temperature-responsive color-changing nonwoven fabric has high temperature sensitivity, a large color-changing microcapsule loading capacity, and broad application prospects.

[0018] The third aspect of the present invention provides a sanitary product comprising the temperature-responsive color-changing non-woven fabric described in the second aspect. The sanitary product includes but is not limited to sanitary care products that directly or indirectly contact human skin and can be used to efficiently monitor human body temperature.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention provides a method for preparing a temperature-responsive color-changing non-woven fabric. After the non-woven fabric is impregnated with a polyvinyl pyrrolidone solution and an oxidized sodium alginate solution, microcapsules are loaded onto the surface of the non-woven fabric by a spraying method. The combination with the adhesive components generated by the impregnation enhances the heat conduction efficiency between the interface and the microcapsules, thereby improving the temperature-sensitive color change sensitivity of the color-changing non-woven fabric.

[0021] 2. The temperature-responsive color-changing non-woven fabric obtained by the preparation method of the present invention can efficiently load microcapsules and change color significantly, which is convenient for use in sanitary products to monitor human body temperature and has wide application value. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0023] In one embodiment, a method for preparing a temperature-responsive color-changing nonwoven fabric is provided, comprising the following steps:

[0024] 1. Immerse the ES hot air non-woven fabric in a 1-3 mg / mL polyvinyl pyrrolidone solution for 3-6 hours, and then immerse it in a 0.5-2 mg / mL oxidized sodium alginate solution for 1-2 hours;

[0025] 2. After spraying the mixed solution onto the surface of the impregnated non-woven fabric, vacuum drying is performed at 20-40°C for 10-24 hours to obtain a temperature-responsive color-changing non-woven fabric; the mixed solution is obtained by dispersing color-changing microcapsules in an aqueous solution of polyvinyl pyrrolidone with a concentration of 2-5 mg / mL, and the mass ratio of the color-changing microcapsules to the polyvinyl pyrrolidone is 1:(1.3-1.5); the amount of the mixed solution sprayed per square centimeter of the non-woven fabric is 0.5-2 mL; the color-changing microcapsules are microcapsules with a urea-formaldehyde resin wall layer and an internal coating of a thermochromic material, and have a particle size of 2-7 μm.

[0026] In the above embodiment, the non-woven fabric is impregnated with polyvinyl pyrrolidone solution and oxidized sodium alginate solution, and then the microcapsules are loaded onto the surface of the non-woven fabric by spraying. The combination of the polyvinyl pyrrolidone impregnated in the non-woven fabric enhances the heat conduction efficiency between the interface and the microcapsules, thereby achieving an improvement in the temperature-sensitive color change sensitivity of the color-changing non-woven fabric.

[0027] In the above embodiment, the non-woven fabric is a commonly used hot air non-woven fabric; the thermochromic material is an organic reversible thermochromic material commonly used in the art, including but not limited to crystal violet lactone, phenolphthalein, phenol red, methyl red, etc., which changes color by gaining or losing electrons. The color-changing microcapsules can be prepared according to the method of the document "Ji Linxian et al. Preparation of urea-formaldehyde resin microcapsules [J]. Materials Guide, 2005, 19(5):2." The color-changing microcapsules are prepared with urea-formaldehyde resin as the outer shell layer. When present alone, they can sense temperature and change color instantly. The oxidized sodium alginate on the surface of the non-woven fabric reacts with the amino groups on the capsule surface to achieve cross-linking, which can enhance the stability of the microcapsules.

[0028] In a preferred embodiment, the oxidized sodium alginate solution is prepared by mixing a sodium alginate solution with sodium periodate; and the polyvinyl pyrrolidone preferably has a molecular weight of 10,000-50,000.

[0029] In a preferred embodiment, the spraying process uses a spray gun, the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.4-0.6 MPa, and the moving speed is 20-30 cm / s; under the above conditions, the non-woven fabric has the best adhesion to the microcapsules.

[0030] The following are specific implementation examples, which are only preferred and used to verify the technical solutions and technical effects of the above embodiments. The temperature-sensitive color-changing material filled in the color-changing microcapsules used in the examples is crystal violet lactone.

[0031] Example 1

[0032] 1) Immerse a 20 cm × 20 cm, 1 mm thick ES hot air nonwoven fabric in a 1 mg / mL polyvinyl pyrrolidone solution for 6 h, and then in a 1 mg / mL oxidized sodium alginate solution for 2 h.

[0033] 2) Use a spray gun to evenly spray the mixed aqueous solution onto the surface of the impregnated non-woven fabric, wherein the mass ratio of color-changing microcapsules to polyvinyl alkoxide in the mixed aqueous solution is 1:1.3, the concentration of polyvinyl alkoxide is 5 mg / mL, and the spraying amount of the mixed solution is 400 mL; the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.5 MPa, and the moving speed is 20 cm / s; and vacuum drying is performed at 28°C for 24 h to obtain a temperature-responsive color-changing non-woven fabric.

[0034] Example 2

[0035] 1) Immerse a 20 cm × 20 cm, 1 mm thick ES hot air nonwoven fabric in a 3 mg / mL polyvinyl pyrrolidone solution for 3 h, and then in a 2 mg / mL oxidized sodium alginate solution for 1 h.

[0036] 2) Use a spray gun to evenly spray the mixed aqueous solution onto the surface of the impregnated non-woven fabric, where the mass ratio of color-changing microcapsules to polyvinyl alkoxide in the mixed aqueous solution is 1:1.4, the concentration of polyvinyl alkoxide is 3 mg / mL, and the spraying amount of the mixed solution is 600 mL; the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.6 MPa, and the moving speed is 25 cm / s; and vacuum drying is performed at 28°C for 24 h to obtain a temperature-responsive color-changing non-woven fabric.

[0037] Example 3

[0038] 1) Immerse a 20 cm × 20 cm, 1 mm thick ES hot air nonwoven fabric in a 2 mg / mL polyvinyl pyrrolidone solution for 5 h, and then in a 2 mg / mL oxidized sodium alginate solution for 1 h.

[0039] 2) Use a spray gun to evenly spray the mixed aqueous solution onto the surface of the impregnated non-woven fabric, wherein the mass ratio of color-changing microcapsules to polyvinyl alkoxide in the mixed aqueous solution is 1:1.5, the concentration of polyvinyl alkoxide is 2 mg / mL, and the spraying amount of the mixed solution is 800 mL; the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.4 MPa, and the moving speed is 30 cm / s; and vacuum drying is performed at 28°C for 24 h to obtain a temperature-responsive color-changing non-woven fabric.

[0040] Comparative Example 1

[0041] ES hot air non-woven fabric with a specification of 20cm×20cm and a thickness of 1mm was used. The mixed aqueous solution was evenly sprayed onto the surface of the impregnated non-woven fabric using a spray gun. The mass ratio of color-changing microcapsules to polyvinyl alkoxide in the mixed aqueous solution was 1:1.3, the concentration of polyvinyl alkoxide was 5mg / mL, and the spraying amount of the mixed solution was 400mL. The distance between the spray gun and the non-woven fabric was 10cm, the spraying pressure was 0.5Mpa, and the moving speed was 20cm / s. The temperature-responsive color-changing non-woven fabric was obtained by vacuum drying at 28℃ for 24h.

[0042] Comparative Example 2

[0043] 1) Immerse a 20 cm × 20 cm, 1 mm thick ES hot air nonwoven fabric in a 1 mg / mL polyvinyl pyrrolidone solution for 6 h, and then in a 1 mg / mL oxidized sodium alginate solution for 2 h.

[0044] 2) Use a spray gun to evenly spray the mixed aqueous solution onto the surface of the impregnated non-woven fabric, wherein the mass ratio of color-changing microcapsules to polyvinyl alkoxide in the mixed aqueous solution is 1:0.5, the concentration of polyvinyl alkoxide is 5 mg / mL, and the spraying amount of the mixed solution is 400 mL; the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.5 MPa, and the moving speed is 20 cm / s; and vacuum drying is performed at 28°C for 24 h to obtain a temperature-responsive color-changing non-woven fabric.

[0045] Comparative Example 3

[0046] 1) Immerse a 20 cm × 20 cm, 1 mm thick ES hot air nonwoven fabric in a 1 mg / mL oxidized sodium alginate solution for 2 h.

[0047] 2) Use a spray gun to evenly spray the mixed aqueous solution onto the surface of the impregnated non-woven fabric, wherein the mass ratio of color-changing microcapsules to polyvinyl alkoxide in the mixed aqueous solution is 1:1.3, the concentration of polyvinyl alkoxide is 5 mg / mL, and the spraying amount of the mixed solution is 400 mL; the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.5 MPa, and the moving speed is 20 cm / s; and vacuum drying is performed at 28°C for 24 h to obtain a temperature-responsive color-changing non-woven fabric.

[0048] Comparative Example 4

[0049] 1) Immerse a 20 cm × 20 cm, 1 mm thick ES hot air nonwoven fabric in a 1 mg / mL polyvinyl pyrrolidone solution for 6 h, and then in a 1 mg / mL oxidized sodium alginate solution for 2 h.

[0050] 2) Use a spray gun to evenly spray the mixed aqueous solution onto the surface of the impregnated non-woven fabric, wherein the mass ratio of color-changing microcapsules to polyvinyl alkoxide in the mixed aqueous solution is 1:1.8, the concentration of polyvinyl alkoxide is 5 mg / mL, and the spraying amount of the mixed solution is 400 mL; the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.5 MPa, and the moving speed is 20 cm / s; and vacuum drying is performed at 28°C for 24 h to obtain a temperature-responsive color-changing non-woven fabric.

[0051] Comparative Example 5

[0052] The difference from Example 1 is that the color-changing microcapsules used are made of polyurethane wall material.

[0053] Experimental example

[0054] 1) Temperature Sensitivity Test of Temperature-Responsive Color-Changing Nonwoven Fabric: At room temperature of 25°C, the material was placed on a heating table, and the interface temperature of the heating table was gradually adjusted to 38.5°C. The color change of the material surface was recorded and observed. The sensitivity and color change intensity of the temperature-responsive color-changing nonwoven fabrics prepared in Examples 1-3 and Comparative Examples 1-5 were measured by considering the time required for the nonwoven fabric to change color. The results are shown in Table 1.

[0055] 2) The test results of microcapsule loading rate in temperature-responsive color-changing non-woven fabric are shown in Table 1.

[0056] Table 1: Comparison of color change time of each embodiment and comparative example

[0057]

[0058]

[0059] It is not difficult to see from Table 1 that the temperature-responsive color-changing nonwoven fabrics prepared in Examples 1-3 can change color within 40 seconds when subjected to temperature changes, showing high sensitivity, while Comparative Examples 1-4 all have a color change time greater than 100 seconds. Specifically, the fact that Comparative Examples 1 and 3 do not use a polyvinyl alkane solution for impregnation relative to Example 1, and that the reduced amount of polyvinyl alkane in the mixed aqueous solution in Comparative Example 2 results in lower thermal conductivity and a prolonged color change time relative to Example 1, likely due to the fact that polyvinyl alkane can enhance the thermal conductivity between the interface and the microcapsules, improving color change sensitivity. However, when the amount of polyvinyl alkane in Comparative Example 4 is increased to 1:1.8, the color change time is actually prolonged, likely due to the excessively high polyvinyl alkane content, which results in an excessively long thermal path between the interface and the microcapsules.

[0060] Furthermore, as readily apparent from Table 1, Examples 1-3 exhibit high color change intensity and microcapsule loading, overcoming the prior art's drawback of using binders to increase loading but resulting in reduced sensitivity. In contrast, Comparative Example 1, which was not impregnated with the oxidized sodium alginate solution, exhibited a decreased loading, and Comparative Example 5, which used color-changing microcapsules with polyurethane walls, also exhibited a similar decrease in loading. This demonstrates that the oxidized sodium alginate impregnated nonwoven fabric interacts with the amino groups on the surface of the urea-formaldehyde resin microcapsules, thereby increasing loading.

[0061] 3) The longitudinal and transverse softness of the nonwoven fabric products were tested using the GB / T8942 test method. The test results of the softness of the temperature-responsive color-changing nonwoven fabric are shown in Table 2.

[0062] Table 2: Softness test results of temperature-responsive color-changing nonwoven fabrics

[0063] performance Example 1 Example 2 Example 3 Blank ES nonwoven fabric Transverse softness (g) 1.7 1.9 1.8 1.6 Longitudinal softness (g) 1.1 1.2 1.2 1.0

[0064] As can be seen from Table 2, the temperature-responsive color-changing nonwoven fabrics prepared by spraying in Examples 1-3 did not significantly change the softness of the ES nonwoven fabric, and met the softness requirements of sanitary products.

[0065] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and alterations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a temperature-responsive color-changing nonwoven fabric, characterized in that: The steps include: S1. The non-woven fabric is immersed in a polyvinyl pyrrolidone solution and an oxidized sodium alginate solution; S2. After the mixed solution is sprayed onto the surface of the impregnated nonwoven fabric, it is dried to obtain a temperature-responsive color-changing nonwoven fabric; the mixed solution is obtained by dispersing color-changing microcapsules in an aqueous solution of polyvinyl pyrrolidone; the color-changing microcapsules are microcapsules with urea-formaldehyde resin as the wall layer and the internal coating of a thermochromic material; In step S1, the concentration of the polyvinyl pyrrolidone solution is 1-3 mg / mL, and the immersion time is 3-6 hours; the concentration of the oxidized sodium alginate solution is 0.5-2 mg / mL, and the immersion time is 1-2 hours; In step S2, the mass ratio of the color-changing microcapsules to polyvinyl alkoxide in the mixed solution is 1:(1.3-1.5).

2. The preparation method according to claim 1, characterized in that In step S2, the concentration of the polyvinyl pyrrolidone solution is 2-5 mg / mL.

3. The preparation method according to claim 1, characterized in that In step S2, the spraying amount of the mixed solution on the non-woven fabric surface is 0.5-2 mL / cm 2 .

4. The preparation method according to claim 1, characterized in that The particle size of the color-changing microcapsules is 2-7 μm.

5. The preparation method according to claim 1, characterized in that The spraying process uses a spray gun, the distance between the spray gun and the non-woven fabric is 10 cm, the spraying pressure is 0.4-0.6 MPa, and the moving speed is 20-30 cm / s.

6. The preparation method according to claim 1, characterized in that The drying process temperature is 20-40° C., and the vacuum drying is performed for 10-24 hours.

7. The temperature-responsive color-changing nonwoven fabric obtained by the preparation method according to any one of claims 1 to 6.

8. Hygiene product, characterized in that The invention comprises the temperature-responsive color-changing nonwoven fabric according to claim 7.

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