Conductive silver paste for electronic mask and preparation method and application thereof

Abstract

The invention discloses conductive silver paste for an electronic mask and a preparation method and application of the conductive silver paste, and the preparation method of the conductive silver paste comprises the following steps: S1, at 50-100 DEG C, mixing bonding phase polylactic acid and polyurethane resin according to a mass ratio of (70-90): (10-30), and dissolving in a solvent; s2, dissolving an anti-settling additive in a solvent, and stirring to obtain mixed resin; and S3, adding the silver powder into the mixed resin, sequentially adding the thickening agent and the coupling agent, mixing, and stirring the mixture to obtain the conductive silver paste. The electronic mask prepared from the conductive silver paste has good toughness and micro-current stability.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive silver paste, and in particular to a conductive silver paste for electronic facial mask and a preparation method and application thereof. Background Art

[0002] Facial masks are mainly used to hydrate facial skin, and their high permeability makes them moisturizing, nourishing, deep cleansing and other functions. Electronic masks are a method of using electronic technology to introduce microcurrents into the deep layers of the skin for conditioning and repair. They are generally wearable products formed by laying circuits on masks through printing processes. According to care needs, electronic masks must be able to achieve deformation resistance and fracture resistance, so high requirements are placed on printing materials. Currently, the commonly used printed conductive material is silver paste. Conductive silver paste has the advantages of fast conductivity, precise resistance control, and easy printing and molding. It can be used as a printing material for electronic masks. Conductive silver paste is composed of high-purity silver powder, resin adhesive, solvent, dispersant and additives. It can be directly used for screen printing or coating, and solidified at a certain temperature to form a paste or paste with conductive function. According to the high and low curing temperature, conductive silver paste can be divided into high-temperature sintering conductive silver paste, medium-temperature sintering conductive silver paste and low-temperature curing conductive silver paste. High-temperature sintering silver paste can print the paste on high-temperature resistant substrates such as ceramics. After high-temperature sintering and solvent volatilization, it adheres to the substrate to form a conductive film layer. This type of silver paste is mostly used on solar cell electrodes. The sintering temperature of medium-temperature sintering conductive silver paste is generally 200℃-300℃, and it is mainly used on glass or some ceramic substrates. The curing temperature of low-temperature curing conductive silver paste is generally less than 200℃. Because this type of silver paste has a low curing temperature and causes less destructive damage to the substrate, it is suitable for printing on flexible substrates and making flexible circuits. The conductive silver paste used for electronic masks needs to use low-temperature curing silver paste.

[0003] After searching, Chinese patent document CN117747171A discloses a conductive silver paste for electronic facial mask, which includes the following raw materials by weight: 30-50 parts of silver powder, 5-10 parts of polymer resin system, 30-50 parts of solvent and 1-10 parts of auxiliary agent, wherein the polymer resin system includes epoxy resin, polyester resin and bio-based resin, and the mass ratio of epoxy resin, polyester resin and bio-based resin is 1: (2-4): (2-4). The polyester resin is a bio-based unsaturated polyester resin with a glass transition temperature of 110-130°C, a storage modulus of 3000-3500MPa and a tensile strength of 70-80MPa; and the bio-based resin is a high temperature resistant bio-based epoxy resin with a glass transition temperature of 110-130°C, a storage modulus of 3000-3500MPa and an elongation at break of ≥700%.

[0004] Chinese patent document CN114864132A discloses a low-temperature quick-drying facial mask silver paste for gravure printing, which is composed of the following components in the following mass ratio: 30-50wt% flaky silver powder, 40-60wt% organic solvent, 5-10wt% polymer resin and 1-5wt% functional additive, wherein the polymer resin is at least one of chloroacetic acid CP450, chloroacetic acid VAGH-004, polyvinyl butyral SV-16, polyvinyl butyral TB-17, acrylic acid BR113, acrylic acid SGR-3002W, phenoxy PKHH and phenoxy PKHB resins.

[0005] It can be seen that in the prior art, there is no conductive silver paste for electronic facial mask prepared with polylactic acid as the main raw material. Polylactic acid PLA is a biodegradable material that can be made from starch raw materials from renewable plant resources (such as corn). Polylactic acid has good biodegradability. However, the toughness and impact resistance of polylactic acid are poor, and it is difficult to form a good and qualified electronic facial mask.

[0006] To this end, the inventor conducted in-depth research and development, thus resulting in the present invention. Summary of the invention

[0007] In view of this, in order to solve the above-mentioned technical problems, the purpose of the present invention is to propose a conductive silver paste for electronic facial mask and a preparation method and application thereof, so that the electronic facial mask produced has good toughness and microcurrent stability.

[0008] The technical solutions adopted are:

[0009] A method for preparing a conductive silver paste for an electronic facial mask of the present invention comprises the following steps:

[0010] S1. At 50-100 ° C, the adhesive phase polylactic acid and polyurethane resin mass ratio (70-90): (10-30) mixed and dissolved in a solvent;

[0011] S2. The anti-settling additive is dissolved in a solvent and stirred to obtain a mixed resin;

[0012] S3. Add silver powder to the mixed resin, then add a thickener and a coupling agent in sequence to mix, and then stir the mixture to obtain a conductive silver paste.

[0013] Furthermore, in step S1, the solvent is one or more of dibasic acid ester, N,N-dimethylformamide, N,N-dimethylacetamide, hexafluoroisopropanol and ethanol.

[0014] Furthermore, in step S2, the anti-settling additive is one or more of polyamide, CX-108 and EM-610.

[0015] Furthermore, in step S3, the thickener is carboxymethyl cellulose or fumed silica; and / or the coupling agent is one or both of KH550 and KH560.

[0016] Furthermore, the mass content of the adhesive phase polylactic acid and polyurethane resin in the conductive silver paste is 8%-12%; the mass content of the solvent in the conductive silver paste is 38-42%; the mass content of the anti-settling additive in the conductive silver paste is 0.8%-1.2%; the mass content of the silver powder in the conductive silver paste is 43%-47%; the mass content of the thickener and coupling agent in the conductive silver paste is 3%-5%.

[0017] Furthermore, the mass ratio of the thickener to the coupling agent is 1:1-2.

[0018] Furthermore, in step S3, the mixture is transferred to a planetary mixer for stirring, and the program is set to rotate and revolve for 10-30 minutes, a speed of 2000-25000 r / min, and vacuum degassing for 10-30 minutes to mix the mixture evenly.

[0019] Wherein in step S1, the temperature is 50-100°C, preferably 60-90°C, such as 60°C, 70°C, 80°C or 90°C.

[0020] The mass ratio of the polylactic acid and polyurethane resin in the adhesive phase is (70-90):(10-30), and the adhesive phase is composed of polylactic acid and polyurethane resin. The mass ratio of polylactic acid and polyurethane resin can be, for example, 90:10, 80:20, 70:30, etc.

[0021] The conductive silver paste for electronic facial mask of the present invention is prepared by the preparation method described in any of the above schemes.

[0022] The conductive silver paste of the present invention is used in preparing electronic facial masks.

[0023] A method for preparing an electronic facial mask of the present invention comprises the method for preparing the conductive silver paste described in any of the above schemes, and further comprises the following steps:

[0024] S4. Print the conductive silver paste on the non-woven fabric using screen printing technology, and the printed pattern evenly covers the entire non-woven fabric;

[0025] S5. Place the nonwoven printed with the conductive silver paste in an oven and cure it to obtain an electronic mask.

[0026] The electronic facial mask of the present invention is prepared by the above-mentioned method for preparing the electronic facial mask.

[0027] The resin phase of the conductive silver paste of the present invention adopts polylactic acid. The raw material of polylactic acid can be obtained by fermentation of crops, and the final decomposition product can be returned to the plant. The reaction equation for preparing polylactic acid can be expressed as:

[0028]

[0029] Polylactic acid has good thermal stability and mechanical strength, and excellent biocompatibility. It has been widely used in tableware, clothing, drug sustained release and biomedical fields. Its monomer lactic acid has two optical isomers, as shown in the following formula (1) and formula (2), so polylactic acid has three stereo structures: poly-levorotatory, poly-dextrorotatory and poly-racemic. This structure makes polylactic acid have strong tensile strength and good mechanical properties, but its toughness and impact resistance are relatively poor.

[0030]

[0031] To this end, the present invention uses polylactic acid as the base resin and modifies it by adding polyurethane resin TPU to prepare a conductive silver paste with excellent performance. When used in electronic masks, it has good toughness and micro-current stability. Among them, the polyurethane resin TPU plays a toughening role, improving the toughness and impact resistance of polylactic acid.

[0032] In summary, the beneficial effects of the present invention are:

[0033] The electronic facial mask produced by the invention has good toughness and micro-current stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The following is a brief description of the accompanying drawings:

[0035] Figure 1 This is the experimental picture in step (6) of Example 1; Figure 1 a is a photo of an electronic mask after printing conductive silver paste on non-woven fabric using screen printing technology; Figure 1 b is the printed pattern.

[0036] Figure 2 This is a photo of the local pattern on the electronic mask after the conductive silver paste is cured; Figure 2 a is a photo of the local pattern after the conductive silver paste is cured before the electronic mask is stretched; Figure 2 b is a photo of the local pattern after the conductive silver paste of the electronic mask was stretched and cured.

[0037] Figure 3 This is a graph showing the experimental results of testing 8 lines in the pattern printed on the electronic mask; Figure 3 a is a bar graph of the resistance test results of the electronic mask before and after stretching; Figure 3 b is a graph of the resistance change rate of the electronic mask before and after stretching. DETAILED DESCRIPTION

[0038] The present invention is described in detail below through specific examples, but the use and purpose of these exemplary embodiments are only used to illustrate the present invention, and do not constitute any form of limitation on the actual protection scope of the present invention, and do not limit the protection scope of the present invention to these.

[0039] Unless otherwise specified, the experimental materials and experimental equipment used in the following examples and comparative examples can be obtained from commercial sources.

[0040] Example 1

[0041] A method for preparing an electronic facial mask in this embodiment comprises the following steps:

[0042] (1) At 80° C., a bonding phase of polylactic acid and a polyurethane resin TPU are mixed in a certain mass ratio of 80:20 and dissolved in a solvent of N,N-dimethylformamide, wherein the mass contents of the bonding phase and the solvent in the conductive silver paste are 10% and 40%, respectively.

[0043] (2) Dissolving the anti-settling additive polyamide in a solvent, wherein the anti-settling additive accounts for 1% of the conductive silver paste by mass, and then putting the solvent into a planetary mixer for stirring to obtain a mixed resin.

[0044] (3) Add silver powder to the mixed resin, the silver powder accounting for 45% of the conductive silver paste by weight; then add thickener carboxymethyl cellulose and coupling agent KH550 in sequence and mix. The thickener and coupling agent together account for 4% of the conductive silver paste by weight.

[0045] (4) The mixture was transferred to a planetary mixer again and the program was set to rotate for 10 min, rotate at 2000 r / min, and vacuum degassing for 10 min.

[0046] (5) After uniform mixing, the conductive silver paste can be obtained.

[0047] (6) Use screen printing technology to print the conductive silver paste on non-woven fabrics (such as Figure 1 a), the printed pattern is as shown in Figure 1 As shown in b, the printed pattern can evenly cover the entire non-woven fabric.

[0048] (7) The nonwoven printed with the electronic silver paste is placed in an oven and cured at 100° C. for 30 min to obtain an electronic facial mask.

[0049] Example 2

[0050] Referring to Example 1, the difference from Example 1 is that in step (1) of this Example 1, the adhesive phase polylactic acid and the polyurethane resin TPU are mixed in a certain mass ratio of 90:10, and the remaining steps are the same as Example 1.

[0051] Example 3

[0052] Referring to Example 1, the difference from Example 1 is that in step (1) of this Example 1, the adhesive phase polylactic acid and the polyurethane resin TPU are mixed in a certain mass ratio of 70:30, and the remaining steps are the same as Example 1.

[0053] Comparative Example 1

[0054] Referring to Example 1, the difference from Example 1 is that in step (1) of this comparative example 1, the bonding phase only contains polylactic acid and no polyurethane resin TPU. The mass content of polylactic acid in the conductive silver paste is 50%, and the remaining steps are the same as Example 1.

[0055] test:

[0056] 1. The conductive silver paste prepared in step (5) of Example 1-3 was tested using a rotational viscometer, and its viscosity was measured to be 9000-11000 Pa.s.

[0057] 2. The adhesion test experiment was carried out on the conductive silver paste on the mask after curing of Examples 1-3. The adhesion of the conductive silver paste on the mask reached 4B grade. The test method and analysis results refer to the document "GB / T9286-1998 Cross-cut test for paint and varnish films".

[0058] 3. After curing the conductive silver paste on the electronic mask of Example 1, the local pattern is as follows Figure 2 As shown in a, it can be seen from the figure that the formed circuit is uniform and regular, and the morphology of the mask after stretching is as follows Figure 2 As shown in b, the conductive silver paste shows continuity and integrity, and there is no obvious breakage or loss, which reflects the good toughness of the conductive silver paste.

[0059] 4. After curing, the electronic mask of Example 1 was subjected to a resistance test on 8 lines in the printed pattern on the electronic mask. The test results are as follows: Figure 3 As shown in a, the mask has stable resistance before and after stretching, indicating that a stable microcurrent can be generated in the mask. After stretching, the resistance of each circuit increases. This is because the stretching process increases the distance between the conductive particles in the conductive silver paste, increasing the resistance to charge transfer and the difficulty of the tunneling effect. However, the adhesive phase in the conductive silver paste has high toughness, so although the resistance increases after stretching, the resistance change rate is less than 17% (as shown in FIG. Figure 3 b).

[0060] 5. The electronic mask of comparative example 1 was tested. Before stretching, the electronic mask of comparative example 1 was conductive. After stretching, obvious fractures and missing parts appeared, indicating that the electronic mask was not conductive.

[0061] Comparing Example 1 with Comparative Example 1, it is shown that the polyurethane resin TPU improves the toughness of the electronic mask, so that the electronic mask still has good conductivity after stretching, so that the produced electronic mask has good toughness and microcurrent stability.

[0062] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a conductive silver paste for an electronic facial mask, characterized in that: The steps include: S1. At 50-100 ° C, the adhesive phase polylactic acid and polyurethane resin mass ratio (70-90): (10-30) mixed and dissolved in a solvent; S2. The anti-settling additive is dissolved in a solvent and stirred to obtain a mixed resin; S3. Add silver powder to the mixed resin, then add a thickener and a coupling agent in sequence to mix, and then stir the mixture to obtain a conductive silver paste.

2. The method for preparing the conductive silver paste for the electronic mask according to claim 1, characterized in that: In step S1, the solvent is one or more of dibasic acid ester, N,N-dimethylformamide, N,N-dimethylacetamide, hexafluoroisopropanol and ethanol.

3. The method for preparing the conductive silver paste for the electronic mask according to claim 1, characterized in that: In step S2, the anti-settling additive is one or more of polyamide, CX-108 and EM-610.

4. The method for preparing the conductive silver paste for the electronic mask according to claim 1, characterized in that: In step S3, the thickener is carboxymethyl cellulose or fumed silica; and / or the coupling agent is one or both of KH550 and KH560.

5. The method for preparing the conductive silver paste for electronic mask according to claim 1, characterized in that: The mass content of the adhesive phase polylactic acid and polyurethane resin in the conductive silver paste is 8%-12%; the mass content of the solvent in the conductive silver paste is 38%-42%; the mass content of the anti-settling additive in the conductive silver paste is 0.8%-1.2%; the mass content of the silver powder in the conductive silver paste is 43%-47%; the mass content of the thickener and the coupling agent in the conductive silver paste is 3%-5%.

6. The method for preparing the conductive silver paste for electronic mask according to claim 1, characterized in that: In step S3, the mixture is transferred to a planetary mixer for stirring, and the program is set to rotate and revolve for 10-30 minutes, a speed of 2000-25000 r / min, and vacuum degassing for 10-30 minutes to mix the mixture evenly.

7. A conductive silver paste for electronic facial mask, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 6.

8. Use of the conductive silver paste according to claim 7 in the preparation of electronic facial masks.

9. A method for preparing an electronic facial mask, characterized in that: The method of claim 1 further comprising the following steps: S4. Print the conductive silver paste on the non-woven fabric using screen printing technology, and the printed pattern evenly covers the entire non-woven fabric; S5. Place the nonwoven printed with the conductive silver paste in an oven and cure it to obtain an electronic mask.

10. An electronic facial mask, characterized in that: The invention is prepared by the preparation method according to claim 9.

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