Photocuring 3D printing transparent conductive resin as well as preparation method and application thereof

Abstract

The invention relates to the technical field of intelligent polymer materials, and particularly provides light-cured 3D printing transparent conductive resin as well as a preparation method and application thereof, and the light-cured 3D printing transparent conductive resin is prepared from a 3D printing resin base material, bis (trifluoromethanesulfonic acid) imide lithium and 2, 4, 6 (trimethylbenzoyl) diphenyl phosphine oxide; the preparation method comprises the following steps: S1, preparing modified polyurethane acrylate PEA-1; s2, preparing a 3D printing resin base material; s3, preparing 3D printing transparent conductive resin; s4, cleaning and curing; the application comprises the application of using the 3D printing transparent conductive resin as a piezoresistive sensor; the photocuring 3D printing transparent conductive resin prepared by the invention not only has good conductivity, but also has good mechanical strength; the prepared photocuring 3D printing transparent conductive resin is used as a piezoresistive sensor, the movement of a human body can be better detected by utilizing the flexibility of the resin, and the photocuring 3D printing transparent conductive resin has a good application effect.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent polymer materials, and in particular to a photocurable 3D printing transparent conductive resin, a preparation method and an application thereof. Background Art

[0002] With the increasing demand for wearable electronic devices, the research and development of flexible conductive materials is of great significance. Traditional conductive materials are mainly metal materials, but these materials do not have good toughness, and the manufacturing process of metal workpieces with more complex structures is long or cannot be produced. Photocurable polyurethane has the advantage of fast curing speed and can obtain excellent flexibility through structural design, which can meet the performance requirements of preparing flexible sensors. At the same time, with the photocuring 3D technology, very high printing accuracy can be achieved, and its printing accuracy can usually reach a layer thickness of 0.01mm. The printed model has a smooth surface and rich details. It can be used to print diversified and high-precision devices, such as pressure sensors, aviation parts, artificial tissues, etc.

[0003] However, in order to obtain a conductivity that meets actual needs, polyurethane needs to be modified for conductivity. The conventional method is to add conductive carbon black. Since its black color will affect the resin's absorption of light and affect the subsequent photocuring of the material, this will lead to a significant decrease in mechanical properties or the inability to form the device during 3D printing.

[0004] Therefore, how to prepare 3D printing transparent conductive resins with good flexibility and excellent mechanical properties remains a huge challenge. Summary of the invention

[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a photocurable 3D printing transparent conductive resin, a preparation method and its application, which are used to solve the problem in the prior art that polyurethane is modified by adding conductive carbon black and the product cannot be formed during the 3D printing process.

[0006] To achieve the above-mentioned object and other related objects, the present invention provides a photocurable 3D printing transparent conductive resin, which is composed of a 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide. The 3D printing resin base material is composed of modified polyurethane acrylate PEA-1, polyurethane acrylate BW L429, acrylate decaester, and 4-acryloylmorpholine.

[0007] In one embodiment of the present invention, the mass ratio of the 3D printing resin base material, lithium bis(trifluoromethanesulfonyl)imide, and 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide is 80-99:1-20:3.

[0008] In one embodiment of the present invention, the mass ratio of the modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaacrylate, and 4-acryloylmorpholine is 60:15:20:5.

[0009] In one embodiment of the present invention, the modified polyurethane acrylate PEA-1 is a polyetheramine branched modified polyurethane, which includes the following modification process:

[0010] In the first step, 300 g of monofunctional polyetheramine PEA (molecular weight 1000), 66.6 g of isophorone diisocyanate (IPDI) and 0.075 g of dibutyltin dilaurate (DBTDL) were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a spherical condenser; the mixture was stirred and reacted for 2 hours under a nitrogen environment at 50° C. to synthesize a polyurethane semi-finished product IPDI-PEA;

[0011] In the second step, 90 g of polytetramethylene glycol (molecular weight 2000), 39.96 g of isophorone diisocyanate and 0.028 g of dibutyltin dilaurate were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a spherical condenser, and the mixture was stirred and reacted continuously for 3 hours under a nitrogen environment at 50°C; then 6.03 g of trimethylolpropane (TMP) as a chain extender and 54.99 g of IPDI-PEA in step 1 were slowly added to the reactants, and the temperature was raised to 80°C and the reaction was continued for 3 hours; then 0.1 g of inhibitor 4-methoxyphenol was slowly added and 10.44 g of hydroxyethyl acrylate (HEA) was added dropwise, and after the addition was completed, the temperature was raised to 85°C and the stirring was continued for 4 hours to obtain modified polyurethane acrylate PEA-1.

[0012] A method for preparing a transparent conductive resin for photocuring 3D printing, for preparing the transparent conductive resin for photocuring 3D printing, characterized in that it comprises the following steps:

[0013] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0014] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0015] S3, preparing a 3D printing transparent conductive resin: compounding a 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide in a ratio of 80-99:1-20:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain a 3D printing transparent conductive resin;

[0016] S4: Cleaning and curing: LCD 3D printing technology is used to print the prepared 3D printed transparent conductive resin into a frame with micropores; the frame is cleaned and then cured for a second time to obtain a 3D printed transparent conductive resin product.

[0017] In one embodiment of the present invention, in step S3, the ultrasonic oscillation time is 5-30 minutes.

[0018] In one embodiment of the present invention, in step S3, the high-speed stirring of the composite material is performed for a dispersion time of 5-30 minutes, and a stirring speed of 1000-3000 rpm.

[0019] In one embodiment of the present invention, in step S4, the process parameters for printing a frame with micropores using the LCD 3D printing technology are as follows: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s.

[0020] An application of a photocurable 3D printed transparent conductive resin, including an application of a 3D printed transparent conductive resin product prepared by a preparation method for photocurable 3D printed transparent conductive resin as a piezoresistive sensor.

[0021] As described above, the photocurable 3D printing transparent conductive resin, preparation method and application thereof of the present invention have the following beneficial effects:

[0022] The present invention adopts a blending technology and adds lithium bis(trifluoromethanesulfonic acid) amide with high conductivity to the polyurethane acrylate system, thereby giving the polyurethane excellent conductivity and significantly improving the conductivity of the polyurethane. The present invention also adopts LCD 3D printing technology to print a photocurable 3D printed transparent conductive resin into a frame with micropores, so that the photocurable 3D printed transparent conductive resin has a high-precision complex structure and good mechanical properties, thereby enhancing the mechanical strength of the polyurethane. Compared with conventional carbon black and carbon nanotubes, the photocurable 3D printed transparent conductive resin prepared by the present invention has a transparent appearance and will not have the problem of being unable to perform photocuring due to excessive addition. The present invention applies the prepared photocurable 3D printed transparent conductive resin as a piezoresistive sensor, and utilizes the flexibility of the resin itself to better detect the movement of the human body and improve the application performance of the piezoresistive sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The appearance of the 3D printed conductive resin prepared for Examples 3-6 of the present invention and Comparative Examples 1-2.

[0024] Figure 2 The mechanical property change curve diagram of the 3D printing conductive resin prepared for Examples 3-6 of the present invention and Comparative Example 1 is shown.

[0025] Figure 3 Schematic diagram of the change in sensing performance of the piezoresistive sensor in Example 8 of the present invention.

[0026] Figure 4 Schematic diagram of the change in sensing performance of the piezoresistive sensor after multiple cycles in Example 8 of the present invention.

[0027] Figure 5 The chemical formula of the polyurethane semi-finished product IPDI-PEA obtained in the first step of the polyetheramine branched modified polyurethane in Example 1 of the present invention.

[0028] Figure 6 This is the chemical formula of the modified polyurethane acrylate PEA-1 obtained in the first step of the polyetheramine branched modified polyurethane in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0030] See also Figures 1 to 6 It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any structural modification, change in proportion or adjustment of size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0031] Example 1. This example provides a photocurable 3D printing transparent conductive resin, which is composed of a 3D printing resin base material, lithium bis(trifluoromethylsulfonic acid amide), and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide. The 3D printing resin base material is composed of modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, decaacrylate, and 4-acryloylmorpholine. The mass ratio of the 3D printing resin base material, lithium bis(trifluoromethylsulfonic acid amide), and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide is 80-99:1-20:3. The mass ratio of the modified polyurethane acrylate PEA-1, polyurethane acrylate BW L429, decaacrylate, and 4-acryloylmorpholine is 60:15:20:5. The modified polyurethane acrylate PEA-1 is a polyetheramine branched modified polyurethane, please refer to Figure 5-Figure 6, including the following modification process: the first step, adding 300 g of monofunctional polyetheramine PEA (molecular weight 1000), 66.6 g of isophorone diisocyanate (IPDI) and 0.075 g of dibutyltin dilaurate (DBTDL) into a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a spherical condenser; continuously stirring and reacting for 2 hours under a nitrogen environment at 50° C. to synthesize a polyurethane semi-finished product IPDI-PEA;

[0032] In the second step, 90 g of polytetramethylene glycol (molecular weight 2000), 39.96 g of isophorone diisocyanate and 0.028 g of dibutyltin dilaurate were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a spherical condenser, and the mixture was stirred and reacted continuously for 3 hours under a nitrogen environment at 50°C; then 6.03 g of trimethylolpropane (TMP) as a chain extender and 54.99 g of IPDI-PEA in step 1 were slowly added to the reactants, and the temperature was raised to 80°C and the reaction was continued for 3 hours; then 0.1 g of inhibitor 4-methoxyphenol was slowly added and 10.44 g of hydroxyethyl acrylate (HEA) was added dropwise, and after the addition was completed, the temperature was raised to 85°C and the stirring was continued for 4 hours to obtain modified polyurethane acrylate PEA-1.

[0033] The invention adopts the blending technology, and adds lithium bis(trifluoromethanesulfonyl)imide) with high conductivity into the polyurethane acrylate system, thereby giving the polyurethane excellent conductivity and significantly improving the conductivity of the polyurethane.

[0034] Embodiment 2: This embodiment provides a method for preparing a photocurable 3D printing transparent conductive resin, which is used to prepare the photocurable 3D printing transparent conductive resin described in Embodiment 1, comprising the following steps:

[0035] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0036] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0037] S3, preparing a 3D printing transparent conductive resin: compounding a 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide in a ratio of 80-99:1-20:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain a 3D printing transparent conductive resin; the ultrasonic oscillation time is 5-30 min, the high-speed stirring compound is dispersed for 5-30 min, and the stirring speed is 1000-3000 rpm;

[0038] S4: Cleaning and curing: LCD 3D printing technology is used to set the process parameters for printing a frame with micropores: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s. The prepared 3D printed transparent conductive resin is printed into a frame with micropores; after the frame is cleaned and cured for a second time, a 3D printed transparent conductive resin product can be obtained.

[0039] The present invention also uses LCD 3D printing technology to print the photocurable 3D printed transparent conductive resin into a frame with micropores, so that the photocurable 3D printed transparent conductive resin has a high-precision complex structure and good mechanical properties, thereby enhancing the mechanical strength of polyurethane.

[0040] Example 3, based on Example 2, this example provides a method for preparing a photocurable 3D printing transparent conductive resin, which is used to prepare the photocurable 3D printing transparent conductive resin, comprising the following steps:

[0041] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0042] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0043] S3, preparing a 3D printing transparent conductive resin: compounding a 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide in a ratio of 99:1:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain a 3D printing transparent conductive resin; the ultrasonic oscillation time is 5 minutes, the high-speed stirring time for dispersing the compound is 5 minutes, and the stirring speed is 1000 rpm;

[0044] S4: Cleaning and curing: LCD 3D printing technology is used to set the process parameters for printing a frame with micropores: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s. The prepared 3D printed transparent conductive resin is printed into a frame with micropores; after the frame is cleaned and cured for a second time, a 3D printed transparent conductive resin product can be obtained.

[0045] Example 4, based on Example 2, this example provides a method for preparing a photocurable 3D printing transparent conductive resin, which is used to prepare the photocurable 3D printing transparent conductive resin, comprising the following steps:

[0046] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0047] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0048] S3. Preparation of 3D printing transparent conductive resin: Compounding 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide in a ratio of 95:5:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain 3D printing transparent conductive resin; the ultrasonic oscillation time is 15 minutes, the high-speed stirring time for dispersing the compound is 15 minutes, and the stirring speed is 2000 rpm;

[0049] S4: Cleaning and curing: LCD 3D printing technology is used to set the process parameters for printing a frame with micropores: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s. The prepared 3D printed transparent conductive resin is printed into a frame with micropores; after the frame is cleaned and cured for a second time, a 3D printed transparent conductive resin product can be obtained.

[0050] Example 5, based on Example 2, this example provides a method for preparing a photocurable 3D printing transparent conductive resin, which is used to prepare the photocurable 3D printing transparent conductive resin, comprising the following steps:

[0051] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0052] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0053] S3, preparing a transparent conductive resin for 3D printing: compounding a 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide in a ratio of 90:10:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain a transparent conductive resin for 3D printing; the ultrasonic oscillation time is 15 minutes, the high-speed stirring time for dispersing the compound is 15 minutes, and the stirring speed is 2000 rpm;

[0054] S4: Cleaning and curing: LCD 3D printing technology is used to set the process parameters for printing a frame with micropores: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s. The prepared 3D printed transparent conductive resin is printed into a frame with micropores; after the frame is cleaned and cured for a second time, a 3D printed transparent conductive resin product can be obtained.

[0055] Example 6, based on Example 2, this example provides a method for preparing a photocurable 3D printing transparent conductive resin, which is used to prepare the photocurable 3D printing transparent conductive resin, comprising the following steps:

[0056] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0057] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0058] S3. Preparation of 3D printing transparent conductive resin: Compounding 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide in a ratio of 80:20:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain 3D printing transparent conductive resin; the ultrasonic oscillation time is 30 minutes, the high-speed stirring compound is dispersed for 30 minutes, and the stirring speed is 3000 rpm;

[0059] S4: Cleaning and curing: LCD 3D printing technology is used to set the process parameters for printing a frame with micropores: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s. The prepared 3D printed transparent conductive resin is printed into a frame with micropores; after the frame is cleaned and cured for a second time, a 3D printed transparent conductive resin product can be obtained.

[0060] Comparative Example 1: This comparative example provides a transparent conductive resin for photocuring 3D printing, and the preparation method thereof comprises the following steps:

[0061] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0062] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0063] S3, preparing a 3D printing transparent conductive resin: compounding a 3D printing resin base material and 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide in a ratio of 100:3, and dispersing the composite material by high-speed stirring after ultrasonic oscillation to obtain a 3D printing transparent conductive resin; the ultrasonic oscillation time is 15 minutes, the high-speed stirring time for dispersing the composite material is 15 minutes, and the stirring speed is 2000 rpm;

[0064] S4: Cleaning and curing: LCD 3D printing technology is used to set the process parameters for printing a frame with micropores: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s. The prepared 3D printed transparent conductive resin is printed into a frame with micropores; after the frame is cleaned and cured for a second time, a 3D printed transparent conductive resin product can be obtained.

[0065] In this embodiment, lithium bis(trifluoromethanesulfonic acid) amide is removed, and lithium bis(trifluoromethanesulfonic acid) amide is the key to the conductivity of the transparent conductive resin of photocurable 3D printing. Therefore, the 3D printed transparent conductive resin product prepared by the above method does not have conductivity.

[0066] Comparative Example 2, a transparent conductive resin for photocuring 3D printing, the preparation method of which comprises the following steps:

[0067] S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1;

[0068] S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material;

[0069] S3. Preparation of 3D printing transparent conductive resin: Compounding 3D printing resin base material, conductive carbon black and 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide in a ratio of 95:5:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain 3D printing transparent conductive resin; the ultrasonic oscillation time is 15 minutes, the high-speed stirring time for dispersing the compound is 15 minutes, and the stirring speed is 2000 rpm;

[0070] S4: Cleaning and curing: LCD 3D printing technology is used to set the process parameters for printing a frame with micropores: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s. The prepared 3D printed transparent conductive resin is printed into a frame with micropores; after the frame is cleaned and cured for a second time, a 3D printed transparent conductive resin product can be obtained.

[0071] In this embodiment, conductive carbon black is used instead of lithium bis(trifluoromethanesulfonyl)amide. Although the obtained light-cured 3D printing transparent conductive resin has conductivity, the structure of the conductive carbon black is relatively loose. The light-cured 3D printing transparent conductive resin with conductive carbon black added cannot be completely formed during the printing process using the above method.

[0072] Example 7: This example provides a detection method for detecting the properties of Examples 3-6 and the prepared light-cured 3D printing conductive resin. Figure 1 , Figure 1 The appearance photos of the photocurable 3D printing conductive resins prepared in Examples 3-6 of the present invention and Comparative Examples 1-2 show that the appearance of Examples 3-4 and Comparative Example 1 is basically transparent, the appearance of Examples 5-6 is slightly foggy but does not affect light transmission, and the appearance of Comparative Example 2 is black, which is not conducive to photocurable 3D printing.

[0073] Please refer to the attached Figure 2 , Figure 2 The graphs are graphs showing the changes in mechanical properties caused by gradually adding lithium salts to the photocurable 3D printing transparent conductive resins obtained in Examples 3-6 of the present invention and Comparative Example 1, wherein a is the mechanical properties change curve of Comparative Example 1; b is the mechanical properties change curve of Example 3; c is the mechanical properties change curve of Example 4; d is the mechanical properties change curve of Example 5; and e is the mechanical properties change curve of Example 6. It can be seen from the above graphs that the addition of vector lithium salts at the beginning enhances the ionic force inside the resin and improves the mechanical properties of the resin to a certain extent; when too much lithium salt is added, the compatibility of lithium salts with the photocurable 3D printing transparent conductive resin deteriorates, forming defects inside the resin, resulting in a decrease in mechanical properties.

[0074] Therefore, compared with the conventional photocurable 3D printing conductive resin with conductive carbon black added, the photocurable 3D printing transparent conductive resin prepared by the present invention has a transparent appearance and will not cause the problem of being unable to perform photocuring due to excessive addition.

[0075] Example 8, this example provides an application of a photocurable 3D printed transparent conductive resin, including the application of the 3D printed transparent conductive resin product prepared in Example 2 as a piezoresistive sensor, which utilizes the flexibility of the resin itself to better detect the movement of the human body and improve the application performance of the piezoresistive sensor. Figure 3 , Figure 3 This is a schematic diagram of the change in the sensing performance of a 3D printed transparent conductive resin product printed using 3D printing technology in Example 4 of the present invention. Figure 3 It can be seen that when the piezoresistive sensor is compressed, its electrochemical signal changes with the pressure, so the piezoresistive sensor can identify different pressures. Figure 4 ,Depend on Figure 4 It can be seen that the piezoresistive sensor has good stability within 150 cycles.

[0076] In summary, the present invention adds lithium bis(trifluoromethanesulfonic acid) imide to the polyurethane acrylate system, and uses LCD 3D printing technology to print and shape the photocurable 3D printed transparent conductive resin, so that the photocurable 3D printed transparent conductive resin not only has good conductivity but also has good mechanical strength; the present invention uses the prepared photocurable 3D printed transparent conductive resin as a piezoresistive sensor, and utilizes the flexibility of the resin itself to better detect the movement of the human body, improve the application performance of the piezoresistive sensor, and thus has a good application effect. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A photocurable 3D printing transparent conductive resin, characterized in that: The invention is composed of a 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide. The 3D printing resin base material is composed of modified polyurethane acrylate PEA-1, polyurethane acrylate BW L429, acrylate decaester, and 4-acryloylmorpholine.

2. The light-cured 3D printing transparent conductive resin according to claim 1, characterized in that: The mass ratio of the 3D printing resin base material, lithium bis(trifluoromethylsulfonyl)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide is 80-99:1-20:

3.

3. The light-cured 3D printing transparent conductive resin according to claim 1, characterized in that: The mass ratio of the modified polyurethane acrylate PEA-1, polyurethane acrylate BW L429, acrylate decaacrylate and 4-acryloylmorpholine is 60:15:20:

5.

4. The light-cured 3D printing transparent conductive resin according to claim 1, characterized in that: The modified polyurethane acrylate PEA-1 is a polyetheramine branched modified polyurethane, which includes the following modification process: In the first step, 300 g of monofunctional polyetheramine PEA (molecular weight 1000), 66.6 g of isophorone diisocyanate (IPDI) and 0.075 g of dibutyltin dilaurate (DBTDL) were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a spherical condenser; the mixture was stirred and reacted for 2 hours under a nitrogen environment at 50° C. to synthesize a polyurethane semi-finished product IPDI-PEA; In the second step, 90 g of polytetramethylene glycol (molecular weight 2000), 39.96 g of isophorone diisocyanate and 0.028 g of dibutyltin dilaurate were added to a three-necked round-bottom flask equipped with a mechanical stirrer, a thermometer and a spherical condenser, and the mixture was stirred and reacted continuously for 3 hours under a nitrogen environment at 50°C; then 6.03 g of trimethylolpropane (TMP) as a chain extender and 54.99 g of IPDI-PEA in step 1 were slowly added to the reactants, and the temperature was raised to 80°C, and the reaction was continued for 3 hours; then 0.1 g of inhibitor 4-methoxyphenol was slowly added and 10.44 g of hydroxyethyl acrylate (HEA) was added dropwise, and after the addition was completed, the temperature was raised to 85°C and stirred for 4 hours to obtain modified polyurethane acrylate PEA-1.

5. A method for preparing a photocurable 3D printing transparent conductive resin, for preparing the photocurable 3D printing transparent conductive resin according to any one of claims 1 to 4, characterized in that: The steps include: S1. Preparation of modified polyurethane acrylate PEA-1: using polyetheramine side chains to modify polyurethane to obtain modified polyurethane acrylate PEA-1; S2. Preparing a 3D printing resin base material: Compounding modified polyurethane acrylate PEA-1, polyurethane acrylate BWL429, acrylate decaester, and 4-acryloylmorpholine in a mass ratio of 60:15:20:5 to prepare a 3D printing resin base material; S3, preparing a 3D printing transparent conductive resin: compounding a 3D printing resin base material, lithium bis(trifluoromethanesulfonic acid)imide, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide in a ratio of 80-99:1-20:3, and dispersing the compound by high-speed stirring after ultrasonic oscillation to obtain a 3D printing transparent conductive resin; S4: Cleaning and curing: LCD 3D printing technology is used to print the prepared 3D printed transparent conductive resin into a frame with micropores; the frame is cleaned and then cured for a second time to obtain a 3D printed transparent conductive resin product.

6. The method for preparing a transparent conductive resin for photocuring 3D printing according to claim 5, characterized in that: In step S3, the ultrasonic oscillation time is 5-30 min.

7. The method for preparing a transparent conductive resin for photocuring 3D printing according to claim 6, characterized in that: In step S3, the high-speed stirring of the composite material is performed for a dispersion time of 5-30 minutes and a stirring speed of 1000-3000 rpm.

8. The method for preparing a transparent conductive resin for photocuring 3D printing according to claim 5, characterized in that: In step S4, the process parameters for printing the frame with micropores using the LCD 3D printing technology are as follows: the single-layer printing thickness of the frame is 0.5 mm, the single-layer curing time is 5 s, and the bottom layer curing time is 15 s.

9. An application of photocurable 3D printing transparent conductive resin, characterized in that: The invention relates to an application of a 3D printed transparent conductive resin product prepared by the preparation method for photocuring 3D printed transparent conductive resin as described in any one of claims 5 to 8 as a piezoresistive sensor.

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