Method for preparing printable ink with linear temperature response

Abstract

The present invention is a method for preparing a printable ink with a linear temperature response, and the specific steps are: dissolving N-isopropylacrylamide monomer, adding an initiator to prepare a poly-N-isopropylacrylamide solution; performing an oxygen plasma modification treatment on a two-component carbon nanomaterial; adding a dispersant and performing a homogenization treatment; adding an aqueous resin, a leveling agent and a desiccant to prepare an ink base; mixing and stirring the poly-N-isopropylacrylamide solution and the ink base; mechanically stirring and ultrasonically treating after adding an ion solution; centrifugal degassing to prepare a preliminary ink product; filtering and removing impurities to obtain a printable ink with a linear temperature response. The present invention performs a composite regulation on the linear temperature response of the ink by adding a multiphase carbon nanomaterial and doping with a sodium chloride solution, thereby enhancing the stability of the linear response; and by introducing a poly-N-isopropylacrylamide thermosensitive polymer, an optimization effect of a linear response of the ink to temperature is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of printable composite material ink, and in particular to a method for preparing printable ink with linear temperature response. Background Art

[0002] With the rapid development of the Internet of Things and intelligent online monitoring equipment, the demand for functional inks is increasing, especially intelligent inks with linear ambient temperature response. At present, there are some temperature-responsive inks on the market, but there are still many limitations. For example, the temperature response range of the ink is narrow, the ink's own conductivity changes nonlinearly respond to changes in ambient temperature, and the printability of the prepared ink is poor, making it difficult to achieve uniform coating on the substrate.

[0003] At present, printable temperature-responsive inks are mainly prepared by relying on the response of the electrical conductivity of carbon nanomaterials (carbon black, carbon nanotubes, graphene) to temperature changes. The principle is based on the sensitivity of the electrical properties of carbon nanomaterials to temperature changes and the thermal expansion of carbon nanomaterials when heated, which leads to tiny structural changes and affects the electrical properties. Temperature-responsive inks are mainly prepared by using a single-component carbon nanomaterial mixed with a resin.

[0004] However, when using a single-component carbon nanomaterial to prepare ink, it is difficult to achieve a linear temperature response due to poor dispersion technology, thermal expansion of the carbon nanomaterial and the thermal expansion of the matrix material, which will produce a sudden change in temperature response. Therefore, it is necessary to regulate the components and ratio of the carbon nanomaterial to make it have good linear response, stability and wide applicability. Summary of the invention

[0005] The present invention aims to solve the deficiencies of the prior art and provides a method for preparing a printable ink having a linear temperature response.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing a printable ink having a linear temperature response, comprising the following steps:

[0008] S1, dissolving N-isopropylacrylamide monomer in water, adding initiator, heating to 60-70° C. under nitrogen environment protection, stirring and reacting for 4-6 hours to obtain poly N-isopropylacrylamide solution;

[0009] S2, performing oxygen plasma modification treatment on the two-component carbon nanomaterial for 5 minutes;

[0010] S3, mixing the two-component carbon nanomaterial after oxygen plasma modification with the dispersant in a mass ratio of 1:1, adding into water, and stirring with a homogenizer, maintaining the temperature at 20° C., the speed of the homogenizer at 8000 rpm, and the total treatment time for 6 hours;

[0011] S4, adding water-based resin, leveling agent and desiccant, mixing evenly, to obtain ink base material;

[0012] S5, slowly adding the poly (N-isopropylacrylamide) solution obtained in step S1 to the ink base material obtained in step S4, and mechanically stirring until uniform, at a rotation speed of 600 rpm; wherein the weight ratio of poly (N-isopropylacrylamide) to the ink base material is 1:10;

[0013] S6. Add the ion solution to the liquid obtained in step S5, and perform mechanical stirring. The mechanical stirring speed is maintained at 800-1000 rpm. After stirring for 3 hours, continue to perform ultrasonic treatment. The temperature is maintained at 10° C., the ultrasonic power is 1200 W, the ultrasonic on time is 1 second, the ultrasonic off time is 2 seconds, and the total ultrasonic treatment time is 4 hours.

[0014] S7, centrifugally degas the liquid obtained in step S6 for 3 minutes to obtain a preliminary ink product;

[0015] S8. Filter the ink obtained in step S7 with a 200-mesh filter to remove impurities, and finally obtain a printable ink with a linear temperature response.

[0016] The initiator in step S1 is ammonium persulfate.

[0017] The two-component carbon nanomaterial in step S2 is a combination of any two of carbon nanotubes, graphene and carbon black.

[0018] The dispersant in step S3 is sodium dodecylbenzene sulfonate or polyvinyl pyrrolidone.

[0019] The leveling agent in step S4 is an acrylic leveling agent.

[0020] The desiccant in step S4 is an oxidizing desiccant.

[0021] The ion solution in step S6 is a sodium chloride solution.

[0022] The beneficial effects of the present invention are as follows: the present invention performs composite regulation on the linear temperature response of ink by adding multiphase carbon nanomaterials and doping with sodium chloride solution, thereby enhancing the stability of the linear response; by introducing poly (N-isopropylacrylamide) thermosensitive polymer, an optimization effect of the ink presenting a linear response to temperature is achieved; and by reasonable preparation steps, including heating to prepare a poly (N-isopropylacrylamide) solution under a nitrogen environment, oxygen plasma modification treatment, dispersion mixing, combination of mechanical stirring and ultrasonic stirring, centrifugal degassing and filtering, etc., the oxygen plasma modification treatment obtained has better linear temperature response performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flowchart of the specific steps of the method of the present invention;

[0024] Figure 2 is a resistance-temperature response diagram of the printable ink with linear temperature response obtained in the comparative example;

[0025] Figure 3 is a resistance-temperature response graph of the printable ink with linear temperature response obtained in specific example 1;

[0026] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0027] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0030] A method for preparing a printable ink having a linear temperature response, such as Figure 1 As shown, the specific steps are:

[0031] S1, dissolving N-isopropylacrylamide monomer in water, adding initiator, heating to 60-70° C. under nitrogen environment protection, stirring and reacting for 4-6 hours to obtain poly N-isopropylacrylamide solution;

[0032] The initiator is ammonium persulfate;

[0033] S2, performing oxygen plasma modification treatment on the two-component carbon nanomaterial for 5 minutes;

[0034] The two-component carbon nanomaterial is a combination of any two of carbon nanotubes, graphene and carbon black;

[0035] S3, mixing the two-component carbon nanomaterial after oxygen plasma modification with the dispersant in a mass ratio of 1:1, adding into water, and stirring with a homogenizer, maintaining the temperature at 20° C., the speed of the homogenizer at 8000 rpm, and the total treatment time for 6 hours;

[0036] The dispersant is sodium dodecylbenzene sulfonate or polyvinyl pyrrolidone;

[0037] S4, adding water-based resin, leveling agent and desiccant, mixing evenly, to obtain ink base material;

[0038] The leveling agent is an acrylic leveling agent; the desiccant is an oxidizing desiccant;

[0039] S5, slowly adding the poly (N-isopropylacrylamide) solution obtained in step S1 to the ink base material obtained in step S4, and mechanically stirring until uniform, at a rotation speed of 600 rpm; wherein the weight ratio of poly (N-isopropylacrylamide) to the ink base material is 1:10;

[0040] S6. Add the ion solution to the liquid obtained in step S5, and perform mechanical stirring. The mechanical stirring speed is maintained at 800-1000 rpm. After stirring for 3 hours, continue to perform ultrasonic treatment. The temperature is maintained at 10° C., the ultrasonic power is 1200 W, the ultrasonic on time is 1 second, the ultrasonic off time is 2 seconds, and the total ultrasonic treatment time is 4 hours.

[0041] The ionic solution is a sodium chloride solution;

[0042] S7, centrifugally degas the liquid obtained in step S6 for 3 minutes to obtain a preliminary ink product;

[0043] S8. Filter the ink obtained in step S7 with a 200-mesh filter to remove impurities, and finally obtain a printable ink with a linear temperature response. Specific embodiment 1:

[0045] A method for preparing a printable ink with linear temperature response comprises the following steps: dissolving N-isopropylacrylamide monomer in water, adding an initiator, heating to 60-70°C under nitrogen environment protection, stirring and reacting for 4-6 hours to obtain a poly N-isopropylacrylamide solution; selecting graphene and carbon nanotubes as two-component carbon nanomaterials, and performing oxygen plasma modification treatment on 0.1 g of graphene and 0.3 g of carbon nanotubes respectively; mixing the modified graphene and carbon nanotubes with 0.4 g of sodium dodecylbenzene sulfonate, adding the mixture to 100 ml of water, stirring the mixture with a homogenizer, maintaining the temperature at 20°C, rotating the homogenizer at 8000 rpm, and treating the mixture for a total of 6 hours; then sequentially adding 20 g of a water-based resin, 1 g of an acrylic leveling agent, and 1 g oxidizing desiccant, and mixed evenly to obtain an ink base; then add 10 g poly (N-isopropylacrylamide) solution and 1 g sodium chloride, and perform mechanical stirring, the mechanical stirring speed is maintained at 800-1000 rpm, and after stirring for 3 hours, ultrasonic treatment is continued, the temperature is maintained at 10°C, the ultrasonic power is 1200 W, the ultrasonic on time is 1 second, the ultrasonic off time is 2 seconds, and the total ultrasonic treatment time is 4 hours; after the treatment is completed, centrifugal degassing is performed, and a printable ink with a linear temperature response is obtained after filtration.

[0046] Comparative Example 1:

[0047] A method for preparing a printable ink with linear temperature response comprises the following steps: mixing a carbon nano material and a dispersant in a mass ratio of 1:1 and adding the mixture into water; stirring the solution obtained in the previous step by using a homogenizer, maintaining the temperature at 20°C, rotating the homogenizer at 8000 rpm, and treating for 6 hours in total; adding a water-based resin, a leveling agent, and a desiccant; performing mechanical stirring, maintaining the mechanical stirring speed at 800-1000 rpm, and continuously performing ultrasonic treatment after stirring for 3 hours, maintaining the temperature at 10°C, the ultrasonic power at 1200 W, the ultrasonic on time at 1 second, the ultrasonic off time at 2 seconds, and the total ultrasonic treatment time at 4 hours; performing centrifugal degassing on the obtained liquid, and performing the degassing time at 3 minutes, thereby finally obtaining a printable ink with linear temperature response.

[0048] Figure 2 is the resistance-temperature response diagram of the printable ink with linear temperature response obtained in the comparative example, Figure 3 is the resistance-temperature response diagram of the printable ink with linear temperature response obtained in specific embodiment 1, Figure 2 , Figure 3 It can be seen that the ink obtained in Comparative Example 1 has a smaller linear fit than the ink obtained in Specific Example 1.

[0049] The present invention utilizes the different sensitivities of the electrical conductivity of different carbon nanomaterials to temperature changes and the different thermal expansion coefficients of different carbon nanomaterials to regulate the temperature response performance of printable ink using two-phase carbon nanomaterials, and finally obtains printable ink with linear temperature response.

[0050] The present invention utilizes the property that the conductivity of the sodium chloride solution increases with the increase of temperature for regulation. This property is linear within a relatively low concentration and moderate temperature range. At the same time, since the ink is a water-based material, the sodium chloride solution can be well dispersed therein, and the addition of sodium chloride can achieve a linear response to temperature through the change of conductivity.

[0051] The present invention combines temperature-sensitive materials such as carbon nanomaterials with sodium chloride, and adds a thermosensitive polymer such as poly-N-isopropylacrylamide, so as to achieve an enhanced effect of linear response to temperature through a composite system.

[0052] The invention adopts reasonable preparation steps, including heating to prepare a poly (N-isopropylacrylamide) solution in a nitrogen environment, oxygen plasma modification treatment, dispersion mixing, combination of mechanical stirring and ultrasonic stirring, centrifugal degassing and filtering, etc., so that the oxygen plasma modification treatment obtained has better linear temperature response performance.

[0053] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a printable ink having a linear temperature response, characterized in that: The specific steps are: S1, dissolving N-isopropylacrylamide monomer in water, adding initiator, heating to 60-70° C. under nitrogen environment protection, stirring and reacting for 4-6 hours to obtain poly N-isopropylacrylamide solution; S2, performing oxygen plasma modification treatment on the two-component carbon nanomaterial for 5 minutes, wherein the two-component carbon nanomaterial is a combination of carbon nanotubes and graphene; S3, mixing the two-component carbon nanomaterial after oxygen plasma modification with the dispersant in a mass ratio of 1:1, adding into water, and stirring with a homogenizer, maintaining the temperature at 20° C., the speed of the homogenizer at 8000 rpm, and the total treatment time for 6 hours; S4, adding water-based resin, leveling agent and desiccant, mixing evenly, to obtain ink base material; S5, slowly adding the poly (N-isopropylacrylamide) solution obtained in step S1 to the ink base material obtained in step S4, and mechanically stirring until uniform, at a rotation speed of 600 rpm; wherein the weight ratio of poly (N-isopropylacrylamide) to the ink base material is 1:10; S6. Add the ion solution to the liquid obtained in step S5, and perform mechanical stirring. The mechanical stirring speed is maintained at 800-1000 rpm. After stirring for 3 hours, continue to perform ultrasonic treatment. The temperature is maintained at 10° C., the ultrasonic power is 1200 W, the ultrasonic on time is 1 second, the ultrasonic off time is 2 seconds, and the total ultrasonic treatment time is 4 hours. S7, centrifugally degas the liquid obtained in step S6 for 3 minutes to obtain a preliminary ink product; S8. Filter the ink obtained in step S7 with a 200-mesh filter to remove impurities, and finally obtain a printable ink with a linear temperature response.

2. The method for preparing a printable ink having a linear temperature response according to claim 1, characterized in that: The initiator in step S1 is ammonium persulfate.

3. The method for preparing a printable ink having a linear temperature response according to claim 2, characterized in that: The dispersant in step S3 is sodium dodecylbenzene sulfonate or polyvinyl pyrrolidone.

4. The method for preparing a printable ink having a linear temperature response according to claim 3, characterized in that: The leveling agent in step S4 is an acrylic leveling agent.

5. The method for preparing a printable ink having a linear temperature response according to claim 4, characterized in that: The desiccant in step S4 is an oxidizing desiccant.

6. The method for preparing a printable ink having a linear temperature response according to claim 5, characterized in that: The ion solution in step S6 is a sodium chloride solution.

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