An ink to inhibit the marangoni effect of coffee rings and a method of making the same

Abstract

The application discloses a preparation method of ink for inhibiting coffee ring Marangoni effect, which is mixed by functional components and functional components, wherein the functional components include a Marangoni effect driving agent, a Laplace force driving agent and an active agent; the method comprises the following steps: defoaming the Marangoni effect driving agent, the Laplace force driving agent and the active agent under vacuum conditions to complete pretreatment; stirring and heating the pretreated Marangoni effect driving agent to 30-40 DEG C in a constant-temperature water bath; adding the active agent into the Marangoni effect driving agent until the active agent is completely dissolved to obtain a mixed solution one; stirring and mixing the mixed solution one into the Laplace force driving agent to obtain a reaction system; adding the functional components into the reaction system, fully stirring and mixing, adjusting the PH to obtain a mixed system; homogenizing the mixed system to obtain the final Marangoni effect ink; the viscosity of the Marangoni effect ink is 10-25 cP; and the surface tension is 30-40 mN / m. The ink can effectively inhibit the coffee ring effect in the inkjet printing process, improves the printing quality, and can ensure the accuracy and repeatability of the printing features in the application requiring high-precision patterning.

Description

Technical Field

[0001] This invention relates to the field of inkjet printing technology, and in particular to a Marangoni effect ink that suppresses coffee rings and its preparation method. Background Technology

[0002] Inkjet printing is a technology that uses precise control of ink jetting to create images or text on various substrates. It is widely used in office printing, home printing, industrial printing, and professional printing fields, such as advertising production, art reproduction, and even for circuit boards, solar cells, and nanoimprinting. However, during inkjet printing, the so-called "coffee-ring effect" often occurs when ink droplets come into contact with the substrate. This is a common phenomenon that leads to a decrease in print quality. The coffee-ring effect refers to the phenomenon where, upon contact with the substrate surface, the ink droplet's edge evaporates faster than the center due to the rapid evaporation and absorption of the solvent. This results in a higher surface tension at the edge, causing the droplet to shrink towards the center, forming an uneven ring deposition. This phenomenon not only affects the uniformity and aesthetics of the print but can also lead to color deviations and loss of image detail. In the semiconductor field, the coffee-ring effect can affect the uniformity and performance of semiconductor devices fabricated using inkjet printing technology. Similarly, in nanoimprinting technology, the coffee-ring effect is a key factor because it affects material distribution during the imprinting process and the final pattern quality. Nanoimprinting is a technique used to create micro- and nano-scale patterns and is commonly used in the semiconductor and nanotechnology fields. The coffee ring effect may cause excessive deposition at the edges of the embossed pattern while insufficient deposition in the center, which can affect the uniformity and accuracy of the pattern.

[0003] To address this issue, researchers and engineers have explored various methods, including modifying ink formulations to reduce solvent evaporation rates, adjusting printing parameters to optimize droplet deposition patterns, and using specially coated media to improve ink absorption properties. However, these methods often have limitations, such as increased cost, reduced printing speed, or dependence on specific inks and media. In recent years, the Marangoni effect, a hydrodynamic phenomenon driven by surface tension gradients, has attracted considerable attention. The Marangoni effect describes the phenomenon where liquids flow from areas of lower surface tension to areas of higher surface tension when the surface tension is unevenly distributed. In the field of inkjet printing, by cleverly utilizing the Marangoni effect, the coffee ring effect can be effectively suppressed, thereby improving print quality. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a Marangoni effect ink that suppresses coffee rings, in order to overcome the shortcomings of the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This application discloses a method for preparing a Marangoni effect ink that inhibits coffee rings, comprising a mixture of active ingredients and functional ingredients, wherein the active ingredients include a Marangoni effect driver, a Laplace force driver, and a activator; specifically including the following steps: S1. Degas the Marangoni effect driving agent, Laplace force driving agent, and activator under vacuum conditions to complete the pretreatment. S2. In a constant temperature water bath, the pretreated Marangoni effect driving agent is stirred and heated to 30~40℃; the activator is added to the Marangoni effect driving agent until it is completely dissolved to obtain mixture one; S3. Add the mixture to the Laplace force-driven agent and stir to obtain the reaction system; S4. Add the functional ingredients to the reaction system, stir and mix thoroughly, and adjust the pH to obtain a mixed system; S5. The mixture system is homogenized to obtain the final Marangoni effect ink; the viscosity range of the Marangoni effect ink is 10~25 cP; the surface tension is 30~40 mN / m.

[0006] Preferably, the mass ratio of the active ingredient to the functional ingredient is 1:(0.25~0.42).

[0007] Preferably, the mass ratio of the Marangoni effect driver, the Laplace force driver, and the activator in the active ingredient is 1:(0.65~1.5):(0.01~0.075).

[0008] Preferably, the Marangoni effect driving agent is selected from one or more of n-dodecyl alcohol, triethyl citrate, or polyoxyethylene sorbitan monooleate.

[0009] Preferably, the Laplace force driving agent is selected from one or more of n-butanol, methyl isobutyl ketone, or perfluoroethanol; the activator is selected from fatty alcohol polyoxyethylene ether sulfate or fatty acid glyceride.

[0010] Preferably, the functional components include a nanoimprint material and a printing material, wherein the nanoimprint material is selected from PL-R-PC1000 or PL-R-PC2000; and the printing material is selected from EDAG ML 25265.

[0011] Preferably, the stirring speed in step S2 is 400~600 rpm; the stirring speed in step S3 is 800~1200 rpm, and the stirring time is 5~10 minutes.

[0012] Preferably, the homogenization process in step S5 is as follows: the mixture is stirred at a stirring speed of 2500~3500 rpm for 5~10 minutes.

[0013] Preferably, in step S4, trifluoroacetic acid and dimethylamine are used to adjust the pH, and the pH value of the mixed system is 5-8.

[0014] A Marangoni effect ink for suppressing coffee rings is prepared by the method described above. The viscosity range of the Marangoni effect ink is 10~25 cP, and the surface tension is 30~40 mN / m.

[0015] The beneficial effects of this invention are: 1. The ink of the present invention can effectively suppress the coffee ring effect in the inkjet printing process and improve the printing quality. In applications that require high-precision patterning, such as microelectronics, nanotechnology and semiconductor fields, eliminating the coffee ring effect can ensure the accuracy and repeatability of printed features.

[0016] 2. By adjusting the proportions in the ink, precise control of Marangoni flow can be achieved, enhancing material utilization and reducing ink waste.

[0017] 3. Applicable to various substrates, with a wide range of applications, it has promoted the innovation and development of inkjet printing technology in new materials, new processes and new applications.

[0018] 4. High versatility, applicable to various inkjet printing fields.

[0019] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram illustrating the principle of the Marangoni effect in suppressing inkjet-printed coffee ring droplets. Figure 2 Examples of typical ink spraying techniques; Figure 3 This is an example of spraying the ink of the present invention; Figure 4 This is a schematic diagram of the printing effect of Example 3; Figure 5 This is a schematic diagram of the printing effect of Comparative Example 1; Figure 6 This is a schematic diagram of the printing effect of Example 4; Figure 7 This is a schematic diagram of the printing effect of Comparative Example 2; Figure 8 This is a schematic diagram of the printing effect of Example 5; Figure 9This is a schematic diagram of the printing effect of scale 3; Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0022] like Figure 1 As shown, the Marangoni effect suppresses coffee ring formation in inkjet printing droplets. Two basic conditions are required for coffee ring formation: first, the contact line is pinned; second, the droplet adopts a spherical cap shape with minimal surface free energy. Geometrically, this can be explained by radially outward capillary flow to replenish the solvent evaporating near the contact line. Capillary flow refers to liquid flow driven by Laplace pressure caused by changes in the curvature of the liquid-gas interface. The solvent evaporates faster at the contact line than at the apex, enhancing this capillary flow, carrying dispersed solute to the contact line and depositing it there, resulting in a ring-shaped stain. 1. The edges of droplets often exhibit a "pinning effect," and the solvent evaporates faster at the edges. The solution carries the solute towards the three-phase contact line (also known as capillary flow: liquid flow driven by Laplace pressure caused by changes in the curvature of the liquid-gas interface), causing the solute to accumulate near the edge and form coffee rings.

[0023] 2. The Marangoni effect is a phenomenon where liquids flow from regions of low surface tension to regions of high surface tension. When a Marangoni effect driver and a Laplace force driver are chosen as a mixed solvent, the surfactant promotes rapid evaporation at the contact line edge. Therefore, the Laplace force driver is more volatile, leaving behind more functional components. This results in the edge solution tension being lower than the interior solution. However, under the influence of the Marangoni effect driver, transport of solutes away from the edge occurs. For example... Figure 1 As shown, it inhibits the formation of coffee rings and improves film uniformity.

[0024] This invention discloses a method for preparing a Marangoni effect ink that inhibits coffee rings. The ink is composed of a mixture of active ingredients and functional ingredients, wherein the mass ratio of the active ingredients to the functional ingredients is: active ingredients 70-80%, functional ingredients 20-30%. The active ingredients include a Marangoni effect driver, a Laplace force driver, and an activator; specifically, the composition is: Marangoni effect driver 39-60%, Laplace force driver 37-60%, and activator 1-3%. Specifically, the steps include the following: S1. Degas the Marangoni effect driving agent, Laplace force driving agent, and activator under vacuum conditions to complete the pretreatment. The Marangoni effect driving agent is selected from one or more of n-dodecyl alcohol, triethyl citrate, or polyoxyethylene sorbitan monooleate; the Laplace force driving agent is selected from one or more of n-butanol, methyl isobutyl ketone, or perfluoroethanol; and the activator is selected from fatty alcohol polyoxyethylene ether sulfate or fatty acid glyceride. S2. In a constant temperature water bath, the pretreated Marangoni effect driving agent is stirred and heated to 30~40℃; the activator is added to the Marangoni effect driving agent until it is completely dissolved to obtain mixture one; S3. Add the mixture to the Laplace force-driven agent and stir to obtain the reaction system; S4. Add the functional components to the reaction system, stir and mix thoroughly, and adjust the pH to obtain a mixed system; wherein, the functional components include nanoimprint materials and printing materials, the nanoimprint materials are selected as PL-R-PC1000 or PL-R-PC2000; the printing materials are selected as EDAG ML 25265; S5. The mixture system is homogenized to obtain the final Marangoni effect ink; the viscosity range of the Marangoni effect ink is 10~25 cP; the surface tension is 30~40 mN / m.

[0025] The ink can be printed on any substrate, including silicon wafers, glass, PMMA, PC, PET, and metal. For example... Figure 2 These are examples of general ink spraying. The left image shows spraying on glass, and the right image shows spraying on PMMA, showing obvious brown rings. Figure 3 The image shows a spraying example using the ink of this invention. The left image shows spraying on glass, and the right image shows spraying on PMMA. It can be seen that the Marangoni effect suppresses the coffee ring.

[0026] In one feasible embodiment, the stirring speed in step S2 is 400~600 rpm; the stirring speed in step S3 is 800~1200 rpm, and the stirring time is 5~10 minutes.

[0027] In one feasible embodiment, the homogenization process in step S5 is as follows: the mixture is stirred at a stirring speed of 2500~3500 rpm for 5~10 minutes.

[0028] In one feasible embodiment, trifluoroacetic acid and dimethylamine are used to adjust the pH in step S4, and the pH value of the mixed system is 5-8.

[0029] Example 1: Marangoni effect driving agent: n-dodecyl alcohol (20g), triethyl citrate (7.3g); Laplace force driving agent: n-butanol (20g), methyl isobutyl ketone (22g); activator: fatty alcohol polyoxyethylene ether sulfate (0.7g); functional ingredient PL-R-PC2000 (30g); the viscosity of the inkjet printing ink is 20 cP; the surface tension of the inkjet printing ink is 32 mN / m; Example 2: Marangoni effect driver: polyoxyethylene dehydrated sorbitan monooleate (42g); Laplace force driver: perfluoroethanol (25.9g); activator: fatty alcohol polyoxyethylene ether sulfate (2.1g); functional ingredient PL-R-PC2000 (30g); the viscosity of the inkjet printing ink is 21 cP; the surface tension of the inkjet printing ink is 38 mN / m; Example 3: Marangoni effect driving agent: n-dodecyl alcohol (20g), triethyl citrate (10g); Laplace force driving agent: n-butanol (20g), methyl isobutyl ketone (18.6g); activator: fatty alcohol polyoxyethylene ether sulfate (1.4g); functional ingredient PL-R-PC2000 (30g); the viscosity of the inkjet printing ink is 25 cP; the surface tension of the inkjet printing ink is 36 mN / m, such as... Figure 4 The ink, as described, produces inkjet printing without coffee rings on PET. Example 4: Marangoni effect driver: polyoxyethylene dehydrated sorbitan monooleate (37g); Laplace force driver: perfluoroethanol (39.5g); activator: fatty acid glycerides (3g); pH adjuster: dimethylamine (0.5g); functional ingredient PL-R-PC1000 (20g). The inkjet printing ink viscosity is 20 cP; the surface tension of the inkjet printing ink is 34 mN / m; such as Figure 6 The ink, as described, produces inkjet printing without coffee rings on the silicon wafer; Example 5: Marangoni effect driver: triethyl citrate (37g); Laplace force driver: n-butanol (35g); activator: fatty alcohol polyoxyethylene ether sulfate (3g); functional ingredient EDAG ML 25265 (25g). The inkjet printing ink viscosity is 13 cP; the surface tension of the inkjet printing ink is 30 mN / m. Figure 6 As shown, this ink produces no coffee rings when inkjet-printed on metal; Comparative Example 1: The only difference between this comparative example and Example 3 is that: no surfactant is used; the viscosity of the inkjet printing ink is 26 cP; and the surface tension of the inkjet printing ink is 37 mN / m. Figure 5As shown, although the ink in Comparative Example 1 can be inkjet printed on PET, it produces coffee rings.

[0030] Comparative Example 2: The only difference between this comparative example and Example 3 is that the surfactant used is fatty alcohol polyoxyethylene ether sulfate (5g). The results show that although Comparative Example 2 can be inkjet printed on PET, it has coffee rings. As can be seen from Example 3 and Comparative Examples 1 and 2, the appearance of coffee rings can still occur when the surfactant is missing or when the surfactant is used in excess.

[0031] Comparative Example 3: The only differences between this comparative example and Example 4 are: Marangoni effect driver: polyoxyethylene dehydrated sorbitan monooleate (66.5g), Laplace force driver: perfluoroethanol (10g); the inkjet printing ink viscosity is 22 cP; the surface tension of the inkjet printing ink is 36 mN / m; as Figure 7 As mentioned above, although the ink in Comparative Example 2 can be inkjet printed on a silicon wafer, it has a coffee ring. The experimental results from Comparative Example 3 and Example 4 show that when the ratio of the Marangoni effect driver to the Laplace force driver is greater than 1:0.65, coffee rings will still appear.

[0032] Comparative Example 4: The only difference between this comparative example and Example 5 is: Marangoni effect driving agent: triethyl citrate (20g); Laplace force driving agent: n-butanol (52g); the viscosity of the inkjet printing ink is 15 cP; the surface tension of the inkjet printing ink is 33 mN / m; Figure 9 As shown, although this ink can be used for inkjet printing on metal, it produces coffee-colored rings. The experimental results from Comparative Example 4 and Example 5 show that when the ratio of the Marangoni effect driver to the Laplace force driver is less than 1:1.5, coffee rings still appear.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a Marangoni effect ink that suppresses coffee rings, characterized in that, It is composed of a mixture of active ingredients and functional ingredients, wherein the active ingredients include Marangoni effect activators, Laplace force activators, and activators, and the functional ingredients include printing materials; The mass ratio of the active ingredient to the functional ingredient is 1:(0.25~0.42). The mass ratio of the Marangoni effect driver, Laplace force driver, and activator in the active ingredients is 1:(0.65~1.5):(0.01~0.075). The Marangoni effect driving agent is selected from one or more of n-dodecyl alcohol, triethyl citrate, or polyoxyethylene sorbitan monooleate. The Laplace force driving agent is selected from one or more of n-butanol, methyl isobutyl ketone, or perfluoroethanol; the activator is selected from fatty alcohol polyoxyethylene ether sulfate or fatty acid glyceride. The preparation method specifically includes the following steps: S1. Degas the Marangoni effect driving agent, Laplace force driving agent, and activator under vacuum conditions to complete the pretreatment. S2. In a constant temperature water bath, the pretreated Marangoni effect driving agent is stirred and heated to 30~40℃; the activator is added to the Marangoni effect driving agent until it is completely dissolved to obtain mixture one; S3. Add the mixture to the Laplace force-driven agent and stir to obtain the reaction system; S4. Add the functional ingredients to the reaction system, stir and mix thoroughly, and adjust the pH to obtain a mixed system; S5. Homogenize the mixture to obtain the final Marangoni effect ink; The viscosity range of the Marangoni effect ink is 10~25 cP; the surface tension is 30~40 mN / m.

2. The method for preparing a Marangoni effect ink for suppressing coffee rings as described in claim 1, characterized in that: The printing materials include nanoimprint materials and other printing materials; the nanoimprint materials are selected from PL-R-PC1000 or PL-R-PC2000, and the other printing materials are selected from EDAG ML 25265.

3. The method for preparing a Marangoni effect ink for suppressing coffee rings as described in claim 1, characterized in that: The stirring speed in step S2 is 400~600 rpm; the stirring speed in step S3 is 800~1200 rpm, and the stirring time is 5~10 minutes.

4. The method for preparing a Marangoni effect ink for suppressing coffee rings as described in claim 1, characterized in that: The homogenization process in step S5 is as follows: the mixture is stirred at a speed of 2500~3500 rpm for 5~10 minutes.

5. The method for preparing a Marangoni effect ink for suppressing coffee rings as described in claim 1, characterized in that: In step S4, trifluoroacetic acid and dimethylamine are used to adjust the pH, and the pH value of the mixed system is 5-8.

6. A Marangoni effect ink for suppressing coffee rings, characterized in that: The ink is prepared using the method for preparing a Marangoni effect ink that suppresses coffee rings as described in any one of claims 1 to 5. The viscosity range of the Marangoni effect ink is 10 to 25 cP, and the surface tension is 30 to 40 mN / m.

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