Nozzle plate containing borosilicate glass

Abstract

The present invention discloses a nozzle plate, the nozzle plate defining at least one nozzle connected to the nozzle plate at a base, wherein the at least one nozzle has a height and a top, the top having an inner width and an outer width, wherein the ratio of the height to the inner width is greater than 5, and wherein the nozzle plate comprises borosilicate glass. The nozzle plate is formed by the following method: providing a silicon wafer having a surface; providing a borosilicate glass wafer having a surface; etching the surface of the silicon wafer to form a plurality of trenches in the surface; anodically connecting the etched surface of the silicon wafer to the surface of the borosilicate glass wafer to form a bilayer composite; heating the bilayer composite at a temperature of at least about 750 °C; and releasing the silicon wafer from the borosilicate glass to form the nozzle plate.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 084,410, filed on September 28, 2020, the entire content of which is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to nozzle plates, methods of forming such plates, and methods of using such nozzle plates to eject fluid materials. More specifically, the nozzle plate includes borosilicate glass and at least one nozzle for ejecting fluid materials having a high aspect ratio, and the fluid materials do not break up (rupture) into individual droplets before contacting a substrate. Background Art

[0004] The silicon industry is built on the extreme uniformity, chemical properties, and mechanical strength of silicon crystals configured in wafer form for many applications. Silicon may be an ideal substrate for creating electronic structures such as transistors. For example, thinning silicon integrated circuit substrates has now become a common process method to maintain the trend established by Moore's Law and meet the package form factors required for consumer applications. Thinned silicon wafers can be used for stand-alone thin form factor packages or in combination with other thinned silicon device wafers to create three-dimensional structures. However, thinned silicon wafers are very difficult to handle and typically require the use of a carrier substrate attached by a temporary bonding method as an aid in handling.

[0005] Regarding the field of direct printing, there are several applications using piezoelectric inkjet printing processes. However, traditional piezoelectric inkjet printing technologies have various problems such as nozzle clogging, limited ink viscosity range, and difficulty in printing continuous lines. Compared with traditional piezoelectric inkjet technologies, multi-nozzle electrohydrodynamic (EHD) printing has received much attention due to its higher resolution, and various materials have been fabricated by EHD printing technologies. An example of typical EHD printing is given in Figure 2 which is presented. High-speed drop-on-demand (DOD) printing up to 1 kHz is also demonstrated. For example, glass capillaries or metal tubes can be used because a strong field concentration at the capillary tip requires a sharp-shaped capillary. However, the output of a single-capillary EHD printing process is insufficient for commercialization. Therefore, a multi-nozzle printing module composed of capillaries is not suitable for assembling with high positional accuracy for commercial applications. To overcome these drawbacks, a deep silicon etching process can be used to form silicon-based micro-machined nozzles for EHD printing. However, since the conductivity of silicon reduces the field concentration at the meniscus, stable ejection cannot be obtained. In addition, the bias voltage required to eject droplets from the nozzles is higher than several thousand volts. Furthermore, the silicon structure is extremely fragile and cannot be easily disassembled and cleaned without being damaged, making it unusable.

[0006] Due to the useful properties of glass, such as strength, optical transparency, chemical stability, thermal insulation, and electrical insulation, glass is a known complement to silicon as a material for MEMS, microfluidics, and packaging. As just one example, as Figure 1 shown, glass wafers tend to have excellent edge strength when compared to silicon wafers. In particular, the thermal expansion coefficient of borosilicate glass is also similar to that of silicon, providing the possibility of connecting glass to silicon wafers. Wet etching of borosilicate glass using a hydrofluoric acid solution (HF) is a cost-effective process and provides a high etching rate and a smooth surface. However, the isotropic etching profile hinders the use of this technique to create the vertical and high aspect ratio structures typically formed by silicon. Therefore, the above-described printed structures cannot be formed. Fabricating deep glass microstructures using fluorine-based plasma etching methods has shown promising results by using inductively coupled plasma reactive ion etching (ICP-RIE) or magnetically neutral loop discharge (NLD). However, combining vertical sidewall profiles, high aspect ratios, and smooth surfaces to form three-dimensional structures remains a challenge. In addition, such techniques typically require relatively thick metal masks, which are both expensive and cumbersome. Glass forming (molding) is an alternative method for forming glass microstructures. However, there are problems associated with complete filling of the mold cavity, sensitive process conditions, and limitations on the formed structures with high aspect ratios. In addition, there is currently no quantitative understanding of how non-uniform the flow of molten glass through mold cavities of different widths is and at what speed. Therefore, there are many challenges to overcome.

[0007] To address these deficiencies, the prior art describes a single-nozzle printhead with a glass nozzle for batch processing. However, the same technology reports that it is not possible to achieve as high an aspect ratio with this glass as is achieved when using silicon. In fact, several etching processes have been tested in the art without success. For example, wet etching was tested, but the angle of the etched walls was too small. Dry etching processes using metal masks were also tested, but the process took too long. Sandblasting was also evaluated, but still could not produce a high aspect ratio. Therefore, such processes are not suitable for the creation of printing technologies.

[0008] Therefore, there remains room for improvement. In addition, in combination with the accompanying drawings and the background art of the present disclosure, other desired features and characteristics of the present disclosure will become apparent from the following detailed description of the invention and the appended claims. SUMMARY OF THE INVENTION

[0009] The present disclosure provides a nozzle plate that defines at least one nozzle connected to the nozzle plate at a base, wherein the at least one nozzle has a height and a top, the top having an inner width and an outer width, wherein the ratio of the height to the inner width is greater than 5, and wherein the nozzle plate comprises borosilicate glass.

[0010] The present disclosure also provides a method of manufacturing a nozzle plate, the method comprising the steps of: providing a silicon wafer having a surface; providing a borosilicate glass wafer having a surface; etching the surface of the silicon wafer to form a plurality of trenches in the surface; anodically bonding the etched surface of the silicon wafer to the surface of the borosilicate glass wafer to form a bilayer composite; heating the bilayer composite at a temperature of at least about 750 °C to soften the borosilicate glass wafer to a molten state such that the molten borosilicate glass flows into the plurality of trenches to form a plurality of nozzles; and releasing the silicon wafer from the borosilicate glass to form a nozzle plate having the plurality of nozzles, wherein the nozzle plate defines at least one nozzle connected to the nozzle plate at a base, wherein the at least one nozzle has a height and a top, the top having an inner width and an outer width, wherein the ratio of the height to the inner width is greater than about 3, and wherein the nozzle plate comprises borosilicate glass.

[0011] The present disclosure also provides a method of ejecting a fluid material onto a substrate through a nozzle plate, the method comprising the steps of: providing a nozzle plate that defines at least one nozzle connected to the nozzle plate at a base, wherein the at least one nozzle has a height and a top, the top having an inner width and an outer width, wherein the ratio of the height to the inner width is greater than about 3, and wherein the nozzle plate comprises borosilicate glass; and ejecting a fluid material through the at least one nozzle to form a jet of the fluid material that contacts a substrate disposed at a distance (D) from the nozzle, wherein the jet has a breakup length greater than the distance (D) such that the jet does not break up into individual droplets before contacting the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present disclosure will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and

[0013] Figure 1 is a line graph showing the relationship between the edge strength (MPa) measured after finishing and the percentage showing that the glass is generally stronger than silicon;

[0014] Figure 2 is a schematic diagram showing the principle of electrohydrodynamic (EHD) printing employed;

[0015] FIG. 3A is a top view of the top of a nozzle of the present disclosure that is approximately circular;

[0016] FIG. 3B is a side view of a nozzle of the present disclosure that is approximately hyperbolic;

[0017] Figure 4 is a side cross-sectional view of an embodiment of a nozzle of the present disclosure, showing the height (H), the inner width (Wi), and the outer width (Wo);

[0018] Figure 5 It is a schematic diagram showing the respective steps of the various embodiments of the method of the present disclosure;

[0019] Figure 6A is a scanning electron micrograph of various trenches that can be fabricated by the method of the present disclosure;

[0020] Figure 6B is a scanning electron micrograph of additional trenches that can be fabricated by the method of the present disclosure;

[0021] Figure 6C is a scanning electron micrograph of a glass structure that can be fabricated by the method of the present disclosure;

[0022] Figure 7 is a side cross-sectional view of one embodiment of the nozzle of the present disclosure; and

[0023] Figure 8 is a side cross-sectional view of a comparative nozzle (left) that deposits a fluid material drop by drop over a distance (D) and an embodiment of the nozzle of the present disclosure that jets the fluid material (right), wherein the jet has a breakup length greater than the distance (D) such that the jet does not break up into individual droplets before contacting the substrate, as opposed to the comparative nozzle. Detailed Description

[0024] The following detailed description of the invention is exemplary in nature only and is not intended to limit the nozzle plate or method of the present disclosure. Further, there is no intention to be limited by any theory presented in the foregoing background or the following detailed description.

[0025] Embodiments of the present disclosure generally relate to nozzle plates and methods for manufacturing the same. For the sake of brevity, conventional techniques related to nozzle plates and the jetting of fluid materials therethrough may not be described in detail herein. Additionally, the various tasks and method steps described herein may be incorporated into a more comprehensive process or method having additional steps or functions not detailed herein. In particular, the various steps in the manufacture of jetting systems are well known, and thus, for the sake of brevity, many conventional steps are only briefly mentioned herein or will be entirely omitted without providing well-known process details.

[0026] The present disclosure provides a nozzle plate (20) that defines at least one nozzle (24) at a base (22) coupled to the nozzle plate (20). The at least one nozzle (24) has a height (H) and a top (30) having an inner width (Wi) and an outer width (Wo), where the ratio of the height (H) to the inner width (Wi) is greater than 5, and where the nozzle plate (20) comprises borosilicate glass, such as at least as Figure 4 and 7 shown.

[0027] The nozzle plate (20) itself is not particularly limited and can be any nozzle plate known in the art. The nozzle plate (20) is not limited in terms of length, width, or thickness. However, in various embodiments, the length of the nozzle plate (20) is from about 0.5 to about 6, about 1 to about 5, about 2 to about 4 inches, or at least about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 inches or greater. In other embodiments, the width of the nozzle plate (20) is from about 0.1 to about 1, about 0.2 to about 0.0, about 0.3 to about 0.8, about 0.4 to about 0.7, about 0.5 to about 0.6 inches, or at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 inch. In other embodiments, the thickness of the nozzle plate (20) is from about 50 to about 2000, about 100 to about 1950, about 150 to about 1900, about 200 to about 1850, about 250 to about 1800, about 300 to about 1750, about 350 to about 1700, about 400 to about 1650, about 450 to about 1600, about 500 to about 1550, about 550 to about 1500, about 600 to about 1450, about 650 to about 1400, about 700 to about 1350, about 750 to about 1300, about 800 to about 1250, about 850 to about 1200, about 900 to about 1150, about 950 to about 1100, about 1000 to about 1050 microns, or at least about 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1250, 1500, 1750, 2000 microns. Generally, the thickness is defined as the total thickness of the nozzle plate (20), including up to the top (30) of the at least one nozzle (24). Alternatively, the thickness can be defined as the thickness of the nozzle plate (20) from the bottom (34) of the at least one nozzle (24) to the base (22). In various non-limiting embodiments, including those given above and all numerical values and numerical ranges therebetween, including integers and fractions, are expressly contemplated for use herein.

[0028] The nozzle plate (20) defines at the base (22) at least one nozzle (24) connected to the nozzle plate (20). For example, as Figure 4 and 7As shown, the at least one nozzle (24) has a height (H) and a top (30), and the top (30) has an inner width (Wi) and an outer width (Wo). An example of the top (30) of the at least one nozzle (24) is shown in FIG. 3A. Each of the at least one nozzle (24) is connected to a nozzle plate (20) at a base (22) of the at least one nozzle (24). The dimensions of the base (22) are not particularly limited and can be equal to, greater than, or less than the above inner width and / or outer width (Wi / Wo). The at least one nozzle (24) is typically formed / connected to the base (22) in an integral manner with the base (22). However, it is contemplated that the at least one nozzle (24) may not be formed / connected to the base (22) in an integral manner with the base (22).

[0029] In various embodiments, the nozzle plate (20) includes two or more or multiple nozzles (24). For example, the nozzle plate (20) may have greater than or equal to about 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 individual nozzles (24). The nozzles (24) can be arranged in any pattern. For example, the nozzles (24) can be arranged linearly, in a checkerboard pattern, etc. In various non-limiting embodiments, all numerical values and ranges of values, including integers and fractions, including those given above and those in between, are specifically contemplated for use herein.

[0030] As described above, each of the at least one nozzle (24) has a height (H) and an internal width and an external width (Wi / Wo), such as shown in FIG. 3B. Each of the at least one nozzle (24) may have the same or different height (H) and internal and external widths (Wi / Wo) compared to each other. In various embodiments, the height (H) is from about 0.09 to about 1.6, about 0.1 to about 1.5, about 0.2 to about 1.4, about 0.3 to about 1.3, about 0.4 to about 1.2, about 0.4 to about 1.1, about 0.6 to about 1, about 0.7 to about 0.9, about 0.8 to about 0.9, about 0.1 to about 1, about 0.15 to about 0.95, about 0.2 to about 0.9, about 0.25 to about 0.85, about 0.3 to about 0.8, about 0.35 to about 0.75, about 0.4 to about 0.7, about 0.45 to about 0.65, about 0.5 to about 0.6 or about 0.55 to about 0.6 mm. In further embodiments, the internal width (Wi) is from about 0.03 to about 0.16, about 0.04 to about 0.15, 0.05 to about 0.14, about 0.06 to about 0.13, about 0.03 to 0.12, about 0.07 to about 0.12, about 0.08 to about 0.11, about 0.08 to about 0.10 mm, or about 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.1, 0.105, 0.11, 0.115, 0.12, 0.125, 0.13, 0.135, 0.14, 0.145, 0.15, 0.155 or 0.16 mm. In still further embodiments, the internal width (Wi) is from about 0.01 to about 0.5, about 0.05 to about 0.45, about 0.1 to about 0.4, about 0.15 to about 0.35, about 0.2 to about 0.3 or about 0.35 to about 0.3 mm. In other embodiments, the external width (Wo) is about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100... up to about 1000% longer than the internal width (Wi), with the width in mm. In various non-limiting embodiments, all numerical values and numerical ranges given above and those in between, including integers and fractions, are expressly contemplated for use herein.

[0031] The expected top (30) can have any shape, such as rectangular, approximately square, oval, approximately circular, etc. In various embodiments, the top (30) is approximately circular, such that the inner width (Wi) is approximately defined as the inner diameter and the outer width (Wo) is approximately defined as the outer diameter. Thus, the inner diameter and the outer diameter can be the same as or different from the inner width and the outer width (Wi / Wo) described above.

[0032] In other embodiments, the top (30) can be described as defining a nozzle orifice (36) through which a fluid material can be ejected. In various embodiments, the nozzle orifice (36) has a nozzle diameter, such as an inner width (Wi) of from about 0.000001 to about 0.001, or from about 0.000005 to about 0.0005, or from about 0.00002 to about 0.00018 meters (m). The nozzle orifice (36) can have a nozzle diameter, such as an inner width (Wi) of at least 0.000001, or at least 0.000005, or at least 0.00002 meters. Alternatively, the nozzle orifice (36) can have a nozzle diameter, such as an inner width (Wi) of not greater than 0.001, or not greater than 0.0005, or not greater than 0.00018 meters. In various non-limiting embodiments, all numerical values and numerical ranges given above and those in between, including integers and fractions, are expressly contemplated for use herein.

[0033] In various embodiments, the ratio of the height (H) to the inner width (Wi) (or, for example, the ratio of the height (H) to the inner diameter) is greater than about 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75, 5, 5.25, 5.5, 5.75, 6, 6.25, 6.5, 6.75, 7, 7.25, 7.5, 7.75, 8, 8.25, 8.5, 8.75, 9, 9.25, 9.5, 9.75, 10, 10.5, 11, 1.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20 or even greater. In other embodiments, the ratio is from about 3 to about 10, from about 4 to about 9, from about 5 to about 7, from about 5 to about 6, from about 8 to about 10, from about 8 to about 9 or from about 9 to about 10. Alternatively, this can be described as the ratio of the nozzle channel length to the nozzle channel diameter. In various non-limiting embodiments, all numerical values and numerical ranges given above and those in between, including integers and fractions, are expressly contemplated for use herein.

[0034] The shape of the at least one nozzle (24) is not particularly limited. In various embodiments, one or more of the at least one nozzle (24) may be approximately cylindrical, conical, hyperbolic or semi - hyperbolic, or pyramidal, etc. The at least one nozzle (24) as shown in FIG. 3B is described as approximately hyperbolic or semi - hyperbolic.

[0035] Returning to the nozzle plate (20) itself, the nozzle plate (20) can be borosilicate glass, include borosilicate glass, consist essentially of borosilicate glass, or be composed of borosilicate glass. In various embodiments, the term "consist essentially of" describes that the nozzle plate (20) itself does not contain organic compounds or minerals that are not borosilicate glass (e.g., free silicon that is not part of the borosilicate glass lattice or structure), or contains less than 5, 4, 3, 2, 1, 0.5, 0.1, 0.05, or 0.01% by weight of organic compounds or mineral glass that are not borosilicate. For example, the nozzle plate (20) itself may not contain silicon that is not part of the borosilicate glass lattice or structure. It is also contemplated that the at least one nozzle (24) can be described in the same manner as the nozzle plate (20) itself. In various non - limiting embodiments, all numerical values and numerical ranges, including integers and fractions, given above and between them are expressly contemplated for use herein.

[0036] According to the oxide composition (by mass fraction), borosilicate glasses can be roughly divided into the following groups. Borosilicate glasses typically contain a certain amount of silicon dioxide (SiO2) and boron trioxide (B2O3>8%) as glass network formers. The amount of boron trioxide tends to affect the glass properties in a specific way. Borosilicate glasses can be non - alkaline earth metal borosilicate glasses (borosilicate glass 3.3). In these embodiments, the B2O3 content of the borosilicate glass is typically 12 - 13%, while the SiO2 content typically exceeds 80%. Alternatively, borosilicate glasses can be alkaline earth metal - containing or aluminoborosilicate glasses. In addition to about 75% SiO2 and 8 - 12% B2O3, these glasses also contain up to 5% alkaline earth metals and alumina (Al2O3). In other embodiments, borosilicate glasses can be described as high - borate borosilicate glasses, which include 15 - 25% B2O3, 65 - 70% SiO2, and small amounts of alkaline earth metals and Al2O3 as additional components. All of the above combinations are also considered for various embodiments. In various non - limiting embodiments, all numerical values and numerical ranges, including integers and fractions, given above and between them are expressly contemplated for use herein.

[0037] Coating device:

[0038] In other embodiments, the present disclosure provides a coating apparatus for dispensing a fluid material. As will be understood by those skilled in the art, the coating apparatus (not shown in the figures) includes the aforementioned nozzle plate (20) and any other required components. For example, the coating apparatus may further include a positioning mechanism operatively attached to the nozzle plate (20), wherein the positioning mechanism is adapted to operate with multiple degrees of freedom; at least one fluid dispensing conduit operatively coupled to the nozzle plate (20) and coupled to a fluid material supply, wherein the fluid material is dispensed via the nozzle plate (20); and a control mechanism operatively coupled to the positioning mechanism, wherein the control mechanism is adapted to control the positioning mechanism to position the nozzle plate (20) and wherein the control mechanism determines the flow of the fluid material to the nozzle plate (20).

[0039] In various embodiments, the nozzle plate (20) can be combined with a precision robot controller to form an airless conformal coating apparatus. The precision robot controller can be used to accurately position the nozzle plate (20) relative to a target. The precision robot controller typically has multiple degrees of freedom, such as three or more degrees of freedom. The nozzle plate (20) and the precision robot controller can be operatively connected to a fluid material supply, which can deliver the fluid material supply directly to the nozzle plate (20), or alternatively, via the precision robot controller to the nozzle plate (20).

[0040] The apparatus can include a fluid material reservoir operatively coupled to an end effector to which the nozzle plate (20) is also operatively and releasably attached. Alternatively or additionally, the nozzle plate (20) can be attached to a device, such as a multi-degree-of-freedom robotic positioning device, that provides accurate positional displacement relative to the article or surface being coated. For example, when the nozzle plate (20) moves horizontally relative to a target substrate (26), the nozzle plate (20) can coat a large area, resulting in rapid and efficient coating. In one embodiment, the fluid material is typically supplied to the nozzle plate (20) under pressure and then forced through the at least one nozzle (24). At the same time, the nozzle plate (20) can travel (e.g., longitudinally) at a desired height (H) above the target surface. The fluid material flowing out of the at least one nozzle (24) can create a spray pattern on the surface. For example, the spray pattern may have well-defined edges. Additionally, the amount of external material splashed or deposited outside the spray pattern can be minimized or eliminated. In an alternative embodiment, the nozzle plate (20) can rotate about an axis relative perpendicular to the target surface, thereby creating a circular coating pattern. In another alternative embodiment, the nozzle plate (20) can rotate about an axis relative parallel to the target surface, for applications such as coating the inner or outer surface of a hollow container.

[0041] Method of manufacturing a nozzle plate:

[0042] The present disclosure also provides a method of fabricating a nozzle plate (20). Figure 5 A non-limiting implementation is described in. The method includes the steps of: providing a silicon wafer having a surface; providing a borosilicate glass wafer having a surface; etching the surface of the silicon wafer to form a plurality of trenches (32) in the surface; anodically bonding the etched surface of the silicon wafer to the surface of the borosilicate glass wafer to form a bilayer composite (38); heating the bilayer composite (38) at a temperature of at least about 750 °C to soften the borosilicate glass wafer to a molten state such that the molten borosilicate glass flows into the plurality of trenches (32) to form a plurality of nozzles (24); and releasing the silicon wafer from the borosilicate glass to form a nozzle plate (20) having the plurality of nozzles (24), wherein the nozzle plate (20) defines at least one nozzle (24) connected to the nozzle plate (20) at a base (22). None of these steps is particularly limited and each can be accomplished as would be understood by one of ordinary skill in the art.

[0043] In various implementations, the step of providing the silicon wafer and / or the borosilicate glass wafer can be described as delivering or preparing the wafers usable in the method. Relative to the etching step, this step can utilize any etching known in the art that can produce the above-described plurality of trenches (32) in the surface, such as shown in FIGS. 6A and 6B. In various implementations, the etching step is performed using deep reactive ion etching (DRIE), such as the Bosch process described by K.-S. Chen, A.A. Ayon, X. Zhang, and S.M. Spearing in "Effect of process parameters on the surface morphology and mechanical performance of silicon structures after deep reactive ion etching (DRIE)," J. Microelectromech. Syst., Vol. 11, No. 3, pp. 264-275, January 2002.

[0044] In various embodiments, silicon wafers (molded) with a diameter of about 100 mm, p-type, <100> orientation, resistivity of 1 - 10 Ω-cm, and a thickness of 500 μm and borosilicate glass wafers with a thickness of about 500 μm are used. Then, trenches with substantially the same or different widths can be fabricated in the silicon wafers by lithography and / or DRIE. For example, DRIE can be performed using a photoresist mask. The trenches can be etched to a depth greater than or equal to the height (H) of the at least one nozzle (24) using, for example, Advanced Silicon Etch STS ICP. The etching conditions are not particularly limited and can be approximately: 130 sccm of SF6 and 13 sccm of O2, RF coil power of 600 W, RF chuck power of 18 W, etching cycle of 13 seconds, and 85 sccm of C4F8, RF coil power of 600 W, and RF chuck power of 0 W, passivation cycle of 7 seconds (0 seconds overlaps with the etching cycle). The automatic pressure control valve (APC) can be fixed at about 82%, resulting in pressures of about 30 mTorr and about 16 mTorr for the etching and passivation cycles, respectively. In some embodiments, for large trenches (32), the etching rate can be up to 4.3 μm / min. Due to the aspect ratio dependence of the etching rate due to etch (ARDE), the etching depth of narrow trenches (32) may be smaller compared to wider trenches. In various non-limiting embodiments, including those given above and all numerical values and numerical ranges between them, including integers and fractions, are expressly contemplated for use herein.

[0045] The method further includes the step of anodically connecting the etched surface of the silicon wafer to the surface of the borosilicate glass wafer to form a bilayer composite (38). Any type of anodic connection method can be used herein. Before connection, the etched Si wafer and the borosilicate glass wafer can be cleaned, for example, using a Piranha solution (a mixture of about 1:2 H2O2:H2SO4) for about 15 minutes, followed by using an SC1 solution (a mixture of 1:1:5 NH4OH:H2O2:H2O) at about 75 °C for about 15 minutes. The etched silicon wafer can also be immersed in a hydrofluoric acid solution (a mixture of about 1:50 HF:H2O) for about 30 seconds to remove the native oxide. Then both wafers can be rinsed with deionized water and dried with nitrogen. Then the two wafers can be anodically connected in a wafer bonder (AML) to produce a low-pressure sealed microcavity. Any procedure known in the art can be used for the connection. For example, the connection can be performed under vacuum (about 150 μTorr, air). The wafers can be heated to about 370 °C simultaneously to increase the mobility of the positive ions in the borosilicate glass wafer, and then brought into contact with each other. Once the desired temperature is reached and the pressure is stable, the wafers can be brought into contact and a mechanical force of about 200 N can be applied uniformly on the wafer surfaces. Then a voltage of about 500 V can be applied, with the current limit fixed at about 4 mA. When the current decays to a residual value of about 0.1 mA, the connection is complete. The elapsed time can be about 20 minutes. Subsequent cooling can be performed at a rate of 3 °C per minute, cooling to about room temperature. The connection strength can be determined by any crack opening characterization method known in the art. For example, when a wedge with a thickness of 0.3 mm is inserted into the connection surface, the silicon side breaks up. This means that the connection energy is greater than the fracture surface energy of silicon. In various non-limiting embodiments, including those given above and all numerical values and numerical ranges therebetween, including integers and fractions, are specifically contemplated for use herein.

[0046] The method further includes the step of heating the bilayer composite (38) at a temperature of at least about 750 °C to soften the borosilicate glass wafer to a molten state such that the molten borosilicate glass flows into a plurality of grooves (32) to form various shapes, such as shown in FIG. 6C, wherein the shape can be a nozzle (24). For example, after connection, the connected wafers can be heated in a furnace to reduce the glass viscosity. Thus, the softened glass flows into the grooves (32) due to the pressure difference between the grooves (32) and the furnace environment. Nitrogen or argon can be used as the ambient gas. If the top (30) glass surface is deformed, the surface can be ground and polished to flatten and smooth the glass surface. The various shaped structures formed using such grooves (32) are described in Figure 6A-CIn various embodiments, the temperature is at least about 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950 or 2000 °C, or any temperature or range therebetween. Additionally, the heating step can be carried out using any method known in the art. In various non-limiting embodiments, all numerical values and numerical ranges given above, including those in between and including integers and fractions, are expressly contemplated for use herein.

[0047] The method further includes the step of releasing the silicon wafer from the borosilicate glass to form a nozzle plate (20) having the plurality of nozzles (24), wherein the nozzle plate (20) defines at the base (22) the at least one nozzle (24) connected to the nozzle plate (20). The release step can be achieved using any method known in the art. For example, in one embodiment, KOH wet etching is used. In one instance, the wafer is etched in a KOH solution (45% by weight) heated at a temperature of about 95 ± 5 °C. Under these etching conditions, the etching rates of silicon and the shaped glass can be about 2 μm / min and about 50 nm / min, respectively, with a selectivity of about 40:1. In various non-limiting embodiments, all numerical values and numerical ranges given above, including those in between and including integers and fractions, are expressly contemplated for use herein.

[0048] Alternatively, XeF2 can be used. In one instance, an oxygen plasma (e.g., about 60 seconds, about 100 mTorr and about 400 W) can be applied to remove organic contaminants, followed by the application of a CF4 / O2 RIE plasma (about 5 seconds, about 200 mTorr and about 400 W) to remove native oxide. The sample can then be introduced into the pulsed XeF2 etch system E1 (150 mm platen, quartz showerhead) of SPTS to remove silicon. Merely as an example, the XeF2 etch can be performed for about 300 or more cycles to remove silicon. The cycle can include a XeF2 pulse of about 10 seconds at about 3 Torr and an overhead (pumping time between pulses) of about 18 seconds. In various non-limiting embodiments, all numerical values and numerical ranges given above, including those in between and including integers and fractions, are expressly contemplated for use herein.

[0049] Method of ejecting a fluid material through a nozzle plate (20):

[0050] The present disclosure also provides a method of ejecting a fluid material through a nozzle plate (20) and onto a substrate (26). The method includes the steps of providing the nozzle plate (20) described above and ejecting the fluid material through the at least one nozzle (24) to form a jet (28) of the fluid material, the jet of the fluid material contacting the substrate (26) disposed at a distance (D) from the nozzle; wherein the jet (28) has a breakup length greater than the distance (D) such that the jet (28) does not break up into individual droplets before contacting the substrate (26). For example, the ejecting step may include applying an electrostatic charge to the fluid material.

[0051] A schematic illustration of the distance (D) and the breakup length is shown in Figure 8 . In various embodiments, the distance is about 1 to about 100, about 5 to about 50, about 10 to about 30, about 5 to about 95, about 10 to about 90, about 15 to about 85, about 20 to about 80, about 25 to about 75, about 30 to about 70, about 35 to about 65, about 40 to about 60, about 45 to about 55, or about 50 to about 55 mm. In various non-limiting embodiments, including those given above and all numerical values and ranges therebetween, including integers and fractions, are expressly contemplated for use herein.

[0052] The nozzle plate (20) may apply the fluid material via valve ejection, piezoelectric, thermal, acoustic, or ultrasonic membranes. In one embodiment, the nozzle plate (20) is a piezoelectric applicator that includes a piezoelectric element configured to deform between a suction position, a resting position, and an application position. The nozzle plate (20) may be described as having an ejection frequency of about 100 to about 1,000,000 Hz, or about 10,000 Hz to about 100,000 Hz, or about 30,000 Hz to about 60,000 Hz. The nozzle plate (20) may be configured to eject the fluid material through the at least one nozzle (24) at an impact velocity of about 0.2 m / s to about 20 m / s. Alternatively, the nozzle plate (20) may be configured to eject the fluid material through the at least one nozzle (24) at an impact velocity of about 0.4 m / s to about 10 m / s.

[0053] In various embodiments, at least about 80, 85, 90, 95, 96, 97, 98, 99, 99.9, or even up to about 99.99, 99.999, or 99.9999, or about 100% of the fluid material ejected or discharged through the at least one nozzle (24) contacts the substrate (26). This reduces the amount of fluid material entering the environment, increases the application efficiency of the fluid material, reduces waste generation, and reduces maintenance. In various non-limiting embodiments, including those given above and all numerical values and ranges therebetween, including integers and fractions, are expressly contemplated for use herein.

[0054] The nozzle plate (20) and the at least one nozzle (24) can be configured to form any type of line, pattern, or shape. For example, the pattern can be regular or irregular, camouflage, monochromatic, bicolor, striped, or more, etc.

[0055] Two or more nozzle plates (20) can be joined together to form a printhead assembly. In certain embodiments, the nozzle plates (20) are aligned together such that the y-axis of each nozzle plate (20) is parallel to the other y-axes. Additionally, the at least one nozzle (24) of each nozzle plate (20) can be aligned with each other along the x-axis perpendicular to the y-axis such that an "array" is formed. With respect to the x-axis and y-axis, one nozzle can be equally spaced apart from other nozzles (24) that are directly adjacent to the one nozzle. This configuration of the nozzles (24) can be suitable for applying the same fluid material through each of the nozzle plates (20) when the printhead assembly is moved along the x-axis. Without being bound by theory, it is believed that the equal spacing of the nozzles (24) with respect to both the x-axis and y-axis can result in a uniform application of the same fluid material, which can be applicable to monochromatic application, bicolor application, etc. Alternatively, a group of nozzles (24) along a first y-axis can be closely spaced from another group of nozzles (24) with respect to the spacing of each of the nozzles (24) along the y-axis of a single nozzle plate (20). This configuration of the nozzles (24) can be suitable for applying different fluid materials. Different fluid materials may be suitable for logos, designs, signs, stripes, camouflage looks, etc.

[0056] The at least one nozzle (24) of the nozzle plate (20) can have any configuration known in the art, such as linear, concave with respect to the substrate (26), convex with respect to the substrate (26), circular, etc. It may be necessary to adjust the configuration of the at least one nozzle (24) to facilitate the cooperation of the nozzle plate (20) with a substrate (26) having an irregular configuration, such as a vehicle including mirrors, decorative panels, contours, spoilers, etc.

[0057] Now turning to the fluid material itself, it is not particularly limited. In one embodiment, the fluid material is a resin having a viscosity of about 5 to 700 cps. In an alternative embodiment, the fluid material is a resin to which an extrusion pressure in the range of 5 - 500 kg / cm is applied. The fluid material can be paint, coating, ink, or a fluid. In one embodiment, the fluid material forms a coating on the substrate (26). The coating can be used as a primer, clear coat, colored coating, topcoat, one-step paint, intermediate paint, primer, sealant, or a combination thereof. In certain embodiments, the fluid material is used to form a primer. In various non-limiting embodiments, all numerical values and numerical ranges, including integers and fractions, including and between the above numerical values and numerical ranges are expressly contemplated for use herein.

[0058] The term "basecoat" refers to a coating that is opaque and provides most of the protection, color, hiding power (also referred to as "opacity"), and visual appearance. Basecoats typically contain colored pigments, effect pigments such as metallic flake pigments, rheology control agents, ultraviolet absorbers, and other coating additives. The term "basecoat fluid material" refers to a fluid material that can be used to form a basecoat. The term "basecoat layer" refers to a coating formed from a basecoat fluid material. A basecoat layer can be formed by applying one or more layers of the same or different basecoat fluid materials. In automotive coatings, for most of the protection, color, and most of the visual appearance, the substrate (26) is typically coated with a primer layer for protection and adhesion, then a basecoat layer is applied over the primer layer, optionally a sealer is applied on top of the primer, and subsequently a clearcoat is applied over the basecoat to obtain further protection and visual appearance. Sometimes, a single coating referred to as a "topcoat" can be used to provide the functions of both the basecoat and the clearcoat. Additional coatings can also be used. For example, a metallic substrate (26) can be treated with a phosphate material and an electrocoat is applied before the primer layer is applied.

[0059] The term "mid coat" or "mid coat layer" refers to a colored non-opaque coating that is located between the basecoat and the clearcoat in a multi-layer coating system. To achieve some unique and appealing colors or visual effects, the automotive industry and other coating end-use applications can use a multi-layer coating with three or more coatings instead of the traditional "basecoat and clearcoat" two-layer coating system. The multi-layer system typically can include at least a first colored and opaque basecoat layer, a second opaque colored coating deposited on at least a portion of the basecoat layer, and a third clearcoat layer deposited on at least a portion of the second opaque colored coating. The second opaque colored coating is typically referred to as the mid coat, which contains colored pigments. The mid coat is typically formulated to be opaque so that the color of the underlying basecoat can be seen through the mid coat.

[0060] In various embodiments, the fluid material includes various components such as binders, pigments, extender pigments, dyes, rheology modifiers, carriers (such as organic solvents, water, and non-aqueous solvents), catalysts, conventional additives, or combinations thereof. In an embodiment, the carrier is selected from water, non-aqueous solvents, and combinations thereof. Conventional additives can include, but are not limited to, dispersants, antioxidants, ultraviolet stabilizers and absorbers, surfactants, wetting agents, leveling agents, defoamers, anti-cratering agents, or combinations thereof.

[0061] Term " binding agent " refers to the film-forming component of fluid material.Usually, binding agent can comprise for forming the requisite polymer, oligomer or its combination of coating with required performance (such as hardness, protection, adhesion etc.).Other compositions such as carrier, pigment, catalyst, rheology modifier, antioxidant, ultraviolet stabilizer and absorbent, leveling agent, defoamer, anti-crater agent or other conventional additives may not be included in the term " binding agent ", unless any one in these additional components is the film-forming component of fluid material.One or more in these additional components can be included in the fluid material.In certain embodiments, binding agent comprises polymer.

[0062] In embodiments, polymer has crosslinkable functional groups, such as isocyanate reactive groups.Term " crosslinkable functional groups " refers to the functional group or its combination positioned at the end of oligomer, in polymer, in polymer main chain, in the side chain of polymer main chain, positioned at polymer main chain, wherein these functional groups (during the curing step) can be crosslinked with crosslinking functional groups to produce the coating of crosslinked structure form.Typical crosslinkable functional groups can comprise hydroxyl, thiol, isocyanate, thioisocyanate, acetoacetoxy, carboxyl, primary amine, secondary amine, epoxy group(ing), acid anhydride, ketimine, aldimine or its feasible combination.Once ring structure opens some other functional groups that can generate hydroxyl or amido such as orthoester, orthocarbonate or cyclic amide also can be suitable as crosslinkable functional groups.

[0063] The fluid material may include a polyester-polyurethane polymer, a latex polymer, a melamine resin, or a combination thereof. It should be understood that other polymers may be included in the fluid material.

[0064] The polyester of polyester-polyurethane polymer can be linear or branched.Useful polyester can include the esterification product of aliphatic or aromatic dicarboxylic acid, polyol, glycol, aromatic or aliphatic cyclic anhydride and cyclic alcohol.The limiting examples of suitable alicyclic polycarboxylic acid are tetrahydrophthalic acid, hexahydrophthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, tricyclodecanedicarboxylic acid, endethylenehexahydrophthalic acid, camphoric acid, cyclohexanetetracarboxylic acid and cyclobutanetetracarboxylic acid.Alicyclic polycarboxylic acid can be used not only in cis form, but also in trans form and the mixture of these two forms. Other non-limiting examples of suitable polycarboxylic acids can include aromatic and aliphatic polycarboxylic acids, for example phthalic acid, isophthalic acid, terephthalic acid, halogenated phthalic acid (such as tetrachloro or tetrabromophthalic acid), adipic acid, glutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, trimellitic acid and pyromellitic acid. The combination of polyacids, such as the combination of polycarboxylic acids and alicyclic polycarboxylic acids may be suitable. The combination of polyols is also suitable.

[0065] Non-limiting suitable polyols include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, diethylene glycol, cyclohexanediol, cyclohexanedimethanol, trimethylpentanediol, ethylbutylpropanediol, ditrimethylolpropane, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, polyethylene glycol, and polypropylene glycol. If desired, monohydric alcohols such as butanol, octanol, lauryl alcohol, ethoxylated or propoxylated phenols may also be included together with the polyols to control the molecular weight.

[0066] Non-limiting examples of suitable polyesters include branched copolyester polymers. The branched copolyester polymers and production methods described in U.S. Patent No. 6,861,495 may be suitable, and this patent is incorporated herein by reference. Monomers having polyfunctional groups of the type AxBy (where x and y are independently 1 to 3), including those having one carboxyl group and two hydroxyl groups, two carboxyl groups and one hydroxyl group, one carboxyl group and three hydroxyl groups, or three carboxyl groups and one hydroxyl group, can be used to generate a branched structure. Non-limiting examples of such monomers include 2,3-dihydroxypropionic acid, 2,3-dihydroxy-2-methylpropionic acid, 2,2-dihydroxypropionic acid, 2,2-bis(hydroxymethyl)propionic acid, etc.

[0067] The branched copolyester polymers can be conventionally polymerized from a monomer mixture comprising a chain extender selected from hydroxycarboxylic acids, lactones of hydroxycarboxylic acids, and combinations thereof; and one or more branching monomers. Some suitable hydroxycarboxylic acids include glycolic acid, lactic acid, 3-hydroxypropionic acid, 3-hydroxybutyric acid, 3-hydroxypentanoic acid, and hydroxypyvalic acid. Some suitable lactones include epsilon-caprolactone, valerolactone; and lactones of the corresponding hydroxycarboxylic acids such as 3-hydroxypropionic acid, 3-hydroxybutyric acid, 3-hydroxypentanoic acid, and hydroxypyvalic acid. In certain embodiments, epsilon-caprolactone can be used. In an embodiment, the branched copolyester polymers can be prepared by polymerizing a monomer mixture comprising a chain extender and a hyperbranched monomer in one step, or by first polymerizing the hyperbranched monomer and then polymerizing the chain extender. It should be understood that the branched copolyester polymers can be formed from an acrylic-type core having the above incremental monomers.

[0068] Polyester-polyurethane polymers can be produced from polyesters and polyisocyanates. The polyesters can be polymeric or oligomeric organic substances having at least two hydroxyl functional groups or two mercapto functional groups and mixtures thereof. Polyesters and polycarbonates having terminal hydroxyl groups can be effectively used as diols.

[0069] Polyurethane polymers can be produced by reacting (one or more) polyisocyanates with an excess of (one or more) polyols. In certain embodiments, low molar mass polyols such as polyhydric alcohols defined by empirical structural formulas are used to form the polyurethane polymers. Non-limiting examples of polyhydric alcohols include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, diethylene glycol, cyclohexylene glycol, cyclohexanedimethanol, trimethylpentanediol, ethylbutylpropanediol, bis-trimethylolpropane, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, polyethylene glycol, and polypropylene glycol. In other embodiments, oligomeric or polymeric polyols having a number average molar mass of, for example, at most 8000, or at most 5000, or at most 2000 and / or, for example, the corresponding hydroxyl-functional polyethers, polyesters, or polycarbonates are used to form the polyurethane polymers.

[0070] Non-limiting examples of suitable polyisocyanates include aromatic, aliphatic, or cycloaliphatic di-, tri-, or tetra-isocyanates, including polyisocyanates having isocyanurate structural units, such as the isocyanurate of hexamethylene diisocyanate and the isocyanurate of isophorone diisocyanate; adducts of two molecules of a diisocyanate (such as hexamethylene diisocyanate) and a diol (such as ethylene glycol); the uretdione of hexamethylene diisocyanate; the uretdione of isophorone diisocyanate or isophorone diisocyanate; an adduct of trimethylolpropane and m-tetramethylxylene diisocyanate. Other polyisocyanates disclosed herein may also be suitable for the production of polyurethanes.

[0071] Waterborne polyurethane binders and their production are well known to those skilled in the art. Non-limiting examples of typical and useful waterborne polyurethane binders include waterborne polyurethane binder dispersions, which can generally be prepared as follows: First, an NCO-functional hydrophilic polyurethane prepolymer is formed by an addition reaction of a polyol compound and a polyisocyanate, the so-formed polyurethane prepolymer is converted into an aqueous phase, and then the water-dispersed NCO-functional polyurethane prepolymer is reacted with an NCO-reactive chain extender such as a polyamine, a hydrazine derivative, or water. Such waterborne polyurethane binder dispersions, which are conventionally used as binders in basecoat (22) / clearcoat double coatings for the production of vehicle bodies and vehicle body parts, can be used in fluid material A; non-limiting examples of waterborne polyurethane binder dispersions that can be used in fluid material A can be found in US 4851460, US 5342882, and US 2010 / 0048811A1, which are hereby incorporated by reference in their entirety.

[0072] A non-limiting example of a polyester-polyurethane polymer is a polyurethane dispersion resin formed from a linear polyester diol resin (the reaction product of the monomers 1,6-hexanediol, adipic acid, and isophthalic acid) and isophorone diisocyanate. This polyester-polyurethane polymer has a weight-average molecular weight of about 30,000, a solids content of about 35% by weight, and a particle size of about 250 nanometers.

[0073] Another non-limiting example of a polyester-polyurethane polymer is a polyurethane dispersion resin formed from a linear polycarbonate-polyester and isophorone diisocyanate. This polyester-polyurethane polymer has a weight-average molecular weight of about 75,000, a solids content of about 35% by weight, and a particle size of about 180 nanometers.

[0074] In certain embodiments, compared to a fluid material without a polyester-polyurethane polymer, a fluid material containing a polyester-polyurethane polymer can exhibit an increase in the elasticity of the fluid material. The increase in the elasticity of the fluid material can improve the application suitability of the fluid material by increasing the relaxation time of the fluid material. In various embodiments, compared to a fluid material containing a polyester-polyurethane polymer with a weight-average molecular weight of 30,000, when incorporated in a fluid material, a polyester-polyurethane polymer with a weight-average molecular weight of 75,000 increases the relaxation time of the fluid material. It should be understood that the relationship between increasing the weight-average molecular weight and increasing the relaxation time of the fluid material may not be limited to polyester-polyurethane polymers. For example, when incorporated into a fluid material, a polymeric fluid material with a weight-average molecular weight of at least 300,000 can cause the fluid material to exhibit an increased relaxation time compared to a fluid material containing a polymer with a weight-average molecular weight of less than 300,000. It should also be understood that incorporating at least a minor concentration of a high molecular weight (e.g., at least 300,000) polymer in a fluid material can be used to improve the suitability of the fluid material by at least minimizing the formation of satellite droplets.

[0075] Based on the total weight of the fluid material, the fluid material can include the polyester-polyurethane polymer in an amount of about 0.1 to about 50, or about 1 to about 20, or about 1 to about 10% by weight. In an exemplary embodiment, the fluid material includes a polyester-polyurethane polymer with the trade name U 241, which is commercially available from Covestro AG (Leverkusen), Germany.

[0076] Latex polymers such as aqueous (meth)acrylic copolymer latex binders and their production are well known to those skilled in the art. Aqueous (meth)acrylic copolymer latex binders can generally be prepared by free radical emulsion copolymerization of ethylenically unsaturated free radically copolymerizable comonomers. For example, WO2006 / 118974A1, WO2008 / 124136A1, WO2008 / 124137A1 and WO2008 / 124141A1 (incorporated herein by reference in their entirety) disclose aqueous (meth)acrylic copolymer latex binders and their use as binders in aqueous basecoat (22) coating compositions such as conventional coating compositions in basecoat (22) / clearcoat double layer coatings for producing automotive bodies and body parts. The aqueous (meth)acrylic copolymer latex binders disclosed in WO2006 / 118974A1, WO2008 / 124136A1, WO2008 / 124137A1 and WO2008 / 124141A1 are non-limiting examples of aqueous (meth)acrylic copolymer latex binders that can be used in fluid materials, and these patents are incorporated herein by reference in their entirety.

[0077] Melamine resins can be partially or fully etherified with one or more alcohols such as methanol or butanol. A non-limiting example is hexamethoxymethylmelamine. Non-limiting examples of suitable melamine resins include monomeric melamines, polymeric melamine-formaldehyde resins or combinations thereof. Monomeric melamines include low molecular weight melamines having on average three or more hydroxymethyl groups etherified with C1 to C5 monohydric alcohols such as methanol, n-butanol or isobutanol per triazine nucleus, and having an average degree of condensation of up to about 2, and in certain embodiments, the average degree of condensation is in the range of about 1.1 to about 1.8, and the proportion of mononuclear species is not less than about 50% by weight. In contrast, polymeric melamines have an average degree of condensation greater than about 1.9. Some such suitable monomeric melamines include alkylated melamines such as methylated, butylated, isobutylated melamines and mixtures thereof. Many of these suitable monomeric melamines are commercially available. For example, Cytec Industries Inc., West Patterson, N.J. supplies 301 (degree of polymerization 1.5, 95% methyl and 5% hydroxymethyl), 350 (degree of polymerization 1.6, 84% methyl and 16% hydroxymethyl), 303, 325, 327, 370 and XW3106, all of which are monomeric melamines. Suitable polymeric melamines include those supplied by Solutia Inc., St. Louis, Mo. or Cytec Industries Inc. 1158 supplied under the name High amino (partially alkylated, -N, -H) melamine of BMP5503 (molecular weight 690, polydispersity 1.98, butyl 56%, amino 44%). Cytec Industries Inc. also provides 1130 at 80% solids (degree of polymerization 2.5), 1133 (methyl 48%, hydroxymethyl 4% and butyl 48%), both polymeric melamines.

[0078] Based on the total weight of the fluid material, the fluid material may include from about 0.1 to about 50, or from about 1 to about 20, or from about 1 to about 10% by weight of a melamine resin. In an exemplary embodiment, the fluid material includes a melamine-formaldehyde resin commercially available under the trade name 303, which is commercially available from Cytec Industries Inc., West Patterson, N.J.

[0079] The binder of the fluid material may also include a crosslinking agent, which can react with crosslinkable functional groups of the binder polymer to form a crosslinked polymer network, referred to herein as a crosslinked network. It should be understood that a crosslinking agent is not necessary in all fluid materials, but may be used in the fluid material to improve interlayer adhesion, such as between a primer and a topcoat, and for curing, such as within a topcoat.

[0080] The term "crosslinking agent" refers to a component having "crosslinkable functional groups", which are functional groups located in each molecule of a compound, oligomer, polymer, the polymer backbone, side chains of the polymer backbone, at the ends of the polymer backbone, or a combination thereof, where these functional groups are capable of crosslinking (during a curing step) with crosslinkable functional groups to produce a coating in the form of a crosslinked structure. One of ordinary skill in the art will recognize that certain combinations of crosslinkable functional groups and crosslinkable functional groups will be excluded because they cannot crosslink and produce a film-forming crosslinked structure. The fluid material may include more than one type of crosslinking agent having the same or different crosslinkable functional groups. Typical crosslinkable functional groups may include hydroxyl, thiol, isocyanate, thioisocyanate, acetoacetoxy, carboxyl, primary amine, secondary amine, epoxy, anhydride, ketimine, aldehyde imine, orthoester, orthocarbonate, cyclic amide, or a combination thereof.

[0081] Polyisocyanates having isocyanate functional groups can be used as crosslinking agents to react with crosslinkable functional groups such as hydroxyl functional groups and amine functional groups. In certain embodiments, only primary and secondary amine functional groups can react with isocyanate functional groups. Suitable polyisocyanates can have on average 2 to 10, or 2.5 to 8, or 3 to 8 isocyanate functional groups. Generally, the ratio of isocyanate functional groups on the polyisocyanate to crosslinkable functional groups (e.g., hydroxyl and / or amine groups) in the fluid material is from about 0.25:1 to about 3:1, or from about 0.8:1 to about 2:1, or from about 1:1 to about 1.8:1. In other embodiments, melamine compounds having melamine functional groups can be used as crosslinking agents to react with crosslinkable functional groups.

[0082] Non-limiting examples of suitable polyisocyanates include any conventionally used aromatic, aliphatic, or cycloaliphatic di-, tri-, or tetra-isocyanates, including polyisocyanates having isocyanurate structural units such as the isocyanurate of hexamethylene diisocyanate and the isocyanurate of isophorone diisocyanate; adducts of 2 molecules of a diisocyanate such as hexamethylene diisocyanate with a diol such as ethylene glycol; the uretdione of hexamethylene diisocyanate; the uretdione of isophorone diisocyanate or isophorone diisocyanate; the isocyanurate of m-tetramethylxylene diisocyanate.

[0083] Polyisocyanate functional adducts having isocyanurate structural units can also be used, for example, adducts of 2 molecules of a diisocyanate such as hexamethylene diisocyanate or isophorone diisocyanate with a diol such as ethylene glycol; the adduct of 3 molecules of hexamethylene diisocyanate with 1 molecule of water (commercially available from Bayer Corporation, Pittsburgh, Pennsylvania under the trade name N); the adduct of 1 molecule of trimethylolpropane with 3 molecules of toluene diisocyanate (commercially available from Bayer Corporation, Pittsburgh, Pennsylvania under the trade name L); the adduct of 1 molecule of trimethylolpropane with 3 molecules of isophorone diisocyanate or a compound such as 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene; and the adduct of 1 molecule of pentaerythritol with 4 molecules of toluene diisocyanate.

[0084] The fluid material can include monomeric, oligomeric, or polymeric compounds that can be cured by ultraviolet (UV), electron beam (EB), laser, etc. Placing a UV, EB, or laser source on the nozzle plate (20) can result in direct photoinitiation of each droplet of the fluid material applied to the substrate (26) by the nozzle plate (20). Increasing the use of monomers relative to polymers can increase the curable solids of the fluid material without increasing the viscosity of the fluid material, thereby reducing the volatile organic carbon (VOC) released into the environment. However, increasing the use of monomers relative to polymers may affect one or more properties of the fluid material. It may be necessary to adjust the properties of the fluid material to make the fluid material suitable for applications using the nozzle plate (20), and these properties include but are not limited to viscosity (η0), density (ρ), surface tension (σ), and relaxation time (λ). In addition, it may be necessary to adjust the properties of the nozzle plate (20) to make the nozzle plate (20) suitable for application, and these properties include but are not limited to the nozzle diameter (D) of the nozzle plate (20), the impact velocity (v) of the fluid material from the nozzle plate (20), the velocity of the nozzle plate (20), the distance of the nozzle plate (20) from the substrate (26), the droplet size of the fluid material from the nozzle plate (20), the ejection rate of the nozzle plate (20), and the orientation of the nozzle plate (20) relative to gravity.

[0085] The fluid material can include monomeric, oligomeric, or polymeric compounds having a number average molecular weight of from about 400 to about 20,000 and having free-radically polymerizable double bonds. The fluid material can also include a photoinitiator.

[0086] Based on the total weight of the fluid material, the fluid material can include from about 20% by weight to about 90% by weight of monomeric, oligomeric, or polymeric compounds. Based on the total weight of the fluid material, the fluid material can include from about 0.1% by weight to about 2% by weight of photoinitiator. It should be understood that based on the total weight of the fluid material, the fluid material including monomeric, oligomeric, or polymeric compounds can have a solids content of up to 100%.

[0087] In various embodiments, the fluid material is aqueous and comprises, based on the total weight of the composition, from about 40% to about 90% by weight of water, or from about 40% to about 70% by weight of water. The fluid material can include any ultraviolet curable water-dispersible or latex polymer. A "latex" polymer refers to a dispersion of polymer particles in water; latex polymers typically require an auxiliary dispersant (e.g., surfactant) to form a dispersion or emulsion of polymer particles in water. A "water-dispersible" polymer refers to a polymer that is capable of dispersing into water by itself (i.e., no separate surfactant is required) or water can be added to the polymer to form a stable water dispersion (i.e., the dispersion should have a shelf stability of at least 1 month at normal storage temperatures). Such water-dispersible polymers can contain nonionic or anionic functional groups on the polymer, which helps to make them water-dispersible. For such polymers, an external acid or base is typically required to stabilize the anions.

[0088] Suitable ultraviolet curable polymers include, but are not limited to, polyurethanes, epoxy resins, polyamides, chlorinated polyolefins, acrylic resins, oil-modified polymers, polyesters, and mixtures or copolymers thereof. The ultraviolet curable polymer in the fluid material can include a variety of functional groups to alter their properties for specific applications, including, for example, acetoacetyl, (meth)acryloyl (where "(meth)acryloyl" refers to any of methacryloyl, methacrylate, acryloyl, or acrylate), vinyl, vinyl ether, (meth)allyl ether (where (meth)allyl ether refers to allyl ether and methallyl ether), or mixtures thereof.

[0089] The acetoacetyl functional group can be incorporated into a UV-curable polymer by using the following substances: acetoacetic acid 2-acryloyloxyethyl ester, acetoacetic acid 3-methacryloyloxypropyl ester, allyl acetoacetate, acetoacetic acid 4-methacryloyloxybutyl ester, 2,3-bis(acetoacetoxy)propyl methacrylate, 2-(acetoacetoxy)ethyl methacrylate, tert-butyl acetoacetate, diketene, etc. or a combination thereof. Generally, any polymerizable hydroxy-functional or other active hydrogen-containing monomer can be converted into the corresponding acetoacetyl-functional monomer by reaction with diketene or other suitable acetoacetylating agents (see, for example, Comparison of Methods for the Preparation of Acetoacetylated Coating Resins, Witzeman, J.S.; Dell Nottingham, W.; Del Rector, F.J. Coatings Technology; Vol. 62, 1990, 101 (and references contained therein)). In a fluid material, the acetoacetyl functional group is incorporated into the polymer via 2-(acetoacetoxy)ethyl methacrylate, tert-butyl acetoacetate, diketene, or a combination thereof.

[0090] The fluid material can incorporate free-radically polymerizable components, which include at least one component containing a free-radically polymerizable functional group. Representative examples of suitable free-radically polymerizable functional groups include (meth)acrylate groups, ethylenic carbon-carbon double bonds, allyloxy groups, α-methylstyrene groups, (meth)acrylamide groups, cyanate ester groups, (meth)acrylonitrile groups, vinyl ether groups, combinations thereof, etc. Unless otherwise explicitly stated, the term "(meth)acryloyl" as used herein includes acryloyl and / or methacryloyl. In many cases, the acrylic moiety can be used as compared to the methacrylic moiety because the acrylic moiety tends to cure faster.

[0091] Before curing is initiated, the free-radically polymerizable groups can provide a composition with a relatively long shelf life, which prevents premature polymerization during storage. In use, polymerization can be initiated as needed under good control by using one or more suitable curing techniques. Exemplary curing techniques include, but are not limited to, exposure to thermal energy; exposure to one or more types of electromagnetic energy, such as visible light, ultraviolet light, infrared light, etc.; exposure to sound energy; exposure to accelerated particles such as electron beam energy; contact with a chemical curing agent, such as by using a peroxide-initiated polymerization with styrene and / or styrene mimics; peroxide / amine chemistry; combinations thereof; and so on. When the curing of such functional groups is initiated, crosslinking can occur relatively rapidly, and thus the resulting coating will develop early green strength. This curing is generally carried out to completion under a wide range of conditions to avoid excessive levels of residual reactivity.

[0092] In addition to free-radically polymerizable functional groups, the free-radically polymerizable components incorporated into the free-radically polymerizable composition can include other types of functional groups, including other types of curing functional groups, functional groups that promote particle dispersion, adhesion, scratch resistance, chemical resistance, wear resistance, and combinations thereof. For example, in addition to free-radically polymerizable functional groups, the free-radically polymerizable components can also include additional crosslinkable functional groups to allow the composition to form an interpenetrating polymer network upon curing. An example of such other crosslinkable functional groups includes OH and NCO groups, which react together to form urethane bonds. The reaction between OH and NCO can generally be promoted by using a suitable crosslinking agent and catalyst. To aid in the dispersion of particulate additives, particularly ceramic particles, the components of the free-radically polymerizable composition can include pendant dispersant moieties such as the acid or salt moieties of sulfonates / esters, sulfates / esters, phosphonates / esters, phosphates / esters, carboxylates / esters, (meth)acrylonitrile, ammonium, quaternary ammonium, and combinations thereof. Other functional groups can be selected to promote adhesion, gloss, hardness, chemical resistance, flexibility, etc. Examples include epoxy resins, slime, siloxanes, alkoxys, esters, amines, amides, polyurethanes, polyesters; and combinations thereof.

[0093] The one or more free-radically polymerizable components incorporated into the free-radically polymerizable composition can be aliphatic and / or aromatic. For outdoor applications, aliphatic materials tend to exhibit better weather resistance.

[0094] The one or more free-radically polymerizable components incorporated into the free-radically polymerizable composition can be linear, branched, cyclic, fused, combinations thereof, etc. For example, in some cases, branched resins can be used because the viscosities of these resins may be lower than those of their linear counterparts of comparable molecular weight.

[0095] In those embodiments where the fluid material is a fluid dispersion, the free-radically polymerizable composition can be used as at least a portion of the fluid carrier for the particulate components of the composition. The fluid material is as solvent-free as possible such that the radiation-curable component essentially serves as the entire fluid carrier. Some free-radically polymerizable components exist in solid form at room temperature but are often readily soluble in one or more of the other components used to provide the free-radically polymerizable composition. When cured, the resulting matrix serves as a binder for the other components in the composition.

[0096] Illustrative embodiments of the radiation-curable composition desirably include a reactive diluent that comprises one or more free-radically polymerizable components having a weight-average molecular weight of less than about 750, or in the range of about 50 to about 750, or about 50 to about 500. The reactive diluent serves as a diluent, as a reagent for reducing the viscosity of the fluid material, as a coating binder / matrix upon curing, as a crosslinking agent, etc.

[0097] The radiation-curable component also optionally includes at least one free-radically polymerizable resin mixed with a reactive diluent. Generally, if the molecular weight of the resin is too large, the composition may tend to be too viscous to handle. This can also affect the appearance of the resulting coating. On the other hand, if the molecular weight is too low, the toughness or elasticity of the resulting composition may be affected. Controlling the film thickness may also be more difficult, and the resulting coating may be more brittle than expected. Balancing these issues, the term resin generally encompasses free-radically polymerizable materials having a weight-average molecular weight of about 750 or greater, or about 750 to about 20,000, or about 750 to about 10,000, or about 750 to about 5000, or about 750 to about 3000. Generally, if the one or more resins are solids at about room temperature, they are soluble in the reactive diluent such that the radiation-curable component is a single fluid phase. As used herein, unless otherwise expressly stated, molecular weight refers to the weight-average molecular weight.

[0098] Ideally, the reactive diluent includes at least one component that is monofunctional with respect to free-radically polymerizable functionality, at least one component that is difunctional with respect to free-radically polymerizable functionality, and at least one component that is trifunctional or higher-functional with respect to free-radically polymerizable functionality. A reactive diluent including such a combination of components helps to provide a cured coating having excellent abrasion resistance while maintaining a high level of toughness.

[0099] Representative examples of monofunctional, free-radically polymerizable components suitable for use as reactive diluents include styrene, α-methylstyrene, substituted styrenes, vinyl esters, vinyl ethers, lactams such as N-vinyl-2-pyrrolidone, (meth)acrylamides, N-substituted (meth)acrylamides, octyl (meth)acrylate, nonylphenol ethoxylate (meth)acrylate, isononyl (meth)acrylate, 1,6-hexanediol (meth)acrylate, isobornyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, β-carboxyethyl (meth)acrylate, isobutyl (meth)acrylate, alicyclic epoxides, α-epoxides, 2-hydroxyethyl (meth)acrylate, (meth)acrylonitrile, maleic anhydride, itaconic acid, isodecyl (meth)acrylate, dodecyl (meth)acrylate, n-butyl (meth)acrylate, methyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylic acid, N-vinylcaprolactam, stearyl (meth)acrylate, hydroxy-functional caprolactone (meth)acrylate, octadecyl (meth)acrylate, isooctyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxyisopropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxyisobutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and combinations thereof. If one or more such monofunctional monomers are present, these monofunctional monomers can comprise from 0.5 to about 50, or from 0.5 to 35, or from about 0.5 to about 25% by weight of the radiation-curable component, based on the total weight of the free-radically polymerizable components.

[0100] In some embodiments, the monofunctional component of the reactive diluent comprises a lactam having a free-radically polymerizable functional group with a side chain and at least one other component that is monofunctional with respect to free-radical polymerizability functionality. The weight-average molecular weight of at least one such other monofunctional component is in the range of from about 50 to about 500. The weight ratio of the lactam to the one or more other monofunctional components is desirably in the range of from about 1:50 to 50:1, or from 1:20 to 20:1, or from about 2:3 to about 3:2. In an illustrative embodiment, the use of N-vinyl-2-pyrrolidone and octadecyl acrylate in a weight ratio of about 1:1 will provide a suitable monofunctional component of the reactive diluent.

[0101] The di-, tri- and / or higher functionality components of the reactive diluent contribute to improving one or more properties of the cured composition, including crosslink density, hardness, abrasion resistance, chemical resistance, scratch resistance, etc. In many embodiments, these components can include from 0.5 to about 50, or from 0.5 to 35, or from about 0.5 to about 25% by weight of the free-radically polymerizable component, based on the total weight of the free-radically polymerizable component. Examples of such higher functionality radiation curable monomers include ethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, dipentaerythritol penta(meth)acrylate, and combinations thereof, etc. Other suitable free-radically polymerizable monomers include those described in PCT Publication No. WO 02 / 077109.

[0102] In many embodiments, it is desirable that the reactive diluent includes at least one trifunctional or higher functionality material having a molecular weight in the range of about 50 to about 500 to promote abrasion resistance. The amount of such trifunctional or higher functionality material used in the reactive diluent can vary over a wide range. In many desirable embodiments, based on the total weight of the reactive diluent, at least about 15% by weight, or at least about 20% by weight, at least about 25% by weight, or even at least 45% by weight of the reactive diluent is at least trifunctional or higher functionality. These desirable embodiments combine an atypically high level of trifunctional or higher functionality to increase crosslink density and the corresponding high hardness and scratch resistance, but still exhibit excellent toughness.

[0103] Typically, one would expect that using such a high crosslink density would come at too high a cost in terms of toughness and / or elasticity to achieve high hardness and scratch resistance. The conventional expectation would be that the resulting composition would be too brittle to be practical. However, a relatively large amount of trifunctional or higher functionality groups can be incorporated into the reactive diluent while still maintaining a very good level of toughness and elasticity. As described below, in some embodiments, the diluent material can be combined with a performance-enhancing free-radically polymerizable resin and various selected particles, including ceramic particles, organic particles, certain other additives, and combinations thereof.

[0104] The resulting free-radically polymerizable component also has rheological properties to support a relatively large amount of particle distribution. This means that the free-radically polymerizable component can load particles and other additives at very high levels, and the other additives help to promote desired properties such as scratch resistance, toughness, durability, etc. In many embodiments, the composite mixture of the free-radically polymerizable material and the particulate component can have pseudoplastic and thixotropic properties to help control and promote the smoothness, uniformity, aesthetics, and durability of the resulting cured composition. In particular, the desirable thixotropic properties help to reduce particle settling after application. In other words, the free-radically polymerizable component provides a vehicle in which the particle distribution remains very stable during storage and after application to the substrate (26). This stability includes largely helping to hold the particles at the substrate (26) after application to the substrate (26). By maintaining the particle population at the substrate (26), high scratch resistance at the substrate (26) is maintained.

[0105] In some embodiments, in addition to the free-radically polymerizable functional groups, at least one component of the reactive diluent optionally includes epoxy functional groups. In one exemplary embodiment, a diacrylate component having a weight average molecular weight of about 500 to 700 and including at least one backbone moiety derived from an epoxy functional group is incorporated into the reactive diluent. An example of such a material is commercially available under the trade name CN120 from Sartomer Co. A blend containing 80 parts by weight of this oligomer and 20 parts by weight of TMPTA is also available from this source under the trade name CN120C80. In some embodiments, it would be suitable to use about 1 to about 25, or about 8 to 20 parts by weight of such an oligomer per about 1 to about 50, or 5 to 20 parts by weight of the monofunctional component of the reactive diluent. In one exemplary embodiment, it would be suitable to use about 15 to 16 parts by weight of the CN120-80 mixture per about 12 parts by weight of the monofunctional component.

[0106] In addition to the reactive diluent, the free-radically polymerizable component can include one or more free-radically polymerizable resins. When the free-radically polymerizable component includes one or more free-radically polymerizable resins, the amount of such resins incorporated into the composition can vary within a wide range. As a general guideline, the weight ratio of the free-radically polymerizable resin to the reactive diluent can typically be in the range of about 1:20 to about 20:1, or 1:20 to 1:1, or 1:4 to 1:1, or about 1:2 to 1:1.

[0107] In an illustrative embodiment, the free-radically polymerizable resin component desirably includes one or more resins such as (meth)acrylated polyurethanes (i.e., polyurethane (meth)acrylates), (meth)acrylated epoxy resins (i.e., epoxy (meth)acrylates), (meth)acrylated polyesters (i.e., polyester (meth)acrylates), (meth)acrylated (meth)acrylics, (meth)acrylated silicones, (meth)acrylated amines, (meth)acrylated amides; (meth)acrylated polysulfones; (meth)acrylated polyesters, (meth)acrylated polyethers (i.e., polyether (meth)acrylates), vinyl (meth)acrylates, and (meth)acrylated oils. In practice, referring to a resin by its class (e.g., polyurethane, polyester, silicone, etc.) means that the resin includes at least one partial characteristic of that class, even if the resin includes portions from another class. Thus, a polyurethane resin includes at least one urethane bond (linkage), but may also include one or more other types of polymer bonds.

[0108] Representative examples of free-radically polymerizable resin materials include radiation-curable (meth)acrylates, polyurethanes, and polyurethane (meth)acrylates (including aliphatic polyester polyurethane (meth)acrylates), such as the materials described in U.S. Patent Nos. 5,453,451, 5,773,487, and 5,830,937. Other suitable free-radically polymerizable resins include those described in PCT Publication No. WO 02 / 077109. A large number of such materials are commercially available.

[0109] Embodiments of the resin component include at least a first free-radically polymerizable polyurethane resin having a glass transition temperature (Tg) of at least 50 °C and being at least trifunctional, or at least tetrafunctional, or at least pentafunctional, or at least hexafunctional with respect to free-radical polymerizable functionality. The Tg of the first resin is desirably at least about 60 °C, or at least about 80 °C, or at least about 100 °C. In one mode of practice, a free-radically polymerizable polyurethane resin having a Tg of about 50 °C to 60 °C and being hexavalent with respect to (meth)acrylate functionality would be suitable. An exemplary embodiment of such a hexafunctional resin is commercially available from Rahn under the trade name Genomer 4622.

[0110] In some embodiments, the first resin is used in combination with one or more other types of resins. Optionally, at least one such other resin is also free-radically polymerizable. For example, some embodiments mix the first resin with at least a second free-radically polymerizable resin, which can be monofunctional or polyfunctional in terms of the free-radically polymerizable moiety. If present, the second free-radically polymerizable resin can have a wide range of Tg, such as from -30 °C to 120 °C. In some embodiments, the Tg of the second resin is less than 50 °C, or less than about 30 °C, or less than about 10 °C. Many embodiments of such a resin are polyurethane materials. An exemplary embodiment of such a resin is commercially available from Bayer MaterialSciencc AG under the trade name Desmolux U500 (formerly known as Desmolux XP2614).

[0111] The resins can be selected to achieve the desired gloss target. For example, formulating a composition with a first free-radically polymerizable resin having a relatively high Tg of more than about 50 °C in combination with an optional second free-radically polymerizable resin having a relatively low Tg, such as below about 30 °C, helps to provide a coating having a medium range gloss (e.g., about 50 to about 70) or a high range gloss (greater than about 70). Formulating with only one or more free-radically polymerizable resins having a relatively high Tg tends to help provide a coating having a lower gloss (e.g., below about 50).

[0112] The weight ratio of the first resin to the second resin can vary within a wide range. For embodiments where the Tg of the second resin is below about 50 °C, in order to provide a coating having excellent abrasion resistance and toughness, it is desirable if the ratio of the second, lower Tg resin to the first, higher Tg resin is in the range of about 1:20 to 20:1, or less than 1:1, such as in the range of about 1:20 to about 1:1, or about 1:20 to about 4:5, or about 1:20 to about 1:3. In an illustrative embodiment, a weight ratio of about 9:1 would be suitable.

[0113] One exemplary embodiment of a free-radically polymerizable component that includes a trifunctional or higher-functional reactive diluent with an atypically high content includes from about 1 to about 10, or from about 4 to about 8 parts by weight of a lactam such as N-vinyl-2-pyrrolidone; from about 1 to about 10, or from about 2 to about 8 parts by weight of another monofunctional material having a molecular weight of less than about 500, such as octadecyl acrylate; from about 5 to about 25, or from about 7 to about 30 parts by weight of a difunctional reactive diluent such as 1,6-hexanediol diacrylate; from about 1 to about 8, or from about 2 to about 5 parts by weight of a trifunctional reactive diluent having a molecular weight of less than about 500, such as trimethylolpropane triacrylate TMPTA; from about 1 to about 20 parts by weight of a trifunctional oligomer having a molecular weight in the range of about 500 to about 2000; from about 1 to about 40 parts by weight of a difunctional oligomer having an epoxy functional group and a molecular weight in the range of about 500 to about 2000; from about 1 to about 15 parts by weight of a first resin; and from about 1 to about 15 parts by weight of a second resin.

[0114] In an alternative embodiment, the coating includes a first coating that provides a colored graphic (such as a pattern), which is applied by means of a high-transfer-efficiency applicator to apply a colored coating. For the purpose of protecting the first colored coating layer, a second transparent coating consisting of one or more overcoats (or topcoats (30 layers)) is superimposed on the first coating layer.

[0115] In one embodiment, a fluid material is used, including, for example, pigments, oligomers, reactive diluents, and other additives familiar to those skilled in the art. Suitable pigments are, for example, Pigment Yellow 213, PY 151, PY 93, PY 83, Pigment Red 122, PR 168, PR 254, PR 179, Pigment Red 166, Pigment Red 48:2, Pigment Violet 19, Pigment Blue 15:1, Pigment Blue 15:3, Pigment Blue 15:4, Pigment Green 7, Pigment Green 36, Pigment Black 7, or Pigment White 6. Suitable oligomers are, for example, aliphatic and aromatic polyurethane acrylates, polyether acrylates, and epoxy acrylates, and these acrylates can optionally be monofunctional or polyfunctional, such as difunctional, trifunctional to hexafunctional, and decafunctional. Suitable reactive diluents are, for example, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, and isodecyl acrylate. Other additives can be added to the ink to adjust their properties, and such other additives are, for example, dispersant additives, defoamers, photoinitiators, and UV absorbers.

[0116] In one embodiment, an overcoat layer is used. Suitable overcoat layers are, for example, products based on one-component (1K) or two-component (2K) isocyanate crosslinking systems (polyurethanes) or based on 1K or 2K epoxy systems (epoxy resins). In certain embodiments, a 2K system is employed. The overcoat layer used according to the invention can be transparent or translucent.

[0117] In two-component isocyanate crosslinking systems, isocyanates such as oligomers based on hexamethylene diisocyanate (HDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI) or tolylene diisocyanate (TDI), such as isocyanurates, biurets, urethanes and adducts of the above isocyanates with polyols and mixtures thereof are used as curing components. Polyols such as OH-group-containing polyesters, polyethers, acrylates and polyurethanes and mixtures thereof are used as binder components, and the polyols can be solvent-based, solvent-free or water-dilutable.

[0118] In two-component epoxy systems, epoxy resins such as glycidyl ethers of bisphenols (such as bisphenol A or bisphenol F) and epoxidized aliphatic parent substances and mixtures thereof are used as binder components. NH-functional substances such as amines, amides and adducts of epoxy resins with amines and mixtures thereof are used as curing components.

[0119] Conventional commercially available isocyanate curing agents in the case of binders containing polyols and NH-functional curing agents in the case of binders containing epoxy resins can be used as curing components.

[0120] The mixing ratio of the binder and the curing component is selected such that the weights of the respective components are present in a ratio of OH:NCO or epoxy:NH in the range of 1:0.7 to 1:1.5, or 1:0.8 to 1:1.2 or 1:1, in each case based on the amount of substance of the reactive groups.

[0121] 3-layer coatings can be used in various industrial fields. The basecoat is formed from a primer that can be applied to wood, metal, glass and plastic materials. Examples of suitable primers are products based on one-component (1K) or two-component (2K) isocyanate crosslinking systems (polyurethanes) or based on 1K or 2K epoxy systems (epoxy resins).

[0122] As described above, the fluid material can also include pigments. Any pigments known in the art for fluid materials can be used in the fluid material. Non-limiting examples of suitable pigments include metal oxides, metal hydroxides, effect pigments including metal flakes, chromates such as lead chromate, sulfides, sulfates, carbonates, carbon black, silica, talc, kaolin, phthalocyanine blue and green, organic red, organic chestnut, pearlescent pigments, other organic pigments and dyes and combinations thereof. If desired, pigments free of chromates such as barium metaborate, zinc phosphate, aluminum tripolyphosphate and combinations thereof can also be used.

[0123] Other non-limiting examples of suitable effect pigments include bright aluminum flakes, very fine aluminum flakes, medium grain aluminum flakes, and bright medium coarse aluminum flakes; mica flakes coated with titanium dioxide pigments, also known as pearlescent pigments; and combinations thereof. Non-limiting examples of suitable colored pigments include titanium dioxide, zinc oxide, iron oxide, carbon black, monoazo red toner, iron oxide red, quinacridone maroon, transparent iron oxide red, dioxazine carbazole violet, iron blue, indanthrone blue, chromium titanate, titanium yellow, monoazo permanent orange, iron yellow, monoazo benzimidazolone yellow, transparent iron oxide yellow, isoindoline yellow, tetrachloroisoindoline yellow, anthrone orange, lead chromate yellow, phthalocyanine green, quinacridone red, perylene maroon, quinacridone violet, pre-dulled chrome yellow, thioindigo red, transparent iron oxide red flakes, molybdenum orange, molybdenum orange red, and combinations thereof.

[0124] The fluid material may also include extender pigments. Although extender pigments are typically used to replace more costly pigments in the fluid material, the extender pigments contemplated herein can increase the shear viscosity of the fluid material compared to a fluid material without extender pigments. The increase in the shear viscosity of the fluid material can improve the applicability of the fluid material when applied to a substrate (26) using a nozzle plate (20). The extender pigments can have a particle size of from about 0.01 to about 44 microns. The extender pigments can have a variety of configurations including, but not limited to, nodular, flake, needle, and fibrous. Non-limiting examples of suitable extender pigments include chalk, barite, amorphous silica, fumed silica, diatomaceous silica, clay, calcium carbonate, phyllosilicate (mica), wollastonite, magnesium silicate (talc), barium sulfate, kaolin, and aluminum silicate.

[0125] Based on the total weight of the fluid material, the fluid material can include from about 0.1 to about 50, or from about 1 to about 20, or from about 1 to about 10% by weight of extender pigment. In certain embodiments, the fluid material includes magnesium silicate (talc), barium sulfate, or a combination thereof. In various embodiments, including barium sulfate as an extender pigment results in a greater shear viscosity of the fluid material compared to including talc as an extender pigment.

[0126] The fluid material may also include dyes. Non-limiting examples of suitable dyes include triphenylmethane dyes, anthraquinone dyes, xanthene and related dyes, azo dyes, reactive dyes, phthalocyanine compounds, quinacridone compounds, and fluorescent brighteners, and combinations thereof. Based on the total weight of the fluid material, the fluid material can include from about 0.01 to about 5, or from about 0.05 to about 1, or from about 0.05 to about 0.5% by weight of dye. In certain embodiments, the fluid material includes a 10% solution of a black dye, such as Sol. Orasol Negro RL.

[0127] The fluid material may also include a rheology modifier. Many different types of rheology modifiers can be used in the fluid material. For example, a rheology modifier that increases the rheology of the fluid material can be used compared to a fluid material without a rheology modifier. The increase in the rheology of the fluid material can improve the applicability of the fluid material applied to the substrate (26) using the nozzle plate (20). Non-limiting examples of suitable rheology modifiers include urea-based compounds, lithium saponite propylene glycol solutions, acrylic-based alkaline emulsions, and combinations thereof. Based on the total weight of the fluid material, the fluid material may include from about 0.01 to about 5, or from about 0.05 to about 1, or from about 0.05 to about 0.5% by weight of the rheology modifier. In certain embodiments, the fluid material includes a lithium saponite propylene glycol solution, an acrylic-based alkaline emulsion, or a combination thereof. The Laponite propylene glycol solution contains synthetic layered silicate, water, and polypropylene glycol. The synthetic layered silicate is commercially available from Altana AG, Wesel, Germany under the trade name Laponite RD. The acrylic-based alkaline emulsion is commercially available from BASF Corporation, Florham Park, New Jersey under the trade name HV 30.

[0128] The fluid material may also include an organic solvent. In an embodiment, when the organic solvent content is greater than about 50% by weight, or greater than 60% by weight, or greater than 70% by weight, or greater than 80% by weight, or greater than 90% by weight based on the total weight of the liquid carrier in the fluid material, the fluid material is a solvent-based fluid material. Non-limiting examples of suitable organic solvents may include aromatic hydrocarbons such as toluene, xylene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, and diisobutyl ketone; esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, and combinations thereof. In an embodiment, the evaporation rate of the solvent may affect the printing applicability of the fluid material. Certain co-solvents can be incorporated into the fluid material with an increased or decreased evaporation rate, thereby increasing or decreasing the evaporation rate of the fluid material.

[0129] The fluid material may also include water. In an embodiment, when the water content is greater than about 50% by weight, or greater than 60% by weight, or greater than 70% by weight, or greater than 80% by weight, or greater than 90% by weight based on the total weight of the liquid carrier in the fluid material, the fluid material is a water-based fluid material. The fluid material may have a pH of from about 1 to about 14, or from about 5 to about 12, or from about 8 to about 10.

[0130] The fluid material may also include a catalyst. The fluid material may also include a catalyst to reduce the curing time and allow the fluid material to cure at ambient temperature. Ambient temperature generally refers to a temperature in the range of 18 °C to 35 °C. Non-limiting examples of suitable catalysts may include organometallic salts such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dichloride, dibutyltin dibromide, zinc naphthenate; triphenylboron, titanium tetraisopropoxide, triethanolamine titanate chelate, dibutyltin dioxide, dibutyltin dioctoate, stannous octoate, aluminum titanate, chelated aluminum, chelated zirconium, hydrocarbon halophosphorus such as ethyltriphenylphosphonium iodide and other such phosphonium salts and other catalysts or combinations thereof. Non-limiting examples of suitable acid catalysts may include carboxylic acids, sulfonic acids, phosphoric acids or combinations thereof. In some embodiments, the acid catalyst may include, for example, acetic acid, formic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, p-toluenesulfonic acid, phosphoric acid or combinations thereof. Based on the total weight of the fluid material, the fluid material may include from about 0.01 to about 5, or about 0.05 to about 1, or about 0.05 to about 0.5% by weight of the catalyst.

[0131] The fluid material may also include conventional additives. The fluid material may also include an ultraviolet light stabilizer. Non-limiting examples of such ultraviolet stabilizers include ultraviolet absorbers, screening agents, quenchers and hindered amine light stabilizers. Antioxidants may also be added to the fluid material. Typical ultraviolet light stabilizers may include benzophenone, triazole, triazine, benzoate, hindered amines and mixtures thereof. Hindered amine light stabilizers such as 328 and a blend of 123, both of which are commercially available from Ciba Specialty Chemicals, Tarrytown, New York under the trade name commercially available.

[0132] Non-limiting examples of suitable UV absorbers include hydroxyphenylbenzotriazoles such as 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole, 2-[2-hydroxy-3,5-bis(1,1-dimethylbenzyl)phenyl]-2H-benzotriazole, the reaction product of 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-2H-benzotriazole with polyethylene glycol having a weight average molecular weight of 300, 2-(2-hydroxy-3-tert-butyl-5-isooctylphenyl)-2H-benzotriazole; hydroxyphenyltriazines such as 2-[4((2,-hydroxy-3-dodecyloxy / tridecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4(2-hydroxy-3-(2-ethylhexyl)oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(4-octyloxy-2-hydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; hydroxybenzophenone UV absorbers such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-octyloxybenzophenone and 2-hydroxy-4-dodecyloxybenzophenone.

[0133] Non-limiting examples of suitable hindered amine light stabilizers include N-(1,2,2,6,6-pentamethyl-4-piperidinyl)-2-dodecylsuccinimide, N(1-acetyl-2,2,6,6-tetramethyl-4-piperidinyl)-2-dodecylsuccinimide, N-(2-hydroxyethyl)-2,6,6,6-tetramethylpiperidine-4-ol-succinic acid copolymer, 1,3,5-triazine-2,4,6-triamine, N,N’”-[1,2-ethanediylbis[[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazin-2-yl]imino]-3,1-propanediyl]], bis[N,N’”-dibutyl-N’,N’”-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)], poly-[(2,2,6,6-tetramethyl-4-piperidinyl)-imino])bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate [[6-[1,1,3,3-tetramethylbutyl)-amino]-1,3,5-triazine(trianzine)-2,4-diyl][2,2,6,6-tetramethylpiperidinyl)-imino]-1,6-hexanediyl ester, sebacic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl ester), sebacic acid bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl ester), [3,5-bis(1,1-dimethylethyl-4-hydroxy-phenyl)methyl]butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl ester), 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro(4,5)decane-2,4-dione and 3-(2,2,4,4-tetramethyl-2l-oxo-7-oxa-3,20-diazadispiro(5.1.11.2)heneicosan-20-yl)propionic acid dodecyl / tetradecyl ester.

[0134] Non-limiting examples of suitable antioxidants include tetra[methylene(3,5-di-tert-butylhydroxyhydrocinnamate)]methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, tris(2,4-di-tert-butylphenyl)phosphite, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 3,5-bis(1,1-dimethylethyl)-4-hydroxy-C7-C9 branched alkyl phenylpropionate. In certain embodiments, the antioxidant includes a hydroperoxide decomposer such as HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), triphenyl phosphate and other organophosphorus compounds such as those from Ciba Specialty Chemicals TNPP, those from CibaSpecialty Chemicals 168, from GE Specialty Chemicals 626, Mark PEP-6 from Asahi Denka, Mark HP-10 from Asahi Denka, from Ciba Specialty Chemicals P-EPQ, Ethanox 398 from GE Specialty Chemicals, Weston 618 from GE Specialty Chemicals, from Ciba Specialty Chemicals 12, from Ciba Specialty Chemicals 38, from GE Specialty Chemicals 641 and from Dover Chemicals S-9228.

[0135] The fluid material may also include other additives known in the art for fluid materials. Non-limiting examples of such additives can include wetting agents, leveling agents, and flow control agents, such as the respective commercial names S (butyl acrylate), 320 and 325 (high molecular weight polyacrylate), 347 (polyether modified silicone) products, leveling agents based on (meth) acrylic acid type homopolymers; rheology control agents; thickeners, such as partially crosslinked polycarboxylic acids or polyurethanes; and defoamers. Other additives can be used in conventional amounts familiar to those skilled in the art. In an embodiment, the wetting agent, leveling agent, flow control agent, and surfactant of the fluid material can affect the surface tension of the fluid material, and thus can affect the printing suitability of the fluid material. Certain wetting agents, leveling agents, flow control agents, and surfactants can be incorporated into the fluid material to increase or decrease the surface tension of the fluid material.

[0136] Depending on the type of crosslinking agent, the fluid material of the present invention can be formulated into a one-component (1K) or two-component (2K) fluid material. The one-component fluid material can be an air-dried coating or an unactivated coating. The term "air-dried coating" or "unactivated coating" refers to a coating that dries mainly by solvent evaporation and does not require crosslinking to form a coating film with desired properties. If a polyisocyanate having free isocyanate groups is used as a crosslinking agent, the fluid material can be formulated into a two-component fluid material because the crosslinking agent is only mixed with other components of the fluid material immediately before coating. For example, if a blocked polyisocyanate is used as a crosslinking agent, the fluid material can be formulated into a one-component (1K) fluid material.

[0137] "Two-component fluid material" or "two-component liquid material" refers to a thermosetting fluid material containing two components stored in separate containers. These containers are typically sealed to increase the shelf life of the components of the fluid material. The components are mixed prior to use to form a can mix. The can mix is applied as a layer of the desired thickness to a substrate (26), such as an automotive body or body part. After application, the layer is cured under ambient conditions or baked at an elevated temperature to cure to form a coating having the desired coating properties on the substrate (26), such as high gloss, smooth appearance, and durability.

[0138] The fluid material can have a solids content of about 5 to about 90, or 5 to about 80, or about 15 to about 70% by weight. The solids content can be determined according to ASTM D2369-10. In certain embodiments, a fluid material with a higher solids content may be required because the fluid material is not atomized using conventional equipment.

[0139] Based on the total weight of the fluid material, the fluid material can include from about 0.1 to about 30% by weight (wt%), or about 0.5% by weight to about 20% by weight, or about 1% by weight to about 10% by weight of primary or colorant pigments.

[0140] Based on the total weight of the fluid material, the fluid material can include from about 5 to about 70% by weight, or about 10 to about 50% by weight, or about 15 to about 25% by weight of a binder.

[0141] Based on the total weight of the fluid material, the fluid material can include from about 1 to about 20% by weight, or about 2 to about 10% by weight, or about 4 to about 6% by weight of a crosslinking agent.

[0142] The fluid material can be substantially free of dyes. As used herein, the term "substantially" means that the fluid material can contain a non-significant amount of dye such that the color and / or properties of the fluid material are not affected by the added non-significant amount of dye, and the fluid material is still considered to be substantially free of dyes. In embodiments, the fluid material substantially free of dyes includes no more than 5% by weight, or no more than 1% by weight, or no more than 0.1% by weight of dye.

[0143] The fluid material may include one or more pigments. Non-limiting examples of suitable primary color pigments include pigments having color properties useful in the present invention, including: blue pigments, including indanthrone blue pigment blue 60, phthalocyanine blue pigment blue 15:1, 15:, 15:3 and 15:4, and cobalt blue pigment blue 28; red pigments including quinacridone red pigment red 122 and pigment red 202, iron oxide red pigment red 101, perylene scarlet pigment red 149, pigment red 177, pigment red 178 and maroon pigment red 179, Azoic Red pigment red 188 and diketo-pyrrolo-pyrrole red pigment red 255 and pigment red 264; yellow pigments, including benzidine yellow pigment yellow 14, iron oxide yellow pigment yellow 42, nickel titanate yellow pigment yellow 53, indolinone yellow pigment yellow 110 and pigment yellow 139, monoazo yellow pigment yellow 150, bismuth vanadium yellow pigment yellow 184, disazo yellow pigment yellow 128 and pigment yellow 155; orange pigments, including quinacridone orange pigment pigment yellow 49 and pigment orange 49, benzimidazolone orange pigment orange 36; green pigments, including phthalocyanine green pigment green 7 and pigment green 36, and cobalt green pigment green 50; purple pigments, including quinacridone violet pigment violet 19 and pigment violet 42, dioxazine violet pigment violet 23 and perylene violet pigment violet 29; brown pigments, including monoazo brown pigment brown 25 and chromium antimony titanate pigment brown 24, iron oxide chromium pigment brown 29; white pigments such as anatase and rutile type titanium dioxide (TiO2) pigment white 6; and black pigments, including carbon black pigment black 6 and pigment black 7, perylene black pigment black 32, copper chromate black pigment black 28. Alternatively, effect pigments such as metallic flake pigments, mica-containing pigments, glass-containing pigments, and combinations thereof may be included. Functional pigments such as radar-reflective pigments, LiDAR-reflective pigments, corrosion-inhibiting pigments, and combinations thereof may also be included.

[0144] The fluid material may also contain functional additives to improve the properties of the fluid material. The functional additives may be selected from anti-sagging agents, pH regulators, catalysts, surface tension regulators, solubility regulators, adhesion promoters, and combinations thereof.

[0145] If the fluid material is used to form a coating, the coating is not particularly limited. For example, in one embodiment, according to ASTM D4752, the coating may have a solvent resistance of at least 5 double methyl ethyl ketone (MEK) rubs, or at least 20 MEK double rubs, or at least 20 MEK double rubs on a non-porous substrate (26). According to ASTM 5026-15, the coating may have a film tensile modulus of at least 100 MPa, or at least 100 MPa, or at least 200 MPa. According to ASTM D5026-15, a coating formed from a fluid material containing a crosslinking agent may have at least 0.2 mmol / cm 3 、or at least 0.5 mmol / cm 3, or at least 1.0 mmol / cm 3 The crosslink density. According to ASTM 2813, at a 20-degree specular angle, the coating can have a gloss value of at least 75, or at least 88, or at least 92. According to ASTM D7869, after 2000 hours of weathering exposure, the coating can have a gloss retention rate of at least 50%, or at least 70%, or at least 90% of the initial gloss value.

[0146] Now looking at the substrate (26), the substrate (26) is not particularly limited and can be any substrate known in the art. In various embodiments, the substrate (26) can include a metal-containing material, a plastic-containing material, or a combination thereof. In certain embodiments, the substrate (26) is substantially non-porous. As used herein, the term "substantially" means that at least 95%, at least 96%, at least 97%, at least 98%, at least 99% of the coating surface has no pores. Fluid materials can be used to coat any type of substrate (26) known in the art. In an embodiment, the substrate (26) is a vehicle, an automobile, or a motor vehicle. "Vehicle" or "automobile" or "motor vehicle" includes: automobiles, such as cars, vans, minivans, buses, SUVs (sport utility vehicles); trucks; semi-trucks; tractors; motorcycles; trailers; ATVs (all-terrain vehicles); pickup trucks; heavy haulers, such as bulldozers, mobile cranes, and excavators; airplanes; small boats; ships; and other means of transportation. Fluid materials can also be used to coat the substrate (26) in industrial applications such as: buildings; fences; tiles; fixed structures; bridges; pipes; cellulose materials (e.g., wood, paper, fibers, etc.). Fluid materials can also be used to coat the substrate (26) in consumer product applications such as: helmets; baseball bats; bicycles; and toys. It should be understood that the term "substrate" as used herein can also refer to a coating disposed on an article that is also considered to be the substrate (26). It should be understood that the term "substrate" as used herein can also refer to a coating disposed on an article that is also considered to be the substrate (26).

[0147] In various non-limiting embodiments, the disclosures of the following references are expressly incorporated herein by separate reference and in combination with one or more of each other:

[0148] Glass Wafer Mechanical Properties: A Comparison To Silicon; Authors: Dr. Gary R. Trott and Dr. Aric Shorey; Corning Incorporated, Corning, New York 14831;

[0149] Effect of Nozzle Length on Breakup Length of Liquid Jet;Memoirs OfThe School Of Engineering, Okayama University, Volume 4, Issue 1, September 1969;

[0150] US2004 / 0217202;

[0151] Multi Nozzle Electrohydrodynamic Inkjet Printing Head By BatchFabrication; MEMS 2013, Taipei City, Chinese Taipei, January 20 - 24, 2013; and

[0152] Capabilities and Limits to Form High Aspect - Ratio Microstructures byMolding of Borosilicate Glass; Journal of Microelectromechanical Systems, Volume 28, Issue 3, June 2019.

[0153] In various non - limiting embodiments, all combinations of the above - described components, structures, chemical materials, method steps, etc. described herein and / or in any reference incorporated herein by reference are expressly contemplated for use herein, even if they are not described in the same paragraph or in relation to a single embodiment. Further, in various non - limiting embodiments, all values herein, even if not expressly so specified, may be considered exact values or approximate values, e.g., ±0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10%. Additionally, in various non - limiting embodiments, all values and ranges of values, including integers and fractions, including those values described in all of the above paragraphs and values and ranges of values between them are hereby expressly contemplated for use.

[0154] In various non - limiting embodiments, including those described in all of the above paragraphs and all numerical values and ranges of values between them, including integers and fractions, are hereby expressly contemplated for use.

[0155] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that a vast number of variations exist. It should also be understood that the at least one exemplary embodiment is merely exemplary and is not intended to limit the scope, applicability, or construction in any way. Instead, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiment. It should be understood that various changes can be made to the functions and arrangements of the elements described in the exemplary embodiment without departing from the scope defined by the appended claims.

Claims

1. A nozzle plate, the nozzle plate defining at least one nozzle connected to the nozzle plate at a base, wherein the at least one nozzle has a height and a top, the top having an inner width and an outer width, wherein the ratio of the height to the inner width is greater than 5, and wherein the nozzle plate comprises borosilicate glass.

2. The nozzle plate according to claim 1, wherein (i) the ratio of the height to the inner width is from 8 to 10; and / or (ii) the top is circular such that the inner width is defined as the inner diameter and the outer width is defined as the outer diameter, wherein the inner diameter is from 0.03 mm to 0.12 mm.

3. A coating apparatus for dispensing a fluid material, the coating apparatus comprising: The nozzle plate according to any one of claims 1-2; A positioning mechanism operatively attached to the nozzle plate, wherein the positioning mechanism is adapted to operate with multiple degrees of freedom; At least one fluid distribution conduit operatively coupled to the nozzle plate and coupled to a fluid material supply, wherein the fluid material is dispensed via the nozzle plate; And A control mechanism operatively coupled to the positioning mechanism, wherein the control mechanism is adapted to control the positioning mechanism to position the nozzle plate and wherein the control mechanism determines the flow of the fluid material to the nozzle plate.

4. A method of manufacturing a nozzle plate, the method comprising the steps of: Providing a silicon wafer having a surface; Providing a borosilicate glass wafer having a surface; Etching the surface of the silicon wafer to form a plurality of grooves in the surface; Anodically connecting the etched surface of the silicon wafer to the surface of the borosilicate glass wafer to form a bilayer composite; Heating the bilayer composite at a temperature of at least 750 °C to soften the borosilicate glass wafer to a molten state such that the molten borosilicate glass flows into the plurality of grooves to form a plurality of nozzles; And Releasing the silicon wafer from the borosilicate glass to form a nozzle plate having the plurality of nozzles, wherein the nozzle plate defines at least one nozzle connected to the nozzle plate at a base, wherein the at least one nozzle has a height and a top, the top having an inner width and an outer width, wherein the ratio of the height to the inner width is greater than 3, and wherein the nozzle plate comprises borosilicate glass.

5. The method according to claim 4, wherein the ratio of the nozzle height to the inner width is from 8 to 10.

6. The method according to claim 4 or 5, wherein the top is circular such that the inner width is defined as the inner diameter and the outer width is defined as the outer diameter, and wherein the inner diameter is from 0.03 mm to 0.12 mm.

7. A method of ejecting a fluid material onto a substrate through a nozzle plate, the method comprising the steps of: Providing a nozzle plate, the nozzle plate defining at least one nozzle connected to the nozzle plate at a base, wherein the at least one nozzle has a height and a top, the top having an inner width and an outer width, wherein the ratio of the height to the inner width is greater than 3, and wherein the nozzle plate comprises borosilicate glass; And A fluid material is ejected through the at least one nozzle to form a jet of the fluid material, and the jet contacts a substrate disposed at a distance (D) from the nozzle; wherein the jet has a breakup length greater than the distance (D) such that the jet does not break up into individual droplets before contacting the substrate.

8. The method according to claim 7, wherein (i) the ratio of the height to the internal width is from 3 to 10; and / or (ii) the top is circular, such that the internal width is defined as the inner diameter and the external width is defined as the outer diameter, wherein the inner diameter is from 0.03 mm to 0.12 mm.

9. The method according to any one of claims 7-8, wherein the step of ejecting the fluid material through the at least one nozzle to form a jet of the fluid material comprises applying an electrostatic charge to the fluid material.

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