Conductive materials and their methods of preparation by metallization with metal complex conductive ink compositions

Abstract

This disclosure provides conductive materials, including conductive textile materials such as woven or knitted textiles, individual fibers and woven fibers and yarns. These conductive materials comprise: a matrix material, such as a textile or other suitable material; and a metal embedded in the matrix material, specifically, wherein the metal is embedded in and below the surface of the material. A method for producing the conductive material is also provided.

Description

[Technical Field] Cross-reference of related applications This application claims the benefit of U.S. Provisional Application No. 62 / 714,641, filed August 3, 2018, the disclosure of which is incorporated herein by reference in its entirety. Field of Invention The invention relates to a novel conductive material and its preparation method by metallizing a matrix material (such as a textile matrix material) with a metal composite conductive ink composition. [Previous Technology] Background of the Invention For a long time, there has been a search for conductive textiles, fabrics, and other types of materials with suitable electrical and mechanical properties. Specifically, conductive textiles have important and numerous applications, including in electronic clothing and skin patches (i.e., wearable applications), EMI / RF shielding, interconnects, and wires. Key metrics relevant to these materials are performance, aesthetics, safety, and cost. Conductive textiles or fabrics preferably exhibit high conductivity relative to performance, and more importantly, maintain a sufficient level of conductivity after thousands of cycles of dynamic tension and strain. The aesthetics of conductive materials are also important. Ideally, fabrics and fibers made from these materials should resemble their unmodified form as closely as possible, rather than resembling metal patches or strands. Safety and toxicity are equally important, as many of these applications involve consumer wearables and medical devices. Finally, low cost, also related to manufacturability, is crucial for high-volume consumer electronics applications utilizing these materials. Known electronic textiles and fabric materials traditionally consist of a conductive metal layer surrounding fibers (which can then be woven into yarns) or layered on top of the fabric. See, for example, Figure 1. Such materials are typically prepared by depositing a pure metal film (e.g., using common printing techniques such as inkjet, screen printing, or similar techniques) or sputtering it onto the fibers or fabric. Because the metal applied by these techniques cannot penetrate the surface of the treated material, the conductive portion of the material is inherently separated from the underlying fiber or fabric matrix. A key commercial problem with textiles having sputtered metallized layers is that the method is expensive and has low yield. Furthermore, the resulting metal layer is brittle, thus preventing the material's inherent conductivity from being utilized while maintaining its tensile / strain capacity. On the other hand, although relatively more cost-effective, a key commercial problem with textiles and fabrics having a top layer of deposited metal particles / polymer film is poor conductivity, partly due to the need for low curing temperatures for the fabric / textile matrix due to its temperature sensitivity. In both cases, the composition and structure of conductive textiles are limited to a top layer metallized with standard particle-based metallic inks or similar materials. This limits the mechanical and stretchable properties of the material. In other words, conductive fabrics or fibers on the market with metal primarily coated only on the surface will peel or break during mechanical strain, flexure, or stretching, resulting in a significant increase in resistance. This makes current conductive fabrics and fibers unsuitable for commercial purposes. Metal-containing fabrics, particularly silver-containing fabrics, have been reported to possess antibacterial properties. See, for example, U.S. Patent Application Publication No. 2005 / 0037057 A1. In these fabrics, silver is locally applied to the fabric in ionic form so that controlled release of silver ions from the fabric is provided through repeated washing cycles. However, silver-treated fabrics are non-conductive. [Summary of the Invention] Invention Summary This article provides conductive materials such as conductive textile materials, and their preparation methods by metallization of metal composite conductive ink compositions. In one embodiment, this disclosure provides a conductive material comprising a matrix material and a metal embedded in the matrix material, wherein the metal is embedded in and below the surface of the material. More specifically, in some of the conductive materials disclosed herein, the matrix material is a textile matrix material, such as fabric, fiber, yarn, or thread. Even more specifically, the fabric, fiber, yarn, or thread includes polyester, polyether polyurea copolymer, nylon, acrylic, modified cellulose, polyvinyl alcohol, polyvinyl chloride, polyurethane, cotton, wool, linen, or silk. In some embodiments, the matrix material is a thermally degradable matrix material, for example, wherein the matrix material is degradable at temperatures above about 300°C. In some embodiments of the conductive material, the metal comprises silver, copper, gold, palladium, platinum, or an alloy or combination of any of these metals, and more specifically, wherein the metal comprises an alloy or combination of silver, copper, gold, palladium, or platinum, or wherein the metal comprises silver. In another embodiment, conductive materials are also provided, wherein the materials are prepared by treating a matrix material (such as a textile matrix material) with a metal composite conductive ink composition. In certain embodiments, the matrix material is a textile matrix material, such as fabric, fiber, yarn, or filament, and more specifically, the fabric, fiber, yarn, or filament comprises polyester, polyether polyurea copolymer, nylon, acrylic, modified cellulose, polyvinyl alcohol, polyvinyl chloride, polyurethane, cotton, wool, linen, or silk. In other specific embodiments, the matrix material is a thermally degradable material, such as a matrix material that degrades at temperatures above about 300°C. In some embodiments, the metal composite conductive ink composition comprises silver, copper, gold, palladium, or platinum. More specifically, the metal composite conductive ink composition comprises a combination of silver, copper, gold, palladium, or platinum, or the metal composite conductive ink composition comprises silver. In some embodiments, the processing is performed at a temperature of 300°C or lower. In some embodiments, the substrate material is treated with a metal composite conductive ink composition by dyeing, and in other embodiments, the substrate material is treated with a metal composite conductive ink composition by printing. In any of the above embodiments, the conductive material may exhibit a resistance of about 1,000 ohms or less after being stretched by at least about 10%. More specifically, the material may exhibit a resistance of about 1,000 ohms or less after being stretched by at least about 10% and subjected to at least about 100 cycles. In yet another embodiment, this disclosure provides a method for preparing a conductive material, comprising: providing a matrix material, such as a textile matrix material; treating the matrix material with a metal composite conductive ink composition; and curing the treated matrix material to produce a metal embedded in the matrix material. In a particular embodiment, the matrix material is a textile matrix material, such as fabric, fiber, yarn or thread, and more specifically, the fabric, fiber, yarn or thread includes polyester, polyether polyurea copolymer, nylon, acrylic, modified cellulose, polyvinyl alcohol, polyvinyl chloride, polyurethane, cotton, wool, flax or silk materials. In some of these embodiments, the matrix material is a thermally degradable material, such as a matrix material that degrades at temperatures above about 300°C. In some embodiments, the metal composite conductive ink composition comprises silver, copper, gold, palladium, or platinum. More specifically, the metal composite conductive ink composition comprises a combination of silver, copper, gold, palladium, or platinum, or the metal composite conductive ink composition comprises silver. In some method embodiments, the substrate material is treated with a metal composite conductive ink composition by dyeing or printing. In some embodiments, the substrate material is treated with the metal composite conductive ink composition at least twice. In some method embodiments, the curing step is performed at a temperature not exceeding about 300°C, and in some method embodiments, the curing step is performed for no more than about 120 minutes.

Implementation Method

Claims

1. A conductive material comprising: a textile matrix material; and a conductive metal embedded therein; wherein the conductive material is prepared by saturating the textile matrix material with a metal composite conductive ink composition; wherein the metal composite conductive ink composition is cured without further chemical treatment to produce the conductive metal embedded in the textile matrix material; and wherein the textile matrix material exhibits a resistance of about 1,000 ohms or less after being stretched by at least about 10%, as measured by a two-point resistance measurement of more than 10 cm.

2. The conductive material of claim 1, wherein the textile matrix material is a fabric, a fiber, a yarn, or a thread.

3. The conductive material of claim 2, wherein the fabric, the fiber, the yarn or the filament comprises a polyester, a polyether polyurea copolymer, a nylon, an acrylic, a modified cellulose, a polyvinyl alcohol, a polyvinyl chloride, a polyurethane, cotton, wool, flax or silk.

4. The conductive material of claim 1, wherein the textile matrix material is a thermally degradable textile matrix material.

5. The conductive material of claim 4, wherein the textile matrix material is degradable at temperatures above about 300°C.

6. The conductive material of claim 1, wherein the metal comprises an alloy or combination of silver, copper, gold, palladium, platinum or any of these metals.

7. The conductive material of claim 6, wherein the metal comprises an alloy or combination of silver, copper, gold, palladium or platinum.

8. The conductive material of claim 6, wherein the metal comprises silver.

9. The conductive material of claim 1, wherein the material exhibits a resistance of about 1,000 ohms or less after being stretched by at least about 10% and subjected to at least about 100 cycles.

10. A method for preparing a conductive material, comprising: providing a textile matrix material; saturating the textile matrix material with a metal composite conductive ink composition; and curing the metal composite conductive ink composition without further chemical treatment to produce a conductive metal embedded in the textile matrix material; wherein the textile matrix material exhibits a resistance of about 1,000 ohms or less after being stretched by at least about 10%, as measured by a two-point resistance measurement of more than 10 cm.

11. The method of claim 10, wherein the textile matrix material is a fabric, a fiber, a yarn, or a thread.

12. The method of claim 11, wherein the fabric, the fiber, the yarn or the thread comprises a polyester, a polyether polyurea copolymer, a nylon, an acrylic, a modified cellulose, a polyvinyl alcohol, a polyvinyl chloride, a polyurethane, cotton, wool, flax or a silk material.

13. The method of claim 10, wherein the textile matrix material is a thermally degradable material.

14. The method of claim 13, wherein the textile matrix material is degradable at temperatures above about 300°C.

15. The method of claim 10, wherein the metal composite conductive ink composition comprises silver, copper, gold, palladium or platinum.

16. The method of claim 15, wherein the metal composite conductive ink composition comprises a combination of silver, copper, gold, palladium or platinum.

17. The method of claim 15, wherein the metal composite conductive ink composition comprises silver.

18. The method of claim 10, wherein the textile matrix material is treated with the metal composite conductive ink composition by dyeing.

19. The method of claim 10, wherein the textile matrix material is treated with the metal composite conductive ink composition by printing.

20. The method of claim 10, wherein the textile matrix material is treated with the metal composite conductive ink composition at least twice.

21. The method of claim 10, wherein the curing step is performed at a temperature not exceeding about 300°C.

22. The method of request item 10, wherein the solidification step is performed for no more than approximately 120 minutes.

Images