Preparation method of acid and alkali resistant metallic yarn

Abstract

The invention provides an acid and alkali resistant metallic yarn preparation method, which comprises: 1, mixing polyvinylidene fluoride, polyvinylpyrrolidone and a solvent, and carrying out electrostatic spinning to form a PVDF / PVP composite fiber membrane; soaking the PVDF / PVP composite fiber membrane in an aqueous solution, taking out the PVDF / PVP composite fiber membrane after soaking, cleaning and drying to obtain a PVDF fiber membrane with a groove structure; step 2, soaking the PVDF fiber membrane with the groove structure in slurry containing flaky aluminum powder, a cross-linking agent and polyacrylate emulsion, and after soaking is completed, sequentially carrying out rolling and high-temperature drying to obtain a PVDF fiber membrane with an aluminum coating; 3, the PVDF fiber membrane with the aluminum coating is cut into filaments, then a polyester yarn coating layer and a protective coating are sequentially formed on the surface of the PVDF fiber membrane cut into the filaments, and the acid and alkali resistant metallic yarn is obtained. According to the method, the binding strength of the aluminum coating and the fiber membrane is improved, full coating of the aluminum wires is achieved, and the acid and alkali resistance of the metallic yarn fabric in the subsequent dyeing and finishing process is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of textiles, and in particular relates to a method for preparing acid- and alkali-resistant gold and silver threads. Background Art

[0002] Gold and silver threads, also known as metal-coated fibers, present a typical metallic color and are often used as decorative accessories to enhance the appearance of fabrics. The traditional preparation method of gold and silver threads is to first use sputtering technology to plate aluminum on a transparent polymer film to form an aluminum-coated film, then use it as a substrate for double-sided coating to form a colored protective coating, and then cut the aluminum film containing the protective coating into finished products.

[0003] Interweaving gold and silver threads with polyester, nylon and other yarns to form multi-fiber fabrics is a common way to realize the application of gold and silver threads. Gold and silver thread interwoven fabrics usually need to be dyed before they can be used, so gold and silver threads must have properties such as acid and alkali resistance, boiling resistance, sun resistance, organic solvent resistance, abrasion resistance and soft texture. The stability of the aluminum layer is the key factor determining these properties. If the aluminum layer is not firmly bonded to the film, the glossiness of the gold and silver threads will easily decrease or even discolor during the high-temperature printing and dyeing process. At the same time, because traditional methods fail to effectively cover the protective coating on the cross-section of gold and silver threads, the color of the gold and silver threads is easily damaged during the desizing, acid and alkali dyeing and finishing of the fabric, resulting in fading or dullness. Summary of the invention

[0004] This application provides a method for preparing acid- and alkali-resistant gold and silver wire from the perspective of improving the bonding strength between the aluminum coating and the substrate, as well as the all-round protection of the protective coating. This application uses electrospinning and the water solubility of PVP to prepare a film with a groove structure, which cleverly improves the bonding strength between the film and the aluminum coating, and proposes the idea of ​​first preparing aluminum wire and then treating the wire with a protective coating, breaking the traditional idea of ​​first applying a colored protective coating to the aluminum film and then slitting it.

[0005] In the first aspect of the present invention, the present invention provides a method for preparing acid- and alkali-resistant gold and silver threads, comprising the following steps: step 1, mixing polyvinylidene fluoride, polyvinyl pyrrolidone and a solvent, and using electrospinning to form a PVDF / PVP composite fiber membrane; soaking the PVDF / PVP composite fiber membrane in an aqueous solution, taking it out after soaking, cleaning and drying, and obtaining a PVDF fiber membrane with a groove structure; step 2, soaking the PVDF fiber membrane with a groove structure in a slurry containing flaky aluminum powder, a cross-linking agent and a polyacrylate emulsion, and after the soaking is completed, successively performing pressing and high-temperature drying to obtain a PVDF fiber membrane with an aluminum coating; step 3, cutting the PVDF fiber membrane with an aluminum coating into filaments, and then successively forming a polyester silk coating layer and a protective coating on the surface of the PVDF fiber membrane cut into filaments to obtain the acid- and alkali-resistant gold and silver threads.

[0006] In some embodiments of the present invention, the average diameter of the fibers in the PVDF fiber membrane having a groove structure is 2-4 μm.

[0007] In some embodiments of the present invention, the width of the grooves on the PVDF fiber membrane with a groove structure is 30-50 nm.

[0008] In some embodiments of the present invention, the thickness of the flaky aluminum powder is 20-30 nm.

[0009] In some embodiments of the present invention, the solid content of the acrylic emulsion is 45%.

[0010] In some embodiments of the present invention, the cross-linking agent is at least one of polycarbodiimides and epoxysilanes.

[0011] In some embodiments of the present invention, the slurry contains 40% to 50% by mass of flaky aluminum powder, 40% to 45% by mass of acrylic emulsion, 1% to 2% by mass of crosslinking agent, and the remainder is water. Mechanical stirring is required when mixing the flaky aluminum powder, acrylic emulsion and crosslinking agent.

[0012] In some embodiments of the present invention, the thickness of the aluminum coating is 1-1.5 μm.

[0013] In some embodiments of the present invention, in step 3, the steps of slitting the PVDF fiber membrane with aluminum coating into filaments, and then sequentially forming a polyester filament coating layer and a protective coating on the surface of the slitting PVDF fiber membrane into filaments specifically include:

[0014] The PVDF fiber membrane with aluminum coating is cut into filaments step by step using a cutting device, and then the cut PVDF fiber membrane is rolled up;

[0015] A coating device is provided, which coats the polyester yarn on the surface of the filamentary PVDF fiber membrane in an S-direction or Z-direction manner, and two strands are twisted together to form a polyester yarn coating layer, and then the PVDF fiber membrane with the polyester yarn coating layer is rolled up;

[0016] A coating device is provided, which includes a unwinding mechanism, a coating slurry tank, a drying mechanism and a winding mechanism, wherein the unwinding mechanism includes a unwinding shaft rotatably arranged on the coating slurry tank, and an extraction-extrusion mechanism is arranged in the coating slurry tank, wherein the extraction-extrusion mechanism includes two rubber rollers spaced apart and arranged in parallel, and the rubber rollers are far away from the bottom of the coating slurry tank; a rolled filamentary PVDF fiber membrane is placed on the unwinding shaft, and then the front section of the filamentary PVDF fiber membrane is clamped on the two rubber rollers in a "U" shape by using a lead wire, and then the coating slurry is introduced into the coating slurry tank, and the tension is controlled so that the filamentary PVDF fiber membrane enters the extraction-extrusion mechanism after being evenly loaded with liquid, and is dried by the drying mechanism after extrusion, and is wound up after completion, so as to obtain acid and alkali resistant gold and silver wire with a protective coating.

[0017] In some embodiments of the present invention, the coating slurry tank is a centrifugal tube structure, which includes a tank body and a tank cover, the tank cover has two symmetrical holes for the filamentous PVDF fiber membrane to pass through, and the two rubber rollers correspond one-to-one to the positions of the two holes.

[0018] In some embodiments of the present invention, the coating slurry comprises water-based epoxy resin emulsion, color powder, polyvinylidene fluoride emulsion and a friction fastness enhancer.

[0019] In some embodiments of the present invention, the coating slurry contains 35% to 45% by mass of the aqueous epoxy resin emulsion, 0.5% to 1% by mass of the color powder, 3% to 5% by mass of the polyvinylidene fluoride emulsion, 1% to 2% by mass of the friction fastness enhancer, and the remainder is water. Mechanical stirring is required when the aqueous epoxy resin emulsion, color powder, polyvinylidene fluoride emulsion, and friction fastness enhancer are mixed.

[0020] In some embodiments of the present invention, the abrasion fastness enhancing agent is water-based polyurethane.

[0021] In some embodiments of the present invention, the distance between the rubber roller and the bottom of the tank is 5 cm.

[0022] The gold and silver threads formed in the present application can be used to interweave with yarns or fibers such as polyester, viscose, and nylon to obtain interwoven fabrics.

[0023] In a second aspect of the present application, the present application provides an application of acid- and alkali-resistant gold and silver threads, and the formed gold and silver threads can be used to be interwoven with yarns or fibers such as polyester, viscose, and nylon to obtain interwoven fabrics.

[0024] Beneficial effects of this application:

[0025] (1) The present application firstly adopts electrospinning technology to prepare a film, and forms a large number of holes through the spinning and overlapping of electrostatic fibers to obtain a porous PVDF / PVP composite fiber film. Then, the PVP component is removed to form nanoscale pores on the surface of each fiber, thereby obtaining a PVDF fiber membrane with a multi-level groove structure. Compared with the existing commercial PVDF fiber membrane, this membrane significantly increases the adhesion of the aluminum coating on its surface and improves the bonding strength between the aluminum coating and the fiber membrane.

[0026] (2) This application proposes the idea of ​​first preparing aluminum wire and then applying a protective coating to the wire, breaking the traditional idea of ​​first applying a colored protective coating to the aluminum film and then slitting it. The protective coating described in this application achieves full coverage of the gold and silver wire, ensuring the subsequent durability of the gold and silver wire. After the gold and silver wire fabric undergoes pre-treatment, dyeing and post-finishing and other dyeing and finishing processes, the gold and silver wire is still bright and colorful.

[0027] This application forms the idea of ​​preparing aluminum wire first and then applying protective coating to the wire, breaking the traditional idea of ​​first applying colored protective coating to the aluminum film and then cutting it. Undoubtedly, using protective coating to cover the entire gold and silver wire will inevitably improve the tolerance of the gold and silver wire during dyeing and finishing, thereby ensuring its color, which has good practical significance.

[0028] (3) The method for preparing gold and silver wires of the present invention is ingeniously designed, easy to implement, has low equipment requirements, and has good universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0030] Figure 1 This is a scanning electron microscope photograph of the PVDF fiber membrane with a groove structure prepared in the present invention.

[0031] Figure 2 This is a scanning electron microscope photograph of the gold and silver wire prepared in the present invention. DETAILED DESCRIPTION

[0032] The following is a more detailed description of the present invention in conjunction with the following embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or changes made to the present invention will fall within the scope of protection of the present invention.

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0034] In the following examples, unless otherwise specified, the reagents, materials and equipment used can be purchased from commercial sources, or prepared by conventional methods, or commonly used in the industry. Unless otherwise specified, all percentages are in mass units.

[0035] In the textile industry, gold and silver threads are used as a decorative auxiliary material in large quantities to enhance the appearance of textiles. Therefore, the quality of gold and silver threads directly affects the quality of textiles. At present, the conventional preparation method of gold and silver threads is to form an aluminized film by aluminum plating on a polyamide or polyester film, and then coating the aluminum layer of the aluminized film with a coating containing toner and epoxy resin to form a protective coating, and then cutting to form gold and silver threads as thin as hair. According to the application requirements, the gold and silver threads can be coated with polyester yarn to form coated yarn. In the above traditional preparation method, on the one hand, the bonding strength between the film and the aluminum layer is the key to determining the durability of the gold and silver threads. If the aluminum layer is not firmly bonded to the film, the gloss of the gold and silver threads is easy to decrease or even discolor during the high-temperature printing and dyeing process. On the other hand, the upper and lower surfaces of the gold and silver threads formed by cutting have an epoxy resin protective coating, but the side or cross section thereof has no protective coating, which causes the gold and silver threads to be dark or even reduced in color when the fabrics woven from the gold and silver threads are dyed and finished, which limits the application of the gold and silver threads to a certain extent. Therefore, it is of great practical significance to improve the bonding strength between the aluminum layer and the film and to apply a full range of protective coating to the gold and silver wire body.

[0036] Based on this, the present application provides a method for preparing acid- and alkali-resistant gold and silver threads and their application, proposes the use of electrospinning and the water-solubility of PVP to prepare a film with a groove structure to enhance the bonding strength between the film and the aluminum coating, and proposes the idea of ​​first preparing aluminum threads and then subjecting the threads to a protective coating, breaking the traditional idea of ​​first subjecting the aluminum film to a colored protective coating and then slitting it, and achieving all-round coating of the gold and silver threads themselves, aiming to enhance their durability during the dyeing and finishing process.

[0037] The gold and silver threads in the examples and their preparation methods are described in more detail below.

[0038] In a first aspect of the present application, the present application provides a method for preparing acid- and alkali-resistant gold and silver wires, the preparation method comprising the following steps:

[0039] S1. Mix polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone (PVP) and a solvent, and use electrospinning to form a PVDF / PVP composite fiber membrane; soak the PVDF / PVP composite fiber membrane in an aqueous solution, take it out after soaking, wash and dry it, and obtain a PVDF fiber membrane with a groove structure.

[0040] In order to ensure that the aluminum layer has excellent adhesion on the PVDF fiber membrane, the PVDF fiber membrane is pretreated before the aluminum layer is formed. The solution proposed in this application is: using water-soluble PVP as the electrospinning raw material to form micron-sized fibers containing PVP, and then soaking the electrospun fiber membrane in water, and using the water solubility of PVP to construct a PVDF fiber membrane with a groove structure. The groove structure will be conducive to the combination of aluminum powder and membrane material in the later stage, and the bonding strength of the aluminum coating and the film will be improved by increasing the roughness.

[0041] The groove structure formed on the fiber membrane of the present application has a roughness, which is conducive to the adhesion of the aluminum layer. Compared with the etched or purchased membrane, this groove structure is more controllable, and its size and size are more controllable, and the quality control of the finished gold and silver wire is utilized.

[0042] In some embodiments of the present invention, the solvent is a mixed solution of acetone and N,N-dimethylformamide.

[0043] S2, soaking the PVDF fiber membrane with the groove structure in a slurry containing flaky aluminum powder, a cross-linking agent and a polyacrylate emulsion, and after the soaking is completed, sequentially performing pressing and high-temperature drying to obtain a PVDF fiber membrane with an aluminum coating.

[0044] Silk threads made of gold or silver threads as raw materials will present a luxurious luster. As decorative accessories, they can enhance the appearance quality of fabrics and give them a glittering effect. Therefore, yarns or silk threads with such functions are called gold and silver threads. However, gold and silver threads made of gold or silver threads are expensive and not suitable for large-scale applications, which has led to the idea of ​​using aluminum threads as gold and silver threads, aiming to reduce the price of gold and silver threads while continuing to retain the metallic luster. Usually, aluminum threads are based on a transparent polymer substrate, which is first aluminum-plated to form an aluminum-containing film and then further cut. Therefore, the present application also adopts a similar technology to first form an aluminum-containing coating and then cut to obtain aluminum threads. However, it should be noted that the aluminum-containing polymer film described in the present application is not obtained by sputtering to form an aluminum-plated layer, but is directly formed using flaky aluminum powder as a slurry component. Using flaky aluminum powder instead of sputtering aluminum can not only reduce the requirements for equipment, but also avoid the pollution of the environment by sputtering, which has significant advantages.

[0045] S3, cutting the PVDF fiber membrane with aluminum coating into filaments, and then sequentially forming a polyester filament coating layer and a protective coating on the surface of the PVDF fiber membrane cut into filaments to obtain the acid and alkali resistant gold and silver wire.

[0046] The gold and silver wires prepared in the present application have a width of less than 1 cm and are formed by slitting an aluminum-containing polymer film with a width of 60 to 100 cm. The formation of the gold and silver wires has undergone multiple slitting, that is, the aluminum-containing polymer film with a width of 60 to 100 cm is first slitting into an aluminum-containing polymer film with a width of 20 cm, further slitting into an aluminum-containing polymer film with a width of 5 cm, and further slitting into aluminum wires with a width of less than 1 cm.

[0047] After slitting into filaments, a polyester filament coating layer is first formed on the filaments, and then a protective coating is formed. The purpose of using polyester filaments for coating is to improve the strength of the gold and silver filaments, which is beneficial for the subsequent weaving. The protective coating can be formed by a commonly used method in the art, such as coating, sputtering, etc., using a slurry commonly used in the art.

[0048] The present application proposes the idea of ​​first preparing aluminum wire and then applying a protective coating to the wire, breaking the traditional idea of ​​first applying a colored protective coating to the aluminum film and then slitting it; the protective coating achieves full coverage of the gold and silver wires, ensuring the subsequent durability of the gold and silver wires. After the gold and silver wire fabrics undergo pre-treatment, dyeing, and post-finishing and other dyeing and finishing processes, the gold and silver wires remain bright and colorful.

[0049] In some embodiments of the present invention, the average diameter of the fibers in the PVDF fiber membrane having a groove structure is 2-4 μm.

[0050] In some embodiments of the present invention, the width of the grooves on the PVDF fiber membrane with a groove structure is 30-50 nm.

[0051] In some embodiments of the present invention, the thickness of the flaky aluminum powder is 20-30 nm.

[0052] In some embodiments of the present invention, the solid content of the acrylic emulsion is 45%.

[0053] In some embodiments of the present invention, the cross-linking agent is at least one of polycarbodiimides and epoxysilanes.

[0054] In some embodiments of the present invention, the slurry contains 40% to 50% by mass of flaky aluminum powder, 40% to 45% by mass of acrylic emulsion, 1% to 2% by mass of crosslinking agent, and the remainder is water. Mechanical stirring is required when mixing the flaky aluminum powder, acrylic emulsion and crosslinking agent.

[0055] In some embodiments of the present invention, the thickness of the aluminum coating is 1-1.5 μm.

[0056] In some embodiments of the present invention, in step 3, the steps of slitting the PVDF fiber membrane with aluminum coating into filaments, and then sequentially forming a polyester filament coating layer and a protective coating on the surface of the slitting PVDF fiber membrane into filaments specifically include:

[0057] The PVDF fiber membrane with aluminum coating is cut into filaments step by step using a cutting device, and then the cut PVDF fiber membrane is rolled up;

[0058] A coating device is provided, which coats the polyester yarn on the surface of the filamentary PVDF fiber membrane in an S-direction or Z-direction manner, and two strands are twisted together to form a polyester yarn coating layer, and then the PVDF fiber membrane with the polyester yarn coating layer is rolled up;

[0059] A coating device is provided, which includes a unwinding mechanism, a coating slurry tank, a drying mechanism and a winding mechanism, wherein the unwinding mechanism includes a unwinding shaft rotatably arranged on the coating slurry tank, and an extraction-extrusion mechanism is arranged in the coating slurry tank, wherein the extraction-extrusion mechanism includes two rubber rollers spaced apart and arranged in parallel, and the rubber rollers are far away from the bottom of the coating slurry tank; a rolled filamentary PVDF fiber membrane is placed on the unwinding shaft, and then the front section of the filamentary PVDF fiber membrane is clamped on the two rubber rollers in a "U" shape by using a lead wire, and then the coating slurry is introduced into the coating slurry tank, and the tension is controlled so that the filamentary PVDF fiber membrane enters the extraction-extrusion mechanism after being evenly loaded with liquid, and is dried by the drying mechanism after extrusion, and is wound up after completion, so as to obtain acid and alkali resistant gold and silver wire with a protective coating.

[0060] Specifically, in order to improve the strength of the gold and silver threads, polyester yarn is used for coating to form coated yarn, which is beneficial to the subsequent weaving and improves the application effect of the gold and silver threads.

[0061] Specifically, in order to achieve full coverage of the upper and lower surfaces and the sides of the aluminum wire, the present application immerses the aluminum wire with a width of less than 1 cm with a polyester yarn coating layer in the coating slurry, extracts the aluminum wire, and then performs an extrusion process to ensure that the aluminum wire has a uniform amount of liquid, and then performs a drying process at 150-170°C to obtain the aluminum wire with a protective coating, that is, the gold and silver wire product. The coating method adopted by the present invention is simple to operate, the protective coating formed is unevenly coated, and has good bonding with the polyester yarn coating layer.

[0062] In some embodiments of the present invention, the coating slurry tank is a centrifugal tube structure, which includes a tank body and a tank cover, the tank cover has two symmetrical holes for the filamentous PVDF fiber membrane to pass through, and the two rubber rollers correspond one-to-one to the positions of the two holes.

[0063] In some embodiments of the present invention, the coating slurry comprises water-based epoxy resin emulsion, color powder, polyvinylidene fluoride emulsion and a friction fastness enhancer. The present invention uses water-based coating slurry, which has the characteristics of green and environmental protection.

[0064] In some embodiments of the present invention, the coating slurry contains 35% to 45% by mass of the aqueous epoxy resin emulsion, 0.5% to 1% by mass of the color powder, 3% to 5% by mass of the polyvinylidene fluoride emulsion, 1% to 2% by mass of the friction fastness enhancer, and the remainder is water. Mechanical stirring is required when the aqueous epoxy resin emulsion, color powder, polyvinylidene fluoride emulsion, and friction fastness enhancer are mixed.

[0065] In some embodiments of the present invention, the abrasion fastness enhancing agent is water-based polyurethane.

[0066] In some embodiments of the present invention, the distance between the rubber roller and the bottom of the tank is 5 cm.

[0067] The preparation method of the gold and silver threads of the present invention is ingenious in design, simple in implementation, has low requirements on equipment, and has good universality.

[0068] Example 1

[0069] A method for preparing acid- and alkali-resistant gold and silver wire, the preparation method comprising the following steps:

[0070] (1) 14 parts of polyvinylidene fluoride (PVDF) and 3 parts of polyvinyl pyrrolidone (PVP) were dissolved in a mixed solvent consisting of 40 parts of acetone and 43 parts of N,N-dimethylformamide, and electrospinning (feed syringe volume was 10 mL, needle diameter was 1.8 mm, feed rate was 0.06 mm / min, spinning voltage was 15 kV) to obtain a PVDF / PVP composite fiber membrane. The obtained PVDF / PVP composite fiber membrane was immersed in room temperature water, taken out, cleaned and dried, and a PVDF fiber membrane with a clear groove structure was obtained.

[0071] (2) A slurry is prepared by combining 40% by weight of flaky aluminum powder (thickness 20 nm), 40% by weight of acrylic emulsion (solid content 45%), and 1% by weight of a polycarbodiimide crosslinking agent. The PVDF fiber membrane obtained in step (1) is then immersed in the slurry. After being taken out, the slurry is subjected to a rolling treatment at a pressure of 0.1 MPa using a horizontal rolling mill. After being dried at 150° C., a PVDF fiber membrane with an aluminum coating is obtained.

[0072] (3) First, a 60 cm wide aluminum-containing polymer film is slit into a 20 cm wide aluminum-containing polymer film using a slitting device, further slit into a 5 cm wide aluminum-containing polymer film, and further slit into aluminum wires with a width of less than 1 cm, and then rolled up.

[0073] The front section of aluminum wire on the winding drum is introduced into the coating device by means of a lead wire, and the polyester filament is coated on the surface of the filamentary PVDF fiber membrane in an S-direction manner. The two strands are entangled and twisted to form a polyester filament coating layer, and then the PVDF fiber membrane with the polyester filament coating layer is wound up.

[0074] Then use the lead wire to place the front section of the aluminum wire on the winding drum in a "U" shape in the coating slurry tank, and then prepare the coating slurry composed of 35% by mass of water-based epoxy resin emulsion, 1% by mass of red color powder, 3% by mass of polyvinylidene fluoride emulsion and 2% by mass of friction fastness enhancer and pour it into the tank body. After extraction and extrusion treatment, it is placed in a 150°C oven to dry, and aluminum wire with a protective coating can be obtained, which is the gold and silver wire.

[0075] The prepared gold and silver threads are interwoven with polyester threads to obtain partially glittering fabrics, which improves the apparent quality of the fabrics.

[0076] Scanning electron microscope observation showed that the average diameter of the fibers in the PVDF fiber membrane prepared in step (1) was 2 μm, and the width of the grooves on the fiber surface of the PVDF fiber membrane was 30 nm. Figure 1 As shown in the figure, the thickness of the aluminum-containing coating formed in step (2) is about 1 μm as measured by a thickness gauge. Figure 2 This is a scanning electron microscope photograph of the gold and silver wire formed in step (3). It can be found that the gold and silver wire has a uniform coating, and the coating uniformly wraps the aluminum wire.

[0077] Example 2

[0078] A method for preparing acid- and alkali-resistant gold and silver wire, the preparation method comprising the following steps:

[0079] (1) 14 parts of polyvinylidene fluoride (PVDF) and 6 parts of polyvinyl pyrrolidone (PVP) were dissolved in a mixed solvent consisting of 40 parts of acetone and 40 parts of N,N-dimethylformamide, and electrospinning (feed syringe volume was 10 mL, needle diameter was 1.8 mm, feed rate was 0.06 mm / min, spinning voltage was 15 kV) to obtain a PVDF / PVP composite fiber membrane. The obtained PVDF / PVP composite fiber membrane was immersed in room temperature water, taken out, washed and dried, and a PVDF fiber membrane with a clear groove structure was obtained.

[0080] (2) A slurry is prepared by combining 50% by weight of flaky aluminum powder (30 nm thick), 45% by weight of an acrylic emulsion (45% by weight of a solid content), and 1% by weight of an epoxy silane crosslinking agent. The PVDF fiber membrane obtained in step (1) is then immersed in the slurry. After being taken out, the PVDF fiber membrane is subjected to a rolling treatment at a pressure of 0.1 MPa using a horizontal rolling mill. After being dried at 150° C., the PVDF fiber membrane having an aluminum coating is obtained.

[0081] (3) First, a 100 cm wide aluminum-containing polymer film is slit into a 20 cm wide aluminum-containing polymer film using a slitting device, further slit into a 5 cm wide aluminum-containing polymer film, and further slit into aluminum wires with a width of less than 1 cm, and then rolled up.

[0082] The front section of aluminum wire on the winding drum is introduced into the coating device by means of a lead wire, and the polyester filament is coated on the surface of the filamentary PVDF fiber membrane in an S-direction manner. The two strands are entangled and twisted to form a polyester filament coating layer, and then the PVDF fiber membrane with the polyester filament coating layer is wound up.

[0083] Then use the lead wire to place the front section of the aluminum wire on the winding drum in a "U" shape in the coating slurry tank, and then prepare the coating slurry composed of 40% by mass of water-based epoxy resin emulsion, 1% by mass of gold color powder, 3% by mass of polyvinylidene fluoride emulsion and 1% by mass of polyurethane friction fastness enhancer and pour it into the tank. After extraction and extrusion treatment, it is placed in a 170°C oven to dry, and aluminum wire with a protective coating can be obtained, which is the gold and silver wire.

[0084] The prepared gold and silver threads can be interwoven with real silk to obtain partially glittering fabrics, which improves the apparent quality of the fabrics.

[0085] Scanning electron microscope observation showed that the average diameter of the fibers in the PVDF fiber membrane prepared in step (1) was 4 μm, and the width of the grooves on the fiber surface in the PVDF fiber membrane was 50 nm. Using a thickness gauge, the thickness of the aluminum-containing coating formed in step (2) was about 1.5 μm.

[0086] Example 3

[0087] A method for preparing acid- and alkali-resistant gold and silver wire, the preparation method comprising the following steps:

[0088] (1) 14 parts of polyvinylidene fluoride (PVDF) and 4 parts of polyvinyl pyrrolidone (PVP) were dissolved in a mixed solvent consisting of 40 parts of acetone and 42 parts of N,N-dimethylformamide, and electrospinning (feed syringe volume was 10 mL, needle diameter was 1.8 mm, feed rate was 0.06 mm / min, spinning voltage was 15 kV) to obtain a PVDF / PVP composite fiber membrane. The obtained PVDF / PVP composite fiber membrane was immersed in room temperature water, taken out, cleaned and dried, and a PVDF fiber membrane with a clear groove structure was obtained.

[0089] (2) A slurry is prepared by combining 45% by weight of flaky aluminum powder (thickness 25 nm), 45% by weight of acrylic emulsion (solid content 45%), and 1% by weight of an epoxy silane crosslinking agent. The PVDF fiber membrane obtained in step (1) is then immersed in the slurry. After being taken out, the slurry is subjected to a rolling treatment at a pressure of 0.1 MPa using a horizontal rolling mill. After being dried at 150° C., a PVDF fiber membrane with an aluminum coating is obtained.

[0090] (3) First, the aluminum-containing polymer film with a width of 80 cm is slit into an aluminum-containing polymer film with a width of 20 cm by using a slitting device, further slit into an aluminum-containing polymer film with a width of 5 cm, and further slit into aluminum wires with a width of less than 1 cm, and then rolled up.

[0091] The front section of aluminum wire on the winding drum is introduced into the coating device by means of a lead wire, and the polyester filament is coated on the surface of the filamentous PVDF fiber membrane in the Z direction. The two strands are entangled and twisted to form a polyester filament coating layer, and then the PVDF fiber membrane with the polyester filament coating layer is rolled up.

[0092] Then use the lead wire to place the front section of the aluminum wire on the winding drum in a "U" shape in the coating slurry tank, and then prepare the coating slurry composed of 40% by mass of water-based epoxy resin emulsion, 0.5% by mass of gold color powder, 3% by mass of polyvinylidene fluoride emulsion and 2% by mass of polyurethane friction fastness enhancer and pour it into the tank. After extraction and extrusion, it is placed in a 170°C oven to dry, and aluminum wire with a protective coating can be obtained, which is the gold and silver wire.

[0093] The prepared gold and silver threads are interwoven with nylon threads to obtain partially glittering fabrics, which improves the apparent quality of the fabrics.

[0094] Scanning electron microscope observation showed that the average diameter of the fibers in the PVDF fiber membrane prepared in step (1) was 3 μm, and the width of the grooves on the fiber surface in the PVDF fiber membrane was 35 nm. Using a thickness gauge, the thickness of the aluminum-containing coating formed in step (2) was about 1.2 μm.

[0095] Example 4

[0096] A method for preparing acid- and alkali-resistant gold and silver wire, the preparation method comprising the following steps:

[0097] (1) 15 parts of polyvinylidene fluoride (PVDF) and 5 parts of polyvinyl pyrrolidone (PVP) were dissolved in a mixed solvent consisting of 40 parts of acetone and 40 parts of N,N-dimethylformamide, and electrospinning (feed syringe volume was 10 mL, needle diameter was 1.8 mm, feed rate was 0.06 mm / min, spinning voltage was 15 kV) to obtain a PVDF / PVP composite fiber membrane. The obtained PVDF / PVP composite fiber membrane was immersed in room temperature water, taken out, cleaned and dried, and a PVDF fiber membrane with a clear groove structure was obtained.

[0098] (2) A slurry consisting of 45% by weight of flaky aluminum powder (thickness 20 nm), 40% by weight of an acrylic emulsion (solid content 45%), and 0.8% by weight of a polycarbodiimide crosslinking agent was applied to the surface of a PVDF fiber membrane with a width of 80 cm by a roller transfer coating machine, and then dried at 170°C to obtain a PVDF fiber membrane with an aluminum coating.

[0099] (3) First, the aluminum-containing polymer film with a width of 80 cm is slit into an aluminum-containing polymer film with a width of 20 cm by using a slitting device, further slit into an aluminum-containing polymer film with a width of 5 cm, and further slit into aluminum wires with a width of less than 1 cm, and then rolled up.

[0100] The front section of aluminum wire on the winding drum is introduced into the coating device by means of a lead wire, and the polyester filament is coated on the surface of the filamentous PVDF fiber membrane in the Z direction. The two strands are entangled and twisted to form a polyester filament coating layer, and then the PVDF fiber membrane with the polyester filament coating layer is rolled up.

[0101] Then use the lead wire to place the front section of the aluminum wire on the winding drum in a "U" shape in the coating slurry tank, and then prepare the coating slurry composed of 45% by mass of water-based epoxy resin emulsion, 0.8% by mass of red color powder, 4% by mass of polyvinylidene fluoride emulsion and 1.5% by mass of polyurethane friction fastness enhancer and pour it into the tank. After extraction and extrusion, it is placed in a 160°C oven to dry, and aluminum wire with a protective coating can be obtained, which is the gold and silver wire.

[0102] The prepared gold and silver threads are interwoven with polyester threads to obtain partially glittering fabrics, which improves the apparent quality of the fabrics.

[0103] Scanning electron microscope observation showed that the average diameter of the fibers in the PVDF fiber membrane prepared in step (1) was 3.5 μm, and the width of the grooves on the fiber surface in the PVDF fiber membrane was 40 nm. Using a thickness gauge, the thickness of the aluminum-containing coating formed in step (2) was about 1.4 μm.

[0104] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.

Claims

1. A method for preparing acid- and alkali-resistant gold and silver wire, characterized in that: The steps include: Step 1, mixing polyvinylidene fluoride, polyvinyl pyrrolidone and a solvent, and using electrospinning to form a PVDF / PVP composite fiber membrane; soaking the PVDF / PVP composite fiber membrane in an aqueous solution, taking it out after soaking, washing and drying it, and obtaining a PVDF fiber membrane with a groove structure. Step 2, soaking the PVDF fiber membrane with a groove structure in a slurry containing flaky aluminum powder, a crosslinking agent and a polyacrylate emulsion, and after the soaking is completed, sequentially performing pressing and high-temperature drying to obtain a PVDF fiber membrane with an aluminum coating; Step 3, cutting the PVDF fiber membrane with aluminum coating into filaments, and then forming a polyester filament coating layer and a protective coating on the surface of the PVDF fiber membrane cut into filaments in sequence to obtain the acid and alkali resistant gold and silver wire.

2. The preparation method according to claim 1, characterized in that: The average diameter of the fibers in the PVDF fiber membrane with a groove structure is 2-4 μm.

3. The preparation method according to claim 1, characterized in that: The width of the grooves on the PVDF fiber membrane with the groove structure is 30-50 nm.

4. The preparation method according to claim 1, characterized in that: The thickness of the flaky aluminum powder is 20-30 nm.

5. The preparation method according to claim 1, characterized in that: The solid content of the acrylic ester emulsion is 45%.

6. The preparation method according to claim 1, characterized in that: The crosslinking agent is at least one of polycarbodiimides and epoxysilanes.

7. The preparation method according to claim 1, characterized in that: The thickness of the aluminum coating is 1-1.5 μm.

8. The preparation method according to claim 1, characterized in that: In step 3, the PVDF fiber membrane with aluminum coating is cut into filaments, and then the steps of sequentially forming a polyester filament coating layer and a protective coating on the surface of the PVDF fiber membrane cut into filaments specifically include: The PVDF fiber membrane with aluminum coating is cut into filaments step by step using a cutting device, and then the cut PVDF fiber membrane is rolled up; A coating device is provided, which coats the polyester yarn on the surface of the filamentary PVDF fiber membrane in an S-direction or Z-direction manner, and two strands are twisted together to form a polyester yarn coating layer, and then the PVDF fiber membrane with the polyester yarn coating layer is rolled up; A coating device is provided, which includes a unwinding mechanism, a coating slurry tank, a drying mechanism and a winding mechanism, wherein the unwinding mechanism includes a unwinding shaft rotatably arranged on the coating slurry tank, and an extraction-extrusion mechanism is arranged in the coating slurry tank, wherein the extraction-extrusion mechanism includes two rubber rollers spaced apart and arranged in parallel, and the rubber rollers are far away from the bottom of the coating slurry tank; a rolled filamentary PVDF fiber membrane is placed on the unwinding shaft, and then the front section of the filamentary PVDF fiber membrane is clamped on the two rubber rollers in a "U" shape by using a lead wire, and then the coating slurry is introduced into the coating slurry tank, and the tension is controlled so that the filamentary PVDF fiber membrane enters the extraction-extrusion mechanism after being evenly loaded with liquid, and is dried by the drying mechanism after extrusion, and is wound up after completion, so as to obtain acid and alkali resistant gold and silver wire with a protective coating.

9. The preparation method according to claim 8, characterized in that: The coating slurry tank is a centrifugal tube structure, which includes a tank body and a tank cover. The tank cover is provided with two symmetrical holes for the filamentous PVDF fiber membrane to pass through, and the two rubber rollers correspond to the positions of the two holes one by one.

10. The preparation method according to claim 8, characterized in that: The coating slurry comprises water-based epoxy resin emulsion, color powder, polyvinylidene fluoride emulsion and a friction fastness enhancer.

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