CN117862520A - A method for preparing flaky silver powder using shellac - Google Patents

A method for preparing flaky silver powder using shellac Download PDF

Info

Publication number
CN117862520A
CN117862520A CN202410269899.0A CN202410269899A CN117862520A CN 117862520 A CN117862520 A CN 117862520A CN 202410269899 A CN202410269899 A CN 202410269899A CN 117862520 A CN117862520 A CN 117862520A
Authority
CN
China
Prior art keywords
solution
silver powder
shellac
silver
preparing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202410269899.0A
Other languages
Chinese (zh)
Other versions
CN117862520B (en
Inventor
王君
陈悦
冯熙云
沈静
李薇
张旭锋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yunnan Normal University
Original Assignee
Yunnan Normal University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yunnan Normal University filed Critical Yunnan Normal University
Priority to CN202410269899.0A priority Critical patent/CN117862520B/en
Publication of CN117862520A publication Critical patent/CN117862520A/en
Application granted granted Critical
Publication of CN117862520B publication Critical patent/CN117862520B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00Making metallic powder or suspensions thereof
    • B22F9/16Making metallic powder or suspensions thereof using chemical processes
    • B22F9/18Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
    • B22F9/24Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/06Metallic powder characterised by the shape of the particles
    • B22F1/068Flake-like particles

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Powder Metallurgy (AREA)

Abstract

The invention relates to the technical field of metal powder preparation, and discloses a method for preparing flake silver powder by using shellac, which comprises the following steps: step S1: preparing a natural resin sacrificial template: coating the prepared lac solution on a flexible substrate, and curing; step S2: hydrophilic and sensitization treatment; step S3: preparing a silver film: spraying silver-ammonia solution and reducing solution on a natural resin sacrificial template for reaction, purging, flushing a silver film with ultrapure water, and purging at high temperature to obtain a bright silver film; step S4: immersing a natural resin sacrificial template plated with a silver film into an alcohol solution, a ketone solution or an alkaline solution, and stirring to obtain a flaky silver powder mother solution; step S5: crushing the flake silver powder mother liquor by adopting ultrasonic waves, and soaking and washing by ethanol, centrifuging and drying to obtain the flake silver powder. The prepared flake silver powder has uniform morphology and is flake; the surface is flat; the residue is little, and the conductive filler can produce very good conductive effect.

Description

一种使用紫胶制备片状银粉的方法A method for preparing flaky silver powder using shellac

技术领域Technical Field

本发明涉及金属粉末制备技术领域,具体涉及一种使用紫胶制备片状银粉的方法。The invention relates to the technical field of metal powder preparation, and in particular to a method for preparing flaky silver powder by using shellac.

背景技术Background technique

本节中的陈述仅提供与本申请公开相关的背景信息,并且可能不构成现有技术。The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

银粉作为导电相在导电浆料中有着重要的应用,片状银粉在形成导电通路的过程中可以形成面-面接触,相较于其它形貌的银粉具有更好的导电性能。Silver powder plays an important role in conductive pastes as a conductive phase. Flake silver powder can form surface-to-surface contact in the process of forming a conductive path and has better conductive properties than silver powders of other morphologies.

近年来,使用绿色资源制备纳米银粉的研究逐渐增多。目前报道的纳米银绿色合成方法多为从植物资源中提取具有还原性质的物质对银离子进行还原。但由于对提取物成分和剂量难以把控,制备出的纳米银粉形貌和粒径均难以控制,而且产量较低,无法作为导电填料使用。In recent years, the research on the preparation of nanosilver powder using green resources has gradually increased. Currently reported green synthesis methods of nanosilver mostly extract substances with reducing properties from plant resources to reduce silver ions. However, due to the difficulty in controlling the composition and dosage of the extract, the morphology and particle size of the prepared nanosilver powder are difficult to control, and the yield is low, so it cannot be used as a conductive filler.

目前,商用片状银粉的制备以机械球磨法为主,但机械球磨法的能耗高。机械球磨法制备片状银粉时,通常使用硬脂酸作为球磨介质,导致球磨法制备的银粉表面覆盖有硬脂酸膜,该种银粉适合在传统导电浆料中使用。随着可穿戴电子材料的发展,柔性导电复合材料中使用的基体不再是油性体系,而多为水凝胶等亲水体系,球磨法制备的银粉通常需要进行处理才能在柔性导电复合材料中使用,且导电性能也得不到很好的发挥。At present, the preparation of commercial flaky silver powder is mainly based on mechanical ball milling, but the energy consumption of mechanical ball milling is high. When preparing flaky silver powder by mechanical ball milling, stearic acid is usually used as the ball milling medium, resulting in the surface of the silver powder prepared by ball milling being covered with a stearic acid film. This type of silver powder is suitable for use in traditional conductive slurries. With the development of wearable electronic materials, the matrix used in flexible conductive composite materials is no longer an oily system, but mostly a hydrophilic system such as hydrogel. Silver powder prepared by ball milling usually needs to be processed before it can be used in flexible conductive composite materials, and the conductive performance cannot be well exerted.

化学还原法和模板法制备片状银粉也多有报道,但现有的化学还原法存在银粉形貌不易控制、添加剂较多、银粉表面残留物质种类复杂、无法量产等问题;模版法在制备过程中会引入大量合成树脂,存在后处理复杂、废液排放量大、整体生产功耗成本较高等问题,不利于产业的绿色发展。There are also many reports on the preparation of flaky silver powder by chemical reduction method and template method. However, the existing chemical reduction method has problems such as difficult to control the morphology of silver powder, more additives, complex types of residual substances on the surface of silver powder, and inability to mass produce. The template method introduces a large amount of synthetic resin in the preparation process, which leads to complex post-processing, large amount of waste liquid discharge, and high overall production power consumption cost, which is not conducive to the green development of the industry.

银粉制备过程中常用的可溶性树脂包括水溶性环氧树脂、水溶性聚氨酯树脂、水溶性丙烯酸树脂或聚乙烯醇等。但水溶性树脂在合成的过程中需要额外引进亲水基团如羧基、羟基、氨基和酰胺基等,其制备工艺复杂,使得其成本相较于非水溶性的树脂更高;以丙烯酸树脂为例,其售价在4-5万元/吨。如现有技术CN104148655A公开了一种片状银粉的绿色制备方法,其采用水溶性树脂使用真空蒸发镀膜法制备片状银粉,随后将水溶性树脂溶于水中使得银粉脱离。然而根据本领域的公知常识,即使是水溶性树脂其自交联成膜后也具备良好的耐水性,进而无法被纯水溶解,仍然需要使用有机溶剂进行溶解,对环境存在威胁;此外,真空蒸发镀膜法镀膜过程中存在高银损失率,因此使得其银粉的制备成本再次提升。Commonly used soluble resins in the preparation process of silver powder include water-soluble epoxy resin, water-soluble polyurethane resin, water-soluble acrylic resin or polyvinyl alcohol. However, water-soluble resins need to introduce additional hydrophilic groups such as carboxyl, hydroxyl, amino and amide groups during the synthesis process, and their preparation process is complicated, making their cost higher than that of non-water-soluble resins; taking acrylic resin as an example, its selling price is 40,000-50,000 yuan/ton. For example, the prior art CN104148655A discloses a green preparation method for flaky silver powder, which uses a water-soluble resin to prepare flaky silver powder using a vacuum evaporation coating method, and then dissolves the water-soluble resin in water to separate the silver powder. However, according to common knowledge in the art, even water-soluble resins have good water resistance after self-crosslinking and film formation, and thus cannot be dissolved by pure water, and still need to be dissolved using organic solvents, which poses a threat to the environment; in addition, there is a high silver loss rate during the vacuum evaporation coating process, which increases the preparation cost of its silver powder again.

紫胶又称虫胶,是紫胶虫将吸取的植物汁液经过其自身的转化并分泌出的天然树脂,具有粘结性强、绝缘、防潮、成膜性好等特点,且无毒、无味,常用于涂料、医药、食品、水果保鲜等行业。“绿色工业”也如“绿色产品”一样,越来越受到人们的青睐。且我国紫胶资源丰富、价格低廉,相较于合成树脂具有成本更低,获取更加便捷等优势。Shellac, also known as lac, is a natural resin secreted by lac insects after transforming the plant juice they absorb. It has the characteristics of strong adhesion, insulation, moisture resistance, good film-forming properties, and is non-toxic and odorless. It is often used in coatings, medicine, food, fruit preservation and other industries. "Green industry" is also more and more popular with people, just like "green products". In addition, my country has abundant lac resources and low prices. Compared with synthetic resins, it has the advantages of lower cost and more convenient acquisition.

发明内容Summary of the invention

本发明的目的在于:针对目前合成树脂制备片状银粉存在的成本高、降解周期长,增加环境压力的问题,提供了一种使用紫胶制备片状银粉的方法,绿色资源持续可再生,制备过程绿色无污染,成本更低,且制备出的片状银粉厚度均匀,表面均一。The purpose of the present invention is to provide a method for preparing flaky silver powder by using shellac in view of the problems of high cost, long degradation period and increased environmental pressure in the current preparation of flaky silver powder by synthetic resin. The method has the advantages of sustainable and renewable green resources, green and pollution-free preparation process, lower cost, and uniform thickness and surface of the prepared flaky silver powder.

本发明的技术方案如下:The technical solution of the present invention is as follows:

一种使用紫胶制备片状银粉的方法,包括如下步骤:A method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:将紫胶溶解于乙醇中,配制紫胶溶液;随后将紫胶溶液涂覆在柔性PET基底上,固化,固化温度为25-50 ℃,固化时间为5-20 min;Step S1: preparing a natural resin sacrificial template: dissolving shellac in ethanol to prepare a shellac solution; then coating the shellac solution on a flexible PET substrate and curing it at a curing temperature of 25-50° C. for a curing time of 5-20 min;

步骤S2:用十二烷基硫酸钠(SDS)溶液对天然树脂牺牲模板进行亲水处理。用SnCl2溶液对牺牲性模板进行敏化处理;Step S2: hydrophilizing the natural resin sacrificial template with sodium dodecyl sulfate (SDS) solution. Sensitizing the sacrificial template with SnCl2 solution;

步骤S3:制备银膜:配制银氨溶液,将银氨溶液与还原液同时喷涂到天然树脂牺牲模板上进行反应,同时用空压机进行均匀吹扫,用超纯水冲洗银膜,并进行60-90 ℃的高温吹扫,吹扫至银膜表面液体消失,在天然树脂牺牲模板上得到光亮银膜;Step S3: preparing a silver film: preparing a silver ammonia solution, spraying the silver ammonia solution and a reducing solution onto a natural resin sacrificial template simultaneously for reaction, and evenly blowing with an air compressor, washing the silver film with ultrapure water, and blowing at a high temperature of 60-90° C. until the liquid on the surface of the silver film disappears, thereby obtaining a bright silver film on the natural resin sacrificial template;

步骤S4:将镀覆了银膜的天然树脂牺牲模板浸入醇类溶液、酮类溶液或碱性溶液中,搅拌,获得片状银粉母液;Step S4: immersing the natural resin sacrificial template coated with the silver film in an alcohol solution, a ketone solution or an alkaline solution, stirring, and obtaining a flaky silver powder mother solution;

步骤S5:采用超声对片状银粉母液进行破碎化处理,通过乙醇浸洗、离心、干燥,得到纳米尺寸的片状银粉。Step S5: using ultrasound to crush the flaky silver powder mother liquor, and then washing with ethanol, centrifuging, and drying to obtain nano-sized flaky silver powder.

步骤S1中所述涂覆手段为丝网印刷或刮涂。The coating method in step S1 is screen printing or scraping.

优选地,固化温度为50 ℃,固化时间为10 min。Preferably, the curing temperature is 50° C. and the curing time is 10 min.

优选地,所述醇类溶液例如乙醇、甲醇。Preferably, the alcohol solution is such as ethanol or methanol.

使用紫胶进行片状银粉的生产相较于合成树脂具有以下优势:The use of shellac to produce flake silver powder has the following advantages over synthetic resins:

(1)紫胶是天然的生物资源,可持续再生。成本更低,生产过程几乎无排放和废物产生,更加环保。(1) Shellac is a natural biological resource that is sustainable and renewable. It has lower costs, and the production process produces almost no emissions and waste, making it more environmentally friendly.

(2)紫胶可通过碳链断裂而自然降解,而目前报道的用于片状银粉制备的合成树脂需要相当长的时间才能降解。(2) Shellac can be naturally degraded by breaking the carbon chain, while the synthetic resins currently reported for the preparation of flaky silver powder take a considerable amount of time to degrade.

(3)紫胶由于其成膜性好,多用于涂料以及药品和食品中的被膜剂。在本发明中利用紫胶良好的成膜性,制备光滑平整的天然树脂牺牲模板,引导银纳米膜在其上有序生长,实现厚度均匀、表面均一的片状银粉的制备。(3) Shellac is widely used as a coating agent in coatings, medicines and foods due to its good film-forming property. In the present invention, the good film-forming property of shellac is utilized to prepare a smooth and flat natural resin sacrificial template, guide the orderly growth of silver nanofilm thereon, and realize the preparation of flaky silver powder with uniform thickness and uniform surface.

此外,增加了高温吹扫步骤后,天然树脂牺牲模板上得到的银膜更加的光亮,有效减少了银膜表面斑状或条状瑕疵纹的产生,阻止了银膜后续发黑、变黄。In addition, after adding the high-temperature purging step, the silver film obtained on the natural resin sacrificial template is brighter, effectively reducing the generation of spotty or strip-shaped defects on the surface of the silver film, and preventing the silver film from subsequently turning black or yellow.

根据一种优选的实施方式,步骤S1中的紫胶溶液由紫胶和乙基纤维素溶于乙醇制得,紫胶溶液的固含量为15 wt %,紫胶和乙基纤维素的质量比范围为9:1-7:3。According to a preferred embodiment, the shellac solution in step S1 is prepared by dissolving shellac and ethyl cellulose in ethanol, the solid content of the shellac solution is 15 wt %, and the mass ratio of shellac to ethyl cellulose is in the range of 9:1-7:3.

PET基底上涂覆的紫胶溶液固化后形成表面平整的紫胶膜,但紫胶膜在银氨溶液和还原液的作用下存在缓慢的溶解现象,进而会导致镀覆的银膜层出现微小的不均匀,降低制备出的片状银粉的质量。在紫胶溶液中加入乙基纤维素以后,抑制了紫胶膜的溶解,进而进一步保持紫胶膜表面的平整度,保证制备的片状银粉厚度均一。The shellac solution coated on the PET substrate forms a shellac film with a smooth surface after solidification, but the shellac film slowly dissolves under the action of silver ammonia solution and reducing solution, which leads to slight unevenness in the plated silver film layer and reduces the quality of the prepared flaky silver powder. After adding ethyl cellulose to the shellac solution, the dissolution of the shellac film is inhibited, and the flatness of the shellac film surface is further maintained, ensuring that the thickness of the prepared flaky silver powder is uniform.

优选地,紫胶和乙基纤维素的质量比为7:3。Preferably, the mass ratio of shellac to ethyl cellulose is 7:3.

根据一种优选的实施方式,步骤S2中,所述SDS溶液的浓度为0.35 mM;所述SnCl2溶液由10 mL/L的盐酸与44.3mM SnCl2混合而成。According to a preferred embodiment, in step S2, the concentration of the SDS solution is 0.35 mM; the SnCl2 solution is prepared by mixing 10 mL/L of hydrochloric acid with 44.3 mM SnCl2 .

根据一种优选的实施方式,步骤S2中,亲水处理时间为5分钟,敏化处理时间为5分钟。According to a preferred embodiment, in step S2, the hydrophilic treatment time is 5 minutes, and the sensitization treatment time is 5 minutes.

根据一种优选的实施方式,步骤S3中,所述还原液为葡萄糖、酒石酸钾钠中的一种或两种的混合物。According to a preferred embodiment, in step S3, the reducing solution is glucose, sodium potassium tartrate or a mixture of both.

步骤S3中,所述还原液为酒石酸钾钠与葡萄糖的混合物时,其质量比为:5:8-1:8。优选为:1:7。In step S3, when the reducing solution is a mixture of sodium potassium tartrate and glucose, the mass ratio thereof is 5:8-1:8, preferably 1:7.

在还原液中酒石酸钾钠与葡萄糖的质量比为1:8时,银膜的沉积速度太快,银膜平整度会降低,当质量比为5:8时,银膜的沉积速度太慢,银膜表面会有杂质生成,银膜发黄、发黑影响制备的片状银粉的质量。在酒石酸钾钠与葡萄糖的质量比为1:7时,银膜的沉积速度为最佳,既能够保证银膜表面的平整度,又能够保证片状银粉的质量。When the mass ratio of sodium potassium tartrate to glucose in the reducing solution is 1:8, the deposition speed of the silver film is too fast and the flatness of the silver film will be reduced. When the mass ratio is 5:8, the deposition speed of the silver film is too slow, impurities will be generated on the surface of the silver film, and the silver film will turn yellow and black, affecting the quality of the prepared flaky silver powder. When the mass ratio of sodium potassium tartrate to glucose is 1:7, the deposition speed of the silver film is optimal, which can ensure both the flatness of the silver film surface and the quality of the flaky silver powder.

根据一种优选的实施方式,步骤S3中,喷涂到天然树脂牺牲模板上进行反应的反应时间为5-8分钟,优选为6分钟。According to a preferred embodiment, in step S3, the reaction time of spraying onto the natural resin sacrificial template is 5-8 minutes, preferably 6 minutes.

根据一种优选的实施方式,步骤S3中,所述银氨溶液配制方法为:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液。According to a preferred embodiment, in step S3, the silver ammonia solution is prepared by dropping 28 wt% ammonia water into a 58.8 mM AgNO 3 solution, and observing that the solution changes from transparent to turbid, and continuing to drop until the solution becomes transparent. At this time, 1 M NaOH solution is added to make the solution turbid again, and then 28 wt% ammonia water is added to obtain a transparent silver ammonia solution.

根据一种优选的实施方式,步骤S4中,将镀覆了银膜的天然树脂牺牲模板浸入醇类溶液中,所述醇类溶液为乙醇,浸没时间为1-5分钟,优选为2分钟,搅拌速度为500-1000r/min,优选为700 r/min。According to a preferred embodiment, in step S4, the natural resin sacrificial template coated with a silver film is immersed in an alcohol solution, wherein the alcohol solution is ethanol, the immersion time is 1-5 minutes, preferably 2 minutes, and the stirring speed is 500-1000 r/min, preferably 700 r/min.

控制浸没时间和搅拌速度能够控制紫胶膜的溶解速度,紫胶膜溶解慢会使得紫胶膜的溶解时间延长,进而在溶解的过程中可能存在部分紫胶膜再次粘附在片状银粉的表面上的问题。经过实验,本申请的申请人发现在搅拌速度为700 r/min,浸没时间为2分钟的情况下,紫胶膜的溶解速度最为合适,制备出的片状银膜表面几乎无残留。Controlling the immersion time and stirring speed can control the dissolution rate of the shellac film. If the shellac film dissolves slowly, the dissolution time of the shellac film will be prolonged, and there may be a problem that part of the shellac film adheres to the surface of the flaky silver powder again during the dissolution process. After experiments, the applicant of this application found that when the stirring speed is 700 r/min and the immersion time is 2 minutes, the dissolution rate of the shellac film is most suitable, and there is almost no residue on the surface of the prepared flaky silver film.

乙醇的洗脱效果好,杂质残留少,如图5所示,且乙醇对环境友好、可回收循环利用。Ethanol has a good elution effect and less impurities remain, as shown in Figure 5. Ethanol is environmentally friendly and can be recycled.

根据一种优选的实施方式,步骤S3中,所述高温吹扫的温度优选为80-85℃,更优选为85 ℃。According to a preferred embodiment, in step S3, the temperature of the high temperature purge is preferably 80-85°C, more preferably 85°C.

根据一种优选的实施方式,步骤S5中,超声功率为480 W,超声时间为10-50分钟,能够根据后续应用中对银粉的粒径的要求而调整超声时间。According to a preferred embodiment, in step S5, the ultrasonic power is 480 W, and the ultrasonic time is 10-50 minutes. The ultrasonic time can be adjusted according to the requirements for the particle size of the silver powder in subsequent applications.

本申请另一方面还提供紫胶在制备片状银粉中的应用。On the other hand, the present application also provides the use of shellac in the preparation of flaky silver powder.

与现有的技术相比本发明的有益效果是:Compared with the prior art, the present invention has the following beneficial effects:

1、一种使用紫胶制备片状银粉的方法,使用紫胶制备的片状银粉表面无硬脂酸覆盖,在柔性基体中可以很好的分散,导电性能优异。且天然树脂制备片状银粉的工艺中,使用紫胶材料作为镀覆基底材料,为后续实现大规模卷对卷(roll to roll)连续化宏量制备提供了有力保障。工艺中使用的成熟的化学沉积技术也保障了银纳米膜的规模化生产,减少银的浪费;1. A method for preparing flaky silver powder using shellac. The surface of the flaky silver powder prepared using shellac is not covered with stearic acid, can be well dispersed in a flexible matrix, and has excellent conductive properties. In the process of preparing flaky silver powder using natural resin, shellac material is used as a plating base material, which provides a strong guarantee for the subsequent large-scale roll-to-roll continuous mass production. The mature chemical deposition technology used in the process also guarantees the large-scale production of silver nanofilms and reduces silver waste;

2、一种使用紫胶制备片状银粉的方法,利用紫胶良好的成膜性,制备光滑平整的天然树脂牺牲模板,制备出了厚度均匀、表面均一的片状银粉,制备工艺对制备的片状银粉的尺寸可控,表面均匀,适宜用于导电填料中发挥良好的导电作用;2. A method for preparing flaky silver powder using shellac, utilizing the good film-forming property of shellac to prepare a smooth and flat natural resin sacrificial template, and preparing flaky silver powder with uniform thickness and uniform surface. The preparation process can control the size of the prepared flaky silver powder, and the surface is uniform, which is suitable for use in conductive fillers to play a good conductive role;

3、一种使用紫胶制备片状银粉的方法,使用紫胶代替合成树脂,在工业上不仅节约成本,并且能够提升制备出的银粉的整体表面质量,拓宽银粉的使用场景;在环境上,利用自然可再生资源,能够自然快速降解,制备过程操作简单,无需使用丙酮等有机溶剂,而不会对环境造成压力,属于真正的绿色制备片状银粉的工艺方法。3. A method for preparing flaky silver powder using shellac. Using shellac instead of synthetic resin not only saves costs in industry, but also improves the overall surface quality of the prepared silver powder and broadens the application scenarios of the silver powder. Environmentally, it utilizes natural renewable resources, can be naturally and quickly degraded, and the preparation process is simple to operate. It does not require the use of organic solvents such as acetone and will not cause pressure on the environment. It is a truly green process for preparing flaky silver powder.

附图说明BRIEF DESCRIPTION OF THE DRAWINGS

图1为本发明实施例1制备的片状银粉(a)、(b)与商用片状银粉(c)、(d)对比SEM图;图1(a)为本发明制备的片状银粉的总体形貌图,图1(b)为本发明制备的片状银粉的侧截面图;图1(c)为商用片状银粉的总体形貌图,图1(d)为商用片状银粉的侧界面图;FIG1 is a SEM image comparing the flaky silver powder (a), (b) prepared in Example 1 of the present invention and the commercial flaky silver powder (c), (d); FIG1 (a) is a general morphology image of the flaky silver powder prepared in the present invention, and FIG1 (b) is a side cross-sectional view of the flaky silver powder prepared in the present invention; FIG1 (c) is a general morphology image of the commercial flaky silver powder, and FIG1 (d) is a side interface image of the commercial flaky silver powder;

图2为本发明实施例1-5不同超声时长下制备的片状银粉的粒径分布对比图;FIG2 is a comparison diagram of the particle size distribution of flaky silver powder prepared under different ultrasonic durations in Examples 1-5 of the present invention;

图3为本发明实施例1制备的片状银粉的XRD图;FIG3 is an XRD diagram of the flaky silver powder prepared in Example 1 of the present invention;

图4为本发明实施例1制备的片状银粉的AFM图;FIG4 is an AFM image of the flaky silver powder prepared in Example 1 of the present invention;

图5为本发明实施例1制备的片状银粉的TGA图;FIG5 is a TGA graph of the flaky silver powder prepared in Example 1 of the present invention;

图6为本发明中实施例1、2和5中使用不同紫胶和乙基纤维素制备出的天然树脂牺牲模板镀银的效果对比图;FIG6 is a comparison diagram of the silver plating effects of natural resin sacrificial templates prepared using different shellacs and ethyl celluloses in Examples 1, 2 and 5 of the present invention;

图7为本发明中不同吹扫温度下制备出的片状银粉的金相图;FIG7 is a metallographic image of flaky silver powder prepared at different purge temperatures in the present invention;

图8为本发明中不同吹扫温度下制备出的片状银粉的表面电阻;FIG8 is a graph showing the surface resistance of flaky silver powder prepared at different purge temperatures in the present invention;

图9为本发明中实施例7和对比例1制备出的片状银粉的SEM图;FIG9 is a SEM image of flaky silver powder prepared in Example 7 and Comparative Example 1 of the present invention;

图10为本发明对比例2中制备得到的球状银粉的SEM图;FIG10 is a SEM image of the spherical silver powder prepared in Comparative Example 2 of the present invention;

图11为本发明对比例2中制备得到的片状银粉的SEM图。FIG. 11 is a SEM image of the flaky silver powder prepared in Comparative Example 2 of the present invention.

具体实施方式Detailed ways

以下所举实例仅为本发明构思下的基本说明,以便于本领域的技术人员进一步地理解本发明,并非用于限定本发明的范围。再无特殊说明的情况下,本申请中所采用的方法均为常规方法。再无特殊说明的情况下,本申请中所使用的实验材料均为市售。商用片状银粉购于中冶鑫盾合金有限公司。The following examples are only basic descriptions of the present invention, so that those skilled in the art can further understand the present invention, and are not intended to limit the scope of the present invention. Unless otherwise specified, the methods used in this application are all conventional methods. Unless otherwise specified, the experimental materials used in this application are all commercially available. Commercial flaky silver powder was purchased from MCC Xindun Alloy Co., Ltd.

下面结合实施例对本发明的特征和性能作进一步的详细描述。The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

实施例1Example 1

一种使用紫胶制备片状银粉的方法,包括如下步骤:A method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲性模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为7:3的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt % 的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 7:3 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以丝网印刷的方式将紫胶溶液印刷在柔性PET基底上,置入50 ℃烘箱中固化10 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by screen printing, and place it in a 50°C oven for curing for 10 min to form a natural resin sacrificial template.

步骤S2:Step S2:

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入由酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl 2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl 2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl 2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2:将质量比为1:7的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应6分钟后,用超纯水冲洗3次后,以85℃的热风吹扫,获得光亮银膜;Step S3.2: Dissolve potassium sodium tartrate and glucose in ultrapure water at a mass ratio of 1:7, and spray them onto the natural resin sacrificial template simultaneously with the silver ammonia solution at a volume ratio of 1:1, and at the same time, use an air compressor to evenly blow it. After reacting for 6 minutes, rinse with ultrapure water 3 times, and blow it with hot air at 85°C to obtain a bright silver film;

步骤S4:将步骤S3.2得到的银膜浸入乙醇溶液中浸泡2分钟,以700 r/min的速度进行搅拌,获得片状银粉母液;Step S4: immerse the silver film obtained in step S3.2 in an ethanol solution for 2 minutes and stir at a speed of 700 r/min to obtain a flaky silver powder mother solution;

步骤S5:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480 W,超声时间为20分钟,得到平均粒径为12.5 µm的片状银粉。Step S5: The flaky silver powder mother liquor is placed in a high-energy ultrasonic pulverizer for pulverization, the ultrasonic power is set to 480 W, and the ultrasonic time is set to 20 minutes to obtain flaky silver powder with an average particle size of 12.5 µm.

本实施例制备出的片状银粉的SEM图与商用片状银粉(购于中冶鑫盾合金有限公司)的SEM图如图1所示,对比图1(a)和(c)可以看出,本实施例制备的片状银粉形貌均匀,均为薄片状结构,粒径较均匀,表面无润滑层覆盖,而银粉形貌不均匀,有其它形貌银粉掺杂其中。对比图1(b)和(d)可以看出,本发明制备的片状银粉厚度均一,约为55nm;而商用片状银粉侧边不清晰,厚度不均匀。The SEM images of the flaky silver powder prepared in this embodiment and the SEM images of the commercial flaky silver powder (purchased from Zhongye Xindun Alloy Co., Ltd.) are shown in Figure 1. By comparing Figures 1 (a) and (c), it can be seen that the flaky silver powder prepared in this embodiment has a uniform morphology, a thin flaky structure, a relatively uniform particle size, and no lubricating layer covering the surface, while the silver powder has an uneven morphology, with other morphologies of silver powder mixed in. By comparing Figures 1 (b) and (d), it can be seen that the flaky silver powder prepared in the present invention has a uniform thickness of about 55nm; while the commercial flaky silver powder has unclear sides and uneven thickness.

本实施例制备出的片状银粉的XRD图如图3所示,由此图可以看出,片状银粉在38.12º出现一个强峰,分别在44.40º、64.5º、77.40º和81.6º处出现四个弱峰。这五个衍射峰分别代表银面心立方结构的(111)、(200)、(220)、(311)和(222)晶面。除以上五个衍射峰外,图谱上并无其它衍射峰,这与银标准卡片上的衍射峰完全吻合,说明本文所制备出的粉末是非常纯净的银粉。而样品在38.12º处出现的强衍射峰从另一个侧面说明了本文制备出的银粉呈理想的片状结构。The XRD pattern of the flaky silver powder prepared in this embodiment is shown in FIG3 . It can be seen from this figure that the flaky silver powder has a strong peak at 38.12° and four weak peaks at 44.40°, 64.5°, 77.40° and 81.6°. These five diffraction peaks represent the (111), (200), (220), (311) and (222) crystal planes of the silver face-centered cubic structure. In addition to the above five diffraction peaks, there are no other diffraction peaks on the spectrum, which is completely consistent with the diffraction peaks on the silver standard card, indicating that the powder prepared in this article is a very pure silver powder. The strong diffraction peak of the sample at 38.12° shows from another aspect that the silver powder prepared in this article has an ideal flaky structure.

本实施例制备出的片状银粉的AFM图如图4所示,由此图可以看出,本发明制备的片状银粉表面较平整,粗糙度低。这有利于后续导电复合材料的制备,在构建导电通道时,可以形成较好的面-面接触,提高电子的传输速率。The AFM image of the flaky silver powder prepared in this embodiment is shown in FIG4 , from which it can be seen that the surface of the flaky silver powder prepared in the present invention is relatively flat and has low roughness. This is conducive to the subsequent preparation of the conductive composite material, and when constructing the conductive channel, a good surface-to-surface contact can be formed, thereby improving the transmission rate of electrons.

本实施例制备的片状银粉的TGA图如图5所示,由此图可以看出,在整个加热过程中,银片的质量损失很小,仅为1.52wt%,说明本方法制备的片状银粉表面几乎无其它物质残留。The TGA graph of the flaky silver powder prepared in this example is shown in FIG5 , from which it can be seen that during the entire heating process, the mass loss of the silver flakes is very small, only 1.52 wt %, indicating that there is almost no other substance remaining on the surface of the flaky silver powder prepared by this method.

实施例2Example 2

一种使用紫胶制备片状银粉的方法,包括如下步骤:A method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为8:2的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt % 的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 8:2 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以丝网印刷的方式将紫胶溶液印刷在柔性PET基底上,置入50 ℃烘箱中固化10 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by screen printing, and place it in a 50°C oven for curing for 10 min to form a natural resin sacrificial template.

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入由酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl 2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl 2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl 2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2中,将质量比为1:4的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应7分钟后,用超纯水冲洗3次后,以90℃的热风吹扫,获得光亮银膜。In step S3.2, potassium sodium tartrate and glucose in a mass ratio of 1:4 are dissolved in ultrapure water, and sprayed onto the natural resin sacrificial template simultaneously with the silver ammonia solution in a volume ratio of 1:1, and at the same time, the template is evenly purged with an air compressor. After reacting for 7 minutes, the template is rinsed with ultrapure water 3 times, and then purged with hot air at 90°C to obtain a bright silver film.

步骤S4:步骤3.2中得到的光亮银膜浸入50℃,1 M的NaOH溶液中浸泡10分钟,以500 r/min的速度进行搅拌,获得片状银粉母液。Step S4: The bright silver film obtained in step 3.2 is immersed in a 1 M NaOH solution at 50°C for 10 minutes and stirred at a speed of 500 r/min to obtain a flaky silver powder mother solution.

步骤S5:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480 W,超声时间为40分钟,得到平均粒径为9 µm的片状银粉。Step S5: The flaky silver powder mother liquor is placed in a high-energy ultrasonic pulverizer for pulverization, the ultrasonic power is set to 480 W, and the ultrasonic time is set to 40 minutes to obtain flaky silver powder with an average particle size of 9 µm.

本实施例制备出的片状银粉的SEM图、XRD图、AFM图和TGA图与实施例1类似。The SEM image, XRD image, AFM image and TGA image of the flaky silver powder prepared in this example are similar to those in Example 1.

实施例3Example 3

实施例3是对实施例1的进一步改进;一种使用紫胶制备片状银粉的方法,包括如下步骤:Example 3 is a further improvement on Example 1; a method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为7:3的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt % 的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 7:3 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以丝网印刷的方式将紫胶溶液印刷在柔性PET基底上,置入50 ℃烘箱中固化10 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by screen printing, and place it in a 50°C oven for curing for 10 min to form a natural resin sacrificial template.

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入由酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl 2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl 2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl 2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2:将质量比为1:6.5的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应7分钟后,用超纯水冲洗3次后,以80℃的热风吹扫,获得光亮银膜;Step S3.2: Dissolve potassium sodium tartrate and glucose in ultrapure water at a mass ratio of 1:6.5, and spray them onto the natural resin sacrificial template simultaneously with the silver ammonia solution at a volume ratio of 1:1, and at the same time, use an air compressor to evenly blow it. After reacting for 7 minutes, rinse with ultrapure water 3 times, and blow it with hot air at 80°C to obtain a bright silver film;

步骤S4:将步骤S3.2得到的银膜浸入乙醇溶液中浸泡2分钟,以600 r/min的速度进行搅拌,获得片状银粉母液;Step S4: immerse the silver film obtained in step S3.2 in an ethanol solution for 2 minutes and stir at a speed of 600 r/min to obtain a flaky silver powder mother solution;

步骤S5:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480 W,超声时间为30分钟,得到平均粒径为10 µm的片状银粉。Step S5: The flaky silver powder mother liquor is placed in a high-energy ultrasonic pulverizer for pulverization, the ultrasonic power is set to 480 W, and the ultrasonic time is set to 30 minutes to obtain flaky silver powder with an average particle size of 10 µm.

本实施例制备出的片状银粉的SEM图、XRD图和AFM图与实施例1类似。The SEM image, XRD image and AFM image of the flaky silver powder prepared in this example are similar to those in Example 1.

实施例4Example 4

实施例4是对实施例3的进一步改进;一种使用紫胶制备片状银粉的方法,包括如下步骤:Example 4 is a further improvement on Example 3; a method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为7:3的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt % 的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 7:3 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以刮涂的方式将紫胶溶液印刷在柔性PET基底上,置入50 ℃烘箱中固化10 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by blade coating, and place it in a 50 °C oven for curing for 10 min to form a natural resin sacrificial template.

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入由酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl 2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl 2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl 2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2为:将质量比为5:8的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应6分钟后,用超纯水冲洗3次后,以85℃的热风吹扫,获得光亮银膜。Step S3.2 is: dissolving potassium sodium tartrate and glucose in a mass ratio of 5:8 in ultrapure water, spraying them onto the natural resin sacrificial template simultaneously with the silver ammonia solution in a volume ratio of 1:1, and evenly blowing them with an air compressor. After reacting for 6 minutes, rinse with ultrapure water 3 times, and blow with hot air at 85°C to obtain a bright silver film.

步骤S4:将步骤S3.2得到的银膜浸入乙酸乙酯溶液中浸泡2分钟,以900 r/min的速度进行搅拌,获得片状银粉母液;Step S4: immersing the silver film obtained in step S3.2 in an ethyl acetate solution for 2 minutes, stirring at a speed of 900 r/min to obtain a flaky silver powder mother solution;

步骤S5为:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480W,超声时间为50分钟,得到平均粒径为6 µm的片状银粉。Step S5 is: placing the flaky silver powder mother liquor into a high-energy ultrasonic pulverizer for pulverization, setting the ultrasonic power to 480 W and the ultrasonic time to 50 minutes, to obtain flaky silver powder with an average particle size of 6 µm.

本实施例制备出的片状银粉的SEM图、XRD图、AFM图和TGA图与实施例1类似。The SEM image, XRD image, AFM image and TGA image of the flaky silver powder prepared in this example are similar to those in Example 1.

实施例5Example 5

一种使用紫胶制备片状银粉的方法,包括如下步骤:A method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为9:1的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt %的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 9:1 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以刮涂的方式将紫胶溶液印刷在柔性PET基底上,置入40℃烘箱中固化15 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by blade coating, and place it in a 40°C oven for curing for 15 min to form a natural resin sacrificial template.

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入由酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl 2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl 2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl 2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2为:将质量比为1:7的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应6分钟后,用超纯水冲洗3次后,以60℃的热风吹扫,获得光亮银膜。Step S3.2 is: dissolving potassium sodium tartrate and glucose in a mass ratio of 1:7 in ultrapure water, spraying them onto the natural resin sacrificial template simultaneously with the silver ammonia solution in a volume ratio of 1:1, and evenly blowing them with an air compressor. After reacting for 6 minutes, rinse with ultrapure water 3 times, and blow with hot air at 60°C to obtain a bright silver film.

步骤S4:将步骤S3.2得到的银膜浸入乙醇溶液中浸泡4分钟,以500 r/min的速度进行搅拌,获得片状银粉母液;Step S4: immersing the silver film obtained in step S3.2 in an ethanol solution for 4 minutes, stirring at a speed of 500 r/min to obtain a flaky silver powder mother solution;

步骤S5为:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480W,超声时间为10分钟,得到平均粒径为13 µm的片状银粉。Step S5 is: placing the flaky silver powder mother liquor into a high-energy ultrasonic pulverizer for pulverization, setting the ultrasonic power to 480 W and the ultrasonic time to 10 minutes, to obtain flaky silver powder with an average particle size of 13 μm.

本实施例制备出的片状银粉的SEM图、XRD图、AFM图和TGA图与实施例1类似。The SEM image, XRD image, AFM image and TGA image of the flaky silver powder prepared in this example are similar to those in Example 1.

实施例6Example 6

一种使用紫胶制备片状银粉的方法,包括如下步骤:A method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为7:3的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt % 的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 7:3 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以刮涂的方式将紫胶溶液印刷在柔性PET基底上,置入25 ℃烘箱中固化20 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by blade coating, and place it in a 25 °C oven for curing for 20 min to form a natural resin sacrificial template.

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入由酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl 2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl 2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl 2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2为:将质量比为1:3的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应6分钟后,用超纯水冲洗3次后,以85℃的热风吹扫,获得光亮银膜。Step S3.2 is: dissolving potassium sodium tartrate and glucose in a mass ratio of 1:3 in ultrapure water, spraying them onto the natural resin sacrificial template simultaneously with the silver ammonia solution in a volume ratio of 1:1, and evenly blowing them with an air compressor. After reacting for 6 minutes, rinse with ultrapure water 3 times, and blow with hot air at 85°C to obtain a bright silver film.

步骤S4:将步骤S3.2得到的银膜浸入丙酮溶液中浸泡2分钟,以1000 r/min的速度进行搅拌,获得片状银粉母液;Step S4: immersing the silver film obtained in step S3.2 in an acetone solution for 2 minutes, stirring at a speed of 1000 r/min to obtain a flaky silver powder mother solution;

步骤S5为:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480W,超声时间为40分钟,得到平均粒径为9 µm的片状银粉。Step S5 is: placing the flaky silver powder mother liquor into a high-energy ultrasonic pulverizer for pulverization, setting the ultrasonic power to 480 W and the ultrasonic time to 40 minutes, to obtain flaky silver powder with an average particle size of 9 μm.

本实施例制备出的片状银粉的SEM图、XRD图、AFM图和TGA图与实施例1类似。The SEM image, XRD image, AFM image and TGA image of the flaky silver powder prepared in this example are similar to those in Example 1.

图2为本发明实施例1-5制备的片状银粉的粒径分布图,由图2可以看出,银片粒径可以通过超声时间进行控制,随着超声处理时间的增加,银片的粒径分布呈现逐渐减小的趋势。当超声处理时间为50分钟时,银片的平均粒径约为6 µm。FIG2 is a particle size distribution diagram of the flaky silver powder prepared in Examples 1-5 of the present invention. It can be seen from FIG2 that the particle size of the silver flakes can be controlled by the ultrasonic time. As the ultrasonic treatment time increases, the particle size distribution of the silver flakes shows a trend of gradually decreasing. When the ultrasonic treatment time is 50 minutes, the average particle size of the silver flakes is about 6 μm.

如图6所示为本申请中实施例5、2和1中采用紫胶和乙基纤维素不同配比下的紫胶溶液制作的天然树脂牺牲模板镀银后的效果;如图6所示,当紫胶和乙基纤维素的比例为9:1时,镀层不够均匀,表面几乎没有反射效果;而当紫胶和乙基纤维素的比例为8:2时,镀层均匀性有所提升,表面有一定的反射效果,但镀层的表面有瑕疵。当紫胶和乙基纤维素的比例为7:3时,镀层十分均匀,表面的银膜十分光亮,全表面具有反射效果,且表面无可见的瑕疵和凹凸,说明紫胶和乙基纤维素的比例为7:3时,制备出的天然树脂牺牲模板最适宜银膜在其上均匀生长,用此天然树脂牺牲模板能够制备出平整而光亮的银膜。As shown in FIG6, the effect of silver plating of the natural resin sacrificial template made of shellac solution with different ratios of shellac and ethyl cellulose in Examples 5, 2 and 1 of the present application; as shown in FIG6, when the ratio of shellac to ethyl cellulose is 9:1, the coating is not uniform enough, and there is almost no reflection effect on the surface; and when the ratio of shellac to ethyl cellulose is 8:2, the uniformity of the coating is improved, and the surface has a certain reflection effect, but the surface of the coating has defects. When the ratio of shellac to ethyl cellulose is 7:3, the coating is very uniform, the silver film on the surface is very bright, the whole surface has a reflection effect, and there are no visible defects and bumps on the surface, indicating that when the ratio of shellac to ethyl cellulose is 7:3, the prepared natural resin sacrificial template is most suitable for the uniform growth of the silver film thereon, and this natural resin sacrificial template can be used to prepare a flat and bright silver film.

如图7所示为本申请中60℃、70℃、80℃、85℃和90℃吹扫温度下得到的银膜的金相图,从图7可以看出,未吹扫的表面会有瑕疵存在,经过吹扫后,银膜表面瑕疵减少。温度为85℃和90℃时,银膜表面状况最好。采用四探针测试仪对银膜进行表面电阻测试,结果如图8所示,从图8可见,未吹扫的银膜面电阻较高,随着吹扫温度的升高,银膜面电阻逐渐降低。当温度达到80℃以后,银膜表面电阻达到最低值,基本保持不变。可见,最佳吹扫温度为85℃。As shown in Figure 7, it is the metallographic image of the silver film obtained at the purge temperatures of 60°C, 70°C, 80°C, 85°C and 90°C in this application. It can be seen from Figure 7 that there will be defects on the un-purged surface. After purging, the surface defects of the silver film are reduced. When the temperature is 85°C and 90°C, the surface condition of the silver film is the best. The surface resistance of the silver film is tested using a four-probe tester, and the results are shown in Figure 8. It can be seen from Figure 8 that the surface resistance of the un-purged silver film is relatively high. As the purge temperature increases, the surface resistance of the silver film gradually decreases. After the temperature reaches 80°C, the surface resistance of the silver film reaches the lowest value and remains basically unchanged. It can be seen that the optimal purge temperature is 85°C.

实施例7Example 7

一种使用紫胶制备片状银粉的方法,包括如下步骤:A method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为9:1的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt %的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 9:1 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以丝网印刷的方式将紫胶溶液印刷在柔性PET基底上,置入25 ℃烘箱中固化20 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by screen printing, and place it in a 25°C oven for curing for 20 min to form a natural resin sacrificial template.

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2:将质量比为1:4的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应6分钟后,用超纯水冲洗3次后,以80℃的热风吹扫,获得光亮银膜。Step S3.2: Sodium potassium tartrate and glucose in a mass ratio of 1:4 are dissolved in ultrapure water, and sprayed onto the natural resin sacrificial template simultaneously with the silver ammonia solution in a volume ratio of 1:1, and at the same time, the template is evenly purged with an air compressor. After reacting for 6 minutes, the template is rinsed with ultrapure water 3 times, and then purged with hot air at 80°C to obtain a bright silver film.

步骤S4:将步骤S3.2得到的银膜浸入乙醇溶液中浸泡5分钟,以500 r/min的速度进行搅拌,获得片状银粉母液;Step S4: immersing the silver film obtained in step S3.2 in an ethanol solution for 5 minutes, stirring at a speed of 500 r/min, to obtain a flaky silver powder mother solution;

步骤S5:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480 W,超声时间为10分钟,得到平均粒径为13 µm的片状银粉。Step S5: The flaky silver powder mother liquor is placed in a high-energy ultrasonic pulverizer for pulverization, the ultrasonic power is set to 480 W, and the ultrasonic time is set to 10 minutes to obtain flaky silver powder with an average particle size of 13 µm.

实施例8Example 8

一种使用紫胶制备片状银粉的方法,包括如下步骤:A method for preparing flaky silver powder using shellac comprises the following steps:

步骤S1:制备天然树脂牺牲模板:Step S1: Preparation of natural resin sacrificial template:

步骤S1.1:配制紫胶溶液,以质量比为8:2的紫胶和乙基纤维素溶于乙醇溶液中,配制固含量为15 wt % 的紫胶溶液;Step S1.1: preparing a shellac solution, dissolving shellac and ethyl cellulose in an ethanol solution at a mass ratio of 8:2 to prepare a shellac solution with a solid content of 15 wt %;

步骤S1.2:以丝网印刷的方式将紫胶溶液印刷在柔性PET基底上,置入30 ℃烘箱中固化10 min,形成天然树脂牺牲模板。Step S1.2: Print the shellac solution on the flexible PET substrate by screen printing, and place it in a 30°C oven for curing for 10 min to form a natural resin sacrificial template.

步骤S2.1:亲水处理:将天然树脂牺牲性模板置于0.35 mM SDS溶液中,5 min后取出,用超纯水冲洗;Step S2.1: Hydrophilic treatment: Place the natural resin sacrificial template in a 0.35 mM SDS solution, take it out after 5 min, and rinse it with ultrapure water;

步骤S2.2:敏化处理:将步骤S2.1中处理完成的天然树脂牺牲性模板置入酸性SnCl2溶液中,5 min后取出,用超纯水冲洗;所述SnCl2溶液由10 mL/L的盐酸与44.3mMSnCl2混合而成。Step S2.2: Sensitization treatment: Place the natural resin sacrificial template treated in step S2.1 into an acidic SnCl2 solution, take it out after 5 minutes, and rinse it with ultrapure water; the SnCl2 solution is a mixture of 10 mL/L hydrochloric acid and 44.3 mM SnCl2 .

步骤S3.1:按照如下配制方法配制银氨溶液:将28wt%的氨水滴加到58.8mM AgNO3溶液中,观察到溶液由透明变为浑浊,继续滴加直至溶液变为透明。此时,加入1 M的NaOH溶液使溶液再次变浑浊,随后,加入28wt%的氨水以获得透明的银氨溶液;Step S3.1: Prepare a silver ammonia solution according to the following preparation method: add 28 wt% ammonia water to 58.8 mM AgNO 3 solution, observe that the solution changes from transparent to turbid, and continue to add until the solution becomes transparent. At this time, add 1 M NaOH solution to make the solution turbid again, and then add 28 wt% ammonia water to obtain a transparent silver ammonia solution;

步骤S3.2:将质量比为1:3的酒石酸钾钠与葡萄糖溶于超纯水中,以1:1的体积比与银氨溶液同时喷涂到天然树脂牺牲性模板上,同时,用空压机进行均匀吹扫。反应5分钟后,用超纯水冲洗3次后,以85 ℃的热风吹扫,获得光亮银膜。Step S3.2: Sodium potassium tartrate and glucose in a mass ratio of 1:3 are dissolved in ultrapure water, and sprayed onto the natural resin sacrificial template simultaneously with the silver ammonia solution in a volume ratio of 1:1, and at the same time, the template is evenly purged with an air compressor. After reacting for 5 minutes, the template is rinsed with ultrapure water 3 times, and then purged with hot air at 85°C to obtain a bright silver film.

步骤S4:步骤3.2中得到的光亮银膜浸入50℃,1 M的NaOH溶液中浸泡10分钟,以500 r/min的速度进行搅拌,获得片状银粉母液。Step S4: The bright silver film obtained in step 3.2 is immersed in a 1 M NaOH solution at 50°C for 10 minutes and stirred at a speed of 500 r/min to obtain a flaky silver powder mother solution.

步骤S5:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480 W,超声时间为40分钟,得到平均粒径为9.1 µm的片状银粉。Step S5: The flaky silver powder mother liquor is placed in a high-energy ultrasonic pulverizer for pulverization, the ultrasonic power is set to 480 W, and the ultrasonic time is set to 40 minutes to obtain flaky silver powder with an average particle size of 9.1 µm.

步骤S6.1:取0.162g S5中的银粉、0.164g 聚二甲基硅氧烷(主剂:固化剂=10:1)与0.09 g 4-甲基-2-戊酮机械混合30 min。Step S6.1: Take 0.162 g of the silver powder in S5, 0.164 g of polydimethylsiloxane (main agent: curing agent = 10:1) and 0.09 g of 4-methyl-2-pentanone and mechanically mix them for 30 min.

步骤S6.2:通过掩膜在聚二甲基硅氧烷基板上沉积导电弹性体薄膜,并在-8 kPa下抽真空20分钟以消除气泡,在145℃,固化4 h,得到固含量为49.7 wt %的导电复合材料。Step S6.2: A conductive elastomer film was deposited on a polydimethylsiloxane-based substrate through a mask, and vacuumed at -8 kPa for 20 min to eliminate bubbles, and cured at 145 °C for 4 h to obtain a conductive composite material with a solid content of 49.7 wt %.

步骤S6.3:通过四探针测试仪对步骤S6.2中得到的导电复合材料进行测试,得到其电导率为9353.1 S/cm。Step S6.3: The conductive composite material obtained in step S6.2 was tested by a four-probe tester, and its conductivity was found to be 9353.1 S/cm.

对比例1Comparative Example 1

本对比例与实施例7的不同之处在于:The difference between this comparative example and Example 7 is that:

步骤S1:制备丙烯酸树脂牺牲模板:Step S1: Preparation of acrylic resin sacrificial template:

步骤S1.1:将热缩性丙烯酸树脂溶于环己酮溶液中,稀释至15 wt %;Step S1.1: dissolving the heat-shrinkable acrylic resin in a cyclohexanone solution and diluting it to 15 wt %;

步骤S1.2:以丝网印刷的方式将稀释后的丙烯酸树脂印刷在柔性PET基底上,置入80 ℃烘箱中固化1 h,形成丙烯酸树脂牺牲模板。Step S1.2: Print the diluted acrylic resin on the flexible PET substrate by screen printing, and place it in an 80°C oven for curing for 1 h to form an acrylic resin sacrificial template.

步骤S4:将步骤S3.2得到的银膜浸入丙酮溶液中浸泡15分钟,获得片状银粉母液;Step S4: immersing the silver film obtained in step S3.2 in an acetone solution for 15 minutes to obtain a mother solution of flaky silver powder;

步骤S5:将片状银粉母液置入高能超声粉碎机进行粉碎,设定超声功率为480 W,超声时间为50分钟,得到平均粒径为7.5 µm的片状银粉。Step S5: The flaky silver powder mother liquor is placed in a high-energy ultrasonic pulverizer for pulverization, the ultrasonic power is set to 480 W, and the ultrasonic time is set to 50 minutes to obtain flaky silver powder with an average particle size of 7.5 µm.

其余步骤与实施例7均相同。The remaining steps are the same as those in Example 7.

对实施例7和对比例1制备出的银粉进行SEM测试,结果如图9所示,图9a、9b为实施例7制备的银粉,图9c、9d为由对比例1制备的银粉。对比图9a、9b和9c、9d可以看出,当放大倍数相同时,实施例7制备出的银粉表面光滑平整,而由对比例1制备出的银粉表面比较粗糙,银粉表面凹凸不平,对比放大后更加明显。银粉表面粗糙度大、凹凸不平也必将会导致银粉厚度出现波动,均一性下降。The silver powder prepared in Example 7 and Comparative Example 1 was subjected to SEM test, and the results are shown in FIG9 , where FIG9a and FIG9b are the silver powder prepared in Example 7, and FIG9c and FIG9d are the silver powder prepared in Comparative Example 1. By comparing FIG9a and FIG9b with FIG9c and FIG9d, it can be seen that when the magnification is the same, the surface of the silver powder prepared in Example 7 is smooth and flat, while the surface of the silver powder prepared in Comparative Example 1 is relatively rough, and the surface of the silver powder is uneven, which is more obvious after comparison and magnification. The large roughness and unevenness of the silver powder surface will inevitably lead to fluctuations in the thickness of the silver powder and reduced uniformity.

从使用物质层面对比实施例7和对比例1可以发现,实施例7中使用的紫胶、乙基纤维素、乙醇均为环境友好型材料或试剂;而在相应过程中,对比例1中则使用了丙烯酸树脂、丙酮等试剂。实施例7中固化温度25 ℃,固化时间20 min;对比例1中,固化温度80 ℃,固化时间1 h。实施例7使用烘箱进行固化的温度较低、时间较短,因此能耗较小。From the perspective of the materials used, it can be found that the shellac, ethyl cellulose and ethanol used in Example 7 are all environmentally friendly materials or reagents; while in the corresponding process, acrylic resin, acetone and other reagents are used in Comparative Example 1. In Example 7, the curing temperature is 25°C and the curing time is 20 min; in Comparative Example 1, the curing temperature is 80°C and the curing time is 1 h. In Example 7, the curing temperature and time of the oven used for curing are lower, and the energy consumption is lower.

对比例2Comparative Example 2

本对比例使用机械球磨法制备片状银粉。In this comparative example, the flaky silver powder was prepared by mechanical ball milling.

步骤S1:制备类球形银粉作为前驱体:Step S1: preparing spherical silver powder as a precursor:

步骤S1.1:称取4g 聚乙烯吡咯烷酮溶解于200 ml乙二醇中,加入1g AgNO3充分搅拌溶解制得前驱体溶液;Step S1.1: Weigh 4 g of polyvinyl pyrrolidone and dissolve it in 200 ml of ethylene glycol, add 1 g of AgNO 3 and stir thoroughly to dissolve to prepare a precursor solution;

步骤S1.2:将前驱体溶液转移至500 ml烧瓶中,放入磁子,置于160℃油浴中,设置搅拌速度为300 r/min,恒温反应60min。Step S1.2: Transfer the precursor solution to a 500 ml flask, add a magnetic bar, place it in a 160°C oil bath, set the stirring speed to 300 r/min, and react at a constant temperature for 60 minutes.

步骤S1.3:将步骤S1.2中反应结束得到的银粉用乙醇洗涤三次,在8000 r/min的转速下离心分离后,在40 ℃下真空干燥3 h,得到球形银粉,对其形貌进行SEM测试,结果如图10所示。Step S1.3: The silver powder obtained after the reaction in step S1.2 was washed three times with ethanol, centrifuged at 8000 r/min, and vacuum dried at 40 °C for 3 h to obtain spherical silver powder. The morphology was tested by SEM. The results are shown in Figure 10.

步骤S2.1:将25 g的不锈钢磨球装入100 ml的球磨罐中,并向球磨罐中依次放入2.5 g 球形银粉、0.05 g硬脂酸钙、0.05 ml油酸和 3 ml的乙醇作为球磨介质。随后封闭球磨罐;Step S2.1: 25 g of stainless steel grinding balls were placed in a 100 ml ball mill, and 2.5 g of spherical silver powder, 0.05 g of calcium stearate, 0.05 ml of oleic acid and 3 ml of ethanol were placed in the ball mill in sequence as ball milling media. The ball mill was then sealed;

步骤S2.2:将2个球磨罐正对固定在球磨机上,并用50 r/min的转速预球磨0.5h;Step S2.2: Fix two ball milling jars on the ball mill facing each other, and pre-mill at a speed of 50 r/min for 0.5 h;

步骤S2.3:将球磨机转速重新设定为250 r/min,球磨24 h。Step S2.3: The ball mill speed was reset to 250 r/min and the ball milling was continued for 24 h.

步骤S3:将步骤2.3中球磨后的物料用乙醇洗涤3次。在50℃下真空干燥2 h,得到粒径为2-6 µm的片状银粉,对其形貌进行SEM测试,结果如图11所示。Step S3: The ball-milled material in step 2.3 was washed with ethanol three times and vacuum dried at 50°C for 2 h to obtain flaky silver powder with a particle size of 2-6 µm. The morphology was tested by SEM, and the results are shown in FIG11 .

步骤S4.1:取0.651 g S3中的银粉、0.202 g 聚二甲基硅氧烷(主剂:固化剂=10:1)与0.20 g 4-甲基-2-戊酮机械混合30 min。Step S4.1: Take 0.651 g of the silver powder in S3, 0.202 g of polydimethylsiloxane (main agent: curing agent = 10:1) and 0.20 g of 4-methyl-2-pentanone and mechanically mix them for 30 min.

步骤S4.2:通过掩膜在聚二甲基硅氧烷基板上沉积导电弹性体薄膜,并在-8 kPa下抽真空20分钟以消除气泡,在145℃,固化4 h,得到固含量为76.2 wt %的导电复合材料。Step S4.2: A conductive elastomer film was deposited on a polydimethylsiloxane-based substrate through a mask, and vacuum was drawn at -8 kPa for 20 min to eliminate bubbles. The film was cured at 145 °C for 4 h to obtain a conductive composite material with a solid content of 76.2 wt %.

步骤S4.3:通过四探针测试仪对步骤S4.2中得到的导电复合材料进行测试,得到其电导率为7486.3 S/cm。Step S4.3: The conductive composite material obtained in step S4.2 was tested by a four-probe tester, and its conductivity was found to be 7486.3 S/cm.

通过导电性能对比可知:实施例8制备的导电复合材料在银粉固含量为49.7 wt %时的电导率高达9353.1 S/cm,对比例2制备的导电复合材料在银粉固含量为76.2 wt %时的电导率为7486.3 S/cm。由此可见,使用本发明实施例8中制备的银粉当固含量降低约34wt %时,导电复合材料的电导率却得到了较大提升。众所周知,导电复合材料的成本主要来源于银粉的价格,使用本发明制备的片状银粉作为导电填料可以在提升导电性能的同时降低生产成本约34 %。By comparing the conductive properties, it can be seen that the conductivity of the conductive composite material prepared in Example 8 is as high as 9353.1 S/cm when the silver powder solid content is 49.7 wt %, and the conductivity of the conductive composite material prepared in Comparative Example 2 is 7486.3 S/cm when the silver powder solid content is 76.2 wt %. It can be seen that when the solid content of the silver powder prepared in Example 8 of the present invention is reduced by about 34wt %, the conductivity of the conductive composite material is greatly improved. As is known to all, the cost of the conductive composite material mainly comes from the price of silver powder. Using the flaky silver powder prepared by the present invention as a conductive filler can reduce the production cost by about 34% while improving the conductive properties.

以上所述实施例仅表达了本申请的具体实施方式,其描述较为具体和详细,但并不能因此而理解为对本申请保护范围的限制。应当指出的是,对于本领域的普通技术人员来说,在不脱离本申请技术方案构思的前提下,还可以做出若干变形和改进,这些都属于本申请的保护范围。The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims (10)

1. A method for preparing flake silver powder by using lac, which is characterized by comprising the following steps:
step S1: preparing a natural resin sacrificial template: dissolving lac in ethanol to prepare a lac solution; coating the lac solution on a flexible substrate, and curing;
step S2: carrying out hydrophilic treatment and sensitization treatment on the natural resin sacrificial template;
step S3: preparing a silver film: preparing silver-ammonia solution, spraying the silver-ammonia solution and the reducing solution on a natural resin sacrificial template simultaneously for reaction, uniformly purging, flushing a silver film with ultrapure water, and purging at a high temperature of 60-90 ℃ to obtain a bright silver film on the natural resin sacrificial template;
step S4: immersing a natural resin sacrificial template plated with a silver film into an alcohol solution, a ketone solution or an alkaline solution, and stirring to obtain a flaky silver powder mother solution;
step S5: crushing the silver flake mother solution by adopting ultrasonic, and soaking in ethanol, centrifuging and drying to obtain the silver flake.
2. The method for preparing flake silver powder by using shellac according to claim 1, wherein the shellac solution in the step S1 is prepared by dissolving shellac and ethyl cellulose in ethanol, the solid content of the shellac solution is 15 wt%, and the mass ratio of shellac to ethyl cellulose is 9:1-7:3.
3. The method for preparing plate-like silver powder using shellac according to claim 2, wherein the mass ratio of shellac to ethylcellulose is 7:3.
4. The method for preparing flake silver powder by using shellac according to claim 1, wherein in the step S3, the reducing solution is one or two of glucose and sodium potassium tartrate, and when the reducing solution is a mixture of sodium potassium tartrate and glucose, the mass ratio of sodium potassium tartrate to glucose is: 5:8-1:8.
5. The method for preparing flake silver powder by using shellac according to claim 4, wherein in the step S3, when the reducing solution is a mixture of potassium sodium tartrate and glucose, the mass ratio of potassium sodium tartrate to glucose is: 1:7.
6. The method for preparing plate-like silver powder using shellac according to claim 1, wherein the reaction time for spraying onto the natural resin sacrificial template for the reaction in step S3 is 5 to 8 minutes.
7. The method for preparing plate-like silver powder using shellac according to claim 1, wherein in step S4, the natural resin sacrificial template coated with the silver film is immersed in an ethanol solution for 1 to 5 minutes with a stirring speed of 500 to 1000 r/min.
8. The method for preparing plate-like silver powder using shellac according to claim 7, wherein the immersion time of the natural resin sacrificial template coated with the silver film in the ethanol solution is 2 minutes and the stirring speed is 700 r/min in step S4.
9. The method for preparing plate-like silver powder using shellac according to claim 1, wherein the high-temperature purging is performed at 80 to 85 ℃ in step S3.
10. The application of lac in preparing flake silver powder.
CN202410269899.0A 2024-03-11 2024-03-11 Method for preparing flake silver powder by using shellac Active CN117862520B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202410269899.0A CN117862520B (en) 2024-03-11 2024-03-11 Method for preparing flake silver powder by using shellac

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202410269899.0A CN117862520B (en) 2024-03-11 2024-03-11 Method for preparing flake silver powder by using shellac

Publications (2)

Publication Number Publication Date
CN117862520A true CN117862520A (en) 2024-04-12
CN117862520B CN117862520B (en) 2024-05-10

Family

ID=90593306

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202410269899.0A Active CN117862520B (en) 2024-03-11 2024-03-11 Method for preparing flake silver powder by using shellac

Country Status (1)

Country Link
CN (1) CN117862520B (en)

Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007043664A1 (en) * 2005-10-14 2007-04-19 Toyo Ink Mfg. Co., Ltd. Method for producing metal particle dispersion, conductive ink using metal particle dispersion produced by such method, and conductive coating film
CN101569936A (en) * 2009-06-05 2009-11-04 中国乐凯胶片集团公司 Preparation method for flaky micro-aluminum powder
WO2010024256A1 (en) * 2008-08-25 2010-03-04 日本板硝子株式会社 Silver-based photoluminescent pigment and a cosmetic composition, paint composition, adiabatic paint composition, ink composition, and resin composition containing same
JP2011208278A (en) * 2010-03-10 2011-10-20 Dowa Holdings Co Ltd Flaky silver powder and method for producing the same
CN102974839A (en) * 2012-12-04 2013-03-20 中山大学 Method for preparing nanometer flake silver powder through chemical deposition
CN103480838A (en) * 2013-10-16 2014-01-01 哈尔滨工业大学 Preparation method of nano silver-coated copper powder
CN104148655A (en) * 2014-07-14 2014-11-19 中山大学 Environment-friendly flake silver powder preparation method
CN105236760A (en) * 2015-11-02 2016-01-13 云南师范大学 Method for manufacturing mirror by using coated flaky aluminum powder
JP2016035098A (en) * 2014-07-31 2016-03-17 Dowaエレクトロニクス株式会社 Silver-coated flaky copper powder, method for producing the same, and conductive paste using the silver-coated flaky copper powder
JP2017002409A (en) * 2014-07-31 2017-01-05 Dowaエレクトロニクス株式会社 Silver powder and manufacturing method therefor
CN106573300A (en) * 2014-07-31 2017-04-19 同和电子科技有限公司 Silver powder, method for producing same, and conductive paste
CN106573301A (en) * 2014-07-31 2017-04-19 同和电子科技有限公司 Silver powder, method for producing same, and conductive paste
JP2017101268A (en) * 2015-11-30 2017-06-08 Dowaエレクトロニクス株式会社 Spherical silver powder and manufacturing method and conductive paste
CN108580920A (en) * 2018-03-16 2018-09-28 南京林业大学 A kind of preparation method of flake silver powder
CN109663932A (en) * 2018-03-16 2019-04-23 南京林业大学 A kind of preparation method of flake silver powder
CN110832040A (en) * 2017-05-15 2020-02-21 巴斯夫欧洲公司 Method for producing a metal nanoparticle layer and use thereof in decorative or security elements
CN112912191A (en) * 2018-10-25 2021-06-04 巴斯夫欧洲公司 Compositions comprising silver nanoplatelets
CN113677458A (en) * 2019-03-29 2021-11-19 大洲电子材料株式会社 Mixing silver powder and conductive paste containing it
CN113811409A (en) * 2019-05-06 2021-12-17 巴斯夫欧洲公司 Compositions containing silver nanosheets
CN114255906A (en) * 2015-12-09 2022-03-29 C3内诺公司 Method for synthesizing silver nanoplates and noble metal coated silver nanoplates, and use thereof in transparent films
WO2022167377A1 (en) * 2021-02-03 2022-08-11 Basf Se Compositions, comprising silver nanoplatelets

Patent Citations (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007043664A1 (en) * 2005-10-14 2007-04-19 Toyo Ink Mfg. Co., Ltd. Method for producing metal particle dispersion, conductive ink using metal particle dispersion produced by such method, and conductive coating film
WO2010024256A1 (en) * 2008-08-25 2010-03-04 日本板硝子株式会社 Silver-based photoluminescent pigment and a cosmetic composition, paint composition, adiabatic paint composition, ink composition, and resin composition containing same
CN101569936A (en) * 2009-06-05 2009-11-04 中国乐凯胶片集团公司 Preparation method for flaky micro-aluminum powder
JP2011208278A (en) * 2010-03-10 2011-10-20 Dowa Holdings Co Ltd Flaky silver powder and method for producing the same
CN102974839A (en) * 2012-12-04 2013-03-20 中山大学 Method for preparing nanometer flake silver powder through chemical deposition
CN103480838A (en) * 2013-10-16 2014-01-01 哈尔滨工业大学 Preparation method of nano silver-coated copper powder
CN104148655A (en) * 2014-07-14 2014-11-19 中山大学 Environment-friendly flake silver powder preparation method
CN106573300A (en) * 2014-07-31 2017-04-19 同和电子科技有限公司 Silver powder, method for producing same, and conductive paste
JP2017002409A (en) * 2014-07-31 2017-01-05 Dowaエレクトロニクス株式会社 Silver powder and manufacturing method therefor
CN106573301A (en) * 2014-07-31 2017-04-19 同和电子科技有限公司 Silver powder, method for producing same, and conductive paste
JP2016035098A (en) * 2014-07-31 2016-03-17 Dowaエレクトロニクス株式会社 Silver-coated flaky copper powder, method for producing the same, and conductive paste using the silver-coated flaky copper powder
CN105236760A (en) * 2015-11-02 2016-01-13 云南师范大学 Method for manufacturing mirror by using coated flaky aluminum powder
JP2017101268A (en) * 2015-11-30 2017-06-08 Dowaエレクトロニクス株式会社 Spherical silver powder and manufacturing method and conductive paste
CN114255906A (en) * 2015-12-09 2022-03-29 C3内诺公司 Method for synthesizing silver nanoplates and noble metal coated silver nanoplates, and use thereof in transparent films
CN110832040A (en) * 2017-05-15 2020-02-21 巴斯夫欧洲公司 Method for producing a metal nanoparticle layer and use thereof in decorative or security elements
CN109663932A (en) * 2018-03-16 2019-04-23 南京林业大学 A kind of preparation method of flake silver powder
CN108580920A (en) * 2018-03-16 2018-09-28 南京林业大学 A kind of preparation method of flake silver powder
CN112912191A (en) * 2018-10-25 2021-06-04 巴斯夫欧洲公司 Compositions comprising silver nanoplatelets
CN113677458A (en) * 2019-03-29 2021-11-19 大洲电子材料株式会社 Mixing silver powder and conductive paste containing it
CN113811409A (en) * 2019-05-06 2021-12-17 巴斯夫欧洲公司 Compositions containing silver nanosheets
WO2022167377A1 (en) * 2021-02-03 2022-08-11 Basf Se Compositions, comprising silver nanoplatelets
CN117203007A (en) * 2021-02-03 2023-12-08 巴斯夫欧洲公司 Composition comprising silver nanoplates

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
JUN WANG: ""flaky silver powders prepared with nanofilm transition method: application for printable electronics"", JOURNAL OF METERIALS CHEMISTRY C, no. 1, 16 October 2012 (2012-10-16), pages 230 - 233 *
刘朋;文明芬;: "超细银粉的制备及其粒径表征的研究", 中国粉体工业, no. 02, 25 April 2010 (2010-04-25) *

Also Published As

Publication number Publication date
CN117862520B (en) 2024-05-10

Similar Documents

Publication Publication Date Title
KR101789213B1 (en) Method of Manufacturing Silver-Coated Copper Nano Wire Having Core-Shell Structure by Chemical Reduction Method
CN101294047B (en) A kind of radar wave absorbing coating with hollow microspheres as filler and preparation method thereof
TW200849699A (en) Solution of hydroxyalkylated chitosan
US4781980A (en) Copper powder for use in conductive paste
CN102424568A (en) A preparation method of a tungsten-containing alumina ceramic heating substrate
CN112570728A (en) Flaky silver powder and preparation method and application thereof
CN110842191A (en) A kind of silver powder with high sintering activity and its preparation method and application
CN114054769B (en) Silver micro powder and preparation method and application thereof
CN116984621A (en) Silver powder preparation method with adjustable sintering activity
CN115805318A (en) A kind of silver powder with high index crystal plane exposure and its preparation method and application
CN112404450B (en) A chemical synthesis method of highly dispersed and highly spherical porous silver powder
CN114605870B (en) Carbon nanotube/liquid metal conductive ink and preparation method and application thereof
CN102974839A (en) Method for preparing nanometer flake silver powder through chemical deposition
CN117862520B (en) Method for preparing flake silver powder by using shellac
CN108555286A (en) A kind of nickel copper-clad micron film, preparation method and its application of nucleocapsid
JP4195581B2 (en) Copper powder manufacturing method and copper powder obtained by the method
CN108148221A (en) A kind of flexible porous substrate of metal nanoparticle modification and preparation method thereof
CN103834231B (en) A kind of silver-colored catalysis colloidal inks for the ink-jet printed copper figure in flexible parent metal surface and preparation method thereof
CN101312800B (en) Liquid colloidal dispersion of silver particles, coating liquid for forming silver film, manufacturing method and silver film
KR101738494B1 (en) Silver coating method of copper powder
TW201816182A (en) Metal nanoparticle aqueous dispersion
KR100862641B1 (en) Method for producing electromagnetic shielding composition and electromagnetic shielding composition
CN110993927A (en) Method for coating Al and Sm on high-nickel ternary material by washing
CN103949635B (en) A kind of preparation method of flaky silver coated copper powder
CN112811422A (en) Biomass core-shell wave-absorbing material, preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant