WO2016011910A1 - Switch contact with molybdenum alloy plating and preparation method for same - Google Patents

Abstract

A switch contact with molybdenum alloy plating and preparation method for same. The contact component has a three-layered structure, the first layer being a hydrophobic rubber layer (1), the second layer being a metal sheet layer (2), and the third layer being a molybdenum alloy chemical deposition layer (3). The plating solution used in said chemical deposition contains 20-125g/L of a soluble molybdenum compound. When chemical depositing using said plating solution is performed on the layered composite body of the hydrophobic rubber layer (1) and the metal sheet layer (2), the molybdenum alloy plating (3) is selectively deposited on the metal surface. The switch contact prepared using said method has a good metallic hue, low contact resistance, high resistance to electrical arc ablation, and a long service life, and is suitable for heat-cured adhesion and moulding with rubber.

Description

含有钼合金镀层的开关触点及其制备方法Switch contact containing molybdenum alloy plating layer and preparation method thereof 技术领域Technical field

本发明具体涉及一种电力或电子产品中的开关或电路中两个导体之间可通过相互接触从而可供电流通过的零部件(也就是电触头或触点)及其制备方法。More particularly, the present invention relates to a component (i.e., an electrical contact or contact) between two conductors in a switch or circuit in an electrical or electronic product that is electrically contactable by mutual contact and a method of making the same.

背景技术Background technique

电触头或触点是开关或电路中两个导体之间通过相互接触从而可供电流通过的重要零部件，承担接通、承载和分断正常电流和故障电流的功能，其质量和使用寿命直接决定着整个开关或电路的质量和使用寿命。电触头或触点主要应用于继电器、接触器、空气开关、限流开关、电机保护器、微型开关、仪器仪表、电脑键盘、手持机、家用电器、汽车电器(车窗开关、后视镜开关、灯开关、起动电机等负荷开关)、漏电保护开关等。电触点或触点的制备材料很多，主要有银、银镍、银氧化铜、银氧化镉、银氧化锡、银氧化锡氧化铟、银氧化锌、紫铜、黄铜、磷铜、青铜、锡铜、铍铜、铜镍、锌白铜、不锈钢等。An electrical contact or contact is an important component of a switch or two conductors that are in contact with each other to allow current to pass through, and functions to connect, carry and disconnect normal current and fault current, and its quality and service life are directly Determines the quality and service life of the entire switch or circuit. Electrical contacts or contacts are mainly used in relays, contactors, air switches, current limiting switches, motor protectors, micro switches, instrumentation, computer keyboards, handhelds, household appliances, automotive appliances (window switches, rearview mirrors). Switch, light switch, starter motor and other load switches), leakage protection switch, etc. There are many materials for the preparation of electrical contacts or contacts, mainly silver, silver nickel, silver oxide copper, silver cadmium oxide, silver tin oxide, silver tin oxide indium oxide, silver zinc oxide, copper, brass, phosphor bronze, bronze, Tin copper, beryllium copper, copper nickel, zinc white copper, stainless steel, etc.

在汽车电器、家用电器、电脑键盘和手持机等设备中，其开关部件常常是设有触点的印刷电路板(PCB)和设有触点的橡胶按键的组合。PCB上的圆形触点，被一条直线或曲线(如S型曲线)分割成不导通的两半。按键上的触点是不用分割的圆形。用按键上的一个相同直径的圆形触点，与PCB上的一个圆形触点作面对面的接触，就可以接通PCB上的一个电路。按键上的触点材料，是导电橡胶或金属。导电橡胶触点与PCB触点相接触时的接触电阻较大，导电橡胶触点不适用于接通电流较大(例如电流大于50毫安)的PCB电路。金属触点与PCB触点相接触时的接触电阻较小，金属触点既可以用于接通电流较小的PCB电路，也可以用于接通电流较大的PCB电路。但目前金属触点存在耐化学品腐蚀、耐电弧烧蚀性能不理想、制作成本高从而使其应用受到限制等问题。In automotive appliances, household appliances, computer keyboards, and handsets, the switching components are often a combination of a printed circuit board (PCB) with contacts and rubber buttons with contacts. The circular contacts on the PCB are divided into two non-conducting halves by a straight line or curve (such as an S-curve). The contacts on the buttons are circular without splitting. A circuit on the PCB can be turned on by making a face-to-face contact with a circular contact on the PCB with a circular contact of the same diameter on the button. The contact material on the button is conductive rubber or metal. When the conductive rubber contact is in contact with the PCB contact, the contact resistance is large, and the conductive rubber contact is not suitable for the PCB circuit with a large on-current (for example, a current greater than 50 mA). When the metal contacts are in contact with the PCB contacts, the contact resistance is small, and the metal contacts can be used for both the PCB circuit with a small current and the PCB circuit with a large current. However, at present, metal contacts have problems such as chemical corrosion resistance, arc erosion resistance, and high manufacturing cost, which limits their application.

在大气中，开关元件在接通电路或分断电路时常产生电火花或电弧。开关电弧现象的存在，将使触点受到氧化和烧蚀，并且可能使空气中的有机质碳化从而产生积碳，使开关的接触电阻逐渐增大甚至断路。In the atmosphere, switching elements often generate sparks or arcs when switching on or breaking circuits. The presence of the switching arc phenomenon will cause the contacts to be oxidized and ablated, and may carbonize the organic matter in the air to generate carbon deposits, causing the contact resistance of the switch to gradually increase or even break.

申请专利号为201220499100.X的专利文件公开了“一种三层复合电触点”，该触点是在铜基触点本体的接触面上镀一层银，使得触点的导电性能更好，且比完全采用银制成要节省生产成本。虽然银的导电性和传热性在所有的金属中都是最高的，但银的耐大气腐蚀性能较差、耐盐雾性能较差。银易与大气中的硫化氢(H₂S)反应生成黑色的硫化银。银作为点触点使用，虽然初始表面电阻小，但其在大气中的使用寿命也受到限制。虽然镀银的成本比较低，但银也是贵金属之一。另外，在这样的电触点中，没有橡胶层，因此，这种电触点不适于与橡胶进行热硫化粘合和热硫化成型从而制成含有电触点的橡胶按键。只有含有橡胶层的触点，或者全部由导电橡胶构成的触点，才可能顺利与其它橡胶进行热硫化粘合和热硫化成型从而制成含有触点的橡胶按键，而不会在热硫化粘合和热硫化成型过程中产生溢胶、粘合不良等质量问题。 Patent Document No. 201220499100.X discloses "a three-layer composite electrical contact" which is coated with a layer of silver on the contact surface of the copper-based contact body to make the contact have better electrical conductivity. And it is more economical than using silver completely. Although the conductivity and heat transfer properties of silver are the highest among all metals, silver has poor atmospheric corrosion resistance and poor salt spray resistance. Silver easily reacts with hydrogen sulfide (H ₂ S) in the atmosphere to form black silver sulfide. Silver is used as a point contact, and although the initial surface resistance is small, its service life in the atmosphere is also limited. Although the cost of silver plating is relatively low, silver is also one of the precious metals. In addition, in such an electrical contact, there is no rubber layer, and therefore, such an electrical contact is not suitable for thermal vulcanization bonding and thermal vulcanization molding with rubber to form a rubber button containing electrical contacts. Only the contacts containing the rubber layer, or the contacts made entirely of conductive rubber, can be smoothly vulcanized and thermally vulcanized with other rubbers to form a rubber button with contacts, without being thermally vulcanized. In the heat and vulcanization molding process, there are quality problems such as overflowing glue and poor adhesion.

美国专利7169215公开了化学沉积铜钼合金的材料和方法，所得到的不含碱金属离子和碱土金属离子的铜钼合金电阻低于30微欧姆·厘米。该合金沉积于单个硅晶上、硅热氧化层上、硅衬底上的铜和钴薄膜上。该铜钼合金可用作金属层间的阻隔层和芯片上的互连材料。在这些应用中该铜钼合金虽然可以取代铜，但电阻率比铜高。该发明中公开了对基材用钯溶液活化，然后让铜钼在基材上进行化学沉积。U.S. Patent 7,169,215 discloses a material and method for chemically depositing a copper-molybdenum alloy, and the resulting copper-molybdenum alloy containing no alkali metal ions and alkaline earth metal ions has an electrical resistance of less than 30 micro ohm.cm. The alloy is deposited on a single silicon crystal, a silicon thermal oxide layer, and a copper and cobalt film on a silicon substrate. The copper-molybdenum alloy can be used as a barrier layer between metal layers and an interconnect material on a chip. In these applications, the copper-molybdenum alloy can replace copper, but has a higher electrical resistivity than copper. The invention discloses activation of a substrate with a palladium solution followed by chemical deposition of copper molybdenum on the substrate.

日本专利JP2001003179公开了将钼化合物加入到钯的化学镀液中制备钯钼合金的方法，所制得的钯钼合金镀层具有优秀的粘结性能和焊接性。日本专利JP62060878公开了将几种化合物的水溶液混合在一起而形成的一种镍钼合金的化学镀液。Japanese Patent JP2001003179 discloses a method of preparing a palladium-molybdenum alloy by adding a molybdenum compound to an electroless plating solution of palladium, and the palladium-molybdenum alloy plating layer obtained has excellent bonding properties and weldability. Japanese Patent JP62060878 discloses an electroless plating solution of a nickel-molybdenum alloy formed by mixing together aqueous solutions of several compounds.

美国专利4019910公开了制备一种多金属的镍合金的化学镀液。该镍合金中除了含有硼或磷，还含有一种或一种以上的金属如锡、钨、钼或铜。该化学镀液中含有无机酸和多元酸或多元醇反应所得的酯复合物，如葡庚糖酸的二硼酯、钨酸酯或钼酸酯。该镍合金主要由镍组成，镍含量通常在大约60％至大约95％(重量比)的范围内。该合金有优良的机械性能和耐腐蚀性能，其中某些合金如含磷的镍合金，特别是镍-磷-锡-铜合金，具有非磁性或非铁磁性。该发明所公开的多金属的镍合金含有较大含量的硼或磷，如作为触点材料使用，较大含量的硼或磷的存在，将影响触点的初始电阻。我们的测试表明，纯镍、镍含量大的镍合金(如镍铜合金或蒙乃尔合金、镍铬合金等)、含镍的不锈钢、或用化学镀得到的镍为主要组成的镍合金，如果作为开关的触点，都具有较差的耐电弧性能和较低的开关使用寿命。U.S. Patent 4,019,910 discloses the preparation of an electroless plating bath of a multi-metal nickel alloy. The nickel alloy contains, in addition to boron or phosphorus, one or more metals such as tin, tungsten, molybdenum or copper. The electroless plating solution contains an ester complex obtained by reacting a mineral acid with a polybasic acid or a polyhydric alcohol, such as a diboron ester of glucoheptonic acid, a tungstate or a molybdate. The nickel alloy is mainly composed of nickel, and the nickel content is usually in the range of about 60% to about 95% by weight. The alloy has excellent mechanical properties and corrosion resistance, some of which are non-magnetic or non-ferromagnetic, such as phosphorus-containing nickel alloys, particularly nickel-phosphorus-tin-copper alloys. The multi-metal nickel alloy disclosed in the invention contains a relatively large amount of boron or phosphorus, as used as a contact material, and the presence of a relatively large amount of boron or phosphorus will affect the initial resistance of the contact. Our tests have shown that nickel alloys with a high nickel content, nickel content (such as nickel-copper alloy or monel, nickel-chromium alloy, etc.), nickel-containing stainless steel, or nickel obtained by electroless plating are the main constituents of nickel alloys. As the contacts of the switch, they have poor arc resistance and low switching life.

本专利权人的申请专利号为201110193369.5的发明提供了一种“麻面金属与橡胶复合导电粒”，由金属面层与橡胶基体粘合而成，或者粘合后分切而成。金属面层为麻面，具有凹坑、凸点或者两者均有；凹坑或凸点在金属面层的外表面、内表面或者两个表面均有。凹坑的深度小于金属面层厚度，凸点的高度不小于金属面层厚度的十分之一。金属面层的材质为金属或合金，外表面可镀金、银、铜或镍等；橡胶基体为硅橡胶或聚氨酯橡胶等；金属面层与橡胶基体之间可有粘接层，粘接层为热硫化胶粘剂、底涂剂或为与橡胶基体相同的材质。金属面层内表面可涂有偶联剂等助剂。本发明的金属面层强度高、导电性稳定，粘接层强度高，橡胶基体弹性足。该发明没有提出如何在金属面层的外表面上获得一层或多层镀层的具体方法。该发明的麻面上镀金银等贵金属，由于表面积大，贵金属用量多，成本高。The invention of the patent application No. 201110193369.5 provides a "ply-faced metal-rubber composite conductive particle" which is formed by bonding a metal surface layer to a rubber substrate or by cutting after bonding. The metal surface layer is a pockmark having pits, bumps or both; the pits or bumps are on the outer surface, the inner surface or both surfaces of the metal surface layer. The depth of the pit is smaller than the thickness of the metal surface layer, and the height of the bump is not less than one tenth of the thickness of the metal surface layer. The metal surface layer is made of metal or alloy, the outer surface can be plated with gold, silver, copper or nickel; the rubber substrate is silicone rubber or urethane rubber; the metal surface layer and the rubber substrate can have a bonding layer, and the bonding layer is The heat vulcanized adhesive, primer or the same material as the rubber matrix. The inner surface of the metal surface layer may be coated with an auxiliary agent such as a coupling agent. The metal surface layer of the present invention has high strength, stable electrical conductivity, high strength of the adhesive layer, and sufficient rubber base. The invention does not teach a specific method of how to obtain one or more layers on the outer surface of the metal facing. The noble metal such as gold-plated silver on the surface of the invention has a large surface area, a large amount of precious metal, and a high cost.

众所周知，钨和钼是最常用的难熔金属。虽然钨有较高的熔点、较低的蒸气压和蒸发速度，但在纯金属中，钼的电导率排在银、铜、金、铝之后，比钨、锌、镍、镉、钯、铁、铂、锡、铅、锑、钛、汞的电阻率还小。钼作为触点材料时有利于降低触点的接触电阻。此外，钼和钼合金的硬度一般比钨和钨合金硬度低。较低的硬度，不仅有利于进行滚压和冲切加工，而且有利于作为触点与另一触点接触时，接触得更紧密、更可靠，耐尘性更好，从而提高触点的可靠性。钼的密度为10.23g/cm，约为钨的一半(钨的密度19.36g/cm)，得到相同镀层厚度，所用的钼比较少。It is well known that tungsten and molybdenum are the most commonly used refractory metals. Although tungsten has a higher melting point, lower vapor pressure and evaporation rate, in pure metals, the conductivity of molybdenum is higher than that of tungsten, zinc, nickel, cadmium, palladium and iron after silver, copper, gold and aluminum. The resistivity of platinum, tin, lead, antimony, titanium and mercury is still small. When molybdenum is used as a contact material, it is advantageous to reduce the contact resistance of the contact. In addition, the hardness of molybdenum and molybdenum alloys is generally lower than that of tungsten and tungsten alloys. The lower hardness not only facilitates rolling and punching, but also facilitates closer contact, closer reliability, and better dust resistance when the contact is in contact with another contact, thereby improving the reliability of the contact. Sex. The density of molybdenum is 10.23 g/cm, which is about half of that of tungsten (the density of tungsten is 19.36 g/cm), and the same plating thickness is obtained, and the amount of molybdenum used is relatively small.

钼的价格也比钨低，相应地，制备钼合金所需的可溶性钼化合物的价格也比可溶性钨化 合物低。因此，制备钼合金的成本较低。The price of molybdenum is also lower than that of tungsten. Correspondingly, the price of soluble molybdenum compound required for the preparation of molybdenum alloy is also higher than that of soluble tungsten. The composition is low. Therefore, the cost of preparing a molybdenum alloy is low.

本专利申请中，将公开有耐电弧烧蚀的钼合金触点及其制备方法，这种触点由于包含橡胶层，因而可与橡胶进行热硫化粘合和热硫化成型从而制备包含耐电弧烧蚀的触点的橡胶按键。In the present patent application, an arc-resistant ablation molybdenum alloy contact and a preparation method thereof are disclosed, and since the contact includes a rubber layer, it can be thermally vulcanized and thermally vulcanized with a rubber to prepare an arc-resistant burn. The rubber button of the etched contact.

发明内容Summary of the invention

第一发明目的：克服传统镀金、银基或镀银的开关触点成本较高、耐电弧性不太高的缺陷，或者克服铜基、锡基、镍基或不锈钢触点虽然成本较低但耐电弧性较差的缺点、克服钨合金触点虽然耐电弧烧蚀性较好但硬度大、制造成本较高的缺点，提供一种制造成本低、导通电流大、耐电弧烧蚀的镀钼合金的开关触点。The first object of the invention is to overcome the drawbacks of conventional gold-plated, silver-based or silver-plated switch contacts with high cost and low arc resistance, or to overcome copper-based, tin-based, nickel-based or stainless steel contacts, although the cost is low. The disadvantage of poor arc resistance, overcome the shortcomings of tungsten alloy contacts, although good arc ablation resistance but high hardness and high manufacturing cost, providing a plating with low manufacturing cost, large on-current, and arc ablation resistance. Switch contacts for molybdenum alloys.

第一技术方案：本发明提供的一种含有钼合金镀层的开关触点，开关触点是具有三层层状结构的层状复合体，第一层为0.1mm至10mm厚的疏水性橡胶层，第二层为0.01mm至1.0mm厚的金属薄片层，第三层为2*10^-5-0.02mm厚的钼合金镀层；其中，第三层钼合金镀层是第一层和第二层的复合体浸渍在含有可溶性钼化合物的化学镀液，用化学沉积的方法将钼合金的镀层沉积在第一层和第二层的复合体中第二层的表面而形成的，钼合金镀层中含有重量比不低于30％的钼元素、含有重量比为0-70％的过度金属元素镍、钴、铜、或者主族元素锡、锑、铅或铋等，允许含有少量的磷或硼。First technical solution: The present invention provides a switch contact comprising a coating of a molybdenum alloy, the switch contact is a layered composite having a three-layered layer structure, and the first layer is a hydrophobic rubber layer of 0.1 mm to 10 mm thick The second layer is a metal foil layer of 0.01 mm to 1.0 mm thick, and the third layer is a 2*10 ^-5 -0.02 mm thick molybdenum alloy plating layer; wherein the third layer of molybdenum alloy plating layer is the first layer and the second layer The composite is impregnated in an electroless plating solution containing a soluble molybdenum compound, and a plating layer of the molybdenum alloy is deposited by chemical deposition on the surface of the second layer in the composite of the first layer and the second layer, in the molybdenum alloy plating layer. Containing molybdenum element with a weight ratio of not less than 30%, nickel, cobalt, copper or main group element tin, antimony, lead or antimony containing 0-70% by weight, allowing a small amount of phosphorus or boron .

在钼合金的镀液中加入镍、钴、铜、锰等过渡金属元素的离子，是为了使镀层与金属基材粘合牢固，并且为了加快化学沉积的速率。镀液中还可以加入锡、锑、铅或铋等元素的离子，以使镀层获得特定的性能。比如，在镀液中加入少量的亚锡离子，或者同时加入亚锡离子、锑离子和铅离子，可使镀层的硬度下降。由于使用了含磷或含硼的还原剂，少量的磷也可能沉积在镀层中。但由于镀层中磷和硼的含量高，将使镀层的初始表面电阻增大，因此，应采取控制镀液中还原剂的浓度和镀液温度等措施，来控制镀层中磷和硼的含量。The ions of the transition metal element such as nickel, cobalt, copper, manganese, etc. are added to the plating solution of the molybdenum alloy in order to make the plating layer adhere to the metal substrate firmly, and to accelerate the rate of chemical deposition. Ions of elements such as tin, antimony, lead or antimony may also be added to the plating solution to achieve specific properties of the coating. For example, adding a small amount of stannous ions to the plating solution, or simultaneously adding stannous ions, strontium ions, and lead ions, can reduce the hardness of the plating layer. A small amount of phosphorus may also be deposited in the coating due to the use of a phosphorus or boron containing reducing agent. However, since the content of phosphorus and boron in the plating layer is high, the initial surface resistance of the plating layer is increased. Therefore, measures such as controlling the concentration of the reducing agent in the plating solution and the temperature of the plating solution should be taken to control the content of phosphorus and boron in the plating layer.

采用钼合金做最外层原因在于：金属钼在大气中化学性质稳定，是高熔点金属，熔点虽然比钨低一些，但在较低电流的电路中，作为触点使用，其寿命也很长，并且，与金属钨相比，钼合金的硬度也较低，金属钼的电阻率比钨还略小，因此，作为触点材料时有利于降低触点的接触电阻，是良好的触点材料。The reason why the molybdenum alloy is used as the outermost layer is that the metal molybdenum is chemically stable in the atmosphere and is a high melting point metal. Although the melting point is lower than that of tungsten, in a lower current circuit, it is used as a contact and has a long life. Moreover, compared with metal tungsten, the hardness of the molybdenum alloy is also low, and the resistivity of the metal molybdenum is slightly smaller than that of tungsten, and therefore, as a contact material, it is advantageous to reduce the contact resistance of the contact, and is a good contact material. .

钼的价格比钨低，相应地，制备钼合金所需的可溶性钼化合物的价格也比可溶性钨化合物低。因此，制备钼合金的成本较低。The price of molybdenum is lower than that of tungsten, and accordingly, the price of the soluble molybdenum compound required for preparing the molybdenum alloy is also lower than that of the soluble tungsten compound. Therefore, the cost of preparing a molybdenum alloy is low.

镀液中可加入镍、钴、铜以外的其它可溶性过渡金属元素的化合物，以及可溶性主族元素的化合物如锡化合物、锑化合物、铋化合物和铅化合物，但应注意这些化合物对化学镀对所沉积的基材的选择性的影响。此外，也要注意这些化合物的生理毒性、环境毒性和危险性。比如，应尽量少用或不用对人体和环境有害的可溶性铅化合物。虽然银是电触头或触点中常 用的元素，但不建议在钼合金镀液中加入硝酸银等可溶性银化合物。因为我们在实验中发现，在钼合金镀液中加入一定量的硝酸银(如5g/L)后，对第一层的疏水性橡胶层和第二层的金属薄片层的层状复合体进行化学镀时，所发生的化学沉积，将不仅发生在第二层为的金属薄片层上，也发生在第一层的疏水性橡胶层上，这样化学沉积对基材就没有选择性了。当沉积时间足够长时，用肉眼就可清楚地看到疏水性橡胶层上和金属薄片层上都有灰黑色或银白色的沉积层。用X射线荧光光谱分析，发现金属薄片层的表面和疏水性橡胶层的表面都含有大量的银。使用同样的配方取消硝酸银的加入后，则在化学镀的过程中，化学沉积层只生成在金属薄片层的金属面上。Compounds containing soluble transition metal elements other than nickel, cobalt, and copper, and compounds of soluble main group elements such as tin compounds, antimony compounds, antimony compounds, and lead compounds may be added to the plating solution, but attention should be paid to these compounds for electroless plating. The selective effect of the deposited substrate. In addition, attention should be paid to the physiological toxicity, environmental toxicity and risk of these compounds. For example, soluble lead compounds that are harmful to humans and the environment should be used sparingly or not. Although silver is often used in electrical contacts or contacts The elements used, but it is not recommended to add a soluble silver compound such as silver nitrate to the molybdenum alloy plating solution. Because we found in the experiment that after adding a certain amount of silver nitrate (such as 5g / L) to the molybdenum alloy plating solution, the layered composite of the first layer of the hydrophobic rubber layer and the second layer of the metal foil layer is carried out. During electroless plating, the chemical deposition that occurs will occur not only on the metal foil layer of the second layer but also on the hydrophobic rubber layer of the first layer, so that chemical deposition is not selective to the substrate. When the deposition time is long enough, it is clearly visible to the naked eye that there are grayish black or silvery white deposits on the hydrophobic rubber layer and on the metal foil layer. It was found by X-ray fluorescence spectrometry that the surface of the metal foil layer and the surface of the hydrophobic rubber layer contained a large amount of silver. After the addition of silver nitrate is eliminated using the same formulation, the chemical deposition layer is formed only on the metal surface of the metal foil layer during the electroless plating.

一般来说，所用橡胶材料的疏水性越强，越有利于钼合金在本发明中所使用橡胶金属层状复合物中的金属面上沉积，而不在橡胶材料的表面上沉积。亲水性橡胶、含有表面活性剂或抗静电剂的橡胶材料、含有大量亲水性或吸水性填料的橡胶材料、水膨胀橡胶材料，不宜在本发明中使用。如果使用这些橡胶材料，在进行化学镀时，将使钼合金也沉积在这些橡胶材料上。In general, the more hydrophobic the rubber material used, the more advantageous it is for the molybdenum alloy to be deposited on the metal surface of the rubber metal layered composite used in the present invention without depositing on the surface of the rubber material. A hydrophilic rubber, a rubber material containing a surfactant or an antistatic agent, a rubber material containing a large amount of a hydrophilic or water-absorbent filler, and a water-swellable rubber material are not suitable for use in the present invention. If these rubber materials are used, a molybdenum alloy will also be deposited on these rubber materials during electroless plating.

作为优化：所述的疏水性橡胶层是由于橡胶分子链上羧基、羟基、羰基、氨基、酰胺基、腈基、硝基、卤基、巯基、磺酸根和苯磺酸根含量低，从而使橡胶表面的水接触角大于65°的橡胶材料构成；或者，所述的疏水性橡胶层是由于橡胶中不含或含有少量的亲水性的填料或添加剂，从而使橡胶表面的水接触角大于65°的橡胶材料构成。橡胶材料为热固性或热塑性。As an optimization: the hydrophobic rubber layer is caused by a low content of a carboxyl group, a hydroxyl group, a carbonyl group, an amino group, an amide group, a nitrile group, a nitro group, a halogen group, a thiol group, a sulfonate group and a benzenesulfonate group in the rubber molecular chain, thereby making the rubber The surface of the rubber material having a water contact angle greater than 65°; or the hydrophobic rubber layer is due to the rubber containing no or a small amount of hydrophilic filler or additive, so that the water contact angle of the rubber surface is greater than 65 ° The composition of the rubber material. The rubber material is thermoset or thermoplastic.

作为优化：所述的疏水性橡胶层由三元乙丙橡胶、甲基乙烯基硅橡胶或甲基乙烯基苯基硅橡胶制备而成。三元乙丙橡胶、甲基乙烯基硅橡胶和甲基乙烯基苯基硅橡胶是非极性橡胶，疏水性强，同时它们的耐候性好，在大气中能长期保持良好的弹性，因此，它们是所述的疏水性橡胶层的优先使用的材料。高腈基含量的丁腈橡胶和氢化丁腈橡胶、端羧基液体丁腈橡胶、氯磺化聚乙烯橡胶、氯醚橡胶、丙烯酸酯橡胶、聚氨酯橡胶等极性橡胶，以及亲水化的橡胶(如亲水性硅橡胶)和水膨胀橡胶等材料的极性大或含有大量亲水性物质，这些材料表面疏水性不强。这些材料在含可溶性钼化合物的化学镀液中，钼合金镀层就会沉积在这些材料的表面。As an optimization: the hydrophobic rubber layer is prepared from ethylene propylene diene monomer, methyl vinyl silicone rubber or methyl vinyl phenyl silicone rubber. EPDM rubber, methyl vinyl silicone rubber and methyl vinyl phenyl silicone rubber are non-polar rubbers, which are highly hydrophobic, and they have good weather resistance and can maintain good elasticity in the atmosphere for a long time. Therefore, they It is a preferred material for the hydrophobic rubber layer. High nitrile-based nitrile rubber and hydrogenated nitrile rubber, carboxyl-terminated liquid nitrile rubber, chlorosulfonated polyethylene rubber, chloroether rubber, acrylate rubber, urethane rubber and other polar rubber, and hydrophilized rubber (such as pro Materials such as water-based silicone rubber and water-swellable rubber are highly polar or contain a large amount of hydrophilic substances, and these materials are not hydrophobic on the surface. These materials are deposited on the surface of these materials in an electroless plating bath containing soluble molybdenum compounds.

疏水性橡胶层中的疏水性橡胶对水具有排斥能力，水不能在疏水性橡胶表面铺展开来。为了获得钼合金在金属材质上的选择性化学沉积，在由第一层疏水性橡胶层和第二层金属薄片的复合体中的橡胶材质的疏水性越高越好。在用镀液进行化学沉积时，为了使沉积在第一层疏水性橡胶层上的合金少得可以忽略不计，橡胶基材的水接触角需大于65°。这里所谓的选择性化学沉积，指的是钼合金镀层，选择性地沉积在金属材质上，而不沉积在橡胶材质上。橡胶分子链上羧基、羟基、羰基、氨基、酰胺基、腈基、硝基、卤基、巯基、磺酸根和苯磺 酸根，将增大橡胶的极性和亲水性。特别是羧基、羟基、磺酸根和苯磺酸根，将极大的增大橡胶的极性和亲水性。如果在橡胶和金属的复合体中使用的是亲水性强的羧基橡胶，化学沉积将既可以发生在金属材质表面，也同时发生在橡胶材质表面。如果橡胶材质上有钼合金的沉积层，将不仅浪费化学镀的镀液，而且不利于橡胶材质与其它橡胶材质的热硫化粘合或热塑性粘合，而这种热硫化粘合或热塑性粘合是后续加工中所必需的。第一层疏水性橡胶层的存在，就是为了第一层疏水性橡胶层和其它橡胶进行热硫化粘合或热塑性粘合，从而制备包含触点的橡胶按键。The hydrophobic rubber in the hydrophobic rubber layer has a repulsive ability to water, and water cannot be spread on the surface of the hydrophobic rubber. In order to obtain selective chemical deposition of the molybdenum alloy on the metal material, the higher the hydrophobicity of the rubber material in the composite of the first layer of the hydrophobic rubber layer and the second layer of the metal foil, the better. In the case of chemical deposition with a plating solution, in order to make the alloy deposited on the first layer of the hydrophobic rubber layer negligible, the water contact angle of the rubber substrate needs to be greater than 65°. The so-called selective chemical deposition here refers to a coating of a molybdenum alloy which is selectively deposited on a metal material without being deposited on a rubber material. Carboxyl group, hydroxyl group, carbonyl group, amino group, amide group, nitrile group, nitro group, halogen group, sulfhydryl group, sulfonate group and benzenesulfonate The acid radical will increase the polarity and hydrophilicity of the rubber. In particular, carboxyl, hydroxyl, sulfonate and benzenesulfonate will greatly increase the polarity and hydrophilicity of the rubber. If a hydrophilic polyurethane rubber is used in the rubber-metal composite, chemical deposition can occur on both the metal surface and the rubber surface. If the rubber material has a deposited layer of molybdenum alloy, it will not only waste the electroless plating solution, but also be disadvantageous to the thermal vulcanization bonding or thermoplastic bonding of the rubber material with other rubber materials, and the thermal vulcanization bonding or thermoplastic bonding. It is required for subsequent processing. The first layer of hydrophobic rubber layer is present for the purpose of preparing a first layer of hydrophobic rubber layer and other rubbers for thermal vulcanization or thermoplastic bonding to produce a rubber button comprising contacts.

因此，必需限制这些极性基团在橡胶基材中的含量，以获得选择性良好的钼合金化学沉积。为了获得选择性最佳的化学沉积，橡胶基材中不能含有这些基团。同样的道理，橡胶材质本体或表面不含或少量含有亲水性强的填料、添加剂或表面活性剂，也有利于获得选择性的化学沉积。Therefore, it is necessary to limit the content of these polar groups in the rubber substrate to obtain a highly selective molybdenum alloy chemical deposition. In order to obtain the most selective chemical deposition, these groups cannot be contained in the rubber substrate. By the same token, the rubber body or surface contains no or a small amount of hydrophilic fillers, additives or surfactants, which is also beneficial for selective chemical deposition.

三元乙丙橡胶、甲基乙烯基硅橡胶、甲基乙烯基硅苯基橡胶是极性比较弱的、疏水性比较强的橡胶材料，适宜于和金属薄片进行复合制备层状复合体。在使用前述的化学镀液进行化学镀时，化学沉积不发生在橡胶层上。EPDM rubber, methyl vinyl silicone rubber, and methyl vinyl silicon phenyl rubber are weaker and more hydrophobic rubber materials, which are suitable for compounding with metal foil to prepare layered composites. When electroless plating is performed using the aforementioned electroless plating solution, chemical deposition does not occur on the rubber layer.

作为优化：所述的第二层的金属薄片层为具有凸点或凹点的金属片材，具有凸线条或凹线条的金属片材、具有凸面或凹面的金属片材、具有面积小于1mm²的小孔的金属片材、目数大于100的金属网、金属泡沫或者金属纤维烧结毡，以便与PCB上的触点接触压强更大，导通性更好；金属材质为镁、铝、钛、铬、锰、铁、钴、镍、铜、锌、锡或含有这些元素的合金；第二层的金属薄片是单一金属材质的或不同金属材质层状复合的；优选电导率较高且价格比较低的金属或合金。As an optimization: the metal foil layer of the second layer is a metal sheet having bumps or pits, a metal sheet having convex lines or concave lines, a metal sheet having convex or concave surfaces, and an area of less than 1 mm ² The metal sheet of the small hole, the metal mesh with a mesh number greater than 100, the metal foam or the metal fiber sintered felt, so that the contact pressure with the contact on the PCB is greater, and the conductivity is better; the metal material is magnesium, aluminum, titanium , chromium, manganese, iron, cobalt, nickel, copper, zinc, tin or an alloy containing these elements; the second layer of metal foil is a single metal or a different metal layered composite; preferably higher conductivity and price A relatively low metal or alloy.

作为优化：所述的第二层的金属薄片由0.01mm至1.0mm厚的不锈钢、铜或铜合金、镍或镍合金薄片构成，在不锈钢、铜或铜合金、镍或镍合金薄片的一面或两面，镀有0.1微米至10微米的纯镍层或镍合金层；不锈钢、铜或铜合金、镍或镍合金薄片上的镍合金层是由真空镀膜、电镀或化学镀的方法制备的。在不锈钢、铜或铜合金、镍或镍合金薄片上镀一层纯镍层或镍合金层，可以提高金属薄片与钼合金镀层的粘合强度，避免钼合金镀层在触点使用过程中脱落。特别是铜和铜合金薄片，宜在化学沉积钼合金镀层之前，在铜和铜合金薄片上镀上一薄层纯镍层或镍合金，以提高铜和铜合金的耐氧化、耐化学腐蚀的性能。As an optimization: the second layer of metal foil consists of 0.01mm to 1.0mm thick stainless steel, copper or copper alloy, nickel or nickel alloy flakes, on one side of stainless steel, copper or copper alloy, nickel or nickel alloy flakes or Both sides are plated with a pure nickel layer or a nickel alloy layer of 0.1 to 10 micrometers; a nickel alloy layer on a stainless steel, copper or copper alloy, nickel or nickel alloy sheet is prepared by vacuum coating, electroplating or electroless plating. Plating a layer of pure nickel or nickel alloy on stainless steel, copper or copper alloy, nickel or nickel alloy sheets can improve the adhesion strength between the metal foil and the molybdenum alloy coating, and prevent the molybdenum alloy coating from falling off during the use of the contacts. In particular, copper and copper alloy flakes should be coated with a thin layer of pure nickel or nickel alloy on the copper and copper alloy flakes prior to chemical deposition of the molybdenum alloy coating to improve the oxidation and chemical resistance of copper and copper alloys. performance.

不锈钢是普通不锈钢、耐酸钢、或者添加了钼元素的从而改善耐大气腐蚀性的，特别是耐含氯化物大气的腐蚀的特种不锈钢。Stainless steel is ordinary stainless steel, acid-resistant steel, or added with molybdenum to improve atmospheric corrosion resistance, especially for special corrosion resistant stainless steel containing chloride atmosphere.

金属薄片的厚度不宜过薄。如果第二层的金属薄片厚度低于0.01mm，就可不能很好地支撑第三层的钼合金镀层，在与橡胶复合之前、之中或之后的加工中容易破裂。如果第二层的 金属薄片太厚，就会增加触点的整体硬度，同时浪费金属材料。所以，金属薄片的厚度，不宜大于1.0mm。The thickness of the metal foil should not be too thin. If the thickness of the metal foil of the second layer is less than 0.01 mm, the molybdenum alloy plating layer of the third layer may not be well supported, and is easily broken during processing before, during or after the compounding with the rubber. If the second layer If the foil is too thick, it will increase the overall hardness of the contact while wasting metal material. Therefore, the thickness of the metal foil should not be greater than 1.0 mm.

预先将第一层的疏水性橡胶层和第二层的金属薄片制成层状复合体，是为了方便将层状复合体作为触点应用于制备橡胶按键。层状复合体上的疏水性橡胶，可直接与其它橡胶进行热硫化粘合或热塑性粘合而形成橡胶按键。如果将没有橡胶层的金属薄片自己和其他橡胶进行热硫化粘合或热塑性粘合而形成橡胶按键，就会在模塑过程中发生溢胶现象。所谓溢胶现象，是指在模塑过程中，橡胶溢到触点的正面，从而影响触点的导电性能。触点上有溢胶现象，对触点的质量来说是不可接受的。The first layer of the hydrophobic rubber layer and the second layer of the metal foil are formed into a layered composite in advance for the convenience of applying the layered composite as a contact to prepare a rubber button. The hydrophobic rubber on the layered composite can be directly vulcanized or thermoplastically bonded to other rubbers to form a rubber button. If the metal foil without the rubber layer is thermally vulcanized or thermoplastically bonded to other rubbers to form a rubber button, an overflow phenomenon occurs during the molding process. The so-called overflow phenomenon means that during the molding process, the rubber overflows to the front side of the contact, thereby affecting the electrical conductivity of the contact. There is an overflow on the contacts, which is unacceptable for the quality of the contacts.

第二发明目的：提供上述含有钼合金镀层的开关触点的一种制备方法。A second object of the invention is to provide a method of preparing the above-described switch contacts containing a coating of a molybdenum alloy.

第二技术方案：一种含有钼合金镀层的开关触点的制备方法，包括如下步骤：A second technical solution: a method for preparing a switch contact comprising a coating of a molybdenum alloy, comprising the steps of:

(1)金属薄片的处理：金属薄片为0.01mm至1.0mm厚的不锈钢、铜或铜合金、镍或镍合金薄片；用清洗剂和有机溶剂对金属薄片进行除油、清洗；或通过喷砂、打磨将金属薄片进行表面机械粗化处理；或通过化学蚀刻处理以处理出直径小于1mm的凹坑或凸点；或在金属薄片的一面或两面，用电镀或化学镀的方法镀有0.1微米至10微米的纯镍层或镍合金层；然后用清洗剂和有机溶剂对所得到的金属薄片进行除油、清洗；(1) Treatment of metal foil: the metal foil is a stainless steel, copper or copper alloy, nickel or nickel alloy sheet of 0.01 mm to 1.0 mm thick; the metal foil is degreased and cleaned with a cleaning agent and an organic solvent; or by sandblasting Grinding the surface of the metal sheet by mechanical roughening; or chemical etching to treat pits or bumps having a diameter of less than 1 mm; or plating one or both sides of the metal sheet by plating or electroless plating to 0.1 μm To a pure nickel layer or a nickel alloy layer of 10 micrometers; then, the obtained metal foil is degreased and washed with a cleaning agent and an organic solvent;

(2)疏水性橡胶与金属薄片的粘合处理：疏水性橡胶通过热硫化成型，粘合在涂有底涂剂或粘合促进剂的金属薄片上，形成层状的复合片材；或者将具有自粘性疏水性橡胶，通过热硫化成型，粘合在涂有底涂剂或没有底涂剂的金属薄片层上，形成层状的复合片材；(2) Adhesive treatment of hydrophobic rubber and metal foil: the hydrophobic rubber is formed by thermal vulcanization, adhered to a metal foil coated with a primer or an adhesion promoter to form a layered composite sheet; or a self-adhesive hydrophobic rubber which is formed by thermal vulcanization and bonded to a metal foil layer coated with a primer or without a primer to form a layered composite sheet;

(3)切割处理：将上述步骤中的复合片材分割或冲切成直径为2-10mm的圆柱体，用碱性清洗液清洗约5分钟，水洗，然后用5％的盐酸清洗3分钟，然后用去离子水清洗干净，滤干；用5％的盐酸清洗的目的，是为了除去部分金属基材表面的氧化物，使金属基材表面活化，增强金属基材和钼合金镀层之间的结合强度。使用其它清洗和酸液活化方法，也是可行的。(3) Cutting treatment: the composite sheet in the above step is divided or punched into a cylinder having a diameter of 2-10 mm, washed with an alkaline cleaning solution for about 5 minutes, washed with water, and then washed with 5% hydrochloric acid for 3 minutes. Then it is washed with deionized water and dried. The purpose of cleaning with 5% hydrochloric acid is to remove the oxide on the surface of some metal substrate, activate the surface of the metal substrate, and strengthen the metal substrate and the coating between the molybdenum alloy. Bond strength. It is also feasible to use other cleaning and acid activation methods.

(4)钼合金镀层的制备：将上述圆柱体，浸渍在含有可溶性钼化合物的化学镀液中，搅拌，用化学镀的方法形成钼合金镀层；或者，将上述圆柱体放入含有可溶性钼化合物的化学镀液的滚筒中，让滚筒转动，在小圆柱体的金属表面，形成钼合金镀层；(4) Preparation of molybdenum alloy plating layer: immersing the above-mentioned cylinder in an electroless plating solution containing a soluble molybdenum compound, stirring, forming a molybdenum alloy plating layer by electroless plating; or placing the above-mentioned cylinder into a soluble molybdenum compound In the drum of the electroless plating bath, the drum is rotated, and a molybdenum alloy plating layer is formed on the metal surface of the small cylinder;

镀液中含有20-125g/L的可溶性钼化合物、0-60g/L的可溶性的过渡金属铁、镍、钴、铜或锰的化合物或这些化合物的任意组合、0-30g/L的可溶性的锡、锑、铅或铋化合物或这些化合物的任意组合、20-100g/L的还原剂、30-150g/L的络合剂、20-100g/L的pH值调节剂、0.1-1g/L的稳定剂、0.1-1g/L的表面活性剂、0-50g/L的光亮剂或粗糙度调节剂；还可在镀液中添加其它助剂，如化学镀加速剂。加速剂可选用氟化钠。氟化钠即可以作为加速剂，同时亦可增加镀层的光亮度；The plating solution contains 20-125 g/L of soluble molybdenum compound, 0-60 g/L of soluble transition metal iron, nickel, cobalt, copper or manganese compound or any combination of these compounds, 0-30 g/L of soluble Tin, antimony, lead or antimony compound or any combination of these compounds, 20-100 g/L reducing agent, 30-150 g/L complexing agent, 20-100 g/L pH adjusting agent, 0.1-1 g/L Stabilizer, 0.1-1 g/L surfactant, 0-50 g/L brightener or roughness modifier; other additives such as electroless plating accelerator may also be added to the plating solution. The accelerator can be selected from sodium fluoride. Sodium fluoride can be used as an accelerator, and can also increase the brightness of the coating;

优选选用次亚磷酸钠作为还原剂。当用次亚磷酸钠作为还原剂时，钼合金镀层所采用化学镀的温度为65-90℃，时间为30-300分钟，镀液的pH值为8.5-9.5。 Sodium hypophosphite is preferably used as the reducing agent. When sodium hypophosphite is used as the reducing agent, the electroless plating temperature of the molybdenum alloy plating layer is 65-90 ° C for 30-300 minutes, and the pH of the plating solution is 8.5-9.5.

(5)清洗、干燥：取出被镀物，用蒸馏水或去离子水漂洗、沥干、冷风吹干或放在70℃的恒温烘箱中烘干，即得到镀有钼合金的开关触点。(5) Cleaning and drying: The object to be plated is taken out, rinsed with distilled water or deionized water, drained, blown cold air or dried in a constant temperature oven at 70 ° C to obtain a switch contact plated with a molybdenum alloy.

本发明中，所所述的可溶性钼化合物是钼酸钠、钼酸钾、钼酸铵、磷钼酸、磷钼酸铵、钼酸、三氧化钼。使用微溶于水的钼酸或不溶于水的三氧化钼作为钼源时，可先用氢氧化钠溶液使其溶解，然后用其配制化学镀液。In the present invention, the soluble molybdenum compound is sodium molybdate, potassium molybdate, ammonium molybdate, phosphomolybdic acid, ammonium phosphomolybdate, molybdic acid, or molybdenum trioxide. When a slightly water-soluble molybdic acid or water-insoluble molybdenum trioxide is used as a molybdenum source, it may be dissolved with a sodium hydroxide solution and then used to prepare an electroless plating solution.

所述的可溶性过渡金属镍、钴、铜的化合物是硫酸镍、氯化镍、硝酸镍、硫酸镍铵、碱式碳酸镍、氨基磺酸镍、乙酸镍、次磷酸镍、硫酸钴、氯化钴、硝酸钴、硫酸钴铵、碱式碳酸钴、氨基磺酸钴、乙酸钴、草酸钴、硫酸铜、氯化铜、硝酸铜、水合碱式碳酸铜、乙酸铜中的一种或多种。我们在镀钼合金时发现，但化学镀液中镍的前体使用硫酸镍和碱式碳酸镍复配，可使镀得的钼合金层具有较明亮的银白色，所得钼镍合金镀层的表面电阻较低。The soluble transition metal nickel, cobalt, copper compound is nickel sulfate, nickel chloride, nickel nitrate, nickel ammonium sulfate, basic nickel carbonate, nickel sulfamate, nickel acetate, nickel hypophosphite, cobalt sulfate, chlorination One or more of cobalt, cobalt nitrate, cobalt ammonium sulfate, cobalt cobalt carbonate, cobalt sulfamate, cobalt acetate, cobalt oxalate, copper sulfate, copper chloride, copper nitrate, hydrated basic copper carbonate, and copper acetate . We found in the case of molybdenum plating, but the nickel precursor in the electroless plating solution is compounded with nickel sulfate and basic nickel carbonate, so that the plated molybdenum alloy layer has a bright silver white color, and the surface of the obtained molybdenum nickel alloy coating layer. The resistance is low.

所述的还原剂为次亚磷酸钠、硼氢化钠、烷基胺硼烷、肼中的一种或多种。如果以硼氢化物或氨基硼烷为还原剂时，钼合金镀层中将含有少量的硼(质量分数可达7％)。以肼作还原剂，所得到的镀层中非金属(磷或硼)的含量几乎为零，金属含量可达到99％以上。选用次亚磷酸钠为还原剂时，由于有磷析出，发生磷与金属的共沉积，镀层中除有金属钼、钴、镍外还含有少部分的磷(质量分数可达l5％)。磷对触点的导电性是有害的，并且可能伤害钼合金的耐腐蚀性能，因此，必需控制钼合金中的磷含量。通过控制次亚磷酸钠的浓度、络合剂的浓度、pH值等措施，可以控制镀层中的磷含量。控制控制磷含量可得到致密、无孔的钼合金镀层。本发明中优先使用价格较低且毒性较低的次亚磷酸钠。选用次亚磷酸钠作为还原剂，我们所得到的钼合金镀层和钼合金镀层之间的接触电阻，比99.5％的纯镍和99.5％的纯镍之间的接触电阻小，所得到的镀层能显著降低镍合金基材和不锈钢基材的初始接触电阻、提高其耐开关电弧性能。The reducing agent is one or more of sodium hypophosphite, sodium borohydride, alkylamine borane, and hydrazine. If borohydride or aminoborane is used as the reducing agent, the molybdenum alloy coating will contain a small amount of boron (mass fraction up to 7%). With ruthenium as a reducing agent, the content of non-metal (phosphorus or boron) in the obtained coating layer is almost zero, and the metal content can reach 99% or more. When sodium hypophosphite is used as the reducing agent, phosphorus and metal are co-deposited due to phosphorus precipitation. The coating contains a small amount of phosphorus (mass fraction up to 15%) in addition to metal molybdenum, cobalt and nickel. Phosphorus is detrimental to the electrical conductivity of the contacts and may damage the corrosion resistance of the molybdenum alloy. Therefore, it is necessary to control the phosphorus content in the molybdenum alloy. The phosphorus content in the coating can be controlled by controlling the concentration of sodium hypophosphite, the concentration of the complexing agent, and the pH. Controlling and controlling the phosphorus content provides a dense, non-porous molybdenum alloy coating. In the present invention, it is preferred to use a lower-priced and less toxic sodium hypophosphite. Using sodium hypophosphite as a reducing agent, the contact resistance between the molybdenum alloy coating and the molybdenum alloy coating obtained by us is less than the contact resistance between 99.5% pure nickel and 99.5% pure nickel, and the obtained coating energy can be obtained. Significantly reduce the initial contact resistance of the nickel alloy substrate and the stainless steel substrate, and improve its resistance to switching arc.

所述的络合剂为柠檬酸钠、柠檬酸铵、酒石酸钠、酒石酸钾钠、乙二胺四乙酸二钠盐、乙二胺四乙酸四钠盐中的一种或多种。络合剂的作用是控制可供反应的游离金属离子的浓度，提高镀液稳定性，延长镀液寿命，提高镀层质量。络合剂对沉积速率、磷含量和耐腐蚀性等均有影响。The complexing agent is one or more of sodium citrate, ammonium citrate, sodium tartrate, sodium potassium tartrate, disodium edetate, and tetrasodium ethylenediaminetetraacetate. The function of the complexing agent is to control the concentration of free metal ions available for reaction, improve the stability of the plating solution, prolong the life of the plating solution, and improve the quality of the plating layer. Complexing agents have an effect on deposition rate, phosphorus content and corrosion resistance.

作为优选，当采用次亚磷酸钠作为还原剂时，镀液的pH值为8.5-9.5。所述的pH调节剂为氢氧化钠、氢氧化钾、碳酸钠、氨水、焦磷酸钠中的一种或多种。优先使用氨水或氢氧化钠溶液调节镀液的pH值。这样能够获得结合力更强、更稳定，镀层质量更好的钼合金镀层。化学镀的时间越长，沉积在金属基材上的钼合金镀层就会越厚。较厚的钼合金镀层有利于触点的耐开关电弧性能。但化学镀的时间并不是越长越好。化学镀的时间过长，不仅生产效率低，而且带碱性的化学镀液，可能会伤害第一层的疏水性橡胶层和第二层的金属薄片层之间的粘合强度，甚至造成脱层现象。pH值不可大于12，因为过高的pH虽然使沉积速度加快，但使得镀层或沉积层和金属基材之间的附着力变差，使镀层或沉积层的颜色变深，甚至变成黑色。在镀液中可加入强酸弱碱盐或强碱弱酸盐，作为镀液的pH缓冲剂。 Preferably, when sodium hypophosphite is used as the reducing agent, the pH of the plating solution is 8.5 to 9.5. The pH adjusting agent is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia water, and sodium pyrophosphate. The pH of the bath is preferably adjusted with ammonia or sodium hydroxide solution. This makes it possible to obtain a molybdenum alloy coating having a stronger bonding force, a more stable, and a better coating quality. The longer the electroless plating time, the thicker the molybdenum alloy coating deposited on the metal substrate. The thicker molybdenum alloy coating facilitates the switching arc resistance of the contacts. But the time of electroless plating is not as long as possible. The electroless plating time is too long, not only the production efficiency is low, but also the alkaline electroless plating solution may damage the adhesion strength between the first layer of the hydrophobic rubber layer and the second layer of the metal foil layer, and even cause the peeling Layer phenomenon. The pH may not be greater than 12 because the excessively high pH causes the deposition rate to be accelerated, but the adhesion between the plating layer or the deposited layer and the metal substrate is deteriorated, and the color of the plating layer or the deposited layer is darkened or even becomes black. A strong acid weak base salt or a strong base weak acid salt may be added to the plating solution as a pH buffer for the plating solution.

作为优化：在不考虑颜色、光泽时，所述的稳定剂为碘化钾、碘酸钾、苯骈三氮唑、4,5-二硫代辛烷-1,8-二磺酸盐、3-巯基-1-丙磺酸盐、硫代硫酸钠、硫脲中的一种或多种的混合物。在考虑颜色、光泽时，所述的稳定剂优选为硫代硫酸钠、硫脲或者两者的混合物，使得钼合金镀层同时具有良好的金属光泽。稳定剂的作用是抑制化学镀过程中所发生的自催化反应从而稳定镀液，防止激烈的自催化反应、防止生成大量含磷的黑色金属粉末。但稳定剂是化学镀的毒化剂，即反催化反应，所以不能过度使用，需控制其在镀液中的用量，以免影响化学镀效率。As an optimization: when the color and gloss are not considered, the stabilizer is potassium iodide, potassium iodate, benzotriazole, 4,5-dithiooctane-1,8-disulfonate, 3- a mixture of one or more of decyl-1-propane sulfonate, sodium thiosulfate, thiourea. When considering color and gloss, the stabilizer is preferably sodium thiosulfate, thiourea or a mixture of the two, so that the molybdenum alloy coating has a good metallic luster at the same time. The role of the stabilizer is to inhibit the autocatalytic reaction occurring during the electroless plating process to stabilize the plating solution, prevent the intense autocatalytic reaction, and prevent the formation of a large amount of phosphorus-containing ferrous metal powder. However, the stabilizer is a poisoning agent for electroless plating, that is, a countercatalytic reaction, so it cannot be excessively used, and it is necessary to control its amount in the plating solution so as not to affect the electroless plating efficiency.

所述的表面活性剂为：十二烷基苯磺酸盐、十二烷基硫酸盐、正辛基硫酸钠中的一种或多种的表面活性剂；作优先为：十二烷基硫酸钠或十二烷基苯磺酸钠。加入些表面活性剂有助于镀件表面气体的溢出，降低镀层的孔隙率，使镀层致密，从而增加镀层的耐电弧性能。The surfactant is: a surfactant of one or more of dodecylbenzenesulfonate, lauryl sulfate, and sodium n-octyl sulfate; preferably: dodecyl sulfate Sodium or sodium dodecylbenzene sulfonate. The addition of some surfactants helps the gas on the surface of the plated material to overflow, reduces the porosity of the coating, and densifies the coating, thereby increasing the arc resistance of the coating.

作为优化：所述的化学镀采用的镀液中，含有0.05-50g/L的化学镀光亮剂；所述的化学镀光亮剂为丁炔二醇、丙炔醇、1-二乙胺基丙-2-炔、乙氧化丙炔醇、邻磺酰苯酰亚胺钠(糖精钠)、乙烯基磺酸钠、丙炔磺酸钠、吡啶-2-羟基丙磺酸内盐、烷基酚聚氧乙烯醚(例如商品名为OP-10的烷基酚聚氧乙烯醚)或市售等商品化的化学镀光亮剂。As an optimization: the plating solution used for the electroless plating contains 0.05-50 g/L of an electroless plating brightener; the electroless brightening agent is butyne diol, propynyl alcohol, 1-diethylaminopropyl 2-yne, ethoxylated propynyl alcohol, sodium sulphonyl phenylimide (sodium saccharin), sodium vinyl sulfonate, sodium propyne sulfonate, pyridine-2-hydroxypropane sulfonate inner salt, alkyl phenol A polyoxyethylene ether (for example, an alkylphenol ethoxylate having a trade name of OP-10) or a commercially available chemical plating brightener.

化学镀的时间的选定，与开关产品的耐电弧烧蚀的性能要求或使用寿命要求有关。化学镀的时间越长，沉积在金属基材上的钼合金镀层就会越厚。较厚的钼合金镀层有利于触点的耐开关电弧性能。但化学镀的时间并不是越长越好。化学镀的时间过长，不仅生产效率低，而且偏碱性的化学镀液，可能会伤害第一层的疏水性橡胶层和第二层的金属薄片层之间的粘合强度，甚至造成脱层现象。作为优选，如果要求在500mA的导通电流下开关次数可在1万次以上，所述的钼合金镀层所采用化学镀的时间为200分钟。升高化学镀液的温度，会使得化学沉积的速率加快，但过高的镀液温度(高于90℃)，将使化学镀层的颜色变深、镀层对金属基材的附着力下降。The choice of electroless plating time is related to the performance requirements or service life requirements of the arc ablation resistance of the switch product. The longer the electroless plating time, the thicker the molybdenum alloy coating deposited on the metal substrate. The thicker molybdenum alloy coating facilitates the switching arc resistance of the contacts. But the time of electroless plating is not as long as possible. The electroless plating time is too long, not only the production efficiency is low, but also the alkaline electroless plating solution may damage the adhesion strength between the first layer of the hydrophobic rubber layer and the second layer of the metal foil layer, and even cause the peeling Layer phenomenon. Preferably, if the number of times of switching is required to be 10,000 times or more at an on current of 500 mA, the electroless plating time of the molybdenum alloy plating layer is 200 minutes. Increasing the temperature of the electroless plating solution will accelerate the rate of chemical deposition, but too high a bath temperature (above 90 ° C) will darken the color of the electroless plating layer and reduce the adhesion of the plating layer to the metal substrate.

本发明中，使用疏水性橡胶层和金属薄片层的复合体，用上述镀液进行化学镀，可使钼合金镀层沉积在金属的表面。我们用X射线荧光光谱仪(XRF)检测金属表面的钼元素含量，可以发现，在同一镀液中，随着化学镀时间的延长，在金属表面检测到的钼信号越来越强。钼信号越来越强，意味着钼合金镀层随着化学镀时间而越来越厚。但即使化学镀时间长达300分钟，在疏水性橡胶表面检测到的钼信号几乎为零。In the present invention, a composite of a hydrophobic rubber layer and a metal foil layer is used, and electroless plating is performed using the above plating solution to deposit a molybdenum alloy plating layer on the surface of the metal. We used X-ray fluorescence spectrometer (XRF) to detect the content of molybdenum on the metal surface. It can be found that in the same bath, the molybdenum signal detected on the metal surface becomes stronger as the electroless plating time prolongs. The molybdenum signal is getting stronger and stronger, meaning that the molybdenum alloy coating is getting thicker with the electroless plating time. However, even if the electroless plating time is as long as 300 minutes, the molybdenum signal detected on the surface of the hydrophobic rubber is almost zero.

有益效果：Beneficial effects:

本发明在疏水性橡胶层和金属薄片的层状复合体上以化学镀的方法选择性地在金属薄片上镀上一层含钼的合金，可有效地提高金属薄片的导电性和耐开关电弧烧蚀性能。由不锈钢片(如SS304不锈钢片)、镍片(如N6镍片)、镍合金片(如NCu30镍铜合金)制得的镀有钼合金层的触点，与印刷电路板(PCB)上的镀金触点接触，触点间的接触电阻，比没有镀钼合金的同类触点与印刷电路板(PCB)上的镀金触点间的接触电阻小，具有较好的导通性能。由没有镀钼合金的不锈钢片或镍片制得的触点与PCB镀金触点通过300毫安的直流电，室温下 连续开关约2000-4000次后，由于存在开关时的电弧烧蚀，小圆片和PCB镀金触点之间的接触电阻就明显升高(由约1欧姆升高至100欧姆以上，甚至不导通)；而在同样的电路条件下，按本发明镀有钼合金的同类触点与PCB触点通过300毫安的直流电，开关约8000次后，触点和PCB触点之间的接触电阻，仍在1欧姆以下。The invention selectively deposits a layer of molybdenum-containing alloy on the metal foil by electroless plating on the layered composite of the hydrophobic rubber layer and the metal foil, which can effectively improve the electrical conductivity and the switching arc resistance of the metal foil. Ablation performance. A contact plated with a molybdenum alloy layer made of a stainless steel sheet (such as SS304 stainless steel sheet), a nickel sheet (such as N6 nickel sheet), a nickel alloy sheet (such as NCu30 nickel-copper alloy), and a printed circuit board (PCB) Gold-plated contact contacts, contact resistance between contacts, have lower contact resistance than similar contacts with no molybdenum-plated contacts and gold-plated contacts on printed circuit boards (PCBs), and have better conduction performance. Contact made of stainless steel or nickel plate without molybdenum alloy and PCB gold-plated contacts pass 300 mA DC at room temperature After continuous switching for about 2000-4000 times, the contact resistance between the small wafer and the gold-plated contacts of the PCB is significantly increased due to arc ablation at the time of switching (from about 1 ohm to more than 100 ohms, or even no conductance). Under the same circuit conditions, the same type of contacts coated with molybdenum alloy according to the present invention and the PCB contacts pass 300 mA of DC power, and after about 8000 switching, the contact resistance between the contacts and the PCB contacts , still below 1 ohm.

这种镀有钼合金的触点，与镀有黄金、铂或白银的开关触点比较，能够通过或承受更大的电流，具有较好的耐电弧烧蚀性能。而且，金属钼的价格不高于黄金、铂或银，也比钨低。This molybdenum-plated contact has better resistance to arc ablation than a switch contact plated with gold, platinum or silver. Moreover, the price of metallic molybdenum is not higher than gold, platinum or silver, and is also lower than tungsten.

调节镀液的配方组成和化学镀的时间和温度，所得的触点可以有类似于黄金、银、白银、钢或某些氮化钛的颜色、光泽等外观效果。特别地，使用本发明中的钼合金镀液，能比较容易的得到接近于银白色的钼合金。本发明的产品适用于各种高档场所，尤其适合于制作汽车、电动工具、游戏机等电器电子设备中，在按键下需要大于50mA电流通过的开关触点。By adjusting the formulation of the plating solution and the time and temperature of the electroless plating, the resulting contacts can have an appearance similar to that of gold, silver, silver, steel or some titanium nitride. In particular, by using the molybdenum alloy plating solution of the present invention, it is relatively easy to obtain a molybdenum alloy which is close to silver white. The product of the invention is suitable for various high-grade places, and is particularly suitable for making electrical and electronic devices such as automobiles, electric tools, game machines, etc., and requires a switch contact with a current of more than 50 mA under the button.

本发明中的钼合金触点含有疏水性橡胶层，具有易于与橡胶进行热硫化粘合和成型从而制成含触点的橡胶按键产品的特性。The molybdenum alloy contact in the present invention contains a hydrophobic rubber layer and has characteristics of being easily vulcanized and bonded with rubber to form a rubber button product containing a contact.

附图说明DRAWINGS

图1是本发明的一种剖面结构示意图；图中：1、橡胶层；2、金属薄片层；3、钼合金镀层。BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view of the present invention; Figure 1: 1, rubber layer; 2, metal foil layer; 3, molybdenum alloy coating.

图2是本发明的制备方法中一种工艺流程图。Figure 2 is a process flow diagram of the preparation process of the present invention.

具体实施方式detailed description

下面结合具体实施例对本发明作进一步说明。The invention will now be further described in conjunction with specific embodiments.

实施例1：Example 1:

镀液组成：二水钼酸钠50g/L、六水硫酸镍20g/L、一水次亚磷酸钠40g/L、乙酸钠25g/L、柠檬酸钠50g/L、氟化钠2g/L、硫酸铵20g/L、硫脲0.2g/L、酒石酸钾钠30g/L、焦磷酸钠24g/L、碘酸钾40mg/L、十二烷基硫酸钠0.5g/L。氨水适量加入，使镀液的pH值维持在8.5至9.5之间。Composition of plating solution: sodium molybdate dihydrate 50g/L, nickel sulfate hexahydrate 20g/L, sodium hypophosphite sodium 40g/L, sodium acetate 25g/L, sodium citrate 50g/L, sodium fluoride 2g/L , ammonium sulfate 20g / L, thiourea 0.2g / L, sodium potassium tartrate 30g / L, sodium pyrophosphate 24g / L, potassium iodate 40mg / L, sodium lauryl sulfate 0.5g / L. Amount of ammonia water is added to maintain the pH of the bath between 8.5 and 9.5.

工艺路线：Routing:

如图1所示，将0.1mm厚的平整的不锈钢片(不锈钢材质型号304)的一面，进行机械粗化处理(喷砂或砂纸打磨)，然后进行碱性除油，再用去离子水清洗干净，风干，将不锈钢经喷砂粗化的一面用一种橡胶-金属粘合剂

CH238进行底涂处理，然后，将底涂处理过的这一面，和三元乙丙橡胶(EPDM)的混炼胶进行热硫化粘合和热硫化成型，形成1.0mm厚的不锈钢-EPDM复合片材。其中，不锈钢片作金属薄片层2，EPDM为橡胶层1，EPDM混炼胶的配方是：DPDM(牌号Keltan 514)100(重量份，下同)，氧化锌5，硫磺1.5，硬脂酸1.0，气相法白碳黑45，石蜡油15，促进剂BZ 2.0，促进剂DM 1.0，促进剂TETD 0.4，促进剂TMTD 0.4,促进剂TMTM 1.0。 As shown in Figure 1, one side of a 0.1 mm thick flat stainless steel sheet (stainless steel type 304) is mechanically roughened (blasted or sanded), then alkaline degreased, and then rinsed with deionized water. Clean and air-dried, using a rubber-metal binder on the side of the stainless steel that has been sandblasted and roughened.

The CH238 is subjected to a primer treatment, and then the undercoated surface is subjected to thermal vulcanization bonding and thermal vulcanization molding with an EPDM rubber compound to form a 1.0 mm thick stainless steel-EPDM composite sheet. material. Among them, stainless steel sheet is used as metal foil layer 2, EPDM is rubber layer 1, and EPDM rubber compound is formulated: DPDM (brand Keltan 514) 100 (parts by weight, the same below), zinc oxide 5, sulfur 1.5, stearic acid 1.0 , gas phase white carbon black 45, paraffin oil 15, accelerator BZ 2.0, accelerator DM 1.0, accelerator TETD 0.4, accelerator TMTD 0.4, accelerator TMTM 1.0.

将所得的不锈钢-EPDM复合片材冲切成直径为2-10mm的小圆柱体，把这种小圆粒用碱性清洗液清洗约5分钟，水洗，然后用5％的盐酸浸泡3分钟，然后用去离子水清洗干净，滤干，冷风吹干。The obtained stainless steel-EPDM composite sheet was die-cut into small cylinders having a diameter of 2-10 mm, and the small round particles were washed with an alkaline cleaning solution for about 5 minutes, washed with water, and then immersed in 5% hydrochloric acid for 3 minutes. Then rinse with deionized water, filter dry, and blow dry with cold air.

将这样的500粒小圆片，放入70℃的上述300ml镀液中，搅拌，200分钟后取出，用蒸馏水或去离子水漂洗、沥干、冷风吹干或放在70℃的恒温烘箱中烘干，即得到金属面层镀有钼合金镀层3的小圆粒。在化学镀的过程中，应时刻注意溶液的pH值变化情况，及时添加氨水或氢氧化钠溶液控制溶液的pH值，使pH值再8.5至9.0之间。所镀钼合金的厚度与小圆粒在镀液中放置的时间有关。放置的时间越长，钼镍合金镀层的厚度越厚。钼镍合金只在小圆粒中的不锈钢表面沉积，不在小圆粒中的橡胶表面沉积。The 500 small wafers were placed in the above 300 ml plating solution at 70 ° C, stirred, taken out after 200 minutes, rinsed with distilled water or deionized water, drained, blown cold air or placed in a constant temperature oven at 70 ° C. Drying, that is, small round particles having a metal surface layer coated with a molybdenum alloy plating layer 3 are obtained. In the process of electroless plating, always pay attention to the pH value of the solution, and add ammonia or sodium hydroxide solution to control the pH value of the solution in time to make the pH value between 8.5 and 9.0. The thickness of the molybdenum-plated alloy is related to the time during which the small rounds are placed in the bath. The longer the placement time, the thicker the thickness of the molybdenum-nickel alloy coating. The molybdenum-nickel alloy is deposited only on the surface of the stainless steel in the small round grains and is not deposited on the surface of the rubber in the small round grains.

这种镀有钼合金的小圆粒，和上述的EPDM混炼胶进行热硫化粘合和热硫化成型(小圆粒中的橡胶面和其它橡胶进行热硫化粘合，镀有钼合金的一面朝外)，制作含有钼合金触点的橡胶按键。用作橡胶按键中用作电路开关的触点，该触点与印刷电路板(PCB)的镀金触点接触，触点的接触电阻比直接由不锈钢片制得的小圆粒与PCB的镀金触点之间的接触电阻低，而且这种镀有钼合金的小圆粒有更好的导通稳定性：由没有钼合金镀层的不锈钢制得的小圆粒与PCB镀金触点通过300毫安的直流电，开关约3000次后，由于存在开、关时的电弧烧蚀，小圆粒和PCB镀金触点之间的接触电阻就明显升高(由约1欧姆升高至100欧姆以上，多次试验时甚至可以出现不导通的情况)；而在同样的电路条件下，这种镀有钼镍合金的小圆粒与PCB镀金触点通过300毫安的直流电，开关约8000次后，这种小圆片和PCB镀金触点之间的接触电阻，仍在1欧姆以下。The small round particles coated with molybdenum alloy are subjected to thermal vulcanization bonding and hot vulcanization molding with the above EPDM compound (the rubber surface of the small round particles and other rubbers are thermally vulcanized and bonded, and the one coated with the molybdenum alloy) Face-to-face), make rubber buttons with molybdenum alloy contacts. Used as a contact for a circuit switch in a rubber button that is in contact with a gold-plated contact of a printed circuit board (PCB). The contact resistance of the contact is smaller than that of a small round pellet made directly from a stainless steel sheet and a gold plated PCB. The contact resistance between the points is low, and the small round particles coated with molybdenum alloy have better conduction stability: small round particles made of stainless steel without molybdenum alloy plating and gold-plated contacts of the PCB pass 300 mA The direct current, after about 3,000 times of switching, due to the arc ablation during opening and closing, the contact resistance between the small round and the gold-plated contacts of the PCB is significantly increased (from about 1 ohm to more than 100 ohms, more In the second test, the non-conducting case may occur. Under the same circuit conditions, the small round particles coated with molybdenum-nickel alloy and the gold-plated contacts of the PCB pass 300 mA of DC power, and after about 8000 switching, The contact resistance between this small wafer and the gold-plated contacts of the PCB is still below 1 ohm.

实施例2Example 2

镀液组成：二水钼酸钠60g/L、六水硫酸镍10g/L、四水碱式碳酸镍10/L，肼100/L、焦磷酸钠15g/L、酒石酸钾钠20g/L、十二烷基硫酸钠0.5g/L。氨水适量加入，使镀液的pH值维持在8.5至9.5之间。Composition of plating solution: sodium dihydrate molybdate 60g/L, nickel sulfate hexahydrate 10g/L, tetrahydrate basic nickel carbonate 10/L, 肼100/L, sodium pyrophosphate 15g/L, sodium potassium tartrate 20g/L, Sodium lauryl sulfate 0.5 g / L. Amount of ammonia water is added to maintain the pH of the bath between 8.5 and 9.5.

工艺路线Routing

将0.075mm厚的平整的不锈钢片(型号304)的一面，用酸化的三氯化铁蚀刻液蚀刻出均匀分布的直径为0.25mm、深度为0.03-0.04mm的小孔，小孔间距为0.25mm。然后将此不锈钢片进行碱性除油，再用去离子水清洗干净，风干，将不锈钢平整的一面用一种美国罗门哈斯公司生产的水性的橡胶-金属粘合剂Megum^TM W 2535进行底涂处理，然后将涂处理过的这一面和含有1％过氧化二异丙苯(DCP)的日本信越公司生产的硅橡胶KE 751U进行热硫化粘合和热硫化成型，形成1.0mm厚的不锈钢-硅橡胶复合片材，其中不锈钢为金属薄片层2，硅橡胶为橡胶层1。将所得的不锈钢-硅橡胶复合片材冲切成直径为2-10mm的小圆柱体，把这种小圆粒用碱性清洗液清洗约5分钟，水洗，然后用5％的盐酸浸泡3分钟，然后用去离子水清洗干净，滤干。One side of a 0.075 mm thick flat stainless steel sheet (Model 304) was etched with an acidified ferric chloride etching solution to uniformly distribute small holes having a diameter of 0.25 mm and a depth of 0.03-0.04 mm with a small hole pitch of 0.25. Mm. This stainless steel sheet is then subjected to alkali degreasing, cleaned with deionized water, air dried, with one side of the stainless steel produced by Rohm and Haas aqueous flat rubber - metal adhesive for Megum ^TM W 2535 Primer treatment, and then the coated side and the silicone rubber KE 751U produced by Japan Shin-Etsu Co., Ltd. containing 1% dicumyl peroxide (DCP) were subjected to thermal vulcanization bonding and hot vulcanization molding to form a 1.0 mm thick layer. A stainless steel-silicone rubber composite sheet in which stainless steel is a metal foil layer 2 and silicone rubber is a rubber layer 1. The obtained stainless steel-silicone rubber composite sheet was die-cut into small cylinders having a diameter of 2-10 mm, and the small round particles were washed with an alkaline cleaning solution for about 5 minutes, washed with water, and then soaked for 3 minutes with 5% hydrochloric acid. Then rinse with deionized water and drain.

将这样的500粒小圆片，放入90℃的上述500mL镀液中，搅拌，控制pH值在9.0左右200分钟后取出，用蒸馏水或去离子水漂洗，沥干，然后冷风吹干，即得到金属面层镀有钼合金镀层3的小圆粒，这也就是镀有钼合金的触点。 The 500 small wafers were placed in the above 500 mL plating solution at 90 ° C, stirred, and the pH was controlled to be about 9.0 for 200 minutes, taken out, rinsed with distilled water or deionized water, drained, and then dried by cold air. A small round particle having a metal surface layer coated with a molybdenum alloy plating layer 3, which is a contact plated with a molybdenum alloy, is obtained.

所得的镀有钼合金的触点，具有接近于银白色的金属外观，并且这种触点在300毫安电流下的使用寿命(开关次数)，提高了一倍以上，由没有镀钼合金的相对应的触点3000次，提高到了10000次以上。The resulting contact with molybdenum-plated alloy has a metallic appearance close to silvery white, and the service life (number of switching) of this contact at 300 mA is more than doubled, without molybdenum-plated alloy The corresponding contacts were increased by 3,000 times in 3,000 times.

实施例3：Example 3:

以400目的不锈钢平纹网(不锈钢型号为304)代替实施例1中的不锈钢片，采用实施1中的工艺和化学镀液，所制得的触点，也具有较低的接触电阻和较好的耐电弧烧蚀性能。The stainless steel sheet of the first embodiment was replaced by a 400 mesh stainless steel plain mesh (stainless steel model 304), and the contact and the electroless plating solution of the first embodiment were used to obtain a contact having a lower contact resistance and better. Resistance to arc ablation.

400目的不锈钢网网孔很小，在和硅橡胶模压时，硅橡胶不会穿透不锈钢网的网孔。如果选用目数小的不锈钢网，如80目以下的不锈钢网，在模压时就会产生硅橡胶穿透不锈钢网孔的工艺问题。因此，需采用较大目数的不锈钢网来制备有镀层的开关触点。The 400 mesh stainless steel mesh has a small mesh opening, and the silicone rubber does not penetrate the mesh of the stainless steel mesh when molded with the silicone rubber. If a stainless steel mesh with a small mesh size, such as a stainless steel mesh of 80 mesh or less, is used, a process problem in which the silicone rubber penetrates the stainless steel mesh is generated during molding. Therefore, a larger mesh stainless steel mesh is required to prepare a plated switch contact.

对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。 It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principles of the invention.

Claims (10)

1. 一种含有钼合金镀层的开关触点，其特征在于：开关触点是具有三层层状结构的层状复合体；第一层为0.1-10mm厚的疏水性橡胶层，第二层为0.01-2.0mm厚的含镁、铝、钛、铬、锰、铁、钴、镍、铜、锌、铌、钼、银或锡的金属薄片层，第三层为2*10^-5-0.02mm厚的钼合金镀层；其中，第三层钼合金镀层是第一层和第二层的复合体浸渍在含有可溶性钼化合物的化学镀液中，用化学沉积的方法将钼合金沉积在第一层和第二层的复合体中第二层的表面而形成的；第三层钼合金镀层中含有重量比不小于30％的钼元素。A switch contact comprising a coating of molybdenum alloy, characterized in that: the switch contact is a layered composite having a three-layered structure; the first layer is a hydrophobic rubber layer of 0.1-10 mm thick, and the second layer is 0.01 - 2.0mm thick metal foil layer containing magnesium, aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, bismuth, molybdenum, silver or tin, the third layer is 2*10 ^-5 -0.02mm a thick molybdenum alloy coating; wherein the third layer of molybdenum alloy coating is a composite of the first layer and the second layer immersed in an electroless plating solution containing a soluble molybdenum compound, and the molybdenum alloy is deposited on the first layer by chemical deposition And a surface of the second layer in the composite of the second layer; the third layer of the molybdenum alloy plating layer contains molybdenum element in a weight ratio of not less than 30%.
2. 根据权利要求1所述的含有钼合金镀层的开关触点，其特征在于：所述的疏水性橡胶层是由于橡胶分子链上羧基、羟基、羰基、氨基、酰胺基、腈基、硝基、卤基、巯基、磺酸根和苯磺酸根含量低，从而使橡胶表面的水接触角大于65°的橡胶材料构成；或者，所述的疏水性橡胶层是由于橡胶中不含或含有少量的亲水性的填料或添加剂，从而使橡胶表面的水接触角大于65°的橡胶材料构成。The switch contact of the molybdenum alloy plating layer according to claim 1, wherein the hydrophobic rubber layer is due to a carboxyl group, a hydroxyl group, a carbonyl group, an amino group, an amide group, a nitrile group or a nitro group in the rubber molecular chain. a halogen material having a low content of a halogen group, a sulfhydryl group, a sulfonate group and a benzenesulfonate group, so that a water contact angle of the rubber surface is greater than 65°; or the hydrophobic rubber layer is not contained in the rubber or contains a small amount of pro A water-based filler or additive that constitutes a rubber material having a water contact angle of more than 65° on the rubber surface.
3. 根据权利要求1或2所述的含有钼合金镀层的开关触点，其特征在于：所述的疏水性橡胶层由非极性或极性弱的橡胶制备而成；优先选用三元乙丙橡胶、甲基乙烯基硅橡胶或甲基乙烯基苯基硅橡胶。The switch contact comprising a coating of a molybdenum alloy according to claim 1 or 2, wherein the hydrophobic rubber layer is made of a non-polar or weakly-polar rubber; EPDM rubber is preferred. , methyl vinyl silicone rubber or methyl vinyl phenyl silicone rubber.
4. 根据权利要求1或4所述的含有钼合金镀层的开关触点，其特征在于：所述的金属薄片层为具有凸点或凹点的金属片材、具有凸线条或凹线条的金属片材、具有凸面或凹面的金属片材、具有面积小于1mm²的小孔的金属片材、金属网、金属泡沫或者金属纤维烧结毡；金属材质为镁、铝、钛、铬、锰、铁、钴、镍、铜、锌、锡或含有这些元素的合金；所述的金属薄片层是单一金属材质或不同的金属材质的层状复合形成。A switch contact comprising a molybdenum alloy plating layer according to claim 1 or 4, wherein the metal foil layer is a metal sheet having bumps or pits, and a metal sheet having convex or concave lines. a metal sheet having a convex or concave surface, a metal sheet having a small hole having an area of less than 1 mm ² , a metal mesh, a metal foam or a metal fiber sintered felt; the metal material is magnesium, aluminum, titanium, chromium, manganese, iron, cobalt Nickel, copper, zinc, tin or an alloy containing these elements; the metal foil layer is formed by a single metal material or a layered composite of different metal materials.
5. 根据权利要求1或4所述的含有钼合金镀层的开关触点，其特征在于：所述的金属薄片层的金属薄片由0.01-1.0mm厚的不锈钢、铜或铜合金、镍或镍合金薄片构成，在不锈钢、铜或铜合金、镍或镍合金薄片的一面或两面，镀有0.01-10微米的纯镍层或镍合金层、纯钴层或钴合金层；不锈钢、铜或铜合金、镍或镍合金薄片上的纯镍层或镍合金层、纯钴层或钴合金层是由真空镀膜、电镀或化学镀的方法制备的。The switch contact of the molybdenum alloy plating layer according to claim 1 or 4, wherein the metal foil layer has a thickness of 0.01-1.0 mm thick stainless steel, copper or copper alloy, nickel or nickel alloy sheet. Constructed on one or both sides of a sheet of stainless steel, copper or copper alloy, nickel or nickel alloy, with a pure nickel or nickel alloy layer of 0.01-10 microns, a pure cobalt layer or a cobalt alloy layer; stainless steel, copper or copper alloy, A pure nickel or nickel alloy layer, a pure cobalt layer or a cobalt alloy layer on a nickel or nickel alloy sheet is prepared by vacuum coating, electroplating or electroless plating.
6. 一种含有钼合金镀层的开关触点的制备方法，其特征在于：开关触点的制备包括如下步骤：A method for preparing a switch contact comprising a coating of molybdenum alloy, characterized in that the preparation of the switch contact comprises the following steps:

   (1)金属薄片的处理：金属薄片为0.01mm至1.0mm厚的不锈钢、铜或铜合金、镍或镍合金薄片；用清洗剂和有机溶剂对金属薄片进行除油、清洗；或通过喷砂、打磨将金属薄片进行表面机械粗化处理；或通过化学蚀刻处理以处理出直径小于1mm的凹坑或凸点；或在金属薄片的一面或两面，用电镀或化学镀的方法镀有0.1微米至10微米的纯镍层或镍合金层；然后用清洗剂和有机溶剂对所得到的金属薄片进行除油、清洗；(1) Treatment of metal foil: the metal foil is a stainless steel, copper or copper alloy, nickel or nickel alloy sheet of 0.01 mm to 1.0 mm thick; the metal foil is degreased and cleaned with a cleaning agent and an organic solvent; or by sandblasting Grinding the surface of the metal sheet by mechanical roughening; or chemical etching to treat pits or bumps having a diameter of less than 1 mm; or plating one or both sides of the metal sheet by plating or electroless plating to 0.1 μm To a pure nickel layer or a nickel alloy layer of 10 micrometers; then, the obtained metal foil is degreased and washed with a cleaning agent and an organic solvent;

   (2)疏水性橡胶与金属薄片的粘合处理：疏水性橡胶通过热硫化成型，粘合在涂有底涂剂或粘合促进剂的金属薄片上，形成层状的复合片材；或者将具有自粘性的疏水性橡胶，通过热硫化成型，粘合在涂有底涂剂或没有底涂剂的金属薄片上，形成层状的复合片材； (2) Adhesive treatment of hydrophobic rubber and metal foil: the hydrophobic rubber is formed by thermal vulcanization, adhered to a metal foil coated with a primer or an adhesion promoter to form a layered composite sheet; or a self-adhesive hydrophobic rubber which is formed by thermal vulcanization and bonded to a metal foil coated with a primer or without a primer to form a layered composite sheet;

   (3)切割处理：将上述步骤中的复合片材分割或冲切成包含有疏水性橡胶层和金属薄片层的直径为2-10mm的圆柱体，或者将上述步骤中的复合片材分割或冲切成横截面为椭圆形、多边形、十字形、星形、新月形或它们的任意组合的物体；用碱性清洗液清洗约5分钟，水洗，然后用5％的盐酸清洗3分钟，然后用去离子水清洗干净，滤干；(3) Cutting treatment: dividing or punching the composite sheet in the above step into a cylinder having a diameter of 2 to 10 mm including a hydrophobic rubber layer and a metal foil layer, or dividing the composite sheet in the above step or Punching into an object having an elliptical, polygonal, cruciform, star-shaped, crescent-shaped or any combination thereof; washing with an alkaline cleaning solution for about 5 minutes, washing with water, and then washing with 5% hydrochloric acid for 3 minutes, Then rinse with deionized water and filter dry;

   (4)钼合金镀层的制备：将上述圆柱体或物体，浸渍在含有可溶性钼化合物的化学镀液，搅拌，用化学镀的方法在圆柱体或物体的金属表面形成钼合金镀层；或者，将上述圆柱体放入含有可溶性钼化合物的化学镀液的滚筒中，让滚筒转动，用化学镀的方法在圆柱体或物体的金属表面，形成钼合金镀层；(4) Preparation of molybdenum alloy plating layer: immersing the above-mentioned cylinder or object in an electroless plating solution containing a soluble molybdenum compound, stirring, forming a molybdenum alloy plating layer on a metal surface of a cylinder or an object by electroless plating; or The cylinder is placed in a drum of an electroless plating solution containing a soluble molybdenum compound, the drum is rotated, and a molybdenum alloy plating layer is formed on the metal surface of the cylinder or the object by electroless plating;

   镀液中含有20-125g/L的可溶性钼化合物、0-60g/L的可溶性的过渡金属铁、镍、钴、铜或锰的化合物或这些化合物的任意组合、0-30g/L的可溶性的锡、锑、铅或铋化合物或这些化合物的任意组合、20-100g/L的还原剂、30-150g/L的络合剂、20-100g/L的pH值调节剂、0.1-1g/L的稳定剂、0.1-1g/L的表面活性剂、0-50g/L的光亮剂或粗糙度调节剂；The plating solution contains 20-125 g/L of soluble molybdenum compound, 0-60 g/L of soluble transition metal iron, nickel, cobalt, copper or manganese compound or any combination of these compounds, 0-30 g/L of soluble Tin, antimony, lead or antimony compound or any combination of these compounds, 20-100 g/L reducing agent, 30-150 g/L complexing agent, 20-100 g/L pH adjusting agent, 0.1-1 g/L Stabilizer, 0.1-1 g/L surfactant, 0-50 g/L brightener or roughness modifier;

   所述的可溶性钼化合物是钼酸钠、钼酸钾、钼酸铵、磷钼酸、磷钼酸铵、钼酸、三氧化钼。使用微溶于水的钼酸或不溶于水的三氧化钼作为钼源时，可先用氢氧化钠溶液使其溶解，然后用其配制化学镀液；The soluble molybdenum compound is sodium molybdate, potassium molybdate, ammonium molybdate, phosphomolybdic acid, ammonium phosphomolybdate, molybdic acid, molybdenum trioxide. When using a slightly water-soluble molybdic acid or water-insoluble molybdenum trioxide as a molybdenum source, it may be first dissolved with a sodium hydroxide solution, and then used to prepare an electroless plating solution;

   优选次亚磷酸钠为镀液中的还原剂。采用次亚磷酸钠为还原剂时，钼合金镀层所采用化学镀的温度为60-90℃，时间为30-300分钟，镀液的pH值为8.0-10.0；Preferably, sodium hypophosphite is a reducing agent in the plating solution. When sodium hypophosphite is used as the reducing agent, the electroless plating temperature of the molybdenum alloy plating layer is 60-90 ° C, the time is 30-300 minutes, and the pH of the plating solution is 8.0-10.0;

   (5)清洗、冷风吹干：取出后用蒸馏水或去离子水漂洗、沥干、冷风吹干或放在70℃的恒温烘箱中烘干，即得到金属面层镀有钼合金的开关触点。(5) Cleaning, cold air drying: After taking out, rinse with distilled water or deionized water, drain, blow dry air or dry in a constant temperature oven at 70 ° C to obtain the switch contacts with metal surface layer coated with molybdenum alloy. .
7. 根据权利要求6所述的含有钼合金镀层的开关触点的制备方法，其特征在于：选用次亚磷酸钠作为镀液中的还原剂时，镀液的温度为70-85℃，化学镀的时间为150-200分钟；镀液的pH值控制在8.5至9.0之间，镀液中含有具有pH缓冲能力的强碱弱酸盐或强酸弱碱盐和pH调节剂氢氧化钠、氢氧化钾、碳酸钠、乙酸钠、氨水、焦磷酸钠、焦磷酸钾中的一种或多种。The method for preparing a switch contact comprising a molybdenum alloy coating according to claim 6, wherein when the sodium hypophosphite is used as the reducing agent in the plating solution, the temperature of the plating solution is 70-85 ° C, and the electroless plating is performed. The time is 150-200 minutes; the pH of the plating solution is controlled between 8.5 and 9.0. The plating solution contains a strong base weak acid salt or a strong acid weak base salt with pH buffering ability and a pH adjuster sodium hydroxide or potassium hydroxide. One or more of sodium carbonate, sodium acetate, ammonia water, sodium pyrophosphate, and potassium pyrophosphate.
8. 根据权利要求6所述的含有钼合金镀层的开关触点的制备方法，其特征在于：所述的稳定剂为碘化钾、碘酸钾、苯骈三氮唑、4,5-二硫代辛烷-1,8-二磺酸盐、3-巯基-1-丙磺酸盐、硫代硫酸钠、硫脲中的一种或多种的混合物，优选为硫代硫酸钠、硫脲或者两者的混合物。The method for preparing a switch contact comprising a molybdenum alloy coating according to claim 6, wherein the stabilizer is potassium iodide, potassium iodate, benzotriazole or 4,5-dithiooctane. a mixture of one or more of -1,8-disulfonate, 3-mercapto-1-propanesulfonate, sodium thiosulfate, thiourea, preferably sodium thiosulfate, thiourea or both mixture.
9. 根据权利要求6所述的含有钼合金镀层的开关触点的制备方法，其特征在于：所述的化学镀采用的镀液中，含有还原剂次亚磷酸钠、硼氢化钠、烷基胺硼烷、肼或三氯化钛中的一种或多种，优先选用次亚磷酸钠。The method for preparing a switch contact comprising a molybdenum alloy coating according to claim 6, wherein the plating solution used for the electroless plating comprises a reducing agent sodium hypophosphite, sodium borohydride and alkylamine boron. One or more of alkane, hydrazine or titanium trichloride, sodium hypophosphite is preferred.
10. 根据权利要求6所述的含有钼合金镀层的开关触点的制备方法，其特征在于：所述的过渡金属合金镀层、低钨合金层和钨合金层化学镀采用的镀液中，含有0.05-50g/L的化学镀光亮剂；所述的化学镀光亮剂为丁炔二醇、丙炔醇、1-二乙胺基丙-2-炔、乙氧化丙炔醇、邻磺酰苯酰亚胺钠、乙烯基磺酸钠、丙炔磺酸钠、吡啶-2-羟基丙磺酸内盐、烷基酚聚氧乙烯醚或 市售的商品化的化学镀光亮剂。 The method for preparing a switch contact comprising a molybdenum alloy coating according to claim 6, wherein the transition metal alloy plating layer, the low tungsten alloy layer and the tungsten alloy layer are electrolessly plated with a plating solution containing 0.05- 50g / L of electroless plating brightener; the electroless plating brightener is butynediol, propynyl alcohol, 1-diethylaminopropan-2-yne, ethoxylated propynyl alcohol, sulfonyl benzoyl Sodium amide, sodium vinyl sulfonate, sodium propyne sulfonate, pyridine-2-hydroxypropane sulfonate, alkyl phenol ethoxylate or Commercially available chemical plating brightener.

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