塑料电镀的背景知识

塑料电镀的背景知识和进展
（摘译于USP20070059449）
上海北京顺德
[0003] In comparison to the metal materials, the polymer materials have many advantages in that they are inexpensive and light, have good rigidity and processability, are chemically stable and have a good corrosion resistance, and therefore, have recently been used as an alternative material for metals in various fields of applications. Particularly, since the coating of the surface of polymer materials with metal films permits to add the functions of metals, the use of polymeric materials is remarkably broadened. Such materials have both the advantages of metals including hardness, better rigidity, electric conductivity, etc., and the advantages of polymer materials including lightness, processability, productivity, etc., and therefore, are very promising as the alternative material for metal processed articles such as brass, etc.
与金属材料比较，聚合物材料有许多优点。

聚合物材料便宜、质轻，刚性和加工性好，有稳定的化学性能和好的耐腐蚀性，因此近来一直被用于替代金属材料，使用在各种领域。

特别地，由于聚合物表面的金属涂层使聚合物增添了金属的功能，聚合物材料的应用范围被大大拓宽。

这样的材料既有金属的优点，包括硬度、好的刚性、导电性等等，也有聚合物材料的优点，包括质轻、好的加工性，高产率等等，因此这样的材料很有希望取代制造铜之类的金属加工的部件的材料。

[0004] The methods for plating the polymer materials with the metal film for providing metallic properties such as conductivity, electricity shielding and brilliance to the polymer materials can be generally classified into two methods of wet plating and dry plating. Since the polymer materials are a non-conductor, the metal film cannot be deposited on the surface of polymer materials by an electroplating method. 使聚合物产生金属镀层可以让聚合物材料具有金属性质，如导电性、电屏蔽性和金属光泽。

其产生镀层的方法有二：湿镀和干镀。

由于聚合物材料是非导体，不可能用电镀的方法在聚合物表面制造金属膜层。

[0005] The wet plating method permits to improve the adhesion of plating layers by treating the surface of polymers with an acid to generate the concavo-convex and forming the polar functional groups (see, Metal surface Compendium, Plastic Plating Techniques, page 13). However, the wet plating can be easily applied only to some polymer materials, such as ABS, of which the surface can be etched with acids, but has been very restrictively applied to the engineering polymer materials including polycarbonate, polyimide, teflon, etc.
湿镀方法可以改进镀层的粘附能力，其方法是用酸处理聚合物表面，以产生凸凹并形成极性基团。

但是，湿镀只适用于某些聚合物材料，如ABS，这类材料的表面可以用酸蚀刻，也可以有限度地用于工程塑料，包括聚碳酸酯，聚酰胺，TEFLON等。

[0006] Korean Laid-Open Patent Publication No. 1995-0027008 discloses the commercially available product produced by plating the through hole and the surface of a printed circuit board, which uses acrylonitrile/butadiene/styrene (ABS) resins and glass fiber reinforced epoxy resin, with a metal but does not teach the products prepared by plating with the metals the surface of polymer materials such as polyethylene, polypropylene, polycarbonate, polystyrene, Teflon, etc. as generally and conventionally used in this field. The reason is that since the polymer materials are
non-conductive and chemically very stable, it is very difficult to form the metal layer on the surface of polymer materials according to the generally used pre-treatment and electroless plating method.
韩国专利No. 1995-0027008介绍了一种可以在市场上获得的产品，它可以在线路板的孔部和表面进行金属镀，使用的材料是ABS树脂和玻璃纤维增强的环氧树脂。

但是该专利没有教人们如何给聚乙烯、聚丙烯、聚碳酸酯、聚苯乙烯TEFLON等一般的和常用的材料上镀。

[0007] U.S. Pat. Nos. 4,941,940 and 5,049,230 disclose that the electroless plating is conducted either after the polycarbonate is immersed into an organic solvent to swell the surface of the materials, and then subjected to fine roughening treatment, etched with an inorganic acid and allowed them to have a wettability with caustic bath, or after respective solutions are mixed together to form the first solution with which the polycarbonate is pre-treated.
美国专利Nos. 4,941,940 和5,049,230介绍了两种方法化学镀方法。

其一方法是，先将聚碳酸酯浸入有机溶剂，以溶胀其表面，然后用无机酸蚀刻以进行粗化处理，从而使PC具有
对腐蚀性镀液的润湿性。

其二方法为，将用到的各种溶剂混合一起，以形成前面第一种方法提到的对PC进行预处理的溶液。

[0008] British Patent No. 1124556 discloses the method which comprises polymerizing the surface of polymer materials containing styrene with a monomer to form a monovalent cationic group (nitride group), and then treating with an aqueous solution of acetone, etc., etching by immersion into the mixed acid of sulfuric acid and chromic acid, and then subjecting to electroless plating. Further, Japanese Laid-open Patent Publication No. 57-55933 discloses the electroless plating method which comprises subjecting the surface of polypropylene (PP) to roughening treatment in an alkaline solution containing sodium permanganate and sodium sulfite; and U.S. Pat. No. 4,227,963 discloses a method wherein the surface of polymer materials is etched using the mixture of sulfuric acid and carboxylic acid and then subjected to the electroless plating.
英国专利No. 1124556介绍了一种方法，先聚合出一个含苯乙烯与一种单体的聚合物材料
表面，以形成单化合价阳离子基团，然后用丙酮等的水溶液处理，浸入硫酸和铬酸的混合酸进行蚀刻，然后进行化学镀。

还有，日本专利No. 57-55933也介绍了一种化学镀方法。

其方法是，在含高锰酸钠和亚硫酸钠的碱性溶液中进行粗化处理。

美国专利No. 4,227,963介绍了一种方法，其中聚合物材料的表面是用硫酸和羧酸的混合物进行蚀刻的，然后用进行化学镀。

[0009] Recently, the polymer materials which can be plated according to the wet plating method using conductive filler remained after the high rigid materials are mixed with approximately several to few tens percent of etched ABS or inorganic fillers and then etched by treatment with an acid to form much concavo-convex portions have been produced (e.g. Japanese Laid-open Patent Publication Nos. Hei 8-269313, Hei 5-255582, Hei 8-199365 and Hei 6-333418 and Japanese Patent Publication No. Hei 2-36147). However, the addition of excessive inorganic fillers causes the lowering of properties of polymer materials and adhesion of the plated film, and induces an increase in the cost, which makes its commercialization difficult, and further, for improving the adhesion strength of the plated layer the concavo-convex portions should be remained to induce a deterioration of the appearance quality of the product. Furthermore, it also has the disadvantages that in comparison to the plating method wherein the electricity is passed through the aqueous solution, the adhesion
strength itself is necessarily low since a gap present in the surface is filled with reduced metals, and further that since it requires an excessive deposition of metals, the metals and reducing agents should be used in a large amount, thereby waste water being largely produced to cause the environmental problem.
近来，有些可以湿镀的聚合物材料生产出来了，方法是使用导电填料与大约百分之几到百分之几十的可蚀刻ABS混合，或者是与无机填料混合。

然后用酸蚀刻处理，以形成更多的凹凸位。

但是，填充过多的无机填料会导致聚合物性能和金属镀膜的粘附力降低，并导致成本增加，这使其商业化困难。

再者，为了改进镀层的粘附强度，凹凸位可能诱导产品的表面质量恶化。

[0010] The dry plating method is a method for deposition of a metal on the surface of polymer material under vacuum and includes sputtering method, vapor deposition, vacuum deposition, etc. Since the dry plating does not require the reduction using electricity, the dry plating has many advantages in that it permits to plate the surface of non-conductive polymer materials, and further does not use the electrolyte solution so that wastewater is not produced and the plating thickness can be readily controlled. However, it has some disadvantages that adhesion, etching resistance and abrasion resistance of the plated film are inferior, the portions which are not directly exposed to evaporation source or target metals are not uniformly plated, and it is difficult to prepare the thick plated film. Furthermore, the dry plating method is only hardly applied to the other materials than a special product since the maintenance of a vacuum at an extremely high level in order to promote the evaporation of metals costs a great deal.
干镀是一种在真空下在聚合物表面沉积金属的方法，包括溅射、气相沉积、真空沉积等。

由于不要求用电还原，干镀有许多优点，因为它允许对非导电性聚合物进行上镀，其次不使用电镀液，结果不产生废水，而且镀层厚度易于控制。

但是，它也有一些缺点，镀膜的粘附力、耐蚀刻性和耐磨性都很差。

此外，干镀只适用一些特殊的材料，因为要促进金属蒸发而维持的高度的真空花费颇大。

[0011] In order to make up for such disadvantages, the combined method of dry and wet plating processes has been proposed.
为了弥补这些缺点，干湿度并用的方法得以提倡。

[0012] For example, U.S. Pat. No. 3,801,368 discloses the method for sputtering the surface of polymer materials to provide a doping of Au, Pt, etc. and then conducting the electroless plating; and Japanese Patent No. 92-240189 discloses the method for treating PTFE with UV laser in an amine or amide and then conducting the electroless plating. Further, U.S. Pat. No. 4,354,911 discloses the method for cleansing the surface of the materials with oxygen-argon gas plasma, thinly sputtering a catalyst metal, and then conducting the electroless plating. However, in practice, these methods have not been practically used.
例如，美国专利No. 3,801,368介绍了在聚合物材料表面进行溅镀以提供一个Au, Pt镀层，然后进行化学镀。

日本专利No. 92-240189介绍，用UV激光器在胺或者酰胺中处理PTFE，然后进行化学镀。

此外，美国专利. No. 4,354,911介绍的方法是，用氧氩气体的等离子体净化材料表面，溅度一层薄的催化剂金属，然后进行化学镀。

但是，这些方法都没投入实际应用。

[0013] European Patent No. 0268821 and U.S. Pat. No. 5,340,451 disclose the methods for making the surface of polymer materials hydrophilic with the gas plasma treatment and then practicing the electroless plating using Pd catalyst. This method
may be readily available for practical purpose since its procedure is simple and uses the conventional electroless plating. However, it has the disadvantages in that the metal film formed on the polymer materials is not uniform and adhesion with the metal film and the reproducibility for metal film deposition are inferior.
欧洲专利No. 0268821和美国专利No. 5,340,451介绍了用气体等离子体处理聚合物表面以获得极性、然后用Pd催化剂进行化学镀的方法。

该方法实用易得，因为它过程简单并使用传统的化学镀。

但是，该方法是有缺点的，因为在聚合物材料上形成的金属膜不均匀，与金属膜的粘附以及金属膜沉积的重现性差。

[0014] Further, the prior coating methods for shielding electromagnetic wave of electronic equipments include three kinds of methods including 1) a vacuum metalizing wherein the metal is vaporized and deposited on the material surface under vacuum; 2) a conductive paint spray wherein the solution containing metal powder is sprayed onto the material surface; and 3) an electroless plating wherein the materials to be coated are placed in a plating bath and then plated using the reducing agent. At present, it has been known that most of Korean manufacturing companies generally use the conductive paint spray method and some of foreign companies including Nokia, etc. use the vacuum metalizing method using polymer alloy as the substrate. 此外，先前的对电子设备进行电磁波屏蔽的涂层方法有三种方法，包括1）真空金属镀层，这里，金属在真空下被蒸发并沉积在材料表面；2）导电涂料喷溅，这里，含金属粉末的溶液被喷雾到材料表面；3）化学镀，这里，待涂覆的
材料置于镀槽，然后用还原剂进行上镀。

现在，众所周知，大多数韩国制造公司普遍使用导电涂料喷雾方法，一些外国公司，包括诺基亚（Nokia）使用真空金属镀方法，以聚合物合金作为基底材料。

[0015] Among those methods, the vacuum metalizing method has been generally used at the early stage of cellular phone production, but has scarcely used at present due to the problems that the productivity is low, because of low productivity, high cost and poor adhesion of metal film with substrate. Thus, in general, the conductive paint spray method and the electroless plating method have been currently used.
在这些方法中，真空金属镀方法曾普遍使用于早期的蜂窝电话生产中，但是目前罕见使用，由于生产效率低下，成本高，金属镀膜与基底材料的粘附力差。

这样，目前普遍使用的是导电涂料喷雾法。

[0016] Currently many Korean companies use the conductive paints comprising silver or copper, which are mainly imported from America. Although this method can be applied to various materials regardless of thin surface properties and exhibits a good adhesion, it has some disadvantages that harmful material of the gaseous organic solvents may be discharged during drying step, and the cost is high.
目前许多韩国公司使用含银或者铜的导电涂料，它们主要是从美国进口的。

尽管这种这种方法可应用于各种材料，而不管薄层表面的性质如何，并表现出好的粘附性能，但是它还是有一些缺点，在进行涂层干燥时，气体溶剂等有害物质可能排放出来，而且成本也高。

[0017] On the contrary, the electroless plating method, which have been used in some foreign companies, uses a polymer alloy in which ABS resin is mixed as the filler so as to make the plating of high-rigid polycarbonate materials available. However, for such material, although ABS portion is dissolved with the acid so that the plating film can be readily formed, the physical properties including rigidity may be caused to be deteriorate, and further, it has many disadvantages including a generation of harmful materials, a lowering of the productivity, a difficulty in partial plating and a limitation
on the materials to be applied. Although some Korean companies have developed the plating method for shielding electromagnetic wave of the polycarbonate (PC)-based materials, this method could not been practically utilized due to the problems in view of the procedures, including a low productivity and the problem in producing the non-plated area
相反，化学镀方法一直被一些外国公司使用。

这种化学镀使用聚合物合金，在合金中，ABS起导电填料一样的作用，这样使得刚性PC材料可以上镀。

对于这样的材料，尽管ABS组分可以被酸溶解从而能容易形成镀膜，但是物理性能，包括刚性可能变差。

此外，它还有许多缺点，包括存在一系列有害物质，生产效率降低，局部镀困难，所应用的材料种类有限。

尽管一些韩国公司开发了一些用于屏蔽电磁波的PC基材料的方法，鉴于这种工艺存在的问题，如低产率以及在非镀领域存在的问题，该方法不可能有实际应用。

[0018] In addition, recently for the purpose of attaching the metal film to the polymer materials the method for plating the surface of polymer materials into which a hydrophilic functional groups are introduced, with the metal film by introducing said hydrophilic functional group into the surface of polymer materials using plasma and then conducting the electroless plating using a palladium/tin (Pd/Sn) catalyst has been reported (e.g. U.S. Pat. Nos. 4,568,562 and 4,956,197, EP 0 268 821A1, EP 0 478 975A2, U.S. Pat. Nos. 5,696,207 and 5,340,451). However, the result from plating according to the above-indicated patents is not so good and such a method has not been generally used for practical purpose.
此外，最近为了使金属膜附着于聚合物材料，开发了镀聚合物表面的方法。

该方法是，使用等离子体对聚合物引进亲水基团，然后使用钯/锡（Pd/Sn)催化剂进行化学镀。

（例如U.S. Pat. Nos. 4,568,562 和 4,956,197, EP 0 268 821A1, EP 0 478 975A2, U.S. Pat. Nos.
5,696,207 和 5,340,451)。

但是，按照上述专利表明的上镀结果并不好，这样的一种方法也并不普遍实用。

[0019] Due to the above-mentioned problems, it is still required to develop a novel method for plating the polymer material with the metal film so that a composite material utilizing both of the advantage of stable and light polymer materials and the metallic materials having a metal conductivity can be used in various applications.
由于上述提到的问题，仍然有必要开发一种新的聚合物材料上镀金属膜的方法，以便某种复合材料既具有聚合物材料的耐腐蚀性和质轻特点，也具有金属材料的优点，从而可以满足各种应用。

[0020] In order to solve the above-mentioned problems, the present invention provides a method for plating a polymer material with a metal film, which can form the film on the surface of polymer materials, which are difficult to plate by the prior wet plating method, at a relatively low cost in comparison to the dry plating method and exhibits a uniform thickness and a good adhesion of the metal film and further, shows a good reproducibility.
为了解决上述问题，本发明提供了一种给聚合物材料上镀金属膜的方法，用该方法可以在聚合物材料表面形成膜层，这是原来的工艺难于做到的，而且比干镀成本低，镀层厚度均匀，金属膜的粘附性好，最后，还显示出好的重现性。

[0021] Further, the present invention provides a product plated on the polymer materials for shielding electromagnetic wave according to said novel plating method. 此外，按照上述所说的上镀方法，本发明提供了一种在聚合物材料上上镀的产品，该产品可用于电磁屏蔽。