TWI247827B - Electrolytic stripping agent for silver - Google Patents

Abstract

This invention provides an electrolytic stripping agent for silver, which is a silver stripping agent of non-cyano series, with a long life, a highly side stripping ability, and can inhibit the unevenness occurring on the necessary silver side after silver stripping and the luster arising. An electrolytic stripping agent for silver of this invention comprises a hydantoin compound and aminocarboxylic acid or their salts as major ingredients. The preferable hydantoin compound are hydantoin, 5,5-dimethylhydantoin, 5,5-dimethylhydantoin-3-hydromethyl and allantoin, and preferable aminocarboxylic acid of their salts are aspartic acid, glutamic acid or their salts.

Description

1247827 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明[Prior Art] A non-cyanide-based silver stripper is disclosed as a succinimide or a quinone imine (for example, Japanese Patent Laid-Open Publication No. Hei. No. Hei. JP-A-2-175825), 2-m ketone i-acid (for example, refer to the serotonin 6_4 i 8 公 公 乙 醯 醯 化合物 ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( , , , , , , , Because of the decomposition in the electrolyte, the consumption is large and the service life of the electrolyte is short. On the other hand, the carbendazole compound has a small decomposition in the plating solution and consumes less, which is a long life. However, in order to improve productivity, silver peeling is performed at a high current density, and it is necessary to have a color spot on the silver surface and a glossiness to be easily raised in order to solve the problem' in the special Kaiping 9_491 nickname (29391 81 No.) in the bulletin: In the 乂 鲶 鲶 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 Color spots. ^ [Invention content] Xitang When the stripping agent is applied to the lead frame, according to the current demand, it is so long: the south overflows in the lead soul & the next day I &, the V-line wood side does not have part of the silver and the part will not be stripped by silver. After the carving J treatment, the necessary part of the suppression is 3] 5532 Correction 1247827 & first Zedu rise 1 The miniaturization of the lead frame, there is a saying that the silver on the side (four) is contaminated. And when the gloss is too high The present invention provides a silver electrolytic stripping agent that satisfies such needs, and aims to provide a long life in a non-cyanide silver stripper. The side peeling ability is 胄, and it is possible to suppress the occurrence of silver in the necessary portion after the silver stripping agent and the increase in gloss. The inventors of the present invention have found that the silver electrolytic stripping agent can be formed by the following. The above problem is solved. That is, the present invention is as follows. ' (1) A silver electrolytic stripping agent which is mainly composed of an intramethylene urea compound and an aminocarboxylic acid or a salt thereof. (1 And a silver electrolysis stripping agent according to the above (1) or (2), wherein the above-mentioned ethyl uret urea compound is a silver electrolysis stripping agent. Taking 5,5-dimercaptoindolide, 3-hydroxyindole-5,5-dimercaptoinouramide, allantoin or the salt thereof as a main component; the above aminocarboxylic acid or The salt of the present invention is mainly composed of aspartic acid, glutamic acid or the like. The silver electrolytic stripping solution of the present invention is mainly composed of an intramethylene urea compound and an aminocarboxylic acid or a salt thereof. Since it is found that the electrolyte life is prolonged by using the urea compound in the B, and the use of the aminocarboxylic acid or its salt, the exfoliation ability of the unnecessary ore portion can be improved, and the silver plating portion which is not peeled off can be suppressed. After that, the glossiness of the silver-plated surface of the necessary portion is improved and the color of the pigment is produced. 3,5532 Correction 1247827 [Embodiment] (The best form of the invention) The silver electrolytic stripper composition of the present invention, Is the use of the following chemical constituents - the internal carbamide carbendazim, 3-hydroxyindole _5 [: not the carbendazim Salt of 5,5-methyl is preferred. Salt salts: urea, allantoin or such potassium salts are preferred.乙 醯 内醯urea h3c h3c 0’ 5, 5'

Η Ν ^>=0 曱 曱 乙 乙 h h h3c H3C 0s

Η Ν y=====^〇 ‘Ν’ h2n〇cnh, Η CHjOH 3-hydroxydecyl-5, 5-dimercapto-B

^=0 醯Urea Allantoin The concentration of these components in the electrolyte range is as high as that of Zhiqing L. When the concentration is too low, silver passivation is liable to occur; on the other hand, when the concentration is too small, the stripping agent (peeling liquid) has a problem that it is difficult to be ejected, and thus it is not good. 0 315 532 Revision 1247827 The main body of the silver electrolytic stripping agent of the present invention

Salt and bell salt are preferred. Nh2 HOOC - CH2-6h-C〇〇h Aspartic acid nh2

HOOCH3H2-CH2-0h-COOH Glutamine The concentration of these components in the electrolyte ranges from 1 to 5 〇〇g/L, preferably from 5 to 200 g/L. When the concentration is too low, the side peeling ability and the effect of suppressing the increase in color spots and gloss on the silver portion of the necessary portion are low; on the other hand, when the concentration is too high, the effect is not satisfactory. In the silver electrolytic stripper of the present invention, a pH buffer, a surfactant, a copper discoloration preventive agent, an epoxy anti-seepage agent, or the like may be added as necessary. Such pH buffers, surfactants, copper-blocking agents, epoxy barriers, and the like can be used by all of the above. Electrolytic stripping of silver was carried out under the specified conditions using the above-mentioned stripping agent. The release agent can be adjusted to have a pH of 7 or higher, preferably 9 to 12, by a pH adjusting agent such as an alkali metal hydroxide such as sodium hydroxide or an alkaline earth metal oxynitride. When the pH is too low, the peeling speed is slow, and it is easy to form a stain on the silver surface of a necessary portion after the portion is not subjected to the peeling treatment, and the peeling property is poorly selected. On the other hand, if the pH is too high, it is not good. Further, the present invention is based on copper, a copper alloy, a metal substrate such as an iron-nickel alloy such as a 4 2 alloy, a non-ferrous steel, a nickel alloy, or the like, which is silver plated, and 8 315 532 is used to modify the 1247827 silver. The formed silver film is a peeling object. The treated material on which the silver film is formed on the surface is impregnated in the electrolytic stripping (4) as described above, and the anode of the (4) treated material is electrolyzed. The cathode material is not particularly limited, but stainless steel is used. The maleity of the current is 〇] to 5〇Α/-2 with respect to the area of the stripped silver, preferably 〇5 to 20 A/dm2. If the current density is too low, the peeling speed is slow, and if the current density is too high, the silver is liable to cause passivation, which is not preferable. Further, the temperature of the electrolyte is preferably one or more, and it is preferable to carry out electricity at a temperature of 1 Torr to 峨. When the temperature of the electrolyte is too low, the peeling speed is slow. On the other hand, when the temperature is too high, the temperature is too high. In addition, it is preferable to carry out electrolysis in electrolysis:: Γ: good: when the current density is high... does not cause purification, and the degree of enlightenment is accelerated. 部分 Part of the silver-plated film of the treated object is stripped When the solution is peeled off, L privately applies masking to the silver film of the necessary part of the parent, J _, and performs a local impregnation method on the part to be peeled off. Moreover, if the film is thick, and the need is The part of the stripping is not the same. 2. If the disintegration treatment has no effect, the whole frame may be subjected to the impregnation and the lead frame is processed. The thickness of the film is reported, and the part of the wire is not partially electroplated, so that the necessary part of the silver part* is masked and directly carried out - ^, or only the part of the silver plated film can be peeled off. The present invention will be described in more detail in the following examples. 1 to 8, Comparative Example 〗 〖3 315532 Amendment 9 1247827, the peeling solution of the composition shown in Table 1, 1, Table 1-2 and Table 1-3. A wood ^ 'Use steel alloy substrate comprehensive Direct key copper 〇 · 〇 5 #瓜, and applied local mineral silver 5 # m of 28 _ s〇p type lead frame, impregnated in the above peeling

/ 合; The article is subjected to electrolytic stripping under the peeling conditions shown in Table 丨, 丨, 丨_2 and Table 1 _3. The sample after T peeling was evaluated as follows. • Silver appearance and appearance of the substrate surface · · 视 and _ micro mirror (X 5 0) to observe the color spots and shortcomings. If you do not see the color spots and shortcomings, it is good. • Silver gloss: Determined by gloss meter (Greater Japan screen DM-400). The larger the value, the more the glossiness is. The silver gloss before silver peeling was 0.40. • Silver peeling speed: The silver plating film thickness before and after silver peeling was measured by a fluorescent X-ray film thickness meter (Seiko Electronics Industry SFT-3200) to determine the silver peeling speed. • Side peeling ability: The side silver peeling state was observed by #U mirror (X 5 〇). The silver on the side is preferably the one to be stripped. The evaluation results are shown in Table, Table 1-2 and Table 1-3. 10 315532 Amendment, 1247827

Table Example 1 2 3 4 Main component 1 Intraquinoluridine dimercapto B 3-hydroxyindole-5,5-Allantoin 50 g/L guanidine 40 g/L Dimethyl carbendazim 30 g/L 20g/L main ingredient 2 sodium aspartate sodium aspartate sodium aspartate sodium aspartate 50g / L 60g / L 7〇g / L 80g / L electrolyte composition pH buffer - - return Boric acid 15g / L surfactant - - - Polycrystalline vinyl 壬 - - - 10mg / L copper color change agent - - - benzotriene - - - 〇 sitting 50mg / L epoxy anti-seepage agent - - - 16 burning Mercaptan - - - 50mg / L PH 10.5 10.5 10.5 10.5 Current density (A / dm2) 10.0 10.0 10.0 10.0 Stripping conditions Bath temperature (°C) 25 25 25 25 Stirring speed (m / s) 0.5 0.5 0.5 0.5 Time (8) 30 30 30 30 Silver appearance good and good Good good silver gloss 0.41 0.38 0.36 0.34 Good appearance of the substrate surface Good good evaluation results Silver peeling speed (μ, m/min) 1.8 1.9 1.7 1.6 Good side peeling ability Good good good good silver The silver gloss before peeling is 0.40 (the higher the value, the higher the gloss) 1] 315532 revision, 1247827

Example 5 5 7 8 Ingredients 1 Intraquinoluridine Dimethyl Bine 3-hydroxyindolyl-5,5-Allantoin 50g/L Urea urea 40g/L Dimercaptoindolizine 30g/ L 20g/L Principal component 2 Sodium glutamate Sodium glutamate Sodium glutamate sodium glutamate 50g/L 60g/L 7〇g/L 80g/L Electrolyte composition pH buffer - Boric acid 15g/L interface Active agent - - - Polyoxyethylene 壬 ** - - 10mg / L copper-proof color changing agent - - - 1,2,3-benzotriene - - - 〇 sitting 50mg / L epoxy anti-seepage agent - - • lauric acid - - - 50mg/L PH 10.5 10.5 10.5 10.5 Current density (A/dm2) 10.0 10.0 10.0 10.0 Peeling condition Bath temperature (°C) 25 25 25 25 Stirring speed (m/s) 0.5 0.5 0.5 0.5 Time (8) 30 30 30 30 Silver surface is good and good Good good silver gloss 0.42 0.38 0.37 0.35 Good appearance of substrate surface Good good good evaluation result Silver peeling speed (// m/min) 1.8 1.9 1.7 1.6 Good side peeling ability Good good good before silver peeling The silver surface gloss is 0.40 (the higher the value, the higher the gloss)] 2 315532 revision, 1247827

Comparative Example 1 2 3 Electrolyte Composition Main Component 1 Amber succinimide 100 g/L Dimethyl acetyl carbamide 100 g/L Sodium glutamate 100 g/L Main component 2 - - - pH buffer - - - Surfactant - - - Anti-copper discoloration agent - - - Epoxy anti-seepage agent - - - Peeling off condition PH 9.0 10.5 10.5 Current density (A/dm2) 10.0 10.0 10.0 Bath temperature (°C) 25 25 25 Stirring speed (m/ s) 0.5 0.5 0.5 time (8) 30 30 30 5 flat evaluation result silver surface appearance stain spot color good silver surface gloss 0.45 0.66 0.44 good appearance of substrate surface good bad silver peeling speed (// m/min) 1.7 1.9 0.4 side Poor peeling ability, poor silver gloss before peeling is 0.40 (the higher the value, the higher the gloss)

The silver electrolytic stripping agent of the present invention containing a uremium urea compound and an aminocarboxylic acid or a salt thereof as a main component has a long life, a high side peeling ability, and can suppress a silver stain of a necessary portion after silver peeling. Produced as well as elevated gloss. (There is no picture in this case) 13 3] 5532 amendment

Claims (1)

1247827 Pickup, patent application scope: • Silver electrolysis stripping composition, which is in the bath with a concentration range of 5 to 5 g/L, and an aminocarboxylic acid having the same concentration range of 1 to 500 g/L. Or its salt is the main component, and the pH is from 9 to 12. 2. If you apply for a patent range! The silver electroless stripping composition, wherein the aminocarboxylic acid monoamine dicarboxylic acid is used. 3. The composition for silver electrowinning of claim 1 or 2, wherein the above-mentioned carbendazim compound is urinyl urea, dimethyl eucommide, and ruthenium. _5,5_Dimercaptoin, allantoin or the salt as a main component, the above-mentioned amino acid or its salt is mainly aspartic acid, glutamic acid or the salt thereof Ingredients. 315532 Amendment 14