KR20200014763A - Multi-step etching method of resin surface and plating method for resin using the same - Google Patents

Abstract

In etching the surface of the resin, without swelling the resin,
The following steps (a) and (b),
(a) a step of treating with a solution containing an oxidizing agent and adsorbing the oxidizing agent on the resin surface
(b) activating an oxidant adsorbed on the resin surface in step (a)
The etching method of the resin surface characterized by setting it as 1 set and performing 2 or more sets of this provides the new technique which can be operated at industrial level as an etching technique of resin which does not use chromic acid.

Description

Multi-step etching method of resin surface and plating method for resin using the same

The present invention relates to a multistage etching method of a resin surface and a plating method for a resin using the same.

Conventionally, when metallization is performed on a plastic surface by plating, in order to improve the adhesiveness between the plastic surface and the plating film, an etching treatment for roughening the plastic surface with a mixture of chromic acid and sulfuric acid before plating treatment is performed. It is known to carry out.

However, in the said etching process, since it uses the hexavalent chromium which is harmful, it works at the high temperature of 60 degreeC or more, and there existed a problem that working environment worsened and attention was also required for the wastewater treatment.

Moreover, although the technique of etching a surface of a plastic using permanganic acid is reported recently (patent document 1), depending on the use conditions, permanganic acid may be rapidly decomposed, and there is a problem to use industrially. There was.

Thereafter, in order to suppress decomposition of the etching solution using the permanganic acid, the composition for etching treatment containing permanganic acid and a specific inorganic acid, and further, one component selected from halogenoxoacid, halogenoxolate, persulfate and bismuth salt. Although it is also reported (patent document 2), since the said component is used in large quantities, cost is high and it still had a problem to use this industrially.

In order to suppress decomposition of the etching solution using the permanganic acid, the resin is swollen with an aqueous dispersion or aqueous solution containing a specific organic compound, and then contacted with an aqueous solution containing permanganic acid, and further brought into contact with an aqueous solution containing an acid or the like. Although the technique is also reported (patent document 3), the swelling process is essential, the adhesiveness of the plating after etching, etc. may be low, and this also had a problem to use this industrially.

WO2005 / 094394 pamphlet Japanese Patent Publication No. 5177426 Japanese Unexamined Patent Publication No. 2007-100174

An object of the present invention is to provide a new technique that can be operated at an industrial level as an etching technique of a resin that does not use chromic acid.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, as a result, surprisingly, the etching process using the oxidizing agent of a resin was divided into two steps, and also iteratively performed, and sufficient resin surface was not carried out without performing a swelling process of resin. Since it can be etched, it discovered that high adhesiveness was obtained by plating subsequent to it, and completed this invention.

That is, the present invention does not swell the resin in etching the surface of the resin,

The following steps (a) and (b),

(a) a step of treating with a solution containing an oxidizing agent and adsorbing the oxidizing agent on the resin surface

(b) activating an oxidant adsorbed on the resin surface in step (a)

It is set as one set, and it implements two or more sets of this, The etching method of the resin surface characterized by the above-mentioned.

In addition, the present invention is a plating method for a resin characterized in that the resin is plated after the resin is etched by the etching method of the resin surface without performing a swelling step of the resin.

The etching method of the resin surface of this invention can suppress decomposition | disassembly of the oxidizing agent used for etching. Moreover, although the etching method of the resin surface of this invention repeats an etching process, it can etch efficiently in a short time rather than performing an etching process for a long time in one step. In addition, the etching method of the resin surface of this invention can fully etch a resin surface, and does not need to perform the swelling process of resin conventionally required.

Therefore, when the resin is plated after the etching method, a plated product that can withstand high adhesiveness, particularly a severe heat shock test, can be obtained.

The etching method (henceforth "the present invention method") of the resin surface of this invention makes the following process (a) and (b) one set, and implements this two or more sets. Moreover, even if a sufficient number of sets cannot be etched, increasing the number of sets enables sufficient etching.

(a) a step of treating with a solution containing an oxidizing agent and adsorbing the oxidizing agent on the resin surface

(b) activating an oxidant adsorbed on the resin surface in step (a)

In addition, before performing the method of the present invention, the resin may be subjected to treatment such as degreasing, front face, and the like. However, the swelling step for making it easier to etch the resin is not performed. You may perform water washing and hot water appropriately before and after the process of degreasing, a front surface, etc.

Although it does not restrict | limit especially as resin which can be processed with the etching liquid of this invention, For example, acrylonitrile butadiene styrene (ABS), polycarbonate / acrylonitrile butadiene styrene (PC / ABS), acryl Ronitrile styrene acrylate (ASA), silicone composite rubber-acrylonitrile-styrene (SAS), noryl, polypropylene, polycarbonate (PC), acrylonitrile styrene, polyacetate, polystyrene, polyamide, aromatic Polyamide, polyethylene, polyether ketone, polyethylene terephthalate, polybutyrene terephthalate, polysulfone, polyether ether sulfone, polyetherimide, modified polyphenylene ether, polyphenylene sulfide, polyamide, polyimide, epoxy resin The liquid crystal polymer etc., the copolymer of each said polymer, etc. are mentioned. Among these resins, ABS and PC / ABS are particularly preferable. Moreover, the shape of resin is not specifically limited, either.

The oxidizing agent used in the step (a) of the method of the present invention is not particularly limited. For example, permanganate such as potassium permanganate and sodium permanganate, manganese sulfate, manganese nitrate, manganese carbonate, manganese chloride, manganese acetate, manganese dioxide And manganese salts such as sodium manganate and potassium manganate. Especially among these oxidizing agents, permanganate is preferable. Moreover, these oxidizing agents can use 1 type (s) or 2 or more types.

The solution containing the said oxidizing agent is what melt | dissolved the said oxidizing agent in solvent, such as water, for example. Although content of the oxidizing agent in this solution is not specifically limited, For example, it is 0.0005 mol / L or more, Preferably it is 0.005-2.0 mol / L.

In addition, the solution containing the oxidizing agent may contain a pH buffer or a surfactant in an amount that the pH buffer or the surfactant exhibits performance, so long as the oxidation action of the solution is not inhibited. Moreover, pH of the solution containing the said oxidizing agent is not specifically limited, pH 3.0-10.0 are preferable.

Although it does not specifically limit as a pH buffer, For example, a phosphate, a citrate, a borate, a carbonate, an acetate, a diethyl barbiturate, a tris hydroxymethyl amino methane, hydroxyethyl piperazine ethane sulfonic acid, ethylenediamine 4 Acetic acid etc. are mentioned. These pH buffers can use 1 type (s) or 2 or more types.

Although it does not specifically limit as surfactant, For example, an amine salt type surfactant, a quaternary amine salt type surfactant, an amino acid type surfactant, a betaine type surfactant, a carboxylate type surfactant, sulfonate type surfactant, sulfuric acid Ester salt type surfactant, phosphate ester salt type surfactant, ether type surfactant, ester type surfactant, nitrogen-containing surfactant, fluorine-containing surfactant, etc. are mentioned. These surfactant can use 1 type (s) or 2 or more types. By using a surfactant, the coating power of plating can be improved.

The method of treating the resin with the solution containing the oxidant and adsorbing the oxidant on the surface of the resin is not particularly limited. For example, the resin may only be immersed in the solution containing the oxidant. The conditions for immersing the resin are not particularly limited, for example, the resin may be immersed for 30 seconds or more, preferably 1 to 5 minutes, in a solution of 0 to 100 ° C, preferably 60 to 70 ° C.

After making an oxidizing agent adsorb | suck to a resin surface in a process (a), you may wash with water as needed. Thereafter, the oxidizing agent adsorbed on the resin surface is activated in the step (b).

The method of activating an oxidizing agent is not specifically limited, For example, the solution containing 1 type, or 2 or more types of activators chosen from the group which consists of an inorganic acid, an organic acid, hydrogen peroxide, a halogenoxo acid, a halogenoxolate, and a persulfate salt It only needs to be immersed in resin.

Among the activators, examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and hydrofluoric acid. Examples of the organic acid include acetic acid, methanesulfonic acid, and the like. Examples of the halogen oxoates include potassium perchlorate, sodium periodate, perbromic acid, and the like, and persulfates include, for example, sodium peroxo sulfate and ammonium peroxo sulfate. have. Among these activators, hydrogen peroxide, phosphoric acid and sulfuric acid are preferred. These activators are, for example, a solution dissolved in a solvent such as water. Although content of the activator in this solution is not specifically limited, For example, it is 0.05 mol / L or more, Preferably it is 0.5-17 mol / L.

Moreover, you may contain surfactant in the quantity containing the said activator unless the activating effect of this solution is impaired, in the quantity which surfactant performs. Although it does not specifically limit as surfactant, For example, an amine salt type surfactant, a quaternary amine salt type surfactant, an amino acid type surfactant, a betaine type surfactant, a carboxylate type surfactant, sulfonate type surfactant, sulfuric acid Ester salt type surfactant, phosphate ester salt type surfactant, ether type surfactant, ester type surfactant, nitrogen-containing surfactant, fluorine-containing surfactant, etc. are mentioned. These surfactant can use 1 type (s) or 2 or more types. By using a surfactant, the coating power of plating can be improved.

The method of activating the oxidizing agent adsorbed on the resin surface is not specifically limited, For example, when using the solution containing an activator, it is 0-100 degreeC, More preferably, it is 60-70 degreeC In the solution, the resin may be immersed for 30 seconds or more, more preferably 1 to 5 minutes.

Although the above process (a) and (b) become one set, after this process (b), you may perform neutralization, a reduction process, a conditioner process, etc. as needed. Moreover, 30 second or more is preferable respectively, and, as for process (a) and (b), 1 to 5 minutes are more preferable.

The resin surface can be etched by the method of the present invention described above. Moreover, the method of this invention can be used for the etching of the resin surface in the plating method with respect to a conventionally well-known resin, The other process can use the plating method with respect to a conventionally well-known resin.

As a plating method with respect to conventionally well-known resin, an electroless plating method, the direct plating method, etc. are mentioned, for example.

Hereinafter, the plating method with respect to resin using the method of this invention is demonstrated.

The resin etched by the method of the present invention then provides a catalyst with the catalyst imparting treatment liquid. The catalyzing treatment liquid is not particularly limited as long as it is generally used for catalyzing the plating step, but preferably contains a noble metal, more preferably contains palladium, and particularly preferably a palladium / tin mixed colloidal catalyst solution. Do. In order to provide these catalysts to the resin surface, the liquid temperature of a catalyst application process liquid is 10-60 degreeC, Preferably it is 20-50 degreeC, Resin is immersed there for 1 to 20 minutes, Preferably it is 2 to 5 minutes, You can do it.

The resin surface to which the catalyst was provided in this way next metalizes the resin surface by metal plating, such as electroless metal plating and electrometal plating (direct plating).

When electroless metal plating is used for metallization of a resin surface, after providing a catalyst with a catalyst provision process liquid, you may further process with the activation process liquid containing hydrochloric acid or a sulfuric acid. The concentration of hydrochloric acid or sulfuric acid in this activation treatment liquid is 0.5 mol / L or more, preferably 1-4 mol / L. To treat the resin surface with these activation treatment liquids, the liquid temperature of the activation treatment liquid is 0 to 60 ° C, preferably 30 to 45 ° C, and the resin is immersed therein for 1 to 20 minutes, preferably 2 to 5 minutes. You can do it.

The resin subjected to the provision and activation treatment of the catalyst as described above is then subjected to an electroless metal plating treatment. An electroless metal plating process can be performed according to a conventional method using electroless metal plating, such as a well-known electroless nickel plating liquid, an electroless copper plating liquid, an electroless cobalt plating liquid, and the like. Specifically, when plating the resin surface with an electroless nickel plating solution, the resin may be immersed for 5 to 15 minutes in an electroless nickel plating solution having a pH of 8 to 10 and a liquid temperature of 30 to 50 ° C.

In addition, in the case of using an electrometal plating (direct plating) for metallization of the resin surface, after the catalyst is imparted with the catalyzing treatment liquid, pH 7 or more, preferably pH 12 or more, containing copper ions is further included. You may process with an activation process liquid. The origin of the copper ion contained in this activation process liquid is not restrict | limited, For example, copper sulfate is mentioned. To treat the resin surface with the activation treatment liquid, the liquid temperature of the activation treatment liquid is 0 to 60 ° C, preferably 30 to 50 ° C, and the resin is immersed therein for 1 to 20 minutes, preferably 2 to 5 minutes for treatment. Just do it.

The resin subjected to the provision and activation of the catalyst as described above is then immersed in a general-purpose electric copper plating bath such as a copper sulfate bath, and then subjected to normal conditions, for example, 1 to 5 A / dm 2 for 2 to 10 minutes. You can do it.

In addition, as described above, the surface of the resin is subjected to metal plating such as electroless plating or electrometal plating, and the metallized plastic surface is further subjected to various electric copper plating, electric nickel plating, and electrochromium plating according to the purpose. It is also possible.

In addition, after performing the method of the present invention, water washing or hot water may be performed between the respective steps.

The resin plating obtained in this way has high adhesiveness.

Example

An Example and a comparative example are shown to the following, and this invention is demonstrated more concretely. However, this invention is not limited at all by these descriptions.

Example 1

<Formation of Electroless Nickel Plating>

As a sample, a test piece of 300 x 100 x 3 mm ABS resin (3001M: manufactured by UMGABS Corporation) was used. This sample was immersed in 60 degreeC degreasing washing | cleaning liquid PC-1 and PC-2 (made by JCU Corporation) for 10 minutes, and then to the 50 degreeC front liquid containing 10 ml / L of ENILEX WE (made by JCU Corporation). Soak for 10 minutes.

The sample subjected to degreasing and front side was processed in the etching process of Table 1, and also it was immersed in the 25 degreeC conditioner (catalyst addition enhancement) treatment solution D-POP CDV (made by JCU Corporation) for 1 minute.

In addition, the etching liquid used at the etching process of Table 1 is as follows.

Chromic Acid Etching (Prior Method)

 Chromic anhydride: 3.8 mol / l

 Sulfuric acid: 3.8 mol / l

 68 ℃ liquid temperature

Invention method

 Process (a)

  Potassium permanganate: 0.3 mol / l

  Fluorine-containing surfactant MISTSHUT PF (manufactured by JCU Co., Ltd.): 2 ml / ℓ

  Boric acid / 4 sodium borate buffer: 10 ml / ℓ

  68 ° C, pH 6.5

 Process (b)

  Sulfuric acid: 10 mol / l

  Fluorine-containing surfactant MISTSHUT PF (manufactured by JCU Co., Ltd.): 2 ml / ℓ

  68 degrees C, pH 1.0 or less

Next, it was immersed for 4 minutes in 35 degreeC palladium / tin mixed colloidal catalyst solution containing 20 mL / L CT-580 (made by JCU Co., Ltd.) and 2.5 mol / L hydrochloric acid, and a catalyst was provided on ABS resin. It was. The catalyst-impregnated sample was immersed in an activated treatment solution at 35 ° C. made of 1.2 mol / L hydrochloric acid for 4 minutes to activate the catalyst, followed by electroless nickel plating solution ENILEX NI-100 (JCU Co., Ltd.) at pH 8.8 and 35 ° C. (Manufacture)) was immersed for 10 minutes, and electroless nickel plating was performed so that a film thickness might be set to 0.5 micrometer on ABS resin.

<Measurement of Peel Strength and Sample Preparation Method> (JIS H8630 Annex 6)

The sample subjected to electroless nickel plating was sufficiently washed with water or hot water, and then immersed in an acid active solution V-345 (manufactured by JCU Co., Ltd.) at room temperature for 1 minute. Next, according to JIS H8630 Annex 6, copper sulfate plating EP-30 (made by JCU Corporation) was implemented so that a film thickness might be set to 20 micrometers. Then, this was annealed at 70 degreeC for 1 hour, and adhesive strength was measured by the tensile strength tester AGS-H500N (made by Shimadzu Corporation).

<Heat shock test and sample production method>

The sample subjected to electroless nickel plating was sufficiently washed with water or hot water, and then immersed in an acid active solution V-345 (manufactured by JCU Co., Ltd.) at room temperature for 1 minute. Next, copper sulfate plating CU-BRITE EP-30 (made by JCU Corporation) was implemented so that a film thickness might be set to 20 micrometers by the electroplating method. Further, semi-gloss nickel plating CF-24T (manufactured by JCU Co., Ltd.) was carried out so that the film thickness was 10 μm, and polished nickel plating # 88 (manufactured by JCU Co., Ltd.) was further provided so that the film thickness was 10 μm. Microporous nickel plating MP-309 (made by JCU Corporation) was performed so that a film thickness might be set to 1 micrometer. Finally, gloss chrome plating EBACHROM E-300 (manufactured by JCU Co., Ltd.) was applied so that the film thickness was 0.2 µm, and each plating film was formed sequentially. Then, this was annealed at 70 degreeC for 1 hour.

The heat shock test of 40 cycles (cyc) and 80 cycles was performed using the process which hold | maintains the said sample 30 minutes at -30 degreeC, and 30 minutes at 70 degreeC as 1 cycle. (Circle) and that expansion generate | occur | produce the thing which expansion does not generate | occur | produce in a plating film were evaluated as x.

<Result>

In the case of chromic acid etching of the conventional method, although adhesiveness improves by extending processing time, it turned out that adhesiveness does not improve even if the etching process of the method of this invention simply extends processing time. It was found that the adhesiveness is improved by repeating the etching step even with a short treatment time. Moreover, also in the implementation method 1, by performing 5 sets of process (a) and (b), the more severe 80-cycle heat shock test became (circle).

Example 2

In Example 1 of Example 1, the pH of the etching liquid used in a process (a) was set as Table 2, and it carried out similarly to Example 1 except having used the thing of Table 3 as pH buffer according to the pH. Electroless nickel plating was performed. In addition, sodium hydroxide and sulfuric acid were used for adjustment of pH. Moreover, electroless nickel plating was carried out similarly to Example 1, and the peel strength measurement and the heat shock test were done. The results are shown in Table 2.

In the method of this invention, there was no problem in any pH.

Example 3

In Example 1 of Example 1, electroless nickel plating was carried out in the same manner as in Example 1 except that the pH buffer was removed from the liquid used in the steps (a) and (b). This electroless nickel plating was carried out similarly to Example 1, and the peel strength measurement and the heat shock test were performed, and it was the same result as Example 1.

Example 4

In the implementation method 1 of Example 1, the process (a) and the test piece (3001M: UMGABS Corporation make) of the three-dimensional shape (the shape which air collects) of 50x180x3 mm ABS resin was used as a sample, and Except for using the surfactant of Table 4 for the liquid used by (b), it carried out similarly to Example 1, and electroless nickel plating was performed. The appearance of the electroless nickel plating was visually evaluated. The results are shown in Table 4.

In the method of the present invention, the three-dimensional resin was plated in a small number of times by using a surfactant.

Industrial availability

Since the surface of a resin can be etched by the method of this invention, it can be used for the plating method with respect to conventionally well-known resin.

Claims (6)

In etching the resin surface, the resin swelling step is not performed.
The following steps (a) and (b),
(a) Process of treating with solution containing oxidant and adsorbing oxidant on resin surface
(b) step of activating an oxidant adsorbed on the resin surface in step (a)
It is set as 1 set, and this is performed 2 or more sets, The etching method of the resin surface characterized by the above-mentioned. The method of claim 1,
The method of etching the resin surface whose processes (a) and (b) are 30 second or more, respectively. The method of claim 1,
The etching method of the resin surface whose oxidizing agent used at a process (a) is permanganic acid or its salts. The method of claim 1,
In the step (b), the activation of the oxidizing agent is carried out by treating the oxidizing agent with a solution containing one or two or more kinds of activators selected from the group consisting of inorganic acids, organic acids, hydrogen peroxide, halogenoxoacids, halogenoxolates and persulfates. The etching method of the resin surface. The method of claim 1,
The activation of the oxidant in step (b) is selected from the group consisting of sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, methanesulfonic acid, hydrogen peroxide, peroxo bisulfate, periodioic acid, perchloric acid and perbromic acid. The etching method of the resin surface which is performed by processing with the solution to contain. In plating resin, after resin is etched by the etching method of the resin surface in any one of Claims 1-5, without performing a swelling process of resin, plating is carried out to resin characterized by the above-mentioned. For plating method.