METHOD FOR PREPARING METAL-POLYMER RESIN COMPOSITE

Abstract

The present disclosure relates to a method for preparing a metal-polymer resin composite with excellent bonding strength and bonding uniformity. The method includes a pretreatment step (S1) of etching a metal member, an electrolysis process step (S2) of forming an adhesive coating layer on a surface of the pretreated metal member, a drying step (S3) of drying the metal member with the adhesive coating layer formed on the surface, and an injection-molding process step (S4) of bonding a polymer resin to the dried metal member, and the electrolysis process is performed in an electrolyte solution containing a sulfur-containing compound and a metal chelate compound.

Claims

1. A method for preparing a metal-polymer resin composite, the method comprising: a pretreatment step (S1) of etching a metal member, which is one or more selected from a group consisting of copper, a copper clad, and a copper alloy; an electrolysis process step (S2) of forming an adhesive coating layer on a surface of the pretreated metal member; a drying step (S3) of drying the metal member with the adhesive coating layer formed on the surface; and an injection-molding process step (S4) of bonding a polymer resin to the dried metal member, wherein the electrolysis process is performed in an electrolyte solution containing a sulfur-containing compound and a metal chelate compound, and wherein the injection-molding process step (S4) is performed by preheating the metal member to an injection-molding temperature and then directly injection-molding the polymer resin onto the preheated metal member.

2. The method of claim 1, wherein the electrolyte solution is prepared by adding and mixing the sulfur-containing compound and the metal chelate compound to and with distilled water.

3. The method of claim 1, wherein the electrolyte solution is prepared by mixing 5 g to 500 g of the sulfur-containing compound and 1 g to 100 g of the metal chelate compound for each 1L of distilled water.

4. The method of claim 1, wherein the sulfur-containing compound is one or more selected from sulfuric acid, ammonium sulfate, and sodium sulfate.

5. The method of claim 1, wherein the metal chelate compound is one or more selected from a group consisting of copper ethylenediaminetetraacetate (EDTA-Cu), disodium copper ethylenediaminetetraacetate (EDTA-2NaCu), and diammonium copper ethylenediaminetetraacetate (EDTA-Cu (NH.sub.4).sub.2).

6. The method of claim 1, wherein the electrolyte solution further contains one or more copper organic compounds selected from a group consisting of cupric chloride, copper (II) trifluoroacetate hydrate, cupric hydroxide, cupric carbonate, and copper oxide.

7. The method of claim 1, wherein the electrolysis process (S2) is performed by immersing the metal member in the electrolyte solution and performing electrolysis at a temperature in a range from 15 C. to 80 C. for 60 seconds to 3600 seconds at a constant voltage in a range from 0.1V to 50V.

8. The method of claim 1, wherein the pretreatment step (S1) is performed by sequentially performing a degreasing process step (S1-1), an etching process step (S1-2), and a desmut step (S1-3).

9. The method of claim 8, wherein the etching process step (S1-2) is performed by immersing the metal member in an etching solution at a temperature in a range from 15 C. to 80 C. for 30 seconds to 300 seconds.

10. The method of claim 9, wherein the etching solution is a mixed solution of 5 g to 500 g of strong acid and 5 g to 200 g of hydrogen peroxide for each 1 L of distilled water.

11. The method of claim 8, wherein the desmut step (S1-3) is performed via immersing the metal member in an alkaline aqueous solution; or via immersing the metal member in the alkaline aqueous solution and performing an ultrasonic treatment, wherein the immersing is performed at a temperature in a range from 15 C. to 80 C. for 30 seconds to 300 seconds.

12. The method of claim 11, wherein the alkaline aqueous solution is a mixed solution of 5 g to 200 g of at least one selected from alkali metal hydroxide and alkaline earth metal hydroxide for each 1 L of distilled water.

13. The method of claim 1, wherein the metal member is washed with hot water before the drying in the drying step (S3).

14. The method of claim 13, wherein the hot water washing is performed using distilled water at a temperature in a range from 15 C. to 100 C.

15. The method of claim 1, wherein the polymer resin is one or more selected from a group consisting of polybutylene terephthalate, polyphenylene sulfide, polyphthalamide, polyethylene terephthalate, polycarbonate, polypropylene, polyimide, polyethylene, liquid crystal polymer, polyether ether ketone, polyaryl ether ketone, polyamide, polyamide6, and polyamide66.

Description

EXAMPLES

[0073] Hereinafter, the present disclosure will be described in more detail via present examples. However, following present examples are intended to illustrate the present disclosure and do not limit the scope of the present disclosure.

Example 1

[0074] Twenty specimens were prepared by processing a 3 mm-thick copper metal member (C1100) into a size of 40123 mm. An additional hole of 4 mm in size was machined into each of the previously prepared specimens such that each specimen is able to be mounted on a rack during bonding. The specimens were mounted on the rack using the machined holes. The rack on which the prepared specimens are mounted was put into alcohol and then ultrasonic degreasing was performed for 60 seconds to remove oil and impurities from surfaces of the specimens. The specimens washed above were etched by being put in a mixture of sulfuric acid (20% by weight) and hydrogen peroxide (20% by weight) in distilled water (50 C.) in a bubble stirrer for 5 minutes, then immersed in a desmut solution (sodium hydroxide 5% aqueous solution), and then ultrasonic-cleaned to remove impurities and smut. The washed specimens were put into an electrolyte solution, a mixture of sulfuric acid (10% by weight) and EDTA-2NaCu (3% by weight) in distilled water (60 C.) and electrolyzed at a constant voltage of 5V for 1200 seconds to form a coating layer. Thereafter, the specimens were hot water-washed with distilled water at 80 C. and then dried with a hot air dryer at 120 C. for 1200 seconds.

[0075] Thereafter, copper-resin composites were prepared by injection-molding polyphenylene sulfide (PPS, SABIC) onto the 20 specimens. As an injection-molding machine, a 15-ton injection-molding machine from Daekyung Hydraulics Co. was used, and the injection-molding was performed by setting an injection-molding temperature to 170 C., a nozzle temperature to 300 C., an injection-molding pressure to 70 bar, and a hold pressure to 5 seconds. In this regard, the specimens were preheated such that a temperature of the specimens before the injection-molding becomes similar to the injection-molding temperature. Of a total of the 20 specimens, 10 were used for a tensile strength test and the remaining 10 were used for an airtightness test.

Example 2

[0076] A copper-resin composite was prepared in the same manner as Example 1, except that the hot water washing was not performed as in Present Example 1.

Example 3

[0077] A copper-resin composite was prepared in the same manner as Example 1, except that the specimen preheating before the injection-molding was not performed.

Comparative Example 1

[0078] A copper-resin composite was prepared in the same manner as Example 1, except that a mixture of sulfuric acid (10% by weight) in distilled water (60 C.) was used as the electrolyte solution during the electrolysis process in Example 1.

Comparative Example 2

[0079] A copper-resin composite was prepared in the same manner as Example 1, except that the etching process was not performed in Example 1.

Comparative Example 3

[0080] A copper-resin composite was prepared in the same manner as Example 1, except that the electrolysis process was not performed in Example 1.

Experimental Example

[0081] Bonding strengths (tensile strengths) and airtightness of the copper-resin composites prepared in Present Examples and Comparative Examples were subjected to comparative analysis, and results are shown in Table 1 below.

(1) Bonding Strength (Tensile Strength)

[0082] Using a tensile tester (UTM, Time Group), the tensile strengths at a time point when copper and resin are separated from each other were measured via pulling at a speed of 5 mm/min. The same experiment was repeated 10 times and the results are expressed as average values.

(2) Airtightness

[0083] To identify the bonding uniformity, amounts of helium leakage at an interface were measured using a helium leakage test equipment (Canon ANELVA). When the helium leakage amount is equal to or smaller than 10.sup.8Pa.Math.m.sup.3/s, the bonding uniformity is marked as good, and when the helium leakage amount exceeds 10.sup.8Pa.Math.m.sup.3/s, the bonding uniformity is marked as bad. As for the airtightness test, the same experiment was also repeated on the 10 specimens to identify the number of defects.

TABLE-US-00001 TABLE 1 Tensile Airtightness strength (units) Division (MPa) Pass Fail Example 1 46.04 10 0 Example 2 43.22 8 2 Example 3 43.67 6 4 Comparative 41.31 2 8 Example 1 Comparative 39.39 5 5 Example 2 Comparative 25.36 0 10 Example 3

[0084] As shown in Table 1, it was identified that the copper-resin composites of Example 1 to Example 3 were superior to Comparative Example 1 to Comparative Example 3 in both the bonding strength and the airtightness. It was identified that, in the case of the copper-resin composite of Comparative Example 1 prepared in the same manner as Example 1 except that the electrolyte solution that does not contain the metal chelate compound was used during the electrolysis process, and the copper-resin composite of Comparative Example 2 prepared in the same manner as Example 1 except that the etching process was not performed, the tensile strengths were significantly reduced to 90% and 85% and the airtightness was also significantly reduced, compared to Present Example 1.

[0085] In addition, it was identified that, in a case of Comparative Example 3, both the tensile strength and the airtightness were poor, with the tensile strength being half that of Example 1 and a passing rate for the airtightness being 0%. In this regard, Comparative Example 3 was prepared under the same conditions as Example 1, except that the electrolysis process was not performed.

[0086] Accordingly, it was identified that the method for preparing the metal-polymer resin composite including the pretreatment step, the electrolysis process step, the drying step, and the injection-molding process step is effective in preparing the metal-resin conjugate with the excellent bonding strength and bonding uniformity.

[0087] On the other hand, Example 2 and Example 3 showed tensile strength and airtightness decreased by about 6% and 5% compared to those of Example 1. In this regard, Example 2 and Example 3 were subjected to the same other processes as Example 1, but were not subjected to the hot water washing before the drying (Example 2) or were not subjected to the specimen preheating during the injection-molding process (Example 3).

[0088] With the above results, it was identified that, in terms

[0089] of obtaining the metal-polymer resin composite with more excellent bonding strength and bonding uniformity, it may be advantageous to further include the hot water washing and metal member preheating steps in the method for preparing the metal-polymer resin composite of the present disclosure.

[0090] The method for preparing the metal-polymer resin composite according to the present disclosure may prepare the metal-polymer resin composite with the excellent bonding strength and bonding uniformity (airtightness).

[0091] Hereinabove, although the present disclosure has been described with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.