JPS6130032B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for obtaining a plated molded product of polyolefin resin by modifying the surface of polyolefin resin to enable electroless metal plating.

Conventionally known resins for metal plating include polypropylene, polycarbonate vinyl chloride, and carbon fiber-containing FRP, which are not suitable for metal plating on polyethylene. Plating grade polypropylene is commercially available, and the composition used is one in which an inorganic filler with a particle size of about 0.1 to 10 μm is added and kneaded in a range of 10 to 40 wt%. Furthermore, at present, general-use polypropylene is subjected to special treatment and metal plating is performed. This process is shown below.

Degreasing - Pre-etching - Etching - Sensitizing - Activating - Metal plating In this process, pre-etching is a special treatment for general polypropylene, and specifically, stirring is performed in xylene at 70°C. this is,
At the same time as eluting the amorphous portion and low molecular weight substances of polypropylene, xylene has the effect of swelling the polypropylene and promoting the next etching. This method has no problems when the polypropylene is in the form of pellets, but when it is made into a film or molded product, this effect causes softening and waving phenomena, resulting in changes in dimensions, film thickness, and other quality issues. This becomes a fatal flaw.

Furthermore, as mentioned above, there is currently no metal plating method for polyethylene.

Furthermore, in conventional metal plating, it is said that it is better to make the surface to be plated porous, and the above-mentioned plating resin (polypropylene, vinyl chloride) is filled with a filler. This is to etch the filler to make the surface porous and promote metal plating. In this case, no special handling is required.

In the present invention, a metal-plated thermoplastic resin could be obtained by a method different from that described above. Specifically, maleic anhydride is graft-polymerized onto the surface of a polyolefin such as polyethylene or polypropylene and its copolymer resin, and then electroless plating is performed.

That is, the present invention is characterized in that electroless plating is applied to a modified polyolefin having a polar group on its surface. For example, when such a polyethylene resin is used, it is possible to apply metal plating to polyethylene, which was previously impossible. In addition, polypropylene resin can be bonded without special treatment.
Quality defects such as dimensional changes and film thickness changes due to special treatment of general-use polypropylene are improved, and unlike filler-containing polypropylene, etching acceleration treatment is not required, and metal plating can be performed using a general metal plating method. In general, regarding the adhesion of metal plating,
When the plated surface is etched, the plated metal enters the recessed area and the metal acts as an anchor and has adhesion, while primary or secondary bonding between the functional group appearing by etching and the plated metal occurs. According to the present invention, since the polyethylene or polypropylene resin has a polar group, the primary or secondary bonding effect generated at the interface is stronger than in conventional methods. Therefore, it is thought that metal plating becomes possible without special treatment. More specifically, when graft polymerizing the surface of a polyolefin molded article with maleic anhydride, ketone peroxide, diallyl peroxide, hydroperoxide, etc. are used as an organic radical generator.
These organic radical generators are used in polyethylene or polypropylene molded products at a concentration of 0.01 to 1.5.
Suitably, it is added in weight percent. Also,
Maleic anhydride is preferably reacted in an amount of 1 to 5 percent by weight based on the polyolefin molded article.

According to the manufacturing method of the present invention as described above, the adhesive strength between the base material and the plating layer can be generally satisfied, that is, at least about 2 to 3 kg/25 mm (peel strength measured by a tensile tester). this is,
This means that a plating layer with strong adhesive strength can be applied to a polyolefin resin without requiring any special pretreatment or intermediate layer, which is extremely useful. Furthermore, since it does not cause any dimensional changes to the base material, it is excellent as a plating method for already molded base materials. According to the present invention, the shape of the base material to be plated is not limited to film or plate shape, but may be any shape such as container shape or bottle shape as long as the surface can be contacted with maleic anhydride. Even in the case of a laminate or a combination of a polyolefin resin and another resin, a plating layer can be applied to the surface of the polyolefin resin. The present invention is also extremely excellent in that it is now possible to electrolessly plate polyethylene molded products, which have conventionally been difficult to plate.

Examples will be described below.

Example 1 A polyethylene film (65μ thick) was immersed in pure water 4 maintained at 90°C, 0.06g of benzoyl peroxide was added thereto, held at 85°C for 35 hours, and then 0.2g of maleic anhydride was added. In addition, 85℃,
After holding for 35 hours, the graft polymerization process is stopped by washing with pure water. These treated polyethylene films are treated with the conventional catalyst accelerator method, i.e. chromium trioxide 1140.
~1170g/, 60% in etching solution of sulfuric acid 50c.c./
℃ for 5 minutes, pulled out, drained the etching solution thoroughly, washed with water, then immersed in 10% hydrochloric acid for 1 minute, palladium chloride 1g/, stannous chloride 20
After soaking in a solution of 100 c.c./g/, hydrochloric acid for 3 minutes, washing with deionized water and further soaking in a 10% sulfuric acid solution for 2 minutes.
The catalyst was applied by a method of immersion for minutes to activate it. After washing this with deionized water, it was immersed in an electroless nickel plating bath having the following composition for 10 minutes, and a precipitate of metallic nickel was obtained.

Nickel chloride 20g/bath temperature 45℃ Sodium citrate 40g/PH 8.5 Sodium hypophosphite 10g/ Ammonium chloride 40g/ The plating thickness in this case was 0.6μ.

After chemical plating, electric nickel plating (20μ
When the peel strength was measured using a tensile tester, the strength was 2.4 kg/25 mm, which was satisfactory.

Example 2 A polyethylene film graft-polymerized with maleic anhydride in the same manner as in Example 1 was used as a base material, and this base material was treated with 1140 g of chromium trioxide and 50 g of sulfuric acid.
The sample was immersed in an etching solution of 1.5 g/g for 5 minutes at 60°C, pulled out, thoroughly drained, and thoroughly washed with water.
The sensor was then immersed in a solution of 30 g of stannous chloride and 15 ml of hydrochloric acid for 2 minutes, washed with deionized water, and then activated by immersed in a solution of 0.2 g of palladium chloride and 3 ml of hydrochloric acid for 2 minutes. A catalyst was applied using a tizer activator method. After these treatments, the sample was washed with deionized water and immersed in the same electroless nickel plating bath as in Example 1 for 10 minutes, resulting in a metal nickel precipitate with good adhesion.

Example 3 A polyethylene film graft-polymerized in the same manner as in Example 1 was coated with a catalyst using the same sensitizer activator method as in Example 2. After washing this with deionized water, it was immersed in an electroless copper plating bath having the following composition for 10 minutes.

Copper sulfate 35g/Rotussel salt 170g/sodium hydroxide 50g/sodium carbonate 30g/EDTA 20ml/formalin 37% by weight A copper precipitate was thus obtained on a polyethylene film, and electrolytic copper plating was further applied to a thickness of 20μ. When the peel strength of this plated copper layer was measured by a tensile test, a value of 2.3 kg/25 mm was obtained, which was extremely good.

Example 4 A polyethylene film subjected to graft polymerization as in Example 1 was coated with a catalyst using the sensitizer activator method as in Example 2. After washing with deionized water, the sample was immersed in an electroless copper plating bath having the same composition as in Example 3 for 10 minutes to obtain a metallic copper plating composition with good adhesion to the substrate.

Example 5 A polypropylene film (50μ) was immersed in pure water 4 maintained at 90°C, 0.05g of benzoyl peroxide was added thereto, held at 85°C for 3.5 hours, then 0.2g of maleic anhydride was added, After further holding at ℃ for 3.5 hours, the graft polymerization process was stopped by washing with pure water. As in Example 1, a catalyst was applied to the polypropylene film subjected to these treatments using a catalyst accelerator method. After washing with deionized water, the sample was immersed in an electroless nickel plating bath having the same composition as in Example 1 for 10 minutes to obtain a metallic nickel deposit with excellent adhesion to the substrate.

Example 6 A polypropylene film that had been subjected to graft polymerization in the same manner as in Example 5 was coated with a catalyst using the sensitizer activator method as in Example 5. After washing with deionized water, an electroless nickel plating bath having the same composition as in Example 1 was applied. When immersed in water for 10 minutes, metallic nickel was deposited which had good adhesion to the substrate.

Example 7 A polypropylene film subjected to graft polymerization in the same manner as in Example 5 was coated with a catalyst using the catalyst accelerator method as in Example 1. Thereafter, after washing with deionized water, the sample was immersed in an electroless copper plating bath having the same composition as in Example 3 for 10 minutes, and a metallic copper precipitate having good adhesion to the substrate was obtained.

Example 8 A polypropylene film subjected to graft polymerization in the same manner as in Example 5 was coated with a catalyst using the sensitizer activator method as in Example 2. Thereafter, after washing with deionized water, the sample was immersed in an electroless copper plating bath having the same composition as in Example 3 for 10 minutes to obtain a metallic copper precipitate with good adhesion to the substrate.

Example 9 A two-layer bottle having an outer layer made of graft-polymerized polyethylene based on Example 1 and an inner layer made of polyethylene was used as a base material for plating, and a catalyst was deposited using the sensitizer activator method as in Example 2.
After washing this with deionized water, it was immersed in an electroless nickel plating bath having the same composition as in Example 1 for 10 minutes, resulting in a metallic nickel precipitate that adhered well to the outer layer.

Example 10 Based on Example 1, graft polymerized polypropylene was used as the outer layer and polypropylene was used as the inner layer 2
The layer bottle was used as a base material for plating. After washing this with deionized water, a catalyst was deposited using the sensitizer activator method as in Example 2. After washing this with deionized water, it was immersed for 10 minutes in an electroless copper plating bath having the same composition as in Example 3, resulting in a metallic copper precipitate that adhered well to the outer layer.

Claims (1)

[Claims] 1. A method for producing a polyolefin resin-plated molded article, which involves graft polymerizing maleic anhydride on the surface of a polyolefin resin molded article molded from a polyolefin resin as a raw material, and then subjecting it to electroless plating.