JPH0639712B2 - Method for producing surface metallized thermoplastic polyester resin molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for surface metallizing a thermoplastic polyester resin molded article by plating. More specifically, the present invention relates to a method for producing a surface metallized thermoplastic polyester resin molded article having a good adhesive property to a plated film and a good surface appearance.

<Prior art> Generally, the plastic plating treatment is (1) pretreatment, (2) roughening treatment (etching), (3) sensitization treatment (sensitizing) or catalyst treatment, and (4) activation treatment ( It is carried out by sequentially passing through each step of (Activating) or acceleration treatment, (5) electroless plating and (6) electrical plating, and the above (3) step and thereafter are usually called plating steps. Above all, the roughening treatment (2) is an important step that influences the adhesion of the metal plating film applied in the subsequent plating step, and various means are used depending on the type of plastic.

As a means for roughening the surface of a thermoplastic polyester resin for plating, for example, a method in which a polyester resin containing a filler in advance is roughened with an alkaline solution and then plated (JP-A-54-15977), glass fiber,
A method of roughening a surface of a calcium carbonate-reinforced polyester resin with an alkali hydroxide solution containing an oxidizing agent and then plating the same (Japanese Patent Laid-Open No. 53-6374), in which the glass fiber-reinforced polyester resin is immersed in an aqueous nitric acid solution. Then, a method of immersing in an aqueous solution of alkali hydroxide and roughening after roughening (JP-A-53-6376), a method of treating a resin film with an alkaline solution, and then treating with a chromic acid mixed solution, and then plating (Japanese Patent Laid-open No. Sho-63-376) No. 58-149924) is known, but in some of these methods, the adhesiveness of the plating film is slightly improved, but it does not reach a substantially effective level, and a glittering appearance of the plating is obtained. Therefore, it is impossible to obtain a surface metallized thermoplastic polyester resin molded article which is practically excellent.

<Problems to be Solved by the Invention> The object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to practically provide a metallized film with excellent adhesion and surface appearance, especially surface metallization excellent in brilliance. It is to provide a thermoplastic polyester resin molded product.

<Means and Actions for Solving Problems> According to the studies by the present inventors, a molded article of a thermoplastic polyester containing a powdery filler is treated with an acidic chromic acid solution and then with an alkaline solution. It has been found that the problems to be solved by the present invention can be solved by applying a plating treatment after the application to roughen the surface.

That is, in the present invention, a molded article of a thermoplastic polyester resin composition containing 5 to 250 parts by weight of a powdered filler is treated with an acidic chromic acid solution and then with an alkaline solution with respect to 100 parts by weight of the thermoplastic polyester. Is a surface metallized thermoplastic polyester resin molded article characterized by performing a plating treatment after roughening the surface, and as a particularly preferred embodiment, in this manufacturing method, a powdered filler The present invention provides a method for producing a surface metallized thermoplastic polyester resin molded article using one or more selected from titanium dioxide, aluminum oxide, calcium metasilicate, mica, talc and calcium carbonate.

The thermoplastic polyester used in the present invention is usually 9
A polymer obtained by polycondensing a dicarboxylic acid component having a terephthalic acid component of 0 mol% or more and a diol component is used.

The terephthalic acid component as used herein is terephthalic acid and its ester-forming derivative, and other dicarboxylic acid components used together with the terephthalic acid component are isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 1, 5-naphthalenedicarboxylic acid, bis (P
-Carboxyphenyl) methaneanthracene dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, aromatic dicarboxylic acid such as 5-sodium sulfoisophthalic acid , Adipic acid, sebacic acid, azelaic acid, dodecanedioic acid and other aliphatic dicarboxylic acids, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids and their ester-forming derivatives, etc. Is mentioned. As the diol component, an aliphatic glycol having 2 to 20 carbon atoms, that is, ethylene glycol, propylene glycol, 1,4-butanediol,
Neopentyl glycol, 1,5-pentanediol, 1,6
-Hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, etc.,
And their ester-forming derivatives.

Preferred specific examples of these polymers or copolymers are polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / terephthalate /
Decanedicarboxylate), polyethylene terephthalate, polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate),
Polybutylene (terephthalate / 5-sodium sulfoisophthalate), polyethylene (terephthalate / 5)
-Sodium isophthalate) and the like. Polybutylene terephthalate, polybutylene (terephthalate / adipate),
Polybutylene (terephthalate / decanedicarboxylate), polyethylene terephthalate, polyethylene (terephthalate / adipate), polybutylene (terephthalate / 5-sodium sulfoisophthalate) and the like are particularly preferably used. These thermoplastic polyesters were prepared by adding 0.5% o-chlorophenol solution at 25 ° C.
Relative viscosity is 1.2 to 2.0, especially 1.3 to 1.8
Those in the range of 5 are preferable.

Moreover, these can be used in mixture of 2 or more types.

The powdery filler used in the present invention is a filler having a form such as granular, needle-like, flaky, plate-like, and titanium dioxide, aluminum oxide, calcium metasilicate, mica, talc, calcium carbonate, sulfuric acid. Barium, stone stove,
Examples thereof include zirconium oxide, antimony trioxide, clay, silica, potassium titanate, sericite, magnesium oxide, kaolin, diatomaceous earth, magnesium carbonate, feldspar, vermiculite, carbon black, glass beads, shirasu balloon and siloid. Of these, titanium dioxide, aluminum oxide, calcium metasilicate,
Mica, talc and calcium carbonate are preferably used, and titanium dioxide, aluminum oxide and mica are particularly preferably used.

You may use these powdered fillers in mixture of 2 or more types.

The amount of the powdered filler added is 5 to 250 parts by weight based on 100 parts by weight of the thermoplastic polyester.
0 parts by weight is preferred. If it is less than 5 parts by weight, the effect of improving the adhesiveness of the plating film is insufficient. If it exceeds 250 parts by weight, the surface roughness of the molded article becomes too large, and on the contrary, the adhesive strength of the plating film and the glitter of the plating are lost, and the mechanical properties of the thermoplastic polyester resin itself are deteriorated, which is not preferable.

Further, a fibrous reinforcing agent such as glass fiber or carbon fiber is added in an amount of 0.4 to 100 with respect to 100 parts by weight of the thermoplastic polyester.
It can be used together with the powdered filler in the range of parts by weight.

Also, other additives such as aluminum stearate,
Lubricants such as barium stearate, mold release agents such as montan wax, wax metal montanate and the like, plasticizers, heat stabilizers, UV absorbers, pigments, dyes, and other thermoplastic resins can be added.

The blending means of the thermoplastic polyester of the present invention and the powdered filler and other additives is not particularly limited, but for example, a raw material obtained by blending the thermoplastic polyester, the powdered filler and other additives together is a screw type extruder. Supply to
A method such as melt extrusion mixing can be adopted.

As the thermoplastic polyester resin composition molded article of the present invention, any resin molded article such as an injection molded article, an extrusion molded article, and a blow molded article can be adopted.

In producing a surface metallized molded article by the method of the present invention, which influences the adhesiveness of the plating film and the brilliance of the plating, the rough surface treatment step is a treatment with an acidic chromic acid solution, and then a rough treatment with an alkaline solution. It is important to surface.

Although the principle that the adhesive force of the plating film is dramatically improved by passing through these steps is not clear, the acidic chromic acid solution selectively permeates the interface between the filler and the thermoplastic polyester, and Swell
When the polyester is subsequently hydrolyzed in an alkaline solution, this swollen part is hydrolyzed faster than others,
It is presumed that the filler is likely to be released, and unevenness with a deep bottom and excellent anchor effect is formed on the surface of the molded product.

On the other hand, when the surface is roughened only with the alkaline solution, the above-mentioned dipping selectivity does not occur, so that it is considered that the detachment of the filler is slow and only unevenness with a shallow bottom is obtained, so that the adhesive force to the plated film cannot be sufficiently obtained.

The acidic chromic acid solution of the present invention is an acidic oxidizing solution containing a chromium compound having a valence of 6 as a main component, sulfuric acid and water as the main components, and optionally other mineral acids.

The composition of the solution is 0.02 to 50% by weight of a hexavalent chromium compound, 10 to 99.95% by weight of sulfuric acid, 0 to 97% by weight of water, and 0 to 50% by weight of other mineral acids, and particularly chromium of a hexavalent value. Compound 0.2 to 20% by weight, sulfuric acid 20 to 98.8% by weight, water 0 to
80% by weight is preferably used.

Examples of the hexavalent chromium compound include chromium trioxide, chromate salts (eg potassium chromate, sodium chromate etc.), dichromate salts (eg potassium dichromate, sodium dichromate etc.) and the like. it can. Chromium trioxide, potassium dichromate and sodium dichromate can be preferably used.

Examples of other mineral acids include phosphoric acid and nitric acid.

The treatment conditions with the acidic chromic acid solution of the present invention are 5 to 95.
It is preferable to immerse the molded article in the acidic chromic acid solution at a temperature of 0.25 to 60 minutes, particularly 40 to 90 ° C.
The immersion treatment is optimally performed within the range of 1 to 40 minutes.

It is then desirable to wash with water.

The alkaline solution of the present invention is an alkaline component such as potassium hydroxide, sodium hydroxide or magnesium hydroxide,
It is a solution dissolved in a solvent such as water, phenols, alcohols or the like, or a mixed solvent thereof at a concentration of 5 to 50% by weight, in particular, an aqueous solution of 10 to 40% by weight of sodium hydroxide and / or potassium hydroxide. It is preferably used.

If necessary, a surfactant or the like can be added.

The treatment conditions with the alkaline solution of the present invention are preferably such that the molded product is immersed in the alkaline solution at 5 to 95 ° C. for 1 to 120 minutes, particularly at 40 to 90 ° C. and 2 to 60 minutes.
It is desirable to perform the immersion treatment within the range of minutes.

Next, it is desirable to wash thoroughly.

The treatment with the acidic chromic acid solution and the treatment with the alkaline solution are roughening treatments for improving the adhesive force of the plating film without losing the glitter property of the plating, and it is necessary to perform them in this order. The purpose of the present invention cannot be achieved by processing in the reverse order or only one of them.

After the treatment with the alkaline solution is completed, the molded article may be sufficiently washed with water, and then further surface-treated with an acidic aqueous solution having a pH of 3 or less. Mineral acids such as sulfuric acid and hydrochloric acid are used as the acid component in this case, and the treatment conditions are preferably 5 to 70 ° C. and 2 to 60 minutes.

By subjecting the resin molded product subjected to the rough surface treatment to the ordinary plating treatment subsequently, it is possible to obtain a surface metallized thermoplastic polyester resin molded product having a remarkably excellent adhesion property of the plating film and good surface brilliance. .

The plating treatment is also performed, for example, by sensitizing with a stannous chloride solution-activating with a palladium chloride solution-electroless copper or nickel plating-electric plating process or by catalyzing-accelerating-electroless plating-electric plating process. The conventional chemical plating method consisting of can be applied.

The surface metallized thermoplastic polyester resin molded article of the present invention has excellent heat resistance, mechanical properties, adhesiveness to the plating film, and surface glitter, and thus is useful as various automobile parts, electric parts and mechanical parts.

The effects of the present invention will be further described with reference to examples.

<Examples 1 to 14, Comparative Examples 1 to 13> Polybutylene terephthalate 1 having a relative viscosity of 1.57 when a 0.5% orthochlorophenol solution was measured at 25 ° C.
65 parts by weight of the filler shown in Table 2 was mixed with 100 parts by weight, and melt-kneaded with an extruder having a 65 mmφ screw set at 250 ° C. to form a pellet. Then, the pellets thus obtained were subjected to a 5 ounce injection molding machine set at 250 ° C., and a disk molded product of 100φ × 3 mm was molded under the condition of a mold temperature of 80 ° C. to obtain a test piece.

Then, this test piece was subjected to a plating treatment by the following method including treatment with the acidic chromic acid solution and the alkaline solution shown in Table 1.

The adhesive strength of the plating film is 10 mm wide and 20 mm long for the plating film of the test piece that has been subjected to the above (9) electrical plating (bright copper plating).
It was evaluated by measuring the force (g) at the time of T-peeling over mm.

The glitter test of the plating was evaluated by (11) visually observing the gloss of the test piece subjected to the electrical plating (chrome plating).

The results are shown in Table 2.

As is clear from the results shown in Table 2, the surface metallized thermoplastic polyester resin molded article of the present invention is superior in mating adhesive strength and glitter of the mating article in comparison with the mating article prepared by the conventional method.

<Effects of the Invention> The surface metallized thermoplastic polyester resin molded product obtained by the method of the present invention has excellent adhesive strength to a plated film and bright surface gloss.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location C25D 5/56 B (56) Reference JP-A-54-28370 (JP, A) JP-A-53-6376 ( JP, A) JP 58-149924 (JP, A) JP 46-38884 (JP, B1) JP 53-19628 (JP, B2)

Claims (2)

[Claims] 1. A molded article of a thermoplastic polyester resin composition containing 100 parts by weight of a thermoplastic polyester and 5 to 250 parts by weight of a powdery filler is treated with an acidic chromic acid solution and then with an alkaline solution. A method for producing a surface-metallized thermoplastic polyester resin molded article, which comprises subjecting to roughening to give a rough surface, and then performing a plating treatment. 2. The surface metallized thermoplastic polyester resin according to claim 1, wherein the powdery filler is one or more selected from titanium dioxide, aluminum oxide, calcium metasilicate, mica, talc and calcium carbonate. Molded article manufacturing method.