JPS61253370A - Production of surface-metallized thermoplastic polyester resin molding - Google Patents

Abstract

PURPOSE:To obtain the titled molding having the excellent adhesive power of a plating film and the thermal cycling characteristic of plating by subjecting the molding formed by adding a specific ratio of filler to a thermoplastic polyester to a heat treatment at a specific temp. then to a surface roughening treatment with an acidic chromic acid soln. and alkaline soln. followed by plating. CONSTITUTION:The compsn. formed by incorporating 5-250pts.wt. filler such as titanium dioxide into 100pts.wt. thermoplastic polyester obtd. by the comdensation polymn. of dicarboxylic acid component in which about >=90mol% is a terephthalic acid component and diol component is molded. Such molding is heat-treated in an atmosphere kept at 70-170 deg.C and is then treated at about 5-95 deg.C with the acidic chromic acid soln. consisting essentially of a hexavalent chromium compd., sulfuric acid and water and thereafter the molding is treated at about 5-95 deg.C with the alkaline soln. such as sodium hydroxide, by which the surface thereof is roughened. The molding subjected to the surface roughening is plated and the surface-metallized molding having excellent surface brightness is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> 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 that has excellent plating film adhesion and plating thermal cycleability, and has a good surface appearance.

<Conventional technology> Plastic plating generally involves (1) pretreatment, (2)
) roughening treatment (etching), (31 sensitizing treatment (sensitizing) or catalyst treatment, (4)
It is performed by sequentially repeating the steps of activation treatment (activation) or acceleration treatment, (5) electroless plating, and (6) electroplating, and the steps after the above (3) are usually called the plating process. It is. Among them, the above (
The surface roughening treatment (2) is an important process that affects the adhesion of the metal plating film applied in the subsequent plating process, and various means are used depending on the temperature of the plastic.

As a means for roughening the surface in plating thermoplastic polyester resin, for example, a method of roughening a polyester resin containing a filler in advance with an alkaline solution and plating it (Japanese Patent Application Laid-open No. 15977/1983), glass fiber, etc.
A method of roughening a polyester resin reinforced with calcium carbonate with an alkaline hydroxide solution containing an oxidizing agent and then plating it (Japanese Patent Application Laid-Open No. 1983-6374), a method in which a polyester resin reinforced with glass mIa is immersed in an aqueous nitric acid solution. , a method in which the surface is roughened by immersing it in an aqueous alkali hydroxide solution and then plated (Japanese Unexamined Patent Publication No. 53-6376); a method in which a resin film is treated with an alkaline solution, then treated with a chromic acid mixture and then plated (Japanese Patent Application Laid-Open No. 1986) 58-149924)
However, although these methods improve the adhesion of the plating film to some extent, they do not reach a substantially effective level, and they do not provide the brightness of the plating appearance, making it difficult to achieve practical results. Surface metallized thermoplastic polyester resin molded articles cannot be obtained.

<Problems to be Solved by the Invention> An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to practically improve the adhesion of the plating film and the plating thermal cyclability, and to improve the surface appearance, especially the brightness. The purpose of the present invention is to provide a thermoplastic polyester resin molded product with excellent surface metallization.

Means and operation for solving the problems> According to the studies of the present inventors, molded articles of thermoplastic polyester containing fillers were heat-treated in an atmosphere of 70 to 170°C and then treated with an acidic chromic acid solution. It has been found that the problems to be solved by the present invention can be solved by roughening the surface by roughening the surface by processing with .

That is, the present invention provides a molded article of a thermoplastic polyester resin composition containing 5 to 250 parts by weight of a filler per 100 parts by weight of thermoplastic polyester.
A method for producing a surface metallized thermoplastic polyester resin molded article, which comprises heat treatment in an atmosphere of 70°C, followed by treatment with an acidic chromic acid solution, followed by treatment with an alkaline solution to roughen the surface, and then plating. Also, as a particularly preferred embodiment, there is (7) Production method 1c, in which one or more selected from titanium dioxide, aluminum oxide, calcium metasilicate, mica, talc, calcium carbonate, and glass W4 fiber is used as a filler. The present invention provides a method for producing a surface metallized thermoplastic polyester resin molded article.

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

The cocoteiuterephthalic acid component is terephthalic acid and its ester-forming derivatives, and the other cycarphonic acid components used together with the terephthalic acid component are isophthalic acid and orthophthalic acid (orthophthalic acid). H12,6-naphthalenedicarboxylic acid, 1.5-naphthalenedicarboxylic acid, bis(P-carboxyphenyl)methaneanthracenedicarboxylic acid, 4.4'-diphenyldicarboxylic acid, 1.2
- Bis(phenoxy)ethane-4,4'-dicarboxylic acid, aromatic dicarboxylic acids such as 5-sodium sulfoisophthalic acid, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1.3 -Cyclohexanedicarboxylic acid (1?, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and ester-forming derivatives thereof, etc.).As the diol component, aliphatic glycols having 2 to 2o carbon atoms, i.e., ethylene glycol, propylene glycol,
1,4-butanediol, neopentyl glycol,
Examples include 1,5-bentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexane dimetatool, cyclohexanediol, and ester-forming derivatives thereof.

Preferred examples of A-forms of these polymers or copolymers include polybutylene terephthalate, polybutylene (terephthalate/isophthalate), polybutylene (terephthalate/adipate), polybutylene (terephthalate/cephalic acid), and polybutylene (terephthalate/decanedicarboxylate). ), polyethylene terephthalate, polyethylene (terephthalate/isophthalate), polyethylene (terephthalate/adipate),
Polybutylene (terephthalate 15-sodium sulfoisophthalate), polyethylene (terephthalate 15-sodium sulfoisophthalate)
-sodium isophthalate), etc.; polybutylene terephthalate, polybutylene (terephthalate/adipate), polybutylene (terephthalate/adipate),
Polybutylene (terephthalate/decane dicarboxylate), polyethylene terephthalate, polyethylene (
Particularly preferably used are terephthalate/7dipate), polybutylene (terephthalate 15-sodium sulfoisophthalate), and the like. In addition, these thermoplastic polyesters were prepared by adding a 0.5% O-chlorophenol solution at 25°C.
Relative viscosity when measured at L2~2.0, especially 13
-L85 is preferable.

Moreover, these can be used in combination of two or more types.

The fillers used in the present invention are fillers having shapes such as granules, needles, flakes, plates, and fibers, such as titanium dioxide, aluminum oxide, calcium metasilicate, mica, talc, calcium carbonate, Barium sulfate, gypsum, zirconium oxide, antimony dioxide, clay, silica, sericite, magnesium oxide, kaolin, diatomaceous earth, magnesium carbonate, feldspar, vermiculite, carbon black,
Glass peas, shirasu balloons, thyroids and glass fibers, carbon fibers, ceramics IIM, gypsum fibers,
Examples include potash titanate whiskers. Among these, titanium dioxide, aluminum oxide, calcium metasilicate, mica, talc, calcium carbonate, and glass fiber are preferably used, and titanium dioxide, aluminum oxide, mica, and glass fiber are particularly preferably used.

Two or more of these fillers may be used in combination.

The amount of filler added is required to be 5 to 250 parts by weight, preferably 30 to 100 parts by weight, per 100 parts by weight of the thermoplastic polyester. At 5 parts by weight at rice temperature, the effect of improving the adhesion of the plating film is insufficient. If it exceeds 250 parts by weight, the surface roughness of the molded product will become too large, and conversely, the adhesion of the plating film will decrease.
This is not preferable because the plating loses its luster and the mechanical properties of the thermoplastic polyester resin itself deteriorate.

The method of blending the thermoplastic polyester of the present invention with fillers and other additives is not particularly limited. It is possible to adopt a method such as supplying the liquid to a liquid and melting and extruding the mixture.

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, a blow molded article, etc. can be adopted.

The heat treatment of the present invention is to heat-treat the molded product obtained as described above, which can greatly improve the mechanical properties and thermal properties of the plated product. It has the effect of greatly improving thermal cyclability.

The heat treatment conditions include a heat treatment temperature of 70 to 170°C, preferably 90 to 150°C, and a heat treatment time of 1
It is suitable to carry out the treatment for 0 minutes to 10 hours, preferably 30 minutes to 5 hours. i.e. less than 703°C or 1
If it is less than 0 minutes, the effect of the present invention will be insufficient, and if it is 170° C. or more or more than 10 hours, the mechanical properties or thermal properties of the plated product will deteriorate, making it difficult to achieve the object of the present invention.

This heat treatment is carried out by placing the molded product in a heating device adjusted to a predetermined temperature and heating it for a predetermined period of time. There are no particular restrictions on the type of heating device, but an electric heating oven is usually convenient; As for the atmosphere inside,
For example, a hot air circulation type, a hot air circulation type, etc. can be used.

In addition, in the present invention, one or more specific thermoplastic resins selected from aliphatic dicarboxylic acid copolymerized polyesters, polyester elastomers, and glycidyl group-containing olefin copolymers may be added to the thermoplastic polyester and filler of the present invention. For example, it is possible to further improve the mechanical properties and thermal properties of the plated product of the present invention.

The amount of thermoplastic resin of 1 m or more selected from these aliphatic dicarboxylic acid copolyesters, polyester elastomers, and glycidyl group-containing olefin copolymers is 0.5% by weight based on 100% by weight of the thermoplastic polyester. -80% by weight, preferably 5-50% by weight.

The aliphatic dicarboxylic acid copolyester herein is a copolymer consisting of a dicarboxylic acid and a diol component, of which 10 to 50 mol%, preferably 15 to 40 mol%, is an aliphatic dicarboxylic acid component.

Specific examples of these copolymers include polybutylene (terephthalate/adipate), polybutylene (terephthalate/separate), and polybutylene (terephthalate/adipate).
Examples include decane dicarboxylate), polybutylene (terephthalate/isophthalate/tebacate), polybutylene (terephthalate/isophthalate/decane dicarboxylate), polyethylene (terephthalate/adipate), and polyethylene (terephthalate/sepacate).

In addition, aliphatic dicarboxylic acid copolyester is 0.5
% O-chlorophenol solution when measured at 25°C has a relative viscosity of 12-2. Especially preferred is Ol in the range of 13 to L85.

Moreover, these can be used in combination of two or more types.

The polyester elastomer used in the present invention refers to a polyether ester block copolymer, a polyester/ester block copolymer, a polyester block copolymer, and a polyester block copolymer having polyester as a hard segment and poly(alkylene oxide) glycol and/or aliphatic polyester as a soft segment. It is an ester/ester block copolymer.

The aromatic polyester constituting the hard segment is a polymer obtained by condensation polymerization of a dicarboxylic acid component of which 60 mol % or more is a terephthalic acid component and a diol component. Dicarboxylic acid components other than terephthalic acid and diol components are the same as in the case of the thermoplastic polyester, and therefore will not be described here.

Preferred examples of the aromatic polyester include polyethylene terephthalate, polyethylene terephthalate, polyethylene (terephthalate/isophthalate)% polybutylene (terephthalate/isophthalate), and the like.

In addition, as specific examples of poly(alkylene oxide) glycol and aliphatic polyester that constitute the soft segment, polyethylene glycol, poly(alkylene oxide)
, 2- and 1,3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, copolymers of ethylene oxide and tetrahydrofuran, polyethylene adipate, polybutylene adipate, poly-C-caprolactone Preferred examples include polyethylene sepacate, polybutylene sepacate, and the like.

The weight ratio of the soft segment to the polyester 7X-do segment of the polyester elastomer is 9.
It is preferably from 515 to 10/90, particularly from 90/10 to 30/70.

Specific examples of polyester elastomers include polyethylene terephthalate and poly(tetramethylene oxide).
Glycol block copolymer, polyethylene terephthalate/isophthalate/poly(tetramethylene oxide) glycol block copolymer, polybutylene terephthalate/poly(tetramethylene oxide) glycol block copolymer, polybutylene terephthalate/isophthalate/poly(tetra methylene oxide) glycol block copolymer, polybutylene terephthalate/decanedicarboxylate/poly(tetramethylene oxide) glycol block copolymer, polybutylene terephthalate/poly(propylene oxide/ethylene oxide) glycol block copolymer, polybutylene Terephthalate/Isophthalate poly(propylene oxide/
(ethylene oxide) glycol block copolymer, polybutylene terephthalate/decane dicarboxylate,
Poly(propylene oxide/ethylene oxide) glycol block copolymer, polybutylene terephthalate
Poly(ethylene oxide) glycol block copolymer, polybutylene terephthalate/polyethylene adipate block copolymer, polybutylene terephthalate/polybutylene adipate block copolymer, polybutylene terephthalate/l-liptylene sebacate block copolymer, polybutylene terephthalate - Poly-C-caprolactone block copolymer etc. are preferably mentioned.

Among these polyester elastomers, especially polybutylene terephthalate and poly(tetramethylene oxide)
Glycol block copolymer, polybutylene terephthalate/isophthalate/#lJ (tetramethylene oxide) glycol block copolymer, polybutylene terephthalate/pri(propylene oxide/ethylene oxide) glycol block copolymer, polybutylene terephthalate/isophthalate/ Poly(propylene oxide/ethylene oxide) glycol block copolymer, polybutylene terephthalate/polybutylene adipate block copolymer, polybutylene terephthalate/poly-
A C-caprolactone block copolymer is preferably used because it has a large effect of improving the physical properties of plated products of the polyester resin composition.

Also said thermoplastic of these polyester elastomers? The relative viscosity measured in the same way as the real ester was 14-40.
Particularly suitable is one in the L6 to 3.0 range.

Two or more of these polyester elastomers can be used in combination.

The glycidyl group-containing olefin copolymer used in the present invention includes 50 to 99.5% by weight of a-olefin and α, β-
It is a copolymer consisting of 50 to 0.5% by weight of glycidyl ester of unsaturated carboxylic acid and θ to 49.5% of vinyl acetate. The α-olefins herein include ethylene, propylene, butene-1, etc., and ethylene is preferably used. In addition, glycidyl ester of a,β-unsaturated carboxylic acid is a compound represented by the general formula (R in the formula represents a hydrogen atom or a lower alkyl group), and specifically, glycidyl acrylate, glycidyl methacrylate, glycidyl Examples include methacrylate, among which glycidyl methacrylate is preferably used.

a in an olefin copolymer having a glycidyl group
The copolymerization amount of glycidyl ester of β-unsaturated carboxylic acid is suitably 0.5 to 50% by weight, and 1 to 20% by weight, and if it is less than 0.5% by weight, the effects of the present invention cannot be obtained. However, a 50-fold star shape or more is not preferable because the composition tends to gel during melt mixing.

Specific examples of the olefin copolymer having a glycidyl group include ethylene/glycidyl methacrylate copolymer and ethylene/glycidyl methacrylate/vinyl acetate copolymer. These can be used in combination of two or more types.

When using a glycidyl group-containing olefin copolymer, organic sulfonic acid metal salts such as sodium dodecylbenzene sulfonate and sodium dodecyl sulfonate, and alcohol sulfate ester salts such as lauryl sulfate sodium salt should be used. etc. can be added in small amounts.

Also, other additives, such as aluminum stearate,
Lubricants such as barium stearate, release agents such as montan wax, montan acid wax metal salts, plasticizers, heat stabilizers, ultraviolet absorbers, pigments, dyes, etc., and other thermoplastic resins, etc. can be added. .

The acidic chromic acid solution of the present invention is an acidic oxidizing solution whose main components are a hexavalent chromium compound, sulfuric acid, and water, and optionally contain other mineral acids.

The composition of the solution is 0.02 to 5 chromium compounds with a valence of 6
0% by weight, 10-99.95% by weight of sulfuric acid, 0-97% by weight of water, 0-50% by weight of other mineral acids, especially 0.2-20% by weight of hexavalent chromium compounds, 20% by weight of sulfuric acid. ~98.8
% by weight, 0 to 80% by weight of water is preferably used.

Examples of hexavalent chromium compounds include chromium dioxide, chromates (e.g., potassium chromate, sodium chromate, etc.), dichromates (e.g., potassium dichromate, sodium dichromate, etc.). . Chromium dioxide, potassium dichromate, and sodium dichromate can be preferably used.

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

In addition, 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.
It is optimal to carry out the immersion treatment at a temperature in the range of 1 to 40 minutes.

It is then desirable to wash with water.

The alkaline solution of the present invention is prepared by adding an alkaline component such as potassium hydroxide, sodium hydroxide, or magnesium hydroxide to a solvent such as water, phenols, or alcohols, or a mixed solvent thereof to a concentration of 5 to 50% by weight. Among them, an aqueous solution containing 10 to 40% by weight of sodium hydroxide and/or potassium hydroxide is preferably used.

Further, a surfactant or the like may be added if necessary.

Furthermore, the processing conditions for 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°C.
It is desirable that the immersion treatment be carried out for a period of minutes.

It is then desirable to wash thoroughly.

The treatment with an acidic chromic acid solution and the treatment with an alkaline solution are surface roughening treatments that improve the adhesion of the plating film without losing its brightness, and it is necessary to perform them in this order. The object of the present invention cannot be achieved by processing in the reverse order or by processing only one of them.

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

By subjecting the resin molded product that has been surface-roughened in this way to subsequent plating treatment, it is possible to obtain a surface-metallized thermoplastic polyester resin molded product that has significantly superior plating film adhesion and good surface brightness. .

The plating process can also include, for example, sensitizing with a stannous chloride solution - activating with a palladium chloride solution - electroless copper or nickel plating - each step of electroplating or catalytic staining - accelerating - each step of electroless Metsky electroplating. A conventional chemical plating method can be applied.

The surface metallized thermoplastic polyester resin molded product of the present invention has excellent heat resistance, mechanical properties, metal film adhesion, and surface brightness, and is therefore useful as various automobile parts, 1-gas parts, and mechanical parts. .

The effects of the present invention will be further explained below with reference to Examples.

In addition, each abbreviation in an Example means the following.

PBT: Polybutylene terephthalate PBT/D:
Polybutylene (terephthalate/decanedicarboxylate) (Terephthalic acid component/decanedicarboxylic acid component copolymerization molar ratio = 80/20) E/GMA: Ethylene/glycidyl methacrylate copolymer (copolymerization weight ratio 90/10) PBT-PTMG :Polybutylene terephthalate poly(tetramethylene oxide) glycol block copolymer (soft segment//X-dosegment weight ratio 4 swords/
60) Examples 1 to 15, Comparative Examples 1 to 6 Polybutylene terephthalate having a relative viscosity of L57 when a 0.54 orthochlorophenol solution was measured at 25°C and aliphatic dicarboxylic acid copolymerized polyester shown in Table 2 , to 1001 parts of thermoplastic polyester in which a polyester elastomer and a glycidyl group-containing olefin copolymer were blended in the proportions shown in Table 2, fillers shown in Table 2 were further blended in the proportions shown in Table 2, The mixture was melt-kneaded and pelletized using an extruder equipped with a 65Wφ screw set at 250°C. Then, the obtained pellets were
A test piece was obtained by molding a 100φ x 3W disk molded product using a 5-ounce injection molding machine set at 50°C and a mold temperature of 80°C.The test piece was then heat treated as shown in Table 2. Thereafter, plating treatment was performed by the method shown below, including treatment with an acidic chromic acid solution and an alkaline solution, as shown in Table 1.

Treatment process Treatment bath Treatment conditions Yone Okuno Pharmaceutical Co., Ltd. Rip's plating The adhesive strength of the chemical plating film is (9) Electroplating (bright copper plating)! Evaluation was made by measuring the strength it (f) of the plated film of test piece A applied in 101EI width and 20 lengths when T-peeled.

In the thermal cycling test of plating, a test piece that had been subjected to electroplating (11) (chrome plating) was treated under the following conditions, and three cycles of 0100°C (lhr) to -30°C (lhl) were performed.

After performing ■■, continue to 130℃ (lhr) - 30'C
(1 hr) for 3 cycles.

After performing ■■, continue to 150℃ (lhr) - 40'C
(1 hr) for 3 cycles.

After performing ■■, continue to 150℃ (lhr) - 40'C
(lhr) was carried out for 3 cycles.

After completion of (1), (2), and (2), the appearance was visually inspected to determine whether there were any abnormalities (blister, flaking, cracks, etc.) on the plating surface.

These results are shown in Table 2.

As is clear from the results shown in Tables 1 and 2, the surface-metallized polyester molded product of the present invention has superior plated thermal cycle properties compared to plated products produced by conventional methods.

<Effects of the Invention> The surface-metallized thermoplastic polyester resin molded product obtained by the method of the present invention has excellent plating film adhesion and plating thermal cyclability.

Claims (2)

[Claims] (1) A molded article of a thermoplastic polyester resin composition containing 5 to 250 parts by weight of a filler per 100 parts by weight of thermoplastic polyester is heat treated in an atmosphere of 70 to 170°C and then treated with an acidic chromic acid solution. A method for producing a surface-metallized thermoplastic polyester resin molded article, which comprises the steps of: - roughening the surface by treating it with an alkaline solution; and then subjecting it to plating treatment. (2) Surface metallized thermoplastic polyester resin molding according to claim 1, wherein the filler is one or more selected from titanium dioxide, aluminum oxide, calcium metasilicate, mica, talc, calcium carbonate, and glass fiber. method of manufacturing the product.