JPH0454743B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for metallizing the surface of a polyester resin molded article by plating.
More specifically, the present invention relates to a method for producing a surface-metallized polyester resin molded article that has excellent plating film adhesion, thermal cycleability, and brightness of the plated metal, and also has good mechanical properties of the plated product. Generally, plastic plating treatment involves (1) pretreatment;
(2) Surface roughening treatment (etching), (3) Sensitizing treatment (4) Activation treatment (5) Electroless plating and (6) Electroplating steps The process from step (3) above is usually called the plating process. Among these, the surface roughening treatment (2) above is an important step that affects 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 thermoplastic polyester resin in plating, for example, a method is known in which a filler is preliminarily added to a polyester resin and then subjected to surface roughening treatment (Japanese Patent Laid-Open No. 15977/1983).
However, although these conventional methods slightly improve the adhesion of the plating film on polyester resin-plated products, the thermal cycleability, plating brightness, and mechanical properties of the plating products are significantly inferior. It was not possible to obtain a resin molded product. Therefore, the present inventors aimed to obtain a surface-metallized polyester resin molded product that has excellent mechanical properties such as impact resistance, and also has excellent plating film adhesion, thermal cycling properties, and plating brightness. As a result of extensive studies, it was discovered that the above object can be effectively achieved by roughening the surface of a molded article made of a thermoplastic polyester, a glycidyl group-containing olefin copolymer, and titanium dioxide with an alkaline solution, and then plating it.The present invention has been made. reached. That is, the present invention uses thermoplastic polyester 99.7
A resin molded product for plating containing 5 to 250 parts by weight of titanium dioxide to 100 parts by weight of a polyester resin composition consisting of ~55% by weight and 0.3 to 45% by weight of a glycidyl group-containing olefin copolymer is prepared in an alkaline solution. The present invention provides a method for producing a surface-metallized polyester resin, which is characterized in that the surface is roughened using a metallized polyester resin and then subjected to a plating treatment. The polyester resin composition used in the present invention is a polyester resin mixture containing a thermoplastic polyester and a glycidyl group-containing olefin copolymer. The thermoplastic polyester referred to herein 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. Examples of the terephthalic acid component herein include terephthalic acid and ester-forming derivatives thereof. In addition, other dicarboxylic acid components include isophthalic acid, orthophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid,
Bis(p-carboxyphenyl)methane, anthracenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-
Aromatic dicarboxylic acids such as 4,4'-dicarboxylic acid, 5-sodium sulfoisophthalic acid, 1,3-
Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid,
Examples thereof include aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, decanedionic acid, dodecanedioic acid, hexadecanedioic acid, octadodecanedioic acid, dimer acid, and ester-forming derivatives thereof. In addition, as the diol component, aliphatic glycol having 2 to 20 carbon atoms, ie, ethylene glycol,
Propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol,
cyclohexanediol etc. or molecular weight
Mention may be made of long chain glycols of 400 to 6000, such as polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and their ester-forming derivatives. Specific examples of these polymers include polybutylene terephthalate, polybutylene terephthalate isophthalate, polybutylene terephthalate adipate, and polybutylene terephthalate.
Sebacate, polybutylene terephthalate/decanedicarboxylate, polyethylene terephthalate, polyethylene terephthalate/isophthalate, polyethylene terephthalate/adipate, polybutylene terephthalate/5-sodium sulfoisophthalate, polyethylene terephthalate/5-sodium isophthalate, etc. Particularly preferably used are butylene terephthalate, polybutylene terephthalate adipate, polybutylene terephthalate, decanedicarboxylate, polyethylene terephthalate, polyethylene terephthalate adipate, polybutylene terephthalate/5-sodium sulfoisophthalate, and the like. In addition, these thermoplastic polyesters have a relative viscosity of 1.2 to 2.0 when a 0.5% o-chlorophenol solution is measured at 25°C.
In particular, those in the range of 1.3 to 1.85 are preferred. Moreover, these can be used in combination of two or more types. The content of these thermoplastic polyesters is preferably 99.7 to 55% by weight of the polyester resin composition. What is the glycidyl group-containing olefin copolymer used in the present invention? 50 to 99.5% by weight of α-olefin
It is a copolymer consisting of 50 to 0.5% by weight of glycidyl ester of α,β-unsaturated carboxylic acid and 0 to 49.5% by weight of vinyl acetate. The α-olefins mentioned here are ethylene, propylene, butene-1
etc., and ethylene is preferably used. In addition, the glycidyl ester of α,β-unsaturated carboxylic acid has the general formula (R in the formula represents a hydrogen atom or a lower alkyl group), specific examples include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, etc.
Among them, glycidyl methacrylate is preferably used. The copolymerized amount of the glycidyl ester of α,β-unsaturated carboxylic acid in the glycidyl group-containing olefinic copolymer is suitably 0.5 to 50% by weight, particularly 1 to 20% by weight; No effect can be obtained, and if it exceeds 50% by weight, the composition tends to gel during melt-kneading, which is not preferable. Specific examples of glycidyl group-containing olefin copolymers include ethylene/glycidyl methacrylate copolymer, ethylene/glycidyl methacrylate/vinyl acetate copolymer, ethylene/glycidyl acrylate copolymer, and ethylene/glycidyl acrylate/vinyl acetate copolymer. Among them, ethylene/glycidyl methacrylate copolymer and ethylene/glycidyl methacrylate/vinyl acetate copolymer are preferably used. Two or more of these glycidyl group-containing olefin copolymers can be used in combination. The content of the glycidyl group-containing olefin copolymer is preferably 0.3 to 45% by weight, particularly preferably 1 to 40% by weight of the polyester resin composition. If it is less than 0.3% by weight, the impact resistance improvement effect and thermal cyclability improvement effect of plated products will be small, and 45% by weight.
If it exceeds this value, the adhesion of the plating film will decrease significantly, which is not preferable. When adding the glycidyl group-containing olefin copolymer, it is necessary to add organic sulfonic acid metal salts such as sodium dodecylbenzenesulfonate and sodium dodecylsulfonate, and sulfuric acid of alcohols such as sodium lauryl sulfate ester. A small amount of ester salt or the like can be added together, and by adding these, the effect of improving the impact resistance and thermal cycle of the plated product is further exhibited. The titanium dioxide used in the present invention is anatase-type and rutile-type titanium dioxide with a purity of 95% or more, which is produced by a sulfuric acid method or a chlorine method. The particle size of titanium dioxide is not particularly limited, but
Particularly preferably used are those having an average particle diameter of 1 to 6 μm as indicated by the maximum frequency diameter (mode diameter) determined from the particle size distribution measured by the sedimentation balance method. The amount of titanium dioxide added is 100% of polyester resin.
It is preferably 5 to 250 parts by weight, particularly 30 to 100 parts by weight. If the amount is less than 5 parts by weight, 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 becomes large, and the adhesion of the plating film and the brightness of the plating are lost, which is not preferable. In addition, when blending the thermoplastic polyester with the glycidyl group-containing olefin copolymer and titanium dioxide, other thermoplastic resins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene -butene-1 copolymers, polyolefin resins such as ethylene-propylene terpolymers, polyamides, ABS resins, polycarbonates, polyesters (other than the present invention), etc., and other additives, such as aluminum stearate, barium stearate, etc. lubricants, crystal nucleating agents such as talc, clay, kaolin, alumina, montan wax,
Mold release agents such as montanic acid wax metal salts, plasticizers, heat stabilizers, ultraviolet absorbers, pigments, dyes, fibrous reinforcing agents, etc. can also be added as necessary. The method of blending the thermoplastic polyester, glycidyl group-containing olefin copolymer, titanium dioxide, and other additives is arbitrary and is not limited, but for example, a method of simultaneous mixing using a screw extruder etc. is adopted. can. For manufacturing resin molded parts for plating from the compound, any ordinary thermoplastic resin molding methods such as injection molding, extrusion molding, and blow molding can be used, and resin molded parts for plating in the desired shape can be easily obtained. Can be done. When plating according to the method of the present invention, it is important to first perform a preliminary treatment such as wiping off an oil film on the surface of the molded article as necessary, and then roughen the surface using an alkaline solution. The alkaline solution used for surface roughening treatment is potassium hydroxide,
Add 5-50% of alkaline components such as sodium hydroxide and magnesium hydroxide to a solvent such as water, phenols, alcohols, or a mixed solvent of these.
Among them, aqueous solutions of sodium hydroxide and potassium hydroxide are preferably used. The conditions for this surface roughening treatment (alkali etching) are preferably that the molded product is immersed in an alkaline solution at 30 to 95°C for 1 to 120 minutes, and then thoroughly washed. After sufficient washing, the surface may be further 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 applying normal plating treatment to the resin molded product for plating that has been subjected to surface roughening treatment in this way,
It is possible to obtain a surface-metallized polyester resin molded article which has significantly excellent plating film adhesion, thermal cycling properties, and plating brightness, and also has good mechanical properties of the plated product. The plating process includes, for example, sensitizing with a stannous chloride solution, activating with a palladium chloride solution, electroless copper or nickel plating, electroplating, or catalyst staining, accelerating, electroless plating, and electroplating. A conventional plating method consisting of steps can be applied. The surface metallized polyester resin molded article of the present invention has excellent heat resistance, mechanical properties, thermal cycling properties, plating film adhesion, and surface brightness, and is therefore useful as various automobile parts, electrical parts, and mechanical parts. The effects of the present invention will be further explained below with reference to Examples. Examples 1 to 9, Comparative Examples 1 to 10 100 weight resin compositions prepared by dry blending polybutylene terephthalate with a relative viscosity of 1.58 and the glycidyl group-containing olefin copolymer shown in Table 1 in the proportions shown in Table 1. Average particle size: 3.0 μm
Titanium dioxide was further dry-blended in the proportions shown in Table 1, and this was melt-mixed using a screw extruder set at 250°C and pelletized.
Next, the obtained pellets were put into an injection molding machine set at 250°C, and the mold temperature was 80°C.
Box-shaped molded product of 80 mm x height 35 mm, thickness 2.5 mm (test piece A) and impact test piece of width 1/2" x length 2 1/2" x thickness 1/8" with mold notch (test Piece B) was molded. Next, each test piece was immersed in a 30% aqueous sodium hydroxide solution at 70°C for 10 minutes, and then immersed in a 2% aqueous hydrochloric acid solution.
After being immersed for 10 seconds at 30°C, it was thoroughly washed in running water to obtain a test piece with a roughened surface. Each test piece with a roughened surface was subjected to plating treatment by the method shown below. (1) Catalyst The sample was immersed in a solution of A-30 Catalyst (manufactured by Okuno Pharmaceutical Co., Ltd.) at 25°C for 3 minutes. (2) Washing with water (3) Accelerator Immersed in 10% H ₂ SO ₄ solution at 40°C for 3 minutes. (4) Washing with water (5) Electroless nickel plating It was immersed in TMP chemical nickel plating (manufactured by Okuno Pharmaceutical Co., Ltd.) solution at 40°C for 8 minutes. (6) Washing with water (7) Electroplating (bright copper plating) Electroless plating test piece was washed with 50g of concentrated sulfuric acid,
200g copper sulfate (pentahydrate), SCB as brightener
-MU10c.c., SCB-1 1c.c. (Okuno Pharmaceutical Co., Ltd.)
product) and water in an acidic copper plating bath consisting of 1000 c.c. at a temperature of 25 to 30°C and a current density of 4 A/dm ^2.
Electroplated under these conditions to form a copper plating film approximately 30μ thick. (8) Water washing (9) Electric plating (bright nickel plating) After bright copper plating, the test piece was coated with 40 g of boric acid, 50 g of nickel chloride hexahydrate, 300 g of nickel sulfate heptahydrate, and 1 c.c. of monolite as a brightening agent. ., Acuna B-1 20c.c. (Okuno Pharmaceutical Co., Ltd. product) and water
It was placed in a nickel plating bath consisting of 1000 c.c. and electroplated under conditions of a temperature of 50°C and a current density of 5 A/dm ² to form a nickel plating film with a thickness of 15 μm. (10) Water washing (11) Electroplating (chrome plating) After bright nickel plating, the test piece was placed in a chrome plating bath consisting of 5 g of sulfuric acid, 250 g of chromium oxide, and 1000 c.c. of water, at a temperature of 50°C and a current density of 40 A/cm.
Plated under dm ² conditions to form a chrome plating film with a thickness of 0.2μ. The adhesion strength of the plating film is the strength (g) when peeling off the plating film of test piece A, which has been subjected to the above (7) electroplating (bright copper plating), over a 10 mm width and 20 mm length.
It was evaluated by measuring. The thermal cycle test for plated products was performed using (11) test piece A that had been subjected to electroplating (chrome plating) at -30
℃ (1 hr) = 1 cycle was exposure to an atmosphere of 150 ℃ (1 hr), and after 4 consecutive cycles, evaluation was made by visually observing and determining the presence or absence of abnormalities on the plating surface. The impact resistance of the plated product was evaluated by measuring the Izot impact strength of test piece B, which had been subjected to (11) electroplating (chrome plating). These results are the first
Shown in the table. The abbreviations in Table 1 mean the following. PBT: Polybutylene terephthalate P (E/GMA): Ethylene/glycidyl methacrylate copolymer copolymerization ratio 90/10 (weight ratio) P (E/GMA/VA): Ethylene/glycidyl methacrylate/vinyl acetate copolymer copolymer Ratio 80/10/10 (weight ratio)

[Table] As is clear from the results in Table 1, the surface metallized polyester molded products of the present invention include molded products plated with thermoplastic polyester alone, molded products plated with thermoplastic polyester and titanium dioxide, and molded products plated with thermoplastic polyester and titanium dioxide. Compared to a plated molded product made of thermoplastic polyester and a glycidyl group-containing olefin copolymer, the plated film adhesion, the plated product's thermal cycling properties, and the plated product's impact resistance are balanced and excellent. .

Claims (1)

[Claims] 1. A plating resin containing 5 to 250 parts by weight of titanium dioxide to 100 parts by weight of a polyester resin composition consisting of 99.7 to 55% by weight of a thermoplastic polyester and 0.3 to 45% by weight of a glycidyl group-containing olefin copolymer. A method for producing a surface-metallized polyester resin molded product, which comprises roughening the surface of the molded product using an alkaline solution and then plating the product.