JPH03130374A - Plating method - Google Patents

Abstract

PURPOSE:To improve the adhesive property between a base material and a metal plating layer by compounding a specific ratio of titanium oxide having a specific grain size in the plating method for an arom. polyester resin molding which can form an anisotropic molten phase. CONSTITUTION:The resin compsn. prepd. by packing 35 to 80wt.% titanium dioxide of 1 to 15mu average grain size to the arom. polyester which can form the anisotropic molten phase is made into the molding. This molding is subjected to a surface treatment by using an aq. alkaline soln. and then to a metal plating treatment. The adhesive property of the plating is insufficient if the average grain size of the titanium dioxide is <1mu. The surface condition after the plating is degraded if the average grain size is >15mu. There is no effect in the adhesive property of the plating if the amt. of the titanium dioxide to be packed is <35%. The molding is difficult and the material strength is low if the amt. exceeds 80%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of plating an aromatic polyester resin molded body capable of forming an anisotropic melt phase. More specifically, the present invention relates to a method of plating an aromatic polyester resin molded body, which can form an anisotropic melt phase that can easily form a metal plating layer on the resin surface.

[Issues to be solved by the prior art and the invention a] Aromatic polyesters capable of forming an anisotropic melt phase have higher heat resistance and lower coefficient of linear expansion than general aromatic polyesters, and have a low flow rate during melting. Due to its good properties, it is used in many fields including automobiles and electrical and electronic parts. Furthermore, in these fields, metal plating on the surface of the molded product is often required for functional or decorative purposes. By the way, polymer molded products are insulators, so in order to apply a metal plating layer to the polymer surface, there are two methods: forming a finely uneven surface on the surface layer and utilizing the anchor effect of the metal, or adding functional groups to the surface layer. A method is being used that utilizes the chemical bonding force with metals.

The method of utilizing the above-mentioned anchor effect is a method of eluting inorganic substances or rubber components that have been dispersed in the resin in advance using an acid, alkali aqueous solution, or an organic solvent;
Alternatively, it is a mechanical roughening method such as sandblasting. In addition, the method of utilizing chemical bonding strength is a method of improving the adhesion of the metal plating layer by subjecting the base material to acid, alkali, or plasma irradiation treatment to form functional groups on the surface of the resin. These methods include painting, vacuum deposition,
It is commonly used as a pretreatment method for dry and wet plating such as sputtering, ion blating, and electroless plating.

For plating aromatic polyester resins capable of forming an anisotropic melt phase, attempts have generally been made to use a composition filled with glass fibers and carry out plating after surface roughening treatment. Also,
A method for surface treatment of liquid crystal polyester resin compositions is known, which is described in JP-A-1-92241. This method is
Composition of an inorganic filler containing one or more elements selected from the group consisting of elements of groups mA, nB, IIIA, IVA, and VA of the periodic table in a melt-processable polyester capable of forming an anisotropic melt phase. A molded article made of a liquid crystal polyester resin composition containing 5 to 80 parts by weight based on the total amount of the product is brought into contact with an aqueous solution containing an alkali metal hydroxide or an alkaline earth metal hydroxide as a main component. This is a surface treatment method for liquid crystal polyester resin molded products, which is characterized by subjecting them to a treatment.

However, in many fields such as ornaments, automobile parts, and electrical and electronic parts, metal plating forms an anisotropic molten phase with superior surface smoothness and good sticking and adhesion than described in the above patent publication. It is desired to develop a plating method using an aromatic polyester resin composition.

[Means for Solving the Problems] In view of the above-mentioned current situation, the present inventors aimed to obtain a polyester resin molded article that can impart excellent plating adhesion to a metal plating layer, and in particular can form an anisotropic melt phase. He carried out intensive research. As a result, it was found that by blending a specific amount of titanium oxide with a specific average particle size, it is possible to obtain a polyester resin molded article that can form an anisotropic melt phase with significantly improved adhesion and improved mechanical properties. I found a headline.

That is, the present invention provides a molded article of a resin composition comprising an aromatic polyvarnish capable of forming an anisotropic melt phase, a chilled resin filled with 35 to 80% by weight of titanium oxide having an average particle size of 1 to 15 μm, The present invention relates to a plating method characterized in that the molded body is surface-treated using an alkaline aqueous solution and then subjected to metal plating treatment.

The present invention will be explained in detail below.

The aromatic polyester resin capable of forming an anisotropic melt phase, which is the object of the present invention, is a thermoplastic resin that exhibits optical anisotropy when melted, and is generally classified as a thermotropic liquid crystal polymer. The polyester that forms the above-mentioned anisotropic melt phase may be an aromatic polyester obtained by copolymerizing one or more compounds selected from aromatic hydroxycarboxylic acids, or a polyester containing aromatic hydroxycarboxylic acid as the main component. An aromatic compound copolymerized with at least one or more compounds capable of forming an ester bond stoichiometrically from aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic diols, and aliphatic diols. Polyester, and aromatic dicarboxylic acid.

Examples include aromatic polyesters obtained by copolymerizing aliphatic dicarboxylic acids and one or more compounds selected from aromatic diols and aliphatic diols.

Examples of aromatic hydroxycarboxylic acids that are constituents of polyester include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, etc. aromatic hydroxycarboxylic acids or 4-hydroxy-2-methylbenzoic acid, 4-hydroxy-3-methylbenzoic acid, 4-hydroxy-2-phenylbenzoic acid, 2-
Chloro-4-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 6-hydroxy-5-chloro-2-
Examples include alkyl, allyl, and halogen-substituted aromatic hydroxycarboxylic acids such as naphthoic acid, 6-hydroxy-7-chloro-2-naphthoic acid, and 6-hydroxy-5,7-dichloro-2-naphthoic acid.

Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 4,4-diphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, Diphenoxyethane-4,4'-dicarboxylic acid, diphenoxybutane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenylsulfide-4,4'-dicarboxylic acid, diphenylketone- 4,4′-dicarboxylic acid, 3゜4′-diphenyldicarboxylic acid, diphenyl ether-3,4゛-dicarboxylic acid, diphenylmethane-3,4゛-dicarboxylic acid, diphenoxyethane-3,4-monodicarboxylic acid, dicarboxylic acid Phenoxybutane-3,4'-dicarboxylic acid, diphenylsulfone-3,4'-dicarboxylic acid, diphenylsulfide-3,4-monodicarboxylic acid, diphenylketone-3,4-monodicarboxylic acid, 3,3'- Diphenyl dicarboxylic acid, diphenyl ether-3゜3''-dicarboxylic acid, diphenylmethane-3゜3゛-dicarboxylic acid, diphenoxyethane-3゜3゛-dicarboxylic acid, diphenoxybutane-3゜3'-dicarboxylic acid, diphenyl sulfone Aromatic dicarboxylic acids such as -3°3'-dicarboxylic acid, diphenylsulfide-3,3'-dicarboxylic acid, and diphenylketone-3'3'-dicarboxylic acid, or chloroterephthalic acid and bromoterephthalic acid.

such as methyl terephthalic acid, t-butyl terephthalic acid,
Examples include alkyl and halogen-substituted aromatic dicarboxylic acids.

Examples of the aliphatic dicarboxylic acids include cycloaliphatic dicarboxylic acids such as trans-1°4-cyclohexanedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, and 1,3-cyclohexanedicarboxylic acid, and derivatives thereof.

Aromatic diols include hydroquinone, resorcinol, and 4,4-dihydroxydiphenyl.

4.4゛-dihydroxydiphenyl ether, 3゜4゛-dihydroxydiphenyl, 3.4-dihydroxydiphenyl ether, 4.4=-dihydroxybenzophenone, 3.4"-dihydroxybenzophenone, 3.3
"-dihydroxybenzophenone, 4.4-dihydroxydiphenylsulfone, 4.4-dihydroxydiphenylsulfide, 4.4-dihydroxydiphenylmethane, 3.4-dihydroxydiphenylsulfone.

3.4'-dihydroxydiphenyl sulfide, 3'4'-dihydroxydiphenylmethane, 3,3-dihydroxyphenyl sulfone, 3.3-dihydroxydiphenyl sulfide, 3.3-dihydroxydiphenylmethane, 2.6-naphthalenediol , 1.6-naphthalene diol.

2.2-monobis(4-hydroxyphenyl)propane,
Aromatic diols such as bis(4-hydroxyphenoxy)ethane, or chlorohydroquinone.

Bromohydroquinone, methylhydroquinone.

t-Butylhydroquinone, 4-chlorresorcinol, 4
Examples include the above-mentioned alkyl- and halogen-substituted aromatic diols such as -methylresorcinol.

Examples of aliphatic diols include trans-1,4-cyclohexanediol, cis-1,4-cyclohexanediol, trans-1,4-cyclohexane dimetatool,
Cis-1,4-cyclohexane dimetatool, trans-1,3-cyclohexanediol, cis-1,2-cyclohexanediol, trans-1,3-cyclohexane dimetatool, ethylene glycol, 1,4-butane Diol, cyclic, linear, or branched aliphatic diols such as 1,6-hexanediol and 1,8-octanediol, and derivatives thereof.

Among the aromatic polyesters made of each of the above components, there are those that form an anisotropic melt phase and those that do not, depending on the constituent components, the composition ratio in the polymer, and sea fence distribution. is an aromatic polyester capable of forming an anisotropic melt phase.

There are no particular limitations on the method for producing an aromatic polyester capable of forming an anisotropic melt phase using the monomers described above. For example, a typical manufacturing method includes a method in which 4-acetoxybenzoic acid is reacted with 4.4'-diacetoxydiphenyl, terephthalic acid, or isophthalic acid. The reaction is generally carried out in a nitrogen stream starting at a low temperature and continuously increasing the temperature as the reaction progresses. The obtained granular product is further heated under reduced pressure or at normal pressure to a temperature of 200 to 350
The secondary solid-state polycondensation reaction can be carried out at a temperature of °C. This operation increases the molecular weight and significantly improves the properties of the polyester obtained.

In addition, in order to promote the above reaction, a catalyst such as a Lewis acid, a hydrogen halide, an organic acid, or an inorganic acid salt, and a compound of antimony or germanium is used in an amount of 0.01 to 1.0% by weight based on the monomer. You can also do that.

Aromatic polyester resins capable of forming an anisotropic melt phase suitable for use in the present invention have a melt viscosity that is equal to or less than the flow onset temperature (F) of the polyester resin.

T,) from 10 to 100,000 poise, especially less than 10,000 poise, when measured at a shear rate of 103 sec-' at a temperature of ~400°C. (Here, the flow start temperature was measured using a normal high-speed flow tester equipped with a die with an inner diameter of lll1!1 and a length of 10 m1.
The temperature was raised at a rate of 6° C./min under a pressure of 0 kg/cd to give a melt viscosity of 4,800 poise. Further, the melt viscosity was measured using a Koka type flow tester equipped with a die having an inner diameter of 0.5 mm and a length of 2 mm. ) If the above-mentioned melt viscosity is less than 10 poise or more than 100,000 poise, it is not preferable because molding of the resin becomes difficult.

In the present invention, the titanium oxide contained in the aromatic polyester resin capable of forming an anisotropic melt phase is titanium dioxide, and rutile and anatase types manufactured by various manufacturing methods can be used. .

The average particle size of titanium dioxide is preferably 1 to 15 μm, particularly preferably 5 to 10 μm. If the average particle size is less than 1 μm, the plating adhesion is insufficient.

Furthermore, particles with an average particle size exceeding 15 μm are not preferred in practice because the surface condition after plating deteriorates.

The titanium oxide mentioned above is used in a range of 35 to 8%. Here, if the filling amount of titanium oxide is less than 35% by weight, there is no effect on plating adhesion, and 80ff1m%
If it exceeds , it is not preferable because moldability becomes difficult and material strength decreases.

In addition, it may be filled with fibrous material. Here, filling with fibrous material is preferable because the heat distortion temperature and mechanical strength are improved compared to a system filled with titanium oxide. The fibrous materials used in this case include glass fibers, carbon fibers, graphitized fibers, whiskers, metal fibers, and inorganic fibers with an average fiber diameter of 0.1 to 30 μm and an aspect ratio (average fiber length/average fiber diameter) of 10 or more. Fibers, organic fibers, mineral fibers, etc. can be used. Examples of these fibrous materials include the following.

In addition to regular glass fibers, glass fibers coated on metals such as nickel and steel, silane fibers, aminosilicate glass fibers, hollow glass fibers, and non-hollow fibers can be used as carbon fibers. , PAN fibers made from polyacrylonitrile, and pitch fibers made from pitch. Inorganic fibers include rock wool, zirconia, alumina silica, potassium titanate, barium titanate, silicon carbide, alumina, and silica.

Various fibers such as blast furnace slag are used.

Mineral fibers include asbestos, wolastenite,
Magnesium oxysulfate and the like are used.

Organic fibers include fully aromatic polyamide fibers.

Phenol resin fibers, cellulose fibers, hemp threads, etc. are used.

Examples of whiskers include silicon nitride whiskers, basic magnesium sulfate whiskers, barium titanate whiskers, potassium titanate whiskers, silicon carbide whiskers,
Boron whiskers etc. are used.

In particular, when the average fiber diameter is 0.1 to 30 μm, the aspect ratio (
Glass fibers, aramid fibers, potassium titanate fibers, and wolastenite fibers having an average fiber length/average fiber diameter of 10 or more are preferred.

Here, if the average fiber diameter is less than 0.1 μm, there is no effect of improving material strength, and if it exceeds 30 μm, the appearance of the surface after metal plating will be impaired, which is not preferable. Moreover, when the aspect ratio is less than 10, it is not preferable because it lowers the material strength.

The fibrous material can be filled with titanium oxide in an amount of 5 to 20% by weight within a range of 35 to 80% by weight. Here, the amount of fibrous materials in the total filler can be arbitrarily used within the above range, but if the total amount of titanium oxide and fibrous materials in the total filler exceeds 80% by weight, molding This is not preferable because it makes processability difficult and reduces material strength.

Next, if the filling amount of the fibrous material is less than 5% by weight, it will not be effective in improving heat distortion temperature and mechanical strength, and if it exceeds 20% by weight, the surface appearance after metal plating will be poor. do not have.

Furthermore, antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, and mold release agents within the range that does not impair the purpose of the present invention.

One or more conventional additives such as colorants such as dyes and pigments, flame retardant aids, and antistatic agents may also be added.

The aromatic polyester resin composition capable of forming the above-mentioned anisotropic melt phase is molded into arbitrary shapes of various parts, sheets, plates, and containers by conventional molding means such as extrusion molding and injection molding.

In the plating method of the present invention, dirt such as an oil film on the surface of the molded article is removed by a conventional degreasing process, and then the surface is treated with an alkaline aqueous solution. The alkaline aqueous solution used for surface treatment is not particularly limited, but it is preferable to use an aqueous solution of 113 or more consisting of potassium hydroxide, sodium hydroxide, lithium hydroxide, ammonium hydroxide, amine hydroxide, and the like. Alternatively, a surface treatment solution obtained by mixing alcohols, surfactants, etc. with the above alkaline aqueous solution may be used.

The surface treatment conditions for this molded article vary depending on the alkaline compound used, but it is preferable to use an alkaline aqueous solution adjusted to 400 g/l to 800 g/l. The concentration of the alkaline aqueous solution is 600 g/l to 750 g/
1 is preferred. Here, if the concentration of the alkaline aqueous solution is less than 400 g/1, it is undesirable because it requires a long processing time, and if it exceeds 800 g/1, it is not preferred because it is dangerous for the work.

Next, the surface treatment of the molded body can be carried out at a temperature range of 50°C to 80"C. If the surface treatment temperature is less than 50"C, the surface treatment takes a long time and is not practical; If the temperature exceeds ℃, a large amount of alkaline mist will be generated, which is dangerous.

Next, the time for surface treatment of the molded body varies depending on the surface treatment temperature and alkali concentration of the molded body, but 10 to 60 minutes is appropriate. When the surface treatment time is less than 10 minutes, the etching effect on the surface is small and there is no effect on plating adhesion. Moreover, if it exceeds 60 minutes, it is not preferable because it causes deterioration of the base material and reduces productivity.

After the alkali surface treatment is completed, the molded body is thoroughly washed, and then surface treated with an acidic aqueous solution such as sulfuric acid or hydrochloric acid to remove trace amounts of alkali metal salts adhering to the surface of the molded body. The surface treatment conditions for the molded body using this acidic aqueous solution were 10
1 to 15 minutes in a temperature range of ~50°C is appropriate.

Aromatic polyester resin moldings that can form an anisotropic melt phase after such surface treatment undergo a general electroless plating process to significantly improve plating adhesion and improve the appearance of the plated surface. A plated molded body with excellent properties can be obtained.

[Example] Next, the present invention will be specifically explained using examples.

In addition, the adhesion test using the tape peeling method and the adhesion strength test using a tensile tester in the Examples were conducted by the following method.

○ Tape peeling method: After electroless plating, 1mm on the plating surface
After making 11 vertical and horizontal scoring lines at intervals of , and pasting cellophane tape, it was peeled off at 90 degrees to the metal-coated surface, and the proportion of the lattice that remained on the metal-coated surface without being peeled off was measured.

○Tensile test: After electroless plating, bright sulfuric acid steel plating was applied to about 7
After drying at 80° C. for 2 hours, it was left at room temperature. Next, a 1 cm wide cut was made in the plated product, and a tensile tester (manufactured by Shimadzu Corporation, Autograph 5D-10) was used.
The metal coating was pulled perpendicularly to the resin base using a 0-C), and the adhesion force was determined as Apl.

(Examples 1 and 2) The above aromatic polyester resin (flow start temperature (F, T,
) is 100 kg/c using a Koka type flow tester manufactured by Shimadzu Corporation and equipped with a die with an inner diameter of 1 mm and a length of 10 mm.
The temperature was raised at a rate of 6°C/min under a pressure of
The measurement result was 335°C at the temperature that gave the poise.

In addition, the melt viscosity was measured at a temperature of -1340°C and a shear rate of 10 sec using a Koka type flow tester manufactured by Shimadzu Corporation and equipped with a die of 0.5 mm in inner diameter and 2 lengths, and the result was 2,000 poise. Met. ) and average particle size 10μm
Titanium dioxide (manufactured by Ishihara Sangyo Co., Ltd.) was mixed with the composition shown in Table 2, and a twin-screw extruder (Nippon Steel New TEX30S) was used.
Extrusion granulation was performed using S) at a temperature of 310°C to create pellets.

Next, after dehumidifying and drying the pellets at 150°C for 2 hours, they were molded into a 50-ton injection molding machine (Toshiba Machine 1550EP).
cylinder temperature of 330℃.

7cm width x 7cm length x 111I under the conditions of injection pressure 1000 kg/cJ, high injection speed, and mold temperature 150℃.
A test piece having a thickness of 11 was prepared and subjected to electroless copper plating according to the method shown in Table 1.

The obtained plated products were tested for adhesion by tape peeling method,
After bright copper sulfate plating, an adhesion strength test was conducted using a tensile tester. The results are shown in Table 2.

(Example 3) The same aromatic polyester resin as in Example 1, glass fiber (milled fiber with a fiber diameter of 13 μm and cut length of 140 μm), and titanium dioxide (manufactured by Ishihara Sangyo Co., Ltd.) with an average particle size of 10 μm were prepared in Table 2. The compositions shown were mixed and extrusion granulation was performed at a temperature of 310° C. using a twin-screw extruder (Nippon Steel Shinsei TEX30SS) to create pellets.

Next, after dehumidifying and drying the pellets at 150°C for 2 hours, they were molded into a 50-ton injection molding machine (Toshiba Machine 1550EP).
cylinder temperature of 330℃.

7cm width x 7cm length x lllll under the conditions of injection pressure 1000 kg/cd, high injection speed, and mold temperature 150℃
A test piece having a thickness of 11 was prepared and subjected to electroless copper plating according to the method shown in Table 1.

The obtained plated products were tested for adhesion by tape peeling method,
After bright copper sulfate plating, an adhesion strength test was conducted using a tensile tester. The results are shown in Table 2.

(Comparative Example 1) The same polyester resin as in Example was extruded and granulated at a temperature of 310°C using an extruder (Nippon Steel Shin-made TEX30SS) to create pellets.

Next, after dehumidifying and drying the pellets at 150°C for 2 hours, they were molded using a 50-ton injection molding machine (Toshiba Machine 1550EP) at a cylinder temperature of 330°C and an injection pressure of 1000 kg/cd.
, 7cm width X under the conditions of high injection speed and mold temperature of 150℃
A test piece with a length of 7 cm and a thickness of 1 cm was prepared.

Using the obtained test piece, electroless nickel plating was performed using the method shown in Table 1. The resulting preset product was subjected to an adhesion test using a tape peeling method and an adhesion strength test using a tensile tester after plating bright sulfuric acid steel.

The results are shown in Table 2.

(Comparative Example 2) A test piece was prepared in the same manner as in Example 1, except that the content of titanium dioxide was changed to 20% by weight. Electroless copper plating was performed using the obtained test piece according to the method shown in Table 1.

The obtained plated products were tested for adhesion by tape peeling method,
After bright copper sulfate plating, an adhesion strength test was conducted using a tensile tester. The results are shown in Table 2.

(Comparative Example 3) The same aromatic polyester resin as in Example 1 had an average particle size of 0.
．． A test piece was prepared in the same manner as in Example 1 using 40% of 5 μm titanium dioxide (manufactured by Ishihara Sangyo Co., Ltd.).

Electroless copper plating was performed using the obtained test piece according to the method shown in Table 1. The obtained plated product was subjected to an adhesion test using a tape peeling method and an adhesion strength test using a tensile tester after bright copper sulfate plating. The results are shown in Table 2.

(Effects of the Invention) According to the present invention, the average particle size of titanium dioxide is added to the aromatic polyester resin capable of forming an anisotropic melt phase.

After mixing with a limited amount of filling and performing etching treatment,
The present invention provides a resin composition in which the adhesion between a base material and a metal plating layer is significantly improved by electroless plating. In this way, the adhesion strength between the base material and the metal plating layer is at least 0.7k.
g/am.

Since the resin composition according to the present invention can improve the adhesion between the resin layer and the metal plating layer due to the anchor effect, it can be easily deposited by ordinary vapor deposition or sputtering.

It is clear that the plating strength can be improved even when applied to vacuum plating methods such as ion blating.

Claims (1)

[Claims] (1) A resin composition prepared by filling an aromatic polyester capable of forming an anisotropic melt phase with 35 to 80% by weight of titanium oxide having an average particle size of 1 to 15 μm is used as a molded body, and the molded body is alkalineized. A plating method characterized by surface treatment using an aqueous solution and then metal plating treatment.