JPH05140448A - Platable, high-specific-gravity thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition improved in adhesion of platings, kneadability, moldability and surface smoothness by adding a specified iron oxide to a polyamide or PBT. CONSTITUTION:50-95wt.% iron oxide of a median diameter of 0.1-30.0mum is added to a polyamide resin or a PBT resin of an intrinsic viscosity of 0.7-1.2dl/g.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition and a PBT resin composition, and more particularly to a polyamide resin composition and a PBT resin composition which are suitable as a substitute material for metal products and which can be plated and have a high specific gravity.

[0002]

2. Description of the Related Art Plastics originally have advantages in production processability, electrical insulation, corrosion resistance and the like as compared with metal materials and ceramics materials, and have achieved remarkable growth in the past few years. Recently, lightness, thinness, shortness, and miniaturization of various materials have progressed, and while application development that makes use of the lightness and specific strength of plastics has been made, metal development is one of the application developments that make use of plastics production processability. Development of high specific gravity plastics materials, which can be used as a substitute for products, is being actively conducted. Particularly, it is disclosed in JP-A-55-78 that a high specific gravity material is obtained by highly filling with a metal or a metal oxide.
032, JP-A 59-179538, JP-A 59-223735, JP-A 64-1765.
Japanese Patent Laid-Open No. 64-26673, Japanese Patent Laid-Open No. 1-33
No. 04157, JP-A-2-117933, JP-A-2-185540 and the like. Further, in order to obtain a high specific gravity material by adding inorganic fibers such as glass fiber and potassium titanate fiber in order to provide a reinforcing effect in addition to metal or metal oxide, it is disclosed in JP-A-60-2.
45668, JP-A-61-258862,
JP-A-61-246252, JP-A-61-264
No. 049, Japanese Patent Laid-Open No. 64-11163, etc. However, all of them give a metallic high weight feeling, but their plating properties are insufficient.

On the other hand, as a method for providing a thermoplastic resin having a high specific gravity and good plating property, a method of adding a silicic acid compound or a calcium compound which easily forms an anchor by acidic etching is disclosed in JP-A-63- 2736
No. 64 and JP-A-63-284262, it is necessary to add such an additive considerably in order to improve the plating property, and the originally desired high specific gravity characteristics are obtained. It could be halved.

[0004]

As described above, in the prior art, it is possible to provide a metallic weight feeling, but the plating workability is still insufficient, or the plating workability is improved. I was forced to sacrifice the metallic weight. Therefore, an object of the present invention is to provide a resin composition that imparts excellent plating workability and surface smoothness without impairing a metallic weight feeling, and is also excellent in kneading moldability. is there.

[0005]

The inventors of the present invention have made extensive studies to solve the above problems, and as a result, use a polyamide resin or PBT resin as a matrix resin.
By highly filling iron oxide powder, particularly spherical iron oxide powder, as a filler in this, a resin composition having excellent plating processability, surface smoothness and kneading processability without impairing the metallic weight feeling. The present invention has been completed by finding that a product can be obtained.

That is, the present invention has a median diameter of 0.1.
A high specific gravity polyamide resin composition for plating and a high specific gravity PBT resin composition for plating, which contain 50 to 95% by weight of iron oxide powder having a particle size of 30.0 μm.

The present invention will be described in detail below. First, the resins used in the present invention are thermoplastic resins, particularly polyamide and PBT. The reason for using these resins is that they have very good fluidity among the thermoplastic resins and can easily be filled with a high amount of filler. Resins with good fluidity include crystalline PP, PPS, other than polyamide and PBT.
Although there are POM and the like, PP has a specific gravity of about 0.9 and is disadvantageous for increasing the specific gravity. PPS and POM have a large specific gravity, but are very fragile and are not suitable for practical use. Not suitable. In addition, amorphous PS, ABS,
PC-modified PPO, PS and the like have extremely poor fluidity, cannot be filled with a high amount of filler, and have a very poor surface condition even if they are possible, and are not suitable for the present invention. As long as these properties of polyamide and PBT are not impaired, alloys of polyamide and PBT, and other resins such as ABS,
You may mix a small amount of PC and the like.

The polyamide resin used in the present invention means, as a diamine component, ethylenediamine, hexamethylenediamine, p-aminocyclohexylmethane, m-xylenediamine, 1,4-bis (3-aminopropoxy).
One or more selected from cyclohexane, transhexahydro-p-phenylenediamine and the like, and as dicarboxylic acid components, succinic acid, glutaric acid, adipic acid, speric acid, sebacic acid, bis (p-carboxyl). Phenoxy) alkane, terephthalic acid, isophthalic acid or the like, and one or more selected from α-pyrrolidone, ω-aminocaproic acid, ε-caprolactam, lauryllactam, aminododecanoic acid, and 11 as aminocarboxylic acid components. -Aminoundecanoic acid, para-aminobenzoic acid, 4-aminophenyl-4-carboxyphenyl ether, etc. are used individually or in combination, and polymers and copolymers obtained by subjecting them to a condensation reaction are listed. You can These polyamide resins may be used alone or in combination of two or more.

The PBT resin used in the present invention is produced by a method of polymerizing an ester of terephthalic acid and 1,4-butanediol, or a method of heating terephthalic acid or its halide derivative and glycol. In general, it is easily available on the market. The PBT resin has an intrinsic viscosity of 0.7 to 1.2 dl / g, preferably 0.8 to 1.0 dl / g measured at 30 ° C. in a mixed solution of 60 parts by weight of phenol and 40 parts by weight of tetrachloroethane. It is suitable and preferably has a relatively low melt viscosity.

Next, the filler for high specific gravity used in the present invention is iron oxide powder. As a filler for high specific gravity, metal powder is more advantageous than metal oxide powder in terms of specific gravity, but the particle size used in the present invention is as fine as 0.1 to 30.0 μm, and metal powder In the case of, the crushing is difficult and the adjustment is difficult. Even if it can be adjusted, there is a risk of fire. On the other hand, in the case of the metal oxide powder, the risk of ignition is very small, and the particle size can be adjusted relatively easily. Although there are various metal oxide powders, iron oxide powder is most suitable for the present invention. As the metal oxide powder other than iron, for example, lead oxide, zinc oxide, copper oxide, manganese oxide, etc. can be considered, but they become a catalyst poison when performing plating treatment, or an effective anchor by etching. It cannot be created, or the plating properties are adversely affected. However, the iron oxide used in the present invention does not have such a problem and can be plated smoothly.

[0011] Therefore, the iron oxide powder used in the present invention, as a typical, Fe0, Fe ₂ 0 ₃ and Fe
_{It has} a chemical formula of ₃ O ₄ , but may be a mixture thereof. In addition, Mn, Ni, Zn and
Impurities of oxides such as Si, Al and Mg do not pose any problem in the present invention. As a method of obtaining iron oxide powder, a method of crushing iron ore, a method of spraying an iron aqueous solution in a heating furnace, a method of heating iron hydroxide, an alkali is added to the iron aqueous solution and an oxidizing gas is blown into the solution. There are various methods such as a wet method for synthesizing an oxide, and a method which is generated from a blast furnace or a converter during steel making, and any method may be used. The method for obtaining spherical iron oxide can be obtained by the above method, but can also be obtained by further performing heat treatment at a higher temperature.

The iron oxide powder used in the present invention has a median diameter of 0.1 to 30.0 μm. When the median diameter is less than 0.1 μm, the specific surface area is too large, the viscosity of the resin composition increases, the moldability deteriorates, and the plating property is adversely affected. If the particle size is too small, the etching will be performed too rapidly, resulting in an unnecessarily large anchor on the surface of the molded product, and the catalyst palladium will fall off by washing with water, etc. It is thought that it will worsen and the skip will appear, and the plating adhesion will deteriorate. On the other hand, if it exceeds 30 μm, the surface condition of the molded product is poor, the surface roughness increases, the adhesion strength with the metal plating decreases, and pinholes and surface swelling tend to occur. Further, an anchor formed by etching iron oxide having a large grain size as it is becomes too large as in the case of iron oxide having a very small grain size, and also has an adverse effect on the plating property. Therefore, the particle size of the iron oxide powder used in the present invention is preferably 0.1 to 30 μm in terms of median diameter, as described above, and preferably 0.5.
μm to 20 μm. More preferably, the iron oxide powder has a spherical shape. If 50% by weight or more of the iron oxide powder is spherical, the adhesion strength with the metal plating is further improved, and since the powder is spherical, the dispersibility in the resin and the surface smoothness of the molded product are also improved. This is because kneading and molding processability are further improved. The amount of iron oxide added to the present invention is 50 to 95% by weight, preferably 60 to 90% by weight, based on the total amount of the composition. Below 50% by weight,
The specific gravity of the molded product is 2 or less, and the effect of obtaining a weight feeling close to that of a metal is not sufficient. This is because the appearance of is also deteriorated. The surface of the iron oxide powder may be treated with a treating agent such as a silane coupling agent or a titanium coupling agent for improving the adhesion with the polyamide resin or the PBT resin. Further, if at least the surface portion is iron oxide, the inside may be pure iron.

Further, the polyamide resin composition and the PBT resin composition of the present invention include glass fibers, carbon fibers, aramid fibers, potassium titanate fibers, aluminum borate fibers, and minerals to the extent that the plating properties are not deteriorated, if necessary. Fiber reinforcing material such as crushed fiber, silica fiber, alumina fiber, gypsum fiber, magnesium hydroxide fiber, silicon carbide fiber, zirconia fiber, or mica, wollastonite, calcium carbonate, barium sulfate, kaolin, clay, bentonite, and seri Inorganic fillers such as sights, glass beads, glass flakes, talc, graphite, carbon black, metals or metal oxides, also in the preparation of the composition,
Flame retardants, colorants, plasticizers, stabilizers, antioxidants, UV absorbers, crosslinking agents, dispersants, other additives, unsaturated carboxylic acid copolymers that are usually added to thermoplastic resins. You may add a small amount of modifiers such as and other resins. Polyamide resin composition containing the above iron oxide powder, P
The method for preparing the BT resin composition is to uniformly knead the resin component and iron oxide powder within the above-mentioned mixing ratio by a conventional method using a pressure kneader, a single-screw and a twin-screw extruder which are generally used. To prepare a kneaded product. The kneaded product is preferably pelletized. The resin composition thus prepared is molded into a desired product by ordinary extrusion molding or injection molding.

[0014]

EXAMPLES The present invention will be specifically described below based on Examples and Comparative Examples.

[0015]

Examples 1 to 6 Iron oxide powder and other fillers were kneaded in a polyamide resin at a ratio shown in Table 1 by an extruder to prepare pellets. However, a silane coupling agent (S-330 manufactured by Chisso) was added in an amount of 0.5% by weight in order to improve the adhesiveness with the resin to the iron oxide powder uniformly.

A test piece was molded by injection molding using this pellet, and the tensile strength (ASTM
D 639) and specific gravity (ASTM D 792) were measured. Regarding the plating property, a flat plate of 100 mm × 50 mm × 3 mm was molded from the above pellets, and the plating was performed as follows according to the nylon plating process of Okuno Chemical Industries Co., Ltd. Nylon plating process 1) Etching (hydrochloric acid TN etchant 40 ° C 3
2) Post etching (hydrochloric acid 20 ℃, 1 minute) 3) Catalyst (hydrochloric acid TN catalyst, 20 ℃ 3)
Min) 4) Accelerator (sulfuric acid solution 40 ° C 3 min) 5) Post accelerator (caustic soda solution TN post accelerator 40 ° C 3 min) 6) Chemical nickel plating (20 ° C 10 min) 7) Electrolytic copper plating (20 ° C) 10 minutes)

The plating adhesion is determined by electroplating copper and then scribed in strips on the film surface at an angle of 90 degrees and a peeling speed of 20 mm.
It was measured in minutes. The surface smoothness of the molded product was evaluated by Ra (center line average value), Rmax (maximum height), and Rz (ten-point average value) of a flat plate using a surface roughness meter. The kneading / molding processability was evaluated in four levels: ⊚: very excellent, ∘: excellent, Δ: normal and ×: troublesome. The results are shown in Table 1.
Shown in.

[0018]

[Table 1]

[0019]

[Examples 7 to 10] PBT resin was kneaded with iron oxide powder and other fillers in the proportions shown in Table 2 by an extruder to prepare pellets. However, a silane coupling agent (S-330 manufactured by Chisso) was added in an amount of 0.5% by weight in order to improve the adhesiveness with the resin to the iron oxide powder uniformly. Using this pellet, a test piece was molded by injection molding in the same manner as in Examples 1 to 6, and the physical properties were evaluated. The plating property was determined as follows according to the PBT plating process of Okuno Chemical Industries Co., Ltd.

PBT plating process 1) PBT pre-etching (sulfuric acid, chromic acid solution 68 ° C.)
6 minutes) 2) Etching (caustic soda solution PBT etchant 68 ° C 15 minutes) 3) Neutralization (hydrochloric acid TMP neutralizing additive 20 ° C 2 minutes) 4) Catalyst (hydrochloric acid TN catalyst 20 ° C 3)
5) Accelerator (sulfuric acid solution 40 ° C for 3 minutes) 6) Chemical nickel plating (20 ° C for 10 minutes) 7) Electrolytic copper plating (20 ° C for 10 minutes) Plating adhesion, surface adhesion of molded products and kneading molding processing The sex was evaluated in the same manner as in Examples 1-6. The results are shown in Table 2.

[0021]

[Table 2]

[0022]

[Comparative Examples 1 to 6] Polyamide resin and PBT resin are shown in Table 3
Iron oxide powder and other fillers were kneaded in an extruder at a ratio shown in to prepare pellets. However, in order to improve the adhesion to the resin evenly with iron oxide powder or other metal powder or metal oxide powder, 0.5 wt% of silane coupling agent (Chisso S-330) is used. % Added.
Using this pellet, the same evaluation as in the example was carried out.
The results are shown in Table 3.

[0023]

[Table 3]

Materials used in the above Examples and Comparative Examples are shown below. (1) Polyamide Nylon 6; Ube Industries Ltd. Product Name [UBE Nylon 1011FB] Nylon 12; Ube Industries Ltd. Product Name [UBE Nylon 3014B] Nylon 66; Ube Industries Ltd. Product Name [UBE Nylon 2015B] PBT Mitsubishi Kasei Co., Ltd. product name [Novadur 500
8] (2) Iron oxide spherical Fe ₃ O ₄ ; Nippon Steel Corp. Fe ₃ O ₄ was finely pulverized and further heat-treated to obtain spherical particles, which were classified to a predetermined size. Cubic Fe ₃ O ₄ ; Nippon Steel Co., Ltd. Fe ₃ O ₄ obtained by blowing air into an aqueous solution of ferrous hydroxide and thoroughly washing with water. Amorphous α-Fe ₂ O ₃ ; Nippon Steel Corp. Iron chloride aqueous solution heated and cultivated. (3) Other fillers Aluminum borate fiber; Shikoku Chemicals trade name [Arbolex G] crushed mineral fiber; Nippon Steel Chemical Co., Ltd. trade name [Esfiber FF] zinc oxide powder; Sakai Chemical Co., Ltd. grade name [ No. 1 average particle size 0.52 μm] Copper powder; Mitsui Metal Industry Co., Ltd. Grade name [MA-C
(D) Atomized powder containing 350-mesh under 70 to 90%]

[0025]

According to the present invention, the polyamide resin and the PBT resin are highly filled with iron oxide powder of a predetermined size, so that excellent plating adhesion can be imparted without deteriorating the metallic weight. And a polyamide resin composition and a PBT resin composition having excellent surface smoothness, and excellent kneading and molding processability. The resin composition and the PBT resin composition are extremely practical molding materials as materials for substituting for metals which require high specific gravity.

Claims (2)

[Claims] 1. A high specific gravity polyamide resin composition for plating, which contains 50 to 95% by weight of iron oxide powder having a median diameter of 0.1 to 30.0 μm. 2. A high specific gravity PBT resin composition for plating, which contains 50 to 95% by weight of iron oxide powder having a median diameter of 0.1 to 30.0 μm.