JPS63275660A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in adhesion to plating metals, Moldability and mechanical properties and useful as a molding material for electrical and electronic components and mechanical parts, etc., by mixing a specified polyester resin with a metal silicate and/or carbonate. CONSTITUTION:100pts.wt. polyester resin containing 0.5-10mol.%, preferably, 1-5mol.% copolymerized metal sulfoisophthalate and having a main chain at least 80mol.% of which is composed of butylene terephthalate units (e.g., polybutylene terephthalate having copolymerized 5-sodiosulfoisophthalic acid) is mixed with 5-100pts.wt., preferably, 10-50pts.wt. metal silicate, preferably, aluminum silicate or calcium silicate and/or a metal carbonate which is preferably CaCO3 and, optionally, a particulate metal oxide and a fibrous reinforcing material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applicable to electrical components 9 that require heat resistance and mechanical strength.
The present invention relates to a polyester resin composition having excellent plating properties suitable for mechanical parts.

(Conventional technology) Generally, plastic plating methods include (1) degreasing;

This is carried out by the following processes: (2) etching, (3) sensitizing, (4) actipation, (5) chemical plating, and (6) electroplating. For example, in the case of AB8 resin, (
By performing the etching process in 2) with a mixture of chromic acid and sulfuric acid, the butadiene in the AB8 resin is preferentially eluted and fills the dents, and the plating is deposited even inside the dents, forming an anchor. show the effect. Furthermore, when the polar groups on the surface of MuBS resin combine with the metal constituting the plating layer,
A metal plating layer with excellent adhesion strength is formed. Furthermore, in the case of polyester resins such as polyethylene terephthalate and polybutylene terephthalate, the surface is roughened by hydrolyzing the skin sebum surface using an alkaline solution in the etching step. However, A
There is no equivalent to butadiene in BS resin, and even when etched, no depressions are formed, no anchor effect is obtained, and the adhesion strength is insufficient.

For this reason, conventional methods for improving the plating properties of polyester resins have been studied. For example, Japanese Patent Application Publication No. 54
-15977 Publication “Polyester resin plating method”
discloses a method in which a polyester resin composition containing a filler such as calcium carbonate or calcium silicate is brought into contact with an alkaline solution and then plated.

In this paper, the improvement of the properties of polyester resin by adding filler and the effect of improving plating performance by alkaline solution treatment are described.

(Problems to be Solved by the Invention) Polybutylene terephthalate resin has attracted attention as a resin that has a faster crystallization rate and excellent moldability than polyethylene terephthalate resin.

However, the alkali reduction rate is about 115 that of polyethylene terephthalate resin, which requires time for the etching process, and a decrease in resin strength poses a practical problem.

Therefore, even if a filler is added to provide an anchor effect, the adhesion to the metal coating is not sufficient.

(Means for Solving the Problems) As a result of intensive research to solve the problems of the prior art, the present inventors have found that metal salts of sulfoisophthalic acid are filled into copolymerized polybutylene terephthalate resin. The present invention has been achieved based on the discovery that a resin composition having a fast alkali weight loss rate and excellent adhesion to a plated metal film can be obtained by blending these materials.

That is, the polyester resin composition of the present invention copolymerizes 0.5 to 10 mol % of a metal salt of sulfoisophthalic acid, and contains at least 80 mol % of the main chain of the polyester resin based on 100 parts by weight of a polyester resin composed of butylene terephthalate units. hand,
It is characterized by containing 5 to 100 parts by weight of metal silicate and/or metal carbonate.

The present invention will be explained in detail below.

The metal species of the sulfoiphthalic acid metal salt in the present invention is not particularly limited, but it is preferable to use sodium salt. It is important that the copolymerized amount of the sulfoisophthalic acid metal salt is 0.5 to 10 mol% of the total dicarboxylic acid components, and particularly preferably 1 to 6 mol%. If the copolymerization amount of the sulfoisophthalic acid metal salt is less than 0.6 mol %, a sufficient alkali weight loss rate cannot be obtained, and the etching process requires a long time. On the other hand, if it exceeds 10 mol %, the physical properties of the resin will deteriorate significantly.

The polyester resin used in the present invention has at least 80% of its main chain composed of butylene terephthalate units.

The butylene terephthalate unit referred to herein is one obtained from terephthalic acid or its lower alkyl ester and 1,4-butanediol.

Although there are no particular limitations on the metal species of the metal silicate and metal carbonate used in the present invention, aluminum silicate, calcium silicate, and calcium carbonate are preferred.

It is important that the amount of metal silicate and/or metal carbonate is 5 to 100 parts by weight, preferably 10 to 60 parts by weight, based on 100 parts by weight of the polyester resin. The amount of this metal silicate and/or metal carbonate is 6
If the amount is less than 1 part by weight, the formation of depressions will not be sufficient even if alkali etching is performed, and therefore the adhesion to the plated metal film will be insufficient. On the other hand, if it exceeds 100 parts by weight, the fluidity during heating and melting will decrease and molding will become difficult;
The resulting molded product is brittle and has a poor appearance after plating.

In the present invention, in addition to metal silicate and metal carbonate, one or more of granular metal oxides such as silica, antimony dioxide, and titanium oxide, and fibrous reinforcing materials such as glass fiber and carbon fiber are used in combination. It is also possible to do so.

Various methods can be considered for blending metal silicate and metal carbonate into polyester resin, but from the viewpoint of the appearance of the molded product after plating, it is desirable to disperse it as uniformly as possible before molding. Examples include a method of melt-kneading using a screw or multi-screw extruder.

(Example) A more detailed explanation will be given below using examples.

The physical properties shown in the Examples were measured by the following method.

(1) Tensile strength Measured according to ASTM D-688.

(2) Flexural modulus Measured according to ASTM D-790.

(3) Impact strength ASTM D-256 (Izots, with notches.

1/4 inch).

(4) Adhesion strength of plated metal film Peeling speed I Q Cm/min, 9 of adhesion surface of 1 cm width
It is expressed as peel strength in the 0° direction.

Example 1 Calcium silicate (N
(manufactured by YCO, NYAD1250), and using a vent type 3Qmmφ241 outlet machine, the cylinder temperature was 2.
The mixture was melt-kneaded at 50 to 260°C to obtain pellets for molding.

The obtained pellets were used for injection molding, which is commonly practiced in the molding process of polybutylene terephthalate resin.

After washing and degreasing this injection molded product with a neutral detergent, it was immersed in an 80% sodium hydroxide aqueous solution at 70°C for 2 minutes, and then
% aqueous hydrochloric acid solution, washed with water, and subjected to electrolytic copper plating according to the conventional method shown below.

(1) Sensitizing Immerse for 2 minutes at 45° C. in a mixture of 20 g of stannous chloride, 10 ml of 88% aqueous hydrochloric acid solution, and 10,100 O of water, and then wash with water.

(2) Activate/G Mixture of 0.5 g of palladium chloride, 5 ml of 88% aqueous hydrochloric acid solution, and 10,100 O of water. Soak overnight at 46°C for 2 minutes and then rinse with water.

(3) Chemical nickel plating nickel sulfate 20g/1. Ammonium a-acid 50 g/
l, sodium hypophosphite 15 g/l.

It is immersed in a solution containing 20 g/l of sodium citrate at 45°C for 80 minutes and then washed with water.

(4) Steel plated sulfuric acid steel 220g/1. In an aqueous solution of sulfuric acid 50 g/l, 2
Electricity was applied for 40 minutes at a current density of 1.5 A/dm2 at 5°C to form a plated metal film having a thickness of about 80 μm on the metal steel.

Tensile strength of the molded product obtained through the above process.

The flexural modulus, impact strength, and peel strength of the plated copper film are shown in Table 2.

Table-1 - Table of blending amount based on 100 parts by weight of polyester -2 (Effects of the invention) The polyester resin composition according to the present invention has excellent moldability, mechanical performance, and adhesion to plated metal. It is useful as a molding material for electrical, electronic parts, mechanical parts, etc.

Claims (6)

[Claims] (1) Polyester resin 1 copolymerized with 0.5 to 10 mol% of a metal salt of sulfoisophthalic acid, and at least 80 mol% of the main chain is composed of butylene terephthalate units.
A polyester resin composition containing 5 to 100 parts by weight of a metal silicate and/or a metal carbonate per 00 parts by weight. (2) The composition according to claim 1, wherein the metal salt of sulfoisophthalic acid is a sodium salt. (3) The composition according to claim 1, wherein the copolymerized amount of the sulfoisophthalic acid metal salt is 1 to 5 mol%. (4) The composition according to claim 1, wherein the metal silicate is aluminum silicate or calcium silicate. (5) The composition according to claim 1, wherein the metal carbonate is calcium carbonate. (6) The amount of metal silicate and/or metal carbonate is 10
50 parts by weight of the composition of claim 1.