JPS61287927A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition low in a content of free electrolytic impurities, by using a polyphenylene sulfide resin having a specified average particle diameter as a component. CONSTITUTION:A polyphenylene sulfide (PPS) resin composition having an average particle diameter of 1-20mu. When the average particle diameter of said PPS resin is smaller than 1mu, it is inconveniently handled in washing, filtration, transportation, etc. On the contrary, when it is larger than 20mu, it is impossible to remove impurities inside even by repeated washing and extraction operations because of the excessively small surface area of the polymer, though it is possible to remove impurities adhering to the surface. Therefore, it is difficult to obtain a PPS resin of such an impurity content as to satisfy the level necessary for a material for coating or sealing electronic parts. As the PPS resin used, for example, one having a melt index <=10,000 (g/10min) as measured according to ASTM D1238-70 is desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a polyphenylene sulfide resin composition used as a molding material or the like.

[Background technology]

Polyphenylene sulfide resin (hereinafter referred to as "PPS resin")
) has excellent heat resistance, chemical resistance, mechanical properties, etc., so it is used in various types of molded products such as parts of machines and equipment, housings, films, and fibers.

When using PPS resin for films, fibers, and various electrical and electronic parts, in order to utilize the inherent moldability and electrical insulation properties of PPS resin, it is necessary to remove inorganic electrolyte impurities such as sodium chloride contained in the PPS resin as much as possible. It is preferable to reduce the amount. In addition, when PPS resin is used as a coating or sealing material for electronic components such as ICs, transistors, and capacitors, the electrodes and wiring of the components may corrode or break, resulting in increased leakage current. In order to prevent such troubles from occurring, it is necessary to improve moisture resistance and the like by minimizing the electrolyte impurities mentioned above.

By the way, as a general method for producing PPS resin, Japanese Patent Publication No. 45-3368 discloses a method in which an aromatic halide such as p-dichlorobenzene is reacted with sodium sulfide in an organic amide solvent, and High degree of polymerization P
In order to obtain a PS resin, an improved method using an alkali metal carboxylate as a polymerization aid is disclosed in Japanese Patent Publication No. 52-12240.

However, when PPS resin is produced by such a method, electrolyte impurities are inevitably produced as a by-product in an amount approximately equal to that of the produced PPS resin, and as a result, a considerably large amount of electrolyte impurities remains in normal processing. PPS resin (molded product) containing a large amount of such electrolyte impurities is
Electrical characteristics, moisture resistance reliability, etc. are significantly inferior.

Therefore, as a method to remove electrolyte impurities, the PPS resin powder obtained through normal processing is repeatedly boiled in hot water for a long time using deionized water.
A method for reducing impurities by eluting water-extractable electrolyte components was developed, and published in JP-A-55-1563.
It is disclosed in Publication No. 42.

However, this method has the drawback of requiring a long processing time, and no matter how many times the extraction operation is repeated, PPS with a satisfactory impurity content for use as a coating or sealing material for electronic components can be obtained. The disadvantage is that it is difficult to obtain resin.

Solvent extraction treatment is used instead of hot water extraction, and P is removed during treatment.
Even if the PS resin is heated, the results are still not satisfactory.

Additionally, US Pat. No. 4,071,509 discloses a method for reducing the content of inorganic components in PPS resin by heating a mixture of PPS resin and alkali metal carboxylate or lithium halide in an organic amide solvent. However, even with this method,
It is difficult to obtain a PPS resin with a satisfactory impurity content [Object of the Invention] This invention has been made in view of the above circumstances, and the content of free electrolyte impurities is extremely low. PP
The purpose of the present invention is to provide a S resin composition.

[Disclosure of the invention]

In order to achieve the above objects, the inventors have conducted various studies. As a result, it was discovered that if the average particle size of the polymer was set to 1 to 20 μm, it could be purified very efficiently using ordinary washing and extraction operations, and the present invention was hereby completed.

Therefore, in this invention, the average particle size of the polymer is 1 to 2.
The gist of the present invention is a polyphenylene sulfide resin composition characterized by a polyphenylene sulfide resin composition of 0 μm.

The PPS resin used in the present invention has, for example, an MI (melt index) value measured according to the method of ASTM 01238-70, that is,
The value measured at a load of 5 kg and a temperature of 315.6°C (600°F) is 10,000 (g/10 min) or less, or
Alternatively, it is suitable that the molecular weight M determined by conversion from the intrinsic viscosity as described below is 0.05 or more. However, it is not limited to this.

The molecule fiM is calculated by heating a sample with a polymer solution concentration of 0.4 g/100 m6 in α-chlornaphthalene at 206”C (40
The natural logarithm of the value obtained by dividing the relative viscosity value obtained based on the viscosity measured at 3° F. by the polymer concentration, that is, the following formula (A) [η) = 1n (relative viscosity value/polymer concentration)・... (A
) is graphed using the polymer concentration as a variable, it can be obtained by extrapolating the polymer concentration to infinitesimal (0).

If the pps resin contains 70 mol% or more, preferably 90 mol% or more of a structure having a repeating unit represented by the following formula (B), it can be copolymerized with the (th-) component. Alternatively, the copolymer alone may be used as long as the mol% of the repeating unit in the copolymer is 70 mol% or more, preferably 90 mol% or more. case,
Even if some of the other copolymer components have a branched or crosslinked structure, they can be used in combination or alone.

In this case, other copolymerization component units and typical units include trifunctional units as shown below, ether units as shown below, -o-o -os-s - as shown below. There are sulfone units as shown below, ketone units as shown below, meta units as shown below, or substituted sulfide units as shown in the following general formula.

However, R in the formula is an alkyl group or a phenyl group.

It is an alkoxy group, carboxyl group, amino group, sulfone group or nitro group.

Furthermore, the amount of inorganic electrolyte impurities contained in the resin is arbitrary, and there is no particular need to keep it small in advance. Note that, in general, the PPS resin in the present invention before heating and mixing contains at least 0.1% by weight of, for example, sodium ions.

The average particle size of the PPS resin in this invention is 1 to 20 μm
It is. If it is less than 1 μm, handling such as washing, filtration, transportation, etc. is inconvenient. On the other hand, if the particle size exceeds 20 μm, no matter how many times the washing and extraction operations are repeated, the surface area of the polymer particles is too small, so even if the impurities attached to the surface can be removed, the impurities contained inside cannot be removed. First, it is difficult to obtain a PPS resin with a satisfactory impurity content for use as a coating or sealing material for electronic parts.

As described above, as long as the PPS resin has an average particle size in the range of 1 to 20 μm, it is possible to obtain a PPS resin with a low impurity content using ordinary washing and extraction operations.

Materials using this material have excellent electrical properties and moisture resistance.

Next, Examples and Comparative Examples will be explained (Example) 1385 g of N-methylpyrrolidone and crystalline sodium sulfide (water content 52%) were placed in a 51 autoclave equipped with a stirrer.
845g and stirred under nitrogen atmosphere for about 2 hours.
The temperature was gradually raised to 205° C. over time, and 305 g of water was distilled off. Next, after cooling the reaction system to 170°C, 750 g of P-dichlorobenzene and 500 g of N-methylpyrrolidone were added, the system was sealed with nitrogen at 1 kg/cm'', and the temperature was raised to 250°C in about 25 minutes. , 25
The reaction was carried out at 0°C for 3 hours. The internal pressure at the end of the polymerization reaction is 9
, 8 kg/cm".

After the reaction was completed, the autoclave was cooled and the contents were filtered. The obtained solid was washed twice with deionized water at 80°C.
Next, it was washed twice with acetone, further washed twice with deionized water, and then dried at 120° C., and the white powdery PPS resin 5-5 was 93.5%.

The average particle diameter of this PPS resin was measured using a centrifugal automatic particle size distribution analyzer (model CAPA-500, manufactured by Ageba Manufacturing Co., Ltd.). When measuring, set the sample to 0.

A 2% Tween 20 solution was used, which had been previously dispersed by ultrasonic cleaning. The average particle size obtained was 7.1 μm.
Met.

(Comparative example) V-1 and P-4 obtained as commercially available PPS resins (
(manufactured by Phillips Petroleum Company) was measured in the same manner as in the examples. The average particle size of each is 23.7
μm and 50.5 μm.

20 g of each sample was mixed with 200 mA of deionized water, heated to 100° C., and extracted for 10 minutes.

For the extraction residue, the same extraction operation was repeated up to 10 times.

Each extraction residue was dried at 120°C and used as a sample for impurity ion measurement.

The results of measuring impurity ion concentrations for Examples and Comparative Examples are shown in the table below.

As is clear from the table, the example of PPS resin with an average particle size of 7.1 μm can be purified extremely efficiently. On the other hand, the comparative example V-1 has an average particle size of 23.7 μm and requires extraction operations more than 10 times, and P-4 with an average particle size of 50.5 μm remains impure even after repeated extraction operations. There are limits to the reduction of ions.

Note that the impurity ion concentration was measured as follows.

The sample was placed in an aluminum ring with a diameter of 30 m/m, and
A tablet was made under pressure of 1.5 kg/cm. The Na content in this tablet was measured using a fluorescent
Measured using YSTEM 3080E2).

A calibration curve for the Na content in the resin was prepared in advance by adding a known amount of sodium chloride to the PPS resin as a blank, and the calibration curve was compared with the measured values to obtain the Na content.

〔Effect of the invention〕

Since the PPS resin composition according to the present invention has a polymer having an average particle size of 1 to 20 μm, it can be purified extremely efficiently by ordinary washing and extraction operations.

Claims (1)

[Claims] (1) A polyphenylene sulfide resin composition characterized in that the average particle diameter of the polymer is 1 to 20 μm.