JPS62143933A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition outstanding in reliability for moisture resistance, etc., suitable for coating and sealing for electronic parts, etc., from such a polyphenylene solfide resin that the amount of specific sulfur-contg. oligomer components extracted by reflux extraction process represents value below a specified level. CONSTITUTION:The objective composition can be obtained from a polyphenylene sulfide resin in which the total amount of sulfur-contg. oligomer components of formulae I-V (n is 1-4), respectively, extracted by reflex extraction process represents a value <=1.2wt%. The amount extracted of a cyclic phenylene sulfide derivative of formula I represents pref. <=0.5wt%, whereas such amounts of straight-chain phenylene sulfide derivatives of formulae II and III <=0.1wt%, respectively.

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 Q [<rppSPPS
Because resins have excellent heat resistance, chemical resistance, and mechanical properties, they are used in various types of molded products such as parts and housings for machines and equipment, 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. When PPS resin is used as a coating or sealing material for electronic components such as IC transistors and capacitors, the electrodes and wiring of the components may corrode or break, resulting in large leakage currents. (In order to prevent such troubles from occurring, it is necessary to reduce the electrolyte impurities as described above as much as possible to improve moisture resistance and reliability.

By the way, as a general method for producing PPS resin, a method of reacting an aromatic halide such as p-dichlorobenzene with sodium sulfide in an organic amide solvent is disclosed in Japanese Patent Publication No. 45-3368, and also 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.

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. has been done.

When using the former method to coat or seal electronic components such as ICs, transistors, and capacitors using PPS resin that has halved the amount of water-extractable electrolyte components, the electrodes, wiring, etc. of the components The occurrence of troubles such as corrosion and increased leakage current tends to be somewhat reduced. However, the moisture resistance reliability etc. could not be improved as much as expected. For example, Na1l is 1
Even if it was reduced to /3, the moisture resistance reliability was not improved as much as expected. Also, the latter method did not meet my expectations.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a PPS resin composition having excellent performance such as moisture resistance and reliability.

[Disclosure of the invention]

In order to achieve the above objectives, the inventors have conducted repeated research. As a result, if the content of the sulfur-containing oligomer component extracted from PPS resin by reflux extraction is 1.2% by weight or less, the moisture resistance reliability of electronic parts will be reduced when coating or sealing them. We have found that this invention can be significantly improved and have now completed this invention.

Therefore, the present invention uses a PPS resin having a sulfur-containing oligomer component of 1.2% by weight or less, which is extracted by a reflux extraction method and is represented by the following general formula (al to (el). The gist is a PPS resin composition.

(n=1-4)...(a) (n=1-4) (n=1-4) (n=1-4) The present invention will be explained in detail below.

The PPS resin used in this invention is:
For example, the Ml (melt index) value measured according to the method of ASTM 0123B-70, i.e., the value measured at a load of 5 kg and a temperature of 315.6°C (600'F), is 10000 (g/10 minutes). or 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 molecular weight M is 206"C (403
The natural logarithm of the value obtained by dividing the relative viscosity value obtained based on the viscosity measured at °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).

A PPS resin is one that contains 70 mol% or more, preferably 90 mol% or more of a structure having a repeating unit represented by the following formula (B), and is considered to be a t-t copolymerized with other components. Alternatively, the copolymer alone may be used as long as the mol% of the repeating units in the copolymer is 70 mol% or more, preferably 90 mol% or more. In this case, even if some of the other co-electrolytic synthetic resins have a branched or cross-linked structure, they can be used in combination or alone.

In this case, other copolymerization component units and representative units include trifunctional units as shown below, ether units as shown below, sulfone units as shown below, and sulfone units as shown below. There are ketone units as shown below, meta units as shown below, substituted sulfide units as shown in the following general formula, etc.

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.

The sulfur-containing oligomer component is a phenylene sulfide derivative represented by the general formula (al to (el),
Broadly speaking, there are three types. That is, a cyclic phenylene sulfide derivative represented by the formula (a), (b),
They are linear phenylene sulfide derivatives represented by formulas (c) and +d), and benzothiophene represented by formula (e).

According to the inventors' research, these sulfur-containing oligomer components can be found in ordinary PPS resins by reflux extraction method.
It was found that the amount extracted was about 3% by weight. Therefore, the content of the sulfur-containing oligomer component extracted by the reflux extraction method in the PPS resin is set to 1.2% by weight or less.

Surprisingly, when electronic parts, etc. are coated or sealed with a PPS resin composition in which such a PPS resin is used,
This significantly improves the moisture resistance and reliability of parts, etc.

In the sulfur-containing oligomer, the amount of the cyclic phenylene sulfide derivative represented by formula (a) extracted by the reflux extraction method is preferably 0.5% by weight or less based on the amount of the PPS resin.

This is because the moisture resistance reliability etc. of the PPS resin composition are further improved. Furthermore, among the linear phenylene sulfide derivatives in the sulfur-containing oligomer, compounds containing chlorine,
That is, the amount of the compound represented by formula (bl, (c)) extracted by the reflux extraction method is 0 of the amount of PPS resin.
．． More preferably, the content is 1% by weight or less. This is because the moisture resistance reliability, etc. of the PPS resin composition is improved even more markedly. It should be noted that the amount of electrolyte impurities in the PPS resin should be reduced as much as possible.The reflux extraction method used here refers to the extraction method using a Soxhlet extractor using 100 ml of dimethylformamide (DMF) for 10 g of PPS resin. Reflux for 2 hours and extract (Soxhlet extraction)
It is to do. This reflux extraction method is only used as a standard for measuring sulfur-containing oligomer components, and any method may be used to actually remove the sulfur-containing oligomer components from PPS resin. Needless to say.

When using the PPS resin composition as a sealing molding material, etc.
Usually, inorganic fillers are used. As the inorganic filler, conventionally known ones can be used. For example, glass fiber, fused silica, crystalline silica, alumina, zirconia,
Calcium silicate.

Talc, glass peas, glass powder, zinc white, calcium carbonate, clay, and metal powder whose surface is coated with an insulating film. can give. Such inorganic fillers may be used alone, or two or more types may be used in combination. Further, it is preferable that such an inorganic filler is surface-treated with a silane-based or titanate-based surface treatment agent.

When used for sealing, etc., in addition to inorganic fillers, additives such as colorants and internal lubricants may be added to the PPS resin composition as necessary. Generally, only small amounts of additives are used.

The PPS resin composition according to the present invention can be produced by a known method using Ouki raw materials. For example, the raw materials are mixed in a mixer such as a Henschel mixer or a tumbler, and then melt-kneaded in an extruder. Then, a PPS resin composition (PPS resin molding material)' can be easily obtained.

When sealing electronic components using the PPS resin composition according to the present invention, it is usually preferable to carry out low-pressure sealing molding at a pressure of 100 kg/cnl or less.

Next, N-methylpyrrolidone 138
5g and 845g of crystalline sodium sulfide (water content 52%)
The temperature was gradually raised to 205°C over about 2 hours while stirring under a nitrogen atmosphere, and 305 g of water was distilled off. Next, after cooling the reaction system to 170°C, P
-750g of dichlorobenzene and 5g of N-methylpyrrolidone
00g and sealed with nitrogen at 1 kg/cra, heated to 250°C in about 25 minutes, and heated to 250°C.
The reaction was allowed to proceed for 3 hours at °C. The internal pressure at the end of the polymerization reaction is 9,
It was 8 kg/cra.

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, and further washed twice with deionized water, and then dried at 120° C., resulting in a white powdery PPS resin with a resin content of 93.5%. This resin immediately after synthesis is referred to as "resin A."

For 10g of this resin AJ, dimethylformamide (
Soxhlet extraction was performed using 100 ml of DMF for 2 hours, followed by drying at 120° CT under reduced pressure.

As a result, the extracted oligomer component was 3.2% by weight. The extraction residue obtained here is referred to as "resin B".

Next, "Resin B" was subjected to Soxhlet extraction in the same manner as described above. As a result, the extracted oligomer component was 1.5% by weight. The extraction residue obtained here is referred to as "Resin C".

Furthermore, "Resin C" was subjected to Soxhlet extraction in the same manner as described above. As a result, the oligomer component extracted was 1.0%. The extraction residue obtained here is
"Resin D".

"Resin D" was subjected to Soxhlet extraction in the same manner as described above. As a result, the extracted oligomer component was 0.
It was 8% by weight. The extraction residue obtained here is referred to as "Resin E".

"Resin E" was subjected to Soxhlet extraction in the same manner as described above. As a result, the extracted oligomer component was 0.
It was 6% by weight.

These results are shown in Table 1 below.

The extract extracted from resin A-E was analyzed by GPC (gel permeation chromatograph, HLC-803 manufactured by Toyo Soda Co., Ltd.).
D). The separation column is AD-8 manufactured by Showa Denko (■).
We decided to use two 03/S. All measurement curves were approximately as shown in FIG.

Components A-D corresponding to each peak shown in Figure 1 were fractionated and analyzed using a mass spectrometer (Shimadzu @) at a vacuum level of 1.
The gas generated was analyzed by increasing the temperature from 30° C. to 400° C. at 0-7 torr. As a result, component A is a benzothiophene represented by the above +et formula, component B is a linear phenylene sulfide derivative represented by the above formula (d), and component C is represented by the above formulas (b) and (c). The resulting linear phenylene sulfide derivative was found to be a cyclic phenylene sulfide derivative represented by the above formula C81.

Therefore, for each oligomer component extracted from resins A-E, components A-D separated therefrom were dried under reduced pressure at 120° C., and the weight ratio of components A-D was measured. The results are also shown in Table 1.

On the other hand, deionized water 100
Both were mixed at a ratio of ml, heated to 100°C, and extracted for 1 hour. The same extraction operation was repeated three times for this extraction residue. The resin that has been extracted three times is
"Resin F".

Impurity ions (N a
)? ffi degree was measured. The results are shown in Table 2.

Note that the impurity ion concentration was measured as follows.

Place the sample in an aluminum ring with a diameter of 30m/m and heat it for 400k.
g/c++? Tablets were made under pressure. The Na content in this tablet was determined by Rigaku Denki Kogyo (transversely split fluorescent X-ray).
SYSTEM 3080E2).

A calibration curve for the Na content in the resin was created 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.

Table 2 From Table 2, Resin F has a higher N content than the original commercially available PPS resin.
It can be seen that the atQ degree has decreased. However, the amount of sulfur-containing oligomers was hardly reduced, and it is thought that the amount extracted by the reflux extraction method would greatly exceed 1.2% by weight.

Examples 1 to 3 as a molding material using the above resins A-F
And PPS resin compositions of Comparative Examples 1 to 3 were made. However, Example 1 is resin C1, Example 2 is resin C, Example 3 is resin C1, and Example 2 is resin C1.
Resin E was used for Comparative Example 1, Resin B was used for Comparative Example 2, and Resin F was used for Comparative Example 3. The manufacturing method is as follows.

2 glass fibers with an average fiber length of 3 to 40 parts by weight of resin
0 parts by weight and 40 parts by weight of fused silica were added and uniformly mixed using a Henschel mixer. Thereafter, the mixture was melt-kneaded at 300°C using a -shaft extruder to obtain a PPS resin composition.

Using the PPS resin compositions of Examples 1 to 3 and Comparative Examples 1 to 3, a semiconductor element power IC was sealed and molded using an injection molding machine at a pressure of 80 kg/cnl to produce a molded product.

Applying a bias to the obtained molded product, P CT
(Pressure Cooker Te5t) method under the conditions of water vapor pressure of 2 atm and temperature of 121°C.
A deterioration test was conducted for up to 00 hours. However, a molded product in which the bonding wire is cut or the leakage current increases to more than 500% of the allowable value is determined to be a defective product, and the state of deterioration can be checked by checking the number of defective products out of 100 samples after a predetermined period of time has elapsed. I decided to do so.

The results are shown in Table 3. However, in the table, the denominator indicates the total number of samples, and the numerator indicates the number of defective products.

Table 3 shows that the molded products using the PPS resin compositions of Examples 1 to 3 showed less deterioration and significantly improved moisture resistance reliability than the molded products using the PPS resin compositions of Comparative Examples 1 to 3. You can see that

〔Effect of the invention〕

In the PPS resin composition according to the present invention, a PPS resin containing 1.2% by weight or less of the sulfur-containing oligomer component extracted by reflux extraction is used, so it can be used for sealing electronic parts, etc. When molded, etc., the moisture resistance reliability becomes extremely high.

[Brief explanation of drawings]

FIG. 1 is a graph showing the results of GPC analysis. Agent Patent Attorney Takehiko Matsumoto Figure 1

Claims (3)

[Claims] (1) The polyphenylene sulfide resin used is a polyphenylene resin extracted by a reflux extraction method and containing 1.2% by weight or less of a sulfur-containing oligomer component represented by the following general formulas (a) to (e). Sulfide resin composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(n=1-4)...
・(a) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(n=1-4)...
・(b) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(n=1-4)...
・(c) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(n=1-4)...
・(d) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(e) (2) The polyphenylene sulfide resin according to claim 1, wherein the extracted amount of the cyclic phenylene sulfide derivative represented by formula (a) among the sulfur-containing oligomer components is 0.5% by weight or less based on the amount of the polyphenylene sulfide resin. Composition. (3) Among the sulfur-containing oligomer components, formula (b) and (
The polyphenylene sulfide resin composition according to claim 1 or 2, wherein the extracted amount of the chlorine-containing phenylene sulfide derivative represented by formula c) is 0.1% by weight or less based on the amount of the polyphenylene sulfide resin.