JPS61120833A - Purification of polyphenylene sulfide resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin extremely small in a content of free electrolytic impurities, by heating a mixture of a polyphenylene sulfide resin and a hydrotalcite in the presence of deionized water and/or N-methylpyrrolidone. CONSTITUTION:The titled high-purity resin excellent in electrical properties, reliability of moisture resistance, etc., is obtained by heating a mixture of 100pts. wt. polyphenylene sulfide resin comprising 70mol% or above one having repeating units of formula I and, optionally, 30mol% or below one having repeating units of formulae II, III, etc., and 0.1-5pts.wt. hydrotalcite of formula IV (wherein M<2+> is a bivalent metal ion of Mg, Mn, Fe, Cu or the like, M<3+> is a trivalent metal ion of Al, Fe, Cr or the like, A<n-> is an n-valent anion of OH, F, Cl, Br, NO3, SO4<2-> or the like, and x is in the range of 0<x<=0.33) in the presence of 1-100pts.wt. deionized water and/or 200-1,000pts.wt. N- methylpyrrolidone.

Description

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

[Background technology]

Polyphenylene sulfite resin (rPPS 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, L-transistors, and capacitors, it is important to note that if the electrodes or wiring of the components corrode or become disconnected, leakage current increases. In order to prevent such troubles from occurring, it is necessary to reduce the electrolyte impurities 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-dichlorohenzene with sodium sulfide in an organic amide solvent is disclosed in Japanese Patent Publication No. 45-3368, and also, 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 properties and moisture resistance! The n-characteristics 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 disadvantage of requiring a long processing time, and no matter how many times the extraction operation is repeated, it still does not contain enough impurities to be used as a material for coating or sealing electronic components. It also has the disadvantage that it is difficult to obtain PPS 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.

Further, 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 was made in view of the above circumstances. PP with a very low content of free electrolyte impurities
[Disclosure of the Invention] In order to achieve the above object, the inventors have conducted various studies. As a result, it was discovered that a mixture of PPS resin and hydrotalcites can be heated in the presence of deionized water and/or N-methylpyrrolidone, and the present invention has now been completed.

Therefore, this invention provides deionized water and/or N
- A method for purifying PPS resin in which a mixture of PPS resin and hydrotalcites is heated in the presence of methylpyrrolidone. The present invention will be explained in detail below.

In carrying out the xppsPPS resin method of this invention, the PPS resin used is, for example, AS
Ml (melt index) value measured according to the method of TM old 238-70, that is, load 5 kg, temperature 3
1.The value measured at 5.6°C (60,0°F) is 10
000 (g/10 min) or less, or the molecular weight M calculated by conversion from the intrinsic viscosity as follows:
is 0.05 or more. However, it is not limited to this. Molecular weight M
is the value obtained by dividing the relative viscosity value obtained based on the viscosity of a sample with a polymer solution concentration of 0.4 g/Loomβ at 206°C (403'P) in α-chlornaphthalene divided by the polymer concentration. The natural logarithm of , that is, the following equation (A
) [η)-1n (relative viscosity value/polymer concentration)... (
A) When η calculated by is plotted as a graph with polymer concentration as a variable, it is obtained by extrapolating the polymer concentration to infinitesimal (0).

PPS resins are copolymerized with other components if they contain 70 mol% or more, preferably 90 mol% or more of a structure having a repeating unit represented by the following formula (B). 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 copolymer components have a branched structure or a crosslinked structure, they can be used in combination or alone.

In this case, typical units of other copolymerization components include trifunctional units as shown below, ether units as shown below (blank below), Examples include a sulfone unit as shown in , a ketone unit as shown below, a meta unit as shown below, or a substituted sulfide unit 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.

Such PPS resin is known from the aforementioned Japanese Patent Publication No. 45-3368.
It can be manufactured by the manufacturing method disclosed in Japanese Patent Publication No. 52-122340.

Hydrotalcites have the following general formula (C)
Alternatively, it is a non-stoichiometric compound formed by (D).

CM product M', ÷ (OH)2) ”+ [A; Enter/m
H2O) ”-... (C) M,-,MX OI+XA
・ ・ ・ (D) Here, M2+:
Mg”, Mn”, Fe2+, Co”, Ni”;
Divalent metals such as Cu'' and Zn2.

M”: AI”+Fe”
+Cr”, C03+, 1n3) and other trivalent metals.

A”-: OH-, F-, CI-, Br-, NO:
+, CO3”-+ so, “-, Fe (CN)62
-, CH3COO-, oxalate ion, n-valent anion such as salicylate ion.

X is in the range O<x≦0.33.

The product represented by the formula (D>) can be obtained by firing the product represented by the formula (C).

Commercially available hydrotalcites include KW-1000, KW-1015, KW-1100, manufactured by Kyowa Kagaku.
KW-2000, KW'-2007゜KW-2015,
There are KW-2100, etc. KW-1000, KW-10
15, KW-1100 is Mga, s A 1 g (
OH) ++CO3・mH, o, (m=3-3.5)
, KW-2000, KW-2007, KW-2015 and KW-2100 Mgo, 7A 10.301.1
Each has a chemical composition of 5.

As deionized water, for example, water made by using a combination of a cation exchange resin and an anion exchange resin can be used.

A mixture of PPS resin and hydrotalcites is heated in the presence of at least one of deionized water and N-methylpyrrolidone. When blending raw materials, P
For 100 parts by weight of PS resin, 0.1 to 5 parts by weight of hydrotalcite type number, 1 to 200 parts by weight of deionized water,
It is preferable to use 200 to 1000 parts by weight of N-methylpyrrolidone.

Hydrotalcites can be prepared using deionized water and/or N
- When heated in the presence of methylpyrrolidone, it produces extremely high anion exchange ability and neutralization ability, and it exchanges and adsorbs a large amount of halogen ions such as 01- and other anions, as well as a large amount of Na1, etc. Adsorbs and inactivates both metal ions by converting them into their hydroxides and adsorbing them.

Therefore, the content of free electrolyte impurities contained in the PPS resin is extremely small, and the electrical properties, moisture resistance reliability, etc. are extremely excellent.

Note that the purification of the PP'S resin is preferably carried out in the presence of deionized water or in the presence of deionized water and N-methylpyrrolidone.

Next, Examples and Comparative Examples will be explained (Example) A 200 cc Au 1-crepe with a stirrer was prepared using 55.4 g of N-methylpyrrolidone and 4 ml of sodium sulfide nonahydrate.
B g '' (0.2 mol) was charged, and the temperature was gradually raised to 200°C over about 2 hours while stirring under a nitrogen atmosphere, and 26 g of water was distilled off. Next, the reaction system was heated to 160° C.
After cooling to ℃, 30 g of p-dichlorobenzene (0,
204 mol) and 10 g of N-methylpyrrolidone,
The temperature was raised to 245°C in 20 minutes, and the reaction was carried out at 245°C for 3 hours. The internal pressure at the end of the polymerization reaction is 7.6 kg/
It was ct. After the reaction is complete, cool the autoclave and
The contents were separated by filtration.The resulting solid content was washed 10 times with deionized water at 80°C, and then twice with acetone, and then dried at 120°C to form a light gray fine powder of PPS.
17.8 g of resin was obtained. The yield was 95%.

Hydrotalcites (KW-1000 or KW-200'O manufactured by Kyowa Chemical Industries) and deionized water are added to the PPS resin thus obtained in the proportions shown in Table 1, In Examples 3.4 and 5, further N
-After adding methylpyrrolidone, heat treatment was performed according to the treatment method shown in the same table. Next, the treated product was filtered to remove deionized water and N-methylpyrrolidone, and the filtered product was washed with deionized water and dried to obtain a purified product.

(Comparative Example) Deionized water was added in Comparative Example 1, and N-methylpyrrolidone was added in Comparative Example 2 to the same PPS resin used in the example in the proportions shown in Table 1. Heat treatment was performed according to the treatment method shown in the same table. After that, the same operation as in the example was performed to obtain a purified product.

(Left below) Purified PPS obtained in Examples 1 to 5 and Comparative Example 1.2
The impurity ion concentrations of Na+ and Cl- were measured for the resin (extraction treated product). The results are shown in Table 2. However, the impurity ion concentration was measured as follows.

After putting 2.5 g of sample into a 100 cc glass container, add 4 cc of methanol special reagent and 46 cc of deionized water.
was added and treated under boiling conditions for 20 hours. Treating solution with Na3
A test solution was prepared by filtration with filter paper. Impurity ions in the test solution were measured using ion chromatography manufactured by Toyo Soda Kogyo 11 (product number HLC-803D), and the measured values were compared with a calibration curve prepared in advance using a sodium chloride standard solution to determine the amount of impurity ions. I got it.

(The following is a blank space) Table 2 From Table 2, the purified PPS resins obtained in Examples 1 to 5 have significantly lower concentrations of Na'' and C than those obtained in Comparative Examples 1 and 2.
It can be seen that there is little I-.

As a result of measuring the concentration of impurity ions generated from electrolytes other than sodium chloride, the purified PPS resin obtained in the example also contained significantly less impurity ions than that obtained in the comparative example.

〔Effect of the invention〕

In the method for purifying PPS resin according to the present invention, PPS resin is purified in the presence of deionized water and/or N-methylpyrrolidone.
Since the PS resin mixed with hydrotalcites is heated, it is possible to obtain a PPS resin with a very low content of free electrolyte impurities.

Agent Patent Attorney Takehiko Matsumoto Yukikyoryu Rokune ↑ Seisho M) Rou 060 January 15, 2, Name of the invention Method for purifying polyphenylene sulfide resin 3, Relationship with the person making the amendment Patent application Address 1048 Oaza Kadoma, Kadoma City, Osaka Name (583) Matsushita Electric Works Co., Ltd. Representative Director Iku Kobayashi 4, Agent 6, Tadashi Neili's subject specification 7, Contents of amendment (]) Akira , ■Correct the word ``toitsu'' in line 20 of page 2 of book 1 to ``toi.''

(2) It says "method" on page 5, line 18 of the specification,
Correct it to "How."

(3) r52-122340 on page 9, line 11 of the specification.”
The statement has been corrected to r52-1'2240J.

(4) r F on page 10, line 6 to line 7 of the intervening page of the specification
e (CN) e It says 2J, rFe(CN)
63-", corrected.

(5) From line 13 to line 14 on page 10 of the specification: “
Kyowa Chemical Co., Ltd. (Kiku) has been corrected to read Kyowa Chemical Industry Co., Ltd.

(6) The statement "95%" on page 13, line 4 of the specification is corrected to "83%."

Claims (4)

[Claims] (1) A method for purifying polyphenylene sulfide resin, which involves heating a mixture of polyphenylene sulfide resin and hydrotalcites in the presence of deionized and/or N-methylpyrrolidone. (2) The method for purifying polyphenylene sulfide resin according to claim 1, wherein 0.1 to 5 parts by weight of hydrotalcites are mixed with 100 parts by weight of polyphenylene sulfide resin. (3) Deionized water is polyphenylene sulfide resin 10
The method for purifying polyphenylene sulfide resin according to claim 1 or 2, wherein 1 to 200 parts by weight is used per 0 parts by weight. (4) The method for purifying polyphenylene sulfide resin according to any one of claims 1 to 3, wherein 200 to 1000 parts by weight of N-methylpyrrolidone is used per 100 parts by weight of polyphenylene sulfide resin.