JPH0240262B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] This invention relates to a polyphenylene sulfide resin composition having a very low content of free electrolyte impurities. [Background technology] Polyphenylene sulfide resin composition (hereinafter referred to as
Polyphenylene sulfide resin (hereinafter referred to as "PPS resin") has excellent heat resistance, chemical resistance, and mechanical properties, so it is used for injection molding, extrusion molding, etc. Using this method, it is used to form various types of molded products such as machine and device parts, housings, films, and fibers. When using PPS resin compositions for films, fibers, and various electrical and electronic parts, in order to exhibit the moldability and electrical insulation properties inherent to PPS resin, it is necessary to
It is preferable to minimize inorganic electrolyte impurities such as sodium chloride contained in the PPS resin. Additionally, when PPS resin compositions are used as coatings or sealing materials for electronic components such as ICs, 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 much as possible to improve moisture resistance and reliability. By the way, the general manufacturing method for PPS resin is as follows:
Japanese Patent Publication No. 45-3368 discloses a method of reacting an aromatic halide such as p-dichlorobenzene with sodium sulfide in an organic amide solvent.
Further, in order to obtain a PPS resin with a high degree of polymerization, an improved method using an alkali metal carboxylate as a polymerization aid is disclosed in Japanese Patent Publication No. 12240/1983. However, when PPS resin is produced using this method, electrolyte impurities are produced as a by-product in an amount that is almost the same as the produced PPS resin.
Conventional processing leaves a considerable amount of electrolyte impurities behind. Compositions (molded products) obtained using PPS resin containing large amounts of such electrolyte impurities
The electrical characteristics and moisture resistance reliability will be significantly inferior. Therefore, as a method to remove electrolyte impurities,
PPS resin powder obtained through normal processing is repeatedly boiled in deionized water for a long period of time to reduce impurities by eluting water-extractable electrolyte components. A method has been developed and disclosed in Japanese Patent Application Laid-Open No. 156342/1983. However, this method has the disadvantage that it takes a long time to process, and no matter how many times the extraction operation is repeated, it still does not contain enough impurities to be used as a coating or encapsulation material for electronic components. Another drawback is that it is difficult to obtain PPS resin. Instead of hot water extraction, solvent extraction treatment is used to
Even if the PPS resin is heated, the results are still not satisfactory. Additionally, US Pat. No. 4,071,509 discloses a method of 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] 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 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 is sufficient to mix the hydrotalcites described below with PPS resin and heat it.
Among these hydrotalcites, we have found that similar substances are better than hydrotalcite itself, and have now completed this invention. That is, the present invention provides a PPS obtained by heating and mixing a PPS resin with a hydrotalcite-like substance described below.
Its gist is resin compositions. This invention will be explained in detail below. Used in the PPS resin composition according to this invention
For PPS resin, the MI (melt index) value measured according to the method of ASTM D1238-70,
In other words, the value measured at a load of 5Kg and a temperature of 315.6℃ (600〓) is 10000 (g/10 minutes) or less.
Alternatively, it is suitable that the molecular weight M calculated from the intrinsic viscosity is 0.05 or more as shown below. 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/100 ml in α-chlornaphthalene at 206°C (403〓) divided by the polymer concentration. In other words, the natural logarithm of the following formula (A) [η] = In (relative viscosity value/polymer concentration)...When η calculated by the following formula (A) is graphed with the polymer concentration as a variable, the polymer concentration is infinitesimal ( 0)
can be obtained by extrapolating to PPS resin has the following formula (B) The structure with the repeating unit shown is 70
Copolymerized with other components may be used in combination as long as it contains mol % or more, preferably 90 mol % or more, and the mol % of the above repeating unit in the copolymer is 70 mol %. % or more, preferably 90 mol% or more, the copolymer alone may be used. 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 the following trifunctional units, Ether units as shown below, Sulfone units as shown below, A ketone unit as shown below, A meta unit as shown below, Alternatively, there are substituted sulfide units as shown in the following general formula. However, R in the formula is an alkyl group, 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. This kind of PPS resin was developed by the aforementioned Japanese Patent Publication No.
It can be manufactured by the manufacturing method disclosed in Japanese Patent Publication No. 52-12240. Hydrotalcites include not only the hydrotalcite itself represented by the general formula (C) below, but also its similar substance represented by the general formula (D) below.The effect of addition is that of this similar substance. It's more expensive. Therefore, in this invention, this similar substance is used. [M ²⁺ _1-x M ³⁺ _x (OH) ₂ ] ^x+ [A ^n- _x/o・mH ₂ O] ^x- …(C) M ²⁺ _1-x M ³⁺ _x O _{1+x/ 2} ...(D) Here, M ²⁺ : Mg ^2- , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ ,
Divalent metals such as Zn ²⁺ . M ³⁺ : Trivalent metal such as Al ³⁺ , Fe ³⁺ , Cr ³⁺ , Co ³⁺ , In ³⁺ , etc. A ^n- : OH ^- ., F ^- , Cl ^- , Br ^- , NO ₃ ^- , CO ₃ ^2- ,
n-valent anions such as SO ₄ ^2- , Fe(CN) ₆ ^3- , CH ₃ COO ^- , oxalate ion, and salicylate ion. x is in the range 0<x≦0.33. The product represented by formula (D) can be obtained by firing the product represented by formula (C). Commercially available hydrotalcites include KW-1000, KW-1015, and KW manufactured by Kyowa Chemical Industry Co., Ltd.
−1100, KW−2000, KW−2007, KW−2015,
There are KW-2100 etc. KW−1000, KW−1015,
KW-1100 is Mg _4.5 Al ₂ (OH) ₁₃ CO ₃・mH ₂ O (m=
3-3.5), KW-2000, KW-2007, KW-2015
and KW-2100 each have a chemical composition of Mg _0.7 Al _0.3 O _1.15 . Any conventionally used method may be used for heating and mixing the PPS resin and hydrotalcites. For example, mixing roll,
Both are placed in a kneading extruder, etc., and the PPS resin is melted and mixed by heating. Hydrotalcites are preferably mixed in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the PPS resin. Hydrotalcites have anion exchange ability and neutralization ability under high temperature and humid conditions (preferably high humidity conditions), so they can ion-exchange halogen ions such as Cl ^- and other ionic ions. At the same time, it adsorbs both metal ions such as Na ⁺ by converting them into their hydroxides and adsorbing them.
Inactivate. Therefore, if a heated mixture of PPS resin and hydrotalcites is used in a PPS resin composition, the content of free electrolyte impurities will be extremely small, resulting in very poor electrical properties, moisture resistance reliability, etc. It will be excellent. Note that, if necessary, the PPS resin composition may contain additives such as reinforcing fibers and inorganic fillers. In this case, when mixing and kneading the PPS resin and additives, hydrotalcites may be added and heated. In short, it is only necessary that the PPS resin and the hydrotalcites be heated and mixed at any point in the process of forming the PPS resin composition. Next, Examples and Comparative Examples will be described. (Comparative Example 1) In a 200 c.c. autoclave equipped with a stirrer, 55.4 g of N-methylpyrrolidone and 48 g of sodium sulfide nonahydrate were added.
(0.2 mol) and gradually raised the temperature to 200°C over about 2 hours while stirring under a nitrogen atmosphere.
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 were added, the temperature was raised to 245°C over 20 minutes, and the mixture was reacted at 245°C for 3 hours. The internal pressure at the end of the polymerization reaction is 7.6Kg/cm ²
It was hot. After the reaction was completed, the autoclave was cooled and the contents were filtered. The obtained solid content was washed 10 times with deionized water at 80°C, and further washed with acetone 2 times.
After washing twice, it was dried at 120° C. to obtain 17.8 g of pale gray fine powder PPS resin. The yield was 83%. 100 parts by weight of the obtained PPS resin and hydrotalcites (KW-1000 manufactured by Kyowa Chemical Industry Co., Ltd.) 3
Add weight parts to V mixer (vertical stirrer)
After stirring and mixing for 2 minutes using a 320° C. mixer, the mixture was heated and mixed in a kneading extruder at 320° C. to obtain a homogeneous composition. This composition was pulverized to obtain a PPS resin composition (powder) of 100 meshes. (Example) 100 mesh was prepared in the same manner as in Example 1, except that 1 part by weight of hydrotalcite (KW-2000 manufactured by Kyowa Chemical Industry Co., Ltd.) was used for 100 parts by weight of PPS resin. An under PPS resin composition was obtained. (Comparative Example 2) Only the PPS resin was crushed to obtain 100 mesh under. The impurity ion concentrations of Na ⁺ and Cl ^- were measured for Examples and Comparative Examples. The results are shown in Table 1. However, the impurity ion concentration was measured as follows. After putting 2.5 g of sample into a 100 c.c. glass container, add 4 c.c. of methanol special reagent and 46 g of deionized water.
cc was added and treated under boiling conditions for 20 hours. processing liquid
A test solution was prepared by filtration using No. 2 filter paper. Ion chromatography manufactured by Toyo Soda Kogyo Co., Ltd. (product number
Impurity ions in the test solution were measured using HLC-803D), and the measured values were compared with a calibration curve prepared in advance using a sodium chloride standard solution to obtain the amount of impurity ions.

〔Effect of the invention〕

In the PPS resin composition according to the present invention, since the PPS resin is heated and mixed with a hydrotalcite-like substance, the content of free electrolyte impurities is extremely small.

Claims (1)

[Scope of Claims] 1. A polyphenylene sulfide resin composition obtained by heating and mixing a polyphenylene sulfide resin with a hydrotalcite-like substance represented by the following formula. M ²⁺ _1-x M ³⁺ _x O _1+x/2 where, M ²⁺ : Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , CO ²⁺ , Ni ²⁺ , Cu ²⁺ ,
Divalent metal M ³⁺ such as Zn ²⁺ : 3 such as Al ³⁺ , Fe ³⁺ , Cr ³⁺ , CO ³⁺ , In ³⁺
Value metal x: 0<x≦0.33 2 The mixing ratio of the polyphenylene sulfide resin and the hydrotalcite-like substance is 0.1 to 5 parts by weight of the hydrotalcite-like substance to 100 parts by weight of the polyphenylene sulfide resin. A polyphenylene sulfide resin composition according to claim 1.