JP2008231249A - Polyphenylene sulfide resin composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyphenylene sulfide resin composition having a structure stably controllable from nano-meter order to micro-meter order. <P>SOLUTION: The polyphenylene sulfide resin composition is composed of (A) a polyphenylene sulfide resin having a molecular weight falling within a specific range and an alkali metal content falling within a specific range and (B) a thermoplastic resin selected from polyesters, polyamides, polyetherimides, polyamide-imides, polyimides, polycarbonates, polyether ketones, polythioether ketones, polyether ether ketones, polyphenylene oxides, polysulfones and polyether sulfones, and has a bicontinuous phase structure having a structural period of 0.01-1 μm or a disperse structure having a particle-to-particle distance of 0.01-1 μm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyphenylene sulfide resin composition capable of structural control from nanometer order to micron order, which can be usefully used as a structural material taking advantage of excellent mechanical properties and a functional material taking advantage of excellent regularity.

  Polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) has excellent properties as engineering plastics such as excellent heat resistance, flame retardancy, chemical resistance, dimensional stability, rigidity and electrical insulation. It is used for various electrical / electronic parts, machine parts, automobile parts, etc., mainly for molding.

  However, the PPS resin is known to be brittle and inferior in impact resistance and mechanical properties, and as a method for improving the toughness of the PPS resin, a method of blending another thermoplastic resin is known. For example, Patent Document 1 discloses a composition composed of a PPS resin and a thermoplastic polyester resin, Patent Document 2 includes a composition composed of a PPS resin and a polycarbonate resin, and Patent Document 3 includes a PPS resin and a polyamide resin. A composition is disclosed. However, even if any resin is used, the compatibility with the PPS resin is poor only by simply blending, and a sufficient effect for improving toughness has not been obtained.

  Patent Document 4 discloses a PPS resin composition having a structure in which both phases are continuously connected by kneading a PPS resin and a thermoplastic resin selected from polycarbonate, polysulfone, and polyetherketone under specific melt-kneading conditions. Things are disclosed. However, since the biphasic continuous structure obtained by this method is of the order of several micrometers and the regularity of the structure is low, the present situation is that a sufficient effect for improving toughness has not been obtained.

  On the other hand, as a PPS resin composition whose structure is controlled to the nanometer order, Patent Document 5 discloses that a phase decomposition is performed by spinodal decomposition or nucleation and growth, and a biphasic continuous structure having a structure period of 0.01 to 1 μm, or between particles. A PPS resin composition having a dispersed structure with a distance of 0.01 to 1 μm is described. However, in the invention described in the publication, the PPS resin has a weight average molecular weight (Mw) used in the present invention of 10,000 or more and a dispersity represented by weight average molecular weight / number average molecular weight (Mn) of 2.5 or less. The use of a PPS resin having an alkali metal content of 50 ppm or less is not described.

  As a specific production method of PPS resin, a method of reacting an alkali metal sulfide such as sodium sulfide with a polyhaloaromatic compound such as p-dichlorobenzene in an organic amide solvent such as N-methyl-2-pyrrolidone is proposed. This method is widely used as an industrial production method for PPS resins. However, in this method, only a PPS resin having a low molecular weight and a low melt viscosity can be obtained, and this PPS resin contains a large amount of low molecular weight components, and the dispersity represented by the ratio of the weight average molecular weight to the number average molecular weight is very large. The molecular weight distribution is wide. For this reason, when used for molding processing, sufficient mechanical properties are not exhibited, and there are problems such as a large amount of gas components when heated and a large amount of eluted components when in contact with a solvent. Further, since a large amount of by-product salt such as sodium chloride is produced in this production method, a by-product salt removal step is necessary after the polymerization reaction, but it is difficult to completely remove the by-product salt by a known treatment, and it is commercially available. The general-purpose PPS resin contains an alkali metal content of about 1000 to 3000 ppm. Thus, when the alkali metal salt remains in the produced polymer, when the PPS resin and the thermoplastic resin are polymer-alloyed, the thermal stability is inferior, and a biphasic continuous structure having a structural period of 0.01 to 1 μm, or There has been a problem that it is difficult to maintain a dispersed structure having an interparticle distance of 0.01 to 1 μm, and improvement has been desired.

  In order to improve the low melt viscosity, which is a problem of the PPS resin by the above production method, for example, a step of forming a crosslinked structure and increasing the molecular weight by performing a gas phase oxidation treatment in an oxidizing atmosphere such as in air Is required, and the process is further complicated and productivity is reduced (for example, see Patent Document 6).

  As a method of improving one of the problems of the PPS resin, that is, the point that the PPS resin contains a large amount of low molecular weight components and has a wide molecular weight distribution, the minimum temperature at which the PPS resin forms a molten phase is used for the mixture of PPS resin containing impurities In a higher state, a method of purifying impurities by subjecting them to thermal extraction by phase separation into a polymer melt phase containing PPS resin and a solvent as a main solvent phase, or collecting and recovering granular polymer after cooling A method has been proposed. In these methods, impurities are extracted by the heat extraction effect, so it is expected that the metal content of the PPS resin is reduced and the molecular weight distribution is narrowed, but the effect is insufficient, and expensive organic solvents are used. The process was complicated due to the method used. In addition, this method certainly reduces the amount of low molecular weight components contained in the PPS resin, but the effect is insufficient, and particularly the weight reduction rate when the PPS resin is heated is large, and there are many gas components, so that the molding processability is high. There is a problem that the mechanical strength is insufficient and the mechanical strength is insufficient (for example, Patent Documents 7 and 8).

  Further, as a method for producing a PPS resin having a narrow molecular weight distribution, a method in which a cyclic arylene sulfide oligomer is subjected to heat ring-opening polymerization under an ionic ring-opening polymerization catalyst is disclosed. In this method, unlike the above-mentioned patent documents 7 and 8, it can be expected to obtain a PPS resin having a narrow molecular weight distribution without performing a complicated organic solvent washing operation, and a PPS resin having a low low molecular weight component can be obtained. I can expect. However, this method has a problem that a large amount of alkali metal remains in the resulting PPS resin because an alkali metal salt of sulfur such as sodium salt of thiophenol is used as a ring-opening polymerization catalyst in the synthesis of PPS resin. Further, in this method, when the amount of residual alkali metal in the PPS resin is reduced by reducing the amount of the ring-opening polymerization catalyst used, there is a problem that the molecular weight of the obtained PPS resin is insufficient. Furthermore, although there is no disclosure about the weight reduction rate when the PPS resin obtained by this method is heated, the initiator used in the method has a lower molecular weight than the PPS resin, so that the PPS resin obtained by the method is used. The weight loss during heating was large and the amount of gas generated was large, which was a factor that caused a decrease in molding processability and mechanical strength. (For example, patent documents 9 and 10).

  The problem of the PPS resin obtained by the above method, that is, a method for reducing the residual amount of alkali metal in the PPS resin, is the ring-opening polymerization of a cyclic aromatic thioether oligomer in the presence of a polymerization initiator that generates sulfur radicals by heating. A method for producing a PPS resin is disclosed. In this method, since a nonionic compound is used as the polymerization initiator, it is considered that the alkali metal content of the obtained PPS resin is reduced. However, the glass transition temperature of the PPS resin obtained by this method is as low as 85 ° C., which is probably because the molecular weight is low and the PPS resin contains a large amount of low molecular weight components. Furthermore, although there is no disclosure about the weight reduction rate when the PPS resin obtained by the method is heated, the polymerization initiator used in the method has a lower molecular weight than the PPS resin and is inferior in thermal stability. When the PPS resin obtained by this method is heated, a large amount of gas is generated, and there is a concern that molding processability is inferior (for example, Patent Document 11).

  Also known is a polymerization method of PPS resin in which a mixture of cyclic PPS resin and linear PPS resin is heated as a monomer source (Non-patent Document 1). This method is an easy polymerization method for PPS resin, but the resulting PPS resin has a low degree of polymerization and is not suitable for practical use. Although this document discloses that the degree of polymerization can be improved by increasing the heating temperature, it still does not reach a molecular weight suitable for practical use, and in this case, the formation of a crosslinked structure is not achieved. It has been pointed out that only PPS resins that cannot be avoided and have inferior thermal properties can be obtained, and a high-quality PPS resin polymerization method more suitable for practical use has been desired.

  On the other hand, as a method of reducing the weight reduction rate when the PPS resin is heated, many proposals have been conventionally made on a method of heat-treating the PPS resin. For example, a method of heat-treating the PPS resin in an oxygen atmosphere below the melting point, A method of heat-treating a PPS resin under an inert gas atmosphere at a temperature lower than the melting point has been disclosed (for example, Patent Documents 12 and 13). Although the PPS resin obtained by these methods certainly has a tendency to reduce the weight reduction rate when heated compared to the PPS resin not subjected to heat treatment, the weight reduction rate when heated is still satisfactory. It wasn't. Furthermore, the PPS resin obtained by this method contains many low molecular weight components, has a very high degree of dispersion expressed by the ratio of the weight average molecular weight and the number average molecular weight, has a wide molecular weight distribution, and has an alkali metal content. The problem of the low purity of the product has not been solved.

Another method for heat-treating PPS resin is to perform melt extrusion while purging the vent port with nitrogen and keeping the vent port under reduced pressure when melt-extruding the PPS resin using an extruder having a vent port. The obtained PPS resin pellet is disclosed (for example, patent document 14). In this method, since the heat treatment is performed under a reduced pressure condition higher than the melting point of the PPS resin, the degas effect during the heat treatment is excellent, and the PPS resin obtained by this method can be expected to reduce the weight reduction rate when heated. The level was still not satisfactory. Furthermore, the PPS resin pellets produced by this method also have molecular weight distribution characteristics and alkali metal content characteristics similar to those of the PPS resin, and it is difficult to say that the purity is sufficiently high.
JP 59-58052 A (first page) JP 51-59952 A (first page) JP 53-69255 A (first page) JP 2000-248179 A (second page) JP 2003-113307 A (second page) Japanese Examined Patent Publication No. 45-3368 (pages 7-13) Japanese Patent Publication No. 1-25493 (page 23) Japanese Patent Publication No. 4-55445 (pages 3-4) Japanese Patent No. 3216228 (pages 7 to 10) Japanese Patent No. 3141459 (pages 5-6) US Pat. No. 5,869,599 (pages 27-28) US Pat. No. 3,793,256 (page 2) JP-A-3-41152 (Claims) JP 2000-246733 A (page 4) Polymer, vol. 37, no. 14, 1996 (pages 3111-3116)

  The present invention has been achieved as a result of studying the solution of the problems in the prior art described above as an issue. Therefore, the present invention is a polyphenylene sulfide resin that can be effectively used as a structural material utilizing its excellent mechanical properties and a functional material utilizing its excellent regularity, and whose structure can be stably controlled from the nanometer order to the micron order. It is an object to provide a composition.

In response to the above problems, the present invention is as follows.
(1) (A) The weight average molecular weight (Mw) is 10,000 or more, the dispersity represented by the weight average molecular weight / number average molecular weight (Mn) is 2.5 or less, and the alkali metal content is 50 ppm or less. One or more selected from polyphenylene sulfide resin, (B) polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenyleneoxide, polysulfone, polyethersulfone A polyphenylene sulfide resin composition comprising a thermoplastic resin, wherein the polyphenylene sulfide resin composition has a biphasic continuous structure having a structural period of 0.01 to 1 μm or a dispersed structure having a distance between particles of 0.01 to 1 μm. Polyphenylenesulfur Resin composition,
(2) From (A) polyphenylene sulfide resin, (B) polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenyleneoxide, polysulfone, polyethersulfone The polyphenylene sulfide resin composition according to (1) above, wherein (A) the polyphenylene sulfide resin is 50% by weight or more based on the total amount of the one or more thermoplastic resins selected,
(3) The polyphenylene sulfide resin composition according to (1) or (2) above, wherein the alkali metal contained in the polyphenylene sulfide resin is sodium,
(4) The lactone type compound in the generated gas component when the polyphenylene sulfide resin is heated is 500 ppm or less based on the weight of the polyphenylene sulfide, and the aniline type compound is 300 ppm or less based on the weight of the polyphenylene sulfide. The polyphenylene sulfide resin composition according to any one of 1) to (3),
(5) The above (1) to (4), wherein the polyphenylene sulfide resin is a polyphenylene sulfide resin obtained by melting and heating a cyclic polyphenylene sulfide mixture represented by the following general formula (1): The polyphenylene sulfide resin composition according to any one of the above,

(M may be an integer of 4 to 20, m may be a mixture of 4 to 20)
(6) A polyphenylene sulfide resin composition comprising at least two components of resin separated by spinodal decomposition and containing at least one polyphenylene sulfide resin, and has a structural period of 0.001 to 0 in the initial stage of the spinodal decomposition. After the formation of a 1 μm biphasic continuous structure, it is further developed into a biphasic continuous structure with a structural period of 0.01 to 1 μm, or a dispersed structure with an interparticle distance of 0.01 to 1 μm. The polyphenylene sulfide resin composition according to any one of (1) to (5),
(7) The polyphenylene sulfide resin composition according to any one of (1) to (6), wherein the polyphenylene sulfide resin composition is produced through melt-kneading.
(8) The polyphenylene sulfide resin composition according to the above (6), wherein the spinodal decomposition is compatible under shear during melt kneading and phase-separated under non-shear after discharge, and (9) (A) Polyphenylene sulfide resin having a weight average molecular weight (Mw) of 10,000 or more, a dispersity represented by weight average molecular weight / number average molecular weight (Mn) of 2.5 or less, and an alkali metal content of 50 ppm or less. (B) one or more thermoplastic resins selected from polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenylene oxide, polysulfone, and polyethersulfone A polyphenylene sulfide resin composition comprising A method for producing a polyphenylene sulfide resin composition that is phase-separated by the decomposition of a ring, and after forming a biphasic continuous structure having a structural period of 0.001 to 0.1 μm in the initial stage of spinodal decomposition, further a structural period of 0.01 to 1 μm A process for producing a polyphenylene sulfide resin composition characterized by being developed to a continuous structure of both phases, or a dispersed structure having a distance between particles of 0.01 to 1 μm,
(10) (A) The weight average molecular weight (Mw) is 10,000 or more, the dispersity represented by the weight average molecular weight / number average molecular weight (Mn) is 2.5 or less, and the alkali metal content is 50 ppm or less. One or more selected from polyphenylene sulfide resin, (B) polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenyleneoxide, polysulfone, polyethersulfone The method for producing a polyphenylene sulfide resin composition according to (9), wherein spinodal decomposition is induced by melt-kneading a polyphenylene sulfide resin composition comprising a thermoplastic resin,
(11) The method for producing a polyphenylene sulfide resin composition according to (10) above, wherein at least two components of the resin are mixed under shear during melt-kneading and phase separation is performed under non-shear after discharge. is there.

  According to the present invention, polyphenylene sulfide that can be effectively used as a structural material by utilizing excellent mechanical properties and a functional material by utilizing excellent regularity, and capable of stably controlling the structure from the nanometer order to the micron order. A resin composition can be provided.

(1) Polyphenylene sulfide resin (PPS resin)
The PPS resin of the present invention is a polymer containing 70 mol% or more, more preferably 90 mol% or more of the repeating unit represented by the structural formula (2). When the repeating unit is less than 70 mol%, the heat resistance Is unfavorable because it is damaged.

  Moreover, PPS resin can comprise less than 30 mol% of the repeating units with repeating units having the following structural formula.

  The molecular weight of the PPS resin of the present invention is 10,000 or more, preferably 15,000 or more, more preferably 18,000 or more in terms of weight average molecular weight. When the weight average molecular weight is less than 10,000, properties such as mechanical strength are lowered. Although there is no restriction | limiting in particular in the upper limit of a weight average molecular weight, Less than 1,000,000 can be illustrated as a preferable range, More preferably, it is less than 500,000, More preferably, it is less than 200,000, Within this range, it is high mechanical strength. Can be obtained.

  The dispersity represented by the spread of the molecular weight distribution of the PPS resin in the present invention, that is, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 2.5 or less, more preferably 2 .3 or less, more preferably 2.1 or less, and particularly preferably 2.0 or less. When the degree of dispersion exceeds 2.5, the amount of low molecular weight components contained in the PPS resin tends to increase, which tends to cause a decrease in mechanical strength.

  The weight average molecular weight and the number average molecular weight can be calculated, for example, in terms of polystyrene by gel permeation chromatography (GPC) which is a kind of size exclusion chromatography (SEC).

  The melt viscosity of the PPS resin used in the present invention is not particularly limited as long as it can be melt-kneaded. However, one having a viscosity of 5 to 5000 Pa · s (300 ° C., shear rate 1000 sec-1) is usually used.

  The PPS resin of the present invention is characterized by being higher in purity than conventional ones, and the content of alkali metal as an impurity is 50 ppm or less, more preferably 30 ppm or less, still more preferably 10 ppm or less. If the alkali metal content exceeds 50 ppm, the alloy tends to be inferior in thermal stability when alloyed with a thermoplastic resin described later.

  Here, the alkali metal content of the PPS resin in the present invention is a value calculated from, for example, the amount of alkali metal in the ash, which is a residue obtained by baking the PPS resin using an electric furnace or the like. It can be quantified by analyzing by a method or atomic absorption method.

  The alkali metal refers to lithium, sodium, potassium, rubidium, cesium, and francium belonging to Group IA of the Periodic Table, but the PPS resin of the present invention preferably does not contain sodium as an alkali metal. When an alkali metal is included, the thermal stability of the PPS resin tends to be adversely affected. Among various metal species, compared to metal species other than alkali metals, such as alkaline earth metals and transition metals, alkali metals tend to have a strong influence on the thermal stability of PPS resins. Therefore, it is estimated that the thermal stability of the PPS resin can be improved by controlling the alkali metal content within the above range among various metal species. Furthermore, among the alkali metals, in the polymerization of the PPS resin, alkali metal sulfides represented by sodium sulfide are most commonly used, and the quality of the PPS resin can be improved by setting the sodium content within the above range. I guess.

  The PPS resin of the present invention preferably contains substantially no halogen other than chlorine, that is, fluorine, bromine, iodine, or astatine. When the PPS resin of the present invention contains chlorine as a halogen, the PPS resin is stable in the temperature range in which it is normally used, so even if it contains a small amount of chlorine, there is little effect on the mechanical properties of the PPS resin. When these halogens are contained, their unique properties tend to deteriorate the properties of the PPS resin, such as electrical properties and residence stability. When the PPS resin of the present invention contains chlorine as a halogen, the preferable amount is 1% by weight or less, more preferably 0.5% by weight or less, and further preferably 0.2% by weight or less. The amount of generated volatile gas is reduced, the apparatus corrosion can be reduced, and the electrical characteristics and the retention stability tend to be better.

  Another feature of the PPS resin of the present invention is that the amount of lactone type compound and / or aniline type compound generated when heated is remarkably small. Examples of the lactone type compound include β-propiolactone, β-butyrolactone, β-pentanolactone, β-hexanolactone, β-heptanolactone, β-octanolactone, β-nonalactone, and β-decalactone. , Γ-butyrolactone, γ-valerolactone, γ-pentanolactone, γ-hexanolactone, γ-heptanolactone, γ-octalactone, γ-nonalactone, γ-decalactone, δ-pentanolactone, δ-hexa Nolactone, δ-heptanolactone, δ-octanolactone, δ-nonalactone, δ-decalactone, etc. can be exemplified, and aniline type compounds include aniline, N-methylaniline, N, N-dimethylaniline, N -Ethylaniline, N-methyl-N-ethylaniline, 4-chloro-aniline, 4-chloro-N-methyl Niline, 4-chloro-N, N-dimethylaniline, 4-chloro-N-ethylaniline, 4-chloro-N-methyl-N-ethylaniline, 3-chloro-aniline, 3-chloro-N-methylaniline, Examples include 3-chloro-N, N-dimethylaniline, 3-chloro-N-ethylaniline, 3-chloro-N-methyl-N-ethylaniline and the like.

  Occurrence of lactone type compounds and / or aniline type compounds when heated causes factors such as foaming during molding and mold fouling, and may not only deteriorate moldability but also adversely affect defects in molded products. The amount of lactone type compound generated is preferably 500 ppm or less, more preferably 300 ppm, still more preferably 100 ppm or less, and still more preferably 50 ppm, based on the weight of the PPS resin before heating. The following is desirable. Similarly, the amount of aniline type compound generated is preferably 300 ppm or less, more preferably 100 ppm, still more preferably 50 ppm or less, and even more preferably 30 ppm or less. As a method for evaluating the amount of lactone type compound and / or aniline type compound generated when the PPS resin is heated, the gas generated when treated at 320 ° C. for 60 minutes in a non-oxidizing atmosphere is measured by gas chromatography. Quantify by the method of component quantification.

(2) Production method of PPS resin The weight average molecular weight (Mw) of the present invention is 10,000 or more, the dispersity represented by the weight average molecular weight / number average molecular weight (Mn) is 2.5 or less, and the alkali metal content As a production method for producing a PPS resin, wherein the weight average molecular weight is 10,000 or more by melting and heating a cyclic polyphenylene sulfide compound represented by the following general formula (1): It is exemplified that it is produced by converting it to a high degree of polymerization, and according to this method, the PPS resin of the present invention having the above-mentioned characteristics can be obtained.

(3) Cyclic PPS compound As the cyclic PPS compound of the present invention, a cyclic PPS compound represented by an integer of m = 4 to 20 represented by the following general formula (1) can be used, and m is 4 to 4: A mixture of 20 may be used.

(M may be an integer of 4 to 20, m may be a mixture of 4 to 20)

  The repeating unit m in the above formula is an integer of 4 to 20, preferably 4 to 15, and more preferably 4 to 12.

  In addition, although the single-cycle cyclic PPS has a difference in easiness of crystallization, it is obtained as a crystal, so that the melting temperature becomes high, and therefore the temperature when converted to a high degree of polymerization tends to be high. Show. On the other hand, in the case of a mixture having different m, the melting temperature is lower than that of a single cyclic PPS, and the temperature at the time of conversion to a high molecular weight body can be reduced. Due to this feature, even if there is no polymerization initiator containing an alkali metal, the degree of polymerization proceeds rapidly, and side reactions at the time of increasing the degree of polymerization are further suppressed. It becomes possible to produce a PPS resin with a small amount of gas components.

  For example, m = 6 cyclic PPS simple substance (cyclohexa (p-phenylene sulfide)) has a high melting point of 348 ° C., so that the cyclic product has a high molecular weight unless the heating temperature for melting is increased. There is a problem of not. Therefore, a method in which a cyclic PPS compound is dissolved in a solvent to be converted into a high molecular weight body, and a crystallized cyclic PPS simple substance is once melted at a melting point or higher, and then rapidly cooled to suppress crystallization and make it amorphous. Thereafter, a method of converting to a high degree of polymerization, or a method of setting the premelter to be equal to or higher than the melting point of the cyclic PPS alone, melting only the cyclic PPS alone in the premelter, and supplying it as a melt can be adopted.

  Due to the characteristics of the cyclic PPS compound, the cyclic PPS compound used in the present invention is preferably a cyclic PPS compound having a different m from the viewpoint of easy high molecular weight and easy manufacture.

  The content of cyclic PPS of m = 6 with respect to the cyclic PPS compound is preferably less than 50% by weight, more preferably less than 30% by weight, still more preferably less than 10% by weight (single cyclic PPS of m = 6 (weight ) / (Cyclic PPS compound (weight) × 100).

  The ratio of each different m in the cyclic PPS compound is not particularly limited, but in order to achieve the effects of the present invention, the cyclic PPS simple substance of m = 6 having the highest melting point and easy to crystallize among the cyclic PPS compounds. Is preferably less than 50% by weight, more preferably 30% by weight, particularly preferably less than 10% by weight (m = 6 cyclic PPS (weight) / (cyclic PPS mixture (weight) × 100). Here, the content of m = 6 cyclic PPS alone in the cyclic PPS mixture is attributed to the compound having a PPS structure when the cyclic PPS mixture is divided into components by high performance liquid chromatography equipped with a UV detector. The ratio of the peak area attributed to the cyclic PPS simple substance with m = 6 to the total peak area to be obtained can be determined as a compound having a PPS structure. A compound having at least a PPS structure, for example, a cyclic PPS compound or a linear PPS, and a compound having a structure other than phenylene sulfide as a part thereof (for example, as a terminal structure) is also referred to as a compound having a PPS structure. In addition, the qualitative characteristics of each peak divided into components by this high performance liquid chromatography can be obtained by fractionating each peak by preparative liquid chromatography and performing an absorption spectrum or mass spectrometry in infrared spectroscopic analysis. .

  Such a cyclic PPS compound can be obtained by obtaining a PPS mixture containing PPS and a cyclic PPS compound by a known PPS production method and then extracting the cyclic PPS compound from the PPS mixture. The manufacturing method will be described below.

(4) Production method of PPS mixture as raw material of cyclic PPS compound As a production method of PPS mixture, a known technique can be used, for example, polyhalogenated aromatic compound represented by at least p-dichlorobenzene, A mixture containing an alkali metal sulfide typified by sodium sulfide and an organic polar solvent typified by N-methyl-2-pyrrolidone is heated to prepare a reaction solution containing a polyphenylene sulfide mixture and an alkali metal halide, Examples thereof include a method of obtaining a PPS mixture (PPS and cyclic PPS compound) by treating the reaction solution with water or the like, and a method of obtaining a PPS mixture by oxidative polymerization of diphenyl disulfides or thiophenols. However, since the cyclic PPS compound generally contained in the PPS mixture generally obtained by these methods is as low as less than 5% by weight, in order to obtain a PPS mixture containing 5% by weight or more of the cyclic PPS compound, for example, polymerization of the PPS mixture is performed. In particular, a special method such as using a large amount of a polymerization solvent is necessary, and it is economically disadvantageous to obtain a large amount of PPS mixture efficiently by such a method, and it is difficult to establish industrially. .

  Examples of other methods for producing a PPS mixture include polyhalogenated aromatic compounds represented by at least p-dichlorobenzene, alkali metal sulfides represented by sodium sulfide, and N-methyl-2-pyrrolidone. At least granular PPS and a PPS mixture other than granular PPS, organic polar solvent, water, and alkali halide obtained by heating and polymerizing a mixture containing an organic polar solvent A preferred example is a method of obtaining a PPS mixture from a recovered slurry obtained when granular PPS is removed from a reaction solution containing a metal salt. Here, granular PPS refers to a PPS component that can be recovered with a standard sieve (80 mesh sieve) having an average aperture of 0.175 mm. The PPS mixture obtained by this method contains a large amount of low molecular weight PPS having a weight average molecular weight of 5,000 or less. For example, the properties such as mechanical properties are significantly inferior to those of the granular PPS. Has been conventionally recognized as being difficult and not worth industrial use. Therefore, the PPS mixture obtained by this method has usually been treated as industrial waste.

  As a result of detailed analysis of the PPS mixture other than the granular PPS, the present inventors include 10% by weight or more of the cyclic PPS represented by the formula (1) (m = 4 to 20). In particular, since these are obtained as a mixture of m = 4 to 20, it has been found preferable as a raw material for obtaining the cyclic PPS compound of the present invention. This is significant from the viewpoint of recovering a compound having an extremely high industrial utility value from what was conventionally regarded as industrial waste by the method of the present invention.

  As a method for recovering PPS from the recovered slurry, for example, at least 50% by weight or more of an organic polar solvent is removed from the recovered slurry, a residue is obtained, water is added thereto, and then an acid is added as desired. A method in which at least the residual organic polar solvent and the alkali metal halide are removed and the PPS mixture is separated and recovered, or a method in which the PPS mixture is precipitated from the recovered slurry and PPS is recovered as a solid component, for example, in the recovered slurry Examples thereof include a method of obtaining PPS as a solid component by a method such as decantation, centrifugation, and filtration, which are known solid-liquid separation methods, after PPS is precipitated by adding water.

(5) Preparation of cyclic PPS compound-containing solution In the present invention, a solution containing a cyclic PPS compound is prepared by bringing the PPS compound into contact with a solvent capable of dissolving the cyclic PPS compound (m = 4 to 20) described in formula (1). Prepare.

  The solvent used here is not particularly limited as long as it is a solvent capable of dissolving the cyclic PPS compound, but a solvent that dissolves the cyclic PPS compound but dissolves PPS in a dissolving environment is preferable, and a solvent that does not dissolve PPS. Is more preferable. The pressure of the reaction system when PPS is brought into contact with the solvent is preferably normal pressure or slight pressure, and particularly preferably normal pressure, and the reaction system of such pressure is advantageous in that the members of the reactor for constructing it are inexpensive. There is. From this point of view, it is desirable that the reaction system pressure avoid pressurizing conditions that require an expensive pressure vessel. As the solvent to be used, those which do not substantially cause undesirable side reactions such as decomposition and crosslinking of PPS and cyclic PPS compounds are preferable, and as a preferable solvent when the operation of bringing the PPS mixture into contact with the solvent is performed, for example, under atmospheric pressure reflux conditions. Are, for example, hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclohexane, cyclopentane, benzene, toluene, xylene, chloroform, bromoform, methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, chlorobenzene Halogen solvents such as 2,6-dichlorotoluene, ketone solvents such as acetone, diethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, acetophenone, diethyl ether, tetrahydrofuran, diisopropyl ether Examples include polar solvents such as ether solvents such as tellurium, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, trimethyl phosphoric acid, N, N-dimethylimidazolidinone, among others, benzene, toluene, Xylene, chloroform, bromoform, methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, chlorobenzene, 2,6-dichlorotoluene, acetone, diethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, diethyl ether, Tetrahydrofuran, diisopropyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, trimethyl phosphoric acid, N, N-dimethylimidazolidinone are preferred, and toluene Xylene, chloroform, methylene chloride, acetone, diethyl ketone, methyl ethyl ketone, tetrahydrofuran may be cited more preferably.

  There is no particular limitation on the atmosphere when PPS is brought into contact with the solvent, but when PPS and the solvent are deteriorated by oxidation depending on conditions such as temperature and time at the time of contact, it is desirable to carry out in a non-oxidizing atmosphere. . Note that the non-oxidizing atmosphere is an atmosphere having a gas phase oxygen concentration of 5% by volume or less, preferably 2% by volume or less, more preferably an oxygen-free atmosphere such as nitrogen, helium, argon, or the like. Among these, a nitrogen atmosphere is particularly preferable from the viewpoints of economy and ease of handling.

  The temperature at which the PPS mixture is brought into contact with the solvent is not particularly limited, but generally, the higher the temperature, the more the dissolution of the cyclic PPS compound in the solvent tends to be promoted. As described above, since the PPS mixture is preferably contacted with the solvent under atmospheric pressure, the upper limit temperature is preferably set to the reflux condition temperature under atmospheric pressure of the solvent used. For example, 20 to 150 ° C. can be exemplified as a specific temperature range.

  The time for bringing the PPS mixture into contact with the solvent varies depending on the type of solvent used, the temperature, etc., and cannot be uniquely limited. For example, 1 minute to 50 hours can be exemplified, but if it is too short, the cyclic PPS is not sufficiently dissolved in the solvent If it is too long, dissolution in the solvent reaches a saturated state, and no further effect can be obtained.

  The method of bringing PPS into contact with a solvent is not particularly limited as long as a known general method is used. For example, a method of collecting a solution part after mixing a PPS mixture and a solvent and stirring as necessary, various filters Any method can be used, such as a method of dissolving the cyclic PPS in the solvent while simultaneously showering the solvent in the above PPS mixture, or a method based on the Soxhlet extraction principle. Although there is no restriction | limiting in particular in the usage-amount of the solvent at the time of making PPS and a solvent contact, For example, the range of 0.5-100 can be illustrated by the bath ratio with respect to PPS weight. When the bath ratio is too small, not only the mixing of the PPS mixture and the solvent becomes difficult, but also the cyclic PPS compound tends to be insufficiently dissolved in the solvent. A larger bath ratio is generally advantageous for dissolving a cyclic PPS compound in a solvent, but if it is too large, no further effect can be expected, and conversely an economic disadvantage due to an increase in the amount of solvent used may occur. . In the case where contact between the PPS and the solvent is repeated, a sufficient effect can often be obtained even with a small bath ratio. In addition, the Soxhlet extraction method, in principle, has the same effect as when PPS and the solvent are repeatedly contacted. In this case, a sufficient effect can often be obtained with a small bath ratio.

  When the solution in which the cyclic PPS compound is dissolved after the PPS is brought into contact with the solvent is obtained in the form of a solid-liquid slurry containing the remaining solid PPS, the solution part is recovered using a known solid-liquid separation method. . Examples of the solid-liquid separation method include separation by filtration, centrifugation, and decantation. For the solution thus separated, the solvent described later is removed. On the other hand, for the remaining solid component, when the cyclic PPS compound still remains, specifically when 0.05% by weight or more of the cyclic PPS compound remains on a weight basis, A cyclic PPS compound can be obtained with higher yield by repeatedly performing contact and solution recovery. Further, when the cyclic PPS compound hardly remains, specifically, when the residual cyclic PPS compound is less than 0.05% by weight, the remaining solid PPS is removed by removing the residual solvent. Can be suitably recycled as high-purity PPS.

(6) Removal of solvent from cyclic PPS compound solution In the present invention, the solvent is removed from the solution containing the cyclic PPS compound (m = 4 to 20) represented by the formula (1) obtained as described above. To obtain a cyclic PPS compound. The removal of the solvent can be exemplified by, for example, a method of heating and treating at normal pressure or less, or removal of the solvent using a film. However, from the viewpoint of obtaining a cyclic PPS compound with higher yield and efficiency. A method of removing the solvent by heating at a pressure lower than the pressure is preferred. The solution containing the cyclic PPS compound obtained as described above may contain a solid depending on the temperature. Since the solid in this case also belongs to the cyclic PPS compound, the solvent is removed when the solvent is removed. It is desirable to recover together with the soluble component, whereby the cyclic PPS compound can be obtained with good yield.

  In removing the solvent, it is desirable to remove at least 50% by weight, preferably 70% by weight or more, more preferably 90% by weight or more, and still more preferably 95% by weight or more. Although the temperature at which the solvent is removed by heating depends on the characteristics of the solvent used, it cannot be limited uniquely. However, the temperature can usually be selected from 20 to 150 ° C, preferably from 40 to 120 ° C. In addition, the pressure for removing the solvent is preferably normal pressure or lower, which makes it possible to remove the solvent at a lower temperature.

(7) Other post-treatments The cyclic PPS compounds obtained by the methods described in (4) to (6) are sufficiently high in purity and can be suitably used as cyclic PPS compounds of m = 4 to 20, Further, post-treatment described below can be additionally performed to obtain a higher-purity cyclic PPS compound and m = 6 cyclic PPS alone.

  The cyclic PPS compound obtained by the operations (4) to (6) may contain an impurity component contained in PPS depending on the characteristics of the solvent used. Impurities are dissolved in the cyclic PPS compound containing such a small amount of impurities, but the cyclic PPS compound is not dissolved, or the cyclic PPS compound is contacted with a second solvent in which the cyclic PPS compound is difficult to dissolve, thereby selectively removing the impurity component. Often it is possible to do.

  The pressure of the reaction system when the cyclic PPS compound is brought into contact with the second solvent is preferably normal pressure or slight pressure, and particularly preferably normal pressure, and the reaction system having such pressure is inexpensive to construct the members. There is an advantage. From this point of view, it is desirable that the reaction system pressure avoid pressurizing conditions that require an expensive pressure vessel. As the preferred solvent as the second solvent, those which do not substantially cause undesirable side reactions such as decomposition and crosslinking of the target cyclic PPS compound are preferable. For example, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, Examples include alcohol-phenol solvents such as propylene glycol, phenol, cresol, and polyethylene glycol, and hydrocarbon solvents such as pentane, hexane, heptane, octane, cyclohexane, and cyclopentane. Among them, methanol, ethanol, propanol, butanol, pen Tanol, ethylene glycol, propylene glycol, pentane, hexane, heptane, octane, cyclohexane, cyclopentane are preferred, methanol, ethanol, propanol, Ji glycol, pentane, hexane, heptane, octane, cyclohexane is particularly preferred. These solvents can be used as one kind or a mixture of two or more kinds.

  There is no particular limitation on the temperature at which the cyclic PPS compound is brought into contact with the second solvent, but the upper limit temperature is desirably the reflux condition temperature under normal pressure of the second solvent to be used. When using, 20-100 degreeC can be illustrated as a preferable temperature range, for example, More preferably, 25-80 degreeC can be illustrated.

  The time for which the cyclic PPS compound is brought into contact with the second solvent cannot be uniquely limited because it varies depending on the type of solvent used, the temperature, etc., but for example 1 minute to 50 hours can be exemplified, and if it is too short, impurities in the cyclic PPS compound In this case, the dissolution of the impurities in the second solvent reaches a saturated state, and no further effect can be obtained.

  As a method for bringing the cyclic PPS compound into contact with the second solvent, a method in which the solid cyclic PPS compound and the second solvent are mixed with stirring as necessary, and the second solvent is added to the cyclic PPS compound solid on various filters. A method of dissolving impurities in a second solvent at the same time as showering, a method using Soxhlet extraction of a solid cyclic PPS compound using a second solvent, a cyclic PPS compound slurry containing a solution-like cyclic PPS compound or a solvent For example, the cyclic PPS compound may be precipitated in the presence of the second solvent by bringing the compound into contact with the second solvent. In particular, the method of bringing the cyclic PPS compound slurry containing the solvent into contact with the second solvent is an effective method because the cyclic PPS compound obtained after the operation has high purity.

  After contacting the cyclic PPS compound with the second solvent, a slurry in which the cyclic PPS compound is precipitated in the second solvent is obtained, so that the solid cyclic PPS compound is recovered using a known solid-liquid separation method. To do. Examples of the solid-liquid separation method include separation by filtration, centrifugation, and decantation. If impurities still remain in the cyclic PPS compound obtained after the solid-liquid separation, the cyclic PPS compound and the second solvent can be contacted again to further remove the impurities.

(8) Characteristics of the cyclic PPS compound of the present invention The cyclic PPS compound thus obtained has m of 4 to 20 in the formula (1), and m = 4 to 20 represented by the formula (1). A cyclic PPS compound having m is preferable, and a cyclic PPS compound having a cyclic PPS content of m = 6 in the cyclic PPS compound is preferably less than 50% by weight.

As described above, m of the cyclic PPS compound of the present invention is m = 4 to 20, and m may be a mixture of 4 to 20, but as a cyclic PPS compound, m = 4 to 12 In the case where m is in this range, it has been found that the degree of polymerization by melting and heating of the cyclic PPS compound rapidly proceeds as described later.
In addition, although the possibility that the cyclic PPS compound whose m is 12 or more exists is high, it is difficult to qualitatively and quantitatively with the current analysis technique. This is because, as will be described later, it is difficult to distinguish between a linear PPS oligomer contained in a cyclic PPS compound and a cyclic PPS having m = 13 or more with the latest analysis technique at present. However, when a cyclic PPS compound of m = 4 to 20 is melted and heated, the degree of polymerization of the cyclic PPS compound rapidly increases, and the amount of volatile gas components in the resulting PPS resin is reduced. When the content of the single cyclic PPS of m = 6 is less than 50% by weight, these effects are further enhanced, so that a cyclic PPS compound having m of 13 or more is included within the range not impairing the effects of the present invention. It may be.

  Moreover, although the cyclic PPS compound obtained by the method as described in (4)-(7) is sufficiently high purity, depending on conditions, a linear PPS oligomer may contain as an impurity. Further, as described above, it is difficult to distinguish this linear PPS oligomer from a cyclic PPS compound having m = 13 or more with the latest analysis technique at present. The weight average molecular weight (Mw) of the oligomer component estimated to be a linear PPS oligomer varies depending on the production method of PPS used as the raw material of the cyclic PPS compound described in (4) above, but is usually 5000 or less. Yes, in some cases it is 2000 or less.

  The linear PPS oligomer remaining as an impurity in the cyclic PPS compound has poor thermal stability and increases the amount of volatile gas components as compared with the cyclic PPS compound. When these are contained in a large amount as impurities, there arises a problem that the conversion of the cyclic PPS compound into PPS by melting and heating becomes insufficient.

  Therefore, the amount of the linear PPS oligomer in the cyclic PPS compound obtained by the method described in (4) to (7) is preferably less than 50% by weight and less than 40% by weight with respect to the total cyclic PPS compound. More preferably, it is less than 30% by weight.

  The amount of linear PPS oligomer in the cyclic PPS compound at this time can be quantified by MALDI-TOF-MS as the total amount with the cyclic PPS compound of m = 13 or more according to the present analysis technique. It is.

  Further, as described in JP-A-10-77408, a cyclic PPS compound is Soxhlet extracted from a cross-linking type PPS, the extract is cooled, and the precipitated white solid is converted into m = No. 6 cyclic PPS is obtained with high purity (cyclohexa (p-phenylene sulfide). Although the recovery amount is small compared with the cross-linked PPS, it is the same from the linear PPS. In the same manner, it is possible to obtain a cyclic PPS simple substance with m = 6 with high purity by performing the extraction operation and recrystallizing.

  The cyclic PPS simple substance of m = 6 has an extremely stable needle-like crystal structure and is easy to crystallize. Therefore, while it is a ring suitable for the method of “recrystallization”, its stable needle-like crystal structure is Reflecting this, the melting point becomes as high as 348 ° C., so it is necessary to increase the melting heating temperature for increasing the degree of polymerization.

  When only cyclic PPS of m = 6 is used, a method of dissolving and supplying the cyclic PPS compound in a solvent that dissolves the cyclic PPS compound, and once crystallized cyclic PPS is melted above the melting point, it is rapidly cooled to suppress crystallization. A method of supplying amorphous powder, or a method in which the premelter is set to have a melting point higher than that of the cyclic PPS alone, and only the cyclic PPS is melted in the premelter and supplied as a melt. it can. In this way, when using cyclic PPS alone, it is necessary to increase the melting heating temperature for increasing the degree of polymerization, or as described above, once the cyclic PPS is melted once, the crystallization is suppressed to be amorphous. From the aspect of productivity and melt processability for increasing the degree of polymerization of cyclic PPS, it is necessary to melt only cyclic PPS in the premelter and supply it as a melt. The content of m = 6 cyclic PPS alone in the PPS compound is preferably less than 50% by weight, more preferably less than 30% by weight, still more preferably less than 10% by weight.

  The reason for this is currently interpreted as follows. That is, when the content of the cyclic PPS simple substance of m = 6 is reduced, there is an effect that the cyclic PPS simple substance does not act as a crystal nucleus. As a result, the cyclic PPS compound composed of a mixture of m = 4 or more It is considered that crystallization is suppressed and the melting point of the cyclic PPS compound is lowered, so that the cyclic PPS compound is easily melted, and as a result, the degree of polymerization can be easily increased by melting and heating.

  In addition, since cyclic monomers other than m = 6 are difficult to crystallize compared to m = 6, it has been difficult to obtain a monomer by a method called “recrystallization” (isolated by a method called recrystallization). Only the cyclic PPS simple substance of m = 6 is possible), and the inventors separated and recovered these monomers by a collection liquid chromatogram, and obtained the cyclic PPS simple substance (cyclotetra (p-phenylene sulfide), melting point of m = 4. 296 ° C.), m = 5 cyclopenta (p-phenylene sulfide) (melting point 257 ° C.), m = 7 cyclohepta (p-phenylene sulfide) (melting point 328 ° C.), m = 8 cycloocta (p-phenylene sulfide) (Melting point 305 ° C.).

  That is, according to the methods described in (4) to (7), the obtained cyclic PPS compound is a mixture having different m, and the content of the cyclic PPS simple substance of m = 6 is less than 50% by weight. . Depending on the conditions, it is possible to obtain a cyclic PPS having a content of m = 6 of less than 30% by weight, or even less than 10% by weight. The obtained cyclic PPS compound has a characteristic that the melting temperature is lower than that of a single cyclic PPS composed of m. For example, a cyclic PPS compound can be obtained by a simple method by using a high molecular weight polymer at a low melting heating temperature. It is possible to convert to

(9) Conversion of cyclic PPS compound to high polymerization degree The above-described PPS of the present invention is preferably produced by a method in which the cyclic PPS compound is melt-heated and converted to a high polymerization degree. The temperature of this melting and heating is preferably a temperature at which the cyclic PPS compound melts and is not particularly limited as long as it is such a temperature condition. If the heating temperature is lower than the melting temperature of the cyclic PPS compound, a long time tends to be required to increase the degree of polymerization of PPS. The temperature at which the cyclic PPS compound melts varies depending on the composition and purity of m present in the cyclic PPS compound as described above. For example, by analyzing the cyclic PPS compound with a differential scanning calorimeter, By grasping, it is possible to melt and heat above its melting temperature. However, if the temperature is too high, undesirable side reactions such as cross-linking reactions and decomposition reactions between PPS molecules generated by heating and between PPS and cyclic PPS compounds tend to occur, and the resulting PPS Therefore, it is desirable to avoid a temperature at which such an undesirable side reaction is remarkably generated. 180-400 degreeC can be illustrated as melt-heating temperature, Preferably it is 200-380 degreeC, More preferably, it is 250-360 degreeC.

  The time for performing the melting and heating cannot be uniformly defined because it varies depending on the composition of m in the cyclic PPS compound to be used, various properties such as the purity of the cyclic PPS compound, and the conditions such as the heating and melting temperature. It is preferable to set so that undesirable side reactions do not occur as much as possible. Examples of the heating and melting time include 0.05 to 100 hours, preferably 0.1 to 20 hours, and more preferably 0.1 to 10 hours. If it is less than 0.05 hours, the conversion of the cyclic PPS compound to PPS tends to be insufficient, and if it exceeds 100 hours, there is a high possibility that adverse effects on the properties of the resulting PPS due to undesirable side reactions will become apparent. Not only that, but there may be economic disadvantages.

  Conversion of the cyclic PPS compound to a high degree of polymerization by melting and heating is usually performed in the absence of a solvent, but can also be performed in the presence of a solvent. The solvent is not particularly limited as long as it does not substantially cause undesirable side reactions such as inhibition of conversion of the cyclic PPS compound to a high degree of polymerization by heating and decomposition or crosslinking of the produced PPS. Nitrogen-containing polar solvents such as methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, sulfoxide / sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, dimethyl ether, dipropyl ether , Ether solvents such as tetrahydrofuran, halogen solvents such as chloroform, methylene chloride, trichloroethylene, ethylene chloride, dichloroethane, tetrachloroethane, chlorobenzene, methanol, ethanol, propano Le, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, alcohol phenol based solvents such as polyethylene glycol, benzene, toluene, and aromatic hydrocarbon solvents such as xylene. It is also possible to use an inorganic compound such as carbon dioxide, nitrogen, or water as a solvent in a supercritical fluid state. These solvents can be used as one kind or a mixture of two or more kinds.

  The conversion of the cyclic PPS compound into a high degree of polymerization by heating may be performed in a mold for producing a molded product, as well as by a method using a normal polymerization reaction apparatus, an extruder, Any apparatus equipped with a heating mechanism, such as a melt kneader, can be used without particular limitation, and known methods such as a batch method and a continuous method can be employed.

  The atmosphere during the conversion of the cyclic PPS compound to a high degree of polymerization by heating is preferably a non-oxidizing atmosphere, and is also preferably performed under reduced pressure. Moreover, when it carries out under pressure reduction conditions, it is preferable to make it the pressure reduction conditions after making the atmosphere in a reaction system once non-oxidizing atmosphere. This tends to suppress the occurrence of undesired side reactions such as a crosslinking reaction and a decomposition reaction during conversion to a degree of polymerization due to overheating. The non-oxidizing atmosphere is an atmosphere in which the oxygen concentration in the gas phase in contact with the cyclic PPS compound is 5% by volume or less, preferably 2% by volume or less, and more preferably substantially free of oxygen, that is, nitrogen, helium, argon, etc. In particular, a nitrogen atmosphere is preferable from the viewpoint of economy and ease of handling. The reduced pressure condition means that the reaction system is lower than atmospheric pressure, and the upper limit is preferably 50 kPa or less, more preferably 20 kPa or less, and even more preferably 10 kPa or less. An example of the lower limit is 0.1 kPa or more, and 0.2 kPa or more is more preferable. When the decompression condition exceeds the preferable upper limit, an undesirable side reaction such as a crosslinking reaction tends to occur. On the other hand, when the pressure reduction condition is less than the preferable lower limit, the cyclic PPS compound having a low molecular weight contained in the cyclic PPS compound volatilizes depending on the reaction temperature. It tends to be easier.

  The PPS resin thus obtained is excellent in heat resistance, chemical resistance, flame retardancy, electrical properties and mechanical properties, and is suitably used for various applications.

(10) Polyphenylene sulfide resin composition The polyphenylene sulfide resin composition of the present invention needs to have a biphasic continuous structure with a structural period of 0.01 to 1 μm or a dispersed structure with a distance between particles of 0.01 to 1 μm. . In order to obtain such a two-phase continuous structure having a structural period of 0.01 to 1 μm, or a dispersed structure having a distance between particles of 0.01 to 1 μm, the PPS resin and other thermoplastic resin are once dissolved in phase, The structure is preferably formed by spinodal decomposition, and the combination that causes the spinodal decomposition is preferably a partial miscible system described later or a system that undergoes shear field-dependent phase dissolution / phase decomposition. As the combination that causes the spinodal decomposition, a thermoplastic resin that interacts with the PPS resin is preferable, and polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, and polythioetherketone having a carbonyl group are included therein. It is necessary to select one or more thermoplastic resins selected from polyetheretherketone, polyphenylene oxide having an aromatic ring, polysulfone, and polyethersulfone.

  Although there is no restriction | limiting in particular about the composition of the resin component which comprises the polyphenylene sulfide resin composition in this invention, Usually PPS resin is 50-97 with respect to a total of 100 weight% of the resin component which comprises a polyphenylene sulfide resin composition. The range of wt% is preferably used, more preferably 50 to 95 wt%, and particularly preferably 50 to 75 wt% because a biphasic continuous structure can be obtained relatively easily.

  In general, polymer alloys composed of two-component resins are compatible with these compositions in a practical system where the glass transition temperature is higher than the thermal decomposition temperature or lower, and vice versa. There are incompatible systems that dissolve, and partially compatible systems that are compatible in one region and phase separated in another region. In this partially compatible system, phase separation is performed by spinodal decomposition depending on the conditions of the phase separated state. And phase separation by nucleation and growth.

  Furthermore, in the case of a polymer alloy composed of three or more components, a system in which all three or more components are compatible, a system in which all three or more components are incompatible, a compatible phase having two or more components, and the rest There is a system in which one or more phases are incompatible, two components are partially compatible, and the remaining components are distributed in a partially compatible system composed of these two components. The polymer alloy composed of 3 or more components preferred in the present invention is a system in which 2 components are partially compatible and the remaining components are distributed to the partially compatible system composed of 2 components. In this case, the structure of the polymer alloy is 2 Since it can be replaced by a partially compatible structure composed of components, the following description will be made on behalf of a polymer alloy composed of a two-component resin.

  Phase separation by spinodal decomposition refers to phase separation that occurs in an unstable state inside the spinodal curve in phase diagrams for different two-component resin compositions and temperatures, and phase separation by nucleation and growth refers to the phase separation. In the figure, it refers to phase separation that occurs in the metastable state inside the binodal curve and outside the spinodal curve.

  The spinodal curve refers to the difference (ΔGmix) between the free energy when compatibilized and the sum of the free energies in two phases that are not compatible (ΔGmix) when two different resins are mixed with respect to the composition and temperature. φ) is a curve that is partially differentiated twice (∂2ΔGmix / ∂φ2), and is an unstable state where ダ ル 2ΔGmix / ∂φ2 <0 inside the spinodal curve and ∂ on the outside. 2ΔGmix / ∂φ2> 0.

  The binodal curve is a boundary curve between the region where the system is compatible and the region where the system is separated with respect to the composition and temperature.

  Here, the case of being compatible in the present invention is a state in which they are uniformly mixed at the molecular level. Specifically, both phases having different two-component resins as main components are 0.001 μm or more. The case where the phase structure is not formed is indicated, and the case where the phase is incompatible is the case where the phase is not in a compatible state, that is, the phases mainly composed of two different resin components are 0.001 μm or more. It refers to the state of forming a phase structure. Whether or not they are compatible is determined by, for example, an electron microscope, a differential scanning calorimeter (DSC), or other various methods as described in Polymer Alloys and Blends, Leszek A Utracki, hanser Publishers, Munich Viema New York, P64. Judgment can be made.

  According to detailed theory, in spinodal decomposition, once the temperature of a mixed system that has been uniformly mixed at the temperature of the compatible region is rapidly increased to the temperature of the unstable region, the system will rapidly phase-separate toward the coexisting composition. To start. At that time, the concentration is monochromatized at a constant wavelength, and a two-phase continuous structure is formed in which both separated phases are continuously intertwined regularly with a structure period (Λm). After the formation of the two-phase continuous structure, the process in which only the concentration difference between the two phases increases while keeping the structure period constant is called the initial process of spinodal decomposition.

Furthermore, the structural period (Λm) in the initial process of the above-mentioned spinodal decomposition has a thermodynamic relationship as shown in the following equation.
[Lambda] m- [| Ts-T | / Ts] ^-1/2
(Where Ts is the temperature on the spinodal curve)

  Here, the two-phase continuous structure referred to in the present invention refers to a structure in which both components of the resin to be mixed each form a continuous phase and are entangled three-dimensionally. A schematic diagram of this two-phase continuous structure is described, for example, in “Polymer Alloy Fundamentals and Applications (Second Edition) (Chapter 10.1)” (edited by the Society of Polymer Science: Tokyo Kagaku Dojin).

  In spinodal decomposition, after going through such an initial process, it goes through a medium-term process in which an increase in wavelength and an increase in concentration difference occur simultaneously, and a later process in which an increase in wavelength occurs in a self-similar manner after the concentration difference reaches the coexisting composition. In order to obtain the structure defined in the present invention, the desired structural period before the final separation into the macroscopic two phases has been reached. What is necessary is just to fix a structure in a step.

  In addition, in the process of increasing the wavelength from the mid-stage process to the late-stage process, depending on the influence of the composition and the interfacial tension, the continuity of one phase may be interrupted and the above-described biphasic continuous structure may be changed to a dispersed structure. In this case, the structure may be fixed when the desired interparticle distance is reached.

  Here, the dispersion structure referred to in the present invention is a so-called sea-island structure in which particles mainly composed of the other resin component are interspersed in a matrix mainly composed of one resin component. Point.

  The polyphenylene sulfide resin composition of the present invention needs to be structurally controlled to have a biphasic continuous structure with a structural period of 0.01 to 1 μm or a dispersed structure with a distance between particles of 0.01 to 1 μm. However, by controlling the structural period 2 in the initial process of spinodal decomposition to a range of 0.001 to 0.1 μm, the structural period of 0.01 to 1 μm can be achieved even if the wavelength and concentration difference increase after the above-described intermediate period. The structure can be controlled to have a biphasic continuous structure in the range of 1 or a dispersed structure having a distance between particles of 0.01 to 1 μm. In order to obtain more excellent mechanical properties, after the structure is developed, a biphasic continuous structure with a structural period in the range of 0.01 to 0.5 μm, or a dispersed structure with a distance between particles of 0.01 to 0.5 μm. It is preferable to control to a two-phase continuous structure with a structural period of 0.01 to 0.3 μm or a dispersed structure with a distance between particles of 0.01 to 0.3 μm. . A structure having excellent mechanical properties can be effectively obtained by using the polyphenylene sulfide resin composition which is controlled within the range of the structural period and the range of the distance between particles and the difference in concentration is sufficiently developed. In addition, in the structure of the initial process where the concentration difference is not sufficiently developed here, the structure having excellent mechanical properties is obtained, which is almost the same as the compatible structure that is an intermediate property between the two components. It is difficult to get things.

  On the other hand, in the nucleation and growth, which is the phase separation in the metastable region described above, a dispersed structure that is a sea-island structure is formed from the initial stage, and it grows. It is difficult to form a biphasic continuous structure in the range of 0.01 to 1 μm or a dispersed structure in the range of a distance between particles of 0.01 to 1 μm.

Moreover, in order to confirm the biphasic continuous structure by these spinodal decompositions or a disperse structure, it is important to confirm a regular periodic structure. For example, in addition to confirming that a two-phase continuous structure is formed by observation with an optical microscope or a transmission electron microscope, the scattering maximum in a scattering measurement performed using a light scattering device or a small-angle X-ray scattering device Confirmation of appearing is necessary. Note that the light scattering device and the small-angle X-ray scattering device have different optimum measurement regions, so that they are appropriately selected according to the size of the structure period. The existence of the scattering maximum in this scattering measurement is a proof that it has a regular phase separation structure with a certain period, and its period Λm corresponds to the structure period in the case of the biphasic continuous structure, and the interparticle distance in the case of the dispersion structure. Correspond. The value can be calculated by the following equation using the wavelength λ of the scattered light in the scatterer and the scattering angle θm that gives the scattering maximum.
Λm = (λ / 2) / sin (θm / 2)

  In order to realize the spinodal decomposition, it is necessary to make the PPS resin and another resin compatible with each other, and then make the unstable state inside the spinodal curve.

  First, as a method of realizing a compatible state with a resin composed of two or more components, after dissolving in a common solvent, spray drying, freeze drying, coagulation in a non-solvent substance, film formation by solvent evaporation, etc. from this solution is used. Examples thereof include a solvent casting method and a melt-kneading method in which a partially compatible system is melt-kneaded under compatible conditions. Among these, compatibilization by melt kneading, which is a dry process that does not use a solvent, is preferably used in practice.

  For compatibilization by melt kneading, an ordinary extruder is used, but a twin screw extruder is preferably used. Further, depending on the combination of resins, there are cases where compatibilization can be achieved in the plasticizing process of the injection molding machine. The temperature for compatibilization needs to be a condition in which the partially compatible resin is compatible.

  Next, when the resin composition made into a compatible state by the above melt kneading is in an unstable state inside the spinodal curve, the temperature for making the unstable state when the spinodal decomposition is performed, and other conditions vary depending on the combination of the resins. Although it cannot be generally stated, it can be set by performing a simple preliminary experiment based on the phase diagram. In the present invention, as described above, after the structural period of the initial process is controlled to a specific range, the structure is further developed after the intermediate process to obtain a specific biphasic continuous structure or a dispersed structure defined in the present invention. preferable.

  The method for controlling the specific structural period in this initial process is not particularly limited, but it is not less than the lowest glass transition temperature of the individual resin components constituting the polyphenylene sulfide resin composition, and the above-described thermodynamics. It is preferable to perform heat treatment at such a temperature as to reduce the structural period specified in terms of the size. Here, the glass transition temperature can be obtained from an inflection point generated at the time of temperature increase from room temperature at a temperature increase rate of 20 ° C./min with a differential scanning calorimeter (DSC).

  The method for developing the structure from the initial process is not particularly limited, but a method of heat treatment at the lowest temperature or higher among the glass transition temperatures of the individual resin components constituting the polyphenylene sulfide resin composition is usually preferably used. Further, it is preferable that the heat treatment temperature is equal to or higher than the crystal melting temperature of the crystalline resin because the structural development by the heat treatment can be effectively obtained, and that the heat treatment temperature is within the crystal melting temperature ± 20 ° C. Is preferable in order to facilitate the control of the crystal, and more preferably, the crystal melting temperature is within ± 10 ° C. Here, when two or more kinds of crystalline resins including PPS resin are used as the resin component, the heat treatment temperature is within the crystal melting temperature within ± 20 ° C. based on the highest temperature among the crystal melting temperatures of the crystalline resin. It is preferable that the crystal melting temperature is within ± 10 ° C. Here, the crystal melting temperature of the crystalline resin can be determined from the peak temperature of the melting curve generated at the time of temperature increase from room temperature at a temperature increase rate of 20 ° C./min with a differential scanning calorimeter (DSC).

  In addition, as a method of immobilizing the structure product by spinodal decomposition, the structure fixing of one or both components of the phase-separated phase in a short time by rapid cooling or the like, and when one of them is a thermosetting component, a thermosetting component Structural fixation using the fact that the phase of the resin cannot freely move due to the reaction, and structural fixation using the fact that the crystalline resin phase cannot be freely moved by crystallization when the other is a crystalline resin. However, in particular, when at least one of the crystalline resins is used as in the PPS resin composition, structural fixation by crystallization is preferably used.

  The crystalline resin referred to in the present invention is not particularly limited as long as it is a resin whose crystal melting temperature is observed by a differential scanning calorimeter (DSC). For example, nylon 6, nylon 66, etc. Aliphatic polyamides, aromatic polyamides such as nylon 6T and nylon 6I, aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate and copolymers thereof, and poly-ε-caprolactam And the like, and the like.

  In the present invention, the PPS resin and the other resin are phase-separated by the above spinodal decomposition to obtain the polyphenylene sulfide resin composition of the present invention. It is preferable to combine a resin that is a system that undergoes phase decomposition.

  In general, partial compatible systems are known to have a low-temperature compatible phase diagram that is easy to be compatible on the low temperature side in the same composition, and a high temperature compatible phase diagram that is easy to be compatible on the high temperature side. It has been. The lowest temperature between the compatible and incompatible branching temperatures in this low-temperature compatible phase diagram is called the lower critical solution temperature (LCST for short). The highest temperature among the incompatible branching temperatures is called the upper critical solution temperature (UCST).

  In the case of a low-temperature compatible phase diagram, a resin of two or more components that have become compatible using a partially compatible system can be brought to a temperature higher than the LCST and a temperature inside the spinodal curve. In the case of the figure, spinodal decomposition can be performed by setting the temperature below UCST and the temperature inside the spinodal curve.

  In addition to spinodal decomposition by this partially compatible system, spinodal decomposition is also induced by melt kneading in non-compatible systems, for example, once compatible under shearing during melt kneading, etc., and then in an unstable state again under non-shearing. Phase separation by spinodal decomposition is also possible by so-called shear field-dependent phase dissolution / phase decomposition in which phase decomposition occurs. Has a continuous structure. Furthermore, this shear field-dependent phase dissolution / phase decomposition is the same as the method based on the temperature change of the partially miscible system in which the spinodal curve does not change because the spinodal curve changes due to the shear field and the unstable region expands. The substantial degree of supercooling (| Ts−T |) also increases in the temperature change range, and as a result, it is easy to reduce the structural period in the initial process of spinodal decomposition in the above relational expression, so that it is preferably used. It is done. In order to achieve compatibilization by shearing during such melt kneading, a normal extruder is used, but a twin screw extruder is preferably used. Further, depending on the combination of resins, there are cases where compatibilization can be achieved in the plasticizing process of the injection molding machine. In this case, the temperature for compatibilization, the heat treatment temperature for forming the initial process, the heat treatment temperature for developing the structure from the initial process, and other conditions differ depending on the combination of the resins, and cannot be generally stated. The conditions can be set by performing a simple preliminary experiment based on the phase diagram under the shear conditions. Also, as a method of reliably realizing the compatibilization in the plasticizing process of the injection molding machine, it is melt-kneaded with a twin-screw extruder in advance and compatibilized. Preferred examples include injection molding using a sample.

  In addition, the addition of a third component that is a copolymer such as a block copolymer, a graft copolymer, or a random copolymer that further includes a component that constitutes a polymer alloy to the polyphenylene sulfide resin composition that constitutes the present invention In order to reduce the free energy of the interface, it is preferably used in order to easily control the structural period in the biphasic continuous structure and the distance between dispersed particles in the dispersed structure. In this case, the third component such as the copolymer is usually distributed to each phase of the polymer alloy composed of the two-component resin except the copolymer, and thus can be handled in the same manner as the polymer alloy composed of the two-component resin.

  In the polyphenylene sulfide resin composition of the present invention, using an alkoxysilane compound in combination is effective for obtaining excellent mechanical strength. Examples of the alkoxysilane compound include an alkoxysilane compound having at least one functional group selected from an epoxy group, an amino group, an isocyanate group, a hydroxyl group, a mercapto group, and a ureido group. Specific examples thereof include epoxy group-containing alkoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, Mercapto group-containing alkoxysilane compounds such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ- (2-ureidoethyl) amino Ureido group-containing alkoxysilane compounds such as propyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanate Isocyanato group-containing alkoxysilane compounds such as natopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, γ-isocyanatopropylethyldiethoxysilane, γ-isocyanatopropyltrichlorosilane, γ- (2-aminoethyl) Amino group-containing alkoxysilane compounds such as aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-hydroxypropyltrimethoxysilane, γ-hydroxypropyltriethoxy Examples thereof include hydroxyl group-containing alkoxysilane compounds such as silane, among which γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxy Chlohexyl) Epoxy group-containing alkoxysilane compounds such as ethyltrimethoxysilane, ureido groups such as γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ- (2-ureidoethyl) aminopropyltrimethoxysilane Alkoxysilane compound, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, Isocyanato group-containing alkoxysilane compounds such as γ-isocyanatopropylethyldiethoxysilane and γ-isocyanatopropyltrichlorosilane are preferred. Particularly preferred are epoxy group-containing alkoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. .

  An alkoxysilane compound having at least one functional group selected from such epoxy group, amino group, isocyanate group, hydroxyl group, mercapto group, and ureido group is used to obtain better mechanical strength. The addition amount is selected in the range of 0.05 to 5 parts by weight and more preferably in the range of 0.2 to 3 parts by weight with respect to 100 parts by weight of the PPS resin. If the amount is too small, the effect of improving the mechanical strength due to the addition of the alkoxysilane compound is not sufficiently exhibited. If the amount is too large, the above-described improvement effect not only reaches saturation but also tends to increase the amount of gas generated in the composition.

  In the present invention, a filler may be used as necessary in order to improve strength and dimensional stability. The filler may be fibrous or non-fibrous, or a combination of fibrous filler and non-fibrous filler may be used. Examples of the filler include glass fiber, glass milled fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, stone-kow fiber, metal Fibrous fillers such as fibers, wollastonite, zeolite, sericite, kaolin, mica, clay, pyrophyllite, bentonite, asbestos, talc, alumina silicate and other silicates, alumina, silicon oxide, magnesium oxide, zirconium oxide, Metal compounds such as titanium oxide and iron oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, hydroxides such as magnesium hydroxide, calcium hydroxide and aluminum hydroxide, Rasubizu, ceramic beads, non-fibrous fillers such as boron nitride and silicon carbide and the like, which may be hollow, it is also possible to further combination of these fillers 2 or more. In addition, these fibrous and / or non-fibrous fillers are pretreated with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, an epoxy compound, It is preferable in terms of obtaining superior mechanical strength.

  In order to improve strength, dimensional stability, etc., when such a filler is used, the amount of the filler is not particularly limited, but is usually 30 to 400 parts by weight based on 100 parts by weight of the PPS resin.

  As long as the effects of the present invention are not impaired in the PPS resin composition of the present invention, a plasticizer such as a polyalkylene oxide oligomer compound, a thioether compound, an ester compound, an organic phosphorus compound, talc, kaolin, an organic phosphorus compound, Crystal nucleating agents such as polyether ether ketone, release agents such as polyolefin compounds, silicone compounds, long chain aliphatic ester compounds, long chain aliphatic amide compounds, anticorrosives, coloring inhibitors, antioxidants Ordinary additives such as heat stabilizers, lubricants, UV inhibitors, colorants, flame retardants and foaming agents can be added.

  These additives can be blended at an arbitrary stage for producing the polyphenylene sulfide resin composition of the present invention. For example, a method of adding at least two resins at the same time, or two components in advance. There are a method of adding the resin after melt kneading, and a method of adding the resin to one resin first and then melt-kneading and then blending the remaining resin.

  The method for molding the polyphenylene sulfide resin composition obtained from the present invention can be any method, and the molding shape can be any shape. Examples of the molding method include injection molding, extrusion molding, inflation molding, blow molding and the like. Among them, injection molding is preferable because heat treatment and structural fixation can be simultaneously performed in the mold after injection. If it is and / or sheet extrusion molding, heat treatment is preferably performed when the film and / or sheet is stretched, and the structure can be fixed during natural cooling before subsequent winding. Of course, it is possible to heat-treat the molded product separately to form a structure.

  The polyphenylene sulfide resin composition in the present invention can be suitably used for, for example, automobile parts and electric parts.

  The molded body of the polyphenylene sulfide resin composition of the present invention includes connectors, coils, sensors, LED lamps, sockets, resistors, relay cases, small switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various types Terminal board, transformer, plug, printed circuit board, tuner, speaker, microphone, headphones, small motor, magnetic head base, power module, semiconductor, liquid crystal, FDD carriage, FDD chassis, motor brush holder, parabolic antenna, computer-related parts, etc. Suitable for electronic component applications such as generators, motors, transformers, current transformers, voltage regulators, rectifiers, inverters, relays, power contacts, switches, breakers, knife switches, other poles Rod, electrical part Electrical equipment parts such as cabinets, VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, audio / laser discs / compact discs, audio / video equipment parts such as DVDs, lighting parts, Homes such as refrigerator parts, air conditioner parts, typewriter parts, word processor parts, office electrical product parts; office computer-related parts, telephone-related parts, facsimile-related parts, copier-related parts, cleaning jigs, motor parts Machine-related parts typified by lighters, typewriters, etc .: Optical equipment typified by microscopes, binoculars, cameras, watches, etc., precision machine-related parts; Alternator terminals, alternator connectors, IC regulators, potentiometers for light dials , Various valves such as exhaust gas valves, various pipes related to fuel, exhaust system, intake system, air intake nozzle snorkel, intake manifold, fuel pump, engine cooling water joint, carburetor main body, carburetor spacer, exhaust gas sensor, cooling water Sensor, oil temperature sensor, brake pad wear sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake pad wear sensor, thermostat base for air conditioner, heating hot air flow control valve, brush holder for radiator motor, water pump impeller , Turbine vane, wiper motor related parts, distributor, starter switch, starter relay, transmitter Wiring harness, window washer nozzle, air conditioner panel switch board, coil for fuel related electromagnetic valve, fuse connector, horn terminal, electrical component insulation plate, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, solenoid Applicable to various applications such as automobile / vehicle related parts such as bobbins, engine oil filters, and ignition device cases.

  Hereinafter, the method of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, the measuring method of a physical property is as follows.

<Molecular weight measurement>
The molecular weight of the PPS resin was calculated in terms of polystyrene by gel permeation chromatography (GPC) which is a kind of size exclusion chromatography (SEC). The measurement conditions for GPC are shown below.
Equipment: Senshu Science SSC-7100
Column name: Senshu Science GPC3506
Eluent: 1-chloronaphthalene detector: differential refractive index detector Column temperature: 210 ° C
Pre-constant temperature: 250 ° C
Pump bath temperature: 50 ° C
Detector temperature: 210 ° C
Flow rate: 1.0 mL / min
Sample injection amount: 300 μL (sample concentration: about 0.2% by weight).

<Quantification of alkali metal content>
The quantitative determination of the alkali metal content contained in the PPS resin was performed as follows.
(A) The sample was weighed in a quartz crucible and incinerated using an electric furnace.
(B) After the ashed product was dissolved with concentrated nitric acid, the volume was adjusted to a constant volume with diluted nitric acid.
(C) The obtained constant volume solution was subjected to ICP gravimetric analysis (apparatus; 4500 manufactured by Agilent) and ICP emission spectroscopic analysis (apparatus; Optima 4300DV manufactured by PerkinElmer).

<Analysis of gas components generated during heating of PPS resin>
The components generated when the PPS resin was heated were quantified by the following method. In addition, the sample used the fine granule of 2 mm or less.

(A) Collection of gas generated during heating Approximately 10 mg of PAS is heated for 60 minutes at 320 ° C. under a nitrogen stream (50 ml / min), and the generated gas components are collected in a tube trap 400 for heating and desorption for atmospheric collection. did.

(B) Analysis of gas component The gas component collected in the tube was thermally desorbed by raising the temperature from room temperature to 280 ° C. over 5 minutes using a thermal desorption device TDU (manufactured by Supelco). The thermally desorbed component was divided into components using gas chromatography, and γ-butyrolactone and 4-chloro-N-methylaniline in the gas were quantified.

[Reference Example 1]
<Preparation of slurry containing PPS mixture>
In a stainless steel reactor 1 equipped with a stirrer, 1169 kg (10 kmol) of 48% aqueous sodium hydrosulfide solution, 841 kg (10.1 kmol) of 48% aqueous sodium hydroxide solution, N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) ) 1983 kg (20 kmol) and 50% aqueous sodium acetate solution 322 kg (1.96 kmol), gradually heated to about 240 ° C. over about 3 hours while flowing nitrogen at normal pressure, and 1280 kg of water and 26 kg of NMP was distilled off. In addition, 0.02 mol of hydrogen sulfide per 1 mol of the sulfur component charged during this liquid removal operation was scattered out of the system.

  Subsequently, after cooling to about 200 degreeC, the content was transferred to the stainless steel reactor 2 with another stirrer. The reactor 1 was charged with 932 kg of NMP, the inside was washed, and the washing liquid was transferred to the reactor 2. Next, 1477 kg (10.0 kmol) of p-dichlorobenzene was added to the reactor 2, sealed under nitrogen gas, and heated to 200 ° C. with stirring. Next, the temperature was raised from 200 ° C. to 270 ° C. at a rate of 0.6 ° C./min, and held at this temperature for 140 minutes. While 353 kg (19.6 kmol) of water was injected over 15 minutes, the mixture was cooled to 250 ° C. at a rate of 1.3 ° C./min. Thereafter, it was cooled to 220 ° C. at a rate of 0.4 ° C./min, and then rapidly cooled to about 80 ° C. to obtain a slurry (A).

  This slurry (A) was diluted with 2623 kg of NMP to obtain a slurry (B). The slurry (B) heated to 80 ° C. was filtered through a sieve (80 mesh, opening 0.175 mm) to obtain a granular PPS resin containing the slurry as a mesh-on component, and a slurry (C) as a filtrate component.

[Reference Example 2]
<Preparation of PPS mixture 1>
1000 kg of the slurry (C) obtained in Reference Example 1 was charged into a stainless steel reactor, the inside of the reactor was replaced with nitrogen, and then treated at 100 to 150 ° C. under reduced pressure for about 1.5 hours while stirring. Part of the solvent was removed.

  Next, 1200 kg of ion-exchanged water (1.2 times the amount of slurry (C)) was added, and the mixture was stirred at about 70 ° C. for 30 minutes to form a slurry. The slurry was filtered to obtain a white solid. Add 1200 kg of ion-exchanged water to the obtained solid, stir again at 70 ° C. for 30 minutes, re-slurry in the same way, and after filtration, dry at 120 ° C. in a nitrogen atmosphere, and then dry under reduced pressure at 80 ° C. 11.6 kg of product was obtained.

  From the absorption spectrum in the infrared spectroscopic analysis of the solid, it was found that the solid was a PPS mixture composed of PPS units. As a result of performing GPC measurement of this PPS mixture and analyzing the chromatogram, the weight fraction of the component having a molecular weight of 5000 or less was 39%, and the weight fraction of the component having a molecular weight of 2500 or less was 32%.

[Reference Example 3]
<Preparation of PPS mixture 2>
To 1000 kg of the slurry (C) obtained in Reference Example 1, 4000 kg of ion exchange water was added and stirred at 70 ° C. for 30 minutes. Then, it was allowed to stand, and the transparent supernatant was removed by decantation to obtain about 300 kg of a slurry containing solids. To this, 1200 kg of ion-exchanged water was added and stirred at 70 ° C. for 30 minutes, and then the slurry was filtered to obtain a white solid. Add 1200 kg of ion-exchanged water to the obtained solid, stir again at 70 ° C. for 30 minutes, re-slurry in the same way, and after filtration, dry at 120 ° C. in a nitrogen atmosphere, and then dry under reduced pressure at 80 ° C. 11.2 kg of product was obtained.

  From the absorption spectrum in the infrared spectroscopic analysis of the solid, it was found that the solid was a PPS mixture composed of PPS units. As a result of performing GPC measurement of this PPS mixture and analyzing the chromatogram, the weight fraction of the component having a molecular weight of 5000 or less was 40%, and the weight fraction of the component having a molecular weight of 2500 or less was 33%.

[Reference Example 4]
10 kg of the PPS mixture 1 obtained by the method of Reference Example 2 was collected, and 150 kg of chloroform was used as a solvent, and the mixture was stirred for 1 hour under reflux at normal pressure to bring the PPS mixture 1 and the solvent into contact with each other. Subsequently, solid-liquid separation was carried out by hot filtration to obtain an extract. After adding 150 kg of chloroform to the solid matter separated here and stirring for 1 hour under reflux at normal pressure, solid-liquid separation was similarly performed by hot filtration to obtain an extract, which was mixed with the previously obtained extract. . The obtained extract was in the form of a slurry partially containing solid components at room temperature.

  By treating this extract slurry under reduced pressure, a portion of chloroform was distilled off until the weight of the extract reached about 40 kg to obtain a slurry. Next, this slurry mixture was added dropwise to 600 kg of methanol with stirring. The resulting precipitate was filtered to recover the solid content, and then dried under reduced pressure at 80 ° C. to obtain 3.0 kg of white powder. The yield of white powder was 30% based on the PPS mixture 1 used.

  From the absorption spectrum in the infrared spectroscopic analysis of this white powder, it was confirmed that the white powder was a compound composed of PPS units. In addition, mass spectrum analysis (device: Hitachi M-1200H) of components separated from high performance liquid chromatography (device; Shimadzu LC-10, column; C18, detector; photodiode array), MALDI-TOF From the molecular weight information by -MS, it was found that this white powder was a mixture mainly composed of cyclic PPS having 4 to 12 repeating units, and the weight fraction of cyclic PPS was about 94%. Moreover, as a result of performing GPC measurement of this mixture, the weight average molecular weight was 900.

[Reference Example 5]
A white powder of 2.9 kg was obtained in the same manner as in Reference Example 4 except that 10 kg of the PPS mixture 2 obtained by the method of Reference Example 3 was used and acetone was used instead of methanol. The yield of white powder was 29% based on the PPS mixture 2 used.

  From the absorption spectrum in the infrared spectroscopic analysis of this white powder, it was confirmed that the white powder was a compound composed of PPS units. Moreover, from the mass spectrum analysis of the component divided into components by high performance liquid chromatography, and further from the molecular weight information by MALDI-TOF-MS, this white powder is a mixture containing cyclic PPS having 4 to 12 repeating units as a main component, The weight fraction of cyclic PPS was found to be about 96%. Moreover, as a result of performing GPC measurement of this mixture, the weight average molecular weight was 1000.

[Reference Example 6]
Here, the preferable manufacturing method of PPS resin used for the polyphenylene sulfide resin composition of this invention is described.

  The cyclic PPS mixture obtained in Reference Example 4 was charged into a 5 liter autoclave with a stirrer and replaced with nitrogen, and then heated to 320 ° C. over about 1 hour while reducing the pressure to about 2 kPa with a vacuum pump. . During this time, stirring was performed at 10 rpm until the internal temperature reached about 250 ° C., and stirring was performed at 50 rpm above 250 ° C. After reaching 320 ° C., stirring was continued at 320 ° C. for 60 minutes while reducing the pressure. Then, the inside of the reactor was pressurized by introducing nitrogen from the upper part of the autoclave, the contents were taken out in a gut shape from the discharge port, and the gut was pelletized to obtain pellets.

  The obtained pellet was a slightly blackish resin. This product was found to have a PPS structure from the absorption spectrum obtained by infrared spectroscopy. Further, it was completely dissolved in 1-chloronaphthalene at 210 ° C. As a result of GPC measurement, it was found that the obtained PPS resin had a weight average molecular weight of 55,400 and a dispersity of 2.20. Moreover, as a result of conducting the elemental analysis of the obtained product, Na content was 7 ppm and other alkali metals were not detected.

  Furthermore, as a result of analyzing the generated gas component at the time of heating for the PPS resin obtained here, the lactone type compound and the aniline type compound were below the detection limit.

[Reference Example 7]
Here, a preferred method for producing a PPS resin used in the polyphenylene sulfide resin composition of the present invention will be described using an example in which a raw material different from that of Reference Example 6 is used.

  Pellets were obtained in the same manner as in Reference Example 6 using the cyclic polyphenylene sulfide mixture obtained in Reference Example 5.

  The obtained pellet was a resin with a slight brownishness. This product was found to have a polyphenylene sulfide structure from the absorption spectrum obtained by infrared spectroscopy. Further, it was completely dissolved in 1-chloronaphthalene at 210 ° C. As a result of GPC measurement, it was found that the obtained PPS resin had a weight average molecular weight of 79100 and a dispersity of 1.93. Moreover, as a result of conducting the elemental analysis of the obtained product, Na content was 6 ppm and other alkali metals were not detected.

  Furthermore, as a result of analyzing the generated gas component at the time of heating for the PPS resin obtained here, the lactone type compound and the aniline type compound were below the detection limit.

[Reference Example 8]
<Preparation of granular PPS resin>
Here, preparation of a granular PPS resin according to the prior art is shown.

  About 100 kg of NMP was added to 100 kg of the granular PPS resin containing the slurry obtained in Reference Example 1, washed at 85 ° C. for 30 minutes, and filtered through a sieve (80 mesh, opening 0.175 mm). The operation of diluting the obtained solid with 500 kg of ion-exchanged water, stirring at 70 ° C. for 30 minutes, and filtering through an 80 mesh sieve to collect the solid was repeated 5 times in total. The solid material thus obtained was dried at 130 ° C. in a nitrogen atmosphere to obtain granular polyphenylene sulfide.

  The obtained granular PPS resin was completely dissolved in 1-chloronaphthalene at 210 ° C. As a result of GPC measurement, the weight average molecular weight was 48600, and the degree of dispersion was 2.66. Moreover, as a result of conducting an elemental analysis of the obtained product, the Na content was 1020 ppm and no other alkali metals were detected.

  Furthermore, as a result of analyzing the generated gas component at the time of heating for the PPS resin obtained here, 618 ppm of γ-butyrolactone and 416 ppm of 4-chloro-N-methylaniline were detected with respect to the weight of the PPS resin before heating. It was done.

[Examples 1 to 5]
Examples 1-5
The raw material which consists of a composition of Table 1 is supplied to the twin-screw extruder (Ikegai Kogyo Co., Ltd. PCM-30) set to the extrusion temperature of 320 degreeC, the gut after discharge from a die | dye is rapidly quenched into ice water, Fixed structure. Next, an extruded pellet obtained by cutting the gut into pellets using a strand cutter was obtained. The extruded pellet was stained with a PPS resin by a ruthenium acid staining method, and the sample obtained by cutting out an ultrathin section was observed at a magnification of 100,000 times with a transmission electron microscope. It was confirmed that a structure having a size of 001 μm or more was not seen and the structure was compatible. This shows that this system is compatibilized under shear in an extruder having an extrusion temperature of 320 ° C.

  Here, a part of the extruded pellets is supplied to an injection molding machine (PS20E2ASE manufactured by Nissei Plastic Industry Co., Ltd.) set at a resin temperature of 320 ° C. and a mold temperature of 20 ° C., with an injection speed of 60% and an injection pressure described later. Injection molding was carried out with a time cycle of an injection time of 10 seconds and a holding pressure of 60 seconds under the condition of one speed and one pressure to obtain an injection molded product (molding after injection molding under the condition that the mold temperature was 20 ° C. By rapidly cooling the product in the mold, the phase decomposition stopped, meaning that the structure was frozen in the initial stage of spinodal decomposition). A sample cut out from the surface layer of the obtained molded article, stained with PPS resin by ruthenium acid staining method, and further cut out an ultrathin section was observed with a transmission electron microscope at a magnification of 100,000 times. A continuous structure of both phases of 0.01 to 0.5 μm was also observed in this sample.

  Next, a sample cut out from the surface layer part of the molded product obtained by injection molding in the same manner as described above except that a part of the extruded pellet was separately set at a mold temperature of 150 ° C. Table 2 similarly shows the results of the structural period or interparticle distance obtained from small-angle X-ray scattering and the observation of the structural state from a transmission electron microscope. At the mold temperature of 150 ° C. in this example, it can be seen that the structure is developed after the structure is formed in the initial process of spinodal decomposition as described above.

  Further, a part of the extruded pellet is supplied to an injection molding machine (PS20E2ASE manufactured by Nissei Plastic Industry Co., Ltd.) set at a resin temperature of 320 ° C. and a mold temperature of 150 ° C., and filled to the tip at an injection speed of 60%. Injection molding is performed with a time cycle of 10 seconds for injection time and 60 seconds for holding pressure under the condition of one speed and one pressure at the minimum pressure + 3 kgf / cm2 (gauge pressure), and an Izod impact test piece conforming to ASTM D256 is used. Obtained. Table 2 shows the results of measuring the Izod impact strength of the obtained molded product in accordance with ASTM D256.

  In addition, among the above extruded pellets, another part was supplied to an injection molding machine (PS20E2ASE manufactured by Nissei Plastic Industry Co., Ltd.) set at a resin temperature of 320 ° C. and a mold temperature of 150 ° C. and retained for 5 minutes. Injection molding is performed with a time cycle of 10 seconds for injection time and 60 seconds for holding time under the condition of one speed and one pressure at the minimum pressure to fill to the tip + 3 kgf / cm2 (gauge pressure), and similarly conforms to ASTM D256 An Izod impact test piece was obtained. The obtained molded product was measured for Izod impact strength according to ASTM D256, and the retention rate of Izod impact strength with no residence (Izod impact strength after 5-minute residence / Izod impact strength with no residence × 100) are shown in Table 2.

In addition, the following resins were used.
PA-1: Nylon 4,6 resin ("STANYL" manufactured by DSM, The Netherlands, relative viscosity 3.0 at 96 g sulfuric acid 1 g / dl)
PEI: polyetherimide resin ("Ultem 1010" manufactured by GE Plastics).

[Comparative Examples 1-2]
The same pelletizing and evaluation as in Example 1 were performed except that the PPS resin obtained in Reference Example 8 was used. The results were as shown in Table 1. It is apparent that the PPS resin composition of the present invention shown in the Examples is superior in thermal stability during injection molding and has a significantly superior Izod impact strength retention rate as compared with the PPS resin composition according to the prior art.

  As described above, the molecular weight distribution of the PPS resin is narrower than that of the conventional PPS resin, and the alkali metal content in the PPS resin is further reduced, so that the polyphenylene sulfide resin composition obtained from the raw material of the PPS resin is reduced. The thermal stability of the structure has been improved, and it has become possible to provide a polyphenylene sulfide resin composition having a stable and high impact even when stagnation or the like occurs during injection molding, and a method for producing the same.

Claims (11)

(A) Polyphenylene sulfide resin having a weight average molecular weight (Mw) of 10,000 or more, a dispersity represented by weight average molecular weight / number average molecular weight (Mn) of 2.5 or less, and an alkali metal content of 50 ppm or less. (B) One or more thermoplastic resins selected from polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenylene oxide, polysulfone, and polyethersulfone A polyphenylene sulfide resin composition comprising: a polyphenylene sulfide resin composition having a biphasic continuous structure having a structural period of 0.01 to 1 μm or a dispersed structure having a distance between particles of 0.01 to 1 μm Sulfide tree Fat composition. 1 selected from (A) polyphenylene sulfide resin, (B) polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenyleneoxide, polysulfone, and polyethersulfone 2. The polyphenylene sulfide resin composition according to claim 1, wherein (A) the polyphenylene sulfide resin is 50% by weight or more based on the total amount of the thermoplastic resin of at least one species. 3. The polyphenylene sulfide resin composition according to claim 1, wherein the alkali metal contained in the polyphenylene sulfide resin is sodium. The lactone type compound in the gas component generated when the polyphenylene sulfide resin is heated is 500 ppm or less based on the weight of the polyphenylene sulfide, and the aniline type compound is 300 ppm or less based on the weight of the polyphenylene sulfide. The polyphenylene sulfide resin composition according to any one of the above. The polyphenylene sulfide resin is a polyphenylene sulfide resin obtained by melting and heating a cyclic polyphenylene sulfide mixture represented by the following general formula (1). A polyphenylene sulfide resin composition.

(M may be an integer of 4 to 20, m may be a mixture of 4 to 20) A polyphenylene sulfide resin composition comprising at least two components of resin separated by spinodal decomposition and containing at least one polyphenylene sulfide resin, and having a structure period of 0.001 to 0.1 μm in the initial stage of the spinodal decomposition. The double phase continuous structure is formed and further developed into a double phase continuous structure having a structural period of 0.01 to 1 μm or a dispersed structure having a distance between particles of 0.01 to 1 μm. 6. The polyphenylene sulfide resin composition according to any one of 5 above. The polyphenylene sulfide resin composition according to any one of claims 1 to 6, wherein the polyphenylene sulfide resin composition is produced through melt-kneading. The polyphenylene sulfide resin composition according to claim 6, wherein the spinodal decomposition is compatible under shearing during melt kneading and phase-separated under non-shearing after discharge. (A) Polyphenylene sulfide resin having a weight average molecular weight (Mw) of 10,000 or more, a dispersity represented by weight average molecular weight / number average molecular weight (Mn) of 2.5 or less, and an alkali metal content of 50 ppm or less. (B) one or more thermoplastic resins selected from polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenylene oxide, polysulfone, and polyethersulfone A method of producing a polyphenylene sulfide resin composition in which a polyphenylene sulfide resin composition comprising the above components is phase-separated by spinodal decomposition, and forms a biphasic continuous structure having a structural period of 0.001 to 0.1 μm in the initial stage of spinodal decomposition The method of the polyphenylene sulfide resin composition characterized in that allowed to develop further both-phase continuous structure of the structure cycle 0.01 to 1 [mu] m or until dispersion structure of the distance between the particles 0.01 to 1 [mu] m,. (A) Polyphenylene sulfide resin having a weight average molecular weight (Mw) of 10,000 or more, a dispersity represented by weight average molecular weight / number average molecular weight (Mn) of 2.5 or less, and an alkali metal content of 50 ppm or less. (B) one or more thermoplastic resins selected from polyester, polyamide, polyetherimide, polyamideimide, polyimide, polycarbonate, polyetherketone, polythioetherketone, polyetheretherketone, polyphenylene oxide, polysulfone, and polyethersulfone 10. The method for producing a polyphenylene sulfide resin composition according to claim 9, wherein spinodal decomposition is induced by melt-kneading the polyphenylene sulfide resin composition. 11. The method for producing a polyphenylene sulfide resin composition according to claim 10, wherein at least two components of the resin are mixed under shear during melt kneading and phase separation is performed under non-shear after discharge.