JP4998231B2 - Polyphenylene sulfide resin composition - Google Patents

Description

  The present invention relates to a polyphenylene sulfide resin composition, and by blending a cyclic polyphenylene sulfide compound having a specific ring structure, it has excellent fluidity and high crystallization characteristics, and is a resin molded product, sheet, film, fiber and It is an object of the present invention to provide a PPS resin composition that has less processability and gas generation at the time of melt processing of pipes and the like, and can suppress generation of burrs during injection molding.

  Polyphenylene sulfide resin (hereinafter abbreviated as PPS) has been put to practical use in engineering plastics and heat-resistant films at first, taking advantage of excellent heat resistance and chemical resistance. In particular, it has excellent heat resistance, chemical resistance, rigidity, flame retardancy, and has excellent molding processability and dimensional stability. Therefore, it is used as an engineering plastic for injection molding, as an electrical / electronic equipment part, an automobile part, and a precision equipment part. Widely used.

  In recent years, the use of fibers has also been expanding. For example, it is useful for applications such as bag filters and insulating paper, and the amount of demand is also increasing.

  PPS is a resin that has a good molding processability among thermoplastic resins, but in recent years, especially as electric and electronic parts have become smaller, more complicated, and introduced with insert molding technology with multiple materials. There is an increasing demand for improvement in moldability. In order to meet these requirements and improve the moldability, it is necessary to increase the fluidity and the crystallization speed (solidification speed) during melting of PPS.

  On the other hand, PPS is excellent in heat resistance, heat resistance, chemical resistance, rigidity, flame retardancy, and has excellent molding processability and dimensional stability. However, when used for injection molding applications, it is suitable for other engineering plastics. In comparison, it is also a resin that has been regarded as a problem that a large amount of burrs are generated during injection molding.

  The use of PPS is expanding not only for resin molded products but also for film and fiber fields. When PPS is processed into a fiber or a film, the die pressure fluctuates due to the influence of the resin pressure at the time of molding derived from the resin viscosity, the influence of crystallization characteristics (solidification rate), and the like. Therefore, in the case of yarn processing, there are problems such as uneven thickness of the yarn and yarn breakage, and in film processing, there are problems such as uneven thickness of the film. Furthermore, the residence time during fiber and film processing is longer than that of resin injection molding, etc., and the generation of decomposition gas during residence also causes the problem of thread breakage during yarn processing and the problem of bubble defects during film processing. there were. In order to improve the fluidity, a method of decreasing the resin viscosity by increasing the processing temperature is a general technique, but PPS resin has a problem of generating a decomposition gas as the temperature rises. It has been difficult to achieve both improvement in properties and suppression of gas generation only at the processing temperature.

  For improving the flowability of PPS and improving the molding processability such as the pressure drop due to the decrease in resin viscosity, a method of adding N, N′-alkylenebis (cyclic amide), aliphatic carboxylic acid glyceride, aliphatic carboxylic acid ester and the like ( Patent Document 1), a method of adding a silicon compound having a mercapto group (Patent Document 2), a method of adding a PPS resin and a thermotropic liquid crystal polyester (Patent Documents 3 and 4) have been proposed.

  However, in the methods described in Patent Documents 1 to 4, although the improvement effect of molding processability due to good fluidization, low resin viscosity, and improvement of crystallization characteristics is recognized, on the other hand, it is blended to achieve these purposes. Additives are generated as a large amount of volatile gas during molding, and it is difficult to achieve both good fluidization, low resin viscosity, improved melt processability by improving crystallization characteristics, and suppression of gas generation. Met. Also, in the fiber and film processing using these known techniques, the generation of volatile gas also has an effect, such as yarn breakage during continuous spinning, uneven yarn thickness, and film processing may cause film bubbles and film thickness unevenness. There was no solution.

  Although different from the problem to be solved by the present invention, by adding cyclic PPS as a melt stabilizer to a resin composition containing linear PPS and a filler, deterioration during melt processing is suppressed, and mechanical properties are reduced. Patent Document 5 discloses a technique for suppressing the decrease. However, in the PPS resin composition obtained by the present technology, no effect of improving fluidity, improvement of crystallization characteristics, and reduction of burrs during injection molding were observed. Cyclic PPS used in Patent Document 5 is cyclohexa (p-phenylene sulfide) having a purity of 99.9% obtained by Soxhlet extraction from a cross-linked PPS resin with chloroform and recrystallization (m = 6 in formula (I)). ) Is disclosed. According to the follow-up experiments by the authors, the melting point is 347 ° C., which is much higher than the melting point of PPS (277-282 ° C.), and it does not melt at a general PPS resin molding temperature of about 320 ° C. It was clarified that the effect of improving the speed was not recognized and the effect of reducing the occurrence of burrs during the injection molding was not recognized. That is, it has been clarified that cyclohexa (p-phenylene sulfide) does not melt at a PPS molding processing temperature of about 320 ° C. and acts as a filler.

Moreover, in patent document 5, the phenomenon of the drawing at the time of a shaping | molding process is suppressed by carrying out shaping | molding processing in the temperature range which cyclohexa (p-phenylene sulfide) melt | dissolves, ie, shaping | molding temperature 330-380 degreeC, and the same conditions. The PPS resin composition containing cyclohexa (p-phenylene sulfide) is less deteriorated in mechanical properties than the PPS resin composition not containing cyclohexa (p-phenylene sulfide) molded in step 1. However, there is no disclosure at all regarding the improvement of fluidity, the improvement of crystallization characteristics in the vicinity of the molding processing temperature of general PPS, and the effect of reducing the generation of burrs during injection molding. According to the follow-up experiment by the authors, the PPS resin composition blended with cyclohexa (p-phenylene sulfide) has no appreciable effects on improving fluidity and crystallization characteristics even at a molding temperature of 320 ° C. for general PPS resins. It became clear that it was not possible.
Japanese Patent Application Laid-Open No. 64-51463 JP-A-2-225565 Japanese Patent Laid-Open No. 1-292058 Japanese Patent Laid-Open No. 5-230371 Japanese Patent Laid-Open No. 10-77408

  The present invention relates to a PPS resin composition that solves the above problems, has excellent fluidity during melt processing, has a low melt viscosity, has high crystallization characteristics, and suppresses the amount of gas generated during melting. Furthermore, it relates to a PPS resin composition that is suitable for melt-processability of resin molded products, sheets, films, fibers, pipes, etc., and particularly suitable as an injection-molded product capable of suppressing the occurrence of burrs during injection molding processing. is there.

  With regard to the PPS composition, the authors have excellent fluidity and high crystallization characteristics by blending a cyclic PPS mixture having a specific ring structure, and into molded articles such as resin molded articles, fibers, and films. The present inventors have succeeded in obtaining a PPS resin composition in which the melt processability during processing and the gas generated during melt processing are small, and further, the generation of burrs during injection molding is reduced. That is, the present invention provides the following.

That is, the present invention
[1] (A) A cyclic PPS mixture represented by the general formula (1) with respect to 100 parts by weight of PPS having a weight average molecular weight of 10,000 or more, wherein the content of cyclic PPS with m = 6 is 50 A PPS resin composition comprising 1 to 50 parts by weight of a cyclic PPS mixture that is less than wt%,

(M is an integer from 4 to 20)
[2] The polyphenylene sulfide resin composition according to [1], wherein the content of cyclic polyphenylene sulfide of m = 6 in the (B) cyclic polyphenylene sulfide mixture is less than 30% by weight,
[3] The polyphenylene sulfide resin composition according to any one of [1] and [2], wherein m of the cyclic polyphenylene sulfide mixture represented by the general formula (1) is 4 to 12,
[4] The polyphenylene sulfide resin composition according to any one of [1] to [3], wherein the amount of the (B) cyclic polyphenylene sulfide mixture is 2 to 10 parts by weight,
[5] (A) For 100 parts by weight of polyphenylene sulfide having a weight average molecular weight of 10,000 or more , (B) a cyclic polyphenylene sulfide mixture represented by the general formula (1), wherein m = 6 A method for producing a polyphenylene sulfide resin composition comprising blending 1 to 50 parts by weight of a cyclic polyphenylene sulfide mixture having a content of less than 50% by weight,

(M is an integer from 4 to 20)
[6] A molded article comprising the polyphenylene sulfide resin composition according to any one of claims [1] to [4],
[7] An injection-molded article comprising the polyphenylene sulfide resin composition according to any one of claims [1] to [4],
[8] A method for producing a molded article comprising a polyphenylene sulfide resin composition, wherein the polyphenylene sulfide resin composition obtained by the production method according to [5] is injection-molded,
It is about.

  According to the present invention, the PPS resin composition has excellent fluidity and high crystallization speed, and has low processability and gas generation at the time of injection molding, fiber and film processing, and reduced burr generation at the time of injection molding. Further, by using the resin composition, a melt processing method having excellent processability can be provided. Furthermore, it is possible to provide a PPS resin composition in which the occurrence of burrs during injection molding is reduced.

  Hereinafter, the present invention will be described in detail.

(1) Polyphenylene sulfide (PPS)
The (A) polyphenylene sulfide (PPS) used in 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). If it is less than 70 mol%, the heat resistance is impaired.

  Further, PPS can constitute less than 30 mol% of the repeating units with repeating units having the following structural formula.

  The molecular weight of the PPS 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. If the weight average molecular weight is less than 10,000, the moldability at the time of processing is low, and the properties such as mechanical strength and chemical resistance of the molded product are low. 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. Sex can be obtained. Here, the molecular weight of PPS is a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

The melt viscosity of the PPS used in the present invention is not particularly limited as long as melt kneading is possible, but a melt viscosity of 5 to 5000 Pa · s (320 ° C., shear rate 1000 sec ⁻¹ ) is usually used.

  Such PPS is generally known, that is, a method for obtaining a polymer having a relatively low molecular weight described in JP-B-45-3368 or JP-B-52-12240 and JP-A-61-7332. Or a method for obtaining a polymer having a relatively large molecular weight. In the present invention, the PPS obtained as described above is crosslinked / polymerized by heating in air, washed with an organic solvent, hot water, an aqueous acid solution, etc., and activated with a functional group-containing compound such as acid anhydride, epoxy, isocyanate, etc. Of course, it is also possible to use after performing various treatments.

  The cyclic PPS mixture used in the present invention will be described.

(2) Cyclic PPS mixture The cyclic PPS mixture of the present invention is a mixture of cyclic PPS represented by an integer of m = 4 to 20 represented by the following general formula (1), and in the cyclic PPS mixture, The content of cyclic PPS with m = 6 is less than 50% by weight.

(M is an integer from 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 cyclic PPS having a single m has a difference in ease of crystallization, the cyclic PPS mixture of the present invention tends to have a higher melting temperature because it is obtained as a crystal. However, the cyclic PPS mixture of the present invention is a mixture having different m. Therefore, compared with a single cyclic PPS, the melting temperature is specifically reduced and the process temperature of the PPS is approached, and by blending the cyclic PPS mixture into the PPS, for the purposes of the present invention, It has the characteristics that it has excellent fluidity improvement effect during certain melt processing and an improvement effect of crystallization characteristics. This means that melt processing is possible even when the heating temperature is low when the resin composition of the present invention is melt processed. It expresses the feature of being excellent in.

  Furthermore, the fluidity improvement effect and the crystallization property improvement effect will manifest the feature that the occurrence of burrs during injection molding is remarkably suppressed.

  For example, cyclic PPS (cyclohexa (p-phenylene sulfide)) with m = 6 has a melting point of 348 ° C., which is 60 ° C. higher than the melting point of PPS (277-282 ° C.), and therefore the melt processing temperature is increased. The authors have found that there is a problem that the annular material does not melt if it is not. Due to the characteristics of the cyclic PPS, the cyclic PPS compound used in the present invention has different m from the viewpoint of improving the fluidity during melt processing, improving the crystallization characteristics, and suppressing the occurrence of burrs during injection molding. It is a mixture of PPS.

  There is no particular limitation on the ratio of each different m in the cyclic PPS mixture. However, in order to achieve the effects of the present invention, the highest melting point of the cyclic PPS mixture of m = 6 which is easy to crystallize. The content is less than 50% by weight, more preferably 30% by weight, particularly preferably less than 10% by weight (cyclic PPS (weight) of m = 6 / (cyclic PPS mixture (weight) × 100). Here, the cyclic PPS content of m = 6 in the cyclic PPS mixture is the total peak 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. It can be determined as the ratio of the peak area attributed to the cyclic PPS with m = 6 to the area, where the compound having a PPS structure is at least a PPS structure. A compound having a PPS structure, such as a cyclic PPS or a linear PPS, having a structure other than phenylene sulfide in its part (for example, as a terminal structure) belongs to this compound. The qualitative characteristics of each peak divided into components by liquid chromatography can be obtained by separating each peak by preparative liquid chromatography and performing an absorption spectrum or mass spectrometry in infrared spectroscopic analysis.

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

(3) Manufacturing method of PPS mixture used as raw material of cyclic PPS As a manufacturing method of PPS mixture, a known technique can be used. For example, polyhalogenated aromatic compound represented by at least p-dichlorobenzene, sulfide A mixture containing an alkali metal sulfide typified by sodium and an organic polar solvent typified by N-methyl-2-pyrrolidone is heated to prepare a reaction solution containing a PPS mixture and an alkali metal halide, and the reaction solution For example, a method of obtaining a PPS mixture (a mixture of PPS and cyclic PPS) by treating with water or the like, and a method of obtaining a PPS mixture by oxidative polymerization of diphenyl disulfides or thiophenols can be exemplified. However, since the cyclic PPS mixture 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 mixture, 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 have found that the cyclic PPS mixture represented by the formula (1) (mixture of m = 4 to 20) is 10% by weight in the PPS mixture. It has been found that these are preferable as raw materials for obtaining the cyclic PPS mixture 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 the PPS mixture from the recovered slurry, for example, at least 50 wt% or more of the 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. In addition, at least the residual organic polar solvent and the alkali metal halide are removed and the PPS mixture is separated and recovered, or the PPS mixture is precipitated from the recovered slurry and the PPS mixture is recovered as a solid component, for example, recovery Examples thereof include a method of obtaining a PPS mixture as a solid component by a known solid-liquid separation method such as decantation, centrifugation, and filtration after the PPS mixture is precipitated by adding water to the slurry.

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

  The solvent used here is not particularly limited as long as it is a solvent that can dissolve the cyclic PPS mixture, but the cyclic PPS mixture dissolves in the dissolving environment, but the PPS mixture is preferably a solvent that is difficult to dissolve, and PPS does not dissolve. A solvent is more preferable. The pressure of the reaction system when the PPS mixture 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 inexpensive for the components of the reactor for constructing it. There are advantages. 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 or crosslinking of PPS or cyclic PPS mixture 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. 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 restriction on the atmosphere in which the PPS mixture is brought into contact with the solvent, but if the PPS mixture or solvent is subject to oxidative degradation due to conditions such as the temperature and time at which it is brought into contact, it should be performed in a non-oxidizing atmosphere. Is desirable. 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 mixture 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 which the PPS mixture is brought into contact with the solvent varies depending on the type of solvent used, the temperature, etc., and cannot be uniquely limited. However, for example, 1 to 50 hours can be exemplified. Even if it is too long, dissolution in the solvent reaches a saturated state, and no further effect can be obtained.

  The method of bringing the PPS mixture into contact with the solvent is not particularly limited as long as a known general method is used. For example, the PPS mixture and the solvent are mixed and stirred as necessary. Any method such as a method of dissolving the cyclic PPS mixture in the solvent while simultaneously showering the solvent in the PPS mixture on the filter and a method based on the Soxhlet extraction method principle can be used. Although there is no restriction | limiting in particular in the usage-amount of the solvent at the time of making a PPS mixture and a solvent contact, For example, the range of 0.5-100 can be illustrated by the bath ratio with respect to a PPS mixture weight. When the bath ratio is too small, mixing of the PPS mixture and the solvent becomes difficult, and the cyclic PPS mixture tends to be insufficiently dissolved in the solvent. A larger bath ratio is generally advantageous for dissolving the cyclic PPS mixture in the solvent, but if it is too large, no further effect can be expected, and conversely, there may be an economic disadvantage due to an increase in the amount of solvent used. . When the contact between the PPS mixture and the solvent is repeated, sufficient effects can often be obtained even with a small bath ratio. The Soxhlet extraction method, in principle, provides the same effect as when the PPS mixture 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 mixture is dissolved is obtained in the form of a solid-liquid slurry containing the remaining solid PPS after the PPS mixture is brought into contact with the solvent, the solution portion 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. For the solution thus separated, the solvent described later is removed. On the other hand, for the remaining solid component, when the cyclic PPS mixture still remains, specifically, when 0.05% by weight or more of the cyclic PPS mixture remains on a weight basis, A cyclic PPS mixture can be obtained with higher yield by repeatedly performing contact and solution recovery. When the cyclic PPS mixture hardly remains, specifically, when the cyclic PPS mixture remains less than 0.05% by weight, the residual solid PPS is removed by removing the residual solvent. Can be suitably recycled as high-purity PPS.

(5) Removal of solvent from cyclic PPS solution In the present invention, the solvent is removed from the solution containing the cyclic PPS mixture (m = 4 to 20) represented by the formula [I] obtained as described above. To obtain a cyclic PPS mixture. 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 membrane. However, it is usual in terms of obtaining a cyclic PPS mixture 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 cyclic PPS obtained as described above may contain a solid depending on the temperature. In this case, the solid belongs to the cyclic PPS mixture. It is desirable to recover together with the soluble components, so that a cyclic PPS mixture can be obtained with a high 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.

(6) Other post-treatments The cyclic PPS mixture obtained by the methods described in (3) to (5) has a sufficiently high purity and is suitably used as a cyclic PPS mixture which is a necessary component of the resin composition of the present invention. However, it is possible to obtain an even more pure cyclic PPS mixture by additionally performing the post-treatment described below.

  The cyclic PPS mixture obtained by the operations (3) to (5) may contain impurity components contained in the PPS mixture depending on the characteristics of the solvent used. Impurities are dissolved in the cyclic PPS mixture containing such a small amount of impurities, but the cyclic PPS mixture is not dissolved, or the cyclic PPS mixture is contacted with a second solvent that is difficult to dissolve, thereby selectively removing the impurity components. Often it is possible to do.

  The pressure of the reaction system when the cyclic PPS mixture is contacted with the second solvent is preferably normal pressure or slight pressure, and particularly preferably normal pressure, and the reaction system of 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 mixture 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 mixture 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 mixture 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 mixture 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 of bringing the cyclic PPS mixture into contact with the second solvent, a method in which the solid cyclic PPS mixture and the second solvent are mixed with stirring as necessary, and the second solvent is added to the cyclic PPS mixture 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 mixture using a second solvent, a cyclic PPS mixture containing a solution or a cyclic PPS mixture slurry containing a solvent Or the like, and a method of allowing the cyclic PPS mixture to precipitate in the presence of the second solvent. In particular, the method of bringing the cyclic PPS mixture slurry containing the solvent into contact with the second solvent is an effective method because the cyclic PPS mixture obtained after the operation has a high purity.

  After contacting the cyclic PPS mixture with the second solvent, a slurry in which the cyclic PPS mixture is precipitated in the second solvent is obtained, so that the solid cyclic PPS mixture 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 mixture obtained after the solid-liquid separation, the cyclic PPS mixture and the second solvent can be contacted again to further remove the impurities.

(7) Characteristics of the cyclic PPS mixture of the present invention In the cyclic PPS mixture thus obtained, m in the formula (1) is not single, and m = 4 to 20 represented by the formula (1) is different. The cyclic PPS mixture has a characteristic that the cyclic PPS content of m = 6 in the cyclic PPS mixture is less than 50% by weight.

  Note that m of the cyclic PPS mixture of the present invention is m = 4 to 20 as described above, but it has been confirmed by the authors that m = 4 to 12 exist as cyclic PPS. , M is within this range, as will be described later, the flowability improvement effect and the crystallization speed improvement effect of a resin composition comprising a cyclic PPS mixture in PPS, and the workability when melt-processing the resin composition It was confirmed that the generation of gas and gas was reduced, and further, the generation of burrs during injection molding was suppressed.

  Although cyclic PPS with m of 12 or more is likely to exist, 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 mixture and a cyclic PPS having m = 13 or more with the latest analysis technique at present. However, in the present invention, it is important for formulating the effect of the present invention that the cyclic PPS mixture is blended with the PPS, and that the content of the cyclic PPS of m = 6 in the cyclic PPS mixture is a specific amount. A cyclic PPS having m of 13 or more may be contained within a range not impairing the effects of the invention.

  Moreover, although the cyclic PPS mixture obtained by the method as described in (3)-(6) 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 of m = 13 or more with the latest analysis technique at present. The weight average molecular weight (Mw) of the oligomer component presumed to be a linear PPS oligomer varies depending on the production method of the PPS mixture used as the raw material of the cyclic PPS described in the above (3), but is usually 5000 or less. Yes, in some cases it is 2000 or less.

  Linear PPS oligomers are also included in ordinary PPS, but the amount of the cyclic PPS mixture of the present invention is difficult to separate and analyze with the cyclic PPS mixture and the current analysis technique. A value including a linear PPS oligomer and a cyclic PPS in which m is 13 or more is defined as a “cyclic PPS mixture”.

  The linear PPS oligomer remaining as an impurity in the cyclic PPS mixture has poor thermal stability as compared with the cyclic PPS mixture. Therefore, if these are contained in a large amount as an impurity, the effect of the present invention is impaired. In particular, there is a problem that the amount of gas generated during molding is increased, and burrs are easily generated during injection molding.

  Therefore, the amount of the linear PPS oligomer in the cyclic PPS mixture obtained by the method described in (3) to (6) is less than 50% by weight and less than 30% by weight with respect to the total cyclic PPS mixture amount. Is preferable, and more preferably less than 10% by weight.

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

In addition, as described in Patent Document 5, when adopting a method in which a cyclic PPS is Soxhlet extracted from a cross-linked PPS, the extract is cooled, and the precipitated white solid is recovered by a “recrystallization method” In the obtained cyclic PPS, it has been disclosed that a simple cyclic PPS of m = 6 can be obtained with high purity (cyclohexa (p-phenylene sulfide). Although the recovered amount is small compared with the cross-linked PPS, Similarly, the chain PPS is extracted in the same manner and “recrystallized”, whereby a cyclic PPS simple substance of m = 6 can be obtained with high purity.
The cyclic PPS with m = 6 has an extremely stable needle-like crystal structure and is easy to crystallize, so it is a ring suitable for the method of “recrystallization”, but reflects its stable needle-like crystal structure. The melting point becomes as high as 348 ° C. In the resin composition comprising PPS and cyclic PPS of m = 6, no improvement in fluidity and improvement in crystallization characteristics are observed, and the molding processability when the resin composition is melt processed is only PPS. The authors found that the results were rather inferior.

  In the case where only m = 6 cyclic PPS alone, the effect of the present invention is not recognized as described above, but the cyclic PPS content of m = 6 in the cyclic PPS mixture is preferably less than 50% by weight and less than 30% by weight. Furthermore, it has been found that the effect of the present invention is confirmed more preferably at less than 10% by weight.

  The reason for this is currently interpreted as follows. That is, when the cyclic PPS content of m = 6 is reduced, there is an effect that the cyclic PPS does not act as a crystal nucleus, and as a result, crystallization of a cyclic PPS mixture composed of a mixture of m = 4 or more is achieved. And the melting point of the cyclic PPS mixture is lowered, whereby both the PPS and the resin composition comprising the cyclic PPS mixture are melted and compatible with each other. It is thought that it is acting as an agent.

  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 cyclic PPS with m = 6 is possible), the authors separated and recovered these monomers by a collection liquid chromatogram, and obtained cyclic PPS with m = 4 (cyclotetra (p-phenylene sulfide), melting point 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 (3) to (6), the obtained cyclic PPS mixture is a mixture having different m, and a cyclic PPS content of m = 6 is less than 50% by weight. Depending on the conditions, it is also possible to obtain a cyclic PPS content of m = 6 of less than 30% by weight or a post-treatment described above of less than 10% by weight. The obtained cyclic PPS mixture is characterized by a low melting temperature compared to a single cyclic PPS composed of m, which means, for example, a low processing temperature when the cyclic PPS mixture is melted and used, and Flowability is improved even at relatively low temperatures, crystallization characteristics such as crystallization speed are improved, and good moldability and low gas generation can be achieved during melt processing of the PPS composition containing the cyclic PPS. It exhibits excellent characteristics, and also exhibits excellent characteristics of suppressing the generation of burrs, particularly during injection molding, during melt processing.

(8) PPS resin composition The resin composition of the present invention is a cyclic PPS mixture represented by (B) general formula (1) with respect to (A) 100 parts by weight of PPS, containing m = 6 cyclic PPS. A PPS resin composition comprising 1 to 50 parts by weight of a cyclic PPS mixture having an amount of less than 50% by weight.

  When the blending amount of the cyclic PPS mixture is less than 0.1 part, a sufficient fluidity improving effect, a crystallization speed improving effect, and a molding processability improving effect when the resin composition is melt processed are small. On the other hand, when the blending amount of the cyclic PPS mixture is 50% by weight or more, the characteristics of the PPS resin itself may be lowered, or the viscosity may be drastically lowered, and the moldability may be lowered.

  Therefore, the addition amount of the cyclic PPS mixture is 1 to 50 parts by weight, preferably 2 to 20 parts by weight, and more preferably 2 to 10 parts by weight.

It is known that (A) PPS forms a cyclic PPS mixture as a by-product during the polymerization. Therefore, although (A) PPS itself already contains a cyclic PPS mixture, it is known that this amount is extremely small, 0.1 to 1% by weight. However, the effect of the present invention cannot be obtained if the amount of the PPS mixture by-produced during the polymerization is only 0.1 to 1% by weight, and it is possible to blend the cyclic PPS mixture more than the amount of the PPS mixture contained in the single PPS. It is important to get an effect. Therefore, the addition amount of the cyclic PPS mixture is 1 to 50 parts by weight, preferably 2 to 20 parts by weight, and more preferably 2 to 10 parts by weight.
The PPS resin composition of the present invention is obtained by blending the (B) cyclic PPS mixture obtained by the above-described method or the like with (A) the PPS resin.

  The resin composition of the present invention may further contain a fibrous and / or non-fibrous filler as necessary. The blending amount can be blended in a range of up to 400 parts by weight with respect to (A) 100 parts by weight of PPS. In terms of obtaining higher mechanical properties, dimensional stability, etc., (A) 100 parts by weight of PPS It is preferable to blend 40 to 350 parts by weight of fibrous and / or non-fibrous filler.

  Examples of the fibrous and / or non-fibrous filler blended as necessary in the present invention include glass fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, Fibrous filler such as stone fiber, metal fiber, wollastonite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, alumina silicate and other silicates, alumina, silicon oxide, magnesium oxide, zirconium oxide, oxidation Metal compounds such as titanium and iron oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, ceramic beads, boron nitride, silicon carbide, calcium phosphate and silica Non-fibrous filler such as These may be hollow, it is also possible to further combination of these fillers 2 or more. In addition, it is more preferable to use these fibrous and / or non-fibrous fillers after pretreatment with a coupling agent such as a silane or titanate from the viewpoint of mechanical strength.

  To the PPS resin composition of the present invention, usual additions such as an antioxidant, a heat stabilizer, a lubricant, a plasticizer, a crystal nucleating agent, an ultraviolet light inhibitor, a colorant, a flame retardant, etc. An agent can be added. In addition, the PPS resin composition of the present invention is within the range that does not impair the effects of the present invention. Polyamide, polyphenylene oxide, polysulfone, tetrafluoropolyethylene, polyetherimide, polyamideimide, polyimide, polycarbonate, polyethersulfone, polyetherketone , Polyether ether ketone, epoxy resin, phenol resin, polyethylene, polystyrene, polypropylene, ABS resin, polyester, polyamide elastomer, polyester elastomer and the like may be included.

  Furthermore, in the PPS resin composition of the present invention, γ-glycidoxypropyltrimethoxysilane, γ-glycidide are used for the purpose of improving mechanical strength and moldability such as burrs, etc. within the range not impairing the effects of the present invention. Xylpropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, γ-ureidopropyl Trimethoxysilane and γ- (2-ureidoethyl) aminopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanato Propylmethyldie Kishishiran, .gamma.-isocyanatopropyl ethyl dimethoxy silane, .gamma.-isocyanatopropyl ethyldiethoxysilane, may be added to the organic silane compound such as .gamma.-isocyanatopropyl trichlorosilane.

  The method for preparing the PPS resin composition of the present invention is not particularly limited, but the mixture of raw materials is supplied to a commonly known melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, a mixing roll, and the like. A method of kneading at a temperature of 380 ° C. can be mentioned as an example. Also, the mixing order of the raw materials is not particularly limited, and PPS, the cyclic PPS mixture of the present invention and other additives as needed are dry-blended in a lump and then melt-kneaded by the above-described method or the like, or PPS A typical method is to dry-blend and knead two or three of the cyclic PPS mixture of the present invention and other additives as required, and then melt and knead the remaining one or two. is there.

  The PPS resin composition of the present invention is superior in fluidity and crystallization characteristics as compared with ordinary PPS, and has less fluidity and gas generation during melt processing, so that it can be used for injection molding, injection compression molding, blow molding, etc. It is suitable not only for resin molding applications but also for extrusion molding such as sheets, films, fibers and pipes by extrusion molding. Furthermore, the PPS resin composition of the present invention is particularly suitable for injection molding among melt processing, and has a feature that generation of burrs during injection molding is suppressed.

  As a method for producing a PPS film using the PPS resin composition of the present invention, a known melt film-forming method can be employed, for example, after melting the PPS resin composition in a single-screw or twin-screw extruder. A method of producing a film by extruding from a film die and cooling on a cooling drum, or biaxially stretching a film produced in this way vertically and horizontally with a roller-type longitudinal stretching apparatus and a transverse stretching apparatus called a tenter A stretching method and the like can be exemplified, but are not particularly limited thereto.

  The characteristics of the good flowability and crystallization characteristics of this PPS resin composition are not only the effect of reducing the film thickness unevenness by suppressing the fluctuation of the pressure of the film die at the time of melt film formation, but also the melt production at low pressure. Since film formation is possible, there is also an effect that the production discharge amount can be greatly increased. Usually, in order to lower the melt viscosity, the technique of increasing the film forming temperature is generally used, but there is a problem that a bubble defect occurs during film formation due to generation of decomposition gas, but this PPS resin composition is used. By doing so, melt film formation at a relatively low temperature is possible, and there is an effect that generation of decomposition gas does not occur.

  Similarly, as a method for producing PPS fibers using the PPS resin composition of the present invention, a known melt spinning method can be applied. For example, a chip made of a PPS resin composition as a raw material is uniaxial or biaxial. Kneading while feeding to the extruder, and then extruding from the spinneret through the polymer streamline changer, filtration layer, etc. installed at the tip of the extruder, cooling, stretching, heat setting etc. Although it is possible, it is not particularly limited to this.

  Furthermore, the characteristics of the good flowability and crystallization characteristics of the PPS resin composition are not only the effect that the fluctuation of the pressure of the filtration layer and the base during melt spinning can be suppressed and the unevenness of the thickness of the yarn is small, but also the low pressure In addition to being able to greatly increase production discharge volume, melt spinning can be performed at a relatively low temperature, and there is no problem of yarn breakage without generation of decomposition gas. is there.

(9) Use of the PPS resin composition of the present invention The PPS resin composition of the present invention is excellent in molding processability, mechanical properties, and electrical properties, and as its use, for example, sensors, LED lamps, connectors, sockets, Resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules , Semiconductors, liquid crystal, FDD carriage, FDD chassis, motor brush holder, parabolic antenna, electric / electronic parts represented by computer-related parts; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, Acoustic components Audio / video equipment parts such as audio / laser discs (registered trademark), compact discs, digital video discs, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, etc. Machine-related parts such as office computer-related parts, telephone-related parts, facsimile-related parts, copier-related parts, cleaning jigs, motor parts, lighters, typewriters, etc .: Representatives such as microscopes, binoculars, cameras, watches, etc. Optical equipment, precision machinery-related parts; water faucet tops, mixing faucets, pump parts, pipe joints, water volume control valves, relief valves, hot water temperature sensors, water volume sensors, water meter housings, and other water-related parts; valve alternator terminals , Alternator connector, IC Regulators, potentiometer base for light deer, various valves such as exhaust gas valves, various pipes for fuel, exhaust system, intake system, air intake nozzle snorkel, intake manifold, fuel pump, engine coolant joint, carburetor main body, carburetor Spacer, exhaust gas sensor, cooling water sensor, oil temperature 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 switchー, Transmission wire harness, Window washer nozzle, Air conditioner panel switch board, Fuel related electromagnetic valve coil, Fuse connector, Horn terminal, Electrical component insulation plate, Step motor rotor, Lamp socket, Lamp reflector, Lamp housing, Brake piston Examples include solenoid bobbins, engine oil filters, fuel tanks, ignition device cases, vehicle speed sensors, cable liners and other automobile / vehicle-related parts, and various other uses.

  In the case of PPS film, it has excellent mechanical properties, electrical properties, and heat resistance, and is used for dielectric films of film capacitors and chip capacitors, circuit boards, insulating substrates, motor insulating films, transformer insulating films, It can be suitably used for various applications such as mold film applications.

  In the case of PPS monofilament or short fiber, it can be suitably used for various applications such as paper-making dryer canvas, net conveyor, bag filter, insulating paper and the like.

  Hereinafter, the present invention will be specifically described with examples. The present invention is not limited to the following examples. The following examples were examined using the reagents described below.

<Reagents used>
Diphenyl disulfide (Tokyo Kasei)
Palladium acetate (special grade Wako Pure Chemical)
Vanadyl acetylacetonate (Tokyo Kasei)
Trifluoromethanesulfonic acid (Tokyo Kasei)
Trifluoroacetic acid (Aldrich)
Trifluoroacetic anhydride (Kanto Chemical Deer Special)
1,2-dichloroethane (Aldrich)
Cupric chloride (Tokyo Kasei)
Oxygen (Toa Techno Gas)

<Molecular weight measurement>
The molecular weight was calculated in terms of polystyrene by gel permeation chromatography (GPC), which is a type 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 (slurry: about 0.2% by weight)

<Gas generation>
The amount of gas generated was evaluated by the weight loss rate during heating using a thermogravimetric analyzer. In addition, the sample used the fine granule of 2 mm or less.
Apparatus: Perkin Elmer TGA7
Measurement atmosphere: Sample preparation weight under nitrogen stream: Approximately 10 mg
Measurement condition:
(A) Hold for 1 minute at a program temperature of 50 ° C. (b) When thermogravimetric analysis was performed from a program temperature of 50 ° C. to 320 ° C. at a rate of temperature increase of 20 ° C./minute, the sample weight (W1) when the temperature reached 100 ° C. From the sample weight (W2) when held for 30 minutes after reaching 320 ° C as a reference,
ΔW _{320 ° C.} = (W1−W2) / W1 × 100 (%)
Was measured, and the ΔW was calculated as the amount of generated gas. Similarly, ΔW _{360 ° C.} was calculated from the sample weight loss (W2) when reaching 360 ° C.

<Fluidity>
In order to evaluate the fluidity, using a capillary type melt viscosity measuring apparatus (CAPIROGRAPH-1C manufactured by Toyo Seiki Co., Ltd.), orifice L / D = 20 (inner diameter 1 mm), measurement temperature 320 ° C. and 360 ° C., shear rate 1000 sec− The melt viscosity (Pa · s) measured under the condition 1 was used as an evaluation item for fluidity.

<Crystalling characteristics>
The thermal properties of the polymer obtained using a Perkin Elmer DSC7 were measured. Under the following measurement conditions, the crystallization temperature Tc was 1st Run, and the melting point Tm was 2nd Run.
First Run
・ 50 ° C × 1 minute hold ・ Raise from 50 ° C to 340 ° C, temperature increase rate 20 ° C / minute ・ 340 ° C × 1 minute hold ・ Drop from 340 ° C to 100 ° C, temperature decrease rate 20 ° C / minute (at this time The crystallization peak temperature is Tmc)
Second Run
・ 100 ℃ × 1 minute hold ・ Raise the temperature from 100 ℃ to 340 ℃, the heating rate is 20 ℃ / min (the melting peak temperature at this time is Tm)

[Reference Example 1] (Example of production of PPS mixture as a raw material for cyclic PPS)
<Measurement of burr length during injection molding>
Using a disk-shaped mold of 80 mm diameter x 2 mm pressure having two protrusions (a) 4 mm wide x 20 mm long x 400 μm on the circumference and (b) 4 mm wide x 20 mm long x 20 μm thick, Perform injection molding at a temperature of 320 ° C. and a mold temperature of 130 ° C., and measure the filling length of the thin (b) protrusion when the thick (a) protrusion is focused to the tip. Is the burr length. The gate position was the center of the disk. PS20E2ASE manufactured by Nissei Plastic Industry Co., Ltd. was used for injection molding.

A production example of a PPS mixture as a raw material for the cyclic PPS described in the text (3) will be described below.

<Preparation of PPS mixture>
In a 1000 L autoclave with a stirrer, 42.7% sodium hydrosulfide 82.7 kg (700 mol), 96% sodium hydroxide 29.6 kg (710 mol), N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) In some cases, 114.4 kg (116 mol), sodium acetate 17.2 kg (210 mol), and 100 kg of ion-exchanged water are charged and gradually heated to about 240 ° C. over about 3 hours while passing nitrogen at normal pressure. After distilling 143 kg of water and 2.8 kg of NMP through the rectification tower, the reaction vessel was cooled to 160 ° C. 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.

  Next, 103 kg (703 mol) of p-dichlorobenzene and 90 kg (910 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. While stirring at 240 rpm, the temperature was raised to 270 ° C. at a rate of 0.6 ° C./min and held at this temperature for 140 minutes. While 12.6 kg (700 mol) of water was injected over 15 minutes, it was cooled to 250 ° C. at a rate of 1.3 ° C./min. Thereafter, the slurry was cooled to 220 ° C. at a rate of 0.4 ° C./min, and then rapidly cooled to near room temperature to obtain a slurry (A). This slurry (A) was diluted with 200 kg of NMP to obtain a slurry (B).

  100 kg of the slurry (B) heated to 80 ° C. is filtered with a sieve (80 mesh, opening 0.175 mm) at a 25 kg / 1 batch scale, and a granular PPS resin containing the slurry as a mesh-on component is used as a filtrate component. About 75 kg of slurry (C) was obtained.

  Of the obtained slurry (C), 75 kg was charged in a devolatilizer at 25 kg / 1 batch and replaced with nitrogen, and then treated at 100 to 150 ° C. under reduced pressure for 1.5 hours, and then 150 wt. A solid was obtained by treatment at 1 ° C. for 1 hour. After adding 100 kg of ion-exchanged water (1.2 times the amount of slurry (C)) to this solid, it was stirred at 70 ° C. for 30 minutes to make a slurry again. This slurry was subjected to vacuum suction filtration with a filter having an opening of 10 to 16 μm. 100 kg of ion-exchanged water was added to the obtained white cake and stirred again at 70 ° C. for 30 minutes to make a slurry again. Similarly, after suction filtration, vacuum drying was performed at 70 ° C. for 5 hours to obtain 0.9 kg of a PPS mixture.

  Next, production examples of the cyclic PPS mixture by the methods described in the texts (4) to (6) will be described below.

[Reference Example 2] (Production of cyclic PPS mixture (cPPS-1))
500 g of the PPS mixture obtained by the method of Reference Example 1 was collected, and 12 kg of chloroform was used as a solvent, and the PPS mixture and the solvent were contacted by a Soxhlet extraction method at a bath temperature of about 80 ° C. for 3 hours to obtain an extract. . The obtained extract was in the form of a slurry partially containing solid components at room temperature. Chloroform was distilled off from the extract slurry using an evaporator and then treated at 70 ° C. for 3 hours in a vacuum dryer to obtain 210 g of a solid (42% yield based on the PPS mixture).

  The solid thus obtained was confirmed to be a compound having a phenylene sulfide skeleton from an absorption spectrum in infrared spectroscopic analysis (apparatus; FTIR-8100A manufactured by Shimadzu Corporation). 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 -Based on molecular weight information by MS and GPC, this solid is a mixture mainly composed of cyclic PPS having 4 to 12 repeating units, and the weight fraction of cyclic PPS is about 87%, and 13% is a linear PPS oligomer. And m = 13 or more of cyclic PPS (Mw = 2000).

  A series of results are shown in Table 1.

  According to the present invention, it was found that a high-purity cyclic PPS mixture containing about 87% by weight of cyclic PPS can be obtained in high yield.

[Reference Example 3] (Production of cyclic PPS mixture (cPPS-2))
After obtaining a solid in the same manner as in Reference Example 2, 2 kg of chloroform was added to the obtained solid, and an ultrasonic wave was applied at room temperature to obtain a slurry mixture. In order to bring this into contact with methanol as the second solvent, the slurry mixture was slowly added dropwise to 25 kg of methanol over about 10 minutes while stirring. After completion of dropping, stirring was continued for about 15 minutes. The precipitate was collected by suction filtration with a glass filter having an opening of 10 to 16 μm, and the resulting white cake was vacuum dried at 70 ° C. for 3 hours to obtain 180 g of a white powder. The yield of white powder was 35% based on the PPS mixture 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, the white powder is mainly composed of cyclic PPS having 4 to 12 repeating units based on mass spectral analysis of components separated by high performance liquid chromatography, molecular weight information by MALDI-TOF-MS and molecular weight information by GPC. It was a mixture, and the weight fraction of cyclic PPS was found to be about 94%, and 6% was linear PPS oligomer and cyclic PPS with m = 13 or more (Mw = 2000).

[Reference Example 4] (Production of cyclic PPS mixture (cPPS-3))
After obtaining a solid in the same manner as in Reference Example 3, the following operation was further added. That is, 3 kg of chloroform was again added to the obtained solid, and ultrasonic mixture was applied at room temperature to obtain a slurry mixture. In order to bring this into contact with methanol as the second solvent, the slurry mixture was slowly added dropwise to 25 kg of methanol over about 10 minutes while stirring. After completion of dropping, stirring was continued for about 15 minutes. The precipitate was suction filtered through a glass filter having an opening of 10 to 16 μm, and the resulting white cake was vacuum dried at 70 ° C. for 3 hours to obtain 140 g of a white powder. The yield of white powder was 28% based on the PPS mixture used.

  From the absorption spectrum in the infrared spectroscopic analysis of this white powder, it was confirmed that the white powder was a polymer compound composed of phenylene sulfide units. In addition, this white powder is a mixture containing cyclic PPS having 4 to 12 repeating units as a main component based on mass spectral analysis of components separated by high performance liquid chromatography and molecular weight information by MALDI-TOF-MS. It was found that the weight fraction of PPS was about 97%, 3% was a linear PPS oligomer and cyclic PPS with m = 13 or more (Mw = 2000).

[Reference Example 5] (Production of PPS mixture using diphenyl disulfide and production of cyclic PPS mixture (cPPS-4))
22.4 g (0.1 mol) of palladium acetate was dissolved in 20 L of 1,2-dichloroethane, and 30.02 g (0.2 mol) of trifluoromethanesulfonic acid and 840.12 g (4 mol) of trifluoroacetic anhydride were added. It was. Thereto, 436.69 g (2 mol) of diphenyl disulfide was added, the inside of the reaction system was replaced with oxygen, heated to 40 ° C., and reacted at 40 ° C. for 5 hours. In addition, disappearance of diphenyl disulfide was confirmed 2 hours after the start of the reaction by gas chromatography analysis of the reaction solution. After completion of the reaction, the reaction solution was poured into 20 kg of 10% by weight hydrochloric acid methanol solution to obtain a precipitate. The precipitate was filtered, washed with 10 kg of water and 10 kg of methanol, and then dried at 80 ° C. under reduced pressure to obtain a PPS mixture (280 g) at a yield of 64%. The following operations were performed in the same manner as in Reference Example 2. That is, 280 g of the obtained PPS mixture was collected, and 12 kg of chloroform was used as a solvent, and the PPS mixture and the solvent were brought into contact with each other by a Soxhlet extraction method at a bath temperature of about 80 ° C. for 3 hours to obtain an extract. The obtained extract was in the form of a slurry partially containing solid components at room temperature. Chloroform was distilled off from this extract slurry using an evaporator, and the mixture was then treated at 70 ° C. for 3 hours to obtain 50 g of a solid. The yield of white powder was 18% based on the PPS mixture used.

  The solid thus obtained was confirmed to be a compound having a phenylene sulfide skeleton from an absorption spectrum in infrared spectroscopic analysis (apparatus; FTIR-8100A manufactured by Shimadzu Corporation). 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, this solid is a mixture mainly composed of cyclic PPS having 5 to 12 repeating units, and the weight fraction of cyclic PPS is about 80%, 20% is linear PPS oligomer and m It was found that the cyclic PPS was equal to or greater than 13 (Mw = 3000).

[Reference Example 6] (Comparative Reference Example) Production of cyclic PPS with m = 6 (cPPS-5)
By a method similar to Patent Document 5, 1000 L of chloroform was extracted from 10 kg of a commercially available cross-linked PPS resin (“Torelina” M2100). Thereafter, the extract was cooled to room temperature, and the precipitated white solid and the solvent were separated by filtration. The obtained white solid was naturally dried overnight and then dried at 160 ° C. for 2 hours. Mass spectral analysis of the components separated from the obtained white solid (50 g) by high performance liquid chromatography (apparatus; Shimadzu LC-10, column; C18, detector; photodiode array) (apparatus; Hitachi M- 1200H), and molecular weight information by MALDI-TOF-MS, cyclohexa (p-phenylene sulfide) with a purity of 99.9%, linear PPS oligomer with 0.1%, and cyclic PPS with m = 13 or more (Mw = 2000) )

[Reference Example 7] (Comparative Reference Example) Production of cyclic PPS with m = 6 (cPPS-6)
500 g of the PPS mixture obtained by the method of Reference Example 1 was collected, and 12 kg of chloroform was used as a solvent, and the PPS mixture and the solvent were contacted by a Soxhlet extraction method at a bath temperature of about 80 ° C. for 3 hours to obtain an extract. . The obtained extract was in the form of a slurry partially containing solid components at room temperature. Chloroform was distilled off from the extract slurry using an evaporator and then treated at 70 ° C. for 3 hours in a vacuum dryer to obtain 210 g of a solid (42% yield based on the PPS mixture).

  210 g of the solid thus obtained was again subjected to Soxhlet extraction with 12 kg of chloroform for 8 hours. The extract was filtered while hot, then the filtrate was gradually cooled to room temperature and left for 24 hours. The precipitated white solid and the solvent were separated by filtration and treated at a vacuum dryer at 70 ° C. for 3 hours to recover 100 g of a solid. Mass spectral analysis of the components separated from the obtained white solid (100 g) by high performance liquid chromatography (apparatus; Shimadzu LC-10, column; C18, detector; photodiode array) (apparatus; Hitachi M- 1200H), and molecular weight information by MALDI-TOF-MS, cyclohexa (p-phenylene sulfide) with a purity of 99.9%, linear PPS oligomer with 0.1%, and cyclic PPS with m = 13 or more (Mw = 2000) )

[Reference Example 8] Isolation of simple cyclic PPS The cyclic PPS mixture (cPPS-3) having a purity of 97% produced in Reference Example 4 was separated into each component using preparative high performance liquid chromatography, and m = 4 to 12 The components were separated and recovered, and the melting point was measured. The melting point is shown in Table 2 for reference.

  From Table 2, it can be seen that the melting point of the simple substance of cyclic PPS is very high and a decrease in the melting point is observed as m increases. In addition, from the comparison between Table 1 and Table 2, the melting point of the cyclic PPS mixture of m = 4 to 12 specifically decreases to around 225 ° C., and is lower than the melting point of PPS alone (277 to 282 ° C.). I understand.

[Reference Example 9] Preparation (cPPS-7, 8) of a cyclic PPS and cyclic PPS mixture product of m = 6 and its thermal properties cPPS-3 (purity 97%) (cyclic PPS mixture) produced in Reference Example 4 With reference to Patent Document 5, cPPS-5 (m = 6 cyclic PPS as the main component) produced in Reference Example 6 was dry blended using a Henschel mixer at the following blending ratio.
cPPS-7: cPPS-3 / cPPS-5 = 80/20 (% by weight)
cPPS-8: cPPS-3 / cPPS-5 = 70/30 (% by weight)
cPPS-9: cPPS-3 / cPPS-5 = 50/50 (% by weight)
The melting points of the obtained blended products are shown in Table 1.

  The melting point of the cyclic PPS mixture (cPPS-7) containing 32% by weight of cyclic PPS with m = 6 shows 250 ° C., and cPPS-5 with 99.9% of cyclic PPS with m = 6 (Reference Example 6) It can be seen that the melting point is lower than that of cPPS-6 (Reference Example 7). As the amount of cyclic PPS with m = 6 increases, the melting point tends to increase. The melting point of cPPS-8 (containing 33.5% by weight of cyclic PPS with m = 6) is 270 ° C., and cPPS-9 ( It can be seen that 41% by weight of cyclic PPS with m = 6) has a melting point almost the same as the melting point of PPS 277-282 ° C.

  The results of Reference Examples 1 to 9 are summarized as follows.

  A cyclic PPS mixture is obtained by the methods described in the texts (3) to (6), and the content of cyclic PPS with m = 6 in the mixture is less than 50% by weight. The amount of linear PPS oligomer contained as an impurity is 20% by weight or less.

It can be seen that the melting point of the cyclic PPS mixture of m = 4 to 12 is specifically around 226 ° C., whereas the melting point of the cyclic PPS alone of m = 6 is extremely high at 348 ° C. Moreover, it can be seen that not only m = 6 but also m = 4, 5, 7-10 isolated by preparative high performance liquid chromatography have a higher melting point than the cyclic PPS mixture.
It can also be seen that in the cyclic PPS mixture, when the content of the cyclic PPS alone with m = 6 is less than 50 weight, the melting point is about 280 ° C., which is almost the same as the melting point P (277-282 ° C.) of PPS.

[Reference Example 10] Polymerization of PPS resin An autoclave equipped with a stirrer was charged with 6.004 kg (25 mol) of sodium sulfide 9 hydrate and 4.5 kg of N-methylpyrrolidone, gradually heated to 205 ° C. while passing nitrogen, Distilled 2.6 liters. Next, after cooling the reaction vessel to 180 ° C., 3.719 kg (25.3 mol) of 1,4-dichlorobenzene and 3 kg of NMP were added, sealed under nitrogen, heated to 270 ° C., heated to 270 ° C. and 1. The reaction was allowed for 5 hours. After cooling, the reaction product was washed twice with warm water, and then the slurry was passed through an autoclave equipped with a stirrer and further washed several times with hot water. This was filtered and dried under reduced pressure at 80 ° C. for 24 hours to obtain 2.45 kg of PPS resin (Mw = 20,000). Subsequently, it processed at 220 degreeC under air | atmosphere for 5 hours. The obtained PPS resin had a melt viscosity of 205 Pa · s (320 ° C., shear rate of 1000 sec-1), a glass transition temperature of 88 ° C., Tm = 277 ° C., and Tmc = 215 ° C. It was Tm-Tmc = 62 degreeC showing a crystallization rate.

[Examples 1 to 10, Comparative Examples 1 to 3]
A raw material having the composition shown in Table 3 is dry blended, set at an extrusion temperature of 320 ° C., has two kneading zones, and is rotated at a high speed of 200 rpm. PCM-30), melt kneaded, pelletized, dried at 130 ° C. for 3 hours, measured for melt viscosity at 320 ° C., DSC measurement and TGA to measure thermogravimetric weight loss (generated gas) Quantity measurement). In addition, in the case of only PPS of the comparative example 1, in order to remove the difference in thermal history with other resin compositions, the PPS simple substance was melt-kneaded in the same manner.

  From Examples 1 to 7, the PPS resin composition containing a cyclic PPS mixture has a markedly lower melt viscosity at a processing temperature of 320 ° C. of general PPS than that obtained by melt kneading only the PPS of Comparative Example 1. You can see that In addition, Tm-Tmc = 62 ° C., which represents the crystallization rate of the PPS simple substance, is reduced to Tm-Tmc = 39-50 ° C. due to the blending of the cyclic PPS mixture, which indicates that the crystallization rate is increased. Is shown. Tm-Tc seems to be a saturation phenomenon in the vicinity of 50 parts by weight of the cyclic PPS mixture (Examples 6 and 7).

  The amount of gas generated does not increase even when the cyclic PPS mixture is blended, and the original thermal stability of PPS is maintained.

  Regarding the burr length generated at the time of injection molding, from Examples 1 to 7, the PPS resin composition containing the cyclic PPS mixture is shorter than that of Comparative Example 1, and therefore, by blending the cyclic PPS mixture, It can be seen that the generation of burrs during injection molding is suppressed.

  From these results, by blending the PPS mixture with PPS, the fluidity and crystallization speed are increased, and the occurrence of burrs during injection molding is suppressed. Further, it can be seen that the amount of gas generated at 320 ° C. is approximately the same as that of the gas not blended by blending these cyclic PPS mixtures.

  On the other hand, in Comparative Examples 2 and 3 in which a cyclic product of m = 6 was blended as the cyclic PPS, the fluidity improvement effect at 320 ° C. was not recognized, but rather the fluidity was lower than the PPS alone product of Comparative Example 1. You can see that Further, no change is observed in the Tm-Tc value, and it can be seen that the effect of improving the crystallization rate is not observed with the cyclic PPS alone having m = 6. Further, it can be seen that the effect of suppressing the occurrence of burrs at the time of injection molding is not observed when only the cyclic PPS simple substance of m = 6 is blended.

  In addition, the results of Examples 8 to 10 and Comparative Examples 2 and 3 show that the effects of the present invention can be obtained when the content of cyclic PPS of m = 6 is less than 50% by weight in the cyclic PPS mixture.

[Example 11, Comparative Examples 4 to 6]
The raw materials having the composition described in Table 4 were dry blended, and the extrusion temperature was set to a relatively high temperature of 360 ° C. as compared with Examples 1 to 10 and Comparative Examples 1 to 3. Examples 1 to 10 The same operations as in Comparative Examples 1 to 3 were performed, and the melt viscosity measurement at 360 ° C. and the thermogravimetric loss measurement at 360 ° C. were performed by TGA. Moreover, about the measurement of the burr | flash length at the time of injection molding, operation similar to Example 1-10 and Comparative Examples 1-3 was performed except having set only the cylinder temperature to 320 to 360 degreeC.

  It can be seen that the PPS resin composition containing the cyclic PPS mixture has a markedly lower melt viscosity at a processing temperature of 360 ° C. than that obtained by melt-kneading only PPS and blending a single cyclic PPS of m = 6. .

  Moreover, about the burr length at the time of injection molding, since the fluidity | liquidity of resin itself goes up with a raise of processing temperature, as a result compared with Examples 1-10 and Comparative Examples 1-3, burr length is relatively Although it tends to be long, it can be seen that the PPS resin composition containing the cyclic PPS mixture has a higher burr suppressing effect than that obtained by blending only PPS by melt kneading m = 6.

  In addition, the amount of gas generated does not increase even when the cyclic PPS mixture is blended, but rather tends to improve.

  From these results, by adding the cyclic PPS mixture to PPS, fluidity and crystallization speed are increased, but the amount of gas generated at 360 ° C. due to the addition of these cyclic PPS mixtures is not blended. It can be seen that the amount of generated gas is almost the same as that.

  On the other hand, in Comparative Examples 2 and 3 in which a cyclic product of m = 6 was blended as cyclic PPS, the fluidity improvement effect was not recognized even at 360 ° C., and the fluidity was lower than the PPS alone product of Comparative Example 4. I understand that.

  Here, Example 3 and Comparative Examples 4 to 6 are compared. In Example 3 in which the cyclic PPS mixture was blended, the melt viscosity at 320 ° C. was as low as 123 Pa · s, whereas in Comparative Example 4 in which no cyclic PPS was blended, the melt viscosity was 120 Pa · s at around 360 ° C. . That is, as shown in Example 3, it can be seen that by adding the cyclic PPS mixture, the fluidity of PPS is improved when the processing temperature is increased by about + 40 ° C.

  On the other hand, the gas generation amount is about 200 ppm under the conditions of Example 3 where 320 ° C. and 123 Pa · s can be obtained, whereas the gas generated under the condition of Comparative Example 4 where 360 ° C. and 120 Pa · s can be obtained. It can be seen that the amount generated increases to 800 ppm. That is, by blending the cyclic PPS mixture, high fluidity can be obtained at a relatively low processing temperature, and the amount of generated gas can be suppressed.

  Similarly, the PPS resin composition containing cyclic PPS of m = 6 of Comparative Examples 5 and 6 tended to have a higher melt viscosity rather than a single PPS containing no cyclic PPS, and was fluid even at 360 ° C. It is clear that no improvement effect is observed.

  As described above, regarding a PPS resin composition, by blending a cyclic PPS compound having a specific ring structure, it has excellent fluidity, high crystallization characteristics, low burr characteristics during injection molding, and resin molding. It has become possible to provide a PPS resin composition with less processability at the time of melt processing, such as products, sheets, films, fibers and pipes, and less generated gas.

Claims (8)

(A) For 100 parts by weight of polyphenylene sulfide having a weight average molecular weight of 10,000 or more , (B) a cyclic polyphenylene sulfide mixture represented by the general formula (1), wherein the content of cyclic polyphenylene sulfide of m = 6 is A polyphenylene sulfide resin composition comprising 1 to 50 parts by weight of a cyclic polyphenylene sulfide mixture of less than 50% by weight.

(M is an integer from 4 to 20) 2. The polyphenylene sulfide resin composition according to claim 1, wherein the content of cyclic polyphenylene sulfide of m = 6 in the cyclic polyphenylene sulfide mixture is less than 30% by weight. The polyphenylene sulfide resin composition according to claim 1, wherein m of the cyclic polyphenylene sulfide mixture represented by the general formula (1) is 4 to 12. 5. (B) The polyphenylene sulfide resin composition according to any one of claims 1 to 3, wherein the amount of the cyclic polyphenylene sulfide mixture is 2 to 10 parts by weight. (A) For 100 parts by weight of polyphenylene sulfide having a weight average molecular weight of 10,000 or more , (B) a cyclic polyphenylene sulfide mixture represented by the general formula (1), wherein the content of cyclic polyphenylene sulfide of m = 6 is A method for producing a polyphenylene sulfide resin composition comprising blending 1 to 50 parts by weight of a cyclic polyphenylene sulfide mixture that is less than 50% by weight.

(M is an integer from 4 to 20) A molded article comprising the polyphenylene sulfide resin composition according to any one of claims 1 to 4. An injection-molded article comprising the polyphenylene sulfide resin composition according to any one of claims 1 to 4. A method for producing a molded article comprising a polyphenylene sulfide resin composition, wherein the polyphenylene sulfide resin composition obtained by the production method according to claim 5 is injection-molded.