WO2023053529A1

WO2023053529A1 - Polyarylene sulfide resin production method, polyarylene sulfide resin, polyarylene sulfide resin composition, and polyarylene sulfide resin molded article

Info

Publication number: WO2023053529A1
Application number: PCT/JP2022/013800
Authority: WO
Inventors: 拓茨木; まい池田; 高志古沢
Original assignee: Dic株式会社
Priority date: 2021-09-28
Filing date: 2022-03-24
Publication date: 2023-04-06

Abstract

The present invention provides: a polyarylene sulfide (PAS) resin molded article which has little variation in reactivity and has uniform mechanical strength, particularly tensile strength; a resin and resin composition from which the molded article is constituted; and a production method for these. More specifically, provided is a PAS resin production method comprising a step (1) for polymerizing a PAS resin, a step (2) for refining the PAS resin to prepare a refined PAS resin, and a step (3) for evaluating a test piece formed from at least part of the refined PAS resin, wherein step (3) comprises a test piece production step for obtaining the test piece by solidifying molten PAS resin that is obtained by melting the refined PAS resin, a zeta potential measurement step for measuring the zeta potential of the surface of the test piece via a flow potential method at a pH of 7.8-8.2, and a distinguishing step for distinguishing PAS resin for which the zeta potential value measured in the above step is in the range of -50 mV to -65 mV.

Description

Method for producing polyarylene sulfide resin, polyarylene sulfide resin, polyarylene sulfide resin composition, and polyarylene sulfide resin molded article

The present invention relates to a method for producing a polyarylene sulfide resin, a polyarylene sulfide resin, a polyarylene sulfide resin composition, and a polyarylene sulfide resin molded product.

Polyarylene sulfide resins (hereinafter also abbreviated as "PAS resins") typified by polyphenylene sulfide resins (hereinafter also abbreviated as "PPS resins") are excellent in heat resistance, chemical resistance, etc. Therefore, it is widely used for electrical and electronic parts, automobile parts, plumbing parts, fibers, films, and the like. The PAS resin used for the above applications maximizes its functions by combining various additives such as glass fibers, fillers, elastomers, and the like. Therefore, controlling the interfacial reactivity between an additive such as glass fiber and the PAS resin and the reactivity between the elastomer and the PAS resin is an essential technology for the functional expression of the obtained PAS resin (parts). For example, Patent Literature 1 discloses a technique related to a PAS resin having higher reactivity with epoxysilane than conventional PAS resins.

JP-A-06-256517

However, in the technique of Patent Document 1, the functional group at the molecular end of the PAS resin, which is a factor that greatly contributes to the reactivity of the interface between the PAS resin and a different material, is not studied at all. In addition, the PAS resin has a unique circumstance that it is polymerized at a high temperature of 200° C. or higher and under a high pressure. As a result, many side reactions occur during the polymerization of the PAS resin, resulting in the presence of various functional groups at the molecular ends of the PAS resin, which greatly contribute to the reactivity. Furthermore, the high heat resistance/chemical resistance of PAS resins limits the analytical prescriptions, and the present situation is that the amounts of various functional groups have not yet been quantified. Therefore, controlling the reactivity of the interface between the PAS resin and different materials by the molecular terminal structure of the PAS resin is a technique with a very high barrier, but various applications are expected, so it is requested by various technical fields. It is a technology that is being used.

Therefore, the present invention provides a PAS resin molded article having excellent mechanical strength, particularly tensile strength, and small variation in physical properties between lots, a highly reactive resin and resin composition constituting the article, and furthermore, The object is to provide a manufacturing method.

In view of the above problems, the present inventors have made intensive research and repeated experiments. As a result, the above problems can be solved by using a specific polyarylene sulfide resin evaluated by the zeta potential value according to the streaming potential method under specific conditions. We have found that the problem can be solved, and have completed the present invention.

The present invention comprises a step (1) of polymerizing a PAS resin,
A method for producing a PAS resin, comprising the steps (2) of purifying the PAS resin to prepare a purified PAS resin, and (3) evaluating a test piece formed from at least a portion of the purified PAS resin. hand,
The step (3) is a test piece preparation step (3-1) in which the test piece is obtained by solidifying the molten PAS resin obtained by melting the purified PAS resin;
A zeta potential measurement step (3-2) of measuring the zeta potential of the surface of the test piece under conditions of pH 7.8 to 8.2 by streaming potential method;
A method for producing a PAS resin, comprising a discrimination step (3-3) of discriminating a PAS resin having a zeta potential value in the range of -50 to -65 mV as measured in the step (3-2).

Also, the present invention is a PAS resin whose surface zeta potential value of the test piece at pH 7.8 to 8.2 is in the range of -50 to -65 mV. In other words, the present invention provides a PAS resin having a surface zeta potential value in the range of -50 to -65 mV, wherein the surface zeta potential value is measured from a test piece having at least a portion of the PAS resin. A PAS resin characterized by

In addition, a PAS resin having a zeta potential value on the surface of the test piece at pH 7.8 to 8.2 in the range of -50 to -65 mV and a substance having a reactive functional group are blended, It is a PAS resin composition.

The molded article of the present invention is obtained by melt-molding the PAS resin composition described above.

In the method for producing a PAS resin composition of the present invention, the PAS resin obtained by the production method according to any one of claims 1 to 3 and a substance having a reactive functional group are blended and melted. Having a kneading step, and
The zeta potential value of the surface of the test piece at pH 7.8 to 8.2 of the PAS resin is in the range of -50 to -65 mV.

The method for producing a molded product of the present invention is characterized by including the step of melt-molding the PAS resin composition obtained by the production method described above.

According to the present invention, by quantifying and determining the surface characteristics of the PAS resin with high accuracy, it is possible to obtain a resin having specific reactivity with higher accuracy than in the past. In addition, by using the resin, it is possible to provide a PAS molded article having less variation in physical properties, excellent mechanical strength, particularly excellent tensile strength, a resin composition constituting the PAS molded article, and a method for producing the same.

FIG. 1 is a schematic diagram showing an example of a method for measuring zeta potential by streaming potential method.

Hereinafter, embodiments of the present invention (hereinafter referred to as "present embodiments") will be described in detail. can be implemented.

<Method for producing PAS resin>
The method for producing a PAS resin according to the present embodiment includes a step (1) of polymerizing a PAS resin, a step (2) of purifying the PAS resin to prepare a purified PAS resin, and the purification step. and a step (3) of evaluating a test piece made from at least a portion of the purified PAS resin. The step (3) comprises a test piece preparation step (3-1) in which the purified PAS resin is melted to prepare a molten PAS resin, and then the molten PAS resin is solidified to obtain the test piece; The zeta potential measurement step (3-2) of measuring the zeta potential on the surface of the test piece by a streaming potential method under conditions of pH 7.8 to 8.2, and the zeta measured in the step (3-2) A discrimination step (3-3) for discriminating PAS resins having potential values in the range of -50 to -65 mV.

In other words, in the method for producing a PAS resin of the present embodiment, for the purpose of evaluating the surface properties of the obtained PAS resin, after preparing a test piece as an evaluation sample from at least a part of the PAS resin, the By measuring the zeta potential of the test piece, the surface characteristics of the obtained PAS resin are grasped. As a result, it is possible to quantify the surface characteristics of the PAS resin with high accuracy, so that it is possible to identify resins having more uniform reactivity than conventional methods. As a result, it is possible to provide a PAS resin molded product with little variation in physical properties and excellent mechanical strength, particularly excellent tensile strength, and a method for producing the same.

In this specification, for convenience of explanation, the PAS resin obtained through the purification treatment of step (2) is referred to as purified PAS resin, and the melted PAS resin is referred to as molten PAS resin.

Each step of the method for producing a PAS resin according to this embodiment will be described below.
・Step (1) (polymerization step)
Step (1) is a step of polymerizing a PAS resin. The step (1) is not particularly limited, and a known polymerization method can be applied depending on the chemical structure of the target PAS resin. In addition, as a preferred aspect of the polymerization step in the present embodiment, the zeta potential value of the surface of the test piece, which is an evaluation sample formed from at least a part of the obtained PAS resin, tends to be in the range of -50 to -65 mV. further apply the polymerization conditions of Therefore, after explaining a general polymerization method applicable to the present embodiment, raw materials and specific polymerization conditions will be explained in detail.

<Polymerization method>
The method of polymerizing the PAS resin that can be applied to the present embodiment is not particularly limited. (Manufacturing method 2) in a polar solvent in the presence of an alkali metal sulfide and/or alkali metal hydrosulfide (hereinafter sometimes abbreviated as a sulfidation agent) agent, etc. A method of polymerizing an aromatic compound by adding, if necessary, a polyhalogeno aromatic compound or other copolymerization components, (manufacturing method 3) adding p-chlorothiophenol and, if necessary, other copolymerization components, (Manufacturing method 4) A method of melt-polymerizing a diiodo aromatic compound and elemental sulfur under reduced pressure in the presence of a polymerization inhibitor that may have a functional group such as a carboxy group or an amino group, etc. Among these methods, the method of (manufacturing method 2) is versatile and preferable. During the reaction, an alkali metal salt of carboxylic acid or sulfonic acid, or an alkali hydroxide may be added in order to adjust the degree of polymerization. Among the methods described above (manufacturing method 2), an alkali metal salt of a carboxylic acid or a sulfonic acid, or an alkali hydroxide may be added during the reaction in order to adjust the degree of polymerization. Among the above (manufacturing method 2) methods, a compound containing a dihalogenoaromatic compound, a polar organic solvent, and a sulfidating agent has a ratio of (polar organic solvent)/(sulfidating agent)=0.02/1 to 0. .9/1 (molar ratio) is charged to the reactor, and the temperature is preferably started to rise in an open system under an inert gas atmosphere to dehydrate the compound and solidify as the dehydration progresses. After precipitating the substance and obtaining a low water content solid in which each component is uniformly dispersed, it is cooled to a predetermined temperature, and if necessary, a polar organic solvent and / or a dihalogeno aromatic compound is further added to the low water content solid. and, if necessary, a dihalogeno aromatic compound in the presence of a solid alkali metal sulfide and an aprotic polar organic solvent. A polyhalogeno aromatic compound or other copolymerization components are added, and an alkali metal hydrosulfide and an organic acid alkali metal salt are added in an amount of 0.01 to 0.9 mol per 1 mol of the sulfur source. Particularly preferred is a method of conducting the reaction while controlling the amount of water in the reaction system within the range of 0.02 mol or less per 1 mol of the aprotic polar organic solvent (see WO2010/058713 pamphlet).

As the step (1) of the present embodiment, the polymerization method using the above production method 2, more specifically, at least one polyhalogenoaromatic compound and at least one An example of the process of obtaining a reaction mixture (slurry) containing a PAS resin obtained by reacting with a sulfidating agent under appropriate polymerization conditions will be described below. In addition, in the present embodiment, a form obtained by reacting the slurry in the presence of a sulfidating agent and an organic solvent while continuously or intermittently adding a polyhalogenoaromatic compound and/or an organic solvent is also included. do.

The polyhaloaromatic compound used in the present embodiment is, for example, a halogenated aromatic compound having two or more halogen atoms directly bonded to an aromatic ring, specifically p-dihalobenzene, m-dihalobenzene , o-dihalobenzene, 2,5-dihalotoluene, 1,4-dihalonaphthalene, 1-methoxy-2,5-dihalobenzene, 4,4′-dihalobiphenyl, 3,5-dihalobenzoic acid, 2,4- Dihalobenzoic acid, 2,5-dihalonitrobenzene, 2,4-dihalonitrobenzene, 2,4-dihaloanisole, p,p'-dihalodiphenyl ether, 4,4'-dihalobenzophenone, 4,4' -dihalodiphenyl sulfone, 4,4'-dihalodiphenyl sulfoxide, 4,4'-dihalodiphenyl sulfide, and compounds having an alkyl group having 1 to 18 carbon atoms in the aromatic ring of each of the above compounds. . The above dihalogeno aromatic compounds may be used alone or in combination of two or more. Polyhalogeno aromatic compounds other than dihalogeno aromatic compounds include 1,2,3-trihalobenzene, 1,2,4-trihalobenzene, 1,3,5-trihalobenzene, 1,2,3,5- tetrahalobenzene, 1,2,4,5-tetrahalobenzene, 1,4,6-trihalonaphthalene and the like. Moreover, you may block-copolymerize these compounds. Among the above specific examples, preferred are dihalogenated benzenes, and particularly preferred are those containing 80 mol % or more of p-dichlorobenzene. The polyhalogeno aromatic compounds described above may be used alone or in combination of two or more. Further, the halogen atoms contained in each halogenoaromatic compound are preferably chlorine atoms and/or bromine atoms.

For the purpose of increasing the viscosity of the PAS resin by forming a branched structure, a polyhalogeno aromatic compound having 3 or more halogen substituents in one molecule may be used as a branching agent as desired. Examples of such polyhalogenoaromatic compounds include 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6-trichloronaphthalene and the like.

Furthermore, polyhalogeno aromatic compounds having functional groups with active hydrogen such as amino groups, thiol groups, hydroxyl groups, etc. can be mentioned, and specifically, 2,6-dichloroaniline and 2,5-dichloroaniline. , 2,4-dichloroaniline, 2,3-dichloroaniline and other dihaloanilines; 2,3,4-trichloroaniline, 2,3,5-trichloroaniline, 2,4,6-trichloroaniline, 3, trihaloanilines such as 4,5-trichloroaniline; dihaloaminodiphenyl ethers such as 2,2'-diamino-4,4'-dichlorodiphenyl ether and 2,4'-diamino-2',4-dichlorodiphenyl ether and compounds in which an amino group is replaced with a thiol group or a hydroxyl group in a mixture thereof.

In addition, active hydrogen-containing polyhalogens in which the hydrogen atoms bonded to the carbon atoms forming the aromatic ring in these active hydrogen-containing polyhalogeno aromatic compounds are substituted with other inert groups, for example, hydrocarbon groups such as alkyl groups. Aromatic compounds can also be used.

Among these various active hydrogen-containing polyhaloaromatic compounds, the active hydrogen-containing dihalogenoaromatic compounds are preferred, and dichloroaniline is particularly preferred.

Examples of polyhalogenoaromatic compounds having a nitro group include mono- or dihalonitrobenzenes such as 2,4-dinitrochlorobenzene and 2,5-dichloronitrobenzene; 2-nitro-4,4'-dichlorodiphenyl ether and the like. dihalonitrodiphenyl ethers; 3,3′-dinitro-4,4′-dichlorodiphenyl sulfones such as dihalonitrodiphenyl sulfones; 2,5-dichloro-3-nitropyridine, 2-chloro-3,5 - mono- or dihalonitropyridines such as dinitropyridine; or various dihalonitronaphthalenes.

Polar organic solvents include formamide, acetamide, N-methylformamide, N,N-dimethylacetamide, tetramethylurea, N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, Amides such as hexamethylphosphoramide, N-dimethylpropylene urea, 1,3-dimethyl-2-imidazolidinoic acid, ureas and lactams; sulfolane, sulfolane such as dimethylsulfolane; nitriles such as benzonitrile; methyl Mention may be made of ketones such as phenyl ketone and mixtures thereof, among which N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, hexamethylphosphoramide, N -Dimethylpropylene urea, amides having an aliphatic ring structure of 1,3-dimethyl-2-imidazolidinoic acid are preferred, and N-methyl-2-pyrrolidone is more preferred.

The sulfidation agent used in this embodiment includes alkali metal sulfides and/or alkali metal hydrosulfides.

Alkali metal sulfides include lithium sulfide, sodium sulfide, rubidium sulfide, cesium sulfide and mixtures thereof. Such alkali metal sulfides can be used as hydrates or as aqueous mixtures or as anhydrates. Alkali metal sulfides can also be derived from the reaction between alkali metal hydrosulfides and alkali metal hydroxides. A small amount of alkali metal hydroxide may be added to react with alkali metal hydrosulfide and alkali metal thiosulfate, which are usually present in trace amounts in alkali metal sulfide.

Alkali metal hydrosulfides include lithium hydrogen sulfide, sodium hydrogen sulfide, rubidium hydrogen sulfide, cesium hydrogen sulfide, and mixtures thereof. Such alkali metal hydrosulfides can be used as hydrates or as aqueous mixtures or as anhydrates.

Also, the alkali metal hydrosulfide is used together with the alkali metal hydroxide. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. These may be used alone, or two or more of them may be mixed. You can use it as Among these, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferred because they are readily available, and sodium hydroxide is particularly preferred.

The method for producing the PAS resin used in the present embodiment can also use a hydrous sulfidation agent as a raw material. It is preferable to use it for the polymerization reaction of the resin. Further, when the amount of the aprotic polar solvent charged is small, for example, when it is less than 1 mol with respect to 1 mol of sulfur atoms in the sulfidation agent, in the presence of the polyhaloaromatic compound, the hydrous sulfidation agent and the non- It is preferred to dehydrate the protic polar solvent.

For dehydration of the hydrous sulfidating agent, at least aprotic polar solvent and hydrous alkali metal sulfide or hydrous alkali hydrosulfide and alkali metal hydroxide as hydrous sulfidating agent are charged into a reaction vessel equipped with a distillation apparatus. , a temperature at which water is removed azeotropically, specifically, in the range of 300 ° C. or less, preferably in the range of 80 to 220 ° C., more preferably in the range of 100 to 200 ° C., and water is removed by distillation. It is carried out by discharging out of the system. In the dehydration step, dehydration is performed until the amount of water in the system in which the polymerization reaction is performed is 5 mol or less, more preferably in the range of 0.01 to 2.0 mol, per 1 mol of the sulfur atom of the sulfidating agent. is preferred.

The polymerization conditions for the PAS resin generally range from a temperature of 200 to 330° C., and the pressure should be such that the polymerization solvent and the polyhaloaromatic compound, which is the polymerization monomer, are substantially kept in the liquid phase. is selected from the range of 0.1 to 20 MPa, preferably from the range of 0.1 to 2 MPa. The amount of the polyhaloaromatic compound charged is in the range of 0.2 mol to 5.0 mol, preferably in the range of 0.8 to 1.3 mol, more preferably in the range of 0.8 to 1.3 mol, per 1 mol of the sulfur atom of the sulfidating agent. It is prepared so as to be in the range of 0.9 to 1.1 mol. In addition, the amount of the aprotic polar solvent charged is in the range of 1.0 to 6.0 mol, preferably in the range of 2.5 to 4.5 mol, per 1 mol of the sulfur atom of the sulfidating agent. adjust. The polymerization reaction is preferably carried out in the presence of a small amount of water, and the proportion thereof is preferably adjusted appropriately in consideration of the polymerization method, the molecular weight of the resulting polymer, and productivity. Specifically, the dehydration operation is carried out so that the amount becomes 2.0 mol or less, preferably 1.6 mol or less per 1 mol of the sulfur atom of the sulfidation agent, and the dehydration is performed in the presence of the polyhaloaromatic compound. When the operation is performed (for example, the method of "5)" in the specific embodiment below), it is 0.9 mol or less, preferably 0.05 to 0.3 mol, more preferably 0.01 to 0.02 mol or less. Dehydration operation may be performed so that the range of

Specific embodiments of polymerizing the sulfidating agent and the polyhaloaromatic compound in the presence of the polar organic solvent include, for example:
1) A method using a polymerization aid such as an alkali metal carboxylate or lithium halide,
2) A method using a branching agent such as an aromatic polyhalogen compound,
3) a method of conducting a polymerization reaction in the presence of a small amount of water and then adding water to further polymerize;
4) a method of cooling the gas phase portion of the reaction vessel during the reaction between the alkali metal sulfide and the aromatic dihalogen compound to condense a portion of the gas phase in the reaction vessel and reflux it to the liquid phase;
5) reacting an alkali metal sulfide, or a hydrous alkali metal hydrosulfide and an alkali metal hydroxide with an amide, urea or lactam having an aliphatic cyclic structure in the presence of a polyhaloaromatic compound while dehydrating; a step of producing a slurry containing a solid alkali metal sulfide, a step of adding a polar organic solvent such as N-methyl-2-pyrrolidone after producing the slurry, distilling off water to dehydrate, and then , in the slurry obtained through the dehydration step, the polyhaloaromatic compound, the alkali metal hydrosulfide, and the alkali metal salt of the hydrolyzate of the amide, urea or lactam having an aliphatic ring structure are added to N- and a method comprising, as an essential production step, a step of polymerizing by reacting 1 mol of a polar organic solvent such as methyl-2-pyrrolidone with the amount of water present in the reaction system being 0.02 mol or less.

Further, in the present embodiment, the coarse slurry containing the PAS resin obtained in step (1) is subjected to suitable means (e.g., vacuum distillation method, centrifugal separation method, screw decanter method, vacuum filtration method, pressure filtration method, etc.). A suitable method can be selected) to separate and remove the organic solvent, and then the crude PAS resin (the PAS resin that has not undergone the purification step) can be recovered.

<Specific polymerization conditions>
In the present embodiment, the zeta potential value of the surface of the test piece, which is an evaluation sample formed from at least a part of the PAS resin obtained in the step (1) and the step (2) described later, is pH 7.8 to 8. It preferably exhibits a range of -50 to -65 mV at .2 (eg pH = 8.0). The specific polymerization conditions necessary for the zeta potential value of the surface of the test piece to tend to show a range of -50 to -65 mV at pH 7.8 to 8.2 (eg, pH = 8.0) are as follows. conditions (a) to (c).
(a) The total amount of the organic solvent used from the charging of the raw materials to the completion of the polymerization reaction is preferably in a ratio of 1 to 6 mol per 1 mol of the sulfidating agent, which is the sulfur source.
(b) The amount of the organic solvent initially charged is preferably 0.01 to 0.50 mol with respect to 1 mol of the sulfidating agent, which is the sulfur source.
(c) It is preferable to add an acid or a hydrogen salt to the PAS resin (or slurry) after the polymerization reaction in step (1). More preferably, an acid or hydrogen salt is added to the PAS resin (or slurry) after the polymerization reaction in the polymerization step to adjust the pH of the reaction mixture to 7-11.

Examples of the acid under the condition (c) include saturated fatty acids such as carbonic acid, oxalic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and monochloroacetic acid; acrylic acid, crotonic acid, oleic acid, and the like; aromatic carboxylic acids such as unsaturated fatty acids, benzoic acid, phthalic acid and salicylic acid; dicarboxylic acids such as oxalic acid, maleic acid and fumaric acid; organic acids such as methanesulfonic acid and sulfonic acids such as p-toluenesulfonic acid; Inorganic acids such as sulfuric acid, sulfurous acid, nitric acid, nitrous acid or phosphoric acid may be mentioned. Examples of the hydrogen salt under the condition (c) include sodium hydrogen sulfate, disodium hydrogen phosphate, sodium hydrogen carbonate, and the like. Organic acids that cause less corrosion to metal members are preferred for use in actual machines.

In the step (1) of the present embodiment, when the above condition (a) is adopted, the concentration of the PAS resin during polymerization is increased, so that the ring-opened product of the aliphatic cyclic compound is added to the end of the PAS resin. can exhibit a certain zeta potential value because it is easier for In step (1) of the present embodiment, if the above condition (b) is adopted, the concentration of the PAS resin during polymerization increases, so that the ring-opened product of the aliphatic cyclic compound is attached to the end of the PAS resin. A specific zeta potential value can be exhibited because the reaction that occurs is likely to proceed. In addition, when the above condition (c) is adopted in the step (1) of the present embodiment, the acidic component is included in the PAS resin, and the acidic component oozes out in the purification step, resulting in terminal functionalization of the PAS resin. Certain zeta potential values can be exhibited because some of the groups ion exchange and protonate.

In the present embodiment, in order for the zeta potential value of the surface of the test piece to be in the range of -50 to -65 mV at pH 7.8 to 8.2 (eg, pH = 8.0), the polymerization step or the following purification step WHEREIN: It is preferable to add an acid to the said PAS resin. Therefore, among the above polymerization conditions (a) to (c), particularly by satisfying (c), there is a strong tendency for the zeta potential value to fall within a predetermined range. In addition, the zeta potential value of the surface of the test piece tends to show a range of -30 to -45 mV at pH 4.8 to 5.2 (for example, pH = 5.0). Conditions (a) to (c) can be applied.

・Step (2) (purification step)
In this embodiment, it is preferable to further perform the purification step of step (2) after step (1). In the step (2) of the present embodiment, a known purification treatment can be applied according to the chemical structure of the PAS resin to be evaluated, etc. However, the slurry containing the PAS resin obtained in the step (1) Alternatively, it is preferable to add a washing solution to the crude PAS resin, which is the solid content of the slurry, and perform washing treatment, filtration treatment and drying treatment. In addition, each of the washing treatment, filtration treatment and drying treatment can be optionally performed at least once or more than once.

Hereinafter, after explaining the purification process applicable to this embodiment, the above-mentioned specific purification conditions will be explained in detail.

In the present embodiment, the purification treatment of the PAS resin (slurry containing the PAS resin) obtained in step (1) is not particularly limited. The reaction mixture is used as it is, or after adding an acid or base, the solvent is distilled off under reduced pressure or normal pressure, and then the solid after solvent distillation is treated with water, a reaction solvent (or an equivalent solubility in a low-molecular-weight polymer). organic solvent), acetone, methyl ethyl ketone, a method of washing with a solvent such as alcohols once or twice or more, and further neutralization, washing with water, filtration and drying, or (purification treatment 2) After the polymerization reaction is completed, the reaction Solvents such as water, acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, and aliphatic hydrocarbons (which are soluble in the polymerization solvent used and are at least poor for PAS) are added to the mixture. A method of adding a solvent) as a precipitant to precipitate solid products such as PAS and inorganic salts, and filtering, washing, and drying them, or (purification process 3) after the polymerization reaction is completed, After adding a reaction solvent (or an organic solvent having an equivalent solubility to the low-molecular-weight polymer) to the reaction mixture and stirring, filtering to remove the low-molecular-weight polymer, water, acetone, methyl ethyl ketone, alcohols, etc. A method of washing with a solvent once or twice or more, followed by neutralization, washing with water, filtration and drying; (Purification treatment 5) After completion of the polymerization reaction, the reaction mixture is filtered, and if necessary, washed with a reaction solvent once or twice or more, and then dried. methods of water washing, filtering and drying, and the like.

The drying method in the above refining treatment is not particularly limited, and it is preferable to dry at a drying temperature of 120-270°C. Moreover, the atmosphere of the drying treatment includes under vacuum, under reduced pressure, under nitrogen or inert gas inert gas atmosphere, under oxidizing atmosphere such as oxygen or air, and under mixed gas atmosphere of air and nitrogen. The drying time is preferably 0.5 to 53 hours. The filtration treatment is not particularly limited as long as it is a method capable of solid-liquid separation, and examples include a method of solid-liquid separation using a filter, a centrifuge, or the like.

<Specific purification conditions>
In step (2) in the present embodiment, the zeta potential value of the surface of the test piece tends to be in the range of -50 to -65 mV at pH 7.8 to 8.2 (eg, pH = 8.0). Specific purification conditions include the following conditions (d) to (f).
(d) In step (2), it is preferable to acid-treat the crude PAS resin with a predetermined amount or more of an acid solution. More preferably, the acid treatment is performed using an acid solution of about twice the total weight of the PAS resin.
(e) The pH of the acid solution used in the acid treatment of (d) is preferably 6 or less.
(f) In step (2), it is preferable to wash with hot water of 140 to 260° C. with 1.5 to 10 times the total weight of the PAS resin.

When the conditions (d) to (f) above are employed in step (2) in the present embodiment, the terminal functional groups of the PAS resin can be protonated by an ion exchange reaction. The acid used for the acid solution is not particularly limited as long as an acid solution having a pH of 6 or less can be prepared, and the acid under the condition (c) above can be used.

In this embodiment, the step (1 ) or in the step (2), an acid may be added to the PAS resin. More specifically, the preferred purification step of the present embodiment is solid-liquid separation of the PAS resin (including slurry) obtained in step (1) or the slurry containing the PAS resin obtained in step (1). It includes acid treatment by adding an acid solution to the crude PAS resin, which is a solid content.

Another preferred embodiment of step (2) is the PAS resin (including slurry) obtained in step (1) or crude PAS, which is the solid content of the slurry containing the PAS resin obtained in step (1). During the steps of adding a washing solution to the resin, washing, filtering and drying, the crude PAS resin is subjected to acid treatment by adding an acid solution one or more times.

As another aspect of the present embodiment, the zeta potential value of the surface of the test piece tends to be in the range of -30 to -45 mV at pH 4.8 to 5.2 (eg, pH = 5.0). As the necessary specific purification steps, conditions (d) to (f) above can be applied in the same manner as in the measurement system at pH 7.8 to 8.2 (eg, pH=8.0).

・Process (3) (evaluation process)
Step (3) in the present embodiment is a step of evaluating a test piece produced from at least part of the PAS resin obtained through steps (1) and (2). The step (3) includes a test strip preparation step (3-1), a zeta potential measurement step (3-2) and a discrimination step (3-3). In other words, step (3) in the present embodiment involves preparing a test piece (=evaluation sample) from at least a portion of the PAS resin obtained in steps (1) and (2), and subjecting the test piece to a predetermined It is a step of evaluating the surface physical properties of the test piece by measuring the zeta potential under the conditions and grasping the physical properties of the PAS resin. Therefore, in step (3) of the present embodiment, the chemical properties of the PAS resin, which is the raw material of the test piece, are quantified based on the zeta potential value of the surface of the test piece, which is an evaluation sample formed from the PAS resin. Accordingly, it is not necessary to evaluate the entire amount of the PAS resin obtained through steps (1) and (2), and it is sufficient to evaluate the PAS resin obtained through steps (1) and (2). Since the step (3) in the present embodiment makes it possible to identify a PAS resin having a zeta potential value within a predetermined range, the surface characteristics of the PAS resin can be quantified with high accuracy, and the PAS resin can be distinguished and sorted.

・ Process (3-1) <Test piece preparation process>
Step (3-1) is a step of melting the PAS resin obtained in steps (1) and (2) to prepare a molten PAS resin, and then solidifying the molten PAS resin to prepare a test piece. is. In other words, the test piece preparation step in the present embodiment comprises extracting at least part of the PAS resin obtained in steps (1) to (2), melting it once, and then solidifying the melted PAS resin. , which is the process of producing a test piece with a predetermined shape and surface properties. From the viewpoint of performing evaluations that are more in line with the molten state, the test piece of the present embodiment is preferably in an amorphous state.

The term "amorphous state" as used herein refers to a state in which no crystalline phase exists in the PAS resin constituting the test piece, and more specifically, the following condition (i) is satisfied.
(i) In the DSC measurement of the PAS resin film which is the test piece, when the temperature range from 40 ° C. to 350 ° C. is raised at 20 ° C./min, an exothermic peak accompanying crystallization occurs between 100 ° C. and 200 ° C. is not confirmed.

In addition, in the evaluation method of the present embodiment, the chemical properties of the PAS resin, which is the raw material of the test piece, are quantified using the zeta potential value of the surface of the test piece made from the PAS resin. The reason why the reactivity of the PAS resin is evaluated from the surface chemical properties is that the PAS resin has extremely high chemical resistance. With respect to PPS resin, which is a particularly preferred embodiment of PAS resin, the presence of a solvent capable of dissolving the PPS resin at 200° C. or lower has not yet been found. This is because there is practically no technique for directly evaluating the molecular ends in the PAS resin, which greatly contributes to reactivity. Therefore, in the present invention, by using a specific test piece as a reference, the characteristics of the PAS resin, which is the constituent material of the test piece, are grasped.

<melting>
In this embodiment, the method of melting the PAS resin to prepare the molten PAS resin is not particularly limited as long as the PAS resin can be heated and melted, and known heating means can be employed. Specific examples include a hot plate, hot air/cold air circulating constant temperature oven, microwave or (far) infrared heater, or hot press. The heating time for heating the PAS resin using the heating means is not particularly limited as long as the PAS resin is melted, and is, for example, about 30 seconds to 10 minutes. The temperature for melting the PAS resin may be the melting point of the PAS resin or higher, preferably 300° C. or higher and 400° C. or lower. Since the PAS resin undergoes an oxidative cross-linking reaction at a temperature of 200° C. or higher, it may be thermally melted in a non-oxidizing inert gas atmosphere.

In step (3-1), the PAS resin may be heated and melted through the sheet body. When the sheet body is used to prepare the test piece, the sheet body preferably has a melting point higher than that of the PAS resin and preferably has a hydrophobic surface. As a more detailed heat-melting method, after placing a PAS resin (for example, a powdered PAS resin) on a sheet body, the sheet body is heated using a heating means to melt the PAS resin. It is preferable to prepare a molten PAS resin by As another method, a PAS resin (for example, solid or powdered purified PAS resin) is sandwiched between a pair of sheets, and then the pair of sheets is heated by heating means. Alternatively, it is preferable to melt the PAS resin by heating one of the pair of sheet bodies to prepare a molten PAS resin. By using the sheet body, it is possible to easily collect the test piece in which the molten PAS resin is solidified. In particular, the sheet body preferably has releasability. As a result, the test piece can be easily collected without the solidified PAS resin adhering to it, so that damage to the appearance characteristics (cracking, rough skin, etc.) can be reduced, or breakage of the test piece can be suppressed.

The material of the sheet body must have a melting point higher than that of the PAS resin, and examples thereof include metal materials (martensitic stainless steel such as SUS404C), fluororesins, polyimides, and ceramics. Examples of the fluororesin include polytetrafluoroethylene (PTFE), tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene/ethylene copolymer (ETFE), tetrafluoroethylene/hexafluoropropylene copolymer polymer (FEP), polyvinylidene fluoride (PVDF) or ethylene-chlorotrifluoroethylene copolymer (ECTFE). In addition, the fluororesin may contain an inorganic filler such as glass fiber, if necessary.

<Solidification>
In step (3-1), the method of solidifying the molten PAS resin includes a method of solidifying the molten PAS resin by cooling. The cooling may be natural cooling or rapid cooling, and rapid cooling is preferred. A known cooling means can be employed as the cooling method. Examples of the cooling means include rolls whose surface temperature can be adjusted (cooling rolls), air knives, immersion in water (a water tank, etc.), and direct or indirect contact with metal materials at 35° C. or lower.

Further, as described above, the test piece of the present embodiment is preferably made of amorphous PAS resin. As a method for producing such an amorphous PAS resin, it is preferable to solidify the molten PAS resin by rapidly cooling it. By rapid cooling, it is possible to produce an amorphous PAS resin that does not contain a crystalline phase. Therefore, it becomes easier to uniformly evaluate the PAS resin even by surface measurement, and it becomes an index of reactivity in the molten state. This is preferable from the viewpoint of ease of use.

In the test piece preparation process according to the present embodiment, the PAS resin obtained through steps (1) and (2) is melted and then cooled at a rate of 10 ° C./second or more. It is more preferable to cool at a speed of 100° C./s or less. Moreover, the cooling rate is preferably maintained in the temperature range from 400° C. to at least the Tg of the PAS resin. As a result, the PAS resin can be solidified in an amorphous state, the PAS resin can be uniformly evaluated even by surface measurement, and the measurement can easily serve as an index of reactivity in the molten state. In the present embodiment, it is preferable to cool the molten PAS resin at a cooling rate of 10° C./sec or more and 100° C./sec or less to the Tg or less of the PAS resin, preferably 90° C. or less.

In the step (3-1) of this embodiment, the molten PAS resin may be solidified through the sheet body for the purpose of easily obtaining a test piece of a predetermined size. As a more detailed method of solidifying the molten PAS resin, it is preferable to use cooling means to cool the sheet on which the molten PAS resin is placed, thereby solidifying the molten PAS resin and recovering the test piece. Another method for solidifying the molten PAS resin is to solidify the molten PAS resin between the pair of sheet bodies by cooling at least one of a pair of sheet bodies placed so as to sandwich the molten PAS resin. It is preferable to collect the test piece by As a result, the test piece can be easily collected without the solidified PAS resin adhering to it, so that deterioration of the appearance characteristics (thickness, etc.) can be reduced, or breakage of the test piece can be suppressed.

<Test piece>
The test piece in the present embodiment is an example of the object to be measured for zeta potential measurement. ) must be provided. Therefore, in the step (3-1) of the present embodiment, a test piece having a certain shape, size and thickness is prepared as an object to be measured for convenience of zeta potential measurement. It is considered that the test piece in this embodiment is not particularly limited as long as it does not affect the measured value itself for each zeta potential measurement as much as possible.

In this specification, the test piece is 4.5 to 5.5 cm (length) × 2.5 to 3.5 cm (width) × 0.05 to 0.15 cm (thickness) for convenience of zeta potential measurement. A film-like PAS resin is used. However, it goes without saying that the shape, size, thickness, etc. of the test piece are not particularly limited as long as they do not affect the zeta potential measurement value itself as much as possible.

In the test piece preparation process in this embodiment, a flat plate (film-like including) and is preferably a step of producing a test piece composed of a PAS resin in an amorphous state.

In this specification, the "length and width of the test piece" are measured using vernier calipers. On the other hand, the "thickness of the test piece" means that the test piece is cut at 5 points in the longitudinal direction at 8 mm intervals in the direction perpendicular to the longitudinal direction, and 5 test pieces at 5 mm intervals in the width direction on each cut surface. The thickness of the film was measured using a TH-104 film thickness measuring machine (manufactured by Tester Sangyo Co., Ltd.), and refers to the average value of the thickness of a total of 25 points.

In addition, in the present embodiment, the surface of the test piece or the surface of the sheet body may be surface-treated for the purpose of suppressing variation in measured values. The surface treatment method is not particularly limited, and can be appropriately selected from known methods within a range that does not impair the characteristics of the test piece. For example, degreasing with an organic solvent such as acetone in which the PAS resin is insoluble is mentioned.

・Step (3-2) <Zeta potential measurement step>
The step (3-2) is a step of measuring the zeta potential of the surface of the test piece obtained in the test piece preparation step by streaming potential method. By using the zeta potential value as an index of the surface properties of the PAS resin, it is possible to relatively easily measure the surface properties of the evaluation sample and to easily grasp the properties of the PAS resin. In addition, when the zeta potential value is measured multiple times for the same PAS resin sample, the fluctuation range (variation coefficient) of the zeta potential value due to the measurement is smaller than in the viscosity increase measurement using the conventional MFR.

The step (3-2) in the present embodiment is preferably a step of measuring the zeta potential of the surface of the test piece by the streaming potential method under conditions of pH 7.8 to 8.2. By setting the zeta potential measurement conditions within the range of pH 7.8 to 8.2, not only the variation in the measured values is further reduced, but also the absolute value of the observed zeta potential value itself can be increased. can. As a result, for example, the amount of difference in zeta potential value increases, so that it becomes easier to detect the difference in zeta potential value between the same or different PAS resins, and it becomes easier to evaluate the properties of the PAS resins with higher accuracy.

Further, in step (3-2) in the present embodiment, the zeta potential of the surface of the test piece may be measured under a plurality of different pH ranges by streaming potential method. Furthermore, for example, when it is difficult to adjust pH near pH = 8 (eg, pH 6.5 to 8.4) near the inflection point of the titration curve, near pH = 5 (eg, pH 4.5 to 6.0 ), the zeta potential of the surface of the test piece may also be measured.

<Zeta potential>
The zeta potential in the present embodiment is measured within a pH range of 7.8 to 8.2 using streaming potential method. The zeta potential by streaming potential method is generated by forming an electric double layer at the solid-liquid interface between the test piece and the electrolytic solution. It is calculated from the Helmholtz-Smolkowschki equation by measuring the difference between the laminar flow of the solution, the viscosity of the electrolyte solution, and the dielectric constant of the electrolyte solution. The measurement of zeta potential by the streaming potential method will be described below with reference to FIG.

FIG. 1 shows, as an example of the measurement of zeta potential by the streaming potential method, the electric potential of the solid-liquid interface between the evaluation sample (=measurement object), which is a flat plate-like (including film-like) test piece 2, and the electrolytic solution 3. It is a schematic diagram which represented the mode of the multilayer typically. For convenience of explanation, FIG. 1 shows an example in which the test piece 2 made of PAS resin is negatively charged.

In the zeta potential measurement by the streaming potential method of the present invention, a PAS film, which is a test piece 2, was set on at least one side of the clamp cell 1 shown in FIG. is flowed, the voltage generated by the pressure difference (Δp) is measured, and the zeta potential is measured from the Helmholtz-Smoluchowski formula (formula (II)) described later.

As shown in FIG. 1, when the test piece 2 is negatively charged, positively charged fine particles or ions gather on the surface of the test piece 2 in the electrolytic solution 3 to form a so-called electric double layer. When an electric field is applied between the electrodes 4a and 4b in this state, a flow (laminar flow) toward the negative electrode 4a occurs near the surface of the test piece 2 due to positively charged fine particles or ions. As a result, a flow in the opposite direction (laminar flow) occurs in the central portion of the clamp cell 1 in order to compensate for this flow (laminar flow). In FIG. 1 , arrows indicate the direction of flow of the electrolytic solution 3 . Compressed air or an inert gas may also be used to sweep away the electrolyte solution 3 with a constant pressure difference (ΔP) to create a flow. Then, using the values of the laminar flow velocity difference (or pressure difference), the viscosity of the electrolytic solution 3, the dielectric constant of the electrolytic solution 3, etc., measured by the above principle, the following Helmholtz-Smoluchowski formula formula:

(In the above formulas (I) and (II), I _str represents the streaming current, U _str represents the streaming potential, Δp represents the differential pressure, η represents the viscosity of the electrolyte solution, and εr × ε0 represents the electrolyte solution. represents the dielectric constant of , KB represents the electrical conductivity, and L/A represents the parameters of the channel.)
The zeta potential (ζ) is calculated from

<Zeta potential measurement conditions>
In the present embodiment, the electrolytic solution that can be used to measure the zeta potential is preferably an aqueous solution containing a monovalent-monovalent electrolyte, such as an aqueous potassium chloride solution, an aqueous sodium chloride solution, an aqueous lithium chloride solution, an aqueous potassium hydroxide solution, An aqueous sodium hydroxide solution or an aqueous lithium hydroxide solution may be mentioned.

In addition, as the pH-adjusting acid or alkali used when measuring the zeta potential, a general acid or alkali aqueous solution is used, and HCl or KOH is mainly used. The electrolyte concentration in the electrolytic solution is preferably 0.1 to 1000 mmol/L. In this embodiment, when zeta potential measurement is performed under conditions of a specific pH range, a buffer solution may be used as an electrolytic solution that can be used. The buffer solution can be appropriately selected according to the pH conditions to be measured. Further, the buffer solution refers to a weak acid and its salt (conjugate base), or a mixed solution of a weak base and its salt (conjugate acid), which can be combined to adjust the desired pH. For example, when setting the pH to 6 or more and less than 8, phosphate buffer, MES buffer, Tris buffer or HEPES buffer can be used. Furthermore, when setting to pH 8 or more and less than 9, CHES buffer solution, TAPS buffer solution, or Bicine buffer solution is mentioned.

The pH of the electrolytic solution used in step (3-2) in the present embodiment is preferably in the range of 7.8 to 8.2. electrolyte solution is used. Also, the conductivity of the zeta potential electrolyte solution in this embodiment may be in the range of 14-15 mS/m. In addition, the pH and conductivity measurement methods in this specification are measured using a pH and conductivity meter (SurPASS3 (Anton Paar)). Moreover, the temperature for measuring the zeta potential in the present embodiment is preferably around room temperature (22 to 28° C.).

The step (3-2) in this embodiment uses the following conditions as an example.
・Type of electrolytic solution: KCl aqueous solution ・Ultrapure water used for electrolytic solution: ASTM I grade ・Concentration of electrolytic solution: 1 mmol/L
・Electrolytic solution conductivity: 14 to 15 mS/m
・Measurement temperature: 20 to 28°C
・pH: 7.8 to 8.2
・Cell type: Clamp cell ・Cell material: PVDF
・Gap between cell and test piece (evaluation sample): adjusted to 100 to 120 μm ・Measurement pressure range: 200 to 450 mbar

・ Process (3-3) <discrimination process>
The step (3-3) in this embodiment is a discrimination step of discriminating PAS resins having a zeta potential value in the range of -50 to -65 mV as measured by the zeta potential measurement step. A preferred aspect of the step (3-3) is that the zeta potential value measured under conditions of pH 7.8 to 8.2 (eg pH = 8.0) in the zeta potential measurement step is -50 to -65 mV. It can be a determination step of determining whether or not it is included in the range.

PAS resin, which exhibits a zeta potential value on the surface of the test piece in the range of -50 to -65 mV at pH 7.8 to 8.2 (eg, pH = 8.0), has excellent reactivity. Excellent mechanical properties can be exhibited in the PAS resin composition in which the material is further blended and the molded article thereof.

When the zeta potential of the surface of the test piece is measured at a predetermined pH (for example, pH 3 to 9), if the zeta potential value is large, a reactive functional group (for example, , a functional group containing an oxygen atom or a nitrogen atom) tends to be large, the reactivity of the prepared PAS resin is naturally considered to be high. In particular, when the zeta potential values of test pieces having the same molecular weight of PAS resin as constituent components are compared, it is confirmed that the reactivity of the PAS resin used in the test piece having a large zeta potential value tends to be high.

In another aspect of the present embodiment, in combination with the step (3-3), the step (3-2) is measured under the conditions of pH 4.8 to 5.2 (eg, pH = 5.0). It may have a determination step of determining whether the zeta potential value of the surface of the test piece that has been applied is within the range of -30 to -45 mV. If it is included in this range, a PAS resin with more excellent reactivity can be provided. In addition, the measurement system of pH 7.8 to 8.2 (eg, pH = 8.0) is the same or Since the zeta potential values and their differences between different PPS resins become larger, it becomes easier to evaluate the properties of the PPS resins with higher accuracy.

When the zeta potential value of the PAS resin is -50 mV or more, the hot water resistance of the PAS resin tends to decrease. On the other hand, when the zeta potential value is -65 mV or less, the reactivity between the PAS resin and the substance having a reactive functional group tends to decrease.

A step (selection step) of selecting a PAS resin having a specific zeta potential may be included after the determination step of step (3-3). Thereby, a PAS resin having a specific reactivity can be selected. If the selected lot of resin has the same zeta potential, the reactivity with a substance having a reactive functional group will also be the same, so the mechanical strength etc. when made into a resin composition or molded product can be the same. . Therefore, by sorting using the zeta potential as an index, it is possible to obtain a molded article with less variation in physical properties between lots and a resin composition constituting the molded article than when the degree of viscosity increase, which is a conventional index, is used. .

<PAS resin composition>
Next, the PAS resin composition will be explained. The PAS resin composition according to the present embodiment has a zeta potential on the surface of the test piece at pH 7.8 to 8.2 obtained through the above steps (1) to (3) in the range of -50 to -65 mV. A PAS resin composition containing a certain PAS resin and a substance having a reactive functional group.

The PAS resin contained in the PAS resin composition of the present embodiment exhibits high reactivity because it has a zeta potential value within a specific range. As a result, when a resin composition is prepared by melt-kneading another raw material, particularly a substance having a reactive functional group, and a PAS resin having a zeta potential value within a specific range, the PAS resin and the reactive functional group are produced. It exhibits excellent mechanical strength because it reacts well with substances. In addition, since the PAS resin contained in the PAS resin composition has a zeta potential value within a specific range, variations in reactivity are reduced, and as a result, variations in the physical properties of the entire PAS resin composition are reduced. .

The substance having a reactive functional group in the present embodiment is not particularly limited as long as it is a substance having a reactive functional group capable of interacting (including chemical bonding) with the PAS resin. It is preferably one or more substances selected from the group consisting of agents, elastomers, epoxy resins, and surface-treated inorganic fillers. Substances having suitable reactive functional groups are described below.

<Silane coupling agent>
The PAS resin composition according to this embodiment preferably contains a silane coupling agent. The silane coupling agent is not particularly limited as long as it does not impair the effects of the present invention, but a functional group capable of reacting with at least one group selected from the group consisting of a hydroxyl group, an amino group, a carboxyl group, and a salt of a carboxyl group. A silane coupling agent having Such functional groups include epoxy group, amino group, hydroxyl group, carboxyl group, mercapto group, isocyanate group, oxazoline group, and formula: R (CO) O (CO) - or R (CO) O - (in the formula, R represents an alkyl group having 1 to 8 carbon atoms.). Examples of such silane coupling agents include epoxy groups such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like. Alkoxysilane compound containing, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane , γ-isocyanatopropylethyldiethoxysilane, γ-isocyanatopropyltrichlorosilane and other isocyanato group-containing alkoxysilane compounds, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)amino Examples include amino group-containing alkoxysilane compounds such as propyltrimethoxysilane and γ-aminopropyltrimethoxysilane, and hydroxyl group-containing alkoxysilane compounds such as γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane.

In the present embodiment, the silane coupling agent is an optional component, and the ratio when blending is not particularly limited. For example, it is preferably 0.3 parts by mass or more with respect to 100 parts by mass of the PAS resin. , more preferably 0.4 parts by mass or more, more preferably 0.5 parts by mass or more. On the other hand, from the viewpoint of ensuring better fluidity and workability of the resin composition, it is more preferably 10 parts by mass or less, more preferably 8 parts by mass or less, relative to 100 parts by mass of the PAS resin. , 6 parts by mass or less.

<Elastomer>
The PAS resin composition according to this embodiment preferably contains an elastomer. By including the elastomer, the toughness and thermal shock resistance of the PAS resin composition can be further enhanced. From the same point of view, it is preferable to use a thermoplastic elastomer as the elastomer. The thermoplastic elastomer is not particularly limited as long as it does not impair the effects of the present invention. Examples of the thermoplastic elastomer include polyolefin-based elastomers, fluorine-based elastomers, and silicone-based elastomers.

The elastomer (particularly thermoplastic elastomer) preferably has a functional group capable of reacting with at least one group selected from the group consisting of hydroxyl group, amino group, carboxyl group and carboxyl group. Such functional groups include epoxy group, amino group, hydroxyl group, carboxyl group, mercapto group, isocyanate group, oxazoline group, and formula: R (CO) O (CO) - or R (CO) O - (in the formula, R represents an alkyl group having 1 to 8 carbon atoms.). A thermoplastic elastomer having such a functional group can be obtained, for example, by copolymerizing an α-olefin and a vinyl polymerizable compound having the functional group. Examples of α-olefins include α-olefins having 2 to 8 carbon atoms such as ethylene, propylene and butene-1. Examples of the vinyl polymerizable compound having the functional group include α,β-unsaturated carboxylic acids and their alkyl esters such as (meth)acrylic acid and (meth)acrylic acid esters, maleic acid, fumaric acid, itaconic acid and Other examples include α,β-unsaturated dicarboxylic acids having 4 to 10 carbon atoms and derivatives thereof (mono- or diesters, acid anhydrides thereof, etc.), glycidyl (meth)acrylate, and the like. Among these, an epoxy group, a carboxyl group, and a formula: R (CO) O (CO) - or R (CO) O - (wherein R represents an alkyl group having 1 to 8 carbon atoms) Ethylene-propylene copolymers and ethylene-butene copolymers having at least one functional group selected from the group consisting of the groups represented are preferred from the standpoint of improving toughness and impact resistance.

In the present embodiment, the elastomer is an optional component, but the ratio when blending is not particularly limited. 1 part by mass or more, preferably 1 part by mass or more, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

<Epoxy resin>
The PAS resin composition according to the present embodiment preferably contains an epoxy resin. The epoxy resin is not particularly limited as long as it does not impair the effects of the present invention. Examples include bisphenol type epoxy resins such as bisphenol A type and bisphenol F type; glycidyl ester type epoxy resins; glycidyl amino type epoxy resins; and epoxy resins having a polyarylene ether structure.

In the present embodiment, the epoxy resin is an optional component, but the ratio at the time of blending is not particularly limited. parts or more, more preferably 5 parts by mass or more, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 15 parts by mass or less.

These epoxy resins contained in the PAS resin composition used in the present invention lose epoxy groups due to a curing reaction during melt-kneading when a curing agent is present. Therefore, the amount of active groups in the curing agent is 0.1 equivalents or less, more preferably 0.01 equivalents or less, and most preferably 0 equivalents, ie, absent.

<Surface-treated inorganic filler>
The PAS resin composition according to the present embodiment preferably contains a surface-treated inorganic filler. As these inorganic fillers, known and commonly used materials can be used as long as they do not impair the effects of the present invention. and inorganic fillers. Specifically, fibers such as glass fiber, carbon fiber, silane glass fiber, ceramic fiber, aramid fiber, metal fiber, potassium titanate, silicon carbide, calcium silicate, wollastonite, and fibrous filler such as natural fiber are used. It can also be used for glass beads, glass flakes, barium sulfate, clay, pyrophyllite, bentonite, sericite, mica, talc, attapulgite, ferrite, calcium silicate, calcium carbonate, glass beads, zeolite, milled fiber, calcium sulfate, etc. Non-fibrous fillers can also be used. Specific examples of the surface treatment agent for surface-treating the inorganic filler include epoxy-based compounds, isocyanate-based compounds, silane-based compounds, titanate-based compounds, borane treatment, ceramic coating, and the like. Among them, epoxy-based compounds and silane-based compounds are preferred.

The inorganic filler is not an essential component in the present invention, and when blended, its content is not particularly limited as long as it does not impair the effects of the present invention. The amount of the inorganic filler compounded is, for example, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 20 parts by mass or more with respect to 100 parts by mass of the PAS resin. preferable. On the other hand, from the viewpoint of obtaining more excellent fluidity and workability of the resin composition and smoothness of the surface of the molded product, it is more preferably 350 parts by mass or less, and 300 parts by mass or less with respect to 100 parts by mass of the PAS resin. More preferably, it is particularly preferably 250 parts by mass or less.

<Other ingredients>
Depending on the performance required, the PAS resin composition according to the present embodiment may contain a synthetic resin other than the PAS resin, a coloring agent, an antistatic agent, an antioxidant, a heat stabilizer, an ultraviolet stabilizer, an ultraviolet absorber, Additives such as foaming agents, flame retardants, flame retardant aids, rust inhibitors, and coupling agents (hereinafter referred to as "other components") may be included. The other components are, for example, preferably 0.01 parts by mass or more and preferably 1000 parts by mass or less with respect to 100 parts by mass of the PAS resin, depending on the purpose and application so as not to impair the effects of the present invention. It may be used after adjusting as appropriate.

Examples of the synthetic resin include polyester resin, polyamide resin, polyimide resin, polyetherimide resin, polycarbonate resin, polyphenylene ether resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyetherketone resin, poly Synthetic resins such as arylene resins, polyethylene resins, polypropylene resins, polytetrafluoroethylene resins, polydifluoroethylene resins, polystyrene resins, ABS resins, phenol resins, urethane resins, and liquid crystal polymers can be used.

The synthetic resin is not an essential component, and the mixing ratio is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected according to each purpose. For example, in the PAS resin composition according to the present embodiment, it can be about 5 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the PAS resin. In other words, the ratio of the PAS resin to the total of the PAS resin and the synthetic resin is preferably (100/115) or more, more preferably (100/105) or more, on a mass basis.

<Method for producing PAS resin composition>
Next, a method for producing the PAS resin composition will be described. The method for producing a PAS resin composition according to the present embodiment includes a step of blending the PAS resin obtained through the above steps (1) to (3) and a substance having a reactive functional group, and melt-kneading them. and the zeta potential value of the surface of the test piece at pH 7.8 to 8.2 of the PAS resin is in the range of -50 to -65 mV.

The PAS resin composition according to the present embodiment contains each essential component and optionally optional components. The essential components and optional components are the same as those described in the PAS resin composition according to the present embodiment.
The method of blending and kneading the essential components and optional components is not particularly limited, but a method of blending the essential components and optionally optional components and melt-kneading them, more specifically, a tumbler if necessary Alternatively, a method of homogeneously dry-mixing with a Henschel mixer or the like and then introducing into a twin-screw extruder to melt-knead may be used.

Melt-kneading is carried out in a temperature range in which the resin temperature is equal to or higher than the melting point of the PAS resin, preferably the melting point +10°C or higher, more preferably the melting point +10°C or higher, further preferably the melting point +20°C or higher, Preferably, the melting point is +100° C. or lower, more preferably, the melting point is +50° C. or lower.

As the melt-kneader, a twin-screw kneading extruder is preferable from the viewpoint of dispersibility and productivity. It is preferable to melt-knead while appropriately adjusting the range of and melt-kneading under conditions where the ratio (discharge rate / screw rotation speed) is in the range of 0.02 to 5 (kg / hr / rpm). is more preferred.
Moreover, addition and mixing of each component to the melt-kneader may be performed simultaneously, or may be performed separately. For example, when an additive is added among the above components, it is preferable from the viewpoint of dispersibility to feed it into the extruder from the side feeder of the twin-screw kneading extruder. Regarding the position of the side feeder, the ratio of the distance from the extruder resin input part (top feeder) to the side feeder with respect to the total screw length of the twin-screw kneading extruder is preferably 0.1 or more, and 0 .3 or more is more preferable. Also, the ratio is preferably 0.9 or less, more preferably 0.7 or less.

The PAS resin composition according to the present embodiment obtained by melt-kneading in this manner has a morphology in which the PAS resin forms a continuous phase and other essential components and optional components are dispersed. After the melt-kneading, the PAS resin composition according to the present embodiment is processed into pellets, chips, granules, powder, and the like by a known method, for example, extruding the resin composition in a molten state into strands. After that, it is preferable to perform pre-drying in a temperature range of 100 to 150° C., if necessary.

<PAS resin molded product, method for manufacturing molded product>
The molded article according to this embodiment is obtained by melt-molding the PAS resin composition according to this embodiment described above. Further, the method for producing a molded product according to the present embodiment is characterized by having a step of melt-molding the PAS resin composition obtained by the above-described method for producing a PAS resin composition according to the present embodiment.

Since the molded article according to the present embodiment uses the PAS resin composition according to the present embodiment as a material, physical properties such as mechanical strength are maintained at a high level, and excellent moist heat resistance and moldability are realized. It has the effect of

The PAS resin composition can be molded by injection molding, compression molding, extrusion molding of composites, sheets, pipes, etc., pultrusion molding, blow molding, transfer molding, and the like. Also suitable for injection molding applications. When molding by injection molding, various molding conditions are not particularly limited, and molding can be performed by a general method. For example, in an injection molding machine, the resin temperature is in the range of the melting point of the PAS resin or higher, preferably the melting point +10°C or higher, more preferably the melting point +10°C to the melting point +100°C, further preferably the melting point +20°C. After passing through the step of melting the PAS resin composition in a temperature range of up to the melting point +50° C., it may be molded by injecting it into a mold from the resin discharge port. At that time, the mold temperature may also be set within a known temperature range, for example, room temperature (approximately 23°C) to 300°C, preferably 120 to 180°C.

<Application>
Products using the molded article according to the present embodiment are not particularly limited, and can be used for the following various applications. For example, electrical and electronic parts such as connectors, printed circuit boards, and sealed molded products; automobile parts such as lamp reflectors and various electrical parts; interior materials for various buildings, aircraft, and automobiles; It can be widely used as injection molding/compression molding products such as precision parts such as watch parts, extrusion molding/pultrusion molding products such as fibers, films, sheets, and pipes, and 3D printer modeling products.

The present invention will be specifically described below with reference to examples. These examples are illustrative and not limiting. In the following, unless otherwise specified, "%" and "parts" are based on mass.

<Examples 1-2, Comparative Examples 1-3>
・ PPS resin production example (1-1) Polymerization of PPS resin 22.050 kg of p-dichlorobenzene (p-DCB) in a 150 L autoclave equipped with a stirring blade and a bottom valve connecting a pressure gauge, a thermometer, a condenser and a decanter ( 150 mol), 2.974 kg (30 mol) of N-methyl-2-pyrrolidone (NMP), 12.362 kg (150 mol) of 68% NaSH, and 12.500 kg (150 mol) of 48% NaOH and stirred nitrogen The temperature was raised to 173° C. under the atmosphere. After distilling off 12.353 kg of water, the kettle was closed. At that time, the p-DCB distilled azeotropically was separated with a decanter and returned to the kettle as needed. After dehydration, the internal temperature of the autoclave was cooled to 160°C, and 29.486 kg (297 mol) of NMP was supplied, then the temperature was raised to 220°C and stirred for 2 hours, and then the temperature was raised to 250°C and stirred for 1 hour. bottom. The final pressure was 0.28 MPa. After the reaction, the bottom valve of the autoclave is opened, NMP is extracted into a 150 L vacuum stirring dryer with stirring blades while the pressure is reduced, and then the NMP is sufficiently removed by stirring at 150 ° C. for 2 hours under reduced pressure, and the powder is obtained. A mixture (A-1) of PPS resin and salts was obtained.

Example (1-2) Purification and Preparation of PPS Resin To 417 g of the mixture (A-1), 1,000 g of ion-exchanged water at 70° C. was added, stirred for 20 minutes, and filtered. The process was repeated twice. The resulting hydrous cake and 600 g of ion-exchanged water were supplied to a 1 L autoclave equipped with a stirrer and stirred at 160° C. for 30 minutes. After cooling to room temperature, 800 g of ion-exchanged water at 70° C. was further added to the water-containing cake obtained by filtration, followed by filtration. The resulting water-containing cake and 600 g of ion-exchanged water were placed in a 1 L autoclave equipped with a stirrer, stirred at 220° C. for 30 minutes, cooled to room temperature, and filtered. Added and filtered. After that, 600 g of carbonated water having a pH of 4 at 20° C. was added and filtered, and further 600 g of ion-exchanged water at 70° C. was added and filtered. The resulting water-containing cake was dried in a hot air circulation dryer at 120° C. for 6 hours to obtain a white powdery PPS resin. The same operation was repeated to obtain 3 lots of PPS resin.

Example (1-3) Evaluation of PPS resin 0.5 g of the obtained PPS resin was weighed and sandwiched between two glass fiber-containing polytetrafluoroethylene resin sheets (Nitto Denko Co., Ltd., Nitoflon). Heated for 1 minute using a hot plate heated to 350°C. At this time, the PPS resin melted, so that it was pressed from above with a metal plate heated to 350° C. to form a film with a thickness of 0.1 cm. After further heating the film-like PPS resin for 1 minute, the two polytetrafluoroethylene resin sheets sandwiching the film-like molten PPS resin were transferred from the hot plate onto a metal plate at room temperature (28° C.), and immediately The melted PPS resin was solidified by sandwiching it from above with metal plates at room temperature (28° C.) and cooling down to room temperature (28° C.). Thereafter, the solidified film-like PPS resin was cut into 5 cm×3 cm pieces to obtain amorphous test pieces. It was confirmed by DSC measurement that the test piece was in an amorphous state. After degreasing the surface of the test piece with acetone, the zeta potential value of the surface of the test piece was measured by the streaming potential method under the following measurement conditions using a solid-only zeta potential meter, SurPASS3 (Anton Paar). It was measured. Table 1 shows the results.
"Measurement condition"
・Electrolyte solution: 1 mmol/L KCl aqueous solution ・Measurement temperature: 22 to 26°C
・pH: 8.0

Example (2-1) Polymerization of PPS Resin 19.413 kg of flaky hydrous sodium sulfide (60.3 wt% Na ₂ S) and , and 45.0 kg of NMP. The temperature was raised to 209° C. while stirring under a nitrogen stream, and 4.644 kg of water was distilled off (the remaining water content was 1.13 mol per 1 mol of sodium sulfide). The autoclave was then closed and cooled to 180° C. and further cooled while feeding 22.185 kg of p-DCB and 18.0 kg of NMP. At a liquid temperature of 150° C., the inside of the autoclave was pressurized to a gauge pressure of 0.1 MPa by nitrogen gas, and heating was started again. The liquid temperature was raised from 200° C. to 250° C. over 3 hours and held at 250° C. for 1 hour for reaction, then 0.635 kg of water was pressurized and cooled to 220° C. over 40 minutes. Thereafter, cooling was further continued, and 0.284 kg (2.25 mol) of oxalic acid dihydrate and 0.663 kg of NMP were injected under pressure at 200°C. Further cooling was continued, and at 100°C, the bottom valve was opened, the reaction slurry was transferred to a 150L flat plate filter, and pressure filtered at 120°C. Subsequently, 16 kg of NMP was added and filtered under pressure. After filtration, using a 150 L vacuum dryer equipped with a stirring blade, the mixture was stirred at 150° C. under reduced pressure for 2 hours to remove NMP, thereby obtaining a powdery PPS resin-salt mixture (B-1).

Example (2-2) Purification and Preparation of PPS Resin To 417 g of the mixture (B-1), 1000 g of ion-exchanged water at 70° C. was added, stirred for 20 minutes, and filtered. After repeating this operation once more, the resulting water-containing cake and 600 g of ion-exchanged water were supplied to a 1 L autoclave equipped with a stirrer and stirred at 160° C. for 30 minutes. After cooling to room temperature, 600 g of ion-exchanged water at 70° C. was added to the resulting water-containing cake, followed by filtration. The resulting water-containing cake was dried in a hot air circulation dryer at 120° C. for 6 hours to obtain a white powdery PPS resin. The same operation was repeated to obtain 3 lots of PPS resin.

Example (2-3) Evaluation of PPS resin In the same manner as in Example 1, the zeta potential value of the surface of the obtained PPS resin test piece was measured. Table 1 shows the results.

Comparative Example (1-1) Polymerization of PPS resin It was carried out in the same manner as in Example 1-1.

Comparative Example (1-2) Purification and Preparation of PPS Resin The procedure was carried out in the same manner as in Example 1-2, except that the temperature of the ion-exchanged water used for washing and the stirring temperature were all set to 70°C. A PPS resin was obtained. The same operation was repeated to obtain 3 lots of PPS resin.

Comparative Example (1-3) Evaluation of PPS Resin In the same manner as in Example 1, the zeta potential value of the surface of the obtained PPS resin test piece was measured. Table 1 shows the results.

Comparative Example (2-1) Polymerization of PPS Resin The same procedure as in Example 2-1 was performed except that oxalic acid dihydrate was not added at 200° C. during cooling.

Comparative Example (2-2) Purification and Preparation of PPS Resin It was carried out in the same manner as in Example 2-1. The same operation was repeated to obtain 3 lots of PPS resin.

Comparative Example (2-3) Evaluation of PPS Resin In the same manner as in Example 1, the zeta potential value of the surface of the obtained PPS resin test piece was measured. Table 1 shows the results.

Comparative example (3)
The degree of increase in viscosity of the PPS resin when epoxysilane was added was measured, and lots of PPS resin having a degree of increase in viscosity of 9.0 to 9.1 times were selected. Also, in the same manner as in Example 1, the zeta potential values of the surfaces of the selected PPS resin test pieces were measured. The results are shown in Table 1

Production of resin composition 100 parts by mass of each PPS resin obtained in Examples 1 and 2 and Comparative Examples 1 and 3, 10 parts by mass of elastomer and 0.8 parts by mass of silane coupling agent were blended. After that, these compounding materials are put into a vented twin-screw extruder “TEX-30α (product name)” manufactured by The Japan Steel Works, Ltd., and the resin component discharge amount is 30 kg / hr, the screw rotation speed is 200 rpm, and the set resin temperature is 320 ° C. The pellets of the resin composition were obtained by melt-kneading. 50 parts by mass of the glass fiber was fed from the side feeder, and the other materials were preliminarily mixed uniformly in a tumbler and fed from the top feeder. After drying the obtained pellets of the resin composition in a gear oven at 140° C. for 2 hours, they were injection molded to prepare various test pieces, and the following tests were performed.

(1) DSC measurement of PPS resin 4 mg was taken from a film-shaped PPS resin test piece prepared for zeta potential measurement, and 20% from 40 ° C. to 350 ° C. was measured using a differential scanning calorimeter (DSC), Perkin Elmer's DSC8500. The temperature was raised at °C/min. Since no exothermic peak due to crystallization of the resin was observed between 100° C. and 200° C., it was confirmed that each film-like test piece was in an amorphous state.

(2) Measurement of Viscosity Increase of PPS Resin The melt viscosity increase was calculated from the change in viscosity before and after adding the epoxysilane and melt-kneading. 1.0% of γ-glycidoxypropyltrimethoxysilane (mass ratio of solid content to PPS resin) was used as epoxysilane. Melt-kneading was carried out at 320° C. and 100 rpm for 5 minutes using Labo Plastomill (20-200C, using R-60 type mixer, manufactured by Toyo Seiki Seisakusho Co., Ltd.). The degree of increase in melt viscosity was calculated from the following formula. Table 1 shows the results.
Degree of viscosity increase (magnification) = (MFR after addition of epoxysilane)/(MFR when no addition of epoxysilane)

(3) Tensile strength measurement of PPS resin molded product The obtained pellets were supplied to a Sumitomo Heavy Industries injection molding machine (SE-75D-HP) set at a cylinder temperature of 310 ° C., and the mold temperature was adjusted to 140 ° C. Injection molding was performed using an ISO Type-A dumbbell piece molding mold to obtain an ISO Type-A dumbbell piece. In addition, the resin was injected from a single gate so as to produce a test piece that did not include a weld portion. Using the obtained test piece, the tensile strength was measured by the measuring method according to ISO 527-1 and 2. Table 1 shows the results.

(4) Measurement of Charpy impact strength (without notch) of PPS resin molded product (3) The center part of the test piece prepared in the same manner as in (3) was cut into a bar shape with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm. A Charpy impact test was carried out by a method conforming to ISO179-1/1eU to measure the impact strength (kJ/m ² ). Table 1 shows the results.

From the results in Table 1, it was confirmed that the molded articles using the resins of the examples whose zeta potential was within a specific range had small variation (CV) in tensile strength and Charpy impact strength between lots. Comparative Example 3, in which the conventional degree of increase in viscosity was used as an index of reactivity, showed a larger variability (CV) of physical properties than in Examples.

Claims

step (1) of polymerizing a polyarylene sulfide resin;
a step (2) of purifying the polyarylene sulfide resin to prepare a purified polyarylene sulfide resin; and
A method for producing a polyarylene sulfide resin, comprising the step (3) of evaluating a test piece formed from at least a portion of the purified polyarylene sulfide resin,
The step (3) is a test piece preparation step (3-1) in which the test piece is obtained by solidifying the molten polyarylene sulfide resin obtained by melting the purified polyarylene sulfide resin;
A zeta potential measurement step (3-2) of measuring the zeta potential of the surface of the test piece under conditions of pH 7.8 to 8.2 by streaming potential method;
A method for producing a polyarylene sulfide resin, comprising a discrimination step (3-3) for discriminating polyarylene sulfide resins having a zeta potential value in the range of −50 to −65 mV as measured in the step (3-2).
The polyarylene sulfide according to claim 1, wherein an acid is added to the polyarylene sulfide resin in the step (1) or the step (2) so that the zeta potential value is in the range of -50 to -65 mV. A method for producing resin.
In step (2), the polyarylene sulfide resin obtained in step (1) is washed with hot water at 140° C. to 260° C. and an amount of 1.5 to 10 times the total weight of the polyarylene sulfide resin. 3. The method for producing a polyarylene sulfide resin according to claim 1, comprising steps.
A polyarylene sulfide resin whose zeta potential value on the surface of the test piece at pH 7.8 to 8.2 is in the range of -50 to -65 mV.
A polyarylene sulfide resin having a zeta potential value on the surface of the test piece at pH 7.8 to 8.2 in the range of -50 to -65 mV and a substance having a reactive functional group are blended, A polyarylene sulfide resin composition.
A molded article obtained by melt-molding the polyarylene sulfide resin composition according to claim 5.
A step of blending the polyarylene sulfide resin obtained by the production method according to any one of claims 1 to 3 and a substance having a reactive functional group and melt-kneading them, and
A method for producing a polyarylene sulfide resin composition, wherein the surface of the test piece of the polyarylene sulfide resin has a zeta potential value of -50 to -65 mV at pH 7.8 to 8.2.
A method for producing a polyarylene sulfide resin molded article, comprising the step of melt-molding the polyarylene sulfide resin composition obtained by the production method according to claim 7.