JP2023149538A - Method for producing polyarylene sulfide resin - Google Patents

Abstract

To efficiently obtain a PAS resin with reduced gas yield, increased functional group content, and increased molecular weight.SOLUTION: A method for producing a polyarylene sulfide resin includes a polyarylene sulfide resin polymerization step in which a polyarylene sulfide with a weight average molecular weight of 25000 or more is reacted with a halogenated compound having a functional group in a temperature range of 200°C or higher and lower than 290°C; and a heat treatment step for heating a polyarylene sulfide resin obtained in the polymerization step.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a polyarylene sulfide resin that generates a small amount of gas, has a large content of functional groups, and has a high molecular weight.

Polyarylene sulfide (hereinafter sometimes abbreviated as PAS) resin has properties suitable for engineering plastics, such as excellent mechanical strength, flame retardance, heat resistance, and chemical resistance. For this reason, it is widely used in electrical/electronic parts, communication equipment parts, etc. In these applications, component parts such as electronic parts are often sealed inside a box-shaped molded body made of PAS resin to protect them, and epoxy adhesives are often used as sealing adhesives. Although PAS resin has the above-mentioned excellent properties, it has a problem in that it has low adhesiveness with resins other than PAS resin, fillers, metals, and other different materials. When sealing with epoxy adhesive, the interfacial adhesive strength is low, and there is a concern that moisture may be absorbed from the peeled interface and have a negative effect on internal electronic components, so the interfacial adhesive strength is high when sealed with epoxy adhesive. PAS resin is in demand.

In contrast, an improved method has been reported in which the PAS resin is blended with other compounds to enhance its adhesion to different materials, thereby improving its epoxy adhesion. For example, Patent Document 1 discloses a PAS resin composition containing an epoxy resin or an epoxy group-containing polyolefin in addition to a PAS resin and glass fiber.

Furthermore, a method of introducing functional groups into PAS resin has been proposed for the purpose of improving the adhesiveness of PAS resin itself. For example, Patent Document 2 discloses a polyphenylene sulfide resin in which a certain amount of carboxyl groups are introduced into the polymer skeleton by reacting sodium sulfide, dichlorodiphenylsulfone, and dichlorobenzoic acid under specific conditions. Patent Document 3 discloses a polyphenylene sulfide resin in which a certain amount of carboxyl groups are introduced at the terminals by reacting sodium hydrosulfide and paradichlorobenzene under specific conditions. Patent Document 4 discloses a method in which a predetermined amount of a halogenated compound having a functional group is added during polymerization in which sodium hydrosulfide and paradichlorobenzene are reacted in the presence of a polymerization aid.

International Publication No. 2019/208377 Japanese Unexamined Patent Publication No. 4-180925 Japanese Patent Application Publication No. 2012-177015 JP 2021-75695 Publication

However, although the PAS resin composition described in Patent Document 1 can be expected to have a relatively high epoxy adhesion effect, it generates a large amount of gas derived from the epoxy resin and epoxy group-containing polyolefin, resulting in mold stains and molding defects during molding. There's a problem. The PAS resin described in Patent Document 2 can be expected to have a relatively high functional group content, but because the polymerization temperature is low and no polymerization aid is used, the molecular weight is extremely low, and the molding obtained by molding The problem is that the strength of the product is low. In the PAS resin described in Patent Document 3, although a PAS resin having a relatively high molecular weight can be obtained, the content of functional groups is insufficient and there is a problem that the adhesive strength with an epoxy adhesive is low. With the PAS resin described in Patent Document 4, a PAS resin with relatively high molecular weight and functional groups can be obtained, but since the amount of gas generated is large, problems remain during molding.

As described above, it is difficult for the PAS resins described in Patent Documents 2 and 3 to have both a high functional group content and a high molecular weight, and the PAS resin described in Patent Document 4 is difficult to achieve both high functional group content and high molecular weight. The problem was that it could not be used in electrical/electronic parts, communication equipment parts, and automobile parts.

Therefore, the present inventors conducted extensive studies to solve the above problems, and found that in a method for producing PAS resin, PAS with a weight average molecular weight of 25,000 or more and a halogenated compound having a functional group are heated at 200°C or higher and 290°C. By including a polymerization step and a heat treatment step for the PAS resin, which are reacted within a temperature range of less than This discovery led to the present invention.

That is, the present invention is as follows.
1. A polyarylene sulfide resin polymerization step in which a polyarylene sulfide having a weight average molecular weight of 25,000 or more and a halogenated compound having a functional group are reacted within a temperature range of 200 ° C. or more and less than 290 ° C., and a polyarylene sulfide resin obtained in the polymerization step. A method for producing a polyarylene sulfide resin, which comprises performing a heat treatment step of heat treating the polyarylene sulfide resin.
2. 1, characterized in that the halogenated compound having a functional group is a halogenated compound having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, an amino group, a hydroxy group, and derivatives thereof. A method for producing a polyarylene sulfide resin as described in .
3. Any of item 1 or item 2, wherein the halogenated compound having a functional group is a halogenated compound having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, and a derivative thereof. A method for producing a polyarylene sulfide resin as described in the above.
4. Any of items 1 to 3, characterized in that in the heat treatment step, the polyarylene sulfide resin is heat treated in an atmosphere with an oxygen concentration of 2% by volume or more at 160 to 270°C for 0.2 to 50 hours. A method for producing a polyarylene sulfide resin as described in the above.
5. The method for producing a polyarylene sulfide resin according to any one of items 1 to 4, characterized in that after the polymerization step, an acid treatment step of treating the polyarylene sulfide resin with an acid is performed, and then a heat treatment step is performed.
6. The polyarylene according to any one of items 1 to 5, wherein after the polymerization step, a hot water treatment step of treating the polyarylene sulfide resin with hot water is performed, followed by an acid treatment step and a heat treatment step. Method for producing sulfide resin.
7. 7. The method for producing a polyarylene sulfide resin according to any one of items 1 to 6, characterized in that in the polymerization step, the obtained polyarylene sulfide resin is recovered by a flash method.
8. 8. The method for producing a polyarylene sulfide resin according to any one of items 1 to 7, characterized in that the amount of gas that evaporates when the polyarylene sulfide resin is heated and melted is 0.5% by weight or less.
9. The method for producing a polyarylene sulfide resin according to any one of items 1 to 8, characterized in that the weight average molecular weight is 30,000 or more.
10. The method for producing a polyarylene sulfide resin according to any one of items 1 to 9, wherein the functional group content is 80 μmol/g or more and 500 μmol/g or less.
11. The melt flow rate (measured under conditions according to ASTM D-1238-70 at a temperature of 315.5°C and a load of 5000 g) is 500 g/10 minutes or less, according to any one of items 1 to 10. A method for producing polyarylene sulfide resin.
A method for producing a polyarylene sulfide resin composition, which comprises obtaining a polyarylene sulfide resin by the method for producing a polyarylene sulfide resin according to any one of Items 12.1 to 11, and melt-kneading the polyarylene sulfide resin.
A polyarylene sulfide resin composition is obtained by the method for producing a polyarylene sulfide resin composition described in Section 13.12, the polyarylene sulfide resin composition is molded to obtain a box-shaped article, and in the box-shaped article. A method of manufacturing a power module in which electrical and electronic components are placed.

According to the present invention, it is possible to efficiently obtain a PAS resin that generates a small amount of gas, has a large content of functional groups, and has a high molecular weight. Molded products made of such PAS resins have less mold staining and also have excellent mechanical strength and epoxy adhesive strength.

The PAS in the present invention is a homopolymer or copolymer whose main constituent unit is a repeating unit of the formula -(Ar-S)-, preferably containing 80 mol% or more of the repeating unit. Ar includes units represented by the following formulas (A) to (K), among which formula (A) is particularly preferred.

(R1 and R2 are substituents selected from hydrogen, an alkyl group, an alkoxy group, and a halogen group, and R1 and R2 may be the same or different.)
As long as this repeating unit is the main structural unit, a small amount of branching units or crosslinking units represented by the following formulas (L) to (N) etc. can be included. The copolymerized amount of these branching units or crosslinking units is preferably in the range of 0 to 1 mol % with respect to 1 mol of -(Ar-S)- units.

Moreover, the PAS in the present invention may be a random copolymer, a block copolymer, or a mixture thereof containing the above repeating units.

Typical examples of these include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers and block copolymers thereof, and mixtures thereof. Particularly preferable PASs include p-phenylene sulfide units shown below as main constituent units of the polymer.

Examples include polyphenylene sulfide containing 80 mol% or more, especially 90 mol% or more.

The method for producing PAS resin of the present invention will be explained below.

First, the contents of the dihalogenated aromatic compound, sulfidating agent, polymerization solvent, halogenated compound having a functional group, branching/crosslinking agent, polymerization aid, and polymerization stabilizer used in the production method will be explained.

[Dihalogenated aromatic compound]
The dihalogenated aromatic compound refers to a compound having two halogen atoms in one molecule. Specific examples include p-dichlorobenzene, m-dichlorobenzene, o-dichlorobenzene, 2,5-dichlorotoluene, 2,5-dichloro-p-xylene, 1,4-dibromobenzene, 1,4-diiodo. Examples include benzene, 1-methoxy-2,5-dichlorobenzene, and p-dichlorobenzene is preferably used. It is also possible to combine two or more different dihalogenated aromatic compounds to form a copolymer, but it is preferable to use a p-dihalogenated aromatic compound as the main component.

The amount of the dihalogenated aromatic compound to be used is from 90 mol to 120 mol, preferably from 95 mol to 110 mol, more preferably from 99 mol to 105 mol, per 100 mol of the sulfidating agent, in order to obtain a PAS resin with a viscosity suitable for processing. More preferably, the range is from 100.5 mol to 103 mol.

[Sulfiding agent]
Sulfidating agents include alkali metal sulfides, alkali metal hydrosulfides, and hydrogen sulfide.

Specific examples of alkali metal sulfides include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, cesium sulfide, and mixtures of two or more of these, with sodium sulfide being preferably used. These alkali metal sulfides can be used as hydrates or aqueous mixtures or in anhydrous form.

Specific examples of alkali metal bisulfides include sodium bisulfide, potassium bisulfide, lithium bisulfide, rubidium bisulfide, cesium bisulfide, and mixtures of two or more of these. Among these, sodium bisulfide is Preferably used. These alkali metal hydrosulfides can be used as hydrates or aqueous mixtures or in anhydrous form.

Furthermore, an alkali metal sulfide prepared in situ in a reaction system from an alkali metal hydrosulfide and an alkali metal hydroxide can also be used. Alternatively, an alkali metal sulfide can be prepared from an alkali metal hydrosulfide and an alkali metal hydroxide, and the alkali metal sulfide can be transferred to a polymerization tank for use.

Alternatively, an alkali metal sulfide prepared in situ in a reaction system from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide can also be used. Alternatively, an alkali metal sulfide can be prepared from an alkali metal hydroxide such as lithium hydroxide or sodium hydroxide and hydrogen sulfide, and the alkali metal sulfide can be transferred to a polymerization tank for use.

The amount of sulfidating agent charged means the amount remaining after subtracting the loss from the actual amount of sulfidating agent, if a portion of the sulfidating agent is lost before the start of the polymerization reaction due to dehydration or the like.

In addition, it is also possible to use an alkali metal hydroxide and/or an alkaline earth metal hydroxide together with the sulfidating agent. Preferred examples of alkali metal hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, and mixtures of two or more of these. Specific examples of metal hydroxides include calcium hydroxide, strontium hydroxide, barium hydroxide, etc. Among them, sodium hydroxide is preferably used.

When using an alkali metal hydrosulfide as a sulfidating agent, it is particularly preferable to use an alkali metal hydroxide at the same time, and the amount used is 0.95 to 1 mol per 1 mol of the alkali metal hydrosulfide. Examples include a range of .20 mol, preferably 1.00 mol to 1.15 mol, and more preferably 1.005 mol to 1.100 mol.

[Polymerization solvent]
It is preferable to use an organic polar solvent as the polymerization solvent. Specific examples include N-alkylpyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone, caprolactams such as N-methyl-ε-caprolactam, and 1,3-dimethyl-2-imidazolidone. Examples include aprotic organic solvents typified by non-, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, dimethylsulfone, tetramethylene sulfoxide, and mixtures thereof. All of these polymerization solvents are preferably used because they have high reaction stability. Among these, N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) is particularly preferably used.

The amount of the organic polar solvent used is selected in the range of 20 to 1000 moles, preferably 225 to 600 moles, more preferably 250 to 550 moles, per 100 moles of the sulfidating agent.

[Halogenated compound with functional group]
In the present invention, it is essential to use a halogenated compound having a functional group. Specifically, halogenated compounds having functional groups include carboxyl groups, acid anhydride groups, hydroxy groups, amino groups, isocyanate groups, epoxy groups, nitro groups, thiol groups, sulfonamide groups, amide groups, and sulfonic acid groups. The compound is a halogenated compound having at least one functional group selected from the group consisting of acetyl group, an acetyl group, a silanol group, an alkoxysilane group, and derivatives thereof. Among these, from the viewpoint of reactivity and handling, and from the viewpoint of excellent reactivity with different materials when introduced into PAS resin, any one selected from carboxyl groups, acid anhydride groups, amino groups, hydroxyl groups, and their derivatives. is preferred, and one selected from carboxyl groups, acid anhydride groups, and derivatives thereof is more preferred. One molecule or two or more of these functional groups may be present in one molecule. Furthermore, one molecule may have a plurality of different functional groups.

In the present invention, the halogenated compound having a functional group is not particularly limited as long as it has one or more halogens in one molecule, and includes monohalogenated compounds, dihalogenated compounds, trihalogenated compounds, and tetrahalogenated compounds. Examples include compounds. From the viewpoint of obtaining excellent reactivity and a melt viscosity suitable for processing, monohalogenated compounds and dihalogenated compounds are preferred, and monohalogenated aromatic compounds and dihalogenated aromatic compounds are more preferred.

Examples of halogenated compounds having functional groups include 4-chloro-cyclohexane-1-carboxylic acid, 2-chloroaniline, 3-chloroaniline, 4-chloroaniline, 5-chlorobenzene-1,3-diamine, 2- Chlorobenzoic acid, 3-chlorobenzoic acid, 4-chlorobenzoic acid, sodium 4-chlorobenzoate, 5-chlorobenzene-1,2,3-tricarboxylic acid, 3-chlorophthalic anhydride, 4-chlorophthalic anhydride, 5-chloroisophthalic acid, 4-chlorophthalic acid, sodium 2-carboxy-4-chlorobenzoate, disodium 3-chlorophthalate, disodium 4-chlorophthalate, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol , 3-chloroammonium chloride, 4-chlorobenzamide, 4-chlorobenzeneacetamide, 4-chlorobenzenesulfonamide, 4-chlorobenzenesulfonic acid, 4-chlorobenzenethiol, 4'-chlorobenzophenone-2-carboxylic acid, 2-amino-5 -Chlorobenzophenone, 4'-chloro-[1,1'-biphenyl]-4-carboxylic acid, 4-((chlorophenyl)thio)aniline, 6-chloro-2-naphthoic acid, 6-chloronaphthalen-2-amine , 6-chloro-2-naphthol, 6-chloronaphtho[2,3-c]furan-1,3-dione, 4-bromobenzoic acid, 4-iodobenzoic acid, 4-chloronitrobenzene, etc. group compounds, 3,5-dichloroaniline, 2,5-dichlorophenol, 2,5-dichlorobenzoic acid, 4,7-dichloroisobenzofuran-1,3-dione, disodium 3,6-dichlorophthalate, etc. Examples include dihalogenated aromatic compounds.

Among them, from the viewpoint of handling and reactivity, 3,5-dichloroaniline, 4-chlorobenzoic acid, sodium 4-chlorobenzoate, 4-chlorophthalic anhydride, 4-chlorophthalic acid, disodium 4-chlorophthalate, Sodium 2-carboxy-4-chlorobenzoate, 4-chlorophenol are preferred, and 4-chlorobenzoic acid, sodium 4-chlorobenzoate, 4-chlorophthalic anhydride, 4-chlorophthalic acid, disodium 4-chlorophthalate, More preferred is sodium 2-carboxy-4-chlorobenzoate.

In addition, in the present invention, if a halogenated compound has a functional group and also falls under the category of a dihalogenated aromatic compound, it is treated as a halogenated compound having a functional group and is not treated as a dihalogenated aromatic compound. do.

In the present invention, the lower limit of the amount of the halogenated compound having a functional group is preferably 0.05 mol or more, more preferably 0.1 mol or more, per 100 mol of the sulfidating agent. Preferably, it is more preferable to react at 2 mol or more. When the blending amount is equal to or greater than this value, the content of functional groups introduced into the PAS resin increases, which is preferable from the viewpoint of improving adhesiveness. The upper limit of the amount of the halogenated compound having a functional group is preferably 20 mol or less, more preferably 15 mol or less, and 10 mol or less per 100 mol of the sulfidating agent. More preferably. It is preferable that the upper limit of the blending amount of the halogenated compound having a functional group is within the above-mentioned preferred range from the viewpoint of reducing the amount of unreacted halogenated compound having a functional group and reducing the burden of wastewater treatment. The halogenated compound having a functional group may be used alone or as a mixture of two or more different types.

Further, the total amount of the halogenated compound is preferably 98 mol or more and less than 108 mol per 100 mol of the sulfidating agent. The halogenated compound includes not only the above-mentioned dihalogenated aromatic compounds and halogenated compounds having a functional group, but also halogenated compounds used in the branching/crosslinking agent described below.

In the present invention, the halogenated compound having a functional group preferably does not substantially contain water. Substantially not containing water means that the water content of the halogenated compound having a functional group is 5 wt% or less, more preferably 1 wt% or less, still more preferably 0.1 wt%. If the water content of the halogenated compound having a functional group exceeds 5 wt%, it is not preferable because the reactivity with PAS after being supplied into the polymerization system decreases significantly. Although the reason for this is not clear, it is presumed that the interaction between the halogenated compound having a functional group and water is strong and inhibits the reaction with PAS.

[Branching/crosslinking agent]
In the present invention, in order to form a branched or crosslinked polymer, a trihalogenated or higher polyhalogen compound can be used among the polyhalogen compounds (not necessarily aromatic compounds). Among them, polyhalogenated aromatic compounds are preferred, and specific examples include 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, hexachlorobenzene, 1,4 , 6-trichloronaphthalene, among others, 1,3,5-trichlorobenzene and 1,2,4-trichlorobenzene are preferred.

In addition, in the present invention, if a halogenated compound has a functional group and also falls under the category of a trihalogenated compound, it is treated as a halogenated compound having a functional group and is not treated as a trihalogenated aromatic compound. do.

[Polymerization aid]
One of the preferred embodiments is to use a polymerization aid in order to obtain a PAS resin with a relatively high degree of polymerization in a shorter time. Here, the term "polymerization aid" refers to a substance that has the effect of increasing the viscosity of the resulting PAS resin. Specific examples of such polymerization aids include organic carboxylates, water, alkali metal chlorides, organic sulfonates, alkali metal sulfates, alkaline earth metal oxides, alkali metal phosphates, and alkaline earth metal oxides. Examples include similar metal phosphates.

These may be used alone or in combination of two or more. Among these, organic carboxylates, alkali metal chlorides, and water are preferred, and the organic carboxylates are preferably alkali metal carboxylates, and the alkali metal chlorides are lithium chloride.

The alkali metal carboxylate has the general formula R(COOM) _n (wherein R is an alkyl group, cycloalkyl group, aryl group, alkylaryl group, or arylalkyl group having 1 to 20 carbon atoms. M is an alkali metal selected from lithium, sodium, potassium, rubidium and cesium; n is an integer from 1 to 3). Alkali metal carboxylates can also be used as hydrates, anhydrides or aqueous solutions. Specific examples of alkali metal carboxylates include lithium acetate, sodium acetate, potassium acetate, sodium propionate, lithium valerate, sodium benzoate, sodium phenylacetate, potassium p-toluate, and mixtures thereof. can be mentioned.

An alkali metal carboxylate is produced by adding approximately equal chemical equivalents of an organic acid and one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, and alkali metal bicarbonates and reacting them. It may be formed by. Among the alkali metal carboxylates mentioned above, lithium salts have high solubility in the reaction system and have a large auxiliary effect, but are expensive. On the other hand, since potassium, rubidium, and cesium salts are thought to have insufficient solubility in the reaction system, sodium acetate, which is inexpensive and has appropriate solubility in the polymerization system, is most preferably used.

In the present invention, the amount of the polymerization aid added is preferably in the range of 1 mol to 1500 mol per 100 mol of the charged sulfidating agent.

In the present invention, it is preferable to use an alkali metal carboxylate as a polymerization aid, and it is more preferable to use sodium acetate. In this case, from the viewpoint of obtaining a higher degree of polymerization, the amount of the alkali metal carboxylate used is preferably in the range of 1 mol to 200 mol, more preferably in the range of 10 mol to 100 mol, per 100 mol of the charged sulfidating agent. Preferably, the range is from 20 mol to 50 mol, more preferably.

In addition, when water is used as a polymerization aid, the amount added is preferably in the range of 30 mol to 1,500 mol per 100 mol of the charged sulfidating agent, and in the sense of obtaining a higher degree of polymerization, the range is 60 mol to 1,000 mol. More preferably, the amount is in the range of 100 mol to 500 mol.

It is of course possible to use two or more of these polymerization aids in combination. For example, when an alkali metal carboxylate and water are used together, it is possible to increase the molecular weight with a smaller amount of the alkali metal carboxylate and water.

The timing of addition of these polymerization aids is not particularly specified, and they may be added at any time during the pre-process described below, at the start of polymerization, or during polymerization, or may be added in multiple portions. When using an alkali metal carboxylate as a polymerization aid, it is more preferable to add it simultaneously with other additives at the start of the previous step or at the start of polymerization, from the viewpoint of ease of addition. When water is used as a polymerization aid, it is effective to add it during the polymerization reaction after charging the polyhalogenated aromatic compound.

[Polymerization stabilizer]
A polymerization stabilizer can also be used to stabilize the polymerization reaction system and prevent side reactions. The polymerization stabilizer contributes to stabilizing the polymerization reaction system and suppresses undesirable side reactions. One indicator of side reactions is the production of thiophenol. The production of thiophenol can be suppressed by adding a polymerization stabilizer. Specific examples of polymerization stabilizers include compounds such as alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal carbonates. Among these, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferred. The above-mentioned alkali metal carboxylates also act as polymerization stabilizers, and are therefore included as polymerization stabilizers. Furthermore, when using an alkali metal hydrosulfide as a sulfidating agent, it is particularly preferable to use an alkali metal hydroxide at the same time. Oxides can also serve as polymerization stabilizers.

These polymerization stabilizers can be used alone or in combination of two or more. The polymerization stabilizer is usually 0.02 mol to 0.2 mol, preferably 0.03 mol to 0.1 mol, more preferably 0.04 mol to 0.09 mol, per mol of the charged alkali metal sulfide. Preferably, they are used in molar proportions. If this proportion is too small, the stabilizing effect will be insufficient, and if it is too large, it will be economically disadvantageous, and the polymer yield will tend to decrease.

There is no particular specification as to when to add the polymerization stabilizer; it may be added at any time during the pre-process, at the start of polymerization, or during polymerization, which will be described later.Also, it may be added in multiple parts, but It is more preferable to add it simultaneously at the start of the process or at the start of polymerization because it is easy.

Next, a preferred method for producing the PAS resin of the present invention will be specifically explained in order, including a pre-process, a polymerization reaction process, a recovery process, and a post-treatment process, but the method is of course not limited to this. .

[pre-process]
In the production method of PAS resin, the sulfidating agent is usually used in the form of a hydrate, but before adding the polyhalogenated aromatic compound, the mixture containing the organic polar solvent and the sulfidating agent is heated. It is preferable to remove excess water from the system.

Furthermore, as mentioned above, a sulfidating agent prepared from an alkali metal hydrosulfide and an alkali metal hydroxide in situ in the reaction system or in a tank different from the polymerization tank may also be used. I can do it. Although there are no particular limitations on this method, it is preferable to add an alkali metal hydrosulfide and an alkali metal hydroxide to an organic polar solvent under an inert gas atmosphere at a temperature ranging from room temperature to 150°C, preferably from room temperature to 100°C. In addition, there is a method in which the temperature is raised to at least 150°C or higher, preferably 180°C to 260°C, under normal pressure or reduced pressure, and water is distilled off. A polymerization aid may be added at this stage. Further, in order to promote distillation of water, toluene or the like may be added to carry out the reaction.

In the polymerization reaction, the amount of water in the polymerization system is preferably 0.3 mol to 10.0 mol per mol of the charged sulfidating agent. Here, the amount of water within the polymerization system is the amount obtained by subtracting the amount of water removed from the polymerization system from the amount of water charged into the polymerization system. Further, the water to be charged may be in any form such as water, an aqueous solution, or crystal water.

[Polymerization reaction process]
A PAS resin is produced by reacting a sulfidating agent and a dihalogenated aromatic compound in an organic polar solvent within a temperature range of 200°C or higher and lower than 290°C.

When starting the polymerization reaction step, the organic polar solvent, sulfidating agent, and dihalogenated aromatic compound are mixed at a temperature range of room temperature to 240°C, preferably 100°C to 230°C, preferably under an inert gas atmosphere. do. A polymerization aid may be added at this stage. These raw materials may be added in any order or at the same time.

The mixture is heated to a temperature typically in the range of 200°C to less than 290°C. Although there is no particular restriction on the heating rate, a rate of 0.01°C/min to 5°C/min is usually selected, and a range of 0.1°C/min to 3°C/min is more preferable.

Generally, the temperature is finally raised to a temperature of 250° C. to less than 290° C., and the reaction is carried out at that temperature for usually 0.25 hours to 50 hours, preferably 0.5 hours to 20 hours.

A method of reacting at 200° C. to 260° C. for a certain period of time before reaching the final temperature and then raising the temperature to below 270° C. to 290° C. is effective in obtaining a higher degree of polymerization. At this time, the reaction time at 200° C. to 260° C. is usually selected in the range of 0.25 hours to 20 hours, preferably in the range of 0.25 hours to 10 hours.

Note that in order to obtain a polymer with a higher degree of polymerization, it may be effective to perform the polymerization in multiple stages. When polymerization is carried out in multiple stages, it is effective to carry out the polymerization at a time when the conversion rate of the polyhalogenated aromatic compound in the system at 245° C. reaches 40 mol% or more, preferably 60 mol%.

Note that the polyhalogenated aromatic compound mentioned here includes a dihalogenated aromatic compound and a polyhalogenated aromatic compound as a branching/crosslinking agent, but does not include a halogenated aromatic compound having a functional group. Further, the conversion rate of the polyhalogenated aromatic compound (herein abbreviated as PHA) is a value calculated using the following formula. The residual amount of PHA can usually be determined by gas chromatography.
(A) When polyhalogenated aromatic compound is added in excess molar ratio to alkali metal sulfide Conversion rate = [PHA charged amount (mol) - PHA remaining amount (mol)] / [PHA charged amount (mol) - Excess amount of PHA (mol)]
(B) Cases other than the above (A) Conversion rate = [PHA charged amount (mol) - PHA remaining amount (mol)] / [PHA charged amount (mol)]

[Polymerization step of PAS resin (Step A) in which a polyarylene sulfide having a weight average molecular weight of 25,000 or more and a halogenated compound having a functional group are reacted within a temperature range of 200° C. or higher and lower than 290° C.]
In the present invention, it is essential to include a PAS resin polymerization step in which a polyarylene sulfide having a weight average molecular weight of 25,000 or more and a halogenated compound having a functional group are reacted within a temperature range of 200°C or more and less than 290°C. be.

Step A will be explained more specifically. Step A consists of (1) reacting the sulfidating agent and the dihalogenated aromatic compound, and after the weight average molecular weight reaches 25,000 or more, a solution of the halogenated compound having a functional group is pressurized into the polymerization system at high temperature and high pressure. (2) A sulfidating agent and a dihalogenated aromatic compound are reacted, and after the weight average molecular weight reaches 25,000 or more, the mixture is cooled to 150°C or less, and the halogenated compound having a functional group is added to the polymerization system. (3) A method of dry blending a polyarylene sulfide having a weight average molecular weight of 25,000 or more and a halogenated compound having a functional group, but is not limited thereto. Preferably, (1) the sulfidating agent and the dihalogenated aromatic compound are reacted, and after the weight average molecular weight reaches 25,000 or more, a solution of the halogenated compound having a functional group is injected into the polymerization system at high temperature and high pressure. Method of blending, (2) React the sulfidating agent and the dihalogenated aromatic compound, and after the weight average molecular weight reaches 25,000 or more, cool it to 150°C or less, and introduce the halogenated compound having a functional group into the polymerization system. More preferably, (1) the sulfidating agent and the dihalogenated aromatic compound are reacted, and after the weight average molecular weight reaches 25,000 or more, a halogen having a functional group is added into the polymerization system at high temperature and high pressure. A method of blending by press-injecting a chemical compound solution is mentioned. After introducing a halogenated compound having a functional group into the system by any of methods (1) to (3), polyarylene sulfide with a weight average molecular weight of 25,000 or more is produced within a temperature range of 200°C or more and less than 290°C. react with.

As a method of pressurizing the solution of a halogenated compound having a functional group into the polymerization system, a method of dissolving the halogenated compound having a functional group in an organic polar solvent and pressurizing the solution is preferable, and a method of dissolving the halogenated compound having a functional group in an organic polar solvent and pressurizing the solution is preferable. A more preferable example is the method.

The weight average molecular weight of PAS here is a value measured using gel permeation chromatography (GPC) using 1-chloronaphthalene as an eluent at a column temperature of 210° C. and converted to a polystyrene standard.

In the present invention, the halogenated compound having a functional group to be reacted with polyarylene sulfide having a weight average molecular weight of 25,000 or more preferably does not substantially contain water. Substantially not containing water means that the water content of the halogenated compound having a functional group is 5 wt% or less, more preferably 1 wt% or less, and even more preferably 0.1 wt%. . If the water content of the halogenated compound having a functional group exceeds 5 wt%, that is, if it is used in the reaction as an aqueous solution, it is not preferable because the reactivity with PAS after being supplied into the polymerization system decreases significantly. Although the reason for this is not clear, it is presumed that the interaction between the halogenated compound having a functional group and water is strong and inhibits the reaction with PAS.

In the present invention, from the viewpoint of improving the reaction rate of the halogenated compound having a functional group, in step A, the lower limit of the reaction time within the temperature range of 200°C or more and less than 290°C is preferably 15 minutes or more, and 20 minutes. More preferably, the time is more than 25 minutes, and even more preferably 25 minutes or more. It is preferable that the lower limit of the reaction time within the temperature range of 200° C. or more and less than 290° C. be 15 minutes or more because the reaction between PAS and the halogenated compound having a functional group will proceed sufficiently. The upper limit of the reaction time within the temperature range of 200° C. or more and less than 290° C. is preferably 3 hours or less, more preferably 2 hours or less, and even more preferably 90 minutes or less. From the viewpoint of productivity, it is preferable that the upper limit of the reaction time within the temperature range of 200° C. or more and less than 290° C. is 3 hours or less.

[Collection process]
In the method for producing PAS resin, after the polymerization step is completed, solid matter is recovered from the polymerization reaction product containing the polymer, solvent, and the like. As for the recovery method, any known method may be employed.

For example, a method may be used in which after the polymerization reaction is completed, the particulate polymer is recovered by slow cooling. There is no particular limit to the slow cooling rate at this time, but it is usually about 0.1°C/min to 3°C/min. It is not necessary to perform slow cooling at the same speed in all steps of the slow cooling process; slow cooling is performed at a rate of 0.1°C/min to 1°C/min until the polymer particles crystallize and precipitate, and then at a speed of 1°C/min or more. method etc. may be adopted.

Also, one of the preferable methods is to perform the above-mentioned recovery under quenching conditions. Among these recovery methods, a preferred method is the flash method. In the flash method, the polymerization reaction product is flashed from a high temperature and high pressure state (usually 250°C or higher, 8kg/cm2 ^or higher) into an atmosphere of normal pressure or reduced pressure, and the polymer is recovered in powder form at the same time as the solvent is recovered. It's a method. The term "flash" as used herein means that the polymerization reaction product is ejected from a nozzle. Specific examples of the flashing atmosphere include nitrogen or water vapor at normal pressure, and the temperature is usually selected from a range of 150°C to 250°C.

[Post-processing process]
The PAS resin may be produced through the above polymerization and recovery steps and then subjected to acid treatment, hot water treatment, washing with an organic solvent, and alkali metal or alkaline earth metal treatment.

The case where acid treatment is performed is as follows. The acid used for the acid treatment of the PAS resin is not particularly limited as long as it does not have the effect of decomposing the PAS resin, and examples include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propylic acid. Among them, acetic acid and hydrochloric acid are more preferably used. On the other hand, substances that decompose and deteriorate the PAS resin, such as nitric acid, are not preferred.

A method for acid treatment includes, for example, a method in which the PAS resin is immersed in an acid or an aqueous solution of an acid, and it is also possible to stir or heat the resin, if necessary. For example, when acetic acid is used, a sufficient effect can be obtained by immersing the PAS resin powder in an acetic acid aqueous solution of pH 4 heated to 80° C. to 200° C. and stirring for 30 minutes. The pH after treatment may be 4 or more, for example, about pH 4 to 8. In the present invention, the pH after treatment is preferably 6 or less, more preferably 5 or less, and even more preferably 4 or less. It is preferable that the pH after the treatment is 6 or less because the effect of the acid treatment is sufficiently obtained and the reactivity with different materials is improved. In order to remove residual acids or salts from the acid-treated PAS resin, it is preferable to wash it several times with water or hot water. The water used for washing is preferably distilled water or deionized water in order not to impair the effect of the preferable chemical modification of the PAS resin by acid treatment.

When performing hot water treatment, the procedure is as follows. When treating the PAS resin with hot water, the temperature of the hot water is preferably 100°C or higher, more preferably 120°C or higher, even more preferably 150°C or higher, particularly preferably 170°C or higher. If the temperature is less than 100°C, the effect of preferred chemical modification of the PAS resin will be small, which is not preferable.

The water used is preferably distilled water or deionized water in order to achieve the desired effect of chemical modification of the PAS resin by hot water washing. There are no particular restrictions on the operation of hot water treatment. This is carried out by adding a predetermined amount of PAS resin to a predetermined amount of water, heating and stirring it in a pressure vessel, or continuously subjecting it to hot water treatment. Although it is preferable for the ratio of PAS resin to water to be as large as possible, a bath ratio of 200 g or less of PAS resin per 1 liter of water (the weight of the cleaning liquid relative to the weight of dry PAS) is usually selected.

Further, since decomposition of the terminal groups is undesirable, in order to avoid this, it is desirable that the treatment atmosphere be an inert atmosphere. Further, in order to remove residual components, the PAS resin after this hot water treatment operation is preferably washed several times with warm water.

When washing with an organic solvent, the procedure is as follows. The organic solvent used for washing the PAS resin is not particularly limited as long as it does not have the effect of decomposing the PAS resin. For example, nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, 1,3-dimethylimidazolidinone, hexamethylphosphorusamide, and piperazinone; sulfoxides such as dimethylsulfoxide, dimethylsulfone, and sulfolane; Sulfonic solvents, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, ether solvents such as dimethyl ether, dipropyl ether, dioxane, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene dichloride, perchloroethylene, monochloroethane , halogenated solvents such as dichloroethane, tetrachloroethane, perchloroethane, and chlorobenzene, alcohols and phenols such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, and polypropylene glycol. Examples of organic solvents used for cleaning the PAS resin include organic solvents and aromatic hydrocarbon solvents such as benzene, toluene, and xylene. Among these organic solvents, use of N-methyl-2-pyrrolidone, acetone, dimethylformamide, chloroform, and the like is particularly preferred. Further, these organic solvents may be used alone or in combination of two or more.

As a method for cleaning with an organic solvent, for example, there is a method of immersing the PAS resin in an organic solvent, and it is also possible to stir or heat the resin as needed. There are no particular restrictions on the cleaning temperature when cleaning the PAS resin with an organic solvent, and any temperature from room temperature to about 300°C can be selected. Although the higher the cleaning temperature, the higher the cleaning efficiency tends to be, usually a cleaning temperature of room temperature to 150° C. can be sufficiently effective. It is also possible to wash under pressure in a pressure vessel at a temperature above the boiling point of the organic solvent. Furthermore, there is no particular restriction on the cleaning time. Although it depends on the cleaning conditions, in the case of batch cleaning, sufficient effects can usually be obtained by cleaning for 5 minutes or more. It is also possible to wash continuously. In the post-treatment step, it is preferable to perform acid treatment, hot water treatment, or washing with an organic solvent, and it is preferable to use two or more types of treatments in combination from the viewpoint of removing impurities. In the present invention, it is preferable to carry out acid treatment from the viewpoint of improving reactivity with different materials. In addition, the reaction mixture contains not only PAS but also water-soluble substances such as by-product salts and unreacted sulfidating agents, so from a safety perspective, it is necessary to further perform hot water treatment before acid treatment. is preferred.

Methods for treating alkali metals and alkaline earth metals include adding an alkali metal salt or alkaline earth metal salt before, during, or after the preceding step, before the polymerization step, during the polymerization step, or during the polymerization step. Examples include a method in which an alkali metal salt or an alkaline earth metal salt is added later into the polymerization reactor, or a method in which an alkali metal salt or an alkaline earth metal salt is added at the beginning, middle, or end of the washing step. Among them, the easiest method is to remove residual oligomers and salts by washing with an organic solvent or hot water or hot water, and then add an alkali metal salt or alkaline earth metal salt. The alkali metals and alkaline earth metals are preferably introduced into the PAS in the form of alkali metal ions and alkaline earth metal ions such as acetates, hydroxides, and carbonates. Further, it is preferable to remove excess alkali metal salts and alkaline earth metal salts by washing with hot water or the like. The concentration of alkali metal ions and alkaline earth metal ions upon introduction of the alkali metal and alkaline earth metal is preferably 0.001 mmol or more, more preferably 0.01 mmol or more, per 1 g of PAS. The temperature is preferably 50°C or higher, more preferably 75°C or higher, and particularly preferably 90°C or higher. Although there is no particular upper limit temperature, from the viewpoint of operability, 280° C. or lower is usually preferable. The bath ratio (the weight of cleaning liquid to the weight of dry PAS) is preferably 0.5 or more, more preferably 3 or more, and even more preferably 5 or more.

[Heat treatment process]
The method for producing PAS resin of the present invention includes a heat treatment step. Heat treatment refers to heating the PPS resin in a predetermined amount of oxygen atmosphere or by adding a peroxide such as H ₂ O ₂ or a vulcanizing agent such as S. Heating under an oxygen atmosphere is particularly preferred because of the simplicity. By performing a heat treatment step, it is possible to increase the molecular weight through oxidative crosslinking and remove volatile matter.

When performing a heat treatment step for the purpose of increasing the molecular weight by thermal oxidative crosslinking, the temperature is not particularly limited as long as it is below the melting point of the PAS resin, but it is preferably 160°C to 270°C, and in the range of 170°C to 250°C. is more preferable. Further, the oxygen concentration is preferably 2% by volume or more. Further, it is desirable that the content be 5% by volume or more, more preferably 8% by volume or more. There is no particular limit to the upper limit of the oxygen concentration, but an example is about 50% by volume. The treatment time is preferably 0.5 to 50 hours. The lower limit of the treatment time is preferably 0.5 hours or more, more preferably 1 hour or more, and still more preferably 2 hours or more. The upper limit of the treatment time is preferably 50 hours or less, more preferably 25 hours or less. The heat treatment device may be a conventional hot air dryer or a rotating type or heating device equipped with stirring blades. For efficient and more uniform treatment, it is preferable to use a rotating heating device or a heating device equipped with stirring blades.

When performing a heat treatment step for the purpose of suppressing thermal oxidative crosslinking and removing volatile matter, the temperature is not particularly limited as long as it is below the melting point of the PAS resin, but it is preferably 160°C to 270°C, and 170°C to 250°C. A range of 0.degree. C. is more preferred. Further, the oxygen concentration in this case is desirably 5% by volume or less, more preferably 2% by volume or less. The treatment time is preferably 0.5 to 50 hours, more preferably 1 to 20 hours, and even more preferably 1 to 10 hours. The heat treatment device may be a conventional hot air dryer or a rotating or stirring blade-equipped heating device. For efficient and more uniform treatment, it is more preferable to use a rotating heating device or a heating device equipped with stirring blades.

[Characteristics of PAS resin]
In the production method of the present invention, by performing step A and the heat treatment step, it is possible to efficiently obtain a PAS resin with a small amount of gas generation, a large content of functional groups, and a high molecular weight.

The gas generation amount of the PAS resin obtained in the present invention is preferably 0.50% by weight or less, more preferably 0.45% by weight or less, and even more preferably 0.40% by weight or less. When the amount of gas generated is 0.50% by weight or less, there will be less gas components adhering to the mold and the mold vent, and transfer defects and gas burns will be less likely to occur. On the other hand, the lower limit of the amount of gas generated is preferably as small as possible from the viewpoint of reducing mold fouling, so the most preferable is 0% by weight, where the amount of gas generated is not included in the PAS resin at all. The amount of gas generated above refers to the amount of adhesive components that are liquefied or solidified by the gas that evaporates when the PAS resin is heated and melted under vacuum. It is measured by heating an ampoule in a tube furnace. The shape of the glass ampoule is as follows: the abdomen is 100 mm x 25 mm, the neck is 255 mm x 12 mm, and the wall thickness is 1 mm. The specific measurement method is to insert only the body of a glass ampoule vacuum-sealed with PAS resin into a tube furnace at 320°C and heat it for 2 hours. The gas cools and deposits. After cutting out the neck and weighing it, the attached gas is removed by dissolving it in chloroform. The neck is then dried and weighed again. The amount of gas generated is determined from the difference in weight between the neck of the ampoule before and after removing the gas. Components that contribute to the amount of gas generated include unreacted raw materials and cyclic or linear oligomers.

The functional group content of the PAS resin obtained in the present invention is preferably 80 μmol/g or more, more preferably 90 μmol/g or more, and even more preferably 100 μmol/g or more. When the functional group content of the obtained PAS resin is 80 μmol/g or more, it has excellent reactivity with different materials. There is no particular upper limit to the functional group content of the resulting PAS resin, but it is generally 500 μmol/g or less.

In addition, the functional group content of the PAS resin here was measured as follows depending on the type of functional group.

The content of carboxyl groups introduced into PAS resin was determined by measuring the amorphous film of PAS resin using FT-IR (IR-810 model infrared spectrophotometer manufactured by JASCO Corporation). It can be estimated by comparing the absorption near 1,730 cm ^-1 derived from the carboxyl group with the ^absorption near -1.

The acid anhydride content introduced into the PAS resin was determined by measuring the amorphous film of the PAS resin using an FT-IR (IR-810 model infrared spectrophotometer manufactured by JASCO Corporation). It can be estimated by comparing the absorption near 1,850 cm ^-1 derived from the acid anhydride group with the absorption near 900 cm ^-1 .

The content of amino groups introduced into the PAS resin was determined by measuring the amorphous film of the PAS resin using FT-IR (IR-810 infrared spectrophotometer manufactured by JASCO Corporation). It can be estimated by comparing the absorption near 3380 cm ⁻¹ derived from the amino group with the ^absorption near −1.

The content of hydroxyl groups introduced into the PAS resin was determined by measuring the amorphous film of the PAS resin using an FT-IR (IR-810 infrared spectrophotometer manufactured by JASCO Corporation). It can be estimated by comparing the absorption near ³⁴³⁰ cm ^-1 derived from the hydroxyl group with the absorption near -1.

The PAS resin obtained in the present invention preferably has a weight average molecular weight of 30,000 or more, more preferably 35,000 or more, and even more preferably 40,000 or more. When the weight average molecular weight of the PAS resin is 30,000 or more, it has excellent strength and toughness when molded. There is no particular upper limit to the weight average molecular weight of the PAS resin, but if it exceeds 100,000, the fluidity decreases, which is disadvantageous in terms of molding processing, so it is not preferable.

The weight average molecular weight referred to herein is a value measured using gel permeation chromatography (GPC) using 1-chloronaphthalene as an eluent at a column temperature of 210° C. and converted to a polystyrene standard.

The PAS resin obtained by the manufacturing method of the present invention has a melt flow rate (according to ASTM D-1238-70, measured at a temperature of 315.5°C and a load of 5000 g) of 500 g/10 from the viewpoint of excellent strength of molded products. It is preferably at most 480 g/10 minutes, more preferably at most 460 g/10 minutes, even more preferably at most 460 g/10 minutes. Although there is no particular restriction on the lower limit of the melt flow rate, it is preferably 10 g/10 minutes or more from the viewpoint of melt fluidity.

[Characteristics of PAS resin composition]
A PAS resin composition obtained by melt-kneading the PAS resin obtained in the present invention has excellent tensile strength and epoxy adhesive strength.

In the present invention, tensile strength refers to an ISO527-2-5A type test piece obtained by injection molding using an AG-20kNx universal testing machine at a tensile speed of 5 mm/min, an ambient temperature of 23°C, and a relative humidity of 50%. This is a value obtained in accordance with ISO527-1, -2 (2012) under the following conditions. The lower limit of the tensile strength is preferably 50 MPa or more, more preferably 60 MPa or more, and even more preferably 70 MPa or more. It is preferable that the tensile strength is 50 MPa or more because it has excellent mechanical strength and toughness. Although there is no upper limit to the tensile strength in the present invention, it is usually 200 MPa or less.

Further, a specific method for measuring epoxy adhesive strength is as follows. The test piece obtained by injection molding was cut, a spacer was sandwiched between the two cut test pieces, and after fixing with a clip, epoxy resin was injected into the opening, heated in a hot air dryer, and cured. Glued it. After cooling, the spacer was removed, and the resulting test piece was used to measure the tensile strength at break using a tensile tester, and the value divided by the adhesive area was defined as the epoxy adhesive strength. In the present invention, the epoxy adhesive strength is preferably 0.80 MPa or more, more preferably 0.90 MPa or more, and even more preferably 1.00 MPa or more. It is preferable that the epoxy adhesive strength is 0.80 MPa or more because the adhesiveness between the epoxy resin and the PAS resin is excellent.

The PAS resin obtained in the present invention can also be preferably used as a PAS resin composition obtained by melt-kneading with a fibrous inorganic filler. Specifically, such fibrous inorganic fillers include glass fibers, carbon fibers, potassium titanate whiskers, zinc oxide whiskers, calcium carbonate whiskers, wollastenite whiskers, aluminum borate whiskers, aramid fibers, alumina fibers, silicon carbide fibers, and ceramics. Fibers, asbestos fibers, gypsum fibers, metal fibers, etc. are used, and it is also possible to use two or more of these in combination. In addition, pre-treatment of these fibrous fillers with coupling agents such as isocyanate compounds, organic silane compounds, organic titanate compounds, organic borane compounds, and epoxy compounds provides superior mechanical strength. This is preferable in terms of obtaining the following. Among them, glass fiber and carbon fiber are more preferably used.

The PAS resin obtained in the present invention can also be preferably used as a PAS resin composition obtained by melt-kneading with talc. Such talc is mainly composed of hydrated magnesium silicate (structural formula: 3MgO.4SiO ₂ .H ₂ O, SiO ₂ 58-63%, MgO 28-33%), and has a water content of 0.3% or less. Preferably.

The PAS resin obtained in the present invention can also be preferably used as a PAS resin composition obtained by melt-kneading with a non-fibrous inorganic filler other than talc. Such non-fibrous inorganic fillers other than talc include wollastenite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, silicates such as alumina silicate, silicon oxide, magnesium oxide, alumina oxide, Metal compounds such as zirconium, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, and hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide. , glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, graphite, etc., may be hollow, and two or more of these fillers may be used in combination. It is also possible. Further, these non-fibrous fillers may be used after being pretreated with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, or an epoxy compound. Among these, particularly preferred are carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, silicates such as kaolin, clay, and talc, alumina, and graphite.

The PAS resin obtained in the present invention can also be preferably used as a PAS resin composition obtained by melt-kneading with an epoxy resin. Examples of such epoxy resins include bisphenol epoxy resins such as bisphenol A epoxy resin, bisphenol AD epoxy resin, and bisphenol AF epoxy resin, or novolac phenol epoxy resins, with bisphenol epoxy resins being particularly preferred. When a bisphenol A type epoxy resin is used, it is desirable because the adhesive strength with the epoxy adhesive is particularly greatly improved.

As a method for mixing the PAS resin obtained in the present invention with these components, production in a molten state, production in a solution state, etc. can be used, but from the viewpoint of simplicity, production in a molten state is preferably used. For production in a molten state, melt-kneading using an extruder, melt-kneading using a kneader, etc. can be used, but from the viewpoint of productivity, melt-kneading using an extruder that allows continuous production is preferably used. For melt-kneading using an extruder, one or more extruders such as a single-screw extruder, a twin-screw extruder, a multi-screw extruder such as a four-screw extruder, a twin-screw single-screw compound extruder, etc. can be used; From the viewpoint of improving properties, reactivity, and productivity, multi-screw extruders such as a twin-screw extruder and a four-screw extruder can be preferably used, and melt-kneading using a twin-screw extruder is most preferred.

[Applications of PAS resin]
The PAS resin obtained by the present invention is suitably used in applications requiring adhesiveness with resins other than PAS resins such as epoxy resins and silicone resins, fillers, metals, etc. It is preferably used in applications requiring adhesiveness with resins other than PAS resins, such as PAS resins, and more preferably used in applications requiring adhesiveness with epoxy resins.

In addition, the PAS resin obtained by the present invention has excellent heat resistance, chemical resistance, flame retardance, electrical properties, and mechanical properties, and can be used not only for injection molding, injection compression molding, and blow molding, but also for extrusion molding. It can be formed into extruded products such as sheets, films, fibers and pipes.

Applications of the PAS resin of the present invention include, for example, sensors, LED lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, resonators, various terminal boards, transformers, plugs, Electrical and electronic components such as printed circuit boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, computer-related parts, etc. ;VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, audio parts, audio equipment parts such as audio/laser discs (registered trademark)/compact discs, lighting parts, refrigerator parts, air conditioner parts, type Household and office appliance parts, such as lighter parts and word processor parts; office computer-related parts, telephone-related parts, facsimile-related parts, copying machine-related parts, cleaning jigs, motor parts, lighters, typewriters, etc. Typical machine-related parts: Optical instruments such as microscopes, binoculars, cameras, and watches, precision machine-related parts; water faucet tops, mixer faucets, pump parts, pipe joints, water volume control valves, relief valves, hot water temperature Water-related parts such as sensors, water flow sensors, and water meter housing; Valve alternator terminals, alternator connectors, IC regulators, potentiometer bases for light dimmers, various valves such as exhaust gas valves, various fuel-related, exhaust system, and intake system pipes, Air intake nozzle snorkel, intake manifold, fuel pump, engine cooling water joint, carburetor main body, carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake pads Wear sensors, thermostat bases for air conditioners, heating hot air flow control valves, brush holders for radiator motors, water pump impellers, turbine vanes, wiper motor related parts, distributors, starter switches, starter relays, transmission wire harnesses, window washer nozzles , air conditioner panel switch boards, fuel-related electromagnetic valve coils, fuse connectors, horn terminals, electrical component insulation boards, step motor rotors, lamp sockets, lamp reflectors, lamp housings, brake pistons, solenoid bobbins, engine oil filters, ignition devices Examples include automobile/vehicle related parts such as cases, vehicle speed sensors, cable liners, engine control unit cases, engine driver unit cases, capacitor cases, motor insulation materials, hybrid car control system parts cases, and various other uses. Among these, it is particularly suitable for case materials for power modules containing electrical and electronic components.

As a method for producing a PAS film using the PAS resin obtained according to the present invention, a known melt film forming method can be adopted. For example, after melting the PAS resin in a single-screw or twin-screw extruder, A method in which a film is created by extruding it through a film die and cooling on a cooling drum, or a biaxial stretching method in which the film thus created is stretched vertically and horizontally using a roller-type longitudinal stretching device and a horizontal stretching device called a tenter. Although it can be manufactured by a method such as the following, it is not particularly limited thereto.

The PAS film obtained in this way has excellent mechanical properties, electrical properties, and heat resistance, and is suitable for use in various applications such as dielectric film for film capacitors and chip capacitors, and release film. can do.

As a method for producing PAS fibers using the PAS resin obtained according to the present invention, a known melt spinning method can be applied. For example, PAS resin chips as a raw material are fed to a single-screw or twin-screw extruder. It is possible to adopt a method in which the polymer is kneaded, then extruded from a spinneret through a polymer streamline exchanger installed at the tip of the extruder, a filtration layer, etc., and then cooled, stretched, and heat set. It is not limited.

The PAS monofilaments or short fibers thus obtained can be suitably used in various applications such as paper dryer campuses, net conveyors, and bag filters.

Hereinafter, the method of the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples. The various measurement methods are as follows.

[Gas generation amount]
3 g of PPS resin was weighed into a glass ampoule with an abdominal area of 100 mm x 25 mm, a neck area of 255 mm x 12 mm, and a wall thickness of 1 mm, and then vacuum sealed. Only the body of this glass ampoule was inserted into a ceramic electric tubular furnace ARF-30K manufactured by Asahi Rika Seisakusho and heated at 320° C. for 2 hours. After the ampoule was taken out, the neck of the ampoule, which had not been heated by the tube furnace and had volatile gas adhering to it, was cut out with a file and weighed. Next, the attached gas was removed by dissolving it with 5 g of chloroform, and then dried in a glass dryer at 60° C. for 1 hour, and then weighed again. The difference in weight between the neck of the ampoule before and after removing the gas was defined as the amount of gas generated (% by weight).

[Weight average molecular weight of polymer]
The weight average molecular weight (Mw) of the polymer was calculated in terms of polystyrene by gel permeation chromatography (GPC). The GPC measurement conditions are shown below.
Equipment: SSC-7100 (Senshu Science)
Column name: GPC3506 (Senshu Science)
Eluent: 1-chloronaphthalene Detector: Differential refractive index detector Column temperature: 210°C
Pre constant temperature bath temperature: 250℃
Pump constant temperature bath temperature: 50℃
Detector temperature: 210℃
Flow rate: 1.0mL/min
Sample injection amount: 300 μL (slurry form: approximately 0.2% by weight).

[Functional group content]
The functional group content of the PAS resin was measured as follows depending on the type of functional group.

The content of carboxyl groups introduced into the PAS resin was determined by measuring the amorphous film of the PAS resin using FT-IR (IR-810 model infrared spectrophotometer manufactured by JASCO Corporation) ^. It was estimated by comparing the absorption near ^1,730 cm ⁻¹ derived from carboxyl groups with the absorption near 1.

[Melt flow rate (MFR)]
Measured according to ASTM D-1238-70 at a temperature of 315.5°C and a load of 5000g. Using a melt indexer manufactured by Toyo Seiki Co., Ltd. (length 8.00 mm, hole diameter 2.095 mm orifice, sample amount 7 g, preheating time after sample preparation until measurement start 5 minutes, load 5000 g) at 315.5 ° C. Measurements were taken to compare the melt flow rates of the polymers.

[injection molding]
PAS resin molded products were made using a small injection molding machine HAAKE MiniJet Pro manufactured by Thermo Fisher Scientific Co., Ltd. under conditions of a resin temperature of 320°C and a mold temperature of 130°C, using an ISO527-2-5A type test piece. Molded.

[Tensile strength]
The ISO527-2-5A type test piece obtained by injection molding was tested using an AG-20kNx universal testing machine under the conditions of a tensile speed of 5 mm/min, an ambient temperature of 23°C, and a relative humidity of 50%. 2 (2012), and the average value of 5 measurements was determined.

[Epoxy adhesive strength]
A spacer ( ^thickness : 1.8 ~2.2mm, opening: 4mm x 10mm) was sandwiched between two cut ISO527-2-5A type test pieces, fixed using clips, and then the opening was filled with epoxy resin (Nagase ChemteX Co., Ltd.) A liquid type epoxy resin, main resin: XNR5002, curing agent: XNH5002, blending ratio of main resin: curing agent = 100:90) was injected and heated in a hot air dryer set at 135° C. for 3 hours to cure and bond. After cooling for one day at 23°C, the spacer was removed, and the tensile breaking strength was measured using the AG-20kNx universal testing machine at 23°C at a strain rate of 1 mm/min and a distance between supports of 40 mm using the obtained test piece. , the value divided by the adhesive area was defined as the epoxy adhesive strength.

[Example 1]
In an autoclave equipped with a stirrer and a bottom plug valve, 8.26 kg (70.00 mol) of 47.5% sodium bisulfide, 3.19 kg (76.65 mol) of 96% sodium hydroxide, and N-methyl-2-pyrrolidone. (NMP) 14.57 kg (147.00 mol), sodium acetate 1.89 kg (23.1 mol), and ion-exchanged water 5.78 kg were gradually heated to 245°C over about 3 hours while passing nitrogen under normal pressure. When 9.70 kg of water and 0.28 kg of NMP were distilled out, heating was completed and cooling was started. Since the amount of hydrogen sulfide scattered at this point was 1.4 moles, the amount of the sulfidating agent in the system after this step was 68.6 moles.

After that, it was cooled to 200°C, and after adding 10.08 kg (69.29 mol) of p-dichlorobenzene (p-DCB) and 5.55 kg (56.00 mol) of NMP, the reaction vessel was sealed under nitrogen gas and stirred. The temperature was raised from 200°C to 240°C at a rate of 0.6°C/min, then from 240°C to 276°C at a rate of 0.8°C/min, and further reacted at 276°C for 75 minutes. . The bottom plug valve was opened slightly to sample a small amount of the contents, and it was confirmed that the weight average molecular weight (Mw) was 39,000.

Then, 0.65 kg (4.12 mol) of 4-chlorobenzoic acid and 2.07 kg (16.1 mol) of NMP were pressurized into the reaction vessel, and the mixture was further reacted at 276° C. for 60 minutes (polymerization step). Thereafter, the bottom valve of the autoclave was opened, and while pressurized with nitrogen, the contents were flushed into a container equipped with a stirrer over 15 minutes, and stirred for a while at 250°C to remove most of the NMP.

The obtained solid matter and 76 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter. Next, 76 liters of ion-exchanged water heated to 70°C was poured into a glass filter and filtered with suction to obtain a cake.

The resulting cake and 90 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, and acetic acid was added to adjust the pH to 4. After purging the inside of the autoclave with nitrogen, the temperature was raised to 192°C and held for 30 minutes. Thereafter, the autoclave was cooled and the contents were taken out.

After the contents were suction-filtered through a glass filter, 76 liters of ion-exchanged water at 70°C was poured thereinto and suction-filtered to obtain a cake. PAS-1 was obtained by drying the obtained cake at 120° C. under a nitrogen stream.

PAS-1 was placed in a heating device equipped with a stirrer, and heat treated at 200° C. for 2 hours at an oxygen concentration of 2% (heat treatment step). In the heat treatment at an oxygen concentration of 2%, 0.18 liters/min of air and 1.78 liters/min of nitrogen were introduced into the heating device, and an oxygen concentration meter was installed in the heating device to measure the oxygen concentration. The polymer physical properties of the obtained PAS resin were as shown in Table 1.

[Example 2]
Reference Example 1 except that the amount of 96% sodium hydroxide was changed to 3.11 kg (74.55 mol) and the amount of 4-chlorobenzoic acid was changed to 0.32 kg (2.06 mol). Polymerization and washing were performed in the same manner as above to obtain PAS-2.

PAS-2 was placed in a heating device equipped with a stirrer, and heat treated at 200° C. for 2 hours at an oxygen concentration of 2%. In the heat treatment at an oxygen concentration of 2%, 0.18 liters/min of air and 1.78 liters/min of nitrogen were introduced into the heating device, and an oxygen concentration meter was installed in the heating device to measure the oxygen concentration. The polymer physical properties of the obtained PAS resin were as shown in Table 1.

[Example 3]
After pressurizing 4-chlorobenzoic acid into the reaction vessel, polymerization and washing were carried out in the same manner as in Reference Example 1, except that the reaction time at 276°C was changed to 120 minutes to obtain PAS-3.

PAS-3 was placed in a heating device equipped with a stirrer and heat treated at 200° C. for 2 hours at an oxygen concentration of 2%. In the heat treatment at an oxygen concentration of 2%, 0.18 liters/min of air and 1.78 liters/min of nitrogen were introduced into the heating device, and an oxygen concentration meter was installed in the heating device to measure the oxygen concentration. The polymer physical properties of the obtained PAS resin were as shown in Table 1.

[Comparative example 1]
Polymerization and washing were performed in the same manner as in Example 1 except that the heat treatment step was not performed.

[Comparative example 2]
In an autoclave with a stirrer and a bottom plug valve, 8.26 kg (70.00 mol) of 47.5% sodium bisulfide, 2.63 kg (68.53 mol) of 96% sodium hydroxide, and N-methyl-2-pyrrolidone. (NMP) 14.57 kg (147.00 mol), sodium acetate 1.89 kg (23.1 mol), and ion-exchanged water 5.78 kg were gradually heated to 245°C over about 3 hours while passing nitrogen under normal pressure. When 9.70 kg of water and 0.28 kg of NMP were distilled out, heating was completed and cooling was started. Since the amount of hydrogen sulfide scattered at this point was 1.4 moles, the amount of the sulfidating agent in the system after this step was 68.6 moles.

After that, it was cooled to 200°C, and after adding 10.36 kg (70.45 mol) of p-dichlorobenzene (p-DCB) and 5.55 kg (56.00 mol) of NMP, the reaction vessel was sealed under nitrogen gas and stirred. The temperature was raised from 200°C to 240°C at a rate of 0.6°C/min, then from 240°C to 276°C at a rate of 0.8°C/min, and further reacted at 276°C for 75 minutes. Thereafter, the bottom valve of the autoclave was opened, and while pressurizing with nitrogen, the contents were flushed into a container equipped with a stirrer over 15 minutes, and stirred for a while at 250° C. to remove most of the NMP.

The obtained solid matter and 76 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter. Next, 76 liters of ion-exchanged water heated to 70°C was poured into a glass filter and filtered with suction to obtain a cake.

The resulting cake and 90 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, and acetic acid was added to adjust the pH to 4. After purging the inside of the autoclave with nitrogen, the temperature was raised to 192°C and held for 30 minutes. Thereafter, the autoclave was cooled and the contents were taken out.

After the contents were suction-filtered through a glass filter, 76 liters of ion-exchanged water at 70°C was poured thereinto and suction-filtered to obtain a cake. The resulting cake was dried at 120° C. under a nitrogen stream to obtain PAS-4.

[Comparative example 3]
PAS-4 was placed in a heating device equipped with a stirrer and heat treated at 200° C. for 2 hours at an oxygen concentration of 2%. In the heat treatment at an oxygen concentration of 2%, 0.18 liters/min of air and 1.78 liters/min of nitrogen were introduced into the heating device, and an oxygen concentration meter was installed in the heating device to measure the oxygen concentration. The polymer physical properties of the obtained PAS resin were as shown in Table 1.

[Comparative example 4]
PAS-4 was placed in a heating device equipped with a stirrer and heat treated at 200° C. for 4 hours at an oxygen concentration of 12%. In the heat treatment at an oxygen concentration of 12%, 1.0 liter/min of air and 0.96 liter/min of nitrogen were introduced into the heating device, and an oxygen concentration meter was installed in the heating device to measure the oxygen concentration. The polymer physical properties of the obtained PAS resin were as shown in Table 1.

The results of the above example and comparative example will be compared and explained.

In Examples 1 to 3, by performing step A and the heat treatment step, PAS resins with a small amount of gas generation, a high content of functional groups, and a high molecular weight were obtained.

In Comparative Example 1, although step A was performed, the heat treatment step was not performed, so the amount of gas generated was extremely large. Furthermore, compared to Example 1, Comparative Example 1 had a higher gas generation amount and higher functional group content because the heat treatment step was not performed. The reason for this is not clear, but it is presumed that it is because some of the functional groups of the PAS resin volatilize as gas during the heat treatment process.

Comparative Example 2 did not include Step A, so the functional group content of the obtained PAS resin was low, and the heat treatment step was not performed, so the amount of gas generated was large.

In Comparative Examples 3 and 4, in addition to not including step A, a heat treatment step was performed, so the functional group content of the obtained PAS resin was extremely low.

[Example 4, Comparative Examples 5-6]
Next, the PAS resin obtained in the example or comparative example was charged into a melt kneader. The gut obtained by melt-kneading was pelletized using a strand cutter and dried at 130° C. overnight. The pellets were subjected to injection molding, and the resulting molded products were evaluated for tensile strength and epoxy adhesive strength. The results were as shown in Table 2.

In Example 4, the functional group content of the PAS resin used was 100 μmol/g or more and the weight average molecular weight was 40,000 or more, so the resulting molded product had excellent tensile strength and epoxy adhesive strength. there were.

Comparative Examples 5 and 6 used a PAS resin that was not produced by the production method of the present invention, so the epoxy adhesive strength of the resulting molded products was low.

Claims (13)

A polyarylene sulfide resin polymerization step in which a polyarylene sulfide having a weight average molecular weight of 25,000 or more and a halogenated compound having a functional group are reacted within a temperature range of 200 ° C. or more and less than 290 ° C., and a polyarylene sulfide resin obtained in the polymerization step. A method for producing a polyarylene sulfide resin, which comprises performing a heat treatment step of heat treating the polyarylene sulfide resin. A claim characterized in that the halogenated compound having a functional group is a halogenated compound having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, an amino group, a hydroxy group, and derivatives thereof. Item 1. A method for producing a polyarylene sulfide resin according to item 1. Any one of claims 1 and 2, wherein the halogenated compound having a functional group is a halogenated compound having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, and a derivative thereof. A method for producing a polyarylene sulfide resin as described in the above. Any one of claims 1 to 3, wherein in the heat treatment step, the polyarylene sulfide resin is heat treated at 160 to 270° C. for 0.2 to 50 hours in an atmosphere with an oxygen concentration of 2% by volume or more. The method for producing a polyarylene sulfide resin described in . The method for producing a polyarylene sulfide resin according to any one of claims 1 to 4, characterized in that, after the polymerization step, an acid treatment step of treating the polyarylene sulfide resin with an acid is performed, followed by a heat treatment step. The polyarylene according to any one of claims 1 to 5, wherein after the polymerization step, a hot water treatment step of treating the polyarylene sulfide resin with hot water is performed, followed by an acid treatment step and a heat treatment step. Method for producing sulfide resin. The method for producing a polyarylene sulfide resin according to any one of claims 1 to 6, characterized in that in the polymerization step, the obtained polyarylene sulfide resin is recovered by a flash method. The method for producing a polyarylene sulfide resin according to any one of claims 1 to 7, characterized in that the amount of gas that evaporates when the polyarylene sulfide resin is heated and melted is 0.50% by weight or less. The method for producing a polyarylene sulfide resin according to any one of claims 1 to 8, wherein the weight average molecular weight is 30,000 or more. The method for producing a polyarylene sulfide resin according to any one of claims 1 to 9, wherein the functional group content is 80 μmol/g or more and 500 μmol/g or less. According to any one of claims 1 to 10, the melt flow rate (measured under conditions according to ASTM D-1238-70 at a temperature of 315.5°C and a load of 5000 g) is 500 g/10 minutes or less. A method for producing polyarylene sulfide resin. A method for producing a polyarylene sulfide resin composition, which comprises obtaining a polyarylene sulfide resin by the method for producing a polyarylene sulfide resin according to any one of claims 1 to 11, and melt-kneading the polyarylene sulfide resin. A polyarylene sulfide resin composition is obtained by the method for producing a polyarylene sulfide resin composition according to claim 12, and the polyarylene sulfide resin composition is molded to obtain a box-shaped article, and an electric charge is placed in the box-shaped article. A method for manufacturing power modules in which electronic components are placed.