JPH026774B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a process for producing linear aromatic sulfide polymers of extremely high molecular weight. More specifically, it is a substantially anhydrous fine powder of sulfide of at least one metal selected from alkali metals and alkaline earth metals, A substantially anhydrous fine powder of a metal carbonate and a dihalogen-substituted aromatic compound are placed in an organic solvent in the coexistence of a strictly controlled trace amount of solvation water.
The present invention relates to a method for obtaining a linear aromatic sulfide polymer which has a significantly high molecular weight and is easily oxidized by heating to 100 to 250°C. In recent years, there has been an increasing demand for thermoplastic resins with higher heat resistance for use in electronic equipment parts, automobile equipment parts, and the like. Aromatic sulfide polymers also have properties as resins that can meet these demands, but these resins are highly crystalline and difficult to obtain with sufficiently high molecular weights, so they are not suitable for use in films and sheets. However, there were major problems in that it was extremely difficult to mold into fibers, etc., and the molded product was extremely fragile. In order to solve these problems, the present invention provides a method for producing a linear aromatic sulfide polymer having a significantly high molecular weight. The method for producing aromatic sulfide polymers is as follows:
Conventionally, the following are known. (1) A method in which elemental sulfur, dichlorobenzene, and a base (eg, Na ₂ CO ₃ ) are subjected to a melt reaction without a solvent (US Pat. No. 2,513,188, US Pat. No. 2,538,941, etc.). (2) A method of heating an alkali metal sulfide salt, especially Na ₂ S・9H ₂ O, in a polar solvent to dehydrate the crystal water of Na ₂ S・9H ₂ O, adding dichlorobenzene, and heating and polymerizing it (U.S. Patent No. 3354129, etc.). (3) Method (2) above, in which a carboxylic acid salt is coexisted in a polar solvent and heated to dehydrate the crystal water of Na ₂ S・9H ₂ O, and then dichlorobenzene is added and heated to polymerize (U.S. Patent No. 3919177, same no.
4089847 etc.). etc. However, in the method (1) above, the molecular weight of the resulting polymer is too low, making it difficult to obtain a practical linear aromatic sulfide polymer. Although method (2) yields a polymer with a molecular weight slightly higher than that of method (1), it is still difficult to obtain a polymer with a molecular weight sufficient for practical linear aromatic sulfide polymers. Method (3) is a method proposed to improve the disadvantage of method (2) in that the molecular weight of the produced polymer is low, and this method does not result in a considerable improvement in the molecular weight of the produced polymer. Ta. However, even this method is still not sufficient to easily process and manufacture strong films, sheets, fibers, etc. One of the reasons why it is difficult to sufficiently increase the molecular weight using methods (2) or (3) above is that even though the amount of coexisting water has a very large effect on the increase or decrease in the molecular weight of the resulting polymer, Raw material Na ₂ S・9H ₂ O
The reason for this is that it is difficult to completely dehydrate the water because it uses a method of distilling off the large amount of water that enters the solvent by heating it in the solvent, and it is also difficult to control the amount of water removed. It is inferred. Furthermore, the problem with method (3) is that many water-soluble organic acid salts, especially acetates, are allowed to coexist in the polymerization system during polymerization, resulting in a large amount of organic acids being mixed into the treated wastewater after polymerization. There is a risk of causing pollution problems, and a large amount of cost is required to eliminate the pollution. The present invention solves the above-mentioned drawbacks of the conventional manufacturing method and produces linear aromatic sulfide polymers that have a dramatically high molecular weight and are easily oxidized, suitable for processing into molded products such as strong films, sheets, and fibers. The present invention provides a method for producing composites that is substantially free from pollution problems. After intensive studies to obtain a high molecular weight linear aromatic sulfide polymer, the inventors discovered that CO ₃ ^2- participates in the polymerization reaction under alkaline conditions and has the effect of increasing the molecular weight of the resulting polymer. We have discovered that there is a need for a controlled presence of water. Therefore, an attempt was made to involve carbonates of alkali metals or alkaline earth metals in the polymerization reaction.
However, since carbonates of alkali metals or alkaline earth metals are generally substantially insoluble in polymerization reaction solvents, it has been extremely difficult to involve them effectively in polymerization reactions. Therefore, the present inventors used fine powders of a substantially anhydrous metal sulfide and a substantially anhydrous metal carbonate, and made dihalogen-substituted aromatic We were able to solve this problem by developing a polymerization method that involves heating the compound in an organic solvent. In this method, the carbonate is substantially insoluble in the solvent, but by using a finely powdered carbonate, it can be relatively effectively involved in the polymerization reaction. Therefore, it becomes possible to increase the molecular weight of the produced polymer. Furthermore, in this method, not only the carbonate but also the sulfide are used in substantially anhydrous form, making it possible to control trace amounts of water in the polymerization reaction system. That is, in the method of using the carbonate of the present invention as a molecular weight increasing agent, the presence of a particularly large amount of water is not preferable because it lowers the molecular weight of the resulting polymer.
It is presumed that this is because water promotes hydrolysis of the polymer. Therefore, the carbonates and sulfides used in the present invention are preferably substantially anhydrous. However, in a completely water-free state, a decomposition reaction, which is thought to be a slight dehydration reaction due to carbonates or sulfides, occurs, and decomposition of the solvent and polymer occurs.
The presence of a suitable trace amount of water is necessary in the polymerization reaction system. Therefore, it is important to strictly control the amount of coexisting water in the polymerization reaction system. In the present invention, carbonates that should be present in the polymerization reaction system not as a dehalogenating agent but as a catalyst to increase the molecular weight of the produced polymer include:
1 selected from alkali metals and alkaline earth metals
More than one metal carbonate is used, with carbonates of alkali metals such as Na, K or alkaline earth metals such as Ca, Mg being preferred. Among these, Na carbonate is particularly preferred since it has a large molecular weight increasing effect. As mentioned above, carbonates are used that are substantially anhydrous, but if they are substantially anhydrous and contain a trace amount of water, about 1 mole or less per mole of carbonate, It does not significantly reduce the molecular weight increasing effect. Therefore, in the present invention, a substantially anhydrous carbonate is defined as having a residual water content of 1 mol/1, even if it is large.
Molar - shall mean carbonate that has been dried sufficiently to not exceed the carbonate level. The amount of carbonate added is sulfide: carbonate = 1 mole:
A range of 0.5 to 10 moles is preferred. If the amount of carbonate is less than this range, the effect of increasing the molecular weight of the resulting polymer will be undesirably small. On the other hand, if the amount of carbonate exceeds this range, the amount of sulfide charged must be reduced by increasing the amount of carbonate in the polymerization reaction, which is undesirable from the viewpoint of productivity. Sulfide: carbonate = 1 mol: The range of 0.7 to 4 mol is particularly desirable from the viewpoint of molecular weight increasing effect and productivity balance. As mentioned above, it is extremely important to use the substantially anhydrous carbonate used in the polymerization process in as fine a form as possible in order to enhance the catalytic action and increase the molecular weight of the resulting polymer. In order to effectively participate in the polymerization reaction, the carbonate is desirably a fine powder of 1 mm or less, particularly preferably a fine powder of 0.1 mm or less. A fine powder of such carbonate is obtained by ball milling the substantially anhydrous carbonate.
It can be produced by grinding using a common grinder such as a colloid mill, coffee mill, mortar, stone mill, or dietmizer. As the sulfide that functions as a sulfur source and a dehalogenating agent in the polymerization reaction of the present invention, one or more metal sulfides selected from alkali metals and alkaline earth metals are used, and alkali metals such as Na and K are used. Alternatively, sulfides of alkaline earth metals such as Ca and Mg are preferable. Among these, Na sulfide is particularly preferred from the viewpoint of ease of handling and stability. As mentioned above, the sulfide used in the present invention needs to be substantially anhydrous. However, if it is a substantially anhydrous substance containing a trace amount of water, about 1 mol or less per mol, it will not significantly inhibit the molecular weight increasing effect of the carbonate. Therefore, in the present invention, a substantially anhydrous sulfide is a sulfide that has been sufficiently dried to such an extent that the residual moisture content does not exceed 1 mole/1 mole of sulfide even if it is large. shall mean. Substantially anhydrous Na sulfide can usually be produced by directly drying Na ₂ S.9H ₂ O under reduced pressure at high temperature using a vacuum dryer. The particle size of the sulfide is preferably a fine powder of 1 mm or less in order to effectively participate in the reaction field. As mentioned above, the amount of water to be solvated in the polymerization reaction system of the present invention is preferably as small as possible in order to avoid concurrent occurrence of hydrolysis reactions and the like. On the other hand, even if the polymerization reaction system is entirely anhydrous, there is a risk that side reactions such as dehydration reactions due to carbonates or sulfides, which are substantially anhydrous substances, may occur. Therefore, the amount of water added as solvation water in the polymerization reaction system of the present invention is preferably in the range of 0.3 to 2 moles per mole of sulfide. The dihalogen-substituted aromatic compound that can be used in the present invention is represented by the following formula. ●X is Cl, Br, I or F, especially a halogen selected from the group consisting of Cl and Br. ●Y is selected from the group consisting of -R.-OR and -COOH (R is selected from the group consisting of H, alkyl, cycloalkyl, aryl, and aralkyl). ●V is -O-,

[Formula] -S-, -SO-, - SO ₂ - and

[Formula] (R′ and R″ are selected from the group consisting of H, alkyl, cycloalkyl, aryl, and aralkyl). In formula (A), m and n are respectively m=2, 0≦n≦
An integer of 4. ●In formula (B), a and b are respectively a=2, 0≦b≦
An integer of 6. ●In formula (C), c, d, e and f are each c+d=
2, an integer of 0≦e, f≦4. ●In formula (D), g, h, i and j are each g+h=
2, an integer of 0≦i, j≦4. Examples of the dihalogen-substituted aromatic compound having the above general formula include the following. p-dichlorobenzene, m-dichlorobenzene, 2,5-dichlorotoluene, p-dibromobenzene, 1,4-dichloronaphthalene, 1-methoxy-2,5-dichlorobenzene, 4,4' -dichlorbiphenyl, 3,5-dichlorobenzoic acid,
p,p'-dichlorodiphenyl ether, p,p'-
Dichlordiphenyl sulfone, p,p'-dichlorodiphenyl sulfoxide, p,p'-dichlordiphenyl sulfide, etc. are used, among which p-dichlorobenzene, m-dichlorobenzene,
p,p'-dichlorodiphenylsulfone is particularly preferably used. The solvent used in the polymerization reaction of the present invention is an organic solvent that is stable against alkalis at high temperatures and does not contain active hydrogen. Solvents containing active hydrogen may themselves inhibit polymerization, or those generated by the reaction of active hydrogen may cause secondary harmful reactions. As an organic solvent that can be used in the present invention, HMPA
(hexamethylphosphoric acid triamide), NMP (N-methylpyrrolidone), TMU (tetramethylurea),
Amides such as DMA (dimethylacetamide),
Examples include etherified polyethylene glycols such as polyethylene glycol dialkyl ether, and sulfoxides such as tetramethylene sulfoxide. Among them, HMPA or NMP is particularly preferred because of its high chemical stability. The amount of organic solvent used is preferably within the range of 0.1 to 10 per mole of sulfide used for polymerization. If the amount of solvent is less than this, the viscosity of the reaction system becomes too high, which prevents a uniform polymerization reaction, which is not preferable. On the other hand, if the amount of solvent is too large, the amount of solvent used will be enormous compared to the amount of polymer obtained, which is not preferred from an economic standpoint. The polymerization reaction temperature used is within the range of 100 to 250°C. Below 100°C, the reaction rate is extremely low, which is not preferred from an economic standpoint. On the other hand, at a temperature of 250° C. or higher, the carbonate acts not as a catalyst but as a dehalogenating agent, which may cause an abnormal reaction and activate the decomposition of the polymer or solvent, which is not preferable. The polymerization reaction can be carried out at a constant temperature, but it can also be carried out stepwise or continuously while increasing the temperature. In the polymerization method of the present invention, a predetermined amount of trace water and a dihalogen-substituted aromatic compound are first dissolved in a solvent, and a predetermined amount of substantially anhydrous sulfide and carbonate fine powder is added thereto and uniformly dispersed. It is preferable to polymerize by heating. In some cases, it is also possible to add part or all of the carbonate fine powder during the polymerization reaction. Further, various conventional polymerization methods such as a batch method, a batch method, and a continuous method can be employed for the polymerization. The atmosphere during polymerization is preferably a non-oxidizing atmosphere, and the system is preferably purged with an inert gas such as N ₂ or argon at the start of the polymerization reaction. To recover the polymer, first, after the reaction is completed, the reaction mixture is heated under reduced pressure or normal pressure to distill off only the solvent.
Next, remove the remaining solids from the can with water, ketones, alcohol,
This can be carried out by washing or extracting one or more times with a solvent such as an aromatic hydrocarbon, halogenated hydrocarbon, or ether, followed by neutralization, washing with water, separation, and drying. Another method is to add a solvent such as water, ethers, halogenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons, etc. to the reaction mixture as a precipitant after the reaction is completed, and solids such as polymers and inorganic salts are produced. This can also be done by precipitating the product, which is then separated, washed and dried. In either method, since no organic acid salt is used as a molecular weight increaser, there is no problem of contamination due to organic acids that are dissolved in the wash water and released. By appropriately selecting and combining dihalogen-substituted aromatic compounds, a branched polymer or a copolymer containing two or more different reactive units can be obtained.
For example, by using dichlorobenzene as a dihalogen-substituted aromatic compound as a reaction raw material in combination with a small amount of trichlorobenzene, a branched phenylene sulfide polymer can be obtained. p
-If dichlorobenzene and m-dichlorobenzene or p,p'-dichlorodiphenyl sulfone are used in combination,

[Formula] Unit and

[Formula] or

A copolymer containing the unit [Formula] can be obtained. The polymer obtained by the method of the present invention is a linear polymer that has a significantly higher molecular weight than conventional aromatic sulfide polymers and is easily oxidized. 200~ as needed
By performing a slight oxidation treatment at 260℃,
Even with a high melt viscosity, it has excellent spinnability and can be extremely easily molded into tough, heat-resistant films, sheets, fibers, etc. Furthermore, it can be processed into various molded products by injection molding, extrusion molding, rotary molding, etc., but even if it is thick, it is difficult to crack. Furthermore, the polymer of the present invention may be filled with a powder filler such as carbon black, calcium carbonate powder, silica powder, titanium oxide powder, or a fibrous filler such as carbon fiber, glass fiber, asbestos, or polyaramid fiber. be able to. The present invention also relates to polycarbonate, polyphenylene oxide, polysulfone, polyarylene,
It is also possible to use a mixture of one or more synthetic resins such as polyacetal, polyimide, polyamide, polyester, polystyrene, and ABS. Examples 1 to 12 Production of sulfide and carbonate anhydrides Substantially anhydrous sodium sulfide was obtained by putting sodium sulfide nonahydrate in a vacuum dryer and drying it at 140°C overnight. Ta. Anhydrous sodium carbonate and anhydrous calcium were obtained by drying commercially available anhydrous reagents in a vacuum dryer at 120°C overnight to obtain almost complete anhydrides. Polymerization A predetermined amount of a solvent was placed in a stainless steel autoclave equipped with a stirring blade, and a precisely measured amount of water and a predetermined amount of a dihalogen-substituted aromatic compound were added thereto and dissolved. and the aforementioned sulfides and carbonates,
In Method A, the mixture was charged into a ball mill at a predetermined mixing ratio, pulverized, and a predetermined amount was weighed and added to the solution. After replacing the autoclave with N ₂ , it was sealed and stirred at 100° C. for 30 minutes to sufficiently disperse the fine powder, and then the temperature was raised to the polymerization temperature to perform polymerization. Method B involves pulverizing the sulfide and carbonate individually in a ball mill, weighing a predetermined amount of each of the resulting fine powders, adding them to the solution, stirring and mixing thoroughly in an autoclave, and then pulverizing them in the same manner. A polymerization reaction was carried out. The carbonate fine powder was usually charged from the beginning of the polymerization to carry out the polymerization. However, in Example 4, only the sulfide was charged at the beginning of the polymerization, and after the polymerization had progressed to some extent, carbonate fine powder was added to carry out the polymerization. After the polymerization was completed, it was cooled and taken out, and the solvent was distilled off by evaporation under reduced pressure while heating at 110 to 130° C. using a rotary evaporator, and then washed with acetone and filtered. The separated cake was dispersed in water, neutralized by adding dilHCl, and then separated. Furthermore, wash with hot water,
Purification was repeated three times. The mixture was then dried at 70°C overnight to obtain an aromatic sulfide polymer. The melt viscosity of the obtained polymer was measured using a Koka type flow tester (300°C, 20 kg load). These results are summarized in Table 1.

【table】

[Table] Comparative Examples 1 to 7 Production of sulfide and carbonate anhydrides Sodium sulfide and sodium carbonate containing 1 mole or more of water were dried by drying nonahydrate and decahydrate, respectively, at 90°C in a vacuum dryer overnight. Manufactured by Complete anhydride of sodium acetate was prepared by drying a commercially available anhydride reagent under reduced pressure at 100° C. overnight in a vacuum dryer. Polymerization Polymerization was carried out using the same apparatus and method as in Example 1 using the carbonate and sulfide described above. The results are summarized in Table 2. Comparative Example 1 is when carbonate is not shared in Na ₂ S, Comparative Example 2 is when acetate is shared instead of carbonate, Comparative Example 3 is when coarse particles are used as carbonate, and 4 is when coarse particles are used as carbonate.
and 5 are cases where too much water is shared, 6 is a case where too little water is shared, and 7 is a case where the polymerization temperature is too high. Both have significantly lower melt viscosity than Example 1, that is, lower molecular weight.

【table】

[Table] Comparative Example 8 Known technology (U.S. Patent No. 3919177, U.S. Patent No. 4089847)
The same equipment as in the example was used according to the method of
Charge 400 ml of NMP and add (i) 0.500 mol of sodium sulfide nonahydrate and 0.500 mol of sodium acetate trihydrate, or (ii) 0.500 mol of sodium sulfide nonahydrate, 0.500 mol of sodium acetate trihydrate, and sodium carbonate decahydrate. Add 0.100 mol each under a stream of _N2
After heating at 180℃ for 2 hours to dehydrate (incomplete), p-DCB0.500 was dissolved in 100ml of NMP.
Each mole was added and a polymerization reaction was carried out at 250°C for 3 hours. The polymer was recovered by the same post-treatment as in the example. Polymer recovery rates are 96.0% and 96.4, respectively.
%, but the melt viscosity was 15 Poise and
It was extremely low compared to Example 1 at 60 Poise.

Claims (1)

[Scope of Claims] 1. Substantially anhydrous fine powder of at least one metal sulfide selected from alkali metals and alkaline earth metals, at least one metal sulfide selected from alkali metals and alkaline earth metals. A linear aromatic aromatic composition characterized by heating a substantially anhydrous fine powder of the above metal carbonate and a dihalogen-substituted aromatic compound in an organic solvent to 100 to 250°C in the coexistence of a controlled trace amount of solvation water. A method for producing a group sulfide polymer. 2. The method for producing a linear aromatic sulfide polymer according to claim 1, wherein Na or K is used as the alkali metal, or Ca or Mg is used as the alkaline earth metal. 3 Sulfide: carbonate = 1: 0.5-10 (mol/mol)
A method for producing a linear aromatic sulfide polymer according to claim 1 or 2, which falls within the scope of claim 1 or 2. 4. The method for producing a linear aromatic sulfide polymer according to any one of claims 1 to 3, wherein 0.9 to 1.1 mol of the dihalogen-substituted aromatic compound is used per mol of sulfide. 5. The linear aromatic compound according to any one of claims 1 to 4, characterized in that a controlled trace amount of 0.3 to 2 moles of water per mole of sulfide is added to the polymerization medium. Method for producing sulfide polymer. 6 Organic solvent 0.1 to 10 per mole of sulfide
A method for producing a linear aromatic sulfide polymer according to any one of claims 1 to 5, which uses the following. 7. The method for producing a linear aromatic sulfide polymer according to any one of claims 1 to 6, which uses dichlorobenzene as the dihalogen-substituted aromatic compound. 8. The linear shape according to any one of claims 1 to 7, in which a fine powder of 1 mm or less is used as the substantially anhydrous sulfide and a fine powder of 1 mm or less is used as the substantially anhydrous carbonate. A method for producing an aromatic sulfide polymer.