JPS58125721A - Preparation of aromatic sulfide polymer - Google Patents

Abstract

PURPOSE:To obtain an aromatic sulfide polymer, by reacting simple sulfur with a polyhalogen substituted aromatic compound, an alkali metallic salt of formic acid and a caustic alkali present in a specific proportion in an organic solvent, and advancing the reaction rapidly and smoothly. CONSTITUTION:Simple sulfur is present with a polyhalogen-substituted aromatic compound, e.g. 1,4-dichlorobenzene, an alkali metallic salt of formic acid, e.g. sodium formate, and a caustic alkali, e.g. caustic soda, at 1:(0.8-1.2):(1.6- 3.0):(0.8-1.5) gram equivalent ratio at the same time in an organic solvent, e.g. N-methylpyrrolidone, and then the resultant mixture is reacted at 100-300 deg.C to give the aimed aromatic sulfide polymer.

Description

[Detailed description of the invention]

The present invention relates to a method for producing an aromatic sulfide polymer used as a sulfur source. More specifically, the simple substance Den Huang, polyhalogen IIq-substituted aromatic compound, alkali 4'ZkJ' + salt of formic acid as a reducing agent,
Furthermore, is it a powerful alkali as a carbon dioxide scavenger?
The present invention relates to a method for producing an aromatic sulfide polymer, which is characterized in that the aromatic sulfide polymer is coexisting and reacted in an organic solvent at a specific ratio. In recent years, thermoplastic resins with high heat resistance are increasingly required for mechanical parts and electronic equipment parts, and aromatic sulfide polymers are one of the resins that can meet this demand. The following method is disclosed as a method for producing aromatic sulfide polymers in which the cheapest sulfur raw material is used as the main raw material. Namely, ■ Elemental sulfur, dichlorobenzene and inorganic bases (
Mainly NaC05)? Method of simultaneously melting and reacting with a hot solvent (U.S. Patent No. 251g1sa, U.S. Patent No. 25)
38941) and (2) a method in which elemental sulfur, dichlorobenzene and an inorganic group (mainly NcL2C03) are reacted in a polar solvent (US Pat. No. 6,878,176). All of these methods have a stoichiometric excess of oxygen as shown in the formula below.

[0] is generated. (Here, x, hr and M each represent a rogen atom, an aromatic ring and an alkali metal. ) This excess oxygen

[0] is a side reaction (e.g. oxidation reaction, hydrogen abstraction reaction, condensation cyclization reaction, etc.) with the sulfur atom bonded to the end or inside of the simple sulfur dipolymer, or the hydrogen atom bonded to the polymer or solvent molecule. , and even secondary reactions accompanying it), which may impede the smooth polymerization reaction or cause the polymer to become pitch-like. It is thought that this causes carbonization. Therefore, according to the conventional production method, the presence of this excess oxygen inhibits the normal polymerization reaction, so firstly, the polymerization yield is low and reaches a plateau, and only products with low molecular weight can be obtained, and secondly, when Depending on the type of polymer, there are problems such as pitch formation and carbonization of the polymer. As a result, it has been difficult to obtain useful aromatic sulfide polymers due to their limited physical properties. The inventors discovered that as a means of solving the drawbacks of this conventional method, the polymerization reaction could proceed extremely quickly and smoothly by performing the polymerization reaction while removing this excess oxygen by coexisting with a suitable reducing agent. That's what I did. Therefore, the present inventors first attempted to react by simultaneously coexisting an elemental sulfur, bo+)/logogen-substituted aromatic compound and an alkali gold salt of formate as a reducing agent in an organic solvent. We have developed a method for synthesizing aromatic sulfide polymers by preventing harmful reactions and allowing normal polymerization reactions to proceed smoothly. z・s+n・X−Ar−X+2nHCOOM−++Ar
-892 rLMX+ycH20+ncO2+rbc
(Furthermore, the inventors found that the CO2 produced in this method slightly hinders the increase in polymerization yield at the final stage of polymerization, and by coexisting an appropriate amount of acetic alkali,
succeeded in controlling it. −
The present invention is based on these discoveries, and the main mechanism of polymerization is presumed to be as follows. n・s+n・X−4r−X+2n・HCOOM+2n−
MOH-+ +Ar -8+3+ 23・MX+ 2r
L-HzO+n .MzCOx + ncO Excess oxygen can thus be removed as water, while the CO2 produced can be removed as carbonate. It is also thought that this small amount of water combines with the carbonate produced. As described above, by using an alkali metal salt of formate in combination with a strong alkali, harmful side reactions caused by excess oxygen and generated CO2 can be prevented, and it has become possible to efficiently produce an aromatic sulfide polymer. Also, since the amount of water produced is small, it hardly interferes with the reaction. Incidentally, a method for producing an aromatic sulfide polymer using Nα2S・9H20 as a sulfur raw material is also known (U.S. Patent No. 3,354,129, U.S. Patent No. 5,919,177, etc.), but in this method, the crystals contained in Nα2S・9H20 are The present invention will be explained in detail below. The elemental sulfur, which is one of the raw materials for the polymerization method of the present invention, includes orthorhombic sulfur, monoclinic sulfur, etc. Either crystalline sulfur or amorphous sulfur can be similarly used. The polyhalogenated aromatic compound that can be used as a reaction starting material in the present invention is represented by the following formula: (A) CB) X is C1l , Br, I or F, especially CI and B
A halogen selected from the group consisting of r. Y is -R, -OR and -〇〇OH (R is H, alkyl,
selected from the group consisting of cycloalkyl, aryl, aralkyl] R# Vbar0-, -C-, -8-, -8O-, -8O2-rl' (selected from the group consisting of alkyl, aryl, aralkyl). In formula (A), m and le are respectively 2≦m≦6゜0≦ru≦
An integer of 4. In formula (B), α and b are respectively 2≦α≦8゜0≦b≦
An integer of 6. In formula (C), c, d, a and f are 1≦c, d≦, respectively.
5. An integer of 0≦t, f≦4. In formula (D)! I*"+' and ノ" are integers of 1≦g, h≦5, 0≦t, and ≦4, respectively. Preferred compounds of the above general formula are those containing 2 to 3 halogen atoms, and particularly preferred are those containing 2 to 3 halogen atoms.
It contains halogen atoms. Examples of polyhalogen-substituted aromatic compounds having the above general formula include p-dichlorbenzene-dichlorobenzene, 2,5-dichlorotoluene, p-dibromobenzene, 1,5. 5-Trichlorobenzene, 1.
4-dichloronaphthalene, 1-methoxy-2,5-dichlorobenzene, 4,4'-dichlorobiphenyl. 3.5-dichlorobenzoic acid, p, p'-dichlordiphenyl ether, 5.3'-dichlorodiphenyl sulfone, 5.3'-dichlorodiphenyl sulfoxide, 3
．． 5'-dichlorodiphenyl sulfide and the like are used, among them 1,4-dichlorobenzene, 77L-dichlorobenzene, 1,3.5-)lichlorobenzene, 3.5
'-Dichlorodiphenylsulfone is particularly preferably used. The alkali metal of formic acid as a reducing agent that is used as an excess oxygen scavenger when coexisting during the reaction, which is a feature of the present invention!
(expressed as HCOOM) is a neutral inorganic salt usually produced industrially by reacting CO with MOH (power alkali). In the chemical formula represented by HCOOM, the alkali metals corresponding to MK are Li and Nα. K or Rh can be used. NIZ is most preferred from an economic standpoint. In addition, R-COOM (R;
When an organic acid salt represented by an alkyl group or an aryl group (eg, acetate, benzoate, etc.) is used, it is not effective for the purpose of removing excess oxygen because it has no or insufficient reducing power. In the method of the present invention, a strong alkali is used to collect carbon dioxide gas generated during the reaction, and in particular Li, Nα,
Alkali metal hydroxides of K or Rh are preferred. CZ
Although hydroxides or oxides of alkaline earth metals such as , Mg, and Bα are also effective to some extent, they are not preferred because they may cause harmful side reactions such as reacting with raw material sulfur and forming insoluble salts. do not have. Elemental sulfur is used as a medium for the polymerization reaction of the present invention. A polyhalogen-substituted aromatic compound, an alkali metal salt of formic acid as a reducing agent, and an organic solvent that can be completely or partially dissolved in a force alkali for collecting carbon dioxide and does not contain active hydrogen. is used. The solvent containing active hydrogen itself may inhibit polymerization, or the solvent generated by the reaction of active hydrogen may cause secondary harmful reactions. Organic solvents that can be used in the present invention include amides such as HMP A (hexamethylphosphoric triamide), NMP (N-methylpyrrolidone), TMU (tetramethylurea), and DMA (dimethylacetamide), and etherified polyethylene glycol dialkyl ethers. Polyethylene glycol. Examples include sulfoxides such as tetramethylene sulfoxide. Among them, HMPA or NMP is particularly preferred because of its high chemical stability. The organic solvent used in the reaction system in the polymerization method of the present invention is desirably in a range of 0.02 to 51 parts per unit sulfur (Durham equivalent). If the amount of solvent is larger than this, the concentration of the reactant will become too low, resulting in a significant decrease in the reaction rate, which is not preferred from an economic standpoint. Smooth progress of the reaction may be significantly delayed. In the method of the present invention, the mutual charging ratio of elemental sulfur, polyhalogen-substituted aromatic compound, alkali metal formate as a reducing agent, and alkali as a carbon dioxide gas scavenger is determined by Durham equivalent (JTI Yellow 1). On the other hand, polyhalogen-substituted aromatic compound 08-1.2 preferably 0.9-1.1. Alkali metal formate salt 1.6-30 preferably 18-2,41 alkali 08-1.5 preferably 0 They are used at a ratio of .9 to 1.2. If these mutual ranges are exceeded, there is a risk that excess reaction raw materials may inhibit the normal polymerization reaction. ) 6 In particular, elemental sulfur, polyhalogen 1θ-substituted aromatic compounds, alkali metals, and caustic alkalis weigh 1% per gram:
0.9-1.1: 1.8-2.4: 0.9-1
It is preferable to use 2 because the smoothest polymerization reaction is carried out. It is necessary that these four components coexist simultaneously in the above-mentioned organic solvent in this ratio for reaction. By causing these reaction materials to coexist simultaneously, the reaction proceeds extremely quickly and smoothly. The polymerization reaction temperature is preferably within the range of 100 to 600°C. At temperatures below 100°C, the reaction rate is markedly reduced, which is unfavorable from a pharmaceutical standpoint, and at temperatures above 0°C, the solvent dipolymer may cause abnormal side reactions. Especially 150-2
A temperature range of 80°C is preferred for smooth reaction. In the method of the present invention, conventional polymerization methods such as batch, semi-batch, and continuous polymerization methods can be employed for the reaction. Furthermore, in a batch system, a split charging system can be used in which all reaction raw materials are charged in several parts at the same composition ratio. In particular, in the method of the present invention, anhydrous compounds may be used in combination as reducing agents. This method does not require any dehydration process, so even if you use the continuous polymerization method or the split charge method mentioned above, +IJ! This is particularly suitable. The split charging method is a particularly effective means for controlling the heat of reaction. In addition, there is no need for energy or time for dehydration, etc.
There are major advantages in terms of polymerization method. After the reaction is completed, the polymer is usually recovered by adding a precipitating agent such as water, ether, halogenated hydrocarbon, aromatic or aliphatic hydrocarbon to the reaction mixture to precipitate the polymer and inorganic salts, and separate the mixture. This can be done by washing with water and drying. By appropriately selecting and combining polyhalogenated aromatic compounds, unbranched polymers and copolymers containing two or more different reactive units can be obtained. For example, if dichlorobenzene and a small amount of trichlorobenzene are used in combination as the polyhalogen 1θ-substituted aromatic compound as a reaction raw material, a branched phenylene sulfide polymer can be obtained. P-Jik J Morinzen and m-
A copolymer containing dichlorobenzene and p,p'-dichlorodiphenyl units can be obtained. The polymers obtained by the method of the present invention can be molded into a variety of useful articles by known molding techniques. Suitable molding methods include injection molding, pressure molding, two-turn extrusion molding, and similar molding methods. By curing these molded products after molding, they can be made into molded products with higher heat resistance. The polymer of the present invention may be filled with powder fillers such as carbon black, calcium carbonate powder, silica powder, and titanium oxide powder, or fibrous fillers such as carbon fiber, glass fiber, asbestos, and polyaramid fiber. can. The polymer of the present invention may also be used in combination with one or more synthetic resins such as polycarbonate, polyphenylene oxide, polysulfone, polyarylene, polyacetal, polyimide, polyamide, polyester, polystyrene, and ABS. Examples 1 to 4 The polymerization reactor had an internal volume of 500 m and was equipped with a magnetic stirring device.
l SUS! 104 (7) autoclave was used. The polymerization was carried out by completely purging the interior of the Iliffi yellow crepe shown in Table 1 with N2 gas in an autoclave, and heating it to a predetermined temperature with stirring to carry out the reaction. After the reaction was completed, the autoclave was cooled, the reaction solution was taken out, water was added to precipitate the polymer, and the resulting cake was washed three times with hot water and once with acetone, and dried at 70°C for one day. The polymer was recovered. The city yield was calculated based on the recovered amount and the amount of sulfur charged. Table 1 shows the results of polymerization performed by changing the raw material composition 1 reaction conditions based on the above polymerization method (Examples 1 to 1).
4). However, dichlorobenzene & DCB, dichlorobenzene is abbreviated as TCB, N-methylpyrrolidone (NMP), and hexamethylphosphoric triamide is abbreviated as HMPA. In addition, the grams of polyhalogen-substituted aromatic compounds are
This value is calculated as t6 per gram, which is 1 mole/number of balogen it substituents. Comparative Examples 1 to 6 Comparative Examples 1 to 3 corresponding to Examples 1 and 2 are collectively shown in Table 2. The experimental conditions were the same as those of Example 1 or 20, except for the charging composition. Comparative Examples 1 and 2 are cases where no hard alkali was used as a rock acid gas scavenger. As the polymerization time becomes longer, there is a tendency for the yield to decrease and separation to occur as compared to Example 1 or 2 due to the influence of carbon dioxide gas. Comparative Example 6 is an example in which CHISCOONIZ, which has no reducing power, was used instead of the reducing salt H-COONα of Comparative Example 1. If the salt has no reducing power, the yield will be poor. Table 2 Procedural Amendment Document January 21, 1982 Patent ff! '! ! , (C:
1. Indication of the case 1982 Patent Application No. 144988 2. Name of the invention Process for producing an aromatic sulfide polymer 3. Person making the amendment Relationship to the case Applicant 4. Agent Chiyoda-ku, Tokyo Marunouchi 2-chome 6-2 401 Room A 5,
Date of amendment order: Showa year, month, day 6, subject of amendment: Contents of the amendment in the Detailed Explanation column (Z) in the description (C) + l), 4 lines from the bottom of page 13 of the specification subdivision may be used together. '' I corrected it to ``can be used.'' Written amendment (method) February 28, 1980 1. Indication of the case 1982 Patent Application No. 144988 2. Name of the invention Process for producing aromatic sulfide compound 3. Person making the amendment Case and Relationship: Applicant 4, Agent 5, Date of amendment order: February 22, 1980 6, Subject of amendment: Description 9 - Contents of the amendment (1) to the title Z, Title of the invention in the late specification I made a mistake, so I will correct it as follows. "Method for producing aromatic sulfide polymer"

Claims (5)

[Claims] (1), elemental sulfur, polyhalogen-substituted aromatic compound, alkali metal salt of formic acid, and alkali in a ratio of 1: [1
, 8-1.2: 1.6-3. [l: 0.8~1
．． A method for producing an aromatic sulfide polymer, characterized by coexisting in an organic solvent at a ratio of 5 (gram equivalent ratio) and reacting at a temperature of 100 to 300°C. (2) Elemental sulfur, polyhalogen-substituted aromatic compound, alkali metal salt of formic acid, and alkali in a ratio of 1:0.
9-1.1: 1.8-2.4: 0.9-1.2
The method for producing an aromatic sulfide polymer according to claim 1, wherein the reaction is carried out at a ratio of (gram equivalent ratio) and at a temperature of 150 to 280°C. (3), 0.0 per gram equivalent of elemental sulfur in organic solvent
2-51 A method for producing an aromatic sulfide polymer according to claim 1 or 2. (4) A method for producing an aromatic sulfide 1f combination according to any one of claims 1 to 3, wherein sodium formate is used as the alkali metal salt of formic acid. (5) A method for producing an aromatic sulfide polymer according to any one of claims 1 to 4, in which hydric soda is used as the hydric alkali.