KR100513115B1 - Process for preparing high molecular weight polyarylene sulfide copolymer - Google Patents

Abstract

The present invention relates to a method for producing a high molecular weight polyarylene sulfide copolymer, and more particularly, to a polyhalogen aromatic compound and a polyhalogen aromatic in a solution dissolved by adding alkali metal sulfide and water containing crystal water to an organic polar solvent. The copolymerization of sulfone compounds increases the solubility in solvents and prevents premature precipitation of growing polymer chains, thereby increasing the molecular weight and glass transition temperature, eliminating the need for heat curing after polymerization, and having low melting temperature. It relates to a method of manufacturing.

Description

Process for preparing high molecular weight polyarylene sulfide copolymer

The present invention relates to a method for producing a high molecular weight polyarylene sulfide copolymer, and more particularly, to a polyhalogen aromatic compound and a polyhalogen sulfone in a solution dissolved by adding an alkali metal sulfur compound and water containing crystal water in an organic polar solvent. The present invention relates to a method for producing a polyarylene sulfide copolymer having a high molecular weight and a glass transition temperature, a low melting temperature, and excellent heat resistance by polymerizing a compound.

Polyphenylene sulfide, which is one of synthetic resins generally called polyarylene sulfide, has excellent thermal stability and mechanical properties, and has excellent chemical resistance and self-extinguishing property. Therefore, it is widely used for special engineering plastics such as electric, electronic parts and automobiles. In the case of the polymer used in such plastic applications, a high viscosity is required to improve moldability. In general, polyphenylene sulfide has a lower glass transition temperature and lower molecular weight than other engineering plastics. Thus, in order to prepare a polymer of high viscosity, polyphenylene sulfide is crosslinked by heat treatment in the presence of oxygen at a high temperature of 250 ° C. or higher. The polymer thus prepared is deteriorated in various physical properties such as tensile strength due to crosslinking of the molecular chain during heat treatment, and the color is deteriorated by oxidation, so that other polymers, reinforcing agents, fillers, etc. may be suitable for use in molding plastics. Must be added.

In addition, as a conventional method for preparing polyphenylene sulfide, US Patent No. 3,354,129 discloses an alkali metal sulfide such as sodium sulfide and a polyhalogen aromatic compound having two or more halogen atoms such as para-dichlorobenzene in an organic polar solvent. Although a method of reacting is disclosed, in this process, a part of the alkali metal sulfide is decomposed into an alkali metal hydroxide and a hydrogen sulfide gas in the process of dehydrating the alkali metal sulfide containing crystalline water in a nitrogen atmosphere. The composition of the whole will change. As such, decomposition of the alkali metal sulfide during dehydration deviates the molar ratio of the reaction with the polyhalogen aromatic compound from equivalents to equivalents (1: 1), thereby lowering the molecular weight of the resulting polymer. Polyphenylene sulfide having a low molecular weight compared to the molecular weight of other engineering plastics has a problem that it can be used as a molding material only by increasing the molecular weight and melt viscosity by introducing a crosslinking reaction through heat treatment in the presence of oxygen. The polyphenylene sulfide which is not heat-treated does not have high heat resistance in the range of 70-85 degreeC of glass transition temperature, and melt temperature is comparatively high in the range of 275-280 degreeC. In addition, the polyphenylene sulfide partially crosslinked by heat treatment has a problem in that the melting temperature is increased to be molded at a temperature of 320 ° C. or higher.

Therefore, the present inventors have tried to overcome the problems of low molecular weight, low glass transition temperature and high melting temperature of the polyphenylene sulfide due to the conventional manufacturing methods, the alkali containing crystalline water without dehydration process in the organic polar solvent The polyhalene aromatic compound and the polyhalogen aromatic sulfone compound were polymerized in a solution dissolved by adding a metal sulfur compound and water, thereby developing a method for preparing a polyaliene copolymer having a high molecular weight, a high glass transition temperature, and a low melting temperature. Was completed on this basis.

Accordingly, an object of the present invention is to provide a method for producing a polyarylene sulfide copolymer having improved heat resistance and processability in a method of manufacturing a polyarylene sulfide copolymer, which does not require a dehydration process and a heat treatment process.

In order to achieve the above object, the method of the present invention dissolves 1 mol of alkali metal sulfide containing crystal water in 500-1500 g of organic polar solvent, and adds 8-10 mol of water to 1 mol of the alkali metal sulfide. , 0.9-1.1 mole of a mixture of a polyhalogen aromatic compound and a polyhalogen aromatic sulfone compound mixed at a molar ratio of 95: 5 to 70:30 is added, followed by heating and stirring for 1 to 10 hours at a polymerization temperature of 180 to 300 ° C. It consists of.

Hereinafter, the present invention will be described in detail.

In the present invention, in the method of preparing a polyarylene sulfide by melting an alkali metal sulfide containing crystalline water in an organic polar solvent and undergoing a dehydration step, and then adding and polymerizing a polyhalogen compound, omitting the dehydration process and mixing in a reaction solution In addition to the polyhalogen aromatic compounds (eg, p-dihalogenbenzene) while adding water such that the water content used as the solvent is 9 mols to 1 mol of the alkali metal sulfide, the polyhalogen aromatic sulfone compounds (eg, dichlorophenyl And a method of preparing a polyarylene sulfide copolymer having a high molecular weight and a low glass transition temperature and a low melting temperature by polymerization. In the polymerization method according to the present invention, a polyarylene sulfide copolymer can be prepared by polymerizing the above components in any order, but a preferred method is to first add an alkali metal sulfide and water containing crystal water to an organic polar solvent. After that, a method of polymerization is carried out by adding comonomers which are polyhalogen aromatic compounds.

In more detail describing the method for preparing a polyarylene sulfide copolymer according to the present invention, alkali metal sulfide and water containing crystalline water are first added to the organic polar solvent before the polymerization process. In this case, the amount of water to be added may include 8 to 10 moles of 1 mole of alkali metal sulfide, including crystal water contained in the alkali metal compound, but preferably 9 moles of mole of alkali metal sulfide. In this case, when the amount of water is less than 8 mol relative to 1 mol of the alkali metal sulfide, a problem may occur in which the alkali metal sulfide is not completely dissolved in the organic polar solvent, and when it exceeds 10 mol, problems may occur in the process due to vapor pressure.

The alkali metal sulfide is one selected from the group consisting of sodium sulfide, lithium sulfide, potassium sulfide and rubidium sulfide, of which sodium sulfide is preferably used. In addition, the organic polar solvent is N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dipropylacetamide, N, N-dimethylbenzoic acid amide, capro Lactam, N-propylcaprolactam, N-methylcaprolactam, N-cyclohexylcaprolactam, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidinone, N-isopropyl-2-pyrroli Dinon, N-isobutyl-2-pyrrolidinone, N-propyl-2-pyrrolidinone, N-butyl-2-pyrrolidinone, N-cyclhexyl-2-pyrrolidinone, N-methyl-3- Methyl-2-pyrrolidinone, N-cyclohexyl-2-pyrrolidinone, N-methyl-2-piperidone, N-methyl-2-oxo-hexamethyleneimine, N-ethyl-2-oxo-hexamethylene Imine, hexamethyl phosphate triamide, hexaethyl phosphate triamide, tetramethyl urea, 1,3-dimethylethylene urea, 1,3-dimethylethylene urea, 1,3-dimethylpropylene urea, 1-methyl-1-oxosulphate Porane, 1-ethyl-1-oxosulforan, 1-phenyl-1-oxosulforan, 1-methyl-1-oxophosphane , 1-propyl-1-oxophosphane and 1-phenyl-1-oxophosphane. It is preferable to use N-alkyllactam and N-alkylpyrrolidinone among the said organic polar solvents, More preferably, it is N-methyl- 2-pyrrolidinone. The use amount of the organic polar solvent is usually 500 to 1500 g with respect to 1 mol of the alkali metal sulfide, and more preferably 900 to 1100 g. At this time, if the amount of the organic polar solvent used is less than 500 g with respect to 1 mol of the alkali metal sulfide, the viscosity may be too high to cause stirring, and if it exceeds 1500 g, a problem may occur in which a desired molecular weight cannot be obtained.

The polyhalogen aromatic sulfone compound added as a polyhalogen aromatic compound and a co-monomer in the solution is polymerized, and the sum of the polyhalogen aromatic compound and the polyhalogen aromatic sulfone compound added during the polymerization reaction is compared to 1 mole of alkali metal sulfide. 0.9 mole to 1.1 mole, preferably 0.95 to 1.05 mole, the molar ratio of less than 0.9 mole can cause the polymer to be decomposed by alkali during polymerization, and if it exceeds 1.1 mole, the polyhalogen aromatic compound and the polyhalogen aromatic sulfone Not only is the loss of the compound large and uneconomical, but the molecular weight does not rise to obtain an industrially useful polyarylene sulfide copolymer.

The polymerization reaction of polyarylene sulfide is a nucleophilic aromatic substitution reaction in which a thiolet anion attacks a halogen ring in a solvent and a substitution reaction occurs. Therefore, the polymerization reaction is greatly influenced by temperature due to high activation energy. This will not proceed. However, when the reaction temperature is too high, a phenomenon of causing a side reaction or decomposition of the produced polymer or deterioration of the organic polar solvent is caused, resulting in deterioration of the quality of the polyarylene sulfide. Therefore, the polymerization of the polyarylene sulfide varies depending on the reactivity of the polyhalogenated aromatic monomer, but the polymerization temperature of the copolymer of the polyarylene sulfide of the present invention is in the range of 180 to 300 ° C, preferably 190 to 250 ° C. . In addition, a two-stage polymerization method in which the temperature is divided into two stages and polymerized is also possible. When the difference in reactivity between the polyhalogen aromatic compound and the polyhalogen aromatic sulfone compound is small, the yield and the molecular weight of the polymer increase at low temperatures. In addition, the polymerization reaction time is usually 1 to 10 hours, more preferably 3 to 6 hours, and if the reaction time is less than 1 hour, there is a problem that a sufficient reaction does not occur, and if more than 10 hours, depolymerization This results in a problem that the desired molecular weight cannot be obtained.

The monomer used in the copolymerization reaction is a mixture of two or more kinds, and the molar ratio of the polyhalogen aromatic compound and the polyhalogen aromatic sulfone compound monomer is usually 95: 5 to 70:30. However, the addition of a polyhalogen aromatic sulfone compound introduces a sulfonic group into the growing polymer chain, thereby increasing the solubility in the solvent and preventing precipitation. As it has the effect of obstacles, the crystallinity is lowered, and as a result, the mechanical properties of the polyacetylene sulfide are lowered. Therefore, in order to increase the molecular weight while maintaining high crystallinity and heat resistance, the molar ratio of the polyhalogen aromatic compound and the polyhalogen aromatic sulfone compound monomer is preferably in the range of 95: 5 to 85:15, more preferably 95: 5 to It is in the range of 90:10.

The polyhalogen aromatic compounds include p-dichlorobenzene, p-dibromobenzene, p-diiodinebenzene, 1-chloro-4-bromobenzene, 1-chloro-4-iodobenzene, 1-ethyl-2,5 -Dichlorobenzene, 1-ethyl-2,5-dibromobenzene, 1-tripromethylmethyl-2,5-dichlorobenzene, 1-tripromethylmethyl-2,5-dibromobenzene, 1-cyclo Hexyl-2,5-dichlorobenzene, 1-phenyl-2,5-dichlorobenzene, 1-benzyl-2,5-dichlorobenzene, 1-phenyl-2,5-dibromobenzene, 1-p-toluyl -, 25-dichlorobenzene, 1-p-toluyl-2,5-dibromobenzene and 1-hexyl-2,5-dichlorobenzene. The polyhalogen aromatic sulfone compound is one selected from the group consisting of 4-chlorophenyl sulfone, 4-bromophenyl sulfone and 4-iodine phenyl sulfone. Among them, p-diboromobenzene is preferably used as the polyhalogen aromatic compound, and 4-chlorophenylsulfone is preferably used as the polyhalogen aromatic sulfone compound.

In order to recover the polyarylene sulfide copolymer prepared by the polymerization method from the reaction mixture, it is directly separated from the reaction solution by standard methods such as filtration or centrifugation, or diluted with a washing solution such as water, acetone, methanol, and the like. It can fractionate and obtain from a reaction solution. The filtration process is followed by rinsing with water to remove inorganic constituents which may adhere to the polymer, and in addition to or after this rinsing step with other rinsing solutions such as N-methyl-2-pyrrolidinone, acetone, methanol, etc. It can be washed or extracted.

The polyarylene sulfide obtained by the above recovery process may be injection molding or extrusion molding alone, and various kinds of additives may be added to the polymer to be molded as necessary. The additives include, for example, ceramic fibers such as glass fibers, carbon fibers and alumina fibers, metal fibers, calcium titanate, mica, silica, barium sulfate, potassium sulfate, kaolin, calcium silicate, magnesium carbonate, antimony trioxide, zinc oxide, titanium oxide , Magnesium oxide, iron oxide, molybdenum disulfide, graphite, gypsum, glass powder, quartz, silicon glass, and / or organic or inorganic pigments.

In addition, other additives that can be used in admixture with polyarylene sulfide include, for example, silane-based release agents such as aromatic hydroxy derivatives or titanic acid-based coupling agents, lubricants, heat stabilizers, weathering agents, foaming agents, corrosion inhibitors, ion barrier agents, and flame retardants. And / or flame retardant aids.

In addition, homopolymers, random or block copolymers, and graft copolymers can be mixed with polyarylene sulfides alone or as a mixture thereof, and representative examples thereof include polyethylene, polybutadiene, polyisoprene, polychloroprene, polystyrene, poly Acetal, polyphenyloxide, polysulfone, polyarylsulfone, polyethersulfone, polyetherketone, polyetheretherketone, polyimide, polyamideimide, silicone resin and / or fluororesin.

As described above, the polyarylene sulfide copolymer prepared according to the present invention has a melt viscosity that can be used directly without heat treatment, and also has a low melting temperature, and thus can be processed at a lower temperature than conventional polyarylene sulfide. have.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the following Examples.

Example 1

Synthesis of polyarylene sulfide copolymer was carried out in a high pressure reactor equipped with a mechanical stirrer and a temperature and pressure indicator attached to a 600 ml sodium sulfide (Na ₂ S.3H ₂ O) containing 13.2 g of crystal water under argon gas atmosphere. (0.1 mol), N-methyl-2-pyrrolidinone (hereinafter referred to as "NMP") 100g, sodium hydroxide 0.12g (0.003mol) and 10.81g (0.6mol) of distilled water are added and mixed, where the water content is sulfide 9 mol to 1 mol of sodium. Then, 22.41 g (0.095 mol) of p-dibromobenzene and 1.44 g (0.005 mol) of 4-chlorophenylsulfone were added thereto, followed by closing the high pressure reactor, and replacing the inside of the reactor three times with argon gas. It heated up to 240 degreeC, stirring over time, and reacted for 5 hours, continuing stirring at this temperature. After the copolymerization reaction, ice water was placed in a 2 L beaker and completely quenched to the upper end of the high pressure reactor, and then the reaction was poured into 1 L methanol, which is a non-solvent, to precipitate a polymer. The precipitated copolymer was recovered by filtration and washed again in the order of 1 L of methanol, 1 L of distilled water and 1 L of acetone. The copolymer purified by repeated washing was dried in a vacuum dryer at 100 ° C. for at least 24 hours and used for yield measurement and analysis. After the completion of the reaction, the mixture was cooled to room temperature, and then the reaction product of the slurry development was taken out, washed twice with acetone and distilled methanol, and dried in a vacuum dryer at 100 DEG C for at least 24 hours to obtain a polyphenylene sulfide copolymer. .

Examples 2 to 3

A polyarylene sulfide copolymer was prepared in the same manner as in Example 1, except that the amount of p-dibromobenzene and 4-chlorophenylsulfone was changed as shown in Table 1 below.

Comparative Example 1

13.21 g (0.1 mol) of sodium sulfide (Na ₂ · 3H ₂ O) containing crystalline water in a 200 ml pressure reactor equipped with a stirrer and a dehydration tower, NMP 50 g, 0.12 g (0.003 mol) of distilled water 10.81 g (0.6 mol) was mixed and the reactor was replaced with a nitrogen gas. Under nitrogen stream, the mixture was distilled off while the mixture was continuously heated to 190 ° C. The spilled component was 16.21 g of water.

After cooling the internal temperature of the high-pressure reactor to 170 ° C, 14.7 g (0.1 mol) of p-dichlorobenzene was dissolved in 50 g of NMP, and then this solution was added, the high-pressure reactor was sealed, and the temperature was raised to 265 ° C for 5 hours to carry out the polymerization reaction. It was done. After completion of the reaction, the reaction mixture was cooled to room temperature, and then the reaction product of the slurry development was taken out, washed twice with 1 L of methanol, acetone and distilled water, and then dried in a vacuum dryer at 120 DEG C for at least 24 hours to prepare polyphenylene sulfide. Got it.

Experimental Example

The molecular weight of the polymer was measured by gel permeation chromatograph (GPC), analyzed using a 1-chloronaphthalene as a solvent in the conditions of 1.0ml / 1 flow rate, the calibration was a polystyrene standard sample.

In addition, a differential scanning calorimeter (hereinafter referred to as "DSC") was used to analyze the thermal properties of the polymer. In DSC analysis, in order to remove the thermal history of the polymer sample, isothermal treatment was performed at 20 ° C./1 min to a temperature 30 ° C. higher than the melting point (Tm) for 1 minute, followed by quenching with liquid nitrogen, followed by quenching with liquid nitrogen again. The glass transition temperature (Tg) and melting temperature (Tm) were measured by heating (2nd run) at / 1 minute. The temperature at which half of the heat capacity change (ΔCp) of the sample occurs was defined as the glass transition temperature (Tg), and the temperatures at the maximum points of the crystallization peak and the melting peak were determined as the crystallization temperature (Tcc) and Tm.

Comparison of Polymerization Conditions and Physical Properties of Polyarylene Sulfide Copolymer and Polyphenylene Sulfide Sample Sample number Molar ratio of input (DBB / CPS mole%) Tg (℃) Tcc (℃) Tm (℃) yield(%) Mw MWD Comparative Example 1 100/00  69.9 100.5 277.5 91.3  7,480   4.31 Example 1 95/05  83.3 118.7 274.4 92.5 10,300 12.28 Example 2 90/10  95.7 132.9 266.8 84.5  7,710  6.73 Example 3 80/20 119.8 ^{-a -a} 79.6  6,860  3.70

DBB: p-dibromobenzene

CPS: 4-chlorophenylsulfone

a: not measured

As can be seen in Table 1, the polyarylene sulfide copolymer prepared in Examples 1-3 of the present invention has a higher glass transition temperature (Tg) than the polyphenylene sulfide which has been dehydrated in Comparative Example 1 It is excellent, it can be seen that the melting temperature (Tm) is low, not only easy processing, but also have an increased molecular weight. Therefore, the polyarylene sulfide copolymer prepared according to the present invention has a higher glass transition temperature (Tg) than the conventional polyphenylene sulfide that has undergone dehydration, and thus has excellent heat resistance, and has a low melting temperature (Tm) to facilitate processing. As well as having a higher molecular weight, it is industrially useful.

Claims (4)

Dissolve 1 mole of alkali metal sulfide containing crystal water in 500-1500 g of organic polar solvent, add 8-10 moles of water to 1 mole of the alkali metal sulfide, and then add a polyhalogen aromatic compound and a polyhalogen aromatic. After adding 0.9-1.1 mol of the mixture which mixed the sulfone compound in the molar ratio of 95: 5-70: 30, it heats and stirs for 1 to 10 hours at the polymerization temperature of 180-300 degreeC, The high molecular weight poly Method for preparing arylene sulfide copolymer. The high molecular weight polyarylene sulfide copolymer according to claim 1, wherein the polyhalogen aromatic sulfone compound is one selected from the group consisting of 4-chlorophenyl sulfone, 4-bromophenyl sulfone, and 4-iodine phenyl sulfone. Manufacturing method. The method of claim 1, wherein the polyhalogen aromatic compound is p-dichlorobenzene, and the polyhalogen aromatic sulfone compound is 4-chlorophenyl sulfone. The method for producing a high molecular weight polyarylene sulfide copolymer according to claim 1, wherein the molar ratio of the polyhalogen aromatic compound and the polyhalogen aromatic sulfone compound is 95: 5 to 85:15.