Halogen-containing polymer and production method for same

Abstract

To provide a highly heat resistant flame retardant. A polymer having repeating units represented by the following formula (1), which has a weight average molecular weight as calculated as standard polystyrene of at least 6,000: ##STR00001##
wherein R is a C.sub.1-6 alkylene group, —S— or —SO.sub.2—.

Claims

1. A method for producing a polymer having repeating units represented by the following formula (1) ##STR00010## wherein R is a C.sub.1-6 alkylene group, —S— or —SO.sub.2—, which comprises reacting a compound represented by the following formula (2) and a compound represented by the following formula (3): ##STR00011## wherein R is a C.sub.1-6 alkylene group, —S— or —SO.sub.2—, and X is a halogen atom; ##STR00012## wherein R is a C.sub.1-6 alkylene group, —S— or —SO.sub.2—, and M is an alkali metal ion or a substituted or non-substituted ammonium ion; wherein the polymer has a weight average molecular weight as calculated as standard polystyrene of at least 6,000.

2. The method of claim 1, wherein the polymer has a weight average molecular weight as calculated as standard polystyrene of at least 7,500.

3. The method of claim 1, wherein the content of a monomer represented by the following formula (2) is at most 3% in the entire polymer having repeating units represented by the formula (1), as measured by GPC: ##STR00013## wherein R is a C.sub.1-6 alkylene group, —S— or —SO.sub.2—, and X is a halogen atom.

4. The method of claim 1, wherein the polymer has a melting point of at least 255° C.

5. The method of claim 1, wherein the 20 wt % weight loss temperature of the polymer is at least 365° C. at a temperature-raising rate of 10° C/min.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a GPC chart of a polymer prepared in Example 1.

(2) FIG. 2 is a GPC chart of a polymer prepared in Comparative Example 1.

REFERENCE SYMBOLS

(3) 1: peak derived from monomer (compound represented by the formula (2)) 2: peak derived from TBA material

EXAMPLES

(4) Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted to such specific Examples.

Reference Example 1: Preparation of Tetrabromobisphenol A Bis(2-Chloroethyl) Ether

(5) Into a 2 L glass separable flask equipped with a stirrer, a condenser and a dropping funnel, 200 g (0.368 mol) of tetrabromobisphenol A, 399 g (4.70 mol) of dichloroethane, 6.3 g (18.5 mmol) of tetrabromoammonium hydrosulfate and 250 g of pure water were added in this order at room temperature, followed by heating to 60° C. with stirring in a nitrogen stream. A 23 wt % sodium hydroxide aqueous solution was dropwise added at the same temperature over a period of 20 minutes, followed by reaction at 90° C. for 24 hours. After completion of the reaction, the reaction liquid was left to cool to room temperature and poured into methanol. The precipitated solid was collected by filtration, washed and dried to obtain a white solid with a yield of 83%.

(6) 1H-NMR (ppm): 1.64 (s, 6H), 3.95 (m, 4H), 4.32 (m, 4H), 7.35 (s, 4H)

Reference Example 2: Preparation of Tetrabromobisphenol a Bissodium Salt

(7) Into a 1 L glass eggplant flask, 100 g (0.184 mol) of tetrabromobisphenol A, 198 g of methanol and 14.7 g (0.368 mmol) of sodium hydroxide were added in this order at room temperature, followed by heating to 60° C. with stirring. After stirring at the same temperature for 1 hour, the solvent was distilled off, and the residue was further dried in vacuum to obtain a white solid with a quantitative yield.

Reference Example 3: Preparation of Tetrabromobisphenol a Bispotassium Salt

(8) Into a 500 mL glass eggplant flask, 30 g (0.055 mol) of tetrabromobisphenol A, 59 g of methanol and 6.19 g (0.110 mol) of potassium hydroxide were added in this order at room temperature, followed by heating to 60° C. with stirring. Thereafter, the same operation as in Reference Example 2 was carried out to obtain a white solid with a quantitative yield.

Example 1: Preparation of Polymer

(9) Into a 500 mL glass eggplant flask, 7.14 g (12.2 mmol) of tetrabromobisphenol A bis(2-chloroethyl) ether obtained in Reference Example 1, 8.12 g (12.1 mmol) of tetrabromobisphenol A bissodium salt obtained in Reference Example 2 and 30 mL of dimethylformamide were added, followed by heating to 130° C. with stirring. After stirring at the same temperature for 17 hours, the reaction mixture was left to cool to room temperature. Water was added to the reaction mixture, and the precipitated solid was collected by filtration, washed and dried to obtain a white solid (polymer) having a molecular weight of 8,400 with a yield of 91%. The GPC chromatogram of the obtained polymer is shown in FIG. 1. It is found that low molecular weight components remarkably reduced as compared with Comparative Example 1. From the GPC chart, the monomer content in the polymer was 0%.

Comparative Example 1: Preparation of Oligomer (Conventional Method)

(10) In accordance with the method disclosed in Example 14 in Patent Document 2 (JP-B-S56-8809), an oligomer having a molecular weight of 3,500 was obtained with a yield of 78%. The GPC chromatogram of the obtained oligomer is shown in FIG. 2. The monomer content in the obtained oligomer was 11%.

Comparative Example 2: Preparation of Oligomer (Conventional Method)

(11) In accordance with the method disclosed in Patent Document 2 (JP-B-S56-8809, Example 14) except that the reaction time was 17 hours, an oligomer having a molecular weight of 5,000 was obtained with a yield of 86%.

Comparative Example 3: Preparation of Oligomer (Conventional Method)

(12) In the same manner as in Comparative Example 2 except that the reaction scale was 2.29 times (that is, the weight of tetrabromobisphenol A was 250 g, and the amounts of other materials used were also increased on the same scale), an oligomer having a molecular weight of 3,500 was obtained with a yield of 80%.

Example 2: Preparation of Polymer

(13) In the same manner as in Example 1 except that into a 5 L glass eggplant flask, 540.5 g (0.808 mol) of tetrabromobisphenol A bis(2-chloroethyl) ether obtained in Reference Example 1, 475.0 g (0.808 mol) of tetrabromobisphenol A bissodium salt obtained in Reference Example 2 and 4 L of dimethylformamide were added, a polymer having a molecular weight of 8,300 was obtained with a yield of 94%. The monomer content in the polymer was less than 1%.

Example 3: Preparation of Polymer

(14) In the same manner as in Example 1 except that 30 mL of N-methylpyrrolidone was used instead of 30 mL of dimethylformamide, a polymer having a molecular weight of 9,300 was obtained with a yield of 94%. The monomer content in the polymer was less than 1%.

Example 4: Preparation of Polymer

(15) In the same manner as in Example 1 except that 30 mL of dimethylacetamide was used instead of 30 mL of dimethylformamide, a polymer having a molecular weight of 6,300 was obtained with a yield of 89%. The monomer content in the polymer was less than 1%.

Example 5: Preparation of Polymer

(16) In the same manner as in Example 1 except that 7.53 g (12.1 mmol) of tetrabromobisphenol A bispotassium salt obtained in Reference Example 3 was used instead of 8.12 g (12.1 mmol) of tetrabromobisphenol A bissodium salt obtained in Reference Example 2, a polymer having a molecular weight of 9,200 was obtained with a yield of 94%. The monomer content in the polymer was less than 1%.

Example 6: Preparation of Polymer

(17) In the same manner as in Example 1 except that 9.81 g (12.1 mmol) of tetrabromobisphenol A biscesium salt was reacted instead of 8.12 g (12.1 mmol) of tetrabromobisphenol A bissodium salt obtained in Reference Example 2, a polymer having a molecular weight of 6,300 was obtained with a yield of 90%. The monomer content in the polymer was less than 1%.

Example 7: Preparation of Polymer

(18) Into a 100 mL glass eggplant flask, 6.60 g (12.1 mmol) of tetrabromobisphenol A, 30 mL of dimethylformamide and 0.971 g (24.2 mmol) of sodium hydroxide were added in this order at room temperature, followed by heating to 60° C. with stirring. After stirring at the same temperature for 1 hour, the reaction mixture was heated to 130° C. and stirred at the same temperature for 1 hour, water in the reaction solution was distilled off, and the reaction mixture was left to cool to room temperature, and 8.12 g (12.1 mmol) of tetrabromobisphenol A bis(2-chloroethyl) ether obtained in Reference Example 1 and 30 mL of dimethylformamide were added. The mixture was stirred at 130° C. for 17 hours and left to cool to room temperature. Water was added, and the precipitated solid was collected by filtration, washed and dried to obtain a white solid (polymer) having a molecular weight of 6,200 with a yield of 93%. The monomer content in the polymer was less than 1%.

Example 8: Preparation of Polymer

(19) Into a 500 mL glass eggplant flask, 30.0 g (55.2 mmol) of tetrabromobisphenol A, 11.6 g (138 mmol) of sodium hydrogencarbonate, 55.0 g (556 mmol) of dichloroethane and 170 mL of dimethylformamide were added in this order at room temperature, followed by heating to 90° C. with stirring. After stirring at the same temperature for 3 hours, the reaction mixture was heated to 130° C., and unreacted dichloroethane was distilled off. Then, the reaction mixture was left to cool to room temperature, and 30.0 g (55.2 mmol) of tetrabromobisphenol A, 9.27 g (110 mmol) of sodium hydrogencarbonate and 170 mL of dimethylformamide were added. The reaction mixture was stirred at 130° C. for 17 hours and then left to cool to room temperature. Water was added, and the precipitated solid was collected by filtration, washed and dried to obtain a white solid (polymer) having a molecular weight of 10,000 with a yield of 96%. The monomer content in the polymer was less than 1%.

(20) Measurement of Weight Loss Temperature

(21) Using a TG-DTA measurement apparatus (manufactured by BrukerAXS, TG-DTA2020SA), TG analysis was conducted with respect to samples (polymer or oligomer) obtained in Examples 1 and 5 and Comparative Examples 1, 2 and 3. Measurement was carried out by raising the temperature at a rate of 10° C./min in the air using 10 mg of the sample. The results are shown in Table 1.

(22) TABLE-US-00001 TABLE 1 Example Example Comparative Comparative Comparative 9 10 Example 4 Example 5 Example 6 Example Example Comparative Comparative Comparative Sample 1 5 Example 1 Example 2 Example 3 3% weight ° C. 365 369 344 351 342 loss temperature 10% weight ° C. 376 374 356 361 354 loss temperature 20% weight ° C. 381 378 362 365 360 loss temperature 30% weight ° C. 385 380 363 366 364 loss temperature
Measurement of Melting Point and Coloring Starting Temperature

(23) Using a melting point measurement device (manufactured by AS ONE Corporation, ATM-01), the melting point of each of the polymer in Example 1 and the oligomer in Comparative Example 1 was measured. Further, the coloring starting temperature when the temperature raising was continued, was measured. The results are shown in Table 2.

(24) TABLE-US-00002 TABLE 2 Example 11 Comparative Example 7 Sample Example 1 Comparative Example 2 Melting point 267-275 230-242 Coloring starting 280 230 temperature ° C.
Measurement of Flame Retardancy

(25) Materials used for measurement of flame retardancy are shown below.

(26) <Polyamide Resin (A)>

(27) Polyamide 66: manufactured by TORAY INDUSTRIES INC., (trademark) AMILAN.

(28) <Brominated Flame Retardant (B)>

(29) The polymer of the present invention or brominated polystyrene was used.

(30) Brominated polystyrene (hereinafter referred to as B-2): manufactured by Albemarle Corporation, (trademark) Saytex 7010.

(31) <Inorganic Reinforcing Agent (C)>

(32) Glass fibers: manufactured by Nitto Boseki Co., Ltd., chopped strands, (trademark) CSF3PE-455S.

(33) <Antimony Flame Retardant Synergist (D)>

(34) Antimony trioxide: manufactured by SUZUHIRO CHEMICAL CO., LTD., (trademark) AT3CN.

(35) <Anti-Dripping Agent (E)>

(36) Polytetrafluoroethylene: manufactured by Mitsubishi Chemical Corporation, (trademark) METABLEN.

(37) The respective components as identified in Table 3 were charged in a twin screw extruder (ZSK-26, manufactured by Coperion), mixed at a temperature of from 230°C. to 325°C., discharged as strands and then pelletized. The obtained pellets of the polyamide resin composition were formed at a temperature of from 270 to 330° C. to obtain a standard test specimen (126 mm×12 mm×1.5 mm or 126 mm×12 mm×0.8 mm) for flame retardancy test.

(38) Flame retardancy test UL94V was conducted to evaluate flame retardancy of each test specimen. Flame retardancy is rated V-0, V-1 and V-2 in a descending order from higher flame retardancy. The results are shown in Table 3.

(39) TABLE-US-00003 TABLE 3 Comparative Example 12 Example 8 Flame retardant (B) Example 2 B-2 Parts Polyamide resin (A) 45.7 45.7 Flame retardant (B) 18.0 18.0 Glass fibers (C) 30.0 30.0 Antimony flame 6.0 6.0 retardant synergist (D) Anti-dripping agent (E) 0.3 0.3 Flame Test specimen thickness: V-0 V-0 retardancy 1.5 mm UL 94V Test specimen thickness: V-0 V-0 0.8 mm

(40) It is found from Table 3 that the polymer of the present invention has flame retardancy equal to that of brominated polystyrene which has been widely used as a flame retardant for a polyamide resin.

(41) Measurement of Mechanical Properties

(42) The pellets prepared in each of Example 12 and Comparative Example 8 were formed to obtain a standard test specimen for mechanical property test. The mechanical property test was conducted by tensile test and bending test. The tensile test was carried out using a IA test specimen using a universal testing machine 5566 (manufactured by INSTRON) in accordance with ISO527-2. The bending test was carried out using a multipurpose A1 test specimen using a universal testing machine 5566 (manufactured by INSTRON) in accordance with ISO178. The results are shown in Table 4.

(43) TABLE-US-00004 TABLE 4 Comparative Example 13 Example 9 Flame retardant (B) Example 2 B-2 Mechanical Tensile strength (MPa) 165.7 157.4 properties Bending strength (MPa) 250.7 244.7
Measurement of Heat Resistance (Melt Flow Rate)

(44) The pellets (pellets after the first kneading) prepared in each of Example 12 and Comparative Example 8 was kneaded again by a twin screw extruder (ZSK-26, manufactured by Coperion) at a temperature of from 230 to 325° C. and pelletized again. The pellets were taken as pellets after the second kneading. Likewise, pellets after the third kneading subjected to kneading three times and pellets after the fourth kneading subjected to kneading four times were prepared.

(45) With respect to the above-prepared pellets, the melt flow rate (hereinafter referred to as MFR) was measured using melt indexer (TP-401, manufactured by TESTER SANGYO CO., LTD.) in accordance with JIS K7210-1995 (two measurement conditions of temperature: 280° C., load: 1.20 kg and retention time: 6 minutes; and temperature: 300° C., load: 1.20 kg and retention time: 6 minutes).

(46) The results are shown in Table 5.

(47) The smaller the changes in the MFR values among four samples of the pellets after the first kneading, the second kneading, the third kneading and the fourth kneading, the smaller the deterioration of the resin composition by re-kneading, and the more excellent the heat resistance.

(48) TABLE-US-00005 TABLE 5 Comparative Example 14 Example 10 Flame retardant (B) Example 2 B-2 Heat resistance After first kneading 17.5 15.7 (MFR value) After second kneading 18.7 31.0 280° C. × 1.2 kg After third kneading 21.4 37.3 After fourth kneading 23.0 39.1 Heat resistance After first kneading 21.1 33.5 (MFR value) After second kneading 30.5 71.7 300° C. × 1.2 kg After third kneading 29.3 75.6 After fourth kneading 22.4 100.6

(49) It is found from Table 5 that the halogen-containing oligomer composition of the present invention has a stable MFR value even after kneading several times, and it is hardly deteriorated and is excellent in heat resistance as compared with a brominated polystyrene.

(50) The present invention has been described in detail with reference to specific embodiments, but, it is obvious for the person skilled in the art that various changes and modifications are possible without departing from the intension and the scope of the present invention.

(51) The entire disclosures of Japanese Patent Application No. 2017-133921 filed on Jul. 7, 2017 and Japanese Patent Application No. 2017-219687 filed on Nov. 15, 2017 including specifications, claims, drawings and summaries are incorporated herein by reference in their entireties.