阅读说明：本技术 一种低氯聚苯硫醚的制备方法 (Preparation method of low-chlorine polyphenylene sulfide ) 是由 陈敏 唐泽晴 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种低氯聚苯硫醚的制备方法,采用振动流化床进行脱水,得到无水硫化钠,在合成体系中分三次向无水硫化钠以不同的滴加速率滴加对二氯苯NMP溶液,在185-200℃的情况下,先向聚合釜中滴加五分之一体积的对二氯苯的NMP溶液,滴加时间为30min,保温1-2小时；在200-220℃的情况下,再次向聚合釜中滴加三分之一体积的对二氯苯的NMP溶液,滴加时间为60min,保温2-3小时；在240-260℃的情况下,最后滴加剩下体积的对二氯苯的NMP溶液,滴加时间为90min,保温5-5.5小时,采用本发明合成生产的低氯聚苯硫醚树脂,可广泛用于航空航天、电子机械等领域。(the invention discloses a preparation method of low-chlorine polyphenylene sulfide, which comprises the steps of dehydrating by adopting a vibrated fluidized bed to obtain anhydrous sodium sulfide, dripping p-dichlorobenzene NMP solution into the anhydrous sodium sulfide at three times at different dripping rates in a synthesis system, firstly dripping one fifth volume of the p-dichlorobenzene NMP solution into a polymerization kettle at 185-200 ℃, dripping for 30min, and preserving heat for 1-2 hours; dripping one third volume of NMP solution of p-dichlorobenzene into the polymerization kettle again at the temperature of 200-220 ℃, wherein the dripping time is 60min, and keeping the temperature for 2-3 hours; and finally, dropwise adding the residual volume of p-dichlorobenzene NMP solution at 240-260 ℃, wherein the dropwise adding time is 90min, and the heat preservation time is 5-5.5 h.)

1. The preparation method of the low-chlorine polyphenylene sulfide is characterized by comprising the following steps:

1) Dehydrating sodium sulfide nonahydrate: putting sodium sulfide nonahydrate and soda lime from a feeding hole into a vibrating fluidized bed dryer, heating nitrogen to 200-220 ℃, introducing the nitrogen from the bottom of the vibrating fluidized bed, continuously taking out water vapor by the nitrogen, discharging the water vapor from an air outlet, discharging dried anhydrous sodium sulfide from a discharge outlet, and feeding the dried anhydrous sodium sulfide into a polymerization kettle;

2) Adding NMP, LiCl and sodium benzoate into a polymerization kettle, wherein the weight ratio of NMP: LiCl: sodium benzoate: na (Na)₂S·9H₂The molar ratio between O is between 0.08 and 0.1: 0.5-0.75: adding in the ratio of 0.1-0.2: 1;

3) Replacing air with nitrogen for 2-3 times, punching at 0.4-0.5MPa, heating, and adding N-dichlorobenzene and Na solution into the polymerization kettle for three times₂S·9H₂The molar ratio of O is 1:1, under the condition of keeping the temperature constant at 185-200 ℃, firstly, dripping one fifth of the volume of an NMP solution of p-dichlorobenzene into a polymerization kettle for 20-30min, and preserving the heat for 1-2 hours; under the condition of keeping the temperature constant at 200-220 ℃, dropwise adding one third of the volume of the NMP solution of p-dichlorobenzene again into the polymerization kettle for 50-60min, and preserving the heat for 2-3 hours; under the condition of keeping the temperature constant at 240-260 ℃, finally, dropwise adding the NMP solution of the p-dichlorobenzene with the rest volume into the polymerization kettle for 90-100min, and preserving the heat for 5-5.5 hours;

4) after the reaction is finished, cooling the obtained polymer mixed slurry to 130-140 ℃, filtering, washing the solid with water, and drying to obtain the polyphenylene sulfide resin with the chlorine content of 300-650 ppm.

2. The method for preparing low-chlorine polyphenylene sulfide according to claim 1, wherein the mass ratio of sodium sulfide nonahydrate to soda lime is 100: 3-5.

3. The method according to claim 1, wherein the concentration of p-dichlorobenzene in said NMP solution of p-dichlorobenzene is 20-30 wt%.

4. The method of claim 1, wherein the polyphenylene sulfide resin has a melt flow rate of 250 to 280.

Technical Field

The invention relates to a preparation method of low-chlorine polyphenylene sulfide.

Background

Polyphenylene Sulfide (PPS) has excellent heat resistance, and has a continuous use temperature of 220-240 ℃ and a heat distortion temperature of 260 ℃ or higher under a load of 1.82 MPa; PPS has good flame retardance, can reach UL94-VO and 5-V grades (no dripping) without adding any flame retardant, and has low smoke generation amount in the combustion process; PPS has excellent corrosion resistance, is second to polytetrafluoroethylene, and is insoluble in any organic solvent below 200 ℃; PPS is good in electrical insulation and dielectric strength and does not change much even under high-temperature, high-humidity and high-frequency conditions; PPS also has good mechanical properties, excellent creep resistance and fatigue resistance, and because of good chemical properties and physical properties, (PPS) is widely applied to the industrial and technical fields of aerospace, electronic machinery, petrochemical industry, food, light industry and the like, and the synthesis process thereof is increasingly valued by countries in the world.

the reduction of the content of the polyphenylene sulfide chloride can improve the insulating property of the polyphenylene sulfide material, and can be used as electronic and electrical, electronic packaging materials and the like.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to solve the defects of the prior art and provide a preparation method of low-chlorine polyphenylene sulfide, wherein the chlorine content of the polyphenylene sulfide resin is 650ppm or less, and the polyphenylene sulfide resin has excellent flowability and thermal stability.

The technical scheme is as follows: in order to achieve the purpose, the technical scheme adopted by the invention is as follows:

1) dehydrating sodium sulfide nonahydrate: putting sodium sulfide nonahydrate and soda lime from a feeding hole into a vibrating fluidized bed dryer, heating nitrogen to 200-220 ℃, introducing the nitrogen from the bottom of the vibrating fluidized bed, continuously taking out water vapor by the nitrogen and discharging the water vapor from an exhaust hole, discharging dried anhydrous sodium sulfide from a discharge hole, and feeding the dried anhydrous sodium sulfide into a polymerization kettle;

2) adding NMP, LiCl and sodium benzoate into a polymerization kettle, wherein the weight ratio of NMP: LiCl: sodium benzoate: na (Na)₂S·9H₂The molar ratio between O is between 0.08 and 0.1: 0.5-0.75: adding in the ratio of 0.1-0.2: 1;

3) Replacing air with nitrogen for 2-3 times, punching at 0.4-0.5MPa, heating, and adding N-dichlorobenzene and Na solution into the polymerization kettle for three times₂S·9H₂The molar ratio of O is 1:1, under the condition of keeping the temperature constant at 185-200 ℃, firstly, dripping one fifth of the volume of an NMP solution of p-dichlorobenzene into a polymerization kettle for 20-30min, and preserving the heat for 1-2 hours; under the condition of keeping the temperature constant at 200-220 ℃, dropwise adding one third of the volume of the NMP solution of p-dichlorobenzene again into the polymerization kettle for 50-60min, and preserving the heat for 2-3 hours; while keeping the temperature constant at 240-260 ℃, the remaining volume of a solution of p-dichlorobenzene in NMP was finally added dropwise to the polymerization vesselThe dripping time is 90-100min, and the temperature is kept for 5-5.5 hours;

4) After the reaction is finished, cooling the obtained polymer mixed slurry to 130-140 ℃, filtering, washing the solid with water, and drying to obtain the polyphenylene sulfide resin with the chlorine content of 300-650 ppm.

Preferably, the mass ratio of the sodium sulfide nonahydrate to the soda lime is 100: 3-5.

Preferably, the concentration of p-dichlorobenzene in said NMP solution of p-dichlorobenzene is between 20 and 30 wt%.

Preferably, the polyphenylene sulfide resin has a melt flow rate of 250 to 280.

Has the advantages that: the invention adopts sodium sulfide nonahydrate and p-dichlorobenzene as raw materials, LiCl as a catalyst, sodium benzoate as a cocatalyst and NMP as a solvent to synthesize the low-chlorine polyphenylene sulfide resin; the method comprises the steps of dehydrating by adopting a vibrating fluidized bed to obtain anhydrous sodium sulfide, adding soda lime to reduce the generation of hydrogen sulfide, dropwise adding p-dichlorobenzene NMP solution into the anhydrous sodium sulfide at different dropwise adding rates for three times in a synthesis system, wherein the molar ratio of p-dichlorobenzene to sodium sulfide nonahydrate is 1:1, and carrying out polycondensation reaction.

Detailed Description

For the purpose of enhancing understanding of the present invention, the present invention will be further described in detail with reference to the following examples, which are provided for illustration only and are not to be construed as limiting the scope of the present invention.