Preparation method for dispersed graphite filled polytetrafluoroethylene resin

Abstract

The invention belongs to the technical field of fluorine-containing plastics and a preparation method thereof, and relates to a method for preparing dispersed graphite filled polytetrafluoroethylene (PTFE) resin by taking PTFE dispersion as a base material and graphite as a filling material and adopting a wet mixing method and an auxiliary agent system. The method is characterized by comprising the steps of: (1) preparing a graphite dispersion with solid content of 5% by taking 0.1% sodium polyacrylate solution as a dispersing agent; (2) uniformly mixing the graphite dispersion with PTFE dispersion with solid content of 12.7%, wherein the graphite solid content accounts for 5-70%; and (3) adding 3% succinic acid solution as an agglomeration auxiliary agent, stirring, filtering, washing and drying to obtain solid powdery resin. The preparation method provided by the invention has the beneficial effects that: the preparation process is simple and easy to industrialize, the raw material loss is low, the filling accuracy is high, the filling material is uniformly distributed, and the required filling amount can be adjusted in a large range while not changing the equipment condition so as to prepare PTFE resin with low filling amount or high filling amount, thus different needs are satisfied.

Description

technical field

[0001] The invention relates to a polytetrafluoroethylene (PTFE) dispersion liquid as a base material, graphite as a filling material, adopting a wet mixing method and an auxiliary agent system to prepare dispersed graphite-filled polytetrafluoroethylene resin. It belongs to the technical field of fluorine-containing plastics and a preparation method thereof. Background technique

[0002] Polytetrafluoroethylene (PTFE) is a widely used thermoplastic with high chemical stability and excellent lubricity, strong corrosion resistance, high and low temperature resistance, and is an important anti-corrosion and anti-friction material. It is mainly used in anti-corrosion linings, sealing materials, shock absorption and low friction parts. However, PTFE has poor mechanical properties and thermal conductivity, which limits its application range in engineering; poor wear resistance, which affects the service life of product components; insufficient electrical conducti...

Examples

Embodiment 1

[0015] A preparation method of dispersed graphite filled polytetrafluoroethylene resin, characterized in that the steps are:

[0016] (1) Preparation of graphite dispersion: take 0.1% sodium polyacrylate solution as a dispersant, add the graphite powder into the dispersant sodium polyacrylate solution under stirring, and continue stirring for 5 minutes to uniformly mix and disperse the graphite. Make the solid content of graphite in the dispersion liquid be 5%, and let it stand for use.

[0017] ⑵ Mix 2.4 liters of step ⑴ graphite dispersion with 12 liters of polytetrafluoroethylene dispersion with a solid content of 12.7% (specific gravity 1.08), and keep mechanical stirring (50-100rpm) for 5 minutes to evenly mix.

[0018] (3) Adding the succinic acid solution with a weight percent concentration of 3% in the mixed solution is a coagulation aid, and the coagulation aid addition is 240 milliliters, coagulated with mechanical stirring at 300 rpm for 5 minutes, filtered, washed,...

Embodiment 2

[0023] Change the volume of the graphite dispersion in Example 1 to 7.2 liters, add 360 grams of graphite, change the volume of the polytetrafluoroethylene dispersion to 4 liters, and change the solid content of the dispersed polytetrafluoroethylene to 549 grams, and change the coagulation aid add-on to 720 grams. Milliliters, other operation with embodiment 1. The composition of the graphite-filled tetrafluoroethylene resin in this embodiment is: the solid content of dispersed polytetrafluoroethylene is 549 grams, and the graphite is 360 grams, so the calculated filling amount is 39.6%, the thermal weight loss is 60.8%, and the actual filling amount is 39.2%.

Embodiment 3

[0025] Change the volume of the graphite dispersion in Example 1 to 7.2 liters, add 360 grams of graphite, change the volume of the polytetrafluoroethylene dispersion to 1.2 liters, and change the solid content of the dispersed polytetrafluoroethylene to 165 grams, and change the coagulation aid addition to 720 grams. Milliliters, other operation with embodiment 1. The composition of the graphite-filled tetrafluoroethylene resin in this embodiment is as follows: the solid content of dispersed polytetrafluoroethylene is 165 grams, and the graphite is 360 grams, so the calculated filling quantity is 68.6%, the thermal weight loss is 31.7%, and the actual filling quantity is 68.3%.

technical field

[0001] The invention relates to a polytetrafluoroethylene (PTFE) dispersion liquid as a base material, graphite as a filling material, adopting a wet mixing method and an auxiliary agent system to prepare dispersed graphite-filled polytetrafluoroethylene resin. It belongs to the technical field of fluorine-containing plastics and a preparation method thereof. Background technique

[0002] Polytetrafluoroethylene (PTFE) is a widely used thermoplastic with high chemical stability and excellent lubricity, strong corrosion resistance, high and low temperature resistance, and is an important anti-corrosion and anti-friction material. It is mainly used in anti-corrosion linings, sealing materials, shock absorption and low friction parts. However, PTFE has poor mechanical properties and thermal conductivity, which limits its application range in engineering; poor wear resistance, which affects the service life of product components; insufficient electrical conducti...

Examples

Embodiment 1

[0015] A preparation method of dispersed graphite filled polytetrafluoroethylene resin, characterized in that the steps are:

[0016] (1) Preparation of graphite dispersion: take 0.1% sodium polyacrylate solution as a dispersant, add the graphite powder into the dispersant sodium polyacrylate solution under stirring, and continue stirring for 5 minutes to uniformly mix and disperse the graphite. Make the solid content of graphite in the dispersion liquid be 5%, and let it stand for use.

[0017] ⑵ Mix 2.4 liters of step ⑴ graphite dispersion with 12 liters of polytetrafluoroethylene dispersion with a solid content of 12.7% (specific gravity 1.08), and keep mechanical stirring (50-100rpm) for 5 minutes to evenly mix.

[0018] (3) Adding the succinic acid solution with a weight percent concentration of 3% in the mixed solution is a coagulation aid, and the coagulation aid addition is 240 milliliters, coagulated with mechanical stirring at 300 rpm for 5 minutes, filtered, washed,...

Embodiment 2

[0023] Change the volume of the graphite dispersion in Example 1 to 7.2 liters, add 360 grams of graphite, change the volume of the polytetrafluoroethylene dispersion to 4 liters, and change the solid content of the dispersed polytetrafluoroethylene to 549 grams, and change the coagulation aid add-on to 720 grams. Milliliters, other operation with embodiment 1. The composition of the graphite-filled tetrafluoroethylene resin in this embodiment is: the solid content of dispersed polytetrafluoroethylene is 549 grams, and the graphite is 360 grams, so the calculated filling amount is 39.6%, the thermal weight loss is 60.8%, and the actual filling amount is 39.2%.

Embodiment 3

[0025] Change the volume of the graphite dispersion in Example 1 to 7.2 liters, add 360 grams of graphite, change the volume of the polytetrafluoroethylene dispersion to 1.2 liters, and change the solid content of the dispersed polytetrafluoroethylene to 165 grams, and change the coagulation aid addition to 720 grams. Milliliters, other operation with embodiment 1. The composition of the graphite-filled tetrafluoroethylene resin in this embodiment is as follows: the solid content of dispersed polytetrafluoroethylene is 165 grams, and the graphite is 360 grams, so the calculated filling quantity is 68.6%, the thermal weight loss is 31.7%, and the actual filling quantity is 68.3%.