Method for recovering polytetrafluoroethylene dispersion resin

Abstract

The invention relates to a method for recovering polytetrafluoroethylene dispersion resin, and the method comprises the following steps: 1) extracting a polytetrafluoroethylene dispersion resin material containing paraffin once or multiple times by using an extracting agent until the paraffin content in the material is less than 10%; and (2) continuously carrying out continuous reflux extraction on the material treated in the step (1) by using the extracting agent until the paraffin is fully leached, and controlling the outflow volume of leach liquor in unit time to be the same as the drippingvolume of the condensed extracting agent in the extraction process. Firstly, by carrying out first-step solvent extraction, most of the paraffin in waste residues is extracted; and then a small amount of tightly wrapped paraffin is subjected to continuous reflux extraction, so that the separation effect of the paraffin and the polytetrafluoroethylene dispersion resin can be effectively improved,and the method has the advantages of short separation time, low heating temperature, low solvent consumption and low energy consumption in the whole separation process, and is suitable for industriallarge-scale application.

Description

technical field

[0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a method for recovering polytetrafluoroethylene dispersed resin through the combination of multistage solvent extraction and continuous reflux extraction. Background technique

[0002] Polytetrafluoroethylene dispersion resin is an important chemical product, which is a high polymer produced by polymerization of tetrafluoroethylene monomer. It has a wide range of uses and can be used to process small rods, tubes, raw material tapes and other products with fine shapes. With the development of the economy, the product of PTFE dispersion resin will play a more important role in many fields. Its industrial production process is generally to add a certain amount of deionized water, emulsifier, initiator, stabilizer and other additives to the polymerization kettle, then close the polymerization kettle, start stirring, carry out pressure holding test and vacuum test,...

Examples

Embodiment 1

[0046] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0047] 1) Dry the waxy PTFE waste residue to a water content of 3.7%, crush it to a fineness of 100 mesh, use a thermogravimetric analyzer to carry out quantitative analysis of the wax content to 48.5%, accurately weigh 420.2g of the sample and add 3L of In the spherical three-port opening reactor, according to the solid-to-liquid ratio of paraffin and chloroform of 1:10g / mL, add 2040mL of corresponding extractant chloroform to it. Start the cantilever-type constant-speed powerful mixer to stir at a speed of 300r / min; at the same time, use the SXKW digital display temperature-controlled electric heating mantle to heat, the temperature is controlled at 50°C, and stir for 4 hours to complete the leaching. Quickly filter and separate the extract (extract phase) and residue (raffinate phase) on an all-copper double-layer hot filter funnel while hot t...

Embodiment 2

[0053] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0054] 1) Dry the waxy PTFE waste residue to a water content of 3.7%, crush it to a fineness of 100 mesh, use a thermogravimetric analyzer to carry out quantitative analysis of the wax content to 48.5%, accurately weigh 321.0g of the sample and add 3L of In the spherical three-port opening reactor, according to the solid-to-liquid ratio of paraffin and chloroform of 1:10g / mL, 1560mL of corresponding extractant chloroform was added thereto. Start the cantilever-type constant-speed powerful mixer to stir, the speed is 100r / min; at the same time, use the SXKW digital display temperature control electric heating mantle to heat, the temperature is controlled at 45°C, and stir for 4 hours to complete the leaching. Quickly filter and separate the extract (extract phase) and residue (raffinate phase) on an all-copper double-layer hot filter funnel while ...

Embodiment 3

[0060] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0061] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0062] 1) Dry the waxy PTFE waste residue to a water content of 3.7%, crush it to a fineness of 100 mesh, use a thermogravimetric analyzer to carry out quantitative analysis of the wax content to 48.5%, accurately weigh 402.1g of the sample and add 3L of In the spherical three-port open reactor, according to the solid-to-liquid ratio of paraffin and carbon tetrachloride 1:10g / mL, add 1950 mL of the corresponding extractant carbon tetrachloride to it. Start the cantilever-type constant-speed powerful mixer to stir at a speed of 300r / min; at the same time, use the SXKW digital display temperature-controlled electric heating mantle to heat, the temperature is controlled at 65°C, and stir for 4 hours to complete the lea...

technical field

[0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a method for recovering polytetrafluoroethylene dispersed resin through the combination of multistage solvent extraction and continuous reflux extraction. Background technique

[0002] Polytetrafluoroethylene dispersion resin is an important chemical product, which is a high polymer produced by polymerization of tetrafluoroethylene monomer. It has a wide range of uses and can be used to process small rods, tubes, raw material tapes and other products with fine shapes. With the development of the economy, the product of PTFE dispersion resin will play a more important role in many fields. Its industrial production process is generally to add a certain amount of deionized water, emulsifier, initiator, stabilizer and other additives to the polymerization kettle, then close the polymerization kettle, start stirring, carry out pressure holding test and vacuum test,...

Examples

Embodiment 1

[0046] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0047] 1) Dry the waxy PTFE waste residue to a water content of 3.7%, crush it to a fineness of 100 mesh, use a thermogravimetric analyzer to carry out quantitative analysis of the wax content to 48.5%, accurately weigh 420.2g of the sample and add 3L of In the spherical three-port opening reactor, according to the solid-to-liquid ratio of paraffin and chloroform of 1:10g / mL, add 2040mL of corresponding extractant chloroform to it. Start the cantilever-type constant-speed powerful mixer to stir at a speed of 300r / min; at the same time, use the SXKW digital display temperature-controlled electric heating mantle to heat, the temperature is controlled at 50°C, and stir for 4 hours to complete the leaching. Quickly filter and separate the extract (extract phase) and residue (raffinate phase) on an all-copper double-layer hot filter funnel while hot t...

Embodiment 2

[0053] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0054] 1) Dry the waxy PTFE waste residue to a water content of 3.7%, crush it to a fineness of 100 mesh, use a thermogravimetric analyzer to carry out quantitative analysis of the wax content to 48.5%, accurately weigh 321.0g of the sample and add 3L of In the spherical three-port opening reactor, according to the solid-to-liquid ratio of paraffin and chloroform of 1:10g / mL, 1560mL of corresponding extractant chloroform was added thereto. Start the cantilever-type constant-speed powerful mixer to stir, the speed is 100r / min; at the same time, use the SXKW digital display temperature control electric heating mantle to heat, the temperature is controlled at 45°C, and stir for 4 hours to complete the leaching. Quickly filter and separate the extract (extract phase) and residue (raffinate phase) on an all-copper double-layer hot filter funnel while ...

Embodiment 3

[0060] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0061] Present embodiment relates to a kind of method of reclaiming polytetrafluoroethylene dispersion resin, comprises the steps:

[0062] 1) Dry the waxy PTFE waste residue to a water content of 3.7%, crush it to a fineness of 100 mesh, use a thermogravimetric analyzer to carry out quantitative analysis of the wax content to 48.5%, accurately weigh 402.1g of the sample and add 3L of In the spherical three-port open reactor, according to the solid-to-liquid ratio of paraffin and carbon tetrachloride 1:10g / mL, add 1950 mL of the corresponding extractant carbon tetrachloride to it. Start the cantilever-type constant-speed powerful mixer to stir at a speed of 300r / min; at the same time, use the SXKW digital display temperature-controlled electric heating mantle to heat, the temperature is controlled at 65°C, and stir for 4 hours to complete the lea...

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