CN109503734B - Method for continuously extracting latex - Google Patents
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- CN109503734B CN109503734B CN201811324243.5A CN201811324243A CN109503734B CN 109503734 B CN109503734 B CN 109503734B CN 201811324243 A CN201811324243 A CN 201811324243A CN 109503734 B CN109503734 B CN 109503734B
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Abstract
The invention discloses a method for continuously extracting latex, which is a continuous latex extracting device consisting of a conductive roller as a positive electrode and a negative electrode, wherein latex is introduced into a continuous electrolytic device from a rubber inlet, the distance between the roller and the continuous electrolytic device is adjusted until the positive electrode and the negative electrode are in contact with the latex, direct-current voltage is adjusted to electroextract the rubber, a film coagulated from the positive electrode is pulled to a conveying device through a scraper, and the film is conveyed to a spray cleaning device through the conveying device to be cleaned, and then is dried and packaged to obtain a finished rubber product. The method has simple process, the obtained rubber has excellent performance, the rubber components are completely reserved, no flocculation process is generated, the method is green and environment-friendly, and the cost is saved. The process has few artificial influence factors, can realize continuous production, has stable product quality and is easy for industrial research.
Description
Technical Field
The invention relates to a method for continuously extracting latex, which solves the key problems of automatic production, acid flocculation, waste glue water treatment and the like. The rubber obtained by the method is mainly applied to the fields of car tread rubber, engineering tread rubber and the like.
Background
Traditionally, the production of solid rubber such as natural rubber is generally a flocculation process method of pouring a flocculating agent into latex and waiting for latex coagulation, and the flocculation equipment has simple process, but the long-time coagulation process of the method causes that the product quality is not easy to control and the product is unstable; the direct flocculation process has many disadvantages which limit the industrialization degree, and the main disadvantages are poor continuous production capacity, big taste of the glue product and great corrosion to equipment. The process of flocculating latex by pouring it into a flocculant is a deflocculating process, which can be used for most synthetic gums. Although the reverse flocculation process is suitable for industrial continuous production, the quality of the produced product is stable, but a large amount of flocculating agents such as sulfuric acid, inorganic salt and the like are inevitably used, on one hand, the cost is high, and on the other hand, the waste water containing sulfate radicals and the like generated in the production process needs to be treated, so that the environmental pollution is large.
The rubber particle surface is composed of lipid and charged protein, and these components have good hydrophilicity, so that they can form a function similar to a protective layer to make the latex keep a stable colloid state. Based on this principle, if the function of the protective layer is released, the latex is caused to gel or coagulate.
Acid coagulants, inorganic salt coagulants, and microbial coagulants all destroy the stability of the latex. The mechanism of acid coagulated latex is mainly to increase the content of H ions in the latex, further reduce the pH value and compress the double electric layers on the surfaces of latex particles, thereby making the hydrated film thin. When the hydrogen ion content of the latex reaches a certain concentration, the electromotive potential becomes zero, the repulsive force between the rubber particles disappears, and they are aggregated with each other to coagulate into a mass. The metal cations in the inorganic salt are also effective in coagulating the natural rubber latex. When polyvalent metal cations are added to the latex, the colloidal particle charge is neutralized, the zeta potential is lowered, and the latex destabilizes and gels.
In order to solve the problems in the rubber flocculation process, the subject provides a method for electrically extracting latex, which adopts the principle of electrophoresis method, destroys the electric double layer charged on the surface of colloidal particles under the action of charges, causes the latex particles to generate directional movement, thereby generating a flocculated rubber block through demulsification and finishing the flocculation process. The process greatly reduces manpower and material resources required by latex flocculation, saves the use of a flocculating agent, reduces the cost and saves the problem of post water treatment.
The present application has made intensive studies on industrial equipment and has proposed a practical method and apparatus for continuous electrowinning of latex.
Disclosure of Invention
The invention discloses a method for continuously extracting latex, which is characterized in that a conductive roller is used as a continuous latex extracting device consisting of an anode and a cathode, latex is introduced into the continuous latex extracting device from a latex inlet, the distance between the roller and the continuous latex extracting device is adjusted until the anode and the cathode are in contact with the latex, direct-current voltage is adjusted to electroextract the latex, a film coagulated from the anode is pulled to a conveying device through a scraper, cleaning water is sprayed out of the upper part of the conveying device to clean the film, and then the film is dried and packaged to obtain finished rubber. The method has simple process, the obtained rubber has excellent performance, the rubber components are completely reserved, no flocculation process is generated, the method is green and environment-friendly, and the cost is saved. The process has few artificial influence factors, can realize continuous production, has stable product quality and is easy for industrial research.
The process of the invention adopts the following steps:
a method for continuously extracting latex, characterized in that: the continuous latex extraction device comprises a conductive roller as a positive electrode and a negative electrode, wherein latex with the dry rubber content of 0.1-60% is introduced into the continuous latex extraction device from a rubber inlet, the roller distance is adjusted until the positive electrode and the negative electrode are in contact with the latex, the direct current voltage is adjusted to be 1.5-500V, a thin film coagulated from the positive electrode is pulled to a conveying device through a scraper, cleaning water is sprayed out from the upper part of the conveying device to clean the thin film, and then the thin film is dried and packaged to obtain the finished rubber.
The positive and negative rollers of the continuous latex extraction device are arranged closely, the distance between the rollers is adjustable, the material of the positive roller can be inert materials such as gold, platinum and the like, or the surface of the roller is coated with a conductive polymer film; the cathode roller is made of a conductive material.
The latex comprises field natural latex, concentrated latex, skim latex, styrene-butadiene latex, butyronitrile latex, chloroprene latex, butyl latex or a mixture of the above latexes, or waste glue obtained by acid, inorganic salt or polymeric flocculant and biological flocculation latex.
The method of claim 1, wherein: the drying method can be low temperature air drying, superheated steam drying, hot air drying, microwave drying, etc.
The invention realizes the purpose of continuously producing and extracting latex by self-designed equipment, and simultaneously can solve the following two industrial problems: firstly, the flocculant of the rubber is gelled, so that the consumption cost is high; the other is that the use of the flocculating agent causes great pollution to the environment and the water treatment cost is high.
The equipment and the method for extracting latex adopted by the invention fully solve the problems. The fundamental reason why latex particles are kept stable and do not break emulsion and aggregate is that the latex particles are protected by a protective layer made of hydrophilic substances such as charged proteins and lipids on the surface of colloidal particles, and the purpose can be achieved by destroying the stability of an electric double layer of the latex particles when destabilizing and breaking emulsion.
The invention provides a method for continuously extracting latex, which takes a conductive roller as a continuous latex extracting device consisting of an anode and a cathode, leads the latex into the continuous latex extracting device from a latex inlet, adjusts direct current voltage to perform electroextraction on the latex, continuously introduces a film coagulated from the anode roller into a spray cleaning device through a traction device for cleaning, and then performs drying and packaging through a drying traction device to obtain the finished rubber. The process can realize the effect of quick flocculation dehydration, and the close-type double-roller mode can ensure that the electrode plate is fully contacted with latex, improve the extraction efficiency, thereby realizing the continuous production purpose of feeding and discharging materials at the same time.
The method can be used for latex with different concentrations, including concentrated latex, field latex and the like, and simultaneously solves the key problems of flocculation drying, waste glue water treatment and the like. The produced natural rubber can be applied to the fields of car tread rubber, engineering tread rubber and the like.
The method avoids or reduces the use of a large amount of flocculating agent, and greatly reduces the cost of the rubber. Meanwhile, strong acid is also avoided being used as a coagulant of the skim coating, the sewage treatment is less, and the environment is friendly. Compared with the traditional acid method, the electrophoresis method has small artificial influence factors, is easy to obtain products with stable quality, and is suitable for continuous industrial production.
The invention has the advantages of
A process for the continuous extraction of latex, which has the advantages of:
1. the use of a large amount of flocculating agent is avoided or reduced, and the cost of the rubber is greatly reduced.
2. Avoids using strong acid as a coagulant of the skim coating, has less sewage treatment and is environment-friendly.
3. The invention has the advantages of few production steps and high quality uniformity.
4. The non-glue components in the skim latex are completely reserved, and the quality of the skim latex is improved.
5. The equipment is self-innovative equipment, the process is simple, the automation degree of the equipment is high, and the production efficiency is high.
6. The preparation process has small artificial influence factors, is easy to obtain products with stable quality, and is suitable for continuous industrial production.
All performance test standards of the invention are carried out according to corresponding national standards.
Drawings
FIG. 1 is a schematic view of the apparatus of the present invention.
1, a negative pole roller; 2, a feed inlet; 3, a positive roller; 4, a material blocking scraper plate; 5, spraying a cleaning device; 6, heating a device; 7, heating the traction device by the material; 8 material cleaning and traction device
Detailed Description
Example 1
The positive pole of the continuous latex extraction device takes gold as a roller material, the conductive electrode plate is a negative pole, 1000g of concentrated natural latex with the dry glue mass content of 25% is introduced into the continuous latex extraction device from a glue inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 500V, the film coagulated from the positive pole is continuously introduced into a spray cleaning device through a traction device to be cleaned, the residual quantity of clear liquid rubber is 0.2g, and 249.8g of finished rubber is obtained through drying and packaging.
100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of anti-aging agent 1010NA, 1g of N33030 g, 1.2g of accelerator CZ and 2g of sulfur are taken to be mixed, and after standing for 8 hours, the vulcanization curve and the rubber processability are measured, and the mechanical properties are measured after vulcanization at 150 ℃.
Example 2
The positive electrode of the continuous latex extraction device takes platinum as a roller material, the conductive electrode plate is a negative electrode, 1000g of natural latex with the dry rubber mass content of 60% is introduced into the continuous latex extraction device from a rubber inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 1.5V, a film rubber sheet coagulated from the positive electrode is continuously introduced into a spray cleaning device through a traction device to be cleaned, the residual quantity of clear liquor rubber is 0.4g, and 599.6g of finished rubber is obtained after drying and packaging. 100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of an anti-aging agent 1010NA, 1g of N33030 g, 1.2g of an accelerator CZ and 2g of sulfur are taken, rubber is mixed, and after standing for 8 hours, a vulcanization curve and rubber processability are measured, and vulcanization is carried out at 150 ℃ to measure mechanical properties.
Example 3
The positive electrode of the continuous latex extraction device takes platinum as a roller material, the conductive electrode plate is a negative electrode, 2500g of skim latex with the dry gum mass content of 6% is introduced into the continuous latex extraction device from a gum inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 110V, the film rubber sheet coagulated from the positive electrode is continuously introduced into a spray cleaning device through a traction device to be cleaned, the residual amount of clarified liquid rubber is 0.4g, and 149.6g of finished rubber is obtained through drying and packaging. 100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of an anti-aging agent 1010NA, 1g of N33030 g, 1.2g of an accelerator CZ and 2g of sulfur are taken, rubber is mixed, and after standing for 8 hours, a vulcanization curve and rubber processability are measured, and vulcanization is carried out at 150 ℃ to measure mechanical properties.
Example 4
The positive pole of the continuous latex extraction device takes platinum as a roller material, the conductive electrode plate is a negative pole, 1000g of neoprene latex with the dry glue content of 40 percent is led into the continuous latex extraction device from a glue inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 130V, a film coagulated from the positive pole is continuously led into a spray cleaning device through a traction device to be cleaned, the residual quantity of clear liquor rubber is 0.4g, and 399.6g of finished rubber is obtained after drying and packaging.
100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of anti-aging agent 1010NA, 1g of N33030 g, 1.2g of accelerator CZ and 2g of sulfur are taken to be mixed, and after standing for 8 hours, the vulcanization curve and the rubber processability are measured, and the mechanical properties are measured after vulcanization at 150 ℃.
Example 5
The positive electrode of the continuous latex extraction device is made of a roller material coated with a polypyrrole conductive polymer film, a conductive electrode plate is a negative electrode, 1500g of nitrile butadiene latex with the dry glue mass content of 40% is introduced into the continuous latex extraction device from a glue inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 180V, a film sheet coagulated from the positive electrode is continuously introduced into a spray cleaning device through a traction device to be cleaned, the residual quantity of clear liquid rubber is 0.6g, and 599.4g of finished rubber is obtained through drying and packaging.
100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of anti-aging agent 1010NA, 1g of N33030 g, 1.2g of accelerator CZ and 2g of sulfur are taken to be mixed, and after standing for 8 hours, the vulcanization curve and the rubber processability are measured, and the mechanical properties are measured after vulcanization at 150 ℃.
Example 6
The positive pole of the continuous latex extraction device takes Fe-Cu-Ni alloy as a roller material with a surface layer coated with a film, a conductive electrode plate is a negative pole, 1200g of styrene-butadiene latex with the dry glue mass content of 40% is introduced into the continuous latex extraction device from a glue inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 220V, a film sheet coagulated from the positive pole is continuously introduced into a spray cleaning device through a traction device to be cleaned, the residual amount of clarified liquid rubber is 0.6g, and 479.4g of finished rubber is obtained through drying and packaging.
100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of anti-aging agent 1010NA, 1g of N33030 g, 1.2g of accelerator CZ and 2g of sulfur are taken to be mixed, and after standing for 8 hours, the vulcanization curve and the rubber processability are measured, and the mechanical properties are measured after vulcanization at 150 ℃.
Example 7
The positive pole of the continuous latex extraction device takes iron-nickel oxide as a roller material coated with a film, the conductive electrode plate is a negative pole, 1800g of butyl latex with the dry glue mass content of 40% is introduced into the continuous latex extraction device from a glue inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 150V, a film sheet coagulated from the positive pole is continuously introduced into a spray cleaning device through a traction device to be cleaned, the residual quantity of clarified liquid rubber is 0.5g, and 719.5g of finished rubber is obtained through drying and packaging.
100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of anti-aging agent 1010NA, 1g of N33030 g, 1.2g of accelerator CZ and 2g of sulfur are taken to be mixed, and after standing for 8 hours, the vulcanization curve and the rubber processability are measured, and the mechanical properties are measured after vulcanization at 150 ℃.
Example 8
The positive pole of the continuous latex extraction device takes platinum as a roller material, the conductive electrode plate is a negative pole, 150kg of flocculated waste glue with the dry glue mass content of 0.1 percent is introduced into the continuous latex extraction device from a glue inlet, the distance between two rollers is adjusted to be fully contacted with the introduced latex, the direct current voltage is adjusted to be 380V, a thin film coagulated from the positive pole is continuously introduced into a spray cleaning device through a traction device to be cleaned, the residual quantity of clear liquid rubber is 0.3g, and 149.7g of finished rubber is obtained after drying and packaging.
100g of the solid rubber, 5g of ZnO, 2g of stearic acid, 1g of anti-aging agent 1010NA, 1g of N33030 g, 1.2g of accelerator CZ and 2g of sulfur are taken to be mixed, and after standing for 8 hours, the vulcanization curve and the rubber processability are measured, and the mechanical properties are measured after vulcanization at 150 ℃.
Comparative example 1
On a double-roller milling machine, according to the formula: 100g of smoked sheet rubber, 5g of ZnO, 2g of stearic acid, 1g of anti-aging agent 1010NA, 1.2g of accelerator CZ, 2g of sulfur, rubber mixing, standing for 8h, measuring a vulcanization curve and rubber processability, vulcanizing at 150 ℃ and measuring mechanical properties.
Comparative example 2
Adopting formic acid to flocculate 400g of concentrated latex with solid content of 60%, drying to obtain 240g of natural rubber, taking 100g of natural rubber, and mixing on a double-roller mill according to the formula: ZnO 5g, stearic acid 2g, antiager 1010NA 1g, N33030 g, accelerant CZ1.2g, sulfur 2g, rubber refining, standing for 8h, measuring vulcanization curve and rubber processing property, vulcanizing at 150 deg.C, and measuring mechanical property.
Comparative example 3
Flocculating 400g of styrene butadiene rubber with the solid content of 40% by using sulfuric acid, drying to obtain 120g of natural rubber, taking 100g of natural rubber, and mixing on a double-roller milling machine according to the formula: ZnO 5g, stearic acid 2g, antiager 1010NA 1g, N33030 g, accelerant CZ1.2g, sulfur 2g, rubber refining, standing for 8h, measuring vulcanization curve and rubber processing property, vulcanizing at 150 deg.C, and measuring mechanical property.
Comparative example 4
Flocculating 400g of nitrile rubber with the solid content of 40% by using calcium chloride, drying to obtain 160g of nitrile rubber, taking 100g of nitrile rubber, and mixing on a double-roller milling machine according to the formula: ZnO 5g, stearic acid 2g, antiager 1010NA 1g, N33030 g, accelerant CZ1.2g, sulfur 2g, rubber refining, standing for 8h, measuring vulcanization curve and rubber processing property, vulcanizing at 150 deg.C, and measuring mechanical property.
TABLE comparison of mechanical Properties of examples and comparative examples
Claims (4)
1. A method for continuously extracting latex, characterized in that: the continuous latex extraction device comprises a conductive roller as a positive electrode and a negative electrode, wherein latex with the dry rubber content of 0.1-60% is introduced into the continuous latex extraction device from a rubber inlet, the roller distance is adjusted until the positive electrode and the negative electrode are in contact with the latex, the direct current voltage is adjusted to be 1.5-500V, a thin film coagulated from the positive electrode is pulled to a conveying device through a scraper, cleaning water is sprayed out from the upper part of the conveying device to clean the thin film, and then the thin film is dried and packaged to obtain the finished rubber.
2. The method of claim 1, wherein: the distance between the positive roller and the negative roller of the continuous latex extraction device can be adjusted, and the positive roller is made of gold or platinum or a conductive polymer film is coated on the surface of the roller; the cathode roller is made of a conductive material.
3. The method of claim 1, wherein: the latex comprises field natural latex, concentrated latex, skim latex, styrene-butadiene latex, butyronitrile latex, chloroprene latex, butyl latex or a mixture of the above latexes, or waste glue obtained by acid, inorganic salt or polymeric flocculant and biological flocculation latex.
4. The method of claim 1, wherein: the drying method is low temperature air drying, superheated steam drying, hot air drying or microwave drying.
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| CN110317285A (en) * | 2019-06-12 | 2019-10-11 | 北京化工大学 | A kind of method that the deformable roller of extremely strong electric field extracts latex |
| CN110256610B (en) * | 2019-06-12 | 2021-06-08 | 北京化工大学 | Method for extracting latex by using extremely-strong electric field roller electrode |
| CN110204633A (en) * | 2019-06-12 | 2019-09-06 | 北京化工大学 | A kind of method that extremely strong electric field extracts latex |
| CN110256609B (en) * | 2019-06-12 | 2021-03-26 | 北京化工大学 | Device for extracting latex by using extremely strong electric field |
| CN110923774B (en) * | 2019-12-16 | 2021-07-20 | 海南省先进天然橡胶复合材料工程研究中心有限公司 | Electrodeposition method for preparing dried latex from fresh latex |
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| CN107629150A (en) * | 2017-07-23 | 2018-01-26 | 北京化工大学 | A kind of extracting method of latex |
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