CN108276528A - A kind of environment protection type ABS resin and preparation method thereof - Google Patents
A kind of environment protection type ABS resin and preparation method thereof Download PDFInfo
- Publication number
- CN108276528A CN108276528A CN201711446441.4A CN201711446441A CN108276528A CN 108276528 A CN108276528 A CN 108276528A CN 201711446441 A CN201711446441 A CN 201711446441A CN 108276528 A CN108276528 A CN 108276528A
- Authority
- CN
- China
- Prior art keywords
- temperature
- preparation
- abs resin
- polymerisation
- environment protection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F279/00—Macromolecular compounds obtained by polymerising monomers on to polymers of monomers having two or more carbon-to-carbon double bonds as defined in group C08F36/00
- C08F279/02—Macromolecular compounds obtained by polymerising monomers on to polymers of monomers having two or more carbon-to-carbon double bonds as defined in group C08F36/00 on to polymers of conjugated dienes
- C08F279/04—Vinyl aromatic monomers and nitriles as the only monomers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/02—Polymerisation in bulk
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F6/00—Post-polymerisation treatments
- C08F6/26—Treatment of polymers prepared in bulk also solid polymers or polymer melts
- C08F6/28—Purification
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The invention belongs to field of polymer material preparing technology, and in particular to a kind of low VOC, low smell environment protection type ABS resin and preparation method thereof.This method carries out process control based on the technological process for synthesizing ABS resin using continuous bulk, the additive amount of initiator and chain-transferring agent when by reducing polymerisation；Improve temperature when polymerisation；Improve the temperature of extrusion die when fusant squeezes out after two-stage devolatilization；And reduce second level devolatilizer vacuum pressure, reduce final condenser control temperature and improve the process control of second level devolatilizer flat plate heat exchanger temperature, to achieve the purpose that reduce product odour, to synthesize the ABS resin for meeting environmental requirement.
Description
Technical field
The invention belongs to field of polymer material preparing technology, and in particular to a kind of low VOC, low smell environment protection type ABS
Resin and preparation method thereof.
Background technology
In recent years, with the rapid development of China's automobile industry, the continuous improvement of automotive light weight technology level, introduction of production line
Increasing, auto industry increases sharply to the demand of ABS resin, and has become the most plastic products of the dosage on automobile
One of kind.Meanwhile the requirement of safety and environmental protection is also being improved year by year in automotive light weight technology evolution.2012, China was put into effect
《Air Quality Evaluation guide in passenger car》(GB/T 27630-2011), but be non-imposed.2016, National Environmental was protected
Shield portion revises the standard, has not only tightened the limit value of harmful substance, and this standard is changed to pressure standard, and in
It is come into effect from 1 day January in 2017.Therefore, how to produce low VOC, low smell ABS products become each factory research and development side
To.
The main production of ABS resin includes emulsion graft polymerization-ontology SAN blending methods and continuous bulk.Emulsion graft polymerization-
Ontology SAN blending methods use emulsion polymerization technology, can add 20 kinds or more additives in process of production, devolatilization processes are mainly
Completion is vacuumized by two-stage in being granulated extrusion, it is larger to product degree of purity and reduction volatile matter operation difficulty, cause
ABS products are partially yellow, VOC higher, and generate a large amount of waste water in process of production, Organic Pollutants in Wastewater content is high, at
Divide complexity, biodegradability poor, it is extremely difficult to handle.And continuous bulk process only adds 3-5 kind additives, product is purer, polymerization
Object passes through two-stage devolatilization in the molten state, is granulated by die head extrusion after further vacuumizing, technical process is easy to wave
Object control is sent out, the art production process tool three wastes are few, pollute small, energy-saving and environmental protection advantageous features.But using continuous bulk
ABS resin prepared by method still remains product odour greatly and VOC numerical value gets problem.By being carried out to the ABS products prepared
Detection and analysis find that influencing ABS product odours and the high factor of VOC numerical value essentially consists in following several respects：(1) residual monomer
In the presence of：Including styrene, ethylbenzene and acrylonitrile monemer；(2) influence of auxiliary agent：Including initiator and chain-transferring agent, (alcohols is to gas
Taste is affected).Therefore, it is necessary to be directed to existing continuous bulk ABS preparation methods to be improved, pass through the lean to process control
Optimization and stable operation improve the smell and VOC numerical value of ABS products.
Invention content
(1) technical problems to be solved
The present invention proposes a kind of environment protection type ABS resin and preparation method thereof, with solve how to reduce ABS resin smell and
The problem of reducing VOC numerical value.
(2) technical solution
In order to solve the above-mentioned technical problem, the present invention proposes a kind of preparation method of environment protection type ABS resin, the preparation method
Process control is carried out based on the technological process for synthesizing ABS resin using continuous bulk；Process control packet in the preparation method
Include one of following operation：
The additive amount of initiator and chain-transferring agent when a, reducing polymerisation；
B, temperature when polymerisation is improved；
C, the temperature of extrusion die when fusant squeezes out after two-stage devolatilization is improved；
D, second level devolatilizer vacuum pressure is reduced, final condenser is reduced and controls temperature, and improve second level devolatilization
Device flat plate heat exchanger temperature.
Further, it operates in a, the additive amount of initiator is 130~140ppm；The additive amount of chain-transferring agent is
1430ppm。
Further, it operates in b, each zone temperature of the first stage reactor when polymerisation is promoted 1~3 DEG C.
Further, it operates in c, the temperature of extrusion die is 241~249 DEG C.
Further, it operates in d, the vacuum pressure of second level devolatilizer is 25~30mbar；Final condenser control temperature
Degree is 55~65 DEG C；Second level devolatilizer flat plate heat exchanger temperature is 241~250 DEG C.
Further it is proposed that a kind of environment protection type ABS resin, which is obtained using the preparation method of any of the above-described
.
(3) advantageous effect
The preparation method of environment protection type ABS resin proposed by the present invention, initiator and chain tra nsfer when by reducing polymerisation
The additive amount of agent；Improve temperature when polymerisation；Improve the temperature of extrusion die when fusant squeezes out after two-stage devolatilization；
And second level devolatilizer vacuum pressure is reduced, final condenser control temperature is reduced and improves the heat exchange of second level devolatilizer tablet
The process control of device temperature, to achieve the purpose that reduce product odour, to synthesize the ABS resin for meeting environmental requirement.
Description of the drawings
Fig. 1 is that continuous bulk used in the embodiment of the present invention synthesizes the technological process of ABS resin and each unit setting is shown
It is intended to；
Fig. 2 is influence of chain-transferring agent of the embodiment of the present invention additive amount to smell and melt index；
Fig. 3 is influence of the conversion ratio of the embodiment of the present invention to residual monomer total amount and impact strength；
Fig. 4 is influence of extrusion die of the embodiment of the present invention temperature to residual monomer total amount.
Specific implementation mode
To keep the purpose of the present invention, content and advantage clearer, with reference to the accompanying drawings and examples, to the tool of the present invention
Body embodiment is described in further detail.
The present embodiment proposes that a kind of preparation method of environment protection type ABS resin, the preparation method are based on using continuous bulk
The technological process for synthesizing ABS resin carries out process control.
Technological process and each unit setting of ABS resin are synthesized using continuous bulk, as shown in Figure 1.Wherein, main single
Member includes：Material unit, additive unit, colloidal sol unit, polymerisation unit, devolatilization unit and pelletizing unit；Adjunct unit
Including circulation fluid unit, refrigeration unit, public engineer system and heat-conducting oil system.The effect of each formant is as follows：
1, material unit：Styrene, acrylonitrile and rubber are provided.
2, additive unit：Corresponding initiator, antioxidant, mineral oil, chain-transferring agent, silicon are provided in each step
Oil, antistatic agent and plasticizer.
3, colloidal sol unit：Rubber is transmitted to bale splitter entrance by conveyer belt, blob of viscose is cut into small pieces by hobboing cutter, later
It is pushed into homogenizer by spiral propeller, fritter rubber is cut into tiny rubber grain, later by using styrene, propylene
The rubber grain that homogenizer exports is delivered to glue pot by nitrile and circulation fluid together, by the blender at the top of glue pot by rubber
Particle and several solns are dissolved into the continuous phase materials of dispersion.
4, polymerisation unit：(1) material is preheating to 80-90 DEG C by preheater, continuously enters first order reactor top
Portion, material are further heated to the setting temperature of reactor in an area, while with the addition in area's initiator, material starts
Polymerisation occurs and generates a large amount of heat, polymerization conduction oil system of the heat by each subregion of generation during the reaction
Regiment commander walks, and with being incremented by for polymerization temperature, the viscosity of monomer conversion, polymer and monomer mixture improves therewith, and material is logical
The conversion ratio crossed after the first stage reactor is about 20% or so.(2) unreacted monomer, polymer and transfer line circulation fluid
(as diluent) is flowed out from first order reactor bottom, is continued into the top of the second stage reactor with the growth of polymerization temperature
Polymerisation, with the shear action of blender, the grain size of polymer determines that material passes through second substantially in the second stage reactor
Conversion ratio after stage reactor is about 40% or so.(3) unreacted monomer, polymer and transfer line circulation fluid (as
Diluent) from the second stage reactor be delivered to third stage reactor continue polymerisation, after material is by third stage reactor
Conversion ratio is about 50%~55%.Wherein, antioxidant, silicon can be added according to the difference of the trade mark in 8th area of third stage reactor
Oil additive is come physical property such as the glossiness that increases product.(4) unreacted monomer, polymer and transfer line circulation fluid (as
Diluent) top that flow to the 4th reactor from third level reactor bottom continues polymerisation, with the raising of polymerization temperature,
The conversion ratio of material is further enhanced, and 65-75% is promoted to 12 area's conversion ratios.
5, devolatilization unit：Devolatilization unit is total in two steps.First order devolatilization processes operate under normal pressure, second level devolatilization processes
It is operated under negative pressure.Wherein, (1) polymer solution enters first order devolatilization after four tandem reactors polymerize
Solution is heated to 175-200 DEG C by device, the panel heater of first order devolatilizer, flashes some diluents in material and not instead
The monomer (mainly acrylonitrile) answered.The temperature of first order devolatilizer panel heater is maintained by the way that hot-oil circulation circuit is added
Degree, the unreacted monomer in part and diluent flash to gas to first order condenser, and gas is condensed and flows into condensate liquid and connects
Closed cans is delivered to cycle liquid storage tank by recycle liquid pump.(2) polymer after first order devolatilization passes through Polymer Gear Pump
It is transported to second level devolatilizer, generally (devolatilization temperature is main at 230-250 DEG C for the temperature of the panel heater of second level devolatilizer
Depending on product grade), second level devolatilization operates that (vacuum degree is controlled by vacuum system, and general absolute pressure is small under vacuum
In 0.005MPa), remaining circulation fluid, monomer and oligomer flash under the heating of second level devolatilizer, and volatile component is first
It first passes through fractional distilling tube to condense out, oligomer is condensed and is collected into receiving tank at first, is then transported to by tar pump
In tar storage tank, cooling gas enters second level condenser, by freezing ethylene glycol solution by monomer condensation, and is collected into cold
Lime set storage tank is delivered to by pump in cycle liquid storage tank, and the gas and portion of residual monomer that are not condensed are arranged by vacuum system
Pneumatic transmission send to heating furnace and burns to exhaust gas storage tank, to achieve the purpose that technological process of production process environmental protection.
6, pelletizing unit：Polymer removes unreacted monomer and circulation fluid by the flash distillation of devolatilizer, passes through later
Gear pump after two level devolatilization is delivered at the die head of pelletizing unit, is water-cooled to 45-60 DEG C by the desalination of water bath, conveying
Material strip is cut into particle to pelleter, material is delivered to by buffering hopper by negative pressure wind, passes through the further mistake of vibrating screen later
Filter is delivered to feed bin by air blower and carries out packaging and product storage.
Based on the above-mentioned technological process for synthesizing ABS resin using continuous bulk, the environment protection type ABS resin system of the present embodiment
Process control in Preparation Method includes following operation：
1, additive dosage is reduced：
Continuous bulk synthesis ABS resin is chemistry initiation reaction, using peroxide initiator, is remained in production
Peroxide can generate the organic volatiles such as alcohol, aldehyde.Chain-transferring agent has stronger thorn using mercaptan, alcohol type organic
Nose smell, the penetrating odor smelt in ABS resin process are mainly the residual of mercaptan.Therefore, in process of production, not
In the case of influencing product quality, need to optimize control to the additive amount of auxiliary agent.Including reducing initiator additive amount, by original
Technique additive amount 155ppm is reduced to 130~140ppm；And reduce chain-transferring agent additive amount.Wherein, as shown in Fig. 2, chain turns
When shifting agent addition total amount drops to 1430ppm, smell falls below 3.5 grades, and melt index is within the scope of product requirement；It drops to
When 1400ppm, melt index declines larger.Therefore, chain-transferring agent addition total amount is optimized to 1430ppm, ABS can be reached
Product is to odor standards requirement.
2, conversion ratio is improved, residual monomer is reduced, specifically includes：
(1) polymeric reaction temperature is improved：Ontology synthesizes in the reaction process of ABS resin, in order to control glue content in product,
Ensure its toughness, substantially 75% or so, other 25% or so residual monomers are cooled down by two-stage devolatilization and recycled conversion ratio
Afterwards, it is added in reaction system again as circulation fluid.Therefore, in devolatilization cyclic process, increase the residual single control difficulty of product.
During process control optimization, while ensureing toughness of products, in order to control devolatilization system residual monomer total amount, improve de-
Quality is waved, by adjusting temperature of reactor, optimization crosslinking improves conversion rate of products so that the residual monomer total amount of product is apparent
It reduces.Specifically, adjustment each zone temperature of the first stage reactor, respectively promotes 1~3 DEG C on the basis of former technological parameter, wherein
1 area's temperature is promoted to 106.6~108.6 DEG C by 105.6 DEG C, and 2 area's temperature are promoted to 110.2~112.2 DEG C by 109.2 DEG C, 3rd area
Temperature is promoted to 110.9~112.9 DEG C by 109.9 DEG C.Influence of the conversion ratio to residual monomer total amount and impact strength, such as Fig. 3
It is shown.
(2) extrusion die temperature is improved：After the reaction of ontology ABS resin, fusant by two-stage devolatilization, with molten condition from
Die head squeezes out, and die head overdraught mouth squeezes out material strip and complete to cut after underwater cooling by vacuum pumped volatile residue monomer
Grain.The promotion of extrusion die temperature is affected to volatile matter, but temperature is excessively high, and influences material strip conveying, therefore how not
In the case of influencing continuous smooth granulation, extrusion die temperature is adjusted, is the direction optimized to process control lean.By multiple
Optimum Experiment steps up extrusion die temperature to 241~249 DEG C by 240 DEG C, realizes the maximum that product residual monomer reduces
Change.Influence of the extrusion die temperature to residual monomer total amount, as shown in Figure 4.
(3) optimization devolatilization control：Ontology ABS residual monomers and generation volatile organic compounds are mainly de- by two-stage devolatilization
Go out, devolatilization system control optimization be realize product reduce volatile matter main means, therefore from adjustment second level devolatilization system
The control of final condenser temperature optimization is set about after system vacuum degree and devolatilization, and product residual monomer total amount, which has, to be obviously improved.
Adjusted Option is：The vacuum pressure of second level devolatilizer is reduced to 25~30mbar by 35mbar；Final condenser
It is reduced to 55~65 DEG C controlled at by 70 DEG C；Second level devolatilizer flat plate heat exchanger temperature increases as 241 by 240 DEG C~
250℃.After devolatilization system optimization, product residual monomer total amount is reduced to 500ppm by the 800ppm before optimizing.
It is manufactured in the present embodiment by carrying out process control to the technological process for synthesizing ABS resin using continuous bulk
ABS resin, on the basis of product main performance is stablized, product VOC falls below 400 or so, and oder levels reach 3.5 grades, reach
ABS product environmental requirements have been arrived, customer responsiveness is good,
The above is only a preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art
For member, without departing from the technical principles of the invention, several improvement and deformations can also be made, these improvement and deformations
Also it should be regarded as protection scope of the present invention.
Claims (6)
1. a kind of preparation method of environment protection type ABS resin, the preparation method is based on using continuous bulk synthesis ABS resin
Technological process carries out process control；It is characterized in that, the process control in the preparation method includes one of following operation：
The additive amount of initiator and chain-transferring agent when a, reducing polymerisation；
B, temperature when polymerisation is improved；
C, the temperature of extrusion die when fusant squeezes out after two-stage devolatilization is improved；
D, second level devolatilizer vacuum pressure is reduced, final condenser is reduced and controls temperature, and improve second level devolatilizer and put down
Sheet heat exchanger temperature.
2. preparation method as described in claim 1, which is characterized in that in the operation a, the additive amount of the initiator is
130~140ppm；The additive amount of the chain-transferring agent is 1430ppm.
3. preparation method as described in claim 1, which is characterized in that in the operation b, by the first order reaction when polymerisation
Each zone temperature of device promotes 1~3 DEG C.
4. preparation method as described in claim 1, which is characterized in that in the operation c, the temperature of the extrusion die is
241~249 DEG C.
5. preparation method as described in claim 1, which is characterized in that in the operation d, the vacuum of the second level devolatilizer
Pressure is 25~30mbar；The final condenser is controlled at 55~65 DEG C；The second level devolatilizer flat plate heat exchanger
Temperature is 241~250 DEG C.
6. a kind of environment protection type ABS resin, which is characterized in that the ABS resin uses such as Claims 1 to 5 any one of them
Preparation method obtains.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711446441.4A CN108276528A (en) | 2017-12-27 | 2017-12-27 | A kind of environment protection type ABS resin and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711446441.4A CN108276528A (en) | 2017-12-27 | 2017-12-27 | A kind of environment protection type ABS resin and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108276528A true CN108276528A (en) | 2018-07-13 |
Family
ID=62802454
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711446441.4A Pending CN108276528A (en) | 2017-12-27 | 2017-12-27 | A kind of environment protection type ABS resin and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108276528A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113858576A (en) * | 2021-11-04 | 2021-12-31 | 辽宁北方华锦五洲化工工程设计有限公司 | Devolatilization recovery method and recovery system of ABS extruder |
| CN114409839A (en) * | 2022-01-27 | 2022-04-29 | 万华化学集团股份有限公司 | SAN resin and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5569709A (en) * | 1993-12-10 | 1996-10-29 | General Electric Company | Grafting, phase-inversion and cross-linking controlled multi-stage bulk process for making ABS graft copolymers |
-
2017
- 2017-12-27 CN CN201711446441.4A patent/CN108276528A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5569709A (en) * | 1993-12-10 | 1996-10-29 | General Electric Company | Grafting, phase-inversion and cross-linking controlled multi-stage bulk process for making ABS graft copolymers |
Non-Patent Citations (2)
| Title |
|---|
| 周川等: "《连续本体法制备ABS树脂工艺优化研究》", 《中国塑料》 * |
| 屠晓萍等: "《聚合物残单和挥发物的形成和移除》", 《化学世界》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113858576A (en) * | 2021-11-04 | 2021-12-31 | 辽宁北方华锦五洲化工工程设计有限公司 | Devolatilization recovery method and recovery system of ABS extruder |
| CN114409839A (en) * | 2022-01-27 | 2022-04-29 | 万华化学集团股份有限公司 | SAN resin and preparation method thereof |
| CN114409839B (en) * | 2022-01-27 | 2023-12-19 | 万华化学集团股份有限公司 | SAN resin and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104385475B (en) | The process units of not aqueous and solvent polymer | |
| TWI580696B (en) | Production method and molded article of methacrylic acid polymer composition | |
| JP6257570B2 (en) | Method for producing nitrile rubber free from water and solvent | |
| CN108948522A (en) | A kind of preparation method of high fluidity punching proof acrylic material | |
| SA111320291B1 (en) | Process for the production of water and solvent-free halobutyl rubbers | |
| CN108276528A (en) | A kind of environment protection type ABS resin and preparation method thereof | |
| CN110724219B (en) | Method for intermittently producing polypropylene propylene-butylene copolymer | |
| CN108473605A (en) | The method and apparatus being blended online for polymer | |
| CN101137687A (en) | Method for removing residual monomers from polyoxymethylenes | |
| CN112661910A (en) | Impact-resistant polystyrene with capacity of more than 5 ten thousand tons and equipment and production process thereof | |
| CN103044598B (en) | Method for flash evaporating and concentrating of liquid ethylene propylene rubber | |
| CN110563870A (en) | Industrial production method of synthetic rubber and industrial device for implementing method | |
| JP5855083B2 (en) | Method for producing polymer free of water and solvent | |
| CN114080403A (en) | Acrylic rubber bale with excellent processability and water resistance | |
| CN107257808B (en) | Continuous process for preparing high heat resistant copolymers | |
| CN102101898A (en) | Method for continuously preparing polymer and device thereof | |
| CN106188400B (en) | A kind of preparation process of polystyrene multi-component copolymer high molecular material | |
| CN112142900A (en) | Preparation method of styrene-acrylonitrile copolymer | |
| CN102202851B (en) | Method for producing vinyl alcohol resin | |
| CN107915900A (en) | A kind of suitable blow molding process prepares the acrylic resin of clear hollow product | |
| CN113527584A (en) | Switching method for switching GPPS production method to HIPS production method | |
| CN108299784A (en) | A kind of resistance to thermal level ABS resin and preparation method thereof | |
| CN106397089A (en) | Method and system for recovering and purifying hexane solvent in ethylene propylene rubber production | |
| CN110981998A (en) | Preparation method and preparation device of general polystyrene material | |
| CN108341897A (en) | A method of removing solvent from polymer solution |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20180713 |