CN101899152A - Preparation of titanium dioxide additive in nylon-6 continuous polymerization production process - Google Patents
Preparation of titanium dioxide additive in nylon-6 continuous polymerization production process Download PDFInfo
- Publication number
- CN101899152A CN101899152A CN 201010226531 CN201010226531A CN101899152A CN 101899152 A CN101899152 A CN 101899152A CN 201010226531 CN201010226531 CN 201010226531 CN 201010226531 A CN201010226531 A CN 201010226531A CN 101899152 A CN101899152 A CN 101899152A
- Authority
- CN
- China
- Prior art keywords
- hexanolactam
- water
- section
- suspension
- extraction
- 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.)
- Granted
Links
Images
Landscapes
- Polyamides (AREA)
Abstract
The invention relates to preparation of a titanium dioxide additive in a textile nylon-6 continuous polymerization production process. Liquid caprolactam or solid caprolactam is used as a raw material. High-performance nylon-6 slices with certain molecular weight are produced by processes of melting, storage, preparation of the additive, continuous polymerization, casting and dicing, slicing and extraction, slice drying, slice conveying, metering, packing, extraction water evaporation, concentrated solution treatment and the like.
Description
Technical field:
The present invention relates to a kind of textile raw material continuous polymerization production technology for polyamide fibre 6.
Background technology:
The polymerization of hexanolactam, the difference according to its used ring opening agent (also have claim initiator) can be divided into two classes: a kind ofly make ring opening agent with alkaloids, therefore be called the alkaline process polymerization, the fast polymerization of expressing one's gratification again; Another kind uses water as ring opening agent, therefore is called hydrolytic polymerization.This device adopts hydrolytic polymerization technology.
The hydrolytic polymerization process of hexanolactam is made up of initiation addition, the growth of chain, chain balance three phases.
(1) initiation of hexanolactam and addition stage
After hexanolactam was hydrolyzed into hexosamine, the hexanolactam molecule will be connected one by one on the molecule of hexosamine and become the short molecular chain that certain reaction is arranged.
Because participating in the hexanolactam molecule of hydrolysis is minority, so the also utmost point of the molecule number of the hexosamine of hydrolysis generation
Few, therefore in this stage, mainly show as addition reaction, the initiation of addition reaction is owing to the formed negative ions of ring opening agent, the cause of having facilitated the hexanolactam molecular polarization.
(2) build phase of chain
Between the short chain molecule that in a last chemical reaction process, generates, form long chain molecule by polycondensation.
H-[-NH(CH
2)
5CO-]
n-OH+H-[-NH(CH
2)
5CO-]
m-OH＝H-[-NH(CH
2)
5CO-]
n+m-OH+H
2O
Above-mentioned two reactions steps are not well-separated in time, and two are reflected at greatly on the time sequence all and intert mutually.Just in the initial stage, take reaction as the leading factor with open loop, addition, that continues then takes reaction as the leading factor with transfer reaction.
(3) chain equilibrium stage
This stage is mainly carried out the chain permutoid reaction.Amido linkage on the long chain molecule of various differential responses is subjected to holding amino effect, carrying out acidolysis and ammonia and separating, thereby the exchange of initiation chain makes polymeric molecular-weight average reach certain value.
H-[-NH(CH
2)
5CO-]
K1-OH+H-[-NH(CH
2)
5CO-]
K2--[-NH(CH
2)
5CO-]
K3-OH
＝H-[-NH(CH
2)
5CO-]
K2-OH+H-[-HN(CH
2)
5CO-]
K1--[-NH(CH
2)
5CO-]
K3-OH
During this period, hydrolysis and polycondensation are also carried out at the same time.
According to chemical equation, store liquid caprolactam that operation sends here after the preheating of hexanolactam preheater by hexanolactam, the concentrated solution of handling with additive for preparing and recovery process is mixed in proportion, send into pressure polymerization pot, pressure polymerization pot is a pressurized operation, and hexanolactam at first carries out open loop, addition reaction in this reactor.The oligomer of initial reaction is sent to the post polymerization device through toothed gear pump in the pressure polymerization pot, and the post polymerization device is normal pressure or decompression operation, finishes polycondensation at this reactor interpolymer, and water is discharged from outside the tower, thereby makes polymer chain rise to the needed polymerization degree.
Polymer melt becomes regular cylindrical section through casting, cooling, curing in the dicing machine inscribe.Contain section quilt thermal process water extraction of counter current contact with it in extraction tower of low-grade polymer, the extraction water that contains oligopolymer is discharged by cat head, delivers to the extraction water evaporization process.Constantly dry through the hot nitrogen that the section that extracts is recycled in drying tower, one joins the drying tower epimere hot nitrogen, this strand hot nitrogen is mainly removed the surface water of section, and another strand hot nitrogen is sent into the hypomere of drying tower, and this hot nitrogen then is used for removing the residual water-content in the section.
Dried section is moisture≤0.06%, cooled section is delivered to chip bunker and slice packaging feed bin with the pulse pneumatic conveying e Foerderanlage under nitrogen protection, after be delivered to again that the spinning process feed bin is directly used in spinning or behind metering packing as international sale.
The processing technology routine of home and abroad caprolactam polymerization production at present mainly contains following three classes:
(1) one section polymerization under atmospheric pressure technology;
Two sections polymerization under atmospheric pressure technology of (2) one sections pressurizations;
Two sections decompressions of (3) one sections pressurizations polymerization technique.
Broadness (η=2.2～4.0) and device versatility characteristics according to the handiness of producing, product relative viscosity, the present invention selects two sections decompressions of one section pressurization or non-pressurized processing technology routine for use, produces a kind of textile raw material continuous polymerization production technology for polyamide fibre 6 through craft screening.
Summary of the invention:
The present invention is a raw material with liquid caprolactam or solid hexanolactam, through preparation, successive polymerization, casting pelletizing, the operations such as extraction, chip drying, section conveying, metering packing and extraction water evaporation, concentrated solution processing of cutting into slices of fusion (solid hexanolactam), storage, additive, produce the high-performance chinlon 6 section of certain molecular weight.
Production technique of the present invention may further comprise the steps:
1) processing of raw material hexanolactam,
If raw material hexanolactam solid hexanolactam is then used the hot water fusion, insulation obtains liquid caprolactam, when the raw material hexanolactam need not fusion during for liquid caprolactam, and insulation, directly use,
2) preparation of additive
Tio_2 suspension and the suspension mixed preparation of titanium dioxide hexanolactam,
The preparation of properties-correcting agent
PTA (pure terephthalic acid) and properties-correcting agent S-EED (material of a kind of nylon stabilizer S-EED, market is on sale) filter after mixing with liquid caprolactam, obtain modifier solution,
3) hexanolactam successive polymerization
Tio_2 suspension, liquid caprolactam behind the modifier solution thorough mixing, is carried out ring-opening reaction respectively, polyaddition reaction, the polyreaction of molecular chain lengthening obtains polymkeric substance,
4) pelletizing
The cooling of fused polymkeric substance, curing, moulding, the particle section of being cut into the specification equalization at last by dicing machine,
5) extraction
The section water extracts,
6) drying
Section after the extraction obtains chinlon 6 section through the super-dry cooling,
The compound method of wherein said tio_2 suspension is: the titanium dioxide de-salted water is thorough mixing under agitation, after the mixing, sedimentation 24 hours, obtain tio_2 suspension, the suspension mixed compound method of described titanium dioxide hexanolactam is: tio_2 suspension adds liquid caprolactam and obtains titanium dioxide hexanolactam mixing suspension.
The compound method of preferred tio_2 suspension is:
The de-salted water of 30% parts by weight of titanium oxide and 70% weight part is thorough mixing under high-speed stirring, mixes back sedimentation 24 hours, obtains tio_2 suspension,
Preferred titanium dioxide hexanolactam mix suspending liquid making method is as follows:
The de-salted water of 30% parts by weight of titanium oxide and 70% weight part is thorough mixing under high-speed stirring, mix back sedimentation 24 hours, obtain tio_2 suspension, tio_2 suspension add 40% weight part liquid caprolactam obtain titanium dioxide hexanolactam mixing suspension.
Preferred processing method of the present invention is as follows:
1) fusion of hexanolactam
When adopting the solid hexanolactam to be raw material, the solid hexanolactam is pulverized after the hot water fusion is heated to 85～90 ℃, and by 85 ℃ of hot water thermal insulatings,
When adopting liquid caprolactam, raw material need not fusion,
2) preparation of additive
The preparation of titanium dioxide
The de-salted water of 30% parts by weight of titanium oxide and 70% weight part is thorough mixing under high-speed stirring, mix back sedimentation 24 hours, obtain tio_2 suspension, tio_2 suspension add 40% weight part liquid caprolactam obtain titanium dioxide hexanolactam mixing suspension.
The preparation of properties-correcting agent
The properties-correcting agent of the PTA of 10% weight part, 5% weight part (use be the material of a kind of nylon stabilizer S-EED, market is on sale) and the liquid caprolactam of the de-salted water of 10% weight part and 75% weight part after agitator stirs thorough mixing, filter, obtain modifier solution
3) caprolactam polymerization
Add 0.45% weight part modifier solution, the liquid caprolactam of 99.55% weight part be preheated to 180 ℃, can add (the preferred adding) 0.3% parts by weight of titanium oxide hexanolactam mixing suspension in case of necessity, carry out the pressure polymerization ring-opening reaction, 240 ℃ of its temperature of reaction are carried out polyaddition reaction then, and temperature of reaction is 275 ℃, 3～4 hours time, the polymer viscosity that obtains is about 1.7.
Polymkeric substance carries out the polyreaction of molecular chain lengthening, is reflected under normal pressure or the vacuum and operates, and temperature is at 255 ℃, and the melt drop temperature is at 250～260 ℃, and 10 hours residence time of polymkeric substance, the viscosity of polymkeric substance is 2.4～3.5 when going out the post polymerization device,
4) pelletizing
The water quench that the fused polymkeric substance is sprayed into continuously, curing, moulding, the particle section of being cut into the specification equalization at last by dicing machine,
5) extraction
After extracting in advance in the pre-extraction of the section water pot, send into extraction and take extraction, section in extraction tower with the water counter current contact,
The blending ratio of section and water is controlled by the add-on of regulating fresh de-salted water, its bath raio 1: 1, section 24 hours residence time in extraction tower, extractable drops to below 0.5% by original 10% in the section, after separating water, drying is carried out in section
6) drying
The section of moisture percentage about 8～15% dry dwell time in the tower 24 hours, obtains moisture at the chinlon 6 section below 0.06%.
Production technique of the present invention comprises that also technology is reclaimed in the recycling of following raw material, as:
The extraction water evaporation
The extraction water that contains hexanolactam and oligomer concentrations about 10% by the pre-extraction of extraction process is concentrated to about 80%,
The concentrated solution aftertreatment
80% concentrated solution carries out aftertreatment.The concentrated solution of handling is mixed into pressure polymerization pot with fresh hexanolactam in proportion by pressure reduction and carries out polyreaction, realizes the closed cycle of hexanolactam.
Production technique of the present invention need be used some industrial equipmentss, and these equipment are general polymerization unit, as refluxing, and pressurization, drying, equipment such as controlled temperature all belong to the category of prior art.The invention reside in through screening and obtain good reaction conditions and processing step, make product meet industrialized high-level efficiency and high quality more.
Technology of the present invention has following characteristics:
1. caprolactam polymerization is a two-section type successive polymerization flow process, pre-polymerization pressurization, post polymerization decompression or normal pressure.Gas phase or liquid phase biphenyl segmentation control heating, thus polyreaction is complete in can guaranteeing to produce, the polymer viscosity fluctuation is little, and molecular weight distribution is even, regular, helps post-treatment.
2. adopt extraction water concentrated solution direct reuse novel process after high temperature, autoclaving, be equipped with the charging of certain proportion of additive with fresh hexanolactam with after the hexanolactam concentrated solution that high temperature, autoclaving are crossed is mixed in proportion again as polymerization process.
3. the multi-stage continuous extraction technology of the pre-extraction of band is adopted in the section extraction, novel tower inner member is adopted in the extraction tower design, thereby can improve extraction efficiency, after the extraction, extractable is less than 0.6% in the section, and extraction water concentration can be brought up to more than 10%, and therefore the energy consumption that makes hexanolactam reclaim can reduce greatly.
4. chip drying adopts two sections nitrogen circulation adverse current successive drying flow processs, and when dry, by successive drying, drying effect is good like this in closed system in section, and the section water ratio is low, and can not be subjected to atmospheric oxidation, so chipping qualities is good.Both can satisfy and produce the section of polyamide fibre 6 high speed spinnings, and can carry out solid phase polycondensation again and produce full-bodied engineering plastics.
5. section is carried and is adopted home-made closed nitrogen circulation pulse pneumatic conveying delivery technology.
6. the technology of triple effect evaporation is adopted in the extraction water evaporation.
7. titanium dioxide mixes back sedimentation 24 hours with de-salted water, obtains superior in quality tio_2 suspension, adds titanium dioxide hexanolactam mixing suspension simultaneously in the polyreaction, and reaction is accelerated.
Description of drawings:
Fig. 1: process flow diagram
Fig. 2: apparatus and process schematic flow sheet
Embodiment:
Further specify the present invention by the following examples, but not as limitation of the present invention.
Embodiment 1
1. the fusion of hexanolactam and storage
When adopting the solid hexanolactam to be raw material, the solid hexanolactam that is stored in the warehouse is carried to melting zone through fork truck, and Kai Bao is after after hexanolactam charging system (X-1100) pulverizing, send in the hexanolactam fusion pot (V-1101) through screw feeder again.The solid hexanolactam of Jia Ruing is after the hot water fusion first, circulate through hexanolactam recycle pump (P-1101) supercharging by hexanolactam prefilter (X-1101), be heated to 85～90 ℃ by hexanolactam well heater (E-1101), the hexanolactam well heater is by steam heating.Hexanolactam after the heating is back to the fusion pot; with initiate solid hexanolactam mixed melting; the fused liquid caprolactam is delivered to hexanolactam middle vessel (V-1103) after hexanolactam strainer (X-1102) filters, basin is established the protection of nitrogen envelope, by 85 ℃ of hot water thermal insulatings.
When adopting liquid caprolactam, raw material is transported to the tank field with tank car, and liquid caprolactam is from the tank car discharge by pump and deliver to hexanolactam middle vessel (V-1103).
The liquid caprolactam that is stored in the hexanolactam middle vessel is delivered to additive preparation and polymerization process by hexanolactam charge pump (P-1102) through hexanolactam strainer (X-1103).
2. the preparation of additive
The preparation of titanium dioxide
Titanium dioxide is used for producing half delustring or full-dull nylon 6-slice, packed titanium dioxide weight is on request poured titanium dioxide preparing tank (V-1141) into, with de-salted water thorough mixing under high-speed stirring, be made into tio_2 suspension, deliver to titanium dioxide slurry tank (V-1142), after sedimentation in 24 hours, suspension is delivered to titanium dioxide weighing jar (V-1144), allocate a certain amount of hexanolactam into, regulate the concentration of titanium dioxide, it is stand-by to deliver to tio_2 suspension basin (V-1145) again.
The thick tio_2 suspension of discharging from titanium dioxide slurry tank (V-1142) bottom drains into titanium dioxide accumulator tank (V-1146), will reclaim titanium dioxide after the water evaporates with the steam coils heating.
The preparation of properties-correcting agent
Packed PTA and properties-correcting agent are after solid properties-correcting agent feeding unit (X-1131) metering, join properties-correcting agent Preparation tank (V-1131), with liquid caprolactam after agitator stirs thorough mixing, filter through properties-correcting agent strainer (X-1133), deliver to properties-correcting agent susceptor (V-1133), deliver to polymerization process through properties-correcting agent volume pump (P-1132) again.
3. hexanolactam successive polymerization
Polyreaction comprises two stages.Be the compressive reaction of fs and the normal pressure or the decompression reaction of subordinate phase.
When producing half delustring section, add a certain amount of tio_2 suspension from pressure polymerization pot (R-1201) ingress.The fresh liquid hexanolactam is delivered to hexanolactam preheater (E-1201) through hexanolactam charge pump (P-1102) and is preheated to 180 ℃, the concentrated solution that titania solution (in case of necessity), modifier solution and the recovery process of sending here with the additive preparation process handled is by a certain percentage by behind the static mixer thorough mixing, send into pressure polymerization pot (R-1201) top again, the pressure of pressure polymerization pot (R-1201) is controlled at 0.15MPa (G) by the top exhaust regulating valve.Epimere at polymerizing pipe mainly carries out ring-opening reaction, 240 ℃ of its temperature of reaction, the hexanolactam hydrolysis need absorb heat, the reactor upper design a built-in well heater, come heat supplied with biphenyl steam (270～280 ℃).After biphenyl steam is condensed, heats again vaporization cycle at biphenyl vaporizer (E-1202) with liquid phase heating agent (320 ℃) and use.Polyaddition reaction is carried out in the pressure polymerization pot bottom, and temperature of reaction is 275 ℃, and reaction institute heat requirement is provided by the gas diphenyl (270～280 ℃) that the wall chuck feeds by biphenyl vaporizer (E-1203) heating.Polymkeric substance stopped in pressure polymerization pot about 3～4 hours, and when going out pressure polymerization pot, polymer viscosity can reach about 1.7.
The reinforced liquid level control by flow and pressure polymerization pot of hexanolactam, feeding quantity is measured with a mass flowmeter.Hexanolactam preheater (E-1201) and heat with a secondary liquid phase heating agent loop to the product pipeline of pressure polymerization pot (R-1201), the temperature in this loop can independently be controlled.
By the liquid level control of preceding poly-discharging pump (P-1201) and post polymerization device (R-1202), prepolymer is sent to post polymerization device (R-1202), and what the post polymerization device mainly carried out is the polyreaction of molecular chain lengthening.Post polymerization device (R-1202) is in normal pressure (also can in vacuum) operation down, heat with gas diphenyl on its top, in, the bottom is with the heat exchange of liquid phase biphenyl, the built-in interchanger of particular design cools off with liquid phase biphenyl, remove the reaction liberated heat, the heat of cooling section is recovered and is used for the preheating hexanolactam.The upper temp of control post polymerization device is at 255 ℃, the melt drop temperature is at 250～260 ℃, about 10 hours of the residence time of polymkeric substance, the viscosity of polymkeric substance can reach 2.4～3.5 when going out the post polymerization device, and the special construction of this equipment can guarantee that product flows therein equably.Factory can be according to the demand of market to product specification, the vacuum tightness that the control post polymerization is produced, thereby the polymerization section of producing different viscosity.
When reacting in pressure polymerization pot (R-1201) and post polymerization device (R-1202), water and hexanolactam are evaporated.Steam is through separation column (T-1203) distillation, and the solution that contains hexanolactam is delivered to hexanolactam water enrichment process through separation column (T-1203), and outer dispatch sewage works is handled after the overhead vapours condensation.。
Post-polymerization device bottom material is discharged with a melt discharging pump (P-1205).Pump is delivered to fondant filter (X-1204) and casting head (X-1202) with polymkeric substance through the polymkeric substance pipeline of heating.Fondant filter is the strainer that do not stop, and when needs switch filtering device, reserve filter switches by valve and just can start.
4. pelletizing
Extrude the aperture of fused polymkeric substance from end of extruded band, the particle of specification equalization is cut in water quench, curing, the moulding that is sprayed into continuously on the cooling plate of dicing machine (M-1201) under water at last by dicing machine.Section falls into pre-extraction water pot (V-1301) after vibratory screening apparatus (M-1202) separates underproof section and surperficial moisture content.
The pelletizing water coolant of finishing after the pelletizing flows into pelletizing water basin (V-1208); extract out by pelletizing water-circulating pump (P-1209); deliver to pelletizing water filter (X-1203) and filter out solids, and pelletizing watercooler (E-1212) is cooled to 16 ℃ by 7 ℃ refrigerated water and sends dicing machine back to and recycle.
The monomer vapours at the monomer vapours at end of extruded band place and dicing machine place is by air-breathing squirt pump (J-1202) sucking-off; the injection water of air-breathing squirt pump is provided by injection water recycle pump (P-1208); the injection water recycle pump is extracted injection water out from pelletizing water basin (V-1208) and is sent into air-breathing squirt pump, has drawn the injection water inflow pelletizing water basin (V-1208) behind the monomer and has used repeatedly.
The frequency transformer and the discharging gear pump motor frequency transformer of underwater pelletizer (M-1201) motor are chain, and dicing machine can be regulated automatically according to what of polymer flow rate, work in the best condition with the maintenance machine.
5. continuous extraction
Section falls into pre-extraction water pot (V-1301) from vibratory screening apparatus, after section extracts in pre-extraction water pot in advance, rotational lock inlet valve (X-1301) quantitative discharging at the bottom of jar, section and water are extracted out through section slush pump (P-1302) and are sent into the hydathode (X-1303) that is located at the extraction cat head, after separating big water gaging, section falls into extraction and takes (T-1301).Extraction is extracted water-circulating pump (P-1304A/B) with de-salted water and extracts out from extraction water pot (V-1304), after extraction water strainer (X-1304) filters out solids, ℃ entered extraction tower (T-1301) through extraction water well heater (E-1302) by 0.3MPa (G) steam heating to 97 again from the tower bottom, section in extraction tower with the water counter current contact.Throughput according to device, the forms such as single-stage extractions such as one-level extraction tower, secondary extraction tower and three grades of extraction towers or multi-stage solvent extraction that are provided with of extraction tower, multi-stage solvent extraction and single-stage extraction process form are basic identical, the just repetition of single-stage extraction, level extracts in principle that extraction temperature is higher than the prime extraction after the technology controlling and process.
The section and the blending ratio of water are controlled by the add-on of regulating fresh de-salted water, and its bath raio 1: 1 is cut into slices about 24 hours of the residence time in extraction tower, and extractable drops to below 0.5% by original 10% in the section.Qualified section rotational lock inlet valve (X-1305 or X-1308) at the bottom of tower is controlled continuous discharging, to cut into slices by section cement slurrypump (P-1305 or P-1307) and water is delivered to the water extracter (M-1301) that is located at the drying tower top, separating cuts into slices behind the water falls into drying tower (T-1401) again.
The water that water extracter (M-1301) is told flows into extraction water sealed cans (V-1307) with one of the de-salted water that replenishes, extraction water sealed cans inner coil pipe feeds the steam of 0.3MPa (G), the temperature of extraction water is heated to about 95 ℃, extraction water is discharged from extraction water sealed cans top, flow into extraction water pot (V-1306) from top, here the gas of carrying secretly in the water is discharged from outdoor and controls the liquid level that extracts water pot and exceeds 500mm than extraction tower (T-1301) liquid level.The extraction water of getting rid of at the bottom of the jar is divided into two-way, one the road flows into rotational lock inlet valve (X-1308) provides water for the section conveying, one the road flows into extraction water recycle pump (P-1306), after extraction water strainer (X-1307) filters, ℃ entered extraction tower (T-1302) through extraction water well heater (E-1303) by 0.3MPa (G) steam heating to 98 again from the tower bottom, with the section counter current contact, extraction monomer and oligomer wherein.
The extraction water that contains monomer concentration about 7.5% flows out from one-level extraction tower top, with the hydration of getting rid of from hydathode (X-1303) also, one the road flows into rotational lock inlet valve (X-1301) provides water for the section conveying, one the road flows into pre-extraction water pot (V-1301) end, from the effusive extraction water monomer concentration about 10% in pre-extraction water pot top, be sent to extraction water pot (V-1601) and store, hexanolactam is stand-by as reclaiming.
In pre-extraction water pot and extraction tower equipment, be provided with multi-layer efficient, no stagnant area and strengthen extraction water and the tower inner member of cutting into slices and fully contacting.Pre-extraction water pot is provided with a heating jacket, feeds the low-pressure steam heating of 0.05MPa (G) in the chuck, to keep pre-extraction water temperature.Be provided with a special built-in well heater at the bottom of the extraction Tata, the low-pressure steam heating of interior feeding 0.3MPa (G) guarantees the extraction efficiency to oligopolymer with convenient adjusting to extraction temperature.
6. successive drying
The section moisture percentage that comes out from water extracter (M-1301) is about 8～15%, enters the drying tower (T-1401) from the top, according to the throughput of device, establishes a cover drying tower system or two covers drying tower system arranged side by side.Desiccant hot nitrogen divides two strands from tower bottom and tower middle part adding tower, the hot nitrogen that top adds is mainly used in dry sliced surface-moisture, and the heating section, and the hot nitrogen that the bottom adds removes the remaining moisture of section, and the heated polymerizable thing, its molecular weight is improved.Section about 24 hours at dry dwell time in the tower.It is moisture below 0.06% to cut into slices when going out drying tower, and dry good section is sent to section cooling feed bin (V-1403) after star is measured transfer valve (X-1401) dominant discharge.Under the circulation cooling of cold nitrogen gas stream, after section is cooled to qualified temperature, be sent to section blending bun (V-1506) through pneumatic conveyer.
Nitrogen ejects from drying tower, after the pressurization of the first nitrogen circulation blower fan (C-1401), part nitrogen is entered drying tower by after 1.0MPa (G) steam heating to 130 ℃ from the middle part through nitrogen heater (E-1401), another part nitrogen enters nitrogen heat exchanger (E-1402) with after the next cold nitrogen heat exchange in cooling tower (T-1402) top, go into tower from the cooling tower bottom, with the spraying cooling water counter current contact that adds from tower top, nitrogen is washed, cooling back temperature is controlled at 12 ℃ and comes out from cat head, after entering nitrogen heat exchanger (E-1402) and high temperature nitrogen heat exchange, enter the second nitrogen circulation blower fan (C-1402), enter nitrogen deoxygenator (R-1401) after the supercharging, nitrogen heater (E-1404) is by 1.0MPa (G) steam heating to 125 ℃, enter drying tower from the bottom, recycle.
Cooling tower (T-1402) bottom spray water is delivered to spray water recycle pump (P-1401) and is cycled back to cooling tower top spray after spray water water cooler (E-1403) is cooled to 12 ℃ extremely down, cooling shunts to wet nitrogen from the drying tower top, cool down unnecessary water of condensation from the cooling tower overflow to water-sealed tank (V-1404), and overflow effluxes again.
Cool nitrogen is delivered to nitrogen cooler (E-1405) by nitrogen three-circulation wind machine (C-1403), be cooled with circulating water, send into the bottom of section cooling feed bin (V-1403) then, nitrogen is discharged by the equipment top from bottom to top, loops back the three-circulation wind machine after dust filter unit (X-1403) dedusting.
Also can carry out the solid phase aftercondensated in drying tower, but the temperature requirement of nitrogen is higher, the residence time of section is more longer.When carrying out the solid phase aftercondensated, the nitrogen that comes out in the drying tower top need all be delivered to cooling tower and wash.
7. section is carried and packing
Being located at the beneath pulse transfer pot (V-1502) of section cooling feed bin (V-1403) is used for section is transported to section blending bun (V-1506), cuts into slices and store feed bin (V-1507).Finished product section can be stored under the feed bin (V-1507) through wrapping machine (M-1501) metering, packing in section blending bun (V-1506) or section, puts export trade in storage after dressing up the pouch of the sack of 750kg or 25kg.
Option: be located at pulse transfer pot (V-1503) under section blending bun (V-1506) and be used for that section is transported to section and store feed bin (V-1507) or directly be delivered to the spinning feed bin and be used for spinning.
Underproof section is directly delivered to packaging system and is packed separately.
Conveying is used with nitrogen circulation, delivers to the pulse transfer pot again after sack cleaner (X-1501), nitrogen compressor (C-1501) and circulating nitrogen gas basin (V-1501) pressurization.
8. extraction water evaporation
Extract the extraction water that contains hexanolactam and oligomer concentrations about 10% that water pot (V-1301) is sent here in advance by extraction process, flow into extraction water pot (V-1601) (all water that contain hexanolactam all are collected in wherein in the device).Extract out, filter through extraction water charge pump (P-1601), send into one and imitate evaporator tower (T-1601).One thermal source of imitating reboiler (E-1601) is provided by two secondary steams of imitating evaporator tower, extraction water is heated to 80 ℃ and enters an effect evaporator tower (T-1601), this tower working pressure is 0.04MPa (absolute pressure), the aqueous vapor that cat head steams is cooled off through condenser (E-1602) condensation, phlegma flows into phegma holding tank (V-1602), and a phlegma of imitating reboiler is also collected phegma holding tank (V-1602).Partial condensation liquid squeeze into through reflux pump (P-1602) one imitate, two imitate, the triple effect evaporation tower refluxes, all the other phlegmas return extraction process and make extraction water usefulness, the closed cycle of realization water.Non-condensable gas is extracted out through vacuum pump (K-1601), to keep cat head negative-pressure operation condition.Through an effect evaporation, extraction water concentration brings up to 15% at the bottom of the tower, is extracted out by hexanolactam water pump (P-1603) and delivers to two effect evaporator towers (T-1602).
The thermal source of two effect reboilers (E-1602) is provided by the secondary steam of triple effect evaporation tower, extraction water is heated to 98 ℃ and enters two effect evaporator towers (T-1602), this tower working pressure is 0.08MPa (absolute pressure), the aqueous vapor that cat head steams is used as a thermal source of imitating reboiler (E-1601), and two phlegmas of imitating reboiler are collected phegma holding tank (V-1602) too.Through an effect evaporation, extraction water concentration brings up to 25% at the bottom of the tower, is extracted out by hexanolactam water pump (P-1604) and delivers to triple effect evaporation tower (T-1603).
By two imitate the extraction water come through triple effect reboiler (E-1603) by 1.0MPa (G) steam heating to 138 ℃, triple effect evaporation tower working pressure is 0.04MPa (G), extraction water is concentrated to about 80% at this tower, and spissated caprolactam water solution flows into the hexanolactam water feed pot (V-1604) at the bottom of tower certainly by the jacket pipe by 0.3MPa (G) steam insulation.
9. concentrated solution aftertreatment
80% concentrated solution is stored in the hexanolactam water feed pot (V-1604), and by concentrated solution recycle pump (P-1604) pump circulation, hexanolactam water feed pot and circulation line are by 0.3MPa (G) steam insulation.Partial concentration liquid is pressurized to 2.9MPa (G) by concentrated solution fresh feed pump (P-1605), is heated to 250 ℃ by concentrated solution well heater (E-1605) and enters in the cracking reactor (R-1601) and carry out aftertreatment.The concentrated solution of handling is mixed in the pressure polymerization pot (R-1201) with fresh hexanolactam in proportion by pressure reduction and carries out polyreaction, realizes the closed cycle of hexanolactam.
The required heat of concentrated solution aftertreatment is supplied with by biphenyl steam (275 ℃), after biphenyl steam is condensed, heats again vaporization cycle at biphenyl vaporizer (E-1606) with liquid phase heating agent (320 ℃) and uses.
10. hot-water system
The hot water that is come by house steward hot water backwater is delivered to hot water heater through hot water circulating pump (P-8101) and is circulated after the needed temperature with 0.3MPa (G) steam heating and deliver to each hot water user.Divide another branch road supply and demand low-temperature water heating user after hot water water cooler (E-8101) is cooled to needed temperature to use behind the hot water circulating pump.The return main need be connected to hot water expansion slot (V-8101).
11. steam condensate
Each steam user's vapor condensation moisture different pressures grade is delivered to hot well (V-9421) through coagulating the supply mains, and fusion workshop (far away) user's steam condensate is sent back to by condensated water recovering pump.Hot well (V-9421) has the special setting interchanger and is used to reclaim overheated condensed water heat.Water of condensation in the receiving tank is then delivered to the boiler house by condensate pump (P-9421).
12. biphenyl is reinforced and collection
Liquid phase biphenyl is stored in the biphenyl holding tank (V-8201), is sent to each user through biphenyl fresh feed pump (P-8201).Biphenyl holding tank escape pipe is provided with condensing works, and by the gas diphenyl of water coolant and air cooling discharging, non-condensable gas discharges through height point.
Each gas diphenyl system establishes one's own system, by charging of gas phase furnace bottom and discharge, condensation biphenyl also returns from the bottom, gas diphenyl is expelled to each user's point from furnace roof portion, escape pipe is provided with safety valve, and the gassy system vertex is provided with the biphenyl vapor-liquid separation tank, and non-condensable gas irregularly drains into the biphenyl holding tank (V-8201) from the vapor-liquid separation tank deck, lime set is returned the gas phase stove
Liquid phase biphenyl system is made up of biphenyl recycle pump, well heater and biphenyl expansion slot, the shared biphenyl expansion slot of two cover liquid phase biphenyl systems of post polymerization device, the height point of system is provided with vent line and inserts expansion slot, and expansion slot is provided with manual exhaust (advancing the biphenyl holding tank) and safety valve.Liquid phase systems biphenyl is reinforced to be arranged on expansion slot top, and the blowing pipeline is arranged on the lower-most point of system.The outlet line of well heater is provided with safety valve.
The blowing pipeline of each system and the outfall pipeline of safety valve all insert the biphenyl holding tank.
13. primary fluid heating system
The heating system of pressure polymerization pot (R-1201), post polymerization device (R-1202) and cracking reactor (R-1601) is no matter vapour phase or liquid phase all heat with primary fluid.
The primary fluid medium is modification terphenyl or biphenyl-biphenyl ether, as uses biphenyl-biphenyl ether, and the primary fluid system needs pressurized treatment.Primary fluid is delivered to each user after the heating agent process furnace is heated to 320 ℃ of temperature, the heating agent that each user flows back to is delivered to the heating of heating agent process furnace through heat medium circulation pump, realizes the recycle of heating agent.The high point of return main is provided with the primary fluid expansion slot, is used for the expansion and the exhaust of primary fluid, and low spot is provided with the heating agent blowdown vessel.
14. the process control system of device
The technology controlling and process of whole device is finished by a general distributed control system (DCS), and distributed control system all has redundancy on communication function and technology controlling and process function.
Other complete supply of material equipment such as section flow delivery systems and underwater pelletizer system are established the field control cabinet in addition.
Claims (2)
1. continuous polymerization production technology for polyamide fibre 6 may further comprise the steps:
1) processing of raw material hexanolactam,
If raw material hexanolactam solid hexanolactam is then used the hot water fusion, insulation obtains liquid caprolactam, when the raw material hexanolactam need not fusion during for liquid caprolactam, and insulation, directly use,
2) preparation of additive
Tio_2 suspension and the suspension mixed preparation of titanium dioxide hexanolactam,
The preparation of properties-correcting agent
After PTA and properties-correcting agent S-EED and liquid caprolactam mix, filter, obtain modifier solution,
3) hexanolactam successive polymerization
Tio_2 suspension, liquid caprolactam behind the modifier solution thorough mixing, is carried out ring-opening reaction respectively, polyaddition reaction, the polyreaction of molecular chain lengthening obtains polymkeric substance,
4) pelletizing
The cooling of fused polymkeric substance, curing, moulding, the particle section of being cut into the specification equalization at last by dicing machine,
5) extraction
The section water extracts,
6) drying
Section after the extraction obtains chinlon 6 section through the super-dry cooling,
It is characterized in that, the compound method of wherein said tio_2 suspension is: the titanium dioxide de-salted water is thorough mixing under agitation, after the mixing, sedimentation 24 hours, obtain tio_2 suspension, the suspension mixed compound method of described titanium dioxide hexanolactam is: tio_2 suspension adds liquid caprolactam and obtains titanium dioxide hexanolactam mixing suspension.
2. according to the production technique of claim 1, step is as follows:
1) fusion of hexanolactam
When adopting the solid hexanolactam to be raw material, the solid hexanolactam is pulverized after the hot water fusion is heated to 85～90 ℃, and by 85 ℃ of hot water thermal insulatings,
When adopting liquid caprolactam, raw material need not fusion,
2) preparation of additive
Tio_2 suspension and the suspension mixed preparation of titanium dioxide hexanolactam,
The preparation of properties-correcting agent
The liquid caprolactam of the de-salted water of the properties-correcting agent of the PTA of 10% weight part, 5% weight part and 10% weight part and 75% weight part is filtered after agitator stirs thorough mixing, obtains modifier solution,
3) caprolactam polymerization
Add 0.45% weight part modifier solution, the liquid caprolactam of 99.55% weight part is preheated to 180 ℃, add 0.3% parts by weight of titanium oxide hexanolactam mixing suspension in case of necessity, carry out the pressure polymerization ring-opening reaction, 240 ℃ of its temperature of reaction are carried out polyaddition reaction then, temperature of reaction is 275 ℃, 3～4 hours time, the polymer viscosity that obtains is about 1.7
Polymkeric substance carries out the polyreaction of molecular chain lengthening, is reflected under normal pressure or the vacuum and operates, and temperature is at 255 ℃, and the melt drop temperature is at 250～260 ℃, and 10 hours residence time of polymkeric substance, the viscosity of polymkeric substance is 2.4～3.5 when going out the post polymerization device,
4) pelletizing
The water quench that the fused polymkeric substance is sprayed into continuously, curing, moulding, the particle section of being cut into the specification equalization at last by dicing machine,
5) extraction
After extracting in advance in the pre-extraction of the section water pot, send into extraction and take extraction, section in extraction tower with the water counter current contact,
The blending ratio of section and water is controlled by the add-on of regulating fresh de-salted water, its bath raio 1: 1, section 24 hours residence time in extraction tower, extractable drops to below 0.5% by original 10% in the section, after separating water, drying is carried out in section
6) drying
The section of moisture percentage about 8～15%, dry dwell time in the tower 24 hours, obtain moisture at the chinlon 6 section below 0.06%,
It is characterized in that the compound method of described tio_2 suspension is as follows:
The de-salted water of 30% parts by weight of titanium oxide and 70% weight part is thorough mixing under high-speed stirring, mixes back sedimentation 24 hours, obtains tio_2 suspension,
Described titanium dioxide hexanolactam mix suspending liquid making method is as follows:
The de-salted water of 30% parts by weight of titanium oxide and 70% weight part is thorough mixing under high-speed stirring, mix back sedimentation 24 hours, obtain tio_2 suspension, tio_2 suspension add 40% weight part liquid caprolactam obtain titanium dioxide hexanolactam mixing suspension.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010102265314A CN101899152B (en) | 2010-07-09 | 2010-07-09 | Preparation of titanium dioxide additive in nylon-6 continuous polymerization production process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010102265314A CN101899152B (en) | 2010-07-09 | 2010-07-09 | Preparation of titanium dioxide additive in nylon-6 continuous polymerization production process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101899152A true CN101899152A (en) | 2010-12-01 |
| CN101899152B CN101899152B (en) | 2012-11-28 |
Family
ID=43225102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010102265314A Active CN101899152B (en) | 2010-07-09 | 2010-07-09 | Preparation of titanium dioxide additive in nylon-6 continuous polymerization production process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101899152B (en) |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102060992A (en) * | 2010-11-02 | 2011-05-18 | 北京三联虹普新合纤技术服务股份有限公司 | Process for producing high-viscosity chips by applying solid-phase viscosifying technology |
| CN102775600A (en) * | 2012-08-01 | 2012-11-14 | 武汉森大科技研究发展中心 | Polymerization manufacturing technique and device for polyamide |
| CN103466869A (en) * | 2013-07-23 | 2013-12-25 | 江苏海阳化纤有限公司 | Total reuse and recovery system for polyamide 6 monomer |
| CN104313722A (en) * | 2014-11-05 | 2015-01-28 | 湖南金帛化纤有限公司 | Method for centrifugally preparing titanium dioxide suspension |
| CN104499076A (en) * | 2014-12-12 | 2015-04-08 | 广东新会美达锦纶股份有限公司 | Preparation method of flame-retarded polyamide 6 fiber |
| CN104558591A (en) * | 2015-01-09 | 2015-04-29 | 长乐恒申合纤科技有限公司 | Continuous polymerization production process for chinlon 6 |
| TWI506180B (en) * | 2013-07-05 | 2015-11-01 | Chain Yarn Co Ltd | Method for modifying nylon 6 |
| CN105350106A (en) * | 2015-12-01 | 2016-02-24 | 北京三联虹普新合纤技术服务股份有限公司 | Method for preparing delusterant suspension |
| CN106419697A (en) * | 2016-08-31 | 2017-02-22 | 金华洁灵家居用品有限公司 | Preparation method of slow-release solid-state plant essential oil bath ball |
| CN107022076A (en) * | 2017-04-14 | 2017-08-08 | 长乐力恒锦纶科技有限公司 | A kind of preparation method of the deep dye section of polyamide fibre 6 |
| CN107955160A (en) * | 2017-12-05 | 2018-04-24 | 李慧文 | Polymerization formula, polymerization, polycaprolactam polymerization unit and its functional additive polymerizing reactor of polycaprolactam |
| CN108434781A (en) * | 2018-05-29 | 2018-08-24 | 长乐力恒锦纶科技有限公司 | A kind of closed and the controllable chinlon 6 section that pressurizes extraction process |
| CN109811423A (en) * | 2018-12-25 | 2019-05-28 | 中国纺织科学研究院有限公司 | The production method and the functional polyamide fiber of continuous polymerization fused mass directly spinning functional polyamide fiber |
| CN110105563A (en) * | 2019-04-10 | 2019-08-09 | 江苏海阳锦纶新材料有限公司 | A kind of additive agent modified lab scale craft of functional nylon PA6 in-situ polymerization |
| CN110760061A (en) * | 2019-10-14 | 2020-02-07 | 江苏海阳化纤有限公司 | Black chinlon 6 slice production device and production method |
| CN114805790A (en) * | 2021-01-28 | 2022-07-29 | 海阳科技(江苏)研究院有限公司 | Production device and process of extinction black environment-friendly polyamide-6 slice |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1345890A (en) * | 2000-09-29 | 2002-04-24 | 中国石油化工股份有限公司巴陵分公司 | Method for producing low viscosity chinlon 6 section |
| CN101314673A (en) * | 2008-07-18 | 2008-12-03 | 广东新会美达锦纶股份有限公司 | Production method for full-dull nylon 6-slice |
-
2010
- 2010-07-09 CN CN2010102265314A patent/CN101899152B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1345890A (en) * | 2000-09-29 | 2002-04-24 | 中国石油化工股份有限公司巴陵分公司 | Method for producing low viscosity chinlon 6 section |
| CN101314673A (en) * | 2008-07-18 | 2008-12-03 | 广东新会美达锦纶股份有限公司 | Production method for full-dull nylon 6-slice |
Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102060992B (en) * | 2010-11-02 | 2012-12-12 | 北京三联虹普新合纤技术服务股份有限公司 | Process for producing high-viscosity chips by applying solid-phase viscosifying technology |
| CN102060992A (en) * | 2010-11-02 | 2011-05-18 | 北京三联虹普新合纤技术服务股份有限公司 | Process for producing high-viscosity chips by applying solid-phase viscosifying technology |
| CN102775600A (en) * | 2012-08-01 | 2012-11-14 | 武汉森大科技研究发展中心 | Polymerization manufacturing technique and device for polyamide |
| CN102775600B (en) * | 2012-08-01 | 2014-02-26 | 武汉森大科技研究发展中心 | Polymerization manufacturing technique and device for polyamide |
| TWI506180B (en) * | 2013-07-05 | 2015-11-01 | Chain Yarn Co Ltd | Method for modifying nylon 6 |
| CN103466869A (en) * | 2013-07-23 | 2013-12-25 | 江苏海阳化纤有限公司 | Total reuse and recovery system for polyamide 6 monomer |
| CN104313722B (en) * | 2014-11-05 | 2016-03-30 | 湖南金帛化纤有限公司 | A kind of centrifugal method preparing tio_2 suspension |
| CN104313722A (en) * | 2014-11-05 | 2015-01-28 | 湖南金帛化纤有限公司 | Method for centrifugally preparing titanium dioxide suspension |
| CN104499076A (en) * | 2014-12-12 | 2015-04-08 | 广东新会美达锦纶股份有限公司 | Preparation method of flame-retarded polyamide 6 fiber |
| CN104558591A (en) * | 2015-01-09 | 2015-04-29 | 长乐恒申合纤科技有限公司 | Continuous polymerization production process for chinlon 6 |
| CN105350106A (en) * | 2015-12-01 | 2016-02-24 | 北京三联虹普新合纤技术服务股份有限公司 | Method for preparing delusterant suspension |
| CN106419697A (en) * | 2016-08-31 | 2017-02-22 | 金华洁灵家居用品有限公司 | Preparation method of slow-release solid-state plant essential oil bath ball |
| CN107022076A (en) * | 2017-04-14 | 2017-08-08 | 长乐力恒锦纶科技有限公司 | A kind of preparation method of the deep dye section of polyamide fibre 6 |
| CN107955160A (en) * | 2017-12-05 | 2018-04-24 | 李慧文 | Polymerization formula, polymerization, polycaprolactam polymerization unit and its functional additive polymerizing reactor of polycaprolactam |
| CN108434781A (en) * | 2018-05-29 | 2018-08-24 | 长乐力恒锦纶科技有限公司 | A kind of closed and the controllable chinlon 6 section that pressurizes extraction process |
| CN109811423A (en) * | 2018-12-25 | 2019-05-28 | 中国纺织科学研究院有限公司 | The production method and the functional polyamide fiber of continuous polymerization fused mass directly spinning functional polyamide fiber |
| CN109811423B (en) * | 2018-12-25 | 2021-10-26 | 中国纺织科学研究院有限公司 | Production method of continuous polymerization melt direct spinning functional polyamide fiber and functional polyamide fiber |
| CN110105563A (en) * | 2019-04-10 | 2019-08-09 | 江苏海阳锦纶新材料有限公司 | A kind of additive agent modified lab scale craft of functional nylon PA6 in-situ polymerization |
| CN110760061A (en) * | 2019-10-14 | 2020-02-07 | 江苏海阳化纤有限公司 | Black chinlon 6 slice production device and production method |
| CN110760061B (en) * | 2019-10-14 | 2024-05-31 | 海阳科技股份有限公司 | Black nylon 6 slice production device and production method |
| CN114805790A (en) * | 2021-01-28 | 2022-07-29 | 海阳科技(江苏)研究院有限公司 | Production device and process of extinction black environment-friendly polyamide-6 slice |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101899152B (en) | 2012-11-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101885842B (en) | Continuous polymerization production technology for polyamide fibre 6 | |
| CN101880386B (en) | Recovery method of hexanolactam in polyamide-6 continuous polymerization production process | |
| CN101899152B (en) | Preparation of titanium dioxide additive in nylon-6 continuous polymerization production process | |
| JP5591111B2 (en) | Method for producing low-hydrolyzable polyester granules made of high-viscosity polyester melt, and apparatus for producing the polyester granules | |
| RU2451036C2 (en) | Method of producing polyamide | |
| CN105754139B (en) | Method and apparatus for recycling polyester material | |
| CN104387580A (en) | Nylon-6 slice production method capable of improving polymerization conversion rate | |
| RU2556929C2 (en) | Method of increasing molecular weight using residual heat of granular polyester | |
| CN108570148A (en) | A kind of anti-oxidation nylon 6 slice polymerization production device and method | |
| CN106430228B (en) | Molecular sieve mother solution processing method | |
| CN102691130A (en) | Process for manufacturing fire-retardant polyester fiber | |
| CN1978503A (en) | Production process for manufacturing food-level polyester bottle flakes utilizing polyester recovered bottles | |
| WO2019090883A1 (en) | Method for preparing polypropylene or propylene-ethylene copolymer | |
| CN106279477A (en) | The production method of a kind of modified PVC and process units | |
| CN103483580A (en) | Polyamide-6 granula device and process capable of recovering all monomers | |
| CN102691131A (en) | Manufacturing equipment system of flame-retardant polyester fiber | |
| CN112094406A (en) | Nylon 6 production process and system and product thereof | |
| CN105218470A (en) | Solid and gas tripping device in a kind of Melamine Production | |
| CN212269951U (en) | High-viscosity high-strength nylon-666 copolymerization polymerization continuous polymerization device | |
| CN114437343A (en) | Method for synthesizing copolymerized nylon by continuously copolymerizing caprolactam and nylon 66 salt | |
| CN203269840U (en) | Device for continuously preparing polyamide 6 | |
| CN206937708U (en) | A kind of high-cleanness nylon chips production line | |
| CN107674198A (en) | A kind of preparation method of high-viscosity polyamide 6 | |
| CN210560194U (en) | Oligomer separation system in nylon-6 polymerization process | |
| CN114011357B (en) | High-viscosity copolyester production system and method with mixed alcohol separation and recovery functions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |