CN1081650C - Process for subsequent condensation of polycondensates, in particular of polyamide 6, 6 - Google Patents
Process for subsequent condensation of polycondensates, in particular of polyamide 6, 6 Download PDFInfo
- Publication number
- CN1081650C CN1081650C CN95197723A CN95197723A CN1081650C CN 1081650 C CN1081650 C CN 1081650C CN 95197723 A CN95197723 A CN 95197723A CN 95197723 A CN95197723 A CN 95197723A CN 1081650 C CN1081650 C CN 1081650C
- Authority
- CN
- China
- Prior art keywords
- carrier gas
- pellet
- gas
- temperature
- dew point
- 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.)
- Expired - Fee Related
Links
Landscapes
- Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
Abstract
The present invention relates to a method for condensing polycondensate, particularly to granular materials of polyamide 6.6 after the single stage in a fluidized-bed reactor (1) and with the condition that nitrogen gas (N2) is used as a gas carrier, wherein branched streams of the gas carrier of which the temperature is between 20 DEG C and 230 DEG C is separated from the mainstream and passes through a gas scrubbing tower (15) supplied with water in order that the branched stream of the gas carrier of which the humidity is regulated can be sent back to the mainstream of the gas carrier when the dew point reaches 10 to 80 DEG C (100% of relative humidity). In the granulate cooling stage, the supply of the branched stream stops; after being cooled, granular materials can be discharged to be directly reused. When the method of the present invention is used, the required viscosity of polymers can be obtained, and the accurate and prescribed humidity which is important for reprocessing can be obtained.
Description
The present invention relates to a kind of polycondensate that makes, especially polyamide 6 .6 pellet is in fluidized-bed reactor, with nitrogen (N
2) as the method for carrying out condensation (Nachkondensation) after the single-stage under the carrier gas condition.
In order to be used for the long filament of industrial yarn with the polycondensate manufacturing, require under solid state, to carry out hot aftertreatment, to regulate its polymerization degree, the thermal treatment of condensation is known usually after this being referred to as.In the back condensation process of polyamide 6 .6, usually the particulate state polymeric amide is handled under the heating, vacuum condition, perhaps, pellet is by a kind of rare gas element, and the nitrogen that is dried is usually blown over.A part that has the rare gas element of moisture and impurity is discharged from after passing the pellet bed.In the rare gas element circulation, be typically provided with dewatering unit, as cryogenic condensation trap, silica gel or molecular sieve, so that the polymkeric substance drying.
All have been disclosed to make that the method for condensation all needs the very long back condensation time behind the polyamide 6 .6, usually more than 20 hours.
During condensation, the pellet of the white drying of toing many or too much for use usually begins after with solid state.Adjust the humidity of polymeric amide pellet by adding water, this is disclosed.For example, in being divided into the described method of two stage EP-A-0092898 at least, at first be the back condensation, next, regulating moisture phase, the water yield of control directly adds to polymeric amide before melting in extrusion machine.Adopt this disclosed method, the water-content in the polymkeric substance should be adjusted before extruding as far as possible exactly.But, have following shortcoming, can cause the metering fluctuation or cause undesirable temperature fluctuation to the pellet that is cooled or to heat extruder amount water distribution decided at the higher level but not officially announced.Usually, shunting arrives such position, many places from extrusion machine, promptly for example must be interrupted when changing spinneret, and therefore, the rationing of water must adapt to it in the mode of costliness.When the fluctuation of the long filament of manufacturing should be avoided, no matter be that manual operations is reinforced, still use the pump quantitative ingredient, all too inaccurate.
Task of the present invention is, makes water contained in the polymkeric substance, and these water are overflowed from polymkeric substance by the heating pellet, drain with plain mode.
Another task of the present invention also is, drains the reaction water that is generated.
Another task of the present invention is, gives the moisture content definite, that provide in advance of polymkeric substance that is cooled.Therefore, by the present invention, can abandon before extrusion machine, adding water.
Another task is that moisture content is adjustable in wide scope.
Another task is, removes contained monomer, oligopolymer and impurity in the carrier gas.
Another task is, stops and replaces the contingent unnecessary nitrogen consumption of moistening nitrogen by drying nitrogen.
According to the present invention, above-mentioned task will be finished in the following manner, be that temperature is that 20-230 ℃ carrier gas shunting is separated from its main flow, and,, dew point is sent back in the carrier gas main flow so that being the carrier gas shunting that is conditioned humidity of 10-80 ℃ (100% relative humidity) by a gas wash tower that adds water.
Main advantage is that when introducing the carrier gas shunting of heat in the water, but all condensing and the resublime component as oligopolymer, at first is deposited in the water in process of cooling.Simultaneously, the temperature of the carrier gas that is so washed is automatically provided in advance by the temperature of water in the washing tower, and thus, the dew point that enters the backflow of reactor also can accurately be adjusted (saturated).Dew point in the reactor along with process carrying out forward automatically and the washer head temperature adapt.
Also have other special advantage, promptly regulate and to realize very simply.Therefore, in fluidized-bed reactor, pellet humidity can be with plain mode Be Controlled very through dew point under the pressure ratio controlled condition in the condensation process of whole back.
When carrier gas with 20-230 ℃, when preferably 40-200 ℃ temperature entered gas wash tower, they were cooled, and disturbed the impurity of fusion pressure, were discharged from as monomer and oligopolymer.That come out, that be washed and be 10-80 ℃ with steam-laden carrier gas in the temperature when gas wash tower comes out, especially 13-40 ℃, preferably 13-30 ℃, it is always numerically consistent with dew point.
Therefore, finish in the back condensation (by polymer phase to viscosimetric analysis, the thermopolymer pellet can absorb the desirable water yield) afterwards, at pellet in the fluidized-bed reactor internal cooling stage, carrier gas from the shunting that is conditioned humidity interrupts feeding, and only main flow is stopping heating, promptly continues circulation under cooling conditions.After reaching desirable drop temperature, the moisture content of polymkeric substance is so promptly adjusted, so that pellet can be discharged from once.According to corresponding dew point, the final moisture content of pellet is 0.025% to 0.08%, is preferably 0.03% to 0.07%.Any desirable pellet moisture content can be adjusted by dew point exactly by above-mentioned this mode.
Be surprisingly found out that when pellet humidity finished in the back condensation process, promptly after cooling stages, the carrier gas dew point was relevant when only beginning with cooling stages.Dew point itself only with gas wash tower in condition, especially wash temperature is relevant.
With reference to synoptic diagram the inventive method is described further.
Fig. 1 represents method synoptic diagram of the present invention,
Fig. 2 represents according to back condensation of the inventive method and refrigerative distribution curve.
In Fig. 1, represent a fluidized-bed reactor with symbol 1.This fluidized-bed reactor 1 is provided with a feeding mouth 2 and the used discharge port 3 of polymkeric substance for quilt back condensation that confession polymkeric substance to be processed is used.In the bottom of fluidized-bed reactor 1, be provided with a pressure pipeline that is used for feeding carrier gas by heat exchanger 5.The discharge of carrier gas is finished by pipeline 6, cyclonic separator 7 at the top of fluidized-bed reactor 1.Between pipe section 9 and heat exchanger 5, be provided with a ventilator 10.Another pipeline 11 feeds pressure pipeline 4, and this pipeline feeds in the pipe section 13 by a valve 12, and pipeline 13 connects the bottom that same gas distributing device 14 feeds in the gas wash tower 15.Gas wash tower 15 has a pipeline 16 at an upper portion thereof, and this pipeline is by control valve 17 closures.Pipe section 18 is fed the pipe section 9 of gas carrier stream by another control valve 19 and pipeline 12 by pipeline 16.In pipeline 20, be provided with one for adding the control valve 21 that nitrogen is used.The adjustable cooling water recirculation system of temperature belongs to gas wash tower, and it is made up of a bottom pipe 22, pump 23, a heat exchanger 24 and a upper pipe 25.
Fig. 2 shows in the inventive method the pellet temperature in heating, back condensation and process of cooling and the distribution curve of dew point.Shown in it is that a kind of dew point rated value is that 32 ℃ back condensation rove is at pellet temperature and the dew point of hot stage in the pellet discharge process.For vision is clear, the ordinate zou on the left side is applicable to curve 1; The ordinate zou on the right is applicable to curve 2.Curve 1 shows pellet temperature, and curve 2 shows the dew-point temperature distribution.As can be seen, before pellet reached its top temperature of 195 ℃ summary, dew point had been crossed its about 40 ℃ maximum value from curve, after this reduced and the in fact constant stretching, extension until entering cooling stages.
When operation, in fluidized-bed reactor 1, infeed its water-content and be up to 0.4% polyamide 6 .6 pellet.Moist granular polymer rises thereby gas cuts the dew point of body by adding heat abstraction water.Thus, the dew point of carrier gas at first may be too high.If this is the case, will make the major cycle dehydration by gas wash tower.Fluidized-bed will circulate by carrier gas and realize, at this, at the bottom of ventilator 10 is blown over heat exchanger with carrier gas and fed the sieve of unshowned fluidized-bed reactor 1 with overpressure, thereby brush pellet.After cyclonic separator 7, pressure reduces, and still the inlet pressure with ventilator 10 is suitable for it.Simultaneously, temperature is that 190 ℃ carrier gas shunting is left pressure pipeline 4 and is admitted to gas distributing device 14 by pipeline 11 and pipe section 13.Contained water in the gas distributing device 14 fumigating gas washing towers.At this, for example 190 ℃ carrier gas is cooled to 40 ℃.The temperature of the water in gas wash tower 15 is controlled by heat exchanger 24, at this, water leaves gas wash tower by pump 23 by pipeline 22, and passes heat exchanger 24, and is transported to the top of gas wash tower 15 again by pipeline 25 by a jet apparatus.Monomer and oligopolymer are separated in gas wash tower 15.The carrier gas that is conditioned temperature leaves gas wash tower 15 by pipeline 16 between 13 to 14 ℃, and is sent back to major cycle by pipeline 20, in the pipeline 9 before the ventilator.
Embodiment 1
400 kilograms of polyamide 6 .6 pellets are 90m at a cubic capacity
3Reactor in, under turbulent-flow conditions, be heated to 195 ℃ by time curve shown in Figure 2.This moment, the carrier gas shunting is transferred by gas scrubber, water temperature is 32 ℃ at this moment.In about 2 hours time, keep processing temperature, simultaneously, dew point reaches 32 ℃ of desirable values.At this moment, shunting is stopped and is cooled.In process of cooling, water contained in the nitrogen is absorbed by polyamide 6 .6.After the cooling, the final moisture content of pellet is 0.055%, and its tolerance range is better than 0.003%.
Embodiment 2
In embodiment 2, the polyamide 6 .6 of same quantity is under turbulent-flow conditions, be heated to 189 ℃ according to being similar to time curve shown in Figure 2.In the constant high temperature stage, its dew point is fluctuation near 13 ℃ of values desirable and that be scheduled to by the washer temperature.After this be cooled.As a result, the final moisture content of pellet is 0.033%, and its tolerance range is less than ± 0.003%.
It the results are shown in the following table.
Table:
| Test number | Dew point [℃] | Relative viscosity [RV] | Temperature [%] |
| 1 | 13.0 | 75.6 | 0.033 |
| 2 | 13.0 | 93.5 | 0.026 |
| 3 | 25.0 | 76.0 | 0.045 |
| 4 | 32.0 | 75.6 | 0.055 |
| 5 | 38.0 | 91.5 | 0.070 |
As can be seen from the table, pellet humidity can be conditioned by dew point with plain mode in wide region.In contrast, viscosity then changes with the time curve of pellet temperature.
According to method of the present invention, back condensation and damping (adjusting desirable pellet temperature) can be carried out with a processing step.The gaseous byproduct and the grit that produce during back condensation are removed from technological process immediately with plain mode.Especially, the uniform distribution of pellet moisture only just is reached by at high temperature adjusting the humidity level.In addition, by as the nitrogen of carrier gas by recirculation constantly and only must replenish seldom may be because the loss amount that blow-by and temperature effect cause, thereby aspect production cost, greatly reduce its expense.
By the present invention, the relevant a plurality of processing steps of polymkeric substance water yield equilibrated are finished during the condensation of back simultaneously.Thus, not only can avoid before extrusion machine, adding water, and processing steps such as the part removal of the moisture control of back condensation, drying, pellet and impurity are carried out simultaneously.Therefore also can save a large amount of nitrogen.In a word, utilize the present invention, it is more efficient and more economical that whole technological process becomes.
Claims (3)
- One kind make polyamide 6 .6 pellet in fluidized-bed reactor (1), the method for condensation after carrying out single-stage under as the carrier gas condition with nitrogen, it is characterized in that, temperature is that 20-230 ℃ carrier gas shunting is separated from its main flow, and, be transferred and get back in the carrier gas main flow so that dew point reaches 10-80 ℃ the carrier gas shunting that is conditioned humidity by a gas wash tower (15) that is added into water.
- 2. in accordance with the method for claim 1, it is characterized in that,, stop to feed of carrier gas shunting in the granulate cooling stage.
- 3. according to claim 1 or 2 described methods, it is characterized in that when discharge, the control of pellet final moisture content is finished by the dew point of carrier gas, wherein, pellet humidity should be measured under less than ± 0.003% condition in error.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95197723A CN1081650C (en) | 1995-12-27 | 1995-12-27 | Process for subsequent condensation of polycondensates, in particular of polyamide 6, 6 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95197723A CN1081650C (en) | 1995-12-27 | 1995-12-27 | Process for subsequent condensation of polycondensates, in particular of polyamide 6, 6 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1181096A CN1181096A (en) | 1998-05-06 |
| CN1081650C true CN1081650C (en) | 2002-03-27 |
Family
ID=5083321
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN95197723A Expired - Fee Related CN1081650C (en) | 1995-12-27 | 1995-12-27 | Process for subsequent condensation of polycondensates, in particular of polyamide 6, 6 |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1081650C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1331236A1 (en) * | 2002-01-25 | 2003-07-30 | Dsm N.V. | Solid-state post-condensation process for increasing the molecular weight of a polyamide |
| TWI671121B (en) * | 2014-07-29 | 2019-09-11 | 荷蘭商帝斯曼知識產權資產管理有限公司 | Process for preparing a polyamide, a nylon salt to be used therein and a process for making the salt |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0009898A1 (en) * | 1978-09-11 | 1980-04-16 | University Of Miami | Novel anti-hypertensive mercaptoacylamino acid derivatives, their preparation and use |
| US4301105A (en) * | 1980-04-21 | 1981-11-17 | American Cyanamid Company | Process for spinning poly(polymethylene terephthalamide) fiber |
| US4381272A (en) * | 1980-05-27 | 1983-04-26 | Battenfeld Maschinenfabrik Gmbh | Method of and system for injecting a fluid into a plastified mass in an extruder |
-
1995
- 1995-12-27 CN CN95197723A patent/CN1081650C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0009898A1 (en) * | 1978-09-11 | 1980-04-16 | University Of Miami | Novel anti-hypertensive mercaptoacylamino acid derivatives, their preparation and use |
| US4301105A (en) * | 1980-04-21 | 1981-11-17 | American Cyanamid Company | Process for spinning poly(polymethylene terephthalamide) fiber |
| US4381272A (en) * | 1980-05-27 | 1983-04-26 | Battenfeld Maschinenfabrik Gmbh | Method of and system for injecting a fluid into a plastified mass in an extruder |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1181096A (en) | 1998-05-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2476314C2 (en) | Method of making granules of low-hydrolysis ether from ether heavy melts and device to this end | |
| CN1309544C (en) | Device for drying and thermally treating granulates with inert gas stream | |
| US20230158713A1 (en) | Process for drying granular polymeric material and plant operating according to said process | |
| CN1081650C (en) | Process for subsequent condensation of polycondensates, in particular of polyamide 6, 6 | |
| CN103834007A (en) | Solid phase tackifying method for continuous production of high viscosity polyamide 6 chips | |
| US6197093B1 (en) | Method and apparatus for the purification of waste gas of a drying apparatus | |
| EP1316770A2 (en) | Method and apparatus for drying plastics | |
| US5859177A (en) | Process for subsequent condensation of polycondensates, in particular of polyamide 6.6 | |
| CN101270955A (en) | Continuous drier suitable for high retraction polyester chip and fabrication technique thereof | |
| US11066518B2 (en) | Method and device for the production of polyamide 6 with low extract content | |
| CN106696117B (en) | A kind of inexpensive prilling of nylon 6 and dual-screw pelletizer | |
| US6716959B2 (en) | Device and method for treating plastic material | |
| US4652278A (en) | Solids drying | |
| US20070130791A1 (en) | Dehumidification process for granulated plastic materials and a plant operating in accordance with the process | |
| EP1923649A2 (en) | Method for drying a material to be dried and plant for carrying out the method | |
| WO2004080691A9 (en) | Polyethylene terephthalate regrind particle processing system | |
| EP3230039A1 (en) | A process for transforming a bulk polymer material by moulding or extrusion, and apparatus operating according to the process | |
| US20230382014A1 (en) | Plant for drying granular polymer material | |
| CN216400508U (en) | Extruded material cooling arrangement | |
| WO2024033800A1 (en) | Drying plant for drying granular polymeric material and relevant drying process | |
| JPS5949881B2 (en) | Continuous countercurrent drying method for synthetic resin chips | |
| CN1035510C (en) | One-step process for after-treating molten polyformaldehyde | |
| CN114636308A (en) | Continuous drying process for high-performance polylactic acid (PLA) slices |
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 | ||
| ASS | Succession or assignment of patent right |
Owner name: RHODIA INDUSTRIAL YARN CO. LTD,. Free format text: FORMER OWNER: SCHWEIZERISCHE VISCOSE Effective date: 20020617 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| C56 | Change in the name or address of the patentee |
Owner name: SCHWEIZERISCHE VISCOSE Free format text: FORMER NAME OR ADDRESS: RHONE-POULENC VISCOSUISSE S. A. |
|
| CP01 | Change in the name or title of a patent holder |
Patentee after: Viscosuchi Co. Patentee before: Rhone-Poulenc Viscosuisse S.A. |
|
| TR01 | Transfer of patent right |
Effective date of registration: 20020617 Patentee after: RHODIA INDUSTRIAL YARNS AG Patentee before: Viscosuchi Co. |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20020327 Termination date: 20101227 |