CN216031794U

CN216031794U - Modified material continuous production device

Info

Publication number: CN216031794U
Application number: CN202121715989.6U
Authority: CN
Inventors: 王赛博; 孙朝阳
Original assignee: Pujing Chemical Industry Co Ltd
Current assignee: Pujing Chemical Industry Co Ltd
Priority date: 2021-07-27
Filing date: 2021-07-27
Publication date: 2022-03-15
Anticipated expiration: 2031-07-27

Abstract

The utility model discloses a modified material continuous production device. The device comprises a melt mixing kettle, a static mixer connected with a discharge port of the melt mixing kettle, tackifying equipment arranged at the downstream of the static mixer, and a blending modification unit coupled with the tackifying equipment. The device is suitable for blending modification of the polyglycolic acid resin, can realize continuous production of production and blending modification of the polyglycolic acid resin, avoids secondary heating and melting of the polyglycolic acid resin, can perform personalized regulation and control on plasticization of the modified resin, and further effectively reduces or inhibits thermal degradation of the modified resin in the blending processing process.

Description

Modified material continuous production device

Technical Field

The utility model relates to the field of polymer preparation, in particular to a continuous production device suitable for blending modification of polyglycolic acid resin.

Background

At present, the conventional blending modification operation is to add the polyglycolic acid resin and other resins and/or processing aids into an extrusion device (such as a twin-screw extruder) together, and then perform blending modification processing at uniformly set plasticizing temperature, blending temperature and extrusion temperature, but such processing mode ignores the influence of the same processing temperature on the thermal degradation degree of different resins. For example, the processing temperature of PGA is usually 220-250 ℃, the processing temperature of PBAT is usually 130-190 ℃, the processing temperature of PBS is usually 120-160 ℃, if the PGA is subjected to blending modification with PBAT and/or PBS, PBAT and/or PBS can be seriously thermally degraded, small acidic impurity molecules are generated and mixed in the resin base material, which can cause serious negative effects on the mechanical strength, maintenance, aging resistance, service life, and the like of the final material.

In addition, in the conventional blending modification operation, an extrusion device is usually used as a separate modification device, and continuity between the extrusion device and a production device of the polyglycolic acid resin (such as polyglycolic acid) is poor, so that the produced polyglycolic acid resin (such as polyglycolic acid) needs to be heated and melted for the second time to perform blending modification processing, but the secondary heating and melting usually inevitably causes thermal degradation of part of the polyglycolic acid resin (such as polyglycolic acid), and the performance of a final material is adversely affected.

Therefore, the development of a continuous production device suitable for blending modification of polyglycolic acid resin and a corresponding preparation method are urgently needed in the field.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a continuous production device for blending modification of polyglycolic acid resin and a preparation method thereof.

In a first aspect of the present invention, there is provided a continuous production apparatus for a modified material, comprising a melt-mixing kettle, a static mixer connected to a discharge port of the melt-mixing kettle, a viscosity-increasing device disposed downstream of the static mixer, and a blending modification unit coupled to the viscosity-increasing device.

In another embodiment, the blending modification unit comprises an I-th mixing and extruding device coupled with the tackifying device, the I-th mixing and extruding device is sequentially provided with a plasticizing section, a blending section and an extruding section along the material feeding direction, and a discharge port of the tackifying device is connected with the blending section of the I-th mixing and extruding device.

In another embodiment, the blending modification unit comprises an I mixing extrusion device coupled with the tackifying device and an II mixing extrusion device coupled with the I mixing extrusion device, the I mixing extrusion device is provided with a blending section and an extrusion section in sequence along the material feeding direction, and the II mixing extrusion device is only provided with a plasticizing section;

and a discharge port of the tackifying device and a discharge port of the II-th mixing and extruding device are respectively connected with the blending section of the I-th mixing and extruding device.

In another embodiment, the apparatus further comprises an external circulation heat exchange unit coupled to the melt mixing kettle.

In another embodiment, the external circulation heat exchange unit comprises an external circulation discharge port, an external circulation feed port, an external circulation pipeline connecting the external circulation discharge port and the external circulation feed port, a heat exchanger arranged on the external circulation pipeline, and a circulation pump.

In another embodiment, the external circulation discharge port and the external circulation feed port are respectively connected to the lower part of the melting and mixing kettle, and the joint of the external circulation feed port and the lower part of the melting and mixing kettle is higher than the joint of the external circulation discharge port and the lower part of the melting and mixing kettle.

In another embodiment, the apparatus has a reaction aid storage tank connected to the melt mixing kettle feed port.

In another embodiment, the static mixer is connected with the tackifying equipment through a material conveying component, and the material conveying component comprises a material conveying pipeline connecting a discharge port of the static mixer and a feed port of the tackifying equipment, a melt pump arranged on the material conveying pipeline, and a cleaning liquid drain pipe connected with the melt pump in parallel on the material conveying pipeline.

In another embodiment, a cleaning liquid drainage branch is arranged on a material conveying pipeline between the melt pump and the feed inlet of the double-screw extruder.

In another embodiment, a three-way valve is arranged at the position where the cleaning liquid dredging pipe is connected with the material conveying pipeline.

In another embodiment, the cleaning solution draining branch is connected with the material conveying pipeline through a three-way valve.

In another embodiment, a melt metering pump is arranged between the discharge port of the melt mixing kettle and the static mixer.

In a second aspect of the present invention, there is provided a method for continuously producing a modified material by the apparatus provided by the present invention as described above, the method comprising the steps of:

(1) uniformly mixing the monomer and the reaction auxiliary agent in a melting and mixing kettle to obtain a fluid premix;

(2) pre-polymerizing the fluid premix obtained in the step (1) in a static mixer to obtain a prepolymer;

(3) carrying out final polymerization on the prepolymer obtained in the step (2) through tackifying equipment to obtain a final polymer;

(3') obtaining a modifying component containing a melt-modified resin for blending with the final polymer in a plasticizing section of the first mixing and extruding apparatus or a second mixing and extruding apparatus;

(4) and (3) mixing the final polymer obtained in the step (3) and the modified component obtained in the step (3') in a blending section of the mixing and extruding equipment I, and then extruding and granulating the mixture in an extruding section of the mixing and extruding equipment I to obtain the modified material.

In another embodiment, in step (1), the monomers and the reaction auxiliary agent are heated, stirred and mixed in the melt mixing kettle, or heated, circulated, flowed and mixed in the melt mixing kettle and an external circulation heat exchange unit coupled with the melt mixing kettle, so as to obtain the fluid premix.

In another embodiment, the reaction auxiliary used in step (1) comprises a catalyst, an initiator and a dehydrating agent.

In another embodiment, glycolide is used in step (1), and the purity of the glycolide is 98% or more; preferably not less than 98.5%, and acidity not exceeding 20 mmol/kg.

In another embodiment, the monomer used in step (1) is glycolide, the catalyst is used in an amount of 0.001 to 5 wt% thereof, the initiator is used in an amount of not more than 5 wt% (for example, but not limited to, 0.1 to 4 wt%, 1 to 3 wt%, etc.), and the dehydrating agent is used in an amount of 0.2 to 1.6 wt%, based on the mass of glycolide.

In another embodiment, the static mixer used in step (2) employs at least 2-stage gradient temperature raising method, the first stage temperature range is between 120 ℃ and 220 ℃, and the last stage temperature range is between 220 ℃ and 250 ℃.

In another embodiment, the tackifying equipment in step (3) is devolatilized under the absolute pressure of less than or equal to 500Pa and the temperature of 220-250 ℃.

In another embodiment, the temperature of the plasticizing section of the first mixing and extruding apparatus or the second mixing and extruding apparatus in the step (3') is set to be 0 to 20 ℃ higher than the melting point of the modified resin.

In another embodiment, the temperature of the blending section of the mixing and extruding device I in the step (4) is 220-230 ℃, and the temperature of the extruding section is 230-240 ℃.

Accordingly, the utility model provides a continuous production device suitable for blending modification of polyglycolic acid resin and a corresponding preparation method.

Drawings

FIG. 1A is a schematic view of a continuous production apparatus for a modified material provided in example 1 of the present invention.

FIG. 1B is a schematic view of a continuous production apparatus for a modified material provided in example 2 of the present invention.

FIG. 2A is a schematic view of a continuous production apparatus for a modified material provided in example 3 of the present invention.

FIG. 2B is a schematic view of a continuous production apparatus for a modified material provided in example 4 of the present invention.

FIG. 3 shows the connection mode of the viscosity increasing device and the mixing extrusion device I in the continuous modified material production device provided in examples 1 and 3 of the present invention.

FIG. 4 shows the connection mode of the viscosity increasing device, the first mixing and extruding device and the second mixing and extruding device in the modified material continuous production device provided by the embodiments 2 and 4 of the utility model.

Detailed Description

The inventor develops a continuous production device suitable for blending modification of polyglycolic acid resin through extensive and intensive research, can realize continuous output of polyglycolic acid resin production and blending modification, can avoid secondary heating and melting of polyglycolic acid resin, can individually regulate and control plasticization of modified resin (serving as a modified component), and further effectively reduces or inhibits thermal degradation of the modified resin in the blending processing process. On the basis of this, the present invention has been completed.

It should be noted that in the present invention, "tackifying device" plays a role in devolatilization, and can promote further polymerization of glycolic acid prepolymer, and timely remove the generated small molecules, so as to further increase the molecular weight of the polymer, and correspondingly, the viscosity of the polymer; the "tackifying means" in the present invention may be, for example, but not limited to, a twin-screw extruder provided with only a devolatilization section.

Continuous production device for modified material

The utility model provides a device suitable for continuous production of modified materials, which comprises a melt mixing kettle, a static mixer coupled with the melt mixing kettle, tackifying equipment arranged at the downstream of the static mixer, and a blending modification unit coupled with the tackifying equipment.

As used herein, "modified material" refers to a material obtained by adding other modified resins and/or additives to a matrix resin and melt-blending the resulting material, and the like, and the properties of the resulting material in terms of toughness, strength, and the like are improved as compared with the matrix resin.

In one embodiment of the present invention, the modified material is a polyglycolic acid-based resin, and is a material obtained by adding another modified resin (e.g., PBS or PBAT) and/or an auxiliary agent to a polyglycolic acid-based resin (e.g., polyglycolic acid or a polyglycolic acid-lactic acid copolymer) and melt-blending the mixture.

As used herein, "coupled" means that two devices are operatively connected and in an interactive, interactive relationship with each other.

And a melt metering pump is arranged between the static mixer and the melt mixing kettle, and a kettle bottom discharge port of the melt mixing kettle is connected with a feed port of the static mixer through the melt metering pump.

And a discharge port of the static mixer is connected with a feed port of the tackifying device through a material conveying assembly.

The material conveying assembly comprises a material conveying pipeline, a melt pump and a cleaning liquid dredging pipeline, wherein the material conveying pipeline is used for connecting a discharge port of the static mixer with a feed port of the tackifying device, the melt pump is arranged on the material conveying pipeline, the cleaning liquid dredging pipeline is connected with the melt pump in parallel, and a cleaning liquid discharging branch is arranged on the material conveying pipeline between the melt pump and the feed port of the tackifying device.

Preferably, the liquid inlet end and the liquid discharge end of the cleaning liquid dredging pipeline are connected in parallel to two sides of the melt pump through a three-way valve I.

Preferably, the cleaning liquid draining branch is connected with the material conveying pipeline through a three-way valve II.

Static mixers commonly used in the art, such as, but not limited to, SK type static mixers, SX type static mixers, SV type static mixers, and the like, may be used.

The blending modification unit comprises an I-th mixing extrusion device connected with a discharge port of the tackifying device.

In one embodiment of the utility model, a plasticizing section, a blending section and an extrusion section are sequentially arranged in the mixing and extruding device I along the feeding direction of the material.

In one embodiment of the utility model, the mixing and extruding device I is provided with a blending section and an extruding section in sequence along the feeding direction of materials.

And a discharge port of the tackifying device is connected with a blending section in the I-th mixing and extruding device. For example, the discharge port of the tackifying device is connected with the beginning of the blending section in the mixing and extruding device I.

As used herein, "feed direction" refers to the direction in which the molten material travels forward.

In another embodiment of the utility model, the blending modification unit comprises an I mixing extrusion device connected with the discharge port of the tackifying device and an II mixing extrusion device coupled with the I mixing extrusion device; and the I mixing and extruding equipment is sequentially provided with a blending section and an extruding section along the material feeding direction.

And a discharge port of the tackifying equipment and a discharge port of the II-th mixing and extruding equipment are respectively connected with the blending section of the I-th mixing and extruding equipment.

In a preferred mode, the joint of the II th mixing and extruding device and the blending section in the I th mixing and extruding device is positioned at the downstream of the joint of the tackifying device and the blending section in the I th mixing and extruding device.

There is a way that the discharge port of the tackifying device is connected with the beginning of the blending section in the mixing and extruding device I.

The tackifying apparatus used in the present invention may be, for example, a twin-screw extruder provided with only a devolatilization section; the mixing extrusion device I used may be, for example, a twin-screw extruder provided with a plasticizing section, a blending section and an extrusion section, or a twin-screw extruder provided with a blending section and an extrusion section; the II th mixing extrusion apparatus used may be, for example, a twin-screw extruder provided with only a plasticizing section.

In one embodiment of the utility model, the apparatus further comprises an external circulation heat exchange unit coupled to the melt mixing kettle.

The external circulation heat exchange unit comprises an external circulation discharge port, an external circulation feed port and an external circulation pipeline for connecting the external circulation discharge port and the external circulation feed port.

The external circulation discharge port and the external circulation feed inlet are respectively connected to the lower part of the melting mixing kettle, and the joint of the external circulation feed inlet and the lower part of the melting mixing kettle is higher than the joint of the external circulation discharge port and the lower part of the melting mixing kettle.

Preferably, in a working state, the joint of the external circulation discharge port and the lower part of the melting and mixing kettle is located below the liquid level of the molten material in the melting and mixing kettle, and further, the horizontal line of the joint of the external circulation discharge port and the lower part of the melting and mixing kettle is lower than the lower edge of the stirring blade in the melting and mixing kettle.

The junction of external circulation feed inlet and melt mixing cauldron lower part is arranged in the top of melt material liquid level in the melt mixing cauldron, furtherly, the water flat line of the junction of external circulation feed inlet and melt mixing cauldron lower part is higher than melt material liquid level in the melt mixing cauldron, but should not be too high, for example can be a little higher than melt material liquid level, does not hinder to return the feeding can.

The external circulating heat exchange unit also comprises a heat exchanger and a circulating pump which are arranged on the external circulating pipeline.

A heating jacket is arranged on the outer side of the melting and mixing kettle; aiming at the condition that no external circulating heat exchange unit exists, the temperature of the heating jacket is set to be 90-120 ℃ in a working state; aiming at the condition that an external circulation heat exchange unit is arranged, in a working state, the initial temperature of a heating jacket is set to be 85-90 ℃, after a monomer which is firstly added into a melting and mixing kettle is heated and melted, the heating jacket can stop working, at the moment, a heat preservation effect can be realized, then the melted monomer is heated and heated through the external circulation heat exchange unit, the temperature of a heat exchanger can be set to be 90-120 ℃, the flow rate of the melted monomer passing through the heat exchanger is adjusted through a circulating pump, so that the melted monomer (such as glycolide) can be heated to be 90-120 ℃, and then the melted monomer is returned to the melting and mixing kettle through an external circulation pipeline, and the internal circulation of a reaction material in the melting and mixing kettle can be established; in order to reduce heat loss, a layer of heat-insulating jacket can be wrapped on the external circulation pipeline; in addition, the external circulation pipeline can also be provided with conventional heat tracing.

For the situation that the external circulation heat exchange unit is arranged, the heat exchange efficiency of the heat exchanger is far higher than that of the melting and mixing kettle, so that the volume of the melting and mixing kettle can be reduced in a heat supply and outward movement mode, namely, the melting and mixing kettle with smaller volume can be selected to meet the heat requirement for heating and melting the monomer (such as glycolide) aiming at a certain heat exchange (heating) area under the condition that the external circulation heat exchange unit exists, and the requirement for the space of an industrial land is favorably reduced; in addition, due to the establishment of the external circulation heat exchange unit, the melted monomer (such as glycolide) enters the heat exchanger through the external circulation pipeline to be heated and then is circulated back to the melting and mixing kettle, so that the internal circulation flow of the reaction materials can be realized, and the phenomenon that the melted monomer (such as glycolide) in a certain area at the bottom of the kettle is not uniformly heated (such as being excessively heated) to cause coking and deterioration due to the insufficient disturbance capacity of a stirring paddle of the melting and mixing kettle can be avoided.

And electromagnetic valves are arranged at the kettle bottom discharge port, the external circulation discharge port and the external circulation feed port of the melting mixing kettle.

Further, the top of the melting mixing kettle is also provided with a reaction material feeding port and a reaction auxiliary agent feeding port, wherein the reaction material feeding port is connected with the weightlessness scale through a material feeding pipe, the reaction auxiliary agent feeding port is connected with a reaction auxiliary agent storage tank arranged at the upstream of the melting mixing kettle through an auxiliary agent feeding pipe, and a liquid metering pump is further arranged on the auxiliary agent feeding pipe between the reaction auxiliary agent storage tank and the reaction auxiliary agent feeding port.

In one embodiment of the utility model, the weight loss scale is connected between a discharge port at the bottom of the screen and a reaction material feed port at the top of the melt mixing kettle.

In the technical device, a pipeline, a material conveying pipeline, a cleaning liquid dredging pipeline, a melt metering pump, a melt pump, a three-way valve I and a three-way valve II between a kettle bottom discharge port of a melting mixing kettle and a feed inlet of a static mixer are all provided with conventional heat tracing. In addition, the model of the metering pump can be selected according to the reaction time of the materials in the melting and mixing kettle and the volume of the pipeline, and the model requirements of the melt pump and the tackifying equipment are matched with the model of the melt metering pump.

In practical application, the weightlessness scale, the liquid metering pump, the electromagnetic valve, the circulating pump, the melt metering pump, the melt pump, the tackifying device, the I mixing and extruding device, the II mixing and extruding device and the like in the technical device can be connected with a computer through the existing known electric connection mode, so that the online control from the PGA production to the blending modification is realized.

Continuous production method of modified material

The utility model provides a continuous production method of a modified material, which comprises the following steps:

firstly, uniformly mixing a monomer and a reaction auxiliary agent in a melt mixing kettle to obtain a fluid premix;

secondly, conveying the fluid premix into a static mixer for prepolymerization to obtain a prepolymer;

thirdly, conveying the prepolymer to tackifying equipment for final polymerization to obtain a final polymer; at the same time, the user can select the desired position,

heating, melting and mixing the modified resin and the processing aid in a plasticizing section of a first mixing and extruding device or a second mixing and extruding device to obtain a modified component;

and fourthly, mixing the final polymer and the modified component in the blending section of the first mixing and extruding device, and then extruding and granulating the mixture in the extruding section of the first mixing and extruding device to obtain the modified material.

In one embodiment of the present invention, the monomer in the first step may be a intermolecular cyclic ester and lactone of α -hydroxycarboxylic acid, preferably glycolide, the hydroxycarboxylic acid prepolymer (e.g., glycolic acid prepolymer) obtained in the second step, the polyhydroxycarboxylic acid (e.g., polyglycolic acid) obtained in the third step, and the polyglycolic acid-based resin obtained in the fourth step.

In the above first step, glycolide having a purity of not less than 98%, preferably not less than 98.5% and an acidity of not more than 20mmol/kg is used.

In an embodiment of the present invention, in the first step, glycolide powder with a purity of not less than 98.5% is introduced into a melt mixing kettle, the temperature is raised to 90-120 ℃ under normal pressure, and a proper amount of reaction auxiliary agent is added while stirring, so that the molten glycolide and the reaction auxiliary agent are uniformly mixed, and a fluid premix is obtained.

The reaction auxiliary agent used in the first step comprises a catalyst, an initiator and a dehydrating agent; in terms of the amount of the reaction auxiliary agent, the catalyst is used in an amount of about 0.001-5 wt% based on the mass of the glycolide powder, the initiator is used in an amount of not more than about 5 wt% based on the mass of the glycolide powder, and the dehydrating agent is used in an amount of about 0.2-1.6 wt% based on the mass of the glycolide powder.

The catalyst may be selected from at least one of tin-based compounds, antimony-based compounds, or zinc-based compounds, such as, but not limited to, stannous octoate, stannous chloride, tin lactate, antimony trioxide, diethyl zinc, or zinc acetate dihydrate.

The initiator may be selected from one or both of alkane substances having a hydroxyl structure such as primary or secondary alcohols (e.g., n-propanol, isopropanol, n-butanol, isobutanol, etc.) or aromatic substances having a hydroxyl active group (e.g., benzyl alcohol, phenethyl alcohol, etc.).

The dehydrating agent may be selected from carbodiimide, polycarbodiimide, or carbodiimide-based compounds (such as, but not limited to, N' -diisopropylcarbodiimide, dicyclohexylcarbodiimide, etc.).

To prevent local excess concentrations of the reaction aid in molten glycolide, in one embodiment of the utility model, the reaction aid may be added dropwise to the melt-mixing kettle by injection.

The static mixer in the second step adopts at least 2-section gradient heating mode, for example, 2-10 section gradient heating mode; preferably, 3 to 7 stages are employed.

In one embodiment of the present invention, the first temperature range of the static mixer is between 120-220 ℃, such as, but not limited to, 140-170 ℃, 150-180 ℃, 130-200 ℃ and the like; the last temperature range is 130-250 deg.C, such as but not limited to 150-200 deg.C, 190-230 deg.C, 170-220 deg.C, etc.

In one embodiment of the utility model, the second stage of the static mixer is increased in temperature by between 10-90 ℃ over the first stage, such as but not limited to 40-50 ℃, 20-70 ℃, 30-60 ℃, etc.; the last segment is raised from the previous adjacent segment by 0-50 deg.C, such as but not limited to 0-20 deg.C, 10-30 deg.C, etc.

In an embodiment of the utility model, the static mixer has four sections, the first section temperature is set to be 120-.

In an embodiment of the utility model, the static mixer has five sections, the first section temperature is set to be 150-.

In an embodiment of the utility model, the static mixer has three sections, the first section temperature is set to 190-.

In one embodiment of the utility model, the total length of time the material is in the static mixer during operation is generally not more than 150 minutes, such as, but not limited to, 60-90 minutes.

The glycolic acid prepolymer obtained in the second step has a weight average molecular weight of about 5 to 15 ten thousand.

In the practical application of the static mixer, if the viscosity of the material in the fluid state between two adjacent sections is too high, a melt pump can be additionally arranged between the two adjacent sections to promote the forward flow of the material.

In the third step, the tackifying equipment is only provided with a devolatilization section, the absolute pressure of the devolatilization section is less than or equal to 500Pa, and the temperature is set to be 220-250 ℃.

Preferably, the screw length to diameter ratio of the devolatilization section is set to 30 to 100, such as, but not limited to, 40 to 50, 60 to 90, and the like.

It should be noted that, in the present technology, the tackifying device plays a role in devolatilizing, which can promote further polymerization of the glycolic acid prepolymer, and timely remove the generated small molecules to further increase the molecular weight of the polymer.

The proportion of the modified resin and the processing aid used in the third step is 1: 0.1-1; the modified resin is selected from one or more of PBAT (poly adipic acid-butylene terephthalate), PBS (poly butylene succinate), PBST (poly butylene succinate-terephthalate), and PBSA (poly butylene succinate-adipic acid-butylene succinate); the processing aid is selected from one or more of compatilizer, antioxidant, plasticizer, heat stabilizer and the like. Compatibilizers conventional in the art may be used, such as, but not limited to, commercially available maleic anhydride grafted compatibilizers, and the like; antioxidants conventional in the art may be used, such as, but not limited to, commercially available antioxidants 168, 1010 or 1076, and the like; plasticizers conventional in the art may be used, such as, but not limited to, commercially available glycerin, epoxidized soybean oil, epoxidized butyl furoate, acetyl tributyl citrate, or the like; stabilizers conventional in the art may be used, such as, but not limited to, commercially available fatty acid soaps of calcium (e.g., calcium stearate soap, calcium oleate soap, calcium palmitoleate soap, or calcium linoleate soap, etc.) or zinc (e.g., zinc stearate soap, zinc palmitate soap, or zinc oleate soap, etc.).

In one embodiment of the present invention, the temperature of the plasticizing section in the third mixing and extruding apparatus of the third step I or the second mixing and extruding apparatus of the third step II is set to be 0 to 20 ℃ higher than the melting point of the modified resin.

In one embodiment of the present invention, the weight ratio of the final polymer to the modifying component entering the blending section of the mixing and extruding device of the I in the fourth step is 1-10: 1.

In one embodiment of the present invention, the temperature of the blending section in the mixing and extruding device of the fourth step I is 220-.

In a preferred embodiment of the utility model, the temperature of the individual lines is regulated as follows:

the temperature of a pipeline between a discharge port at the bottom of the melting and mixing kettle and a feed port of the melt metering pump is set to be 90-120 ℃, the temperature of a pipeline between a discharge port of the melt metering pump and a feed port of the static mixer is set to be 160 ℃ for the first time, and the temperature of a material conveying pipeline is set to be 250 ℃ for the second time.

In an embodiment of the present invention, in the first step, the monomers and the reaction assistant are circulated in the melt mixing kettle and an external circulation discharge port, an external circulation feed port, and an external circulation pipeline connecting the external circulation discharge port and the external circulation feed port in the external circulation heat exchange unit coupled to the melt mixing kettle to achieve the purpose of uniform mixing.

The junction of external circulation discharge gate and melt mixing cauldron lower part is located the below of melt material liquid level in the melt mixing cauldron, furtherly, the water flat line of the junction of external circulation discharge gate and melt mixing cauldron lower part is less than the lower limb of stirring rake blade in the melt mixing cauldron.

In one embodiment of the utility model, the temperature of the heat exchanger can be set to 90-120 ℃, so that the molten glycolide can be heated to 90-120 ℃, and then the molten glycolide is returned to the melt mixing kettle through an external circulation pipeline, and internal circulation of reaction materials in the melt mixing kettle can be established; in order to reduce heat loss, a layer of heat-insulating jacket can be coated on the external circulation pipeline.

Aiming at the condition that no external circulating heat exchange unit exists, the temperature of the heating jacket is set to be 90-120 ℃ in a working state; aiming at the condition that an external circulating heat exchange unit is arranged, in a working state, the initial temperature of the heating jacket is set to be 85-90 ℃, after the monomers which are firstly added into the melting mixing kettle are heated and melted, the heating jacket can stop working, at the moment, the heating jacket can play a role in heat preservation, and then the melted monomers are heated and heated through the external circulating heat exchange unit.

The modified material produced by the process of the present invention has a molecular weight distribution index of about 1.2 to 1.6, such as, but not limited to, about 1.3 to 1.5.

As used herein, "distribution index" is a parameter D representing the breadth of the molecular weight distribution, where m (w) is the weight average molecular weight, m (n) is the number average molecular weight, D ═ 1 is a uniform molecular weight polymer, and the broader the molecular weight distribution, the greater the degree of polydispersity, the greater the numerical value of D than 1. The measurement method generally includes measuring M (w), M (n) and the ratio of M (w) to M (n) of a sample by Gel Permeation Chromatography (GPC).

The glycolide content of the reaction mass (i.e. the monomer mass, e.g. the glycolide mass) used in the first step of the process according to the utility model can be determined by gas chromatography methods well known in the art, and the acidity by potentiometric titration methods well known in the art (e.g. by means of an automated potentiometric titrator).

To make the features and effects of the present invention comprehensible to those skilled in the art, general description and definitions are made below with reference to terms and expressions mentioned in the specification and claims. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The theory or mechanism described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, i.e., the present disclosure may be practiced without limitation to any particular theory or mechanism.

All features defined herein as numerical ranges or percentage ranges, such as values, amounts, levels and concentrations, are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to cover and specifically disclose all possible subranges and individual numerical values (including integers and fractions) within the range.

As used herein, the term "about" when used to modify a numerical value means within + -5% of the error margin measured for that value.

The features mentioned above with reference to the utility model, or the features mentioned with reference to the embodiments, can be combined arbitrarily. All features disclosed in this specification may be combined in any combination, provided that there is no conflict between such features and the combination, and all possible combinations are to be considered within the scope of the present specification. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, the features disclosed are merely generic examples of equivalent or similar features.

The main advantages of the utility model are:

1. the utility model couples the melt mixing kettle, the static mixer and the tackifying device with the blending modification unit, can realize the continuous production and the online automatic control from the synthesis of the polyhydroxycarboxylic acid (such as polyglycolic acid) to the blending modification thereof, can effectively improve the production efficiency, is beneficial to reducing the energy consumption and saves the production cost.

2. In the design aspect of the melting and mixing kettle, the external circulating heat exchange unit coupled with the melting and mixing kettle is adopted, and the heat exchange efficiency of the heat exchanger is far higher than that of the melting and mixing kettle, so that the volume of the melting and mixing kettle can be reduced in a mode of 'heat supply and outward movement', namely, under the condition of the external circulating heat exchange unit, the melting and mixing kettle with a smaller volume can be selected to meet the heat requirement for heating and melting glycolide aiming at a certain required heat exchange (namely heating) area, and the requirement for industrial space is favorably reduced; in addition, due to the establishment of the external circulation heat exchange unit, molten monomers (such as glycolide) enter the heat exchanger through the external circulation pipeline to be heated and then are circulated back to the melting and mixing kettle, so that the internal circulation flow of reaction materials can be realized, and the phenomenon of coking and deterioration caused by nonuniform heating (such as over-strong heating) of the molten monomers (such as glycolide) in a certain area at the bottom of the kettle due to insufficient disturbance capacity of the stirring paddle can be avoided.

3. The method provided by the utility model comprises the steps of fully and uniformly mixing a monomer (such as glycolide) and a reaction auxiliary agent through a melt mixing kettle to obtain a premix, then introducing the premix into a static mixer for prepolymerization, wherein the premix can be subjected to multiple shunting, confluence and redistribution when running in the static mixer, namely, the mixing effect is enhanced in a cross flow mode, the premix can be subjected to low-shear high-dispersion effect, the heat accumulation in a local area of a material can be prevented and eliminated, the occurrence of side reactions such as thermal degradation and the like caused by overhigh temperature in the local area due to nonuniform heating in the material can be effectively prevented, so that the monomer (such as glycolide) can be subjected to good prepolymerization reaction, a prepolymer with a certain molecular weight can be obtained, then the prepolymer is introduced into tackifying equipment for final polymerization, and the conditions that the material is polymerized in the tackifying equipment (for example, a double screw extruder with only a devolatilization section) is subjected to high shearing action, which is beneficial to inhibiting the occurrence of side reactions such as thermal degradation and the like and ester exchange reaction, thereby reducing the content of oligomers and/or low molecular chain substances in the system, and the obtained final polymer not only has obviously improved molecular weight, but also has relatively smaller molecular weight distribution index and more uniform molecular weight distribution.

4. The utility model introduces a fluid premix of a molten monomer (such as glycolide) into a static mixer, utilizes a cross flow mode to enhance the mixing effect between the monomer (such as glycolide) and a reaction auxiliary agent, enables the reaction auxiliary agent to be more uniformly dispersed in a reaction system, simultaneously utilizes a gradient temperature raising mode to firstly mildly initiate ring-opening polymerization reaction of the monomer (such as glycolide) at a relatively low temperature and in a relatively short time, then appropriately raises the temperature and appropriately prolongs the time to form a relatively stable and reactive hydroxycarboxylic acid molecular chain (such as a glycolic acid molecular chain) in the reaction system, and then further promotes the growth of the hydroxycarboxylic acid molecular chain (such as a glycolic acid molecular chain) at a relatively high temperature and in a relatively long time to obtain a hydroxycarboxylic acid prepolymer (such as a glycolic acid prepolymer) with a certain molecular weight, the gradient temperature rise process of the static mixer is beneficial to inhibiting the rapid change of the viscosity of the reaction system, and the phenomenon of coking and slagging caused by excessive heat accumulation due to the rapid change of the local viscosity of the reaction system can be effectively avoided.

5. Compared with the prior art that monomers (such as glycolide) are directly added into a reactive double-screw extruder for polymerization reaction, the main polymerization reaction in the production method provided by the utility model is carried out in a static mixer, and compared with a double-screw extruder in a dynamic mixing range, the static mixer has better air tightness and can reduce the influence of oxygen and moisture on the polymerization reaction to the maximum extent The heat aging resistance is adversely affected.

6. In the actual operation process of the device provided by the utility model, a molten final polymer (such as polyglycolic acid) obtained by prepolymerization through a static mixer and final polymerization of tackifying equipment is directly introduced into a blending section of mixing extrusion equipment I, and is blended and modified with a modification component under the condition of adapting to the processing temperature of the final polymer (such as polyglycolic acid), so that on one hand, the operation of carrying out secondary melting plasticization on a final polymer (such as polyglycolic acid) material can be omitted, the process is shortened, the production efficiency is improved, the phenomenon that the degree of self thermal degradation is deteriorated due to the secondary melting of the final polymer (such as polyglycolic acid) material can be avoided, on the other hand, the modification component (mainly, a modified resin, such as PBAT resin) can be plasticized under the condition of adapting to the self processing temperature, and further the final polymer (such as polyglycolic acid) and the final polymer (such as polyglycolic acid) are prevented from being plasticized under the condition of adapting to the processing temperature of the final polymer (such as polyglycolic acid) A phenomenon occurs in which the molten plastic is plasticized to cause severe thermal degradation of itself.

7. The device provided by the utility model is suitable for industrial scale-up production, can be used for modifying a production line by using the existing production equipment, has good flexibility and applicability, can realize stable output of modified material products, realizes low-carbonization production, and has good economic benefit.

The utility model will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers. All percentages, ratios, proportions, or parts are by weight unless otherwise specified. The units in weight volume percent in the present invention are well known to those skilled in the art and refer to, for example, the weight (g) of solute in 100ml of solution. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred embodiments and materials described herein are intended to be exemplary only.

In the examples described below, the glycolide content of the purified glycolide powders concerned can be determined by gas chromatography methods known in the art, the glycolide powder particle size being determined by the mesh size of the sieve, for example by using a 70 mesh (corresponding to about 200 μm) sieve or by using a sieve with more than 70 mesh, the glycolide powder being capable of being sieved and having a particle size substantially satisfying "D₉₀Less than or equal to 200 μm ", and the acidity is determined by potentiometric titration methods known in the art (for example, by means of an automated potentiometric titrator).

For the test of the molecular weight and the distribution of polyglycolic acid, Gel Permeation Chromatography (GPC) method is used for the test, which is as follows:

a0.2 g sample of PGA was dissolved in 100mL of hexafluoroisopropanol solution having a sodium trifluoroacetate content of 5mmol/L, filtered through a polytetrafluoroethylene filter having a pore size of 0.4. mu.m, and 20. mu.L of the filtrate was introduced into an "LC-20 AD GPC" sample injector manufactured by Shimadzu (Japan) under test conditions: the column temperature is 40 ℃; eluent: hexafluoroisopropanol with 5mmol/L of sodium trifluoroacetate dissolved therein; the flow rate is 1 mL/min; a detector: an RI detector; and (3) correction: five different standards of polymethyl methacrylate with molecular weights varying between 7000 and 200000 were used for molecular weight correction.

In the following examples, the melt stirring tank used had a volume of 50L, the static mixer 8L, the melt metering pump had a maximum delivery flow rate of 10L/h, and the melt pump had a maximum delivery flow rate of 12L/h.

The static mixer used in the following examples is a commercially available SK type static mixer.

Apparatus example 1

A continuous producing apparatus for a reforming material as shown in FIG. 1A is provided.

The modified material continuous production apparatus 1A includes a melt-mixing tank 100, a static mixer 200 coupled to the melt-mixing tank, a tackification device 300 (for example, a twin-screw extruder provided with only a devolatilization section) disposed downstream of the static mixer, and a blending modification unit 400 coupled to the tackification device 300.

A melt metering pump 120 is arranged between the static mixer 200 and the melting and mixing kettle 100, and a kettle bottom discharge port 110 of the melting and mixing kettle 100 is connected with a feed port of the static mixer 200 through the melt metering pump 120.

The outlet of the static mixer 200 is connected with the inlet of the viscosity increasing device 300 through the material conveying component 230.

The blending modification unit 400 comprises a plasticizing section 421, a blending section 422 and an extrusion section 423 of an I-th mixing and extrusion device 420 (for example, a double-screw extruder provided with the plasticizing section, the blending section and the extrusion section), wherein a discharge port of the tackifying device 300 is connected with a feeding part of the plasticizing section 421 of the I-th mixing and extrusion device 420, a discharge port of the plasticizing section 421 of the I-th mixing and extrusion device 420 is connected with a feeding part of the blending section 422, and a discharge port of the blending section 422 is connected with a feeding port of the extrusion section 423. The weight loss scales 4001-II are connected to the feeding part of the plasticizing section 421 of the mixing and extruding device I420.

The axis of the tackifying device 300 is at 90 degrees to the material feed direction of the I-th mixing and extrusion device (see fig. 3).

The material conveying assembly 230 comprises a material conveying pipeline 231 for connecting the discharge port of the static mixer 200 with the feed port of the tackifying device 300, a melt pump 232 arranged on the material conveying pipeline, and a cleaning solution dredging pipeline 233 arranged in parallel with the melt pump 232, wherein a cleaning solution drainage branch 234 is arranged on the material conveying pipeline 231 between the melt pump 232 and the feed port of the tackifying device 300.

The liquid inlet end and the liquid outlet end of the cleaning liquid dredging pipeline 233 are connected in parallel to both sides of the melt pump 232 through a three-way valve 235-I.

The cleaning solution draining branch 234 is connected with the material conveying pipeline 231 through a three-way valve 235-II.

The top of the melting mixing kettle 100 is provided with a reaction material inlet and a reaction auxiliary agent inlet, wherein the reaction material inlet is connected with a weightlessness scale 1112-I through a material inlet pipe 112, the reaction auxiliary agent inlet is connected with a reaction auxiliary agent storage tank 1110 arranged at the upstream of the melting mixing kettle through an auxiliary agent inlet pipe 111, and a liquid metering pump 1111 is further arranged on the auxiliary agent inlet pipe 111 between the reaction auxiliary agent storage tank 1110 and the reaction auxiliary agent inlet.

The pipeline between the bottom discharge port 110 of the melt mixing kettle 100 and the feed port of the static mixer 200, the material conveying pipeline 231, the cleaning liquid dredging pipeline 233, the melt metering pump 120, the melt pump 232, the three-way valve 235-I and the three-way valve 235-II are all provided with conventional heat tracing.

Apparatus example 2

A continuous producing apparatus for a reforming material as shown in FIG. 1B is provided.

The modified material continuous production apparatus 1B includes a melt-mixing tank 100, a static mixer 200 coupled to the melt-mixing tank, a tackification device 300 (for example, a twin-screw extruder provided with only a devolatilization section) disposed downstream of the static mixer, and a blending modification unit 400 coupled to the tackification device 300.

The blending modification unit 400 comprises a II-th mixing and extruding device 430 (for example, a double-screw extruder only provided with a plasticizing section), a blending section 422 and an extruding section 423 of an I-th mixing and extruding device 420 (for example, a double-screw extruder provided with a blending section and an extruding section), wherein a discharge port of the tackifying device 300 is connected with a feeding part of the plasticizing section 421 of the I-th mixing and extruding device 420, a connection position of a discharge port of the II-th mixing and extruding device 430 and the feeding part of the blending section 422 is positioned at the downstream of a material feeding direction of a connection position of the discharge port of the tackifying device 300 and the feeding part of the plasticizing section 421 of the I-th mixing and extruding device 420, and a discharge port of the blending section 422 of the I-th mixing and extruding device 420 is connected with a feeding port of the extruding section 423. Weight loss scales 4001-II are attached to the feeding portion of the II th mixing and extrusion apparatus 430.

The axes of the tackifying device 300 and the II mixing and extruding device 430 are respectively at 90 degrees to the material feeding direction of the I mixing and extruding device 420 (see figure 4).

Apparatus example 3

A continuous producing apparatus for a reforming material as shown in FIG. 2A is provided.

The modified material continuous production apparatus 2A includes a melt-mixing kettle 100, an external circulation heat exchange unit 500 coupled to the melt-mixing kettle, a static mixer 200 coupled to the melt-mixing kettle, a tackifying device 300 (for example, a twin-screw extruder provided with only a devolatilization section) disposed downstream of the static mixer, and a blending modification unit 400 coupled to the tackifying device 300.

The external circulation heat exchange unit 500 comprises an external circulation discharge port 510, an external circulation feed port 520 and an external circulation pipeline 530 connecting the external circulation discharge port and the external circulation feed port; the external circulation discharge port 510 and the external circulation feed port 520 are respectively connected to the lower part of the melting and mixing kettle 100, and the connection part of the external circulation feed port 520 and the lower part of the melting and mixing kettle 100 is higher than the connection part of the external circulation discharge port 510 and the lower part of the melting and mixing kettle 100; the external circulation feed inlet 520, the circulation pump 542, the heat exchanger 541 and the external circulation discharge outlet 510 are connected in sequence on the external circulation pipeline 530.

Apparatus example 4

A continuous producing apparatus for a reforming material as shown in FIG. 2B is provided.

The modified material continuous production apparatus 2B includes a melt-mixing kettle 100, an external circulation heat exchange unit 500 coupled to the melt-mixing kettle, a static mixer 200 coupled to the melt-mixing kettle, a tackifying device 300 (for example, a twin-screw extruder provided with only a devolatilization section) disposed downstream of the static mixer, and a blending modification unit 400 coupled to the tackifying device 300.

Preparation examples 1 to 6

Continuous production of modified resins

In examples 1 to 6 described below, example 1 was a modified resin prepared based on the apparatus of the above apparatus example 1, example 2 was a modified resin prepared based on the apparatus of the above apparatus example 2, examples 3 and 5 were modified resins prepared based on the apparatus of the above apparatus example 4, and examples 4 and 6 were modified resins prepared based on the apparatus of the above apparatus example 3.

In addition, D of glycolide powders used in examples 1 to 6 described below₉₀Less than or equal to 200 mu m, purity more than or equal to 98.5 percent and acidity less than or equal to 20 mmol/kg.

Preparation example 1:

adjusting a weight loss scale 1112-I by a computer, controlling the feeding amount (generally determined according to the yield and the volume of a melt mixing kettle) of glycolide (refining) in the melt mixing kettle, adjusting a liquid metering pump by the computer after the glycolide in the melt mixing kettle is completely melted to control the adding amount of a reaction auxiliary agent, adding the reaction auxiliary agent while stirring, obtaining a premix in a fluid state after the materials are uniformly mixed, then controlling an electromagnetic valve at a kettle bottom discharge port of the melt mixing kettle to open by the computer, adjusting a melt metering pump to convey the premix to a static mixer for prepolymerization to obtain a glycolic acid prepolymer with a certain molecular weight (about 5-15 ten thousand), and then controlling a melt pump by the computer to convey the glycolic acid prepolymer to tackifying equipment (for example, a double-screw extruder only provided with a devolatilization section) for final polymerization, meanwhile, the computer controls the I mixing and extruding equipment to start working, the weight loss scale 4001-II is adjusted to control the amount of the modified components (including modified resin and other processing aids) entering the plasticizing section of the I mixing and extruding equipment, the molten PGA prepared by final polymerization of the tackifying equipment is directly introduced into the blending section of the I mixing and extruding equipment, and is blended with the plasticized modified components, and then the components are extruded and granulated by the extruding section of the I mixing and extruding equipment to obtain the modified material. In the process, the feeding time and the feeding amount of the glycolide and the reaction auxiliary agent can be adjusted by a computer, and the reaction materials are timely supplemented into the melting and mixing kettle, so that stable and continuous production is realized.

Preparation example 2:

adjusting a weight loss scale 1112-I by a computer, controlling the feeding amount of glycolide (refining) in a melting and mixing kettle, after the glycolide in the melting and mixing kettle is completely melted, adjusting a liquid metering pump by the computer to control the adding amount of a reaction auxiliary agent, adding the reaction auxiliary agent while stirring, after the materials are uniformly mixed, obtaining a premix in a fluid state, controlling an electromagnetic valve at a kettle bottom discharge outlet of the melting and mixing kettle to open by the computer, adjusting the melt metering pump to convey the premix to a static mixer for prepolymerization to obtain a glycolic acid prepolymer with a certain molecular weight (about 5-15 ten thousand), controlling a melt pump by the computer to convey the glycolic acid prepolymer to tackifying equipment (for example, an extruder with only a devolatilization section of a twin-screw extruder) for final polymerization, and simultaneously controlling an I mixing and extruding equipment and a II mixing and extruding equipment to start to work by the computer, and the weight loss scale 4001-II is adjusted to control the amount of the modified component (containing modified resin and other processing aids) entering the second mixing and extruding device, then the melted PGA prepared by final polymerization of the tackifying device is directly introduced into the blending section of the first mixing and extruding device, and the modified component entering the second mixing and extruding device is plasticized and then directly introduced into the blending section of the first mixing and extruding device, blended with the melted PGA conveyed from the upstream, and extruded and granulated by the extruding section of the first mixing and extruding device, so that the modified material can be prepared. In the process, the feeding time and the feeding amount of the glycolide and the reaction auxiliary agent can be adjusted by a computer, and the reaction materials are timely supplemented into the melting and mixing kettle, so that stable and continuous production is realized.

Preparation examples 3 and 5:

adjusting a weightlessness scale 1112-I by a computer, controlling the feeding amount of glycolide (refining) in the melting mixing kettle, after the glycolide in the melting mixing kettle is completely melted, controlling a circulating pump, an electromagnetic valve at an external circulating discharge port and an electromagnetic valve at an external circulating feed port to be opened by the computer, enabling the melted glycolide to enter a heat exchanger through an external circulating pipeline to be heated and heated, returning the heated glycolide to the melting mixing kettle through the external circulating pipeline, thereby constructing internal circulation of reaction materials in the melting mixing kettle, then adjusting a liquid metering pump by the computer to control the addition amount of the reaction auxiliary agent, adding the reaction auxiliary agent while stirring, obtaining a premix in a fluid state after the materials are uniformly mixed, then controlling the electromagnetic valve at the discharge port at the bottom of the melting mixing kettle to be opened by the computer, and conveying the premix to a static mixer to perform prepolymerization by adjusting a melt metering pump, obtaining glycolic acid prepolymer with certain molecular weight (about 5-15 ten thousand), then controlling a melt pump by a computer to convey the glycolic acid prepolymer to tackifying equipment (for example, a twin-screw extruder only provided with a devolatilization section) for final polymerization, wherein at the same time, the computer controls the first mixing extrusion equipment and the second mixing extrusion equipment to start working, and controls the amount of modified components (containing modified resin and other processing aids) entering the second mixing extrusion equipment by adjusting weight loss scales 4001-II, then molten PGA finally polymerized by the tackifying equipment is directly introduced into the blending section of the first mixing extrusion equipment, and the modified components entering the second mixing extrusion equipment are plasticized and then directly introduced into the blending section of the first mixing extrusion equipment, blended with the molten PGA conveyed from upstream, and then extruded from the extrusion section of the first mixing extrusion equipment, And (4) granulating to obtain the modified material. In the process, the feeding time and the feeding amount of the glycolide and the reaction auxiliary agent can be adjusted by a computer, and the reaction materials are timely supplemented into the melting and mixing kettle, so that stable and continuous production is realized.

Preparation examples 4 and 6:

adjusting a weightlessness scale 1112-I by a computer, controlling the feeding amount of glycolide (refining) in the melting mixing kettle, after the glycolide in the melting mixing kettle is completely melted, controlling a circulating pump, an electromagnetic valve at an external circulating discharge port and an electromagnetic valve at an external circulating feed port to be opened by the computer, enabling the melted glycolide to enter a heat exchanger through an external circulating pipeline to be heated and heated, returning the heated glycolide to the melting mixing kettle through the external circulating pipeline, thereby constructing internal circulation of reaction materials in the melting mixing kettle, then adjusting a liquid metering pump by the computer to control the addition amount of the reaction auxiliary agent, adding the reaction auxiliary agent while stirring, obtaining a premix in a fluid state after the materials are uniformly mixed, then controlling the electromagnetic valve at the discharge port at the bottom of the melting mixing kettle to be opened by the computer, and conveying the premix to a static mixer to perform prepolymerization by adjusting a melt metering pump, obtaining a glycolic acid prepolymer with a certain molecular weight (about 5-15 ten thousand), then controlling a melt pump by a computer to convey the glycolic acid prepolymer to tackifying equipment (for example, a twin-screw extruder only provided with a devolatilization section) for final polymerization, controlling the I mixing and extruding equipment to work by the computer at the same time, controlling the amount of modified components (containing modified resin and other processing aids) entering a plasticizing section of the I mixing and extruding equipment by adjusting weight loss scales 4001-II, directly introducing molten PGA prepared by final polymerization of the tackifying equipment into a blending section of the I mixing and extruding equipment, blending the molten PGA with the plasticized modified components, extruding and granulating the mixture by an extruding section of the I mixing and extruding equipment, and thus obtaining the modified material. In the process, the feeding time and the feeding amount of the glycolide and the reaction auxiliary agent can be adjusted by a computer, and the reaction materials are timely supplemented into the melting and mixing kettle, so that stable and continuous production is realized.

The amounts of the reaction assistants added in examples 1 to 6 are shown in tables 1 to 1 below.

TABLE 1-1

The kinds of reaction assistants in examples 1 to 6 are shown in the following tables 1 to 2.

Tables 1 to 2

Item	Catalyst and process for preparing same	Initiator	Dehydrating agent
				Example 1	Stannous octoate	Isopropanol (I-propanol)	Carbodiimides
Example 2	Diethyl zinc	N-propanol	N, N' -diisopropylcarbodiimide
				Example 3	The diethyl zinc and the tin lactate are mixed according to the mass ratio of 1:1	N-propanol	N, N' -diisopropylcarbodiimide
Example 4	The stannous chloride and the antimony trioxide are mixed according to the mass ratio of 1:2	N-butanol	Dicyclohexylcarbodiimide
				Example 5	Stannous octoate, antimony trioxide and zinc acetate dihydrate according to the mass ratio of 5:2:3	Benzyl alcohol	Carbodiimides
Example 6	Antimony trioxide	Benzyl alcohol	Polycarbodiimide

The temperatures of the heated molten glycolide in the melt-mixing tank in examples 1 to 6 are shown in tables 1 to 3 below.

Tables 1 to 3

Item

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Temperature (. degree.C.)

About 90

About 112

About 120

About 115

About 116

Note: the time from the time each batch of glycolide powder entered the melt-mixing kettle to the time the premix was obtained was about 20min.

The temperature parameters of the stages of the static mixer of the above examples 1-6 are shown in the following Table 2-1:

TABLE 2-1

Item

Static mixer

First stage

Second section

Third stage

Fourth stage

Fifth stage

Example 1

Four sections in total

About 120 deg.C

About 190 deg.C

About 213 deg.C

About 224 deg.C

/

Example 2

Four sections in total

About 180 deg.C

About 210 deg.C

About 220 deg.C

About 230 deg.C

/

Example 3

Five sections in total

About 170 deg.C

About 200 deg.C

About 210 deg.C

About 220 deg.C

About 230 deg.C

Example 4

Five sections in total

About 150 deg.C

About 190 deg.C

About 202 deg.C

About 213 deg.C

About 220 deg.C

Example 5

Three segments in total

About 190 deg.C

About 210 deg.C

About 221 deg.C

/

Example 6

Three segments in total

About 220 deg.C

About 238 deg.C

About 250 deg.C

/

The time required for the materials to pass through the stages in the static mixer of the above examples 1-6 is shown in tables 2-2 below:

tables 2 to 2

Item

Static mixer

First stage

Second section

Third stage

Fourth stage

Fifth stage

Example 1

Four sections in total

About 5min

About 15min

About 20min

About 50min

/

Example 2

Four sections in total

About 5min

About 15min

About 20min

About 50min

/

Example 3

Five sections in total

About 5min

About 10min

About 15min

About 55min

Example 4

Five sections in total

About 5min

About 10min

About 15min

About 55min

Example 5

Three segments in total

About 5min

About 20min

About 65min

/

Example 6

Three segments in total

About 5min

About 20min

About 65min

/

In examples 1 to 6 above, the parameter settings of the devolatilization section in the tackifying equipment are shown in the following table 3:

TABLE 3

Item	Temperature (. degree.C.)	Absolute pressure (Pa)	Length-diameter ratio of screw	Screw rotation speed (r/min)
					Example 1	About 220	200	52	30
Example 2	About 240	120	50	45
					Example 3	About 240	120	50	45
Example 4	About 232 f	150	60	30
					Example 5	About 238	280	50	45
Example 6	About 250 f	500	54	60

The temperature settings of the lines from the melt mixing kettle to the viscosity increasing equipment in examples 1-6 above are shown in Table 4 below:

TABLE 4

Note: the conveying flow rates of the melt-metering pump and the melt pump used in examples 1 to 3 were set to about 6.7L/h, and the conveying flow rates of the melt-metering pump and the melt pump used in examples 4 to 6 were set to about 5.3L/h.

The weight average molecular weight of glycolic acid prepolymer formed by the static mixer, the number average molecular weight, weight average molecular weight and molecular weight distribution index of the molten PGA obtained by the type I twin-screw extruder in the above examples 1 to 6 are shown in table 5 below.

TABLE 5

In the above examples 1 to 6, the modifying components used are shown in Table 6 below:

TABLE 6

Note: in table 6, the weight average molecular weight of PBAT was about 6 ten thousand, with the proportion of butylene terephthalate repeat units being about 85 mol%; the compatilizer is ABS-g-MAH which is sold in the market, and the grafting rate is about 6 percent; the antioxidant is commercially available pentaerythritol diisodecyl diphosphite; the heat stabilizer is commercially available brown calcium oleate soap.

The process conditions for blending the modifying units in examples 1-6 above are shown in Table 7 below.

TABLE 7

The length-diameter ratio of a screw of the first mixing and extruding device is 52, and the rotating speed is 150 r/min.

The length-diameter ratio of a screw of a plasticizing section of the II-th mixing and extruding equipment is 35, and the rotating speed is 120 r/min.

Comparative examples 1 to 3

Comparative examples 1-3 modified materials were prepared using the following formulations: 75 parts of PGA, 25 parts of PBAT, 5 parts of compatilizer, 0.8 part of antioxidant and 0.2 part of heat stabilizer. The PBAT, the compatibilizer, the antioxidant and the heat stabilizer used were the same as those in the above examples.

The PGA used in comparative example 1 was obtained by extruding and granulating the material finally polymerized by the above-mentioned viscosity increasing apparatus in example 1.

The PGA used in comparative example 2 was obtained by extruding and granulating the material finally polymerized by the above-mentioned viscosity increasing apparatus in example 3.

PGA used in comparative example 3 was prepared from glycolide powder (D)₉₀Not less than 200 μm, purity not less than 98.5% and acidity not more than 20mmol/kg) by a conventional reaction type twin-screw extruder, the reaction auxiliary agents used are the same as in the above example 3, and the specific process conditions and parameters are shown in the following tables 8-1 and 8-2.

TABLE 8-1

Note: in comparative example 3, glycolide powder and the reaction assistant were uniformly mixed and then added from the beginning of the first stage of the mixing section.

TABLE 8-2

The PGA obtained in comparative example 3 had a data molecular weight (Mn) of 88016, a weight average molecular weight (Mw) of 163711, and a molecular weight distribution index of 1.86.

Comparative examples 1-3 the preparation method of the modified materials was: adding PGA and PBAT in parts by weight from a main feeding port of a double-screw extruder, then adding a compatilizer, an antioxidant and a heat stabilizer from a side feeding port of the double-screw extruder, controlling the rotating speed of the double-screw extruder to be 200r/min, controlling the temperature of a plasticizing section of the double-screw extruder to be 220 ℃, the temperature of a blending section to be 220 ℃, the temperature of an extruding section to be 230 ℃ in a comparative example 1, controlling the temperature of the plasticizing section of the double-screw extruder to be 220 ℃, the temperature of the blending section to be 226 ℃ and the temperature of the extruding section to be 238 ℃ in comparative examples 2 and 3, and then extruding and granulating to obtain the modified material.

Performance testing

The tensile strength and impact strength of the modified materials obtained in examples 1-6 and comparative examples 1-3 were measured according to GB/T1040.1-2006 and GB/T1043.1-2008 test standards, and the specific results are shown in Table 9 below.

TABLE 9

Note: the tensile rate in the above tensile test was 50mm/min

The foregoing is merely a preferred embodiment of the utility model and is not intended to limit the scope of the utility model, which is defined by the claims appended hereto, and any other technical entity or method that is encompassed by the claims as broadly defined herein, or equivalent variations thereof, is contemplated as being encompassed by the claims.

Claims

1. The continuous production device of the modified material is characterized by comprising a melt mixing kettle, a static mixer connected with a discharge port of the melt mixing kettle, tackifying equipment arranged at the downstream of the static mixer, and a blending modification unit coupled with the tackifying equipment.

2. The continuous production device of the modified material according to claim 1, wherein the blending modification unit comprises an I-th mixing extrusion device coupled with the tackifying device, the I-th mixing extrusion device is provided with a plasticizing section, a blending section and an extrusion section in sequence along the material feeding direction, and the discharge port of the tackifying device is connected with the blending section of the I-th mixing extrusion device.

3. The continuous production device of the modified material according to claim 1, wherein the blending modification unit comprises an I mixing extrusion device coupled with the tackifying device and an II mixing extrusion device coupled with the I mixing extrusion device, the I mixing extrusion device is provided with a blending section and an extrusion section in sequence along the material feeding direction, and the II mixing extrusion device is provided with only a plasticizing section.

4. The continuous production device of modified materials according to claim 3, wherein the discharge port of the tackifying device and the discharge port of the II mixing and extruding device are respectively connected with the blending section of the I mixing and extruding device.

5. The continuous production device of modified materials according to claim 4, wherein the junction of the discharge port of the II-th mixing and extruding device and the blending section of the I-th mixing and extruding device is located downstream of the junction of the discharge port of the tackifying device and the blending section of the I-th mixing and extruding device in the material feeding direction.

6. The apparatus for continuously producing a modified material according to claim 1, further comprising an external circulation heat exchange unit coupled to the melt-mixing tank.

7. The continuous production device of modified materials according to claim 6, wherein the external circulation heat exchange unit comprises an external circulation discharge port, an external circulation feed port, an external circulation pipeline connecting the external circulation discharge port and the external circulation feed port, a heat exchanger and a circulation pump arranged on the external circulation pipeline.

8. The continuous production apparatus for modified materials according to claim 7, wherein the external circulation discharge port and the external circulation feed port are connected to the lower part of the melt-mixing tank, respectively, and the junction of the external circulation feed port and the lower part of the melt-mixing tank is higher than the junction of the external circulation discharge port and the lower part of the melt-mixing tank.

9. The continuous production device of modified materials according to claim 1, wherein the static mixer is connected with the viscosity-increasing equipment through a material conveying component, and the material conveying component comprises a material conveying pipeline connecting a discharge port of the static mixer and a feed port of the viscosity-increasing equipment, a melt pump arranged on the material conveying pipeline, and a cleaning liquid drain pipe connected with the melt pump in parallel on the material conveying pipeline.