CN115025732A

CN115025732A - Device and process for continuously producing graphite EPS and application

Info

Publication number: CN115025732A
Application number: CN202210952870.3A
Authority: CN
Inventors: 徐月宏; 邹若东; 吴敬标
Original assignee: Tianjin Rentai New Material Co ltd
Current assignee: Tianjin Rentai New Material Co ltd
Priority date: 2022-08-10
Filing date: 2022-08-10
Publication date: 2022-09-09

Abstract

The invention provides a device and a process for continuously producing graphite EPS and application thereof, relating to the technical field of expandable polystyrene production. The device for continuously producing the graphite EPS comprises a reaction kettle, a devolatilization device, a mixer, a filter and an EPS molding system which are sequentially communicated; wherein, be connected with first pumping device between reation kettle and the devolatilization ware, be connected with second pumping device between devolatilization ware and the blender. The device is a continuous production device, and the investment of production equipment is low under the condition of the same production capacity. The device has the advantages of short production period, closed product energy consumption, unit consumption and production process, less three wastes, continuous and automatic control of the whole production process, stable product quality and obvious advantages in large-scale industrial production.

Description

Device and process for continuously producing graphite EPS and application

Technical Field

The invention relates to the technical field of expandable polystyrene production, in particular to a device and a process for continuously producing graphite EPS and application thereof.

Background

With the further awareness of energy conservation and emission reduction, Expandable Polystyrene (EPS) plates are paid much attention to as heat-insulating materials. The heat-insulating material EPS has the advantages of low heat conductivity coefficient, certain strength and toughness, large-scale forming, mature process, convenient construction and the like. In order to further reduce the thermal conductivity, graphite/expandable polystyrene composites have emerged.

The existing production methods of graphite EPS (expandable polystyrene) beads are suspension polymerization method and extrusion method of blending extruder. The suspension polymerization method is a method in which a monomer containing an initiator dissolved therein is suspended in water in the form of droplets to perform radical polymerization. Styrene monomer, foaming agent, graphite powder and other auxiliary agents are added into a reaction kettle together for polymerization, namely polymerization and impregnation are carried out in the same reaction kettle at the same time, and centrifugation and drying are carried out after the reaction is finished, so that the graphite EPS beads are obtained finally. The production belongs to batch operation, the graphite EPS quality difference can occur, the product quality stability is poor, the suspension polymerization method can generate more waste water and waste gas, the environmental management cost is high, and the production cost is increased.

The extrusion method by a melt-blown extruder is a method in which an additive such as graphite powder is mixed into polystyrene pellets, the mixture is melt-blown and extruded through an extruder, a blowing agent is pressed into a molten polystyrene resin in the extruder and kneaded, the molten resin containing the blowing agent is directly extruded into a liquid for cooling through a small hole of a die attached to the tip of the extruder, the extrudate is cut by a high-speed rotating knife while being extruded, and the extrudate is cooled and solidified by contact with the liquid, thereby obtaining graphite EPS pellets. Polystyrene particles and graphite are mechanically mixed and subjected to secondary high-temperature plasticization, so that a large amount of electric energy is consumed, and the polystyrene particles are inevitably coked, cracked and carbonized in the high-temperature plasticization, so that the mechanical strength of the product is seriously influenced.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

One of the objectives of the present invention is to provide a device for continuously producing graphite EPS, so as to alleviate the technical problems of discontinuous production process, low productivity and non-uniform product quality of graphite EPS in the prior art.

The second purpose of the invention is to provide a process for continuously producing graphite EPS, so as to relieve the technical problems of discontinuous production process, poor quality stability and high cost of the graphite EPS in the prior art.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

the invention provides a device for continuously producing graphite EPS (expandable polystyrene), which comprises a reaction kettle, a devolatilization device, a mixer, a filter and an EPS molding system which are sequentially communicated.

Wherein, be connected with first pumping device between reation kettle with the devolatilization ware, be connected with second pumping device between devolatilization ware and the blender.

Optionally, the reaction kettle is further communicated with a raw material tank and a solvent tank.

Preferably, the solvent tank, the mixing tank and the reaction kettle are communicated in sequence.

Optionally, the devolatilizer comprises a primary devolatilizer and a secondary devolatilizer in communication with a third pumping device.

Preferably, the reaction kettle, the primary devolatilization device and the secondary devolatilization device are respectively and independently communicated with a condenser.

Preferably, the primary devolatilizer is communicated with a primary recovery tank.

Preferably, the secondary devolatilizer is communicated with a secondary recovery tank.

Optionally, the primary recovery tank is in communication with the solvent tank.

Preferably, the reaction kettle, the primary recovery tank and the secondary recovery tank are respectively and independently communicated with a vacuum system.

Optionally, the mixer is in communication with a feed system.

Preferably, the feed system comprises a high pressure feed system and/or an atmospheric feed system.

The second aspect of the invention provides a process for continuously producing graphite EPS, which mainly adopts the device for continuously producing graphite EPS of the first aspect to produce.

Optionally, the process for continuously producing graphite EPS comprises the steps of: styrene monomer, additive and graphite are subjected to polymerization reaction in a reaction kettle, unreacted raw materials of the mixed materials obtained by the reaction are removed through devolatilization and filtration to obtain polystyrene plastic melt, the polystyrene plastic melt is added with foaming agent and mixed in a mixer, and the graphite EPS is obtained through an EPS forming system.

Preferably, the method comprises the following steps: and carrying out polymerization reaction on a styrene monomer and an additive in a reaction kettle, devolatilizing and filtering a mixed material obtained by the reaction to remove unreacted raw materials to obtain a polystyrene plastic melt, mixing the polystyrene plastic melt with graphite and a foaming agent in a mixer, and then obtaining the graphite EPS through an EPS molding system.

Optionally, the graphite includes at least one of ordinary graphite, expanded graphite, flake graphite, modified graphite, and composite graphite.

Preferably, the additive comprises at least one of a thermoplastic, a plastic modification aid, an antioxidant, an age resistor, a toughening agent, and a flame retardant.

Preferably, the thermoplastic comprises at least one of methyl methacrylate, cyclic olefin, and olefin-based monomers.

Preferably, the toughening agent comprises a rubber.

Preferably, the rubber includes at least one of acrylic rubber, SBS rubber, ABS rubber, and olefin rubber.

Preferably, the flame retardant comprises a halogen-free flame retardant, an inorganic flame retardant and/or an organic flame retardant.

Preferably, the organic flame retardant comprises a halogen-free flame retardant.

Preferably, the blowing agent comprises at least one of butane, pentane, carbon dioxide or a composite blowing agent.

Optionally, the graphite has a particle size of 1 μm to 400 μm, preferably 2 μm to 180 μm.

Preferably, the mass ratio of the graphite to the styrene monomer is (0.1-35): 100.

Preferably, the mass ratio of the additive to the styrene monomer is (0.001-20): 100, preferably (0.001-15): 100.

preferably, the melt index of the polystyrene plastic melt is 1.1g/10min-10.0g/10min, preferably 2.2g/10min-3.7g/10 min.

Preferably, the mass ratio of the foaming agent to the polystyrene plastic melt is (1-20): 100, preferably (2-15): 100.

preferably, the temperature of the polymerization reaction is 110 ℃ to 160 ℃, preferably 120 ℃ to 150 ℃.

Preferably, the temperature of the devolatilization is from 240 ℃ to 290 ℃, preferably from 250 ℃ to 280 ℃.

Preferably, the pressure of the devolatilization is from 0.01kpa (a) to 3kpa (a), preferably from 0.01kpa (a) to 2kpa (a).

Preferably, the temperature at which the mass is conveyed in the apparatus after the polymerization is from 200 ℃ to 260 ℃, preferably from 220 ℃ to 250 ℃.

The third aspect of the invention provides the use of said apparatus or said process for the production of graphite EPS.

Compared with the prior art, the invention has at least the following beneficial effects:

the device for continuously producing the graphite EPS is a continuous production device, and has low production equipment investment under the condition of the same production capacity. The device has the advantages of short production period, closed product energy consumption, unit consumption and production process, less three wastes, continuous and automatic control of the whole production process, stable product quality and obvious advantages in large-scale industrial production.

The process for continuously producing the graphite EPS provided by the invention comprises the steps of uniformly mixing in a reaction kettle for polymerization reaction, conveying materials generated by the reaction to a devolatilization unit through a pipeline by a melt transfer pump, refining in the devolatilization and filtration unit, separating unreacted raw material monomers, mixing a plastic melt refined by devolatilization and filtration with a foaming agent, and then obtaining a graphite EPS product by an EPS molding system. The process is continuous in process, high in mechanization degree and suitable for large-scale industrial production.

The device and the process provided by the invention are applied to the production of the graphite EPS, so that the device and the process with higher efficiency and better yield are provided for the production of the graphite EPS, the production cost of the graphite EPS is reduced, and the application range of the graphite EPS is expanded.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is an apparatus for continuously producing EPS, as provided in example 1;

FIG. 2 shows another apparatus for continuously producing EPS, which is provided in example 1.

An icon: 1-a raw material tank; 2-a solvent tank; 3-a mixing tank; 4-a reaction kettle; 5-a gear pump; 6-first-stage devolatilization device; 8-a secondary devolatilization device; 10-a mixer; 11-a filter; 12-a granulation system; 13-a dewatering screening system; 14-pneumatic packaging systems; 15-a condenser; 18-first stage recovery tank; 19-a secondary recovery tank; 20-a vacuum system; 21-normal pressure feeding system; 22-high pressure feed system.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to embodiments and examples, but it will be understood by those skilled in the art that the following embodiments and examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Graphite is an important natural carbon material, has excellent physical and mechanical properties, electrical and thermal conductivity and chemical stability, and is widely regarded as an ideal filler for preparing high-performance and multifunctional polymer composite materials.

Polystyrene is a general thermoplastic resin, has good service performance and processing performance, and is widely applied to various fields and layers of production and life of people. But as an organic material, which is flammable and an electrical, thermal insulator, these drawbacks limit its higher-level applications. In order to solve this problem, researchers often add some functional fillers to meet different performance requirements, and achieve good effects.

Optionally, the mixer is in communication with a feeding system.

The invention provides a process for continuously producing graphite EPS, which mainly adopts the device for continuously producing graphite EPS of the first aspect to produce.

The process for continuously producing the graphite EPS provided by the invention comprises the steps of uniformly mixing in a reaction kettle for polymerization reaction, conveying materials generated by the reaction to a devolatilization unit through a pipeline by a melt transfer pump, refining in the devolatilization and filtration unit, separating unreacted raw material monomers, mixing the devolatilized, filtered and refined plastic melt with a foaming agent, and then obtaining a graphite EPS product by an EPS forming system. The process is continuous in process, high in mechanization degree and suitable for large-scale industrial production.

Preferably, the method comprises the following steps: and carrying out polymerization reaction on a styrene monomer and an additive in a reaction kettle, devolatilizing and filtering a mixed material obtained by the reaction to remove unreacted raw materials to obtain a polystyrene plastic melt, mixing the polystyrene plastic melt with graphite and a foaming agent in a mixer, and then obtaining the graphite EPS through an EPS forming system.

The invention provides two process routes, one is adding graphite in the polymerization reaction process, the other is adding foaming agent at the later stage, and the specific route can be selected according to the production requirement. In one embodiment of the invention, the polystyrene raw material is also used for producing other products, and the foaming agent is added at the later stage and simultaneously graphite is added, and the polystyrene raw material is divided before entering the mixer and enters other production lines.

When the particle size of the graphite is larger than 400 mu m, the graphite is difficult to disperse in styrene monomer/polystyrene and is easy to settle, and well-dispersed graphite EPS can not be prepared, so that the infrared ray reflecting performance of the graphite can not be fully exerted, and the mechanical property of the material is influenced. The smaller the particle size of the graphite is, the less the sedimentation amount is; the larger the particle size, the more the amount of sedimentation. The smaller the amount of sedimentation, the more advantageous the reaction. However, the smaller the graphite particle size, the higher the price, and the more the dispersion and cost factors are considered, the more the graphite particle size is selected to be between 1 μm and 400 μm, preferably between 2 μm and 180 μm.

In some embodiments of the invention, the particle size of the graphite is typically, but not limited to, 1 μm, 2 μm, 10 μm, 50 μm, 100 μm, 180 μm, 200 μm, 300 μm, or 400 μm.

When the graphite is added in the polymerization reaction, if the addition amount of the graphite is less than 0.1:100, the graphite amount is too low, so that the infrared ray reflecting performance of the graphite cannot be fully exerted, and the heat resistance is poor; when the addition amount of the graphite is more than 35:100, the mechanical property of the material is reduced due to more graphite, and the mechanical property of a molded product is poor.

In some embodiments of the invention, the polymerization reaction adds graphite in a mass ratio of graphite to styrene monomer that is typically, but not limited to, 0.1:100, 1:100, 10:100, 15:100, 20:100, 25:100, 30:100, or 35: 100.

in some embodiments of the invention, the mass ratio of additive to styrene monomer is typically, but not limited to, 0.001:100, 0.01:100, 0.1:100, 1:100, 5:100, 10:100, or 20: 100.

Preferably, the toughening agent comprises a rubber.

The melt index refers to the fluidity value of the polystyrene plastic during melt processing, and the larger the value is, the better the fluidity of the polystyrene plastic during melt processing is. Under the same condition, the larger the melt index is, the lower the mechanical property of the product is, but when the melt index is lower, the mechanical property of the product is improved, the processing and manufacturing difficulty is generated, and the product yield is reduced, so that the processing difficulty and the mechanical property of the product are considered, and the melt index of the polystyrene plastic melt is preferably 1.1g/10min-10.0g/10 min.

In some embodiments of the invention, the melt index of the polystyrene plastic melt is typically, but not limited to, 1.1g/10min, 2.2g/10min, 3.3g/10min, 3.7g/10min, 4.5g/10min, 5.4g/10min, 6.2g/10min, 7.6g/10min, 9.1g/10min, or 10.0g/10 min.

in another process route of the invention, a foaming agent and graphite are added in the mixing step, when the mass ratio of the foaming agent to the polystyrene plastic melt is lower than 1:100, the foaming multiple is not ideal, the formed product is not fully foamed, and the product is unqualified; when the mass ratio of the blowing agent to the polystyrene plastic melt is higher than 20:100, waste of the blowing agent is caused to increase the production cost.

In some embodiments of the invention, the mass ratio of blowing agent to graphite melt is typically, but not limited to, 1:100, 2:100, 5:100, 10:100, 15:100, or 20: 100.

In some embodiments of the invention, the temperature of the polymerization reaction is typically, but not limited to, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃ or 160 ℃.

In some embodiments of the invention, the temperature of the devolatilization is typically, but not limited to, 240 ℃, 250 ℃, 260 ℃, 270 ℃, 280 ℃, or 290 ℃.

In some embodiments of the invention, the pressure of the devolatilization is typically, but not limited to, 0.01kpa (a), 0.1kpa (a), 0.5kpa (a), 1kpa (a), 2kpa (a), or 3kpa (a).

After the polymerization reaction, a polystyrene plastic melt is obtained, and in order to keep the polystyrene plastic melt in a molten state, the conveying temperature is typically but not limited to 200 ℃, 210 ℃, 220 ℃, 230 ℃, 240 ℃, 250 ℃ or 260 ℃.

The particle size of the graphite EPS product obtained by the invention is 0.50-4 mm; the oxygen index is 26-40%, the product is spherical or cylindrical, and the color of the product is gray, grey white or black.

The invention is further illustrated by the following specific examples and comparative examples, but it should be understood that these examples are for purposes of illustration only and are not to be construed as limiting the invention in any way. The raw materials used in the examples and comparative examples of the present invention, those having no particular reference to conditions, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are conventional products which are not indicated by manufacturers and are commercially available.

Example 1

This example provides an apparatus for continuously producing graphite EPS, as shown in fig. 1, which comprises a reaction kettle 4, a devolatilizer, a mixer 10, a filter 11 and an EPS forming system, which are connected in sequence.

A first pumping device is connected between the reaction kettle 4 and the devolatilizer, and a second pumping device is connected between the devolatilizer and the mixer.

The first pumping means, the second pumping means and the third pumping means each independently comprise a gear pump 5 or a centrifugal pump. The EPS forming system includes a pelletizing system 12; a dewatering and screening system 13 and an air conveying and packaging system 14.

In an EPS forming system, a graphite EPS melt is cooled and cut into spherical or cylindrical graphite EPS beads, cooling water containing the graphite EPS beads enters a bead dewatering and screening system, the graphite EPS beads are separated from the cooling water through dewatering and screening, the cooling water circulates back to the melt granulating system, and the graphite EPS beads enter a bead air-conveying and packaging system for packaging. The temperature of the extrusion die head is 180 ℃ and 260 ℃, the extrusion pressure is 2-25MPa, the temperature of the cooling water is 30-80 ℃, and the pressure of the cooling water is 0.25-15 MPa.

In some embodiments of the present invention, the reaction vessel 4 is further connected to a raw material tank 1 and a solvent tank 2.

In some embodiments of the present invention, the solvent tank 2, the mixing tank 3 and the reaction kettle 4 are communicated in sequence.

In some embodiments of the present invention, as shown in fig. 2, the devolatilizer comprises a primary devolatilizer 6 and a secondary devolatilizer 8 in communication with a third pumping means. Can set up multistage devolatilization ware according to actual demand, it is corresponding, the devolatilization ware can set up multistage accumulator.

In some embodiments of the present invention, the reaction vessel 4, the primary devolatilizer 6 and the secondary devolatilizer 8 are each independently communicated with a condenser 15.

In some embodiments of the present invention, the primary devolatilizer 6 is in communication with a primary recovery tank 18.

In some embodiments of the present invention, the secondary devolatilizer 8 is in communication with a secondary recovery tank 19.

In some embodiments of the present invention, the primary recovery tank 18 is in communication with the solvent tank 2 for recovering the solvent recovered by the primary devolatilizer 6.

In some embodiments of the present invention, the reaction vessel 4, the primary recovery tank 18 and the secondary recovery tank 19 are each independently in communication with a vacuum system 20.

In some embodiments of the invention, the mixer 10 is in communication with a feed system.

In some embodiments of the invention, the feed system comprises a high pressure feed system 22 and/or an atmospheric feed system 21.

In some embodiments of the present invention, as shown in fig. 2, the raw material in the raw material tank 1 is pumped into the reaction vessel 4, the solvent in the solvent tank 2 is pumped into the mixing tank 3, and the graphite and the additive are added into the mixing tank 3, so that the graphite, the additive and the solvent are uniformly mixed and then pumped into the reaction vessel 4. The method comprises the steps of generating a polystyrene plastic melt with uniformly distributed graphite in a reaction kettle 4 through a micro-negative pressure polymerization reaction, conveying the generated polystyrene plastic melt with uniformly distributed graphite to a primary devolatilization device 6 through a gear pump 5, separating unreacted raw materials in the primary devolatilization device through high vacuum heating, cooling the separated raw material gas phase through a condenser 15, then feeding the cooled raw material gas phase into a primary recovery tank 18 as a circulating solvent, pumping the circulating solvent into a solvent tank 2 for recycling, wherein the vacuum pressure of a reaction system is provided by a vacuum system 20. The polystyrene plastic melt which is separated from unreacted raw materials by the primary devolatilizer 6 and is uniformly distributed with graphite enters a secondary devolatilizer 8 by a gear pump 5, the unreacted raw materials and the solvent are separated again under vacuum, the unreacted raw materials and the solvent are condensed and recycled to a secondary recycling tank 19 by a condenser 15, the materials in the secondary recycling tank 19 are recycled, and the vacuum pressure is provided by a vacuum system 20. Qualified graphite EPS melt produced is sequentially conveyed to a mixer 10 through a gear pump 5, a foaming agent is added into the mixer 10 through a high-pressure feeding system 22 in the mixer 10, materials are fully mixed through the mixer 10 and then enter a filter 11, after passing through the filter 11, the graphite EPS melt enters a granulating system 12, the melt forms solidified bead-shaped particles under the action of the granulating system 12, the graphite EPS beads and water enter a dewatering and screening system 13, and after dewatering and screening, the particles enter an air-conveying packaging system 14 for packaging.

In another embodiment of the present invention, as shown in fig. 2, the raw material in the raw material tank 1 is pumped into the reaction vessel 4 by a pump, the solvent in the solvent tank 2 is pumped into the mixing tank 3, and the additive is added into the mixing tank 3, so that the additive and the solvent are uniformly mixed and then pumped into the reaction vessel 4 by a pump. The method comprises the steps of generating polystyrene plastic melt with uniformly distributed graphite in a reaction kettle 4 through micro negative pressure polymerization, conveying the generated polystyrene plastic melt with uniformly distributed graphite to a primary devolatilization device 6 through a gear pump 5, separating unreacted raw materials in the primary devolatilization device through high vacuum heating, cooling separated raw material gas phase through a condenser 15, then feeding the cooled raw material gas phase into a primary recovery tank 18 to serve as a circulating solvent, pumping the circulating solvent into a solvent tank 2 for recycling, wherein the vacuum pressure of a reaction system is provided by a vacuum system 20. The polystyrene plastic melt separated from unreacted raw materials by the primary devolatilizer 6 enters the secondary devolatilizer 8 through the gear pump 5, the unreacted raw materials and the solvent are separated again under vacuum, the unreacted raw materials and the solvent are condensed and recycled to the secondary recycling tank 19 through the condenser 15, the materials in the secondary recycling tank 19 are recycled, and the vacuum pressure is provided by the vacuum system 20. The qualified EPS melt is sequentially conveyed to a mixer 10 through a gear pump 5, graphite and a foaming agent are added into the mixer 10 through a normal-pressure feeding system 21 and a high-pressure feeding system 22 in the mixer 10 correspondingly, the materials are fully mixed through the mixer 10 and then enter a filter 11, after passing through the filter 11, the graphite EPS melt enters a granulating system 12, the melt forms solidified bead-shaped particles under the action of the granulating system 12, the graphite EPS beads and water enter a dewatering and screening system 13, and after dewatering and screening, the particles enter an air-conveying packaging system 14 for packaging.

Example 2

The embodiment provides a process for continuously producing graphite EPS, which specifically comprises the following steps:

1. styrene monomer, zinc stearate (0.05 percent of the mass of the styrene monomer), graphite accounting for 3 percent of the mass of the styrene monomer and solvent are added into a reaction kettle to carry out polymerization reaction in the reaction kettle at the polymerization temperature of 147 ℃ and the pressure of 80kpa (a), the generated mixed material is heated to 270 ℃, and is subjected to primary devolatilization treatment through high vacuum degree of 2kpa (a), and unreacted raw material styrene and circulating liquid are separated out.

2. And (4) continuing the secondary devolatilization treatment of the material subjected to the primary devolatilization treatment at the secondary devolatilization temperature of 260 ℃ and under the pressure of 2kpa (a). And 6% of foaming agent pentane is added into the melt containing the graphite after separation, and the mixture is sent into a granulation system after being uniformly mixed.

3. The extrusion head temperature of the granulation system is 230 ℃, the extrusion pressure is 8MPa, the water temperature is 75 ℃ and the water pressure is 5MPa, solidified bead-shaped particles are obtained, and then the particles are dehydrated, sieved and packaged to obtain the graphite EPS product.

The EPS melt index of the graphite obtained in the example is 2.7g/10min, and the particle size of the graphite is 1.0 mm.

Example 3

This example provides a process for continuously producing graphite EPS, which is different from example 2 in that 3% of graphite and 6% of pentane as a blowing agent are added simultaneously in the mixing step, and the remaining raw materials and steps are the same as those in example 2, and are not described again here.

The melt index of the graphite EPS obtained in the example is 2.7g/10min, and the particle size of the graphite EPS is 1.0 mm.

Example 4

The embodiment provides a process for continuously producing graphite EPS, which is different from embodiment 2 in that the addition amount of graphite is 4%, additives comprise 5% of halogen-free flame retardant, the polymerization temperature is 150 ℃, the pressure is 78kpa (a), the secondary devolatilization temperature is 275 ℃, the pressure is 2.5kpa (a), and other raw materials and steps are the same as those in embodiment 2 and are not repeated herein.

The melt index of the graphite EPS obtained in the embodiment is 3g/10min, the oxygen index of the foamed product is 40%, and the particle size is 0.5 mm.

Example 5

The embodiment provides a process for continuously producing graphite EPS, which is different from embodiment 3 in that the addition amount of graphite is 4%, additives comprise 5% of halogen-free flame retardant, the polymerization temperature is 150 ℃, the pressure is 78kpa (a), the secondary devolatilization temperature is 275 ℃, the pressure is 2.5kpa (a), and other raw materials and steps are the same as those in embodiment 3 and are not repeated herein.

Comparative example 1

This comparative example provides a process for the continuous production of EPS, in which, unlike example 2, no graphite is added. The rest of the raw materials and steps are the same as those in example 2, and are not described again.

The EPS melt index obtained in this comparative example was 2.7g/10min and the particle size was 1.5 mm.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for continuously producing graphite EPS is characterized by comprising a reaction kettle, a devolatilization device, a mixer, a filter and an EPS molding system which are communicated in sequence;

and a first pumping device is connected between the reaction kettle and the devolatilizer, and a second pumping device is connected between the devolatilizer and the mixer.

2. The apparatus for continuously producing graphite EPS as claimed in claim 1, wherein the reaction vessel is further communicated with a raw material tank and a solvent tank;

the solvent tank, the mixing tank and the reaction kettle are communicated in sequence.

3. The apparatus for continuously producing an EPS of graphite according to claim 2, wherein said devolatilizer comprises a primary devolatilizer and a secondary devolatilizer which are communicated by a third pumping means;

the reaction kettle, the primary devolatilization device and the secondary devolatilization device are respectively and independently communicated with a condenser;

the primary devolatilization device is communicated with a primary recovery tank;

the secondary devolatilization device is communicated with a secondary recovery tank.

4. The apparatus for the continuous production of graphite EPS according to claim 3, wherein said primary recovery tank is in communication with said solvent tank;

the reaction kettle, the primary recovery tank and the secondary recovery tank are respectively and independently communicated with a vacuum system.

5. An apparatus for the continuous production of graphite EPS as claimed in claim 4, wherein the mixer is connected to a charging system;

the charging system comprises a high-pressure charging system and/or a normal-pressure charging system.

6. A process for continuously producing graphite EPS, characterized in that it is mainly carried out by using the apparatus for continuously producing graphite EPS as claimed in any of claims 1 to 5.

7. The process according to claim 6, comprising the steps of: styrene monomer, additive and graphite are subjected to polymerization reaction in a reaction kettle, unreacted raw materials of the mixed materials obtained by the reaction are removed through devolatilization and filtration to obtain polystyrene plastic melt, the polystyrene plastic melt is added with foaming agent and mixed in a mixer, and the graphite EPS is obtained through an EPS forming system.

8. The process according to claim 7, characterized in that it comprises the following steps: and carrying out polymerization reaction on a styrene monomer and an additive in a reaction kettle, devolatilizing and filtering a mixed material obtained by the reaction to remove unreacted raw materials to obtain a polystyrene plastic melt, mixing the polystyrene plastic melt with graphite and a foaming agent in a mixer, and then obtaining the graphite EPS through an EPS molding system.

9. The process according to claim 7, wherein the mass ratio of graphite to styrene monomer is (0.1-35): 100;

the mass ratio of the additive to the styrene monomer is (0.001-20): 100, respectively;

the melt index of the polystyrene plastic melt is 1.1g/10min-10.0g/10 min;

the mass ratio of the foaming agent to the polystyrene plastic melt is (1-20): 100.

10. use of the apparatus of any one of claims 1 to 5 or the process of any one of claims 6 to 9 for the production of graphite EPS.