TW581781B - Method for collapsing and recycling foamed polystyrene - Google Patents

Abstract

An improved method of recycling polystyrene foam involving collapsing the polystyrene foam in a solvent/cosolvent system without dissolving the polystyrene and then separating and recovering the softened polystyrene typically floating of the liquid solvent system phase. The solvent system useful for collapsing foamed polystyrene comprises a dibasic organic acid ester solvent selected from the group consisting of dialkyl adipate, dialkyl glutarate, dialkyl succinate and mixtures thereof and a cosolvent selected from the group consisting of ethylene glycol, propylene glycol, propylene carbonate, dimethyl sulfoxide, diacetone alcohol, isopropyl alcohol, and mixtures thereof wherein the cosolvent is present in said solvent/cosolvent system from at least 10 weight percent up to 40 weight percent. Such a process is particularly useful for isolating and recovering both polystyrene and PET in that PET is denser than the liquid solvent system phase and is soluble in the liquid solvent phase at elevated temperatures.

Description

581781 A7

BACKGROUND OF THE INVENTION 1. Field of the Invention: The present invention relates to an improved method for recovering polystyrene foam, including collapsing the polystyrene foam in a solvent / co-solvent system without dissolving the polystyrene. In detail, but without limitation, the present invention relates to dialkyl adipate, dialkyl glutarate, dialkyl succinate, and mixtures thereof with at least one selected from the group consisting of ethylene glycol, propylene glycol, and propylene carbonate , Dimethyl sulfite, diacetone alcohol, isopropanol, and a combination of co-solvent groups thereof, which is used to collapse polystyrene foam to soften the collapsed polymer Polyethylene and liquid solvent systems are physically separated into two distinct phases that cannot be miscible with each other. This method is particularly useful for separating and recovering polystyrene from a mixture containing polystyrene and polyethylene terephthalate (PET). 2 · Related skills description · Order

As environmental issues / awareness is increasing, the need to establish a safe and cost-effective technology for recycling polystyrene and polyethylene terephthalate ρET is gaining increasing attention. Disposal of polystyrene foam has traditionally been performed by incineration or heat treatment. Although incineration was a disposal method, the polystyrene material could not be recovered. Reducing the volume of polystyrene by heat treatment results in damage to polystyrene ', resulting in poor quality recycled materials. Another type of recycled polystyrene known in the art world (refer to, for example, U.S. Patent No. 5,629,352; No. 4,031,039; No. 5,223,543; No. 5,891,403; and No. 4,51 7,312) The method is to dissolve polystyrene in an organic solvent. In particular, dimethyl adipate, dimethyl glutarate, dimethyl succinate, and mixtures of these diesters have been manufactured in Japan -4-This paper size applies to Chinese National Standard (CNS) Α4 specifications ( (210X297 mm) 581781 A7-B7 V. Description of the invention (2) One technique of dissolving and foaming poly (styrene) in the center of the polystyrene requires one of several techniques to recover the dissolved polystyrene from the organic solvent. This technique includes, but is not limited to, sinking, extrusion, and rapid evaporation. It is a preferred method to dissolve fluorene ethylene in an organic solvent at a low temperature without degrading the polyethylene. The need to recover the dissolved polystyrene from the solvent leads to an extra step in the process and requires more energy rotation. Summary of the Invention The present invention is a modification of the existing method in the prior art because the solvent / co-solvent system does not dissolve the polystyrene. However, the solvent system of the present invention collapses the polyethylene lattice. The lattice collapse achieves the desired volume reduction of polystyrene, and simple filtration can separate the collapsed polystyrene from the solvent without the need for > children: or rapid evaporation. In the presence of polyethylene terephthalate, this polyethylene terephthalate pET sinks and is separated and recovered by simple decantation. In the presence of polyethylene terephthalate and other insoluble polymers such as polyolefins, the polyethylene terephthalate pET sinks simultaneously with the polyolefin, and is then redissolved by heating, After that, it was recovered by sedimentation from this solution and precipitation. A solvent system mainly containing succinic acid, glutaric acid, and dimethyl adipate and a co-solvent, preferably propylene glycol, has a solubility property that is sufficient to collapse the polystyrene structure without dissolving it. The present invention proposes a method for safely and more efficiently recovering polystyrene using the aforementioned solvent system. Therefore, the present invention proposes a method for recovering polystyrene and polyethylene terephthalate from a mixture of plastics, wherein the mixture of plastics includes expanded polystyrene and propylene glycol, including the following steps: -5- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 581781

Description of the invention (a) The polystyrene foam is brought into contact with a solvent system containing at least one auxiliary solvent per 1,000 parts by weight of a binary organic acid ester at a temperature of 0 to 50 ° C, so that Foamed polystyrene collapsed in a mixture of polystyrene and polyethylene terephthalate without dissolving polystyrene or polyethylene terephthalate, resulting in three separate phases In the miscible phase, the binary organic acid ester is selected from the group consisting of dialkyl adipate, di-succinate glutarate, dialkyl succinate and mixtures thereof, wherein the alkyl groups are the same or different And having from 1 to 12 carbon atoms, the co-solvent is selected from the group consisting of: (ϋ from 10 to 66.7 parts by weight of ethylene glycol, from 10 to 6 · 6.7 parts by weight of propylene glycol, From 17.6 to 42.8 parts by weight of propylene carbonate, from 53.8 to 66. 7 parts by weight of dimethyl isocyanate, (ν) from 53.8 to 66.7 parts by weight of diacetone alcohol And isopropyl alcohol from 42.8 to 66.7 parts by weight; and (b) separation and recovery of softened collapsed polyphenylethylbenzene floating on top of the phase of the liquid solvent system .-Phase, the present invention also provides a method of recycling polystyrene foam, comprising the steps of: at l

(a) At a temperature of 0 to 5 ° C, contact the polystyrene foam with a solvent system containing a dibasic organic acid ester solvent and a co-solvent to collapse the polystyrene of the S foam without dissolving it. Polystyrene, two immiscible phases of Sagittarius. The binary organic acid ester solvent is selected from the group consisting of Q-acid di-burning vinegar, glutaric acid dialkyl ester, and succinic acid dialkyl ester. And its mixtures, in which -6- this paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X 297 mm) " -------- --- 581781 A7 _____ Β7 V. Description of the invention (4) The alkyl Are the same or different and have from 1 to 12 carbon atoms, and the co-solvent is selected from the group consisting of ethylene glycol, propylene glycol, propylene carbonate, dimethyl sulfene, diacetone alcohol, isopropyl alcohol, and mixtures thereof Group, wherein the content of the co-amplifier in the solvent / co-solvent system is from at least 10% to 40% by weight of the solvent / co-solvent system; (b) phase separation from the liquid solvent system after softening and collapse聚 polystyrene phase; and (c) recovered polystyrene. In a specific embodiment, wherein polystyrene is expanded The mixture of ethylene and polyethylene terephthalate is contacted with the solvent system of the present invention to collapse the expanded polystyrene, and the step of separating the collapsed polyethylene phase from the liquid solvent system phase further includes the following steps : (C) heating the liquid solvent system phase containing the residual plastic produced in step (b) to a temperature of 160 to 225 ° C to dissolve the polyethylene terephthalate phase; (d) separating and dissolving Liquid solvent system phase of polyethylene terephthalate and undissolved plastics; and (e) recovering the polyethylene terephthalate phase from the liquid solvent system phase. In another specific embodiment, This includes a plastic mixture of expanded polystyrene, polyethylene terephthalate, and at least one other insoluble polymer in contact with the solvent system of the present invention to collapse the expanded polystyrene from the liquid solvent system. The phase separation step after softening the collapsed polystyrene phase additionally includes the following steps: (c) heating the liquid solvent system phase containing the residual plastic produced in step (b) to a temperature of 160 to 225 ° C to dissolve the Ethylene terephthalate paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm) 581781 A7 __B7 V. Description of the invention (5) Glycol ester phase; (d) Polyterephthalic acid dissolved The liquid solvent system phase of the glycol ester is separated from the undissolved plastic; and (e) the polyethylene terephthalate phase is recovered from the liquid solvent system phase. The solvent / co-solvent polymer that can be used in the foregoing method The mixture preferably comprises from 1 to 40 weight percent polystyrene, collapsed in a solvent / co-solvent system from 99 to 60 weight percent. The softened collapsed polymer is based on the relative density of the phases. The styrene phase floats on the liquid solvent system phase, while the polyethylene terephthalate phase does not float. The object of the present invention is to propose an improved method for recovering polystyrene, which is a novel solvent system using collapsed polystyrene foam without dissolving the polystyrene. Another object of the present invention is to provide the solvent system, which is based on at least one polystyrene solvent with a Hansen solubility parameter clearly within the corresponding polystyrene hanson solubility boundary, and at least one polystyrene solvent corresponding to A mixture of a combination of co-solvents with a Hansen solubility parameter clearly outside the Hansen solubility boundary of the polyethylene was used as a substrate. After fully reading the attached description and the scope of patent application with reference to the drawings, the realization of these purposes and existence and the realization of other purposes can be understood. Brief description of the circle type Figure 1 is a two-dimensional representation of the Hansen solvent map. The selected solvent is illustrated relative to the polystyrene polymer solubility boundary. Figure 2 is a flowchart illustrating a method for recovering polystyrene and polyethylene terephthalate PET from a mixed plastic waste stream. Detailed description of the invention -8-This paper size applies to China National Standard (CNS) A4 specification (210X 297 mm) 581781 V. Description of the invention (6 A7 B7

Liquid phase solvent systems that can be used in the present invention include blends or compositions of two different cocoa and six-mix components. The first component is a dialkyl ester of a dibasic organic acid (DBE), or it can be used individually or in combination. These so-called DBes (in themselves) are indeed solvents for polystyrene because DBE dissolves polystyrene under a wide range of conditions and concentrations. The organic ester that can be used in the present invention is preferably a derivative of a mono-organic acid such as adipic acid, glutaric acid, succinic acid, and this stem --- Ci_C4 alkyl substituted acid , Its mixtures and the like, formed or prepared by reacting with alcohols or alcohol mixtures having 1 to 12 carbons. Of particular interest are adipic acid, glutaric acid, and —_____ τ, a mixture of these vinegars, and vinegars and adipic acid of 2-ethylsuccinic acid and 2-methylglutaric acid. A mixture of acids, glutaric acid, and diisobutyl succinate. The agent is a DuPont (E j β) company located in Wilmington, Delaware.

The product name of Pont de Nemours and Company, lnc ·) is dbe. The second component that can be used in the liquid-phase solvent system of the present invention is an organic liquid co-solvent selected from the group consisting of ethylene glycol, propylene glycol, propylene carbonate, dimethyl sulfene, diacetone alcohol, and isopropyl alcohol. group. In the present invention, these second components are called co-solvents because they are miscible with the first solvent component of DBE under a wide range of conditions and concentrations. However, unlike DBE, these second components (in themselves) are indeed not solvents for polystyrene. For this purpose and the purpose of the present invention, the liquid-phase solvent system is also referred to herein as a "solvent / elixir". It is defined as a kind of polymer that can soften foamed polyethylene into: a softened polymer. Phase (as plasticized polystyrene), but does not dissolve the liquid phase of the polystyrene. In other words, or the liquid-phase solvent system contains the remainder of the soluble polystyrene and the auxiliary solvent component of the insoluble polystyrene which is -9-

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The content of the co-solvent in the multi-component solvent / co-solvent composition is sufficient to prevent the dissolution of the polystyrene, and sufficient to prevent the collapse of the foamed polystyrene lattice or honeycomb-like foam structure. A The novel liquid-phase solvent system of the present invention, its mode of action, and its principle that is very different from the behavior of the pre-admixture of the prior art may be fully explained and understood with reference to Figure i and the Hansen solubility parameter system. Basically, each solvent has unique solvent capability characteristics described by its Hansen parameter: dispersion or "non-polar, parameter; == polarity parameter; and a hydrogen bonding parameter. These parameters are for polar, non-polar Polarity and the tendency of hydrogen bonding describe the bonding characteristics of solvents. Traditionally, solvents are found on the upper edge of Hansen's map, where the X-axis system is polar bonding 'and the y-axis system is hydrogen bonding. The solvents all have a unique position on the map, resulting in different solvent capabilities for the polymer. The solubility of the polymer in the cereals is developed by emphasizing room temperature and pressure conditions. It is also known that increasing the temperature will increase the solvent Ability. Non-solvent at low temperature may become solvent when the temperature increases. The component parameters for the polymer can also be assigned and plotted on the Hansen map, so the solubility adhesion zone (or boundary) is generated on the Hansen map. So that any solvent whose parameters are in this space should dissolve the polymer under study. Furthermore, according to the Hansen solubility parameter system, a simple arithmetic mixing rule can be applied to And the volume fraction of the component in the blend, and the individual Hansen parameters of the solvent blend are estimated or calculated. Therefore, according to this mixing rule and w㈣ •, where t • is the blend In the composition, the volume fractions of the components are based on all; the components. For further details and explanations of the Hansen solubility parameter system, refer to, for example, Hansen, CM and Beerbwer, -10. Applicable to China National Standard (CNS) A4 specification (210X297 public love) 581781 A7 ____B7 V. Description of invention (8)

Kirk-Othmer, Encyclopedia of Chemical Industry

Chemical Technology, (Suppl · Voi · 2nd Ed), 1971, pages 889-910, and Charles Hansen's "Hansen Solubility Parameters A User (s Handbook),", CRC Press, 1999 o Figure 1 is the aforementioned two-dimensional Hansen map, the x-axis system represents the polar bond p, and the y-axis system represents the hydrogen bond η. It should be known that this figure 1 is an approximate diagram, and the third one is not illustrated. Parameters. This general test is basically based on the non-polar parameter D. Most of the commonly used organic solvents are unchanged and very similar to each other. As shown in Figure 1, the ρ relative η position of many known organic solvents is Draw with various markers to show the unique position of the general name or the initials of the compound for individual solvents. A curve marked "pS solubility limit line" is also drawn at the bottom left of Figure 1. This line indicates the solvent for polystyrene The boundary between the ability and non-solvent ability. The dissolved polystyrene solvent was found in a closed area where the X-axis and y-axis intersect the PS solubility boundary. Outside this area, significant insolubility was found Polystyrene is a non-solvent. Therefore, and as previously explained, the co-solvents ethylene glycol, propylene carbonate (PC), and difluorene (DMS0) are outside the solubility limit of polystyrene, and dbe It is within the solubility limit of polystyrene. Conceptually and basically (actually not the present invention), the line between the DBE position and the co-solvent position (not shown in the figure) will cross the polystyrene solubility line to This line is quantitatively divided into two line segments, the length of which is proportional to the volume fraction of the solvent and co-solvent required to make the blend, which represents the transition of the solvent to the non-solvent (as predicted by the aforementioned mixing rule) ). Conversely, now -11-This paper size applies to China National Standard (CNS) A4 (210X 297 mm) 581781

It has been found that the DBE solvent and the choice of supplements have the following advantages. The composition of the extract has another effect on the expanded polystyrene, which does not comply with the Hansen parameter mixing rule known to the sociologist ^ ^ ^ σ. As far as the surface is concerned, the present invention is novel and incorporates ^ X, and σ is lacking in the solubility of polystyrene, and the mixing rule may or may not predict Γ U and indeed predicts) the blend should dissolve the polymer Styrene. In addition, the ^^ ^ ^ unclear solvent / co-solvent system of the present invention has the ability to collapse the foamed polystyrene lattice and / or honeycomb structure. Therefore, the entrained, foaming agent or gas phase is very and characteristically released, resulting in a softened or plasticized polymer. It is easy to float on the liquid phase solution. Dissolved in it. The relative amounts of co-solvents and sun solvents used in the liquid-phase solvent system mainly change according to the choice of co-solvent, and also slightly change depending on the choice of _ or dirty mixture. The lower limit corresponds to the starting point for the insolubility of polystyrene in the blend. In other words, the blend needs to contain an amount sufficient to achieve the desired lack of polystyrene solubility. It is preferred to have at least 10 weight percent of a co-solvent or co-solvent mixture to obtain the desired lack of polystyrene solubility. The upper limit of the amount of co-solvent relative to the amount of solvent / co-solvent blend corresponds to the starting point of the blend's lack of ability to collapse the expanded polystyrene. In other words, a solvent sufficient to collapse the foamed structure is needed, but a co-solvent is not sufficient to inhibit this process. A weight percentage of co-solvent exceeding 40% in the blend results in the collapse rate of the expanded polystyrene not being practically achieved. As shown in the following examples, the weight percentage of co-solvent required to achieve the desired result varies depending on the co-solvent. Ethylene glycol is 10 to 40 weight percent of the liquid phase system; propylene glycol is 10 to 40 weight percent. Percentage, propylene glycol carbonate needs to be cut from 15 to 30 papers. Standards for China National Standards (CNS) A4 (210 X 297 mm)

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The amount of the amount of 'difluorenyl sulfoxide needs to be from 35 to 40 weight percent of diacetone alcohol from 35 to 40 weight percent, and the isopropanol needs to be from 30 to 40 weight percent. Based on 100 parts by weight of dibasic organic acid esters, these eighty-eight ratios correspond to 10 to 66.7 parts by weight of ethylene glycol; from 10 to 66 parts by weight of propylene glycol; from 17.6 to 42.8 parts by weight Propylene carbonate carbonate; dimethyl sulfoxide from 53.8 to 66.7 parts by weight; dipropylene silk alcohol from 53.8 to 66.7 parts by weight; and isopropyl alcohol from 42 8 to 66 7 parts by weight. The actual formation or manufacture of the liquid solvent phase can be performed by any known method commonly used in the art to add one miscible liquid to another. It should be known that the choice of the concentration of each co-solvent will be affected by the details of the individual co-solvents described above. The amount of the co-solvent is preferably in the middle part of the range, unless the end use results in selective consumption of the solvent or co-solvent, thus affecting the priority of one or the other of the operability. It should also be known that the liquid phase need not be water-free, and that commercial grade solvents contain part of the water. In the present invention, the presence of part of the water is actually regarded as equivalent to the co-solvent, and as a supplementary co-solvent. The use of a solvent system in the method of the present invention is generally considered to be particularly applicable and advantageous for use in collapsed polystyrene foams, after which the collapsed polystyrene is separated, recovered, and recycled. The improved separation and recycling method of the present invention is considered to collapse any general low-density polystyrene foam, and particularly includes open and closed honeycomb foams and so-called granular polystyrene foams. Therefore, the collapsed polystyrene and the solvent mixture formed by the collapsed or plasticized polystyrene floating from the collapsed foam can be simply phase-separated, separated, and recovered. This method can be foamed as low as 1% by weight. -13 · The size of this paper is applicable to China National Standard (CNS) A4 (210X 297 mm).

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Polystyrene and 99% by weight of solvent / co-solvent to 40% by weight: umbelliferous styrene & 60 ' The recovered softened polystyrene can also be reprocessed by subsequent methods such as injection and / or extrusion molding and the like to remove and recover the residual solvent. The volatile solvent taken out from the subsequent treatment can be advantageously recycled to the expanded polystyrene contacting step. Figure 2 illustrates the steps of collapsing expanded polystyrene using the liquid solvent system of the present invention and subsequent or simultaneous separation and recovery of softened polystyrene in the presence of polyethylene terephthalate pET. Basic concepts. As described above, when the expanded polystyrene is in contact with the liquid solvent / co-solvent, it collapses into a softened state, so it can be easily separated from the top of the liquid solvent system. It is known that the collapse and floatation of polystyrene from mixed plastic waste streams can be performed prior to liquid phase contact by selective grinding or segmentation steps. And 'any non-expanded polystyrene tends to be removed simultaneously with collapsed polystyrene. The softened or plasticized polystyrene is simply led to an extruder to recover and recycle the solvent / co-solvent entrained while manufacturing polystyrene or the like (· not shown in Figure 2). In addition, it should be known in the specific embodiment of the present invention that the expanded polystyrene is recovered in the absence of other plastics, and the description of FIG. 2 can still be applied. The difference is that the recovery of the polymer from the bottom of the solvent / co-solvent solution is omitted. PET terephthalate. In addition, mixed plastic waste composed of, for example, foamed polyethylene, polyethylene terephthalate PET, low density polyethylene (LDPE), high density polyethylene (HDPE), and polypropylene (PP) In the flow, polystyrene can be immersed in or mixed with the liquid solvent / co-solvent through the mixed plastic waste stream. -14- This paper size applies to China National Standard (CNS) A4 (210X 297 mm) 581781 A7 B7 V. Description of the invention (12 touches and separated from other plastics at room temperature and pressure. In this specific example, the liquid solvent system and PET, LDPE, HDpE, and PP are separated and removed after the polystyrene is heated. To a temperature in the range of 160 to 225 ° C. PET remaining in the mixed plastic is dissolved in the liquid solvent / co-solvent phase at these temperatures at atmospheric pressure. The advantage of the present invention is that the dimethyl ether The vinegar solvent system generally has a boiling point higher than 20 rc, so the system does not require pressure (extra energy input) to keep the solvent in a liquid state. This also makes the separation flow chart less complicated, because the separation always includes liquid flow. Because some polymers are degraded by It begins to occur at about 25 {rc, so the existence of a solvent system is ideal. The actual separation of the PET can be achieved by thermal filtration (or other similar separation methods known in the art) to separate the dissolved PET from other undissolved plastics. After this step (not illustrated in Figure 2), the dissolved pET is cooled to 160 ° C to precipitate the PETβ. Preferably, the PETβ is separated from the mixed plastic stream by 1 to 40% by weight of polyethylene and / or pET. The examples are used to more fully explain and further explain various individual aspects and features of the present invention, and the description is to further explain the differences and advantages of the present invention. Thus, the reaction is not intended to be a limitation and is used to illustrate The present invention is not intended to mean improper restrictions. Example 1 At room temperature and pressure, foamed polystyrene was added to the solvent / co-solvent to prepare a series of contact with 80 weight percent liquid-phase solvent / co-solvent. Include 20 weight percent of individual mixtures of expanded polystyrene and observe. The DBE solvent used is a blend of succinic acid, glutaric acid and dimethyl adipate (ie 20 weight Amount of succinate, 60% by weight 戍 • 15- This paper size applies to China National Standard (CNS) Α4 specification (210X297 mm)

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Line 581781 A7 B7 V. Description of the invention (13) Diester, and 20% by weight adipate). The relative amount of the co-solvent relative to the DBE (i.e., the relative weight percentage in the liquid phase) is varied to establish a range of concentrations for operational use. The following results were obtained: solvent / co-solvent results 90% DBE / propylene glycol (PG) 10% collapsed polystyrene 80% DBE / 20 ° / 〇PG collapsed polystyrene 60 ° / 〇DBE / 40% PG collapsed polystyrene 90% DBE / 10% ethylene glycol (EG) collapsed polystyrene 80% DBE / 20% EG collapsed polystyrene 60% DBE / 40 ° / 〇EG collapsed polystyrene 90% DBE / 10% propylene carbonate (PC) dissolved polystyrene 80% DBE / 20 ° / 〇PC collapsed polystyrene 60% DBE / 40% PC does not collapse or dissolve polystyrene 60% DBE / 40 ° / 〇PC does not collapse or dissolve polystyrene 90% DBE / 10% difluorene fluorene (DMSO) dissolves polystyrene 80% DBE / 20% DMSO dissolve polystyrene 70% DBE / 30% DMSO dissolve polystyrene 60 ° / 〇DBE / 40% DMSO collapsed polystyrene 90% DBE / i0% isopropyl alcohol (IPA) dissolve polystyrene Ethylene 80% DBE / 20% IPA dissolved polystyrene 70% DBE / 30% IPA collapsed polystyrene 60% DBE / 40% IPA collapsed polystyrene-16-This paper is for China National Standard (CNS) A4 specification (210X297 mm) 581781 A7 B7 V. Description of invention (14) 90% DBE / 10% Diacetone alcohol (DAA) Dissolved polystyrene 80% DBE / 20% DAA Dissolved polystyrene 70% DBE / 30% DAA Dissolved polystyrene 60% DBE / 40% DAA Collapsed foamed polystyrene Example 2 As in Example 1, observing the behavior of a series of individual mixtures of ethylene that were in contact with 80% by weight of liquid, it was obtained that the comparative example included 20% by weight of foamed polybenzene 3 as a single solvent at room temperature and pressure and the following results were obtained: Solvent Results DBE Dissolved Polystyrene Tertiary Butanol Insoluble or Collapsed Polystyrene Diacetone Alcohol (DAA) Insoluble or Collapsed Polystyrene Glycol (EG) Insoluble or Collapsed Polystyrene Propylene Carbonate Insoluble or collapsed polystyrene isopropyl alcohol (IPA) insoluble or collapsed polystyrene ethylene dimethylene insoluble or collapsed polystyrene propylene NMP) Dissolved Polystyrene Dipropylene Glycol Methyl Ether Dissolved Polybenzyl Ethylene Toluene Dissolved Polystyrene Example 3 Expanded polystyrene was added to 80 weight percent dimethyl ester (which is 20 percent succinate, 60 percent Diester, 20% adipic acid ) And 20% by weight of propylene glycol solvent to determine the solvent collapse -17- This paper size applies Chinese National Standard (CNS) A4 specifications (210X 297 mm) 581781 A7 B7 V. Description of the invention (15) Stupid vinyl capabilities. It has been found that from 1% to 40% by weight expanded polystyrene can be added to the solvent / co-solvent. Example 4 Expanded polystyrene was added to three other solvent systems: 80 weight percent succinate / 20 weight percent propylene glycol; 80 weight percent dimethyl glutarate / 20 weight percent propylene glycol; and 80 weight percent Dimethyl adipate / 20% by weight propylene glycol. Expanded polystyrene collapsed when placed in three solvent systems. The recovery of this polystyrene in all three solvent systems was 100%. Example 5 20% by weight of PET was added to a solvent containing succinic acid, glutaric acid, and adipic acid ester of adipic acid, and the resulting mixture was heated. At 180 ° C, the PET begins to "soften", and at 200 ° C, the PET dissolves. When the solvent is cooled to a range of 160 to 170 ° C, the PEG is again precipitated from the DBE solution. The thermal analysis of the PET precipitated by Shen Dian by differential scanning calorimetry showed that the thermal properties of the studied PET were the same as the original. Both PET specimens showed hot spots at 245 ° C and hot spots at 453 ° C. Comparative Example 6 PET is not soluble in the following other solvents at up to 225 ° C (the solvent system is under the pressure required to maintain the liquid state): heptane, diethylene glycol butyl ether, ethylene glycol, diisobutyl Ketones, toluene, propylene glycol, propylene glycol methyl ether, and diacetone alcohol. -18- This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 mm) binding

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AB c D 々, patent application range 16 Example 7: Separate polystyrene from PET 4 g expanded polystyrene, 4 g PET mixed plastic stream is added to 100 g of succinic acid, glutaric acid, and hexamethylene In a solvent consisting of dimethyl diacid and 20% co-solvent propylene glycol. The polystyrene collapsed at room temperature, and the collapsed polystyrene was separated and recovered by decantation (that is, in this case, the collapsed polystyrene was floated out together with a part of the solvent). The PET was then dissolved in the residual solvent by heating to 205 ° C and recovered as a circulating solution. The resulting solution was cooled to 160 ° C and the PET was filtered from the circulating solvent. The percentage of polystyrene recovered from mixed plastics is 100%, and the recovery of PET is 98%. After describing and exemplifying the present invention in specific cases, it should be known that the scope of the following patent applications is not limited by them, but is based on the application The scope of patents and equivalent statements are appropriately derived from their scope. -19-Chinese paper standard (CNS) A4 size (210 X 297 mm)

Claims (1)

Replacement of Patent Application No. 6707 (April 1992) Patent Application Scope I A method for recovering expanded polystyrene, including the following steps: (a) Making the polystyrene at a temperature of 0 to 50 t. Foaming 100 parts by weight of the binary organic acid ester contains at least "" mother, / / a co-solvent (contact of the solvent system, making the foamed polystyrene collapse, and inadvertently depolymerizing acetophenone). Two individually immiscible phases, the binary organic acid vinegar is selected from the group consisting of dialkyl adipate, 1 alkyl glutarate, dialkyl succinate, and mixtures thereof, wherein Are the same or different and have from 1 to 12 carbon atoms, so that the co-solvent is selected from the group consisting of: ⑴ ethylene glycol from 10 to 66.7 parts by weight, (ii) from 10 to 66.7 weight Parts of propylene glycol, (out) from H6 to 42.8 parts by weight of propylene carbonate carbonate, (iv) from 53.8 to 66.7 parts by weight of dimethyl sulfene, (ν) from 53.8 to 66.7 parts by weight Parts of diacetone alcohol, and (vi) isopropyl alcohol from 42.8 to 66.7 parts by weight; (b) phase separation from a liquid solvent system The softened polystyrene phase; and (c) recovering the polystyrene. 2. The method of claim 1 in which the solvent / co-solvent polymer mixture is from 1 to 40 weight percent Polystyrene and a solvent / co-solvent system from 99 to 60 weight percent. 3. A method for recovering expanded polystyrene, including the following steps: (a) polymerize the polymer at a temperature of 0 to 50 ° C. The styrene foam is in contact with a solvent system containing a binary organic acid ester solvent and a co-solvent. According to the paper size, the Chinese National Standard (CNS) A4 specification (210X 297 mm) is applicable. 581781 6. The scope of the patent application The expanded polystyrene does not dissolve polyphenylene terephthalate to produce two immiscible phases. The binary organic acid ester solvent is selected from the group consisting of dialkyl dialkyl esters, Groups of dialkyl glutarate, dialkyl succinate, and mixtures thereof, wherein the alkyl groups are the same or different and have from "to 12 carbon atoms, JL This co-solvent is selected from the group consisting of ethylene glycol Propylene glycol, propylene glycol carbonate, dimethyl sulfoxide, diacetone alcohol, isopropyl alcohol, and mixtures thereof, wherein the content of the co-solvent in the solvent / co-solvent system is determined by the content of the solvent / co-solvent system At least 10% by weight to 40% by weight; (b) phase separation of the softened collapsed polyphenylene phase from the liquid solvent system (c) recovery of polyphenylene oxide. 4. The method according to item 3 of the patent application, wherein The solvent / co-solvent polymer mixture is composed of 1 to 40 weight percent of polyphenylene terephthalate and a solvent / co-solvent system of 99 to 60 weight percent. 5 ·-A kind of self-expanding polystyrene and polyethylene terephthalate Polyethylene glycol and polyethylene terephthalate mixed with glycol vinegar A method for a diol ester, comprising the following steps: (a) A solvent system comprising the polystyrene foam and at least one co-solvent per 100 parts by weight of a binary organic acid vinegar at a temperature of 0 to 5 (TC) The contact causes the expanded polystyrene in the mixture of expanded polyethylene and polyethylene terephthalate to collapse without dissolving the polystyrene or polyethylene terephthalate. Two separate immiscible phases are generated. The binary organic acid ester is selected from the group consisting of -2-^ paper size applicable to China National Standard (CNS) A4 (210 X 297 mm) '------ -6. Scope of patent application: Groups of dialkyl adipate, dialkyl glutarate, dialkyl succinate and mixtures thereof, in which the alkyl groups are the same or different and have from 1 to 12 As a whole, the auxiliary agent is selected from the group consisting of ⑴ from 10 to 66.7 parts by weight of ethylene glycol '(ϋ) from 10 to 66.7 parts by weight of propylene glycol, and (iii) from 17.6 to 42.8 parts by weight Propylene carbonate, (iv) dimethyl sulfoxide from 53.8 to 66.7 parts by weight, (v) dipropylene from 53.8 to 66.7 parts by weight Alcohol, and (vi) isopropanol from 42.8 to 66.7 parts by weight; (b) separating and recovering the softened collapsed polystyrene phase floating on top of the liquid solvent system phase; and (c) from the liquid solvent system Phase separation and recovery of polyethylene terephthalate phase. 6 · —A kind of polystyrene and polyethylene terephthalate recovered from a mixture of foamed polystyrene and polyethylene terephthalate. A method for an alcohol ester includes the following steps: (a) contacting the polyphenylenesulfonium foam at a temperature of 0 to 50 ° C with a solvent system containing a dibasic organic acid ester and at least one auxiliary solvent, so that Expanded polystyrene collapses in a mixture of expanded polystyrene and polyethylene terephthalate without dissolving polystyrene or polyethylene terephthalate, resulting in three Individual immiscible phases, the binary organic acid ester solvent is selected from the group consisting of dialkyl adipate, dialkyl glutarate, dialkyl succinate, and mixtures thereof. 3-Applicable to this paper standard China National Standard (CNS) A4 specification (210X 297 mm) 581781 A8 B8 C8 A _ _ D8 patent application scope Mountain ,,,,, and ㈡ called i to 12 vermiculite antiatoms, and the co-solvent is selected from the group consisting of acetone, malon, malonite, anti-bismuth propylene glycol ester, monofluorene fluorene, diacetone, and fluorene And its mixtures, wherein the content of the co-solvent in the solvent continuum is from at least 101% to 40% by weight of the solvent / co-solvent system; weight (b) separation and recovery of floating in the liquid solvent system- The softened polyphenylene terephthalate phase; and (c) separating and recovering the polyparaphenylene glycol phase from the liquid solvent system phase. — Two methods for recovering polystyrene and polyethylene terephthalate from a plastic mixture, wherein the plastic mixture comprises foamed polystyrene and terephthalate and at least one other non- The soluble polymer includes the following steps: (a) at a temperature of 0 to 50 ° C, the polystyrene foam and the solvent containing at least one auxiliary solvent per 100 parts by weight of the binary organic acid ester System contact to collapse foamed polystyrene in a mixture of foamed polystyrene and polyethylene terephthalate without dissolving polystyrene or polyethylene terephthalate, Three individual immiscible phases are thus generated, the binary organic acid esters being selected from the group consisting of adipic acid adipate, glutaric acid dioctyl ester, succinic acid difluorenyl ester, and mixtures thereof, wherein the Alkyl groups are the same or different and have from 1 to 12 carbon atoms. The co-solvent is selected from the group consisting of the following 4- This paper size applies to China National Standard (CNS) A4 specifications (210 X 297 public love) Decoration § 7 1X 8 (i) from 10 to 66 · 7 parts by weight of ethylene glycol, (⑴ from 10 to 66.7 parts by weight of propylene glycol, (iii) from 17.6 to 42.8 parts by weight of propylene carbonate, (iv) from 53.8 To 66.7 parts by weight of dimethyl sulfoxide, (v) from 53.8 to 66.7 parts by weight of diacetone alcohol, and (vi) from 42.8 to 66.7 parts by weight of isopropanol; (b) separation and recovery of floating The softened collapsed polystyrene phase on top of the liquid solvent system phase; (c) The liquid solvent system phase containing the residual plastic produced in step (b) is heated to a temperature of 160 to 225 ° C to dissolve the polymer The polyethylene terephthalate phase; (d) separating the liquid solvent system phase and the undissolved plastic containing the dissolved polyethylene terephthalate; and (e) recovering the polymer pair from the liquid solvent system phase Phthalate phase 08—a method for recovering polystyrene and polyethylene terephthalate from a plastic mixture, wherein the plastic mixture includes expanded polystyrene and polyethylene terephthalate The objective of benzyl alcohol and at least one other insoluble gathering character, including the following steps: (a) At a temperature of 0 to 50 ° C, the polystyrene foam is contacted with a solvent system containing a dibasic organic acid ester and at least one auxiliary solvent, and the foamed polyphenylene terephthalate and polyterephthalic acid are contacted. Ethylene glycol § The purpose of foaming polystyrene in a mixture: Collapse: without dissolving polystyrene or polyethylene terephthalate 'thus resulting in three separate immiscible paper sizes applicable China National Standard (CNS) A4 specification (210 X 297 mm) 581781 8 8 8 8 AB c D 6. The scope of patent application is mixed. The binary organic acid ester solvent is selected from the group consisting of dialkyl adipate, Groups of dialkyl glutarate, dialkyl succinate and mixtures thereof, wherein the alkyl groups are the same or different and have from 1 to 12 carbon atoms, and the co-solvent is selected from the group consisting of ethylene glycol, A group of propylene glycol, propylene carbonate, dimethyl fluorene, diacetone alcohol, isopropanol, and mixtures thereof, wherein the content of the co-solvent in the solvent / co-solvent system is at least from the solvent / co-solvent system 10 weight percent to 40 weight percent; (b) separation and recovery of floating solvents The softened and collapsed polystyrene phase on top of the system phase; (c) The liquid solvent system phase containing the residual plastic produced in step (b) is heated to a temperature of 160 to 225 ° C to dissolve the polyparaphenylene Ethylene glycol diformate phase; (d) separating a liquid solvent system phase containing dissolved polyethylene terephthalate and undissolved plastics; and (e) recovering poly (p-phenylene terephthalate) from the liquid solvent system phase Ethylene glycol formate phase-6-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)