CN106750510B

CN106750510B - Method for treating polyurethane oligomer waste liquid and polyurethane elastomer

Info

Publication number: CN106750510B
Application number: CN201710025725.XA
Authority: CN
Inventors: 崔跃伟; 乔建强; 荆建林
Original assignee: ZHENGZHOU ZHONGYUAN SPANDEX ENGINEERING TECHNOLOGY CO LTD
Current assignee: ZHENGZHOU ZHONGYUAN SPANDEX ENGINEERING TECHNOLOGY CO LTD
Priority date: 2017-01-13
Filing date: 2017-01-13
Publication date: 2020-04-03
Anticipated expiration: 2037-01-13
Also published as: CN106750510A

Abstract

The present application relates to a method for treating a waste liquid of a polyurethane oligomer and a polyurethane elastomer containing a product of the treatment method as a filler. The processing method comprises the following steps: 1) adding precipitator powder into the polyurethane oligomer waste liquid, and uniformly stirring to obtain a mixture A; 2) adding a polyisocyanate crosslinking agent into the mixture A to obtain a mixture B; 3) dropwise adding water into the mixture B, uniformly stirring until granular precipitates appear, and quickly adding water to obtain a mixture C; and 4) filtering the mixture C to obtain a filtrate D and a solid component E for recovery. By this treatment method, the urethane oligomer and the solvent can be recovered and reused at the same time.

Description

Method for treating polyurethane oligomer waste liquid and polyurethane elastomer

Technical Field

The invention relates to the field of polyurethane industry, in particular to a treatment method of polyurethane oligomer waste liquid and a polyurethane elastomer taking a product of the treatment method as a filler.

Background

With the increasing prominence of environmental problems such as greenhouse effect and ozone depletion, research and development on waste treatment technologies are rapidly progressing in recent years. From the viewpoint of recycling of resources, chemical recycling using chemical treatment as a raw material is useful.

The polyurethane material is widely applied to the fields of furniture industry, household electrical industry, building industry, traffic industry, shoe making and leather making industry, sports industry and the like, and the global polyurethane demand reaches more than 2000 million tons/year in 2016. While the polyurethane industry benefits mankind, it also produces large amounts of waste, with associated environmental concerns.

So far, a large amount of polyurethane industrial waste is not effectively recycled, and the main treatment methods are a landfill method and a burning method. Wherein, the burying method hardly degrades the polyurethane industrial waste, occupies land and consumes resources; and the incineration treatment generates toxic gas due to insufficient combustion, thereby causing secondary pollution.

In order to improve the dilemma that large amounts of industrial wastes of polyurethane are not effectively recycled, many researchers have worked. The patent (JP-A2000-239961A) describes a method for recycling foamed polyurethane waste, which comprises decomposing polyurethane at 220-280 deg.C under 0.5-10 MPa by using a decomposition liquid containing methylene dianiline, toluenediamine and diethylene glycol, and then utilizing the decomposition liquid. In the patent publication (Japanese patent publication No. 53-029359), waste polyurethane is decomposed by heating and mixing in an excess of diol to produce polyol, and the polyol is recovered. The patent publication (JP-A-7-309816 and JP-A-7-224141) disclose that a primary amine in a decomposition mixture obtained by a glycol decomposition method is reacted with an alkylene oxide to convert the primary amine into a polyol. In addition to the above-mentioned methods, there are also methods described in the patent publication (Japanese patent laid-open Nos. 2002-212336 and 2002-241538) in which when the product obtained by decomposing the waste polyurethane is used as a polyurethane raw material, the reactivity is low and a large amount of catalyst must be added. The patent (CN1037851C) describes the preparation of polyesters by insertion reaction of polyethers with cyclic anhydrides in the presence of Lewis acid catalysts. The invention is a practical method for converting polyurethane recycled polyether polyol into curable unsaturated polyester resin. Patent (CN104694064) relates to a method for preparing polyurethane adhesive by modifying waste polyurethane recovery product with montmorillonite.

The above patent technologies are all methods for recycling the waste of the end products of polyurethane industry, which is obviously insufficient. The preparation process of polyurethane has a long route, various wastes are generated in the process, and the problem needs to be solved. The patent (CN102251316A) mentions a method of recycling waste polyurethane elastic fiber for spinning, but it involves the problem of removing oil from the waste fiber, and also causes secondary pollution. The patent (201010249001.1) discloses a method for recovering N, N-dimethylacetamide from waste polyurethane urea solution, which is a method of soaking in deionized water to extract N, N-dimethylacetamide, which is not only inefficient, but also produces new polyurethane waste. Patent (CN103409846B) provides a method for producing delustering spandex filament by utilizing polyurethane urea solution, but the property of the produced spandex filament is unstable, and the service cycle of equipment is also shortened seriously, which affects the production stability.

The problem to be solved by the invention is different from the problems mentioned in the above patents, and the key point is to solve the technical problem of recovering the waste liquid of the N, N-dimethylacetamide of the polyurethane oligomer, and simultaneously effectively utilize the recovered product to realize the aim of zero emission.

Disclosure of Invention

The embodiment of the application provides a treatment method of polyurethane oligomer waste liquid, a solid product obtained by the treatment method and a polyurethane elastomer containing the solid product as a filler.

In a first aspect, embodiments of the present application provide a method for treating a waste polyurethane oligomer solution, which may include the following steps:

1) adding precipitator powder into the polyurethane oligomer waste liquid, and uniformly stirring to obtain a mixture A;

2) adding a polyisocyanate crosslinking agent into the mixture A to obtain a mixture B;

3) dropwise adding water into the mixture B, uniformly stirring until granular precipitates appear, and quickly adding water to obtain a mixture C; and

4) and filtering the mixture C to obtain filtrate D and a solid component E for recovery.

In one embodiment, the precipitant powder may be an inorganic salt capable of forming a crystalline hydrate, for example, one or more selected from anhydrous copper sulfate, calcium oxide, hydrotalcite with low crystalline water content, sodium carbonate, ferrous sulfate, zinc sulfate, aluminum potassium sulfate, calcium sulfate, sodium sulfate, and the like. Preferably, the adding amount of the precipitant powder in the step 1) may be 10% to 50% of the mass of the polyurethane oligomer.

In another embodiment, the polyisocyanate crosslinker may be selected from triisocyanates or tetraisocyanates, for example one or more selected from polymethylene polyphenyl polyisocyanates, triphenylmethane triisocyanate, tris (4-phenylisocyanate) thiophosphate, 2 ' -dimethyl-3, 3', 5,5 ' -triphenylmethane tetraisocyanate, lysine triisocyanate, triisocyanatononane, biuret triisocyanate, adducts of toluene diisocyanate and trimethylolpropane. Preferably, the polyisocyanate crosslinking agent may be added in the step 2) in an amount of 1% to 20% by mass of the polyurethane oligomer.

In yet another embodiment, the stirring in step 1) is carried out at 45 to 60 ℃ for 3 to 15 hours, and the stirring speed may be 1400 to 2800 rpm.

In still another embodiment, the stirring in step 2) is carried out at 45 to 60 ℃ or 70 to 100 ℃ for 30 to 180 minutes, and the stirring speed may be 1000 to 2000 rpm.

In another embodiment, the stirring is performed while adding water dropwise in the step 3), the stirring speed may be 100 to 500 rpm, and the reaction temperature may be 70 to 100 ℃.

In still another embodiment, the amount of water rapidly added in the step 3) may be 10 to 50% by mass of the urethane oligomer waste liquid.

In one embodiment, the recovery of the solid component E may comprise: and drying the mixture at 80-120 ℃ for 24-48 hours, and then crushing to obtain a powdery solid component E. The steam obtained by drying may be condensed and refluxed, and then may be recycled by being introduced into a refining apparatus.

In a second aspect, embodiments of the present application provide a solid product, which includes a precipitant powder and a crosslinked polymer of a polyisocyanate and water coated on a surface of the precipitant powder, wherein a polyurethane oligomer is entrapped in a space structure of the crosslinked polymer. The solid product is the solid component E obtained by the treatment process according to the invention. Thus, the above description of the precipitant powder and the polyisocyanate of the first aspect is equally applicable to the solid product of the second aspect.

In a third aspect, embodiments herein also provide a polyurethane elastomer comprising the solid product of the present invention as a filler, wherein the solid product is in the form of a powder.

Detailed Description

As described above, in the treatment of the urethane oligomer, the urethane oligomer cannot be separated from the N, N-dimethylacetamide solvent, but is often treated by incineration, which is obviously likely to cause a secondary pollution problem. The treatment method of the polyurethane oligomer waste liquid provided by the invention can effectively separate the polyurethane oligomer and the N, N-dimethylacetamide solvent, and can realize the recycling of the polyurethane oligomer and the N, N-dimethylacetamide solvent.

Specifically, the method for treating the polyurethane oligomer waste liquid of the present invention may comprise the steps of:

Polyurethane oligomers are present in various polyurethane industrial wastes. For example, in polyurethane synthesis, when the reaction of diisocyanate with polyester or polyether diol is carried out in a prepolymerization reactor for a certain period of time, the prepolymerization reactor is often cleaned, and a large amount of polyurethane oligomer waste liquid is generated. For polyurethane, it is often washed with, for example, N-Dimethylacetamide (DMAC) solvent, and therefore the polyurethane oligomer waste liquid is generally a solution of DMAC and polyurethane oligomer. However, the treatment method of the present invention is applicable to polyurethane oligomers of any origin as long as the number average molecular weight thereof is 2000 to 10000. The treatment method of the present invention is also applicable to any solution containing the polyurethane oligomer, wherein the solvent is a common solvent used in the production of polyurethane; when DMAC is used as the solvent, the mass concentration of the urethane oligomer waste liquid may be 10% to 30%.

The present inventors have unexpectedly found that, with such a waste liquid of polyurethane oligomer, when a polyisocyanate is used as a trapping agent, it is possible to trap the polyurethane oligomer by a chemical crosslinking method and also to precipitate the resulting crosslinked polymer by using a precipitating agent, thereby achieving thorough separation of the polyurethane oligomer from the solvent.

For this purpose, polyisocyanates having a functionality of 3 or 4 can be selected as trapping agents to ensure a better crosslinking effect. As examples of the trapping agent or the crosslinking agent, polymethylene polyphenyl polyisocyanate, triphenylmethane triisocyanate, tris (4-phenylisocyanate) thiophosphate, 2 ' -dimethyl-3, 3', 5,5 ' -triphenylmethane tetraisocyanate, lysine triisocyanate, triisocyanatononane, biuret triisocyanate, an adduct of toluene diisocyanate and trimethylolpropane, and the like can be mentioned. They may be used alone or in combination. Polymethylene polyphenyl polyisocyanates (PAPIs) are preferred, which are mixtures of 50% diphenylmethane diisocyanate (MDI) and 50% polyisocyanates having a functionality greater than 2 or greater.

The precipitant used in the method of the present invention is required not only to precipitate the crosslinked polymer formed, but also to have a certain water-removing effect at the initial stage of the reaction and to promote the crosslinking reaction. The inventors have found that inorganic salts capable of forming crystalline hydrates are particularly suitable for use as precipitating agents in the process of the invention, for example anhydrous copper sulphate, calcium oxide, hydrotalcite with a low water of crystallization content, sodium carbonate, ferrous sulphate, zinc sulphate, aluminium potassium sulphate, calcium sulphate, sodium sulphate and the like. Of course, these inorganic salts may be used alone or in combination as a precipitant. It is preferable to use anhydrous copper sulfate, calcium oxide, hydrotalcite with a low crystal water content, or a combination thereof, and calcium oxide is more preferable if consideration is also given to the price, compatibility with polyurethane materials, and the like. As used herein, "low water of crystallization" in "hydrotalcite with low water of crystallization" means that the water of crystallization is lower than the water of crystallization of the corresponding hydrotalcite crystal at normal temperature and pressure; for example, hydrotalcite crystals are heated to remove part of crystal water, thereby obtaining "hydrotalcite with low crystal water content". Hydrotalcite with low crystal water content is more conveniently ground into powder.

In step 1), the precipitant added to the polyurethane oligomer waste liquid is preferably in the form of powder; if the precipitant is not in the form of powder as usual, it may be processed into powder by grinding, crushing, or the like. The addition amount of the polyurethane oligomer can be 10-50% of the mass of the polyurethane oligomer. The precipitant powder is rapidly stirred while and after being added to mix the powder uniformly. For example, the whole waste liquid may be emulsified by high-speed shearing at a stirring speed of 1400 to 2800 rpm for 3 to 15 hours at 45 to 60 ℃. Meanwhile, the precipitator powder can absorb water possibly existing in the polyurethane oligomer waste liquid.

In the step 2), adding a polyisocyanate crosslinking agent into the mixture A of the polyurethane oligomer waste liquid and the precipitator powder obtained in the step 1), and quickly and uniformly stirring. The amount of polyisocyanate added may be 1% to 20% of the amount of polyurethane oligomer. The stirring speed can be 1000-2000 r/min, and the stirring is carried out for 30-180 min at the temperature of 45-60 ℃. If the polyurethane oligomer waste liquid is not stored for a long time, the temperature in the process can be increased to 70-100 ℃, so that the added polyisocyanate can react with the carbamido group of the polyurethane oligomer to generate biuret, thereby achieving the purpose of capturing part of the polyurethane oligomer.

In the step 3), water is firstly dripped into the mixture B containing the polyurethane oligomer waste liquid, the precipitator powder and the polyisocyanate crosslinking agent (in some cases, a small amount of biuret may be further contained) obtained in the step 2), the dripping speed can be 5-15 seconds/drop, and the mixture B is rapidly stirred, the stirring speed can be 100-500 r/min, and the reaction temperature can be 70-100 ℃. In the process, the dropping speed of water is controlled as much as possible, and the whole reaction system is uniformly stirred, so that the problem that the solid component E finally obtained is not crushed well due to the fact that the cross-linking reaction of the polyisocyanate and the water is too violent and even the polyisocyanate is gelatinized into blocks is avoided. And (3) as the reaction proceeds, once granular precipitates appear, rapidly adding water to stop the crosslinking reaction to continue, wherein the added water amount can be 10-50% of the mass of the polyurethane oligomer waste liquid.

By step 3), almost all of the urethane oligomer and the biuret, if any, in the urethane oligomer waste liquid are entrapped into the spatial structure of the crosslinked polymer formed, and the crosslinked polymer formed by the polyisocyanate and water is coated on the surface of the precipitant powder, and finally precipitated as a solid component E as a whole.

Therefore, in step 4), the mixture C is filtered to obtain a filtrate D and a solid component E, which are recovered. The filtrate D is mainly a solvent of the polyurethane oligomer waste liquid, such as an N, N-dimethylacetamide solvent, so that the method can realize the recycling of the cleaning solvent. The recovery of the solid component E may include: drying the mixture at 80-120 ℃ for 24-48 hours, and then crushing to obtain a powdery solid component E; the resulting vapor from the dry bake (containing mainly water and solvent such as N, N-dimethylacetamide) can be refluxed for condensation and fed to a refining unit for further solvent recovery.

In connection with the embodiments of the method of the invention can be seen: according to the invention, a cross-linked polymer with higher molecular weight is generated through a chemical cross-linking reaction, so that a polyurethane oligomer is captured, and the polyurethane oligomer is effectively fixed; meanwhile, the polyurethane oligomer is conveniently separated from the waste liquid by adopting a common precipitation technology. More importantly, the method not only solves the technical problem that the polyurethane oligomer is difficult to separate, but also realizes the effective recycling of the separated product, thereby achieving the environmental protection high standard of zero emission.

The embodiment of the application also provides a solid product, namely the solid component E obtained by the processing method. As described above, the solid component E is a precipitant powder whose surface is coated with a crosslinked polymer formed from polyisocyanate and water, wherein a polyurethane oligomer and possibly biuret are entrapped in the spatial structure of the crosslinked polymer.

Accordingly, embodiments of the present application also provide a polyurethane elastomer comprising the solid product of the present invention as a filler, wherein the solid product is in the form of a powder.

Examples

The present invention will be described in more detail below with reference to examples.

Example 1

1) Adding calcium oxide powder into the polyurethane oligomer waste liquid, and quickly and uniformly stirring, wherein the mass percentage concentration of the polyurethane oligomer waste liquid is 10%, the solvent is DMAC, the number average molecular weight of the polyurethane oligomer is 5000, and the addition amount of the calcium oxide is 30% of the mass of the polyurethane oligomer. The reaction was stirred at 45 ℃ for 3 hours at a stirring rate of 1800 rpm to give mixture A.

2) Adding polymethylene polyphenyl polyisocyanate (PAPI) into the mixture A, and rapidly and uniformly stirring, wherein the adding amount of the PAPI is 5% of the mass of the polyurethane oligomer. The reaction was stirred at 45 ℃ for 50 minutes at a stirring speed of 1000 rpm to give a mixture B.

3) And (3) dropwise adding water into the mixture B at a dropping speed of 9 seconds per drop, quickly and uniformly stirring, wherein the reaction temperature is 90 ℃, the stirring speed is 500 r/min, and when white granular precipitates appear, quickly adding a large amount of water, wherein the amount of the quickly added water is 30% of the mass of the polyurethane oligomer waste liquid to obtain a mixture C.

4) And filtering the mixture C to obtain filtrate D and a solid component E. D, feeding the mixture into a refining device for recycling. E after drying at 90 ℃ for 24 hours, grinding the filler used as the polyurethane elastomer; the resulting vapor was condensed and refluxed and sent to a refining apparatus for further recovery of DMAC.

Example 2

1) Adding anhydrous copper sulfate powder into the polyurethane oligomer waste liquid, and quickly and uniformly stirring, wherein the mass percentage concentration of the polyurethane oligomer waste liquid is 15%, the solvent is DMAC, the number average molecular weight of the polyurethane oligomer is 10000, and the addition amount of the anhydrous copper sulfate is 20% of the mass of the polyurethane oligomer. The reaction was stirred at 45 ℃ for 4 hours at a stirring rate of 1400 rpm to give a mixture A.

2) Adding polymethylene polyphenyl polyisocyanate (PAPI) into the mixture A, and rapidly and uniformly stirring, wherein the adding amount of the PAPI is 10% of the mass of the polyurethane oligomer. The reaction was stirred at 100 ℃ for 90 minutes at a stirring speed of 1000 rpm to give a mixture B.

3) And (3) dropwise adding water into the mixture B at a dropping speed of 12 seconds per drop, quickly and uniformly stirring, wherein the reaction temperature is 90 ℃, the stirring speed is 300 r/min, and quickly adding a large amount of water when blue granular precipitates appear, wherein the amount of the quickly added water is 25% of the mass of the polyurethane oligomer waste liquid to obtain a mixture C.

4) The mixture C was filtered to give filtrate D and a blue solid fraction E. D, feeding the mixture into a refining device for recycling. E, after drying at 80 ℃ for 36 hours, grinding the filler used as the polyurethane elastomer; the resulting vapor was condensed and refluxed and sent to a refining apparatus for further recovery of DMAC.

Example 3

1) Adding calcium oxide and hydrotalcite (Mg) with low crystal water content into polyurethane oligomer waste liquid₄Al(OH)₉CO₃·H₂O), rapidly and uniformly stirring, wherein the mass percentage concentration of the polyurethane oligomer waste liquid is 20%, the solvent is DMAC, the number average molecular weight of the polyurethane oligomer is 3000, the adding amount of the mixed powder is 30% of the mass of the polyurethane oligomer, and the mass ratio of calcium oxide to hydrotalcite with low crystal water content in the mixed powder is 5: 5. The reaction was stirred at 60 ℃ for 3 hours at a stirring rate of 2000 rpm to give a mixture A.

2) And adding a mixture of an addition product of toluene diisocyanate and trimethylolpropane and biuret triisocyanate into the mixture A, and rapidly and uniformly stirring, wherein the addition amount of the polyisocyanate mixture is 10% of the mass of the polyurethane oligomer, and the mass ratio of the addition product of toluene diisocyanate and trimethylolpropane to biuret triisocyanate is 5: 5. The reaction was stirred at 45 ℃ for 45 minutes at a stirring rate of 1000 rpm to give a mixture B.

3) And (3) dropwise adding water into the mixture B at a dropping speed of 15 seconds per drop, quickly and uniformly stirring, wherein the reaction temperature is 90 ℃, the stirring speed is 400 r/min, and quickly adding a large amount of water when white granular precipitates appear, wherein the amount of the quickly added water is 15% of the mass of the polyurethane oligomer waste liquid to obtain a mixture C.

4) And filtering the mixture C to obtain filtrate D and a solid component E. D, feeding the mixture into a refining device for recycling. E after drying at 80 ℃ for 48 hours, grinding the filler used as the polyurethane elastomer; the resulting vapor was condensed and refluxed and sent to a refining apparatus for further recovery of DMAC.

Example 4

1) Adding 2000 parts by weight of polycaprolactone (hydroxyl value 56) into 1000 parts by weight of toluene-2, 4-diisocyanate (TDI) under stirring, keeping the reaction temperature of the system at 75 ℃, and reducing the temperature to 45 ℃ when the NCO content reaches 4%;

2) taking 100 parts by weight of the product obtained in the step 1), adding 15 parts by weight of the solid component E powder obtained in the example 3 into the product, and stirring the mixture for 60 minutes at 45 ℃;

3) adding 10 parts by weight of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (MOCA) into the substance obtained in the step 2), and reacting at 45 ℃ for 60 minutes to obtain the polyurethane elastomer. The performance parameters of the elastomer are as follows by detection: the tensile strength is 9.2MPa, the notch tearing strength is 48.8kN/m, and the breaking elongation is 750 percent.

Compared with the polyurethane elastomer prepared by the same method as the example 4 but without the solid component E powder (the performance parameters are as follows: the tensile strength is 8.8MPa, the notch tearing strength is 49.3kN/m, and the breaking elongation is 790%), the performance of the polyurethane elastomer obtained by the example is basically not changed, and the solid component E powder is used as the filler, so that the preparation cost of the polyurethane elastomer is saved, and the reutilization of waste is completed. Moreover, by selecting the precipitant powder, the polyurethane elastomer can be made to exhibit different colors. For example, using anhydrous copper sulfate as a precipitant, the final polyurethane elastomer is blue in color.

Claims

1. A solid product comprises precipitator powder and a cross-linked polymer formed by polyisocyanate and water coated on the surface of the precipitator powder, wherein a polyurethane oligomer is entrapped in the space structure of the cross-linked polymer.

2. The solid product according to claim 1, characterized in that the precipitant powder is an inorganic salt capable of forming crystalline hydrates.

3. The solid product according to claim 2, characterized in that the precipitant powder is selected from one or more of anhydrous copper sulfate, calcium oxide, hydrotalcite with low water of crystallization content, sodium carbonate, ferrous sulfate, zinc sulfate, potassium aluminum sulfate, calcium sulfate, sodium sulfate.

4. Solid product according to claim 1, characterized in that the polyisocyanate crosslinking agent is selected from triisocyanates or tetraisocyanates.

5. Solid product according to claim 4, characterized in that the polyisocyanate crosslinker is selected from one or more of polymethylene polyphenyl polyisocyanates, triphenylmethane triisocyanate, tris (4-phenylisocyanate) thiophosphate, 2 ' -dimethyl-3, 3', 5,5 ' -triphenylmethane tetraisocyanate, lysine triisocyanate, triisocyanatononane, biuret triisocyanate, adducts of toluene diisocyanate and trimethylolpropane.

6. The solid product according to any of claims 1 to 5, characterized in that the amount of precipitant powder is 10-50% of the mass of polyurethane oligomer.

7. The solid product according to any one of claims 1 to 5, characterized in that the amount of polyisocyanate crosslinker is 1% to 20% of the amount of polyurethane oligomer.

8. The method for preparing a solid product according to any one of claims 1 to 7, comprising the steps of:

9. The method according to claim 8, characterized in that the precipitant powder is an inorganic salt capable of forming crystalline hydrates.

10. The method according to claim 9, wherein the precipitant powder is selected from one or more of anhydrous copper sulfate, calcium oxide, hydrotalcite with low crystal water content, sodium carbonate, ferrous sulfate, zinc sulfate, aluminum potassium sulfate, calcium sulfate, and sodium sulfate.

11. The method according to claim 8, wherein the amount of the precipitant powder added in step 1) is 10-50% of the mass of the polyurethane oligomer.

12. The process according to claim 8, characterized in that the polyisocyanate crosslinking agent is selected from triisocyanates or tetraisocyanates.

13. The process according to claim 12, characterized in that the polyisocyanate crosslinking agent is selected from one or more of polymethylene polyphenyl polyisocyanates, triphenylmethane triisocyanate, tris (4-phenylisocyanate) thiophosphate, 2 ' -dimethyl-3, 3', 5,5 ' -triphenylmethane tetraisocyanate, lysine triisocyanate, triisocyanatononane, biuret triisocyanate, adducts of toluene diisocyanate and trimethylolpropane.

14. The method according to claim 8, wherein the polyisocyanate crosslinking agent is added in step 2) in an amount of 1 to 20% by mass of the polyurethane oligomer.

15. The process according to any one of claims 8 to 14, wherein the stirring in step 1) is carried out at 45 to 60 ℃ for 3 to 15 hours at a stirring speed of 1400 to 2800 revolutions per minute.

16. The method according to any one of claims 8 to 14, wherein the stirring in step 2) is carried out at 45 to 60 ℃ or 70 to 100 ℃ for 30 to 180 minutes at a stirring speed of 1000 to 2000 rpm.

17. The method according to any one of claims 8 to 14, wherein the stirring is performed while adding water dropwise in step 3), the stirring speed is 100 to 500 rpm, and the reaction temperature is 70 to 100 ℃.

18. The method according to any one of claims 8 to 14, wherein the amount of water rapidly added in step 3) is 10 to 50% by mass of the urethane oligomer waste liquid.

19. The process according to any one of claims 8 to 14, characterized in that the recovery of the solid component E comprises: and drying the mixture at 80-120 ℃ for 24-48 hours, and then crushing to obtain a powdery solid component E.

20. The method of claim 19, wherein the steam from the drying is condensed back into the refining apparatus for recovery.

21. A polyurethane elastomer comprising the solid product according to any one of claims 1 to 7 as a filler, wherein the solid product is in the form of a powder.