KR19990024063A - Method for preparing polyurethane using tolylene diisocyanate by-product - Google Patents

Abstract

The present invention relates to a method for preparing a polyurethane using tolylene diisocyanate (TDI) by-products, the object of which is to modify the TDI tar by-products generated during the production of tolylene diisocyanate (TDI) to produce a polyurethane Is to be recycled to isocyanate compounds used as.

In one embodiment of the present invention, TDI tar, an isocyanate compound, and an active hydrogen material are completely dissolved in a temperature range of 45 to 55 ° C. using a solvent, and then gradually warmed up, and the temperature is about 75 to 85 ° C. Reacting for 2-3 hours to prepare a TDI tar modified product; The TDI tar modified product is added to a polyol and various additive mixtures and reacted, and then molded into a mold of a predetermined form to produce a rigid polyurethane product.

In another embodiment of the present invention, TDI tar, an isocyanate compound, and an active hydrogen material are completely dissolved in a temperature range of 45 to 55 ° C. using a solvent, and then gradually warmed up, and the temperature is about 75 to 85 ° C. Reacting for 2-3 hours to prepare a TDI tar modified product; Putting the discarded hard polyurethane scrap into a mold of a predetermined form, and then stirring and reacting with the TDI tar modified body, the polyol and various additive mixtures to prepare a recycled hard polyurethane product.

Description

Method for preparing polyurethane using tolylene diisocyanate by-product

The present invention relates to a method for producing polyurethane using tolylene diisocyanate (C ₉ H ₆ N ₂ O ₂ ) by-products, in particular to the production of tolylene diisocyanate (TDI) which is one of the raw materials of polyurethane It relates to a method for producing a rigid polyurethane using TDI tar, a by-product generated in the process.

Generally, polyurethane is a urethane bond obtained by chemical reaction between a substance containing an isocyanate group (-NCO-) and a substance having activated hydrogen, as shown in the following formula (I). It is a polymer compound with), which is widely used in all industries such as cushioning materials for automobiles and furniture, insulation materials for buildings, adhesives, waterproofing agents, flooring materials, artificial leather, coating materials, sealing agents and artificial fibers according to raw materials and applied technologies. It is attracting much attention recently as a polymer material.

_(Ⅰ)

The isocyanate compound used as a raw material in the preparation of such polyurethane is diphenylmethanediisocyanate (C ₁₅ H ₁₀ N ₂ O ₂ , MDI), hexamethylene diisocyanate (Hexamethylenediisocyanate: OCN (CH ₂ ) ₆ NCO} And tolylene diisocyanate (C ₉ H ₆ N ₂ O ₂ : TDI) mentioned above, and the compound having activated hydrogen includes amine (Amine), phenol (Phenol), alcohol (Alcohol), and water (H ₂ O). ), And various active materials such as activated methylene compounds are used depending on the use and application.

On the other hand, the typical synthesis process of TDI used as a raw material of polyurethane is as follows.

According to the TDI synthesis process, 2,4-obtained by nitrification of paranitrotoluene or o-Nitrotoluene, which is an isomer separated from mononitrotoluene, first Dinitrotoluene (2,4-Dinitrotoluene) or 2,6-dinitrotoluene (2,6-Dinitrotoluene) is reduced in the presence of hydrogen gas (H ₂ ) to prepare tolylenediamine (TDA).

Then, phosgene, a colorless choking gas obtained by heating carbon monoxide (CO) separated when reforming chlorine gas (Cl ₂ ) and naphtha in the presence of a catalyst such as activated carbon, COCl ₂ ) is purified after the reaction with the TDA to obtain the desired TDI product.

In the refining process of the TDI synthesis process, TDI tar containing an isocyanate group (-NCO-) is inevitably generated as a by-product. Currently, about 50,000 M / T or more of TDI is produced in Korea, and TDI tar is a by-product. The amount of produced is about 4,000 M / T per year.

As such, TDI tar generated during the refining process of TDI synthesis process is incinerated as a fuel of boiler because it cannot find a proper treatment method. In this case, serious poisoning causes various toxic gases and pollutes the air. there is a problem.

In addition, in order to process the toxic gas generated during incineration of the TDI tar, there is a problem that a huge equipment cost is required, such as a separate dust collector must be provided.

In addition, since polyurethane foam, which is used as a heat insulating material in various industrial fields, is difficult to recycle once used, the discarded polyurethane foam becomes a major cause of polluting the environment as it is mainly incinerated or landfilled after crushing. have.

Therefore, there is an urgent need for a method for recycling waste polyurethane foam generated in various industrial fields.

An object of the present invention is to prepare a polyurethane using tolylene diisocyanate by-products that can be recycled to the isocyanate compound used as a raw material in the production of polyurethane by modifying the TDI tar, a by-product generated during the production of tolylene diisocyanate (TDI) To provide a way.

Another object of the present invention is to prepare a polyurethane using tolylene diisocyanate by-products that can be recycled back to the polyurethane foam by reacting the rigid polyurethane foam discarded after being used as a heat insulating material in various industries with the TDI tar modified body To provide a way.

In order to achieve the above object, the present invention completely dissolves TDI tar, an isocyanate compound, and an activated hydrogen substance in a temperature range of 45 to 55 ° C. using a solvent, and then gradually warms up the temperature to 75 ° to 85 ° C. Reacting for about 2 to 3 hours at a temperature range to produce a TDI tar modified product; The TDI tar modified product is added to a polyol and various additive mixtures and reacted, and then molded into a mold of a predetermined form to produce a rigid polyurethane product.

In the present invention, in the step of preparing the TDI tar modified body, 10 to 40 wt% of an activated hydrogen substance having a molecular weight of 100 to 5000, and an isocyanate group content of 25 to 30 wt% based on 100 wt% of TDI tar, 10 to isocyanate compound 10 to 40 wt% and 5 to 50 wt% of solvent are mixed and reacted.

In the step of preparing the rigid polyurethane product in the present invention as described above, 1 to 5 wt% of water, 10 to 40 wt% of freon, 1 to 2 wt% of foaming agent, 1 to 2 wt% of catalyst, and 5 to 15 wt of flame retardant based on 100 wt% of polyol. % And 80 wt% to 120 wt% of the TDI tar modified body is mixed with the additive 1 wt% to 2 wt%.

In order to achieve the above another object, the present invention uses a solvent to completely dissolve the TDI tar, the isocyanate compound and the activated hydrogen substance in the temperature range of 45 ~ 55 ℃ and then slowly increase the temperature, 75 ~ 85 ℃ Reacting for about 2 to 3 hours at a temperature range of to prepare a TDI tar modified product; After the scrap of scraped polyurethane foam is put into a mold of a certain form, the step of preparing a recycled rigid polyurethane product by adding and stirring while stirring the TDI tar modified body, polyol and various additive mixtures obtained above. Has

In the step of preparing the modified TDI tar in the present invention as described above, 10 to 40 wt% of an activated hydrogen substance having a molecular weight of 100 to 5000 based on 100 wt% of TDI tar, and an isocyanate group content of 25 to 30 wt% isocyanate compound 10 -40 wt% and 5-50 wt% of a solvent mix and react.

In the present invention, in the step of preparing the rigid polyurethane product in 1 to 5wt% of water, 10 to 40wt% of freon, 1 to 2wt% of foaming agent, 1 to 2wt% of catalyst, 5 to 15wt of flame retardant based on 100wt% of polyol %, 1 to 2 wt% of additives and 600 to 1,400 wt% of discarded hard polyurethane foam scrap.

Hereinafter, preferred embodiments of the present invention will be described in more detail.

In one embodiment of the present invention, 10-40 wt% of isocyanate compound MDI based on 100 wt% of TDI tar obtained during the purification of the TDI synthesis process in a 5L flask equipped with a thermometer, a reflux cooler, a nitrogen reflux device, and an agitator. 10-40 wt% of polyethylene glycol (PEG), an active hydrogen substance, and 5-50 wt% of ethyl acetate (R = C ₂ H ₅ ) as a solvent were completely dissolved in the range of 45-55 ° C., and then slowly The mixture was heated to react for about 2 to 3 hours in the range of 75 to 85 ° C to prepare a TDI tar modified product.

The above process is then carried out with 1 to 5 wt% of water, 10 to 40 wt% of freon, 1 to 2 wt% of foam stabilizer, 1 to 2 wt% of catalyst, 5 to 15 wt% of flame retardant, and 1 to 2 wt% of additive with respect to 100 wt% of polyol. 80-120 wt% of the TDI tar modified product obtained in the above was mixed and reacted to produce a rigid polyurethane product.

In another embodiment of the present invention, 10-40 wt% of isocyanate compound MDI based on 100 wt% of TDI tar obtained in the purification process of the TDI synthesis process in a 5L flask equipped with a thermometer, a reflux condenser, a nitrogen reflux device, and an agitator. , 10-40 wt% of polyethylene glycol (PEG), an active hydrogen substance, 5-50 wt% of ethyl acetate as a solvent, completely dissolved in the range of 45-55 ° C., and then gradually warmed up to 75-85 ° C. To react for about 2 to 3 hours in the range of to prepare a TDI tar modified body.

Then, TDI was added to the mixed liquid added with 1 to 5 wt% of water, 10 to 40 wt% of freon, 1 to 2 wt% of foam stabilizer, 1 to 2 wt% of catalyst, 5 to 15 wt% of flame retardant, and 1 to 2 wt% of additive based on 100 wt% of polyol. 80 to 120 wt% of tar modified material and 900 wt% of discarded hard polyurethane foam scrap are mixed and reacted to form a recycled hard polyurethane product.

In each embodiment of the present invention described above, as the solvent, linear, nonlinear hydrocarbon compounds, ketones or ethers represented by the following chemical formulas are used.

, ,

(In the above formula, a, b, c, and m are each an integer of 1 or more, X is a halogen compound, R _6, R ₇ , R ₈ , R ₉ represents a linear, non-linear hydrocarbon compound)

According to the present invention, a rigid polyurethane product manufactured from TDI tar modified material as a raw material or manufactured from discarded rigid polyurethane foam scrap is used as a polyurethane product manufactured from conventional TDI and its physical properties. Since there is no difference, manufacturing cost can be reduced and environmental pollution caused by incineration or landfill of TDI tar and discarded polyurethane foam can be prevented at the source.

Example 1

2,600 g of TDI tar, 600 g of MDI (% NCO, 28.5 ± 1) as an isocyanate compound, and a molecular weight of 1,000 ± 50 as an active hydrogen substance in a 5 L flask equipped with a thermometer, a reflux condenser, a nitrogen reflux device, and a stirrer. 600 g of PEG) and 200 g of ethylacetate (Ethylacetate) as a solvent were accurately weighed and completely dissolved within 50 ° C., then slowly heated up, and reacted at 80 ° C. for about 2 to 3 hours to prepare a TDI tar modified body.

A certain amount of the TDI tar modified product thus prepared was taken to measure the content and viscosity of the target isocyanate group (-NCO-), and the results are shown in Table 1.

Table 1. Specifications of TDI Tar Modifiers

Isocyanate group (-NCO-) content rate Max. 40% Viscosity Min. 100 (cps / 25 ℃) Solid Content 0-90%

According to the specifications of the TDI tar modified body shown in Table 1, it can be seen that there is no difference from the specifications of the conventional TDI products that are typically used as a raw material for polyurethane production.

Example 2

110 g of the TDI tar modified product prepared in Example 1 was added to a mixture added at a ratio of 1.0 g of water, 30 g of freon, 1.5 g of foam stabilizer, 1.5 g of catalyst, 10 g of flame retardant, and 1.0 g of additive with respect to 100 g of polyol prepared in advance. Then, the mixture was reacted with stirring and molded into a mold of a predetermined form to prepare a rigid polyurethane foam.

The physical properties of the rigid polyurethane foam (Inventive Material 1) thus prepared were measured, and the results are shown in Table 2.

Table 2. Physical Properties of Rigid Polyurethane Foam (Invention 1)

Density (kg / m ³ ) 30 ± 0.3 60 ± 0.6 90 ± 0.9 Compressive strength (kg _f / cm ² ) 0.8 min. 4.0 min. 6.0 min. Tensile Strength (kg _f / cm ² ) 2.0 min. 6.0 min. 8.0 min. Elastic strength (kg _f / cm ² ) 2.0 min. 6.5 min. 8.0 min. Absorption Rate (%) 3.0 max. 2.0 max. 2.5 max. Independent Bubble Rate (%) 80 min. 80 min. 80 min. Dimensional stability (%) ± 1.0 max. ± 1.0 max. ± 1.0 max.

On the other hand, the physical properties of the polyurethane foam (comparative material) used as the most common heat insulating material was measured, and the results are shown in Table 3 below.

Table 3. Properties of Comparative Material

Density (kg / m ³ ) 40 ± 0.4 Compressive strength (kg _f / cm ² ) 2.5 Tensile Strength (kg _f / cm ² ) 2.8 Elastic strength (kg _f / cm ² ) 3.5 Absorption Rate (%) 2.5 Independent Bubble Rate (%) 90 min. Dimensional stability (%) ± 0.8

Comparing the physical properties of the polyurethane foam (Inventive Material 1) prepared using the TDI tar modified body with the physical properties of the Comparative Material, it can be seen that the physical properties of the Inventive Material 1 never fall in comparison with those of the comparative material. .

Example 3

150 g of TDI tar modified product prepared in Example 1 and discarded hard polyurethane foam scrap in a mixed solution added at a ratio of 0.75 g of water, 1.5 g of foaming agent, 1.5 g of catalyst, 7.5 g of flame retardant, and 1.5 g of additive with respect to 150 g of polyol. 700g was mixed and reacted, and then molded using a predetermined mold to prepare recycled rigid polyurethane products.

The physical properties of the recycled rigid polyurethane foam (Inventive Material 2) thus prepared were measured and the results are shown in Table 4.

Table 4. Properties of Recycled Rigid Polyurethane Foam (Invention 2)

Density (kg / m ³ ) 50 ± 0.5 80 ± 0.8 Compressive strength (kg _f / cm ² ) 3.0 min. 5.0 min. Tensile Strength (kg _f / cm ² ) 3.0 min. 7.0 min. Elastic strength (kg _f / cm ² ) 3.0 min. 7.0 min. Absorption Rate (%) 2.0 max. 2.0 max. Independent Bubble Rate (%) 80 min. 80 min. Dimensional stability (%) ± 1.0 max. ± 1.0 max. Thermal Conductivity (kcal / mhr ℃) 0.02 max. 0.02 max.

When comparing the physical properties of the recycled hard polyurethane foam (Inventive Material 2) prepared using the TDI tar modified body with the waste polyurethane foam scrap and the physical properties of the comparative material measured in Example 2, the present invention in each item It can be seen that the physical properties of 2 never fall as compared with the comparative material.

According to the present invention, the TDI tar modified product obtained by chemically treating TDI tar, a by-product generated in the preparation of tolylene diisocyanate, can be recycled into an isocyanate compound, which is a raw material of polyurethane, thereby disposing of TDI tar. And environmental and air pollution due to incineration is prevented at the source.

In addition, by selecting a polyol and various additives corresponding to the TDI tar modified body, it is possible to recover the substantially discarded polyurethane foam.

In addition, since the physical properties and processability of polyurethane products using TDI modified materials are not significantly different compared to those of existing products, production costs are significantly lowered, thereby increasing competitiveness.

Claims (12)

TDI tar, the isocyanate compound and the activated hydrogen substance were completely dissolved in the temperature range of 45-55 ° C using a solvent, and then gradually warmed up, and reacted for about 2-3 hours at the temperature range of 75-85 ° C. Preparing a TDI tar modified product; The method of producing a polyurethane using a tolylene diisocyanate by-product comprising the step of preparing a rigid polyurethane product by putting the TDI tar modified product into a polyol and various additive mixtures and reacted and then molded in a mold of a predetermined form. The method of claim 1, In the step of preparing the TDI tar modified body, 10-40 wt% of an active hydrogen substance having a molecular weight of 100-5000 based on 100 wt% of TDI tar, an isocyanate compound having a isocyanate group content of 25-30 wt%, and a solvent of 10-40 wt% A method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that 5 to 50wt% is mixed and reacted. The method of claim 1, In the step of preparing the rigid polyurethane product, 1 to 5 wt% of water, 10 to 40 wt% of freon, 1 to 2 wt% of foam stabilizer, 1 to 2 wt% of catalyst, 5 to 15 wt% of flame retardant, and additive 1 based on 100 wt% of polyol. A method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that 80 ~ 120wt% TDI tar modified material is mixed with ~ 2wt%. The method of claim 1, The solvent is a method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that the linear, non-linear hydrocarbon compound having the following formula. (In the formula, a, b, c, and m are each an integer of 1 or more, X is a halogen compound) The method of claim 1, The solvent is a method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that the ketones having the following formula. (In the formula, R ₆ , R ₇ is a linear, nonlinear hydrocarbon compound.) The method of claim 1, The solvent is a method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that the ether having the following formula. (In the formula, R ₈ , R ₉ is a linear, nonlinear hydrocarbon compound.) TDI tar, the isocyanate compound and the activated hydrogen substance were completely dissolved in the temperature range of 45-55 ° C using a solvent, and then gradually warmed up, and reacted for about 2-3 hours at the temperature range of 75-85 ° C. Preparing a TDI tar modified product; Tolylene diisocyanate comprising putting a predetermined amount of waste polyurethane foam scrap into a mold of a predetermined form, and then adding recycled TDI tar modified body, polyol and various additive mixtures and reacting with stirring to prepare a recycled hard polyurethane product. Method for producing polyurethane using byproducts. The method of claim 7, wherein In the preparing of the TDI tar modified body, 10 to 40 wt% of an activated hydrogen substance having a molecular weight of 100 to 5000 and 10 to 40 wt% of an isocyanate group containing 25 to 30 wt% based on 100 wt% of TDI tar, A method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that 5 to 50 wt% of the solvent is mixed and reacted. The method of claim 7, wherein In the manufacturing of the recycled hard polyurethane product, 1 to 5 wt% of water, 10 to 40 wt% of freon, 1 to 2 wt% of foaming agent, 1 to 2 wt% of catalyst, 5 to 15 wt% of flame retardant, and additives based on 100 wt% of polyol A method for producing a polyurethane using tolylene diisocyanate by-products, characterized in that 1 to 2 wt% and 600 to 1,400 wt% of discarded hard urethane foam scraps are mixed. The method of claim 7, wherein The solvent is a method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that the linear, non-linear hydrocarbon compound having the following formula. (In the formula, a, b, c, and m are each an integer of 1 or more, X is a halogen compound) The method of claim 7, wherein The solvent is a method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that the ketones having the following formula. (In the formula, R ₆ , R ₇ is a linear, nonlinear hydrocarbon compound.) The method of claim 7, wherein The solvent is a method for producing a polyurethane using tolylene diisocyanate by-product, characterized in that the ether having the following formula. (In the formula, R ₈ , R ₉ is a linear, nonlinear hydrocarbon compound.)