KR100300656B1 - Method for preparing polyurethane by using tolylenediisocyanate by-product - Google Patents

Abstract

PURPOSE: Provided is a method for preparing a polyurethane by using dimethylterephthalate, which can synthesize a polyol from DMT(dimethylterephthalate), that is a by-product generated in producing DMT, and recycle the polyol into a material of polyurethane. CONSTITUTION: The method comprises the steps of (i) completely melting a DMT slurry and an activated hydrogen material having molecular weight of 60-5000 at 90-100 deg.C by using solvent; (ii) gradually warming the solution, and completely reacting the solution at 180-250 deg.C, and then cooling the solution to obtain a DMT slurry-based polyol; (iii) introducing an isocyanate compound and a mixture of various additives into the polyol with stirring, and introducing the mixture into a scrap of predetermined waste polyurethane foam with stirring; and (iv) charging the mixture into mold having predetermined shape to form a recycled hard polyurethane product.

Description

Method for preparing polyurethane using dimethyl terephthalate by-product

The present invention relates to a method for producing a polyurethane (Polyurethane) using a dimethyl terephthalate (C ₁₀ H ₁₀ O ₄ ) by-products, in particular in the manufacturing process of dimethyl terephthalate (DMT) which is one of the raw materials of polyurethane It relates to a method for producing a rigid polyurethane using the by-product DMT slurry (Slurry) generated.

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, building materials, insulation materials, 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.

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

On the other hand, DMT having an activated hydrogen to react with the isocyanate compound in the preparation of the polyurethane to form a urethane bond is produced by the following reaction formula.

TPA + CH ₃ OH DMT + Slurry

According to the above reaction scheme, DMT reacts terephthalic acid (TPA), an isomer of phthalic acid (C ₈ H ₆ O ₄ ), and methanol (Methanol: CH ₃ OH) to react each carboxyl group (-COOH) contained in terephthalic acid. In-), the hydrogen atom is generated as it is substituted with the methyl group (CH ₃ ), and in this process, a by-product DMT slurry is generated.

The composition of the DMT slurry generated as described above is shown in Table 1 below.

At present, more than 600M / T DMT slurry is generated in Korea annually, and the DMT slurry generated in the manufacturing process of DMT is incinerated mainly because it cannot find a proper treatment method. In this case, various toxic gases are generated when incinerated. There is a serious problem that will pollute the air.

In addition, in order to process the toxic gas generated during the incineration of the DMT slurry, there is a problem in that a huge facility cost is required, such as a separate treatment facility such as a dust collector.

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 synthesize a polyol from a DMT slurry, which is a by-product generated in the production of dimethyl terephthalate (DMT), and to recycle the polyol to a polyol, which is a raw material of polyurethane. It is to provide a manufacturing method.

It is another object of the present invention to recycle recycled polyurethane foams by reacting rigid polyurethane foams which are used as thermal insulation in various industrial fields with a mixture of polyisomers prepared from previously prepared isocyanate compounds and DMT slurry and various additives. It is to provide a method for producing a polyurethane using a dimethyl terephthalate dispersion to be made.

In order to achieve the above object, the present invention completely melts the DMT slurry and the activated hydrogen substance having a molecular weight of 60 to 5000 at a temperature range of 90 to 100 ° C. using a solvent, and then gradually increases the temperature to 180 to 180 °. Completely reacting at a temperature of 250 ° C. and then cooling to prepare a DMT slurry-based polyol; A mixture of an isocyanate compound and various additives in the DMT slurry base polyol is added to the scrap of waste polyurethane foam, which has been quantified in advance, and then stirred and mixed to make recycled rigid polyurethane products into a mold of a certain type. It is characterized by a step.

In the step of preparing the DMT slurry base polyol in the present invention has a characteristic that 50 to 100 parts by weight of activated hydrogen material having a molecular weight of 60 to 5000 and 1 to 200 parts by weight of the solvent is mixed with respect to 100 parts by weight of DMT slurry.

Examples of the activated hydrogen material used in the present invention include polyhydric alcohols, sugars, aliphatic amine compounds, alkanolamines, polyamines, aromatic amine compounds, polyhydric phenol compounds, and polyoxyalkyl having a molecular weight of 60 to 5000 as an initiator. Lene polyols; and the like. Preferably, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1, 4-butylene glycol, glycerin, diglycerin, hexatriol, trimethylolpropane, pentaerythritol, sorbitol, textose, sucrose, Methylglycoside, dihydroxydiphenyl ether, dihydroxybiphenyl, hydroquinone, resorcin, pologlycine, naphthalindiol, aminophenyl, iminonaphthol, phenolformaldehyde condensate, methyldiethanolamine, Ethyldiisopropanolamine, monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, propylenediamine, hexamethylenediamine, bismethane, aniline, toluidine, tolylenediamine, diphenylmethanediamine, naphthalindiamine and the like are selected from compounds 1 type, or 2 or more types of compounds.

In addition, a hydrocarbon compound, ketones or ethers may be used as the solvent, for example, metaol or ethyl acetate may be preferably used.

In the step of preparing the recycled polyurethane product in the present invention by stirring the mixture of 80 to 200 parts by weight of isocyanate compound, 0.1 to 1.0 parts by weight of safety agent, 0.5 to 3.0 parts by weight of catalyst based on 100 parts by weight of DMT slurry base polyol It is characterized by adding to the scrap 500 ~ 800 parts by weight of the polyurethane foam to react.

The isocyanate compound used in the present invention may be, for example, 2,4-tolylenediisoisonate, 2,6-tolylenediisoyanate, or a mixture thereof, 4,4'-diphenylmethane diisoa Nate, 2,4'- diphenylmethane diisocyanate, 2,2'- diphenylmethane diisocyanate, an isomer mixture of diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, dicyclohexyl methane diisocyanate, etc.

In addition, a tertiary amine compound may be used as the catalyst used in the reaction of the DMT slurry-based polyol and isocyanate. For example, dimethylcyclohexylamine (DMCHA), tetramethylenediamine (TMHDA), pentamethylenediethylenediamine (PMDETA), terraethylenediamine (TEDA), and the like, each of these catalysts is characterized by the characteristics of the product. It is preferable to use two or more types of catalysts in combination because they only serve to promote specific reactions in the production of urethane foams. In this case, the amount of catalyst used is preferably 0.5 to 6 parts by weight, more preferably 0.5 to 3.0 parts by weight based on 100 parts by weight of the DMT slurry base polyol component.

The stabilizer is a surface active agent containing an organosilicon component and fluorine which are commonly used, and preferably a polyalkylene glycol silicone block copolymer is used. Such stabilizer is preferably used in an amount of 0.1 to 1 parts by weight based on 100 parts by weight of the DMT slurry base polyol component.

In addition, in the step of producing a recycled polyurethane product according to the present invention may be added an appropriate amount of blowing agent, foam stabilizer and flame retardant. As the blowing agent, a fluorocarbon foaming agent or an alternative blowing agent such as HCFC-141b, cyclopentane, or the like may be used. As the foaming agent, L-5420 (Witco) or B-8404 (Glodschmidt) may be used. For example, tris (2,4-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2-chloroethyl) phosphate, chlorinated organic polyphosphate, tris (polyoxyalkylene) phosphate, tris (chlorinated polyol) ) Phosphonates, trichlorobutylene oxide polyether polyols and the like can be used.

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

In an embodiment of the present invention, 50 to 100 diol (Diol), which is an active hydrogen material, is based on 100 parts by weight of DMT slurry generated in a DMT manufacturing process in a 5L flask equipped with a thermometer, a reflux cooler, a nitrogen reflux device, and an agitator. 1 part by weight to 200 parts by weight of ethyl acetate (Ethylacetate) as a solvent, and completely melted in a temperature range of 90 ~ 100 ℃.

Then, the reaction is slowly raising the temperature, completely reacted at a temperature range of 180 ~ 250 ℃ and then cooled to prepare a DMT slurry base polyol produced as a by-product.

As such, the activated hydrogen materials used to prepare the DMT slurry base polyols are diols, polyhydric alcohols, and diamines. For example, ethylene glycol, 1,4-butanediol, glycerin, trimethylolpropane, ethylenediamine, 1,6- Hexamethylenediamine and the like. And the preferred activated hydrogen material used to prepare the DMT slurry base polyol is a diol represented by the following formula (Diol).

(N is an integer of 1 or more in the formula, R1, R2 is a linear, non-linear hydrocarbon compound)

Then, 50 to 100 parts by weight of the DMT slurry base polyol prepared as described above and 80 to 200 parts by weight of tolylene diisoisanate (TDI), an isocyanate compound, and 0.1 to 1.0 weight of a polyamethylene glycol silicone block copolymer as a stabilizer as an additive. In addition, a mixture of 0.5 to 3.0 parts by weight of a dimethylcyclohexylamine (DMCHA), which is a catalyst, is stirred and added to 500 to 800 parts by weight of scrap of waste polyurethane foam to produce a recycled hard polyurethane product.

Recycled polyurethane products made from the DMT slurry base polyol and waste polyurethane foam scraps produced from such DMT slurry have no difference in the properties and the properties of polyurethane manufactured using the existing DMT. It is possible to greatly reduce the.

In addition, it is possible to fundamentally prevent the environmental pollution caused by incineration or landfill of DMT slurry and waste polyurethane foam.

Example 1

Accurately weigh 1400 g of DMT slurry, 1,400 g of diol and 2,000 g of ethyl acetate into a 5 L flask equipped with a thermometer, reflux condenser, nitrogen reflux cabinet and agitator, and melt completely at 100 ° C. Thereafter, while slowly raising the temperature, the produced methanol (CH3OH) and the like were discharged through a cooler at about 180 ° C.

The temperature is continuously increased while discharging methanol, and when no more methanol is discharged at a maximum of 250 ° C., the reaction is terminated, cooled to room temperature, and the OHV, viscosity and solid content of the final product are measured and the results are shown in Table 2. It was.

According to the specification of the DMT slurry base polyol shown in Table 2, it can be seen that there is no difference from the specification of the conventional DMT base polyol products typically used in the production of polyurethane.

Example 2

30 g of ethylene glycol (Ethyleneglycol), which is a substance having activated hydrogen prepared in advance in 70 g of the DMT slurry base polyol obtained in Example 1, various additives (foaming agent HCFC-141b 38g, foaming agent L-5420 1g, catalyst dimethylcyclohexylamine 2g) , 0.5 g of stabilizer polyacylene glycol silicone block copolymer, 3.5 g of other flame retardant tris (2,4-dichloropropyl) phosphate, etc.) were mixed to form a premixture, and then 145 g of tolylene diisocyanate was mixed. Put in a mold of a certain shape to produce 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 3.

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 4 below.

Comparing the physical properties of the rigid polyurethane foam (Inventive Material 1) manufactured with the DMT slurry base polyol as a raw material and the physical properties of the comparative material, it is understood that the physical properties of the Inventive Material 1 in each item never fall as compared with those of the comparative material. Able to know.

Example 3

After stirring the mixture of 100 g of DMT slurry base polyol prepared in Example 1 and 120 g of tolylene diisocyanate, 0.5 g of polyaylene glycol silicone block copolymer as a stabilizer, and 1.0 g of dimethylcyclohexylamine as a catalyst, the waste poly 750 g of the urethane foam scrap was added to the reaction and put into a mold of a predetermined form to produce a hard polyurethane product recycled.

The physical properties of the recycled hard polyurethane product thus prepared (Inventive Material 2) were measured and the results are shown in Table 5.

When comparing the physical properties of the polyurethane product (Inventive Material 2) prepared by using the DMT slurry base polyol and the waste polyurethane foam scrap and the physical properties of the comparative material measured in Example 2, the physical properties of the Inventive Material 2 in each item It can be seen that it never falls in comparison with the physical properties of this comparative material.

As described above, according to the present invention, the DMT slurry base polyol obtained by chemically treating the DMT slurry, which is a by-product generated in the DMT manufacturing process, can be recycled into a material having activated hydrogen which is a raw material of polyurethane. Environmental and air pollution from disposal and incineration is prevented at the source.

In addition, selecting isocyanate compounds and various additives corresponding to the DMT slurry base polyols enables the regeneration of substantially discarded polyurethane foams.

In addition, since the physical properties and processability of polyurethane products based on DMT slurry-based polyols manufactured from DMT slurry are not significantly different compared to those of existing products, production costs are significantly lowered, thereby increasing competitiveness. .

Claims (4)

Using a solvent, the DMT slurry and the activated hydrogen substance having a molecular weight of 60 to 5000 are completely melted at a temperature range of 90 to 100 ° C., and then slowly reacted in a temperature range of 180 to 250 ° C. while gradually warming up, followed by cooling. To produce a DMT slurry-based polyol; A mixture of an isocyanate compound and various additives in the DMT slurry base polyol is added to the scrap of waste polyurethane foam, which has been quantified in advance, and then stirred and mixed to make recycled rigid polyurethane products into a mold of a certain type. Method for producing a polyurethane using a dimethyl terephthalate by-product comprising the step. The method of claim 1, Activated hydrogen material used to prepare the DMT slurry-based polyol is a method for producing a polyurethane using dimethyl terephthalate by-product, characterized in that the diol represented by the following formula. (N is an integer of 1 or more in the formula, R1, R2 is a linear, nonlinear hydrocarbon compound) According to claim 1, wherein the step of preparing the DMT slurry base polyol dimethyl, characterized in that 50 to 100 parts by weight of activated hydrogen material having a molecular weight of 60 to 5,000 and 1 to 200 parts by weight of the solvent is mixed with respect to 100 parts by weight of DMT slurry Method for producing polyurethane using terephthalate by-product. According to claim 1, In the step of preparing the recycled polyurethane product 80 to 200 parts by weight of isocyanate compound, 0.1 to 1.0 parts by weight of stabilizer as an additive, 0.5 to 3 parts by weight of a catalyst based on 100 parts by weight of DMT slurry base polyol A method for producing a polyurethane using dimethyl terephthalate by-products, characterized in that by stirring to add to the scrap 500 ~ 800 parts by weight of the waste polyurethane foam.