KR20120135971A - Recycling method of polyol for producting polyurethane with superior mechanical properties - Google Patents

Abstract

PURPOSE: A regenerating method of polyol is provided to economically regenerate polyol which can prepare polyurethane with excellent physical property such as density, compressive strength, etc. CONSTITUTION: A regenerating method of polyol comprises: a step of preparing waste polyurethane scraps; a step of preparing a propylene oxide adduct and glycol; a step of stirring the propylene oxide adduct and glycol in a reactor; a step of increasing the temperature of the reactor and injecting ammonia into the reactor; a step of putting the waste polyurethane scrap into the reactor and regenerating polyol through a reaction; and a step of mixing the regenerated polyol and propylene oxide and maintaining a reaction temperature of 65-75 °C. [Reference numerals] (AA) Preparing waste polyurethane scrap; (BB) Preparing oxide adduct and glycol; (CC) Mixing; (DD) Injecting ammonia; (EE) Injecting scrap; (FF) Regenerating polyol; (GG) Mixing polyol and propylene oxide; (HH) Reaction; (II) Maturing

Description

Recycling method for producing polyurethane with excellent physical properties {RECYCLING METHOD OF POLYOL FOR PRODUCTING POLYURETHANE WITH SUPERIOR MECHANICAL PROPERTIES}

The present invention relates to a polyol regeneration method for producing a polyurethane having excellent physical properties.

In general, polyurethane is produced by a chemical reaction between a polyol having a hydroxyl group (-OH) and a material having an isocyanate group (-NCO-), and is a polymer material having a crosslink in a urethane three-dimensional network. Polyurethane foam uses the heat of reaction generated in the polymerization step of diisocyanate and polyol to vaporize the physical blowing agent or bubbles generated by the reaction of diisocyanate with chemical blowing agent to undergo solidification by growth, stabilization and curing. Is generated.

Polyols are alcohols having three or more hydroxyl groups in a molecule, mainly aromatic polyether polyols having aromatics in the main chain and aliphatic polyester polyols having aliphatic in the main chain, and diisocyanates are m-phenylene diisocyanate and p-phenylene. Diisocyanate, toluene diisocyanate, methylene diisocyanate and the like are used.

Due to their outstanding properties, polyurethanes are used today for soft cushioning materials such as clothing, shoes, sofas, beds, car seats, etc. In addition, it is used as an elastomer, an adhesive, a coating agent, and the like, such as flooring material, land track packing (sealing), sealant (sealant) and the like.

Polyurethanes are classified into thermoplastic and thermosetting resins, whereas thermosetting polyurethanes are relatively easy to recycle, whereas thermosetting polyurethanes are difficult to recycle. There are physical and chemical methods for regeneration of thermosetting polyurethane, and chemical methods include depolymerization of polyurethane using solvent, hydrolysis with water, depolymerization with glycols, and depolymerization with amines. Etc. Since the hydrolysis method among chemical methods is low in economic efficiency, the method of regenerating a polyol by the method of depolymerizing a polyurethane attracts attention.

It is an object of the present invention to provide a method for regenerating a polyol capable of producing a polyurethane having excellent physical properties.

Another object of the present invention is to provide a polyol regeneration method capable of economically regenerating polyols.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the particular embodiments that are described. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, There will be.

The present invention for achieving the above object is a first step of preparing a waste polyurethane scrap; A second step of preparing 45 to 100 parts by weight of propylene oxide adduct and 0.01 to 30 parts by weight of glycol with respect to 100 parts by weight of the waste polyurethane scrap; A third step of adding the prepared propylene oxide adduct and glycol to a reactor and stirring the mixture; A fourth step of injecting 0.1 to 30 parts by weight of ammonia with respect to 100 parts by weight of the glycol in the reactor under an environment of 3 to 17 atmospheres after the temperature is raised to 100 to 230 ° C; A fifth step of regenerating the polyol by injecting the waste polyurethane scrap into the reactor in which the ammonia is introduced to bubble and reacting for 1 to 15 minutes; And a sixth step of controlling the reaction temperature to maintain 65 ° C to 75 ° C after mixing the regenerated polyol and propylene oxide.

The propylene oxide adduct is preferably a propylene oxide adduct containing either sorbitol or ethylene diamine.

The regenerated polyol and propylene oxide are mixed at a ratio of 1: 0.3 to 3.

The sixth step may further include the step of aging for 5 to 6 hours at a temperature of 60 ℃ to 75 ℃ after the recycled polyol and propylene oxide.

According to the present invention, the functional group of the regenerated polyol is increased to increase the degree of crosslinking in the reaction of isocyanate to produce a polyurethane having excellent physical properties such as density, compressive strength, and the like, and furthermore, the polypropylene having better mechanical properties due to the inclusion of propylene oxide. Urethane can be prepared.

1 is a flow chart showing a polyol regeneration method of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Detailed descriptions of well-known functions and constructions that may unnecessarily obscure the gist of the present invention will be omitted.

Polyol regeneration method from the waste polyurethane of the present invention,

a) preparing waste polyurethane scrap;

b) preparing 45 to 100 parts by weight of propylene oxide adduct and 0.01 to 30 parts by weight of glycol relative to 100 parts by weight of the waste polyurethane scrap;

c) adding prepared propylene oxide adduct and glycol to the reactor and stirring;

d) injecting 0.1 to 30 parts by weight of ammonia with respect to 100 parts by weight of the glycol in the reactor after raising the temperature to 100 to 230 ° C .;

e) injecting waste polyurethane scrap into the reactor in which bubble was generated by ammonia injection and reacting for 1 to 15 minutes to regenerate the polyol; And

Mixing the regenerated polyol and propylene oxide and controlling the reaction temperature to maintain 65 ° C to 75 ° C;

.

Waste polyurethane used as a raw material in the present invention can be used as long as it is a rigid polyurethane irrespective of its type, such as a refrigerator, a freezing container, a double-insulated heat insulating tube, an insulation material for an L & G storage tank, and after washing the waste hard polyurethane Use small pieces of crushed scrap.

The glycol is selected from ethylene glycol, propylene glycol, dipropylene glycol, a copolymer of ethylene glycol and propylene glycol as a solvent, and preferably 0.01 to 30 parts by weight based on 100 parts by weight of the waste polyurethane scrap. . If the amount used is less than 0.01 part by weight, the function as a solvent is inferior, and if it exceeds 30 parts by weight, it is added to the propylene oxide adduct and the solvent is used in excess, so that a special effect cannot be expected.

Propylene oxide adduct is a main component that satisfies solvent function, functional group increasing function, and polyurethane production function with excellent physical properties. The propylene oxide adduct containing either sorbitol or ethylene diamine is used, thereby greatly improving the above three functions. Satisfy.

The propylene oxide adduct is preferably used in an amount of 45 to 100 parts by weight based on 100 parts by weight of the waste polyurethane scrap. If the amount used is less than 45 parts by weight, it is difficult to expect the solvent function, functional group increase function, mechanical properties improvement function, if the amount is more than 100 parts by weight a polyol having a very high functional group, etc. is produced, there is a fear that the physical properties of the polyurethane is lowered. .

Waste polyurethane scrap is decomposed by contact with ammonia. Ammonia is injected into the reactor in liquid or gaseous form to degrade waste polyurethane. In the state where the agitator in the reactor is heated to 100 ° C to 230 ° C, ammonia is injected to cause bubbles, and then the waste polyurethane scrap introduced is decomposed.

At the time of ammonia introduction, the reactor is placed under an environment of 3 to 17 atmospheres, and the stirring is continuously heated while ammonia is injected. As such, the use of ammonia as the waste polyurethane disintegrator facilitates the obtaining of the polyurethane disintegrant, and greatly shortens the reaction time, thereby obtaining significant economic benefits.

Ammonia is preferably used 0.1 to 30 parts by weight based on 100 parts by weight of glycol. If the amount used is less than 0.1 part by weight based on 100 parts by weight of glycol, it is difficult to expect a reaction with the waste polyurethane scrap, and if it exceeds 30 parts by weight, no special effect on the reaction can be expected.

Waste polyurethane scrap is introduced into the bubbled reactor by ammonia injection, and when the reaction takes place for 1 to 15 minutes, the polyol reacting with isocyanate to produce fresh polyurethane is regenerated from the waste polyurethane.

That is, the reaction is carried out in an autoclave equipped with a stirring device and a temperature control device, and ammonia is injected into a stirring material of propylene oxide adduct and glycol, that is, a solvent. The pressure is 3 to 17 atmospheres, under which the stirring is heated while ammonia is injected. When the ammonia is bubbled through the heated agitator, the scrapped polyurethane foam is put into the agitated compound mixed with ammonia, and when the reaction occurs for 1 to 15 minutes, the functional group is increased and the mechanical properties are excellent. Polyols that can produce are recycled. As such, when the regeneration process of the polyol is completed, the first process is completed.

The polyol obtained through the first process is regenerated into a polyol which can react with propylene oxide to produce a polyurethane having better mechanical properties. At this time, the reaction temperature is controlled to maintain 65 ℃ to 75 ℃. The propylene oxide is preferably mixed in a ratio of 1: 0.3 to 3 in terms of the mechanical properties of the polyurethane obtained by the subsequent reaction of the polyol with isocyanate. When propylene oxide is mixed in less than 0.3 ratio, it is difficult to expect the improvement of mechanical properties from the polyurethane obtained by reaction of the polyol with isocyanate, and when exceeding 3 ratio, it is impossible to expect a more special effect on the physical properties. After the reaction is completed, a process of aging for 5 to 6 hours at a temperature of 60 to 75 ℃ is carried out, thereby achieving stabilization of the molecule.

That is, the reaction is carried out in an autoclave equipped with a stirring device and a temperature control device, and the polyol and propylene oxide obtained in the first step are mixed at a ratio of 1: 0.3 to 3. When the reaction temperature is controlled to maintain 65 ℃ to 75 ℃, the process of maturing for 5 to 6 hours at a temperature of 60 ℃ to 75 ℃ after the reaction is complete, a polyol capable of producing a polyurethane having more mechanical properties The second process of regenerating is completed.

When explaining this invention based on an Example, it is as follows and it turns out that this invention is not limited by the Example.

1st process

55 g of propylene oxide adduct containing sorbitol and 25 g of glycol were added to an autoclave equipped with a cooler, a gas injection tube, a stirring device, and a temperature controller, and stirred. The stirring was heated to 150 ° C. Subsequently, when the temperature of the stirred solution reached 150 ° C, 6 g of ammonia gas was injected through a gas injection tube under an atmosphere of 5 atmospheres. When ammonia gas was injected and bubbles were generated, 100 g of polyurethane scrap obtained from the waste refrigerator was slowly added through a cooler and reacted for 10 minutes to obtain a polyol.

The autoclave was carried out in the same manner as in Example 1 except that 75 g of propylene oxide adduct containing sorbitol, 23 g of glycol, and 5 g of ammonia were added.

The autoclave was carried out in the same manner as in Example 1 except that 100 g of propylene oxide adduct containing sorbitol, 20 g of glycol, and 4 g of ammonia were added.

The autoclave was carried out in the same manner as in Example 1 except that 45 g of propylene oxide adduct containing sorbitol, 27 g of glycol, and 8 g of ammonia were added.

The autoclave was carried out in the same manner as in Example 1 except that 55 g of propylene oxide adduct containing sorbitol, 25 g of glycol, and 7 g of ammonia were added.

The autoclave was carried out in the same manner as in Example 1 except that 75 g of propylene oxide adduct containing ethylene diamine, 23 g of glycol, and 6 g of ammonia were added.

The autoclave was carried out in the same manner as in Example 1 except that 100 g of propylene oxide adduct containing ethylene diamine, 20 g of glycol, and 5 g of ammonia were added.

It carried out similarly to Example 1 except having added 45 g of propylene oxide addition products containing ethylene diamine, 27 g of glycols, and 3 g of ammonia to an autoclave.

The autoclave was carried out in the same manner as in Example 1 except that 55 g of propylene oxide adduct containing ethylene diamine, 25 g of glycol, and 5 g of ammonia were added.

The autoclave was carried out in the same manner as in Example 1 except that 75 g of propylene oxide adduct containing ethylene diamine, 23 g of glycol, and 2 g of ammonia were added.

Table 1 shows the composition of the components used in the first step.
Propylene Oxide Additives Containing Sorbitol
(g)


Glycol
(g)

Ammonia gas
(g)

Waste Polyurethane Scrap
(g)
Example 1
55
25
6
100
Example 2
75
23
5
100
Example 3
100
20
4
100
Example 4
45
27
8
100
Example 5
55
25
7
100
Propylene Oxide Additives Containing Ethylene Diamine
(g)


Glycol
(g)

Ammonia gas
(g)

Waste Polyurethane Scrap
(g)
Example 6
75
23
6
100
Example 7
100
20
5
100
Example 8
45
27
3
100
Example 9
55
25
5
100
Example 10
75
23
2
100

Second Step

100 g of polyol and 120 g of propylene oxide obtained in Example 1 were added to an autoclave equipped with a stirring device and a temperature controller, and the reaction temperature was maintained at 65 ° C. After the reaction was completed, it was aged for 6 hours at a temperature of 60 ℃.

100 g of polyol and 30 g of propylene oxide obtained in Example 6 were added to an autoclave equipped with a stirring device and a temperature control device, and the reaction temperature was maintained at 65 ° C. After the reaction was completed, it was aged for 6 hours at a temperature of 60 ℃.

[Experimental Example 1]

Each of the polyols obtained through Example 11 or Example 12 was added at 20 wt% of the new polyol to synthesize a rigid polyurethane foam. The isocyanate used in the polyurethane synthesis was polymeric MDI with 31 ± 0.5% NSF index of BASF, and the surfactant was used as a silicon based surfactant (B-8404) of Goldschmidt, and the catalyst was dimethylcyclohexylamine (PC of Air products). -8) and 33% triethylenediamine + 67% dipropylene glycol (33LV) were used in combination, and HFC-365mfc was used as the blowing agent. The amount of the material used for foaming is as follows.

GP-280 80g

Example 11 or 12 20 g

Distilled water 0.7pph

1.7pph surfactant

PC-8 0.6pph

33-LV 0.5pph

HFC-365mfc 7.4,7.3,7.68,7.93,8.14pph

NCO index (P-MDI, M-20R) 125

To the solution containing the polyol and various additives except MDI, MDI was calculated by NCO index 125 and added by the amount, and then the polyurethane foam was prepared by stirring for 20 seconds at a speed of 3000 rpm for a high speed impeller. Reaction rate was measured by cream time, gel time, tack free time, density was measured by the method of ASTM-D1621. Compressive and tensile strengths were measured using UTM Series Ⅵ model of Rigid Corporation, and glass transition temperature was measured by DSC-2010 model of TA instrument.

As a result of the measurement, the polyurethane foam prepared by adding each polyol obtained in Example 11 or Example 12 by weight ratio of the new polyol did not show a significant difference in reaction rate and mechanical properties regardless of the type of recycled polyol. , This was a result that there is no big difference in the physical properties of the foam prepared only by the new polyol. The glass transition temperature measured to determine the degree of crosslinking was also not different according to the type of the regenerated polyol, and was similar to the glass transition temperature of the foam prepared only with the new polyol. The cause of this similar physical property is interpreted by the action of the hydroxyl value and the amine value, which can affect the physical properties of the foam. As a result, it can be seen that the application of the recycled polyol to foam production does not lead to a significant drop in the physical properties of the foam.

As described above, according to the present invention, the functional group of the regenerated polyol is greatly increased, thereby making it possible to produce a polyurethane having excellent physical properties that is second to the polyurethane produced using the new polyol, and furthermore, due to the inclusion of propylene oxide, It is possible to produce a polyurethane with better physical properties.

In addition, the use of ammonia as the waste polyurethane disintegrating agent makes it easy to obtain a polyurethane disintegrating substance, and can significantly shorten the reaction time to obtain significant economic benefits.

In addition, a large economic benefit can be obtained by reducing the cost of the polyol used in the production of the polyurethane.

The present invention has been described with reference to the preferred embodiments, and those skilled in the art to which the present invention pertains to the detailed description of the present invention and other forms of embodiments within the essential technical scope of the present invention. Could be. The scope of the present invention is defined by the appended claims, and all differences within the scope of the claims are to be construed as being included in the present invention.

Claims (4)

A first step of preparing waste polyurethane scrap;
A second step of preparing 45 to 100 parts by weight of propylene oxide adduct and 0.01 to 30 parts by weight of glycol with respect to 100 parts by weight of the waste polyurethane scrap;
A third step of adding the prepared propylene oxide adduct and glycol to a reactor and stirring the mixture;
A fourth step of injecting 0.1 to 30 parts by weight of ammonia with respect to 100 parts by weight of the glycol in the reactor under an environment of 3 to 17 atmospheres after the temperature is raised to 100 to 230 ° C;
A fifth step of regenerating the polyol by injecting the waste polyurethane scrap into the reactor in which the ammonia is injected to generate bubbles and reacting for 1 to 15 minutes; And
And a sixth step of controlling the reaction temperature to maintain 65 ° C to 75 ° C after mixing the regenerated polyol and propylene oxide.
Polyol regeneration method for producing a polyurethane having excellent physical properties.
The method of claim 1,
The propylene oxide adduct is a polyol regeneration method for producing a polyurethane having excellent physical properties, characterized in that the propylene oxide adduct containing any one of sorbitol or ethylene diamine.
The method of claim 1,
The regenerated polyol and propylene oxide are mixed in a ratio of 1: 0.3 to 3, polyol regeneration method for producing a polyurethane having excellent physical properties.
The method of claim 1,
The sixth step further comprises the step of aging for 5 to 6 hours at a temperature of 60 ℃ to 75 ℃ after the reaction of the regenerated polyol and propylene oxide, polyol regeneration method for producing a polyurethane having excellent physical properties.

Images