KR101159856B1 - Method for preparing polyester resin having fast crystallization - Google Patents

Abstract

In the polymerization of polyester-based polymers, particularly polyesters using antimony-based catalysts, the preparation of the catalyst greatly influences the physical properties of the polyester. In particular, the present invention provides a method for preparing a polyester resin for use in applications requiring rapid crystallization. It relates to a specific preparation method of the antimony catalyst solution to which the amine compound is added. The present invention is applied to the preparation of a catalyst solution made of antimony triacetate and antimony trioxide, which are antimony catalysts for general use.

Description

Method for preparing polyester resin with fast crystallization {Method for preparing polyester resin having fast crystallization}

The present invention relates to a process for producing polyethylene terephthalate (PET), which is used as a raw material for transparent packaging containers, to have a high crystallization rate. More specifically, it is related with the method of adjusting the atmosphere of the catalyst solution prepared by melt | dissolving in ethylene glycol (EG) with a certain additive.

Since polyester has excellent mechanical strength, heat resistance, transparency and gas barrier property, polyester is most suitable as a material for beverage filling containers such as juices, soft drinks, carbonated drinks, packaging films, audio, and video films. Is being used.

It is also used in large quantities on a global scale as an industrial material for medical fibers and tire cords.

As a method of improving the heat resistance of a polyester bottle for beverage, a method has been proposed in which the bottle cap is heat treated to increase the degree of crystallinity or heat-set the stretched bottle. In particular, when the crystallization of the stopper part is insufficient or the variation in the degree of crystallinity is large, the sealability with the stopper may deteriorate, and leakage of the contents may occur. In addition, when the degree of crystallinity of the shoulder, the trunk and the like of the bottle is insufficient, thermal deformation may occur and product value may be lowered.

Specifically, in the case of beverages requiring heat charging, such as juice drinks, oolong tea, mineral water, etc., a method of crystallizing by heat-treating the stopper of the preform or molded bottle (Japanese Patent Publication No. 55-79237) Japanese Patent Application Laid-Open No. 58-110221). In the case of heating and crystallizing the preform stopper in the amorphous state, the so-called spherical crystallization is promoted and the stopper appearance becomes white, but the crystallinity is increased to improve the heat resistance (that is, the heat deformation temperature is high). Moreover, in order to improve the heat resistance of a bottle trunk part, the method of heat-processing by making temperature of a stretch blow mold high temperature is employ | adopted (Japanese Patent Publication No. 59-6216).

When heat treatment is performed by contacting the shoulder and the body of the bottle obtained by stretching blow such a preform with a high temperature mold wall surface, in addition to the orientation crystallization by the stretching blow, the formation of microcrystals having a small crystal grain size is promoted, resulting in high crystallinity. The heat resistance of the bottle can be improved.

Such a method, that is, a method of heat-treating the plug portion and the shoulder portion to improve the heat resistance, preferably has a high crystallization rate PET that can be processed in a short time at low temperature due to the time of crystallization treatment and the temperature greatly affecting the productivity. Do. On the other hand, the trunk portion is required to be transparent even if the heat treatment during molding is performed in order not to deteriorate the color tone of the contents of the bottle, and in terms of designability, and the opposite characteristics are required at the stopper portion and the trunk portion.

In general, a catalyst solution prepared by dissolving while heating in ethylene glycol has a problem in that the solubility is lowered after a certain period of time or after a certain time in cooling at room temperature, so that the catalyst is precipitated and dissolves well even when heated again. Thus, there is a risk that the prepared catalyst solution must be kept at a high temperature under continuous heating or warming conditions.

The present invention relates to a catalyst preparation method which speeds up the crystallization rate of polymerized polyester while preventing the dissolved antimony catalyst from being precipitated and reducing the reactivity.

In order to achieve the above object, the present invention is the configuration of the main invention to induce the production of antimonate salt using a certain additive in the atmosphere of the catalyst solution. Here, the additive to be used is an amine-based compound, such as triethylamine [TEA (Triethylamine)], triethylamine hydroxide [TEAH (Triethylamin hydroxide)], ammonia (Amonia), and the like. Ethylamine was used.

Catalyst composition for producing polyester according to the invention is characterized in that it comprises 100 parts by weight of the diol compound, 0.3 to 1.5 parts by weight of the antimony compound and 8 to 30 parts by weight of the amine compound.

Preferably, the antimony compound is selected from the group consisting of antimony trioxide and antimony triacetate.

Preferably, the amine compound is selected from the group consisting of triethylamine, triethylamine hydroxide, ammonia and mixtures thereof.

Preferably, the diol compound is selected from the group consisting of ethylene glycol, diethylene glycol (diethylene glycol), propylene glycol (propylene glycol), butylene glycol (polyglycol) thereof It is done.

Method for producing a catalyst for producing polyester according to the present invention,

(a) dissolving 0.3-1.5 parts by weight of the antimony compound in 100 parts by weight of the diol compound; And

(b) adding 8 to 30 parts by weight of the amine compound to a solution in which the antimony compound is dissolved;

Characterized in that it comprises a.

The polyester resin according to the present invention is characterized in that it is prepared by the polycondensation reaction in the presence of the esterification reaction of the carboxylic acid component and the diol component and the catalyst according to claim 1.

Hereinafter, the present invention will be described in detail.

The antimony compounds used in the examples of the present invention are antimony trioxide and antimony triacetate, and the solvent for dissolving the catalyst was ethylene glycol. In addition, triethylamine was used as an additive to control the atmosphere of the catalyst solution. The catalyst solution prepared by using triethylamine has the advantage of being transparent and not easily precipitated. When the solution is added to the precipitated catalyst solution and dissolved therein, the solubility increases to be transparently dissolved again.

Here, ethylene glycol, an antimony compound, and an additive can be prepared by throwing them in from the beginning. However, if the additives are prepared at a low temperature of 100 ° C. or less to prevent scattering, the reaction time is long because the solubility decreases. Therefore, the preparation of the catalyst with ethylene glycol and an antimony compound at a high temperature first and then cooling the additives is necessary. desirable.

The additive amount of the additive is 8 to 30 parts by weight, preferably 10 to 20 parts by weight, based on mass based on the ethylene glycol used. If the added amount is less than 8 parts by weight, the solution atmosphere control effect is small, the prepared catalyst solution is opaque, when the amount exceeds 30 parts by weight there is a problem that the solution is yellow with a strong smell.

In this case, the amount of antimony-based compound used depends on the method and the amount to be added to the polymerization process, but for precise injection, it is generally prepared in an amount of 0.3 to 1.5 parts by weight based on ethylene glycol.

Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples. The following examples are intended to illustrate the present invention more specifically, but the scope of the present invention is not limited by the following examples.

Comparative Example 1

100 ml of ethylene glycol was added to the Erlenmeyer flask, and 0.65 g of antimony trioxide was added to mount the Erlenmeyer flask with a cooling condenser on a hot plate to dissolve the catalyst while maintaining an internal temperature of 120 占 폚 to prepare a catalyst solution.

200 g of terephthalic acid and 90 g of ethylene glycol were added to a three-necked circular flask reactor and stirred well to prepare a slurry. The slurry was stirred at 30 rpm while maintaining the internal temperature of 265 ° C. using a heating mantle. Then, nitrogen was introduced into the reactor to circulate nitrogen by allowing a certain amount of nitrogen to flow under pressurization of about 0.2 bar into the nitrogen atmosphere. The ester reaction was completed by using the condenser as the end point of the water, which is no longer a byproduct of the reaction.

After the ester reaction was completed, 100ppm of the antimony trioxide catalyst prepared above was added to the reactor, 0.1torr vacuum was slowly applied, and the condensation polymerization reaction was performed for 1 hour while maintaining the reactor internal temperature at 280 ° C. The polycondensation reaction was carried out while controlling the output of the stirrer in consideration of the decrease in the stirring speed according to the rise of the viscosity of the reactant as the reaction time elapsed, while maintaining the stirring speed at a constant 30rpm. The polycondensation reaction of which condensation polymerization was completed was quenched in a bath containing cold water to prepare polyethylene terephthalate. After drying the prepared sample of polyethylene terephthalate, a flat specimen having a thickness of 2 mm was injection molded to measure color, and crystallization temperature was measured by DSC.

Example 1

100 ml of ethylene glycol was added to the Erlenmeyer flask, and 0.65 g of antimony trioxide was added, and the Erlenmeyer flask was equipped with a cooling condenser on a hot plate to dissolve the catalyst while maintaining an internal temperature of 120 占 폚 to prepare a catalyst solution. After completion of the catalyst dissolution, the temperature was lowered to 50 ° C., the flask was wrapped with silver foil, and then 10 g of triethylamine was added thereto, followed by stirring for 1 hour. Polymer polymerization was carried out according to the comparative example above, and the color was measured by molding the same injection specimen, and the crystallization temperature was measured by DSC.

Example 2

A catalyst was prepared in accordance with Example 1, and 15 g of triethylamine was added thereto, followed by stirring for 1 hour. Polymer polymerization was carried out according to the comparative example above, the same injection specimen was molded and the color was measured, and the crystallization temperature was measured by DSC.

Example 3

A catalyst was prepared according to Example 1, 20 g of triethylamine was added thereto, and the mixture was stirred for 1 hour. Polymer polymerization was carried out according to the comparative example above, and the color was measured by molding the same injection specimen, and the crystallization temperature was measured by DSC.

No. Color-L (whiteness) Color-b Crystallization temperature Crystallization peak size Comparative Example 1 91.1 2.4 167 ℃ 30 J / g Example 1 89.7 2.9 156 ℃ 25 J / g Example 2 88.3 3.2 150 ℃ 22 J / g Example 3 86.5 4.1 145 ℃ 15 J / g

From Table 1, it can be seen that in the case of the embodiment polymerized using the catalyst preparation method used in the present invention, the crystallization temperature is lower and the size of the crystallization peak is smaller than that of the comparative example which is not used, so that the crystallization rate has a high physical property.

As described above, the color and crystallization properties of the polyester could not be controlled by the commonly used catalyst dissolution method. However, the catalyst preparation mentioned in the present invention can be used to prepare polyester resins for applications requiring high crystallization rates by controlling color and crystallization rate.

Claims (9)

As a catalyst composition for polyester manufacture containing 100 weight part of diol compounds, 0.3-1.5 weight part of antimony compounds, and 8-30 weight part of amine compounds, The diol compound is selected from the group consisting of ethylene glycol, diethylene glycol, dipropylene glycol, propylene glycol, butylene glycol, and poly glycols thereof, The antimony compound is selected from the group consisting of antimony trioxide and antimony tri acetate, and The amine-based compound is selected from the group consisting of triethylamine (triethylamine), triethylamine hydroxide (triethylamine hydroxide), ammonia (ammonia) and mixtures thereof, catalyst composition for polyester production. delete delete delete (a) dissolving 0.3-1.5 parts by weight of the antimony compound in 100 parts by weight of the diol compound; And (b) adding 8 to 30 parts by weight of the amine compound to a solution in which the antimony compound is dissolved; As a method for producing a catalyst for producing a polyester containing, The diol compound is selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, butylene glycol and polyglycols thereof; The antimony compound is selected from the group consisting of antimony trioxide and antimony tri acetate, and The amine-based compound is triethylamine, triethylamine hydroxide, ammonia and a method for producing a catalyst for producing a polyester which is selected from the group consisting of a mixture thereof. delete delete delete A polyester resin produced by a polycondensation reaction in the presence of an esterification reaction of a carboxylic acid component and a diol component and a catalyst according to claim 1.