KR930006256B1 - Process for preparation of polyester binder - Google Patents

Abstract

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Description

Process for preparing polyester binder

The present invention provides a method for producing a polyester binder (BINDER) used for ink, paint binding and various adhesives, and more specifically, using a polyester to produce a polyester binder having excellent physical properties as a convenient and economical process step. It is about how to.

Polyester binders are widely used as binders and adhesives in all fields because of their excellent physical properties. However, since the method of producing a binder using polyester for a monomer is economically burdensome, methods using pepolyester have been researched and developed in recent years.

U.S. Patent No. 4,578,502 discloses a method for regenerating terephthalic acid and its derivatives by directly decomposing the pepolyester with water or methanol, but it is not a manufacturing method for the polyester binder itself, and the apparatus and process are complicated. .

U.S. Patent No. 4,609,680 and Korean Patent Publication No. 83-2644 disclose methods for decomposing pepolyesters into ethylene glycol to make polyester oligomers (BHT) for use in the following processes, but also for depolymerization. There is a need for a separate reaction tank, and the entire process from the pepolyester to the final product is complicated, and economical efficiency is lowered. As a result, the probability of formation of a side reaction product is increased due to a long reaction at a high temperature, and thus the physical properties of the final product tend to be lowered.

The present invention uses waste polyester such as waste chips, waste sand, waste film, etc., produced during polyester application or film production, and can produce a polyester binder having a simpler, more economical and superior physical properties compared to conventional methods. Is to provide. As a result of the research, the inventors found that the depolymerization conditions of the waste polyester pulverized product and the catalyst were controlled to be the same as the esterification reaction, and the polymer was easily satisfied by satisfying the conditions of simultaneously proceeding the depolymerization of the waste polyester and the esterification reaction of the monomer at the same time. It was confirmed that a polyester binder of physical properties can be prepared.

According to the present invention, (a) ethylene glycol and neopentyl glycol are added to the waste polyester pulverized product, and at least one of isophthalic acid, adipic acid or esters thereof is added as a dicarboxylic acid component, and as a catalyst. Using zinc acetate, calcium acetate, germanium oxide or a mixed catalyst of 100ppm to 400ppm and reacting at 180 ° C to 240 ° C for 2-4 hours; (b) A method for producing a polyester binder is provided which comprises adding a heat stabilizer and a polymerization catalyst to a reaction mixture and polymerizing in a high vacuum at 270-300 ° C. Polyester binders produced by the process of the present invention are generally about 15-35 mole percent terephthalic acid 15-25 mole percent isophthalic acid, 20 mole percent or less adipic acid, 20-30 mole percent ethylene glycol and It contains 20-30 mole% of neopentin glycol, although adipic acid may not optionally be included.

In the present invention, the waste polyester component is preferably used sand, waste chips or waste film. The waste sand or waste chips are 50 mesh or less, and the waste film is ground to a size of 3 mm x 3 mm or less.

In the production method of the present invention, the depolymerization of the polyester and the esterification of the monomers are simultaneously performed in step (a). When isophthalic acid, adipic acid or a mixture thereof is used as the acid component in the reaction, the molar ratio of (ethylene glycol + neopentyl glycol) to (waste polyester + acid component) is about 1.3-1.7: 1, and the reaction temperature is 180-220 ℃, the reaction pressure is 1-2atm, the reaction time is preferably 2-4 hours.

On the other hand, when isophthalic acid ester, adipic acid ester, or a mixture thereof is used as the acid component in the reaction, the molar ratio of (ethylene glycol + neopentyl glycol) to (waste polyester + acid ester) is about 1.5-2.0: 1. , The reaction temperature is 200-240 ℃, the reaction temperature is atmospheric pressure, the reaction time is preferably 2-4 hours. If the amount of glycol, the amount of added catalyst, or the temperature is higher than this condition, the physical properties of the polyester binder may deteriorate, such as by-products increase, diethylene glycol (DEG) content increases, and color decreases. On the other hand, if the amount of glycol, the amount of input catalyst, or the reaction temperature is low, the copolymer may be formed in the resultant product, and the solvent solubility and adhesion of the polyester binder may be deteriorated.

In the preparation method step (b) of the present invention, the thermal stabilizer and the polymerization catalyst may be any one well known in the art, the preferred thermal stabilizer is trimethyl phosphate, the preferred polymerization catalyst is intimon oxide, and the amount of use is It is the same. As described above, in the preparation method of the present invention, the depolymerization conditions and the catalyst conditions of the waste polyester are matched with the monomer esterification reaction conditions, thereby simultaneously proceeding the waste polyester depolymerization and the monomer esterification reaction, so that the physical properties are changed through a simple process step. It is possible to produce improved polyester binders. Preferred polyester binders prepared according to the present invention have the following physical properties.

A) Molecular weight: 15,000-30,000

B) Glass transition temperature (Tg): 5 ℃ -70 ℃

C) Intrinsic viscosity (Ⅳ): 0.60-0.80

D) DEG content: 0.5-20.%

E) Color: Pale Yellow

Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1

Into the reactor, 320g of waste polyester film pulverized product, 250g of isophthalic acid, 190ml of ethylene glycol, 190g of neopentylglycol and 0.1g of zinc acetate as a catalyst were sealed and sealed at a reaction temperature of 210 ° C and a reaction pressure of 1.5atm under a nitrogen engine. The reaction was carried out for 3 hours. 0.3 g of trimethyl phosphate and 0.3 g of antimony oxide were added to the water and the reaction mixture under reduced pressure, and the temperature was raised to 280 DEG C in 1 hour, and the pressure was kept under vacuum of 0.5 Torr, and the reaction was continued for 2 hours under the conditions. As a result, a pale yellow polyester copolymer (binder) having an intrinsic viscosity (IV) of about 0.67 was calculated.

Example 2

Except 320g of waste polyester film pulverized product, 295g of dimethylisophthalate, 200ml of ethylene glycol, and 210g of neopentalglycol were reacted for 2 hours at 220 ° C at atmospheric pressure using 0.2g of zinc acetate + 0.2g of germanium oxide as a catalyst. The process was performed similarly to Example 1, and computed the polyester copolymer (binder).

Example 3

A polyester copolymer was produced in the same manner as in Example 1 except that the waste polyester chip mill was used instead of the waste polyester film mill.

Example 4

A polyester copolymer was produced in the same manner as in Example 1 except that 170 ml of ethylene glycol was added and 180 g of neopentyl glycol was added.

Example 5

A polyester copolymer was produced in the same manner as in Example 1 except that the reaction was carried out using 204 g of waste polyester film, 204 g of dimethylisophthalate, 25 g of adipic acid, 180 ml of ethylene glycol, and 320 g of neopentylglycol. .

Comparative Example 1

A polyester copolymer was produced in the same manner as in Example 1 except that 320 g of dimethylphthalate was used instead of 320 g of the waste polyester film pulverized product.

Comparative Example 2

A polyester copolymer was produced in the same manner as in Example 1 except that 421 g of polyester oligomer (BHT) was used instead of 320 g of waste polyester film pulverized product. On the other hand, the used BHT was calculated by reacting waste polyester, 800 g, and 370 ml of ethylene glycol at 240 ° C. under 2 kg / cm 2 for 4 hours.

Comparative Example 3

A polyester copolymer was produced in the same manner as in Example 1 except that 320 g of finely ground waste polyester chip was used instead of 320 g of waste polyester film pulverized product.

The glass transition temperature, intrinsic viscosity, DEG content and adhesion of the polyester copolymers produced in Examples 1-5 and Comparative Examples 1-3 were measured and evaluated by the following method, and the results are summarized in a chart.

[Measurement of properties]

(1) Glass transition temperature (Tg): DSC rapid cooling method measured at -20 / min speed

(2) Intrinsic Viscosity: Measured with a ubbelohde viscometer at 25 ° C using tetrahydrofurin as a solvent

(3) DEG content: The sample was decomposed into monoethanolamine and placed in GC, and hexanediol was used as a standard to evaluate the peak area.

(4) Adhesive force: After bonding two polyester film specimens (width 25mm), they were left to stand for 1 day, and then measured by pulling at a rate of 200mm / min at 25 ° C at a 90 degree angle (vertical).

As shown in the diagram, the binder prepared using the waste polyester pulverized according to the present invention had properties comparable to those produced from raw monomers (Comparative Example 1), and the waste polyester depolymerized oligomo ( Compared with BHT) (Comparative Example 2), it had more excellent physical properties.

Claims (1)

In the preparation of a polyester binder composed of terephthalic acid, isophthalic acid, adipic acid, ethylene glycol and neopentyl glycol, (a) ethylene glycol and neopentyl glycol in waste polyester ground products and isophthalic acid, A dicarboxylic acid compound selected from the group consisting of esters, adipic acids, esters thereof and mixtures thereof is added at a molar ratio of 1.3-2.0: 1 of (ethylene glycol + neopentyl glycol) / (waste polyester + acid component), and the catalyst As a zinc acetate, calcium acetate, germanium oxide or a mixed catalyst of 100ppm to 400ppm, after reacting for 2-4 hours at 180-240 ℃; (b) adding a thermal stabilizer and a polymerization catalyst to the reaction mixture and polymerizing under a high vacuum at 270-300 ° C.