KR830001088B1 - Manufacturing method of colorless transparent polyester - Google Patents

Abstract

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Description

Manufacturing method of colorless transparent polyester

The present invention relates to a method for producing a colorless polyester with good transparency.

Polyesters and copolyesters of dicarboxylic acids and aliphatic glycols (e.g. polyesters based primarily of polyethylene terephthalate) have numerous uses due to their excellent properties, especially in textiles, films and other plastic products. It is becoming.

One of the excellent properties of polyester is its transparency, but due to the catalyst used in the preparation of the polyester and additives for improving the physical properties, the transparency is poor and there is a closed end where the polymer is colored.

As a technique for preventing such a decrease in transparency and coloring, there is a demand for a technique for using a new catalyst that can eliminate unwanted reactions between the esterification catalyst and the additive which are the main cause of the decrease in transparency.

As a related art, Mn, Sb and phosphorus compounds are used as catalysts in Japanese Patent Application No. 50-4710, Sn, Sb and Phosphorus Compounds in Japanese Patent Application No. 52-51494, Co. As the polycondensation catalyst, Sb and phosphorus compounds were used in Japanese Patent Application No. 55-5535, and SD compounds and trialkylsis halides were used.

The use of such a catalyst for improving transparency and color reduces the transparency of a polyester produced with a typical antimony compound as a polyester polycondensation catalyst, thereby lowering the color of the polymer, which is a metal antimony as the antimony compound is reduced. It is intended to solve these factors due to antimony compounds because it is believed that the precipitated metal antimony is reacted with other compounds in the reaction system to produce inert fine particles.

However, the present inventors could not expect a marked improvement in transparency in the catalysts used in the prior art and the method for producing the polyesters. Therefore, the present inventors have found polyesters suitable for manufacturing fibers, films and other molded articles as well as improving transparency and color. As a result of extensive research, the ratio of the catalyst used to produce the desired polyester and its catalytic amount was determined. Hereinafter, the present invention will be described in detail.

Initiation of esterification or transesterification in the preparation of a polyester by esterification or transesterification of the functional carboxylic acid or its ester-forming derivative with at least one glycool and polycondensation of the product thus obtained For example, one or two or more metal compounds selected from La, Ti, and Sn, in addition to Li and Mg of alkali metals or alkaline earth metals, may be present with respect to all the acid components constituting polyester. It is a manufacturing method of polyester characterized by adding in the range which satisfy | fills following Formula.

(next)

〈2.2………③100? M? … … ① 1.0

<2.2.. … … ③

200 ≦ Sb + M ≦ 700... … … ②

Where M is a metal compound of metal Mg, Li, La, Ti, Sn

Sb: antimony compound P: phosphorus compound

P ': Phosphoric acid

는 ppm의 비이다.P: P '= 3: 2 (wt%),

Is the ratio of ppm.

These are expressed in ppm relative to dicatic acid.

As the bifunctional carboxylic acid or ester-forming derivative thereof used in the present invention, terephthalic acid, microterephthalic acid, P, P'dicarboxylic diphenylene,

P, P'-acid diphenylcarboxylic acid

P, P'-dicarboxydiphenylhexane

PP'-dicarboxydiphenyl ether

PP'- dicarboxyphenoxy ethane, etc. are mentioned,

Moreover, these dialkyl esters containing 1-5 carbon atoms in an alkyl group are mentioned.

Aliphatic glycols suitable for the production of polyesters and copolyesters Aliphatic glycols containing 2 to 10 carbon atoms, in particular represented by the general formula HO (CH ₂ ) nOH (where n is an integer from 2 to 10). Methylene glycol, terramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol, 3-ethyl-1,5-pentanediol, 1,4-xylene glycol, 2, 2,4,4-tetramethyl-1,3-cyclobutanediol etc. are mentioned.

The catalyst used in the present invention is a compound of the following metals, that is, a compound of magnesium, magnesium acetate, lithium acetate, dibutytin oxide, lentanium acetate, lithium chloride, magnesium methoxide, etc. And particularly preferably, magnesium diglyclate, richum glycate, lentanum triglycol date and the like. In addition, the addition time of these metal compounds was added before initiation of esterification or transesterification reaction.

As the catalyst of the polycondensation reaction used in the present invention, an antimony compound represented by the following structural formula was used.

The addition time of the polycondensation reaction catalyst was added before the start of the polycondensation reaction.

As the stabilizer used in the present invention, P of Formula 3 used triethyl phosphate, triphenyl phosphate, and the like, which are derivatives of phosphoric acid, and the addition time was one or two of the selected compounds before the start of the condensation polymerization reaction. P 'was added in the middle of the polycondensation reaction added with phosphoric acid.

As described above, the derivative (P) of the Sb compound and the phosphoric acid can be added almost simultaneously before the start of the condensation polymerization, and the phosphoric acid (P ') is added in the middle of the condensation polymerization reaction.

The reason for adding phosphoric acid (P ') later here is one means for improving the transparency of the polymer.

The amount of such catalysts and additives used in the present invention should satisfy the above formula, and if it is outside this range, the desired colorless and transparent polymer cannot be obtained. That is, when a large amount of M is added to the range in order to improve transparency, transparency of the resulting polymer is degraded, and the amount of M must be increased as the amount of P + P 'increases. As the amount of P + P 'increases, a small amount of M does not cause a decrease in transparency.

However, since the addition of P = P 'outside the range cannot restore the transparency even if the amount of M is increased, the range of the amount of P + P' and M used is expressed as a formula.

In other words, transparency is lowered even when M is added a large amount, and when P + P 'is added, transparency is deteriorated regardless of the amount of M used, and the ratio of P: P' must be maintained at 3: 2. Gets worse. In the following Examples, the present invention will be described in more detail. In the examples, the intrinsic viscosity is a measured value at 25 ° C. with a solvent mixture of tetrachloromethane: phenol 3: 2. In order to measure the color tone and transparency of the polymer, L, a, and b were determined using a color system (color meter) of the polyester chip after the condensation polymerization reaction at room temperature.

L is lightness (higher value means better brightness)

a is red-green color (+ is red,-is green)

b represents the yellow-blue color (+ is yellow,-is blue).

The color tone of a polymer is so good that L value is large, a value approaches 0, and b value is small.

EXAMPLE

1. Prepare 249g (1.5mole) of terephthalic acid and 0.075g of 186.2g (3mole) richum glyclate of ethylene glycol in a separation tube, place it in a glass flask, and heat it at 180 ° -210 ℃ under normal pressure for 3 hours. Heated in the presence.

Water was distilled out of the reactor during the ester reaction. It was then raised to 218 ° -250 ° C. and held for about 1 hour to complete the esterification.

The transesterification product was transferred to a condensation polymerization reactor, 0.07 grams of antimony triglycate and 0.022 g of triethyl force white were added, and the pressure was gradually reduced to 0.1 Torr or less. 0.015 g is added. The reaction temperature was maintained at 275-285 ° C. for 3 hours.

The inherent viscosity of the obtained polymer was 0.60, and the color tone of L = 118a = + 2 and b = -3 was obtained.

2. In the same manner as described in Example 1, 249 grams of terephthalic acid, 186.2 grams of ethylene grade lysine, 0.06 grams of dibutytin oxide as an esterification catalyst, 0.07 grams of antimony tricyclic lysate (condensation polymerization catalyst) triphenylphosph white 0.021 Polyester was prepared using gram, 0.014 gram phosphoric acid. The color tone of the polymer was colorless and transparent (L = 76, a = 3 b = -1) and had an intrinsic viscosity of 0.60.

3. In the same manner as described in Example 1, 249 grams of terephthalic acid, 186.2 grams of ethylene grade leak, 0.07 grams of magnesium acetate (esterification catalyst) 0.06 grams of antimony trihydride (condensation polymerization catalyst), 0.018 g of phosphoric acid Polyesters were prepared using 0.012 g.

The color tone of the polymer was colorless and transparent (L = 79, a = 1 B = -2) and had an inherent viscosity of 0.59.

4. In the same manner as described in Example 1, 249 grams of terephthalic acid, 186.2 grams of ethylene glycol, lanthanum acetate 0.06 g (esterification catalyst), 0.07 g antimony glycolate 0.018 g, triethylphosphate 0.018 g, phosphoric acid 0.012 g Using to prepare a polyester.

The color tone of the polymer was colorless and transparent with L = 76 a = 5 b = -1 and had an inherent viscosity of 0.62.

Claims (1)

In preparing a polyester by polycondensing a product obtained by esterifying or transesterifying a bifunctional carboxylic acid or its ester-forming derivative with at least one glycool, the polyester is formed before the esterification or transesterification reaction is started. Glycolate of metals Li, Mg, La, Ti, Sn and magnesium acetate, lithium acetate, dibutyltin oxide, lanthanum acetate, lithium chloride, magnesium methoxide, etc. After terminating the ester reaction in the presence of two or more species, add an amount of the antimony trioxide, phosphorus compound, phosphoric acid, triethylphosph white, and triphenylphosph white, which satisfy the following formula, before starting the polycondensation reaction. Method for producing a colorless transparent polyester, characterized in that. (next) 100? M? … … 1 200 ≤ Sb + M ≤ 700... … … ② 1.0

<2.2.. … … ③ M: Mg, Li, La, which are metals. Metal compounds such as Ti and Sn Sb: Antimony Compound P: Phosphorus Compound P ': Phosphoric acid The ratio of P: P 'is 3: 2 and these are expressed in ppm relative to the dicarboxylic acid.