SU891679A1 - Bis-(chelate)-bis-(hydroxyalkylenoxy)titanium as catalysts for producing polyethyleneterephthalate - Google Patents

Description

where R is alkyl, aryl, cycloalkyl, alkylaryl, oxyalkyl; alkylene. These compounds are used as starting materials in the preparation of a catalyst for polypeesterification and polycondensation for the preparation of f2J polyesters. However, a comparative assessment of the catalytic activity of these compounds is not possible, since they are used only after preliminary hydrolysis and only in combination with other active catalysts. Tetrakis (hydroxyalkyleneoxy) titans are the closest to the proposed ones as catalysts for the production of polyethylene terephthalate 2. The disadvantage of these catalysts is the relatively low depth of conversion both at the transesterification stage and at the polycondensation stage, as well as the process duration up to 3 , 5 h, The purpose of the invention is bis- (chelate - bis-C hydroxyalkyleneoxy-titans as catalysts for the preparation of ethylene terephthalate. The goal is achieved by the replacement of bis- (chelate -bis- (hydroxy alkyleneox and; titans of the general formula t NOHA-Ti-OROH-8-hydroxyquinoline; R-CHg-CH -,. dibenzoylmethane; R-CH-CH-ethyl salicylate, - (;: n-Si-SIH-CHCH3 CH 2, Ch - acetylacetone; R -CH, -CH2, -0-CHj-CH poppy catalyst for the preparation of polyethylene terephane. The preparation of bis (chelate) bis (hydroxyalkyleneoxy) titans is carried out by the reaction of bis (chelate) dialkyl tanates of the general formula (Ch), Ti ( OR) 2, where R is alkyl, for example ethyl, buty Ch is a negligent ligand, for example, 8-hydroxyquinoline, dibenzoylmethane, acetylacetone, ethyl salicylate, with glycols of the general formula HO-R-OH alkylene or alkyleneoxy, for example ethylene, 2,5- hexylene, diethie enoksi at a molar reactant ratio of 1: 2 in solution at room temperature or under heating to 60 ° C followed by distilling off the solvent and recovering the alcohol generated in the reaction in vacuo. Example 1. 1.8 g (0.029 mol) of ethylene glycol is placed in a flask, dissolved in 5 g of methylene chloride, and 6.99 g (0.0145 mol) of bis- (8-hydroxyquinolinate) dibutoxytitanium dissolved in 38 g are poured into it. methylene chloride. The reaction mixture is stirred for 2 hours at room temperature and, gradually lowering the residual pressure of 2 mm Hg, methylene chloride is distilled off and the butyl alcohol evolved as a result of the reaction, first at room temperature and then at BS + 3 ° C. to a constant weight of the reaction mass. 6.56 g of a yellow powder soluble in methylene chloride, dimethylformamide, tetrahydride, rofuran, pyridine, methyl alcohol are obtained. ; Found: C 58.06, H, 99; {OCHiCHgOHJg J .: t 3200-3500 cm stretching vibrations of the OH group. Re-precipitation of bis- (8-hydroxyquinolinate) -bis- (hydroxyethyleneoxy) titanium. 2.5 g of the product obtained is dissolved in 31 g of methylene chloride and 63.9 g of ether are added. The precipitate formed is filtered off and dried to constant weight at room temperature and a residual pressure of 2 mm Hg. Obtain 0.53 g of yellow powder, soluble5

; In chloroform, dimethylformamide, tetrahydrofuran, pyridine, methyl alcohol.

Found: С 58, О; H 5.10; Ti 11, N 6.38.

Another 142 g of sulfuric ether is added to the obtained filtrate. The precipitate thus formed is filtered and dried under vacuum to a high weight. Obtain 0.81 g of yellow powder, soluble in methylene chloride, dimethylformamide, pyridine, methyl alcohol.

Found,%: C 58.02; H, 10; Ti 10.21; N 6.61.

From the mother liquor, remaining after reprecipitation of two portions of the product, 0.57 g of yellow-colored powder soluble in methylene chloride, dimethylformamide, pyridine, methyl alcohol is recovered.

Found: C, 58.16; H 4.77; Ti 10.69; N 6.33.

Thus, all three portions resulting from the reprecipitation of bis- (8-hydroxyquinolinate) -bis- (hydroxyethylenoxy) titanium are identical in appearance, solubility, and composition within the limits of the allowable errors of analysis.

Example 2. In the flask are placed l, g (0.023 mol) of ethylene glycol, dissolved in methylene chloride, and 7.4t g (0.0166 mol) of bis- (dibenzoylmethanate) -dibutoxytitanium dissolved in methylene chloride is added.

The reaction mixture is stirred at room temperature for 2 hours and, gradually, the temperature is raised to 60 ° C and f 5 ° C and the residual pressure is reduced to 2 mm Hg. Art., methylene chloride is distilled off and the butyl alcohol released as a result of the reaction. The evacuation of the reaction mass is carried out to a constant weight. 7.16 g of red-orange powder, soluble in methylene chloride, carbon tetrachloride, benzene, pyridine, dimethylformamide, tetrahydrofuran, dioxane, are obtained.

Found,%: C 66, H 5.07, Ti 8.0.

Ji -foCH CHpCW

916794

Calculated: C 66,24; H 5.23. T (7.77.

Example C-flask is placed 5.57 g (0.0472 mol) of 2.5-hexanedio and P, 05 g (0.0236 mol) of bis- (ethyl salicylate) diethoxytitanium, dissolved in 9.6 g of methylene chloride, is poured. The reaction mixture is stirred at room temperature for 2 hours. 10 The distillation of methylene chloride and the ethyl alcohol released by the reaction is carried out at room temperature and the residual pressure is gradually reduced to 2 mm IS Hg. Vacuuming is carried out to a constant weight of the reaction mass. 14, 65 g of a yellow viscous liquid soluble in methylene chloride, dichloroethane, acetone, black ether, cyclohexane, dimethylformamide, tetra-hydrofuran, ethyl acetate are obtained.

Found: C 58.94; H 7.64, Ti 7.68. IS

m

Calculated,%: C 58.86; H 7.24, Ti 7.82.

Example 4. The flask is placed

6.43 g (0.0.0 mol) of diethylene glycol, dissolved in 6.05 g of methylene chloride, and 10.19 g (0.0303 mol) of bis- (acetylacetonate) diethoxytitanium dissolved in

14.80 g of methylene chloride. The reaction mixture is stirred for 2 hours at room temperature, gradually reducing the residual pressure to 2 mm Hg. methylene chloride and the ethyl alcohol liberated by the reaction are distilled off. Evacuation is carried out until constant weight of the reaction: the mass.

13.83 g of a yellow clear viscous liquid soluble in methylene chloride, dichloroethane, acetone, pyridine, benzene, dimethylformamide, tetra hydrofuran are obtained.

carbon tetrachloride.

Found,%: C47.251 H 6.83; Ti 10.31.

B

.-.

; TI - OCHiCHiOCHjCHiOHlj.

NA

-about

HN,

Calculated D: C, 38; H 7.07, TG 10.50,

The resulting bis (chelate) bis (hydroxyalkyleneoxy) titans were tested as catalysts in the transesterification stage of dialkyl esters of terephthalic acid with glycol and in the polycondensation stage of the resulting products during the preparation of polyethylene terephthalate.

Dimethyl terephthalate and ethylene glycol in a molar ratio of 1: 2 are charged to a reactor equipped with a stirrer, a reflux condenser, a cooler and a receiver to collect low molecular weight reaction products. Catalyst bis- (chelate) -bis- (hydroxyalkyleneoxy-titanium in the amount of 0.006-0.3% by weight of the starting components) is introduced into the reaction mixture. The process is carried out with constant stirring. The transesterification reaction is carried out at atmospheric pressure in the temperature range 166 -2kQC In this case, the theoretically calculated amount of methanol is distilled off within 80–1.0 min.The residual pressure in the system is then reduced to mm Hg and polycondensation with distillation of glycol is carried out at 220–280 ° C for min. color floor ethylene capable stretchable elastic fibers to colorless. The results obtained with bis (chelate) -bis- (gidroksietilenoksi) and titan. kochestve catalysts in

obtain polyethylene terephthalate are presented in table 1.

Table 2 presents data relating to the use of tetrakis- (hydroxydiethylenoxy) titanium and tetrakis- (hydroxytriethylenoxy) titanium as catalysts according to the author. St. No. and the following proposed compounds: bis- (8-hydroxyquinolate) -bis- (hydroxyethylenoxy) titanium, is- (dibenzoylmethanate) -bis- (hydroxyethylenoxy) titanium, bis- (ethyl salicylate) -bis- (2-hydroxyhexylene-5-hydroxy) ) titanium and bis- (acetylacetonate) -bis- (hydroxydiethylenoxy) titanium.

As can be seen from the above data, using bis (chelate) bis (hydroxyalkylenoxy) titans as the catalyst for the production of polyethylene terephthalate at the same or even lower temperature limits of the reaction provides a number of advantages compared with tetrakis (hydroxyalkyleneoxy) titanium.

The proposed catalysts are more effective at both stages of the process, since they allow a greater conversion depth to be achieved: 100%

against at the transesterification stage and 60-72% against 35-i6% at. polycondensation stages,

In addition, the process is less time consuming, the total duration of the process is

5, the proposed method is 110-190 minutes against minutes by a known method, and the polyethylene terephthalate obtained using the proposed catalysts is less colored,

0 has a smaller melting point and is soluble in organic solvents, i.e. possesses better Kai ecTBOM compared to the product obtained using

3 tetrakis- (hydroxyalkyleneoxy) titans.

X

c "about

irv

SO

uh a

X -o

ki

with; and

about X

about

00 fM

I

about

"N

eleven

891679

Stage of transesterification

Depth of reaction,%

Duration, min. Temperature, C

Polycondensation stage

35-46 105-2 0 230-290

Claims (2)

1. Japanese Patent No. 14235., cl. 26 D 6, publ. 1968. 2. USSR author's certificate number 654635, cl. C 07 F 7/28, 1978.