KR810000094B1 - New high melting n,n'-terephthaloyl bisphthalamide and its use as an ester interlinking agent for polyesters - Google Patents

Abstract

The imide(I) with a high m.p. was prepd. and used to increase the mol. wt. of polyesters such as poly(ethylene terephthalate). Thus, K phthalimide in dioxane and Ph2O was treated slowly with dioxane contg. telephthaloyl chloride, refluxed at 70-170≰C, freed of dioxane by distn., refluxed 200-400≰C, filtered and cooled to >= 60≰C to give N,N'-terephthaloyl-bisphthalimide (b.p. >= 330≰C).

Description

Method for preparing N, N'-terephthaloyl bis-phthalimide

The present invention relates to a process for the preparation of N, N'-terephthaloyl bis-phthalimide having a high melting point and used as an interconnecting agent in the preparation of high molecular weight polyesters and copolyesters.

US Pat. No. 2,558,675 discloses a process for producing polyimide derivatives of carboxylic acids by condensing acid imides (particularly in the form of alkali metal salts) with polyacyl chlorides or polyacyl bromides of carboxylic acids. This patent and US Pat. No. 2,594,145 also describe a process for producing highly polymeric materials using such derivatives to link or interconnect molecules of the appropriate molecular weight. Many attempts have been made on the method disclosed in US Pat. No. 2,558,675, in particular on the preparation of N, N'-terephthaloylbis-phthalimide, and the method described in Example 5 of this patent has been studied very carefully. . A product having a melting point (270 ° to 275 ° C. (decomposition)) corresponding to the melting point published for the product of Example 5 of this patent was obtained, but contrary to this patent the product was added to a sample of molten polyester When the end ring was not mutually coupled. In other words, the polyester sample was actually reduced in molecular weight as evidenced by the reduction in intrinsic viscosity. The same was true when a sample of recrystallized product was used. That is, it was found that the product prepared according to Example 5 of US Pat. No. 2,558,675 did not enhance the ester crosslinking reaction of the polyester ring.

However, in the present invention, in contrast to the above-mentioned US Pat. No. 2,558,675, an alkali metal salt of terephthaloyl chloride and an alkali metal salt of phthalimide and phthalimide, that is, lithium phthalimide, sodium phthalimide, potassium phthalimide and the like When the dehydration compound is reacted in a mixture containing a high boiling aromatic or aliphatic ether, or a mixture containing a high boiling aromatic or aliphatic ether component and a low boiling cyclic or aliphatic ether component, the product has a melting point of at least 330 ° C. Found. Moreover, this product has ester intercompetitive properties and is effective in increasing the polymerization rate of the polyester forming reactants and increasing the molecular weight of the condensed polyester.

The reaction between terephthaloyl chloride and phthalimide or their alkali metal salts to produce new N, N'-terephthaloyl bis-phthalimide with high melting point in high yield is 70 to 170 in the first step. At a temperature of < RTI ID = 0.0 > C, < / RTI >

These reaction conditions are preferably achieved by using a solvent medium composed of a mixture of a high boiling ether component selected from aromatic and aliphatic aromatic ethers with a low boiling ether component selected from aliphatic and cyclic ethers. The high boiling point and low boiling ether components are selected so that the reaction temperature is maintained at 70 to 170 ° C. during the first reaction step (first 0.5 to 5.0 hours) in the preparation of high melting point N, N′-terephthaloyl bis-phthalimide do.

As the reaction proceeds, the low boiling ether component is slowly distilled out of the reaction mixture and is completed at a temperature of 200 to 400 ° C., preferably at the boiling point of the high boiling ether component. Given each boiling point of a particular high boiling point and low boiling ether, one skilled in the art will be able to readily determine the respective amount needed to make the solvent mixture to provide an initial reaction temperature within this range.

For example, the solvent mixture used in the method for preparing N, N'-terephthaloyl bis-phthalimide having a high melting point described in Example 1 below has diphenyl ether having a boiling point of 254 ° C. and a boiling point of 101. It consists of dioxane which is ° C. Thus it can be readily determined that a mixture of these two ethers with a volume of 50:50 can provide a reaction temperature range of 70 to 170 ° C described above. The actual boiling point of this mixture is observed in the range of 110 to 115 ° C.

The N, N'-terephthaloyl bis-phthalimide of the present invention having a high melting point can also be prepared using the high boiling ether described below as a single solvent medium. In addition, when using a mixed solvent system, the initial stage of the reaction, that is, the reaction within 0.5 to 5.0 hours after the start of the reaction is carried out in the temperature range of 70 to 170 ℃. In the final stage of the reaction, the temperature is set to 200 to 400 ° C., preferably as the boiling point of the high boiling ether solvent, thereby terminating the reaction. Misobserving the reaction temperature, especially the initial temperature when using high boiling ether as a single solvent system, lowers the conversion rate by volatilization of the terephthaloyl chloride reactant.

The term “high boiling point” ether component refers to aromatic and aliphatic ethers having a boiling point of 200 to 400 ° C. and a melting point of 50 ° C. or less, preferably 30 ° C. or less. It is convenient to use liquid high boiling ether at ambient temperature, but diphenyl ether, the most preferred high boiling ether, is solid at ambient temperature and must be melted immediately before use. The term “low boiling point” ether component refers to aliphatic and cyclic ethers having a boiling point of 65 to 150 ° C.

Other useful high boiling point ethers besides diphenyl ethers include benzylbutyl ether, butylphenyl ether, isoamylphenyl ether, hexylphenyl ether, heptylphenyl ether, octylphenyl ether, propyltolyl ether, butyl tolyl ether, methylnaphthyl ether, Ethyl naphthyl ether and propyl naphthyl ether. Examples of useful low boiling ethers include, in addition to dioxane, isopropyl ether, ethyl isobutyl ether, ethyl isoamyl ether, isobutyl ether, ethylhexyl ether, butyl ether, tetrahydrofuran, tetrahydropyran and the like.

According to a preferred method for preparing N, N'-terephthaloyl bis-naphthalimide having a high melting point, terephthaloyl chloride and potassium phthalimide are converted into 50 vol% diphenyl ether and 50 vol% dioxane. It reacts in the mixed solvent system comprised. Using such a mixed solvent system, the reaction temperature is 110 to 115 ° C for the first 1 to 2 hours. During the reaction and after the first one to two hours of reaction, the dioxane is distilled off from the reaction mixture and after one to two hours, the reaction ends at the boiling point of diphenyl ether. Therefore, during the reaction, the temperature is 110 to 254 ° C. At the end of this time, the reaction mixture is filtered to remove by-product potassium chloride, cooled and dried by taking N, N'-terephthaloyl bis-naphthalimide which precipitates from diphenyl ether at a temperature of 60 ° C or higher.

The following examples illustrate the invention in more detail. The percentages and parts used herein are by weight unless otherwise indicated and “IV” is the intrinsic viscosity measured at 60 ° C. in a mixed solvent of phenol / tetra chloroethane at 30 ° C., a measure of the molecular weight of polyester to be.

Example 1

The apparatus used to produce the high melting point N, N'-terephthaloyl bis-phthalimide was 2000 mL with a plugged outlet drive located at the bottom of the stirrer, thermometer, cooler, nitrogen inleter and reaction vessel. As a glass reaction vessel, it is a semi-melt glass distribution plate located directly above the outlet of the stopper. The reaction vessel is in contact with a collecting flask equipped with a vacuum outlet via a plugged outlet. 37.4 g (0.203 mol) of potassium phthalimide and a mixture of 250 ml of dioxane and 500 ml of diphenylether are added to the reaction vessel. 20.3 g (0.1 mole) of terephthaloyl chloride is then dissolved in 250 ml of dioxane and the mixture is slowly added to the reaction vessel with continued stirring. The contents of the reaction vessel are gradually heated to the reflux temperature (between 110 and 115 ° C.) and continuously refluxed for one hour. At the end, the dioxane solvent component is gradually distilled from the reaction mixture through a fractional distillation column. After complete removal of dioxane, the reaction mixture is further maintained at the boiling point of diphenyl ether (about 254 ° C.) for one hour. The hot solution containing the by-product potassium chloride in suspension is quickly filtered at the boiling point under vacuum and received in a collection flask. A white crystalline product of N, N'-terephthaloyl bis-phthalimide (TBP) is formed immediately in the liquid. The filtrate is cooled to about 100 ° C., the white crystals are collected by filtration and dehydrated under high temperature vacuum. The dried crystals (Product I) had a weight of 36.5 g, a yield of 87.3%, and a melting point of 340 to 345 ° C. As the filtrate is cooled to about 60 ° C., more white crystals are formed which are collected and dehydrated under high temperature vacuum. The melting point of the crystal (product II) is 330 to 336 占 폚. Precipitation (product III) collected below 60 ℃ is also dried under high temperature vacuum and its melting point is 315 ~ 325 ℃.

If a part of the product (I) is recrystallized from diphenyl ether, the melting point of the recrystallized material is 354 to 357 ° C. The elemental analytical value of the latter material is 68.08% carbon, 2.85% hydrogen and 6.35% nitrogen, and the calculated values for the compound having the above structure are 67.93% carbon, 2.85% hydrogen and 6.60% nitrogen.

From the above analysis, it can be assumed that the product has the following structure whose chemical name is N, N'-terephthaloyl bis-phthalimide.

In the present specification, this chemical name is simply referred to as abbreviation TBP.

A widely used method to increase the polycondensation rate during the polyester forming process is to add a reactant capable of interlinking polymer rings. Such ester interconnects are effective and economical for the production of high molecular weight polymers. In the production of poly (ethylene terephthalate), for example, the use of aromatic orthocarbonates (US Pat. No. 3,714,125), the use of carbonate derivatives of monohydric phenols (US Pat. No. 3,444,141) the use of diaryl esters of dicarboxylic acids ( U.S. Patent No. 3,433,770), but only a few materials are used to produce polymeric polyesters that increase the polycondensation rate and shorter than conventional condensation reaction times. Therefore, the development of new cross-linking material will be a significant contribution to the field, and the new product was tested and found to be an excellent cross-linking agent.

The use of high binder crosslinkers is shown in the following examples.

Example 2-5

A glass reaction tube equipped with a nitrogen gas inlet tube and a stirrer was filled with 50 g of dimethyl terephthalate, 40 g of ethylene glycol and 0.01% (calculated by metal) of octo-manganese acid, 35 cm long and equipped with a nitrogen gas inlet tube and a stirrer. . Nitrogen gas is slowly passed through the reaction tube to infiltrate the mixture and then the mixture is stirred and heated by a 240 ° C. steam bath surrounding the tube. After the end of the transesterification reaction, the pressure in the tube was reduced to 0.05 mmHg, 0.0123 g of intimonium trioxide (measured by metal) was added, the temperature of the mixture was increased to 280 ° C, and the pressure in the tube was reduced to 0.5 mmHg, thereby causing polycondensation. To perform. In Examples 2 and 3, the polycondensation reaction is carried out for 50 minutes and samples of the mixture are taken to determine the intrinsic viscosity (I.V.). The polycondensation reaction is continued for 2 minutes after adding to these mixtures while varying the amount of TBP of Example 1 which is recrystallized twice.

Examples 4 and 5 were also carried out in the same manner except that the polycondensation reaction was performed for 65 minutes before sampling and addition of the twice recrystallized TBP prepared in Example 1. All relevant data in each case were observed and recorded and shown in Table 1 below.

TABLE 1

( ^* ) Parts by weight per 100 parts by weight of dimethyl terephthalate

Example 6

To determine the normal polycondensation rate, the control example is carried out without adding a high melting point TBP using the same equipment, materials and amounts as in Examples 2-5. Samples are removed every 10 minutes during the polycondensation reaction. The results are shown in Table II.

TABLE 2

Comparing Table 1 and Table 2, the addition of only a small amount of pure TBP can be seen that the polycondensation rate is significantly accelerated than the conventional polycondensation reaction rate.

Example 7-12

In each of Examples 7-12, 50 g of poly (ethylene terephthalate) having an intrinsic viscosity of 0.809 was prepared in a glass of 35 cm in length and 38 mm in diameter with a nitrogen gas inlet tube and a stainless steel stirrer. Fill the reaction tube. In each example the poly (ethylene terephthalate) is melted at 280 ° C. under a nitrogen gas.

To each of Examples 8-12, one of TBP, the product of Example 1, is added at 0.5 parts by weight per 100 parts by weight of polyester. The mixture is stirred for 5 minutes at a constant rate under a temperature of 280 ° C. and nitrogen atmosphere and then discharged. The intrinsic viscosity of each polymer sample is measured again and the results are shown in Table 3. These results show that only TBP with a melting point of at least 330 ° C can interconnect the end rings of polyester, and the higher the purity, the greater the ability. These examples also show the ability of TBP with high melting point to cause polymerization of high viscosity polyesters under melt polymerization conditions and can be performed under solid state polymerization conditions.

TABLE 3

( ^* ) Control

As can be seen from the results of Example 8, it should be borne in mind that TBP with melting points below 330 ° C. surprisingly reduces the initial intrinsic viscosity of the polyester.

Example 13-15

In each of Examples 13-15, 30 pounds of commercial poly (ethyleneterephthalate) pieces having an intrinsic viscosity of 0.972 were added to a three cubic feet of mixing dryer and shaken for two hours under vacuum at 150 ° C. and 0.1 mmHg.

In addition, Example 14 contains 0.4 parts by weight of two recrystallized TBP samples of Example 1 per 100 parts by weight of polyester, and Example 15 contains 0.4 parts by weight of TBP samples per 100 parts by weight of polyester (US Pat. No. 2,558,675). Manufactured). Each sample is extruded into fibers using an 1 inch extruder. The resin residence time in the extruder is 1 minute and other physical data are shown in Table 4 below.

TABLE 4

As can be seen from Example 14, the TBP of the present invention, which has a high melting point, is most effective in retaining a high molecular weight polyester feed resin in the fiber, whereas the conventional TBP does not. In addition, it is most surprising that the pollen (ethylene terephthalate) sample containing the conventional TBP (Example 15) shows a greater loss in intrinsic viscosity than the sample without adding TBP.

Example 16-24

The method used in Examples 13 to 15 is repeated while varying the amount of TBP of Example 1 twice and the original intrinsic viscosity of the poly (ethylene terephthalate) resin. All samples are extruded into fibers using an 1 inch extruder. Appropriate data is shown in Table 5 below.

TABLE 5

(a) parts by weight of TBP per 100 parts by weight of polyester

(b) a control that did not bind the TBP of the polyester

(c) g / d-gram / denier

The above examples demonstrate the ability of TBP with high melting point to produce fibers with higher intrinsic viscosity than resins. In the absence of a high melting point TBP, the fibers exhibit lower intrinsic viscosity than the starting resin. This reduction in intrinsic viscosity is due to the mechanical and thermal sensitivity of the resin to the extrusion or spinning machine during formation into the fiber.

Example 25-26

70 g of poly (tetramethylene terephthalate) having an inherent viscosity of 0.8 and 30 g of poly (tetramethylene isophthalate / azelate) having an intrinsic viscosity of 0.75 in Examples 25 and 26, respectively, were 35 cm in length and had an internal diameter. It is 38 mm and filled in a glass reaction vessel equipped with a nitrogen inlet tube and a stainless stirrer. The polyester mixture of Example 25 is stirred under nitrogen atmosphere at 280 ° C. with continued stirring. The polyester mixture was completely dissolved once, and 1.5 parts by weight of polyester per 100 parts by weight of TBP of high remelting point, which was recrystallized twice, the product of Example 1, was added and the reaction mixture was stirred for 5 minutes. At this time, the intrinsic viscosity of the produced material is 0.98.

The polyester mixture of Example 26 is melted under stirring at 280 ° C. under vacuum. Once again the polyester mixture is completely melted and 1.5 parts by weight of 100 parts by weight of the recrystallized TBP prepared in Example 1 is added and stirred for 5 minutes. At this time, the intrinsic viscosity of the produced material is 1.05.

The use of novel TBPs with high melting points using poly (ethylene terephthalate) and a mixture of poly (tetramethylene terephthalate) and poly (tetramethylene isophthalate / azate) is as described above. The novel TBPs with high melting points can also be used in combination with other glycols and other polyesters and copolyesters derived from various other dicarboxylic acids or their lower alkyl esters using known polyester formation methods. Representative examples of other useful dicarboxylic acids include aromatic dicarboxylic acids such as isophthalic acid, 2,6- and 2,7-naphthaic acid, P, P-diphenylcarboxylic acid and the like, cycloaliphatic dicarboxylic acids such as hexahydroterephthalic acid. And aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid and sebacic acid, and mixtures of these acids may be used. Representative examples of the alkyl esters having 1 to 4 carbon atoms of these acids include dimethyl, diethyl, dipropyl, diisopropyl, dibutyl and diisobutyl esters or mixtures thereof. Finally, in addition to ethylene glycol, glycols, alicyclic glycols and aromatic glycols of HO (CH ₂ ) nOH where n is an integer from 2 to 10 can be used, for example propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol , Decamethylene glycol, cyclohexanedimethanol, di-β-hydroxy-ethoxybenzene, and the like. Mixtures of these various glycols can also be used. However, due to commercial importance, poly (methylene terephthalate) made from terephthalic acid or dimethyl terephthalate and ethylene glycol is the preferred polyester for use with the high melting point TBP described above.

The increase in maximum molecular weight that can be achieved using a high melting point TBP material depends on the number of moles of polyester or polyester resin to be polymerized and the concentration of hydroxy end groups. In order to obtain the maximum molecular weight, an increase in TBP of nx / 2 mole of high melting point is required, where n is the number of moles of polyester or polyester resin to be polymerized, and X is the hydroxyl end group of each molecule of the polyester. Indicates a number. However, the high melting point TBP can be used in various amounts to achieve a desired increase in molecular weight or to prevent a decrease in the molecular weight, and the actual amount used is the purpose of using the high melting point TBP, and the addition of polyester resin to be polymerized. It depends on the intrinsic viscosity of the city and the desired molecular weight.

In general, the amount of TBP having a high melting point is based on 100 parts by weight of the original dicarboxylic acid or its lower alkyl ester when added to the melt of the polyester to be polymerized, or TBP is remelted polyester resin, solid state. When added to the polyester to be polymerized, or the polyester resin supplied during extrusion or spinning into fibers, it is in the range of 0.1 to 25.0 parts by weight based on 100 parts by weight of the polyester resin. In particular, when a high melting point TBP is added to a melt polymerized polyester having an intrinsic viscosity of 0.2 or more, the amount of TBP is in the range of 1.0 to 20.0 parts by weight per 100 parts by weight of the dicarboxylic acid or lower alkyl ester thereof. This amount increases the rate of polymerization and leads to obtaining a higher molecular weight polyester in a shorter time than in conventional methods. When high melting point TBP is added to a melt-integrated polyester having an intrinsic viscosity of 0.6 or more, the amount is 0.1 to 5.0 parts by weight per 100 parts by weight of the dicarboxylic acid or its lower alkyl ester as starting material, and a higher molecular weight polyester can be obtained. Will be. The amount of high melting point TBP added to polyester particles having a intrinsic viscosity of 0.6 or a portion thereof for melting or solid polymerization or spinning is 0.1 to 5.0 parts by weight based on 100 parts of polyester resin. The amount used when adding a high melting point TBP to a fiber-forming polyester resin having an intrinsic viscosity of 0.8 or more depends on whether the purpose is to produce a fiber having the same intrinsic viscosity as the starting resin or to produce a fiber having a higher intrinsic viscosity. According to the range of 0.01 to 3.0 parts by weight per 100 parts by weight of the polyester resin.

The high melting point TBP may be added to the fiber-forming polyester before or simultaneously with the polyester resin in the extrusion or spinning machine. Both of these methods provide desirable results.

While there are certain exemplary embodiments to illustrate the present invention, it is apparent that those skilled in the art can make various changes and improvements without departing from the scope of the present invention.

Claims (1)

Terephthaloyl chloride comprising an ether solvent selected from aromatic and aliphatic-aromatic ethers having a boiling point of 200 to 400 ° C., or at least one cyclic or aliphatic having a boiling point of 65 to 150 ° C. with at least one of said aromatic or fatty-aromatic ethers. With an imide selected from phthalimide or its alkali metal salt, in the presence of a mixed solvent with ether, in the temperature range of 70 ° to 170 ° C. during the initial stage of the reaction and in the temperature range of 200 to 400 ° C. during the final stage of the reaction. When the reaction is carried out and the imide is a phthalimide and an alkali metal salt, the mixture is filtered, and N, N'-terephthaloyl bis-phthalimide precipitated from the ether solvent is collected at a temperature of 60 ° C or higher. Method for producing a N, N'- terephthaloyl bis-phthalimide having a melting point of 330 ℃ or more.