DE1595043B2 - METHOD FOR MANUFACTURING POLYAETHERESTERS AND THEIR USE - Google Patents

Description

Numerous copolymers of polyesters, polyethers and polyether esters are already known. In the In most cases, however, it was found that the desired degree of crystallinity with increasing content of the copolymer decreases in comonomer units compared to the corresponding Horaopolymeren and that in the central regions of the copolymer composition there is no crystallization for this reason can be observed.

So z. B. copolymers made from ethylene glycol, '° Terephthalic acid or a derivative forming its ester and an acid such as isophthalic acid, adipic acid, Sebacic acid or hydroxybenzoic acid, or a derivative forming its ester, are produced, processed into cold-stretchable fibers or films' 5. However, there are disadvantages during manufacture the molding made from these copolymers. In addition, the products obtained have poor properties on the lack of crystallinity and the very broad softening range and the low Softening temperatures of the copolymers are based in the medium composition range.

These disadvantages are particularly evident in those made from terephthalic acid, sebacic acid or oxybenzoic acid or their ester-forming derivatives of composite copolymers clearly noticeable.

British patent specification 913 436 describes a process for the preparation of copolymers, in which an acidic component of the general formula

COOR '

35

in which X is an omega-hydroxyalkyl radical with 2 to 8 carbon atoms, R a hydrogen atom or a methoxy group and R 'a hydrogen atom, a / I-hydroxyethyl, a methyl or ethyl radical means having an acidic component of the general formula

- " V- COOR"

R-OOC

wherein R "can be the same or different and a hydrogen atom, a methyl radical or a / I-hydroxyethyl radical means, and ethylene glycol is reacted in the presence of an esterification catalyst. Likewise, a copolymeric polyether ester of terephthalic acid is used in the cited patent. Ethylene glycol and an acid of the general formula

XO

COOH

55 , where; i is 2, 4, 5, 6, 7 or 8, have a reduced crystallizability and an extended softening range compared to polyesters of terephthalic acid with polymethylene glycols.

It has now been found that the polyether esters which can be prepared according to the invention over the entire range the copolymer composition are easily crystallizable and are therefore suitable for further processing into molded bodies such as fiber and films with excellent properties such as high tensile strength and good dimensional stability.

The invention relates to a process for the production of polyether esters by polycondensation of ethylene glycol with terephthalic acid and a p - <»- hydroxyalkoxybenzoic acid or ester-forming Derivatives of these acids, which is characterized in that p - <»- Hydroxyalkoxybenzoic acid the p-γ-hydroxypropoxybenzoic acid or its ester-forming derivatives are used.

The invention also relates to the use of these copolymers for the production of fibers. Films and molded parts.

It is shown that the inventively producible Polyether ester has excellent crystallinity over the entire range of the copolymer composition and that the structure of the copolymers differs from that of the corresponding homopolymers differs.

The most likely reason for this is the identity of the repetition periods of each individual component in the copolymer and the equality of the number of backbone atoms each between the benzene rings

lie.

In the case of synthetic high-molecular substances, such phenomena have so far only rarely been seen noticed. To date, there are therefore only a few reports on mixed crystal formation in copolymer systems published on mixed crystal formation in copolymer polyamides and stereoregular Copolymers of styrenes and substituted styrenes. The formation of mixed crystals in copolymer polyesters and polyether polyesters have not yet been described in the literature. On the contrary, E d g e 1 and Hill have the option such a mixed crystal formation in »J iurnal of Polymer Science ", p. 1. Issue 8, August 1952, answered in the negative.

The process of the invention can be carried out by the processes known for the preparation of other linear polyesters or polyether esters, preferably by the esterification method or the ester interchange method. According to the invention, in this way, polyether esters of ethylene glycol and the lower alkyl esters, such as the methyl esters of terephthalic acid and py-hydroxypropoxybenzoic acid or their lower alkyl esters, such as the

described, in which X is an omega -hydroxyalkyl radical with 2 to 8 carbon atoms. R eiti hydrogen atom or is a Mrlhoxylrest.

The copolymeric polyether esters that make up the units

- CH ₂ CH ₁ OOC

COO

-COO methyl esters of py-hydroxypropoxybenzoic acid can be produced, for example, by separating a mixture of p'V'-hydroxypropoxybenzoic acid or an ester-forming derivative thereof with ethylene glycol and a mixture of terephthalic acid or one of its ester-forming derivatives with ethylene glycol are heated, first of all the corresponding glycol esters or lower condensation products thereof being formed and that both products are then subjected together to the copolycondensation at elevated temperatures.

The linear molecules that can be produced according to the invention Polyetheresters with a high average molecular weight are so constructed that the two different building blocks that repeat themselves, namely ethylene terephthalate and p-trimethyleneoxybenzoate units, are randomly distributed along the polymer chain. The polyether esters which can be prepared according to the invention can be easily processed into fibers and filaments, which are characterized by high tensile strengths, good Elasticities as well as high resistance to heat shrinkage are characterized and the slightly cold can be stretched.

example 1

200 g of dimethyl terephthalate, 153 g of ethylene glycol, 216 g of methyl p-γ-hydroxy-propoxybenzoate are used in a condensation vessel provided with a stirrer, a gas inlet and a vacuum line is heated to 220 ° C.

In the process, methanol is distilled off. It is heated until almost the theoretical amount of methanol has distilled off. The temperature is then ^{increased to 250 °} C. within 1 hour, and at the same time the pressure is lowered to 30 to 100 mm Hg. After most of the ethylene glycol split off during the polycondensation has distilled over, the pressure is gradually reduced to 0.1 to 1 mm Hg, which takes about 1 hour. The heating in vacuo is then continued for 3 to 4 hours with thorough stirring, the viscosity of the vessel contents increasing more and more and finally reaching a very high value. The copolymer obtained has an intrinsic viscosity of 0.736 and a melting point between 162 and 164 ° C. The molar ratio of ethylene terephthalate to py-trimethyleneoxybenzoate units is 50:50. Filaments formed from the molten mass can be cold drawn into fibers, the characteristic X-ray diffraction image of which shows an orientation of the molecules along the fiber axis. The X-ray diffraction pattern of the copolymer differs both from that of the polyethylene terephthalate and that of the poly-p-trimethyleneoxybenzoate.

There were now copolymers of ethylene terephthalate and p-trimethylene oxybenzoate in the most varied Quantities produced, the times required for the polymerization being selected that the values for the intrinsic viscosity of the polymers obtained are all between 0.70 and 0.80 lie. The melting point and viscosities of these polymers are listed in the table.

The intrinsic viscosities were measured in a mixture of trachloroethane and phenol (50:50) at 25.degree measured.

From units of ethylene terephthalate and

p-trimethylene oxybenzoate compound

Copolymers

Mole percent 5 40 Melting point Γ C) ('/ I Trimethyleneoxy 50 benzoate entities 60 70 183 0.746 80 163 0.763 90 159 0.716 174 0.747 182 0.721 195 0.756

Mole percent
Trimethylene «^
ben / .oaleinheillen Melting point ( ⁰ C) 0.725
0.7: 51
0.718 10
20th
30th 241
225
20 »

The copolymers in the table have all been prepared according to the '5 procedure of Example 1. the Products readily crystallize and exhibit over the entire range of the copolymer composition good spinning and stretchability. The fibers made from the copolymers have a * ° high tensile strength and good elasticity properties. They are suitable for making films.

Example 2

80 g methyl p-γ-hydroxypropoxybenzoate were mixed with 95.8 g of the terephthalic acid diglycol ester. Tetra-n-butyl orthotitanate was added to the mixture added as a catalyst. The reaction mixture was stirred well under normal pressure and

then heated ^{to 190 to 230 °} C. to carry out the ester exchange reaction. The methanol thereby distilled off was removed from the system. The temperature was then increased to 270 to 280 ° C. The pressure was gradually reduced to 0.5 to 0.1 mm Hg and the copolycondensation reaction was continued for 2 to 3 hours to obtain a polyether ester having a relative viscosity of 1.32 as measured on a 5% solution in a mixture of equal parts by weight of tetrachloroethane and

Phenol, and had a melting point of 165 to 170 ^0C .

The copolymerized polyether ester obtained was processed by melt spinning at 190 ° C. The threads were drawn 4.5 times, the threads being obtained which had a strength of 4.5 g / denier, an elongation of 26% and a shrinkage of 0.5 to 1% ^{in hot water (100 ° C.).}

The polyether ester prepared in the manner described was subjected to X-ray analysis.

The recorded spectra showed that the fiber was not crystallized before drawing and the Molecules were not oriented along the fiber axis. The X-ray diagrams of this copolymer were from the X-ray diagrams of the two homopoly-

mers whose monomers were used as starting materials, various. The X-ray diffraction pattern of the crystallized polymer produced according to this example showed sharp main maxima at rf = * 5.34, 3.92 and 3.50 A (d = spacing between planes).

For comparison, a similar thread was made using the methyl ester of 4 - /? - oxyethoxybenzoic acid and the diglycol ester of terephthalic acid in the same molar ratio. Of the

⁶ S thread could not be crystallized (softening point about 70 ° C; strength 1.7 g / den; elongation 45%; shrinkage 75 to 85% in hot water at 100 ° C),

Example 3

175 g of dimethyl ester of terephthalic acid, 128 g of ethylene glycol and 21 g of the methyl ester of py-hydroxypropoxybenzoic acid were mixed. Antimony oxide and zinc acetate were added to the mixture as catalysts, and the mixture was heated under normal pressure to carry out the ester interchange reaction. The methanol thereby distilled off was removed from the system. Subsequently, the copolycondensation under reduced pressure of 0.5 was carried out to 0.1 mm Hg, with a Poiyätherester was obtained (melting point 240 to 243 ° C measured, specific viscosity at 20 ⁰ C in l% solution in o-chlorophenol).

The polyether ester obtained was processed by melt spinning at a temperature of 270 ° C. and then stretched 4.6 times. The thread obtained had a strength of 6.2 g / denier, an elongation of 24% and a Young's modulus of 520 kg / mm ² .

The X-ray diffraction pattern of the copolymer prepared according to this example was different from the X-ray diffraction patterns of the two homopolymers whose monomers were used as starting materials. The copolymer was highly crystallizable and, in the crystallized state, showed main maxima in the X-ray diffraction pattern at d = 3.46, 5.08 and 3.93 A.

Example 4

A mixture of 58 g of the dimethyl ester of terephthalic acid and 43 g of ethylene glycol was treated with cobalt acetate mixed as a catalyst and heated to 220 ° C to carry out the ester exchange reaction. Separated of this was a mixture of 52 g of ethylene glycol and 157 g of the ethyl ester of p-γ-hydroxypropoxybenzoic acid with antimony acetate as a catalyst in another vessel and to carry out the Ester interchange reaction heated to 190-230 ° C.

The two reaction mixtures obtained were combined and heated under a reduced pressure of 0.5 to 0.1 mm Hg to 270 to 280 ° C. in order to carry out the polycondensation reaction. This gave a polyether ester which had a specific viscosity of 1.43, measured at 20 ° C on a 0.5% solution in a mixture of phenol and tetrachloroethane (60:40), and had a melting point of 180 to 182 ° C. The product obtained in this way was processed by melt spinning at 200 ° C, The felts were drawn 4.3 times to give a product having a strength of 5.6 g / denier, an elongation of 32%, a Young's modulus of 490 kg / cm ² and a shrinkage of 1 to 2% in had hot water at 100 ° C.

The X-ray diffraction pattern of the copolymer was different from the X-ray diffraction pattern of the two homopolymers whose monomers were used as starting materials. The crystallized product showed sharp main maxima at d = 4.34, 3.30 and 3.77 Å.

A similar thread was made for comparison, but using the unit

O - - CH ₂ - CH ₂ O

CO-

and the ethylene terephthalate unit in the same molar ratio as in the previous example. Here a thread was obtained whose X-ray diffraction pattern showed no crystallinity. Softening point 80 ° C, strength 1.6 g / den, elongation 42%, Young's modulus

160 kg / cm ⁷ , shrinkage 75 to 80% in hot water of 100 ° C.

Example 5

From the copolyether ester prepared according to Example 4, a film which had a width of 50 cm and a thickness of 0.1 mm was produced by extrusion. The film was subsequently stretched first in the longitudinal direction and about 3 times in the transverse direction 2.7 times at a temperature of 80 to 85 ⁰ C to obtain a transparent isotropic film was obtained

which had a tensile strength of 20 to 22 kg / cm ² and an elongation of 40 to 45%.

Claims (2)

Patent claims: 1. Process for the production of polyether esters by polycondensing ethylene glycol with terephthalic acid and a ρ-ω-hydroxyalkoxybenzoic acid or ester-forming derivatives of these acids, characterized in that that as p-w-hydroxyalkoxybenzoic acid the p-y-hydroxypropoxybenzoic acid or their esler-forming derivatives are used. 2. Use of the polyether esters obtained according to claim 1 for the production of fibers and films and molded parts.