DD152569A1 - METHOD FOR PRODUCING STABILIZED LINEAR POLYESTERS OR COPOLYESTERS - Google Patents

Abstract

The invention relates to a process for the preparation of colorless and clear linear polyesters or copolyesters with high thermooxidative stability and their processing into films, fibers and foreign bodies. The essence of the invention is the use of ester amides or phosphorous acids of the general formula wherein Y = aliphatic or aromatic rings and R &sub1;! = Alkyl-substituted aryl radicals, as thermal stabilizers in the manufacturing process.

Description

Title of the invention. ·.

Process for the preparation of stabilized linear polyesters or copolyesters

field of use

The invention relates to a process for the preparation of colorless and clear linear polyesters or copolyesters with high thermal and thermooxidative stability.

Characteristic of the known technical solutions

In the preparation of linear polyesters or copolyesters by transesterification of dimethyl terephthalate with glycols and subsequent polycondensation, it is known to transesterification catalysts, such as Zn (ac) p, Mn (ac) ₂ or Co (ac) ₂ , the thermal and therroooxidative degradation of Promote polyester melt to deactivate after completion of Urnesterungsreaktion by a suitable blocking agent. The polycondensation is then carried out using catalysts such as antimony trioxide, germanium dioxide or titanium tetrabutylate 5 whose catalytic activity is not significantly affected by the blocking agent (DWP 30,903). As blocking agents for the mentioned Uinesterungskatalysatoren are inorganic or organic .Phosphorverbindungen, such as H ₃ PO ₃ (Ja P 7 461 279), H ₃ PO ₄ . (DAS 1152 259)> (ϊίΗ, _μ ) ₂ ΗΡ0 ₄ (DAS 1 141 453), esters of phosphoric acids (DWP 30 903) and phosphonates (DOS 1 958.168). A disadvantage of .these methods is the '.Tatsache that the Thernoosidative degradation of. Polyesters are not essential to these compounds. improve.

BOB 44 »^» "^ ™ *

It is also known polyester by adding antioxidants such as Dodeoylgallat (DWP 85 84-5) _? Tri-p-tert-butylphenyl phosphite (DOS 1,694,550) or o-phenylene ~ 3,5-di-tert-butyl-ii-thiophene-3-phosphate (DWP 135,209) to protect against thermo-dative degradation , The disadvantage of these methods is that, in addition to the antioxidant, blocking agents are required for the esterification catalyst. Another disadvantage is the yellow or gray color of the polyester when using the compounds mentioned *

Aim of the invention

Ci *

The aim of the invention is the preparation of colorless and clear, linear polyesters or copolyesters with high stability against thermal and therniooxidative degradation. "By the use of the method, once by the transesterification catalysts such as _e Zn (ac) pj Mn (ae) p and Co ( ac) ₂ favored thermal degradation of polyester melts eliminated, as well as the stability against oxidative influences are substantially increased «

Explanation of the essence of the invention

The invention has for its object to provide a comparison with the prior art improved process for producing linear polyester or copolyester with high thermal and thermooxydatiyer stability and good color to develop, the stabilizer acts as a blocking agent of the transesterification catalysts and at the same time as an antioxidant. It has been found that in the production and processing of linear polyesters or copolyesters, products having high thermal and thermo-oxidative stability and light color are obtained when organic phosphorus-nitrogen compounds of the general formula.

X ^ ^> P -N- P ^ "^ Y

Oj-O ^ alkyl, cycloalkyl "aryl and substituted Ar: / Ir st 'and

alkyl

a bivalent radical consisting of "the radicals of formulas, A j B, C. and D

C.

-CH ₂

where R-, to R,

^CH

(A)

(B)

(O)

(D)

_{1 are} independently hydrogen, C ₁ -C 6 alkyl, C ₁ -C 4 hydroxyalkyl or carboxyethyl groups in formulas (A) and (B)

before the transesterification, after the transesterification during or after the polycondensation or before or during the processing in a concentration of 0.1 to 10 times, preferably 0.5 to 2 ^ 0 times the molar concentration of the transesterification or esterification catalysts used as stabilizers. "

The efficacy of these compounds is surprising, since, in general stabilizers, the nitrogen and / or sulfur in the molecule _s a considerable deterioration of color property of the polyester-condition, ·

applications

Example 1 (Comparative Example of the Prior Art)

2000 g of dimethyl terephthalate are with. 14-00 g of alkylene glycol in an autoclave with the addition of 0.6 g of Mn (ac) _o with stirring at a [temperature of 150 - 220 ⁰ C reacted. The transesterification product is treated with O ', 7 g antimony trioxide and 3 mol -Priphenylphos-

ix. ".

phat per mole of Mn (ac) p and then polycondensed under a pressure of 66 Pa at 290 ⁰ C in 120 min. The polyester showed the following properties (see table).

Example 2 (Comparative Example of the Prior Art)

Production of polyester as described in Example 1, in place of Tripheny! Phosphate 1.5 moles per mole EUPCU Mn (ac) ₂ used as a blocking agent 7? Ird _e Eigenschaften.siehe table,

Example 3

Preparation of polyester as in Example 1, wherein instead of Tripheny! Phosphate 1.0 mol of the "compound

P-N-P

per mole of Mn (ac) o is used. Properties see table

Example 4.

Preparation of Polj ^ ester as in Example 1, ^ obei in place of Tripheny! Phosphate 1.2 mol of the compound

per mole of Hin (ac) 2 is used. Properties see table,

Table of analytical data of the polyesters of Examples 1-4

1 LV, GOOH · ~ 1 yx Agu.g) colour φ (° o) (Min) RTB (SS) example 2 1,382 23 light . Gray 235 - 94.0 example 3 1,391 29 Gray 242 ' .- 94.5 example 4 1 _p 384 24 White 102 97.3 example 1,387 22 White - 163 98.0

Solution viscosity; measured in phenol / tetrachloroethane 1 j1 at 20 ⁰ O.

Concentration of the carboxyl endgroups.

(Temperature of the onset of oxidation in dynamic differential diagnosis (DTA) Heating rate 4IC per min,.

Stability Period in the isothermal DTA, isothermal temperature 24.5 ⁰ O

Relative temperature resistance, reduction of the relative solution viscosity after annealing at 306 ⁰ C and. 36 min

Claims (1)

claim Process for the preparation of stabilized linear polyesters or copolyesters with high thermal and theraooxidative stability and light color, characterized in that organic phosphorus-nitrogen compounds of the general formula X ^ "^, P-N-P ^^ Y R, -. C 1 -C 4 alkyl is cyanoalkyl, aryl and C 1 -C 4 alkyl-substituted aryl and X is a bivalent radical consisting of the radicals of the formulas (A), (B), (C) and (D) ^R 2 R ₈ R -C- y 3 1 C. -CHp CHp- • R⁹ / \ ° ^R 10 ^R 11 -CH 1 CH ₂ - (A) (B) (C) (D) in which R ₂ to R ₁ independently of one another are hydrogen, C ₁ -C 10 -alkyl, C 1 -C 4 -hydroxyalkyl or carboxyalkyl groups in the formulas (A) and (B) are before the transesterification after the transesterification, during or after the polycondensation or before or during the processing of the polyester in a concentration of 0.1 to 10 times, preferably 0.5 to 2 times the molar concentration of the for the transesterification or esterification catalysts used corresponds -Be ^ AIS stabilizers added _o