Use of an additive composition for the preparation of polycondensation polymers

Abstract

The present invention relates to the use of an additive composition for the preparation of polycondensation polymers wherein the additive combination is present in the polycondensation reaction and wherein the additive combination comprises one or more compounds of the formula (A) wherein R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17, and R.sub.18 are independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert.-butyl, linear or branched pentyl, linear or branched hexyl, linear or branched heptyl, linear or branched octyl or linear and branched nonyl groups, and R.sub.21 and R.sub.22 are independently selected from the group consisting of hydrogen, methyl, O(C.sub.1-C.sub.6-Acyl) and OR.sub.3, wherein R.sub.3 is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert.-butyl linear or branched pentyl, linear or branched hexyl, linear or branched heptyl, linear or branched octyl or linear and branched nonyl groups, and one or more sterically hindered organic phosphorous(lll) compounds selected from the group consisting of sterically hindered phenyl phosphonites and sterically hindered phosphites. ##STR00001##

Claims

1. A process for preparing a polycondensation polymer, the process comprising preparing the polycondensation polymer from a polycondensation reaction of monomers wherein an additive combination is present in the polycondensation reaction, wherein the additive combination comprises one or more compounds of the formula (A) ##STR00015## wherein R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17, and R.sub.18 are independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert.-butyl, linear or branched pentyl, linear or branched hexyl, linear or branched heptyl, linear or branched octyl or linear and branched nonyl groups, and R.sub.21 and R.sub.22 are independently selected from the group consisting of hydrogen, methyl, O(C.sub.1-C.sub.6-Acyl) and OR.sub.3, wherein R.sub.3 is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert.-butyl linear or branched pentyl, linear or branched hexyl, linear or branched heptyl, linear or branched octyl or linear and branched nonyl groups, and one or more sterically hindered organic phosphorous(III) compounds of formula (B) ##STR00016## wherein each R.sub.41, R.sub.42, R.sub.43, R.sub.44, R.sub.51, R.sub.52, R.sub.53 and R.sub.54, are independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert.-butyl linear or branched pentyl, linear or branched hexyl, linear or branched heptyl, linear or branched octyl or linear or branched nonyl, and cumyl groups, and wherein the additive combination comprises a proportion of from 95% to 98% by weight of the compounds of the formula (A) and 2% to 5% by weight of the sterically hindered organic phosphorous(III) compounds based on the total amount of the additive combination, and wherein the additive combination is used in the presence of an acid.

2. The process as claimed in claim 1, wherein the additive combination is present in the polycondensation reaction mixture before the polymerization reaction starts.

3. The process as claimed in claim 1, wherein the additive combination is present in the polycondensation reaction mixture before the reaction temperature is higher than 100 C.

4. The process as claimed in claim 1, wherein the polycondensation polymer is a polyamide or a polyester.

5. The process as claimed in claim 1, wherein the sterically hindered organic phosphorous(III) compounds are sterically hindered phenyl phosphonites.

6. The process as claimed in claim 1, wherein the sterically hindered organic phosphorous(III) compound is a compound of the formula (B1) ##STR00017##

7. The process as claimed in claim 1, wherein the compound of the formula (A) corresponds to formula (A1) ##STR00018##

8. The process as claimed in claim 1, wherein the additive combination is used in an amount of from 0.01 to 10 weight percent, relative to the weight of the polycondensation polymer prepared.

9. The process as claimed in claim 1, wherein the additive combination is used in an amount of from 0.1 to 0.5 weight percent, relative to the weight of the polycondensation polymer prepared.

10. The process as claimed in claim 1, wherein the acid is selected from the group consisting of acetic acid, adipic acid, paraterephthalic acid, isophthalic acid and benzoic acid or a mixture thereof.

11. The process as claimed in claim 1, wherein the total amount of the acid is from 0.01 to 5 weight percent, relative to the weight of the polycondensation polymer prepared.

Description

EXAMPLES

(1) Polymerization speed (RT/min) has been measured in comparison to the state-of-the art existing chain stopping systems taken as market reference (based on paraterephthalic acid).

(2) Polyamide chips have been characterized in terms of Color, Relative Viscosity (RV), Amino End Groups (AEG) and Carboxylic End Groups (CEG).

(3) Amino End Groups (AEG) and Carboxylic End Groups (CEG) were determined using acid/base titration.

(4) RV was measured using capillary viscometric analysis with a 50/50 by weight mixture of phenol/orthodichlorobenzene at 25 C.

(5) Typical example for the polymerization of caprolactam:

(6) In the batch wise process, caprolactam is molten with a small amount of water (less than 2 wt.-%) at a starting temperature of about 80-85 C. The chain stopping and catalytic formulations 1 to 6 (Table 2) are then added (0.28% acid, 0.1% composition, 0.05%-0.1% amine) to the mixture. After 8 hours of stirring at 80-85 C., the solution is heated at higher temperature (250-260 C.) until the desired molecular weight is achieved. The finished polymer is then granulated and the pellets extracted with a Soxlhet for 24 hours.

(7) Thereafter, the pellets are dried at 80 C. under vacuum for 24 hours and samples of the obtained material analysed. The polymer is analysed by conventional analytical methods as shown in Table 2.

(8) Additive composition 1, 2, and 3: compound of formula (A1)+compound of formula (B1) in different relative proportions as listed in Table 1

(9) TABLE-US-00001 TABLE 1 RT (reaction time in min) of different composition of A1 and B1 A1 B1 RT No. Formulation (weight %) (weight %) (min) 0 PA-6 (reference) 100 1 Composition 1 95.0 5.0 80 2 Composition 2 91.0 9.0 90 3 Composition 3 (comp) 83.0 17.0 100

(10) Composition 1 shows the optimum reaction time.

(11) TABLE-US-00002 TABLE 2 Polyamide-6 chips characterization. AEG CEG YI No. Formulation RT RV (meq/kg) (meq/kg) (DIN 6174) 1 PTA (comp.) 100 1.76 32 78 37 3 PTA/Nylostab S-EED 100 1.76 39 81 36 (comp.) 4 PTA/Additive comp. 1 80 1.79 40 78 34 5 PTA/Additive comp. 1/ 80 1.76 42 69 35 Benzylamine 6 PTA/Additive comp. 1/ 80 1.77 33 72 38 Hostavin N30 comp.: comparative example RT: reaction time in min RV: relative viscosity AEG: Amino End Group CEG: Carboxylic End Group Color YI: DIN 6174 PTA: paraterephthalic acid

(12) TABLE-US-00003 TABLE 3 Color measurement (YI) after thermal treatment at 200 according to DIN 6174 1 5 10 No. Formulation (min) (min) (min) 3 PTA/Nylostab S-EED (comp.) 0.8 12.05 19.18 4 PTA/Composition 1 0.2 6.0 11.6

(13) The tested specimens were prepared as follows. The different polyamide pellets were formed into panels 1 mm thick by injection molding at temperatures of from 280 to 300 Celsius, followed by either punching of the tested samples to 35 mm40 mm or by direct injection molding of tensile bar specimens.

(14) The color determination is reported in terms of the Yellowness Index (YI) determined in accordance with the ASTM E-313 Yellowness Test. The higher the value, the lower the color quality.

(15) In addition, the color is measured according to the regulations of the CIE (International Commission on Illumination) and in accordance with the ISO 7724/3 and DIN 6174 standards. The higher the positive value of b*, the more pronounced the yellowing.