RU2270280C1 - Composition for manufacturing polycaproamide thread - Google Patents

Abstract

FIELD: polymer materials.

SUBSTANCE: invention relates to polymer composition based on granulated polycaproamide, which contains polycaproamide, oligomers, water, titanium dioxide, and, additionally, complex modifying additive constituted by 1,1,5-trihydroperfluoripentanol and N,N-bis(2,2,6,6-yrytamethyl-4-piperidiniyl) 1,3-benzenedicarbamide.

EFFECT: increased engineering and thermal resistance of granulate, reduced appearance of low-molecular oligomer compounds during formation, and improved essential properties of thread such as thermal resistance and resistance against oxidative UV destruction.

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Description

The invention relates to the chemistry and technology of polymers, namely to polymer compositions based on granular polycaproamide (granulated PCA), intended for the production of polycaproamide yarn (PKA-yarn).

A known method of producing polycaproamide by hydrolytic polymerization of ε-caprolactam in the presence of an amine thermal stabilizer and octafluoropentanol in an amount of 0.00085-0.001 wt.% (RU 2187517 C 08 G 69/02, 08/20/2002). Its disadvantages are lower light stability and hydrolytic stability of polycaproamide yarn in comparison with the proposed one.

The closest is a composition comprising polycaproamide, oligomers (0-2% wt.), Water (less than 0.4%) and target additives (RU 2114939 D 01 F 6/60, 10.07.1998).

The disadvantage of this composition is the relatively high content of low molecular weight fractions - oligomers. Oligomers and caprolactam plasticize PKA, worsen its processability into PKA-thread (D.E. Floyd. Polyamides. M .: GNTI. 1960, p. 51.), and also worsen the consumer properties of the materials obtained.

The technical result of the invention is to obtain granulate-PCA with increased chemical and thermal resistance, reduction in the formation process of the formation of low molecular weight oligomeric compounds, as well as the production of PCA-filaments with high thermal stability and stability during oxidative UV degradation.

The technical result is achieved by the fact that the proposed composition for the manufacture of polycaproamide filaments, including polycaproamide having a residual moisture content of 0.01-0.015% and containing a low molecular weight fraction - oligomers, and modifying additives, it contains TiO ₂ and complex modifying additive as modifying additives, including 1.1.5-trihydroperfluoropentanol, 1.3-benzene dicarbamide NN-bis (2.2.6.6.-tetramethyl-4-piperidinyl), in the following ratio, wt.%:

Polycaproamide 99,000-99,183 Oligomers 0.650-0.870 TiO ₂ 0,060-0,090 1.1.5-trihydroperfluoropentanol 0.005-0.007 1.3-benzene dicarbamide N.N-bis (2.2.6.6.-tetramethyl-4-piperidinyl) 0,050-0,06 water 0.010-0.015

The essence of the invention is to use the combined effect on the high-temperature process (278 ° C) of the formation of the granular PKA composition composition, its effect on reducing the contribution of adverse reactions leading to the formation of low molecular weight oligomer fractions in the bristles. The proposed composition allowed to reduce the content of low molecular weight fractions of oligomers in the bristles (% wt.) To 0.650-0.870 instead of 2 for the prototype.

Granular polycaproamide is obtained by hydrolytic polymerization of ε-caprolactam, followed by extraction of low molecular weight oligomer fractions, followed by drying in a vacuum drum dryer (where a modifying additive is introduced), followed by spinning, extrusion and drawing of a thread.

Example 1: the invention is illustrated by the following example: in a rotary (4 rpm) vacuum drum dryer operating at a temperature of 110-115 ° C and a vacuum of 20 mm Hg in a nitrogen atmosphere, 400 kg of PKA granulate is loaded with a content of low molecular weight oligomer fractions of not more than (wt%): 0.650-0.870 and 0.060-0.090 TiO ₂ . At the end of the drying stage, 0.02 kg (0.005% wt.) Of 1.1.5-trihydroperfluoropentanol, 0.2 kg (0.05% wt.) Of 1,3-benzenedicarbamide NN-bis (2.2.6.6-tetramethyl-4- pipiredinyl) and continue drying to a residual moisture content of not more than 0.010-0.015%.

Granulate formation (minimum quantity of 100 kg) was carried out on a PP-60-I # 4 spinning machine.

The thread was drawn on a machine KB-150-I-4 at a temperature of 100 ° C.

Breaking load, elongation was determined according to GOST 6611.0-73 and 6611.4-73.

Granular PKA in the proposed composition is resistant to concentrated acids.

In the process of drawing, a PCA thread with a small number of defects was obtained, which is resistant to thermal and oxidative UV destruction. (table 1, 2)

Table 1
Physico-mechanical properties (averaged from 10 experiments) PKA-threads obtained from the proposed composition by heating (temperature 100 ° C) Heating time, min Breaking Strength, N Elongation at break,% Residual elongation,% before heating 14.7 25.1 10.0 90 14.2 23.2 9.3 120 14.2 22.6 9.0 150 11.9 14.6 6.3

table 2 Comparative data on the residual tensile strength of the modified PKA filament when irradiated with light with λ> 300. Modification method The residual tensile strength,% (exposure 575 hours) The residual tensile strength,% (exposure 710 hours) Unmodified PKA 37 thirty Unmodified yarn 1.1.5-trihydroperfluoropentane, 3.5-10 ^-2 % 75 60 1,3-benzenedicarbamide N.N-bis (2.2.6.6-tetramethyl-4-piperidinyl), 0.5% 70 52 The proposed additive is 1.15-trihydroperfluoropentanol, 0.005% and N.N-bis (2.2.6.6-tetramethyl-4-piperidinyl), 0.05% 80 80

Oxidative UV degradation of PKA filaments obtained with the addition of only 1.1.5-trihydroperfluoropentanol to the composition proceeds at a lower rate and is accompanied by an induction period of up to 288 hours (irradiation with light with λ> 300 nm), and after 575 hours the residual tensile strength of PKA- the filament is 75%, while in a mixture of 1.1.5-trihydroperfluoropentanol with 1.3-benzenedicarbamide NN-bis (2.2.6.6-tetramethyl-4-pipiredinyl), the residual tensile strength increased to 80% (Table 2). When the exposure time of 710 hours, the residual tensile strength in the proposed composition remains about 80%. Whereas each of the separately taken ingredients in the amounts used for the PKA strand does not give the desired result. The thermal stability of the filament, which was judged by the change in the physicomechanical parameters of the PKA filament (table 2) during heating, is higher for samples obtained from the proposed composition.

The technical result achieved is explained: firstly, by a decrease in defective structures in the polycaproamide yarn at the stage of its drawing, which leads to a decrease in oxygen diffusion through the defective sections, and secondly, by the participation of polyfluorinated alcohol in the regeneration of nitroxyl radicals due to the formation of hydroxylamine and its participation in reactions with peroxy radicals. Regeneration of nitroxyl radicals in the presence of 1.1.5-trihydroperfluoropentanol according to the scheme:

at the next stage, nitroxyl radicals are generated and their reaction with alkyl radicals:

Thus, when using the proposed composition, an increase in light fastness is achieved by 43-50% compared with the prototype.

Claims (1)

Composition for the manufacture of polycaproamide yarn, comprising polycaproamide having a residual moisture content of 0.01-0.015% and containing a low molecular weight fraction - oligomers, and modifying additives, characterized in that it contains TiO ₂ and a complex modifying additive as modifying additives, including 1.1.5 -trihydroperfluoropentanol, 1.3-benzene dicarbamide NN-bis (2.2.6.6.-tetramethyl-4-piperidinyl) in the following ratio, wt.%: Polycaproamide 99,000-99,183 Oligomers 0.650-0.870 TiO ₂ 0,060-0,090 1.1.5-trihydroperfluoropentanol 0.005-0.007 1.3-benzene dicarbamide N.N-bis- (2.2.6.6.-tetramethyl-4-piperidinyl) 0,050-0,06 Water 0.010-0.015