CS221014B1 - Polyamides, especially fibers, resistant to the degradation effects of heat and light - Google Patents

Abstract

The invention deals with polyamides, especially polycaprolactate, with increased resistance to the degrading effects of heat and light. Increased resistance of the polyamide is achieved by adding a complex compound of copper with benzimidazole in an amount corresponding to 20 to 300 ppm, preferably 50 to 250 ppm of copper per weight of the polyamide.

Description

221014

The invention relates to polyamides, in particular fibers resistant to the degradation effects of heat and light.

Increasing the resistance of polyamide fibers to the adverse effects of heat, light and atmospheric effects is virtually the start of their production by one of the prime problems in extending their useful life. During the development of new polyamide fiber manufacturing techniques, many effective protective agents have been found, but only a few have found application in the high-performance scale.

The stabilizers used are agents which increase the resistance of the polyamide fibers to the effects of heat or light, or have a universal character. Inter-stabilizers with universal character can also include some complex compounds of metals, mainly media. Their application to the most effective methods of stabilizing polyamides, since due to their high potency, the use of several times less than the application of known organic compounds is sufficient.

In selecting the stabilizers, they are not only bound by the fiber production conditions and the effectiveness of the stabilizer, but the condition of further processing of the fibers and the purpose of their use is required. For example, in the manufacture of cord fibers, it is necessary to influence the effect of the stabilizers not only in terms of increasing the resistance of the fibers to heat-degradable degradation, but also in terms of dynamic fiber fatigue values and rubber adhesion. In our production conditions, the use of a universal stabilizing system is most advantageous, since the use of specific heat or light stabilizers would leave production from one kind of stabilized fiber to the other, significant raw material losses, and loss of production capacity.

SUMMARY OF THE INVENTION The present invention relates to polyamides, particularly filaments, stabilized against degradation effects of heat and light, comprising polyamide and the addition of a complex benzimidazole compound in an amount corresponding to 20 to 300ppm of medium, preferably 50 to 250ppm of media weight polyamide. Said system can be applied at any stage of the production of polyamides, preferably prior to polymerization or dusting of the granulate.

We have found that the complex compound with benzimidazole is one of the universal stabilization systems. This compound provides polyamide, high fiber resistance, very good thermal and light degradation resistance. Experimental tests have shown that it is most preferred to apply said complex compound in an amount corresponding to 20 to 300 ppm of medium, preferably 50 to 250 ppm of medium per weight of polyamide.

The stabilizing system can be added at any technological point of production of the polyamides, preferably before polymerization or to the polymer prior to spinning. The addition of a complex compound with benzimidazole prior to polymerization is made possible by its sufficient thermostability under the polymerization conditions, as determined by differential temperature analysis records. In the application of stabilizers, it is very important to detect the corrosive effects of the stabilizing system on the construction material of the process equipment under the conditions of the production of polyamide fibers. As we found out in the laboratory conditions, the corrosive effects of the mentioned system on the structural material ČSN 17 246 after 1000 hours of treatment are negligible. The preparation of a complex compound with benzimidazole consists in dissolving 10 g of copper (II) acetate in 150 cm 3 of water and 5 g of ortho-phenylenediamine in 50 cm 3 of methanol.

The solutions are decanted and 8 g of formaldehyde in 20 cm @ 3 of methanol are added. On occasional warm water, the mixture was shaken with occasional shaking. In a short time, the compound will start to be cleared by the medium.

After disappearance of the blue coloration of the copper compound, the precipitate is filtered off on a frit, washed with several times with water and methanol. The resulting complex is dried in the desiccator and dried in a drying oven at 110-120 ° C. The preparation yields 7 g of the benzimidazole complex compound, which corresponds to a yield of 78.1%.

The color of the compound is viable, but the air preparations oxidize to a complex compound of a monobasic medium with a benzimidazole which is highly stable so that the samples have different shades of brown.

Theoretical: 35.17% Cu, 46.53% C, 2.79% H, 15.50% N; Found: 32.56% Cu, 41.33% C, 2.66% H, 12.52% N.

The complex is practically insoluble in ordinary solvents, dissolves only or in dioxane. It thermally decomposes at 270 ° C. The compound is likely to have a chain structure consisting of polymeric backbones. Two contiguous media atoms linked through two nitrogen atoms from a pendant imidazole ring. Example 1

The dried polyamide granulate with a relative viscosity of 2.9 (20 ° C, H 2 SO 4) was dusted with a complex compound with benzimidazole in such a way that the medium content was 80 ppm, and the granulate thus treated was spun in a conventional extruder method. tensile strength of 6.7cN / dtex and elongation of 26.8%.

The polyamide fiber thus stabilized

Claims (2)

Polyamides, in particular fibers, resistant to the degradation effects of heat and light, characterized in that they consist of polyamide and the addition of a complex compound of the medium with benzYNALEZ imidazole in an amount corresponding to 20 to 300 ppm, preferably 50 to 250 ppm of medium per weight of polyamide.