RU2487205C1 - Method of modifying polyester fibre - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves modifying polyester fibres by treating, at room temperature, with a composition which contains 20.00-25.00 pts.wt methylphosphite borate, 75.00-80.00 pts.wt water, 20.00-25.00 pts.wt ammonia and 0.30-0.75 pts.wt phenol-formaldehyde resin SF-282. Treatment is carried out for 1 minute at 20°C, followed by temperature control at 150°C for 30 minutes.

EFFECT: high fire-resistance, improved physical and mechanical properties and heat-resistance of polyester fibre, considerable simplification of the method of modifying said fibre.

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Description

The invention relates to the textile industry, to methods for flame retardant processing of polyester fibers, and can be used in aircraft, automotive, for the manufacture of technical textiles and for other special purposes.

A known method of fire-retardant finishing of textile materials from cellulose fibers, which consists in impregnating them with a composition comprising the reaction product of nitrilotrimethylphosphonic acid with a nitrogen-containing substance and water, at a temperature of 30-70 ° C for 3-10 s and squeezed to a wet gain of 80-90%. Next, the material is dried at 90-220 ° (US Pat. 2184184 Russia, D06M 13/432; publ. 06/27/01).

However, this method requires drying the impregnated cord at high temperature and is intended only for materials made of cotton, linen and viscose fibers.

A known method of flame retardant processing of textile materials, which consists in impregnating samples of nylon fabric and cotton knitted fabric with a composition containing a derivative of chlorendic acid and an organic solvent, in a batch at 20 ° C for 5 minutes, followed by drying in air (Copyright certificate 953045 USSR, D06M 13/20; publ. 08.23.82).

However, this method uses a multicomponent modifying composition in conjunction with a solvent harmful to the environment and human health.

Also known is a method of modifying polyamide fibers, which consists in impregnating them with a composition containing methyl phosphite borate, water and polyethylene polyamine, followed by drying and temperature control (US Pat. 2346095 Russia, D06M 13/50; publ. 02/10/09).

However, this method requires drying the impregnated fibers and is intended only for materials made of polyamide fibers.

A known method of modifying synthetic fibers, which consists in impregnating them with a composition containing phosphorus-containing methacrylate, ammonia and sodium persulfate, followed by drying (Pat. 2330136 Russia, D06M 14/08; publ. 07.27.08).

However, this method does not increase the heat resistance of the modified fibers.

The closest in technical essence is a method of modifying polyamide fibers by treating them with a composition including methylphosphite borate, water, triethanolamine and an aqueous solution of carboxymethyl cellulose at 20 ° C for 1 min, followed by drying in air and thermostating at 100 ° C for 30 min ( Patent No. 2378427 Russia, D06M 13/447; publ. 10.01.10).

However, this method of obtaining flame retardant polyamide fibers is time-consuming.

Objective: to develop a method for producing modified polyester fibers that does not require complex hardware design, is not time-consuming and allows to obtain products based on them with increased fire resistance, physical and mechanical properties, and heat resistance.

The technical result is to simplify the method of producing modified polyester fibers, increase their fire resistance, strength, heat resistance and resistance to thermal oxidative degradation.

The technical result is achieved by the fact that the method of modifying polyester fibers by treating at room temperature with a composition comprising a phosphorus-containing compound methylphosphate borate 20.00-25.00 wt.h. and water 75.00-80.00 parts by weight for 1 minute at 20 ° C followed by temperature control for 30 minutes, characterized in that the treatment is carried out by a composition additionally containing ammonia 20.00-25.00 wt.h. and phenol-formaldehyde resin SF-282 0.30-0.75 parts by weight, and thermostating is carried out at 150 ° C.

It is established that the reason for increasing fire resistance, heat resistance, and resistance to thermal oxidative degradation of polyester fibers is the formation of a thin fire-retardant film on the fiber surface, which inhibits the combustion process due to the formation of a “coke cap” that covers the surface from the heat flux, which limits the flow of oxygen to the combustion source.

The increase in fiber strength is due to the bonding of individual filaments to each other during thermal fixation and the localization of microdefects on their surface with an impregnating composition, since microdefects are the root cause of the destruction of fibers when exposed to external stresses.

Methyl phosphite borate was previously used for flame retardant modification of cellulosic materials (RF patent No. 2254341, C1 CB 15/05, publ. 06/20/05).

Ammonia (GOST-6221-90) is used for the production of nitrogen fertilizers (ammonium nitrate and sulfate, urea), explosives and polymers, nitric acid, soda.

Phenol-formaldehyde resin SF-282 (TU 2221-034-10687966-2000) is intended for the manufacture of latex-resin compositions for the impregnation of tire cord and fastening rubbers to textile materials.

This method can significantly simplify the modification of polyester fibers by eliminating the drying stage.

The use of a 20-25% aqueous solution of methylphosphite borate is most optimal. A decrease in the concentration of methylphosphite borate does not allow the self-extinguishing effect to be achieved, and an increase in the concentration reduces the strength of the fiber.

Using 20-25 parts by weight ammonia is most optimal. With a decrease or increase in the ammonia content in the flame retardant, the flame retardant and strength properties of the polyester fibers deteriorate, as the acidity of the medium changes.

The use of 0.30-0.75 parts by weight of phenol-formaldehyde resin SF-282 is most optimal. With an increase or decrease in the content of phenol-formaldehyde resin in the impregnating composition, the fire resistance, heat resistance and strength of the polyester fibers decrease.

It should be noted that this modification method does not require high temperatures and complex hardware design.

The treatment is carried out as follows: the initial samples of polyester fibers are treated with a composition containing a 20% aqueous solution of methylphosphite borate, ammonia and a 15% aqueous solution of phenol-formaldehyde resin SF-282. Then the fibers are thermostated for 30 minutes at 150 ° C.

The invention is illustrated by the following examples.

Example 1. Samples of polyester fibers (50 cm long) are placed for 1 minute in a 20% aqueous solution of methylphosphite borate, previously neutralized with an ammonia solution of 20 wt.h. to pH 7, containing 0.3 wt.h. phenol-formaldehyde resin SF-282, followed by extraction and thermostating for 30 minutes at 150 ° C.

Examples 2-3 are carried out as in example 1, changing the content of methyl phosphite borate, ammonia and phenol-formaldehyde resin.

The obtained samples are tested for resistance to burning (OST 190094-79), breaking load and elongation at break (GOST 23785.1-2001), heat resistance (GOST 23785.6-2001), resistance to thermal oxidative degradation (studies were carried out at a temperature of 400 ° C for 30 minutes). The results are shown in table 2.

From table 2 it is seen that the processed polyester fibers exhibit greater resistance to thermal oxidative degradation. For example, the presence of a coke residue of 60% at 400 ° C in the polyester fibers according to recipe 1 indicates the effective action of the flame retardant composition as a coke formation catalyst during thermal oxidative degradation of the studied fibers. The use of this composition helps to increase the breaking load from 18 kgf to 26 kgf, as well as increase the heat resistance of polyester fibers from 89% to 96%.

Table 1 Composition Components The content of components, parts by weight I II III Methyl Phosphite Borate 20.00 25.00 25.00 Water 80.00 75.00 75.00 Ammonia 20.00 25.00 25.00 Phenol formaldehyde resin (SF-282) 0,300 0.375 0.750

table 2 The properties Indicators for composition No impregnation one 2 3 Breaking load, kgf eighteen 25 26 26 Elongation mm eighteen 32 33 33 Fire resistance Burns Fades out Fades out Fades out Heat resistance,% 89 92 96 92 Coke residue,% (400 ° C) 0 60 39 fifty Weight gain,% - 7 9 10

The technical and economic effect obtained from the use of this modification method consists in the fact that its application can significantly increase fire resistance, resistance to thermal oxidative degradation, heat resistance, breaking load of polyester fibers, does not require complex hardware design, long processing time, excluding the drying stage, which avoids the multi-stage process of impregnation.

Claims (1)

A method of modifying polyester fibers by treating at room temperature with a composition comprising a phosphorus-containing compound methylphosphite borate 20.00-25.00 parts by weight and water 75.00-80.00 parts by weight for 1 min at 20 ° C, followed by temperature control for 30 min, characterized in that the treatment is carried out by a composition additionally containing ammonia 20.00-25.00 wt.h. and phenol-formaldehyde resin SF-282 0.30-0.75 parts by weight, and thermostating is carried out at 150 ° C.