RU2378428C1 - Composition for fire-resistant treatment of polyamide fibres - Google Patents

Abstract

FIELD: textile industry.

SUBSTANCE: composition for fire-resistant treatment contains the following components, wt parts: 20 of methyl phosphite borate, 1.3 of triethanolamine, 80 of water and 0.20-0.65 of 1% water solution of carboxymethylcellulose.

EFFECT: increased fire-resistance, water resistance, strength and resistance to thermal-oxidative destruction of polyamide fibres, increased strength of polyamide cord connection to rubber on the basis of chloroprene rubber.

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Description

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

A known composition for fire-retardant finishing of textile materials from cellulose fibers, including the product of the interaction of nitrilotrimethylphosphonic acid with a nitrogen-containing substance and water, and it contains urea as a nitrogen-containing substance (Pat. 2184184 Russia, D06M 13/432. Publ. 27.06.01).

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

A known composition for flame retardant processing of textile materials, including a derivative of chlorendic acid and an organic solvent, and in order to increase the fire resistance of materials from polyamide or cellulose fibers, it additionally contains antimony trioxide (Copyright certificate 953045 USSR, D06M 13/20. Publ. 23.08.82).

However, this composition has a complex formulation, and a toxic substance is used as a solvent.

Closest to the invention in technical essence is a composition for flame retardant chemical fibers based on a 5-7% aqueous solution of phosphorus-containing monomer (Fakril-M) using a redox system Fe ²⁺ -N ₂ About ₂ (Application for invention 93012912 Russia, publ. 09/20/96).

However, this composition must be grafted onto the fibers for a long time and at high temperature.

Objective: development of a composition for flame retardant processing of polyamide fibers, providing increased fire resistance and physical and mechanical properties of the fibers.

The technical result is to increase fire resistance, strength and resistance to thermal oxidative degradation of polyamide fibers, water resistance, increase the bond strength of polyamide fiber with rubber based on chloroprene rubber.

The technical result is achieved in that the composition for flame retardant treatment of polyamide fibers, including a phosphorus-containing compound and water, moreover, as a phosphorus-containing compound, it contains methylphosphite borate and additionally triethanolamine and a 1% aqueous solution of carboxymethyl cellulose in the following ratio, wt.h. : methylphosphite borate - 20, water - 80, triethanolamine - 1.3, 1% aqueous solution of carboxymethyl cellulose - 0.20-0.65.

We found that the reason for increasing fire resistance and resistance to thermal oxidative degradation of polyamide fibers is the formation of a thin fire-retardant film on the surface of the fibers, which inhibits the combustion process due to the formation of a foamed layer with better thermal conductivity.

The increase in fiber strength is due to the localization of microdefects on its surface with an impregnating composition, since microdefects are the root cause of the destruction of the fiber when exposed to external stresses.

The increase in water resistance is explained by the introduction of a 1% aqueous solution of carboxymethyl cellulose into the impregnating composition, which prevents the washing out of the impregnating composition from the surface of the fiber.

The adhesion of the polyamide fiber to the rubber increases, apparently due to the emergence of new polar functional groups on the surface of the fiber, which enter into physical interaction with chloroprene rubber.

Methylphosphite borate - was used earlier for flame retardant modification of cellulosic materials (RF Patent 2254341 C1, СВВ 15/05. Publ. 20.06.05).

Triethanolamine (TU 6-02-916-79) is used as an absorbent of "acid" gases, as a raw material for the production of surfactants, in pharmaceuticals and cosmetics.

Carboxymethyl cellulose (TU 6-55-39-90) is used in synthetic detergents as a stabilizer, as a thickener for aqueous media.

The use of this composition can significantly simplify the modification of polyamide fibers. So, to achieve a positive effect, the use of highly concentrated flame retardants is not required. The use of a 20% 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 fibers.

With a decrease or increase in the content of triethanolamine in the flame retardant composition, the flame retardant and strength properties of polyamide fibers deteriorate, as the acidity of the medium changes.

With an increase in the content in the impregnating composition of a 1% aqueous solution of carboxymethyl cellulose, the fire resistance of the fiber decreases, and with a decrease in the strength of the polyamide fiber and the resistance to leaching of the impregnating composition from the surface of the fiber decreases.

It should be noted that the use of this composition for flame retardant processing of polyamide fibers does not require high temperatures and complex hardware design.

An example of the preparation of flame retardant modifying composition.

Triethanolamine is poured into a stirred reactor containing a 20% aqueous solution of methylphosphite borate with stirring. Stirring is carried out for 1-2 minutes at room temperature, then a 1% aqueous solution of carboxymethyl cellulose is added and mixed for 5 minutes.

Get impregnating compositions 1-3, the formulation of which is shown in table 1.

Compounds 1-3 are impregnated for 1 minute polyamide cord brand 232 KNTS and dried at room temperature (20 ° C) to constant weight. Then thermostat for 30 minutes at 100 ° C.

The invention is illustrated by the following examples.

Example 1. Samples of polyamide fibers (20 cm long) are placed for 1 minute in a 20% aqueous solution of methylphosphite borate, previously neutralized with a solution of triethanolamine to pH 7 and containing 0.20 wt.h. 1% aqueous solution of carboxymethyl cellulose, followed by drying at room temperature, then thermostating is carried out for 30 minutes at 100 ° C.

Examples 2-3 are carried out as in example 1, changing the content of a 1% aqueous solution of carboxymethyl cellulose.

The obtained samples are tested for resistance to combustion (GOST 21793-76), tensile strength (GOST 20403-75), resistance to thermal oxidative degradation (studies were carried out at a temperature of 300 ° C for 30 minutes), water absorption (GOST 4650-65 ) The bond strength of the impregnated cord with rubber based on chloroprene rubber (F.F.Koshelev et al. General technology of rubber. - M .: Chemistry, 1978, p.85) was determined by the N-method (GOST 23785.7-89) on a RMI tensile testing machine -60. The results are shown in table 2.

The table shows that with a decrease in a 1% aqueous solution of carboxymethyl cellulose, the physical and mechanical properties of the modified fibers improve. So, when processing polyamide fiber with a flame retardant according to recipe 1, the breaking load increases from 17.5 kgf to 37.6 kgf. In addition, modified fibers exhibit greater resistance to thermal oxidative degradation. The decrease in weight loss from 3.6% to 0.117% at 300 ° C for polyamide fiber indicates the effective action of the flame retardant, as a coke formation catalyst during thermal oxidative degradation of the studied fibers. The use of this composition helps to increase the bond strength of the polyamide fiber with rubber from 3.2 kgf to 4.3 kgf when using the composition of recipe 1.

Table 1 Component The content of components, parts by weight, in the composition one 2 3 Methyl Phosphite Borate 20,0 20,0 20,0 Water 80.0 80.0 80.0 Triethanolamine 1.3 1.3 1.3 1% aqueous carboxymethyl cellulose solution 0.20 0.33 0.65

table 2 Type of test Without Sample No. for examples impregnation one 2 3 Breaking load, kgf 17.5 37.6 21.5 27.6 Elongation mm 32,0 43.6 34.0 40.6 Water absorption,% 17.4 -7.0 -12.4 -13.6 Mass loss% 3.6 0.117 0,120 1,145 Fire resistance Burns Samozatu-
hay h / s 5 s Self extinguishing Do not ignite. Adhesion to rubber based on HC (H-method), kgf 3.2 4.3 3.9 3,5

The technical and economic effect obtained from the use of this composition is that its use can significantly increase fire resistance, water resistance, strength and resistance to thermo-oxidative degradation and adhesion to polyamide fiber rubber, does not require complex hardware design, long processing time, which allows Avoid multi-stage processing.

Claims (1)

Composition for flame retardant treatment of polyamide fibers, including a phosphorus-containing compound and water, characterized in that as a phosphorus-containing compound it contains methyl phosphite borate and additionally triethanolamine and a 1% aqueous solution of carboxymethyl cellulose in the following ratio of components, parts by weight:
Methyl Phosphite Borate twenty Water 80 Triethanolamine 1.3 1% aqueous carboxymethyl cellulose solution 0.20-0.65