RU2491376C2 - Method of obtaining cellulose fibre - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: fibre is impregnated in centrifuge with modifying water composition, with module 2.5-3.5. Fibre is kept in modifying composition for 10-30 minutes in static state, then in rotating centrifuge at rate 800-1200 rev/min for 10-30 minutes. Fibres are pressed up to residual moisture content 70-90% and dried to residual moisture content 5-14%.

EFFECT: method is economical due to reduction of amount of technological equipment; obtained cellulose fibres possess high parameters of flame retardation and resistance to wet treatment.

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Description

Introduction

The invention can be used in the textile industry for the production of mechanically peeled short flax fiber and other cellulose fibers with fire and / or bioprotective properties, suitable for the manufacture of nonwoven materials of various surface densities for industrial use, used in the construction industry (heat and noise insulation materials, linoleum substrate etc.), automotive industry (soundproofing and decorative panels), furniture industry (cushioning material).

State of the art

The use of technical materials involves contact with microorganisms (sometimes at elevated humidity and temperature), so the need to protect cellulose fibers from biodegradation is obvious. An equally important property of technical materials is fire protection.

Processing with biocidal preparations during or after the manufacture of the nonwoven fabric is not always possible or technically difficult and expensive. So, applying the drug to non-woven materials containing synthetic fibers, sometimes in an amount of at least 50%, leads to the expenditure of the drug on fibers that do not require bioprotection, while cellulose fibers lack it.

A known method of processing fiber (Pat. RF No. 2350700, publ. 03/27/2009), which consists in impregnating pre-mechanically cleaned flax fiber with an aqueous composition, which gives the fiber resistance to fungal and bacterial cultures. The composition contains, as an active component, a quaternary ammonium base or metal salts or a guanidine derivative. The impregnation is carried out to the content of the active component of 0.5-10%, after which the fiber is squeezed and dried.

The disadvantage of this method is the low efficiency of the process.

There is also known a method for producing flax fiber (Pat. RF No. 2347860, publ. 02.27.2009) by impregnation with module 10-50 of mechanically cleaned short flax fiber with an aqueous composition containing flame retardant preparations, in particular 30 ethylene ethyl diphosphonic acid, in the amount of 30 -70 g / l and an ammonium salt in an amount of 80-130 g / l at 50-70 ° C for 30-60 minutes. Then the fiber is squeezed to 100-150% weight gain and dried.

Processing can be carried out in apparatuses of continuous or periodic action or by aerosol application of a working solution.

The method has a number of significant disadvantages:

1. Insufficiently high quality indicators of fire protection of the fibers, especially with aerosol application of drugs;

2. Insufficient resistance of fire-retardant processing of fibers and non-woven materials obtained from them to wet treatments;

3. Low efficiency of the process due to:

- the need to use a large liquid module for processing flax fiber (M = 10 ÷ 50);

- the need to heat the entire volume of the working solution;

- using additional equipment;

- the presence of a large number of effluents that must be treated.

A known method of producing materials based on cellulose-containing fibers having flame retardant properties (US Pat. RF No. 2212781, publ. September 20, 2003). The method consists in impregnating the material at 30-70 ° C for 3-10 seconds with an aqueous composition containing a dye, trisodium phosphate, an acidic phosphorus-containing compound, urea and water. Then the material is squeezed to 80-90% weight gain and dried at a temperature suitable for the specific raw material composition.

This method allows you to give the material the property of fire resistance and resistance to wet treatments.

There is also a method of producing flame-retardant textile products, in particular non-woven materials from flax fibers (Pat. RF №2184184, publ. June 27, 2002). It consists in the impregnation of the material with a composition containing 80-350 g / l nitrilotrimethylphosphonic acid and 80-350 g / l urea at 30-70 ° C for 3-10 s, extraction and drying. Processing materials with the specified composition provides high fire resistance.

The disadvantage of these methods is that it is possible to process finished non-woven fabrics by impregnation only at their low surface density (not more than 400-500 g / m). But even in this case, due to the deformability of the structure of the nonwoven fabric when removing excess moisture by mechanical extraction, the moisture content on the material can exceed 200% and drying becomes too expensive.

SUMMARY OF THE INVENTION

The objective of the invention is to search for a method for producing cellulose fiber having fire and / or biostable properties, which would improve the fire retardancy of cellulose fiber and products based on it, their resistance to wet treatments and reduce the cost of processing the material.

The problem is solved by the method of obtaining cellulose fiber having fire and / or biostable properties, impregnating in a centrifuge of the initial fiber with a modifying aqueous composition containing at least one substance selected from the group consisting of alkyl dimethylbenzylammonium chloride, copper 8-hydroxyquinolate, 1,6- Di- (para-chlorophenyl-guanido) -hexane, polyhexamethylene guanidine chloride, polyhexamethylene guanidine hydrochloride, Tezagran-L, which is a product of the interaction of alkylphosphonic, phosphoric acids and carbamide, Tezagra -Bio, which is a product of the interaction of alkylphosphonic, phosphoric acids and urea with a module of 2.5-3.5, including keeping the fiber in the specified composition for 10-30 minutes in a static state, then when the centrifuge is rotated at a speed of 800-1200 rpm min for 10-30 min, pressing the fiber to a residual moisture content of 70-90% and drying it to a residual moisture content of 5-14%. The invention allows to obtain the following advantages:

1. To increase the fire retardancy of cellulose fibers;

2. To give flax fibers and nonwovens based on them flame retardant properties that are resistant to wet treatments that can be carried out during the operation of finished products;

3. To increase the efficiency of the process by reducing the number of technological equipment, reducing labor costs, as well as the almost complete elimination of effluents due to the reuse of the working solution that has passed the filtration stage;

In addition, the invention allows to give the fiber not only fire or bio, but also fire and bioprotective properties.

Information confirming the possibility of carrying out the invention As the starting material, you can use cotton and viscose fibers, as well as flax fibers in the form of carding waste, waste rubbing, shaking, etc. If necessary, preparatory processing of the waste is carried out so that its quality is not worse than that of short flax fiber No. 3.

To impart fire and / or biostable properties to cellulose fibers, preparations are used that meet the following requirements:

- high solubility;

- compatibility of drugs;

- lack of influence on the physicomechanical parameters of cellulose fibers;

- lack of salt spots.

The following chemicals can be used, for example:

Catamine AB (alkyldimethylbenzylammonium chloride) (TU 9392-003-48482528-99). Formula: R (CH ₃ ) ₂ (CH ₂ C ₆ H ₅ ) N] ⁺ Cl ^- , where R = C ₁₀ H ₂₁ -C ₁₈ H ₃₇ ; C ₁₂ H ₂₅ -C ₁₄ H ₂₉ . The average molecular weight of Catamine AB is 357 ± 10 - a viscous transparent liquid from colorless to yellow, the mass fraction of alkyldimethylbenzylammonium chloride (active substance) is not less than 49.0-51.0%. Gives biosecurity properties.

8-hydroxyquinolate of copper (MRTU 6-14). Cu-8-hydroxyquinoline - is a thick paste from greenish yellow to dark green in color with a copper content of at least 3.3% and a pH of 7-8. Gives biosecurity properties.

Desin (chlorhexidine) (TU 9392-001.18885462-99) 1,6-Di- (para-chlorophenyl-guanido) -hexane is chemically a dichloro-containing derivative of biguanide. It is a clear, odorless liquid. Available as a 20% aqueous solution. Gives biosecurity properties.

Polyhexamethylene guanidine chloride (TU 9392-006-41547288-99) - refers to the high molecular weight derivatives of guanidine. It is available in the form of a solid form or an aqueous solution with an active component content of from 20 to 97%. The aqueous solution is a uniform, odorless, clear liquid. Gives biosecurity properties.

Polyhexamethylene guanidine hydrochloride (TU 9392-010-41547288-2000) - refers to the high molecular weight derivatives of guanidine. It is available in the form of a solid form, paste or aqueous solution with an active component content of from 20 to 95%. The aqueous solution is a uniform, odorless, clear liquid. Gives biosecurity properties.

Tezagran-L (TU 2484-002-37022343-02) is a product of the interaction of alkylphosphonic, phosphoric acids and urea. Available in the form of a powder of light color, odorless, soluble in water. Gives fire protection properties.

Tezagran-Bio (TU 2484-002-37022343-02) is a product of the interaction of alkylphosphonic, phosphoric acids and urea. Available in the form of a solid form or an aqueous solution with an active component content of from 20 to 95%. The aqueous solution is a uniform, odorless, clear liquid. Gives properties of fire protection.

The method is implemented by sequentially carrying out the following operations:

- cellulose fiber is loaded into a centrifuge, for example brand FMK-1521-1;

- fill the centrifuge with a solution containing fire and / or bioprotective preparations, for example Tezagran-L or Tezagran-Bio, and incubate with a centrifuge drain blocked for 10-30 minutes with a 2.5-3.5 liquid module. Thus, this processing step is carried out in a static state;

- turn on the centrifuge and at a speed of its rotation of 800-1200 rpm maintain the material for 10-30 minutes;

- open the drain and squeeze the fiber to a residual moisture content of 70-90%;

- dried fiber to a residual moisture content of 5-14%.

To obtain the correct comparative data, flax fiber was processed according to the method described in RF patent No. 2184184 by impregnation in the AKD apparatus for 30 minutes. with a liquid module 10 with subsequent extraction in a centrifuge brand FMK-1521-1 at a speed of rotation of 1000 rpm for 15 minutes and drying to a residual moisture content of 10%. The low cost of fiber processing by this method is due to the presence of additional equipment (AKD apparatus), higher labor costs (the need to transfer fibers from the AKD apparatus to a centrifuge) and energy costs (the need to heat the entire volume of working solution in the AKD apparatus).

Analysis of the quality indicators of the fiber processed according to the claimed method and the method closest to the achieved quality indicators were carried out identically:

- fire resistance was judged by the oxygen index and weight loss during combustion in accordance with GOST 12.1.044-89;

- fiber biostability was determined by the degree of fiber fouling with fungal cultures after it was kept in an isolated space at a temperature of 35-37 ° C and a humidity of 97-99% (0 - no visible changes were found on the surface of the material; 1 - a slight change, the appearance of mycelium on the surface area up to 1 cm ^2; 3 - a noticeable change, the development of fungi covering up to 10% of the test surface; 5 - the most significant changes, the development of mushrooms covering more than 25% of the test surface is clearly visible);

- the biostability of the fibers was also evaluated by the biostability coefficient, defined as the ratio of the breaking loads of the fibers after and before biodegradation;

- the resistance of the effect of fire and / or biosecurity to wet treatments was carried out by keeping the materials in running water at 15-20 ° C for 5 minutes

The quality indicators of the fiber obtained after communicating to it the properties of fire and biostability are shown in tables 1 and 2.

The data in tables 1 and 2 show that the fiber that has been processed by the proposed method achieves higher fire-, bio-, or fire-resistant properties.

Claims (1)

A method of obtaining a cellulose fiber having fire and / or biostable properties, impregnated in a centrifuge of the initial fiber with a modifying aqueous composition containing at least one substance selected from the group consisting of alkyl dimethylbenzylammonium chloride, copper 8-hydroxyquinolate, 1,6-di- ( para-chlorophenyl-guanido) -hexane, polyhexamethylene guanidine chloride, polyhexamethylene guanidine hydrochloride, Tezagran-L, which is the product of the interaction of alkylphosphonic, phosphoric acids and urea, Tezagran-Bio, which is a the product of the interaction of alkylphosphonic, phosphoric acids and urea, with a module of 2.5-3.5, including keeping the fiber in the specified composition for 10-30 minutes in a static state, then when the centrifuge is rotated at a speed of 800-1200 rpm for 10 -30 min, pressing the fiber to a residual moisture content of 70-90% and drying it to a residual moisture content of 5-14%.