RU2283164C1 - Filtering material, the method of production of the filtering material and the breathing mask - Google Patents

Abstract

FIELD: means of individual protection; production of the fine-fiber filtering materials for the means of individual protection of respiratory organs.

SUBSTANCE: the invention is pertaining to the fine-fiber filtering materials for the means of individual protection of respiratory organs. The invention presents the filtering material, the based on it breathing mask and the method of production of the fibrous material by the electrostatic molding at feeding of two various polymeric solutions onto the applicable spinning components. At that one of the solutions contains the copolymer of styrene and acrylonitrile in ethyl acetate, and the second solution contains chlorinated polyvinyl chloride with no more than 10 mass % additive of butadiene-nitrile caoutchouc in ethyl acetate. The produced material contains 50-90 mass % of the fibers composed of styrene copolymer and acrylonitrile and 10-50 mass % of the fibers made out of chlorinated polyvinyl chloride with the additive of no more than 10 mass % of butadiene-nitrile caoutchouc with respect to the mass of chlorinated polyvinyl chloride, at the fibers of 1-10 microns. The invention allows to produce the filtering material with the improved mechanical properties and to ensure stability of the production without utilization of toxic solvents.

EFFECT: the invention ensures stability of production of the filtering material with the improved mechanical properties without utilization of toxic solvents.

5 cl, 2 tbl, 2 dwg

Description

The invention relates to the field of production of fibrous filter materials of the type FP (Petryanov Filters) used to protect the environment, as well as respiratory organs from toxic aerosols.

Known filter material from perchlorovinyl fibers with a diameter of 1-10 μm obtained in an electrostatic field, from a dichloroethane dope containing electrolytic additives selected from the series: tetraethylammonium iodide or bromide or tetrabutylammonium iodide or bromide, and solvent additives from the series: acetone or methyl ethyl ketone or ethyl acetate or butyl acetate. The filter material has a surface density of 20-50 g / m ² and an aerodynamic resistance of 3-50 Pa at an air flow rate of 1 cm / s. A respirator of the Lepestok type is made of filtering material (RU 2182510, 05.20.2002).

Known material obtained from a solution of a copolymer of styrene with acrylonitrile, contained in an amount of 10-20 wt.% In a solution of dichloroethane, with the addition of acetone, or methyl ethyl ketone, or ethyl acetate, or butyl acetate in an amount of 5-30 wt.%. The filter material contains fibers with a diameter of 1-10 microns, has a surface density of 20-80 g / m ² and an aerodynamic resistance of 3-60 Pa at an air flow rate of 1 cm / s. Also known is a respiratory protective device containing a working layer of fibers of this material with a diameter of 1-10 microns, a protective layer of gauze and a filter holder (RU 2182511, 05.20.2002).

Known filter material obtained by electroforming from a solution of perchlorovinyl and a copolymer of styrene with methyl methacrylate and acrylonitrile in a mass ratio of 10 / 1-1 / 1 in dichloroethane in the presence of salts selected from the series: iodide or tetraethylammonium bromide or tetrabutylammonium iodide or bromide tetrabutylammonium iron taken in an amount of 0.01-0.2 wt.% (RU 2135263, 08.27.1999).

Known filter material for respiratory protection, containing the outer and inner protective layers and the working layer of fibers of perchlorovinyl and a copolymer of styrene with methyl methacrylate and acrylonitrile, while the fibers contain 1-9 wt.% Perchlorovinyl and 91-99 wt.% Styrene copolymer with methyl methacrylate and acrylonitrile, or 91-99 wt.% perchlorovinyl and 1-9 wt.% copolymer of styrene with methyl methacrylate and acrylonitrile. A method for producing a known material involves electrostatically forming fibers from a 5-25% solution in dichloroethane of a mixture of perchlorvinyl and a copolymer of styrene with methyl methacrylate and acrylonitrile in the presence of 0.01-0.2% tetraethylammonium halides or tetrabutylammonium or iron halides by weight of polymers, perchlorovinyl is taken in an amount of 1-9 wt.% or 91-99 wt.% from the mixture of polymers present in the solution (RU 2170607, 07.20.2001).

The disadvantage of the above technical solutions is the high toxicity of production and toxicity of products due to the residual presence of dichloroethane in the material.

Also known is the material obtained by electrostatic molding from a solution of a styrene-acrylonitrile copolymer in an organic solvent, in the presence of electrostatic additives of tetraethyl or tetrabutylammonium bromide or iodide salts, the solution containing an additive of high molecular weight methyl methacrylate in an amount of 0.001-0.01 wt.%, As a solvent use a mixture of ethyl acetate with butyl acetate with their mass ratio in solution from 1/9 to 9/1, respectively (RU 2248838, 05.27.2003).

The disadvantage of this material is the low mechanical strength and the presence of a residual content of butyl acetate in the material.

Closest to the proposed material is a filter material for respirators containing the outer and inner protective layers and the working layer between them made of fibrous polystyrene or perchlorovinyl or a mixture thereof with a fiber diameter of 1-10 μm with aerodynamic resistance of 1-25 Pa at an air flow rate of 1 cm / s and with a surface density of 10-50 g / m (RU 2042394, 08.27.1995).

Closest to the proposed method is a method of obtaining filter material for respirators by electrostatically forming a fibrous non-woven material from a polymer solution in an organic solvent, in which a solution of polystyrene in dichloroethane and a solution of perchlorovinyl in dichloroethane are taken as polymers, the molding is carried out when these two solutions are fed to the corresponding spinning elements, with a dynamic viscosity of solutions of 0.5-35 poise, electrical conductivity of 10 ^-4 -10 ^-7 Ohm ^-1 cm ^-1 (RU 2042393, 08.27.1995).

The disadvantage of the above method is the lack of stability of the process, low mechanical strength of the obtained fibrous material and its toxicity due to the increased content of dichloroethane in the material.

The present invention is to develop a filter material and a respirator based on it, with increased mechanical strength, as well as a stable process for producing material without the use of toxic solvents.

The problem is solved by the described fibrous filter material made of a mixture of polymer fibers with a fiber diameter of 1-10 μm, which contains 50-90% wt. fibers from a copolymer of styrene and acrylonitrile and 10-50% wt. fibers made of chlorinated polyvinyl chloride with the addition of not more than 10% wt. nitrile butadiene rubber.

The problem is also solved by the described method for producing a fibrous filter material described above, which includes electrostatic molding of a fibrous material from a solution of polymers in an organic solvent by feeding two different polymer solutions to the corresponding spinning elements, while the solutions have a dynamic viscosity of 0.5-35 poise, electrical conductivity 10 ^-4 -10 ^-7 Ohm ^-1 cm ^-1 , while one of the solutions contains a copolymer of styrene and acrylonitrile in ethyl acetate, and the second contains chl oriented polyvinyl chloride with the addition of not more than 10% wt. nitrile butadiene rubber in ethyl acetate.

Preferably, the molding of the material is carried out from solutions with a concentration of the corresponding polymers in ethyl acetate equal to 10-30% wt.

Preferably, the molding is carried out from solutions containing electrolytic additives selected from a number of bromide or iodide salts of tetraethyl or tetrabutylammonium in an amount of 0.001-0.01% wt.

The problem is also solved by a respirator, which contains at least one working layer of fine-fiber filtering material with a diameter of 1-10 microns, aerodynamic resistance of 1-25 Pa, with an air flow rate of 1 cm / s and a surface density of 10-50 g / m ² made from a mixture of fibers containing 50-90% wt. fibers from a copolymer of styrene and acrylonitrile and 10-50% wt. fibers made of chlorinated polyvinyl chloride with the addition of not more than 10% wt. nitrile butadiene rubber by weight of chlorinated polyvinyl chloride, as well as an obturator and fixing means.

The technical result achieved can be explained by the fact that as a result of mixing in a solution of chlorinated polyvinyl chloride and nitrile butadiene rubber, more flexible fibers are formed that improve the mechanical properties of the filter material. In addition, from solutions containing the claimed polymers, it is possible to conduct a stable process of electrospinning from a non-toxic solvent, which allows one to obtain filter material and a respirator based on it that does not contain residual dichloroethane impurities.

Example 1

Solution A. Prepare a 17% spinning solution of styrene-acrylonitrile copolymer (SAN) in ethyl acetate with a dynamic viscosity of 4.8 P; the conductivity of the solution was adjusted to 4 · 10 ^-6 Ohm ^-1 cm ^-1 , introducing an electrolytic additive of 0.0035 wt.% tetraethylammonium iodide (TEAI).

Solution B. Prepare a 15% spinning solution of chlorinated polyvinyl chloride (PCV) in ethyl acetate with the addition of 5% wt. nitrile butadiene rubber (BNK) by weight of chlorinated polyvinyl chloride, with a dynamic viscosity of 5.2 P; the conductivity of the solution is adjusted to 5 · 10 ^-6 Ohm ^-1 cm ^-1 , introducing an electrolytic additive of 0.004 wt.% TEAI.

Then fibrous material is formed in an electrostatic field from two solutions supplied to the corresponding spinning elements (A and B), with a potential difference of 80 kV and a volumetric flow rate of the solution of 5 · 10 ^-3 cm ³ / s per capillary, with a mass content of fibers of styrene-acrylonitrile copolymer 80 wt.%, and fibers from chlorinated polyvinyl chloride 20 wt.% with the addition of nitrile butadiene rubber 10 wt.% by weight of chlorinated polyvinyl chloride.

On a metal grounded electrode, a fibrous layer is obtained from a mixture of ultrafine fibers with an average diameter of 2 μm. The process of getting stable. Drying of the liquid filament emanating from the nozzle is not observed, and as a result, the electroforming process is stable. A diagram of a device for producing filter material is shown in figure 1, where 1 is a rotating support; 2 - precipitation electrode; 3 - trolley wheel; 4 - guides; 5 - chain conveyor with grips of bogies; 6 - gear; 7 - transmission; 8 - spinning elements A and B.

The respirator "Petal" was made from the material obtained and its properties were investigated. The design of the respirator "Petal" is shown in figure 2, where 1 is the working layer of the filter material with a frame layer of finished gauze; 2 - rubber cord; 3 - aluminum plate (inside); 4 - figured strut; 5 - obturator with a point seam; 6 - headband.

Other examples of obtaining material from different compositions of the solution and the test results are shown in table 1.

Table 1
The composition of the spinning solutions Example No. The styrene copolymer with acrylonitrile% Chlorinated polyvinyl chloride,% Additive nitrile butadiene rubber,% of PVC Ethyl acetate,% Electrolytic additive,% Viscosity, P Conductivity, Ohm ^-1 cm ^-1 2 BUT 10 - - 90 0.01 0.5 1 · 10 ^-4 B - thirty 10 67 0.001 35.0 1 · 10 ^-7 BUT thirty - - 70 0.005 32,0 5 · 10 ^-6 3 B - 10 5 89.5 0.06 1,0 7 · 10 ^-6 four BUT 22 - - 78 0.08 12.0 2 · 10 ^-5 B - eighteen one 81.8 0,03 15.0 2 · 10 ^-6 table 2
Properties of filter materials No. p / p The content of polymer fibers Fiber diameter, microns Surface density, g / m ² Hydrodynamic resistance, Pa Breakthrough Ratio,% Breaking length, rkm Relative specificity,% 80% SAN one 20% PVC 8-10 45 3,5 0.8 0.2 58 (containing 10% BNK) 90% SAN 2 10% PVC 4-8 35 8.5 0.5 0.2 56 (containing 10% BNK) 10% SAN 3 90% PVC 2-4 thirty 12.0 0.1 0.2 64 (containing 5% BNK) 50% SAN four 50% PVC 1-3 25 15.3 0.01 0.2 60 (containing 1% BNK)

From the data of table 2 it can be seen that the filter materials obtained in accordance with the invention have filter characteristics at the level of the prototype and higher mechanical strength (see relative elongation).

The obtained materials can be used for the manufacture of personal respiratory protective equipment such as Lepestok, Alina, U-2K, Kama, etc., containing a working layer of the claimed material deposited on a substrate of hygienic material, for example, gauze.

Respirators obtained on the basis of the claimed material do not contain toxic components, have increased filtering abilities at low values of hydrodynamic resistance during breathing. They can be used successfully for protection against toxic aerosols, including radioactive, as well as to protect against aerosol carriers of viral infections, such as bird flu, SARS, etc.

Claims (5)

1. A fibrous filter material made of a mixture of polymer fibers with a fiber diameter of 1-10 μm, characterized in that it contains 50-90 wt.% Fibers from a styrene-acrylonitrile copolymer and 10-50 wt.% Fibers made from chlorinated polyvinyl chloride with the addition of not more than 10 wt.% nitrile butadiene rubber by weight of chlorinated polyvinyl chloride. 2. A method of obtaining a fibrous filter material described in claim 1, comprising electrostatically molding the fibrous material from a polymer solution in an organic solvent by feeding two different polymer solutions to the corresponding spinning elements, while the solutions have a dynamic viscosity of 0.5-35 poise, electrical conductivity 10 ^-4 -10 ^-7 Ohm ^-1 cm ^-1 , characterized in that one of the solutions contains a copolymer of styrene and acrylonitrile in ethyl acetate, and the second contains chlorinated polyvinyl chloride with no more than 10 wt.% nitrile butadiene rubber in ethyl acetate. 3. The method according to claim 2, characterized in that the molding of the material is carried out from solutions with a concentration of the corresponding polymers in ethyl acetate equal to 10-30 wt.%. 4. The method according to claim 2, characterized in that the molding of the material is carried out from solutions containing electrolytic additives selected from a number of bromide or iodide salts of tetraethyl or tetrabutylammonium in an amount of 0.001-0.01 wt.%. 5. A respirator containing at least one working layer of fine fiber filter material with a diameter of 1-10 μm, aerodynamic resistance of 1-25 Pa at an air flow rate of 1 cm / s, and a surface density of 10-50 g / m ² , shutter and fastening means, characterized in that it contains a working layer made of a material described in claim 1.

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