RU2376053C1 - Filtering material, method of producing said material and respirator - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to making filtering materials for respirators. Filtering fibre material is proposed, as well as a method of making said material by electrostatic moulding microfibres from a polymer solution in an organic solvent. The material contains fibre of diametre 1-10 mcm from chlorinated polyethylene, characterised by mass content of chlorine of 60-70%, has surface density of 20-60 g/m and is used as the working layer of the respirator.

EFFECT: high mechanical strength of the material with high retention potential.

4 cl

Description

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

Known filter material obtained by electrospinning, containing a mixture of fibers with a diameter of 1-10 microns, made of chlorinated polyvinyl chloride and from a copolymer of styrene and Actilonitrile (RU 2283164, 09/10/2006).

A disadvantage of the known material is the complexity of its manufacture associated with the use of two spinning solutions.

A known method of obtaining filter material from a copolymer of styrene with acrylonitrile with a fiber diameter of 1-10 μm from a dope solution containing dichloroethane, electrolytic additives and solvents from the series: acetone, or methyl ethyl ketone, or ethyl acetate, butyl acetate. The filter material 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. The filter layer is made of a working layer of a respirator of the type "Petal" (RU 2182511, 05.20.2002).

The disadvantage of the material is its low physical and mechanical characteristics, which complicate the process of assembling a respirator.

Known filter material for respirators, which contains the outer and inner protective layers and the working layer of a polymeric fibrous material made of a mixture of perchlorovinyl and a copolymer of styrene with methyl methacrylate and acrylonitrile, while perchlorovinyl is present in an amount of 1-9 or 91-99 wt.%. A method of obtaining a filter material includes the electrostatic molding of fibrous material from a solution containing a mixture of the above polymers in a solution of dichloroethane (RU 2170607, 07.20.2001).

The disadvantage of the material is the complexity of the production process associated with the complexity of the preparation of the dope.

The closest in technical essence and the achieved result is a filter material from perchlorovinyl fibers with a diameter of 1-10 microns, which has a surface density of 20-50 g / m ² , as well as a method for producing filter material from a spinning solution containing perchlorovinyl, dichloroethane, electrolytic additives and solvents from the series: acetone or methyl ethyl ketone or ethyl acetate or butyl acetate. The filter material is used as the working layer of a respirator with an aerodynamic resistance of 3-50 Pa at an air flow rate of 1 cm / s (RU 2182510, 05.20.2002).

A disadvantage of the known technical solution is the lack of currently perchlorovinyl resin on the market that meets sanitary standards for respiratory filter material.

The objective of the present invention is to provide a filter material for the working layer of the respirator, which has increased mechanical strength while maintaining high retention ability.

The problem is solved by filtering fibrous material obtained by electrostatic molding from a polymer solution in an organic solvent, which contains fibers with a diameter of 1-10 μm from chlorinated polyethylene, characterized by a mass content of chlorine of 60-70%, and has a surface density of 20-60 g / m ² .

The problem is also solved by the method of obtaining a filtering fibrous material, which includes the electrostatic molding of microfibers from a solution in dichloroethane containing 5-20 wt.% Chlorinated polyethylene with a mass content of chlorine of 60-70%, having a dynamic viscosity of 1-10 poise.

Preferably, the molding is carried out from a solution containing a salt electrolytic additive, introduced in an amount providing a conductivity of the solution of 10 ^-7 S / cm-10 ^-4 S / cm.

In addition, the problem is solved by the claimed respirator containing a working layer of filtering fibrous material containing fibers with a diameter of 1-10 microns from chlorinated polyethylene, characterized by a mass chlorine content of 60-70%, and having a surface density of 20-60 g / m ² and aerodynamic drag of 3-30 Pa at an air flow rate of 1 cm / s.

The use of chlorinated polyethylene as a polymer provides increased mechanical strength of the fiber, the choice of a polymer having a mass content of chlorine of 60-70% is due to the fact that only in the claimed range of chlorine content provides good technological quality of the dope in dichloroethane, while the claimed range of polymer concentration in solution by providing optimal dynamic viscosity of the spinning solution allows you to get fiber with a diameter in the specified range. The claimed conductivity of the dope is optimal for a stable process of electrospinning.

Below are examples of the receipt of the claimed material and a respirator based on it.

Example 1

A spinning solution is prepared containing 7 wt.% Of chlorinated polyethylene having a mass content of chlorine of 66% and a dynamic viscosity of 5 P. The electrical conductivity of the solution is adjusted to 1 · 10 ^-5 S / cm by introducing 0.001 wt.% Tetrabutylammonium iodide into the solution.

The solution is subjected to molding by the electrocapillary method. The potential difference at the electrodes is 40 kV, the volumetric flow rate of the solution per capillary is 9 · 10 ^-4 cm ³ / s.

On a grounded electrode receive a layer of microfibers with a diameter of 1-3 microns, a surface density of 35 g / m ² , aerodynamic resistance of 16 PA.

A working layer is made from the obtained material and respirators of the Petal type are assembled.

Below are data on the composition of the spinning solutions and the physico-mechanical and filtering properties of the obtained fibrous material.

Data on the composition of the spinning solutions, the operational properties of the filter materials are summarized in tables 1, 2.

Table 1 No. The composition of the solution, wt.% Solution characteristics Khpe DCE TBA1 η, poise λ, cm / cm one four 95.8 0.2 1,5 8 · 10 ^-5 2 7 92.9 0.1 5,0 1 · 10 ^-5 3 9 90.95 0.05 7.0 2 · 10 ^-6

table 2 Material characteristic Material No. according to table 1 one 2 3 The diameter of the fibers, microns 0.5-1 1-3 7-10 Mass units area, g / m ² twenty 35 60 Aerodynamic resistance at 1 cm / s, Pa thirty 16 5 CMT slip rate,% 0.002 0.012 0.0015 Elongation at break,% 40 46 fifty

As follows from the tables, the physical and mechanical characteristics of the obtained material exceed the corresponding characteristics of the prototype material, while the filtering properties are at the same level.

Claims (4)

1. The filtering fibrous material obtained by electrostatic molding from a polymer solution in an organic solvent, characterized in that it contains fibers with a diameter of 1-10 microns from chlorinated polyethylene, characterized by a mass content of chlorine of 60-70%, and has a surface density of 20- 60 g / m ² . 2. A method of obtaining a filtering fibrous material, comprising electrostatically molding microfibers from a polymer solution in dichloroethane, characterized in that the molding is carried out from a solution containing 5-20 wt.% Chlorinated polyethylene with a mass content of chlorine of 60-70%, having a dynamic viscosity of 1- 10 Poise. 3. The method according to claim 2, characterized in that the molding is carried out from a solution containing a salt electrolytic additive, introduced in an amount providing a conductivity of the solution of 10 ^-7 -10 ^-4 S / cm. 4. A respirator containing a working layer of filtering fibrous material, protective layers, a seal and fastening means, characterized in that the working layer is made of the material described in paragraph 1, and has an aerodynamic resistance of 3-30 Pa at an air flow rate of 1 cm /from.