A method for preparing antibacterial flame-retardant composite microfiber fabric

Abstract

The invention relates to the technical field of composite fabrics, and discloses a method for preparing an antibacterial flame-retardant composite ultrafine fiber fabric. Nylon 6 and low-density polyethylene are spun, stretched and heat-set to obtain a fabric base layer, tri(2-chloroethyl) phosphate, p-dimethylaminobenzaldehyde and the like are used as raw materials, and an antibacterial flame-retardant chain extender is obtained through quaternization and amination reactions, and the antibacterial flame-retardant chain extender is involved in the synthesis of polyurethane to obtain a functional layer; each layer of material is laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer", and the antibacterial flame-retardant composite ultrafine fiber fabric is obtained through hot pressing and compounding; phosphorus and nitrogen elements and Schiff bases in the structure can block the exchange of oxygen and heat between a fiber matrix and the air, and play a flame-retardant role; quaternary ammonium salt cations interfere with the metabolism of bacteria through electrostatic action, so that the bacteria undergo a "bacterial lysis" phenomenon and die, and play an antibacterial role.

Description

Technical Field

[0001] The invention relates to the technical field of composite fabrics, and in particular to a method for preparing an antibacterial and flame-retardant composite ultrafine fiber fabric. Background Art

[0002] Composite microfiber fabric refers to a fabric made of microfiber as a base material, which is processed by a specific textile process and then bonded with other functional materials. It is widely used in clothing, outdoor equipment, furniture and other fields. As people's requirements for quality of life increase, the functional demand for textiles is also growing. Antibacterial and flame retardant are important functional properties of textiles, which are of great significance for improving product safety and comfort. Microfibers have become an ideal material for preparing high-performance textiles due to their excellent physical properties and chemical stability. However, single microfiber fabrics often have deficiencies in antibacterial and flame retardant aspects. Therefore, the development of microfiber composite fabrics with antibacterial and flame retardant functions has become a hot topic in current research.

[0003] The existing microfiber fabrics do not have antibacterial effects, which leads to the breeding of bacteria in the microfiber fabrics. At the same time, the microfiber fabrics will burn quickly after contacting open flames, resulting in reduced antibacterial and flame retardant properties of the microfiber fabrics; in the prior art, flame retardants are generally added for flame retardancy, and directly adding them to the fabric matrix will result in the softness and comfort of the fiber not being retained; through the composite structure design, there is a weak bonding between the flame retardant layer and the base layer, which leads to easy stratification at high temperatures, affecting the flame retardant effect; Patent No. CN115648742A discloses an antibacterial composite fabric and a preparation method thereof, which uses cotton fiber, Tencel fiber and polyester fiber to blend and prepare a base layer, and the base layer, fabric layer and adsorption layer are bonded to prepare an antibacterial composite fabric, but the patent does not explicitly mention that the fabric has flame retardant properties, nor does it describe any technical features or processing procedures related to flame retardancy, so the flame retardant properties of the microfiber fabric are not improved.

[0004] Depending on the purpose of use, ultrafine fiber fabrics must have higher performance in terms of flexibility, surface texture, flame retardancy, antibacterial and mechanical properties, and sometimes need to meet all of the above characteristics at the same time; the present invention aims to prepare a multi-layer composite ultrafine fiber fabric, which maintains the soft and comfortable performance of ultrafine fibers while significantly improving their antibacterial and flame retardant properties, thereby broadening the application field of ultrafine fiber fabrics. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a method for preparing an antibacterial and flame-retardant composite microfiber fabric, so that it has good flame-retardant and antibacterial properties and good barrier properties, and will not reduce the soft touch and strength of the composite fabric, thereby broadening the application range of the microfiber fabric.

[0006] The present invention is achieved through the following technical solutions:

[0007] An antibacterial and flame-retardant composite ultrafine fiber fabric comprises a fabric base layer, an adhesive layer, a barrier layer and a functional layer.

[0008] The preparation method of the fabric base layer is as follows: nylon 6 and low-density polyethylene are added to a spinning machine after drying for spinning, the winding speed is 300-500m / min, the spinning temperatures of screw zones one to four are 160, 250, 265, and 265°C, respectively, followed by stretching and heat setting, the heat setting temperature is 65-80°C, the obtained ultrafine fibers are immersed in xylene at a temperature of 90-100°C, kept for 60-80 minutes, taken out, washed with xylene, and dried to obtain the fabric base layer.

[0009] The adhesive layer is polyethylene-vinyl acetate adhesive.

[0010] The barrier layer is ethylene vinyl alcohol copolymer.

[0011] The preparation method of the functional layer is as follows: placing polytetramethylene glycol in a vacuum environment at a temperature of 100-120°C and a vacuum degree of 0.05-0.1 MPa for vacuum dehydration for 1-2 hours, adding isophorone diisocyanate, introducing nitrogen, and adding a structural formula The antibacterial flame retardant chain extender and stannous octoate are kept at 70-80°C for 2-6 hours, the temperature is lowered, the material is discharged, and calendering is performed to obtain a functional layer.

[0012] Preferably, the mass ratio of nylon 6 to low-density polyethylene is 50-60:40-50.

[0013] Preferably, the single filament fineness of the ultrafine fiber is 0.3-0.6 dtex.

[0014] Preferably, the mass ratio of polytetramethylene ether diol, isophorone diisocyanate, antibacterial flame retardant chain extender and stannous octoate is 60-75:10-25:2-10:0.3-0.8.

[0015] Preferably, the preparation method of the antibacterial flame retardant chain extender is:

[0016] Step (1), under nitrogen atmosphere, add tri(2-chloroethyl) phosphate and acetonitrile to a reaction flask, stir evenly, add p-dimethylaminobenzaldehyde, react at 65-80° C. for 24-48 hours, extract with ethyl acetate and deionized water, concentrate the organic phase, and dry to obtain quaternary ammonium salt benzaldehyde phosphate monomer.

[0017] Step (2), under a nitrogen atmosphere, add quaternary ammonium salt benzaldehyde phosphate monomer and methanol to a reaction flask, stir evenly, add 2-amino-4,6-dimethoxy-1,3,5-triazine, react at 60-75° C. for 16-32 hours, cool to room temperature, filter, wash with ethanol, and dry to obtain a methoxyphosphorus nitrogen quaternary ammonium salt monomer.

[0018] Step (3), under a nitrogen atmosphere, add methoxyphosphorus nitrogen quaternary ammonium salt monomer and dichloromethane to a reaction flask, stir evenly, add boron tribromide, react at 0-20° C. for 8-16 hours, extract with ethyl acetate and deionized water, concentrate the organic phase, and dry to obtain an antibacterial flame retardant chain extender.

[0019] Preferably, in step (1), the mass ratio of tris(2-chloroethyl) phosphate to p-dimethylaminobenzaldehyde is 100:175-210.

[0020] Preferably, in step (2), the mass ratio of the quaternary ammonium salt benzaldehyde phosphate monomer to 2-amino-1,3,5-triazine is 100:52-65.

[0021] Preferably, in step (3), the mass ratio of methoxyphosphorus nitrogen quaternary ammonium salt monomer to boron tribromide is 100:165-190.

[0022] Preferably, the preparation method of the antibacterial and flame-retardant composite microfiber fabric is: laying each layer of material according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer", performing hot-pressing compounding on a hot-pressing molding machine, and standing at room temperature for 16-24 hours to obtain the antibacterial and flame-retardant composite microfiber fabric.

[0023] Preferably, the temperature of the hot pressing composite is 100-125° C., the time is 20-40 seconds, and the pressure is 0.4-0.6 MPa.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention first spins nylon 6 and low-density polyethylene, stretches and heat-sets them to obtain a fabric base layer, uses tris(2-chloroethyl) phosphate, p-dimethylaminobenzaldehyde, 2-amino-4,6-dimethoxy-1,3,5-triazine and the like as raw materials, obtains an antibacterial and flame-retardant chain extender through quaternization and amination reactions, and participates in the synthesis of polyurethane to obtain a functional layer; each layer of material is laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer", and is hot-pressed and composited to obtain an antibacterial and flame-retardant composite ultrafine fiber fabric.

[0026] The antibacterial flame retardant chain extender contains quaternary ammonium cations, which participate in the chain extension synthesis of polyurethane. The positive charge of the formed quaternary ammonium polymer antibacterial agent is more dense, and it is easier to combine with bacterial proteins and phospholipids, causing the bacterial cell membrane to rupture and interfere with the normal metabolism of bacteria. The quaternary ammonium cations promote the uneven distribution of negative charges on the bacterial cell membrane through electrostatic action, causing it to deform, causing the cell contents such as proteins to leak, resulting in "bacterial lysis" and death, thereby playing an antibacterial role.

[0027] The triazine ring contained in the antibacterial flame retardant chain extender has excellent carbon-forming ability. It can undergo thermal decomposition reaction during combustion, absorb a large amount of heat, and release ammonia to dilute the concentration of surrounding combustible gases, thereby slowing down or preventing the spread of flames. In addition, phosphorus-containing substances will decompose at high temperatures to produce compounds such as phosphate esters, which can be used as free radical scavengers in polymer decomposition products, effectively preventing the thermal decomposition of molecular chains. The phosphorus and nitrogen elements synergistically flame retardant and prevent combustion. The aromatic Schiff base in the structure of the antibacterial flame retardant chain extender forms a nitrogen-containing cross-linked network structure with polyamide 6 during high temperature, and further cross-links into a denser carbon layer during combustion, blocking the exchange of oxygen and heat between the fiber matrix and the air, and playing a role in thermal protection of the composite fiber fabric.

[0028] The polyurethane in the functional layer contains a highly polar urethane group, which has good aging resistance and adhesion. As a bonding transition layer, it can significantly enhance the bonding force between the composite microfiber fabric layers. After hot pressing treatment, it can fully contact with the microfiber fabric base layer, reducing the possibility of slippage and effectively improving the service life of the microfiber fabric. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Unless otherwise specified, the raw materials and reagents used in this application are commercially available or can be prepared by known methods.

[0031] The adhesive layer is polyethylene-vinyl acetate adhesive.

[0032] The barrier layer is ethylene vinyl alcohol copolymer.

[0033] Tris(2-chloroethyl) phosphate, CAS number is 115-96-8.

[0034] p-Dimethylaminobenzaldehyde, CAS number is 100-10-7.

[0035] 2-Amino-4,6-dimethoxy-1,3,5-triazine, CAS number is 16370-63-1.

[0036] Low-density polyethylene: brand 1I50A, Beijing Yanshan Branch of Sinopec.

[0037] Nylon 6: relative viscosity 2.8, Yueyang Baling Petrochemical Chemical Fiber Co., Ltd.

[0038] Example 1

[0039] (1) Under nitrogen atmosphere, add 35 g of tri(2-chloroethyl) phosphate and 240 mL of acetonitrile to a reaction flask, stir evenly, then add 63 g of p-dimethylaminobenzaldehyde, react at 75 °C for 32 h, extract with ethyl acetate and deionized water, concentrate the organic phase, and dry to obtain quaternary ammonium salt benzaldehyde phosphate monomer. The preparation reaction formula is as follows:

[0040]

[0041] (2) Under a nitrogen atmosphere, 32 g of quaternary ammonium phosphate benzaldehyde monomer and 400 mL of methanol were added to a reaction flask. After stirring evenly, 19.2 g of 2-amino-4,6-dimethoxy-1,3,5-triazine was added and reacted at 65 °C for 24 h. The mixture was cooled to room temperature, filtered, washed with ethanol, and dried to obtain a methoxyphosphorus nitrogen quaternary ammonium salt monomer.

[0042] (3) Under nitrogen atmosphere, add 30 g of methoxyphosphorus nitrogen quaternary ammonium salt monomer and 750 mL of dichloromethane to the reaction flask, stir evenly, add 54 g of boron tribromide, react at 10 ° C for 12 h, extract with ethyl acetate and deionized water, concentrate the organic phase, and dry it to obtain an antibacterial flame retardant chain extender. The preparation reaction formula is as follows:

[0043]

[0044] (4) 70 g of polytetramethylene glycol was placed in a vacuum environment at a temperature of 110 ° C and a vacuum degree of 0.08 MPa for vacuum dehydration for 2 h, 15 g of isophorone diisocyanate was added, nitrogen was introduced, 2 g of an antibacterial flame retardant chain extender and 0.5 g of stannous octoate were added, and the mixture was kept at 75 ° C for 4 h. The material was cooled and discharged, and calendered to obtain a functional layer.

[0045] (5) After drying, 55 g of nylon 6 and 45 g of low-density polyethylene were added to a spinning machine for spinning. The winding speed was 400 m / min, and the spinning temperatures of screw zones 1 to 4 were 160, 250, 265, and 265 °C, respectively. Then, the fibers were stretched and heat-set at a temperature of 70 °C to obtain ultrafine fibers with a single filament fineness of 0.5 dtex. The fibers were immersed in xylene at a temperature of 95 °C, kept for 70 min, taken out, washed with xylene, and dried to obtain a fabric base layer.

[0046] (6) The various layers of materials are laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer" and hot-pressed on a hot press molding machine. The hot-pressing temperature is 115°C, the time is 30 seconds, the pressure is 0.5 MPa, and the material is allowed to stand at room temperature for 18 hours to obtain an antibacterial and flame-retardant composite microfiber fabric.

[0047] Example 2

[0048] (1) Under nitrogen atmosphere, add 60 g of tri(2-chloroethyl) phosphate and 300 mL of acetonitrile to a reaction flask. After stirring evenly, add 105 g of p-dimethylaminobenzaldehyde and react at 80 °C for 24 h. Extract with ethyl acetate and deionized water, concentrate the organic phase, and dry it to obtain quaternary ammonium salt benzaldehyde phosphate monomer.

[0049] (2) Under a nitrogen atmosphere, 55 g of quaternary ammonium salt benzaldehyde phosphate monomer and 440 mL of methanol were added to a reaction flask. After stirring evenly, 28.6 g of 2-amino-4,6-dimethoxy-1,3,5-triazine was added and reacted at 75 °C for 16 h. The mixture was cooled to room temperature, filtered, washed with ethanol, and dried to obtain a methoxyphosphorus nitrogen quaternary ammonium salt monomer.

[0050] (3) Under a nitrogen atmosphere, 50 g of methoxyphosphorus nitrogen quaternary ammonium salt monomer and 1000 mL of dichloromethane were added to a reaction flask. After stirring evenly, 82.5 g of boron tribromide was added. The mixture was reacted at 20 °C for 8 h. The mixture was extracted with ethyl acetate and deionized water. The organic phase was concentrated and dried to obtain an antibacterial flame retardant chain extender.

[0051] (4) 60 g of polytetramethylene glycol was placed in a vacuum environment at a temperature of 120 ° C and a vacuum degree of 0.1 MPa for vacuum dehydration for 1 h, 10 g of isophorone diisocyanate was added, nitrogen was introduced, 4 g of an antibacterial flame retardant chain extender and 0.3 g of stannous octoate were added, and the mixture was kept at 80 ° C for 2 h. The material was cooled and discharged, and calendered to obtain a functional layer.

[0052] (5) After drying, 50 g of nylon 6 and 50 g of low-density polyethylene were added to a spinning machine for spinning. The winding speed was 500 m / min, and the spinning temperatures of screw zones 1 to 4 were 160, 250, 265, and 265 °C, respectively. Then, the fibers were stretched and heat-set at a temperature of 80 °C to obtain ultrafine fibers with a single filament fineness of 0.6 dtex. The fibers were immersed in xylene at a temperature of 100 °C, kept for 60 min, taken out, washed with xylene, and dried to obtain a fabric base layer.

[0053] (6) The various layers of materials are laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer" and hot-pressed on a hot press molding machine. The hot-pressing temperature is 125°C, the time is 20 seconds, the pressure is 0.6 MPa, and the material is allowed to stand at room temperature for 16 hours to obtain an antibacterial and flame-retardant composite microfiber fabric.

[0054] Example 3

[0055] (1) Under nitrogen atmosphere, add 20 g of tri(2-chloroethyl) phosphate and 200 mL of acetonitrile to a reaction flask. After stirring evenly, add 42 g of p-dimethylaminobenzaldehyde. React at 65 °C for 48 h. Extract with ethyl acetate and deionized water. Concentrate the organic phase and dry it to obtain quaternary ammonium salt benzaldehyde phosphate monomer.

[0056] (2) Under a nitrogen atmosphere, 18 g of quaternary ammonium salt benzaldehyde phosphate monomer and 270 mL of methanol were added to a reaction flask. After stirring evenly, 11.7 g of 2-amino-4,6-dimethoxy-1,3,5-triazine was added and reacted at 60 °C for 32 h. The mixture was cooled to room temperature, filtered, washed with ethanol, and dried to obtain a methoxyphosphorus nitrogen quaternary ammonium salt monomer.

[0057] (3) Under a nitrogen atmosphere, 15 g of methoxyphosphorus nitrogen quaternary ammonium salt monomer and 450 mL of dichloromethane were added to a reaction flask. After stirring evenly, 28.5 g of boron tribromide was added. The mixture was reacted at 0°C for 16 h. The mixture was extracted with ethyl acetate and deionized water. The organic phase was concentrated and dried to obtain an antibacterial flame retardant chain extender.

[0058] (4) 75 g of polytetramethylene glycol was placed in a vacuum environment at a temperature of 100 ° C and a vacuum degree of 0.05 MPa for vacuum dehydration for 2 h, 25 g of isophorone diisocyanate was added, nitrogen was introduced, 6 g of antibacterial flame retardant chain extender and 0.8 g of stannous octoate were added, and the mixture was kept at 70 ° C for 6 h. The material was cooled and discharged, and calendered to obtain a functional layer.

[0059] (5) After drying, 60 g of nylon 6 and 40 g of low-density polyethylene were added to a spinning machine for spinning. The winding speed was 300 m / min, and the spinning temperatures of screw zones 1 to 4 were 160, 250, 265, and 265 °C, respectively. Then, the fibers were stretched and heat-set at a temperature of 65 °C to obtain ultrafine fibers with a single filament fineness of 0.3 dtex. The fibers were immersed in xylene at a temperature of 90 °C, kept for 80 min, taken out, washed with xylene, and dried to obtain a fabric base layer.

[0060] (6) The various layers of materials are laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer" and hot-pressed on a hot press molding machine. The hot-pressing temperature is 100°C, the time is 40 seconds, the pressure is 0.4 MPa, and the material is allowed to stand at room temperature for 24 hours to obtain an antibacterial and flame-retardant composite microfiber fabric.

[0061] Example 4

[0062] (1) Under nitrogen atmosphere, add 25 g of tri(2-chloroethyl) phosphate and 170 mL of acetonitrile to a reaction flask. After stirring, add 46.5 g of p-dimethylaminobenzaldehyde. The mixture is reacted at 70 °C for 30 h. The mixture is extracted with ethyl acetate and deionized water. The organic phase is concentrated and dried to obtain a quaternary ammonium salt of benzaldehyde phosphate monomer.

[0063] (2) Under a nitrogen atmosphere, 22 g of quaternary ammonium salt benzaldehyde phosphate monomer and 190 mL of methanol were added to a reaction flask. After stirring evenly, 12.1 g of 2-amino-4,6-dimethoxy-1,3,5-triazine was added and reacted at 65 °C for 24 h. The mixture was cooled to room temperature, filtered, washed with ethanol, and dried to obtain a methoxyphosphorus nitrogen quaternary ammonium salt monomer.

[0064] (3) Under a nitrogen atmosphere, 18 g of methoxyphosphorus nitrogen quaternary ammonium salt monomer and 405 mL of dichloromethane were added to a reaction flask. After stirring evenly, 33.3 g of boron tribromide was added. The mixture was reacted at 5 °C for 15 h. The mixture was extracted with ethyl acetate and deionized water. The organic phase was concentrated and dried to obtain an antibacterial flame retardant chain extender.

[0065] (4) 72 g of polytetramethylene glycol was placed in a vacuum environment at a temperature of 115 ° C and a vacuum degree of 0.06 MPa for vacuum dehydration for 1.5 h, 15 g of isophorone diisocyanate was added, nitrogen was introduced, 8 g of an antibacterial flame retardant chain extender and 0.65 g of stannous octoate were added, and the mixture was kept at 80 ° C for 5 h. The material was cooled and discharged, and calendered to obtain a functional layer.

[0066] (5) After drying, 54 g of nylon 6 and 46 g of low-density polyethylene were added to a spinning machine for spinning. The winding speed was 450 m / min, and the spinning temperatures of screw zones 1 to 4 were 160, 250, 265, and 265 °C, respectively. Then, the fibers were stretched and heat-set at a temperature of 70 °C to obtain ultrafine fibers with a single filament fineness of 0.4 dtex. The fibers were immersed in xylene at a temperature of 95 °C, kept for 75 min, taken out, washed with xylene, and dried to obtain a fabric base layer.

[0067] (6) The various layers of materials are laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer" and hot-pressed on a hot press molding machine. The hot-pressing temperature is 105°C, the time is 35 seconds, the pressure is 0.45 MPa, and the material is allowed to stand at room temperature for 18 hours to obtain an antibacterial and flame-retardant composite microfiber fabric.

[0068] Example 5

[0069] (1) Under nitrogen atmosphere, add 12 g of tri(2-chloroethyl) phosphate and 125 mL of acetonitrile to a reaction flask. After stirring, add 24.6 g of p-dimethylaminobenzaldehyde. The mixture is reacted at 75 °C for 36 h. The mixture is extracted with ethyl acetate and deionized water. The organic phase is concentrated and dried to obtain a quaternary ammonium salt of benzaldehyde phosphate monomer.

[0070] (2) Under a nitrogen atmosphere, 10 g of quaternary ammonium salt benzaldehyde phosphate monomer and 120 mL of methanol were added to a reaction flask. After stirring evenly, 6.2 g of 2-amino-4,6-dimethoxy-1,3,5-triazine was added and reacted at 70 °C for 24 h. The mixture was cooled to room temperature, filtered, washed with ethanol, and dried to obtain a methoxyphosphorus nitrogen quaternary ammonium salt monomer.

[0071] (3) Under a nitrogen atmosphere, 8 g of methoxyphosphorus nitrogen quaternary ammonium salt monomer and 180 mL of dichloromethane were added to a reaction flask. After stirring evenly, 14.8 g of boron tribromide was added and the mixture was reacted at 0 °C for 12 h. The mixture was extracted with ethyl acetate and deionized water, and the organic phase was concentrated and dried to obtain an antibacterial flame retardant chain extender.

[0072] (4) 65 g of polytetramethylene glycol was placed in a vacuum environment at a temperature of 120 ° C and a vacuum degree of 0.1 MPa for vacuum dehydration for 2 h, 20 g of isophorone diisocyanate was added, nitrogen was introduced, 10 g of an antibacterial flame retardant chain extender and 0.6 g of stannous octoate were added, and the mixture was kept at 75 ° C for 5 h. The material was cooled and discharged, and calendered to obtain a functional layer.

[0073] (5) After drying, 55 g of nylon 6 and 45 g of low-density polyethylene were added to a spinning machine for spinning. The winding speed was 350 m / min, and the spinning temperatures of screw zones 1 to 4 were 160, 250, 265, and 265 °C, respectively. Then, the fibers were stretched and heat-set at a temperature of 75 °C to obtain ultrafine fibers with a single filament fineness of 0.5 dtex. The fibers were immersed in xylene at a temperature of 95 °C, kept for 75 min, taken out, washed with xylene, and dried to obtain a fabric base layer.

[0074] (6) The various layers of materials are laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer" and hot-pressed on a hot press molding machine. The hot-pressing temperature is 115°C, the time is 35 seconds, the pressure is 0.5 MPa, and the material is allowed to stand at room temperature for 18 hours to obtain an antibacterial and flame-retardant composite microfiber fabric.

[0075] Comparative Example 1

[0076] (1) Under nitrogen atmosphere, add 35 g of tris(2-chloroethyl) phosphate and 240 mL of acetonitrile to a reaction flask, stir evenly, and then add 63 g of 4-(methylamino)benzaldehyde (structural formula: , CAS No. 556-21-8), reacted at 75°C for 32h, extracted with ethyl acetate and deionized water, concentrated the organic phase, and dried to obtain benzaldehyde phosphate monomer.

[0077] (2) Under a nitrogen atmosphere, 32 g of benzaldehyde phosphate monomer and 400 mL of methanol were added to a reaction flask. After stirring evenly, 19.2 g of 2-amino-4,6-dimethoxy-1,3,5-triazine was added and the mixture was reacted at 65 °C for 24 h. The mixture was cooled to room temperature, filtered, washed with ethanol, and dried to obtain a methoxyphosphorus nitrogen monomer.

[0078] (3) Under a nitrogen atmosphere, 30 g of methoxyphosphorus nitrogen monomer and 750 mL of dichloromethane were added to a reaction flask. After stirring evenly, 54 g of boron tribromide was added. The mixture was reacted at 10 °C for 12 h. The mixture was extracted with ethyl acetate and deionized water. The organic phase was concentrated and dried to obtain a flame retardant chain extender.

[0079] (4) 70 g of polytetramethylene glycol was placed in a vacuum environment at a temperature of 110° C. and a vacuum degree of 0.08 MPa for 2 h, 15 g of isophorone diisocyanate was added, nitrogen was introduced, 2 g of a flame retardant chain extender and 0.5 g of stannous octoate were added, the mixture was kept at 75° C. for 4 h, the temperature was lowered, the mixture was discharged, and calendering was performed to obtain a functional layer.

[0080] (5) After drying, 55 g of nylon 6 and 45 g of low-density polyethylene were added to a spinning machine for spinning. The winding speed was 400 m / min, and the spinning temperatures of screw zones 1 to 4 were 160, 250, 265, and 265 °C, respectively. Then, the fibers were stretched and heat-set at a temperature of 70 °C to obtain ultrafine fibers with a single filament fineness of 0.5 dtex. The fibers were immersed in xylene at a temperature of 95 °C, kept for 70 min, taken out, washed with xylene, and dried to obtain a fabric base layer.

[0081] (6) The various layers of materials are laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer" and hot-pressed on a hot press molding machine. The hot-pressing temperature is 115°C, the time is 30 seconds, the pressure is 0.5 MPa, and the material is allowed to stand at room temperature for 18 hours to obtain a flame-retardant composite microfiber fabric.

[0082] Comparative Example 2

[0083] (1) 70g of polytetrahydrofuran ether diol was placed in a vacuum dehydration environment at a temperature of 110°C and a vacuum degree of 0.08MPa for 2h, 15g of isophorone diisocyanate was added, nitrogen was introduced, and 2g of dipentaerythritol (structural formula: , CAS No. 126-58-9) and 0.5g of stannous octoate, keep warm at 75°C for 4h, cool and discharge, calender and shape to obtain the functional layer.

[0084] (2) After drying, 55 g of nylon 6 and 45 g of low-density polyethylene were added to a spinning machine for spinning. The winding speed was 400 m / min, and the spinning temperatures of screw zones 1 to 4 were 160, 250, 265, and 265 °C, respectively. Then, the fibers were stretched and heat-set at a temperature of 70 °C to obtain ultrafine fibers with a single filament fineness of 0.5 dtex. The fibers were immersed in xylene at a temperature of 95 °C, kept for 70 min, taken out, washed with xylene, and dried to obtain a fabric base layer.

[0085] (3) The various layers of materials are laid flat according to the structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer" and hot-pressed on a hot press molding machine. The hot-pressing temperature is 115°C, the time is 30 seconds, the pressure is 0.5 MPa, and the material is allowed to stand at room temperature for 18 hours to obtain a composite microfiber fabric.

[0086] Antibacterial performance test: Referring to GB / T 20944.3-2008, Staphylococcus aureus and Escherichia coli were used as test bacteria, and the antibacterial performance of the composite fiber fabric was tested by the oscillation method; Staphylococcus aureus and Escherichia coli were placed in liquid culture medium for activation, and the culture solution was placed in a 37°C constant temperature shaker and cultured for 24 hours at a shaking speed of 130 rpm; then the prepared composite fiber fabric was cut into small pieces of 2 cm × 2 cm, and 1 g of each was weighed and sterilized at 120°C for 60 minutes in a conical flask containing 30 mL of liquid culture medium, and then cultured in a constant temperature shaker at 37°C and 130 r / min for 18 hours. After the culture was completed, the bacterial solution in the culture medium was diluted with PBS buffer to 1.1 × 10 8 CFU / mL, draw 100μL of the diluted solution and drop it on the solid culture medium, spread it evenly, and then put it in a constant temperature incubator at 37℃ for 24h, and finally count the live bacteria on the plate. The antibacterial rate = (W1-W2) / W1×100%, where W1 represents the average value of the concentration of surviving bacteria in the bottle after the control sample has been in full contact with the bacteria for 18h (CFU / mL), and W2 represents the average value of the concentration of surviving bacteria in the bottle after the composite fiber fabric has been in full contact with the bacteria for 18h (CFU / mL). Each group was measured three times and the average value was taken.

[0087] Table 1 Antibacterial performance test

[0088]

[0089] It can be seen from the test results in the above table that with the increase of the content of the antibacterial flame retardant chain extender in the functional layer, the antibacterial rate of the composite fiber fabric to bacteria gradually increases. The antibacterial rates of Staphylococcus aureus and Escherichia coli in Example 4 are 98.6% and 98.2%, respectively. This is because the antibacterial flame retardant chain extender contains quaternary ammonium salt cations, which participate in the chain extension synthesis of polyurethane, and the positive charge of the formed quaternary ammonium salt polymer antibacterial agent is more dense, which is easier to combine with the protein and phospholipid of bacteria, so that the bacterial cell membrane is broken and the normal metabolism of bacteria is interfered. The quaternary ammonium salt cation promotes the uneven distribution of negative charges on the bacterial cell membrane through electrostatic action, causing its deformation, so that the content of the cell, such as protein, leaks, and the "bacterial lysate" phenomenon occurs and dies, thereby playing an antibacterial role. Comparative Examples 1 and 2 do not contain quaternary ammonium salt cations and do not have antibacterial properties.

[0090] Limiting oxygen index (LOI) test: refer to GB / T 5454-1997, use a digital limiting oxygen index instrument to test the sample; the sample size is 140mm×52mm×2mm, and the average value is taken after 3 measurements.

[0091] Vertical burning test: refer to UL 94-2006 for testing, use a vertical burning test box to conduct vertical burning test on the sample; the sample size is 135mm×15mm×2mm.

[0092] Cone calorimetry analysis: Cone calorimetry analysis was performed on the samples using a cone calorimeter with a sample size of 100 mm × 100 mm × 2 mm.

[0093] Table 2 Flame retardant performance test

[0094]

[0095] It can be seen from the test results in the above table that with the increase of the content of the antibacterial flame retardant chain extender in the functional layer, the flame retardant performance of the composite fiber fabric is gradually enhanced, and the embodiments all reach the level of flame retardant materials. This is because on the one hand, the antibacterial flame retardant chain extender contains triazine rings with excellent carbonization ability, which can undergo thermal decomposition reaction during combustion, absorb a large amount of heat, and release ammonia to dilute the surrounding combustible gas concentration, thereby slowing down or preventing the spread of flames; in addition, phosphorus-containing substances will decompose at high temperatures to produce compounds such as phosphate esters, which can be used as free radical scavengers in polymer decomposition products, effectively preventing the thermal decomposition of molecular chains, and phosphorus and nitrogen elements synergistically flame retardant, preventing the combustion from proceeding; on the other hand, the aromatic Schiff base in the antibacterial flame retardant chain extender structure forms a nitrogen-containing cross-linked network structure with polyamide 6 during high temperature, and further cross-links into a denser carbon layer during combustion, blocking the exchange of oxygen and heat between the fiber matrix and the air, and playing a role in thermal protection of the composite fiber fabric. Phosphorus and nitrogen elements and Schiff bases in Comparative Example 2 do not have flame retardant properties.

[0096] The polyurethane in the functional layer contains a highly polar urethane group, which has good aging resistance and adhesion. As a bonding transition layer, it can significantly enhance the bonding force between the composite microfiber fabric layers. After hot pressing treatment, it can fully contact with the microfiber fabric base layer, reducing the possibility of slippage and effectively improving the service life of the microfiber fabric.

[0097] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. An antibacterial flame retardant composite microfiber fabric, characterized in that: The composite ultrafine fiber fabric comprises a fabric base layer, an adhesive layer, a barrier layer and a functional layer; The preparation method of the fabric base layer is as follows: nylon 6 and low-density polyethylene are dried and added to a spinning machine for spinning, the winding speed is 300-500 m / min, the spinning temperatures of the first to fourth zones of the screw are 160, 250, 265, and 265° C. respectively, then stretching and heat setting are performed, the heat setting temperature is 65-80° C., the obtained ultrafine fibers are immersed in xylene at a temperature of 90-100° C., kept for 60-80 minutes, taken out, washed with xylene, and dried to obtain the fabric base layer; The adhesive layer is polyethylene-vinyl acetate adhesive; The barrier layer is ethylene-vinyl alcohol copolymer; The preparation method of the functional layer is as follows: placing polytetramethylene glycol in an environment with a temperature of 100-120° C. and a vacuum degree of 0.05-0.1 MPa for vacuum dehydration for 1-2 hours, adding isophorone diisocyanate, introducing nitrogen, adding an antibacterial flame retardant chain extender and stannous octoate, keeping the temperature at 70-80° C. for 2-6 hours, cooling and discharging, and calendering to obtain the functional layer; The preparation method of the antibacterial flame retardant chain extender is: Step (1), under a nitrogen atmosphere, add tri(2-chloroethyl) phosphate and acetonitrile to a reaction flask, stir evenly, add p-dimethylaminobenzaldehyde, react at 65-80° C. for 24-48 hours, extract with ethyl acetate and deionized water, concentrate the organic phase, and dry to obtain a quaternary ammonium salt benzaldehyde phosphate monomer; Step (2), under a nitrogen atmosphere, add quaternary ammonium salt benzaldehyde phosphate monomer and methanol to a reaction flask, stir evenly, add 2-amino-4,6-dimethoxy-1,3,5-triazine, react at 60-75° C. for 16-32 hours, cool to room temperature, filter, wash with ethanol, and dry to obtain a methoxyphosphorus nitrogen quaternary ammonium salt monomer; Step (3), under a nitrogen atmosphere, add methoxyphosphorus nitrogen quaternary ammonium salt monomer and dichloromethane to a reaction flask, stir evenly, add boron tribromide, react at 0-20° C. for 8-16 hours, extract with ethyl acetate and deionized water, concentrate the organic phase, and dry to obtain an antibacterial flame retardant chain extender.

2. The antibacterial flame-retardant composite microfiber fabric according to claim 1, characterized in that: The mass ratio of nylon 6 to low-density polyethylene is 50-60:40-50.

3. The antibacterial flame-retardant composite microfiber fabric according to claim 1, characterized in that: The single filament fineness of the ultrafine fiber is 0.3-0.6 dtex.

4. The antibacterial flame-retardant composite microfiber fabric according to claim 1, characterized in that: The mass ratio of the polytetramethylene ether diol, isophorone diisocyanate, antibacterial flame retardant chain extender and stannous octoate is 60-75:10-25:2-10:0.3-0.

8.

5. The antibacterial flame-retardant composite microfiber fabric according to claim 1, characterized in that: In the step (1), the mass ratio of tris(2-chloroethyl) phosphate to p-dimethylaminobenzaldehyde is 100:175-210.

6. The antibacterial flame-retardant composite microfiber fabric according to claim 1, characterized in that: In the step (2), the mass ratio of the quaternary ammonium salt benzaldehyde phosphate monomer to 2-amino-4,6-dimethoxy-1,3,5-triazine is 100:52-65.

7. The antibacterial flame-retardant composite microfiber fabric according to claim 1, characterized in that: In the step (3), the mass ratio of the methoxyphosphorus nitrogen quaternary ammonium salt monomer to boron tribromide is 100:165-190.

8. A method for preparing the antibacterial flame-retardant composite ultrafine fiber fabric according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: laying each layer of material in a structure of "fabric base layer-adhesive layer-barrier layer-adhesive layer-functional layer", performing hot pressing compounding on a hot pressing molding machine, and standing at room temperature for 16-24 hours to obtain an antibacterial and flame retardant composite ultrafine fiber fabric.

9. The method for preparing the antibacterial flame-retardant composite ultrafine fiber fabric according to claim 8, characterized in that: The temperature of the hot pressing compound is 100-125° C., the time is 20-40 seconds, and the pressure is 0.4-0.6 MPa.

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