Flame-retardant fire hose lining and preparation method thereof

Abstract

The invention relates to the technical field of rubber products, in particular to a flame-retardant fire hose lining and a preparation method thereof.The preparation method comprises the steps that S1, modified chloroprene rubber, reinforcing filler, a plasticizer and an anti-aging agent are added into an internal mixer to be mixed for 2-3 h and cooled to the room temperature, and a vulcanizing-agent-free rubber compound is prepared; mixing the rubber compound without the vulcanizing agent, a cross-linking agent, the vulcanizing agent and a vulcanization accelerator on a double-roller open mill to prepare a rubber compound containing the vulcanizing agent; s2, molding the rubber compound containing the vulcanizing agent, and vulcanizing on a plate vulcanizing machine to obtain primary vulcanized rubber; and S3, carrying out secondary vulcanization on the primary vulcanized rubber to obtain the flame-retardant fire hose lining. The prepared flame-retardant fire hose lining has the advantages of favorable flame retardancy, high tensile strength, high elongation at break, stable mechanical properties, favorable aging resistance and favorable wear resistance, and can still maintain favorable toughness in a low-temperature environment, thereby obviously enhancing the overall performance and prolonging the service life of the fire hose.

Description

Technical Field

[0001] The present application relates to the technical field of rubber products, and more specifically, to a flame retardant fire hose lining and a preparation method thereof. Background Art

[0002] Fire hoses are important tools for conveying water for firefighting. They are usually composed of an inner lining and an outer sheath. The inner lining is in direct contact with water and undertakes the key task of conveying water. Although existing fire hose lining materials can meet basic water delivery requirements, their flame retardant properties are often insufficient when facing harsh fire environments such as high temperature and open flames. They are easily ignited or rapidly age and damage due to high temperature, causing the hoses to rupture and leak, seriously affecting the efficiency and safety of firefighting and rescue work. In addition, some existing flame-retardant lining materials have defects in mechanical properties, aging resistance, durability, etc., and cannot simultaneously meet the multiple requirements of fire hoses in complex usage scenarios. Moreover, for fire hoses used in low-temperature environments, traditional lining materials also have the problem of high brittleness. When placed under low-temperature conditions, the flexibility of the material decreases significantly, becoming hard and brittle. When the hose is bent, curled, or subjected to slight external force collision, it is very easy to crack or even break. This greatly limits the application of fire hoses in cold areas or low-temperature operation scenarios. Therefore, there is an urgent need to develop a new type of flame-retardant fire hose lining material that is both effectively flame-retardant and has good comprehensive performance. Summary of the invention

[0003] In order to solve the technical problems mentioned in the background technology, the present application provides a flame retardant fire hose lining and a preparation method thereof.

[0004] In the first aspect, the present application provides a flame retardant fire hose lining, which adopts the following technical solution:

[0005] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 50-70 parts of modified chloroprene rubber, 18-25 parts of reinforcing filler, 3-8 parts of plasticizer, 1-2 parts of antioxidant, 1-3 parts of cross-linking agent, 1-3 parts of vulcanizing agent and 1-2 parts of vulcanization accelerator.

[0006] Preferably, the preparation of the modified chloroprene rubber comprises the following steps:

[0007] (1) adding chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 80-100° C., adding an initiator, and reacting for 2-3 hours under stirring and nitrogen protection to obtain an intermediate;

[0008] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 110-130° C., react for 4-6 hours under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry to obtain modified chloroprene rubber.

[0009] Preferably, in step (1), the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer is 40-60:5-8:8-12.

[0010] Preferably, in step (2), the mass ratio of the intermediate, the flame retardant DOPO and cis-allyl phosphoric acid is 10:1-2:0.1-0.3.

[0011] Preferably, the preparation of the reinforcing filler comprises the following steps:

[0012] Chlorinated polyvinyl chloride and acetylene black are added into a twin-screw extruder for melt blending for 20-30 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled at 120-140°C, the mixing temperature is 160-170°C, the homogenization temperature is 180-200°C, the extrusion temperature is 120-170°C, the twin-screw speed is 100-200rpm, the screw aspect ratio is 15-20:1, the mixing is performed for 1-2 hours, the pelletization is performed by extrusion, and the pellets are cooled to room temperature to obtain a reinforcing filler.

[0013] Preferably, the mass ratio of the chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3-8:20-30:1-2.

[0014] Preferably, the plasticizer consists of dioctyl phthalate and dioctyl adipate in a mass ratio of 1-3:1.

[0015] Preferably, the antioxidant is one or more of antioxidant RD, antioxidant MB, antioxidant 264 and antioxidant 4010NA.

[0016] Preferably, the cross-linking agent is one or more of triallyl isocyanurate, bismaleimide and benzoyl peroxide.

[0017] Preferably, the vulcanizing agent is sulfur.

[0018] Preferably, the vulcanization accelerator is one or more of accelerator TMTD, accelerator DM, accelerator M and accelerator TMTM.

[0019] In a second aspect, the present application also provides a method for preparing a flame retardant fire hose lining, comprising the following steps:

[0020] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80-100° C. for 2-3 hours, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1-2 hours to obtain a vulcanizing agent-containing rubber mix;

[0021] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8-12 MPa and a temperature of 150-180° C. for 10-20 minutes to obtain a primary vulcanized rubber;

[0022] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200-220° C. for 3-5 hours to obtain a flame-retardant fire hose lining.

[0023] In summary, this application has the following beneficial effects:

[0024] The present application introduces brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer in the preparation process of chloroprene rubber intermediate. Styrene hard segment and acrylonitrile can provide rigid support and enhance the skeleton structure of chloroprene rubber. When the fire hose is subjected to high water pressure, this rigidity can prevent the rubber from overstretching and tearing. At the same time, the flexibility of the butadiene soft segment enables the rubber to better disperse stress during the deformation process. The brominated styrene-butadiene-styrene block copolymer can prevent the invasion of water molecules, and the chemical structure of acrylonitrile-butadiene-styrene copolymer also helps to improve the material's resistance to hydrolysis, which can better maintain its physical properties and chemical stability, prevent the degradation of rubber performance caused by hydrolysis, such as softening and reduced strength, and ensure the normal use of the fire hose lining in a humid environment. The water resistance, elasticity and flexibility of the chloroprene rubber after combined grafting and modification, as well as the mechanical properties such as tensile strength, flexural strength and impact strength are comprehensively improved. The bromine element in brominated styrene-butadiene-styrene block copolymer can improve the flame retardancy of the material, slow down or prevent the spread of flame, and reduce the burning speed of the material, thereby improving the overall flame retardancy of the material.

[0025] In the process of preparing modified chloroprene rubber, the present application introduces flame retardant DOPO and cis-allyl phosphoric acid. The flame retardant DOPO and cis-allyl phosphoric acid can catalyze the dehydration and carbonization of the rubber molecular chain to form a carbon layer, prevent the rubber lining from burning, and significantly improve the flame retardant performance of the rubber. The phosphoric acid group of cis-allyl phosphoric acid is hydrophilic and can form hydrogen bonds and other interactions with water molecules to a certain extent. When the rubber encounters moisture, cis-allyl phosphoric acid can prevent further penetration of water molecules through these interactions, thereby improving the water resistance of the rubber. At the same time, the introduction of flame retardant DOPO and cis-allyl phosphoric acid can interact with the chloroprene rubber matrix at different sites. The phosphaphenanthrene ring structure and active PH bond in the DOPO molecule can react with the double bond or other active groups on the chloroprene rubber molecular chain. The unsaturated double bond and phosphoric acid group of cis-allyl phosphoric acid can also react chemically with the matrix, which helps to improve the compatibility of the flame retardant with the matrix material, so that the flame retardant is more evenly dispersed in the material to avoid agglomeration, thereby further ensuring the stability and uniformity of the material performance. In addition, cis-allyl phosphoric acid and flame retardant DOPO can participate in the cross-linking reaction of rubber molecular chains, react with active sites on the rubber molecular chains to form additional cross-linking points, thereby increasing the cross-linking density of the rubber. The cross-linking reaction enables the flame retardant DOPO and cis-allyl phosphoric acid to form a three-dimensional network structure with the chloroprene rubber matrix. The flame retardant molecules are chemically bonded to the matrix material, and the stability and resistance to loss are enhanced, which helps to further enhance the strength, hardness, wear resistance and flame retardancy of the rubber.

[0026] In the preparation process of reinforcing filler, the present application first adds chlorinated polyvinyl chloride and acetylene carbon black to mix at the initial stage of blending. The rigid structure and high glass transition temperature of chlorinated polyvinyl chloride can provide a relatively stable dispersion environment for acetylene carbon black, and initially prevent the agglomeration of acetylene carbon black. Chlorinated polyethylene has good flexibility and fluidity, and can be filled in the gap of the preliminary dispersion system formed by chlorinated polyvinyl chloride and acetylene carbon black, further improving the dispersibility of carbon black. The chlorinated polyethylene molecular chain can interact with chlorinated polyvinyl chloride and acetylene carbon black, so that acetylene carbon black is more evenly dispersed in the entire system. Compared with adding chlorinated polyvinyl chloride and chlorinated polyethylene at the same time, this step-by-step addition method can more effectively prevent carbon black agglomeration, has good reinforcement, and can significantly improve the mechanical properties of rubber products. In addition, the first modification with chlorinated polyvinyl chloride can form a gradient structure in the filler system. The inner layer close to the acetylene carbon black particles is a relatively rigid chlorinated polyvinyl chloride layer. This layer of structure provides a good skeleton support for the filler and can improve the compressive strength and dimensional stability of the filler. The outer layer of chlorinated polyethylene gives the entire system flexibility and good processing performance. This gradient structure can better adapt to the needs of the matrix material under different stress conditions after being added to rubber and other matrix materials as a reinforcing filler. For example, when under pressure, the chlorinated polyvinyl chloride structure of the inner layer can resist deformation, and when stretched or bent, the chlorinated polyethylene of the outer layer can buffer external forces through its own flexibility, thereby making the performance of the entire material system more stable. In addition, the joint modification of chlorinated polyethylene and chlorinated polyvinyl chloride can significantly improve the flame retardant properties of the rubber substrate. DETAILED DESCRIPTION

[0027] The present application is further described in detail below with reference to the embodiments.

[0028] The chloroprene rubber used in the examples and comparative examples of the present application was purchased from Shandong Xinheng Chemical Co., Ltd.; brominated styrene-butadiene-styrene block copolymer was purchased from Wuhan Kamik Technology Co., Ltd.; acrylonitrile-butadiene-styrene copolymer was purchased from Wuhan Jiyesheng Chemical Co., Ltd.; flame retardant DOPO (content: 99%) was purchased from Wuhan Smack Biotechnology Co., Ltd.; cis-allyl phosphoric acid was purchased from Tianmen Hengchang Chemical Co., Ltd.; chlorinated polyvinyl chloride (chlorine content: 64%) was purchased from Weifang Hanghao New Material Technology Co., Ltd.; acetylene black was purchased from Jinan Jinlei Chemical Co., Ltd.; and chlorinated polyethylene was purchased from Shandong Guoheng New Material Technology Co., Ltd.

[0029] Embodiment 1-3 provides a flame retardant fire hose lining and a preparation method thereof.

[0030] Example 1

[0031] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 50 parts of modified chloroprene rubber, 18 parts of reinforcing fillers, 3 parts of plasticizers, 1 part of antioxidants, 1 part of cross-linking agents, 1 part of vulcanizing agents, and 1 part of vulcanization accelerators, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 1:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0032] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0033] (1) adding chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 80° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 200 rpm, reacting for 2 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer, acrylonitrile-butadiene-styrene copolymer, azobisisobutyronitrile and toluene is 40:5:8:0.1:180;

[0034] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 110°C, react for 4 hours at a stirring speed of 100 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 60°C for 10 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate, flame retardant DOPO and cis-allyl phosphoric acid is 10:1:0.1.

[0035] Wherein, the preparation of reinforcing filler comprises the following steps:

[0036] Chlorinated polyvinyl chloride and acetylene black are added to a twin-screw extruder, melt-blended at a temperature of 180°C for 20 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled to be 120°C, the mixing temperature is 160°C, the homogenization temperature is 180°C, the extrusion temperature is 120°C, the twin-screw speed is 100rpm, the screw aspect ratio is 15:1, mixing is performed for 1 hour, extrusion granulation is performed, and cooling is performed to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3:20:1.

[0037] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0038] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80° C. for 2 h, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1 h at a mixing temperature of 120° C., and obtaining a vulcanizing agent-containing rubber mix;

[0039] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8 MPa and a temperature of 150° C. for 10 minutes to obtain a primary vulcanized rubber;

[0040] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200° C. for 3 hours to obtain a flame-retardant fire hose lining.

[0041] Example 2

[0042] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 60 parts of modified chloroprene rubber, 22 parts of reinforcing filler, 5 parts of plasticizer, 1.5 parts of antioxidant, 2 parts of cross-linking agent, 2 parts of vulcanizing agent, and 1.5 parts of vulcanization accelerator, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 2:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0043] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0044] (1) adding chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 90° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 250 rpm, reacting for 2.5 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer, acrylonitrile-butadiene-styrene copolymer, azobisisobutyronitrile and toluene is 50:6:10:0.5:190;

[0045] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 120°C, react for 5 hours at a stirring speed of 130 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 70°C for 11 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate, flame retardant DOPO and cis-allyl phosphoric acid is 10:1.5:0.2.

[0046] Wherein, the preparation of reinforcing filler comprises the following steps:

[0047] Chlorinated polyvinyl chloride and acetylene black are added to a twin-screw extruder, melt-blended at a temperature of 190°C for 25 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled to be 130°C, the mixing temperature is 165°C, the homogenization temperature is 190°C, the extrusion temperature is 150°C, the twin-screw speed is 150rpm, the screw aspect ratio is 18:1, mixing is performed for 1.5 hours, extrusion granulation is performed, and cooling is performed to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 5:25:1.5.

[0048] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0049] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 90° C. for 2.5 hours, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1.5 hours at a mixing temperature of 125° C., and obtaining a vulcanizing agent-containing rubber mix;

[0050] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 10 MPa and a temperature of 165° C. for 15 minutes to obtain a primary vulcanized rubber;

[0051] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 210° C. for 4 hours to obtain a flame-retardant fire hose lining.

[0052] Example 3

[0053] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 70 parts of modified chloroprene rubber, 25 parts of reinforcing filler, 8 parts of plasticizer, 2 parts of antioxidant, 3 parts of cross-linking agent, 3 parts of vulcanizing agent, and 2 parts of vulcanization accelerator, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 3:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0054] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0055] (1) adding chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 100° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 300 rpm, reacting for 3 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer, acrylonitrile-butadiene-styrene copolymer, azobisisobutyronitrile and toluene is 60:8:12:1:200;

[0056] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 130°C, react for 6 hours at a stirring speed of 150 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 80°C for 12 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate, flame retardant DOPO and cis-allyl phosphoric acid is 10:2:0.3.

[0057] Wherein, the preparation of reinforcing filler comprises the following steps:

[0058] Chlorinated polyvinyl chloride and acetylene black are added to a twin-screw extruder, melt blended at a temperature of 200°C for 30 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled to be 140°C, the mixing temperature is 170°C, the homogenization temperature is 200°C, the extrusion temperature is 170°C, the twin-screw speed is 200rpm, the screw aspect ratio is 20:1, mixing is carried out for 2 hours, extrusion granulation is carried out, and cooling is carried out to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 4:15:1.

[0059] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0060] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer by weight, mixing at 100° C. for 3 hours, cooling to room temperature, and obtaining a vulcanizing agent-free mixed rubber; then mixing the vulcanizing agent-free mixed rubber, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll mill for 2 hours at a mixing temperature of 130° C., and obtaining a vulcanizing agent-containing mixed rubber;

[0061] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 12 MPa and a temperature of 180° C. for 20 minutes to obtain a primary vulcanized rubber;

[0062] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 220° C. for 5 hours to obtain a flame-retardant fire hose lining.

[0063] Comparative Example 1

[0064] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 50 parts of modified chloroprene rubber, 18 parts of reinforcing fillers, 3 parts of plasticizers, 1 part of antioxidants, 1 part of cross-linking agents, 1 part of vulcanizing agents, and 1 part of vulcanization accelerators, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 1:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0065] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0066] (1) adding chloroprene rubber and brominated styrene-butadiene-styrene block copolymer to toluene, heating to 80° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 200 rpm, reacting for 2 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer azobisisobutyronitrile and toluene is 40:13:0.1:180;

[0067] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 110°C, react for 4 hours at a stirring speed of 100 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 60°C for 10 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate, flame retardant DOPO and cis-allyl phosphoric acid is 10:1:0.1.

[0068] Wherein, the preparation of reinforcing filler comprises the following steps:

[0069] Chlorinated polyvinyl chloride and acetylene black are added to a twin-screw extruder, melt-blended at a temperature of 180°C for 20 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled to be 120°C, the mixing temperature is 160°C, the homogenization temperature is 180°C, the extrusion temperature is 120°C, the twin-screw speed is 100rpm, the screw aspect ratio is 15:1, mixing is performed for 1 hour, extrusion granulation is performed, and cooling is performed to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3:20:1.

[0070] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0071] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80° C. for 2 h, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1 h at a mixing temperature of 120° C., and obtaining a vulcanizing agent-containing rubber mix;

[0072] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8 MPa and a temperature of 150° C. for 10 minutes to obtain a primary vulcanized rubber;

[0073] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200° C. for 3 hours to obtain a flame-retardant fire hose lining.

[0074] Comparative Example 2

[0075] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 50 parts of modified chloroprene rubber, 18 parts of reinforcing fillers, 3 parts of plasticizers, 1 part of antioxidants, 1 part of cross-linking agents, 1 part of vulcanizing agents, and 1 part of vulcanization accelerators, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 1:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0076] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0077] (1) adding chloroprene rubber and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 80° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 200 rpm, reacting for 2 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, acrylonitrile-butadiene-styrene copolymer, azobisisobutyronitrile and toluene is 40:13:0.1:180;

[0078] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 110°C, react for 4 hours at a stirring speed of 100 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 60°C for 10 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate, flame retardant DOPO and cis-allyl phosphoric acid is 10:1:0.1.

[0079] Wherein, the preparation of reinforcing filler comprises the following steps:

[0080] Chlorinated polyvinyl chloride and acetylene black are added to a twin-screw extruder, melt-blended at a temperature of 180°C for 20 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled to be 120°C, the mixing temperature is 160°C, the homogenization temperature is 180°C, the extrusion temperature is 120°C, the twin-screw speed is 100rpm, the screw aspect ratio is 15:1, mixing is performed for 1 hour, extrusion granulation is performed, and cooling is performed to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3:20:1.

[0081] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0082] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80° C. for 2 h, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1 h at a mixing temperature of 120° C., and obtaining a vulcanizing agent-containing rubber mix;

[0083] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8 MPa and a temperature of 150° C. for 10 minutes to obtain a primary vulcanized rubber;

[0084] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200° C. for 3 hours to obtain a flame-retardant fire hose lining.

[0085] Comparative Example 3

[0086] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 50 parts of modified chloroprene rubber, 18 parts of reinforcing fillers, 3 parts of plasticizers, 1 part of antioxidants, 1 part of cross-linking agents, 1 part of vulcanizing agents, and 1 part of vulcanization accelerators, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 1:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0087] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0088] (1) adding chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 80° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 200 rpm, reacting for 2 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer, acrylonitrile-butadiene-styrene copolymer, azobisisobutyronitrile and toluene is 40:5:8:0.1:180;

[0089] (2) Add flame retardant DOPO to the intermediate, stir evenly, heat to 110°C, react for 4 hours at a stirring speed of 100 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 60°C for 10 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate to the flame retardant DOPO is 10:1.

[0090] Wherein, the preparation of reinforcing filler comprises the following steps:

[0091] Chlorinated polyvinyl chloride and acetylene black are added to a twin-screw extruder, melt-blended at a temperature of 180°C for 20 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled to be 120°C, the mixing temperature is 160°C, the homogenization temperature is 180°C, the extrusion temperature is 120°C, the twin-screw speed is 100rpm, the screw aspect ratio is 15:1, mixing is performed for 1 hour, extrusion granulation is performed, and cooling is performed to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3:20:1.

[0092] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0093] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80° C. for 2 h, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1 h at a mixing temperature of 120° C., and obtaining a vulcanizing agent-containing rubber mix;

[0094] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8 MPa and a temperature of 150° C. for 10 minutes to obtain a primary vulcanized rubber;

[0095] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200° C. for 3 hours to obtain a flame-retardant fire hose lining.

[0096] Comparative Example 4

[0097] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 50 parts of modified chloroprene rubber, 18 parts of reinforcing fillers, 3 parts of plasticizers, 1 part of antioxidants, 1 part of cross-linking agents, 1 part of vulcanizing agents, and 1 part of vulcanization accelerators, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 1:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0098] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0099] (1) adding chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 80° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 200 rpm, reacting for 2 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer, acrylonitrile-butadiene-styrene copolymer, azobisisobutyronitrile and toluene is 40:5:8:0.1:180;

[0100] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 110°C, react for 4 hours at a stirring speed of 100 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 60°C for 10 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate, flame retardant DOPO and cis-allyl phosphoric acid is 10:1:0.1.

[0101] Wherein, the preparation of reinforcing filler comprises the following steps:

[0102] Chlorinated polyvinyl chloride, chlorinated polyethylene and acetylene black are added to a twin-screw extruder, and the feed temperature of the twin-screw extruder is controlled to be 120°C, the mixing temperature is 160°C, the homogenization temperature is 180°C, the extrusion temperature is 120°C, the twin-screw speed is 100rpm, the screw aspect ratio is 15:1, mixing is performed for 1 hour, extrusion granulation is performed, and cooling is performed to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3:20:1.

[0103] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0104] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80° C. for 2 h, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1 h at a mixing temperature of 120° C., and obtaining a vulcanizing agent-containing rubber mix;

[0105] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8 MPa and a temperature of 150° C. for 10 minutes to obtain a primary vulcanized rubber;

[0106] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200° C. for 3 hours to obtain a flame-retardant fire hose lining.

[0107] Comparative Example 5

[0108] A flame-retardant fire hose lining comprises the following raw materials in parts by weight: 50 parts of modified chloroprene rubber, 18 parts of reinforcing fillers, 3 parts of plasticizers, 1 part of antioxidants, 1 part of cross-linking agents, 1 part of vulcanizing agents, and 1 part of vulcanization accelerators, wherein the plasticizer is composed of dioctyl phthalate and dioctyl adipate in a mass ratio of 1:1; the antioxidant is antioxidant RD; the cross-linking agent is triallyl isocyanurate; the vulcanizing agent is sulfur; and the vulcanization accelerator is accelerator DM.

[0109] Wherein, the preparation of modified chloroprene rubber comprises the following steps:

[0110] (1) adding chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, heating to 80° C., adding azobisisobutyronitrile, stirring and nitrogen protection at a stirring speed of 200 rpm, reacting for 2 hours to obtain an intermediate, wherein the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer, acrylonitrile-butadiene-styrene copolymer, azobisisobutyronitrile and toluene is 40:5:8:0.1:180;

[0111] (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 110°C, react for 4 hours at a stirring speed of 100 rpm under stirring and nitrogen protection, cool to room temperature, filter, wash, and dry at 60°C for 10 hours to obtain modified chloroprene rubber, wherein the mass ratio of the intermediate, flame retardant DOPO and cis-allyl phosphoric acid is 10:1:0.1.

[0112] Wherein, the preparation of reinforcing filler comprises the following steps:

[0113] Chlorinated polyethylene and acetylene black are added to a twin-screw extruder, melt-blended at a temperature of 180°C for 20 minutes, and then chlorinated polyvinyl chloride is added. The feed temperature of the twin-screw extruder is controlled to be 120°C, the mixing temperature is 160°C, the homogenization temperature is 180°C, the extrusion temperature is 120°C, the twin-screw speed is 100rpm, the screw aspect ratio is 15:1, mixing is performed for 1 hour, extrusion granulation is performed, and cooling is performed to room temperature to obtain a reinforcing filler, wherein the mass ratio of chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3:20:1.

[0114] A method for preparing a flame retardant fire hose lining comprises the following steps:

[0115] Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80° C. for 2 h, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1 h at a mixing temperature of 120° C., and obtaining a vulcanizing agent-containing rubber mix;

[0116] Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8 MPa and a temperature of 150° C. for 10 minutes to obtain a primary vulcanized rubber;

[0117] Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200° C. for 3 hours to obtain a flame-retardant fire hose lining.

[0118] Performance Testing

[0119] The comprehensive properties of the flame-retardant fire hose linings prepared in Examples 1-3 and Comparative Examples 1-5 of the present application are as follows:

[0120] Limiting oxygen index test: Tested in accordance with the national standard GB / T 2406.2-2009 "Determination of combustion behavior of plastics by oxygen index method Part 2: Room temperature test";

[0121] Tensile strength and elongation at break test: Tested in accordance with the national standard GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", type 1;

[0122] Tear strength test: refer to the national standard GB / T 529-2008 "Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser-shaped, right-angled and crescent-shaped specimens)" for testing, right-angled;

[0123] Wear resistance test: The test was carried out in accordance with the national standard GB / T 40797-2021 "Determination of wear resistance of vulcanized rubber or thermoplastic rubber - vertical driven abrasive disc method". The test was carried out using an RCC-1 testing machine with a speed of 800 rpm, a striking frequency of 2.5 Hz, and a test time of 30 minutes.

[0124] Aging test: Refer to the national standard GB / T 3512-2014 "Hot air accelerated aging and heat resistance test for vulcanized rubber or thermoplastic rubber" to test the elongation at break of the aged sample. The aging conditions are 120℃, 48h

[0125] Low temperature brittleness: Tested in accordance with the national standard GB / T 1682-2014 "Single specimen method for determination of low temperature brittleness of vulcanized rubber";

[0126] The test results are shown in Table 1.

[0127] Table 1 Performance parameters

[0128]

[0129]

[0130] It can be seen from Table 1 that the flame retardant fire hose lining prepared in the present application exhibits good flame retardant properties, and at the same time has excellent tensile strength and elongation at break, stable mechanical properties, and also exhibits excellent aging resistance and wear resistance, and can still maintain good toughness in low temperature environments. This comprehensive performance enables the flame retardant fire hose lining to work stably under various extreme conditions, significantly improving the overall performance and service life of the fire hose.

[0131] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A flame retardant fire hose lining, characterized in that: The invention comprises the following raw materials in parts by weight: 50-70 parts of modified chloroprene rubber, 18-25 parts of reinforcing filler, 3-8 parts of plasticizer, 1-2 parts of antioxidant, 1-3 parts of crosslinking agent, 1-3 parts of vulcanizing agent and 1-2 parts of vulcanization accelerator.

2. The flame retardant fire hose lining according to claim 1, characterized in that: The preparation of the modified chloroprene rubber comprises the following steps: (1) Add chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer to toluene, raise the temperature to 80-100°C, add initiator, and react for 2-3 hours under stirring and nitrogen protection to obtain an intermediate; (2) Add flame retardant DOPO and cis-allyl phosphoric acid to the intermediate, stir evenly, heat to 110-130°C, react for 4-6 hours under stirring and nitrogen protection, cool to room temperature, filter, wash and dry to obtain modified chloroprene rubber.

3. The flame retardant fire hose lining according to claim 2, characterized in that: In the step (1), the mass ratio of chloroprene rubber, brominated styrene-butadiene-styrene block copolymer and acrylonitrile-butadiene-styrene copolymer is 40-60:5-8:8-12.

4. The flame retardant fire hose lining according to claim 2, characterized in that: In the step (2), the mass ratio of the intermediate, the flame retardant DOPO and cis-allyl phosphoric acid is 10:1-2:0.1-0.

3.

5. The flame retardant fire hose lining according to claim 1, characterized in that: The preparation of the reinforcing filler comprises the following steps: Chlorinated polyvinyl chloride and acetylene black are added into a twin-screw extruder for melt blending for 20-30 minutes, and then chlorinated polyethylene is added. The feed temperature of the twin-screw extruder is controlled at 120-140°C, the mixing temperature is 160-170°C, the homogenization temperature is 180-200°C, the extrusion temperature is 120-170°C, the twin-screw speed is 100-200rpm, the screw aspect ratio is 15-20:1, the mixing is performed for 1-2 hours, the pelletization is performed by extrusion, and the pellets are cooled to room temperature to obtain a reinforcing filler.

6. The flame retardant fire hose lining according to claim 5, characterized in that: The mass ratio of the chlorinated polyvinyl chloride, acetylene black and chlorinated polyethylene is 3-8:20-30:1-2.

7. The flame retardant fire hose lining according to claim 1, characterized in that: The plasticizer consists of dioctyl phthalate and dioctyl adipate in a mass ratio of 1-3:

1.

8. The flame retardant fire hose lining according to claim 1, characterized in that: The antioxidant is one or more of antioxidant RD, antioxidant MB, antioxidant 264 and antioxidant 4010NA.

9. The flame retardant fire hose liner according to claim 1, characterized in that: The crosslinking agent is one or more of triallyl isocyanurate, bismaleimide and benzoyl peroxide; the vulcanizing agent is sulfur; and the vulcanization accelerator is one or more of accelerator TMTD, accelerator DM, accelerator M and accelerator TMTM.

10. A method for preparing the flame-retardant fire hose lining according to any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: Step S1, adding modified chloroprene rubber, reinforcing filler, plasticizer and antioxidant into an internal mixer according to weight, mixing at 80-100° C. for 2-3 hours, cooling to room temperature, and obtaining a vulcanizing agent-free rubber mix; then mixing the vulcanizing agent-free rubber mix, a crosslinking agent, a vulcanizing agent and a vulcanization accelerator on a double-roll open mill for 1-2 hours to obtain a vulcanizing agent-containing rubber mix; Step S2, forming the mixed rubber containing the vulcanizing agent, and vulcanizing it on a flat vulcanizer at a pressure of 8-12 MPa and a temperature of 150-180° C. for 10-20 minutes to obtain a primary vulcanized rubber; Step S3, subjecting the primary vulcanized rubber to secondary vulcanization at 200-220° C. for 3-5 hours to obtain a flame-retardant fire hose lining.

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