A method for preparing a water-soluble organic phosphorus flame retardant

Abstract

The present invention discloses a method for preparing a water-soluble organophosphorus flame retardant, the method comprising the following steps: (1) adding a polyol to an organic solvent, and heating under stirring until the polyol is completely dissolved; (2) adding an organophosphorus compound to the solution of step (1), and reacting at high temperature; (3) adding an amine compound to the solution of step (2) after the reaction, and continuing the reaction; (4) after the reaction temperature approaches room temperature, adding an alkali to the solution of step (3), and controlling the reaction temperature to be no higher than 60°C during the entire reaction process; (5) adjusting the pH of the solution to neutral after cooling, and adding a bactericide to obtain a water-soluble organophosphorus flame retardant. The water-soluble organophosphorus flame retardant of the present invention does not contain halogen elements, is green and environmentally friendly, can greatly improve the flame retardancy of water-absorbing substrates (wood, paper, textile products), and can form a transparent protective film on the surface of the water-absorbing substrate.

Description

Technical Field

[0001] The invention relates to a method for preparing a water-soluble organic phosphorus flame retardant, belonging to the technical field of fire prevention and flame retardancy. Background Art

[0002] Data shows that most fires in wooden structures are caused by humans, and flammable materials such as curtains, wallpapers, carpets, and mattresses are all fuses that cause fires. Therefore, how to efficiently solve the burning problem of wood, paper, textiles and other items is of great research significance.

[0003] At present, the fire prevention recommendations for wooden structures are mainly to install automatic alarms and sprinkler fire extinguishing devices, or to increase the fire prevention design of buildings, etc. This is difficult to implement for some old or large-scale buildings, and the fire prevention effect is limited. Textile flame retardancy has also flourished in recent years. Companies in the United States and Switzerland generally use phosphorus-nitrogen flame retardants to improve the flame retardancy of textiles through copolymerization, blending and spinning technologies, but the above methods are complex processes, expensive equipment and high product preparation costs, which hinders their widespread popularization; the treatment of flame-retardant paper products usually involves adding flame-retardant substances to the pulp to prepare paperboard, wallpaper and other products with certain flame retardancy, which puts higher and more complex requirements on traditional papermaking processes and procedures.

[0004] In order to prepare wood, paper, textile and other articles with good flame retardant properties at low cost, the prior art has developed a water-soluble flame retardant (such as aqueous silica sol, urea phosphate brine solvent, etc.), but the wood, paper and textile articles treated with the prior art water-soluble flame retardant still have the defect of low flame retardancy. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a method for preparing a water-soluble organophosphorus flame retardant. The flame retardant prepared by this method can greatly improve the flame retardancy of water-absorbing substrates (wood, paper, textile products), and can form a transparent protective film on the surface of the water-absorbing substrate.

[0006] Technical solution: The preparation method of the water-soluble organophosphorus flame retardant of the present invention comprises the following steps:

[0007] (1) adding a polyol to an organic solvent and heating the organic solvent under stirring until the polyol is completely dissolved;

[0008] (2) adding an organic phosphorus compound to the solution of step (1) and reacting at high temperature;

[0009] (3) After the reaction, an amine compound is added to the solution of step (2) to continue the reaction;

[0010] (4) After the reaction temperature approaches room temperature, add a base to the solution in step (3), and control the reaction temperature to be no higher than 60° C. during the entire reaction process;

[0011] (5) After cooling, the pH of the solution is adjusted to neutral, and a fungicide is added to obtain a water-soluble organophosphorus flame retardant.

[0012] Wherein, in step (1), the organic solvent is at least one of xylene, butyl acetate or n-butanol.

[0013] Wherein, in step (1), the polyol is at least one of ethylene glycol, propylene glycol, pentaerythritol, cyclohexanehexol, glucose, starch, cyclodextrin or cellulose.

[0014] Wherein, in step (1), the heating temperature is 60 to 120°C, preferably 60 to 80°C.

[0015] Wherein, in step (2), the organophosphorus compound is at least one of dimethyl phosphite, tributyl phosphate, diphenyl phosphine oxide, diphenyl phosphoric acid, phosphoric acid, aluminum tripolyphosphate, polyphosphoramide or melamine polyphosphate.

[0016] Wherein, in step (2), the reaction temperature is 60-120° C. and the reaction time is 2-4 h.

[0017] Wherein, in step (2), the mass ratio of the added polyol to the organic phosphorus compound is 15-20:70-100.

[0018] Wherein, in step (3), the amine compound is at least one of triethylamine, ethylenediamine, ammonia water, guanidine phosphonate, 2,4-dinitrophenylhydrazone, 1,4-butanediamine, hydroxypropylamine or piperidine.

[0019] Wherein, in step (3), the reaction temperature is 70-120°C, preferably 70-80°C; and the reaction time is 1-2h.

[0020] Wherein, in step (3), the amount of the amine compound added is 1.5 to 11.12% of the total mass of the polyol and the organophosphorus compound.

[0021] Wherein, in step (4), the base is at least one of sodium hydroxide, potassium tert-butoxide, guanidine hydrochloride, triethylamine, dicyandiamide, ammonia water or ethylenediamine.

[0022] Wherein, in step (4), the reaction temperature of the entire reaction process is controlled to be no higher than 60° C. by adding alkali in batches, and the reaction time is 2 to 4 hours.

[0023] Wherein, in step (4), the amount of the base added is 4.3 to 85% of the total mass of the polyol and the organic phosphorus compound.

[0024] Wherein, in step (5), the bactericide is at least one of hydrogen peroxide, sodium hypochlorite, aluminum triethylphosphate, 5,5-dimethylhydantoin, dodecyldimethylbenzyl ammonium chloride or 5,5-dimethylhydantoin.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The water-soluble organophosphorus flame retardant of the present invention is halogen-free, green and environmentally friendly; (2) The water-soluble organophosphorus flame retardant of the present invention can form a transparent protective film on the surface of a water-absorbing substrate; (3) The water-soluble organophosphorus flame retardant of the present invention can greatly improve the flame retardancy of a water-absorbing substrate (wood, paper, textile products), thereby improving its fire resistance level. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The pictures are of wood before and after being soaked in the flame retardant of Example 1;

[0027] Figure 2 These are pictures of the foam before and after being soaked in the flame retardant of Example 1. DETAILED DESCRIPTION

[0028] Example 1

[0029] The preparation method of the water-soluble organophosphorus flame retardant of the present invention comprises the following steps:

[0030] (1) Add 15 g of glucose to a reaction tank, then add 5 mL of n-butanol, heat to 60° C. and stir until completely dissolved;

[0031] (2) adding 100 g of phosphoric acid to the reaction system dissolved in step (1), heating to 60° C. and reacting for 2 h;

[0032] (3) adding 20 mL of ethylenediamine to the reaction system of step (2) at 80° C. and continuing the reaction for 2 h;

[0033] (4) After the reaction temperature is constant and close to room temperature, 100 mL of 30% ammonia water is added to the reaction system of step (3), and the temperature of the reaction system is controlled not higher than 60° C. by adding ammonia water in batches, and the reaction is continued for 4 hours;

[0034] (5) adding 100 mL of water to dilute the reaction solution, and then adding a base (sodium hydroxide, sodium ethoxide, potassium hydroxide or sodium carbonate) to adjust the pH of the solution to neutral;

[0035] (6) Add 5 g of 5,5-dimethylhydantoin to the solution of step (5), and stir evenly to obtain a water-soluble organophosphorus flame retardant.

[0036] Example 2

[0037] The preparation method of the water-soluble organophosphorus flame retardant of the present invention comprises the following steps:

[0038] (1) Add 20 g of starch to a reaction tank, then add 30 mL of water, heat (80° C.) and stir until the starch is completely dissolved;

[0039] (2) adding 70 g of diphenylphosphoric acid to the reaction system dissolved in step (1), heating to 110° C. and reacting for 2 h;

[0040] (3) The temperature was lowered to 80° C., 10 g of guanidine phosphonate was added to the reaction system of step (2), and the reaction was continued for 1 h. After the reaction was completed, the mixture was allowed to stand for half an hour;

[0041] (4) After the reaction in the previous step is completed, after cooling to room temperature, 5 g of guanidine phosphate is added to the reaction system of step (3), and the temperature of the reaction system is controlled not higher than 60° C. by adding guanidine phosphate in batches, and the reaction is carried out for 2 h;

[0042] (5) adding 40 mL of water to dilute the reaction solution, and then adding a base (sodium hydroxide, sodium ethoxide, potassium hydroxide or sodium carbonate) to adjust the pH of the solution to neutral;

[0043] (6) Add 5 g of 5,5-dimethylhydantoin to the solution of step (5), and stir evenly to obtain a water-soluble organophosphorus flame retardant.

[0044] Example 3

[0045] The preparation method of the water-soluble organophosphorus flame retardant of the present invention comprises the following steps:

[0046] (1) Add 15 mL of glycerol to a reaction tank, then add 10 mL of n-butanol, heat (80° C.) and stir until the glycerol is completely dissolved;

[0047] (2) adding 80 mL of dimethyl phosphite to the reaction system dissolved in step (1), heating to 120° C. and reacting for 2 h;

[0048] (3) The temperature was lowered to 70° C., 10 g of 1,4-butanediamine was added to the reaction system of step (2), and the reaction was continued for 1 h;

[0049] (4) After the reaction in the previous step is completed, after cooling to room temperature, 5 g of guanidine phosphate is added to the reaction system of step (3), and the temperature of the reaction system is controlled not higher than 60° C. by adding guanidine phosphate in batches, and the reaction is carried out for 2 h;

[0050] (5) adding 80 mL of water to dilute the reaction solution, and then adding a base (sodium hydroxide, sodium ethoxide, potassium hydroxide or sodium carbonate) to adjust the pH of the solution to neutral;

[0051] (6) Add 8 mL of 30% by mass hydrogen peroxide to the solution of step (5), and stir evenly to obtain a water-soluble organophosphorus flame retardant.

[0052] Comparative Example 1

[0053] A method for preparing a water-soluble flame retardant comprises the following steps:

[0054] (1) Add 15 mL of glycerol to a reaction tank, then add 10 mL of n-butanol, heat (80° C.) and stir until the glycerol is completely dissolved;

[0055] (2) adding 80 mL of dimethyl phosphite to the reaction system dissolved in step (1), heating to 120° C. and reacting for 2 h;

[0056] (3) After the reaction in the previous step is completed, after cooling to room temperature, 5 g of guanidine phosphate is added to the reaction system of step (3), and the temperature of the reaction system is controlled not higher than 60° C. by adding guanidine phosphate in batches, and the reaction is carried out for 2 h;

[0057] (4) adding 80 mL of water to dilute the reaction solution, and then adding a base (sodium hydroxide, sodium ethoxide, potassium hydroxide or sodium carbonate) to adjust the pH of the solution to neutral;

[0058] (5) Add 8 mL of 30% by mass hydrogen peroxide to the solution of step (4), and stir evenly to obtain a water-soluble organophosphorus flame retardant.

[0059] Comparative Example 2

[0060] A method for preparing a water-soluble flame retardant comprises the following steps:

[0061] (1) Add 15 mL of glycerol to a reaction tank, then add 10 mL of n-butanol, heat (80° C.) and stir until the glycerol is completely dissolved;

[0062] (2) adding 80 mL of dimethyl phosphite to the reaction system dissolved in step (1), heating to 120° C. and reacting for 2 h;

[0063] (3) The temperature was lowered to 70° C., 10 g of 1,4-butanediamine was added to the reaction system of step (2), and the reaction was continued for 1 h;

[0064] (4) directly adding 5 g of guanidine phosphate to the reaction system of step (3), without controlling the reaction temperature of the reaction system to be less than 60° C. during the reaction, and reacting for 2 h;

[0065] (5) adding 80 mL of water to dilute the reaction solution, and then adding a base (sodium hydroxide, sodium ethoxide, potassium hydroxide or sodium carbonate) to adjust the pH of the solution to neutral;

[0066] (6) Add 8 mL of 30% by mass hydrogen peroxide to the solution of step (5), and stir evenly to obtain a water-soluble organophosphorus flame retardant.

[0067] The flame retardants of Examples 1 to 3 and Comparative Examples 1 to 2 were respectively prepared into working solutions, and the working solutions were prepared in a ratio of 1 mL of the flame retardant to 3 mL of water; cotton cloth, wood, paper and foam were respectively soaked in the working solutions for 1 to 2 minutes, taken out, and dried naturally or in an oven.

[0068] Characterize the flame retardant properties of cotton, wood, paper and foam before and after immersion:

[0069] Table 1. Cotton test results a

[0070]

[0071]

[0072] a The test standard is: GB 5455-2014 "Determination of vertical damage length, smoldering and after-flaming time of textile combustion performance"

[0073] Table 2. Test results of chemical fiber fabrics a

[0074]

[0075] a The test standard is: GB 5455-2014 "Determination of vertical damage length, smoldering and after-flaming time of textile combustion performance"

[0076] Table 3. Wood test results b

[0077]

[0078] b The test standard is: GB 20284-2006 Single combustion test of building materials or products

[0079] Table 4. Foam test results c

[0080]

[0081] c The test standard is: GB 8624-2012.

[0082] pass Figures 1-2It can be seen that after the water-absorbing substrate is soaked in the flame retardant of the present invention, a transparent protective film is formed on the surface of the water-absorbing substrate.

Claims

1. A method for preparing a water-soluble organophosphorus flame retardant, characterized in that: The steps include: (1) adding a polyol to an organic solvent and heating the organic solvent under stirring until the polyol is completely dissolved; (2) adding an organic phosphorus compound to the solution of step (1) and reacting at high temperature; (3) After the reaction, an amine compound is added to the solution of step (2) to continue the reaction; (4) After the reaction temperature approaches room temperature, add a base to the solution in step (3), and control the reaction temperature to be no higher than 60° C. during the entire reaction process; (5) After cooling, the pH of the solution is adjusted to neutral, and a fungicide is added to obtain a water-soluble organophosphorus flame retardant.

2. The preparation method according to claim 1, characterized in that: In step (1), the organic solvent is at least one of xylene, butyl acetate or n-butanol; the polyol is at least one of ethylene glycol, propylene glycol, pentaerythritol, cyclohexanehexol, glucose, starch, cyclodextrin or cellulose.

3. The preparation method according to claim 1, characterized in that: In step (1), the heating temperature is 60 to 120°C.

4. The preparation method according to claim 1, characterized in that: In step (2), the organophosphorus compound is at least one of dimethyl phosphite, tributyl phosphate, diphenyl phosphine oxide, diphenyl phosphoric acid, phosphoric acid, aluminum tripolyphosphate, polyphosphoramide or melamine polyphosphate.

5. The preparation method according to claim 1, characterized in that: In step (2), the reaction temperature is 60-120° C., the reaction time is 2-4 hours, and the mass ratio of the added polyol to the organic phosphorus compound is 15-20:70-100.

6. The preparation method according to claim 1, characterized in that: In step (3), the amine compound is at least one of triethylamine, ethylenediamine, ammonia water, guanidine phosphonate, 2,4-dinitrophenylhydrazone, 1,4-butanediamine, hydroxypropylamine or piperidine.

7. The preparation method according to claim 1, characterized in that: In step (3), the reaction temperature is 70-120° C., and the reaction time is 1-2 hours; the amount of the amine compound added is 1.5-11.12% of the total mass of the polyol and the organophosphorus compound.

8. The preparation method according to claim 1, characterized in that: In step (4), the base is at least one of sodium hydroxide, potassium tert-butoxide, guanidine hydrochloride, triethylamine, dicyandiamide, ammonia water or ethylenediamine.

9. The preparation method according to claim 1, characterized in that: In step (4), the reaction temperature of the entire reaction process is controlled to be no higher than 60° C. by adding alkali in batches; the reaction time is 2 to 4 hours; and the amount of alkali added is 4.3 to 85% of the total mass of the polyol and the organophosphorus compound.

10. The preparation method according to claim 1, characterized in that: In step (5), the bactericide is at least one of hydrogen peroxide, sodium hypochlorite, aluminum triethylphosphate, 5,5-dimethylhydantoin, dodecyldimethylbenzyl ammonium chloride or 5,5-dimethylhydantoin.

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