A boron amine coordinated phosphorus-boron-nitrogen synergistic flame retardant and preparation method thereof

Abstract

The invention discloses a chelated coordination type phosphorus-boron-nitrogen synergistic flame retardant and its preparation method and use. The flame retardant is prepared by esterification and chelation coordination of phosphonic acid derivatives, boric acid and its derivatives, polyols and urea. It can be used as a raw material additive for cellulose, polyester, polyurethane, polylactic acid, epoxy resin, wood, plywood, particleboard, plastic, rubber, elastomer, etc., a grafting or curing reaction functional material or as the main functional material of a flame retardant coating. The flame retardant adopts esterification reaction and chelation coordination strategy, and improves the flame retardant performance of the flame retardant through the phosphorus-nitrogen-boron synergistic flame retardant mode, and has the advantages of environmental protection and renewable, cheap raw materials, simple preparation, good flame retardant effect, etc.

Description

Technical Field

[0001] The invention relates to the field of flame retardant materials, in particular to a phosphorus-boron-nitrogen synergistic flame retardant and a preparation method and application thereof. Background Art

[0002] Flame retardants are a type of functional additives that can impart flame retardancy to flammable materials. According to the source of raw materials, they can be divided into two categories: organic flame retardants and inorganic flame retardants. Among them, organic flame retardants play an important role in the fields of cellulose, polyester, polyurethane, epoxy resin, plastic, rubber, elastomer, etc. Among organic flame retardants, halogen flame retardants are one of the most widely used flame retardants. There are many types of them, and they are cheap, such as: aliphatic octabromoether, aliphatic cyclohexabromocyclododecane, aromatic tetrabromobisphenol A, aromatic-aliphatic decabromodiphenylethane, brominated polystyrene, brominated epoxy resin, etc. However, during the use of halogen flame retardants, there is a lot of combustion smoke and the release of toxic and corrosive gases, which does not conform to the modern green and environmentally friendly green chemistry concept, so its use is being restricted.

[0003] Phosphorus-based flame retardants are a type of environmentally friendly flame retardants that have been developed in recent years. Phosphorus-nitrogen synergistic flame retardants have the advantages of high flame retardant efficiency and wide flame retardant adaptability, and are gradually becoming the most promising flame retardant in the future. However, phosphorus-nitrogen-based flame retardants still have some problems, such as low flame retardant efficiency, poor thermal stability, and imperfect surface treatment technology. Further development and research are urgently needed to achieve or exceed the flame retardant efficiency and market competitiveness of halogen-based flame retardants.

[0004] However, considering the volatility and low flame retardant efficiency of phosphorus-based flame retardants, the introduction of inorganic flame retardants, especially boron-based flame retardants, to improve their flame retardant efficiency and residual carbon content has significant development value and practical application significance. In order to further improve the flame retardant efficiency of phosphorus-based flame retardants, the phosphorus-boron-nitrogen synergistic flame retardant concept and chelation coordination strategy are adopted to maximize the durable synergistic flame retardancy of the three flame retardant elements of phosphorus, boron and nitrogen. The introduction of boron will give the flame retardant system many advantages such as low smoke, low toxicity, and environmental friendliness. By regulating the content, ratio and chelation coordination mode of flame retardant elements, the durable synergistic flame retardant effect can be enhanced, which will be of great significance and broad application development prospects. Summary of the invention

[0005] In view of the problems existing in existing flame retardants, the key idea to be solved by the present invention is to provide a phosphorus, nitrogen, and boron ternary synergistic flame retardant and a preparation method thereof, which adopts a one-pot synthesis process, has mild reaction conditions, a simple preparation process, and easy post-processing, and is suitable for industrial-scale production. The present invention proposes a chelated coordination flame retardant that significantly improves the flame retardant performance of existing phosphorus-nitrogen flame retardants in target materials, and at the same time, the flame retardant has excellent compatibility and durability with the material.

[0006] The technical solution of the present invention to solve the technical problem is to provide a chelating coordination strategy in the present invention that effectively improves the stability of boron in flame retardants and flame retardant systems compared with the prior art, and the flame retardant elements can be adjusted in proportion so that the flame retardant system can adapt to different polymer materials. The flame retardant prepared has excellent flame retardant efficiency and meets green environmental protection requirements. The flame retardant of the present invention can be applied to plastics, rubber, fiber, elastomers and other polymers and natural cotton, linen, wood, bamboo and other materials through impregnation, addition, grafting and coating. DETAILED DESCRIPTION

[0007] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention in detail and do not limit the protection scope of the claims of this application.

[0008] The invention provides a chelated coordination type phosphorus-boron-nitrogen synergistic flame retardant, which is characterized in that the structure of the flame retardant is an oligomer, wherein phosphonic acid derivatives are phosphorus sources, boric acid and its derivatives are boron sources, and are coordinated with nitrogen to improve the stability and flame retardancy of the flame retardant elements, polyols are used as crosslinking agents for the oligomers to improve the molecular weight and stability of the flame retardant, urea is used as a nitrogen source and supplementary coordination, and ammonium phosphate is formed to provide active reaction groups for crosslinking.

[0009] The present invention provides a chelated coordination type phosphorus-boron-nitrogen synergistic intumescent flame retardant and a preparation method thereof, which is characterized by the following specific steps:

[0010] 1) adding phosphonic acid derivatives, boric acid and its derivatives, polyols (preferably without polyols) and solvents (preferably without solvents) into a flask, stirring and reacting at a certain temperature until the reaction is completed;

[0011] 2) Deionized water and urea are added to the intermediate product, and the mixture is heated and stirred at a certain temperature until the reaction is completed to obtain a viscous liquid, which is the target flame retardant.

[0012] 3) The target flame retardant is used directly as an additive, or is prepared into a solution with a certain solubility, and the target flame retardant material is arranged, and the target flame retardant product can be obtained after drying.

[0013] Furthermore, the solvent in step 1) is a benzene-based water-carrying agent, specifically benzene, toluene, and preferably xylene.

[0014] Furthermore, if a solvent-free method is used in step 1), the esterification reaction and coordination reaction are carried out at a certain temperature until the reaction is complete; the reaction temperature is 60°C-180°C.

[0015] Furthermore, the polyol in step 1) is a dihydric to hexahydric alcohol, and a polyol containing more esterification sites is preferred.

[0016] Furthermore, the phosphonic acid derivatives in step 1) are polyamine-poly(methylene phosphonic acid) compounds such as diethylenetriaminepenta(methylene phosphonic acid), ethylenediaminetetra(methylene phosphonic acid), and aminotri(methylene phosphonic acid).

[0017] Furthermore, the boric acid derivative in step 1) is: boric acid, borax, zinc borate, ammonium pentaborate, sodium metaborate, ammonium fluoroborate, barium metaborate, etc.

[0018] Furthermore, in step 1), the molar ratio of the phosphonic acid derivative, boric acid and its derivatives to the polyol is 1:0.1-10:0-10; (preferably zero addition of polyol) the molar ratio of the intermediate to urea is 1:1-30.

[0019] Furthermore, in step 3), the flame retardant is added in an amount of 3% to 60%, and the solution solubility is configured to be 10 g / L to a saturated solution.

[0020] The above-mentioned chelated coordination type phosphorus-boron-nitrogen synergistic intumescent flame retardant can be used as a raw material additive for cellulose, polyester, polyurethane, polylactic acid, epoxy resin, wood, plywood, particleboard, plastic, rubber, elastomer, etc., or as the main functional material of flame retardant coating, and can also be used as a grafting or curing functional material for fabrics or non-woven fabrics.

[0021] The advantages of the design ideas and technical solutions provided by the present invention are as follows:

[0022] 1) The present invention adopts nitrogen-containing phosphonic acid with a high phosphorus content as a matrix, and improves the stability, high efficiency and durable flame retardancy of the phosphorus-nitrogen-boron synergistic flame retardant through the chelating coordination effect of nitrogen and boron.

[0023] 2) The content ratio of the flame retardant elements phosphorus, boron and nitrogen contained in the chelated coordination flame retardant obtained by the present invention is adjustable. At the same time, the flame retardant elements have a multi-functional synergistic flame retardant effect, which can meet the flame retardant requirements of different flame retardant target objects.

[0024] 3) The present invention adopts nitrogen-containing polyphosphonic acid, which can significantly improve the stability and content ratio of boric acid in the flame retardant, while improving the compatibility of the flame retardant with the target object. The chelating coordination method can significantly reduce the durability problems of the flame retardant such as migration and loss during use.

[0025] 4) The present invention adopts raw materials and reagents, is simple to synthesize, easy to operate, inexpensive, suitable for industrial production, and has broad application prospects and market competitiveness.

[0026] Example 1

[0027] 1) Add ethylenediaminetetramethylenephosphonic acid (0.4 mol), ethylene glycol (0.6 mol), boric acid (0.4 mol) and 100 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0028] 2) Deionized water (0.4 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 5, and a viscous liquid was obtained, which was the target flame retardant.

[0029] Example 2

[0030] 1) Add aminotri(methylenephosphonic acid) (0.6 mol), neopentyl glycol (0.6 mol), boric acid (0.3 mol) and 140 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0031] 2) Deionized water (0.6 mol) and urea (3.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 6, and a viscous liquid was obtained, which was the target flame retardant.

[0032] Example 3

[0033] 1) Add diethylenetriamine penta (methylenephosphonic acid) (0.4 mol), pentaerythritol (0.2 mol) and boric acid (0.6 mol) and 80 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0034] 2) Deionized water (0.3 mol) and urea (6.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 70° C. to react until the pH reached 3, and a viscous liquid was obtained, which was the target flame retardant.

[0035] Example 4

[0036] 1) Add ethylenediaminetetramethylenephosphonic acid (0.4 mol), diethylene glycol (0.2 mol), borax (0.4 mol) and 80 mL of solvent toluene into a flask, stir and reflux to react until the reaction is complete, remove the solvent toluene, and obtain an intermediate;

[0037] 2) Deionized water (0.4 mol) and urea (5.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 90° C. to react until the pH reached 2, and a viscous liquid was obtained, which was the target flame retardant.

[0038] Example 5

[0039] 1) Add aminotri(methylenephosphonic acid) (0.4 mol), dipropylene glycol (0.1 mol), zinc borate (0.4 mol) and 80 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0040] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 6, and a viscous liquid was obtained, which was the target flame retardant.

[0041] Example 6

[0042] 1) Add ethylenediaminetetramethylenephosphonic acid (0.4 mol), xylitol (0.1 mol), boric acid (0.2 mol) and 100 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0043] 2) Deionized water (0.6 mol) and urea (3.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 7, and a viscous liquid was obtained, which was the target flame retardant.

[0044] Example 7

[0045] 1) Add diethylenetriamine penta (methylenephosphonic acid) (0.4 mol) and ammonium pentaborate (0.3 mol) into a flask and heat to 130°C for 16 hours.

[0046] 2) Deionized water (1.0 mol) and urea (3.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 120° C. to react until the pH reached 6, and a viscous liquid was obtained, which was the target flame retardant.

[0047] Example 8

[0048] 1) Add aminotri(methylenephosphonic acid) (0.4 mol) and boric acid (0.3 mol) into a flask, heat to 140°C, stir and react for 8 hours;

[0049] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 6, and a viscous liquid was obtained, which was the target flame retardant.

[0050] Example 9

[0051] 1) Add diethylenetriamine penta (methylenephosphonic acid) (0.3 mol), ethylene glycol (0.2 mol), sodium metaborate (0.5 mol) and 100 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0052] 2) Deionized water (0.6 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 80° C. to react until the pH reached 3, and a viscous liquid was obtained, which was the target flame retardant.

[0053] Example 10

[0054] 1) Add diethylenetriamine penta (methylenephosphonic acid) (0.4 mol), neopentyl glycol (0.8 mol), boric acid (0.3 mol) and 80 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0055] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 6, and a viscous liquid was obtained, which was the target flame retardant.

[0056] Embodiment 11

[0057] 1) Add ethylenediaminetetramethylenephosphonic acid (0.4 mol), pentaerythritol (0.4 mol), ammonium fluoroborate (0.6 mol) and 80 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0058] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 90° C. to react until the pH reached 6, and a viscous liquid was obtained, which was the target flame retardant.

[0059] Example 12

[0060] 1) Add diethylenetriamine penta (methylenephosphonic acid) (0.4 mol), diethylene glycol (0.2 mol), boric acid (0.4 mol) and 120 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0061] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 5, and a viscous liquid was obtained, which was the target flame retardant.

[0062] Embodiment 13

[0063] 1) Add aminotri(methylenephosphonic acid) (0.4 mol), dipropylene glycol (0.3 mol), boric acid (0.6 mol) and 100 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0064] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 4, and a viscous liquid was obtained, which was the target flame retardant.

[0065] Embodiment 14

[0066] 1) Add ethylenediaminetetramethylenephosphonic acid (0.4 mol), xylitol (0.2 mol), barium metaborate (0.3 mol) and 60 mL of toluene solvent into a flask, stir and reflux to react until the reaction is complete, remove the toluene solvent, and obtain an intermediate;

[0067] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 7, and a viscous liquid was obtained, which was the target flame retardant.

[0068] Embodiment 15

[0069] 1) Add diethylenetriamine penta (methylenephosphonic acid) (0.4 mol) and boric acid (0.4 mol) into a flask, heat to 110°C, stir and react for 12 hours;

[0070] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 6, and a viscous liquid was obtained, which was the target flame retardant.

[0071] Example 16

[0072] 1) Add ethylenediaminetetramethylenephosphonic acid (0.4 mol) and boric acid (0.3 mol) into a flask, heat to 140°C, stir and react for 9 hours;

[0073] 2) Deionized water (0.5 mol) and urea (2.0 mol) were added to the intermediate product, and the mixture was heated and stirred at 100° C. to react until the pH reached 4, and a viscous liquid was obtained, which was the target flame retardant.

[0074] The flame retardants were prepared into 100 g / L aqueous solution, impregnated into cotton fibers and then dried to obtain flame retardant cotton fabrics. The flame retardant prepared in Example 15 had the highest limiting oxygen index, with the highest LOI being 48%.

[0075] The flame retardants were prepared into 100 g / L aqueous solution, which was used to immerse poplar wood for 2 hours and then dried. The flame retardant prepared in Example 8 had the highest limiting oxygen index of 45% for the flame retardant poplar wood.

Claims

1. A method for preparing a chelated coordination type phosphorus-boron-nitrogen synergistic flame retardant, characterized in that: An intermediate is prepared by esterification and coordination reaction of phosphonic acid derivatives, boric acid and its derivatives, and then reacted with urea to obtain an ammonium salt complex, which is the target flame retardant; the phosphonic acid derivative is diethylenetriaminepenta(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid) or aminotri(methylenephosphonic acid); the boric acid derivative is borax, zinc borate, ammonium pentaborate, sodium metaborate, ammonium fluoroborate or barium metaborate.

2. The preparation method according to claim 1, characterized in that: The molar ratio of the phosphonic acid derivative, boric acid and its derivative is 1:0.1-10, and the molar ratio of the intermediate to urea is 1:1-30.

3. A chelated coordination phosphorus-boron-nitrogen synergistic flame retardant prepared by the preparation method as claimed in claim 1.

4. The use of the chelated coordination type phosphorus-boron-nitrogen synergistic flame retardant as claimed in claim 3: characterized in that Can be used as a flame retardant for natural cotton, linen or wood.

5. Use of the chelated coordination type phosphorus-boron-nitrogen synergistic flame retardant as claimed in claim 3: it can be used as a flame retardant for rubber, plastic or fiber.