CN105295093A - Ring phosphonitrile type additive flame retardant and preparation method thereof - Google Patents

Abstract

A cyclophosphazene additive flame retardant and a preparation method thereof relate to a flame retardant. Add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), acetone and solvent in sequence in a container equipped with a stirring device, and heat up to react. After the reaction is completed, put it into the refrigerator to freeze, and precipitate solid crystals, wash and dry to obtain DOPOA, a flame retardant intermediate. Under the protection of nitrogen, react DOPOA and hexachlorocyclotriphosphazene under the conditions of solvent and acid-binding agent, and obtain an additive-type phosphazene flame retardant with high thermal stability through rotary evaporation, washing and drying. The halogen-free flame retardant prepared by the invention contains phosphorus and nitrogen elements at the same time, has high flame retardant efficiency, and can be used as an additive flame retardant for polyurethane, epoxy resin and polyester materials.

Description

A kind of cyclophosphazene additive flame retardant and preparation method thereof

technical field

The invention relates to a flame retardant, in particular to a cyclophosphazene additive flame retardant and a preparation method thereof.

Background technique

Phosphazene compounds contain two flame retardant elements, phosphorus and nitrogen, and are new phosphorus-nitrogen synergistic halogen-free flame retardants that have been extensively studied in recent years. According to the shape of phosphazene skeleton, phosphazenes can be divided into two categories: linear phosphazenes and cyclic phosphazenes. Cyclic phosphazene is a six-membered ring structure formed by alternating single and double bonds of P and N. This ring structure can provide excellent thermal stability and flame retardancy. Hexachlorocyclotriphosphazene (HCCP) is the most studied and widely used cyclic intermediate phosphazene compound. Because the chlorine atom on the side chain is highly active and unstable, it can react with some small organic molecules with active hydrogen The SN2 nucleophilic substitution reaction can obtain cyclic phosphazene derivatives with both inorganic and organic properties, which can be added to polymers as flame retardants to endow polymers with good flame retardant properties. Because phosphorus and nitrogen flame retardants have good flame retardant effect and no pollution, they meet the requirements of environmental protection and have become the development direction of flame retardants in the future.

Because DOPO and its derivatives contain biphenyl ring and phenanthrene ring structure in their molecular structure, especially the side phosphorus group is introduced in the form of cyclic O=P-O bond, they are more thermally stable and chemically stable than ordinary non-cyclic organic phosphates. Higher, better flame retardant performance. DOPO and its derivatives can be used as reactive or additive flame retardants for epoxy resins and polyester materials. These flame retardants are halogen-free, smoke-free, non-toxic, non-migrating, and have long-lasting flame retardant properties.

Phosphorus and nitrogen synergistic flame retardants can promote the formation of a dense carbon layer when the phosphorus-nitrogen synergistic flame retardant is burned. The residual carbon contains components of orthophosphoric acid and polyphosphoric acid, which can capture free radicals and terminate the combustion reaction; Ammonia gas will be generated to dilute combustible gas, which is conducive to the formation of intumescent flame retardant materials. Therefore, when phosphorus and nitrogen exist at the same time, the flame retardant effect of the material is better and the applicability is wider. For example, Chinese patent CN102796318A discloses a method for synthesizing a phosphorus-nitrogen flame retardant. The flame retardant uses polyols, phosphoric acid substances, additives, and melamine as the main raw materials. Under certain conditions, the "one-pot method" is synthesized The reaction does not need to be separated and purified, and the reaction is added step by step to obtain a phosphorus-nitrogen flame retardant. However, multi-step feeding is required in the synthesis of the flame retardant, which affects production efficiency, and the molecular structure contains long aliphatic chain ends, which slightly reduces the flame retardant efficiency. Chinese patent CN103059339A discloses a DOPO-based phosphorus-nitrogen flame retardant and its preparation method and application. The flame retardant obtains an imine intermediate product by condensation reaction of 4,4'-diaminobiphenyl and aromatic aldehyde, and then reacts with DOPO Addition reaction synthesis obtained. There are two flame retardant elements, phosphorus and nitrogen, in the molecule, which has excellent flame retardant effect and char formation. Adding the flame retardant to the epoxy resin will form a cured epoxy resin. When the phosphorus content of the cured epoxy is 1.0 wt%, the flame retardancy can reach UL94V-0, and the limiting oxygen index can reach 37.2-37.7.

Contents of the invention

The object of the present invention is to provide a kind of cyclic phosphazene additive flame retardant having both cyclic phosphazene and phosphaphenanthrene structures and a preparation method thereof.

The chemical structural formula of the cyclophosphazene additive flame retardant (HPEOC) is as follows:

where R=H or R=

The specific steps of the preparation method of the cyclophosphazene additive flame retardant (HPEOC) are as follows:

1) Add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), acetone and solvent in sequence in the container, after heating up the reaction, cool and crystallize, filter under reduced pressure, and wash through , and dry to obtain DOPOA, a flame retardant intermediate, whose chemical structural formula is as follows:

2) Under the protection of nitrogen, the flame retardant intermediate DOPOA and hexachlorocyclotriphosphazene are reacted under the conditions of a solvent and an acid-binding agent, and after extraction, washing, rotary evaporation, and drying, the cyclophosphazene additive flame retardant is obtained agent (HPEOC).

In step 1), the container can be a container equipped with a stirring device; the molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and acetone can be It is (0.5～2.0): 1, and described solvent can be selected from a kind of in acetone, chloroform, dichloromethane, dioxane etc.; The consumption of described solvent can be the total mass of each solid raw material by mass ratio 5-30 times; the reaction temperature may be 30-90° C., and the reaction time may be 2-6 hours.

In step 2), the acid-binding agent can be selected from one of triethylamine, potassium carbonate, sodium bicarbonate, sodium carbonate, sodium hydroxide, etc.; the solvent can be selected from DMF, methylene chloride, tetrahydrofuran , chloroform, etc.; the amount of the solvent can be 6 to 20 times the total mass of each solid raw material by mass ratio; the flame retardant intermediate DOPOA, hexachlorocyclotriphosphazene and acid-binding agent The molar ratio can be (8.4～1):1:(9.0～1.5); the temperature of the reaction can be 30～100°C, and the reaction time can be 3～12h.

The invention uses hexachlorocyclotriphosphazene, acetone and DOPO as main raw materials, and utilizes a substitution reaction to obtain the additive phosphazene flame retardant HPEOC.

Compared with the prior art, the present invention has the following characteristics:

1) Through molecular design, the flame retardant elements phosphorus and nitrogen are introduced into the molecule to obtain a new type of flame retardant that has not been reported. Phosphorus and nitrogen synergistically exert the flame retardant effect in the condensed phase and gas phase to overcome the single flame retardant element lack of.

2) The flame retardant (HPEOC) synthesized by the present invention contains the structure of cyclophosphazene and phosphaphenanthrene at the same time, has higher thermal stability and flame retardant efficiency, and can be used as a flame retardant additive in flame retardant polyester PET, Preparation of PBT and flame retardant epoxy resin.

3) The phosphorus-nitrogen synergistic flame retardant of the present invention does not contain halogen, which meets the needs of the current development of flame retardants without halogenation.

Description of drawings

Figure 1 is the ¹ HNMR nuclear magnetic spectrum of the flame retardant HPEOC.

Figure 2 is the infrared spectrum of the flame retardant HPEOC.

detailed description

Below by embodiment and accompanying drawing, the present invention will be further described:

Example 1:

Add 21.6g DOPO, 7.2g acetone and 100ml ethanol into a 250ml round bottom flask, raise the temperature to 55°C for 3 hours, filter under reduced pressure to obtain a white solid precipitate, wash, rotary evaporate, and dry to obtain the flame retardant intermediate DOPOA. Under the protection of nitrogen, 8.69g of hexachlorocyclotriphosphazene, 43.20g of flame retardant intermediate DOPOA and 100ml of chloroform were successively added to a three-necked flask equipped with a condensing reflux tube and a magnetic stirrer, and finally 15.2g of trichloromethane was added dropwise. Ethylamine, then raise the temperature to 60°C, and keep the system under reflux for 3 hours to obtain a light yellow homogeneous solution. After cooling, it was extracted and washed with distilled water for 4 times, dried with anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation to obtain 30.49 g of a white solid, which was an additive-type phosphazene flame retardant (HPMOC).

Example 2:

Add 21.6g DOPO and 72g acetone into a 250ml round-bottomed flask, heat up to reflux for 2.5 hours, cool to room temperature after the reaction and find that crystals are precipitated, put them in the refrigerator for one day, filter with suction, wash, rotary evaporate, and dry to obtain Flame retardant intermediate DOPOA. Under the protection of nitrogen, add 4.35g of hexachlorocyclotriphosphazene, 21.60g of flame retardant intermediate DOPOA and 100ml of tetrahydrofuran into a 250ml three-neck flask equipped with a condensing reflux tube and a magnetic stirrer, and finally add 7.7g of triethyl Amine, and then heated to 68 ° C, the system maintained reflux state for 8 hours, the system changed from turbid to clear and then to turbid, and finally a white suspension was obtained. After cooling, filter with suction, wash with distilled water several times, and then wash with solvent several times. After the solvent is removed by rotary evaporation, 15.22 g of white solid is obtained, which is the additive-type phosphazene flame retardant (HPEOC).

Example 3:

Add 21.6g DOPO, 7.2g acetone and 100ml ethanol into a 250ml round bottom flask, raise the temperature to 55°C for 3 hours, filter under reduced pressure to obtain a white solid precipitate, wash, rotary evaporate, and dry to obtain the flame retardant intermediate DOPOA. Under nitrogen protection, 8.69g of hexachlorocyclotriphosphazene, 21.59g of flame retardant intermediate DOPOA and 100ml of dichloromethane were successively added to a 250ml three-neck flask equipped with a condensing reflux tube and a magnetic stirrer, and finally 7.7g of Triethylamine, then raised the temperature to 60°C, and kept the system under reflux for 7 hours to obtain a light yellow homogeneous solution. After cooling, remove the solvent by rotary evaporation to obtain a white solid, wash the white solid with water several times, and dry to obtain an additive-type phosphazene flame retardant.

Example 4:

Add 21.6g DOPO and 120g acetone into a 250ml round-bottomed flask, heat up to reflux for 2.5 hours, cool to room temperature after the reaction and find that crystals are precipitated, put them in the refrigerator for one day, filter with suction, wash, rotary evaporate, and dry to obtain Flame retardant intermediate DOPOA. Under the protection of nitrogen, add 4.35g of hexachlorocyclotriphosphazene, 10.80g of flame retardant intermediate DOPOA and 50ml of chloroform to a 100ml three-neck flask equipped with a condensing reflux tube and a magnetic stirrer, and finally add 3.9g of Triethylamine, then heated up to 60°C, and the system was kept under reflux for 4 hours to obtain a light yellow homogeneous solution. After cooling, it was washed 5 times with distilled water, dried with anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation to obtain 11.24 g of a white solid, which was an additive-type phosphazene flame retardant.

Claims (10)

1. a ring phosphonitrile class additive flame retardant, is characterized in that its chemical structural formula is as follows:

Wherein R=H or

2. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 1, is characterized in that its concrete steps are as follows:

1) add 9,10-dihydro-9 oxa--10-phosphine in a reservoir successively to mix phenanthrene-10-oxide compound, acetone and solvent, after temperature reaction, crystallisation by cooling, decompress filter, by washing, dry, obtain flame retardant intermediate DOPOA, its chemical structural formula is as follows:

2) under nitrogen protection flame retardant intermediate DOPOA, hexachlorocyclotriphosphazene are reacted under the condition of solvent and acid binding agent, washed by extraction, revolve steaming, after drying, namely obtain ring phosphonitrile class additive flame retardant.

3. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, is characterized in that in step 1) in, described container adopts the container that whipping appts is housed.

4. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, it is characterized in that in step 1) in, described 9,10-dihydro-9 oxa--10-phosphine mixes the mol ratio of phenanthrene-10-oxide compound (DOPO) and acetone for (0.5 ~ 2.0): 1, and the consumption of described solvent is 5 ~ 30 times of each solid material total mass in mass ratio.

5. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, is characterized in that in step 1) in, the one in described solvent selected from acetone, trichloromethane, methylene dichloride, dioxane.

6. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, is characterized in that in step 1) in, the temperature of described reaction is 30 ~ 90 DEG C, and the time of reaction is 2 ~ 6h.

7. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, is characterized in that in step 2) in, described acid binding agent is selected from the one in triethylamine, salt of wormwood, sodium bicarbonate, sodium carbonate, sodium hydroxide.

8. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, is characterized in that in step 2) in, described solvent is selected from the one in DMF, methylene dichloride, tetrahydrofuran (THF), trichloromethane.

9. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, is characterized in that in step 2) in, the consumption of described solvent is 6 ~ 20 times of each solid material total mass in mass ratio; The mol ratio of described flame retardant intermediate DOPOA, hexachlorocyclotriphosphazene and acid binding agent is (8.4 ~ 1): 1: (9.0 ~ 1.5).

10. the preparation method of ring phosphonitrile class additive flame retardant as claimed in claim 2, is characterized in that in step 2) in, the temperature of described reaction is 30 ~ 100 DEG C, and the time of reaction is 3 ~ 12h.