CN103275352A - P-N intumescent flame retardant and preparation method thereof - Google Patents

Abstract

The invention discloses a P-N intumescent flame retardant and a preparation method thereof, which is prepared from hydroxyethylene diphosphonic acid and melamine. The present invention uses hydroxyethylene diphosphonic acid instead of traditional phosphoric acid to react with melamine, and the obtained product has higher phosphorus content, lower water solubility, higher thermal stability and compatibility with polymers than traditional melamine phosphate. Advantages such as better performance.

Description

A kind of P-N intumescent flame retardant and preparation method thereof

technical field

The invention belongs to the field of flame retardant preparation, and in particular relates to a P-N expansion type flame retardant and a preparation method thereof. the

Background technique

With people's further attention to "halogen-free" and "low-smoke" flame retardants and the further requirements and improvement of laws and regulations, intumescent flame retardants have developed rapidly in recent years, and intumescent flame retardants used for plastics Flame retardants have become one of the most active areas of research. This type of flame retardant is composed of acid source, gas source and carbon source, and its active components are nitrogen and phosphorus. It can be a compound or a mixture. When the high polymer containing this kind of flame retardant is pyrolyzed or burned, a layer of expanded carbon layer is formed on the surface. This layer is flame-retardant, heat-insulated, and oxygen-insulated. It produces less smoke and does not produce toxic and corrosive gases. The application of flame retardants is one of the important ways to achieve low toxicity, low smoke, and halogen-free flame retardants. the

At present, there are a large number of commercialized P-N series intumescent flame retardants abroad, such as the Exolit series sold by Hoechst Celanese in the United States, the Spinflan series sold by Montefluos, and more than ten series such as CN-329 and CN-1197 sold by Great Lake. Dozens of products, they can be widely used in the flame retardancy of PP, PE, EVA and other plastics to achieve good results. the

In China, the research on P-N series intumescent flame retardants is mostly concentrated in Beijing Institute of Technology, South China University of Technology, Anhui Chemical Research Institute and other universities and research institutes. For example, the melamine pentaerythritol phosphate (MPP) of Bo Meiping and Luo Ruibin of Beijing Institute of Technology, and the CN-329 and Melabits of Professor Yuxiang of Beijing Institute of Technology and other cage-like phosphate intumescent flame retardants. There are few types of products, and industrialized production has not been realized. the

Contents of the invention

The object of the present invention is to provide a kind of P-N intumescent flame retardant and preparation method thereof, the present invention replaces traditional phosphoric acid with melamine reaction with hydroxyethylene diphosphonic acid, the product obtained has phosphorus content more than traditional melamine phosphate High, lower water solubility, higher thermal stability, better compatibility with polymers, etc. the

To achieve the above object, the present invention adopts the following technical solutions:

A P-N intumescent flame retardant is prepared from hydroxyethylene diphosphonic acid and melamine.

The method for preparing the above-mentioned P-N intumescent flame retardant is to weigh each raw material according to the ratio of raw materials, first dissolve melamine in deionized water, and after it is uniformly dispersed, add hydroxyethylene diphosphonic acid dropwise to control The reaction temperature is increased by stirring, and after a certain period of reaction, hot filtration is carried out directly, and the filter cake is washed with warm boiled water, then placed in an oven for drying, ground and pulverized to obtain the product. the

The molar ratio of hydroxyethylene diphosphonic acid to melamine is 0.5-2:1. the

Dissolve 1-12.6g melamine per 100ml deionized water. the

The reaction temperature is 60-90°C, and the reaction time is 1-2h; the filter cake is washed with sufficient warm water, and then dried in an oven at 100°C. the

Significant advantage of the present invention is:

The P-N intumescent flame retardant of the present invention has not been reported at home and abroad. Compared with its similar products, melamine phosphate and melamine pyrophosphate, melamine diphosphate has a high phosphorus content, lower water solubility, and higher thermal stability. Better compatibility with polymers.

Melamine diphosphate is a white crystalline powder, insoluble in organic solvents such as alcohols, ketones, ethers, hydrocarbons, halogenated hydrocarbons, and extremely difficult to dissolve in water. The decomposition temperature is greater than 250 ° C. It has high thermal stability, good compatibility and durability. , light resistance, non-toxic and other advantages. Melamine bisphosphate is suitable for flame retardant of polyethylene, polypropylene, polyoxymethylene and other plastics. When the high polymer containing this flame retardant is heated, a layer of uniform carbon foam layer can be formed on the surface. This layer is heat-insulating, insulating Oxygen, smoke suppression, and can prevent dripping, has good flame retardant performance, high thermal stability, good compatibility, etc. It conforms to the current development trend of flame retardants with less smoke and low toxicity, and is an environmentally friendly of flame retardants. the

Detailed ways

Example 1

Add 200mL of deionized water to a 500mL three-neck flask equipped with a condenser and a stirrer, add 6.3g of melamine, stir evenly at 60°C, and then weigh hydroxyethylene diphosphonic acid in a molar mass ratio of 1:1 , Dissolve diphosphoric acid in 100mL deionized water, and then add it dropwise into a three-necked flask. After reacting for 1 hour, the solution is directly filtered with hot water, and the filter cake is washed with 300mL hot water, and then dried in an oven at 100°C. A yield of 93.7% was obtained.

Example 2

Add 200mL of deionized water to a 500mL three-necked flask equipped with a condenser and a stirrer, add 6.3g of melamine, stir evenly at 90°C, and then weigh hydroxyethylene diphosphonic acid in a molar mass ratio of 2:1 , Dissolve diphosphoric acid in 100mL deionized water, and then add it dropwise into a three-neck flask. After 2 hours of reaction, the solution is directly filtered with hot water, and the filter cake is washed with 300mL hot water, and then dried in an oven at 100°C. A yield of 95% was obtained.

Example 3

Add 200mL of deionized water to a 500mL three-necked flask equipped with a condenser and a stirrer, add 6.3g of melamine, stir evenly at 75°C, and then weigh hydroxyethylene diphosphonic acid in a molar mass ratio of 1:2 , Dissolve diphosphoric acid in 100mL deionized water, and then add it dropwise into a three-necked flask. After 1.5 hours of reaction, the solution is directly filtered with hot water, and the filter cake is washed with 300mL hot water, and then dried in an oven at 100°C , and the yield was 96%.

The synthesis method adopted in the invention has easy-to-obtain raw materials, short technological process, mild reaction conditions, no toxic gas generated during the reaction, little environmental pollution, high product yield and high phosphorus content. Flame retardant application evaluation: Taking polypropylene as the research object, the flame retardant and mechanical properties of the melamine diphosphate prepared in the above example 1 and pentaerythritol were studied at a mass ratio of 2:1. the

The specific formula is shown in Table 1, and the test results are shown in Table 2. the

Table 1 Basic formulation of flame retardant polypropylene

Sample preparation process: Add accurately measured polypropylene and flame retardant to the mill according to the amount given in Table 1 for blending. The milling temperature is 170-185°C and the milling time is 3-5 minutes. Mix evenly The material is cut into granules by a pulverizer, and then injection molded according to the relevant standard conditions after drying to obtain a standard sample, and the flame retardant performance and mechanical performance test are carried out according to the standard.

The main operating conditions of the injection molding machine: Heating temperature in zone 1-7: 180-205°C, holding pressure: 19MPa, injection holding pressure time: 8s, cooling mold opening time: 10s. the

Table 2 Performance test data table of flame retardant polypropylene

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (4)

1. a P-N expansion type flame retardant is characterized in that: be prepared from by hydroxy ethylene diphosphonic acid and trimeric cyanamide.

2. a method for preparing P-N expansion type flame retardant as claimed in claim 1 is characterized in that: take by weighing each raw material by proportioning raw materials, earlier trimeric cyanamide is dissolved in the deionized water, after treating that it is uniformly dispersed, drip hydroxy ethylene diphosphonic acid again, the control temperature of reaction is accelerated to stir, behind the reaction certain hour, directly carry out heat filtering, filter cake washs with warm boiling water, places baking oven to dry then, grind, pulverize, obtain product.

3. the preparation method of P-N expansion type flame retardant according to claim 2, it is characterized in that: the mol ratio of hydroxy ethylene diphosphonic acid and trimeric cyanamide is 0.5-2:1.

4. the preparation method of P-N expansion type flame retardant according to claim 2, it is characterized in that: temperature of reaction is 60-90 ℃, the reaction times is 1-2h; Filter cake places 100 ℃ of baking ovens to dry with the warm boiling water washing of capacity then.