The invention relates to a halogen-free flame retardant mixture containing between 1 - 99 wt.% of a component A and between 1 - 99 wt.% of a component B. Component A comprises between 85 - 99.995wt.-% of a solid diethylphosphinic acid salt of the metals Mg, Ca, AI, Sb, SN, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K and/or a protonated nitrogen base and between 0.005 - 15 wt.-% of non-combustible additives and component B is in the form of an aluminum phosphite.

Halogen-free solid flame retardant mixture and use thereof

The invention discloses a preparation method of dialkyl phosphinate with high thermal stability. The preparation method comprises the following steps of: (a), adding strong acid to dialkyl phosphinic acid and/or a dialkyl phosphinic acid alkali metal salt aqueous solution to obtain dialkyl phosphinic acid and/or the dialkyl phosphinic acid alkali metal salt aqueous solution with pH lower than 1; (b), reacting a mixture of a metal compound and water with the dialkyl phosphinic acid and/or the dialkyl phosphinic acid alkali metal salt aqueous solution with the pH lower than 1 to generate dialkyl phosphinic acid metal salt, wherein the pH of the solution after the reaction is lower than 1; and (c), filtering, recycling the filtrate, washing and drying the filter cake to obtain the corresponding dialkyl phosphinate. The product prepared by the preparation method disclosed by the invention has a high TG1% weight loss temperature and a high TG5% weight loss temperature and good thermal stability, and is heated up for 8 hours at 250 DEG C without changing color and carbonizing, so that the problems that the flame retardant is easy to fade and easy to decompose in a resin processing process are radically solved.

Preparation method of dialkyl phosphinate with high thermal stability

The invention provides a preparation method for diethyl hypophosphite. The preparation method comprises the following steps: (1) mixing soluble hypophosphite with water so as to obtain a soluble hypophosphite aqueous solution; (2) carrying out heating to 25 DEG C to 30 DEG C, introducing ethylene into a reactor in a form of microbubbles through an aerator at a normal pressure, adding a photoinitiator and a composite catalyst into the aerator drop by drop at the same time, blowing the photoinitiator and the composite catalyst together with ethylene gas into the reactor, maintaining a temperature of 25 DEG C to 30 DEG C under irradiation of ultraviolet light, and carrying out a reaction for 2 to 3 h, wherein the photoinitiator comprises benzophenone and active amine with a volume ratio of 8:2; the ratio of the total volume of the photoinitiator to the mass of the soluble hypophosphite is (0.5-2): 10; the composite catalyst comprises persulfate and threonine with a volume ratio of 3: 7;and the ratio of the total volume of the composite catalyst to the mass of the soluble hypophosphite is (2.5-3.5): 10. According to the invention, the reaction is performed at the normal pressure, anda low temperature is required, so the purpose of rapid synthesis of the diethyl hypophosphite is achieved.

Preparation method for diethyl hypophosphite

The invention discloses a one-step synthesis method of dialkylphosphinic acid mixture. The one-step synthesis method comprises the steps as follows: diisobutylene and hypophosphorous acid solution are taken as raw materials; addition reaction is initiated through ultraviolet light at low temperature, wherein the molar percentage content of bi(1,1,3,3-tetramethylbutyl) phosphinic acid in a purified product is greater than 10 percent; except bi(2,2,4-trimethylpentyl) phosphinic acid and bi(1,1,3,3-tetramethylbutyl) phosphinic acid, the molar percentage content of other phosphorus compounds is lower than 1 percent. The one-step synthesis method has the advantages and positive effects that the production process is safe in technology, simple in procedures, low in cost, easy to control, high in efficiency and low in pollution, and solves the limitation of single use of bi(2,2,4-trimethylpentyl) phosphinic acid or bi(1,1,3,3-tetramethylbutyl) phosphinic acid in industrial application.

One-step synthesis method of dialkylphosphinic acid mixture

Provided in the present invention is a method for preparing bis(2,4,4-trimethyl pentyl) phosphinic acid: mixing sodium hypophosphite with diisobutylene; adding photoinitiator acetone while heating; reacting for 8 to 20h using ultraviolet light for irradiation; acquiring a crude product; and, when the crude product is alkaline-washed, acidified, dehydrated, and negative pressure distilled, acquiring a bis(2,4,4-trimethyl pentyl) phosphinic acid liquid product. The method of the present invention is conducted at a low temperature and atmospheric pressure, is safe, simple, and economic, and has great selectivity and reduced pollution.

Method for preparing bis(2,4,4-trimethyl pentyl) phosphinic acid

The invention relates to a preparation method of diisobutyl phosphinic acid aluminum. According to the preparation method, sodium hypophosphite and isobutene are used as raw materials, ultraviolet light is utilized to excite acetone to result in addition reaction of the isobutene and the sodium hypophosphite to generate diisobutyl phosphinic acid sodium which contains a small amount of isobutyl phosphinic acid sodium, the diisobutyl phosphinic acid sodium is obtained through purification, and then the diisobutyl phosphinic acid sodium is mixed with aluminum salt for double decomposition reaction to obtain white powdery diisobutyl phosphinic acid aluminum with higher purity and good heat stability. According to the preparation process, the synthetic reaction is performed at low temperature and normal pressure, so the preparation method has the advantages of high production safety coefficient, mild condition and simplicity in operation; the acetone is used as an initiating agent in the preparation method, so the preparation method has the advantages of short time, low cost, easiness in control, high efficiency and less byproduct; and the ultraviolet light is used as an energy source to excite the acetone to generate free radicals, so the preparation method has the advantages of high energy and efficiency, good reaction selectivity and great reduction of reaction temperature.

Preparation method of diisobutyl phosphinic acid aluminum

The invention relates to a preparation method of polymerization alkyl aluminum hypophosphite. According to the preparation method, sodium hypophosphite, acetylene and ethylene are used as raw materials, acetic acid is used as a solvent, acetone is used as a photoinitiator, ultraviolet light is used for triggering addition reaction of the acetylene, the ethylene and the sodium hypophosphite, polymerization sodium hypophosphite is synthesized, the polymerization sodium hypophosphite takes reaction with aluminum salt, polymerization aluminum hypophosphite is generated, the washing and the vacuum drying are carried out, and the white powder polymerization alkyl aluminum hypophosphite can be prepared. The preparation method has the advantages that according to a production process, the synthetic reaction is carried out at low temperature and normal pressure, the use of peroxide initiating agents and high pressure are avoided, the production safety coefficient is high, the condition is mild, and the operation is simple; according to the preparation method, the acetone is used as the photoinitiator, the cost is low, the control is easy, the efficiency is high, and the pollution is little; and according to the preparation method, an ultraviolet lamp is used as energy sources to excite the acetone to generate free radicals, the energy is high, the efficiency is high, the reaction selectivity is good, and the reaction temperature can be greatly reduced.

Wanfei Fu

Papers

Preparation method of diisobutyl phosphinic acid aluminum

Preparation method of polymerization alkyl aluminum hypophosphite