CN105085575A - Flame-retardant polyol containing phosphorus linked pendant groups and preparation method of polyol - Google Patents

Abstract

The invention discloses a side-group phosphorus-containing flame-retardant polyol and a preparation method thereof, which specifically includes the following steps: 1) placing a solvent and neopentyl glycol in a reaction kettle, adding phosphorus oxychloride dropwise, and obtaining an intermediate novel Pentanediol phosphorus oxychloride; 2) Put the solvent and small molecule trihydric alcohol or tetrahydric alcohol in the reaction kettle, add the acid-binding agent, drop the intermediate dissolved in the solvent, reflux reaction, cool, filter, wash, and obtain the side Phosphorus-based flame retardant polyol. The side-group phosphorus-containing flame-retardant polyol provided by the invention is cheap and easy to obtain, does not contain halogen, is environmentally friendly and non-toxic, and has a simple and controllable process. The two or three active terminal hydroxyl groups contained can be reacted with isocyanate to prepare side-chain phosphorus-containing polyols. The intrinsically flame-retardant polyurethane material not only overcomes the defects of poor compatibility and easy migration and precipitation of externally added flame retardants in water-based polyurethane systems, but also solves the problem of polyurethane with phosphorus-containing polyols in the main chain due to the intolerance to hydrolysis of phosphate bonds. The breakage of the main chain structure leads to the degradation of the physical and chemical properties of the material.

Description

A side-group phosphorus-containing flame-retardant polyol and its preparation method

technical field

The invention belongs to the technical field of flame retardant synthesis, and in particular relates to a side-group phosphorus-containing flame-retardant polyol and a preparation method thereof.

Background technique

Water-based polyurethane (WPU), as a multi-functional environmental protection material, has been widely used in leather finishing, synthetic leather manufacturing, fabric coating, building materials, adhesives, printing, ink and paper making and other industries. However, the limiting oxygen index (LOI) of water-based polyurethane is only 17%-18%, which is a flammable material and produces a lot of smoke and toxic gases such as HCN and CO when burned, which greatly hinders its further application. At present, the improvement of the flame retardant performance of water-based polyurethane is mainly achieved by adding flame retardants externally, but the externally added flame retardants have defects such as large amount of flame retardants, poor compatibility, easy migration and precipitation, and great influence on the mechanical properties of materials. Therefore, it is the development trend of flame-retardant water-based polyurethane to block polyols or isocyanates containing chlorine, bromine, phosphorus, nitrogen and other flame-retardant elements into the structure of water-based polyurethane to prepare intrinsically flame-retardant water-based polyurethane. Among them, the reactive phosphorus flame retardant has become an ideal choice for flame retardant water-based polyurethane due to its advantages of high flame retardant efficiency, long-lasting and stable flame retardant, and no corrosive gas generated during combustion. However, the traditional reactive phosphorus-based flame retardants have the disadvantage that the phosphate ester is easily hydrolyzed because the flame retardant elements are located in the main chain, resulting in the breakage of the polyurethane main chain and the decline in the mechanical properties of the material. Therefore, providing a side-group phosphorus-containing flame-retardant polyol is of great significance to the development of water-based polyurethane flame-retardant materials.

Chinese invention patent CN201210103713.1 provides a preparation method of phosphorus-halogen synergistic flame-retardant polyether polyol, and applies it to the preparation of flame-retardant polyurethane. The obtained polyurethane material has good flame-retardant properties (LOI is 30.8%), Thermal stability and mechanical properties, but because the flame-retardant polyether polyol contains halogen, which runs counter to the concept of green environmental protection advocated in the world today, it is difficult to meet market requirements.

Chinese invention patent CN201010227072.1 introduces a preparation method of oligomeric phosphate polyols. The synthesized oligomeric phosphate polyols containing terminal hydroxyl groups can partially replace polyether polyols or polyester polyols, and react with isocyanate to prepare flame retardant Polyurethane. Chinese invention patent CN201210581748.6 discloses a method for preparing phosphorus-containing polyols. The phosphorus-containing polyols have a linear structure and are similar in molecular weight to the original polyether/polyester macromolecular polyols in polyurethane, which can give the prepared polyols Good mechanical properties of flame retardant polyurethane. Chinese invention patent CN201310309684.9 provides a halogen-free organic phosphate flame retardant and its preparation method. The prepared phosphate flame retardant containing hydrophobic side chains is embedded in the polyurethane structure to obtain uniform and dense cells. Flame retardant polyurethane foam.

Although the above patents have solved the problem of containing halogens, and the disclosed reactive phosphorus-containing flame retardant block into the polyurethane structure has improved the flame-retardant performance of polyurethane materials to a certain extent, but because the flame-retardant phosphorus elements are located in In the main chain structure of polyols, phosphate ester flame retardants have the defect of easy hydrolysis (M. Sato, J. Appl. Polym. Sci. , 2000, 5:1134; S. Lu, Prog. Polym. Sci. , 2002, 8:1661), the main chain of polyurethane is broken during the hydrolysis process, which leads to the decline of the physical and chemical properties of the material.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the above-mentioned prior art, and provide a side-group phosphorus-containing flame-retardant polyol and a preparation method thereof. The raw materials of the method are cheap and easy to obtain, and the preparation process is simple. Manufacturing fields such as flexible polyurethane foam and flame-retardant water-based polyurethane materials have broad application prospects.

In order to achieve the above object, the present invention provides a side-group phosphorus-containing flame-retardant polyol and its preparation method, which is characterized in that it has the following structural formula:

,

Among them, R ₁ , R ₂ and R ₃ represent H or any one of C ₁ to C ₈ alkyl groups, R ₁ , R ₂ and R ₃ may be the same or different, R ₄ represents H, -CH ₃ , Any of -C ₂ H ₅ , -NO ₂ or -CH ₂ OH.

A side-group phosphorus-containing flame-retardant polyol and a preparation method thereof provided by the invention are characterized in that the specific process steps and conditions of the method are as follows:

(1) Put the neopentyl glycol dissolved in the organic solvent І into the reaction kettle, add phosphorus oxychloride dropwise under the protection of nitrogen atmosphere, and the dropping time is 1-2 hours. After the dropping is completed, slowly raise the temperature to 45~ Reflux reaction at 65°C for 4-6 hours to obtain a white solid, which was cooled, filtered, washed with deionized water, and vacuum-dried at 70-80°C to obtain a white powder intermediate neopentyl glycol phosphorus oxychloride;

(2) Combine small molecule trihydric alcohols or tetrahydric alcohols with organic solvents Put it in the reaction kettle, add the acid-binding agent, and add the organic solvent dropwise The dissolved intermediate neopentyl glycol phosphorus oxychloride, the dropwise addition time is 1~2 h, after the dropwise addition is completed, the temperature is raised to 75~95°C for reflux reaction for 4~6 h, cooled, filtered, and organic solvent After washing and vacuum drying at 70-80°C, the side-group phosphorus-containing flame-retardant polyol can be obtained in the form of white powder or viscous liquid.

The concrete reaction equation of above-mentioned steps is:

.

The molar ratio of phosphorus oxychloride and neopentyl glycol used in the above step (1) is 1:1-1.2:1.

The organic solvent І used in the above-mentioned step (1) is any one in methylene chloride or chloroform.

The small molecule triols or tetraols used in the above step (2) are glycerol, 1,2,4 -butanetriol, 1,2,5 -pentanetriol, 1,2,6 -hexanetriol alcohol, 1,2,7 -heptanetriol, 1,2,8 -octanetriol, 1,2,9-nonanetriol, 1,2,10 - decanetriol , trimethylolethane, three Any of methylolpropane, trimethylolnitromethane or pentaerythritol.

The molar ratio of the small molecule trihydric alcohol or tetrahydric alcohol used in the above step (2) to the intermediate neopentyl glycol phosphorus oxychloride is 1:1-1.2:1.

The acid-binding agent used in the above step (2) is any one of pyridine or triethylamine.

The molar ratio of the acid-binding agent used in the above step (2) to the small molecule triol or tetraol is 1:1-1.5:1.

The organic solvent used in the above step (2) It is any one of acetonitrile, N,N -dimethylformamide or N,N -dimethylacetamide.

The organic solvent used in the above step (2) It is any one of acetone, methyl ethyl ketone, ethanol or tetrahydrofuran or any two in equal volume.

The side-group phosphorus-containing flame-retardant polyol prepared in the above steps can be applied to materials such as flame-retardant polyurethane rigid foam, flame-retardant polyurethane flexible foam, and flame-retardant water-based polyurethane, preferably flame-retardant water-based polyurethane material.

Compared with the prior art, the present invention has the following positive effects:

1. The side-group phosphorus-containing flame-retardant polyol raw material provided by the present invention is cheap and easy to obtain, does not contain halogen, is environmentally friendly and non-toxic, and has a simple and easy-to-control process;

2. The side-group phosphorus-containing flame-retardant polyols provided by the present invention contain 2 or 3 active terminal hydroxyl groups and belong to reactive flame retardants. It can partially or completely replace the small molecule polyol chain extender, react with isocyanate to prepare intrinsically flame-retardant water-based polyurethane materials, and overcome the defects of poor compatibility and easy migration and precipitation of externally added flame retardants in water-based polyurethane systems;

3. The side-group phosphorus-containing flame-retardant polyol provided by the present invention "hangs" the flame-retardant phosphorus element on the side chain of the polyurethane segment when preparing flame-retardant water-based polyurethane, effectively solving the problem of traditional reactive main chain phosphorus-containing polyhydric alcohols. Alcohol is not resistant to hydrolysis, which causes the structural breakage of the polyurethane main chain, which leads to the decline of the physical and chemical properties of the material;

4. The process of preparing water-based polyurethane from the side-group phosphorus-containing flame-retardant polyol provided by the invention is easy to control, and the performance is easy to adjust. The prepared flame-retardant water-based polyurethane is widely used in leather finishing, synthetic leather manufacturing, fabric coating, construction, etc. Materials, adhesives, printing, ink and paper industries.

Description of drawings

Fig. 1 is the infrared spectrogram of the prepared intermediate neopentyl glycol phosphorus oxychloride.

In the infrared spectrogram of intermediate neopentyl glycol phosphorus oxychloride shown in Fig. 1, used test instrument is Nicolet IS10 type Fourier transform infrared spectrometer, KBr tablet method sample preparation. The stretching vibration absorption peaks of –CH ₃ and –CH ₂ are at 2981 cm ^-1 and 2896 cm ^-1 , the stretching vibration peaks of P=O bond are at 1303 cm ^-1 , and the stretching vibration peaks at 1052 cm ^-1 and 1005 cm ^-1 are The stretching vibration peak of P–O–C bond, and the stretching vibration peak of P–Cl bond at 550 cm ^-1 , the appearance of these characteristic absorption peaks indicated the successful preparation of neopentyl glycol phosphorus oxychloride.

Fig. 2 is the infrared spectrogram of the side-group phosphorus-containing flame-retardant polyol synthesized in Example 3.

Figure 2 shows the infrared spectrum of the side-group phosphorus-containing flame-retardant polyol. The test instrument used is a Nicolet IS10 Fourier transform infrared spectrometer, and the sample is prepared by the KBr tablet method. The stretching vibration absorption peak of –OH at 3421 cm ^-1 , the stretching vibration absorption peaks of –CH ₃ and –CH ₂ at 2976 cm ^-1 and 2939 cm- ¹ , the stretching vibration of P=O bond at 1289 cm-1 Absorption peaks, 1036 cm ^-1 and 1010 cm ^-1 are the stretching vibration absorption peaks of the P–O–C bond, and the stretching vibration peak of P–Cl at 550 cm ^-1 completely disappears, which shows that the P–Cl bond It reacted with the hydroxyl group of the small molecule trihydric alcohol, and successfully prepared the side group phosphorus-containing flame-retardant polyol.

Detailed ways

The present invention is described in detail by the following examples, it is necessary to point out that the following examples are only used to further illustrate the present invention, and can not be interpreted as limiting the protection scope of the present invention, those skilled in the art can according to the above-mentioned present invention The contents of the invention make some non-essential improvements and adjustments, which still belong to the protection scope of the present invention.

Example 1

(1) In a 500-meter tank equipped with a mechanical stirrer, a constant pressure dropping funnel, a thermometer, and a nitrogen condensate return tube ml four-neck flask, add 200 ml dichloromethane and 104.2 g (1.0 mol) neopentyl glycol, stir, dissolve, add 184.0 dropwise through a constant pressure dropping funnel g (1.2 mol) phosphorus oxychloride, dropwise for 2 h. After the dropwise addition was completed, heat in an oil bath, slowly raise the temperature to 45°C and reflux for 6 hours to obtain a white solid, cool, filter, wash with deionized water, and dry under vacuum at 70°C to obtain a white powdery intermediate neopentyl glycol phosphorus acid chloride;

(2) In a 500-meter machine equipped with a mechanical stirrer, a constant pressure dropping funnel, a thermometer, and a condensing return pipe ml four-neck flask, add 50 ml acetonitrile and 55.3 g (0.6 mol) glycerol, stir, dissolve, add triethylamine 60.7 g (0.6 mol), add 150 drops through the constant pressure dropping funnel 92.2 g (0.5 mol) intermediate neopentyl glycol phosphorus oxychloride, dropwise for 2 h. After the dropwise addition, heat in an oil bath, raise the temperature to 75 °C and reflux for 6 h, cool, filter, wash with acetone, and dry in vacuum at 70 °C to obtain a viscous liquid side group phosphorus-containing flame-retardant polyol.

Example 2

(1) In a 500-meter tank equipped with a mechanical stirrer, a constant pressure dropping funnel, a thermometer, and a nitrogen condensate return tube ml four-neck flask, add 150 ml chloroform and 104.2 g (1.0 mol) neopentyl glycol, stir, dissolve, add 153.3 dropwise through a constant pressure dropping funnel g (1.0 mol) phosphorus oxychloride, dropwise for 1 h. After the dropwise addition was completed, heat in an oil bath, slowly raise the temperature to 65 °C and reflux for 4 h to obtain a white solid, cool, filter, wash with deionized water, and vacuum dry at 80 °C to obtain a white powdery intermediate neopentyl glycol phosphorus acid chloride;

(2) Add 50 ml N,N -dimethylformamide and 67.1 g (0.5 mol) 1, 2,6 -hexanetriol, stirred, dissolved, added 59.3 g (0.75 mol) of pyridine, and 92.2 g (0.5 mol) of intermediate dissolved in 100 ml N,N -dimethylformamide was added dropwise through a constant pressure dropping funnel Neopentyl glycol phosphorus oxychloride, dropwise for 1 h. After the dropwise addition, heat in an oil bath, raise the temperature to 95 °C and reflux for 4 h, cool, filter, wash with equal proportions of methyl ethyl ketone and ethanol, and dry in vacuum at 80 °C to obtain a viscous liquid side-group phosphorus-containing flame-retardant polyol .

Example 3

(1) In a 500-meter tank equipped with a mechanical stirrer, a constant pressure dropping funnel, a thermometer, and a nitrogen condensate return tube ml four-neck flask, add 200 ml chloroform and 104.2 g (1.0 mol) neopentyl glycol, stir, dissolve, add 168.7 dropwise through a constant pressure dropping funnel g (1.1 mol) phosphorus oxychloride, dropwise for 1.5 h. After the dropwise addition was completed, heat in an oil bath, slowly raise the temperature to 60 °C and reflux for 5 h to obtain a white solid, cool, filter, wash with deionized water, and vacuum dry at 75 °C to obtain a white powdery intermediate neopentyl glycol phosphorus acid chloride;

(2) Add 80 ml of N,N -dimethylacetamide and 66.1 g (0.55 mol) of trihydroxy Methyl ethane, stir, dissolve, add 48.3 g (0.66 mol) of pyridine, add 92.2 g (0.5 mol) of the intermediate neopentyl dimethanol dissolved in 100 ml N,N -dimethylacetamide dropwise through a constant pressure dropping funnel Alcohol phosphorus oxychloride, dropwise for 1.5 h. After the dropwise addition, heat in an oil bath, raise the temperature to 85 °C and reflux for 5 h, cool, filter, wash with tetrahydrofuran, and dry in vacuum at 75 °C to obtain a white powdery side-group phosphorus-containing flame-retardant polyol.

Example 4

(1) In a 500-meter tank equipped with a mechanical stirrer, a constant pressure dropping funnel, a thermometer, and a nitrogen condensate return tube ml four-neck flask, add 200 ml dichloromethane and 104.2 g (1.0 mol) neopentyl glycol, stir, dissolve, add 168.7 dropwise through a constant pressure dropping funnel g (1.1 mol) phosphorus oxychloride, dropwise for 1 h. After the dropwise addition is completed, heat in an oil bath, slowly raise the temperature to 50 °C and reflux for 6 h to obtain a white solid, cool, filter, wash with deionized water, and dry under vacuum at 80 °C to obtain a white powdery intermediate neopentyl glycol phosphorus acid chloride;

(2) In a 500-meter machine equipped with a mechanical stirrer, a constant pressure dropping funnel, a thermometer, and a condensing return pipe ml four-neck flask, add 150 ml acetonitrile and 136.2 g (0.6 mol) pentaerythritol, stir, dissolve, add triethylamine 91.1 g (0.9 mol), add 150 drops through the constant pressure dropping funnel 92.2 g (0.5 mol) intermediate neopentyl glycol phosphorus oxychloride, dropwise for 2 h. After the dropwise addition, heat in an oil bath, raise the temperature to 90 °C and reflux for 6 h, cool, filter, wash with acetone and methyl ethyl ketone in equal proportions, and dry in vacuum at 70 °C to obtain a white powdery side-group phosphorus-containing flame-retardant polyol .

Claims (10)

1. side base phosphor-containing flame-proof polyvalent alcohol and preparation method thereof, is characterized in that having following structural formula:

，

Wherein, R ₁, R ₂and R ₃represent H or C ₁~ C ₈alkyl in any one, R ₁, R ₂and R ₃can be the same or different, R ₄represent H, – CH ₃, – C ₂h ₅, – NO ₂huo – CH ₂any one in OH.

2. side according to claim 1 base phosphor-containing flame-proof polyvalent alcohol and preparation method thereof, it is characterized in that the concrete technology step of the method and condition as follows:

(1) neopentyl glycol of organic solvent dissolution is placed in reactor, phosphorus oxychloride is dripped under nitrogen atmosphere protection, time for adding is 1 ~ 2h, wait to dropwise, slowly be warming up to 45 ~ 65 DEG C of back flow reaction 4 ~ 6h, obtain white solid, cool, filter, with deionized water wash, at 70 ~ 80 DEG C, after vacuum-drying, obtain white powder intermediate neopentyl glycol phosphoryl chloride;

(2) by small molecules trivalent alcohol or tetravalent alcohol and organic solvent be placed in reactor, add acid binding agent, drip organic solvent the intermediate neopentyl glycol phosphoryl chloride dissolved, time for adding is 1 ~ 2h, after dropwising, is warming up to 75 ~ 95 DEG C of back flow reaction 4 ~ 6h, and cooling, filtration, use organic solvent washing, namely obtains the side base phosphor-containing flame-proof polyvalent alcohol of white powder or thick liquid nano in 70 ~ 80 DEG C of vacuum-dryings.

3. side according to claim 2 base phosphor-containing flame-proof polyvalent alcohol and preparation method thereof, is characterized in that the mol ratio of phosphorus oxychloride used in the method and neopentyl glycol is 1:1 ~ 1.2:1.

4. side base phosphor-containing flame-proof polyvalent alcohol according to Claims 2 or 3 and preparation method thereof, is characterized in that organic solvent used in the method is any one in methylene dichloride or chloroform.

5. side according to claim 2 base phosphor-containing flame-proof polyvalent alcohol and preparation method thereof, it is characterized in that small molecules trivalent alcohol used in the method or tetravalent alcohol be glycerol, 1,2,4-trihydroxybutane, 1,2,5-penta triol, 1,2,6-hexanetriol, 1,2,7-heptan triol, 1,2,8-Xin triol, 1,2,9-the ninth of the ten Heavenly Stems triol, 1,2,10-the last of the ten Heavenly stems triol, trimethylolethane, TriMethylolPropane(TMP), any one in trishydroxymethylnitromethane or tetramethylolmethane.

6. side base phosphor-containing flame-proof polyvalent alcohol according to claim 2 or 5 and preparation method thereof, is characterized in that the mol ratio of small molecules trivalent alcohol used in the method or tetravalent alcohol and intermediate neopentyl glycol phosphoryl chloride is 1:1 ~ 1.2:1.

7. side base phosphor-containing flame-proof polyvalent alcohol according to claim 2 or 6 and preparation method thereof, is characterized in that acid binding agent used in the method is any one in pyridine or triethylamine.

8. side according to claim 7 base phosphor-containing flame-proof polyvalent alcohol and preparation method thereof, is characterized in that the mol ratio of acid binding agent used in the method and small molecules trivalent alcohol or tetravalent alcohol is 1:1 ~ 1.5:1.

9. side according to claim 2 base phosphor-containing flame-proof polyvalent alcohol and preparation method thereof, is characterized in that organic solvent used in the method for acetonitrile, n,N-dimethyl formamide or n,Nany one in-N,N-DIMETHYLACETAMIDE.

10. side according to claim 2 base phosphor-containing flame-proof polyvalent alcohol and preparation method thereof, is characterized in that organic solvent used in the method for any one in acetone, butanone, ethanol or tetrahydrofuran (THF) or isopyknic any two.