CN116024809A - A kind of DOPO finishing liquid and its preparation method and application - Google Patents

Abstract

The invention relates to a DOPO finishing liquid and its preparation method and application. The DOPO finishing liquid is composed of DOPO, an alcoholic solvent and water, wherein the content of DOPO is 0.5-2.5wt%, and the volume ratio of the alcoholic solvent to water is 1 : 4‑6, the boiling point of the alcoholic solvent is not lower than 70°C; method: dissolve DOPO in the alcoholic solvent under stirring conditions, and then add water to it to obtain the DOPO finishing liquid; application: make the DOPO finishing liquid After adjusting the pH value to 3-5, the polyamide 6 fabric is immersed in it, taken out and baked to obtain a flame-retardant polyamide 6 fabric. The DOPO finishing liquid of the present invention has the characteristics of low concentration and high efficiency, and the solvent used is mainly water, which is green and environmentally friendly; the method of the present invention is simple, and the DOPO finishing liquid of the present invention is applied to polyamide 6 fabrics, and has a good flame retardant effect and anti-dripping effect.

Description

A kind of DOPO finishing liquid and its preparation method and application

technical field

The invention belongs to the technical field of flame retardant finishing, and relates to a DOPO finishing liquid and a preparation method and application thereof.

Background technique

DOPO has been proved to be a green and environmentally friendly phosphorus-containing flame retardant, therefore, DOPO flame retardant has aroused the interest of many researchers. However, due to its poor water solubility, DOPO cannot be used to prepare flame-retardant textiles through traditional post-finishing methods. In addition, DOPO has poor thermal stability, and its decomposition temperature is 200°C, while the blending temperature of polyamide 6 is generally around 260°C. DOPO decomposes before reaching the blending temperature and loses its activity. Therefore, DOPO cannot be directly used in the blending modification of polyamide 6 fabrics.

At present, researchers mainly modify DOPO to improve its thermal stability and apply it to the preparation of blended modified polyamide textiles.

Patent CN106675007A proposes a method for preparing durable flame-retardant polyamide 6 fibers. Firstly, DOPO-based reactive flame retardants are prepared, and polyamide 6 fibers are synthesized by polycondensation reaction with caprolactam. However, various synergistic effects need to be added during the preparation process Agents, such as aluminum methyl phenyl phosphinate, antimony trioxide, magnesium hydroxide, etc., have high economic costs and are not suitable for mass production.

Document 1 (Insitupreparedpolyamide6/DOPO-derivativenanocompositeformelt-spinningof flameretardanttextilefilaments[J].PolymerDegradationandStability,2019,166:50-59.) and Document2(NewsustainableflameretardantDOPO-NH-functionalizedpolyamide6andfilamentyarn[ J]. Chemical Engineering Journal, 2021, 426: 130760.) are used The method of blend spinning adds DOPO derivatives to polyamide 6 substrates, and the prepared polyamide fibers all reach the UL94V-1 level. The introduction of DOPO derivatives effectively inhibited the dripping of molten droplets and reduced the fire hazard, but did not completely inhibit the dripping of molten droplets. In addition, the addition amount of DOPO derivatives is above 10%, which adversely affects the strength and spinnability of fibers.

In addition, the researchers also used DOPO's flame-retardant properties to obtain flame-retardant materials through other technological means.

Document 3 (Preparation and performance of flexible flame-retardant polyamide wet-coated fabric [J]. Textile Journal, 2021, 42(11): 110-116.) Using polyamide 6 waste silk, DOPO, MCA, methanol/ The calcium chloride system is used to prepare the slurry, and a uniform polyamide film is formed on the surface of the fabric through a wet coating process, but the flame-retardant fabric prepared by this system is not a polyamide fabric, and two flame retardants are used. When the dosage of DOPO reaches 8.5%, a good flame retardant effect can be achieved, and the limiting oxygen index reaches 26.4%, but it does not meet the requirements of flame retardant fabrics (LOI>27%).

Document 4 (Supercritical fluid flame-retardant processing of polyethyleneterephthalate (PET) fiber treated with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO): Changes in physical properties and flame-retardant performance [J]. Journal of CO ₂ Utiliz ation,2021,54:101761.) It is proposed to use supercritical dyeing method to make DOPO enter into PET fiber to prepare flame-retardant and durable PET fiber. When the added amount reaches 9%, the limiting oxygen index reaches 30.7%. However, supercritical dyeing conditions are harsh and energy consumption is high, so it is not suitable for industrial Production.

Therefore, it is of great significance to study a DOPO finishing solution and its preparation method and application to solve the problems of complex process and poor flame retardant effect when DOPO is applied to polyamide 6 fabrics in the prior art.

Contents of the invention

The purpose of the present invention is to solve the problems existing in the prior art, and to provide a DOPO finishing liquid and its preparation method and application.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A DOPO finishing liquid, which is composed of DOPO, an alcoholic solvent and water, wherein the content of DOPO is 0.5-2.5wt%, the volume ratio of alcoholic solvent to water is 1:4-6, and the boiling point of the alcoholic solvent is not low at 70°C.

DOPO in the DOPO finishing solution of the present invention is in a dissolved state, because DOPO can be well dissolved in alcohol solvents, and water can be miscible with alcohol solvents in any proportion, but water is a poor solvent for DOPO, and DOPO will be precipitated first , and then due to the hydration of DOPO with water in the presence of alcohol, DOPO is in a dissolved state;

The azeotropic point of the DOPO finishing liquid of the present invention is higher than the temperature of polyamide 6 immersion dyeing (probably 70-90°C), because the volume ratio of alcoholic solvent to water is 1:4-6, and the boiling point of alcoholic solvent is not low at 70°C, so the azeotropic point of the mixed solvent is higher than 86°C, which can meet the requirement of polyamide 6 immersion temperature.

As a preferred technical solution:

As for the above DOPO finishing solution, the solvent of the DOPO finishing solution has an azeotropic point of 86-90°C.

A kind of DOPO finishing solution as mentioned above, the alcoholic solvent is ethanol or isopropanol.

The present invention also provides a method for preparing a DOPO finishing solution as described in any one of the above items. Under stirring conditions, after dissolving DOPO in an alcoholic solvent, water is added therein to obtain the DOPO finishing solution.

As a preferred technical solution:

In the above method, the stirring temperature is 60-80° C., the stirring time is 15-30 min, and the stirring speed is 800-1000 r/min.

The present invention also provides the application of a kind of DOPO finishing liquid as described in any one of the above, the pH value of DOPO finishing liquid is adjusted to 3-5 (DOPO is a kind of acid, with reference to acid dye dyeing polyamide, so pH value is in this range), the polyamide 6 fabric is immersed in it, taken out and baked to obtain a flame-retardant polyamide 6 fabric, wherein the dipping temperature is not higher than the azeotropic point of the DOPO finishing solution.

As a preferred technical solution:

As mentioned above, the impregnation temperature is 70-90°C, the impregnation time is 50-70min, and the impregnation bath ratio is 1:30-50.

As mentioned above, the baking temperature is 130-150° C., and the baking time is 30-60 minutes.

As mentioned above, the LOI of flame-retardant polyamide 6 fabric is more than 27.1%, the damaged length is not more than 14.8cm, and the number of melted droplets is 0; after 20 times of washing, the LOI of flame-retardant polyamide 6 fabric is more than 25.8% , the damaged length does not exceed 16.2cm, and the number of molten droplets is 0-1.

Principle of invention

In the present invention, DOPO is first dissolved with a small amount of alcohol, and then a large amount of water is quickly added. At this time, DOPO will be precipitated first, and then dissolved again. This method meets the relevant dyeing and finishing requirements, and finally obtains the water/organic solvent system of DOPO. The azeotropic point of this system is higher than the dip dyeing temperature of polyamide 6, so polyamide 6 fabric can be prepared by dipping method.

Put the polyamide 6 fabric into the prepared flame retardant solution, imitate acid dye dyeing, adjust the pH value of the flame retardant solution to 3-5, the dipping temperature is 70-90°C, and the dipping time is 50-70min. DOPO is adsorbed onto the polyamide 6 fabric through hydrogen bonds, and then further baked at 130-150°C for 30-60 minutes. Since the melting point of DOPO is 117°C, high-temperature baking will melt it and adhere to the surface of the fabric to form a film , so as to obtain a flame-retardant polyamide 6 fabric with certain durability.

The P-H bond in DOPO can hydrogen bond with the amide group, endowing the flame-retardant polyamide 6 with certain washing resistance. In addition, the dense film can effectively isolate the immersion of water, and because DOPO has a certain water repellency, it is difficult to wash DOPO away. After the film is formed, it can form a water repellent film on the surface of the fiber to further improve the flame retardant and washable performance.

Beneficial effect

(1) A DOPO finishing solution of the present invention has the characteristics of low concentration and high efficiency, and the solvent used is mainly water, which meets the production requirements of enterprises and the trend of green environmental protection;

(2) the preparation method of a kind of DOPO finishing liquid of the present invention is simple and convenient;

(3) The application of a DOPO finishing solution of the present invention, the prepared flame-retardant polyamide 6 fabric has higher fire safety, and the prepared polyamide 6 fabric belongs to flame-retardant fabric.

Description of drawings

Fig. 1 is the surface topography figure of polyamide 6 fabric after dipping;

Fig. 2 is the surface topography diagram of the polyamide 6 fabric after baking.

Detailed ways

The present invention will be further described below in combination with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

The detection method of relevant performance in following each embodiment is as follows:

LOI is tested with reference to ASTM D2863-17;

The damage length is tested with reference to ASTM D6413-15;

The number of molten drops is tested with reference to ASTM D2863-17;

Water washing refers to AATCC61-2013.

The manufacturers and trade marks of related substances in the following examples are as follows:

DOPO: The manufacturer is Shanghai Dibo Biotechnology Co., Ltd., and the CAS number is 35948-25-5;

Polyamide 6 fabric: the manufacturer is Wujiang Fuhua Weaving Co., Ltd., the brand is CNO015003S, the grammage is 113g/m ² ; the LOI of polyamide 6 fabric is 23.0%, the damage length is 16.0cm, the droplet number is 3, and it is ignited absorbent cotton.

Example 1

A preparation method of DOPO finishing liquid, the specific process is: under the condition of temperature of 60°C, after DOPO is dissolved in ethanol, water is added to it to obtain DOPO finishing liquid; wherein, the whole process is supplemented by stirring, and the stirring speed It is 850r/min, and the stirring time is 25min.

The content of DOPO in the finally prepared DOPO finishing liquid is 1 wt%, and the volume ratio of ethanol and water is 1:4; the azeotropic point of the solvent of DOPO finishing liquid is 86°C.

A kind of application of DOPO finishing liquid, after the pH value of the above-mentioned prepared DOPO finishing liquid is adjusted to 4, polyamide 6 fabric is immersed in it, after taking out (the surface morphology of polyamide 6 fabric after dipping is as shown in Figure 1 ) at a temperature of 135°C for 30 minutes (the surface morphology of the polyamide 6 fabric after baking is shown in Figure 2), to obtain a flame-retardant polyamide 6 fabric; wherein, the impregnation temperature is 75°C, and the The duration is 55min, and the bath ratio of immersion is 1:30.

The LOI of the flame-retardant polyamide 6 fabric finally prepared was 28%, the damaged length was 14 cm, and the number of melted droplets was 0; after 20 times of washing, the LOI of the flame-retardant polyamide 6 fabric was 26.4%, and the damaged length was 14.9 cm , the droplet number is 1.

Example 2

A preparation method of DOPO finishing solution, the specific process is: under the condition of temperature of 80°C, after dissolving DOPO in isopropanol, adding water to it, the DOPO finishing solution is obtained; wherein, the whole process is supplemented by stirring, The stirring speed is 900r/min, and the stirring time is 20min.

The content of DOPO in the finally prepared DOPO finishing solution is 1.5wt%, and the volume ratio of isopropanol to water is 1:5; the azeotropic point of the solvent of DOPO finishing solution is 90°C.

An application of DOPO finishing solution. After adjusting the pH value of the DOPO finishing solution prepared above to 4.2, the polyamide 6 fabric is immersed in it, and after taking it out, it is baked at a temperature of 145°C for 60 minutes to obtain a flame-retardant polymer. Amide 6 fabric; wherein, the dipping temperature is 80°C, the dipping time is 60min, and the bath ratio of dipping is 1:50.

The LOI of the flame-retardant polyamide 6 fabric finally prepared was 28.7%, the damaged length was 13.4 cm, and the number of melted droplets was 0; after 20 times of washing, the LOI of the flame-retardant polyamide 6 fabric was 27.3%, and the damaged length was 14.2 cm. cm, the number of droplets is 0.

Example 3

A preparation method of DOPO finishing solution, the specific process is: under the condition of temperature of 70°C, after DOPO is dissolved in ethanol, water is added thereinto to obtain DOPO finishing solution; wherein, the whole process is supplemented by stirring, and the stirring speed It is 800r/min, and the stirring time is 27min.

The content of DOPO in the finally prepared DOPO finishing solution is 0.5wt%, and the volume ratio of ethanol to water is 1:6; the azeotropic point of the solvent of DOPO finishing solution is 94°C.

An application of DOPO finishing solution. After adjusting the pH value of the DOPO finishing solution prepared above to 3, the polyamide 6 fabric is immersed in it, and after taking it out, it is baked at a temperature of 140°C for 40 minutes to obtain a flame-retardant polyamide. Amide 6 fabric; wherein, the dipping temperature is 70°C, the dipping time is 65min, and the dipping bath ratio is 1:35.

The LOI of the flame-retardant polyamide 6 fabric finally prepared was 27.1%, the damaged length was 14.8 cm, and the number of melted droplets was 0; after 20 times of washing, the LOI of the flame-retardant polyamide 6 fabric was 25.8%, and the damaged length was 16.2 cm. cm, and the number of droplets is 1.

Example 4

A preparation method of DOPO finishing solution, the specific process is: under the condition of temperature of 75°C, after DOPO is dissolved in isopropanol, water is added thereto to obtain DOPO finishing solution; wherein, the whole process is supplemented by stirring, The stirring speed is 1000r/min, and the stirring time is 18min.

The content of DOPO in the finally prepared DOPO finishing solution is 2.5wt%, and the volume ratio of isopropanol to water is 1:5; the azeotropic point of the solvent of DOPO finishing solution is 90°C.

An application of DOPO finishing solution. After adjusting the pH value of the DOPO finishing solution prepared above to 5, the polyamide 6 fabric is immersed in it, and after taking it out, it is baked at a temperature of 150° C. for 45 minutes to obtain a flame-retardant polymer. Amide 6 fabric; wherein, the dipping temperature is 90°C, the dipping time is 58min, and the bath ratio of dipping is 1:40.

The LOI of the flame-retardant polyamide 6 fabric finally prepared was 29.2%, the damaged length was 12.1 cm, and the number of melted droplets was 0; after 20 times of washing, the LOI of the flame-retardant polyamide 6 fabric was 27.7%, and the damaged length was 13.5 cm. cm, and the number of droplets is 1.

Example 5

A preparation method of DOPO finishing solution, the specific process is: under the condition of temperature of 65°C, after DOPO is dissolved in ethanol, water is added thereto to obtain DOPO finishing solution; wherein, the whole process is supplemented by stirring, and the stirring speed It is 880r/min, and the stirring time is 15min.

The content of DOPO in the finally prepared DOPO finishing liquid is 1.8wt%, the volume ratio of ethanol and water is 1:4; the azeotropic point of the solvent of DOPO finishing liquid is 86°C.

An application of DOPO finishing solution. After adjusting the pH value of the DOPO finishing solution prepared above to 3.5, the polyamide 6 fabric is immersed in it, and after taking it out, it is baked at a temperature of 130°C for 55 minutes to obtain a flame-retardant polymer. Amide 6 fabric; wherein, the dipping temperature is 85°C, the dipping time is 50min, and the bath ratio of dipping is 1:45.

The LOI of the flame-retardant polyamide 6 fabric finally prepared was 28.5%, the damaged length was 13.7 cm, and the number of melted droplets was 0; after 20 times of washing, the LOI of the flame-retardant polyamide 6 fabric was 27%, and the damaged length was 14.5 cm. cm, the number of droplets is 0.

Example 6

A preparation method of DOPO finishing solution, the specific process is: under the condition of temperature of 70°C, after dissolving DOPO in isopropanol, water is added thereto to obtain DOPO finishing solution; wherein, the whole process is supplemented by stirring, The stirring speed is 950r/min, and the stirring time is 30min.

The content of DOPO in the finally prepared DOPO finishing solution is 2.2wt%, and the volume ratio of isopropanol to water is 1:6; the azeotropic point of the solvent of DOPO finishing solution is 94°C.

An application of DOPO finishing solution. After adjusting the pH value of the DOPO finishing solution prepared above to 3.8, the polyamide 6 fabric is immersed in it, and after taking it out, it is baked at a temperature of 150°C for 50 minutes to obtain a flame-retardant polymer. Amide 6 fabric; wherein, the dipping temperature is 88°C, the dipping time is 70min, and the bath ratio of dipping is 1:38.

The LOI of the flame-retardant polyamide 6 fabric finally prepared was 29%, the damaged length was 12.6 cm, and the number of melted droplets was 0; after 20 times of washing, the LOI of the flame-retardant polyamide 6 fabric was 27.5%, and the damaged length was 13.8 cm. cm, the number of droplets is 0.

Claims (9)

1. The DOPO finishing liquid is characterized by comprising DOPO, an alcohol solvent and water, wherein the DOPO content is 0.5-2.5wt%, the volume ratio of the alcohol solvent to the water is 1:4-6, and the boiling point of the alcohol solvent is not lower than 70 ℃.

2. A DOPO finishing liquid according to claim 1, wherein the solvent of the DOPO finishing liquid has an azeotropic point of 86-90 ℃.

3. A DOPO finishing liquid according to claim 1, wherein the alcoholic solvent is ethanol or isopropanol.

4. A method for preparing a DOPO finishing liquid according to any one of claims 1-3, wherein the DOPO finishing liquid is obtained by dissolving DOPO in an alcohol solvent under stirring and adding water thereto.

5. The method according to claim 4, wherein the stirring is carried out at a temperature of 60-80℃for 15-30min and at a speed of 800-1000r/min.

6. Use of a DOPO finishing liquid according to any one of claims 1-3, wherein after adjusting the pH of the DOPO finishing liquid to 3-5, the polyamide6 fabric is immersed therein and baked to obtain the flame retardant polyamide6 fabric, wherein the immersion temperature is not higher than the azeotropic point of the DOPO finishing liquid.

7. The use according to claim 6, wherein the temperature of the impregnation is 70-90 ℃, the time of the impregnation is 50-70min, and the bath ratio of the impregnation is 1:30-50.

8. The method according to claim 6, wherein the baking temperature is 130-150deg.C and the baking time is 30-60min.

9. The use according to claim 6, wherein the flame retardant polyamide6 fabric has an LOI of 27.1% or more, a break down length of not more than 14.8cm and a number of drops of 0; after 20 times of water washing, the LOI of the flame-retardant polyamide6 fabric is more than 25.8%, the damage length is not more than 16.2cm, and the number of molten drops is 0-1.

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