CN100412258C - Finishing method for fire-resistant and heat-insulating organic fiber fabrics - Google Patents

Abstract

The invention discloses a finishing method for fire resistance and heat insulation of organic fiber fabrics. The method forms a continuous protective film composed of sheet hydroxide on the surface of organic fibers or fabrics to improve the fire resistance and heat insulation performance of organic fiber fabrics. The method of the invention has simple process and low cost. Since ordinary inorganic compounds are used as raw materials, the processing process has no pollution to the environment, and no toxic gas is released under high temperature conditions.

Description

Finishing method for fire-resistant and heat-insulating organic fiber fabrics

technical field

The invention belongs to the field of functional finishing of organic fiber fabrics, and in particular relates to a finishing method for fire-resistant and heat-insulating organic fiber fabrics.

Background technique

Fire-resistant and heat-insulating organic fiber fabrics are widely used in aerospace, high-temperature filtration, and protective clothing. The fire-resistant and heat-insulating properties of organic fiber fabrics are mainly obtained through three methods: ① post-treatment of fire-resistant and heat-insulating organic fiber fabrics, which is relatively low in cost; ② direct production of fire-resistant and heat-insulating fibers is expensive; ③In the production of additive refractory fibers, the additives will have a negative impact on the processing technology, physical and mechanical properties of the fibers, etc.

Traditionally, the fire-resistant and heat-insulating post-treatment method of organic fiber fabrics is usually used to endow them with fire-resistant and heat-insulating properties. The fire-resistant and heat-insulating materials used are divided into organic materials and inorganic materials. But traditional organic refractories have the following two disadvantages:

含有卤素、磷、氮、氯等元素，遇到高温存在释放有毒气体的问题，

Contains halogen, phosphorus, nitrogen, chlorine and other elements, and there is a problem of releasing toxic gas when encountering high temperature.

通常只是耐火，没有同时具备隔热的功能。

It is usually only fire-resistant, and does not have the function of heat insulation at the same time.

Therefore, in recent years, inorganic fire-resistant and heat-insulating materials with environmental protection, light weight, high-efficiency heat insulation and good fire resistance have developed rapidly, especially flake metal hydroxides, which have attracted more and more attention.

Flake aluminum hydroxide, flake magnesium hydroxide, flake zinc hydroxide, and layered double hydroxide crystals will undergo dehydration reaction at high temperature and absorb a large amount of heat. Produces evenly distributed metal oxides with excellent refractory properties, which can form a dense barrier with other carbides to play a good role in fire resistance and heat insulation. The generated metal oxides can withstand high temperatures of 500-1000 ° C. Therefore, such compounds are widely used as additives for flame retardant and refractory materials.

At present, the application of the above-mentioned metal hydroxides in fire prevention and heat insulation is mainly used as a flame retardant filler in polymer composite materials.

Adding metal hydroxide and layered silicate compounds as fillers to polymers to improve the fire resistance and heat insulation performance of polymer materials has the following disadvantages:

As additives, metal hydroxides and phyllosilicate compounds must first be prepared into ultrafine powders. The cost of the preparation process is high, and there is agglomeration phenomenon in the ultrafine powders.

超细粉体的添加量大，对聚合物材料的物理机械性能有负面影响。

Adding a large amount of ultrafine powder has a negative impact on the physical and mechanical properties of polymer materials.

超细粉体不能在聚合物表面形成连续的防护膜，影响聚合物的耐火、隔热性能。

Ultrafine powder cannot form a continuous protective film on the surface of the polymer, which affects the fire resistance and heat insulation performance of the polymer.

作为添加材料，只能适用于合成或再生有机材料。

As an additive material, only synthetic or recycled organic materials are suitable.

Contents of the invention

The technical problem to be solved by the present invention is to provide a finishing method for fire-resistant and heat-insulating organic fiber fabrics, so as to solve the defects of the prior art.

The principle of the invention is to use inorganic compound raw materials to form a continuous protective film made of sheet hydroxide on the surface of organic fiber fabrics by growing on the surface of organic fibers, so as to improve the fire resistance and heat insulation performance of organic fiber fabrics.

The refractory and heat-insulating finishing method of the organic fiber fabric provided by the present invention comprises the following steps:

①Preparation of hydroxide seed crystals: use water-soluble magnesium, zinc and aluminum salts and alkali agents (inorganic bases, organic bases) as raw materials, and use water as a solvent to prepare magnesium hydroxide, zinc hydroxide or aluminum Flaky seeds of hydroxide.

② Planting of hydroxide flaky seeds on the surface of organic fiber fabrics: Treat surface-modified or unmodified organic fibers/fabrics with different concentrations of seed liquids for a certain period of time to make a certain number of flaky crystals The seeds are adsorbed on the surface of organic fibers and dried for later use; or the hydroxide flaky seeds are applied to the surface of organic fibers/fabrics by padding.

③Secondary growth of flaky hydroxide crystals on the surface of organic fibers: immerse the organic fibers/fabrics with flaky seeds adsorbed on the surface in similar soluble magnesium salts, zinc salts or aluminum salts and alkali agents (inorganic alkalis, organic alkalis, etc.) ) in the reaction liquid, react under appropriate conditions, as the reaction proceeds, the flaky crystals gradually grow up, complete the coating of the organic fiber material, and endow the organic fiber fabric with fire resistance and heat insulation properties.

The specific steps are:

①Preparation of hydroxide seed crystals: add water to the container, and adjust the pH to 7.0-12.0 through alkaline solution; then add alkaline solution and water-soluble The concentrations of magnesium, zinc or aluminum solution, alkaline solution and water-soluble magnesium, zinc or aluminum solution are respectively: 0.01mol～1.0mol/L and 0.01mol～0.50mol/L, and the feeding time is 1～5 hours, (adding The amount of alkaline solution and water-soluble magnesium, zinc or aluminum solution is determined by the feeding speed and feeding time), and the constant temperature reaction is continued for 1 to 5 hours. Seed crystal, the seed crystal particle size is 1-500nm, preferably 10-30nm;

② Planting of hydroxide flaky seeds on the surface of organic fiber fabrics: put modified or unmodified organic fibers/fabrics into the above-mentioned hydroxide seed solution, and add ammonia water/ammonium chloride buffer at the same time Solution, keep the pH value of the system constant at 7.0-11.0, and the temperature is 20-60°C; take out the fiber/fabric after 10-60 minutes, and wash with water until the conductivity of the residual liquid is consistent with the conductivity of the water used;

③Secondary growth of flaky hydroxide crystals on the surface of organic fibers: put the fabric with hydroxide seeds into a water-soluble magnesium, zinc or aluminum solution with a concentration of 0.1-0.8mol/L, and use 1- The speed of 30ml/h is passed into the same volume of alkaline solution with a concentration of 02~2mol/L, the temperature is 20~80°C, and it is aged at the same temperature for 1~120 days, and finally continuous crystals are obtained on the surface of the fiber/fabric membrane.

Wherein said hydroxide is magnesium hydroxide, aluminum hydroxide or zinc hydroxide; said water-soluble magnesium, zinc or aluminum solution is the soluble salt solution of magnesium, the soluble salt solution of aluminum and the soluble salt solution of zinc ; The alkaline solution may be an organic alkaline solution or an inorganic alkaline solution, preferably ammonia water or hexamethylenetetramine solution.

Wherein the preferred soluble salt solution of magnesium is magnesium chloride solution; the preferred soluble salt solution of aluminum is aluminum chloride solution; the preferred soluble salt solution of zinc is zinc chloride solution.

In step ②, the method for modifying fiber/fabric:

Modification solution composition: polycarboxylic acid 0.1-100g/L, catalyst 0.1-60g/L;

Modification process: the cellulose fiber fabric is dipped twice and rolled twice with the modified solution, the excess rate is 50%-100%, pre-baked at 60°C-100°C for 5-10 minutes, baked at 140°C-180°C for 2-5 minutes, and then Wash with water until the residual liquid is neutral, dry for later use.

In step ③, it is also possible to add a high-temperature stage after "aging at 20-80°C for 1-120 days". In the reaction system of aluminum solution and alkaline solution, the concentration of magnesium, zinc or aluminum compound is: 0.01-0.5mol/L, the concentration of alkaline substance is 0.01-2mol/L, and the reaction temperature of the whole reaction is: 120 ℃-160℃, reaction time: 6-48 hours, and finally a continuous crystal film is obtained on the surface of the fiber/fabric.

Advantages of the invention

Compared with traditional methods, the method of the present invention has the following advantages:

通过片状无机化合物在有机纤维表面的原位生长或者二次生长，实现对有机纤维/织物材料的包覆，不需要超细粉体的制备过程，不需要聚合物与超细粉体的混合过程。本发明的方法工艺简单，成本低。由于使用普通无机化合物作为原料，加工过程对环境没有污染，高温条件下没有有毒气体释放。

Through the in-situ growth or secondary growth of flake inorganic compounds on the surface of organic fibers, the coating of organic fibers/fabric materials is realized, without the preparation process of ultrafine powders, and the mixing of polymers and ultrafine powders is not required process. The method of the invention has simple process and low cost. Since ordinary inorganic compounds are used as raw materials, the processing process has no pollution to the environment, and no toxic gas is released under high temperature conditions.

原位生长的片、层状无机化合物在有机纤维表面通过共价键与有机纤维结合，不使用粘合剂，结合牢度高。

In situ grown sheets and layered inorganic compounds are combined with organic fibers through covalent bonds on the surface of organic fibers, without using adhesives, and have high bonding fastness.

片、层状结构无机化合物只集中在有机纤维材料表面，对有机纤维材料的物理机械性能影响小。

Inorganic compounds with sheet and layered structures are only concentrated on the surface of organic fiber materials, and have little effect on the physical and mechanical properties of organic fiber materials.

该方法应用范围广泛，可适用于合成纤维材料、再生纤维材料和天然纤维材料。

The method has a wide range of applications and can be applied to synthetic fiber materials, regenerated fiber materials and natural fiber materials.

Description of drawings

Figure 1: Process flow chart

Detailed ways:

Illustrate with the following non-limiting examples

Embodiment one:

1. Preparation of magnesium hydroxide seed crystals: First, add 100ml of double-distilled water into the four-necked bottle, pass ammonia water to adjust the pH value of the system to 11, and then add ammonia water and Magnesium chloride dilute solution, the concentrations of ammonia water and magnesium chloride are: 0.2mol/L and 0.1mol/L respectively, the feeding time is 2 hours, and the constant temperature reaction is continued for 2 hours. The reaction temperature of the whole process is 40°C, and the seed crystals with a particle size of about 20nm are obtained. .

2. Planting of magnesium hydroxide crystal seeds on cotton fabric: put 0.5g of cotton fabric into 100ml of the above-mentioned magnesium hydroxide seed crystal solution, and add ammonia water/ammonium chloride buffer solution at the same time to keep the pH value of the system at 11. The whole reaction was carried out in a constant temperature water bath at a temperature of 40°C. After 30 minutes, the fabric was taken out and washed with double distilled water until the conductivity of the residue was consistent with that of the double distilled water.

3. Magnesium hydroxide crystals undergo secondary growth: 1) normal temperature stage: the fabric with magnesium hydroxide crystals is dropped into 200ml of magnesium chloride solution with a concentration of 0.1mol/L, and the concentration of 1mol is injected at a rate of 15ml/h. 180ml of ammonia water per L, the whole reaction process is carried out in a constant temperature water bath, the temperature is 40 ℃, and the magnesium hydroxide flake crystals are covered with the surface of the fiber for 20 days at the same temperature. 2) High temperature stage: the normal temperature stage is prepared The fabric is put into 100ml high-temperature secondary growth system, the concentration of magnesium chloride in this system is: 0.5mol/L, the concentration of organic base hexamethylenetetramine is 2mol/L, the whole reaction is carried out in a high-temperature and high-pressure tank, and the reaction temperature is : 160°C, reaction time: 10 hours, and finally a continuous crystal film is obtained on the surface of the cotton fabric.

Embodiment two:

1. Preparation of magnesium hydroxide seed crystals: First, add 100ml of double-distilled water into the four-neck bottle, adjust the pH of the system to 11 with ammonia water, and then add ammonia water and magnesium chloride to the system at the same time at a speed of 40ml/h with a constant flow pump Dilute solution, the concentrations of ammonia water and magnesium chloride are: 0.2mol/L and 0.1mol/L respectively, the feeding time is 2 hours, and the constant temperature reaction is continued for 2 hours. The reaction temperature of the whole process is 40°C, and the seed crystals with a particle size of about 20nm are obtained.

2. Citric acid modification of cotton fabric:

Modification solution composition: citric acid 100g/L, sodium hypophosphite 60g/L Modification process: Cotton fabric is soaked twice and rolled twice with modification solution, the excess rate is 90%-100%, pre-baked at 80°C for 5 minutes, 180°C Bake for 2 minutes, then wash with water until the residual liquid is neutral, and dry for later use.

3. Planting of magnesium hydroxide crystal seeds on cotton fabric: put 0.5g of the above-mentioned modified cotton fabric into 100ml of the above-mentioned magnesium hydroxide seed crystal solution, and add ammonia water/ammonium chloride buffer solution at the same time to make the system pH The value was kept at 11, and the whole reaction was carried out in a constant temperature water bath at a temperature of 40°C. After 30 minutes, the fabric was taken out and washed with double distilled water until the conductivity of the residue was consistent with that of the double distilled water.

4. Magnesium hydroxide crystals undergo secondary growth: 1) normal temperature stage: the fabric with magnesium hydroxide crystal seeds is dropped into 200ml of magnesium chloride solution with a concentration of 0.1mol/L, and the concentration of 1mol is injected at a rate of 20ml/h. 200ml of ammonia water per L, the whole reaction process is carried out in a constant temperature water bath, the temperature is 40 ℃, and the magnesium hydroxide flake crystals are covered with the surface of the fiber for 20 days at the same temperature. 2) High temperature stage: the normal temperature stage is prepared The fabric is put into 100ml high-temperature secondary growth system, the concentration of magnesium chloride in this system is 0.5mol/L, the concentration of organic base hexamethylenetetramine is 2mol/L, the whole reaction is carried out in a high-temperature and high-pressure tank, and the reaction temperature is : 140°C, reaction time: 15 hours, and finally a continuous crystal film is obtained on the surface of the cotton fabric.

Embodiment three:

1. Preparation of aluminum hydroxide seed crystals: First, add 200ml of double-distilled water into the four-neck bottle, adjust the pH of the system to 10 with ammonia water, and then add ammonia water and chlorine to the system at a speed of 10ml/h at the same time with a constant flow pump Dilute aluminum solution, the concentrations of ammonia water and aluminum chloride are: 0.3mol/L and 0.1mol/L respectively, the feeding time is 2 hours, and the constant temperature reaction is continued for 1 hour. The reaction temperature of the whole process is 25°C, and the particle size is about 10nm. of seed crystals.

2. Citric acid modification of cotton fabric:

Modification liquid composition: maleic acid 100g/L, sodium hypophosphite 60g/L

Modification process: Cotton fabric is dipped twice and rolled twice with the modified liquid, the excess rate is 90%-100%, pre-baked at 80°C for 5 minutes, baked at 180°C for 2 minutes, then washed with water until the residual liquid is neutral, dried for later use .

3. Planting of aluminum hydroxide seed crystals on cotton fabric: put 0.5g of the above-mentioned modified cotton fabric into 100ml of the above-mentioned aluminum hydroxide seed crystal solution, and add ammonia water/ammonium chloride buffer solution at the same time to make the system pH The value was kept at 10, and the whole reaction was carried out in a constant temperature water bath at a temperature of 25°C. After 30 minutes, the fabric was taken out and washed with double distilled water until the conductivity of the residue was consistent with that of the double distilled water.

4. Secondary growth of aluminum hydroxide crystals: put the fabric with aluminum hydroxide seeds into the aluminum chloride solution with a concentration of 0.2mol/L, and feed 180ml with a concentration of 0.8mol/L at a rate of 30ml/h Ammonia water, the whole reaction process is carried out in a constant temperature water bath, the temperature is 25 ° C, aged at the same temperature for 30 days, the aluminum hydroxide flake crystals grow up, and finally a continuous crystal film is obtained on the surface of the fiber/fabric.

Claims (4)

1. A finishing method for fire-resistant and heat-insulating organic fiber fabrics, characterized in that the method may further comprise the steps: ①Preparation of hydroxide seed crystals: add water to the container, and adjust the pH to 7.0-12.0 through alkaline solution; then add alkaline solution and water-soluble The concentrations of magnesium, zinc or aluminum solution, alkaline solution and water-soluble magnesium, zinc or aluminum salt solution are: 0.01mol～1.0mol/L and 0.01mol～0.50mol/L, feeding time is 1～5 hours, continue Constant temperature reaction for 1 to 5 hours, the reaction temperature in the whole process is 20°C to 80°C, and the prepared flaky hydroxide seeds; ② Planting of hydroxide flaky seeds on the surface of organic fiber fabrics: put modified or unmodified organic fibers/fabrics into the above-mentioned hydroxide seed solution, and add ammonia water/ammonium chloride buffer at the same time Solution, keep the pH value of the system constant at 7.0-11.0, and the temperature is 20-60°C; take out the fiber/fabric after 10-60 minutes, and wash with water until the conductivity of the residual liquid is consistent with that of water; ③Secondary growth of flaky hydroxide crystals on the surface of organic fibers: put the fabric with hydroxide seeds into a water-soluble magnesium, zinc or aluminum solution with a concentration of 0.1-0.8mol/L, and use 1- The speed of 30ml/h is passed into the same volume of alkaline solution with a concentration of 0.2-2mol/L, the temperature is 20-80°C, and it is aged at the same temperature for 1-120 days, and finally continuous crystals are obtained on the surface of the fiber/fabric membrane. 2. The finishing method according to claim 1, characterized in that in step ③, a high-temperature stage is added after the step of aging for 1-120 days at a temperature of 20-80°C, and the high-temperature stage The specific steps are: put the fiber/fabric prepared above into the reaction system of water-soluble magnesium, zinc or aluminum solution and alkaline solution, wherein the concentration of magnesium, zinc or aluminum compound is: 0.01-0.5mol/L, alkali The concentration of the active substance is 0.01-2mol/L, the reaction temperature is 120°C-160°C, the reaction time is 6-48 hours, and finally a continuous crystal film is obtained on the surface of the fiber/fabric. 3. The finishing method according to claim 1 or 2, wherein said hydroxide is magnesium hydroxide, aluminum hydroxide or zinc hydroxide; said water-soluble magnesium, zinc or aluminum solution is magnesium soluble salt solution, aluminum soluble salt solution and zinc soluble salt solution; the alkaline solution is ammonia or hexamethylenetetramine solution. 4. finishing method according to claim 3, it is characterized in that the soluble salt solution of described magnesium is magnesium chloride solution; The soluble salt solution of described aluminum is aluminum chloride solution; The soluble salt solution of described zinc is Zinc chloride solution.

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