CN104327619A - Water-based intumescent profiled steel structure fire-resistant paint and preparation method thereof - Google Patents

Abstract

The invention relates to a water-based intumescent steel structure fireproof coating and a preparation method thereof. The coating components include emulsion, ammonium polyphosphate, melamine, pentaerythritol, nano-titanium dioxide, sericite, graphene oxide, defoamer, wetting and dispersing agent, fluid Emollient and water. Preparation method: First, ammonium polyphosphate, melamine, pentaerythritol, nano-titanium dioxide, sericite, and graphene oxide are ground and mixed thoroughly, then the ground powder is gradually added to the emulsion diluted with water, mechanically stirred by a mechanical stirrer, and the material is discharged to obtain fire retardant coating. The obtained coating is uniform without agglomeration, has good initial drying crack resistance, no cracks, good adhesion, good combustion expansion, high strength of the carbon layer, and various technical indicators all meet or exceed national standards.

Description

Water-based intumescent steel structure fireproof coating and preparation method thereof

technical field

The invention relates to a fireproof coating, in particular to a water-based intumescent steel structure fireproof coating and a preparation method thereof.

Background technique

The steel structure itself has the advantages of light weight, high strength, high rigidity, good toughness, short construction period, and high degree of mechanization. With the rapid economic development and the gradual improvement of people's needs, steel structures have been widely used in large stadiums, opera houses, bridges, high-rise and super high-rise buildings, etc. Although steel is non-combustible, its fire resistance is extremely poor, and the strength of steel structures decreases rapidly as the temperature rises. When the temperature reaches 350°C, 500°C, and 600°C, its strength decreases by 1/3, 1/2, and 2/3 respectively, and the critical temperature at which ordinary building steel loses static equilibrium stability under full load is about 540°C , The temperature of the unprotected steel structure will rise above the critical temperature in only 0.25 hours, causing the steel structure to bend and deform, and the building to collapse.

The use of fire retardant coatings is one of the more economical and effective measures in the fire protection of steel structures. According to the thickness of the coating, fireproof coatings can be divided into thick type (7-45mm), thin type (3-7mm) and ultra-thin type (≤3mm); according to the different solvents used, they can be divided into water-based fireproof coatings and solvent-based fireproofing coatings. coating. Water-based fire retardant coatings have the advantages of non-toxic, solvent-free odor, and no yellowing. Compared with solvent-based fire-resistant coatings, they are more wear-resistant, more environmentally friendly, more convenient to construct, and more economical. Therefore, water-based fire-resistant coatings have been more and more widely used.

Water-based intumescent steel structure fireproof coatings are mainly composed of water-based base materials (chlorine partial emulsion, pure acrylic emulsion, styrene-acrylic emulsion, etc.), intumescent flame retardant system (ammonium polyphosphate, melamine, pentaerythritol), fillers and additives. The coating expands and carbonizes under the action of flame or high temperature, forming an expanded carbon layer that is several times or even ten times thicker than the original thickness. On the other hand, in a series of physical and chemical processes such as heat softening, melting, and decomposition and expansion of the expansion flame retardant system, the coating absorbs part of the heat and plays a certain role in delaying the temperature rise of the steel structure. . At the same time, the non-combustible gas produced under high temperature conditions also effectively inhibits the progress of combustion.

Research on fire retardant coatings abroad started earlier, and some existing commercial products have been widely used. For example, the Firefilm II water-based fireproof coating of Canada AD Fire Protection Co., Ltd., when the coating thickness is 3.37mm, the fire resistance limit reaches 180min; mm, the fire resistance limit reached 63min [Gan Ziqiong and other coatings industry, 2004, 34 (3), 42-45]. In China, since the Sichuan Fire Research Institute developed the first steel structure fireproof coating - LG steel structure fireproof coating in 1984, solvent-based fireproof coatings have developed rapidly in China. Since the 1990s, with the improvement of people's environmental awareness and technological level Improvement, the rapid development of water-based fire retardant coatings. The B60-2 intumescent water-based fireproof coating developed by Sichuan Fire Research Institute; the FSF-1 intumescent water-based fireproof coating developed by Tianjin Fire Research Institute; the B60-4 intumescent water-soluble fireproof coating successfully developed by Shanghai Paint Co., Ltd. Good products [Du Kemin Shanghai Paint, 2010, 48(7), 20-22].

Most of the water-based fireproof coatings currently on the market use a single emulsion as the matrix. The overall performance of the coating is poor, the weather resistance and water resistance are poor, and the carbon layer formed after combustion is loose and easy to fall off, resulting in loss of fireproof performance.

Contents of the invention

Aiming at the above-mentioned defects currently existing in water-based fireproof coatings for steel structures, the present invention provides a formulation and preparation method of a new type of fireproof coatings for steel structures, using composite emulsion as the matrix, and adding graphene oxide and sericite to increase the height of the carbonaceous layer and strength, the fire-resistant and water-resistant properties of the prepared fire-resistant coatings were tested.

The purpose of the present invention is to provide a novel water-based intumescent steel structure fireproof coating and its preparation method. The coating not only has good fireproof performance, but also has good adhesion, water resistance, weather resistance and other advantages.

A novel water-based environment-friendly steel structure fireproof coating of the present invention comprises the following components and mass fractions: emulsion, 20-40%; water, 15-35%; flame retardant system, 30-50%; nano titanium dioxide, 0.5-3 %; Filler, 3-10%; Auxiliary, 0.1-2%.

A further preferred solution of the present invention is: the emulsion is one or two of chlorine partial emulsion, pure acrylic 2468 emulsion, pure acrylic AC261P emulsion, styrene-acrylic 996 emulsion, and styrene-acrylic 277NS emulsion.

A further preferred solution of the present invention is: the flame retardant system is ammonium polyphosphate, melamine, pentaerythritol compound system, and its proportioning ratio is 4:3:3, 5:3:2, 6:2:2, 4:4 : 2. Wherein the degree of polymerization of ammonium polyphosphate n=1000.

A further preferred solution of the present invention is: the filler is a composite system of graphene oxide and sericite. Described graphene oxide is prepared by following process: take the NaNO _of 1.5g by weighing Solid is dissolved in the concentrated sulfuric acid of 69ml 98%, mixed solution is placed in ice-water bath while magnetic stirring 15min makes NaNO _Solid fully dissolves (reaction temperature control at 0°C); weigh 3.0g of natural graphite and add it to the above mixture, stir for 15min (the temperature is also maintained at 0°C); then, slowly add a certain amount of potassium permanganate, and control the reaction temperature during the addition process Not exceeding 20°C, stir for 20min, adjust the temperature to 35°C and continue stirring for 1h; then add 138ml of deionized water to the mixture and raise the temperature to 98°C, stir for 15min, add 420ml of deionized water again and add 30ml of 30% H ₂ O ₂ to reduce the remaining oxidant, so that the solution becomes bright yellow; turn off the heating and filter while hot, while filtering, wash with 5% hydrochloric acid solution to remove MnO ₂ in the solution; filter the obtained Dilute the filter cake with a certain amount of deionized water, and then perform ultrasonic and centrifugation; take the supernatant obtained after centrifugation, add a certain amount of concentrated hydrochloric acid and deionized water, and centrifuge again after fully stirring; the lower layer obtained after centrifugation The viscous substance was dried in an oven at 65° C. to obtain graphene oxide.

A further preferred solution of the present invention is: the auxiliary agent includes a defoamer, a wetting and dispersing agent, and a thickening and leveling agent.

The preparation method of the above-mentioned water-based intumescent steel structure fireproof coating is carried out batching according to the above components, and its steps are:

Step 1: Weigh the intumescent flame retardant system, filler, and nano-titanium dioxide, and grind them thoroughly in a mortar to obtain solid powder.

Step 2: Weigh the emulsion, mix it well with water, add some additives, gradually add the solid powder obtained in Step 1 into the liquid, stir with a glass rod during the addition, let stand, stir mechanically, and gradually add defoaming during the stirring process Agent, discharge.

A further preferred solution of the present invention is: the mechanical stirring condition is 200-2000r/min stirring for 0.5-2h.

The method adopted in the invention can obtain the water-based intumescent steel structure fireproof coating only through grinding, mixing and stirring, has the characteristics of simple process, low material preparation cost, no environmental pollution and the like, and is easy to realize large-scale preparation.

The invention adopts the compound emulsion as the matrix, and adds graphene oxide and sericite at the same time. After the coating is burned, the carbonaceous layer has high expansion height and high strength, and the coating has good fire and water resistance. The performance meets the requirements of GB 14907-2002, and the steel plate temperature is 260°C after being heated for 60 minutes.

Description of drawings

Accompanying drawing 1 is the scanning electron microscope (SEM) picture of the expanded carbonaceous layer after coating is heated.

Accompanying drawing 2 is the digital photo figure of the expanded carbonaceous layer after coating is heated.

Accompanying drawing 3 is the back temperature curve of the steel plate during the fire resistance test of the coating.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the present invention is described in more detail

Example 1

First prepare graphene oxide, the preparation process is as follows: take by weighing 1.5g of NaNO ₃ solids are dissolved in the vitriol oil of 69ml98%, the mixed solution is placed in ice-water bath while magnetic stirring 15min makes NaNO ₃ solids fully dissolve (reaction temperature is controlled at 0°C); weighing 3.0g of natural graphite was added to the above mixed solution, and stirred for 15min (the temperature was also maintained at 0°C); then, a certain amount of potassium permanganate was slowly added, and the reaction temperature was controlled during the addition process. Over 20°C, stir for 20min, adjust the temperature to 35°C and continue stirring for 1h; then add 138ml of deionized water to the mixture and raise the temperature to 98°C, stir for 15min, add 420ml of deionized water again and add 30ml of 30% H ₂ O ₂ to reduce the residual oxidant, so that the solution becomes bright yellow; turn off the heating and filter while hot, while filtering, wash with 5% hydrochloric acid solution to remove MnO ₂ in the solution; Dilute the cake with a certain amount of deionized water, and then perform ultrasonic and centrifugation treatment; take the supernatant obtained after centrifugation, add a certain amount of concentrated hydrochloric acid and deionized water, and centrifuge again after fully stirring; the viscous lower layer obtained after centrifugation The material was dried in an oven at 65°C to obtain graphene oxide.

Take by weighing 16.0g ammonium polyphosphate, 12.0g melamine, 12.0g pentaerythritol according to mass ratio 4: 3: 3, weigh graphene oxide 5.0g, sericite 3.0g, nano titanium dioxide 1.5g, the solid powder that weighs is mixed, Grind thoroughly with a mortar and pestle. Weigh 31.5g of chlorine partial emulsion and 3.5g of pure acrylic AC261P emulsion according to the mass ratio of 9:1, add 25.0g of deionized water, 1.0g of wetting agent EDSPLAN482, 1 drop of defoamer BMC-806, and mix thoroughly. Gradually add the ground solid powder into the diluted emulsion, stir with a glass rod while adding, stir with a mechanical stirrer at 200r/min for 10min, and at 800r/min for 90min to obtain the coating, add 2 drops of defoamer BMC-806.

The obtained coating is uniform without agglomeration, has good initial drying crack resistance, no cracks, and good water resistance; the coating is evenly painted on the steel plate to measure its fire resistance limit. When the thickness is 2.5mm, its fire resistance performance reaches and exceeds GB 14907 -2002 regulation.

As can be seen from the scanning electron microscope (SEM) image in Figure 1 and the digital photo in Figure 2, the carbonaceous layer formed after the paint is burned has a high expansion height, is uniform and dense, and has good adhesion to the steel plate.

As can be seen from the back temperature curve of the steel plate during the coating fire resistance test in Figure 3, when the thickness is 2.5mm, its fire resistance performance meets the requirements of GB 14907-2002, and the temperature of the steel plate is 260°C after being heated for 60 minutes.

Example 2

The graphene oxide preparation process is the same as in Example 1. Take by weighing 20.0g ammonium polyphosphate, 12.0g melamine, 8.0g pentaerythritol according to the mass ratio of 5:3:2, weigh 6.0g graphene oxide, 2.0g sericite, 1.5g nano-titanium dioxide, mix the weighed solid powder, Grind thoroughly with a mortar and pestle. Weigh 25.0g of chlorine partial emulsion, add 25.0g of deionized water, 1.0g of wetting agent METOLAT288, 1 drop of defoamer BYK-088, and mix well. Gradually add the ground solid powder into the diluted emulsion, stir with a glass rod while adding, stir with a mechanical stirrer at 800r/min for 60min, and at 1100r/min for 30min to obtain the coating, add 2 drops of defoamer BYK-088.

The obtained coating is uniform without agglomeration, has good initial drying crack resistance, no cracks, and good water resistance; the coating is evenly painted on the steel plate to measure its fire resistance limit. When the thickness is 2.5mm, its fire resistance performance reaches and exceeds GB 14907 -2002 regulation.

Example 3

The graphene oxide preparation process is the same as in Example 2. Take by weighing 16.0g ammonium polyphosphate, 16.0g melamine, 8.0g pentaerythritol according to mass ratio 4:4:2, weigh graphene oxide 4.0g, sericite 4.0g, nano-titanium dioxide 1.5g, the solid powder that weighs is mixed, Grind thoroughly with a mortar and pestle. Weigh 22.0g of chlorine partial emulsion and 3.0g of pure acrylic AC261P emulsion according to the mass ratio of 22:3, add 25.0g of deionized water, 1.0g of wetting agent EDSPLAN482, 1 drop of defoamer BMC-806, and mix thoroughly. Gradually add the ground solid powder into the diluted emulsion, stir with a glass rod while adding, stir with a mechanical stirrer at 200r/min for 20min, and at 800r/min for 60min to obtain the coating. During the stirring process Add 2 drops of defoamer BMC-806.

The obtained coating is uniform without agglomeration, has good initial drying crack resistance, no cracks, and good water resistance; the coating is evenly painted on the steel plate to measure its fire resistance limit. When the thickness is 2.5mm, its fire resistance performance reaches and exceeds GB 14907 -2002 regulation.

Example 4

The graphene oxide preparation process is the same as in Example 3. Weigh 20.0g ammonium polyphosphate (n=1000), 12.0g melamine, 8.0g pentaerythritol according to the mass ratio of 5:3:2, weigh 5.0g graphene oxide, 3.0g sericite, and 1.5g nano-titanium dioxide. The solid powder is mixed and thoroughly ground with a mortar. Weigh 12.5g of chlorine partial emulsion and 12.5g of styrene-acrylic 996 emulsion according to the mass ratio of 1:1, add 25.0g of deionized water, 1.0g of wetting agent EDSPLAN482, 1 drop of defoamer BYK-088, and mix thoroughly. Gradually add the ground solid powder into the diluted emulsion, stir with a glass rod while adding, stir with a mechanical stirrer at 200r/min for 10min, and at 800r/min for 90min to obtain the coating, add 2 drops of defoamer BYK-088.

The obtained coating is uniform without agglomeration, has good initial drying crack resistance, no cracks, and good water resistance; the coating is evenly painted on the steel plate to measure its fire resistance limit. When the thickness is 2.5mm, its fire resistance performance reaches and exceeds GB 14907 -2002 regulation.

Preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the described embodiments, and those skilled in the art can also make various equivalent modifications or replacements without departing from the spirit of the present invention. These equivalent modifications or replacements are all within the scope defined by the claims of the present application.

Claims (9)

1. a novel aqueous expansion steel-structure fireproofing coating, is characterized in that, comprises the content of following component and massfraction: emulsion, 20-40%; Water, 15-35%; Flame-retardant system, 30-50%; Nano titanium oxide, 0.5-3%; Filler, 3-10%; Auxiliary agent, 0.1-2%.

2. water expansion steel structure fire-proof paint according to claim 1, is characterized in that, described emulsion be selected from chlorine partial emulsion, pure third 2468 emulsion, pure third AC261P emulsion, phenylpropyl alcohol 996 emulsion, phenylpropyl alcohol 277NS emulsion one or both.

3. water expansion steel structure fire-proof paint according to claim 1, it is characterized in that, described flame-retardant system is selected from ammonium polyphosphate, trimeric cyanamide, tetramethylolmethane, and its proportioning is 4: 3: 3,5: 3: 2,5: 4: 1,6: 2: 2,4: 4: 2.The polymerization degree of described ammonium polyphosphate is 1000.

4. water expansion steel structure fire-proof paint according to claim 1, it is characterized in that, described nano titanium oxide particle diameter is 40nm.

5. water expansion steel structure fire-proof paint according to claim 1, it is characterized in that, described filler is the compound system of graphene oxide and sericite.

6. water expansion steel structure fire-proof paint according to claim 5, it is characterized in that, described graphene oxide is prepared by following technique: the NaNO taking 1.5g ₃solid is dissolved in the vitriol oil of 69ml 98%, mixed solution is placed in ice-water bath simultaneously magnetic agitation 15min make NaNO ₃solid fully dissolves (temperature of reaction controls at 0 DEG C); The natural graphite weighing 3.0g joins in above-mentioned mixed solution, stirs 15min (temperature also maintains 0 DEG C); Subsequently, slowly add a certain amount of potassium permanganate, in adition process, control temperature of reaction be no more than 20 DEG C, stir 20min, temperature is transferred to 35 DEG C and continues to stir 1h; Then in mixed solution, add the deionized water of 138ml and be warming up to 98 DEG C, stirring 15min, again add the deionized water of 420ml and add the H of 30ml 30% ₂o ₂reduce remaining oxygenant, make solution become glassy yellow; Turn off heating and filtered while hot, with the hydrochloric acid soln washing of 5% while filtering, the MnO in removing solution ₂; The filter cake obtained after filtration is diluted with a certain amount of deionized water, then carries out ultrasonic and centrifugal treating; Get centrifugal after the supernatant liquid that obtains, add a certain amount of concentrated hydrochloric acid and deionized water, recentrifuge after fully stirring; The baking oven that the lower floor's viscous substance obtained after centrifugal is placed in 65 DEG C is dried, obtains graphene oxide.

7. water expansion steel structure fire-proof paint according to claim 1, it is characterized in that, described auxiliary agent comprises defoamer (BYK-088, BMC-806), wetting dispersing agent (LOPON895, METOLAT288, METOLAT388 or EDSPLAN482), thickening leveling agent (TAFIGEL PUR42).

8. the preparation method of water expansion steel structure fire-proof paint according to claim 1, is characterized in that comprising the following steps:

Step one: take Intumescent Retardant System, filler, nano titanium oxide, fully grinds in mortar, obtains pressed powder.

Step 2: take emulsion, water fully mixes, and adds part of auxiliary, and pressed powder step one obtained joins in liquid gradually, and stir with glass stick in adition process, leave standstill, mechanical stirring, progressively adds defoamer in whipping process, discharging.

9. the preparation method of water expansion steel structure fire-proof paint according to claim 6, it is characterized in that in step 2, described mechanical agitation for stir 0.5-2h under 200-2000r/min condition.