Lightweight gypsum foaming fireproof coating for steel structure and preparation method of lightweight gypsum foaming fireproof coating

Abstract

The invention belongs to the field of building coatings. The invention provides a light gypsum foaming fireproof coating for a steel structure and a preparation method of the light gypsum foaming fireproof coating, the light gypsum foaming fireproof coating comprises the following components: gypsum powder, pentaerythritol, water, an additive composition and hydrogen peroxide, the additive composition comprises polyvinyl alcohol, cellulose ether, pentaerythritol, sodium molybdate, 1-hydroxyethylidene-1, 1-diphosphonic acid, calcium formate, sodium nitrite, potassium iodide and deionized water. The light gypsum foaming fireproof coating for the steel structure contains 99% or more of inorganic materials, is low in density and high in bonding strength with the steel structure, improves the anti-corrosion effect on the steel structure, performs effective fireproof and heat-insulating protection on the steel structure, is green, harmless and environment-friendly, can tolerate the high temperature of 1700 DEG C, has the fireproof grade of A1 grade, is an A1 grade non-combustible substance, remarkably reduces the heat conductivity coefficient, and is suitable for large-scale popularization and application. The effects of fire insulation and flame retardance are effectively achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of building coatings, and particularly relates to a light-weight gypsum foaming fireproof coating for steel structure and a preparation method thereof. BACKGROUND

[0002] Fireproof coating is a kind of building coating with fireproof function, which has decoration and protection, and is mainly used to improve the fire resistance of materials, has the functions of fireproofing, heat insulation and preventing fire from spreading, and has the function of delaying the expansion of combustion, and is a kind of coating which can prolong the combustion of base material and the destruction of structure.

[0003] According to the main use and use object of the fireproof coating, the fireproof coating can be divided into steel structure fireproof coating, wood structure fireproof coating, decorative fireproof coating, cable fireproof coating, concrete structure fireproof coating and tunnel fireproof coating. According to the dispersion medium, the fireproof coating can be divided into solvent type fireproof coating and water-based type fireproof coating. The former uses organic solvent as the dispersion medium, has good drying performance and construction performance, but may cause certain harm to human body and environment; the latter uses water as the dispersion medium, has better environmental protection performance, but has relatively slow drying speed. According to the fireproof mechanism, the fireproof coating can be divided into intumescent fireproof coating and non-intumescent fireproof coating. The intumescent fireproof coating will expand to form a foam layer when heated, effectively insulating heat and oxygen and delaying the spread of fire; the non-intumescent fireproof coating mainly prevents the spread of fire through its own fire resistance and heat insulation performance. According to the base material, the fireproof coating can be divided into organic fireproof coating, inorganic fireproof coating and organic-inorganic composite fireproof coating. The composite fireproof coating has poor aging resistance and degradation performance, and may not achieve the fireproof effect after being oxidized for a long time, and generates a large amount of toxic smoke. Even if a large amount of flame retardant is added, since the boiling point of the general flame retardant is less than 300 DEG C, the environmental temperature can be as high as 1000-1200 DEG C when fire occurs, and the flame retardant volatilizes, so the fireproof performance is still not ideal.

[0004] As an important fire safety material, fireproof coating plays a crucial role in protecting buildings and people's lives and property. At present, with the acceleration of urbanization and the improvement of building safety awareness, the demand for fireproof coating is increasing. From the market application, steel structure fireproof coating is the main body of the market, and is widely used in high-rise buildings, large workshops and other building structures.

[0005] Fireproof coating technology will continue to develop in the direction of high performance, environmental protection and intelligence. On the one hand, more advanced materials and processes are introduced to improve the fire resistance limit and construction performance of fireproof coating; on the other hand, the awareness of environmental protection and sustainable development is strengthened to promote the development of fireproof coating in the direction of green and harmless.

[0006] The present application aims at providing a light gypsum foaming fireproof coating suitable for steel structure to effectively protect the steel structure from fire and heat insulation according to the fireproof requirements of the fire-fighting market. SUMMARY

[0007] To solve the problems in the prior art, the present application provides a light gypsum foaming fireproof coating for steel structure and a preparation method thereof.

[0008] The present application provides a light gypsum foaming fireproof coating for steel structure, which comprises gypsum powder, pentaerythritol, water, an additive composition and hydrogen peroxide, The additive composition comprises polyvinyl alcohol, cellulose ether, pentaerythritol, sodium molybdate, hydroxyethylidene diphosphonic acid, calcium formate, sodium nitrite, potassium iodide and deionized water.

[0009] The polyvinyl alcohol in the additive composition is used as a film-forming material for the gypsum foam, and together with the cellulose ether and pentaerythritol, it improves the strength of the foaming gypsum; the sodium molybdate is used as a flame retardant; the hydroxyethylidene diphosphonic acid delays the setting time of the gypsum, making the foam structure stable; the calcium formate can promote the setting and hardening process of the gypsum, forming a good crystal structure and improving the hardness and durability of the gypsum, and further improving the overall performance of the material; and the sodium nitrite enhances the adhesion of the foaming gypsum to the metal and prevents corrosion of the metal.

[0010] The additive composition comprises the following components in the following mass percentages: Polyvinyl alcohol 15-50% Cellulose ether 5-10% Pentaerythritol 5-10% Sodium molybdate 0.1-0.5% Hydroxyethylidene diphosphonic acid 10-15% Calcium formate 10-20% Sodium nitrite 5-20% Potassium iodide 1-10% Deionized water 15-50% The sum of the mass percentages of the above components is 100%.

[0011] Preferably, the cellulose ether is hydroxypropyl methyl cellulose ether.

[0012] The light gypsum foaming fireproof coating for steel structure of the present application has the following mass percentage of components, Gypsum powder 40-60% Water 30-50% Pentaerythritol 0.5-5% Additive composition 0.5-5% Hydrogen peroxide 0.1-2% The sum of the mass percentages of the above components is 100%.

[0013] The present application also provides a preparation method of the light gypsum foaming fireproof coating for steel structure, comprising the following steps, (1) Preparation of additive composition: weigh the components of the additive according to the above ratio, add deionized water into a reaction container, add sodium molybdate and calcium formate, and mix uniformly, then add polyvinyl alcohol, cellulose ether and pentaerythritol, and mix uniformly, then add hydroxyethylidene diphosphonic acid, sodium nitrite and potassium iodide, and mix uniformly to obtain the additive composition; (2) Weigh the components according to the above ratio, disperse the water and pentaerythritol uniformly, then add the additive composition and disperse uniformly, then add gypsum powder and mix uniformly, and finally add hydrogen peroxide, and mix uniformly to obtain the light gypsum foaming fireproof coating.

[0014] Compared with the prior art, the present application has the following beneficial effects: (1) The light gypsum foaming fireproof coating of the present application has high stability of foaming bubble structure, small density, light weight, and high bonding strength with steel structure, compared with the existing coating; (2) The corrosion resistance of the steel structure material is improved, and the steel structure material is protected, and no blistering and peeling phenomenon of the coating is found after salt mist corrosion test; (3) The fireproof coating has high high-temperature resistance and fireproof ability, can resist high temperature up to 1700℃, has A1 grade fireproof ability, is an A1 grade non-combustible material, is a poor conductor of heat, and has significantly reduced thermal conductivity, and effectively plays a fireproof and flame-retardant role; (4) The fireproof coating is an inorganic material, does not produce harmful gases to the human body when a fire occurs, is green, environmentally friendly, natural and non-toxic, can be recycled after the steel structure material is scrapped, and does not pollute the environment; (5) The coating has a short surface drying time of 0.5-1 hour, and is convenient to construct. DETAILED DESCRIPTION

[0015] The technical solutions of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0016] Embodiment 1 1. Preparation of additive composition The polyvinyl alcohol, cellulose ether, pentaerythritol, sodium molybdate, hydroxyethylidene diphosphonic acid, calcium formate, sodium nitrite and potassium iodide were weighed according to the mass percentage, and then deionized water was added.

[0017] The deionized water was added to the reaction container, and then the sodium molybdate, calcium formate, polyvinyl alcohol, cellulose ether and pentaerythritol were added and uniformly dispersed. After the cellulose ether and pentaerythritol were fully wetted, the hydroxyethylidene diphosphonic acid, sodium nitrite and potassium iodide were added and uniformly dispersed to obtain the additive composition. The cellulose ether was hydroxypropyl methyl cellulose ether.

[0018] 2. Preparation of lightweight gypsum foaming fireproof coating The gypsum powder, water, pentaerythritol and additive composition were weighed according to the mass percentage, and then the hydrogen peroxide was added.

[0019] The water and pentaerythritol were uniformly dispersed, and then the additive composition was added and uniformly dispersed. Then the gypsum powder was added and uniformly dispersed, and finally the hydrogen peroxide was added. After stirring, the thick-coated lightweight gypsum foaming fireproof coating was obtained.

[0020] The lightweight gypsum foaming fireproof coating was coated on the steel structure by spraying or scraping.

[0021] Comparative Example 1 The gypsum powder, water and pentaerythritol were weighed according to the mass percentage, and then the hydrogen peroxide was added. The gypsum fireproof coating was obtained after stirring. The difference between the comparative example and the embodiment 1 is that the additive composition is not added in the comparative example.

[0022] Performance test 1. Test method Adhesion strength test: the adhesion between the coating and the substrate was measured by using a pull tester; Coating thickness measurement: the non-destructive thickness detection of the fireproof coating was performed by using a thickness gauge to ensure that the coating was uniform and met the design requirements. The thickness gauge included a magnetic thickness gauge and an ultrasonic thickness gauge.

[0023] Fire resistance test: By placing the steel structure coated with fireproof paint in a high temperature environment, observe and record the fire resistance time to test whether the coating can achieve the expected fireproof effect.

[0024] Drying time (surface dry): Record the surface dry time with a timer after spraying.

[0025] Initial dry cracking resistance: Observe the cracking of the coating after initial drying and measure it with a caliper or calipers.

[0026] Specific reference can be made to GB 14907-2018.

[0027] The salt spray corrosion resistance test method is GB 15930-2007.

[0028] The test results of Example 1 and Comparative Example 1 are shown in the following table:

[0029] As can be seen from the test data in the table, compared with Comparative Example 1, Example 1 has high foaming foam stability, large foaming volume, small density, light weight, and significantly reduced thermal conductivity due to the addition of the additive composition; it has high adhesion strength to the steel structure, enhances the corrosion protection effect on the steel structure, and the salt spray corrosion resistant coating has no blistering and peeling phenomenon; and the surface dry time is shortened, and the high temperature and fire resistance are strong.

[0030] Therefore, the lightweight gypsum foaming fireproof paint for steel structure has small density, light weight, good adhesion to the steel structure, significantly improves the corrosion resistance of the steel structure material, and has no blistering and peeling phenomenon after salt spray corrosion test, which protects the steel structure material. It has strong high temperature and fire resistance, can withstand high temperature up to 1700℃, and has A1 grade fireproofing, is A1 grade non-combustible material, is a poor conductor of heat, has significantly reduced thermal conductivity, effectively plays a fireproofing and flame-retardant role, is green, environmentally friendly, natural and non-toxic, and can be recycled after the steel structure material is scrapped, without causing environmental pollution. The fireproof paint is an inorganic material, which will not produce harmful gases to the human body in case of fire, has short surface dry time (0.5-1 hour), and is convenient to construct.

[0031] The above examples are only for illustration of the present application, and are not a limitation of the present application. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the present application, therefore all equivalent technical solutions should belong to the scope of the present application, which should be limited by the claims.

Claims

1. A lightweight gypsum foamed fireproof coating for steel structures, characterized in that, The components thereof include gypsum powder, pentaerythritol, water, additive composition and hydrogen peroxide, The additive composition includes polyvinyl alcohol, cellulose ether, pentaerythritol, sodium molybdate, hydroxyethylidene diphosphonic acid, calcium formate, sodium nitrite, potassium iodide and deionized water.

2. A lightweight gypsum-based foamed fireproof coating for steel structures according to claim 1, characterized in that, The mass percentage of the components of the additive composition is, Polyvinyl alcohol 15-50% Cellulose ether 5-10% Pentaerythritol 5-10% Sodium molybdate 0.1-0.5% Hydroxyethylidene diphosphonic acid 10-15% Calcium formate 10-20% Sodium nitrite 5-20% Potassium iodide 1-10% Deionized water 15-50% The sum of the mass percentages of the above components is 100%.

3. A lightweight gypsum-based foamed fireproof coating for steel structures according to claim 2, characterized in that, The mass percentage of the components is, Gypsum powder 40-60% Water 30-50% Pentaerythritol 0.5-5% Additive composition 0.5-5% Hydrogen peroxide 0.1-2% The sum of the mass percentages of the above components is 100%.

4. A preparation method of the light gypsum foaming fireproof coating for steel structure according to claim 1, comprising the following steps, (1) Preparation of additive composition: weigh the components according to the proportion, add deionized water into the container, add sodium molybdate and calcium formate, disperse and mix uniformly, add polyvinyl alcohol, cellulose ether and pentaerythritol, disperse and mix uniformly after all are wetted, add hydroxyethylidene diphosphonic acid, sodium nitrite and potassium iodide, disperse and mix uniformly, and obtain the additive composition; (2) Weigh the components according to the proportion, disperse and mix uniformly the water and pentaerythritol, then add the additive composition and disperse uniformly, then add gypsum powder and disperse and mix uniformly, finally add hydrogen peroxide, stir uniformly, and obtain the light gypsum foaming fireproof coating.

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