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CN-122011911-A - Polyurea-based water-based expansion type steel structure fireproof coating and preparation method thereof

CN122011911ACN 122011911 ACN122011911 ACN 122011911ACN-122011911-A

Abstract

The invention relates to the field of coatings, in particular to a polyurea-based water-based expansion type steel structure fireproof coating and a preparation method thereof; the components in parts by weight are as follows: 15-30 parts of aqueous polyurea, 20-30 parts of ammonium polyphosphate, 8-10 parts of melamine, 8-10 parts of pentaerythritol, 1-6 parts of synergist, 8-20 parts of titanium dioxide, 1-4 parts of anhydrous calcium sulfate whisker, 1-3 parts of auxiliary agent and a proper amount of water; the invention adopts self-made aqueous polyurea as a base material, adopts ammonium polyphosphate, melamine and pentaerythritol as an intumescent flame-retardant system, sets the proportion and total addition amount of the three materials, adds a synergist to further form a quaternary intumescent system of B-P-C-N, and adds inorganic high-temperature resistant pigment rutile type titanium dioxide as a reinforcing filler, and the inorganic high-temperature resistant pigment rutile type titanium dioxide is added to form an intumescent carbon layer when meeting fire, so that the expansion ratio is moderate, the carbon layer is more compact, the impact on hot air flow can be effectively exerted, and the molecular structure contains urea groups, chemical bonding hydrophilic chains and no small molecule migration, so that the flame-retardant waterborne polyurethane has good water resistance.

Inventors

  • ZHOU JIANXIN
  • CHEN MINGZHENG
  • ZHANG MINGJIE
  • ZHANG MENGFEI
  • Bian Letian

Assignees

  • 江苏兰陵高分子材料有限公司

Dates

Publication Date
20260512
Application Date
20260211

Claims (10)

  1. 1. The polyurea-based water-based intumescent steel structure fireproof coating is characterized by comprising, by weight, 15-30 parts of water-based polyurea, 20-30 parts of ammonium polyphosphate, 8-10 parts of melamine, 8-10 parts of pentaerythritol, 1-6 parts of a synergist, 8-20 parts of titanium dioxide, 1-4 parts of anhydrous calcium sulfate whisker, 1-3 parts of an auxiliary agent and a proper amount of water.
  2. 2. The polyurea-based water-based intumescent steel structure fireproof coating according to claim 1 is characterized in that each part of the water-based polyurea comprises, by weight, 60-65 parts of polypropylene glycol, 30-35 parts of polyethylene glycol, 40-50 parts of isophorone diisocyanate, 20-30 parts of water-soluble amino-terminated polyether, 20-30 parts of acetone and 120-130 parts of deionized water.
  3. 3. The polyurea-based aqueous intumescent steel structure fire protection coating of claim 2 wherein the water soluble amine terminated polyether has a relative molecular mass of 2000 to 2500 and a functionality of 2.
  4. 4. The polyurea-based aqueous intumescent steel structure fire retardant coating according to claim 1, wherein the synergist is a mixture of zinc borate and boron phosphate modified by a silane coupling agent.
  5. 5. The polyurea-based aqueous intumescent steel structure fire retardant coating of claim 4 wherein the mass ratio of said zinc borate to said boron phosphate is (4:1) - (8:1).
  6. 6. The polyurea-based aqueous intumescent steel structure fire retardant coating of claim 1, wherein the auxiliary comprises at least one of a dispersant, a pH regulator, a defoamer, and a thickener.
  7. 7. A method for preparing the polyurea-based water-based intumescent steel structure fireproof coating as claimed in any one of claims 1 to 6, which is characterized by comprising the steps of weighing part of auxiliary agents, mixing with deionized water, dispersing at a speed of 500r/min, adding a synergistic agent and titanium dioxide, dispersing and grinding at 1500r/min until fineness is qualified, adding melamine, pentaerythritol, ammonium polyphosphate and anhydrous calcium sulfate whisker, dispersing at 1000r/min, finally adding water-based polyurea and the rest of auxiliary agents, and stirring uniformly at 500r/min to obtain the polyurea-based water-based intumescent steel structure fireproof coating.
  8. 8. The method of preparing as claimed in claim 7, wherein the step of preparing the aqueous polyurea comprises: s1, adding polypropylene glycol and polyethylene glycol into a dry reaction container, carrying out vacuum dehydration treatment, stirring at 500r/min under an inert atmosphere, and slowly adding isophorone diisocyanate to react to obtain a prepolymer; S2, cooling the prepolymer to 40 ℃, stirring at 1500r/min, slowly adding acetone, and performing dispersion treatment for 40min to obtain a prepolymer emulsion; S3, dissolving water-soluble amino-terminated polyether in water at the temperature of 5 ℃, and stirring and dispersing uniformly at the speed of 500r/min to obtain a water-soluble amino-terminated polyether aqueous solution; S4, slowly dripping the prepolymer emulsion into the water-soluble amino-terminated polyether aqueous solution, and sequentially stirring, distilling, adjusting the solid content and filtering after the dripping is finished to obtain the aqueous polyurea.
  9. 9. The method according to claim 8, wherein in the step S1, the temperature of the vacuum dehydration treatment is 120℃and the reaction time is 3 hours.
  10. 10. The method according to claim 8, wherein in the step S4, the stirring treatment is performed at a speed of 2500r/min for 1-2 hours at a temperature of less than 25 ℃ and the distillation treatment is performed at a temperature of 40 ℃.

Description

Polyurea-based water-based expansion type steel structure fireproof coating and preparation method thereof Technical Field The invention relates to the field of coatings, in particular to a polyurea-based water-based expansion type steel structure fireproof coating and a preparation method thereof. Background In recent years, with the wide application of steel structure buildings in domestic markets, the fireproof performance of the steel structure buildings becomes an important issue of great concern. The steel structure building has the advantages of high strength, light weight, strong deformation resistance, rapid construction, recycling and the like, but has poor fire resistance, which is an unavoidable problem. The bearing capacity of the bare steel can be reduced by 40-45% within 10min in a fire scene, so that the building collapses. Based on the above, the construction of the fireproof paint on the surface of the steel structure is a common method in the fireproof protection of the steel structure. At present, along with the continuous improvement of environmental protection requirements, new VOC emission standards are pushed, such as GB38597-2020 technical requirements for low-volatile organic compound content coating products, GB30981.2-2025 limit on harmful substances in the coating, and the like, and the water-based expansion type steel structure fireproof coating is increasingly used. However, most of film forming substances adopted in the water-based expansion type steel structure fireproof paint in the market are acrylic emulsion, acetic acid tertiary emulsion, acetic acid acrylic emulsion and the like, the strength of the carbon layer polymerization is poor after the coating meets fire, the coating is easy to fall off from the surface of the steel structure under the impact of hot air flow, the fireproof protection is invalid, and the water resistance of the coating is not good. Therefore, there is a need for a fire retardant coating that is effective against thermal current impact and has good water resistance. Disclosure of Invention The invention aims at overcoming the defects in the prior art and provides a polyurea-based water-based expansion type steel structure fireproof coating and a preparation method thereof. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The first aspect of the invention provides a polyurea-based water-based expansion type steel structure fireproof coating, which comprises, by weight, 15-30 parts of water-based polyurea, 20-30 parts of ammonium polyphosphate, 8-10 parts of melamine, 8-10 parts of pentaerythritol, 1-6 parts of a synergist, 8-20 parts of titanium dioxide, 1-4 parts of anhydrous calcium sulfate whisker, 1-3 parts of an auxiliary agent and a proper amount of water. Preferably, each part of the aqueous polyurea comprises, by weight, 60-65 parts of polypropylene glycol, 30-35 parts of polyethylene glycol, 40-50 parts of isophorone diisocyanate, 20-30 parts of water-soluble amino-terminated polyether, 20-30 parts of acetone and 120-130 parts of deionized water. More preferably, the water-soluble amine-terminated polyether has a relative molecular mass of 2000 to 2500 and a functionality of 2. Preferably, the synergist is a mixture of zinc borate modified by a silane coupling agent and boron phosphate. More preferably, the mass ratio of the zinc borate to the boron phosphate is (4:1) - (8:1). Preferably, the auxiliary agent comprises at least one of a dispersing agent, a pH regulator, an antifoaming agent and a thickening agent. The second aspect of the invention provides a preparation method of the polyurea-based water-based expansion type steel structure fireproof coating, which comprises the steps of weighing part of auxiliary agent, mixing with deionized water, dispersing at a speed of 500r/min, adding a synergist and titanium dioxide, dispersing and grinding at 1500r/min until fineness is qualified, adding melamine, pentaerythritol, ammonium polyphosphate and anhydrous calcium sulfate whisker, dispersing at 1000r/min, finally adding water-based polyurea and the rest of auxiliary agent, and stirring uniformly at 500r/min to obtain the polyurea-based water-based expansion type steel structure fireproof coating. Preferably, the preparation step of the aqueous polyurea comprises: s1, adding polypropylene glycol and polyethylene glycol into a dry reaction container, carrying out vacuum dehydration treatment, stirring at 500r/min under an inert atmosphere, and slowly adding isophorone diisocyanate to react to obtain a prepolymer; S2, cooling the prepolymer to 40 ℃, stirring at 1500r/min, slowly adding acetone, and performing dispersion treatment for 40min to obtain a prepolymer emulsion; S3, dissolving water-soluble amino-terminated polyether in water at the temperature of 5 ℃, and stirring and dispersing uniformly at the speed of 500r/min to obtain a water-soluble amino-terminated polyether aqueous solut