Fire retardant coating and preparation method thereof

Abstract

The present invention belongs to the technical field of coatings, and specifically relates to a fire-retardant coating and a preparation method thereof. In the preparation method of the fire-retardant coating of the present invention, a compounded flame retardant is added, wherein the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of the phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.4-0.8. By adding a phytic acid compound and silane modification of pentaerythritol phosphate, the coating has excellent flame retardant and fireproof properties under specific proportion conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and more specifically, relates to a fire-retardant coating and a preparation method thereof. Background Art

[0002] Epoxy resin (EP) has good electrical insulation properties, mechanical properties and bonding strength, as well as the advantages of wide sources and low prices. It is widely used in defense, aerospace, coatings, electronics and construction. However, EP is easily decomposed into low molecular weight combustibles when heated, and releases a large amount of heat, smoke and toxic gases during the combustion process, which not only pollutes the environment, but also causes serious losses to people's production and life. In order to improve the flame retardant properties of EP, it is necessary to add flame retardants to its raw materials to improve its flame retardant properties.

[0003] CN117126585A discloses a high heat flow resistant intumescent fire retardant coating and its preparation method. The high heat flow resistant intumescent fire retardant coating is composed of a topcoat and a primer, wherein the components of the topcoat include, by mass, 50-80 parts of epoxy resin, 20-40 parts of epoxy resin modifier, 10-25 parts of flame retardant, 25-45 parts of carbon forming agent, 20-40 parts of foaming agent, 10-30 parts of refractory fiber, 10-40 parts of inorganic filler, 5-15 parts of curing agent, 5-10 parts of defoaming agent and organic solvent; the components of the primer include, by mass, 70-90 parts of phosphate base material. The intumescent fire retardant coating prepared by the present invention is green and non-toxic, can be cured at room temperature, the viscosity of the coating can be adjusted, the construction method can be sprayed or brushed, the required coating thickness is thin and the bonding strength with the substrate is high, and the excellent and stable flame retardant effect can be improved under high heat flow conditions.

[0004] CN117106362A discloses an intumescent heat-insulating flame-retardant epoxy coating and a preparation method thereof. The intumescent heat-insulating flame-retardant epoxy coating comprises the following raw materials by mass: 100 parts of epoxy resin, 40-120 parts of curing agent, 60-120 parts of diluent, 150-200 parts of flame retardant, 50-100 parts of filler, and 10-30 parts of dispersant. The intumescent heat-insulating flame-retardant epoxy coating has both flame-retardant and heat-insulating effects, can withstand high temperatures of 1300°C without burning through, and has a back temperature below 300°C, and a temperature difference resistance of 1000°C, which overcomes the problem that the current flame-retardant epoxy material is only flame-retardant but not heat-insulating, and can better protect the substrate from high-temperature erosion and damage.

[0005] CN116970325B discloses a fire-retardant coating for buildings and a preparation method thereof. The fire-retardant coating for buildings consists of component A and component B; component A consists of water-soluble epoxy resin, hyperbranched polyglycidol, high modulus potassium silicate, modified expanded graphite, thickener, stabilizer, dispersant, nano-scale inorganic filler and deionized water; component B consists of amino-terminated hyperbranched polyamide, lauryl amphoteric imidazoline and deionized water; the coating prepared by the present invention has an adhesion of 13.2-14.4 MPa, no abnormality in water resistance (immersion for 30 days), no substrate exposure in scrubbing resistance (1000 times), and fire resistance of 141-153 minutes.

[0006] Based on the above content, adding flame retardant to EP can improve the flame retardant and fireproof performance, so the present invention provides a new type of fire retardant coating with excellent flame retardant and fireproof performance. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of the prior art and provide a fire-retardant coating and a preparation method thereof. In the preparation method of the fire-retardant coating of the present invention, a compounded flame retardant is added, wherein the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of the phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.4-0.8. By adding phytic acid compounds and silane modification of pentaerythritol phosphate, the coating has excellent flame retardant and fireproof properties under specific proportion conditions.

[0008] The purpose of the present invention is to provide a method for preparing a fire-retardant coating.

[0009] Another object of the present invention is to provide a fire retardant coating.

[0010] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0011] A method for preparing a fire-retardant coating comprises the following steps: firstly, epoxy resin, flame retardant, dispersant, defoamer, leveling agent, anti-settling agent and deionized water are mixed in a high-speed stirrer, and stirred for 20 to 60 minutes, and then a curing agent is added to the mixture and stirred for 10 to 30 minutes to obtain a green environmentally friendly coating; the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of the phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.4 to 0.8.

[0012] Specifically, the stirring rate is 2000-5000 r / min.

[0013] Specifically, by weight, the epoxy resin is 50-70 parts; the flame retardant is 8-14 parts; the curing agent is 4-6 parts; the dispersant is 1-2 parts; the defoaming agent is 0.5-1.5 parts; the leveling agent is 1-2 parts; the anti-settling agent is 1-2 parts and the water is 28-38 parts.

[0014] In the present invention, preferably, the preparation method of phytic acid-arginine-Co and Mg comprises the following steps:

[0015] Add phytic acid and arginine to deionized water and stir for 30 to 50 minutes at room temperature; then add cobalt salt and magnesium salt, continue stirring for 1 to 3 hours, filter, wash with ethanol for multiple times, then dry and grind to obtain phytic acid-arginine-Co and Mg.

[0016] Further preferably, the molar ratio of the phytic acid, arginine, cobalt salt and magnesium salt is: 1:1:0.01-0.03:0.02-0.04; the cobalt salt is at least one of cobalt nitrate, cobalt chloride and cobalt acetate; the magnesium salt is at least one of magnesium nitrate and magnesium chloride.

[0017] More preferably, the drying is performed at 90-110° C. for 10-18 hours.

[0018] In the present invention, the preferred method for preparing KH-570-PEPA comprises the following steps:

[0019] Pentaerythritol phosphate (PEPA) is added to dioxane, stirred for 10 to 30 minutes to obtain a mixed solution, then heated to a certain temperature, and then KH-570 is added dropwise to the mixed solution, and the pH is adjusted to 3 to 5 with acetic acid, and the heating and stirring are continued for 3 to 5 hours, and then cooled to room temperature, filtered, washed with ethanol and filtered several times, and then dried at 80°C to constant weight to obtain KH-570-PEPA.

[0020] Preferably, the mass ratio of pentaerythritol phosphate to KH-570 is 1:02-0.4.

[0021] More preferably, the certain temperature is 65-85°C.

[0022] A fire retardant coating is prepared based on the above-mentioned method for preparing a fire retardant coating.

[0023] The present invention has the following beneficial effects:

[0024] (1) Phytic acid-arginine salt is prepared by using phytic acid and arginine as raw materials through acid-base neutralization reaction, and then Co and Mg ions are complexed to obtain phytic acid-arginine-Co and Mg, which are added to epoxy resin coating to make it have excellent flame retardant properties.

[0025] (2) Pentaerythritol phosphate (PEPA) has good flame retardant properties, and the flame retardant properties of the coating are further improved by KH-570 modification.

[0026] (3) By compounding phytic acid-arginine-Co and Mg with KH-570-PEPA under specific proportion conditions, the coating has excellent flame retardant properties. DETAILED DESCRIPTION

[0027] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0028] The curing agent is adipic acid dihydrazide; the dispersing agent is BYK-065; the defoaming agent is FoamStarA34; the leveling agent is leveling agent PV88; and the anti-settling agent is hydroxymethyl cellulose.

[0029] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0030] Example 1

[0031] A method for preparing a fire-retardant coating comprises the following steps: firstly, epoxy resin, flame retardant, dispersant, defoamer, leveling agent, anti-settling agent and deionized water are mixed in a high-speed stirrer at a stirring rate of 3500r / min for 40 minutes, and then a curing agent is added to the mixture and the stirring is continued for 20 minutes to obtain a green environmentally friendly coating; the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of the phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.6.

[0032] Among them, by weight, there are 60 parts of epoxy resin; 12 parts of flame retardant; 5 parts of curing agent; 1.5 parts of dispersant; 1 part of defoaming agent; 1.5 parts of leveling agent; 1.5 parts of anti-settling agent and 34 parts of water.

[0033] The preparation method of phytic acid-arginine-Co and Mg comprises the following steps:

[0034] 1 mol of phytic acid and 1 mol of arginine were added to 150 mL of deionized water and stirred at room temperature for 40 min; then 0.02 mol of cobalt nitrate and 0.03 mol of magnesium chloride were added, stirring was continued for 2 h, filtered, washed with ethanol for several times, then dried at 100 ° C for 14 h, and ground to obtain phytic acid-arginine-Co and Mg.

[0035] The preparation method of KH-570-PEPA comprises the following steps:

[0036] 20 g of pentaerythritol phosphate was added to 50 mL of dioxane, stirred for 20 min to obtain a mixed solution, then heated to 75 ° C, and then 6 g of KH-570 was slowly added to the mixed solution, and the pH was adjusted to 4 with acetic acid, and the heating and stirring were continued for 4 h, then cooled to room temperature, filtered, washed with ethanol and filtered several times, and then dried at 80 ° C to constant weight to obtain KH-570-PEPA.

[0037] Example 2

[0038] A method for preparing a fire-retardant coating, characterized in that the preparation method comprises the following steps: firstly, epoxy resin, flame retardant, dispersant, defoamer, leveling agent, anti-settling agent and deionized water are put into a high-speed stirrer for mixing at a stirring rate of 5000r / min for 20 minutes, and then a curing agent is added to the mixture and the stirring is continued for 10 minutes to obtain a green environmentally friendly coating; the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of the phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.8.

[0039] By weight, 70 parts of epoxy resin; 8 parts of flame retardant; 6 parts of curing agent; 1 part of dispersant; 1.5 parts of defoaming agent; 1 part of leveling agent; 2 parts of anti-settling agent and 38 parts of water.

[0040] The preparation method of the phytic acid-arginine-Co and Mg is the same as that in Example 1.

[0041] The preparation method of KH-570-PEPA is the same as that in Example 1.

[0042] Example 3

[0043] A method for preparing a fire-retardant coating, characterized in that the preparation method comprises the following steps: firstly, epoxy resin, flame retardant, dispersant, defoamer, leveling agent, anti-settling agent and deionized water are mixed in a high-speed stirrer at a stirring rate of 2000r / min for 60 minutes, and then a curing agent is added to the mixture and the stirring is continued for 10 minutes to obtain a green environmentally friendly coating; the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of the phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.4.

[0044] By weight, 50 parts of epoxy resin; 14 parts of flame retardant; 4 parts of curing agent; 2 parts of dispersant; 0.5 parts of defoaming agent; 2 parts of leveling agent; 1 part of anti-settling agent and 28 parts of water.

[0045] The preparation method of the phytic acid-arginine-Co and Mg is the same as that in Example 1.

[0046] The preparation method of KH-570-PEPA is the same as that in Example 1.

[0047] Comparative Example 1

[0048] It is basically the same as Example 1, except that it does not contain a flame retardant.

[0049] Comparative Example 2

[0050] It is basically the same as Example 1, except that the flame retardant is only phytic acid-arginine-Co and Mg.

[0051] Comparative Example 3

[0052] It is basically the same as Example 1, except that the flame retardant is only KH-570-PEPA.

[0053] Comparative Example 4

[0054] It is basically the same as Example 1, except that the mass ratio of phytic acid-arginine-Co to KH-570-PEPA is 1:0.6.

[0055] The preparation method of phytic acid-arginine-Co comprises the following steps:

[0056] 1 mol of phytic acid and 1 mol of arginine were added to 150 mL of deionized water and stirred at room temperature for 40 min; then 0.05 mol of cobalt nitrate was added, stirring was continued for 2 h, filtered, washed with ethanol for several times, then dried at 100 °C for 14 h, and ground to obtain phytic acid-arginine-Co.

[0057] Comparative Example 5

[0058] The method is basically the same as Example 1, except that the mass ratio of phytic acid-arginine-Mg to KH-570-PEPA is 1:0.6.

[0059] The preparation method of the phytic acid-arginine-Mg comprises the following steps:

[0060] 1 mol of phytic acid and 1 mol of arginine were added to 150 mL of deionized water and stirred at room temperature for 40 min; then 0.05 mol of magnesium chloride was added, stirring was continued for 2 h, filtered, washed with ethanol for several times, then dried at 100 °C for 14 h, and ground to obtain phytic acid-arginine-Co and Mg.

[0061] Comparative Example 6

[0062] It is basically the same as Example 1, except that: the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.2.

[0063] Comparative Example 7

[0064] It is basically the same as Example 1, except that: the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:1.

[0065] Comparative Example 8

[0066] It is basically the same as Example 1, except that KH-550 is used instead of KH-570.

[0067] The flame retardant properties of Examples 1-3 and Comparative Examples 1-7 were tested. The specific test results are shown in Table 1:

[0068] Among them, the limiting oxygen index (LOI value) is tested using GB / T 2406-2009;

[0069] Table 1:

[0070] LOI value (%) LOI value (%) Example 1 37.8 Comparative Example 4 35.3 Example 2 37.1 Comparative Example 5 34.5 Example 3 36.8 Comparative Example 6 34.1 Comparative Example 1 22.3 Comparative Example 7 33.6 Comparative Example 2 33.4 Comparative Example 8 36.2 Comparative Example 3 23.6

[0071] It can be seen from Table 1 that the flame retardant properties of the coating can be effectively improved by adding flame retardants. By comparing Example 1 with Comparative Examples 2-3 and Comparative Examples 6-7, it can be seen that phytic acid-arginine-Co and Mg have a synergistic effect with KH-570-PEPA under specific ratio conditions; by comparing Example 1 with Comparative Examples 4-5, it can be seen that the complexed metals Co and Mg interact with each other in promoting flame retardant properties. By comparing Example 1 with Comparative Example 8, it can be seen that KH-570 can significantly improve the flame retardant properties of the coating relative to KH-550.

[0072] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a fire retardant coating, characterized in that: The preparation method comprises the following steps: firstly, epoxy resin, flame retardant, dispersant, defoamer, leveling agent, anti-settling agent and deionized water are put into a high-speed mixer and mixed, and stirred for 20 to 60 minutes, and then a curing agent is added to the mixture and stirred for 10 to 30 minutes to obtain a green environmentally friendly coating; the flame retardant is a combination of phytic acid-arginine-Co and Mg and KH-570-PEPA, and the mass ratio of the phytic acid-arginine-Co and Mg to KH-570-PEPA is 1:0.4 to 0.8; the preparation method of phytic acid-arginine-Co and Mg comprises the following steps: adding phytic acid and arginine to deionized water and stirring at room temperature; stirring at room temperature for 30 to 50 minutes; then adding cobalt salt and magnesium salt, continuing stirring for 1 to 3 hours, filtering, washing with ethanol for multiple times, then drying, grinding, and obtaining phytic acid-arginine-Co and Mg; the preparation method of KH-570-PEPA comprises the following steps: adding pentaerythritol phosphate to dioxane, stirring for 10 to 30 minutes to obtain a mixed solution, then heating to a certain temperature, then dropping KH-570 into the mixed solution, and adjusting the pH to 3 to 5 with acetic acid, continuing heating and stirring for 3 to 5 hours, then cooling to room temperature, filtering, washing with ethanol and suction filtering for multiple times, and then drying at 80°C to constant weight to obtain KH-570-PEPA.

2. The method for preparing a fire retardant coating according to claim 1, characterized in that: The stirring rate is 2000-5000 r / min.

3. The method for preparing a fire retardant coating according to claim 1, characterized in that: By weight, 50-70 parts of epoxy resin; 8-14 parts of flame retardant; 4-6 parts of curing agent; 1-2 parts of dispersant; 0.5-1.5 parts of defoaming agent; 1-2 parts of leveling agent; 1-2 parts of anti-settling agent and 28-38 parts of deionized water.

4. The method for preparing a fire retardant coating according to claim 1, characterized in that: The molar ratio of the phytic acid, arginine, cobalt salt and magnesium salt is 1:1:0.01-0.03:0.02-0.04; the cobalt salt is at least one of cobalt nitrate, cobalt chloride and cobalt acetate; the magnesium salt is at least one of magnesium nitrate and magnesium chloride.

5. The method for preparing a fire retardant coating according to claim 4, characterized in that: The drying is performed at 90-110° C. for 10-18 hours.

6. The method for preparing a fire retardant coating according to claim 1, characterized in that: The mass ratio of the pentaerythritol phosphate to KH-570 is 20g:6g.

7. The method for preparing a fire-retardant coating according to claim 6, characterized in that: The certain temperature is 65~85℃.

8. A fire retardant coating prepared according to the method for preparing a fire retardant coating according to any one of claims 1 to 7.