CN115197592B

CN115197592B - Aqueous inorganic paint free of formaldehyde, ultralow VOC and A1 flame resistance and preparation method thereof

Info

Publication number: CN115197592B
Application number: CN202110401745.9A
Authority: CN
Inventors: 张兆国; 王帅; 林惠赐
Original assignee: Nippon Paint China Co Ltd; Zhuhai Caizhu eComerce Co Ltd
Current assignee: Nippon Paint China Co Ltd; Zhuhai Caizhu eComerce Co Ltd
Priority date: 2021-04-14
Filing date: 2021-04-14
Publication date: 2023-05-16
Anticipated expiration: 2041-04-14
Also published as: CN115197592A

Abstract

The invention relates to a formaldehyde-free, ultra-low VOC and A1 flame-resistant aqueous inorganic coating, which comprises a thickening agent, a stabilizing agent, a dispersing agent, a defoaming agent, titanium white powder, calcite powder, water and inorganic modified alkali silicate, wherein the inorganic modified alkali silicate is obtained by modifying low-modulus alkali silicate by silica sol and an iron compound in sequence. The formaldehyde-free, ultralow VOC and A1 flame-resistant water-based inorganic coating provided by the invention is formed by an inorganic film forming material, does not contain any organic synthetic resin emulsion, has the characteristics of health, environmental protection and flame resistance, and can meet the requirements of formaldehyde-free, ultralow VOC and A1 flame resistance.

Description

Aqueous inorganic paint free of formaldehyde, ultralow VOC and A1 flame resistance and preparation method thereof

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to a formaldehyde-free, ultra-low VOC (volatile organic compound) and A1 flame-resistant water-based inorganic coating and a preparation method thereof.

Background

At present, most of water-based inorganic coatings on the market are obtained by organic-inorganic compounding, 5% -12% of organic synthetic resin emulsion is added, and the organic synthetic resin emulsion in the water-based inorganic coatings occupies a large part, and although the performances of washing resistance, water resistance and the like are greatly improved, the defects of the organic synthetic resin emulsion, such as poor fire resistance, poor air permeability, high VOC and formaldehyde content, are also shown.

The requirements of the water-based inorganic paint on the market on fire resistance are mostly A2 grade, and the market products more or less contain organic synthetic resin emulsion, which still can generate toxic gas in the combustion process and has great hidden trouble on the safety in fire. Meanwhile, the inventor finds that the traditional organic synthetic resin coating can meet the A2-level fireproof requirement by adding a small amount of inorganic film-forming substances according to the comparison of the A2-level fireproof coatings on the market, and the inorganic and organic boundaries are not obvious any more.

Meanwhile, environmental awareness of people is gradually enhanced, and requirements for substances, healthy life and green life are also more and more intense. The VOC of the water-based inorganic paint on the market can not reach the requirement of completely removing because the water-based inorganic paint contains partial organic synthetic resin emulsion.

Disclosure of Invention

The invention aims to solve the problems and provide the formaldehyde-free, ultralow VOC and A1 flame-resistant aqueous inorganic coating, which is mainly formed by an inorganic film forming material and does not contain any organic synthetic resin emulsion, has the characteristics of health, environmental protection and flame resistance, and can meet the requirements of formaldehyde-free, ultralow VOC and A1 flame resistance.

In order to solve the problems, the invention is realized by the following technical scheme:

the aqueous inorganic paint which does not contain formaldehyde, ultra-low VOC and A1 and is flame-resistant is characterized in that:

comprises the following components in parts by weight:

the sum of all components is 1000 parts;

the inorganic modified alkali silicate is obtained by modifying alkali silicate with low modulus by silica sol and ferric oxide compound in sequence.

The aqueous inorganic paint which does not contain formaldehyde, has ultralow VOC and A1 flame resistance is further optimized as follows:

the inorganic modified alkali silicate comprises the following preparation steps:

A. preparation of silica sol modified alkali silicate:

taking a proper amount of low-modulus alkali silicate, slowly dropwise adding silica sol into the alkali silicate under the low-speed condition of 600r/min, dropwise adding the mixture to an opacified state, dispersing for a period of time under the low-speed condition, dropwise adding a proper amount of silicate stabilizer, and uniformly mixing;

wherein the weight ratio of the alkali silicate to the silica sol to the silicate stabilizer is (20-40): (1-10): (0.5-3);

wherein the alkali silicate is commonly called water glass, is potassium, sodium and lithium water glass or a combination thereof, the mol ratio of silicon dioxide to alkali metal oxide is 3.0-4.0, and the solid content percentage is 20% -40%;

wherein the silica sol is one or a combination of a plurality of fumed silica, silica aerogel, silica sol and the like;

wherein the silicate stabilizer is a quaternary ammonium salt compound;

B. preparation of inorganic modified alkali silicate:

adding a proper amount of iron compound into the silica sol modified alkali silicate prepared in the step A, stirring for a period of time under the condition of high rotating speed of 1500r/min, and ensuring that the iron compound is fully dispersed in a system to prepare the inorganic modified alkali silicate;

wherein the weight ratio of the alkali silicate mixture modified by the silica sol to the iron compound is (20-40) (0.01-0.05).

the iron compound is one or a combination of more of ferroferric oxide, ferric oxide and ferrous oxide.

the thickening agent is cellulose ether and derivatives thereof, and is one or a combination of more of HEC, MHEC and polysaccharides.

the titanium dioxide is specially customized rutile titanium dioxide, wherein the titanium dioxide accounts for 93% or more by mass, the rutile accounts for 97% or more by mass, and the titanium dioxide is a titanium dioxide pigment subjected to inorganic surface treatment and organic surface treatment of silicon and aluminum. The special customized rutile titanium dioxide and alkali silicate used in the invention can be stably stored, and the chemical reaction of the special customized rutile titanium dioxide and alkali silicate is within an acceptable range, so that no adverse phenomenon occurs. Titanium dioxide and coating materials of aluminum oxide and silicon oxide thereof have stronger reactivity with alkali silicate, and other common titanium dioxide types can be gelled and agglomerated in the technical scheme, so that special designs are necessary in the selection of coating materials, the coating production process and the like, and the selection of the titanium dioxide type is particularly important.

The special titanium dioxide is rutile titanium dioxide customized according to the requirements, and is a professional customized product of Shandong Dong good group.

the calcite powder is prepared by crushing natural calcite ores, the mass percentage content of calcium carbonate is more than or equal to 97%, and the fineness is 500 meshes. The calcium carbonate and the alkali silicate can be stably stored, the chemical reaction of the calcium carbonate and the alkali silicate is within an acceptable range, and no adverse phenomenon occurs; because calcite ore is not pure calcium carbonate, contains various impurities such as magnesium carbonate and the like, has stronger reactivity with alkali silicate, is easy to gel, agglomerate and the like, and cannot be prepared into a coating, calcite powder of carefully selected ore sources is required to be selected, and specific performance indexes are as follows: the ore source adopts a single ore source, the Mg content is below 2 percent, and the conductivity of the aqueous solution is lower than 8s/m.

which has one or more of the following features:

(1) The dispersing agent is one or a combination of a plurality of ammonium salt dispersing agent, sodium salt dispersing agent and high molecular dispersing agent;

wherein:

the ammonium salt dispersing agent is a polycarboxylic acid ammonium salt dispersing agent;

the sodium salt dispersing agent is a polycarboxylate sodium salt dispersing agent;

the high molecular type dispersing agent is an esterified styrene-maleic anhydride copolymer which is prepared by taking an acrylic monomer as a raw material and adopting a controllable free radical polymerization method, and is a dispersing agent with a comb-shaped structure;

(2) The defoaming agent is one or a combination of a plurality of mineral oil defoaming agents, organic silicon defoaming agents and polyether defoaming agents;

(3) The stabilizer is one or a combination of more of quaternary ammonium salt compound, copolymer solution containing polar pigment affinity group, high molecular long chain polymer and anion copolymer of stuffing-philic functional group.

The invention also relates to a preparation method of the formaldehyde-free, ultra-low VOC and A1 flame-resistant aqueous inorganic coating, which comprises the following preparation steps:

the preparation method comprises the following preparation steps:

A. adding a first part of water, a dispersing agent, a first part of defoaming agent, a first part of stabilizing agent, calcite powder and titanium dioxide, and uniformly dispersing in advance under the condition of low-speed stirring to obtain a premix;

B. dispersing the thickener at a high speed by the second part of water in advance under the condition of high-speed stirring to obtain high-viscosity dispersion slurry;

C. adding the dispersion slurry obtained in the step B into the premix liquid obtained in the step A, and dispersing the mixture into a sample with the fineness lower than a specified fineness under the condition of high-speed dispersion;

D. adding inorganic modified alkali silicate and a second part of stabilizing agent into the sample obtained in the step C, and fully dispersing under the condition of high-speed stirring;

E. and D, adding a second part of defoaming agent and a third part of water into the sample after the step D, and uniformly mixing to obtain the formaldehyde-free, ultra-low VOC and A1 flame-retardant water-based inorganic coating.

The preparation method of the formaldehyde-free, ultra-low VOC and A1 flame-resistant water-based inorganic coating is further optimized as follows:

the total weight of the water is the sum of the weight parts of the first part of water, the second part of water and the third part of water, and the weight ratio of the first part of water to the second part of water to the third part of water is (1-3):

(1～3):(1～2)；

the total weight part of the defoaming agent is the sum of the weight parts of the first part of the defoaming agent and the second part of the defoaming agent, and the weight ratio of the first part of the defoaming agent to the second part of the defoaming agent is (1-3) (3-5);

the total weight part of the stabilizer is the sum of the weight parts of the first part of stabilizer and the weight part of the second part of stabilizer, and the weight ratio of the first part of stabilizer to the second part of stabilizer is (1-2).

The water-based inorganic paint on the market at present mostly meets the relevant performance standard of the paint by adding the organic synthetic resin emulsion, and on the premise of not adding the organic synthetic resin emulsion, the requirements of the corresponding standard of the emulsion paint on the washing resistance more than 6000 times are difficult to be met. The flame-retardant aqueous inorganic paint without formaldehyde, ultralow VOC and A1 disclosed by the invention has the advantages that the paint film can be enabled to react with a base material rapidly and fully mainly by using silicate with lower modulus, the resistance to the outside is improved, the wash resistance is more than 10000 times, and meanwhile, the modulus of the aqueous inorganic paint is improved by adding silica sol with a certain content, so that the thermal storage stability of the aqueous inorganic paint is improved; on the other hand, the inorganic modification is carried out on the alkali silicate by adding the iron compound, and the complex protection effect is formed by the iron compound and the alkali silicate, so that the inorganic film forming substance is prevented from reacting with pigment and filler in the system in the storage process, and the inorganic film forming substance is prevented from being lost in the storage process, so that the performance is reduced. The reaction rate and the reaction strength in the paint film curing process are improved, the paint can form a firm paint film in the paint film forming process, the washing resistance times are improved, and meanwhile, the stable existence of metal ions in the paint storage process is ensured through the silicate stabilizer of quaternary ammonium salts, so that the phenomena of caking and gelation can not occur.

In the process of constructing, drying and generating a paint film, along with the processes of moisture volatilization, paint film shrinkage and volume reduction, the generated internal stress gradually accumulates in the paint film, so that a stress release mechanism is needed to achieve the aim of preventing the paint film from cracking. The method for eliminating the drying and cracking of the paint film by the emulsion paint is emulsion plasticization, and high-boiling alcohol ester liquid such as plasticizer is commonly used, wherein dodecanol ester with the boiling point of 250 ℃ is most commonly used; the plasticized paint film has flexibility, can release the solidifying stress and eliminate the phenomenon of drying cracking. The aqueous inorganic coating is also plasticized by an organic emulsion, so that the national standard and the German standard both allow the aqueous inorganic coating to contain a certain amount of organic matters, as shown in Table 8.

Because the alkali silicate has very high reactivity, the alkali silicate is easy to gel, agglomerate and the like when mixed with fillers such as titanium dioxide, calcite powder and the like, the modified aim is to improve the storage stability of the water-based inorganic paint and prolong the shelf life of the water-based inorganic paint, and meanwhile, the water-based inorganic paint is completely formed by reacting inorganic film forming substances, wherein no emulsion plasticizes, a paint film is extremely easy to crack, the modification is helpful to eliminate the curing stress in the drying process of the paint film, and the occurrence of pathological phenomena such as cracking and the like of the paint film is avoided.

Meanwhile, the alkali silicate is modified by adopting a honeycomb stress relief method, and the alkali silicate modified material is fumed silica, silica aerogel, silica sol or a combination thereof, so that a plurality of tiny micropore aggregation small honeycombs are easy to form in a paint film, and curing stress is released in the small honeycombs in the film forming process of the paint film, so that the paint film is ensured to be dried and not cracked on the premise of not influencing the performance of the paint film, and the 0.5mm thick film is dried and not cracked.

The formaldehyde-free ultralow VOC and A1 flame-resistant aqueous inorganic coating is ensured by the composition of the formula, and no organic synthetic resin emulsion is added in the formula, so that a formaldehyde-containing preservative and an organic solvent are not required to be introduced;

the A1 flame resistance can be ensured by the formulation composition, the organic content is below 2 percent, which is far lower than the organic content required by German standard DIN EN 13300 and the modified JG/T26-XXXXXX inorganic liquid coating for the inner and outer walls of the buildings.

The formaldehyde-free, ultra-low VOC and A1 flame-retardant water-based inorganic coating has the following advantages:

1. the flame-retardant aqueous inorganic paint does not contain any organic synthetic resin emulsion, and is prepared by taking inorganic mineral materials as film forming substances, and does not contain formaldehyde, ultra-low VOC and A1;

2. the new material is natural and environment-friendly, the raw material does not contain any organic synthetic resin emulsion, and the ultra-low VOC has no formaldehyde, thus truly achieving the environment-friendly odor removal;

3. fireproof and flame-retardant can meet the A1-level fireproof requirement;

4. excellent performance, and the washing resistance times reach more than 10000 times.

5. The biggest difficulty of A1-grade fireproof paint is that the burning time (0 s) and the heat value generated by burning (less than or equal to 2 kJ/kg) are the minimum organic matter content in the paint, namely no organic synthetic resin emulsion is added, however, the inorganic paint on the market at present is added with partial organic synthetic resin emulsion due to the requirement of paint film strength, and the fireproof requirement of A1 flame resistance is difficult to reach. How to ensure the strength and the performance of the paint film is a key difficulty of the pure inorganic paint under the condition of very few organic matters. According to the invention, silicate is subjected to inorganic modification mainly through silica sol and iron compounds, so that the silicate can still meet the performance requirement of washing resistance 10000 times under the condition of ensuring A1 flame resistance, and meanwhile, through optimizing an experimental formula, proper pigment and filler are selected, and the stability of a system can be ensured under the condition of thermal storage.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to specific embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not limiting. All simple improvements to the preparation method of the invention under the premise of the inventive concept belong to the protection scope of the invention.

Example 1A formaldehyde-free, ultra-Low VOC and A1 flame resistant aqueous inorganic coating

A formaldehyde-free, ultra-low VOC and A1 flame resistant aqueous inorganic coating comprising the following preparation steps:

A. preparation of silica sol modified alkali silicate:

wherein the silicate stabilizer is a quaternary ammonium salt compound;

B. preparation of inorganic modified alkali silicate:

Table 1 shows the raw material composition (parts by weight) of the formaldehyde-free, ultra-low VOC and A1 flame-retardant aqueous inorganic coating material of the invention

Among the component 1#, the preferable scheme is:

the thickener is cellulose thickener, stabilizer is quaternary ammonium salt compound, dispersant is polycarboxylate ammonium salt dispersant, defoamer is organic silicon defoamer, titanium white is specially customized rutile titanium white, calcite powder is calcite powder with mass percent content of more than or equal to 97% and fineness of 500 meshes, mg content is below 2%, aqueous solution conductivity is lower than 8s/m, inorganic modified alkali silicate is obtained by inorganic modification of silicate by the corresponding modification method, and raw materials which are not mentioned are common product raw materials using the components.

In the component 2#, the preferable scheme is as follows:

the thickener is polyurethane thickener, stabilizer is quaternary ammonium salt compound, dispersant is polycarboxylate sodium salt dispersant, defoamer is polyether defoamer, titanium white is specially customized rutile type titanium white, calcite powder is calcium carbonate with mass percentage content of more than or equal to 97%, calcite powder with fineness of 500 meshes and modified alkali silicate are modified sodium silicate obtained by the corresponding preparation method, and unrecited raw materials are common product raw materials using the components.

Among the 3# components, the preferable scheme is:

wherein the thickener is polysaccharide thickener, the stabilizer is quaternary ammonium salt compound, the dispersant is styrene-maleic anhydride copolymer, the defoamer is the combination of organosilicon defoamer and polyether defoamer, the titanium white is specially customized rutile type titanium white, the calcite powder is calcium carbonate with the mass percentage content of more than or equal to 97%, the calcite powder with the fineness of 500 meshes and the modified alkali silicate are modified lithium silicate obtained by the corresponding preparation method, and the unrecited raw materials are common product raw materials using the components.

The following tables 2-5 show the test data of the performance of the formaldehyde-free, ultra-low VOC and A1 flame-retardant waterborne inorganic coating according to the invention, and the test report of A1-grade fire resistance, VOC and formaldehyde content:

table 2 results of Performance test of the formaldehyde-free, ultra-low VOC and A1 flame resistant waterborne inorganic coatings of the invention

TABLE 3A 1 level Performance test results of the formaldehyde-free, ultra-low VOC and A1 flame resistant waterborne inorganic coatings of the invention

Table 2 and Table 3 are specific test data of example 1, and it can be found from Table 2 and Table 3 that the formaldehyde-free, ultra-low VOC and A1 flame-retardant aqueous inorganic coating according to the invention meets the A1 performance requirements in the classification of the combustion performance of GB 8624-2002 building materials and products, meets the relevant performance standards of the current emulsion paint, and meets the requirements even superior to the market superior emulsion paint. Examples 2 and 3 and example 1 are mainly characterized in that the content of the powder is different from that of the auxiliary agent, and the performance test in Table 2 is aimed at and is within the index range; in addition, examples 2 and 3 also meet the A1 class flame retardant requirement

TABLE 4 test results of VOC and formaldehyde of the flame-retardant waterborne inorganic coating of the invention containing no formaldehyde, ultra-low VOC and A1

Note 1: the detection limit of the VOC content is 2g/L,

and (2) injection: the detection limit of formaldehyde content is 5mg/kg.

TABLE 5 VOC results in formaldehyde-free, ultra-low VOC and A1 flame resistant waterborne inorganic coating cans of the invention (GB/T23984-2009)

The test results of formaldehyde and VOC in example 1 are the test results of examples 2 and 3, the test results of which are not detected according to GB 18582-2020, and the test results of which are 178ppm, which are far lower than the VOC content of the emulsion paint on the market at present, are the lower detection limit of the content of volatile organic compounds (in-can VOC) in the paint according to the current VOC test method GB/T23984-2009 in example 1.

Comparative experiment 1

The formaldehyde-free, ultra-low VOC and A1 flame-resistant aqueous inorganic coating provided by the invention is subjected to performance comparison test by comparing the silicate finished product on the market with the inorganic modified alkali silicate provided by the invention.

Comparative experiment 1# 1 is the same as the 1# component in example 1;

comparative experiment 1 differs from example 1 in # 4 in that: a silicate sample with a commercial modulus of about 3.5 and a solid content of about 30% by mass was used.

Comparative experiment 1 differs from example 1 in # 5 in that:

a silicate sample which is commercially available and has a modulus of about 4.0 and a solid content of about 30% by mass and is modified frequently is used.

TABLE 6 washing resistance comparative test results of inorganic modified alkali silicate and ordinary silicate

Detecting items	Inspection method	1#	4#	5#
					Washing-resistant brush	GB/T 9266	>10000	<5000	<6000

By comparing the performance of the commercial silicate finished product with the modified alkali silicate of the present invention, it was found that: the modified alkali silicate adopted in the invention has a washing resistance far greater than that of common and conventional modified silicate samples.

Comparative experiment 2

The aqueous inorganic paint without formaldehyde, ultralow VOC and A1 flame resistance is subjected to a comparison test in the aspect of thermal storage stability by comparing a common titanium white powder sample and a calcite powder sample in the market with the special titanium white powder and calcite powder in the invention.

Comparative experiment 2# 1 was identical to example 1# 1;

comparative experiment 2 differs from example 1 in # 1 in that:

adopts the common domestic titanium white R996 in the market.

The calcium carbonate content 88.59% and the magnesium carbonate content 9.38% of calcite powder in the market are tested.

The difference between # 7 in comparative experiment 2 and # 1 in example 1 is that:

inlet titanium dioxide 902+ is common in the market of No. 5 formulas.

TABLE 7 influence of selection of titanium pigment and calcite raw materials on thermal storage stability of aqueous inorganic coating

Aiming at a powder system in a pure inorganic formula, the special titanium white powder and the decomposed stone powder have obvious improvement effect on the thermal storage stability in the system.

Table 8 environmental standards for inorganic coating at home and abroad

Note that: the VOC content detection limit is 2g/L, and the formaldehyde content detection limit is 5mg/kg.

The VOC content of the formaldehyde-free, ultra-low VOC and A1 flame-resistant water-based inorganic paint is superior to the paint industry level at home and abroad, the VOC content of the domestic paint standard JG/T26-XXXX (report manuscript) is limited below 15g/L according to European Union standard VOC content, the VOC content test result of the formaldehyde-free, ultra-low VOC and A1 flame-resistant water-based inorganic paint of the invention is undetected (the detection limit is 2 g/L), the VOC content is far lower than the relevant standard at home and abroad, the volatile organic compound content (in-tank VOC) in the paint is detected according to the current VOC test method GB/T23984-2009, the detection data is 178ppm, the VOC content is about 0.25g/L, and the VOC content is far lower than the organic compound content of 15-20g/L in the relevant standards at home and abroad.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way; those skilled in the art should appreciate that many modifications, adaptations, and variations of the disclosed technology can be made without departing from the scope of the present invention; meanwhile, any equivalent changes, modifications and evolution made to the above embodiments according to the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The experimental methods of the present invention, in which specific conditions are not specified, are generally performed under conventional conditions or under conditions recommended by the manufacturer.

The various optimized technical schemes in the invention can be combined with each other unless otherwise stated.

Percentages and parts are weight percentages and parts unless otherwise indicated.

The experimental methods in the specification and examples, in which specific conditions are not specified, are generally performed under conventional conditions or under conditions recommended by the manufacturer.

The various raw materials, reagents, components used in the present invention are, unless otherwise indicated, the corresponding raw materials commonly used in the art.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any methods and materials similar or equivalent to those described may be used in the present invention.

Claims

1. A formaldehyde-free, ultra-low VOC and A1 flame-resistant aqueous inorganic coating is characterized in that:

comprises the following components in parts by weight:

1-10 parts of thickening agent;

10-30 parts of stabilizer;

10-30 parts of dispersing agent;

2-10 parts of defoaming agent;

100-300 parts of titanium dioxide;

100-300 parts of calcite powder;

100-500 parts of water;

200-400 parts of inorganic modified alkali silicate;

the sum of all components is 1000 parts;

the inorganic modified alkali silicate is obtained by modifying alkali silicate with low modulus through silica sol and ferric compound in sequence;

A. preparation of silica sol modified alkali silicate:

slowly dropwise adding silica sol into the low-modulus alkali silicate under the low-speed condition of 600r/min, dropwise adding the mixture to an opacified state, dispersing under the low-speed condition, dropwise adding a silicate stabilizer, and uniformly mixing;

wherein the silica sol is one or a combination of a plurality of fumed silica, silica aerogel and silica sol;

wherein the silicate stabilizer is a quaternary ammonium salt compound;

B. preparation of inorganic modified alkali silicate:

adding an iron compound into the silica sol modified alkali silicate prepared in the step A, and stirring under the condition of high rotating speed of 1500r/min to ensure that the iron compound is fully dispersed in a system, so as to prepare the inorganic modified alkali silicate;

wherein the weight ratio of the alkali silicate mixture modified by the silica sol to the iron compound is (20-40) (0.01-0.05);

2. The formaldehyde-free, ultra-low VOC and A1 flame resistant aqueous inorganic coating of claim 1, wherein:

3. The formaldehyde-free, ultra-low VOC and A1 flame resistant aqueous inorganic coating of claim 1, wherein:

the titanium dioxide is rutile titanium dioxide, wherein the titanium dioxide is 93% or more by mass, the rutile is 97% or more by mass, and the titanium dioxide is titanium dioxide pigment subjected to inorganic surface treatment and organic surface treatment of silicon and aluminum.

4. The formaldehyde-free, ultra-low VOC and A1 flame resistant aqueous inorganic coating of claim 1, wherein:

the calcite powder is prepared by crushing natural calcite ores, the mass percentage content of calcium carbonate is more than or equal to 97%, the fineness is 500 meshes, and specific performance indexes are as follows: the ore source adopts a single ore source, the Mg content is below 2 percent, and the conductivity of the aqueous solution is lower than 8s/m.

5. The formaldehyde-free, ultra-low VOC and A1 flame resistant aqueous inorganic coating of claim 1, wherein:

which has one or more of the following features:

wherein:

6. The method for preparing the formaldehyde-free, ultra-low VOC and A1 flame resistant aqueous inorganic coating according to any one of claims 1 to 5, which is characterized in that:

the preparation method comprises the following preparation steps:

E. adding a second part of defoaming agent and a third part of water into the sample after the step D, and uniformly mixing to obtain the formaldehyde-free, ultra-low VOC and A1 flame-retardant water-based inorganic coating;

the total weight part of the water is the sum of the weight parts of the first part of water, the second part of water and the third part of water, and the weight ratio of the first part of water to the second part of water to the third part of water is (1-3) (1-2);