阅读说明：本技术 一种丙烯酸乳液及其制备方法和应用 (Acrylic emulsion and preparation method and application thereof ) 是由 邓强 范威丽 张海峰 于 2021-07-20 设计创作，主要内容包括：本发明公开了一种丙烯酸乳液及其制备方法和应用。一种丙烯酸乳液,制备原料包括：环氧树脂、10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-磷杂菲-10-氧化物(CAS：99208-50-1)、丙烯酸、苯乙烯、共聚单体和添加剂；所述共聚单体包括丙烯酸丁酯、甲基丙烯酸甲酯和双丙酮丙烯酰胺中的至少一种。本发明的丙烯酸乳液,由于原料间的相互作用,因此具备阻燃性能,且应用于水性涂料后,可提升水性涂料的阻燃性能、附着性能、抗腐蚀性能和高温条件下的复合损耗因子。(The invention discloses an acrylic emulsion and a preparation method and application thereof. An acrylic emulsion is prepared from the following raw materials: epoxy resin, 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (CAS: 99208-50-1), acrylic acid, styrene, comonomers and additives; the comonomer comprises at least one of butyl acrylate, methyl methacrylate and diacetone acrylamide. The acrylic emulsion has flame retardant property due to interaction between raw materials, and can improve the flame retardant property, the adhesion property, the corrosion resistance and the composite loss factor under high temperature after being applied to the water-based paint.)

1. The acrylic emulsion is characterized by comprising the following preparation raw materials: epoxy resin, 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, acrylic acid, comonomer and additive; the comonomer comprises at least one of butyl acrylate, methyl methacrylate and diacetone acrylamide.

2. The acrylic emulsion according to claim 1, wherein the acrylic emulsion is prepared from the following raw materials in parts by weight:

3. the acrylic emulsion according to claim 1 or 2, wherein the additive comprises at least one of an emulsifier, a catalyst, a polymerization inhibitor and an initiator; preferably, the catalyst comprises a first catalyst and a second catalyst; preferably, the first catalyst is at least one of boron trifluoride dimethyl ether complex, tertiary amine and triphenylphosphine; preferably, the second catalyst is at least one of triethylbenzylammonium chloride and tetra-n-butylammonium bromide.

4. The method for producing an acrylic emulsion according to any one of claims 1 to 3, comprising the steps of:

s1, modifying the epoxy resin by using the 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a flame-retardant prepolymer;

s2, carrying out esterification reaction on the flame-retardant prepolymer and the acrylic acid;

s3, adding the comonomer into the mixture obtained in the step S2 for emulsification, and carrying out copolymerization reaction to obtain the copolymer;

in step S1, the epoxy equivalent of the flame-retardant prepolymer is 300g/mol to 350 g/mol.

5. The preparation method according to claim 4, wherein in step S3, the temperature of the copolymerization reaction is 80-85 ℃; preferably, the time is 4h to 5 h.

6. A water-based paint is characterized in that preparation raw materials comprise styrene-acrylic emulsion, vinyl chloride-acetate emulsion, flame retardant, filler and the acrylic emulsion as claimed in any one of claims 1 to 3.

7. The aqueous coating of claim 6, wherein the flame retardant is selected from at least one of ammonium polyphosphate, dipentaerythritol, expanded graphite, melamine, and zinc phosphate; preferably, the filler comprises a mixture of at least one of barium sulfate, talcum powder, mica powder, aluminum hydroxide, pottery clay and titanium dioxide and aluminum silicate fibers.

8. The water-based paint according to claim 6, wherein the raw materials for preparing the water-based paint further comprise an auxiliary agent; preferably, the auxiliary agent is at least one of a dispersing agent, a substrate wetting agent, a defoaming agent, a mildew inhibitor, a rheological auxiliary agent, an adhesion promoter, a pH regulator and a film-forming auxiliary agent.

9. A process for the preparation of the aqueous coating according to claim 7 or 8, characterized in that it comprises the following steps:

D1. dispersing the styrene-acrylic emulsion and the aluminum silicate fibers to form a first ingredient;

D2. dispersing the remaining filler and the flame retardant to form a second formulation;

D3. and mixing and dispersing the chlorine-vinegar emulsion, the acrylic emulsion, the first ingredient and the second ingredient to obtain the acrylic emulsion.

10. Use of the aqueous coating according to claims 6 to 7 in the fields of vehicles, engineering machinery and construction.

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to an acrylic emulsion, and a preparation method and application thereof.

Background

The damping material is a material capable of converting solid mechanical vibration energy into heat energy for dissipation, and the concept is firstly appeared in 1784-1920 years. The early development history of damping materials is as follows: cou1omb indicated as early as 1784 that when metals were subjected to cyclic strain, the stress-strain curve would form a hysteresis loop and have energy dissipation; in 1837 Weber measured the damping of a material for the first time with the free damping of a torsional pendulum; from 1850, acousticians studied damped vibration systems; rayleigh gives in 1878 the differential equations and solutions of some of them for linear, viscous damping discrete systems and systems of continuous medium mechanics, acoustics, etc.

In the application environment of mechanical equipment such as automobiles, rail transit, engineering machinery and the like, a large number of noise and vibration sources exist. Causing great trouble to passengers and equipment operators. Meanwhile, the mechanical equipment may resonate with a vibration source, so that the safety of the equipment is greatly damaged. The water-based damping paint is a shock absorption and noise reduction technology developed in recent years. With the development of science and technology, the requirement on the damping performance of materials is higher and higher. Research and development of high-performance water-based damping paint with excellent comprehensive performance become research hotspots of scientists, and the research and development has great significance in theoretical research and practical application.

At present, although a lot of mechanisms and material varieties are developed for damping materials, the materials are not serialized, pure acrylic emulsion or styrene-acrylic emulsion is mostly adopted as a main film forming material in water-based damping coatings used in the industries of automobiles, rail transit, engineering machinery and the like, the coating has the problems of poor flame retardance, poor corrosion resistance and poor damping performance, and meanwhile, the damping performance is not excellent enough, and when equipment is heated and fired, the damping coating can generate smoke and molten drops, thereby causing great harm to the personal safety of passengers or operators.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the acrylic emulsion provided by the invention has certain flame retardant property due to the combination of the preparation raw materials, and further the water-based paint prepared from the acrylic emulsion has the flame retardant property.

The invention also provides a preparation method of the acrylic emulsion.

The invention also provides a water-based paint with the acrylic emulsion.

The invention also provides a preparation method of the water-based paint.

The invention also provides application of the water-based paint in the fields of vehicles, engineering machinery and buildings.

According to one aspect of the present invention, an acrylic emulsion is provided, which is prepared from the following raw materials: epoxy resin, 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (CAS: 99208-50-1), acrylic acid, comonomer and additives; the comonomer comprises at least one of butyl acrylate, methyl methacrylate and diacetone acrylamide.

According to a preferred embodiment of the present invention, at least the following advantages are provided:

(1) in the acrylic emulsion provided by the invention, the 10- (2, 5-dihydroxyphenyl) -10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide chain segment contains phosphorus elements and does not contain halogen elements, so that good flame retardance can be provided, and the problems of serious smoke generation and corrosive gas generation during the combustion of the conventional halogen flame-retardant resin are avoided;

(2) in the acrylic emulsion provided by the invention, the benzene ring in the 10- (2, 5-dihydroxyphenyl) -10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide can improve the heat resistance of the obtained acrylic emulsion;

(3) in the acrylic emulsion provided by the invention, ether bonds (epoxy groups contained in the epoxy resin chain segments) and hydroxyl groups (obtained by ring opening of the epoxy groups) provide good adhesive force for the coating comprising the acrylic emulsion;

(4) in the acrylic emulsion provided by the invention, the diacetone acrylamide in the comonomer provides good self-crosslinking property for the acrylic emulsion, so that the acrylic emulsion forms a net structure, and further, the coating comprising the acrylic emulsion can obtain good coating strength and good composite loss factor (namely damping loss under high temperature condition) under high temperature condition.

In some embodiments of the present invention, the acrylic emulsion is prepared from the following raw materials in parts by weight:

in some embodiments of the invention, the acrylic emulsion has a glass transition temperature of about 55 ℃.

In some embodiments of the present invention, the epoxy resin is selected from E-51 bisphenol A epoxy resins.

In some embodiments of the invention, the E-51 bisphenol A epoxy resin is selected from at least one of Yueyang Barring petrochemical CYD-128, south Asia Plastic NEPL-128, and Dow chemical DER 331.

In some embodiments of the invention, the E-51 bisphenol A epoxy resin is a liquid resin having an epoxy equivalent weight of 180-220 g/mol.

The bisphenol A epoxy resin with the epoxy equivalent range has moderate reactivity and crosslinking degree, and further, the flame-retardant prepolymer prepared from the bisphenol A epoxy resin has moderate reactivity.

In some embodiments of the present invention, the addition amount of the butyl acrylate is 30 to 50 parts, the addition amount of the methyl methacrylate is 40 to 70 parts, and the addition amount of the diacetone acrylamide is 20 to 40 parts by weight in the comonomer.

In some embodiments of the present invention, the raw materials for preparing the acrylic emulsion further comprise a reactive diluent.

In some embodiments of the invention, the reactive diluent is selected from styrene.

In some embodiments of the present invention, the reactive diluent is added in an amount of 30 to 50 parts by weight.

In some embodiments of the invention, the additive comprises at least one of an emulsifier, a catalyst, a polymerization inhibitor, and an initiator.

In some embodiments of the present invention, the emulsifier is added in an amount of 1 to 3 parts by weight.

In some embodiments of the invention, the emulsifier is at least one of Sodium Dodecyl Sulfate (SDS), ammonium salt of sulfuric acid- (-2-p-nonylphenoxy) -ethyl ester, sodium 2-acrylamido-2-methyl-propyl sulfate (AMPS-Na), and 2-methyl-2-acrylamido sulfate (CAS: 3351-73-3).

In some preferred embodiments of the invention, the emulsifier is 2-methyl-2-acrylamido sulfate (CAS: 3351-73-3) (AMPS-NH)₄)。

In some embodiments of the invention, the catalyst comprises a first catalyst and a second catalyst.

In some embodiments of the present invention, the first catalyst is added in an amount of 1 to 3 parts by weight.

In some embodiments of the invention, the first catalyst is at least one of boron trifluoride dimethyl ether complex, a tertiary amine, and triphenylphosphine.

In some preferred embodiments of the invention, the first catalyst is triphenylphosphine.

If the tertiary amine is used as the first catalyst, the chroma of a reaction product is darker;

if the boron trifluoride dimethyl ether is used as the first catalyst, the stability is low, and the catalyst is easy to degrade in the temperature rising process, so that the catalytic efficiency is reduced;

in conclusion, although boron trifluoride dimethyl ether complex and tertiary amine can also satisfy the requirements for preparing the acrylic emulsion in the present invention, the triphenylphosphine has the advantages of low temperature catalysis (about 120 ℃) and light color of reactants, and is therefore the best choice for the first catalyst in the present invention.

In some embodiments of the present invention, the second catalyst is added in an amount of 0.1 to 0.5 parts by weight.

In some embodiments of the invention, the second catalyst is at least one of triethylbenzylammonium chloride and tetra-n-butylammonium bromide.

In some preferred embodiments of the invention, the second catalyst is tetra-n-butylammonium bromide.

In some embodiments of the present invention, the polymerization inhibitor is added in an amount of 0.01 to 0.05 parts by weight.

In some embodiments of the invention, the polymerization inhibitor is at least one of hydroquinone, p-benzoquinone, phenothiazine, and p-tert-butylcatechol.

In some preferred embodiments of the invention, the catalyst is p-tert-butylcatechol.

In some embodiments of the present invention, the initiator is added in an amount of 1 to 3 parts by weight.

In some embodiments of the invention, the initiator is at least one of ammonium persulfate, potassium persulfate, and 2,2 "-azabicyclo (2-imidazoline) dihydrochloride (CAS: 27776-21-2).

In some preferred embodiments of the invention, the initiator is 2, 2' -azobis (2-amidinopropane) dihydrochloride.

In some embodiments of the present invention, the acrylic emulsion, the raw materials for preparing the acrylic emulsion, further comprise water; the addition amount of water is 35-55 parts.

According to still another aspect of the present invention, there is provided a method for preparing the acrylic emulsion, comprising the steps of:

s1, modifying the epoxy resin by using the 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a flame-retardant prepolymer;

s2, carrying out esterification reaction on the flame-retardant prepolymer and the acrylic acid;

s3, adding the comonomer into the mixture obtained in the step S2 for emulsification, and carrying out copolymerization reaction to obtain the copolymer;

in step S1, the epoxy equivalent of the flame-retardant prepolymer is 300g/mol to 350 g/mol.

The preparation method according to a preferred embodiment of the present invention has at least the following advantageous effects:

(1) the flame retardant property and the damping property of the obtained acrylic emulsion can be improved by controlling the feeding sequence and the like in the preparation method; specifically, in step S2, the flame-retardant prepolymer and acrylic acid are subjected to esterification reaction to obtain a compound having a terminal ester group; then, in the resultant compound, the double bond introduced by acrylic acid and the comonomer in step S3 are polymerized to obtain an acrylic emulsion.

(2) In the preparation method of the acrylic emulsion provided by the invention, because the step S1 limits the epoxy resin with proper epoxy equivalent as the reaction endpoint, the epoxy equivalent of the epoxy resin in the flame-retardant prepolymer prepared from the acrylic emulsion is moderate, and the acrylic emulsion has proper reactivity and crosslinking degree.

In some embodiments of the invention, the modifying, in step S1, is at a temperature of 120 ℃ to 130 ℃.

In some embodiments of the invention, in step S1, the modification is performed for 2.0h to 3.0 h.

In some embodiments of the invention, in step S1, the modification is performed under the action of a first catalyst.

In step S1, the modification degree of the epoxy resin and the epoxy equivalent of the obtained flame-retardant prepolymer can be controlled by controlling parameters such as the temperature, the duration of the modification, and the amount of each raw material, so as to maintain a proper amount of epoxy groups to perform esterification with the acrylic acid.

In some embodiments of the invention, in step S1, the modification is performed to a degree of modification of the epoxy resin of about 50%; it is understood that 50% of the epoxy groups contained in the epoxy resin react with 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide.

In some embodiments of the present invention, in step S1, the modification is performed by a mechanism that a P-Ar (Ar represents a benzene ring) group in 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is subjected to a strong electron-withdrawing group P ═ O bond to form a phosphorus anion, which is used as a nucleophile and undergoes a nucleophilic reaction with the epoxy resin; the epoxy group in the epoxy resin is a three-membered ring, and the three-membered ring has high activity because of high tension, is easy to open the ring, and carbon atoms in the ring are attacked by a nucleophilic reagent to generate a stable compound.

In some embodiments of the present invention, in step S2, the esterification reaction includes dissolving the flame-retardant prepolymer in the reactive diluent containing the polymerization inhibitor, raising the temperature, adding a mixture of a second catalyst and the acrylic acid dropwise, and reacting while maintaining the temperature.

In some embodiments of the present invention, the second catalyst and the acrylic acid are added dropwise at a rate of 0.25 to 0.4 ml/min.

Controlling the dropping rate of the mixture of the second catalyst and the acrylic acid can effectively control the reaction rate of the esterification reaction (grafting reaction), and helps to control the molecular weight of the resulting compound.

In some embodiments of the invention, the temperature of the esterification reaction is increased to a temperature of 105 ℃ to 110 ℃.

In some embodiments of the present invention, in the esterification reaction, the incubation reaction is performed for 2.0h to 3.0 h.

In step S2, the flame retardant prepolymer is dissolved with styrene as a reactive diluent before esterification with the acrylic acid, but a polymerization inhibitor is added in the process, so that in step S2, copolymerization of styrene as a reactive diluent with the acrylic acid does not occur.

In some embodiments of the invention, in step S3, the emulsification is performed under the action of an emulsifier.

In some embodiments of the present invention, in step S3, the emulsifying step is performed by adding water in addition to the emulsifier.

In some embodiments of the invention, the emulsifying, in step S3, is at a temperature of 65 ℃ to 75 ℃.

In some embodiments of the invention, in step S3, the emulsifying is performed under stirring conditions for a stirring time of 1.0h to 3.0 h.

In some preferred embodiments of the present invention, in step S3, the emulsification is performed under stirring for 2.0h to 3.0 h.

In some embodiments of the present invention, in step S3, the emulsification is performed under stirring conditions, and the stirring speed is 500-800 rpm.

In some embodiments of the present invention, in step S3, the copolymerization reaction is performed under the action of an initiator.

In some embodiments of the present invention, in step S3, the temperature of the copolymerization reaction is 80-85 ℃.

In some embodiments of the present invention, in step S3, the copolymerization is performed for a time period ranging from 4h to 5 h.

In some embodiments of the present invention, the method for preparing the acrylic emulsion further comprises adding the rest water after the step of S4, and discharging after cooling to about 40 ℃.

According to another aspect of the invention, the invention provides a water-based paint, which is prepared from raw materials including styrene-acrylic emulsion, vinyl chloride-vinyl acetate emulsion, flame retardant, filler and the acrylic emulsion.

The water-based paint according to a preferred embodiment of the invention has at least the following beneficial effects:

(1) in the water-based paint provided by the invention, the vinyl chloride chain segment in the vinyl chloride-vinyl acetate emulsion can provide certain flame retardant property, and the flame retardant property is further improved by matching with the flame retardant filler and the acrylic emulsion;

(2) the invention adopts the mutual matching of the acrylic emulsion with high glass transition temperature (Tg about 55 ℃), the vinyl chloride-vinyl acetate emulsion with medium glass transition temperature (Tg about 26 ℃) and the styrene-acrylic emulsion with low glass transition temperature (Tg about-22 ℃), and the matching of the acrylic emulsion and the styrene-acrylic emulsion with low glass transition temperature and the filler, and the coating formed by the water-based paint coating has good damping performance (composite loss factor) in a wide temperature range (-20 ℃ -50 ℃); namely, the filler is matched with the emulsion, so that the composite loss factor of a coating formed by the water-based paint in each temperature range is further optimized.

(3) The oxygen index of the coating formed by the water-based paint is more than or equal to 50; the 45-degree combustion is extremely difficult to combust, the flame retardance reaches HL3 level, and the flame retardant has good flame retardant property.

In some embodiments of the present invention, the water-based paint is prepared from the following raw materials in parts by weight:

in some embodiments of the present invention, the styrene-acrylic emulsion has a glass transition temperature (Tg) of-22 ℃ to-20 ℃.

The styrene-acrylic emulsion is a main film forming substance of the water-based paint, and the low glass transition temperature (Tg) can provide good low-temperature toughness and a composite loss factor under a low-temperature condition for a coating formed by the water-based paint.

In some embodiments of the present invention, the styrene-acrylic emulsion is a styrene-acrylate copolymer emulsion.

In some preferred embodiments of the present invention, the styrene-acrylic emulsion is selected from Wanhua chemistryAnd baolijia chemical BLJ-9468M.

In some embodiments of the invention, the chloroacetic emulsion has a glass transition temperature (Tg) of 26 ℃ to 30 ℃.

In some embodiments of the present invention, the vinyl chloride-vinyl acetate copolymer emulsion is vinyl chloride-vinyl acetate copolymer emulsion.

In some preferred embodiments of the present invention, the chlorine vinegar emulsion is at least one selected from lanxin chemical LX1612T and sumitomo chemical 850 HQ.

The vinyl chloride-vinyl acetate emulsion is a main film forming substance of the water-based paint, and a vinyl chloride chain segment provides good flame retardance for the water-based paint; a moderate glass transition temperature (Tg) provides a good composite loss factor under moderate temperature conditions.

The mutual matching of the styrene-acrylic emulsion, the self-made acrylic emulsion and the vinyl chloride-vinyl acetate emulsion can improve the cold and heat exchange resistance of a coating formed by the water-based paint.

In some embodiments of the invention, the filler is inorganic.

In some embodiments of the invention, the filler comprises a mixture of at least one of barium sulfate, talc, mica powder, aluminum hydroxide, china clay, and titanium dioxide with aluminum silicate fibers.

The barium sulfate, the aluminum hydroxide, the argil and the titanium dioxide are mainly used for enabling the water-based paint to have thick coating performance through high-filling-amount powder, and meanwhile, the damping effect of a coating prepared by the water-based paint is improved through friction generated by mutual contact among the filling particles and friction between the particles and high-molecular polymers (styrene-acrylic emulsion, acrylic emulsion and vinyl chloride-acetate emulsion).

The mica powder is of a sheet structure, and can shield corrosion of a corrosive medium to a coating while generating a damping effect; thereby improving the acid and alkali resistance and the water resistance of the coating; specifically, the inert material of the mica powder ensures that the mica powder is not corroded by a medium, the lamellar structure of the mica powder can form a labyrinth effect, and if the water-based paint contains the mica powder, the time for a corrosive medium to penetrate through the water-based paint to form a coating is prolonged.

The titanium dioxide also has a coloring function, and the whiteness of the water-based paint is improved.

The aluminum silicate fibers are in a needle-shaped structure and can be arranged in a coating formed by the water-based paint in a crossed mode, and therefore the effects of improving the structural strength and the damping effect of the coating are achieved.

The aluminum silicate fiber in the water-based paint can also improve the corrosion resistance of the water-based paint and the reinforcing effect on a thick coating.

The fillers used in the invention are all inorganic substances, and although the appearances are slightly different, the fillers are all non-combustible, so that the flame retardant effect of a coating system can be further improved.

The filler used in the invention has the functions and also has the damping function.

In some embodiments of the invention, the flame retardant is selected from at least one of ammonium polyphosphate, dipentaerythritol, expanded graphite, melamine, and zinc phosphate.

The flame retardant principle of the ammonium polyphosphate is as follows: on one hand, strong dehydrating agent poly/polyphosphoric acid is generated after thermal decomposition to promote the dehydration and carbonization of the surface of the organic matter; on the other hand, the polyphosphoric acid or the oxide of the non-volatile phosphorus expands when heated, covers the surface of the substrate coated by the water-based paint, and isolates air to achieve the purpose of flame retardance; finally, because the ammonium polyphosphate contains nitrogen elements, the ammonium polyphosphate can release gases such as nitrogen, ammonia and the like by thermal decomposition, and the gases are not easy to burn and dilute oxygen in the air, thereby blocking the supply of the oxygen.

The flame retardant mechanism of the dipentaerythritol and the melamine is as follows: ammonium polyphosphate is preheated and decomposed to form poly/polyphosphoric acid (a strong dehydrating agent), pentaerythritol can be esterified, dehydration and carbonization are performed, vapor formed by reaction and ammonia gas generated by decomposition of melamine expand a carbon layer, and a microporous carbon layer is finally formed, so that air and heat conduction are isolated, a polymer main body (three emulsions) is protected, and the purpose of flame retardance is achieved; that is to say, although the dipentaerythritol, the melamine and the ammonium polyphosphate can independently achieve the purpose of flame retardance, the three flame retardants can play a synergistic role in cooperation, and the flame retardant effect is improved.

The flame retardant principle of the zinc phosphate is as follows: the crystal water is lost after being heated, the process is a strong endothermic reaction, absorbs a large amount of heat, can play a role in cooling a polymer main body (three emulsions), and simultaneously, the water vapor generated by the reaction can dilute combustible gas and support combustion, thereby inhibiting the spread of combustion; meanwhile, when encountering a corrosive medium, the zinc phosphate can react with chloride ions and the like to form zinc salt, so that the corrosion of the corrosive medium on the water-based paint coating substrate is blocked.

The flame retardant principle of the expanded graphite is as follows: at high temperature, the embedded layer in the expandable graphite is easily decomposed by heating, and the interlayer spacing of the graphite is rapidly expanded to dozens of times to hundreds of times by the generated gas; when the expandable graphite is mixed with the polymer main body, a tough carbon layer can be generated on the surface of the polymer main body under the action of flame, so that the flame retardant effect is achieved.

In some embodiments of the present invention, the raw materials for preparing the water-based paint further comprise an auxiliary agent.

In some embodiments of the invention, the adjuvant is at least one of a dispersant, a substrate wetting agent, a defoamer, a mildewcide, a rheology adjuvant, an adhesion promoter, a PH adjuster, and a film forming adjuvant.

In some embodiments of the present invention, the dispersant is added in an amount of 1 to 3 parts by weight.

In some embodiments of the present invention, the dispersant is a polyester-based polymeric dispersant.

The polyester type high molecular dispersing agent has good wetting property and steric hindrance effect, and can enable the filler in the water-based paint to achieve good dispersing effect.

In some embodiments of the invention, the dispersant is selected from at least one of Anjeka6220 and Disperbyk-2015.

The dispersing agent is adsorbed on the surface of the filler through hydroxyl, ether bond and other groups, so that good steric hindrance and same charge repulsion can be formed among the fillers, and meanwhile, the water-soluble chain segment of the dispersing agent has good compatibility with three emulsions; thus, a stable suspension system (comprising the first formulation, the second formulation and the aqueous coating) can be obtained.

In some embodiments of the present invention, the substrate wetting agent is added in an amount of 0.3 to 1.0 parts by weight.

In some embodiments of the present invention, the substrate wetting agent is a polyether modified silicone based substrate wetting agent.

The polyether modified organosilicon base material wetting agent has low surface tension, and can enable the water-based paint to be quickly spread on the surface of a base material to be coated to form a good wetting effect.

In some embodiments of the present invention, the substrate wetting agent is selected from at least one of BYK-3456 and Anjeka 7412.

In some embodiments of the present invention, the defoamer is added in an amount of 0.3 to 1.0 part by weight.

In some embodiments of the invention, the defoamer is a mineral oil based star polymer defoamer prepared by a living radical polymerization (ATRP) process.

The mineral oil-based star polymer defoaming agent has the characteristics of multiple active points and strong microbubble eliminating capability.

In some embodiments of the invention, the antifoaming agent is selected from the group consisting of FoamStar ST 2437 andat least one of A10.

In some embodiments of the present invention, the mildew preventive is added in an amount of 1 to 3 parts by weight.

In some embodiments of the invention, the anti-mold agent is a methylisothiazolinone fungicide, preferably under the designation LJ-222.

The methylisothiazolinone fungicide exerts a bactericidal action by breaking the bonds of proteins in bacteria and algae; after the mildew preventive is contacted with microorganisms, the growth of the mildew preventive can be rapidly and irreversibly inhibited, so that microbial cells are killed, and a coating formed by the water-based paint has a long-acting mildew-proof effect, a corrosion-proof effect and a moisture-proof effect.

In some embodiments of the present invention, the rheological aid is added in an amount of 0.5 to 2 parts by weight.

In some embodiments of the invention, the rheology aid is a hydrophobically modified associative polyurethane thickener.

In some preferred embodiments of the present invention, the rheological aid is at least two of RM-8W, ARS-1, U505 and U905.

In some further preferred embodiments of the present invention, the rheological additive is a mixed rheological additive formed in a mass ratio of ARS-1: U505 to 2: 1.

The action mechanism of the rheological additive is as follows: the micelle (a large amount of molecular ordered aggregates are formed after the concentration of the rheological additive reaches a certain value, in the micelle, hydrophobic groups of rheological additive molecules are aggregated to form a micelle inner core, and hydrophilic polar groups form a micelle outer layer) and emulsion particles are associated to form a network structure, so that the viscosity of the water-based paint is increased, and meanwhile, the micelle also reduces the mobility of water molecules, so that the viscosity of an aqueous phase is also increased; furthermore, by adjusting the combination and the addition amount of the rheological additive, viscosity matching and proper viscosity recovery under three states of low shear rate, medium shear rate and high shear rate can be formed, and the water-based paint with good storage stability and workability is obtained.

In some embodiments of the present invention, the adhesion promoter is added in an amount of 1 to 3 parts by weight.

In some embodiments of the invention, the adhesion promoter is a polyester modified silane product; adhesion promoters under the designation TEGO AddBond DS1300 are preferred.

In the adhesion promoter, the polyester chain segment can provide a good bridging effect for a system on the surface of an organic coating (epoxy primer, electrophoretic primer and the like); the silane chain segment can provide good coupling effect on metal surfaces (carbon steel, aluminum alloy, galvanized plates and the like), so that the silane chain segment can provide excellent adhesion on the surfaces of different substrates after being matched with other components of the water-based paint.

In some embodiments of the present invention, the coalescing agent is added in an amount of 2 to 5 parts by weight.

In some embodiments of the invention, the coalescent is at least one of a dodecyl alcohol ester, ethylene glycol monobutyl ether, diethylene glycol butyl ether, dipropylene glycol methyl ether, and dipropylene glycol butyl ether.

In some embodiments of the invention, the coalescent is a dodecyl alcohol ester: the mass ratio of the diethylene glycol butyl ether to the diethylene glycol butyl ether is 3: 2.

In some embodiments of the present invention, the PH adjusting agent is added in an amount of 0.5 to 3 parts by weight.

In some embodiments of the invention, the pH adjusting agent is at least one of Dimethylethanolamine (DMEA), 2-amino-2-methyl-1-propanol (AMP-95), and Diglycolamine (DGA).

The pH value of the chlorine-vinegar emulsion is 4-7, so that the chlorine-vinegar emulsion is a slightly acidic emulsion; the acrylic emulsion is neutral to weakly alkaline; the compatibility is poor when the two are matched; therefore, the chlorine vinegar emulsion needs to be neutralized to be neutral in advance by the pH regulator, so that the stability of the system can be ensured.

In some embodiments of the present invention, the raw materials for preparing the water-based paint further comprise water, and the water is added in an amount of 15 to 25 parts by weight.

According to a further aspect of the present invention, there is provided a method for preparing the water-based paint, comprising the steps of:

D1. dispersing the styrene-acrylic emulsion and the aluminum silicate fibers to form a first ingredient;

D1. dispersing the remaining filler and the flame retardant to form a second formulation;

D3. and mixing and dispersing the chlorine-vinegar emulsion, the acrylic emulsion, the first ingredient and the second ingredient to obtain the acrylic emulsion.

The preparation method according to a preferred embodiment of the present invention has at least the following advantageous effects:

the preparation method provided by the invention is simple and strong in universality, and meanwhile, the addition sequence of the preparation raw materials is adjusted, so that the dispersion stability of the obtained water-based paint is improved.

In some embodiments of the invention, in step D1, the first formulation, preparation stock further comprises a portion of a dispersant and a portion of a defoamer.

In some embodiments of the invention, the first furnish uses a ratio of partial dispersant to remaining dispersant of 3: (3-4).

In some preferred embodiments of the present invention, the first furnish uses a ratio of partial dispersant to remaining dispersant of 1: 1.

In some embodiments of the invention, the first formulation has a ratio of partial defoamer to remaining defoamer of 2: (2-3).

In some embodiments of the invention, in step D1, the first ingredient, the solvent, is water.

In some embodiments of the present invention, in step D1, the first ingredient is allowed to stand for 16-24 hours before use.

The purpose of standing before use is to fully swell the aluminium silicate fibres.

In some embodiments of the invention, the second furnish, in step D2, further includes the remaining dispersant and defoamer of step D1.

In some embodiments of the invention, step D2, the second compounding further comprises a milling process after the dispersing.

In some embodiments of the present invention, the grinding process is performed by grinding 2-3 times using a three-roll mill.

In some embodiments of the present invention, in step D3, the mixing and dispersing preparation raw material further includes other additives besides the defoaming agent and the dispersing agent, and the remaining water.

In some embodiments of the present invention, the mixing and dispersing in step D3 further includes adding a PH adjuster, a substrate wetting agent, a mildew inhibitor, an adhesion promoter, a film-forming aid, and a rheology aid in sequence for dispersing after the chlorine-vinegar emulsion, the acrylic emulsion, the first ingredient, and the second ingredient are mixed.

In the mixing and dispersing process, the addition sequence of the additives has obvious influence on the performance of the obtained water-based paint, and specifically comprises the following steps: the pH value of the system before the addition of the auxiliary agent is adjusted to be alkalescent, and then other subsequent auxiliary agents can be added; meanwhile, the film forming aid needs to be added first, and then the rheological aid needs to be added, otherwise the rheological aid is ineffective.

According to a further aspect of the invention, the use of said aqueous coating materials in the fields of vehicles and construction and machinery is proposed.

In some embodiments of the invention, the vehicle comprises at least one of an automobile, an aircraft, a water vehicle, and a rail vehicle.

Detailed Description

The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

The description of some embodiments, "exemplary embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Unless otherwise specified, the reagent information used in the detailed description section is as follows:

bisphenol a epoxy resin, available from dow, usa under the model DER 331;

the first catalyst is triphenylphosphine (CAS: 603-35-0);

the polymerization inhibitor is p-tert-butyl catechol (CAS: 98-29-3);

the second catalyst is tetra-n-butylammonium bromide (CAS: 1643-19-2);

the emulsifier is 2-methyl-2-acrylamide sulfate (CAS: 3351-73-3);

the initiator is 2, 2' -azabicyclo (2-imidazoline) dihydrochloride (CAS: 27776-21-2);

dispersant type Anjeka 6220;

the model of the antifoaming agent is FoamStar ST 2437;

the styrene-acrylic emulsion has the model number of

The type of the chlorine vinegar emulsion is LX-1612T;

al in the aluminum silicate fiber₂O₃Not less than 52 wt% (trade mark KB-1260);

the zinc phosphate can pass through a 325-mesh screen, and the zinc content is more than or equal to 45 wt%;

barium sulfate, talcum powder and aluminum hydroxide can pass through a 800-mesh screen;

the mica powder and the argil can pass through a 325-mesh screen;

the type of the titanium dioxide is R-996;

the black paste is BK 17-SK;

the PH regulator is DMEA;

the model of the base material wetting agent is BYK-3456;

the mould inhibitor is LJ-222;

adhesion promoter type TEGO AddBond DS 1300;

the rheological additive comprises ARS-1: U505: 2: 1;

the film-forming additive comprises the following components: diethylene glycol butyl ether is 3: 2.

Example 1

The acrylic emulsion is prepared by the following specific processes:

A1. putting 10- (2, 5-dihydroxyphenyl) -10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), bisphenol A epoxy resin and a first catalyst into a reaction kettle according to a formula; starting stirring, heating to 130 ℃, and reacting until the epoxy equivalent is 350g/mol to obtain a flame-retardant prepolymer;

A2. heating the flame-retardant prepolymer, styrene and a polymerization inhibitor to 105 ℃ according to the formula, dropwise adding an acrylic acid solution dissolved with a second catalyst, carrying out heat preservation reaction for 2.0h, and cooling to 65 ℃;

A3. adding a comonomer, an emulsifier and half of water according to the formula amount, and stirring at a high speed for 1.5h for pre-emulsification to obtain a mixed monomer pre-emulsion;

A4. adding an initiator, and reacting for 4-5h at the temperature of 85 ℃;

A5. adding the rest water for dilution, cooling to 40 ℃, detecting the viscosity and ensuring the solid content to be qualified, and filtering and discharging the material by using 200-mesh silk cloth.

The proportions of the raw materials used in this example are shown in Table 1.

TABLE 1 raw material formulation for preparing acrylic emulsion in examples 1-2 and comparative example 1

Example 2

This example prepares an acrylic emulsion, the specific process differs from example 1 in that:

(1) the raw material formulas are different, and the specific raw material formula is shown in table 1.

Example 3

The embodiment prepares the water-based paint, and the specific preparation method comprises the following steps:

B1. putting deionized water, a first part of dispersing agent, a first part of defoaming agent, styrene-acrylic emulsion and aluminum silicate fiber into a stirring kettle, and stirring at the stirring speed of 500 revolutions per minute for 1.5 hours; standing the dispersed material for 24 hours, and obtaining a first ingredient after the aluminum silicate fiber is fully swelled;

B2. adding deionized water, a second part 1/2 of dispersing agent, a second part of defoaming agent, the rest of filler and flame retardant into a stirring kettle for stirring at the stirring speed of 500 r/min for 1 h;

B3. putting the mixture obtained in the step B2 into a three-roller machine, and grinding for 2 times until no obvious coarse particles exist to obtain a second ingredient;

B4. putting a first ingredient, a second ingredient, the acrylic emulsion, the vinyl chloride-vinyl acetate emulsion, the pH regulator, the substrate wetting agent, the mildew preventive, the adhesion promoter, the film forming aid and the rheological aid which are derived from the acrylic emulsion, the vinyl chloride-vinyl acetate emulsion, the pH regulator, the substrate wetting agent, the mildew preventive, the adhesion promoter and the rheological aid into a stirring kettle in sequence, stirring and mixing at the stirring speed of 800rpm for 1 h;

B5. and (4) adjusting the consistency to a qualified range by using deionized water to obtain the water-based paint.

The formulation of the raw materials used in this example is shown in Table 2.

Table 2 preparation raw material ratios for waterborne coatings in examples 3 to 4

Example 4

This example prepared a waterborne coating using an acrylic emulsion that was still the acrylic emulsion from example 1, and differs from example 3 in that:

(1) the preparation raw materials have different formulas, and the specific formula is shown in table 2.

Comparative example 1

This comparative example prepared an acrylic emulsion, which differs from example 1 specifically in that:

(1) in the step A1, the reaction is stopped when the epoxy equivalent is 1500g/mol-1800g/mol, namely the reaction degree (modification degree) is 95%;

(2) in the step A2, the reaction time is kept at 1h-2 h;

the specific formulation is shown in table 1.

Comparative example 2

This comparative example prepared an acrylic emulsion, which differs from example 1 specifically in that:

(1) the comonomer in example 1 was changed from diacetone acrylamide to lauryl methacrylate.

Comparative example 3

This comparative example prepared a water-based paint, which specifically differed from example 4 in that:

(1) the acrylic emulsion obtained in comparative example 1 was used.

Comparative example 4

This comparative example prepared a water-based paint, which specifically differed from example 3 in that:

(1) the acrylic emulsion obtained in comparative example 2 was used.

Comparative example 5

This example prepares a water-based paint using a commercially available formulation, and the specific process is as follows:

and (3) putting the materials numbered 1-11 in the table 3 into a stirring kettle in sequence according to the weight ratio, starting stirring at a stirring speed of 600 revolutions per minute for 2 hours, adding rheological additives at a stirring speed of 800 revolutions per minute for 30 minutes, adjusting the consistency by using deionized water (numbered 13), and discharging after the materials are qualified.

The raw material ratios used in this comparative example are shown in Table 3.

TABLE 3 raw material ratio of aqueous coating in comparative example 5

Test examples

The first aspect of this test example tested the performance of the acrylic emulsions prepared in examples 1-2 and comparative examples 1-2. Wherein: specific test methods and test results are shown in table 4.

TABLE 4 Performance results of acrylic emulsions obtained in examples 1 to 2 and comparative examples 1 to 2

The comparison of the results of the comparative example 1 and the examples 1-2 shows that if the DOPO-HQ is excessively grafted with the epoxy resin, the subsequent reaction of carboxyl and epoxy groups in the acrylic acid is insufficient, more free acid is generated, the PH is lower than the index requirement, the Tg value is relatively high, and the subsequent adverse effect is generated on the stability of the prepared water-based paint.

In the second aspect of the present test example, the performance of the water-based paint prepared in examples 3 to 4 and comparative examples 3 to 5 was tested, and the test conditions and performance results are shown in table 5.

TABLE 5 test results of the water-based paints obtained in examples 3 to 4 and comparative examples 3 to 5

Remarks 1: the technical requirements of the appearance and the color of the paint are as follows: no crusting, no hard block left after stirring, and gray color;

remarks 2: the technical requirements of the construction performance are as follows: the paint is easy to spray by methods such as compressed air spraying or high-pressure airless spraying, has good leveling property and smooth surface, and has no sagging at 4 mm;

remarks 3: the technical requirements of heat resistance are as follows: vertically putting the sample plate into a 100 +/-2 ℃ oven for 4h, taking out and observing the sample plate, wherein the sample plate has no sagging, no bubbling, no wrinkling and no cracking;

remarks 4: the technical requirements of salt spray resistance are as follows: the plate surface does not blister and is not rusted; the coating has no swelling and no severe softening; the rust or coating failure area at the scratch extends no more than 2mm (one-way).

The results shown in Table 5 show that the water-based paint prepared by the invention has good flame retardance, damping performance and corrosion resistance, the specific oxygen index is more than or equal to 40, the 45-degree combustion is extremely difficult to burn, the flame retardance reaches HL3 level, the composite loss factor at the temperature of-10 ℃ is more than or equal to 0.05, the composite loss factor at the temperature of 20 ℃ is more than or equal to 0.1, and the composite loss factor at the temperature of 50 ℃ is more than or equal to 0.05; the neutral salt spray performance of the single coating is more than or equal to 500 h.

The test results obtained in example 4 and comparative example 3 show that, on the premise of not changing other conditions, the reaction degree (epoxy equivalent) of the acrylic emulsion is changed, and the dielectric resistance, the salt spray resistance and the damping performance of the coating are all changed obviously, wherein the dielectric resistance (acid and alkali resistance) and the salt spray resistance are greatly reduced, and the fundamental reason is as follows: in the acrylic emulsion prepared in the comparative example 1, the DOPO-HQ and the epoxy resin have too high grafting degree, so that the number of epoxy groups reacted with the acrylic resin is insufficient, more free carboxyl groups are generated, the dried coating has stronger hydrophilicity, and the coating fails in advance under the action of a corrosive medium, so that the problems of foaming, softening, stickiness and the like are generated; and because the Tg (glass transition temperature) of the acrylic emulsion synthesized in the comparative example 1 is higher, and the strength of the coating is high at low temperature, the composite loss factor (damping property) of the coating at minus 10 ℃ can not meet the standard requirement.

The test results obtained in example 3 and comparative example 4 are compared; if the diacetone acrylamide monomer as the raw material is replaced by other comonomers when the acrylic emulsion is prepared, although the performances of the obtained acrylic emulsion are not obviously different, the water-based paint containing the corresponding acrylic emulsion has reduced medium (saline water, acid-base) resistance and salt-fog resistance. The fundamental reasons are: in the process of preparing the acrylic emulsion, diacetone acrylamide monomers are not included, so that the obtained acrylic emulsion does not have self-crosslinking property, only latex particles after water volatilization are melted into a film, the compactness and the crosslinking reaction degree of the obtained film are poor, and under the action of a corrosive medium, the wet adhesive force of a paint film fails, so that the paint film is foamed and softened.

In comparative example 5, the acrylic emulsion used is pure acrylic emulsion, which is not self-made, and has poor salt spray resistance; in addition, the filler used in comparative example 5 includes coarse whiting, which is not acid-resistant and is inferior to barium sulfate in salt spray resistance; therefore, the water-based paint obtained in comparative example 5 has a coating layer with reduced cold heat exchange resistance, salt spray resistance and dielectric resistance.

The embodiments of the present invention have been described in detail, but the present invention is not limited to the embodiments, and various changes can be made without departing from the gist of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.