CN110054976B - Aqueous hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomer and preparation method thereof - Google Patents

Abstract

The invention discloses a multi-heterocyclic acrylate monomer modified aqueous hydroxy acrylic acid dispersion and a preparation method thereof. The raw materials comprise, by mass, 20-50 parts of a solvent, 5-10 parts of a multi-heterocyclic acrylate monomer, 50-70 parts of an alkyl acrylate, 25-30 parts of an acrylic functional monomer, 1-3 parts of a chain transfer agent, 2-4 parts of an initiator, 1-3 parts of an anionic reactive emulsifier, 2-4 parts of an initiator, 100 parts of deionized water, 0.1-0.5 part of an antifoaming agent, 0.2-0.6 part of a leveling agent and 0.3-0.8 part of a wetting agent. The glossiness of a paint film is more than 97 degrees, the hardness of the paint film reaches 2H, the paint film has strong impact resistance, good flexibility and excellent adhesive force, simultaneously has excellent chemical corrosion resistance such as acid resistance, alkali resistance, water resistance and the like, meets the national zero VOC (volatile organic compound) paint standard, is environment-friendly, non-toxic and pollution-free, and can be used for water-based wood paint, water-based industrial paint and water-based floor paint.

Description

Aqueous hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomer and its preparation backup method

technical field

The invention relates to a water-based paint, in particular to a water-based hydroxyacrylic acid dispersion modified by a polyheterocyclic acrylate monomer and a preparation method thereof.

Background technique

With the increasingly strict control of VOC emissions in coatings, the use of solvent-based coatings has been unprecedentedly restricted. Environmentally friendly coatings with no or low VOCs are highly valued, and high-performance, aldehyde-free and cross-linked water-based coatings have developed rapidly. Water-based coatings have the advantages of non-flammability, low environmental pollution, and low harm. With the establishment of environmental protection regulations and the enhancement of people's environmental protection awareness, water-based coatings have received extensive attention and are an inevitable trend in the development of the coatings industry.

The hydroxyl components of waterborne two-component polyurethane coatings can be divided into two categories: dispersion type and emulsion type acrylate resin. Dispersion type resin can be divided into polyurethane-acrylate resin hybrid type dispersion, polyurethane dispersion, acrylate resin dispersion Polyester dispersions, polyester dispersions, polyether dispersions, etc. One of the most commonly used resins for the preparation of water-based coatings is acrylic polyol water dispersion. In order to prepare acrylic polyol water dispersion, it is usually required to prepare acrylic polyol resin with higher solid content first, and it is necessary to reduce the relative molecular weight of acrylic polyol to To increase the solid content of the resin. Common approaches include increasing the amount of initiator, using chain transfer agents, increasing solvent and increasing reaction temperature. The hydroxy acrylate resin component and various aliphatic polyisocyanate prepolymer components can be used to make high decorative coatings with light color, excellent gloss and color retention, and good outdoor weather resistance, and can also be made into external anti-corrosion coatings. Decorative paint, such as the finish coating of various large machinery in the port, etc. Because the coating has good external decoration and can be cross-linked and cured at room temperature to form a film, the paint film is wear-resistant, oil-resistant, and has high hardness. variety of decorative and protective coatings.

Many companies and researchers at home and abroad have successfully developed acrylic dispersions, but the product quality is intricate, mainly manifested in low solid content, high viscosity, difficult construction, low hydroxyl content, insufficient crosslinking density of the paint film, mechanical properties and chemicals. Poor resistance, etc. For example, Bayer product Bayhydrol 2646 has high solid content and excellent mechanical properties and chemical resistance, but the product technology is complex and the production cost is high; Wanhua Chemical Antkote 2701 has excellent chemical resistance and high hardness, but the dispersion viscosity is high, It is not conducive to construction; Wanhua Chemical Antkote 2703 has low viscosity and excellent mechanical properties, but the solid content of the dispersion product is low, only 41%, and more curing agent will be consumed when it is mixed with curing agent.

Chinese invention patent application CN108359048A discloses a sulfonate-containing polyacrylate aqueous dispersion and its preparation method and application. The polyacrylate aqueous dispersion is successfully prepared by solution polymerization, neutralization process, solvent removal, and emulsification process , The introduction of vinyl sulfonate monomer into the dispersion contains a large number of hydroxyl groups, which can form a three-dimensional cross-linked network structure after mixing with the curing agent, and improve the water resistance and alcohol resistance of the paint film. However, the solid content of the dispersion prepared by this method is only 20-40%, and the solid content is low. When the water is mixed with the curing agent, a large amount of the curing agent will be consumed, the coating cost will be increased, and the performance of the paint film will be reduced.

Chinese invention patent application CN106854285A discloses a water-based hydroxyacrylic acid dispersion and a preparation method thereof. The water-based hydroxyacrylic acid dispersion is successfully prepared by slowly adding a hydroxyl-containing monomer and an initiator three times to propylene glycol butyl ether and epoxy resin. After being mixed with amine resin, it can be cured at high temperature, and the paint film has good adhesion, full paint film and good weather resistance. However, the reaction temperature of this method is 140-200 ° C, and the reaction temperature is high, which increases the production cost and safety hazard; at the same time, the monomer and the initiator are added dropwise three times, and the total reaction time reaches 8.5-9 hours. Production cycle.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a kind of water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers and a preparation method thereof in view of the deficiencies of the above-mentioned technologies; the reaction temperature of the preparation method is 70-80° C., and the reaction time is controlled At 6-7h, the dispersion solid content is 44-45%, and the paint films prepared with this dispersion have high adhesion, high gloss, high fullness, excellent chemical resistance and physico-mechanical properties.

In the present invention, the hydrophobic polymer containing epoxy group and the hydrophilic polymer containing carboxyl group and sulfonic acid group are successfully co-emulsified into one dispersed particle through the acetone treatment process, and the two polymers have similar polarity and Intermolecular force, the co-emulsification process hydrophilic polymer is wrapped on the surface of the hydrophobic polymer to form particles with a particle size of 100-300nm, the excess hydrophilic polymer forms particles with a particle size of 50-70nm, and the small particles are embedded in the large particles. Between particles, the bulk density of the dispersion particles is significantly increased, so that a hydroxyacrylic acid dispersion with high solid content and low viscosity can be prepared. The oxygen atom in the epoxy group is more electronegative than the carbon atom, which increases the electron cloud density around the oxygen atom, so that the epoxy group forms two reactive centers that can react. The introduction of the epoxy group gives the acrylic acid dispersion Under the action of the curing agent, the epoxy group can significantly increase the crosslinking density and compactness of the paint film after sufficient crosslinking, and at the same time increase the hardness of the paint film.

Hydroxyacrylic acid dispersions were successfully modified with polyheterocyclic acrylate monomers, which have ultra-low odor, high glass transition temperature, and high refractive index; The viscosity reduction effect is better than that of isobornyl (meth)acrylate, which can significantly increase the adhesion of the paint film, improve the hardness, and improve the weather resistance and alcohol resistance of the paint film. Introducing hydroxy monomer and polyheterocyclic acrylate monomer into acrylic dispersion, the prepared dispersion has a large number of hydrogen bonds and intramolecular interactions, hydroxy acrylic dispersion has high ionic stability, strong mechanical stability, dilution stability Well, there is little change in viscosity and solids after storage for more than 6 months. The paint film prepared by mixing the hydroxyacrylic acid dispersion and the polyurethane curing agent can be cured at room temperature. The post-crosslinking ability of the dispersion helps the paint film to form a three-dimensional spatial cross-linked network structure, which increases the compactness of the paint film and gives the paint film. Excellent water resistance, chemical resistance and other resistance and excellent physical and mechanical properties. The present invention adopts part of anionic reactive emulsifier to replace (meth)acrylic monomer, and the anionic reactive emulsifier has hydrophilic group, hydrophobic group and polymer group, wherein the hydrophobic group contains 10-20 carbon atoms and has Lipophilic and hydrophobic ability, the hydrophobic segment of the anionic reactive emulsifier enters the polymer particle during the emulsification process, the alkali thickening effect is not obvious, and the prepared hydroxyacrylic acid dispersion has low viscosity. Using water as solvent and alcohol ethers as co-solvents can be cured with curing agent to form a film, which is environmentally friendly, non-toxic and non-polluting. The paint film prepared by hydroxyacrylic dispersion has high gloss, high half fullness and hardness, excellent chemical resistance and adhesion, and can be used in water-based wood paint, water-based industrial paint and water-based floor paint. The experimental operation process is simple, energy saving, environmental protection and non-toxic, and has a good commercial application prospect.

The technical scheme adopted by the present invention to solve its technical problems is:

The waterborne hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomer, in parts by mass, its raw material components are:

The acrylic functional monomer is one or more of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate and glycidyl methacrylate;

The polyheterocyclic acrylate monomer is one or more of isobornyl acrylate, isobornyl methacrylate, glycidyl tertiary carbonate and polyheterocyclic acrylate monomer SW914;

The anionic reactive emulsifier is one or more of ADEKA REASOAP SR-10, ADEKA REASOAP SR-20, ADEKA REASOAP ER-10 and ADEKA REASOAP ER-20;

The solvent is one or more of acetone, methyl ethyl ketone, dipropylene glycol butyl ether and propylene glycol butyl ether.

To further achieve the object of the present invention, preferably, the alkyl acrylate is one or more of methyl acrylate, ethyl acrylate, n-butyl acrylate and methyl methacrylate.

Preferably, the chain transfer agent is one or more of mercaptoethanol, dodecanethiol and mercaptopropionic acid.

Preferably, the initiator is one or more of azobisisobutyronitrile, azobisisoheptanenitrile and benzoyl peroxide.

Preferably, the neutralizing agent is one or more of N, N-dimethylethanolamine, ethanolamine, diethanolamine, triethanolamine and triethylamine.

Preferably, the antifoaming agent is polysiloxane type LG-20GB antifoaming agent, polysiloxane type LG-20GA antifoaming agent, polysiloxane type LG-10 antifoaming agent, polyether type PE - One or more of Q600 defoamer and SI-510Z defoamer.

Preferably, the leveling agent is one or more of TEGO 410, TEGO 450, TEGO Glide 100 and TEGO Flow 370; the wetting agent is Keying Chemical 642, Keying Chemical 643, Keying Chemical One or more of CHEM 648 and KEYING CHEM 546.

The preparation method of the water-based hydroxyacrylic acid dispersion modified by the polyheterocyclic acrylate monomer is characterized in that it comprises the following steps:

1) Solution polymerization: Mix the solvent and the polyheterocyclic acrylate monomer, and the temperature is raised to 70-80 °C, and the polyheterocyclic acrylate monomer solution is obtained; the alkyl acrylate, acrylic acid functional monomer, chain transfer Mixing agent and initiator to form mixed monomer; take out 5-10wt% of mixed monomer and polyheterocyclic acrylate monomer solution and mix, keep at 70-80 ℃ for 15-30 minutes; under stirring for 4-5 hours Add the remaining 90-95wt% mixed monomer and anionic reactive emulsifier, keep the temperature for 1-2 hours; lower the temperature to below 50°C, and add the neutralizing agent dropwise;

2) Acetone treatment process: add deionized water after neutralization, carry out high-speed shear emulsification, put the emulsified product into a rotary evaporator, set the temperature to 50-60 ° C, and rotate to distill out the acetone and acetone contained in the dispersion. Part of alcohol ether solvent;

3) Preparation of paint film: adding defoamer, leveling agent and wetting agent to the product obtained in step 2), and using a high-speed disperser to stir at a high speed for 10-20 minutes, the obtained product is allowed to stand for 4-6 hours and then mixed with the product. The curing agent is mixed to prepare the paint film.

Preferably, the dropwise addition of the neutralizing agent is completed within 30 minutes; after the neutralization is completed, deionized water is added to the product within 30 minutes.

Preferably, the stirring speed in the solution polymerization is 100-300rpm; the high-speed shearing speed is 1000-3000rpm, and the emulsification time is 15-30min; the curing agent is Bayhydur 304, Bayhydur XP2655 and Garbo One or more of the Lily G610.

Compared with the prior art, the present invention has the following outstanding effects:

1. The acrylic dispersions in the prior art mainly include low product solid content, high product viscosity, difficult construction, low hydroxyl content, insufficient paint film crosslinking density, poor mechanical properties and chemical resistance, etc. In the present invention, the hydrophobic polymer containing epoxy group and the hydrophilic polymer containing carboxyl group and sulfonic acid group are successfully co-emulsified into one dispersed particle through the acetone treatment process, and the two polymers have similar polarities and molecules. In the co-emulsification process, the hydrophilic polymer is wrapped on the surface of the hydrophobic polymer to form particles with a particle size of 100-300 nm, the excess hydrophilic polymer forms particles with a particle size of 50-70 nm, and the small particles are embedded in the large particles. In between, the bulk density of the dispersion particles is significantly increased, so that a hydroxyacrylic acid dispersion with a solids content of 44-45% and a viscosity of 1000-3000 cp can be prepared. The introduction of epoxy groups endows the acrylic dispersion with post-crosslinking ability. Under the action of the curing agent, the epoxy groups can significantly increase the crosslinking density and compactness of the paint film after sufficient crosslinking, and at the same time increase the hardness of the paint film.

2. The present invention successfully modifies the hydroxyacrylic acid dispersion by using polyheterocyclic acrylate monomers. The polyheterocyclic acrylate monomers have ultra-low odor, high glass transition temperature and high refractive index; polyheterocyclic acrylic acid The viscosity reduction effect of the ester monomer is better than that of isobornyl (meth)acrylate, which can significantly increase the adhesion of the paint film, improve the hardness, and improve the weather resistance and alcohol resistance of the paint film. The prepared dispersion has high solid content, and meanwhile, the dispersion has low viscosity, low odor, and is environmentally friendly, non-toxic and non-polluting.

3. Introducing hydroxy monomer and polyheterocyclic acrylate monomer into acrylic dispersion, the prepared dispersion has a large number of hydrogen bonds and intramolecular interactions, hydroxy acrylic dispersion has high ionic stability, strong mechanical stability, dilution Good stability, the storage time is more than 6 months. The paint film prepared by mixing the hydroxyacrylic acid dispersion and the curing agent can be cured at room temperature. The post-crosslinking ability of the dispersion helps the paint film to form a three-dimensional spatial cross-linked network structure, which increases the compactness of the paint film and gives the paint film excellent High water resistance, chemical resistance and excellent physical and mechanical properties; the hardness of the paint film is as high as 2H, the paint film has strong impact resistance, good flexibility, excellent adhesion, and has excellent acid resistance, alkali resistance, water resistance, etc. Chemical corrosive properties.

4. The general acrylic dispersion is to introduce a (meth)acrylic hydrophilic monomer on the polymer segment to achieve the purpose of hydrophilicity, and the α position of the (meth)acrylic monomer is a methyl group or a hydrogen atom, The hydrophobicity of the two is not enough, and the (meth)acrylic monomer tends to be distributed on the surface of the polymer particles during the emulsification process, and has a strong alkali thickening effect, which will significantly increase the viscosity of the dispersion. The present invention adopts part of anionic reactive emulsifier to replace (meth)acrylic monomer, and the anionic reactive emulsifier has hydrophilic group, hydrophobic group and polymer group, wherein the hydrophobic group contains 10-20 carbon atoms and has Lipophilic and hydrophobic ability, the hydrophobic segment of the anionic reactive emulsifier enters the polymer particle during the emulsification process, the alkali thickening effect is not obvious, and the prepared hydroxyacrylic acid dispersion has low viscosity.

5. The water-based hydroxyacrylic acid dispersion prepared by the present invention uses water as a solvent, and alcohol ethers as a co-solvent can be cured with a curing agent to form a film.

6. The paint film prepared by the hydroxyacrylic acid dispersion of the present invention has high gloss, the gloss of the paint film is greater than 97°, high half-fullness and hardness, excellent chemical resistance and adhesion, and can be used for water-based wood paint , water-based industrial paint and water-based floor paint.

7. The preparation method of the present invention has the advantages of simple operation process, energy saving, environmental protection and non-toxicity, and has a good commercial application prospect.

Description of drawings

1 is the infrared spectrum of the aqueous hydroxyacrylic acid dispersion obtained in Example 5.

FIG. 2 is a DSC curve diagram of the aqueous hydroxyacrylic acid dispersion obtained in Example 5. FIG.

Detailed ways

In order to better understand the present invention, the present invention is further described below with reference to specific embodiments, but the embodiments do not constitute a limitation on the protection scope of the claims of the present invention.

Example 1

The preparation method of the water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers comprises the following steps:

1) solution polymerization: in parts by mass, 20 parts of acetone solvent and 5 parts of isobornyl acrylate were mixed into a four-necked flask, and the temperature was raised to 70 ° C; 30 parts of methyl methacrylate, 20 parts of acrylic acid were Butyl ester, 23 parts of hydroxypropyl acrylate, 1 part of glycidyl methacrylate, 2 parts of acrylic acid, 1 part of dodecanethiol and 2 parts of azobisisobutyronitrile are mixed to obtain mixed monomers; take out 5wt% of mixed monomers The monomer was quickly added to the four-necked flask, and kept at 70°C for 15 minutes; after the incubation, the remaining 95% of the mixed monomer and 1 part of SR-10 were fed into the four-necked flask within 4 hours. In the flask, the temperature was kept for 1 hour after the dropwise addition was completed. Lower the temperature to below 50°C, and add 3 parts of triethylamine dropwise within 30 minutes.

2) Acetone treatment process: in parts by mass, 100 parts of deionized water were added to step 1) in 30 minutes after the neutralization was completed to carry out high-speed shear emulsification, and the emulsified product was put into a rotary evaporator, The temperature was set to 50°C, and the acetone and part of the alcohol ether solvent contained in the dispersion were distilled off by rotary distillation.

3) Preparation of paint film: in parts by mass, add 0.1 part of polysiloxane type LG-20GB defoamer, 0.2 part of TEGO410 leveling agent and 0.3 part of Keying Chemical 642 to the product obtained in step 2), Use a high-speed disperser to stir at a high speed for 15 minutes, and after standing for 4 hours, the obtained product is mixed with Bayhydur XP2655 curing agent in a mass ratio of 4:1 to prepare a paint film.

Example 2

The preparation method of the water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers comprises the following steps:

1) Solution polymerization: in parts by mass, mix 20 parts of acetone, 10 parts of methyl ethyl ketone and 6 parts of isobornyl methacrylate into a four-necked flask, and the temperature is raised to 72°C; Methyl methacrylate, 25 parts of n-butyl acrylate, 25 parts of hydroxyethyl acrylate, 2 parts of glycidyl methacrylate, 3 parts of methacrylic acid, 2 parts of mercaptoethanol and 2.5 parts of azobisisoheptanenitrile were mixed to obtain Mix the monomers; take out 6wt% of the mixed monomers and quickly add them to the four-necked flask, keep at 72°C for 20 minutes; after the insulation is over, add the remaining 94wt% of the mixed monomers and 2 parts of SR-20 within 4.2 hours Feed together into the described four-necked flask, and keep the temperature for 1 hour after the dropwise addition. The temperature was lowered to below 50°C, and 4 parts of N,N-dimethylethanolamine were added dropwise within 30 minutes.

2) Acetone treatment process: in parts by mass, 110 parts of deionized water were added to the product within 30 minutes to carry out high-speed shear emulsification, and the emulsified product was put into a rotary evaporator, and the set temperature was At 55°C, the acetone and part of the alcohol ether solvent contained in the dispersion were distilled off by rotary distillation.

3) Preparation of paint film: In parts by mass, 0.2 part of polysiloxane type LG-20GA defoamer, 0.3 part of TEGO450 leveling agent and 0.4 part of Keying Chemical 643 were added to the above-mentioned products, and high-speed dispersion was used. The machine was stirred at high speed for 20 minutes, and the obtained product was allowed to stand for 4.5 hours and then mixed with Bayhydur 304 curing agent according to a mass ratio of 4:1 to prepare a paint film.

Example 3

The preparation method of the water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers comprises the following steps:

1) solution polymerization: in parts by mass, 30 parts of acetone, 20 parts of propylene glycol butyl ether and 7 parts of polyheterocyclyl acrylate monomers SW914 were mixed and put into a four-necked flask, and the temperature was raised to 74 ° C; 30 parts of Ethyl acrylate, 30 parts of n-butyl acrylate, 26 parts of hydroxyethyl methacrylate, 3 parts of glycidyl methacrylate, 4 parts of acrylic acid, 3 parts of mercaptopropionic acid and 3 parts of benzoyl peroxide are mixed to obtain a mixed monomer; take out 7wt% of the mixed monomer and quickly add it to the four-necked flask, keep it at 74°C for 25 minutes; after the insulation is over, add the remaining 93wt% of the mixed monomer and 1 part of SE-10 within 4.4 hours The feed was added to the four-necked flask, and the temperature was kept for 1 hour after the dropwise addition. Lower the temperature to below 50°C, and add 5 parts of triethanolamine dropwise within 30 minutes.

2) Acetone treatment process: in parts by mass, 115 parts of deionized water were added to the product within 30 minutes to carry out high-speed shear emulsification, and the emulsified product was put into a rotary evaporator, and the set temperature was At 60°C, the acetone and part of the alcohol ether solvent contained in the dispersion were distilled off by rotary distillation.

3) Preparation of paint film: in parts by mass, add 0.3 part of polysiloxane type LG-10 defoamer, 0.4 part of TEGOGlide 100 leveling agent and 0.5 part of Keying Chemical 648 The disperser was stirred at high speed for 10 minutes, and the obtained product was allowed to stand for 5 hours and then mixed with Carpoly G610 curing agent according to a mass ratio of 4:1 to prepare a paint film.

Example 4

The preparation method of the water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers comprises the following steps:

1) solution polymerization: in parts by mass, 20 parts of acetone, 40 parts of dipropylene glycol butyl ether and 8 parts of isobornyl acrylate were mixed and put into a four-necked flask, and the temperature was warming up to 76 ℃; 30 parts of ethyl acrylate, 30 parts of n-butyl acrylate, 24 parts of hydroxypropyl methacrylate, 1 part of glycidyl methacrylate, 5 parts of methacrylic acid, 2 parts of dodecanethiol and 3 parts of azobisisobutyronitrile are mixed to obtain a mixed mono Take out 8wt% of the mixed monomer and quickly add it to the four-necked flask, keep at 76°C for 20 minutes; 20 feeds were added into the four-necked flask, and the temperature was kept for 1 hour after the dropwise addition. The temperature was lowered to below 50°C, and 6 parts of diethanolamine were added dropwise within 30 minutes.

2) Acetone treatment process: in parts by mass, 120 parts of deionized water were added to the product within 30 minutes to carry out high-speed shear emulsification, and the emulsified product was put into a rotary evaporator, and the set temperature was At 55°C, the acetone and part of the alcohol ether solvent contained in the dispersion were distilled off by rotary distillation.

3) Preparation of paint film: In parts by mass, 0.4 part of polyether PE-Q600 defoamer, 0.5 part of TEGO Flow370 leveling agent and 0.6 part of Keying Chemical 546 were added to the above product, and a high-speed disperser was used. The product was stirred at high speed for 20 minutes, and after standing for 5.5 hours, the obtained product was mixed with Bayhydur 304 curing agent in a mass ratio of 4:1 to prepare a paint film.

Example 5

The preparation method of the water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers comprises the following steps:

1) solution polymerization: in parts by mass, 30 parts of methyl ethyl ketone, 40 parts of propylene glycol butyl ether and 10 parts of polyheterocyclic acrylate monomers SW914 were mixed and put into a four-necked flask, and the temperature was warming up to 80° C. ; 35 parts of methyl acrylate, 35 parts of n-butyl acrylate, 24 parts of hydroxypropyl acrylate, 3 parts of glycidyl methacrylate, 6 parts of methacrylic acid, 3 parts of dodecanethiol and 3 parts of azodiisobutyl Mix the nitrile to obtain the mixed monomer; take out 10wt% of the mixed monomer and quickly add it to the four-necked flask, keep at 80°C for 30 minutes; 1.5 parts of SR-10 feed was added to the four-necked flask, and the temperature was kept for 1 hour after the dropwise addition. Lower the temperature to below 50°C, and add 7 parts of ethanolamine dropwise within 30 minutes.

2) Acetone treatment process: in parts by mass, 120 parts of deionized water were added to the product within 30 minutes to carry out high-speed shear emulsification, and the emulsified product was put into a rotary evaporator, and the set temperature was At 60°C, the acetone and part of the alcohol ether solvent contained in the dispersion were distilled off by rotary distillation.

3) Preparation of paint film: in parts by mass, add 0.5 part of SI-510Z defoamer, 0.6 part of SI-510Z leveling agent and 0.8 part of Keying Chemical 546 to the above product, and use a high-speed disperser to stir at a high speed. For 20 minutes, the obtained product was allowed to stand for 6 hours and then mixed with Carpoly G610 curing agent in a mass ratio of 4:1 to prepare a paint film.

Fig. 1 is the infrared spectrum of the aqueous hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomer prepared in Example 5: 3440cm ^-1 is a typical hydroxyl absorption peak, 3364cm ^-1 is NH after neutralization by neutralizer ₂ characteristic peaks, 2933cm ^-1 and 2896cm ^-1 are the stretching vibration peaks of methylene and methyl groups, 1730cm ^-1 is the absorption peak of C=O bond in the ester carboxyl group, 1575cm ^-1 proves the successful introduction of anionic reactive emulsifier, 1029 The characteristic absorption peak of ester appears at -1458cm ^-1 , the double bond stretching vibration absorption peak at 1640cm ^-1 and the double bond out-of-plane bending vibration absorption peak at 990cm ^-1 disappear, indicating that the double bond has been polymerized, and the 912cm ^-1 is Characteristic absorption peaks of epoxy groups. Through the above data analysis, it is indicated that Example 5 has prepared a polyheterocyclic acrylate monomer-modified aqueous hydroxyacrylic acid dispersion.

Fig. 2 is the DSC curve diagram of the aqueous hydroxyacrylic acid dispersion modified by the polyheterocyclic acrylate monomer prepared in Example 5, and it can be obtained that the glass transition temperature of the dispersion is 16.6°C. According to the FOX empirical formula, the ratio of soft and hard monomers is controlled, and the glass transition temperature of the polymer is set to 16°C, which is not much different from the glass transition temperature of the product. The lower glass transition temperature endows the paint film with excellent flexibility, reduces the brittleness of the paint film, and enables the prepared dispersion to have excellent flexibility. The dispersion and the curing agent are mutually matched, and the hydroxyl group and the isocyanate group react to form a three-dimensional space cross-linked network structure, which increases the compactness and hardness of the paint film, giving the paint film excellent water resistance, chemical resistance and other resistance and excellent physical properties. Mechanical behavior.

The above-mentioned products of Examples 1 to 5 were tested for performance. According to the following standards, performance tests were carried out on the prepared polyheterocyclic acrylate monomer-modified aqueous hydroxyacrylic dispersions.

Determine the viscosity of the dispersion according to GB/T 11543-1989;

Determination of non-volatile content of dispersions according to GB/T 1725-2007;

Determination of dispersion stability and VOC content according to GBT20623-2006;

The test results obtained are shown in Table 1:

Table 1 Performance test results of water-based hydroxyacrylic acid dispersions modified by polyheterocyclic acrylate monomers

The data in Table 1 shows: the solid content of the aqueous hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers reaches 44-45%, the solid content is high, the viscosity is 1000-3000cp, the viscosity of the dispersion is low, and the production efficiency is high. High, low transportation cost, fast drying rate, low energy consumption, large-scale production and other advantages; the dispersion has good storage stability, and the dispersion viscosity and solid content are almost unchanged after standing for 6 months. There is no phenomenon such as gel flocculation after mixing the dispersion and the water-based polyurethane curing agent, and the compatibility with the water-based polyurethane curing agent is good. The dispersion has strong mechanical stability, which is conducive to the stability of the dispersion during the stirring process, thereby ensuring excellent performance. ; Good dilution stability, the solid content and viscosity of the dispersion can be adjusted by water to meet the construction requirements; the VOC content of the dispersion is extremely low, in line with the national zero VOC paint standard, environmentally friendly, non-toxic and non-polluting.

According to GB/T 1728-1989, the surface dryness and actual dryness of the paint film are determined;

Determine the hardness of the paint film according to GB/T 6739-2006;

Determine the adhesion of paint film according to GB/T 6739-2006;

Determine the impact resistance of the paint film according to GBT 1732-93;

Determine the flexibility of the paint film according to GB/T 1731-1993;

Determine the gloss of the paint film according to GB/T 9754-2007;

Determine the acid and alkali resistance of the paint film according to GB/T 9274-1988;

Determine the water resistance of the paint film according to GB/T 5209-1985;

The test results obtained are shown in Table 2:

Table 2 Test results of performance of water-based hydroxyacrylic acid dispersion paint film

The data in Table 2 are the performance test results of Example 1-5: In Example 1-5, the surface drying time of the paint film is 40-60min, the surface drying time of the paint film is fast, and the hardness is established quickly, which is conducive to shortening the Construction time. Hydroxyl groups react with isocyanate groups to form a dense paint film, and the cross-linking ability of the dispersion will also increase the density of the paint film, improve the hardness and impact resistance of the paint film, so that the impact resistance of the example paint film reaches 100cm, hardness Up to 2H, the impact resistance and hardness are higher, which is beneficial to resist physical damage and the durability of the paint film will be better. The polyheterocyclic acrylate monomer can significantly increase the adhesion of the paint film, and there are more hydrogen bonds in the dispersion, so that a strong inter-molecular force is formed between the paint film and the substrate, and the overall paint film is The adhesion reaches grade 0, the paint film is not easy to fall off, and the coated items are better protected.

According to the FOX empirical formula, the glass transition temperature of the dispersion is designed to be 16°C, and the actual glass transition temperature of the dispersion tested by DSC is 16.6°C. The lower glass transition temperature gives the paint film excellent flexibility, and the flexibility of the paint film reaches 1mm. By controlling the pre-added amount and pre-reaction time of the mixed monomer, and then through high-speed dispersion and emulsification, a dispersion with a smaller particle size is prepared. The paint film prepared from the dispersion with a smaller particle size has a high gloss, and the product (60°) The gloss exceeds 97°, resulting in a high fullness of the paint film. The paint film prepared after the hydroxyacrylic dispersion and the polyurethane curing agent are mixed together. The post-crosslinking ability of the dispersion helps the paint film to form a three-dimensional spatial cross-linked network structure and a dense physical barrier layer, reducing the presence of fine particles inside the paint film. Voids and cracks significantly improve the chemical resistance of the paint film, and the acid resistance, alkali resistance and water resistance of the paint film have passed the national standard test.

The invention adopts the compound method of two hydrophilic monomers, acrylic acid and anionic reactive emulsifier, which effectively reduces the alkali thickening effect of the acrylic emulsion and reduces the viscosity of the dispersion; The synergistic effect of the two can reduce the relative molecular weight of the macromolecular polymer, and the small molecular weight polymer is easier to disperse and emulsify in water, and then the solid content of 44-45% can be prepared. acrylic dispersion.

The present invention adopts the low-temperature initiator azo initiator or peroxy initiator, which has the advantages of short half-life, high initiation efficiency, fast reaction rate, easy reaction control, etc. The reaction temperature of the present invention is 70-80° C. react normally.

The present invention uses a part of the ketone solvent, the boiling point of the ketone solvent is low, and the ketone solvent evaporates and refluxes rapidly at 70-80 DEG C, which is beneficial to the mass transfer, heat transfer and chemical reaction inside the reaction device, so the reaction is carried out at 5-80°C. Completed in 6 hours.

The solid content of the dispersion prepared by Chinese invention patent application CN108359048A is only 20-40%. The solid content is too low. In the process of mixing with the curing agent, the water will consume more curing agent, resulting in the formed paint film with poor compactness and mechanical properties. Poor chemical resistance and poor chemical resistance, while low-solids dispersions produce low gloss films, making it impossible to make high-gloss paint films. The dispersion prepared by the present invention has a viscosity of 1000-3000cp and a solid content of 44-45%. Such a low-viscosity and high-solid dispersion can prepare a dense paint film with excellent physical and chemical properties, and can prepare a high-gloss paint film. Paint film, used in high-gloss topcoats and anti-corrosion coatings.

Chinese invention patent application CN106854285A The reaction temperature is 140-200°C, the reaction temperature is high, the total reaction time reaches 8.5-9 hours, and the reaction time is too long, which increases the production cycle of the product. However, the present invention adopts a low-temperature initiator, the reaction temperature is 70-80 DEG C, the reaction temperature is low, the required heat is less, and the production cost of the factory is reduced. The invention can ensure that the reaction time is only 5-6 hours while the reaction temperature is low, and the production cycle of the product can be effectively reduced.

It can be seen that the polyheterocyclic acrylate monomer-modified aqueous hydroxyacrylic acid dispersion of the present invention has relatively low preparation cost, is environmentally friendly, has high gloss, high fullness, excellent chemical resistance and physical and mechanical properties, and the production process Simple, stable product storage and convenient transportation, environmentally friendly and non-toxic, can be widely used in water-based floor paint, water-based wood paint, water-based anti-corrosion paint and other coatings.

The embodiments of the present invention are not limited by the above examples, and any other changes and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention. within.

Claims (10)

1. the water-based hydroxy acrylic acid dispersion modified by polyheterocyclic acrylate monomer is characterized in that, in parts by mass, its raw material component is: 20-50 parts of solvent 50-70 parts of alkyl acrylate 25-30 parts of acrylic functional monomer 5-10 parts of polyheterocyclic acrylate monomers Anionic reactive emulsifier 1-3 parts 1-3 parts of chain transfer agent 2-4 parts of initiator 3-7 copies of neutralizer 100-120 parts of deionized water Defoamer 0.1-0.5 parts Leveling agent 0.2-0.6 parts Wetting agent 0.3-0.8 parts The acrylic functional monomer is one or more of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate and glycidyl methacrylate; The polyheterocyclic acrylate monomer is one or more of isobornyl acrylate, isobornyl methacrylate, glycidyl tertiary carbonate and polyheterocyclic acrylate monomer SW914; The anionic reactive emulsifier is one or more of ADEKA REASOAP SR-10, ADEKA REASOAP SR-20, ADEKA REASOAP ER-10 and ADEKA REASOAP ER-20; Described solvent is one or more in acetone, methyl ethyl ketone, dipropylene glycol butyl ether and propylene glycol butyl ether; The preparation method of the paint film of the water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers comprises the following steps: 1) Solution polymerization: Mix the solvent and the polyheterocyclic acrylate monomer, the temperature is raised to 70-80 ° C, and the polyheterocyclic acrylate monomer solution; Mix the alkyl acrylate, acrylic functional monomer, chain transfer agent and initiator , form a mixed monomer; take out 5-10wt% of the mixed monomer and the polyheterocyclic acrylate monomer solution and mix, keep at 70-80 ℃ for 15-30 minutes; add the remaining 90% within 4-5 hours under stirring -95wt% mixed monomer and anionic reactive emulsifier, keep warm for 1-2 hours; lower the temperature to below 50℃, add neutralizer dropwise; 2) Acetone treatment process: add deionized water after neutralization, carry out high-speed shear emulsification, put the emulsified product in a rotary evaporator, set the temperature to 50-60 °C, and rotate to distill out the acetone and acetone contained in the dispersion. Part of alcohol ether solvent; 3) Preparation of paint film: add defoamer, leveling agent and wetting agent to the product obtained in step 2), stir at a high speed with a high-speed disperser for 10-20 minutes, and the obtained product is allowed to stand for 4-6 hours. The curing agent is mixed to prepare the paint film. 2. The water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers according to claim 1, wherein the alkyl acrylate is methyl acrylate, ethyl acrylate, n-butyl acrylate and one or more of methyl methacrylate. 3. The water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers according to claim 1, wherein the chain transfer agent is one of mercaptoethanol, dodecyl mercaptan and mercaptopropionic acid. one or more. 4. The water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers according to claim 1, wherein the initiator is azobisisobutyronitrile, azobisisoheptanenitrile and One or more of benzoyl peroxide. 5. The water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers according to claim 1, wherein the neutralizing agent is N, N-dimethylethanolamine, ethanolamine, diethanolamine , one or more of triethanolamine and triethylamine. 6. The water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers according to claim 1, wherein the defoamer is a polysiloxane type LG-20GB defoamer, a poly One or more of silicone-type LG-20GA defoamer, polysiloxane-type LG-10 defoamer, polyether-type PE-Q600 defoamer and SI-510Z defoamer. 7. The water-based hydroxyacrylic acid dispersion modified by polyheterocyclic acrylate monomers according to claim 1, wherein the leveling agent is TEGO 410, TEGO 450, TEGO Glide 100 and TEGO Flow 370 One or more of; the wetting agent is one or more of Keying Chemical 642, Keying Chemical 643, Keying Chemical 648 and Keying Chemical 546. 8. the preparation method of the paint film of the polyheterocyclic acrylate monomer modified water-based hydroxyacrylic acid dispersion described in any one of claim 1-7, is characterized in that comprising the steps: 1) Solution polymerization: Mix the solvent and the polyheterocyclic acrylate monomer, the temperature is raised to 70-80 ° C, and the polyheterocyclic acrylate monomer solution; Mix the alkyl acrylate, acrylic functional monomer, chain transfer agent and initiator , to form a mixed monomer; take out 5-10wt% of the mixed monomer and the polyheterocyclic acrylate monomer solution and mix, keep at 70-80 ℃ for 15-30 minutes; add the remaining 90% within 4-5 hours under stirring -95wt% mixed monomer and anionic reactive emulsifier, keep warm for 1-2 hours; lower the temperature to below 50℃, add neutralizer dropwise; 2) Acetone treatment process: after neutralization, add deionized water, carry out high-speed shear emulsification, put the emulsified product into a rotary evaporator, set the temperature to 50-60 °C, and rotate to distill out the acetone and acetone contained in the dispersion. Part of alcohol ether solvent; 3) Preparation of paint film: add defoaming agent, leveling agent and wetting agent to the product obtained in step 2), use a high-speed disperser to stir at high speed for 10-20 minutes, and the obtained product is allowed to stand for 4-6 hours. The curing agent is mixed to prepare the paint film. 9. the preparation method of the paint film of the water-based hydroxy acrylic acid dispersion modified by polyheterocyclic acrylate monomer according to claim 8, is characterized in that, described dripping neutralizer is dripping in 30 minutes Addition is complete; deionized water is added to the product within 30 minutes after neutralization is complete. 10. The method for preparing a paint film of a polyheterocyclic acrylate monomer-modified aqueous hydroxyacrylic acid dispersion according to claim 8, wherein the stirring speed in the solution polymerization is 100-300rpm; The high-speed shearing speed is 1000-3000rpm, and the emulsification time is 15-30min; the curing agent is one or more of Bayhydur 304, BayhydurXP2655 and Carpoly G610.

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