CN1434063A - Aqueous epoxy modified acrylic heat-reflecting thermo-insulating coating - Google Patents

Abstract

The present invention relates to an epoxy modified polyacrylic emulsion and its preparation, and aqueous heat-reflected heat-insualting paint using said emulsion as base material. Said invented heat-reflected heat-insulating paint is made up by using epoxy modified polyacrylic emulsion as base material, and mixing it with pigment, filling material, hollow glass bead, electric power plant float bead and adjuvant through the processes of grinding and dispersion. Said paint is no-toxic fire-resistant, strong in adhersion, good in pliability and heat-insulating effect, and has no pollution to environment, so that it has extensive application.

Description

Waterborne Epoxy Modified Acrylic Heat Reflective Heat Insulation Coating

technical field

The invention relates to a formula and a preparation process of a water-based high-performance heat-reflecting heat-insulating paint. It belongs to the technical field of chemical composition.

Background technique

Energy saving and environmental protection are the themes of new material development in this century. Traditional coatings are mostly solvent-based, which contain a large amount of organic solvents, and are often diluted with organic solvents during use. These solvents evaporate into the atmosphere after construction, which is harmful to human health and pollutes the environment. There is also a fire hazard. With the gradual enhancement of people's awareness of environmental protection and the increasingly stringent environmental protection laws and regulations around the world, it is the general trend to develop environmentally friendly coatings to replace solvent-based coatings.

Ordinary coatings, especially dark-colored coatings, will absorb the infrared rays in sunlight and convert them into heat energy, causing the temperature of the coating to rise. high. It will cause discomfort in people's work and life in summer or bring about safety problems of pipelines for oil and gas storage tanks. In order to solve this problem, people have developed heat-reflective heat-insulating coatings in recent years. Compared with ordinary coatings, this coating can reflect or scatter infrared rays more, and has a heat-insulating effect, which can significantly reduce the temperature in the room or the container. The walls and roofs of buildings can reduce the electricity consumption of air conditioners in summer. Used in oil refining and chemical plant storage tanks can significantly reduce the temperature inside the storage tanks and improve safety. Most of the existing heat reflective coatings are solvent-based coatings or water-diluted coatings. For example, Japanese Patent Publication JP98-120946 introduces an infrared reflective coating with a dark appearance, which is composed of metal oxide black pigments, indium phosphide, flake aluminum powder, fluororesin, and polysulfone resin. The rate is 31%, and the weather resistance is excellent. The disadvantage of this coating is that the base material is a solvent-based resin, which has environmental pollution problems, and its infrared reflectivity is not ideal. German patent DE19501114 introduces an infrared reflective coating, which is composed of water-diluted acrylic resin as the base material, titanium dioxide, chrome black, iron red and other pigments, talcum powder, mica powder and other fillers, and is coated on a white primer. A coating with a dry film thickness of 45 μm has a reflectivity of >50% for 1200-2000 nm infrared rays. The shortcoming of this coating is that the mixed solution of ether alcohol and water is used as diluent, and there is still an environmental pollution problem. There have been reports on the research of water-based heat-reflective coatings abroad, but the storage stability, workability, heat reflection and heat insulation effects of coatings are not ideal, and have not yet reached the stage of industrialization. There are no reports of water-based heat-reflective coatings in China.

In order to overcome the shortcomings of the existing heat-reflective coatings, the present invention develops a water-based paint that uses epoxy-modified acrylic emulsion as the base material, and cooperates with infrared reflective pigments, fillers, hollow glass microspheres, power plant floating beads, and additives. Heat-reflective and heat-insulating coatings, whose construction performance, drying performance, paint film mechanical properties, decoration, heat reflection and heat-insulating properties all reach or exceed the level of solvent-based heat-reflecting coatings.

Contents of the invention

The invention relates to an epoxy-modified acrylic emulsion and its preparation, and a water-based heat-reflecting heat-insulating coating based on the emulsion.

Epoxy-modified acrylic acid emulsion of the present invention is obtained by following raw material reaction:

Raw material Weight (parts)

Epoxy resin 20-30

Solvent 20-30

Mixed monomer 50-100

Initiator 1-3

Neutralizer 3-7

Demineralized water 100-150

The epoxy resin is a medium molecular weight epoxy resin, preferably the following materials: E-44, E-20, E-12 epoxy resin.

The mixed monomers include: acrylic acid, methacrylic acid, methyl methacrylate, butyl acrylate, and maleic anhydride.

Above-mentioned initiator can be benzoyl peroxide, dicumyl peroxide, azobisisobutyl cyanide; Neutralizer is volatile base, for example ammoniacal liquor, AMP-95, N-methylmorpholine, N- Ethylmorpholine, N, N dimethylethanolamine, triethylamine, the dosage is 70-100% of resin acid equivalent; solvent can be n-butanol, isobutanol, propylene glycol methyl ether, propylene glycol ethyl ether; demineralized water is water or distilled water. It is required that the content of water-soluble substances is less than 100ppm, and the conductivity is less than 20μs/cm.

The preparation method of the above-mentioned epoxy-modified acrylic emulsion: first dissolve the epoxy resin of medium molecular weight in a small amount of solvent, then add the first batch of mixed monomers dropwise, and then add the second batch of mixed monomers dropwise after the reaction is basically complete, and keep warm React for a period of time to obtain epoxy-modified acrylic resin. Stir and emulsify the resin in an alkaline aqueous solution to prepare an epoxy-modified acrylic emulsion.

The prepared epoxy-modified acrylic emulsion is mixed with pigments, fillers, additives, etc. to prepare heat-reflecting and heat-insulating coatings.

The heat-reflecting heat-insulating coating of the present invention is made up of following composition:

Raw material Weight (parts)

Epoxy modified acrylic emulsion 15-35

Pigment 1-20

Filler 5-20

Hollow glass microsphere 0-10

Power plant floating beads 0-10

Auxiliary 0.5-2.5

PH regulator 0.1-0.5

Thickener 0.2-1.5

Demineralized water 20-40

The above-mentioned epoxy-modified acrylic emulsion is self-made.

The pigments are required to have low infrared absorption rate or high infrared radiation rate, and the solar heat reflectance of the bottom composite coating is not less than 50% when the selected pigments are used in the formula dosage. Commonly used pigments can be iron oxide red, iron oxide yellow, titanium dioxide, permanent yellow, permanent red, phthalocyanine blue, etc. The filler can be fine talcum powder, calcined kaolin, precipitated barium sulfate. Hollow glass microspheres are made from glass with a low degree of hydrolysis, and the particle size range of hollow microspheres is 1-200 μm, preferably 5-100 μm. Auxiliaries include dispersants, wetting agents, leveling agents, defoamers, antifungal agents, and preservatives. The choice of dispersant depends on the nature of the pigment. For inorganic pigments such as titanium dioxide and iron oxide red, sodium, ammonium, and amine salts of ethylenic monomers, unsaturated carboxylic acids and their ester copolymers can be used, for example: Germany Henkel's 5040, 5027 dispersants, American Rohm and Haas's T-731 dispersants, the dosage is 0.5-2% of the pigment amount; for organic pigments such as phthalocyanine blue, you can choose high pigment groups with pro-pigment groups Molecular block copolymers, such as Byk184 of German BYK company, 760 dispersant of Degao company or EFKA-4550 dispersant of Dutch Efka company, the dosage is 5-20% of the pigment amount; the wetting agent is polyether Modified acetylenic alcohols, such as SURFYNOL GA and SURFYNOL TG of American Gas Chemical Company, the dosage is 0.1-0.3% of the coating amount; the leveling agent can be silane modified polyether or fluorocarbon modified polyether, such as German BYK Byk348, 307, EFKA-3570 from Efka Company in the Netherlands, 245 and 270 leveling agents from Degao Company; polyether modified silicones are used as defoamers, such as SN-313, NXZ, NDW from Henkel Company in Germany , BYK024 of BYK, 805 and 815 defoamers of Degao Company, the dosage is 0.01-0.1% of the coating amount; the preservative can be KATHON LXE of Dongfang-Rohm and Haas Company, and the dosage is 0.1-0.1% of the coating amount. 0.3%; antifungal agent can be the SKANE M-8 of Oriental-Rohm and Haas Company, the BCM antifungal agent of Xuzhou Pesticide Factory, consumption is 0.1-0.5% of coating amount. PH regulator is a volatile base, such as: ammonia, 2-amino-1-propanol (AMP-95), N-methylmorpholine, N-ethylmorpholine, triethylamine, N,N dimethyl ethanolamine. The thickener is a polyether or alkali-soluble acrylic emulsion thickener, such as the TT-935 thickener of Beijing Dongfang-Rohm and Haas Company, the 2020 thickener, the Rh-278, Rh -288 Thickener. The above-mentioned soft water is deionized water or distilled water, wherein the total amount of water-soluble substances is less than 100ppm, and the conductivity is less than 20μs/cm.

The preparation method of the heat-reflecting and heat-insulating coating of the present invention: (1) add metered demineralized water, additives, and part of epoxy-modified acrylic emulsion into the slurry mixing container, and stir evenly with an adjustable high-speed disperser; (2) add Pigments, fillers, stir well, and grind to the required fineness with a sand mill; (3) Add hollow glass microspheres or (and) power plant floating beads, and disperse evenly at high speed; (4) Add part of thickener, stir well, and get Color paste. (5) Add the color paste and the remaining epoxy-modified acrylic emulsion into the paint mixing container, and stir well. (6) Add the remaining thickener and stir well. (7) Add a pH regulator to adjust the pH value to 8-10. (8) Filtration, packaging, and finished product.

The coating of the present invention can be applied by various methods such as brush coating, roller coating, scraping coating, air spraying, airless spraying, etc., tools can be cleaned with water, and the use is safe and convenient.

Compared with common coatings and existing solvent-based heat-reflecting coatings, the invention has the following advantages: first, the performance of heat reflection and heat insulation is excellent. The pigment used in the invention has low infrared absorption rate or high infrared radiation rate, and the prepared heat-reflective paint can reflect 50-80% of solar heat energy, thereby significantly reducing indoor or container temperature. Second, it is safe and convenient to use. The paint of the invention adopts epoxy-modified acrylic emulsion, is non-toxic, non-combustible, harmless to the health of construction workers and indoor occupants, and has no pollution to the environment; thirdly, it has good decorative properties. The base material of this coating is self-emulsifying epoxy-modified acrylic emulsion, its particle size is small, and uniform, delicate and highly decorative coatings can be obtained. Fourth, the overall performance of the paint film is good. Due to the reasonable combination of acrylic resin and epoxy resin, the paint film has both the excellent weather resistance of acrylic resin and the alkali resistance and adhesion of epoxy resin. The obtained paint has dense film formation, good film adhesion, mechanical properties, water resistance, alkali resistance and weather resistance.

The invention has wide application prospect. The technical indicators of this coating have reached or exceeded the level of solvent-based heat-reflective coatings, and can completely replace solvent-based heat-reflective coatings. The surface of the facility reflects and isolates solar heat, and has a good practical effect in reducing the internal temperature. The water-based heat-reflecting and heat-insulating coating of the invention is used to replace common protective coatings or solvent-based heat-reflecting and heat-insulating coatings, which can save energy and protect the environment.

Detailed ways

The synthetic method of embodiment 1 epoxy-modified acrylic acid emulsion:

(1) Add epoxy resin and solvent in the 1 ^# reaction vessel according to the formula amount, start stirring, ventilate nitrogen, and liter

Warm to 110--130°C, keep warm for 2--3 hours to dissolve the epoxy resin.

(2) Evenly drop the first batch of mixed monomers (including initiator) into 1 ^# reaction vessel, and the time for dropping

0.5-1.0h, keep warm for 1.0-1.5h.

(3) Evenly drop the second batch of mixed monomers (including initiator) into 1 ^# reaction vessel, and the time for dropping

0.5-1.0h, keep warm for 1.5-2.0h.

(4) Add the demineralized water and neutralizer of the formula amount into the 2 ^# reaction container, stir evenly, and 1 ^# reaction

The material in the container is transferred to 2 ^# reaction container, stirred and emulsified for 1--2h to obtain epoxy-modified propylene

acid emulsion.

(5) Remove the solvent in vacuum, filter and pack. The synthesis examples of the epoxy-modified acrylic emulsion prepared by the above method are shown in Table 1, and the properties of the emulsion are shown in Table 2.

Table 1 Synthesis Example of Epoxy Modified Acrylic Emulsion project Example, g 1 2 3 4 5 6 to dissolve E-12 epoxy resin 200 250 300 200 250 300 Propylene Glycol Methyl Ether 100 125 150 100 125 150 Butanol 100 125 150 100 125 150 first step aggregation Methacrylate 12 12 12 12 12 12 Methyl methacrylate 180 150 120 150 120 90 Butyl acrylate 220 200 180 250 230 210 second step aggregation Methacrylate 20 10 0 0 10 10 acrylic acid 0 0 20 10 10 0 maleic anhydride 0 10 0 10 0 20 Methyl methacrylate 210 180 150 170 150 130 Butyl acrylate 190 220 250 230 250 270 Neutralize and emulsify Triethylamine 3 4 5 3 4 5 AMP-95 3 2 1 0 0 0 N,N Dimethylethanolamine 0 0 0 3 2 1 softened water 1100 1200 1300 1100 1200 1300

Table 2 Properties of epoxy-modified acrylic emulsion project Example 1 2 3 4 5 6 Self-emulsifying excellent good excellent good excellent good thermal stability excellent good excellent good excellent good mechanical stability excellent good excellent good excellent good Color paste stability good excellent good excellent good excellent Water resistance of paint film, h 120 168 96 120 96 168

Example 2 Preparation method of heat-reflective and heat-insulating coating: (1) Add metered demineralized water, additives, and part of epoxy-modified acrylic emulsion into the slurry mixing container, and stir evenly with an adjustable high-speed disperser. (2) Add pigments and fillers and disperse to the required fineness at high speed. (3) Add hollow glass microspheres or (and) power plant floating beads to disperse evenly at high speed; (4) Add part of thickener and stir well to obtain color paste. (5) Add the color paste and the remaining epoxy-modified acrylic emulsion into the paint mixing container, and stir well. (6) Add the remaining thickener and stir well. (7) Add a pH regulator to adjust the pH value to 8-10. (8) Filtration, packaging, and finished product. The formulation examples of the heat-reflecting and heat-insulating coating prepared by the above method are shown in Table 3, and the properties of the coating are shown in Table 4.

Formulation embodiment of table 3 heat reflective heat insulation coating Raw material (g) Example 1 2 3 4 5 6 7 8 9 softened water 230 210 220 210 230 215 220 215 225 SURFYNOL GA 2.0 1.5 1.5 1.0 2.0 1.5 2.0 2.0 1.5 Dispersant 5040 1.5 2 1.5 2 2 2 2 1.5 1.5 Dispersant Byk184 2 2 0 0.5 3 0.5 1 0 2 Defoamer NXZ 0.3 0.1 0.2 0.2 0.3 0.1 0.2 0.3 0.1 KATHON LXE 2 1.5 1 1.5 1.5 2 1 1 1 SKANE M-8 1 2 3 2 1 0 1 1 1 Triethylamine 3 2 2 5 5 3 2 2 5 Iron Oxide Red 0 0 50 0 0 0 0 0 0 Iron oxide yellow 0 0 0 50 0 0 0 0 0 Precipitated Barium Sulfate 160 120 110 160 150 100 120 125 180 talcum powder 100 120 80 100 100 60 100 80 120 Kaolin 30 50 20 50 35 50 50 0 30 Titanium dioxide 150 120 100 100 100 150 120 150 60 Everlasting Yellow HR 0 6 0 5 0 3 0 8 10 Everlasting Red FGR 0 2 0 0 0 1 8 0 2 Phthalo blue 0 1 0 0 10 0.5 2 2 1 Power Plant Floating Beads 10 5 0 10 5 0 9 6 3 hollow glass microspheres 5 7 10 0 5 8 2 3 5 Homemade Lotion ^# 1 300 0 0 0 0 0 0 0 0 Homemade Lotion ^# 2 0 350 0 0 0 0 350 0 0 Homemade 3 ^# lotion 0 0 400 0 0 0 0 0 0 Homemade 4 ^# lotion 0 0 0 300 0 0 0 400 0 Homemade 5 ^# lotion 0 0 0 0 350 0 0 0 0 Homemade 6 ^# Lotion 0 0 0 0 0 400 0 0 350 TT-935 thickener 10 8 6 0 0 0 7 6 5 Rh-278 thickener 0 0 0 10 8 6 3 2 1

Table 4 Coating Properties project Example 1 2 3 4 5 6 7 8 9 Coating Appearance qualified qualified qualified qualified qualified qualified qualified qualified qualified Viscosity, s, > 30 30 30 30 30 30 30 30 30 drying time surface dry, h 2 2 2 2 2 2 2 2 2 Hard work, h twenty four twenty four twenty four twenty four twenty four twenty four twenty four twenty four twenty four Adhesion, grade 1 1 1 1 1 1 1 1 1 Impact resistance, Kg.cm 40 40 40 40 40 40 40 40 40 Flexibility, mm 2 2 2 2 2 2 2 2 2 Water resistance, 96h qualified qualified qualified qualified qualified qualified qualified qualified qualified Solar heat reflectance, % 80 71 53 56 65 73 69 72 63 Thermal conductivity, W/mK 0.155 0.156 0.162 0.158 0.165 0.167 0.172 0.157 0.159 Freeze-thaw resistance, cycle 5 5 5 5 5 5 5 5 5

Claims (6)

1. Epoxy-modified acrylic acid emulsion, is characterized in that, obtains by following raw material reaction: Raw materials Weight (parts) Epoxy resin 20-30 Solvent 20-30 Mixed monomer 50-100 Initiator 1-3 Neutralizer 3-7 Demineralized water 100-150 Its preparation method is as follows: first dissolve the epoxy resin of medium molecular weight in a small amount of solvent, then add the first batch of mixed monomers dropwise, after the reaction is basically complete, add the second batch of mixed monomers dropwise, and keep warm for a period of time to obtain epoxy resin Modified acrylic resin. Stir and emulsify the resin in an alkaline aqueous solution to prepare an epoxy-modified acrylic emulsion. 2. according to the epoxy-modified acrylic emulsion of claim 1, it is characterized in that, described mixed monomer is acrylic acid, methacrylic acid, methyl methacrylate, butyl acrylate, maleic anhydride. 3. The epoxy-modified acrylic emulsion according to claim 1, characterized in that, the solvent is selected from one or more of the following: n-butanol, isobutanol, propylene glycol methyl ether, propylene glycol ether. 4. A heat-reflecting heat-insulating paint composition is characterized in that it adopts the epoxy-modified acrylic emulsion of claim 1, and its composition is as follows: Raw material Weight (parts) Epoxy modified acrylic emulsion 15-35 Pigment 1-20 Filler 5-20 Hollow glass microsphere 0-10 Power plant floating beads 0-10 Auxiliary 0.5-2.5 PH regulator 0.1-0.5 Thickener 0.2-1.5 Demineralized water 20-40 5. The heat-reflective and heat-insulating coating composition according to claim 4, characterized in that, the thickener is polyether and (or) alkali-soluble acrylic emulsion-type associative thickener. 6. The heat-reflecting and heat-insulating coating composition according to claim 4, wherein the pigment is one or more of the following: iron oxide red, iron oxide yellow, titanium dioxide, phthalocyanine blue, permanent yellow, Everlasting red.