Durable exterior wall coating not prone to cracking and preparation method thereof

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a durable exterior wall coating not prone to cracking and a preparation method of the durable exterior wall coating. Comprising the following components in parts by weight: 30-60 parts of methyl methacrylate, 30-60 parts of butyl acrylate, 60-100 parts of an organic silicon-fluorine compound, 5-12 parts of azodiisobutyronitrile, 3-8 parts of hexadecane, 2-5 parts of dodecylbenzene sulfonic acid, 2-5 parts of lauryl sodium sulfate, 300-600 parts of deionized water, 5-10 parts of a thickening agent, 2-5 parts of an ultraviolet light absorber, 2-5 parts of an antioxidant and 2-5 parts of pigment filler. The exterior wall coating provided by the invention has excellent weather resistance and comprehensive performance, is not easy to crack in the use process, and is long in service life.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to an exterior wall coating which is not prone to cracking and is durable, and a preparation method thereof. Background Art

[0002] As people's requirements for construction design gradually increase, different exterior wall coatings will be applied to the exterior walls of buildings according to different architectural styles to achieve different exterior wall colors. Special formulas and processes can also be used to achieve a variety of decorative effects such as imitation stone, imitation brick, and imitation wood grain, giving the building's exterior a unique texture. In addition to being beautiful, exterior wall coatings can form a protective film on the surface of the building's exterior wall, effectively resisting the damage of external environmental factors to the wall. For example, it can prevent rainwater from penetrating, avoid the occurrence of moisture, mold, rot, etc. on the wall, thereby extending the service life of the building's exterior wall.

[0003] Although exterior wall paint can protect the exterior walls of buildings, it also has its shortcomings, such as limited durability. Although exterior wall paint has a certain protective effect, its durability is relatively weak compared with some traditional exterior wall materials (such as stone, metal plates, etc.). When exposed to the natural environment for a long time, the paint may fade, peel, and powderize. For example, in buildings near the sea, the exterior wall paint may corrode and be damaged more quickly due to the high salt content in the air; in areas with high temperatures in summer, the weather resistance of exterior wall paint will deteriorate due to long-term high temperature exposure, causing the paint to crack and reduce its service life. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an exterior wall coating that is not prone to cracking and durable, and a preparation method thereof.

[0005] The invention provides an exterior wall paint which is not easy to crack and durable. The exterior wall paint comprises the following components in parts by weight: 30-60 parts of methyl methacrylate, 30-60 parts of butyl acrylate, 60-100 parts of organic silicon-fluorine compound, 5-12 parts of azobisisobutyronitrile, 3-8 parts of hexadecane, 2-5 parts of dodecylbenzenesulfonic acid, 2-5 parts of sodium lauryl sulfate, 300-600 parts of deionized water, 5-10 parts of thickener, 2-5 parts of ultraviolet absorber, 2-5 parts of antioxidant and 2-5 parts of pigment filler.

[0006] Preferably, the following components are included in parts by weight: 35-55 parts of methyl methacrylate, 35-55 parts of butyl acrylate, 65-85 parts of organic silicon fluorine compound, 6-10 parts of azobisisobutyronitrile, 3.5-6.5 parts of hexadecane, 3-4.5 parts of dodecylbenzenesulfonic acid, 3-4.5 parts of sodium lauryl sulfate, 350-550 parts of deionized water, 6-8 parts of thickener, 2-4 parts of ultraviolet absorber, 2-4 parts of antioxidant and 2-4 parts of color filler.

[0007] Preferably, the following components are included in parts by weight: 40-50 parts of methyl methacrylate, 40-50 parts of butyl acrylate, 70-80 parts of organic silicon fluorine compound, 7-9 parts of azobisisobutyronitrile, 4-5.5 parts of hexadecane, 3.5-4 parts of dodecylbenzenesulfonic acid, 3.5-4 parts of sodium lauryl sulfate, 400-500 parts of deionized water, 5.5-7 parts of thickener, 3-4 parts of ultraviolet absorber, 3-4 parts of antioxidant and 3-4 parts of color filler.

[0008] Preferably, the organic silicon-fluorine composite comprises tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide, and the mass ratio of tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide is (25-30): (6-8): 1.

[0009] Preferably, the thickener comprises hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer, and the mass ratio of hydroxyethyl cellulose to the nonionic hydrophobically modified ethylene oxide polyurethane copolymer is (1-5):1.

[0010] Preferably, the ultraviolet absorber is one or more of 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and 2,2'-hydroxy-4-methoxybenzophenone.

[0011] Preferably, the antioxidant is one or more of antioxidant 1010 and antioxidant 1076.

[0012] The present invention also provides a method for preparing a durable exterior wall coating that is not prone to cracking, which is used to prepare any of the above-mentioned durable exterior wall coatings, comprising the following steps:

[0013] Step S1: preparing an aqueous phase: adding dodecylbenzenesulfonic acid, sodium dodecyl sulfate and deionized water into a reaction kettle, stirring evenly, and dissolving dodecylbenzenesulfonic acid and sodium dodecyl sulfate in deionized water;

[0014] Step S2: preparing the oil phase: adding methyl methacrylate, butyl acrylate, organic silicon-fluorine complex, azobisisobutyronitrile and hexadecane into another reaction kettle and stirring evenly;

[0015] Step S3: emulsification: slowly add the oil phase mixture to the water phase mixture, keep stirring, and keep stirring for 30-60 minutes after the addition of the oil phase mixture is completed; cool the crude emulsion to 0°C-2°C and ultrasonicate for 15-30 minutes to obtain an emulsion;

[0016] Step S4: adding a thickener, an ultraviolet absorber, an antioxidant and a pigment filler to the emulsion and stirring for 15-30 minutes;

[0017] Step S5: nitrogen was introduced into the reactor for 10-20 min to expel the air, and then the reactor was sealed, heated to 70°C-80°C, stirred for reaction for 8-10 h, and cooled to room temperature after the reaction.

[0018] Preferably, the organic silicon-fluorine composite is prepared by compounding tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acrylamide, and the mass ratio of tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acrylamide is (25-30): (6-8): 1. The preparation method of the organic silicon-fluorine composite comprises the following steps:

[0019] Step S10: add tridecafluorooctyl triethoxysilane to the reaction kettle, add octamethylcyclotetrasiloxane while stirring, and keep stirring for 15-30 minutes after adding octamethylcyclotetrasiloxane;

[0020] Step S11: Slowly add fluorosilicone acrylamide into the reaction kettle and keep stirring for 15-30 minutes to obtain an organic silicon-fluorine composite.

[0021] Preferably, the thickener is prepared by compounding hydroxyethyl cellulose and non-ionic hydrophobically modified ethylene oxide polyurethane copolymer, and the mass ratio of hydroxyethyl cellulose and non-ionic hydrophobically modified ethylene oxide polyurethane copolymer is (1-5):1. The preparation method of the thickener is:

[0022] Slowly add nonionic hydrophobically modified ethylene oxide polyurethane copolymer into hydroxyethyl cellulose and keep stirring for 20-30 minutes to prepare a thickener.

[0023] The non-cracking and durable exterior wall coating provided by the present invention has at least the following beneficial effects:

[0024] 1. The exterior wall paint provided by the present invention uses an acrylic elastic emulsion compounded with methyl methacrylate and butyl acrylate as a base material. By adding an organic silicon-fluorine composite, it can be better mixed with various components in the preparation process of the exterior wall paint, so that the exterior wall paint is more uniform during the film-forming process. In addition, thanks to the compounded organic silicon-fluorine composite, the high-temperature stability and oxidation resistance of the exterior wall paint can be improved, and it is not easy to crack during use.

[0025] 2. The exterior wall coating provided by the present invention forms a cross-linked structure with the acrylic elastic emulsion compounded with methyl methacrylate and butyl acrylate by adding an organic silicon-fluorine complex during the reaction process, thereby improving the tensile strength of the exterior wall coating and further ensuring the durability of the exterior wall coating.

[0026] 3. The exterior wall coating provided by the present invention also adds ultraviolet absorbers and antioxidants, so that the exterior wall coating of this scheme has excellent weather resistance even when used in high temperature areas in summer, is not easy to oxidize and crack, and has a long service life. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0028] The embodiment of the present invention provides an exterior wall paint that is not prone to cracking and is durable. The exterior wall paint comprises the following components, measured in parts by weight: 30-60 parts of methyl methacrylate, 30-60 parts of butyl acrylate, 60-100 parts of organic silicon-fluorine compound, 5-12 parts of azobisisobutyronitrile, 3-8 parts of hexadecane, 2-5 parts of dodecylbenzenesulfonic acid, 2-5 parts of sodium dodecyl sulfate, 300-600 parts of deionized water, 5-10 parts of thickener, 2-5 parts of ultraviolet absorber, 2-5 parts of antioxidant and 2-5 parts of pigment filler.

[0029] In a preferred embodiment, the following components are included, by weight: 35-55 parts of methyl methacrylate, 35-55 parts of butyl acrylate, 65-85 parts of organic silicon fluorine compound, 6-10 parts of azobisisobutyronitrile, 3.5-6.5 parts of hexadecane, 3-4.5 parts of dodecylbenzenesulfonic acid, 3-4.5 parts of sodium lauryl sulfate, 350-550 parts of deionized water, 6-8 parts of thickener, 2-4 parts of ultraviolet absorber, 2-4 parts of antioxidant and 2-4 parts of color filler.

[0030] In a further preferred embodiment, the following components are included, by weight: 40-50 parts of methyl methacrylate, 40-50 parts of butyl acrylate, 70-80 parts of organic silicon fluoride compound, 7-9 parts of azobisisobutyronitrile, 4-5.5 parts of hexadecane, 3.5-4 parts of dodecylbenzenesulfonic acid, 3.5-4 parts of sodium lauryl sulfate, 400-500 parts of deionized water, 5.5-7 parts of thickener, 3-4 parts of ultraviolet absorber, 3-4 parts of antioxidant and 3-4 parts of color filler.

[0031] In this embodiment, the organic silicon-fluorine composite comprises tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acrylamide, and the mass ratio of tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acrylamide is (25-30): (6-8): 1. Preferably, the ratio can be 25:6:1, 26:6:1, 27:6:1, 28:6:1, 29:6:1, 30:6:1, 25:7:1, 26:7:1, 27:7:1, 28:7:1, 29:7:1, 30:7:1, 25:8:1, 26:8:1, 27:8:1, 28:8:1, 29:8:1, 30:8:1 and the like. Tridecafluorooctyltriethoxysilane has a high fluorine content, which can significantly reduce the surface energy of the coating and extend the service life of the coating; octamethylcyclotetrasiloxane can be ring-opened polymerized during the reaction, and the formed methyl and other organic groups can give the coating good flexibility, and the polymerization to form a siloxane main chain can give the coating good high-temperature stability and oxidation resistance; on this basis, fluorosilicone acrylamide is compounded, and the formed organic silicon-fluorine complex can improve the copolymerization with methyl methacrylate and butyl acrylate, thereby improving the water resistance and durability of the coating.

[0032] In this embodiment, the thickener includes hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer (HEUR), and the mass ratio of hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer is (1-5): 1. Preferably, the mass ratio of hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer can be 1: 1, 2: 1, 3: 1, 4: 1, 5: 1 and the like. Hydroxyethyl cellulose can increase the consistency of the coating, especially water-based coating, improve the rheological properties of the coating, so that the coating can better maintain uniform distribution on the wall surface during the drying process, and reduce cracking caused by uneven drying shrinkage; and the main chain of HEUR is a hydrophilic polymer, comprising one or more polyethylene glycol chains extended with isocyanate and with long-chain hydrophobic segments as end groups. This structure enables it to associate with hydrophobic structures such as latex particles, surfactants, pigments, etc. through the hydrophobic end of the molecule in the coating system. When it is added to the coating, it interacts with other components in the coating to form a three-dimensional network structure to thicken. The use of hydroxyethyl cellulose and HEUR to form a thickener can significantly improve the comprehensive properties of the coating, especially the strength and adhesion of the coating.

[0033] In this embodiment, the ultraviolet absorber is one or more of 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and 2,2'-hydroxy-4-methoxybenzophenone.

[0034] In this embodiment, the antioxidant is one or more of antioxidant 1010 and antioxidant 1076. Antioxidant 100 is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, which can effectively capture free radicals generated during the aging process of the coating and prevent the chain reaction of oxidation; antioxidant 1076 is octadecylβ-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, which has good compatibility and can be evenly dispersed in the coating, and can prevent the oxidation of components such as oil and resin in the coating when exposed to air for a long time, thereby delaying the aging phenomenon of the coating such as discoloration and powdering.

[0035] The present invention also provides a method for preparing a durable exterior wall coating that is not prone to cracking, which is used to prepare any of the above-mentioned durable exterior wall coatings, comprising the following steps:

[0036] Step S1: preparing an aqueous phase: adding dodecylbenzenesulfonic acid, sodium dodecyl sulfate and deionized water into a reaction kettle, stirring evenly, and dissolving dodecylbenzenesulfonic acid and sodium dodecyl sulfate in deionized water;

[0037] Step S2: preparing the oil phase: adding methyl methacrylate, butyl acrylate, organic silicon-fluorine complex, azobisisobutyronitrile and hexadecane into another reaction kettle and stirring evenly;

[0038] Step S3: emulsification: slowly add the oil phase mixture to the water phase mixture, keep stirring, and keep stirring for 30-60 minutes after the addition of the oil phase mixture is completed; cool the crude emulsion to 0°C-2°C and ultrasonicate for 15-30 minutes to obtain an emulsion;

[0039] Step S4: adding a thickener, an ultraviolet absorber, an antioxidant and a pigment filler to the emulsion and stirring for 15-30 minutes;

[0040] Step S5: nitrogen was introduced into the reactor for 10-20 min to expel the air, and then the reactor was sealed, heated to 70°C-80°C, stirred for reaction for 8-10 h, and cooled to room temperature after the reaction.

[0041] In this embodiment, the organic silicon-fluorine composite is prepared by compounding tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide, and the mass ratio of tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide is (25-30): (6-8): 1. The preparation method of the organic silicon-fluorine composite comprises the following steps:

[0042] Step S10: add tridecafluorooctyl triethoxysilane to the reaction kettle, add octamethylcyclotetrasiloxane while stirring, and keep stirring for 15-30 minutes after adding octamethylcyclotetrasiloxane;

[0043] Step S11: Slowly add fluorosilicone acrylamide into the reaction kettle and keep stirring for 15-30 minutes to obtain an organic silicon-fluorine composite.

[0044] In this embodiment, the thickener is prepared by compounding hydroxyethyl cellulose and non-ionic hydrophobically modified ethylene oxide polyurethane copolymer, and the mass ratio of hydroxyethyl cellulose and non-ionic hydrophobically modified ethylene oxide polyurethane copolymer is (1-5):1. The preparation method of the thickener is:

[0045] Slowly add nonionic hydrophobically modified ethylene oxide polyurethane copolymer into hydroxyethyl cellulose and keep stirring for 20-30 minutes to prepare a thickener.

[0046] In order to better illustrate the scheme of the present invention, the following are specific embodiments.

[0047] Example 1

[0048] The formula of the exterior wall coating is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of organic silicon fluoride compound, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0049] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 25:6:1.

[0050] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0051] Preparation method:

[0052] Step S1: preparing an aqueous phase: adding dodecylbenzenesulfonic acid, sodium dodecyl sulfate and deionized water into a reaction kettle, stirring evenly, and dissolving dodecylbenzenesulfonic acid and sodium dodecyl sulfate in deionized water;

[0053] Step S2: preparing the oil phase: adding methyl methacrylate, butyl acrylate, organic silicon-fluorine complex, azobisisobutyronitrile and hexadecane into another reaction kettle and stirring evenly;

[0054] Step S3: emulsification: slowly add the oil phase mixture to the water phase mixture, keep stirring, and keep stirring for 45 minutes after the oil phase mixture is added; cool the crude emulsion to 0°C, and ultrasonicate for 20 minutes to obtain an emulsion;

[0055] Step S4: adding a thickener, an ultraviolet absorber, an antioxidant and a pigment filler to the emulsion and stirring for 30 minutes;

[0056] Step S5: nitrogen was introduced into the reactor for 15 min to expel the air, and then the reactor was sealed, heated to 80° C., stirred for reaction for 8 h, and cooled to room temperature after the reaction.

[0057] Example 2

[0058] The formula of the exterior wall paint is as follows: by weight: 40 parts of methyl methacrylate, 40 parts of butyl acrylate, 70 parts of organic silicon fluoride compound, 7 parts of azobisisobutyronitrile, 4 parts of hexadecane, 3.5 parts of dodecylbenzenesulfonic acid, 3.5 parts of sodium lauryl sulfate, 400 parts of deionized water, 5.5 parts of thickener, 3 parts of ultraviolet absorber, 3 parts of antioxidant and 3 parts of pigment filler;

[0059] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 25:6:1.

[0060] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0061] The preparation method is the same as that in Example 1.

[0062] Example 3

[0063] The formula of the exterior wall coating is as follows: by weight: 60 parts of methyl methacrylate, 60 parts of butyl acrylate, 100 parts of organic silicon fluoride compound, 12 parts of azobisisobutyronitrile, 8 parts of hexadecane, 5 parts of dodecylbenzenesulfonic acid, 5 parts of sodium dodecyl sulfate, 600 parts of deionized water, 10 parts of thickener, 5 parts of ultraviolet absorber, 5 parts of antioxidant and 5 parts of pigment filler;

[0064] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 25:6:1.

[0065] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0066] The preparation method is the same as that in Example 1.

[0067] Example 4

[0068] The formula of the exterior wall coating is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of organic silicon fluoride compound, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0069] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 25:8:1.

[0070] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0071] The preparation method is the same as that in Example 1.

[0072] Example 5

[0073] The formula of the exterior wall coating is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of organic silicon fluoride compound, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0074] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 30:6:1.

[0075] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0076] The preparation method is the same as that in Example 1.

[0077] Example 6

[0078] The formula of the exterior wall coating is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of organic silicon fluoride compound, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0079] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 25:6:1.

[0080] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 3:1.

[0081] The preparation method is the same as that in Example 1.

[0082] Example 7

[0083] The formula of the exterior wall coating is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of organic silicon fluoride compound, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0084] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 25:6:1.

[0085] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 5:1.

[0086] The preparation method is the same as that in Example 1.

[0087] Comparative Example 1

[0088] The formula of the exterior wall paint is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of tridecafluorooctyl triethoxysilane, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0089] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0090] The preparation method is the same as that in Example 1.

[0091] Comparative Example 2

[0092] The formula of the exterior wall paint is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of octamethylcyclotetrasiloxane, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0093] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0094] The preparation method is the same as that in Example 1.

[0095] Comparative Example 3

[0096] The formula of the exterior wall paint is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of fluorosilicone acrylamide, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium lauryl sulfate, 300 parts of deionized water, 5 parts of thickener, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0097] The thickener is prepared by compounding hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in a mass ratio of 1:1.

[0098] The preparation method is the same as that in Example 1.

[0099] Comparative Example 4

[0100] The formula of the exterior wall coating is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of organic silicon fluoride compound, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of hydroxyethyl cellulose, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0101] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicone acrylamide in a mass ratio of 25:6:1.

[0102] The preparation method is the same as that in Example 1.

[0103] Comparative Example 5

[0104] The formula of the exterior wall coating is as follows: by weight: 30 parts of methyl methacrylate, 30 parts of butyl acrylate, 60 parts of organic silicon fluoride compound, 5 parts of azobisisobutyronitrile, 3 parts of hexadecane, 2 parts of dodecylbenzenesulfonic acid, 2 parts of sodium dodecyl sulfate, 300 parts of deionized water, 5 parts of nonionic hydrophobically modified ethylene oxide polyurethane copolymer, 2 parts of ultraviolet absorber, 2 parts of antioxidant and 2 parts of pigment filler;

[0105] The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide in a mass ratio of 25:6:1.

[0106] The preparation method is the same as that in Example 1.

[0107] The coatings of Examples 1 to 7 and Comparative Examples 1 to 5 were subjected to performance tests, and elongation at break, tensile strength, adhesion, water resistance, alkali resistance and water permeability were tested according to standard JG / T172-2005.

[0108] The test results are shown in Table 1 below:

[0109] Table 1 Test results data

[0110]

[0111]

[0112] Table 1 shows the test results of Examples 1 to 7 and Comparative Examples 1 to 5, from which it can be seen that:

[0113] From the comparison of Examples 1 to 3, it can be seen that the exterior wall paint prepared by the formula of the present invention has good elongation at break and tensile strength, indicating that the coating prepared by the exterior wall paint has good strength and is not easy to crack, and the adhesion also meets the requirements of the standard; in addition, it also has good water resistance and alkali resistance, indicating that the exterior wall paint can adapt to the outdoor environment and has good weather resistance.

[0114] From the comparison of Example 1, Example 4 and Example 5, it can be seen that by changing the ratio of tridecafluorooctyltriethoxysilane, octamethylcyclotetrasiloxane and fluorosilicone acrylamide in the organic silicon-fluorine composite to test the performance of the exterior wall coating, it can be seen that under the ratio specified in the scheme, the exterior wall coating still has good performance. Further comparing Comparative Examples 1 to 3, in Comparative Examples 1 to 3, the organic silicon-fluorine complex is replaced with equal amounts of tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicone acrylamide, respectively. From the test results, it can be seen that when the organic silicon-fluorine complex is replaced with tridecafluorooctyl triethoxysilane, the elongation at break, tensile strength and adhesion of the exterior wall coating are significantly reduced, and no longer meet the requirements of the standard; when the organic silicon-fluorine complex is replaced with octamethylcyclotetrasiloxane, the elongation at break, tensile strength, adhesion, water resistance and alkali resistance of the exterior wall coating are significantly reduced, and no longer meet the requirements of the standard; when the organic silicon-fluorine complex is replaced with fluorosilicone acrylamide, the elongation at break, tensile strength, adhesion, water resistance and alkali resistance of the exterior wall coating are significantly reduced, and no longer meet the requirements of the standard; this indicates that when a single organic silicon-fluorine material is used to prepare the coating, the comprehensive performance of the coating does not meet the requirements of the standard.

[0115] From the comparison of Example 1, Example 6 and Example 7, it can be seen that by changing the ratio of hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer in the thickener to test the performance of the coating, it can be seen that under the ratio specified in the scheme, the exterior wall coating still has good performance. Further comparison of Comparative Examples 4-5, in which the thickeners are replaced with equal amounts of hydroxyethyl cellulose and nonionic hydrophobically modified ethylene oxide polyurethane copolymer respectively, it can be seen that the prepared coating still meets the requirements of the standard, but has been significantly reduced compared with Example 1.

[0116] In summary, the solution of the present application can effectively improve the comprehensive performance of exterior wall coatings by compounding the organic silicon-fluorine complex and the thickener.

[0117] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A durable exterior wall coating that is not prone to cracking, characterized in that: The invention comprises the following components in parts by weight: 30-60 parts of methyl methacrylate, 30-60 parts of butyl acrylate, 60-100 parts of organic silicon-fluorine compound, 5-12 parts of azobisisobutyronitrile, 3-8 parts of hexadecane, 2-5 parts of dodecylbenzenesulfonic acid, 2-5 parts of sodium lauryl sulfate, 300-600 parts of deionized water, 5-10 parts of thickener, 2-5 parts of ultraviolet absorber, 2-5 parts of antioxidant and 2-5 parts of color filler.

2. The non-cracking and durable exterior wall paint according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 35-55 parts of methyl methacrylate, 35-55 parts of butyl acrylate, 65-85 parts of organic silicon-fluorine compound, 6-10 parts of azobisisobutyronitrile, 3.5-6.5 parts of hexadecane, 3-4.5 parts of dodecylbenzenesulfonic acid, 3-4.5 parts of sodium lauryl sulfate, 350-550 parts of deionized water, 6-8 parts of thickener, 2-4 parts of ultraviolet absorber, 2-4 parts of antioxidant and 2-4 parts of color filler.

3. The non-cracking and durable exterior wall paint according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 40-50 parts of methyl methacrylate, 40-50 parts of butyl acrylate, 70-80 parts of organic silicon-fluorine compound, 7-9 parts of azobisisobutyronitrile, 4-5.5 parts of hexadecane, 3.5-4 parts of dodecylbenzenesulfonic acid, 3.5-4 parts of sodium lauryl sulfate, 400-500 parts of deionized water, 5.5-7 parts of thickener, 3-4 parts of ultraviolet absorber, 3-4 parts of antioxidant and 3-4 parts of color filler.

4. The non-cracking and durable exterior wall paint according to claim 1, characterized in that: The organic silicon-fluorine composite comprises tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide, wherein the mass ratio of tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acid acrylamide is (25-30): (6-8):

1.

5. The non-cracking and durable exterior wall paint according to claim 1, characterized in that: The thickener comprises hydroxyethyl cellulose and a nonionic hydrophobically modified ethylene oxide polyurethane copolymer, and the mass ratio of the hydroxyethyl cellulose to the nonionic hydrophobically modified ethylene oxide polyurethane copolymer is (1-5):

1.

6. The non-cracking and durable exterior wall paint according to claim 1, characterized in that: The ultraviolet absorber is one or more of 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and 2,2'-hydroxy-4-methoxybenzophenone.

7. The non-cracking and durable exterior wall paint according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 1010 and antioxidant 1076.

8. A method for preparing a durable exterior wall coating that is not prone to cracking, used for preparing the durable exterior wall coating that is not prone to cracking according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1: preparing an aqueous phase: adding dodecylbenzenesulfonic acid, sodium dodecyl sulfate and deionized water into a reaction kettle, stirring evenly, and dissolving dodecylbenzenesulfonic acid and sodium dodecyl sulfate in deionized water; Step S2: preparing the oil phase: adding methyl methacrylate, butyl acrylate, organic silicon-fluorine complex, azobisisobutyronitrile and hexadecane into another reaction kettle and stirring evenly; Step S3: emulsification: slowly add the oil phase mixture to the water phase mixture, keep stirring, and keep stirring for 30-60 minutes after the addition of the oil phase mixture is completed; cool the crude emulsion to 0°C-2°C and ultrasonicate for 15-30 minutes to obtain an emulsion; Step S4: adding a thickener, an ultraviolet absorber, an antioxidant and a pigment filler to the emulsion and stirring for 15-30 minutes; Step S5: nitrogen was introduced into the reactor for 10-20 min to expel the air, and then the reactor was sealed, heated to 70°C-80°C, stirred for reaction for 8-10 h, and cooled to room temperature after the reaction.

9. The method for preparing the non-cracking and durable exterior wall coating according to claim 8, characterized in that: The organic silicon-fluorine composite is prepared by compounding tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acrylamide, wherein the mass ratio of tridecafluorooctyl triethoxysilane, octamethylcyclotetrasiloxane and fluorosilicic acrylamide is (25-30): (6-8):

1. The preparation method of the organic silicon-fluorine composite comprises the following steps: Step S10: add tridecafluorooctyl triethoxysilane to the reaction kettle, add octamethylcyclotetrasiloxane while stirring, and keep stirring for 15-30 minutes after adding octamethylcyclotetrasiloxane; Step S11: Slowly add fluorosilicone acrylamide into the reaction kettle and keep stirring for 15-30 minutes to obtain an organic silicon-fluorine composite.

10. The method for preparing the non-cracking and durable exterior wall coating according to claim 8, characterized in that: The thickener is prepared by compounding hydroxyethyl cellulose and non-ionic hydrophobically modified ethylene oxide polyurethane copolymer, wherein the mass ratio of hydroxyethyl cellulose to the non-ionic hydrophobically modified ethylene oxide polyurethane copolymer is (1-5):

1. The preparation method of the thickener is as follows: Slowly add nonionic hydrophobically modified ethylene oxide polyurethane copolymer into hydroxyethyl cellulose and keep stirring for 20-30 minutes to prepare a thickener.

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