Disclosure of Invention
In order to overcome the defects of the prior art, the invention mainly aims to provide a long-chain siloxane-based fluorine-containing siloxane emulsion and a preparation method thereof. The invention also aims to provide the inorganic silicate coating modified by the long-chain silicon-oxygen-based fluorine-containing siloxane emulsion and the preparation method thereof.
The purpose of the invention is realized by the following scheme:
a long-chain siloxy fluorine-containing siloxane emulsion has a chemical structural formula shown as a formula I:
wherein R is
1、R
2Is methylalkoxy, ethylalkoxy, hydroxy or
R
fIs a fluorine-containing alkyl group having 1 to 8 carbon atoms, n
1、n
2Is a natural number which can be divided by 4 in 4-2000.
Preferably, the emulsion has a solids content of 20% to 50%.
A preparation method of long-chain siloxy fluorine-containing siloxane emulsion comprises the following steps of adding 80-160 parts of water, 2-6 parts of anionic emulsifier, 2-4 parts of nonionic emulsifier and 6-40 parts of octamethylcyclotetrasiloxane into a reactor, reacting for 4-10h at 60-90 ℃ under the protection of nitrogen, adding 10-40 parts of micromolecular fluorine-containing siloxane, and reacting for 2-10h at 65-90 ℃ to obtain the long-chain siloxy fluorine-containing siloxane emulsion.
Preferably, the anionic emulsifier is at least one of dodecylbenzene sulfonic acid, hexadecylbenzene sulfonic acid or octadecylbenzene sulfonic acid.
Preferably, the nonionic emulsifier is at least one of alkylphenol polyoxyethylene ether, polyoxyethylene alkyl ether or polyoxyethylene sorbitan stearate.
Preferably, the small molecule fluorine-containing siloxane is at least one of trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, hexafluorobutylpropyltrimethoxysilane, dodecafluoroheptylpropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane and heptadecafluorodecyltriethoxysilane.
The long-chain silicon-oxygen-based fluorine-containing siloxane emulsion modified inorganic silicate coating comprises the following components in parts by weight:
preferably, the inorganic silicate solution has a modulus of 1.0 to 6.0 of a sodium silicate aqueous solution and/or a modulus of 1.0 to 6.0 of a potassium silicate aqueous solution.
Preferably, the defoaming agent refers to mineral oil defoaming agents and/or polysiloxane defoaming agents; the dispersant is at least one of acrylate, carboxylic acid sodium salt or polyacrylate; the leveling agent is an acrylic leveling agent; the filler is at least one of titanium dioxide, silicon dioxide or light calcium carbonate.
A preparation method of a long-chain siloxy fluorine-containing siloxane emulsion modified inorganic silicate coating comprises the following steps: adding inorganic silicate solution, water and long-chain siloxy fluorine-containing siloxane emulsion into a reactor, and uniformly stirring; and then adding a defoaming agent, a dispersing agent and a flatting agent, stirring uniformly, then adding a filler, and dispersing at normal temperature for 3-12h, and uniformly to obtain the long-chain siloxy fluorine-containing siloxane emulsion modified inorganic silicate coating.
The mechanism of the invention is as follows:
the long-chain silicon-oxygen-containing fluorine-containing siloxane emulsion used by the invention effectively migrates to the surface of a coating by simultaneously introducing the long-chain organic silicon and the fluorine-containing group, and improves the water resistance and the stain resistance of the coating, so that the prepared coating not only has weather resistance, water resistance and acid and alkali resistance, but also can solve the problems of cracking, falling, powder falling and the like of the coating in construction, and has excellent high hydrophobicity and high antifouling property.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) the invention firstly prepares a long-chain silicon-oxygen-based fluorine-containing siloxane emulsion by emulsion polymerization, then further hybridizes with inorganic silicate to obtain a hybrid solution with high hydrophobic property, and develops a high hydrophobic and high antifouling inorganic silicate coating by using the hybrid solution as a main film forming substance.
(2) The inorganic silicate coating modified by the long-chain siloxy fluorine-containing siloxane emulsion contains long-chain organosilicon and fluorine-containing groups, and the fluorine-containing groups migrate to the surface of a coating in the coating film forming process, so that the contact angle (100-145 degrees) of the surface of the coating is effectively improved, and the prepared inorganic silicate coating has high hydrophobic and high antifouling effects.
(3) The long-chain siloxane-containing fluorine-containing silicone emulsion modified inorganic silicate coating has the advantages of water resistance, acid and alkali resistance, no abnormality in alkali resistance for 48 hours, washing resistance (no bottom exposure for 1200 times), and capability of effectively preventing the problems of cracking, falling, powder falling and the like of the coating.
Detailed Description
The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.
Example 1
(1) Preparation of long-chain siloxy fluorine-containing siloxane emulsion
Adding 80g of deionized water, 2g of dodecylbenzene sulfonic acid, 2g of alkylphenol polyoxyethylene ether and 10g of octamethylcyclotetrasiloxane into a reaction container provided with a thermometer, a stirrer, a condenser and nitrogen, reacting at 70 ℃ for 9 hours, adding 15g of trifluoropropyltrimethoxysilane, reacting at 75 ℃ for 9 hours, and then air-cooling and discharging to obtain the long-chain siloxy fluorine-containing siloxane emulsion with the solid content of 26%.
(2) Preparation of long-chain siloxy fluorine-containing siloxane emulsion modified inorganic silicate coating
Adding 100 parts by weight of sodium silicate aqueous solution with the modulus of 2, 10 parts by weight of water and 4 parts by weight of long-chain silicon-oxygen-based fluorine-containing siloxane emulsion into a reaction kettle at one time, and uniformly stirring; then adding 0.5 weight part of mineral oil defoaming agent, 0.5 weight part of acrylate dispersing agent and 0.2 weight part of acrylic flatting agent, stirring uniformly, then adding 100 weight parts of light calcium carbonate, dispersing for 3 hours at normal temperature, and dispersing uniformly to obtain the inorganic silicate coating.
The coating was applied by a spray coater and tested for properties according to JGT 26-2002. The test results were as follows: the surface drying time is 1.8 h; construction performance: coating the second channel without obstacles; the appearance of the coating film is normal; the alkali resistance is not abnormal within 48 hours; washing and brushing resistance: no bottom exposure occurs for 2000 times; contrast ratio: 0.94, the stain resistance is 4 percent (less than or equal to 15 percent, which reaches the II-grade standard in JGT 26-2002), the contact angle is as follows: 105 deg..
Example 2
(1) Preparation of long-chain siloxy fluorine-containing siloxane emulsion
100g of deionized water, 4g of hexadecylbenzene sulfonic acid, 3g of polyoxyethylene alkyl ether and 20g of octamethylcyclotetrasiloxane are added into a reaction container provided with a thermometer, a stirrer, a condenser pipe and nitrogen, the mixture reacts for 6 hours at 80 ℃, 10g of hexafluorobutyl propyl trimethoxy silane is added, the mixture reacts for 4 hours at 80 ℃, and then air cooling and discharging are carried out, so that long-chain siloxane-based fluorine-containing siloxane emulsion is obtained, wherein the solid content is 27%.
(2) Preparation of long-chain siloxy fluorine-containing siloxane emulsion modified inorganic silicate coating
Adding 100 parts by weight of potassium silicate water solution with the modulus of 3, 20 parts by weight of water and 10 parts by weight of long-chain silicon-oxygen-based fluorine-containing siloxane emulsion into a reaction kettle at one time, and uniformly stirring; then adding 1 weight part of polysiloxane defoaming agent, 1 weight part of polyacrylate dispersant and 1.5 weight parts of acrylic flatting agent, stirring uniformly, then adding 150 weight parts of silicon dioxide, dispersing for 4 hours at normal temperature, and dispersing uniformly to obtain the inorganic silicate coating.
The coating was applied by a spray coater and tested for properties according to JGT 26-2002. The test results were as follows: surface drying time is 1.5 h; construction performance: coating the second channel without obstacles; the appearance of the coating film is normal; the alkali resistance is not abnormal within 48 hours; washing and brushing resistance: no bottom exposure occurs for 2000 times; contrast ratio: 0.96, the stain resistance is 3.5 percent (less than or equal to 15 percent, which reaches the II-grade standard in JGT 26-2002), the contact angle is as follows: 125 deg.
Example 3
(1) Preparation of long-chain siloxy fluorine-containing siloxane emulsion
Adding 120g of deionized water, 5g of hexadecylbenzene sulfonic acid, 4g of polyoxyethylene alkyl ether and 40g of octamethylcyclotetrasiloxane into a reaction container provided with a thermometer, a stirrer, a condenser pipe and nitrogen, reacting for 4 hours at 90 ℃, then adding 20g of heptadecafluorodecyltrimethoxysilane, reacting for 2 hours at 90 ℃, and then performing air cooling discharging to obtain the long-chain siloxy fluorine-containing siloxane emulsion with the solid content of 36%.
(2) Preparation of long-chain siloxy fluorine-containing siloxane emulsion modified inorganic silicate coating
Adding 100 parts by weight of potassium silicate aqueous solution with the modulus of 6, 50 parts by weight of water and 30 parts by weight of long-chain silicon-oxygen-based fluorine-containing siloxane emulsion into a reaction kettle at one time, and uniformly stirring; and then adding 4 parts by weight of mineral oil defoaming agent, 3 parts by weight of acrylate dispersing agent and 4 parts by weight of acrylic flatting agent, stirring uniformly, then adding 200 parts by weight of titanium dioxide, dispersing at normal temperature for 12 hours, and dispersing uniformly to obtain the inorganic silicate coating.
The coating was applied by a spray coater and tested for properties according to JGT 26-2002. The test results were as follows: surface drying time is 1.2 h; construction performance: coating the second channel without obstacles; the appearance of the coating film is normal; the alkali resistance is not abnormal within 48 hours; washing and brushing resistance: no bottom exposure occurs for 2000 times; contrast ratio: 0.98, the stain resistance is 2 percent (less than or equal to 15 percent, which reaches the II-grade standard in JGT 26-2002), the contact angle is as follows: 145 deg..
Example 4
(1) Preparation of long-chain siloxy fluorine-containing siloxane emulsion
100g of deionized water, 4g of octadecyl benzene sulfonic acid, 3g of polyoxyethylene sorbitan stearate and 30g of octamethylcyclotetrasiloxane are added into a reaction container provided with a thermometer, a stirrer, a condenser and nitrogen, the mixture reacts for 8 hours at 75 ℃, 15g of trifluoropropyltrimethoxysilane and 10g of dodecafluoroheptyl propyltrimethoxysilane are added, the mixture reacts for 6 hours at 75 ℃, and then air cooling and discharging are carried out to obtain the long-chain siloxy fluorine-containing siloxane emulsion, wherein the solid content is 38%.
(2) Preparation of long-chain siloxy fluorine-containing siloxane emulsion modified inorganic silicate coating
Adding 50 parts by weight of a sodium silicate aqueous solution with a modulus of 4, 50 parts by weight of a sodium silicate aqueous solution with a modulus of 6, 30 parts by weight of water and 20 parts by weight of long-chain silicon-oxygen-based fluorine-containing siloxane emulsion into a reaction kettle at one time, and uniformly stirring; and then adding 1 part by weight of mineral oil defoaming agent, 2 parts by weight of polysiloxane defoaming agent, 2 parts by weight of acrylate dispersing agent and 2 parts by weight of acrylic flatting agent, stirring uniformly, then adding 100 parts by weight of titanium dioxide and 50 parts by weight of silicon dioxide, dispersing at normal temperature for 6 hours, and dispersing uniformly to obtain the inorganic silicate coating.
The coating was applied by a spray coater and tested for properties according to JGT 26-2002. The test results were as follows: surface drying time is 1.5 h; construction performance: coating the second channel without obstacles; the appearance of the coating film is normal; the alkali resistance is not abnormal within 48 hours; washing and brushing resistance: no bottom exposure occurs for 2000 times; contrast ratio: 0.96, the stain resistance is 3 percent (less than or equal to 15 percent, which reaches the II-grade standard in JGT 26-2002), the contact angle is as follows: 135 deg.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.