阅读说明：本技术 一种胶囊型疏水丙烯酸酯乳液、胶囊结构及其制备方法和应用 (Capsule type hydrophobic acrylate emulsion, capsule structure, preparation method and application thereof ) 是由 张�浩 杨帅 谭振华 汪金 马汉峰 于 2020-12-03 设计创作，主要内容包括：本发明涉及疏水材料领域,公开了一种胶囊型疏水丙烯酸酯乳液、胶囊结构及其制备方法和应用。该胶囊型疏水丙烯酸酯乳液以聚二甲基硅氧烷为疏水润滑液,通过高速剪切引入至乳胶粒外表面,再经硅烷低聚体凝胶包覆,可形成稳定的自润滑型疏水乳液。本发明提出通过将起到交联保护作用的硅烷低聚体引入至乳胶粒并形成壳层,很大程度上解决了疏水润滑液容易溢出,从而造成胶囊型自润滑乳液的罐内稳定性等问题。本发明所提供的稳定方法简单有效,疏水润滑液包覆效果稳定性优异,乳液在热储30天后无溢油现象,且150μm刮膜不会出现缩孔；所形成的水性涂层可有效消除液滴的滞后现象,对水滴的滑动角可小于20°。(The invention relates to the field of hydrophobic materials, and discloses a capsule type hydrophobic acrylate emulsion, a capsule structure, a preparation method and an application thereof. The capsule type hydrophobic acrylate emulsion takes polydimethylsiloxane as hydrophobic lubricating liquid, is introduced to the outer surface of emulsion particles through high-speed shearing, and is coated by silane oligomer gel to form stable self-lubricating type hydrophobic emulsion. According to the invention, the silane oligomer which plays a role in cross-linking protection is introduced into the emulsion particles to form a shell layer, so that the problems of easy overflow of the hydrophobic lubricating liquid, in-tank stability of the capsule type self-lubricating emulsion and the like are solved to a great extent. The stabilizing method provided by the invention is simple and effective, the coating effect stability of the hydrophobic lubricating liquid is excellent, the emulsion has no oil spilling phenomenon after being stored for 30 days, and the 150 mu m scraped film has no shrinkage cavity; the formed water-based coating can effectively eliminate the hysteresis phenomenon of the water drops, and the sliding angle of the water drops can be less than 20 degrees.)

1. A capsule structure of a capsule type hydrophobic acrylate emulsion is characterized by comprising a latex particle core layer and a shell layer coated outside the latex particle core layer, wherein a hydrophobic lubricating liquid is arranged between the latex particle core layer and the shell layer.

2. The capsule type hydrophobic acrylate emulsion is characterized by being prepared from the following components in parts by weight: 100 parts of acrylate emulsion, 2.0-5.0 parts of hydrophobic lubricating liquid, 1.0-2.0 parts of silane oligomer, 0.1-0.2 part of crosslinking assistant, 0.1-0.2 part of wetting agent and 0.05-0.1 part of pH regulator.

3. The capsule-type hydrophobic acrylate emulsion according to claim 2, wherein the acrylate emulsion has a solid content of 48 ± 2% and is any one or a combination of two or more of a styrene-acrylic emulsion, a pure acrylic emulsion, a silicone-acrylic emulsion and a tertiary acrylic emulsion.

4. The capsule-type hydrophobic acrylate emulsion of claim 2 wherein the hydrophobic lubricating fluid is polydimethylsiloxane having a viscosity of 10-100mm 2/s.

5. The capsule-type hydrophobic acrylate emulsion according to claim 2, wherein the silane oligomer is any one or a combination of two of methyl or methyl/phenyl siloxane oligomers, and the viscosity is 25-100mm 2/s; the crosslinking coagent is a glycidyl ether siloxane oligomer.

6. The capsule-type hydrophobic acrylate emulsion of claim 2 wherein the wetting agent is a silyl ether copolymer.

7. The capsule-type hydrophobic acrylate emulsion of claim 2 wherein the pH adjusting agent is a silicate compound.

8. The method for preparing the capsule-type hydrophobic acrylate emulsion according to claim 2, comprising the steps of:

(1) injection of hydrophobic lubricating liquid:

at room temperature, firstly, placing the acrylate emulsion in a rotary disc type reactor for dispersion, controlling the rotating speed at 800r/min, adding a wetting agent, and keeping the dispersion time for 5-10 min; and then transferring the emulsion to a homogenizing emulsifier, adjusting the rotating speed to 3000-.

(2) Stabilization of the hydrophobic lubricating fluid:

keeping the rotating speed unchanged, uniformly mixing the silane oligomer and the crosslinking assistant, then dropwise adding the mixture into the homogeneous emulsion for 5-10min, continuing to perform homogeneous emulsification for 10-15min, then reducing the speed to stop emulsification, then transferring the emulsion into a rotary disk type reactor, adding the pH regulator under the condition of the rotating speed of 200-300r/min, and continuing the dispersion for 5-10 min.

9. The hydrophobic coating based on the capsule type hydrophobic acrylate emulsion is characterized by comprising the following components in parts by weight: 100-150 portions of deionized water, 0.1-0.2 portion of wetting agent, 0.1-0.2 portion of defoaming agent, 2.0-3.0 portions of antifreezing agent, 5.0-7.5 portions of film-forming adjuvant, 0.4-0.6 portion of bactericidal preservative, 0.1-0.2 portion of pH regulator, 1.0-1.5 portions of thickening agent, and 150 portions of 100-one of capsule type hydrophobic acrylate emulsion according to any one of claims 2-7.

10. The hydrophobic coating material based on capsule type hydrophobic acrylate emulsion as claimed in claim 9, wherein the wetting agent is alkyl polyoxyethylene ether; the defoaming agent is mineral oil; the antifreezing agent is an alcohol or ether compound; the film-forming auxiliary agent is an alcohol ester compound; the bactericidal preservative is isothiazolinone.

11. The hydrophobic coating material based on capsule type hydrophobic acrylate emulsion as claimed in claim 9, wherein the pH regulator is alcohol amine ether organic substance.

12. The hydrophobic coating of claim 9, wherein the thickener is of the hydrophobically modified alkali swellable association type.

13. The method for preparing the hydrophobic coating based on the capsule type hydrophobic acrylate emulsion according to claim 9, wherein the method comprises the following steps: the components are sequentially added into a reactor and stirred for 20-30min at the rotating speed of 300-500 r/min.

Technical Field

The invention relates to the field of hydrophobic materials, in particular to a capsule type hydrophobic acrylate emulsion which can simply solve the problem of emulsion polymerization instability at low cost, a capsule structure, a preparation method and an application thereof.

Background

In the field of building engineering, the stain-resistant coating can effectively resist stain, provide beautiful environment, reduce the harm of mold, prolong the service life of the functional coating and has wide application value prospect. The key to achieving such functions depends on the composition and structure of the hydrophobic acrylate emulsion. Chinese patent application publication No. CN103864982A, U.S. patent application publication No. US8507601B2, and PCT international application publication No. WO2014097309A1 each disclose a technical scheme for accomplishing hydrophobic modification by introducing a perfluoro (meth) acrylate monomer. However, the above technical solutions are not ideal in the practical application process. In the technical scheme disclosed in U.S. patent application publication No. US8507601B2, a hydrophobic emulsion obtained from perfluorohexylethyl acrylate is used, but fluorine-containing monomers enter emulsion particles during polymerization and are polymerized inside, so that an effective hydrophobic effect is hardly exhibited after film formation. In addition, the high cost of perfluoromonomers also greatly limits the large scale application of the process.

The proposed theory of "super-lubricating Liquid-permeable Porous Surfaces (SLIPS)" proposed for the first time in 2011 by the journal Aizenberg subject group of Harvard university (Harvard) can solve the above problems, and the lubricating characteristics with smooth and low rolling angle concentrated on the Surface layer can greatly improve the hydrophobic effect of low-Surface-energy components and effectively reduce the usage of the hydrophobic components (Li J et al. slip lubricating-impregnated Surfaces: Properties and lubricating Applications [ J ] Advanced Functional Materials,2019.), which becomes the research hotspot of the current self-cleaning Materials. However, SLIPS is mostly obtained by injecting after a porous coating layer is formed so far, and there is no report on the application of SLIPS in an aqueous emulsion system.

Compatibility problems are encountered when introducing SLIPS in aqueous systems and it is critical to how the hydrophobic lubricating fluid is introduced into the aqueous emulsion and can be stabilized. Inspired by a self-repairing capsule model (Szab Lou T, et al. self-healing microcapsules and slow release microcapsules in paints. progress in Organic Coatings,2011), the method for forming the hydrophobic nanocapsule on the basis of the emulsion particle can realize efficient hydrophobic modification on the acrylate emulsion. When the latex particles form a film, the shell layers of the latex particles are pressed and broken, and the hydrophobic lubricating silicone oil can be efficiently and quickly released to form an effective hydrophobic surface. However, the hydrophobic lubricating fluid is not stable in the later application process, is easy to overflow after being placed for 10-30 days, and forms shrinkage cavities in the coating film forming process. The key to the application of the capsule type hydrophobic emulsion is to find a quick and efficient lubricating liquid stabilizing method.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a capsule structure of a capsule-type hydrophobic acrylate emulsion, which stabilizes the efficient hydrophobic modification of the hydrophobic capsule-type latex particles to the acrylate emulsion through a silane oligomer sol-gel reaction, and can enable the hydrophobic emulsion to have more efficient low-adhesion characteristic by means of a super-lubricating liquid permeating porous surface (SLIPS) model and a hydrophobic lubricating liquid covering the surface.

The second purpose of the invention is to provide a capsule type hydrophobic acrylate emulsion.

The third object of the present invention is to provide a method for preparing the capsule type hydrophobic acrylate emulsion.

The third purpose of the invention is to provide the application of the capsule type hydrophobic acrylate emulsion in coating.

In order to realize the purpose of the invention, the invention adopts the technical scheme that: a capsule structure of a capsule type hydrophobic acrylate emulsion comprises a latex particle core layer and a shell layer coated outside the latex particle core layer, wherein a hydrophobic lubricating liquid is arranged between the latex particle core layer and the shell layer. The method comprises the steps of coating the outer surface of emulsion particles with polydimethylsiloxane as a hydrophobic lubricating liquid by a hydrophobic modification method, and coating the surface of the hydrophobic lubricating liquid with silane oligomer gel to form the stable self-lubricating hydrophobic emulsion.

The emulsion particle core layer is acrylate emulsion particles; the shell layer is silane oligomer gel coated with the hydrophobic lubricating liquid.

A capsule type hydrophobic acrylate emulsion has the capsule structure and is prepared from the following components in parts by weight: 100 parts of acrylate emulsion, 2.0-5.0 parts of hydrophobic lubricating liquid, 1.0-2.0 parts of silane oligomer, 0.1-0.2 part of crosslinking assistant, 0.1-0.2 part of wetting agent and 0.05-0.1 part of pH regulator.

The solid content of the acrylic ester emulsion is about 48 +/-2%, and the acrylic ester emulsion can be any one or the combination of more than two of styrene-acrylic emulsion, pure acrylic emulsion, silicone-acrylic emulsion or tertiary acrylic emulsion. Preferably, the emulsion may be RS-998A emulsion of Barde Fukuji, Changhua chemical group, Inc. of Changshan City8119 emulsion, Dow chemical companySF-018 emulsion.

The hydrophobic lubricating fluid is polydimethylsiloxane, preferably with the viscosity of 10-100mm²At 25 ℃ for a period of time. More preferably, the polydimethylsiloxane has a viscosity of 50 to 100mm²/s(25℃)，

The silane oligomer is one or two of methyl or methyl/phenyl siloxane oligomer, preferably with viscosity of 25-100mm²(25 ℃ C.), KR-500 or ShinEtsu from shinEtsu chemical Co., LtdIs KR-510.

The crosslinking assistant is glycidyl ether siloxane oligomer, preferably, the glycidyl ether siloxane oligomer can be selected from Momentive of Melitham (America)MP200, the structural formula is:

the wetting agent is a nonionic wetting agent, and preferably, can be a silicon ether copolymer; more preferably, it can be German DigaoWET 270 of Germany, BYK-346 of Pick, Germany.

The pH regulator is silicate compound, preferably from Wacker, GermanyBS168。

The preparation method of the capsule type hydrophobic acrylate emulsion comprises the following steps:

(1) injection of hydrophobic lubricating liquid:

at room temperature, firstly, placing the acrylate emulsion in a rotary disc type reactor for dispersion, controlling the rotating speed at 800r/min, adding a wetting agent, and keeping the dispersion time for 5-10 min; then transferring the emulsion to a homogenizing emulsifier, adjusting the rotating speed to 3000-;

(2) stabilization of the hydrophobic lubricating fluid:

keeping the rotating speed unchanged, uniformly mixing the silane oligomer and the crosslinking aid, then dropwise adding the mixture into the homogeneous emulsion for 5-10min, continuing to perform homogeneous emulsification for 10-15min, then reducing the speed to stop emulsification, then transferring the emulsion into a rotary disk type reactor, adding a pH regulator under the condition of rotating speed of 200-300r/min, and continuing the dispersion for 5-10min to obtain the capsule type hydrophobic acrylate emulsion.

A hydrophobic coating based on a capsule type hydrophobic acrylate emulsion is prepared from the following components in parts by weight: 100 portions of deionized water, 150 portions of wetting agent, 0.1 portion to 0.2 portion of defoaming agent, 2.0 portion to 3.0 portions of antifreezing agent, 5.0 portion to 7.5 portions of film forming additive, 0.4 portion to 0.6 portion of sterilization preservative, 0.1 portion to 0.2 portion of pH regulator, 1.0 portion to 1.5 portions of thickening agent and 100 portions of capsule type hydrophobic acrylic ester emulsion.

The wetting agent is a nonionic wetting agent, preferably alkyl polyoxyethylene ether; more preferably, Emulsogen LCN 070 from Clariant, Switzerland, Ecosurf EH-9 from Dow chemical company.

The defoaming agent is a mineral oil, preferably of BASFST 2410AC, of Haimax corporation (Elementis) USAAP7010。

The antifreezing agent is an alcohol or ether compound, and preferably ethylene glycol or diethylene glycol.

The film-forming assistant is an alcohol ester compound, preferably of EastmanAlcohol ester-12.

The antiseptic preservative is isothiazolinone, preferably from British Soler company (THOR)MBS type bactericides.

The pH regulator is an alcohol amine ether organic matter, and preferably Dow chemical company (Dow) AMP-95.

The thickener is of hydrophobic modified alkali swelling association type, preferably of Dow chemical typeCompany (Dow) RHOPLEX^TMTT-935 of Wanhua chemical group, IncA-401。

The preparation method of the hydrophobic coating based on the capsule type hydrophobic acrylate emulsion comprises the following steps: the components are sequentially added into a reactor and stirred for 20-30min at the rotating speed of 300-500r/min to obtain the water-based hydrophobic coating.

The hydrophobic coating is applied to the surface of the base material in at least one mode of brushing, roller coating, dip coating, spraying and curtain coating, and is cured at normal temperature for 7 days to obtain the water-based hydrophobic coating.

The base material applied to the hydrophobic coating is a concrete inner/outer wall, steel, stone, glass, ceramic or plastic plate.

The invention is different from the traditional hydrophobic modification method of the acrylate emulsion, and the capsule type emulsion greatly widens the application range of the hydrophobic emulsion on the basis of not influencing emulsion polymerization by a hydrophobic lubricating liquid injection-stabilization method. The stabilizing method of the invention does not need additional curing agent, can be carried out in normal temperature environment, effectively inhibits the overflow problem of the hydrophobic lubricating liquid, overcomes the defects of poor stability, low hydrophobic efficiency and the like in the hydrophobic modification process of the conventional acrylate emulsion, and provides a simple and easy method for realizing the long-acting stable stain resistance effect of the acrylate emulsion.

According to the invention, the hydrophobic modification of the acrylate emulsion can be realized by a hydrophobic nano-capsule method with stable silane oligomer, so that expensive low-surface-energy monomers such as perfluorohexylethyl (methyl) acrylate and the like are prevented from being introduced during emulsion polymerization by a traditional modification method, the problem that the monomers are easy to cause emulsion polymerization instability is solved, and the preparation method of the hydrophobic emulsion is simplified to a great extent. The cross-linked layer stable hydrophobic lubricating liquid is designed on the basis of the capsule structure, and the stability of the lubricating liquid in a water phase is efficiently realized through a silane oligomer sol-gel reaction. The stabilizing process does not need an additional curing agent and can be carried out in a normal temperature environment. The method obtains the hydrophobic emulsion with low cost, long acting and environmental protection, and has great application value and market prospect in the field of building engineering stain resistance. The stabilizing method provided by the invention is simple and effective, the coating effect stability of the hydrophobic lubricating liquid is excellent, the emulsion does not have the oil spilling phenomenon after being stored for 30 days, and the 150 mu m scraped film does not have shrinkage cavity. In addition, the coating method does not influence the release of the hydrophobic lubricating liquid, the formed water-based coating can effectively eliminate the hysteresis phenomenon of liquid drops, and the sliding angle of the water drops can be less than 20 degrees.

Compared with the prior art, the invention has the advantages that:

(1) the process is simple, the cost is low, and the whole preparation and stabilization process of the capsule type emulsion is green and environment-friendly;

(2) the method has no influence on the polymerization process of the acrylate emulsion and the functions of the emulsion;

(3) the hydrophobic lubricating liquid does not influence the release of the hydrophobic lubricating liquid during film forming on the basis of stable water phase;

(4) the stability problem of the hydrophobic capsule type emulsion is solved, and the hydrophobic lubricating liquid does not overflow after the hydrophobic capsule type emulsion is stored at 55 ℃ for 30 days.

Drawings

FIG. 1 is a schematic diagram showing the comparison of particle size and distribution before and after encapsulation of latex particles tested by the laser scattering method in example 1 (wherein, (a) is before encapsulation of latex particles tested by the laser scattering method and (b) is after encapsulation of latex particles tested by the laser scattering method).

Detailed Description

The present invention is further described with reference to the following specific examples, which should be construed as limiting the scope of the invention as claimed.

Example 1

A capsule type hydrophobic acrylate emulsion is prepared from the following components in parts by weight: 100 parts of acrylate emulsion, 2.0 parts of hydrophobic lubricating liquid, 1.0 part of silane oligomer, 0.1 part of crosslinking assistant, 0.1 part of wetting agent and 0.05 part of pH regulator.

The acrylate emulsion is a Badford RS-998A emulsion.

The hydrophobic lubricating fluid is polydimethylsiloxane with the viscosity of 100mm²/s(25℃)。

The silane oligomer is ShinEtsu KR-510 methyl/phenyl siloxane oligomer with the viscosity of 100mm²/s，(25℃)。

The crosslinking auxiliary agent is MomentiveMP200。

The wetting agent isWET 270。

The pH regulator is WackerBS168。

A capsule type hydrophobic acrylate emulsion is prepared from the following components in parts by weight: the method comprises the following steps:

(1) injection of hydrophobic lubricating liquid:

at room temperature (20 +/-5 ℃), firstly, placing the acrylate emulsion in a rotary disc type reactor for dispersion, controlling the rotating speed at 600r/min, adding a wetting agent, and keeping the dispersion time for 6 min; then transferring the emulsion to a homogenizing emulsifier, adjusting the rotating speed to 3000r/min, dropwise adding a hydrophobic lubricating liquid for 10min, and continuing homogenizing and emulsifying for 10 min;

(2) stabilization of the hydrophobic lubricating fluid:

and keeping the rotating speed unchanged, uniformly mixing the silane oligomer and the crosslinking aid, then dropwise adding the mixture into the homogeneous emulsion for 5min, continuing to perform homogeneous emulsification for 10min, slowing down to stop emulsification, then transferring the emulsion into a rotary disk type reactor, adding a pH regulator at the rotating speed of 200r/min, and continuing to disperse for 6min to obtain the final capsule type hydrophobic acrylate emulsion.

The water-based hydrophobic coating comprises, by weight, 100 parts of deionized water, 0.1 part of a wetting agent, 0.1 part of a defoaming agent, 2.0 parts of an antifreezing agent, 5.0 parts of a film-forming aid, 0.4 part of a bactericidal preservative, 0.1 part of a pH regulator, 1.0 part of a thickening agent and 100 parts of the capsule type hydrophobic acrylate emulsion;

the wetting agent is Clariant Emulsogen LCN 070.

The defoaming agent is BASFST 2410AC。

The antifreezing agent is ethylene glycol.

The film-forming additive is EastmanAlcohol ester-12.

The antiseptic preservative is THORMBS type bactericides.

The pH regulator is DOW AMP-95.

The thickener is DOW RHOPLEX^TM TT-935。

The preparation method of the water-based hydrophobic coating comprises the following steps: weighing the components according to the formula ratio, and stirring at the rotating speed of 300r/min for 20min to prepare the water-based hydrophobic coating.

A method of preparing an aqueous hydrophobic coating comprising the steps of: and coating the water-based hydrophobic coating on the surface of a substrate, and standing to obtain the water-based hydrophobic coating.

The coating mode is brush coating.

The substrate is glass.

The rest was kept at 25 ℃ for 7 days.

Example 2

A capsule type hydrophobic acrylate emulsion is prepared from the following components in parts by weight: 100 parts of acrylate emulsion, 5.0 parts of hydrophobic lubricating liquid, 2.0 parts of silane oligomer, 0.2 part of crosslinking assistant, 0.2 part of wetting agent and 0.1 part of pH regulator.

The acrylic ester emulsion is Wanhua8119 an emulsion.

The hydrophobic lubricating liquid is polydimethylsiloxane with the viscosity of 50mm²/s(25

℃)。

The silane oligomer is ShinEtsu KR-510 methyl/phenyl siloxane oligomer with the viscosity of 100mm²/s，(25℃)。

The crosslinking auxiliary agent is MomentiveMP200。

The wetting agent isWET 270。

The pH regulator is WackerBS168。

A capsule type hydrophobic acrylate emulsion is prepared from the following components in parts by weight:

(1) injection of hydrophobic lubricating liquid:

at room temperature (20 +/-5 ℃), firstly, placing the acrylate emulsion in a rotary disc type reactor for dispersion, controlling the rotating speed at 800r/min, adding a wetting agent, and keeping the dispersion time for 10 min; and then transferring the emulsion to a homogenizing emulsifier, adjusting the rotating speed to 5000r/min, dropwise adding the hydrophobic lubricating liquid for 15min, and continuing homogenizing and emulsifying for 20 min.

(2) Stabilization of the hydrophobic lubricating fluid:

and keeping the rotating speed unchanged, uniformly mixing the silane oligomer and the crosslinking aid, then dropwise adding the mixture into the homogeneous emulsion for 10min, continuing to perform homogeneous emulsification for 15min, then reducing the speed to stop emulsification, then transferring the emulsion into a rotary disk type reactor, adding a pH regulator at the rotating speed of 300r/min, and continuing to disperse for 10min to obtain the final capsule type hydrophobic acrylate emulsion.

The water-based hydrophobic coating comprises, by weight, 100 parts of deionized water, 0.2 part of a wetting agent, 0.2 part of a defoaming agent, 3.0 parts of an antifreezing agent, 7.5 parts of a film-forming aid, 0.6 part of a bactericidal preservative, 0.2 part of a pH regulator, 1.5 parts of a thickening agent and 150 parts of the capsule type hydrophobic acrylate emulsion.

The wetting agent is Clariant Emulsogen LCN 070.

The defoaming agent is BASFST 2410AC。

The antifreezing agent is ethylene glycol.

The film-forming additive is EastmanAlcohol ester-12.

The antiseptic preservative is THORMBS type bactericides.

The pH regulator is DOW AMP-95.

The thickener is DOW RHOPLEX^TM TT-935。

The preparation method of the water-based hydrophobic coating comprises the following steps: weighing the components according to the formula ratio, and stirring for 30min at the rotating speed of 500r/min to prepare the water-based hydrophobic coating.

The preparation method of the water-based hydrophobic coating required by the test comprises the following steps: and coating the water-based hydrophobic coating on the surface of a substrate, and standing to obtain the water-based hydrophobic coating.

The coating mode is spraying.

The substrate is ceramic.

The rest was kept at 25 ℃ for 7 days.

Example 3

A capsule type hydrophobic acrylate emulsion is prepared from the following components in parts by weight: 100 parts of acrylate emulsion, 3.0 parts of hydrophobic lubricating liquid, 1.5 parts of silane oligomer, 0.15 part of crosslinking assistant, 0.2 part of wetting agent and 0.1 part of pH regulator.

The acrylic ester emulsion is DowSF-018 emulsion.

The hydrophobic lubricating liquid is polydimethylsiloxane with the viscosity of 10mm²/s(25℃)。

The silane oligomer is ShinEtsu KR-500 methyl siloxane oligomer with viscosity of 25mm²/s，(25℃)。

The crosslinking auxiliary agent is MomentiveMP200。

The wetting agent is BYK-346.

The pH regulator is WackerBS168。

A capsule type hydrophobic acrylate emulsion is prepared from the following components in parts by weight: the method comprises the following steps:

(1) injection of hydrophobic lubricating liquid:

at room temperature (20 +/-5 ℃), firstly, placing the acrylate emulsion in a rotary disc type reactor for dispersion, controlling the rotating speed at 800r/min, adding a wetting agent, and keeping the dispersion time for 10 min; and then transferring the emulsion to a homogenizing emulsifier, adjusting the rotating speed to 4000r/min, dropwise adding the hydrophobic lubricating liquid for 15min, and continuing homogenizing and emulsifying for 15 min.

(2) Stabilization of the hydrophobic lubricating fluid:

and keeping the rotating speed unchanged, uniformly mixing the silane oligomer and the crosslinking aid, then dropwise adding the mixture into the homogeneous emulsion for 10min, continuing to perform homogeneous emulsification for 15min, then reducing the speed to stop emulsification, then transferring the emulsion into a rotary disk type reactor, adding a pH regulator at the rotating speed of 200r/min, and continuing the dispersion for 5min to obtain the final capsule type hydrophobic acrylate emulsion.

The water-based hydrophobic coating comprises, by weight, 150 parts of deionized water, 0.1 part of a wetting agent, 0.2 part of a defoaming agent, 2.5 parts of an antifreezing agent, 6.5 parts of a film-forming aid, 0.5 part of a bactericidal preservative, 0.1 part of a pH regulator, 1.2 parts of a thickening agent and 100 parts of the capsule type hydrophobic acrylate emulsion.

The wetting agent is DOW Ecosurf EH-9.

The antifoaming agent is ElementisAP7010。

The antifreezing agent is diethylene glycol.

The film-forming additive is EastmanAlcohol ester-12.

The antiseptic preservative is THORMBS type bactericides.

The pH regulator is DOW AMP-95.

The thickening agent is WanhuaA-401。

The preparation method of the water-based hydrophobic coating comprises the following steps: weighing the components according to the formula ratio, and stirring at the rotating speed of 400r/min for 25min to prepare the water-based hydrophobic coating.

A method of preparing an aqueous hydrophobic coating comprising the steps of: and coating the water-based hydrophobic coating on the surface of a substrate, and standing to obtain the water-based hydrophobic coating.

The coating mode is roller coating.

The base material is a PVC plate.

The rest was kept at 25 ℃ for 7 days.

Comparative example 1

In comparison to example 1, the acrylate emulsion in the process described in comparative example 1 is the same type of product commercially available as described in example 1, but the test coating preparation process did not include the polydimethylsiloxane hydrophobic lubricant injection and stabilization steps, and the rest of the process was the same as in example 1.

Comparative example 2

In comparison to example 1, the acrylate emulsion in the process described in comparative example 2 is the same type of product commercially available as described in example 1, but the test coating preparation process does not contain a hydrophobic lubricating fluid stabilization step, and the rest of the process is the same as in example 1.

Comparative example 3

In comparison to example 1, the acrylate emulsion in the process described in comparative example 3 is the same type of product commercially available as described in example 1, except that the test coating preparation process did not include a wetting agent addition step and the rest of the process was the same as in example 1.

Product effectiveness testing

The test methods of the embodiments of the present invention were performed in the following manner.

The aqueous stain-resistant coatings prepared in examples 1 to 3 and comparative examples 1 to 3 were subjected to a 55 ℃ heat storage test for 30 days (test after drying the coating film at 25 ℃ for 7 days), and films were formed on black and white paper cards using a 150 μm film scraper before and after the test, and shrinkage was observed to evaluate the stability of the capsule type emulsion, and the results are shown in table 1;

table 1:

the aqueous hydrophobic coating layers prepared in examples 1 to 3 and comparative examples 1 to 3 were subjected to observation of droplet sticking phenomenon and sliding angle test for water (test after drying at 25 ℃ C. for 7 days after preparation of the coating film), the sliding angle (droplet volume of 50. mu.L) was measured using a model JC2000A static hydrophobic angle measuring instrument, 5 points were selected and averaged to evaluate the hydrophobicity of the coating film of the capsule type emulsion, and the results are shown in Table 2;

table 2:

example 1

Example 2

Example 3

Comparative example 1

Comparative example 2

Comparative example 3

Phenomenon of droplet sticking

No tailing

No tailing

No tailing

With trailing

No tailing

-

Water drop sliding angle (°)

29±3

17±2

21±2

76±5

24±3

-

Note: comparative example 3 difficulty in stably observing droplet viscosity and testing water droplet sliding angle when cratering occurred

The prepared water-based hydrophobic coating and comparative examples 1 to 3 (tested after the coating is dried for 7 days at 25 ℃) are taken, the wear resistance is tested according to the method of GB/T9266-.

Table 3:

example 1

Example 2

Example 3

Comparative example 1

Comparative example 2

Comparative example 3

Phenomenon of droplet sticking

No tailing

No tailing

No tailing

With trailing

With trailing

-

Water drop sliding angle (°)

37±3

26±3

34±3

78±4

46±5

-

Note: comparative example 3 difficulty in stably observing droplet viscosity and testing water droplet sliding angle when cratering occurred

As can be seen from tables 1 to 3, the capsule type hydrophobic emulsions prepared in examples 1 to 3 are excellent in thermal stability, the formed coating films are free from the phenomenon of droplet sticking, and the sliding angle test of water droplets is significantly lower than that of the coating films prepared in comparative examples 1 to 3, and they are more excellent in low-viscosity ability and stability to mechanical friction.

Example 1 laser light scattering method measurement of particle size and distribution before and after latex particle encapsulation as shown in fig. 1, measured using a dynamic light scattering instrument (DLS, Malvern ZS 90); the particle size before and after encapsulation is unimodal distribution, the Z-Average particle size of (a) is 104nm, the PDI is 0.088, and the Z-Average particle size of (b) is 118nm, and the PDI is 0.187. It can be seen that the whole capsule forming process is uniform and stable, and the particle size of the capsule type latex particle is still in the nanometer range. The products obtained in example 2 and example 3 have similar experimental effects.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention should not be limited thereby, and all the simple equivalent changes and modifications made in the claims and the description of the present invention are within the scope of the present invention.