CN112574669A

CN112574669A - Modified organic silicon coating and preparation method thereof

Info

Publication number: CN112574669A
Application number: CN201910938658.XA
Authority: CN
Inventors: 杨化彪; 安多; 刘俊杰; 顾翠瑜; 钟炽强
Original assignee: Guangzhou Joining Chemical Material Co ltd
Current assignee: Guangzhou Joining Chemical Material Co ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2021-03-30

Abstract

The invention discloses a modified organic silicon coating and a preparation method thereof, wherein the modified organic silicon coating comprises the following components in parts by weight: 30-50 parts of modified silicone resin; 5-10 parts of white carbon black; 10-30 parts of a phase change material; 0-20 parts of hardening filler; 0-20 parts of pigment; 10-30 parts of a solvent; 1-5 parts of an additive; and 1-5 parts of an auxiliary agent. The phase-change material modified organic silicon coating has good comprehensive performance, adds a specific method for preparing a phase-change micro-material, can effectively make up for the defect of poor temperature and heat resistance change of the existing exterior wall coating system by introducing the phase-change material, and is equivalent to installing a natural 'air conditioner' for the exterior wall of a building, thereby prolonging the weather resistance and the service life of the coating. Meanwhile, the hardness, toughness, impact resistance and dirt resistance of the coating after the coating is cured are improved.

Description

Modified organic silicon coating and preparation method thereof

Technical Field

The invention belongs to the field of coatings, and particularly relates to a modified organic silicon coating and a preparation method thereof.

Background

The outer wall of a building is exposed to wind and sunlight all the year round, and the mineral materials contained in the outer wall have porous surfaces and are easy to absorb moisture, so that the outer wall of the building is damaged by the wind. The exterior wall coating, especially the exterior wall coating taking the organic silicon resin and the modified organic silicon resin as main film forming materials, is an important barrier for protecting exterior walls from being corroded by external factors such as water, environment, climate and the like. The cured organic silicon resin and the modified organic silicon resin coating can form a three-dimensional network structure similar to quartz on the outer surface of the building material, resist the absorption of liquid water from the outside, but allow water vapor to freely pass through, namely that the outside water can be blocked outside the wall body, and the moisture in the wall body can easily escape.

Based on the destruction mechanism of moisture, the coating layer of the paint has the advantages of high hydrophobicity, high water vapor transmission rate, excellent weather resistance, chemical stability and convenient construction. Because pure organic silicon resin has higher production cost and poor adhesion to base materials, the coating is made of modified organic silicon resin, such as acrylic resin, alkyd resin, polyester resin, polyurethane resin and the like, which are commonly used in the market at present. Although the modified organic silicon resin has the characteristics of both organic resin and silicon resin, the modified organic silicon resin still has the defects of poor weather resistance and poor temperature-resistant thermal change; on the other hand, under the condition of large day and night temperature difference and seasonal temperature change, the outer wall material often causes the damage of the wall body and the coating due to thermal expansion and cold contraction, so that the waterproof effect is lost.

Meanwhile, the existing coating has the defects of easy pollution and yellowing, and the like. A coating which has good temperature change resistance and good stain resistance and self-cleaning property is needed in the market.

Disclosure of Invention

In summary, the invention aims to provide a phase change material modified organosilicon coating which is used on a wall, has good heat resistance variability, and has good stain resistance and self-cleaning property.

The invention also aims to provide a preparation method of the phase-change material modified organic silicon coating.

The phase change material modified organic silicon coating comprises the following components in parts by weight:

30-50 parts of modified silicone resin;

5-10 parts of white carbon black;

10-30 parts of a phase change material;

0-20 parts of hardening filler;

0-20 parts of pigment;

10-30 parts of a solvent;

1-5 parts of an additive;

and 1-5 parts of an auxiliary agent.

The preferable formula proportion is as follows:

40-45 parts of modified silicon resin;

5-8 parts of white carbon black;

20-30 parts of a phase change material;

0-18 parts of hardening filler;

0-5 parts of pigment;

15-25 parts of a solvent;

1-2 parts of an additive;

and 1-2 parts of an auxiliary agent.

Preferably, the phase-change material is a phase-change microcapsule with the particle size of 10-20 mu m and the phase-change temperature of 30-50 ℃;

the capsule core of the phase-change microcapsule is linear paraffin of C18-C22, the wall material of the phase-change microcapsule is polyester, and the content of the paraffin in the phase-change microcapsule is 40-60 wt%.

Preferably, the phase-change microcapsule is prepared by the following method:

a. wall material prepolymerization: adding 36.6 parts by weight of 37% formaldehyde aqueous solution and 18g parts by weight into a container in sequence, adjusting the rotating speed to 500rpm, dropwise adding triethanolamine while stirring to adjust the pH value to 8-9, carrying out heat preservation reaction in a 70 ℃ water bath for 1 hour, and adding 100 parts by weight of deionized water to form a stable urea-formaldehyde prepolymer solution for later use;

b. emulsification of the core material: weighing 40 parts by weight of paraffin, heating and melting, adding an emulsifier SMA (styrene grafted maleic anhydride) which accounts for 4% of the mass of the core material and 100 parts by weight of deionized water, emulsifying for 60min at about 60 ℃ and at a stirring speed of 5000rpm, slowly dropwise adding 10 wt% of citric acid solution into the emulsion, and adjusting the pH final value of the solution to 2-4 for later use;

c. microencapsulation: reducing the rotating speed to 500rpm, keeping the temperature at 70 ℃, dropwise adding the urea-formaldehyde prepolymer solution prepared in the step a, reacting for 3 hours in a heat preservation manner, and then adjusting the pH value to 8-9 by using triethanolamine to obtain capsule emulsion;

d. and (3) post-treatment: and after the reaction is finished, pouring out the capsule emulsion, cooling, separating, performing suction filtration, washing the obtained microcapsule for 2 times by using petroleum ether and deionized water respectively, and drying to obtain the white powdery paraffin/urea-formaldehyde resin microcapsule with the paraffin content of 50 wt%.

e. Putting the paraffin/urea-formaldehyde resin microcapsule into a coating pan at one time, adjusting the rotating speed to 80rpm, wherein the mass of the talcum powder is 10-20% of the weight of the paraffin/urea-formaldehyde resin microcapsule; stirring for 5min, adding 10-30 wt% Na₂SiO₃Spraying the aqueous solution with sprayer to the mixture, and adding Na₂SiO₃The mass of the aqueous solution is 10-20% of the weight of the paraffin/urea-formaldehyde resin microcapsule; wrapping for 10min, drying with hot air, spraying dilute hydrochloric acid solution after water is evaporated to dryness, stirring for 20min, and drying with hot air to obtain coated paraffin/urea-formaldehyde resin microcapsule; repeating the above steps for 1-3 times to obtain multilayer wrapping.

Putting the coated paraffin/urea-formaldehyde resin into a 500mL flask, adding a chromic acid-sulfuric acid mixed solution, wherein K is contained in the chromic acid-sulfuric acid mixed solution₂Cr₂O7、H₂SO₄And H₂And the mass ratio of O is 5: 85: 10, stirring is started, the surface of the coated paraffin/urea-formaldehyde resin is subjected to oxidation treatment for 2 hours in a constant-temperature water bath at 40 ℃, and the mixture is filtered, washed by deionized water and dried for later use.

Preferably, the modified silicone resin is selected from one of alkyd modified silicone resin, acrylic modified silicone resin, polyester modified silicone resin and polyurethane modified silicone resin. More preferably, the modified silicone resin is a polyester modified silicone resin. Further, the polyester modified silicone resin is polyester modified methyl phenyl silicone resin.

Preferably, the white carbon black is fumed silica. More preferably, the hydrophobic modified white carbon black has the specific surface area of 150-250 m²/g.

Preferably, the hardening filler is one or more selected from talcum powder, calcium carbonate, barium sulfate, quartz powder and mica powder. Before use, the hardening filler needs to be put into an electric heating oven at 105 ℃ for drying for 6 hours, and is packaged for later use after being naturally cooled to room temperature.

Preferably, the solvent is one or more selected from toluene, xylene, n-butanol, isobutanol, ethyl acetate and petroleum solvent. More preferably, the solvent is a mixture of xylene and isobutanol, and further, the mass mixing ratio of xylene and isopropanol is m (xylene): m (isobutanol) ═ 2:1.

Preferably, the additives are fatty acids, fatty acid esters to improve leveling and storage stability and prevent gelation, skinning and film discoloration. Further, the additive is one or more of diisooctyl adipate, diethyl phthalate and isocyanate.

Preferably, the phase change material modified organosilicon coating needs to contain one or more of auxiliary agents of N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane, vinyl tri (beta-methoxyethoxy) silane and tetra (2-methoxyethoxy) silane. Preferably, the content of the auxiliary agent accounts for 1-5 wt% of the total weight of the coating.

The pigment is selected from titanium dioxide, zinc oxide, black iron oxide, iron oxide red, ultramarine and the like, and is mainly used for adjusting viscosity and glossiness.

A preparation method of a phase-change material modified organic silicon coating is realized by the following steps:

s1, adding the modified silicon resin, the hardening filler and the pigment into a high-speed dispersion machine according to the formula weight, adding 80-90% of solvent, starting high-speed dispersion and uniformly stirring to obtain a mixture for later use;

s2, adding white carbon black while stirring the mixture, after the white carbon black is uniformly dispersed, adjusting high-speed dispersion to low speed, adding the phase-change microcapsules and uniformly stirring to obtain a base material for later use;

s3, adding the required additives and auxiliary agents under the condition of low-speed stirring, adding the remaining 10-20% of solvent to adjust the viscosity, and then filtering and packaging.

The phase-change material modified organic silicon coating has good comprehensive performance, adds a specific method for preparing a phase-change micro-material, can effectively make up for the defect of poor temperature and heat resistance change of the existing exterior wall coating system by introducing the phase-change material, and is equivalent to installing a natural 'air conditioner' for the exterior wall of a building, thereby prolonging the weather resistance and the service life of the coating. Meanwhile, the hardness, toughness, impact resistance and dirt resistance of the coating after the coating is cured are improved.

Detailed Description

The invention is further described below with reference to some specific embodiments. The specific examples are intended to illustrate the present invention in further detail, and are not intended to limit the scope of the present invention.

Description of raw materials:

polyester-modified silicone resin: megash high-tech material, TSR175

White carbon black: winning Chuangdegusai, R8200

The remaining material sources are commercially available:

example 1

The phase-change microcapsule is prepared by the following method:

e. Putting the paraffin/urea-formaldehyde resin microcapsule into a coating pan at one time, and adjusting the rotating speed to 80rpm, wherein the mass of the talcum powder is 10% of the weight of the paraffin/urea-formaldehyde resin microcapsule; stirring for 5min, adding 10 wt% Na₂SiO₃Spraying the aqueous solution with sprayer to the mixture, and adding Na₂SiO₃The mass of the aqueous solution is 10% of the weight of the paraffin/urea-formaldehyde resin microcapsule, hot air drying is carried out after the aqueous solution is wrapped for 10min, a dilute hydrochloric acid solution is sprayed after the water content is evaporated to dryness, and hot air drying is carried out after the aqueous solution is stirred for 20min to obtain the wrapped paraffin/urea-formaldehyde resin microcapsule; the above operation was repeated 1 time.

Putting the coated paraffin/urea-formaldehyde resin into a 500mL flask, adding a chromic acid-sulfuric acid mixed solution, wherein K is contained in the chromic acid-sulfuric acid mixed solution₂Cr₂O₇、H₂SO₄And H₂And the mass ratio of O is 5: 85: 10, stirring is started, the surface of the coated paraffin/urea-formaldehyde resin is subjected to oxidation treatment for 2 hours in a constant-temperature water bath at 40 ℃, filtering is carried out, and then deionized water is used for washing and drying, so that the phase-change microcapsule is obtained.

Adding 45 parts of polyester modified silicone resin and 10 parts of dimethylbenzene into a high-speed dispersion machine, adding 8 parts of hydrophobic white carbon black while stirring, then stirring at a low speed, adding 30 parts of phase change microcapsules, stirring uniformly, then sequentially adding 1 part of diisooctyl adipate and 1 part of N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane, finally adding 5 parts of dimethylbenzene to adjust viscosity, filtering and packaging.

Example 2

The phase change microcapsule is prepared according to the method of the embodiment 1, then 40 parts of polyester modified silicon resin, 10 parts of quartz powder and 10 parts of dimethylbenzene are added into a high-speed dispersion machine, 5 parts of hydrophobic white carbon black is added while stirring, then the low-speed stirring is carried out, 25 parts of phase change microcapsule is added, 2 parts of diisooctyl adipate, 1 part of N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane and 0.5 part of tetra (2-methoxyethoxy) silane are sequentially added after the uniform stirring, finally 7 parts of dimethylbenzene is added to adjust the viscosity, and the filtration and the packaging are carried out.

Example 3

The phase change microcapsule is prepared according to the method described in example 1, then 40 parts of polyester modified silicone resin, 7 parts of barium sulfate, 5 parts of titanium dioxide and 15 parts of xylene are added into a high-speed dispersion machine, 5 parts of hydrophobic white carbon black is added while stirring, then the stirring is carried out at a low speed, 20 parts of phase change microcapsule is added, 1 part of isocyanate and 2 parts of N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane are added in sequence after the uniform stirring, finally 5 parts of xylene is added to adjust the viscosity, and the filtration and the packaging are carried out.

Comparative example 1

Adding 45 parts of polyester modified silicone resin and 10 parts of dimethylbenzene into a high-speed dispersion machine, adding 8 parts of hydrophobic white carbon black while stirring, then stirring at a low speed, adding 30 parts of phase change microcapsules (the specific method is as follows), sequentially adding 1 part of diisooctyl adipate and 1 part of N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane after uniformly stirring, finally adding 5 parts of dimethylbenzene to adjust the viscosity, filtering and packaging.

The phase-change microcapsules of comparative example 1 were prepared as follows:

1) according to the paraffin: taking the methyl methacrylate according to the mass ratio of 1: 3;

2) weighing ethylene glycol dimethacrylate, 1% methacrylic acid, 1% sodium dodecyl sulfate, 1.5% potassium persulfate, 1% -15% ferrite and 400% deionized water according to 0.5% of the total mass in the step 1);

3) adding sodium dodecyl sulfate into deionized water, and heating to 50 ℃;

4) adding ferrite and melted paraffin to the solution of 3;

5) ultrasonic emulsification, adding methyl methacrylate, ethylene glycol dimethacrylate and methacrylic acid;

6) re-emulsifying, transferring the obtained solution into a device with a mechanical stirring device, a condensing tube, an air inlet and a charging hole; 7) aerating and deoxidizing for 0.5 hour, heating in water bath to 70 ℃, adding potassium persulfate, and cooling to room temperature to obtain the phase-change microcapsule.

Comparative example 2

The phase change microcapsule is prepared according to the method of the embodiment 1, then 45 parts of polyester modified silicon resin, 10 parts of quartz powder and 10 parts of dimethylbenzene are added into a high-speed dispersion machine, 5 parts of hydrophobic white carbon black is added while stirring, then the stirring is carried out at a low speed, 25 parts of phase change microcapsule is added, 1 part of diisooctyl adipate is sequentially added after the uniform stirring, finally 5 parts of dimethylbenzene is added to adjust the viscosity, and the filtering and the packaging are carried out.

Comparative example 3

b. emulsification of the core material: weighing 40 parts by weight of paraffin, heating and melting, adding an emulsifier SMA accounting for 4% of the mass of the core material and 100 parts by weight of deionized water, emulsifying for 60min at about 60 ℃ and at a stirring speed of 5000rpm, slowly dropwise adding 10 wt% of citric acid solution into the emulsion, and adjusting the pH final value of the solution to 2-4 for later use;

d. and (3) post-treatment: and after the reaction is finished, pouring out the capsule emulsion, cooling, separating, performing suction filtration, washing the obtained microcapsule for 2 times by using petroleum ether and deionized water respectively, and drying to obtain the white powdery phase-change microcapsule with the paraffin content of 50 wt%.

Performance testing

Description of the test methods:

(1) drying time by touch: according to the touch method of GB/T1728-1989, the surface of the paint film is touched by fingers, if the paint film feels slightly sticky, but no paint adheres to the fingers, namely the surface is dry. The test temperature was 25 ℃.

(2) Curing time: referring to the blade method in GB/T1728-1989, the coating is cut and scraped by a safety blade, and no adhesion phenomenon exists in the bottom layer and the film, namely the actual drying is observed.

(3) Coating hardness: reference is made to standard test methods for astm d3363-00 coating pencil hardness.

(4) Gloss retention ratio: the examples and comparative samples were exposed to the sun outdoors in the Guangzhou area of China for half a year and then tested for gloss retention. The gloss of the samples before and after aging was measured using a gloss meter at an incident angle of 60 degrees.

(5) Hydrophobicity: according to ISO1062-3, a sample to be tested is coated on a sand-lime brick plate, the sand-lime brick plate is dried for 72 hours at room temperature, placed in a 50 ℃ oven for 72 hours, immersed in a water tank for washing for 72 hours (1cm deep), dried for 72 hours in the 50 ℃ oven, the sand-lime brick sample plate is placed on a sponge soaked with water, weighed after 1 hour, 2 hours, 3 hours, 6 hours and 24 hours respectively, and the water absorption amount is calculated.

(5) Adhesion test: and testing by referring to a GB/T9286-88 cross-cut method.

(6) Stability test (test for cracking): and coating the coating on a glass sheet, and observing whether the coating cracks or not after 1000 hours.

(8) Impact resistance: according to the GB/T1732-93 test standard, a falling ball impact test method is adopted, a paint sample is coated on a steel plate with the thickness of 1mm, the thickness of the coating is controlled to be about 0.1mm, and the impact strength of the paint sample is tested after the paint sample is completely cured. Namely, a 500g steel ball was dropped freely from a height of 50cm, and the degree of damage of the contact surface of the coating was observed.

(9) Stain resistance: coating a paint sample on the surface of a stone brick sample block, and after the paint sample is completely cured, smearing the paint on the surface of a coating, namely painting and smearing dust by using an oil pen, standing for one day, and then cleaning the surface of a test board by using a commercially available high-pressure water gun. No residue of soil was evaluated as excellent, 80% of soil was cleaned and evaluated as good, and 50% of soil was cleaned and evaluated as normal.

According to experimental results, the phase-change material organic silicon coating has better shock resistance because the phase-change microcapsules are coated and then are subjected to surface modification by inorganic molecules. The sample coating containing the phase change microcapsule coated by the inorganic molecules has a depression on the surface and is not damaged; the sample coating containing the common phase-change microcapsule has pits and is not damaged, but the coating is whitish inside and the liquid paraffin seeps out from the surface of the coating.

The organic silicon coating well solves the problems that the phase change capsule wall is fragile, and paraffin can generate surface migration, leakage, heat performance degradation and the like in the using process of the existing microcapsule, and the strength of the phase change capsule wall coated by the inorganic material plays a good role in resisting permeation.

Meanwhile, the organic silicon coating has low surface energy, and after the phase-change microcapsule is coated by silicate, the anti-fouling performance and the self-cleaning performance of the coating are obviously improved.

In conclusion, the organic silicon coating disclosed by the invention has better other properties and can be widely applied to the field of buildings.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The phase change material modified organic silicon coating comprises the following components in parts by weight:

30-50 parts of modified silicone resin

5-10 parts of white carbon black

10-30 parts of phase change material

0-20 parts of hardening filler

0 to 20 parts of pigment

10-30 parts of solvent

1-5 parts of additive

And 1-5 parts of an auxiliary agent.

2. The phase change material-modified silicone coating of claim 1, wherein:

the phase-change material is a phase-change microcapsule, the particle size is 10-20 mu m, and the phase-change temperature is 30-50 ℃;

3. The phase change material-modified silicone coating of claim 2, wherein:

the phase change microcapsule is prepared by the following method:

e. Putting the paraffin/urea-formaldehyde resin microcapsule into a coating pot at one time, adjusting the rotating speed to 80rpm, and uniformly adding superfine talcum powder into a coating machine, wherein the mass of the talcum powder is 10-20% of the weight of the paraffin/urea-formaldehyde resin microcapsule; stirring for 5min, adding 10-30 wt% Na₂SiO₃Spraying the aqueous solution with sprayer to the mixture, and adding Na₂SiO₃The mass of the aqueous solution is 10-20% of the weight of the paraffin/urea-formaldehyde resin microcapsule; wrapping for 10min, drying with hot air, spraying dilute hydrochloric acid solution after water is evaporated to dryness, stirring for 20min, drying with hot air to obtain coated paraffin/urea-formaldehyde resin microcapsule, and repeating the above operation for 1-3 times.

4. The phase change material-modified silicone coating of claim 3, wherein:

the modified silicon resin is selected from one of alkyd modified silicon resin, acrylic acid modified silicon resin, polyester modified silicon resin and polyurethane modified silicon resin.

5. The phase change material-modified silicone coating of claim 4, wherein:

the white carbon black is fumed silica.

6. The phase change material-modified silicone coating of claim 5, wherein:

the hardening filler is one or more selected from talcum powder, calcium carbonate, barium sulfate, quartz powder and mica powder.

7. The phase change material-modified silicone coating of claim 6, wherein:

the solvent is selected from one or more of toluene, xylene, n-butanol, isobutanol, ethyl acetate and petroleum solvent.

8. The phase change material-modified silicone coating of claim 7, wherein:

the additive is fatty acid and fatty acid ester to improve leveling property and storage stability, and prevent gelation, skinning and film discoloration. Further, the additive is one or more of diisooctyl adipate, diethyl phthalate and isocyanate.

9. The phase change material-modified silicone coating of claim 8, wherein:

the phase change material modified organic silicon coating needs to contain one or more of auxiliary agents N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane, vinyl tri (beta-methoxyethoxy) silane and tetra (2-methoxyethoxy) silane.

10. A method for preparing the phase-change material modified organic silicon coating of any one of claims 1 to 9, which is realized by the following steps: s1, adding the modified silicon resin, the hardening filler and the pigment into a high-speed dispersion machine according to the formula weight, adding 80-90% of solvent, starting high-speed dispersion and uniformly stirring to obtain a mixture for later use;