CN111558349A - A dual-chamber microcapsule with self-warning function and preparation method thereof - Google Patents

Abstract

The invention discloses a dual-chamber microcapsule with self-warning function and a preparation method thereof. The present invention firstly prepares nano-microspheres with internal encapsulation of color developer by sol-gel method and in-situ polymerization, uses it as Pickering emulsifier to stabilize the oil phase containing hidden dyes to obtain stable Pickering emulsion, and solidifies the emulsion to obtain a stable Pickering emulsion. Two-chambered microcapsules. In the double-chambered microcapsules of the present invention, the color developer is encapsulated in the shell layer emulsifier particles, and the core material is a recessive dye, which realizes the separate loading of the color developer and the recessive dye in the same microcapsule, which not only solves the problem of The traditional self-warning system based on two-component microcapsules has the problem of low contact rate between the color developer and the dye, and achieves a faster and more efficient response to cracks. The dual-chamber microcapsules have broad application prospects in self-warning coatings, composite materials and encapsulation materials.

Description

A dual-chamber microcapsule with self-warning function and preparation method thereof

technical field

The invention relates to a dual-chamber microcapsule with self-warning function and a preparation method thereof, and belongs to the technical field of preparation of microcapsules.

Background technique

When materials are damaged by external action or internal stress, it can have a serious impact on the service life of systems and equipment. The timely detection of defects in materials or components is conducive to reducing losses and ensuring safety. The current non-destructive testing technologies for materials include ultrasonic testing, electron dislocation speckle interference, alternating magnetic field measurement, and X-ray testing technology. Although traditional material defect detection methods can detect damage, there are problems such as expensive and complex equipment and inaccurate measurement results. In order to more intuitively observe the defects in materials, dye molecules and fluorescence methods are introduced into the material damage detection, and a variety of methods to visually observe the material damage have been developed. Among them, the foreign aid detection method has been widely studied due to its advantages of simple system design.

Most of the external aid detection methods are based on responsive dye molecules or fluorescent molecules, which can be directly dispersed or modified into the matrix material to give early warning of color development to damaged parts under specific circumstances. However, these small molecules or molecular groups all have the problems that they are easy to react with active groups in the matrix material, and are prone to photobleaching or UV degradation. In order to better avoid the influence of the external environment on dyes or fluorescent molecules, some researchers encapsulate them in microcapsules to construct a microcapsule-based self-warning system. At the same time, since the preparation process of microcapsules has gradually matured, it is easier to achieve multi-functional, low-cost and industrialized production, so the application prospects of microcapsule-type self-alarming materials are more extensive.

Most microencapsulated self-alert systems rely on chemical reactions between dyes encapsulated in microcapsules and color-developing agents or catalysts embedded in the matrix material, which inevitably results in The loss of color developer or catalyst results in insignificant color development. A dual-microcapsule self-warning system can be constructed by microencapsulating the color developer or catalyst and dye separately and then dispersing them in the matrix material. Although the loss of components during the preparation process can be avoided, there are still two types of microcapsules. Due to the problem of stoichiometric ratio mismatch caused by uneven dispersion, the self-warning effect is still not ideal. In response to the above problems, some researchers have built multi-chamber microcapsules to simultaneously encapsulate a certain stoichiometric ratio of dyes and color developers or catalysts in different chambers to improve the contact speed and color development early warning efficiency of the two components. Compared with single-component microcapsules, the preparation process of multi-chambered microcapsules is more complicated.

At present, for the preparation of multi-chamber microcapsules, microfluidic technology and layer-by-layer self-assembly (LBL) are mostly used. The preparation of multi-chambered microcapsules by microfluidic technology is based on the construction of multiple emulsions or multi-core emulsions. After the emulsion is solidified, microcapsules with multi-chambered structures are obtained. Although the microcapsules prepared by microfluidic technology have good dimensional stability and repeatability, there are still defects such as relatively large size of microcapsules and difficult control of the release of encapsulated components, which make their commercial applications limited to a certain extent. limit. The multi-chambered microcapsules prepared by the layer-by-layer self-assembly method utilize alternate deposition between layers, so that the repairing agent and the curing agent are separately encapsulated in different layers of the microcapsules. The layer-by-layer self-assembly method is a multi-step process. Generally, only one component can be encapsulated in one step. When multiple components, especially active components, need to be encapsulated, in order to ensure the activity of each component, it is inevitable that low encapsulation efficiency, The problem of damage to the active ingredient.

Therefore, in summary, there is still a lack of a simple and efficient method for preparing multi-chambered microcapsules with self-alert function.

SUMMARY OF THE INVENTION

Technical problem: In order to overcome the deficiencies in the prior art, the present invention provides a method for preparing dual-chamber microcapsules with self-warning function by Pickering emulsion method, and the dual-chamber microcapsules can realize a color developing agent with adjustable components It is coated with the recessive dye on different parts of the same microcapsule, which greatly improves the response rate and the early warning efficiency of the self-alarming material when it is damaged. The preparation method has the advantages of simple process, low production cost, wide application range and easy industrialization. The prepared self-warning microcapsules can be widely used in the fields of self-warning coatings, composite materials and packaging materials.

Technical scheme: In order to realize the above-mentioned purpose, the technical scheme adopted in the present invention is:

A dual-chamber microcapsule with self-warning function is composed of an outer shell layer and a dual-chamber microcapsule core material wrapped in the shell layer; wherein, the shell layer is a plurality of nano-microspheres loaded with a color developer and ethylenic polymer, and the core material of the double-chamber microcapsule is a recessive dye that can react with a color developer.

A method for preparing dual-chamber microcapsules with self-warning function by Pickering emulsion method, comprising the following steps:

Step 1: Preparation of nano-microspheres coated with developer

A certain amount of color developer, ethylenic monomer, inorganic nanoparticle precursor and oil-soluble thermal initiator are used as the oil phase, and an appropriate amount of deionized water is added in a certain oil-water ratio, stirred at high speed to form a coarse emulsion, and the pH value of the system is adjusted. High-speed emulsification to form a stable emulsion, and thermal curing to obtain nano-microspheres coated with color developer;

Step 2: Preparation of dual-chambered microcapsules

A certain amount of nano-microspheres coated with color developer are dispersed in water as a Pickering emulsifier to form a certain concentration of water dispersion as the emulsion water phase, and a certain amount of oil phase is added for high-speed emulsification for a period of time to form an emulsion, wherein the oil phase is hidden. The mixture of sexual dye, water-insoluble organic solvent, vinyl monomer and photoinitiator is cured by light such as UV to obtain double-chambered microcapsules.

The nano-microsphere emulsifier and the double-chambered microcapsules prepared by the above steps have uniform and regular morphology, wherein the particle size distribution of the nano-microspheres is 50nm-400nm, the thickness of the microsphere wall is 5nm-40nm, and the content of the color developer core material is 60%-80%, the yield is 70%-90%; the particle size distribution of the dual-chamber microcapsules is 50 μm-300 μm, the thickness of the capsule wall is 4 μm-25 μm, and the content of the core material of the dual-chamber microcapsules is 50%-80%. The rate is 65%-85%.

The method for preparing dual-chamber microcapsules with self-warning function by the Pickering emulsion method, in the preparation process of the Pickering emulsifier, the mass ratio of each component in the oil phase is as follows: 20%-50% color development agent, 10%-40% inorganic nanoparticle precursor, 10-30% olefin monomer and oil-soluble thermal initiator, wherein the olefin monomer is composed of multifunctional monomer and monofunctional monomer according to the mass ratio of 1 : 2-5: 1 composition, and the oil-soluble thermal initiator is 1-4 wt % of the total mass of the ethylenic monomer. The particle size and wall thickness of the microspheres are controlled by changing the amount of the inorganic nanoparticle precursor, the pH value of the system and the emulsification rate. The volume ratio of the oil phase to the water phase is 1:3-1:10, and the high-speed emulsification time is 2-7min; during the thermal curing process, the curing temperature is 60-100°C, and the curing time is 6-12h.

The described method for preparing dual-chamber microcapsules with self-warning function by Pickering emulsion method, in the preparation process of the dual-chamber microcapsules, the mass ratio of each component in the capsule oil phase is as follows: 35-65% non- Water-soluble organic solvent, 35-65% ethylenic monomer, photoinitiator and recessive dye, wherein the concentration of recessive dye in the water-insoluble organic solvent is 5-25mg/mL, wherein the olefinic monomer is composed of many The functional monomer and the monofunctional monomer are composed in a mass ratio of 1:1-5:1, and the photoinitiator is 1-4wt% of the total mass of the ethylenic monomer. The concentration of Pickering emulsifier in the aqueous phase of the emulsion is 5-50mg/ml, the oil-water ratio in the emulsion is 2:1-1:10, and the high-speed emulsification time is 2min-5min. During UV curing, the UV wavelength is 230-420nm, and the curing time is 2-10min.

The method for preparing dual-chamber microcapsules with self-warning function by a Pickering emulsion method, wherein the color developing agent is an acid-base substance or benzotriazoles, phenols, thiourea derivatives, aromatic carboxylate Electron-absorbing color developer such as acid; Described acid-base substance is preferably benzoic acid, oleic acid, ricinoleic acid, stearic acid, palmitic acid, tall oil acid, triethylamine, tri-n-propylamine, tri-n-propylamine, triethylamine One or more mixtures of organic acid and alkaline substances such as n-butylamine, diphenylamine, dibenzylamine, aniline, N-methylaniline, acetanilide, N,N-dimethylaniline, p-toluidine; The electron-absorbing color developer is preferably 5-butylbenzotriazole, nonylphenol, bisphenol A, bisphenol F, 1,5-bishydroxynaphthalene, alkyl p-hydroxybenzoate, allyl One or more mixtures of thiourea, phthalic acid, trimesic acid, salicylic acid and their metal salts.

The method for preparing dual-chamber microcapsules with self-warning function by a Pickering emulsion method, the pH adjusting agent is hydrochloric acid, sulfuric acid, phosphoric acid, sodium hydroxide, triethylamine, ammonia water, dimethylamine, ethyl acetate. One or more of diamine and ethanolamine.

The method for preparing dual-chamber microcapsules with self-warning function by a Pickering emulsion method, wherein the vinyl monomer is a mixture of a monofunctional vinyl monomer and a multifunctional vinyl monomer; the Monofunctional vinyl monomers are glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate Ester, isooctyl (meth)acrylate, hydroxyethyl (meth)acrylate, ethylhexyl (meth)acrylate, (meth)acrylic acid, tert-butyl (meth)acrylate, methoxypolyethylene One or more of glycol acrylate, ethoxyethoxyethyl acrylate, styrene, N-isopropylacrylamide, acrylamide, 2-butenamide; the multifunctional olefin The monomers are divinylbenzene, diethylene glycol diacrylate, ethylene glycol dimethacrylate, tetrapropylene glycol diacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate Esters, Bisphenol A Glycidyl Dimethacrylate, Triethylene Glycol Dimethacrylate, Dipentaerythritol Hexacrylate, Diethylene Glycol Diacrylate Phthalate, Neopentyl Glycol Diacrylate ester, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipropylene glycol diacrylate, 1,3-butanediol diacrylate one or more.

The method for preparing dual-chamber microcapsules with self-warning function by a Pickering emulsion method, the inorganic nanoparticle precursors are tetraethyl silicate, tetramethyl silicate, tetraisopropyl silicate, silicon Tetrabutyl acid, tetrabutyl titanate, tetraethyl titanate, isopropyl titanate, 3-(trimethoxysilyl)propyl acrylate, vinyltrimethoxysilane, vinyltributyl Ketooximosilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, isopropyltris(isostearoyl)titanate, isopropyltris(dioctyl) Pyrophosphoryl) titanate, titanium bis(dioctylpyrophosphoryl)oxyacetate, isopropyltris(dioctylphosphoryl)titanate, isopropyltris(dodecylbenzenesulfonate) acyl) one or more of titanates.

Described a kind of Pickering emulsion method prepares the method for the double-chamber microcapsule with self-warning function, the oil-soluble thermal initiator described in step (1) is dilauroyl peroxide, dodecanoyl peroxide, neodecyl peroxide tert-amyl acid, dicumyl peroxide, azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, azobisisobutyric acid dimethyl ester, azodicyclohexylcarbonitrile One or more of; the photoinitiator described in step (2) is 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl) butanone, 2-hydroxy-methyl Phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin dimethyl ether, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, isopropylthioxanthone, 4-Chlorobenzophenone, 4,4'-dimethyldiphenyl iodonium salt hexafluorophosphate, isooctyl p-dimethylaminobenzoate, 4-methylbenzophenone, o-benzoyl One or more of methyl benzoate, 4-phenylbenzophenone, 2,4,6-trimethylbenzoyl ethyl phenylphosphonate, 2-isopropylthioxanthone .

In the method for preparing dual-chamber microcapsules with self-warning function by a Pickering emulsion method, the leuco dyes described in step (2) are acid-base indicators, fluorane-based leuco dyes, and triarylmethane-based leuco dyes , phthalide leuco dyes and other electron-donating leuco dyes need to be used according to the color developer; when the color developer is an acid-base substance, the dye is an acid-base indicator, preferably acid fuchsin , Alizarin red S, basic blue, basic fuchsin, p-dimethylaminoazobenzene, 2,6-dinitrophenol, Nile blue 2B, m-nitrophenol, 1,4-dihydroxyanthraquinone One or more mixtures of blue, sulfonaphthalene red, tetrabromophenolphthalein ethyl ester, tetraiodophenolsulfonphthalein, and thymol blue; when the color developer is an electron-withdrawing color developer, the dye is a supply Electronic leuco dyes, preferably 3-chloro-6-anilinofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3,3-dibutoxyfluoran, 3- Diethylamino-7-phenylaminofluoran, dimethyl-7,8-phenylfluoran, dihydroxyfluoran, 2-(6-hydroxy-3-oxo-3H-xanthene-9-yl) Benzoic acid, chloranil, 4-aminotriarylmethane, 4,4'-diaminotriarylmethane, 4,4',4"-triaminotriarylmethane, tris(4-diethylaminophenyl)methane, tris(4 -Diethylamino-2-methylphenyl)methane, 3,3-bis(4-dimethylamino)phenylphthalide, 6-dimethylaminobasic compound, 3,3-(diindole- 3-yl)phthalide, diindolephthalide, 7-azaphthalide, 4,7-diazaphthalide, one or more of olefin-substituted phthalide and 3-butadiene-substituted phthalide species mixture.

Described a kind of Pickering emulsion method prepares the method for the double-chambered microcapsule with self-warning function, the water-insoluble organic solvent described in step (2) is alkane, alcohol, mercaptan, ketone ether, phosphate or carbonate A mixture of one or more of the water-insoluble organics.

The preparation method of a dual-chamber microcapsule with self-warning function provided by the present invention is based on the preparation of Pickering emulsion. Compared with traditional emulsion polymerization, Pickering emulsion method uses solid nanoparticles adsorbed on the oil/water interface instead of organic surfactants. During the preparation of Pickering emulsion, the interior of the emulsifier and the interior of the emulsion can form independent spaces to load different substances, which can be used for the preparation of dual-chambered microcapsules. The preparation method has the advantages of simple process, low production cost, wide application range and easy industrialization. The prepared self-warning microcapsules can be widely used in the fields of self-warning coatings, composite materials and packaging materials.

Beneficial effect: Compared with the prior art, the present invention has the following advantages:

(1) The color developer and the recessive dye are located in the shell layer and inside of the same microcapsule, respectively. When the material is damaged, this system can improve the contact speed and early warning efficiency of the two components at the same time;

(2) The color developer and the recessive dye in the dual-chamber microcapsule are independently packaged, and the type and coating amount of the two components can be adjusted according to the actual application.

Description of drawings

Fig. 1 is the preparation flow of the double-chambered microcapsules in the present invention.

Figure 2 is a schematic structural diagram of a dual-chambered microcapsule in the present invention.

Fig. 3 is the self-warning mechanism of the self-warning material based on the dual-chamber microcapsule in the present invention.

Fig. 4 is the scanning electron microscope picture of the nano-microsphere of coating developer N, N-dimethylaniline prepared for embodiment 1 in the present invention, the microsphere described in the figure is regular spherical, and the particle size is relatively evenly.

5 is a scanning electron microscope picture of the dual-chambered microcapsules prepared in Example 1 in the present invention, and the presence of Pickering emulsifier particles can be observed on the surface of the dual-chambered microcapsules in the figure.

Detailed ways

The invention firstly prepares nano-microspheres with internal encapsulation of color developer through sol-gel method and in-situ polymerization, uses it as Pickering emulsifier to stabilize oil phase containing hidden dyes to obtain stable Pickering emulsion, and solidifies the emulsion to obtain a stable Pickering emulsion. Two-chambered microcapsules. In the double-chambered microcapsules of the present invention, the color developer is encapsulated in the shell layer emulsifier particles, and the core material is a recessive dye, which realizes the separate loading of the color developer and the recessive dye in the same microcapsule, which not only solves the problem of The traditional self-warning system based on two-component microcapsules has the problem of low contact rate between the color developer and the dye, and achieves a faster and more efficient response to cracks. The dual-chamber microcapsules have broad application prospects in self-warning coatings, composite materials and encapsulation materials.

The present invention will be further described below with reference to the accompanying drawings and embodiments.

Example

The present invention can be better understood from the following examples. However, those skilled in the art can easily understand that the specific material ratios, process conditions and results described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims. .

Example 1

(1) Preparation of nano-microspheres coated with developer: Weigh 2.4g developer N,N-dimethylaniline, 1g divinylbenzene, 0.2g styrene, 1.85g tetraethyl silicate, 0.55g gγ-(trimethoxysilyl)propyl methacrylate and 0.048 g oil-soluble thermal initiator azobisisobutyronitrile were used as the oil phase, and the thermal initiator was completely dissolved by ultrasound. Add 60ml of deionized water according to the ratio of oil phase:water phase=1:10, add 0.5g of triethylamine, stir at high speed for 30min, emulsification at high speed for 5min to obtain a stable emulsion, heat curing at 80°C for 8h, that is, the coating is obtained. Nanoparticles of colorant N,N-dimethylaniline.

(2) Preparation of double-chambered microcapsules: Weigh 1g of monomer styrene, 1g of solvent carbon tetrachloride, 0.02g of chloranil, 0.03g of photoinitiator 2-hydroxy-methylphenylpropan-1-one as oil phase , the photoinitiator was completely dissolved by ultrasound. The Pickering emulsifier prepared in step (1) was weighed and dispersed to obtain an emulsifier aqueous dispersion with a concentration of 40 mg/ml. According to the ratio of oil phase: water phase = 1:5, it is configured as an emulsion, and a stable emulsion is obtained by high-speed emulsification for 3 minutes, and double-chambered microcapsules are obtained after UV curing for 30 minutes under a 322 nm point light source.

Example 2

(1) Preparation of nano-microspheres coated with developer: Weigh 1.6g of developer polyetheramine, 0.9g of trimethylolpropane triacrylate, 0.2g of methyl methacrylate, 1.2g of tetraethyl silicate ester, 0.4 g vinyl tris(β-methoxyethoxy) silane, 0.02 g oil-soluble thermal initiator azobisisoheptyl nitrile as oil phase, and the thermal initiator is completely dissolved by ultrasound. Add 34.4ml of deionized water according to the ratio of oil phase:water phase=1:8, add 0.22g of triethylamine, stir at high speed for 30min, emulsification at high speed for 4min to obtain a stable emulsion, heat curing at 60 ° C for 7h, that is, the coating is obtained Nanoparticles of color developer polyetheramine

(2) Preparation of double-chambered microcapsules: Weigh 0.8 g of trimethylolpropane triacrylate, 0.2 g of methyl methacrylate, 1.5 g of solvent carbon disulfide, 0.035 g of chloranil, and 0.035 g of photoinitiator benzophenone as Oil phase, sonication to completely dissolve the photoinitiator. Weigh the Pickering emulsifier prepared in step (1) and disperse to obtain an emulsifier aqueous dispersion with a concentration of 30 mg/ml. According to the ratio of oil phase: water phase = 1:4, it is configured as an emulsion, and a stable emulsion is obtained by high-speed emulsification for 2 minutes, and double-chambered microcapsules are obtained by UV curing for 5 minutes under a 255 nm point light source.

Example 3

(1) Preparation of nano-microspheres coated with developer: Weigh 2.0g developer bisphenol A, 0.6g 1,6-hexanediol diacrylate, 0.4g hydroxyethyl acrylate, 1.5g tetraethyl titanate Ester, 0.4 g isopropyl tris(dioctylphosphoryl) titanate, 0.03 g oil-soluble thermal initiator dimethyl azobisisobutyrate were used as oil phase, and the thermal initiator was completely dissolved by ultrasound. Add 39.2ml of deionized water according to the ratio of oil phase:water phase=1:8, add 0.53g triethylamine, stir at high speed for 30min, emulsification at high speed for 6min to obtain a stable emulsion, heat curing at 70 ° C for 10h, that is, the coating is obtained Color developer bisphenol A nanospheres.

(2) Preparation of double-chambered microcapsules: Weigh 1.0g 1,6-hexanediol diacrylate, 0.4g hydroxyethyl acrylate, 1.2g solvent decane, 0.036g crystal violet lactone, 0.056g photoinitiator isopropyl thioxanthone as the oil phase, and ultrasound to completely dissolve the photoinitiator. Weigh the Pickering emulsifier prepared in step (1) and disperse to obtain an emulsifier aqueous dispersion with a concentration of 50 mg/ml. According to the ratio of oil phase: water phase = 1:3, it was configured as an emulsion, and the stable emulsion was obtained by high-speed emulsification for 4 minutes, and the dual-chamber microcapsules were obtained by UV curing for 10 minutes under a point light source of 382 nm.

Example 4

Figure 2 is a schematic diagram of the structure of the double-chambered microcapsule prepared by the present invention, which is composed of an outer shell layer and a recessive dye core material wrapped inside the shell layer; wherein, the shell layer is a plurality of load The coating is composed of a color developer and an ethylenic polymer, and the recessive dye core material is a recessive dye capable of developing a color reaction with the color developer.

From the inside to the outside, the nano-microspheres are the color developer core material 3 and the hybrid microsphere wall (the organic-inorganic hybrid wall material composed of the organic wall material 2 and the inorganic wall material 1), wherein the organic-inorganic hybrid wall material It is generated by the hydrolysis-condensation of the inorganic nanoparticle precursor and the thermal polymerization of olefinic monomers. The particle size distribution of the nano-microspheres is 50nm-400nm, the thickness of the microsphere wall is 5nm-40nm, and the content of the color developer core material is 60 nm. %-80%, and the yield is 70%-90%; the double-chambered microcapsules are composed of a double-chambered microcapsule core material, an organic capsule wall, and a nano-microsphere from the inside to the outside, wherein the double-chambered microcapsule core material is a hidden microcapsule. Sex dye 5, the organic capsule wall is an organic wall material 4 formed by photopolymerization of olefin monomers, the particle size distribution of the dual-chamber microcapsules is 50 μm-300 μm, the wall thickness of the dual-chamber microcapsules is 4 μm-25 μm, The content of the microcapsule core material is 50%-80%, and the yield is 65%-85%.

Fig. 4 is the scanning electron microscope picture of the nano-microsphere of coating color developer N,N-dimethylaniline prepared for embodiment 1 in the present invention, the microsphere described in the figure is regular spherical, and the particle size is relatively evenly. 5 is a scanning electron microscope picture of the dual-chambered microcapsules prepared in Example 1 in the present invention, and the presence of Pickering emulsifier particles can be observed on the surface of the dual-chambered microcapsules in the figure.

Example 5

As shown in FIG. 3 , the repair mechanism of the self-early warning material based on the dual-chamber microcapsules in the present invention is specifically: when the self-repairing material added with dual-chamber microcapsules is damaged due to external effects, the expansion of internal micro-cracks will The dual-chamber microcapsules are induced to rupture, and the color developer and recessive dye loaded in the dual-chamber microcapsules fill the microcracks due to capillary action, and the two components react rapidly and develop color to achieve precise monitoring of cracks.

To sum up, the color developer and the recessive dye are designed in the present invention to be located in the shell layer and inside of the same microcapsule, respectively. The type and coating amount of the two components can be adjusted according to the actual application. When damaged by external force, this system can be simultaneously Improve the contact speed and early warning efficiency of the two components.

Claims (10)

1. a dual-chamber microcapsule with self-warning function is characterized in that, it is composed of an external shell layer and a dual-chamber microcapsule core material wrapped in the shell layer; wherein, the shell layer is a load developer The microcapsule core material is a recessive dye capable of developing a color reaction with a color developer. 2. the preparation method of a kind of dual-chamber microcapsule with self-warning function according to claim 1, is characterized in that, described color developing agent is acid-base substance or comprises benzotriazoles, phenols, One or more electron-withdrawing color-developing agents including thiourea derivatives and aromatic carboxylic acids; the recessive dyes are acid-base indicators or include fluorane-type leuco dyes, triarylmethane-type leuco dyes One or more electron-donating leuco dyes including dyes and phthalide leuco dyes; When the color developer is an acid-base substance, the recessive dye is an acid-base indicator; when the color developer is an electron-absorbing color developer, the recessive dye is an electron-donating leuco dye. 3. a kind of dual-chamber microcapsule with self-warning function according to claim 1, is characterized in that, described nanometer microsphere is microcapsule core material, microsphere wall from inside to outside, and the particle diameter of nanometer microsphere The distribution is 50nm-400nm, the thickness of the microsphere wall is 5nm-40nm, and the content of the color developer core material is 60%-80%; Microspheres, the particle size distribution of the double-chambered microcapsules is 50 μm-300 μm, the thickness of the capsule wall is 4 μm-25 μm, and the content of the core material of the double-chambered microcapsules is 50%-80% of that of the dual-chambered microcapsules. 4. a preparation method of a dual-chamber microcapsule with self-warning function, is characterized in that, at first by sol-gel method and in-situ polymerization, the nano-microsphere of internal encapsulation color developer is prepared, and it is utilized as Pickering emulsifier. Stabilizing the oil phase containing recessive dyes to obtain a stable Pickering emulsion, and solidifying the Pickering emulsion to obtain dual-chambered microcapsules. 5. the preparation method of a kind of dual-chamber microcapsule with self-warning function according to claim 4, is characterized in that, specifically comprises the following steps: (1) Preparation of nano-microspheres coated with developer Use color developer, vinyl monomer, inorganic nanoparticle precursor and oil-soluble thermal initiator as oil phase, add deionized water, stir at high speed to form a coarse emulsion, adjust the pH value of the system, and emulsify at high speed to form a stable emulsion, which is cured by heat to obtain nano-microspheres coated with developer; (2) Preparation of double-chambered microcapsules The nano-microspheres coated with the developer are dispersed in water as a Pickering emulsifier and configured into an aqueous dispersion as the aqueous emulsion phase, and the oil phase of the capsule is added to form an emulsion at high speed. The mixture of solvent, vinyl monomer and photoinitiator is photocured to obtain double-chambered microcapsules. 6. the preparation method of a kind of dual-chamber microcapsule with self-warning function according to claim 5, is characterized in that, in the preparation of nano-microsphere described in step (1), the oil-water volume ratio is 1:3-1 : 10, wherein the oil phase is calculated by mass fraction as: 20-50% color developer, 10-40% inorganic nanoparticle precursor, 10-30% olefinic monomer and oil-soluble thermal initiator, the oil-soluble thermal The initiator is 1-4wt% of the total mass of the vinyl monomer; wherein the vinyl monomer is composed of a multifunctional monomer and a monofunctional monomer in a mass ratio of 1:2-5:1; the pH of the crude emulsion system is 3-6 or 9-12, the curing temperature is 60-90℃, and the curing time is 6-12h. 7. a kind of preparation method of the double-chambered microcapsule with self-warning function according to claim 5, is characterized in that, in the preparation of the described double-chambered microcapsule of step (2), the Pickering emulsifier in the emulsion water phase The concentration is 5-50mg/mL, and the volume ratio of oil to water in the Pickering emulsion is 2:1-1:10, wherein the oil phase, in terms of mass fraction, includes: 35-65% of water-insoluble organic solvent, 35-65% of vinyl monomer , photoinitiator and recessive dye, the photoinitiator is 1-4wt% of the total mass of ethylenic monomer, and the concentration of recessive dye in water-insoluble organic solvent is 5-25mg/mL; The organic solvent is a mixture of one or more of alkanes, alcohols, mercaptans, ketone ethers, phosphates or carbonates; wherein the olefinic monomers are composed of multifunctional monomers and monofunctional monomers in a mass ratio It is composed of 1:1-5:1; the light curing adopts UV curing, wherein the UV curing wavelength is 230-420nm, and the UV curing time is 2-10min. 8. the preparation method of a kind of dual-chamber microcapsule with self-warning function according to claim 51, is characterized in that, the vinyl monomer described in step (1) and step (2) is monofunctional vinyl A mixture of monomers and multifunctional vinyl monomers; the monofunctional vinyl monomers are glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, methyl (meth)acrylate ester, ethyl (meth)acrylate, butyl (meth)acrylate, isooctyl (meth)acrylate, hydroxyethyl (meth)acrylate, ethylhexyl (meth)acrylate, (meth)acrylate Acrylic acid, tert-butyl (meth)acrylate, methoxypolyethylene glycol acrylate, ethoxyethoxyethyl acrylate, styrene, N-isopropylacrylamide, acrylamide, 2-butene One or more of the amides; the multifunctional olefin monomers are divinylbenzene, diethylene glycol diacrylate, ethylene glycol dimethacrylate, tetrapropylene glycol diacrylate, 1,6-Hexanediol diacrylate, Tripropylene glycol diacrylate, Bisphenol A glycidyl dimethacrylate, Triethylene glycol dimethacrylate, Dipentaerythritol hexaacrylate, o-phenylene Diethylene glycol diacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipropylene glycol diacrylate, 1,3-butanediol diacrylate one or more of. 9. The preparation method of a dual-chamber microcapsule with self-warning function according to claim 5, wherein the inorganic nanoparticle precursor described in step (1) is tetraethyl silicate, tetraethyl silicate methyl ester, tetraisopropyl silicate, tetrabutyl silicate, tetrabutyl titanate, tetraethyl titanate, isopropyl titanate, 3-(trimethoxysilyl)propyl acrylate, Vinyltrimethoxysilane, vinyltributanone oximinosilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, isopropyltris(isostearoyl)titanium acid ester, isopropyl tris (dioctyl pyrophosphoryl) titanate, bis (dioctyl pyrophosphoryl) oxyacetate titanium, isopropyl tris (dioctyl pyrophosphoryl) titanate, One or more of isopropyl tris(dodecylbenzenesulfonyl)titanate. 10. the preparation method of a kind of double-chambered microcapsules with self-warning function according to claim 5, is characterized in that, the described oil-soluble thermal initiator of step (1) is dilauroyl peroxide, peroxide ten Diacyl, tert-amyl peroxide neodecanoate, dicumyl peroxide, azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, azobisisobutyric acid dimethyl ester, One or more of azodicyclohexylcarbonitrile; the photoinitiator described in step (2) is 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone , 2-hydroxy-methylphenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin dimethyl ether, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, iso Propylthioxanthone, 4-chlorobenzophenone, 4,4'-dimethyldiphenyl iodonium salt hexafluorophosphate, isooctyl p-dimethylaminobenzoate, 4-methyldiphenyl In ketone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-isopropylthioxanthone one or any of these.

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