CN105860025B - Functional cross-links agent-isocyanate microcapsule and preparation method thereof - Google Patents

Abstract

The invention discloses a functional crosslinking agent-isocyanate microcapsule and a preparation method thereof. The isocyanate microcapsule is prepared from the following raw materials according to the weight ratio: deionized water: 60-90; emulsifier: 2-6; Surfactant: 0-1.5; Isocyanate and/or its prepolymer: 12-14; Solvent: 0-6; Chain extender: 0-5; pH regulator: 0-1.5. The specific preparation method is as follows: (1) preparation of water phase and oil phase; (2) preparation of emulsion; (3) preparation of isocyanate microcapsules. The functional cross-linking agent-isocyanate microcapsule prepared by this method has the following advantages: 1. Improve the service life of isocyanate; 2. Extend the storage period and be more stable; 3. It is convenient to use, transport and store; The control is suitable for different temperatures and different fields; 5. The process is simple and the cost is low.

Description

Functional crosslinking agent-isocyanate microcapsule and preparation method thereof

technical field

The invention relates to an isocyanate microcapsule and a preparation method thereof.

Background technique

Isocyanate adhesives are environmentally friendly adhesives due to their excellent bonding performance, good process performance, good water resistance, and no environmental pollution. They are widely used in construction, light industry, chemical industry, vehicles, ship metallurgy, textiles, household appliances, aerospace, It is more and more widely used in various fields such as electromechanical, mining, medical and health, national economy and national defense construction.

However, because isocyanate is relatively active, it has a short service life, inconvenient storage and transportation, and solvent-based or emulsion-type isocyanate or its prepolymer organic solvent has a strong odor and is volatile, causing air pollution, flammability, or excessive use. Or less toxic and harmful to the human body. Now all countries in the world have formulated strict environmental protection laws and regulations, and people's awareness of life, health and production safety is constantly increasing. Good quality, non-polluting, environmentally friendly adhesives and coatings are gradually becoming the main products used by people.

Therefore, how to solve the environmental protection problems of isocyanate or its prepolymer such as short trial period, poor storage, solvent type or emulsion property is a key issue in the development and application of isocyanate. Recently, the common method in China is to chemically block and protect the active group isocyanate group of isocyanate or prepolymer, that is, to use chemical reagents to react with isocyanate group to form polyurethane and other chemicals, which are directly used or heated or other ways to activate The isocyanate groups are released again, allowing them to react with other substrates for crosslinking. However, in some cases, this method cannot be applied to substrates that are easily deformed by heat due to the generally high unblocking temperature. Discoloration also leads to the application of blocked isocyanates still has certain limitations.

Contents of the invention

The purpose of the present invention is to overcome the problems of existing isocyanate or its prepolymers such as high activity, short service life and unstable storage, and to provide a functional crosslinking agent-isocyanate micropolymer with long service life, stable storage, convenient use and transportation. Capsules and methods of making them.

The purpose of the present invention is achieved through the following technical solutions:

A functional crosslinking agent-isocyanate microcapsule prepared from the following raw materials according to the weight ratio: deionized water: 60-90; emulsifier: 2-6; co-surfactant: 0-1.5; isocyanate and/or its Prepolymer: 12-14; solvent: 0-6; chain extender: 0-5; pH regulator: 0-1.5.

The above-mentioned functional crosslinking agent-isocyanate microcapsules are prepared according to the following method:

(1) Preparation of water phase and oil phase

Water phase preparation: compound emulsifier, co-surfactant, water, stir until dissolved, add pH regulator to make pH 8-13;

Preparation of oil phase: isocyanate and/or its prepolymer, solvent, mixed and stirred evenly.

(2) Emulsion preparation

At room temperature, the water phase and the oil phase are mixed, mechanically stirred, and subjected to ultrasonic treatment for 5-30 minutes to form a stable emulsion.

(3) Preparation of isocyanate microcapsules

Heat the above emulsion to 30-70°C, slowly add the chain extender dropwise into the emulsion, keep it warm for 30-240 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, air-dry to obtain a solid.

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

One, the functional crosslinking agent-isocyanate microcapsule prepared by this method has the following advantages:

1. Increase the service life of isocyanate;

2. The storage period will be extended and more stable;

3. Easy to use, transport and store;

4. Controllable particle size is suitable for different temperatures and different fields;

5. The process is simple and the cost is low.

2. The functional crosslinking agent-isocyanate microcapsules prepared by the present invention can be used directly at different temperatures, and the system is stable, which greatly simplifies the process flow.

3. The isocyanate solid prepared by the present invention can be applied to fields such as wood processing, paper packaging, furniture manufacturing, and rubber.

Description of drawings

Fig. 1 is the physical figure of the functional crosslinking agent-isocyanate microcapsule prepared;

Fig. 2 is the functional cross-linking agent-isocyanate microcapsule scanning electron micrograph of preparation;

Fig. 3 is the functional cross-linking agent-isocyanate microcapsule section scanning electron micrograph of preparation;

Functional cross-linking agent-isocyanate microcapsule average particle size and particle size distribution figure prepared by different stirring speeds of Fig. 4;

Fig. 5 is the functional cross-linking agent-isocyanate microcapsule mean particle size and particle size distribution diagram prepared by different BAC content (relative to isocyanate);

Fig. 6 is the Fourier transform infrared spectrum of functional crosslinking agent-isocyanate microcapsule;

Figure 7 is a functional crosslinking agent-isocyanate microcapsule TGA curve;

Figure 8 is the DSC curve of functional crosslinking agent-isocyanate microcapsules.

Detailed ways

The technical solution of the present invention will be further described below in conjunction with the examples, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered by the present invention within the scope of protection.

Example 1:

The functional crosslinking agent-isocyanate microcapsules of this example are prepared from the following raw materials according to the weight ratio: deionized water: 60-90; composite emulsifier: 2-6; co-surfactant: 0-1.5; isocyanate and/or Or its prepolymer: 12-14; solvent: 0-6; chain extender: 0-5; pH regulator: 0-1.5.

The specific preparation method is as follows:

1. Preparation of water phase and oil phase

Preparation of water phase: Add compound emulsifier and co-surfactant into the mixer, then add water, stir until dissolved, add pH adjuster to make pH 8-13;

Preparation of oil phase: Add isocyanate and/or its prepolymer and solvent into the mixer and mix well.

2. Emulsion preparation

At room temperature, add the water phase and the oil phase into the reactor and mix evenly, mechanically stir at 600-1200 rpm for 5-20 minutes, and at the same time perform ultrasonic treatment for 5-30 minutes to form a stable emulsion.

3. Preparation of isocyanate microcapsules

Heat the above emulsion to 30-70°C, slowly add the chain extender solution dropwise into the emulsion, keep it warm for 30-240 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, and air-dry to obtain a solid.

In this embodiment, the composite emulsifier is a compound of anionic emulsifier and nonionic emulsifier, and the mass ratio of the two is 20-80%: 80-20%; the anionic emulsifier is sodium lauryl sulfate , sodium dodecylsulfonate, sodium dodecylbenzenesulfonate, and sodium caseinate; the nonionic emulsifier is one of Tween, Span, and gum arabic powder.

In this embodiment, the pH regulator is one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate, and ammonia; one or more of hydrochloric acid, sulfuric acid, and acetic acid.

In this embodiment, the solvent is one or more of chlorobenzene, toluene, ethyl acetate, and butyl acetate.

In this embodiment, the isocyanate prepolymer is a chemical prepared by chemical reaction of isocyanate, polyether polyol or polyester polyol and chain extender.

In this embodiment, the chain extender is a compound containing a hydroxyl group or an amino group, specifically water, 1,4-butanediol, dimethylolpropionic acid, glycerol, ethylene glycol, trimethylolpropane , polyethylene glycol 200, polyethylene glycol 400, triethanolamine, ethylenediamine, butylenediamine or one or more.

In this embodiment, the isocyanate is hexamethylene isocyanate (HDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (PAPI), isophorone isocyanate (IPDI), One or more of toluene-2,4-diisocyanate (TDI), 4,4'-dicyclohexylmethane diisocyanate (HMDI).

In the present embodiment, the polyether polyol is polyoxypropylene polyol (polyether 330), polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 1000, polyethylene glycol 2000, polypropylene glycol 200 , Polypropylene Glycol 400, Polypropylene Glycol 600, Polypropylene Glycol 1000, Polypropylene Glycol 2000, one or more of them, the polyester polyol is 1,4-butanediol adipate copolymer 600, 1,4-butanediol One or more of adipate copolymer 1000, 1,4-butanediol adipate copolymer 2000, ethylene glycol adipate copolymer 1000, and ethylene glycol adipate copolymer 2000.

In this embodiment, the mixing ratio of the isocyanate and its prepolymer is 2:8-8:2.

Because isocyanate is liquid, some types of isocyanate have a strong pungent smell, which makes it inconvenient to use, harmful to the human body, and difficult to store and transport, etc., thus limiting the application of isocyanate, and isocyanate is not easy to emulsify, and it is not easy to exist stably for a long time even after emulsification , which is difficult to apply in practice. In this example, the method of emulsion polymerization is adopted. Firstly, the isocyanate is emulsified with an emulsifier, that is, the isocyanate or its prepolymer is dispersed by mechanical stirring and ultrasonic treatment in the presence of an emulsifier. It becomes an emulsion in water, and then the molecular chains of isocyanate or its prepolymer are cross-linked with a water-soluble chain extender to obtain a high molecular polymer. The prepared microcapsule has high -NCO% content, is basically odorless, and is convenient to use, transport and store.

The particle size of the functional crosslinking agent-isocyanate microcapsules prepared in this example is controllable (60-500 μM), and the -NCO% content is controllable (5-25%); the storage is stable, and can be stored stably for more than 180 days -NCO% The content is still high; it has certain water resistance, and the wet strength of wood-based panels has been improved.

As can be seen from Figure 1, the functional crosslinking agent-isocyanate microcapsules prepared in this example are all yellow or milky yellow spherical or spherical solid particles, indicating that the prepared functional crosslinking agent-isocyanate microcapsules are convenient to use, transport and store, and Good storage stability; it can be seen from the scanning electron microscope images of the functional crosslinking agent-isocyanate microcapsules (Fig. The interface is clear. Figure 4 and Figure 5 show the average particle size and particle size distribution of the prepared functional crosslinking agent-isocyanate microcapsules. The analysis results show that the prepared functional crosslinking agent-isocyanate microcapsules have a controllable particle size and can be used in different industries.

The chemical structure of the prepared samples was analyzed by Fourier transform infrared spectroscopy. Figure 6 shows the infrared contrast spectra of PAPI and functional crosslinking agent-isocyanate microcapsules. It can be seen from the infrared contrast spectrum of functional crosslinking agent-isocyanate microcapsules that the spectral characteristic peaks of PAPI and functional crosslinking agent-isocyanate microcapsules are observed at 2244cm ^-1 and 2248cm ^-1 respectively, which shows that the prepared functional crosslinking agent The -isocyanate microcapsule structural unit still contains a large number of -NCO active groups; 1717cm ^-1 and 1714cm ^-1 are the characteristic absorption peaks of C=O; 1510cm ^-1 is the characteristic absorption peak of NH. The capsule of urea.

Thermal Gravimetric Analyzer (Thermal Gravimetric Analyzer) and differential scanning calorimetry (DSC) were used to investigate the thermal stability of the samples. As can be seen from Figure 7, the functional cross-linking agent-isocyanate microcapsules prepared at a heating rate of 10K/min have three distinct peaks (DTG), that is, the first is solvent volatilization, the second is substituted urea decomposition, The third is polyurethane decomposition and isocyanate volatilization. Combined with the DSC curve ( FIG. 8 ), it also shows that the prepared functional crosslinking agent-isocyanate microcapsule has a two-phase separated structure and the capsule material contains a large amount of isocyanate.

Example 2:

The functional crosslinking agent-isocyanate microcapsule of this embodiment is prepared from the following raw materials according to the weight percentage: deionized water: 79%; composite emulsifier: 2.7%; co-surfactant: 0.4%; isocyanate and its prepolymerization Substances (mass ratio: 2:8): 13%; solvent: 1.3%; chain extender: 3%; pH regulator: 0.6%.

Wherein, the composite emulsifier is formed by mixing Tween and sodium dodecylbenzenesulfonate, and the mass ratio is Tween: sodium dodecylbenzenesulfonate=6:1; the cosurfactant is 1-octanol; The isocyanate is diphenylmethane diisocyanate; the isocyanate prepolymer is prepared by chemical reaction of diphenylmethane diisocyanate, polypropylene glycol 2000 and dimethylol propionic acid; the solvent is ethyl acetate; the chain extender is ethylene glycol Alcohol; pH regulator is 10% sodium hydroxide solution and 5% hydrochloric acid.

The above-mentioned functional crosslinking agent-isocyanate microcapsule adhesive is prepared according to the following method:

The specific preparation method is as follows:

1. Preparation of water phase and oil phase

Water phase preparation: 2.7% of mixed compound emulsifier and 0.4% of co-surfactant are added to the mixer, then 79% of water is added, stirred until dissolved, and 0.6% of pH regulator is added to make the pH to 11.5;

Preparation of oil phase: Add 13% of the mixture of isocyanate and its prepolymer and 1.3% of solvent into the mixer, and mix well.

2. Emulsion preparation

At room temperature, the water phase and the oil phase were added into the reactor and mixed evenly, mechanically stirred at 800 rpm for 5 minutes, and ultrasonically treated for 5 minutes at the same time to form a stable emulsion.

3. Preparation of isocyanate microcapsules

Heat the above emulsion to 50°C, slowly add 3% chain extender solution dropwise into the emulsion, keep it warm for 90 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, air dry to obtain a solid.

Example 3:

The functional crosslinking agent-isocyanate microcapsule of this embodiment is prepared from the following raw materials according to the weight percentage: deionized water: 80%; composite emulsifier: 2.8%; co-surfactant: 0.5%; isocyanate or its prepolymerization Chemicals: 13%; chain extender: 3%; pH adjuster: 0.7%.

Wherein, the composite emulsifier is formed by mixing Tween and sodium dodecylbenzenesulfonate, and the mass ratio is Tween: sodium dodecylbenzenesulfonate=6:1; the cosurfactant is 1-octanol; The isocyanate is diphenylmethane diisocyanate; the isocyanate prepolymer is prepared by chemical reaction of diphenylmethane diisocyanate, polypropylene glycol and dimethylol propionic acid 2000; the chain extender is ethylene glycol; the pH regulator is 10% sodium hydroxide solution and 5% hydrochloric acid.

The above-mentioned functional crosslinking agent-isocyanate microcapsule adhesive is prepared according to the following method:

The specific preparation method is as follows:

1. Preparation of water phase and oil phase

Water phase preparation: 2.7% of mixed compound emulsifier and 0.4% of co-surfactant are added to the mixer, then 79% of water is added, stirred until dissolved, and 0.7% of pH regulator is added to make the pH to 12;

Preparation of oil phase: Add 13% isocyanate and its prepolymer (mass ratio: 2:8) into the mixer, and mix well.

2. Emulsion preparation

At room temperature, the water phase and the oil phase were added into the reactor and mixed evenly, mechanically stirred at 800 rpm for 5 minutes, and ultrasonically treated for 5 minutes at the same time to form a stable emulsion.

3. Preparation of isocyanate microcapsules

Heat the above emulsion to 50°C, slowly add 3% chain extender solution dropwise into the emulsion, keep it warm for 90 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, air dry to obtain a solid.

Example 4:

The functional crosslinking agent-isocyanate microcapsules of this embodiment are prepared from the following raw materials in weight percentage: deionized water: 79%; composite emulsifier: 2.7%; co-surfactant: 0.4%; isocyanate: 13%; Solvent: 1.3%; chain extender: 3%; pH regulator: 0.6%.

Wherein, the composite emulsifier is formed by mixing Tween and sodium dodecylbenzenesulfonate, and the mass ratio is Tween: sodium dodecylbenzenesulfonate=6:1; the cosurfactant is 1-octanol; The isocyanate is diphenylmethane diisocyanate; the isocyanate solvent is ethyl acetate; the chain extender is ethylene glycol; the pH regulator is 10% sodium hydroxide solution and 5% hydrochloric acid.

The above-mentioned functional crosslinking agent-isocyanate microcapsule adhesive is prepared according to the following method:

The specific preparation method is as follows:

1. Preparation of water phase and oil phase

Water phase preparation: 2.7% of mixed compound emulsifier and 0.4% of co-surfactant are added to the mixer, then 79% of water is added, stirred until dissolved, and 0.6% of pH regulator is added to make the pH to 11.5;

Preparation of oil phase: Add 13% of isocyanate and 1.3% of solvent into the mixer and mix well.

2. Emulsion preparation

At room temperature, the water phase and the oil phase were added into the reactor and mixed evenly, mechanically stirred at 800 rpm for 5 minutes, and ultrasonically treated for 5 minutes at the same time to form a stable emulsion.

3. Preparation of isocyanate microcapsules

Heat the above emulsion to 50°C, slowly add 3% chain extender solution dropwise into the emulsion, keep it warm for 90 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, air dry to obtain a solid.

Example 5:

The functional crosslinking agent-isocyanate microcapsule of this embodiment is prepared from the following raw materials according to the weight percentage: deionized water: 79%; composite emulsifier: 2.7%; co-surfactant: 0.4%; isocyanate and its prepolymerization Substance: 13%; Solvent: 1.3%; Chain extender: 3%; pH adjuster: 0.6%.

Wherein, the composite emulsifier is formed by mixing Tween and sodium dodecylbenzenesulfonate, and the mass ratio is gum arabic: sodium dodecylbenzenesulfonate=6:1; the cosurfactant is 1-octanol; The isocyanate is diphenylmethane diisocyanate; the isocyanate prepolymer is prepared by chemical reaction of diphenylmethane diisocyanate, polypropylene glycol and dimethylol propionic acid 2000; the solvent is ethyl acetate; the chain extender is ethylene glycol Alcohol; pH regulator is 10% sodium hydroxide solution and 5% hydrochloric acid.

The above-mentioned functional crosslinking agent-isocyanate microcapsule adhesive is prepared according to the following method:

The specific preparation method is as follows:

1. Preparation of water phase and oil phase

Water phase preparation: 2.7% of mixed compound emulsifier and 0.4% of co-surfactant are added to the mixer, then 79% of water is added, stirred until dissolved, and 0.6% of pH regulator is added to make the pH to 11.5;

Preparation of oil phase: Add 13% of isocyanate and its prepolymer (mass ratio: 2:8) and 1.3% of solvent into a mixer, and mix well.

2. Emulsion preparation

At room temperature, the water phase and the oil phase were added into the reactor and mixed evenly, mechanically stirred at 800 rpm for 5 minutes, and ultrasonically treated for 5 minutes at the same time to form a stable emulsion.

3. Preparation of isocyanate microcapsules

Heat the above emulsion to 50°C, slowly add 3% chain extender solution dropwise into the emulsion, keep it warm for 90 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, air dry to obtain a solid.

Embodiment 6:

The functional crosslinking agent-isocyanate microcapsule of the present invention is prepared from the raw materials according to the following weight percentages: deionized water: 79%; composite emulsifier: 2.7%; co-surfactant: 0.4%; isocyanate and its prepolymer : 13%; solvent: 1.3%; chain extender: 3%; pH regulator: 0.6%.

Wherein, the composite emulsifier is formed by mixing Tween and sodium dodecylbenzenesulfonate, and the mass ratio is Tween: sodium dodecylbenzenesulfonate=6:1; the cosurfactant is 1-octanol; The isocyanate is diphenylmethane diisocyanate; the isocyanate prepolymer is prepared by chemical reaction of diphenylmethane diisocyanate, polypropylene glycol and dimethylol propionic acid 2000; the solvent is ethyl acetate; the chain extender is ethylene glycol Alcohol; pH regulator is 10% sodium hydroxide solution and 5% hydrochloric acid.

The above-mentioned functional crosslinking agent-isocyanate microcapsule adhesive is prepared according to the following method:

The specific preparation method is as follows:

1. Preparation of water phase and oil phase

Water phase preparation: 2.7% of mixed compound emulsifier and 0.4% of co-surfactant are added to the mixer, then 79% of water is added, stirred until dissolved, and 0.6% of pH regulator is added to make the pH to 11.5;

Preparation of oil phase: Add 13% of isocyanate and its prepolymer (mass ratio: 2:8) and 1.3% of solvent into a mixer, and mix well.

2. Emulsion preparation

At room temperature, add the water phase and the oil phase into the reactor and mix evenly, and mechanically stir at 800 rpm for 5 minutes to form a stable emulsion.

3. Preparation of isocyanate microcapsules

Heat the above emulsion to 50°C, slowly add 3% monomer solution dropwise into the emulsion, keep it warm for 90 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, air dry to obtain a solid.

Embodiment 7:

The functional crosslinking agent-isocyanate microcapsules of this embodiment are prepared from the following raw materials in weight percentage: deionized water: 79%; composite emulsifier: 2.7%; co-surfactant: 0.4%; isocyanate: 13%; Solvent: 1.3%; chain extender: 3%; pH regulator: 0.6%.

Wherein, the composite emulsifier is formed by mixing Tween and sodium dodecylbenzenesulfonate, and the proportion is Tween: sodium dodecylbenzenesulfonate=6:1; co-surfactant is 1-octanol; isocyanate It is polymethylene polyphenyl polyisocyanate; the solvent is butyl acetate; the chain extender is ethylene glycol; the pH regulator is 10% sodium hydroxide solution and 5% hydrochloric acid.

The above-mentioned functional crosslinking agent-isocyanate microcapsule adhesive is prepared according to the following method:

The specific preparation method is as follows:

1. Preparation of water phase and oil phase

Water phase preparation: 2.7% of mixed compound emulsifier and 0.4% of co-surfactant are added to the mixer, then 79% of water is added, stirred until dissolved, and 0.6% of pH regulator is added to make the pH to 11.5;

Preparation of oil phase: Add 13% of isocyanate and 1.3% of solvent into the mixer and mix well.

2. Emulsion preparation

At room temperature, the water phase and the oil phase were added into the reactor and mixed evenly, mechanically stirred at 800 rpm for 5 minutes, and ultrasonically treated for 5 minutes at the same time to form a stable emulsion.

3. Preparation of isocyanate microcapsules

Heat the above emulsion to 50°C, slowly add 3% chain extender solution dropwise into the emulsion, keep it warm for 90 minutes, cool to room temperature, filter with suction, wash with water until the filtrate is neutral, air dry to obtain a solid.

Claims (7)

1. the preparation method of functional cross-links agent-isocyanate microcapsule, including prepared by following raw material according to weight ratio：Deionization Water：60~90；Compound emulsifying agent：2~6；Cosurfactant：0~1.5；Isocyanates or isocyanates and its prepolymer Mixture：12~14；Solvent：1.3~6；Chain extender：0~5；PH adjusting agent：0~1.5, the compound emulsifying agent is anion The compounding of emulsifier and nonionic emulsifier, the two quality proportioning are 20~80%：80~20%, the isocyanates is pre- with it The weight ratio of isocyanates and its prepolymer is 2 in the mixture of polymers:8~8:2, the solvent is chlorobenzene, toluene, acetic acid second The one or more of ester, butyl acetate, it is characterised in that steps are as follows for the preparation method：

(1) prepared by water phase, oil phase

It is prepared by water phase：Compound emulsifying agent, cosurfactant, water, stirring to dissolve, be added pH adjusting agent make pH be 11.5~ 13；

It is prepared by oil phase：Mixture, the solvent of isocyanates or isocyanates and its prepolymer, are mixed evenly；

(2) prepared by lotion

At room temperature, water phase is mixed, mechanical agitation with oil phase, and carries out supersound process and forms it into stable emulsion in 5~30 minutes；

(3) preparation of isocyanate microcapsule

Above-mentioned emulsion is warming up to 30~70 DEG C, chain extender is slowly dropped in lotion, is kept the temperature 30~240 minutes, is cooled to room Temperature filters, and it is neutrality to be washed to filtrate, air-dries, obtains solid.

2. the preparation method of functional cross-links agent-isocyanate microcapsule according to claim 1, it is characterised in that described the moon Ionic emulsifying agent is lauryl sodium sulfate, dodecyl sodium sulfate, neopelex, casein-sodium therein one Kind；Nonionic emulsifier is that tween, sapn, gum arabic powder are one such.

3. the preparation method of functional cross-links agent-isocyanate microcapsule according to claim 1, it is characterised in that the pH Conditioning agent is the one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate, ammonium hydroxide；The one of hydrochloric acid, sulfuric acid, acetic acid Kind is several.

4. the preparation method of functional cross-links agent-isocyanate microcapsule according to claim 1, it is characterised in that described different Cyanate prepolymer is isocyanates and polyether polyol or polyester polyol and chemistry prepared by chain extender after chemical reaction Product.

5. the preparation method of functional cross-links agent-isocyanate microcapsule according to claim 1 or 4, it is characterised in that institute It is the compound containing hydroxyl or amino to state chain extender.

6. the preparation method of functional cross-links agent-isocyanate microcapsule according to claim 5, it is characterised in that the expansion Chain agent is 1,4- butanediols, dihydromethyl propionic acid, glycerine, ethylene glycol, trimethylolpropane, polyethylene glycol 200, polyethylene glycol 400, the one or more of triethanolamine, ethylenediamine, butanediamine.

7. the preparation method of functional cross-links agent-isocyanate microcapsule according to claim 1 or 4, it is characterised in that institute State isocyanates be hexa-methylene isocyanates, it is methyl diphenylene diisocyanate, poly methylene poly phenyl poly isocyanate, different Phorone isocyanates, Toluene-2,4-diisocyanate, 4- diisocyanate, 4,4 '-dicyclohexyl methyl hydride diisocyanates one or more.