KR20080004237A - Photochromic mesoporous microparticles and method for preparing thereof - Google Patents

Abstract

A photochromic mesoporous microparticle is provided to solve the problem of dye leaching occurring in a conventional capsule containing a photochromic dye, to realize excellent effect of shielding free radicals or oxygen, and good dispersibility, durability, coloring rate, optical density and shelf stability. A photochromic mesoporous microparticle comprises a photochromic dye-grafted polymer dispersed in a mesoporous inorganic material. The photochromic dye is at least one dye selected from the group consisting of benzopyran, naphthopyran, spiropyran, spirooxazine, perylimide, diarylethene and azo compounds. The inorganic material is at least one material selected from the group consisting of metal alkoxides, Ti, Zr, Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W and In. The photochromic mesoporous microparticle has a particle size of 1 micrometer or less.

Description

Photochromic Mesoporous Fine Particles and Manufacturing Method Thereof {PHOTOCHROMIC MESOPOROUS MICROPARTICLES AND METHOD FOR PREPARING THEREOF}

1 to 4 are photographs showing photochromic mesoporous fine particles prepared according to an embodiment of the present invention.

The present invention relates to photochromic mesoporous fine particles and a method for manufacturing the same, and more particularly, to improve dye leaching phenomenon in which photochromic dye leaks into an organic solvent in a conventional capsule, thereby improving not only an aqueous ink but also an oil ink, a paint, and Not only can be applied to the coating, but also the photochromic polymer is wrapped in inorganic material, so it has excellent blocking effect against free radicals or oxygen, and has excellent dispersibility, durability, coloration / discoloration speed, optical density, and storage stability. A mesoporous fine particle and its manufacturing method are related.

A photochromic material absorbs light energy of a specific wavelength and changes its molecular structure. In this state, the color of the externally changed compound is changed. When the energy applied to the material is stopped, the photochromic material reversibly returns to the previous molecular structure. Have

When the photochromic material is composed of inorganic materials such as metal oxides, alkaline earth metals, mercury compounds, and transition metal compounds, it is very stable to external environments such as ultraviolet light, oxygen, and solvents, but it is difficult to utilize because the processing is very difficult. There was this. On the other hand, organic photochromic dyes such as benzopyrans, naphthopyrans, spiropyrans, spiro oxazines, pulzimides, diarylethenes, and azo compounds having the following structures may not be used by dissolving or powdering them in a solvent. Easy to use, but unstable due to light, oxygen, acid, organic solvents, etc. had a problem that the durability is insufficient.

The disadvantage of the photochromic dye is that the side reactions of the chemical molecular structure are destroyed by external environmental factors and the discoloration by light disappears as described above. It is known that the cause of such side reactions is the oxidation of free radicals or active oxygen and the like, which destroys the dye structure alone or simultaneously.

In order to suppress or delay such side reactions, various conventional methods have been proposed.

For example, US Pat. No. 4,166,043 discloses a method in which photochromic dye / PMMA is dissolved in methylene chloride and then dispersed in ethanol, or photochromic dye / cellulose acetate is dissolved in chloroform, solvent is removed and milled using a mill. US Patent No. 5,017,225 discloses a method for encapsulating a photochromic dye using a coacervation method using gelatin.

In addition, PCT / FR2002 / 00116 and U. S. Patent No. 6,740, 699 encapsulate by polymerization using a miniemulsion polymerization of acrylic, methacryl monomers and photochromic dyes in aqueous emulsions, olefin compounds such as methylbutenol, chlorohexane, etc. It is disclosed a method for producing an emulsion in which the concentration of the photochromic dye does not change for several months by mixing together and polymerizing.

As well as Chem. Mater. 15p, 1690 (2003), polystyrene, tetraethyl orthosilicate (TEOS), and a surfactant were added to a solvent to form an basic ethanol and emulsion, and a sol-gel reaction was used to measure 200-500 nm. A method for producing organic-inorganic hybrid particles is disclosed.

However, the above-described conventional techniques of directly making polymer particles containing photochromic dyes using monomers have a disadvantage in that the polymerization process is complicated and the dye cannot be sufficiently added.

In order to solve the problems of the prior art as described above, the present invention improves the dye leaching phenomenon of the photochromic dye leaking into the organic solvent in the conventional capsule photochromic which can be applied to oil-based ink, paint, and coating as well as aqueous ink An object of the present invention is to provide adult mesoporous fine particles and a method for producing the same.

Another object of the present invention is to wrap the photochromic polymer with an inorganic material, excellent in blocking the free radicals or oxygen, photochromic fine mesoporous fine particles excellent in dispersibility, durability, coloration / decolorization rate, optical density, and storage stability And to provide a method for producing the same.

Another object of the present invention is to provide a photochromic mesoporous fine particles and a method of manufacturing the same, which is simple in manufacturing process and capable of mass production.

In order to achieve the above object, the present invention provides a photochromic mesoporous fine particles, characterized in that the photochromic dye-grafted polymer is dispersed in the mesoporous mineral.

In addition, the present invention

a) reacting the photochromic dye and the polymer to prepare a photochromic dye-grafted polymer;

b) preparing an emulsion by mixing the photochromic dye-grafted polymer with a surfactant and a solvent; And

c) putting the emulsion into a droplet generator and spraying it into fine droplets, followed by drying and sol-gel reaction at a high temperature;

It provides a method for producing photochromic mesoporous fine particles comprising a.

Hereinafter, the present invention will be described in detail.

In general, a method of directly making a polymer particle containing a photochromic dye using a monomer is complicated by the polymerization process, and the photochromic dye of the present invention as described above is a solvent, a surfactant, and a photochromic dye because the dye cannot be sufficiently added. The photochromic dye may be sufficiently contained in the polymer by preparing the emulsion by adding the grafted high molecules together.

Specifically, the manufacturing method of the photochromic mesoporous fine particles of the present invention will be described in detail.

a) preparing a polymer grafted with a photochromic dye

This step is to prepare a polymer in which the photochromic dye is grafted by reacting a reactive photochromic dye, an isocyanate, and a polymer having an -OH, -SH, or -NH group.

The photochromic dye may be used as long as it has a nucleophilic group in a conventional photochromic dye such as benzopyran, naphthopyran, spiropyran, spiro oxazine, pulzimid, diaryrylene, or azo compound.

The photochromic dye content may be included in an amount of 5 to 500 parts by weight based on 100 parts by weight of the polymer used for preparing the photochromic dye-grafted polymer. When the content is less than 5 parts by weight, the optical density difference may vary. There is a problem that it is insufficient, if the amount exceeds 500 parts by weight there is a problem that the graft reaction yield is low.

The polymer may be polyacryl polyol, polyester polyol, polyether polyol, polycarbonate polyol, or the like.

The photochromic dye-grafted polymer may be prepared by dissolving a reactive photochromic dye in a diisocyanate component, a catalyst, and a solvent, and then adding a polymer to the reactant to reflux. .

The diisocyanate component used here is preferably aliphatic isocyanate, cycloaliphatic isocyanate, aromatic isocyanate, heterocyclic isocyanate, for example isophorone diisocyanate, hexamethylene diisocyanate, toluene-2,6-diisocyanate, or 4,4 ' -Dicyclohexyl methane diisocyanate etc. can be used.

In the above content ratio of the diisocyanate component and the photochromic dye, the molar ratio of the functional group NCO group and the dye reactor (-OH, -SH, or -NH group) is preferably 0.3 to 0.7, more preferably 0.45 to 0.55 It is If the functional molar ratio is less than 0.3, there is a problem that the unreacted photochromic dye remains. If the functional molar ratio is more than 0.7, unreacted isocyanate is present so that the polyol may gel when reacted with the polyol in the future. have. Moreover, it is especially preferable that the molar ratio of a diisocyanate component and a polyol is (NCO: OH) 0.45-0.55.

If the catalyst can be selected from the group consisting of Lewis base, Lewis acid and intercalation catalyst described in the literature, examples of the catalyst include dibutyltin dilaurate, tin octylate, dibutyltin diacetate, dibutyltin merbactide, Dibutyltin dimaleate, dimethyltin hydroxide, triethylamine and the like can be used.

Suitable solvents for use in the present invention include alcohols, ketones, esters, ethers, and the like. Preferably, toluene, methyl ethyl ketone, acetylacetone, or butyl acetate can be used.

b) emulsion preparation

This step is to prepare an emulsion by mixing the photochromic dye prepared in the above step is grafted polymer, surfactant, solvent, and alkoxy metal. At this time, the size of the final particles can be adjusted through the change in the concentration of the solution, the concentration of the solution should be reduced when producing finer particles.

The type of the surfactant mixed with the photochromic dye is grafted with the polymer may be selected according to the type of the polymer and alkoxy metal, 0.5 to 50 parts by weight based on 100 parts by weight of the solvent, but the range is It may vary depending on the type of surfactant, the solvent used, the alkoxy metal and the like.

Specifically, this step is a step in which a solvent, an acid catalyst or a base catalyst, and an alkoxy metal are mixed to hydrolyze the alkoxy portion of the alkoxy metal to activate M-OH. As an example of the alkoxy metal, an alkoxysilane is preferable, and specifically, tetraethyl orthosilicate, methyl trimethoxy silane, vinyl trimethoxy silane, butyl trimethoxy Butyl trimethoxy silane, methyl tri-isopropoxy silane, di or phenyl ethoxy vinylsilane, and the like can be used.

The alkoxy metal may be included in an amount of 10 to 800 parts by weight based on 100 parts by weight of the photochromic dye-polymer integration, but the range may vary depending on the reaction conditions.

Then, a solvent, a surfactant, and a photochromic dye-grafted polymer are separately mixed, and then the alkoxymetal reactant is mixed to prepare an emulsion. At this time, ultraviolet (UV) stabilizers and antioxidants may be used as the additives, and may be appropriately selected and used by those skilled in the art. The solvent may be water, and the type of the surfactant may be selected according to the polymer and the alkoxy metal, and may be a nonionic, cationic, or anionic surfactant. Examples of the cationic surfactant include cetyltrimethylammonium bromide (CTAB), and anionic surfactants include sodium dodecyl sulfate, sodium dodecyl benzenesulfonate, or sodium sulfonate, and the like. Ethyleneoxide propyleneoxide triblockcopolymer, sorbitan monooleate, or ester-like polymeric surfactant with long chain alkyl and OH-groups hydroxyl groups) and the like, but are not limited thereto.

c) droplet generation and drying

In this step, the emulsion formed in the above step is introduced into a droplet generator to generate fine droplets, which are then dried and subjected to a sol-gel reaction at a high temperature.

The emulsion may be put into the droplet generator under low pressure to generate fine droplets, wherein the droplet generator may be used a conventional droplet generator used in the art.

In addition, the drying can be carried out using a high temperature reactor, the temperature is preferably 60 to 230 ℃.

 The photochromic mesoporous fine particles of the present invention prepared as described above are excellent in durability with a maximum size of 1 μm, and can be applied not only to an aqueous ink but also to an oil ink by solving a dye leaching problem in an organic solvent.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

As a photochromic dye, 4.24 g (12.3 mmol) of a compound represented by the following formula (1), 3.31 g (14.9 mmol) of isophorone diisocyanate (IPDI), and 0.04 g of dibutyltin dilaurate were dissolved in 84.78 g of toluene at 80 ° C. Reaction was carried out for 4 hours. 7.36 g of a polyacrylic polyol (hydroxy equivalent weight = 452 g, Mw = 35,000) was added to the reactant to reflux for 4 hours, and then a solvent was removed to prepare a photochromic dye-grafted polymer.

Next, 10 g of HCl (0.1M) and 20.8 g of tetraethyl orthosilicate (TEOS) were mixed with 24 g of ethanol to prepare a first mixture. In addition, 16 g of ethanol, 0.1 g of Tinuvin 292 (Ciba) as a UV stabilizer, 4.4 g of ethylene oxide propylene oxide triblock copolymer (Pluronic P104) as a surfactant, and 0.4 g of the photochromic dye-grafted polymer 0.4 g were prepared. Put and mix to prepare a second mixture.

The prepared first mixture and the second mixture were placed in a droplet generator to generate droplets of a small size under low pressure, and then dried and sol-gel reacted using a high temperature reactor at 200 ° C. to prepare photochromic mesoporous fine particles. . 1 and 2 are transmission electron micrographs of the fine particles produced by the above method.

[Formula 1]

Example 2

Except for using the compound represented by the following formula 2 as a photochromic dye in Example 1 was carried out in the same manner as in Example 1.

[Formula 2]

Example 3

Except for using Pluronic P-105 instead of Pluronic P104 surfactant in Example 1 was carried out in the same manner as in Example 1.

Example 4

The same method as Example 1 except for using a mixture of tetraethyl orthosilicate: methyl triethoxy silicate 9: 1 in place of tetraethyl orthosilicate in Example 1 Was carried out. 3 and 4 are transmission electron micrographs of the fine particles produced by the above method.

Comparative Example 1

Except for using the photochromic dye represented by the formula (1) in place of the photochromic dye-grafted polymer in Example 1 was carried out in the same manner as in Example 1.

Comparative Example 2

Except that silica was not used in Example 1 was carried out in the same manner as in Example 1.

Using the photochromic fine particles prepared in Examples 1 to 4 and Comparative Examples 1 to 2, the particle size of the photochromic pigment, the dispersibility of the photochromic pigment, and the photochromic properties (optical density and complexing / Bleaching rate), durability, and dye leaching were evaluated and the results are shown in Table 1 below.

end. Particle Size of Photochromic Pigment-After dispersing the photochromic fine particles prepared in Examples 1 to 4 and Comparative Examples 1 and 2, respectively, in water, the average particle of the aqueous ink using microtrac UPA 150 (Nikkiso) and TEM The size was measured.

I. Dispersibility of Photochromic Pigments-The photochromic fine particles prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were respectively diluted in a mixture of water: ethylene glycol (8: 2) with a solid content of 5%, and then at 25 ° C. After standing for 3 months, the storage stability was evaluated by the aggregation and viscosity change of the pigment particles. At this time, storage stability was visually observed because it was difficult to quantify the degree, ○ when the degree of change was slight, △ when there was little change, and when there was agglomeration of pigment particles and significant viscosity change, they were classified as ×. It was.

All. Photochromic (Optical Density and Decolorization Rate)-The photochromic fine particles prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were respectively prepared as Superflex 107M (DIA-ICHI KOGYO SEIYAKU co. Ltd.). , 25% solids) and 5:95 parts by weight of the mixture was mixed, spin-coated on a glass plate at 1,000 rpm for 10 seconds, and then dried in an oven at 120 ℃ for 1 hour to evaluate the photochromic properties. After irradiating with 365 nm ultraviolet rays (1.35 ㎽ / ㎠) for 3 minutes, it was visually evaluated. The evaluation method was 9 points out of total, and the lower the score, the lower the optical density. In addition, the decolorization rate is the time required to block the ultraviolet rays and return to the initial color after exposure to ultraviolet rays, ○ when the decolorization time is less than 30 seconds, △ when less than 1 minute, and × when more than 1 minute. .

la. Durability-The durability of the photochromic microparticles prepared in Examples 1 to 4 and Comparative Examples 1 and 2 was determined to a degree that the optical density difference was reduced by a Quick UV test. Specifically, it was evaluated as the time when the initial optical density difference is reduced by half, and when the time is 0 to 25 hours, it is usually classified as excellent when it is 25 to 50 hours, and very excellent when it is 50 hours or more.

hemp. Dye Leaching-After dispersing the photochromic microparticles prepared in Examples 1 to 4 and Comparative Examples 1 to 2, respectively, in acetone and standing at 25 ° C. for 24 hours, the leaching of the photochromic dye was evaluated. At this time, the photochromic dye melt | dissolved in acetone was classified as defect (x), and the thing which does not melt | dissolve as good ((circle)).

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Particle Size (nm) 280 260 268 275 280 - Dispersibility of Pigment ○ ○ ○ ○ ○ × Optical density 8 8 8 8 8 One Bleaching speed ○ ○ ○ ○ ○ △ durability Very good Very good Very good Very good Great usually Dye leaching ○ ○ ○ ○ × -

As shown in Table 1, the photochromic mesoporous fine particles of Examples 1 to 4 prepared in accordance with the present invention are photochromic in dispersibility, optical density and decolorization rate, compared to Comparative Example 1 and Comparative Example 2, It was confirmed that the durability and dye riching are excellent.

According to the present invention, by improving the dye leaching phenomenon that the photochromic dye leaks into the organic solvent in the conventional capsule, it can be applied not only to the aqueous ink, but also to the oil ink, paint, and coating, and to freely wrap the photochromic polymer with inorganic materials. The blocking effect on radicals or oxygen is excellent. In addition, the photochromic mesoporous fine particles of the present invention has the effect that the production process is simple compared to the conventional mass production.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible without departing from the technical spirit of the present invention. It is evident to those of ordinary knowledge in Esau.

Claims (9)

A photochromic mesoporous fine particle, characterized in that the photochromic dye-grafted polymer is dispersed in a mesoporous inorganic material. The method of claim 1, The photochromic dye is selected from the group consisting of benzopyrans, naphthopyrans, spiropyrans, spiroxazines, pulzimides, diarylethenes, and azo compounds. The method of claim 1, Photochromic mesoporous, characterized in that the inorganic material is selected from the group consisting of alkoxy metal, Ti, Zr, Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, and In Particulates. The method of claim 1, The photochromic mesoporous fine particles, characterized in that the particle size of the photochromic mesoporous fine particles is at most 1 ㎛. a) reacting the photochromic dye and the polymer to prepare a photochromic dye-grafted polymer; b) preparing an emulsion by mixing the photochromic dye-grafted polymer with a solvent and a surfactant; And c) putting the emulsion into a droplet generator to generate droplets, followed by drying and sol-gel reaction; Method for producing photochromic mesoporous fine particles comprising a. The method of claim 5, The photochromic dye of step a) is a method for producing photochromic mesoporous microparticles, characterized in that it comprises 5 to 500 parts by weight based on 100 parts by weight of the polymer used in the preparation of the photochromic dye-grafted polymer. The method of claim 5, The method of producing photochromic mesoporous fine particles, characterized in that the polymer of step a) is selected from the group consisting of polyacrylic polyol, polyester polyol, polyether polyol, and polycarbonate polyol. The method of claim 5, The surfactant of step b) is cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate, sodium dodecyl benzenesulfonate, sodium sulfonate, ethylene oxide propyleneoxide triblockcopolymer, sorbitan At least one member selected from the group consisting of sorbitan monooleate, and ester-like polymeric surfactant with long chain alkyl and hydroxyl groups. Method for producing photochromic mesoporous fine particles. The method of claim 5, Method for producing photochromic mesoporous fine particles, characterized in that the surfactant of step b) is mixed in an amount of 0.5 to 50 parts by weight with respect to 100 parts by weight of the solvent.

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