JP2008037974A - Photochromic particles and method for producing the same - Google Patents

Abstract

The present invention provides a photochromic particle that changes color based on a new principle different from that of a photochromic compound, and has a very clear color change, and a method for producing the same.
A polymer is a complex of a photoacid generator having a cationic substituent and generating an acid upon irradiation with light, and a color-changing dye having an anionic substituent and changing color depending on the acid. The layer is coated. Alternatively, it comprises solid particles in which a photoacid generator that generates an acid upon irradiation with light, a color-changing dye that changes color by the acid, and a polymer are mixed. Alternatively, it is composed of a solid particle in which a photo radical generator that generates radicals upon irradiation of light, a radical decoloring dye that loses its color by radicals, and a polymer are mixed.
[Selection figure] None

Description

  The present invention relates to a photochromic particle whose color changes when irradiated with light and a method for producing the same.

Conventionally, photochromic particles whose color is changed by irradiating light are known. For example, Patent Document 1 describes a microcapsule that encapsulates a photochromic compound solution (Patent Document 1).
Japanese Patent Laid-Open No. 2-110174

  When this microcapsule is irradiated with light, the molecular structure of the encapsulated photochromic compound changes and the color changes.

  An object of the present invention is to provide a photochromic particle that changes in color based on a new principle different from that of a photochromic compound, and in which the color change is very clear, and a method for producing the same.

  The photochromic particles of the first invention have a cationic substituent, a photoacid generator that generates an acid upon irradiation with light, a color-changing dye that has an anionic substituent and changes color depending on the acid, The composite is covered with a polymer layer.

  The inventor uses a photochromic particle based on a new principle that does not use a photochromic compound as a photochromic particle in which a photoacid generator and a dye solution in which a color-changing dye whose color is changed by an acid is dissolved. I was studying discoloring particles. At that time, it was discovered that a complex was deposited by mixing a solution of a photoacid generator having a cationic substituent and a solution of a color-changing dye having an anionic substituent. Furthermore, the present inventors have found that particles obtained by coating this composite with a polymer film undergo a very clear color change upon irradiation with light.

  That is, the photochromic particle of the first invention has a cationic substituent, a photoacid generator that generates an acid upon irradiation with light, and an anionic substituent, and the color changing property that changes color depending on the acid. A complex with a dye is coated on a polymer layer.

  The photoacid generator used in the photochromic particles of the first invention is not particularly limited as long as it has a cationic substituent. For example, triphenylphosphonium hexafluoroantimonate, triphenylsulfonium phosphate, P -(Phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, P- (phenylthio) phenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldisulfenyldisulfenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate Bis [4-diphenyl-sulfonio] phenyl] sulfide-bis-hexafluorophosphate, bis [4-diphenyl-sulfonio] phenyl] sulfide- Bis-hexafluoroantimonate, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Fe-hexafluorophosphate, and the like can be given. Moreover, the onium photoacid generator described in JP-A-2004-255564, the ionic photoacid generator of diphenyliodonium salts of hydroxy group-containing aromatic sulfonic acid, and the like can also be used. These photoacid generators can be used alone or in combination of two or more.

The photoacid generator is preferably a compound represented by the following general formula (1).
(Wherein R ₁ , R ₂ and R ₃ are each independently a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, a phenylalkyl group having 1 to 12 carbon atoms, or a phenyl group. And at least one of R _{1 to} R ₃ may have a hydrogen atom substituted with a halogen atom, a nitro group, or a thienyl group, and X is methanesulfonate, trifluoromethanesulfonate, p-toluene sulfonate (p-toluenesulfonate), 10- camphorsulfonate (10-camphorsulfonate), cyclohexane sulfamethoxazole Mart (cyclohexanesulfamate), perfluoro-1-butane sulfonate (perfluoro-1-butanesulfonate), Cl, Br, SbF 6, BF 4, PF ₆ or AsF ₆₎ a) the photoacid generators other used alone, used in combination of two or more And it can also be.
According to the test results of the inventor, the compound represented by the general formula (1) can easily form a complex with a color-changeable dye having an anionic substituent and color-changing by an acid. Can be made into a color-changing particle by encapsulating in a polymer layer. In addition, since the color-changing particles are solid, the color-changing particles are excellent in stability compared to microcapsules encapsulating a mixed solution of a photoacid generator and a color-changing dye, and the content of the color-changing dye is large. Changes are also very clear.

  If the anionic substituent of the color-changing dye is a sulfonic acid group, it easily forms a complex with a photoacid generator that has a cationic substituent and generates an acid upon irradiation with light, and the color change is Clear color-changing particles can be obtained. Examples of such a color changing pigment include Congo Red, Bromocresol Green, and Thymol Blue.

  Also, various known polymers can be used without any limitation for the polymer constituting the polymer layer. For example, various acrylic polymers and various urethanes can be used.

The photochromic particles of the first invention can be produced as follows.
That is,
A mixed liquid in which a solution of a photoacid generator having a cationic substituent and generating an acid upon irradiation with light and a solution of a color-changing dye having an anionic substituent and changing in color by an acid are mixed. A compounding step of depositing a complex of the photoacid generator and the color-changing dye by adding to water or a solvent containing water, and a coating step of coating the complex with a polymer layer. This is a method for producing photochromic particles.

Although there is no limitation in particular as a method of coat | covering a composite_body | complex with a polymer layer, For example, the following methods are mentioned.
(1) A complex is dissolved in an organic solvent to form a complex solution, and a polymer is dissolved in an organic solvent to form a polymer solution. After the complex solution and the polymer solution are mixed, water or water is added. A method of forming coated particles in which droplets of a composite solution are coated with a polymer layer by adding and mixing in a solvent containing the mixture.
Or
(2) A method in which a complex is dissolved in an organic solvent to form a complex solution, a polyfunctional isocyanate compound solution having a plurality of isocyanate functional groups is mixed with the complex solution, and this mixed solution is added to water or a solvent containing water. .
Etc.

  The photochromic particles of the second invention are characterized by comprising solid particles in which a photoacid generator that generates an acid upon irradiation with light, a color changing dye that changes color by the acid, and a polymer are mixed. And

  According to the test results of the inventor, if the particles are composed of a photoacid generator, a color-changing dye, and a polymer layer, the color changes very clearly by light like the photochromic particles of the first invention. In this case, if the color-changing dye is a leuco dye, the color change is particularly clear, excellent in stability, and the changed color is less likely to return or fade.

  The photoacid generator used in the photochromic particles of the second invention is not particularly limited. In addition to the photoacid generator having a cationic substituent that can be used in the first invention, DNQ (diazonaphthoquinone) s Photoacid generators, nonionic photoacid generators such as nitrobenzyl sulfonic acids, and the like can also be used. These photoacid generators can be used alone or in combination of two or more.

The photochromic particles of the second invention can be produced as follows.
That is,
A liquid mixture preparing step of preparing a liquid mixture containing a photoacid generator that generates an acid upon irradiation with light, a color-changing dye whose color is changed by the acid, and a polymer;
A granulating step of granulating the mixed solution by adding and mixing the mixed solution in water or a solvent containing water; and
It is a manufacturing method of the photochromic particle characterized by including.

The photochromic particles of the second invention can also be produced by the following method.
That is, a mixed solution preparation step of preparing a mixed solution of a photoacid generator that generates an acid upon irradiation with light and a color-changing dye that changes color by the acid,
A polymerization step in which a polyfunctional isocyanate compound solution having a plurality of isocyanate functional groups is mixed with the mixed solution and then added to water or a solvent containing water to polymerize;
It is a manufacturing method of the photochromic particle characterized by including.

  The photochromic particles of the third invention are characterized by comprising solid particles in which a photo radical generator that generates radicals upon irradiation of light, a radical decoloring dye that loses its color by radicals, and a polymer are mixed. To do.

  According to the test results of the inventors, the combination of a photoradical generator and a radical decoloring dye whose color disappears by radicals causes a very clear color change by light, as in the photochromic particles of the first invention.

  The photoradical generator used in the third invention is not particularly limited, and examples thereof include tert-butylperoxy-iso-butrate, 2,5-dimethyl-2,5-bis (benzoyldioxy) hexane, , 4-bis [α- (tert-butyldioxy) -iso-propoxy] benzene, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis (tert-butyldioxy) hexene hydroperoxide, α- ( iso-propylphenyl) -iso-propylhydroperoxide, 2,5-dimethylhexane, tert-butylhydroperoxide, 1,1-bis (tert-butyldioxy) -3,3,5-trimethylcyclohexane, butyl- 4,4-bis (tert-butyldioxy) valerate, cyclohexanone peroxide, 2,2 ′, 5,5′-tetra (tert-butyl) Ruperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (tert-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (tert-amylperoxycarbonyl) benzophenone, 3,3 ′ , 4,4′-tetra (tert-hexylperoxycarbonyl) benzophenone, 3,3′-bis (tert-butylperoxycarbonyl) -4,4′-dicarboxybenzophenone, tert-butylperoxybenzoate, di-tert-butyl Organic peroxides such as diperoxyisophthalate, quinones such as 9,10-anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, benzoin methyl, benzoin ethyl ether , Α-methylbenzo Examples thereof include benzoin derivatives such as in and α-phenylbenzoin. These photo radical generators can be used alone or in combination of two or more.

  The radical decoloring dye used in the third invention is not particularly limited as long as it is a dye that loses its color upon reaction with radicals. Examples of such a dye include Solvent Orange 80, Congo Red, Acid Red, and the like.

The photochromic particles of the third invention can be produced as follows.
That is,
A liquid mixture preparing step of preparing a liquid mixture containing a photo radical generator that generates radicals upon irradiation of light, a radical decoloring dye that loses its color by radicals, and a polymer;
A granulating step of granulating the mixed solution by adding and mixing the mixed solution in water or a solvent containing water; and
It is a manufacturing method of the photochromic particle characterized by including.

The photochromic particles of the third invention can also be produced by the following method.
That is,
A mixed solution preparation step of preparing a liquid mixture of a photo radical generator that generates radicals by irradiation of light and a radical decoloring dye whose color disappears by radicals;
A polymerization step in which a polyfunctional isocyanate compound solution having a plurality of isocyanate functional groups is mixed with the mixed solution and then added to water or a solvent containing water to polymerize;
It is a manufacturing method of the photochromic particle characterized by including.

  Examples 1 to 3 embodying the first invention, Examples 4 to 7 embodying the second invention, and Example 8 embodying the third invention will be described below.

(Example 1)
The photochromic particle of Example 1 uses a photoacid generator (a) of the following chemical formula (Adeka Optomer SP-152, manufactured by Asahi Denka Kogyo Co., Ltd.) as a photoacid generator having a cationic substituent. Congo red was used as a color-changing dye having an anionic substituent, and the color was changed by acid, and polymethyl methacrylate was used as a material for the polymer layer. The manufacturing method is as follows.

<Composite process>
Congo red (15 mg) and photoacid generator (a) (15 mg) are dissolved in 50 ml of diethylene glycol monomethyl ether (hereinafter referred to as DEGME), and this solution is dropped into water, followed by stirring for 24 hours. The complex was obtained by collection by centrifugation.

<Composite dissolution process>
The complex (30 mg) obtained as described above is dissolved in 0.15 g of diethylene glycol and 0.15 g ml of methanol to obtain a complex solution.

<Polymer dissolution process>
Prepare a 10% ethyl acetate solution of PMMA.

<Coating process>
0.33 gml of the above complex solution and 2 gml of 10% ethyl acetate solution of PMMA were mixed, and the mixed solution was dropped into a 4% aqueous solution of polyvinyl alcohol and stirred for 20 hours. Thus, a dispersion liquid of particles in which the composite solution was coated on the PMMA layer was obtained.

<Drying process>
Further, the dispersion was centrifuged, and the particles were washed with water and then vacuum dried to obtain the photochromic particles of Example 1.

(Example 2)
In Example 2, bromocresol green was used as the color-changing dye. Also. In the compounding step, methanol was used instead of DEGME. Other than that, photochromic particles were obtained in the same manner as in Example 1.

In addition, although it tried to form a complex with a compound (a) by the method similar to Example 1 and Example 2 using crystal violet lactone or neutral red, precipitation of the complex did not occur. This is because crystal violet lactone and neutral red do not have an anionic substituent (see the following chemical formula) and are not bonded to the cationic substituent of the photoacid generator (a). it is conceivable that.

(Example 3)
For the photochromic particles of Example 3, thymol blue was used as the color-changing dye, and methanol was used as a solvent for dissolving the complex in the complex dissolving step. Others are the same as in the second embodiment, and a description thereof will be omitted.

<Color test>
The photochromic particles of Examples 1 to 3 were placed on a white fine paper, subjected to ultraviolet irradiation with a low-pressure high-pressure mercury lamp for 2 minutes for 7 seconds, and the color change before and after the irradiation was visually determined. As a result, in Example 1, as shown in FIG. 1, although it was pink before ultraviolet irradiation, it showed a clear change to light blue after irradiation. In addition, as shown in FIG. 2, in Example 2, a clear change from yellow-green to yellow and in Example 3 from orange to red was shown.

  In place of the production methods of Examples 1 to 3, the complex solution in which the complex was dissolved was mixed with a polyfunctional isocyanate compound solution having a plurality of isocyanate functional groups such as tolylene diisocyanate, and this mixed solution was used. You may use the method of adding in the solvent containing water or water. Thereby, a polyfunctional isocyanate compound is bridge | crosslinked with water and photochromic particle | grains are obtained. In this case, a polyol that reacts with isocyanate may be present.

(Example 4) (Example 5) (Example 6) (Example 7)
In Examples 4 to 7, photochromic particles were produced using a leuco dye. The types of leuco dyes are ODB-2 which is a black dye in Example 4, Red-40 which is a red dye in Example 5, Blue-63 which is a blue dye in Example 6, and Green-118, a green pigment, was used. The manufacturing method is as follows.

<Mixed liquid preparation process>
Mixing 0.275g of diethylene glycol monomethyl ether (DEGME) solution containing 2% leuco dye, 0.025g of propylene carbonate solution containing 50% PAG (SP-152), and 2g of ethyl acetate solution containing 10% PMMA (molecular weight: about 90,000) Prepare the solution.

<Granulation process>
Add the above mixture to 2 g of 10% PMMA (molecular weight 90,000) ethyl acetate solution and stir. Add this to 5 g of 4% partially saponified polyvinyl alcohol solution and stir for 20 hours. After almost disappearing, centrifugal separation and water washing were repeated to obtain the photo-modified particles of Examples 4 to 7 .

  In addition, instead of the production methods of Examples 4 to 7, a mixed liquid in which a leuco dye and PAG (SP-152) are mixed is prepared, and this is a polyfunctional having a plurality of isocyanate functional groups such as tolylene diisocyanate. You may use the method of mixing an isocyanate compound solution with a composite solution, and adding this liquid mixture in the solvent containing water or water. Thereby, a polyfunctional isocyanate compound is bridge | crosslinked with water and photochromic particle | grains are obtained. In this case, a polyol that reacts with isocyanate may be present.

<Color test>
The photochromic particles of Examples 4 to 7 were placed on white high-quality paper, subjected to ultraviolet irradiation with a high-pressure mercury lamp for 7 seconds, and the color change before and after irradiation was judged visually. As a result, as shown in FIG. 3, in Example 4, from light brown to dark brown, in Example 5, from light pink to dark pink, in Example 6, from light blue to ultra-blue, Example 7 showed a clear change from light green to green.

(Example 8)
The photochromic particle of Example 8 is a combination of a photoradical generator and a radical decoloring dye, and Irg184 manufactured by Ciba Specialty Chemicals Co., Ltd. represented by the following structural formula was used as the photoradical generator. . Solvent Orange 80 was used as a radical decoloring dye. A manufacturing method is shown below.

<Mixed solution preparation process>
A mixed solution of Irg184 (0.1 g) as a photoradical generator, 0.5 wt% acetone solution (0.2 g) of Solvent Orange 80 as a radical decoloring dye, and 10 wt% ethyl acetate solution of PMMA is prepared.

<Granulation process>
Further, the mixed solution is dropped into 5 g of a polyvinyl alcohol 4% solution and granulated to obtain the photochromic particles of Example 7.

  In place of the production method of Example 8, a mixed liquid in which a photo radical generator and a radical decoloring dye are mixed is prepared, and this is a polyfunctional isocyanate compound solution having a plurality of isocyanate functional groups such as tolylene diisocyanate. May be mixed with the complex solution, and this mixed solution may be added to water or a solvent containing water. Thereby, a polyfunctional isocyanate compound is bridge | crosslinked with water and photochromic particle | grains are obtained. In this case, a polyol that reacts with isocyanate may be present.

<Color test>
FIG. 4 shows the results of a color development test of the photochromic particles of Example 8. As a result, it showed a clear change that the color was dark orange before the ultraviolet irradiation but almost disappeared after the irradiation.

  The present invention can be used for an ink whose color changes by light irradiation.

It is the photograph before and behind ultraviolet irradiation of the photochromic particle of Example 1. It is the photograph before and behind ultraviolet irradiation of the photochromic particle of Example 2 (BCG) and Example 3 (TB). It is a photograph before and after ultraviolet irradiation of the photochromic particles of Examples 4 to 7. It is the photograph before and behind ultraviolet irradiation of the photochromic particle of Example 8.

Claims (12)

  A polymer layer is coated with a complex of a photoacid generator that has a cationic substituent and generates an acid upon irradiation with light, and a discolorable dye that has an anionic substituent and changes color depending on the acid. Photochromic particles characterized in that 2. The photochromic particle according to claim 1, wherein the photoacid generator is a compound represented by the following general formula (1).
In the formula, R ₁ , R ₂ and R ₃ are each independently a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, a phenylalkyl group having 1 to 12 carbon atoms, or a phenyl group. , At least one of R _{1 to} R ₃ may be substituted with a halogen atom, a nitro group or a thienyl group, and X is methanesulfonate, trifluoromethanesulfonate, or p-toluenesulfonate. (p-toluenesulfonate), 10- camphorsulfonate (-10 camphorsulfonate), cyclohexane sulfamethoxazole Mart (cyclohexanesulfamate), perfluoro-1-butane sulfonate (perfluoro-1-butanesulfonate), Cl, Br, SbF 6, BF 4, PF ₆ or AsF ₆ ).   3. The photochromic particle according to claim 1, wherein the anionic substituent is a sulfonic acid group.   The photochromic particle according to any one of claims 1 to 3, wherein the polymer layer is made of an acrylic resin.   A photochromic particle comprising a solid particle in which a photoacid generator that generates an acid upon irradiation with light, a color-changing dye whose color is changed by the acid, and a polymer are mixed.   6. The photochromic particle according to claim 5, wherein the color changing dye is a leuco dye.   A photochromic particle comprising a solid particle in which a photo radical generator that generates radicals upon irradiation of light, a radical decoloring dye that loses color by radicals, and a polymer are mixed. A mixed liquid in which a solution of a photoacid generator having a cationic substituent and generating an acid upon irradiation with light and a solution of a color-changing dye having an anionic substituent and changing in color by an acid are mixed. A compounding step of precipitating a complex of the photoacid generator and the color-changing dye by adding to water or a solvent containing water;
A coating step of coating the composite with a polymer layer;
A method for producing photochromic particles, comprising: A liquid mixture preparing step of preparing a liquid mixture containing a photoacid generator that generates an acid upon irradiation with light, a color-changing dye whose color is changed by the acid, and a polymer;
A granulating step of granulating the mixed solution by adding and mixing the mixed solution in water or a solvent containing water; and
A method for producing photochromic particles, comprising: A mixed solution preparation step of preparing a mixed solution containing a photoacid generator that generates an acid upon irradiation with light and a color-changing dye that changes color depending on the acid;
A polymerization step in which a polyfunctional isocyanate compound solution having a plurality of isocyanate functional groups is mixed with the mixture and then added to water or a solvent containing water to polymerize;
A method for producing photochromic particles, comprising: A liquid mixture preparing step of preparing a liquid mixture containing a photo radical generator that generates radicals upon irradiation of light, a radical decoloring dye that loses its color by radicals, and a polymer;
A granulating step of granulating the mixed solution by adding and mixing the mixed solution in water or a solvent containing water; and
A method for producing photochromic particles, comprising: A liquid mixture preparing step of preparing a liquid mixture containing a photo radical generator that generates radicals upon irradiation of light and a radical decoloring dye that loses color due to radicals;
A polymerization step of mixing a polyfunctional isocyanate compound solution having a plurality of isocyanate functional groups with the mixed solution, and adding the mixed solution to water or a solvent containing water;
A method for producing photochromic particles, comprising: