JPH0733506B2 - Color variable resin particle composition and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a color variable resin particle composition and a method for producing the same. More specifically, the present invention relates to a color-variable resin particle composition having the property of changing its color tone depending on the intensity of irradiation light and useful as a cosmetic material, a decorative material, etc., and a method for producing the same.

(B) Conventional Technology Recently, various compounds (photochromic substances) that undergo a reversible photochemical change by light irradiation to change the color tone have been developed.
Attempts have been made to apply it to recording materials, dyes, paints, etc. ["Photochromism and its application", Kagaku No. 24, No. 6 (Showa 44)].

The application of a photosensitive resin containing such a photochromic substance in a synthetic resin has been studied.

(C) Problems to be Solved by the Invention However, conventionally, it has been difficult to obtain a fine resin particle composition containing a photochromic substance and having a true spherical shape. That is, as a method of containing the photochromic substance in the synthetic resin, a method of kneading the photochromic substance in a molten state of the synthetic resin is conceivable, but spherical resin particles cannot be obtained even if the photochromic substance is thereafter miniaturized by pulverization or the like. . Further, using fine spherical resin particles obtained by suspension polymerization, a method of impregnating the photochromic substance with a solvent can be considered, but in this case it is difficult to uniformly contain the photochromic substance inside the particles. Yes, the color change is also insufficient and uneven color tone occurs,
Further, depending on the selection of the solvent, there is a problem that the solvent is brought into the system for final use and becomes an obstacle, or the photochromic property itself is impaired.

(D) Means and Actions for Solving the Problems In view of the above problems, the present inventors have conducted earnest research on a method of preliminarily containing a photochromic substance in a monomer during suspension polymerization. Since the photochromism of photochromic substances is based on various actions such as photoisomerization, photooxidation reduction, and photoexcitation, it is affected by the polymerization initiator and its decomposition products (catalytic residual roots). easy. In particular, when a vinyl monomer such as a styrene or an acrylic ester is subjected to suspension polymerization, a radical polymerization initiator is used, and therefore it is considered that the photochromic characteristics are greatly affected. In fact, when benzoyl peroxide, t-butyl peroxybenzoate, etc., which are typical radical polymerization initiators, are used, the resulting photochromic substance-containing resin particles are not sufficiently discolored by light, resulting in a color-changing resin. It was not practically usable as a particle composition.

As a result of further studies, the present inventors have found that, among the above radical polymerization initiators, a polymerization initiator having no carboxyl group such as an azonitrile-based peroxyketal-based or dialkyl peroxide-based one, and a benzene ring It has been found that a spherical color-variable resin particle composition can be obtained without any inhibition of the photochromic properties when using a non-containing one.

Thus, according to the present invention, there is provided a color variable resin particle composition in which a spherical resin particle made of a polymer of a hydrophobic vinyl monomer uniformly contains a photochromic substance. Furthermore, according to the present invention, the hydrophobic vinyl monomer is subjected to polymerization conditions in a state of being dispersed in an aqueous medium, and a benzene ring- and carboxyl group-free radical polymerization initiator is used as a polymerization initiator, and There is provided a method for producing a color variable resin particle composition, which comprises incorporating a photochromic substance into the composition.

As the hydrophobic vinyl monomer of the present invention, styrene,
Styrene-based monomers such as α-methylstyrene, chlorostyrene and divinylbenzen, and acrylic-based monomers such as acrylic acid lower alkyl ester and methacrylic acid lower alkyl ester are preferable, and these may be used as a mixture.

The specific polymerization conditions for producing the color-variable resin particle composition of the present invention are basically the same as those of the ordinary resin bead manufacturing method except for the selection of the polymerization initiator and the addition of the photochromic substance. Therefore, it can be easily carried out by dispersing (usually suspending) the hydrophobic vinyl monomer in an aqueous medium in the presence of a polymerization initiator and stirring at an appropriate temperature. A dispersant, a surfactant and the like are added to the aqueous medium. Further, various additives may be contained.

As the polymerization initiator, a radical polymerization initiator containing no benzene ring or carboxyl group is used. An initiator containing a benzene ring and a carboxyl group is not suitable because it adversely affects the photochromism of the photochromic substance. Examples of the carboxyl group-free radical polymerization initiator include azonitrile-based compounds, peroxyketanol-based compounds, and dialkyl peroxide-based compounds, among which, for example, 2,2′-azobisiso compounds having no benzene ring. Butyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile); 1,1-bis (t-butylperoxy) -3,
3,5-Trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t
-Butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, di-t-butylperoxide and the like are preferably used. These polymerization initiators are usually
It is used by adding it to the monomer.
About 0.005 to 1 wt% is sufficient.

The photochromic substance used in the present invention causes a change in color tone (change in visible light absorption property) due to any of isomerization, tautomerization, ionic dissociation, radical dissociation, redox, excited state change, etc. upon irradiation with light. However, it is preferable to use an organic substance from the viewpoint of rapid color change. Specific examples of these include dimethylaminoazobenzenes, salicylideneanilines, nitrobenzylpyridines, spiropyra, spirooxazines, tetrachloro-α-ketodihydronaphthalene, bis (triphenylimidazolyl) s, triphenylmethane. Examples thereof include leuronitriles, tetraphenylhydrazines, bianthrones, and pyridylsidnones. Since the range of color change varies depending on the type of substituent,
Determine and use as appropriate. Among them, spiropyrans are
It has a high efficiency of photo-coloring, is vivid in color and rich in variety, and is preferably used. In addition, spirooxazines are preferable in terms of durability such as repeated coloring.

Such a photochromic substance is usually used by adding it to the monomer. The amount of addition varies depending on the purpose, but usually 0.005 to 1 wt% is suitable for the monomer. If it is less than 0.005, the function of color change is not sufficiently exerted, and if it is more than 1%, it is not enough, it is not economically disadvantageous, and it may hinder the polymerization.
Not preferable.

The resin composition thus obtained in a dispersed state is a spherical resin particle, and its particle size can be arbitrarily controlled to a size of about 5 to 3000 μm by adjusting the dispersion state during polymerization and the stirring speed. is there. As a cosmetic material, the average particle size is 5 to 50 μm
Despite being suitable for such fine particles, the resin particles of the present invention can be actually used as color-variable resin particles because the photochromic substance is uniformly contained in the resin particles without impairing their characteristics. Is.

(E) Example In the autoclave of Example 15, 70 g of tricalcium phosphate,
Sodium dodecylbenzene sulfonate 0.05g, water 3.6Kg
, And then add 2,2'-azobisisobutyronitrile (A
IBN) (0.6 g) and photochromic substance (0.4 g) dissolved in methyl methacrylate (monomer) (400 g) were charged at room temperature, and after nitrogen substitution, polymerization was carried out at 70 ° C. for 6 hours while stirring.
After cooling, the product was taken out from the autoclave and separated to obtain polymethyl methacrylate particles having an average particle size of about 10 μm.

The photochromic material used here is Spirohm 68NM.
(Product name of Anan Fragrance Industry Co., Ltd .; 1,3,3-trimethyl-
6'-nitro-8'-methoxyspiro [indori-2,
2'-benzopyran] was used.

The obtained particles show a pale blue color tone in room light,
It developed the ideal photochromic property of turning blue within 2 minutes when exposed to sunlight or ultraviolet rays.

Example 2 In place of the photochromic substance Spilome 68NM of Example 1, Kayaktormines CB (trade name of Nippon Kayaku Co., Ltd .; spiropyran compound) was used, and a similar average particle size was obtained.
10 μm polymethylmethacrylate particles were obtained.

It was confirmed that these particles are light yellow to light yellow-green under room light, but change to blue when exposed to sunlight or ultraviolet rays.

Comparative Example 1 Polymethyl methacrylate particles were obtained by carrying out the same polymerization using 0.6 g of benzoyl peroxide instead of the radical polymerization initiator AIBN in Example 1.

These particles have a pink color in the room, but no color change was observed even when exposed to sunlight or ultraviolet rays.

Comparative Example 2 Polymethylmethacrylate particles were produced in the same manner as in Comparative Example 1 using Kayaktormines CB instead of the photochromic substance Spilome 68NM, but no discoloration due to light was observed.

Comparative Example 3 Polymerization was carried out in the same manner as in Example 1 without adding a photochromic substance to produce colorless resin particles, and 0.6 g of Kyactolumines CB was added to this dispersion system, followed by treatment at 100 ° C. for 4 hours. The obtained resin particles had a pink color, and although the discoloration due to light was slightly recognized, it was up to a bluish purple color, which was insufficient.

Example 3 1 450 g of water obtained by dissolving 5 g of polyvinyl alcohol (Nippon Gosei Kagaku KK, Gohsenol GH20) in an autoclave
Methyl methacrylate 1 in which 0.23 g of AIBN and 0.15 g of spirohm 68NM (photochromic substance) were dissolved.
50 g was added, and polymerization was carried out at 70 ° C. for 6 hours with stirring to obtain polymethyl methacrylate particles having an average particle size of 30 μm.

The particles had the same color change properties as in Example 1.

Test Example 1 0.1% by weight of a photochromic substance was added to two monomers of methyl methacrylate and styrene, various radical polymerization initiators (1.0% by weight each) were added and dissolved, and then placed in a glass ampoule and subjected to nitrogen substitution. 20 after fusing
Polymerization was carried out in a warm bath for an hour to evaluate the discoloration property of the polymer.

The results are shown in Tables 1 and 2 together with the polymerization initiators used. In addition, Table 1 shows the case of using Spyrome 68NM, and Table 2 shows the case of using Kyactolumines CB.

Thus, 2,2'-azobisisobutyronitrile, 2,2'-azobisisobutyronitrile, 2,
2'-Azobis (2,4-dimethylvaleronitrile), 1,1
It can be seen that a resin having ideal color changing properties can be obtained for the four types of -bis (t-butylperoxy) -3,3,5-trimethylcyclohexane and di-tert-butylperoxide. On the other hand, the radical polymerization initiators having a carboxyl group or a benzene ring did not exhibit their properties or were insufficient.

Example 4 5 An autoclave was charged with 70 g of tricalcium phosphate, 0.05 g of sodium dodecylbenzenesulfonate and 3.6 kg of water, and 2,2'-azobisisobutyronitrile (AIBN).
0.4g of methyl methacrylate in which 0.6g, 0.4g of 5-chlorospironaphthoxazine (Photochrome II made by Nippon Chemix) was dissolved was charged at room temperature, and after nitrogen substitution, while stirring
Polymerization was carried out at 70 ° C. for 6 hours. After cooling, the product was taken out from the autoclave and separated to obtain polymethyl methacrylate particles having an average particle size of about 10 μm. These particles were colorless to light blue in room light, but turned blue within 2 minutes upon irradiation with sunlight or ultraviolet rays.

Example 5 Polymerization was performed in the same manner as in Example 4, except that 5-chlorospirophenanthrooxazine (Photochrome IV, manufactured by Nippon Chemix) was added instead of 5-chlorospironaphthoxazine. The particles obtained had an average particle size of about 10 μm and were colorless to light blue in room light, but turned blue-violet within 2 minutes upon irradiation with sunlight or ultraviolet rays.

Comparative Example 4 Benzoyl peroxide 0.6 g instead of AIBN in Example 4
The same polymerization was carried out except that was used. The particles obtained were yellow-orange in room light, and did not become a vivid blue color tone even when irradiated with sunlight or ultraviolet rays.

(F) Effects of the Invention The color-variable resin particle composition of the present invention is capable of rapidly changing its color tone by light irradiation based on the characteristics of the photochromic substance contained therein. Since it is in the form of fine particles, it is advantageous as various additives and convenient in handling. Therefore, for example, it is useful as a material capable of imparting decorativeness by changing the color tone, for example, as a material for cosmetics and decoration such as powder, foundation, cake, eye shadow, etc., and can be expected to be used for other purposes. is there.

Claims (5)

[Claims] 1. A color-variable resin particle composition in which a photochromic substance is uniformly contained in spherical resin particles made of a polymer of a hydrophobic vinyl monomer. 2. The resin particle composition according to claim 1, wherein the photochromic substance is contained in an amount of 0.005 to 1 wt%. 3. A method comprising subjecting a hydrophobic vinyl monomer to a polymerization condition in a state of being dispersed in an aqueous medium, using a benzene ring- and carboxyl group-free radical polymerization initiator as a polymerization initiator, A method for producing a color-variable resin particle composition, which comprises containing a photochromic substance. 4. The method according to claim 3, wherein the polymerization initiator is a radical polymerization initiator selected from the group consisting of azonitrile type, peroxyketal type and dialkyl peroxide type. 5. The method according to claim 4, wherein the photochromic substance is added to the hydrophobic vinyl monomer.