JPH0730318B2 - Photochromic composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition exhibiting a phenomenon in which an absorption spectrum is reversibly changed by light irradiation, that is, photochromism.

(Prior Art) (Problems to be Solved by the Invention) Conventionally, it has been proposed that an organic photochromic substance is dissolved and dispersed in a polymer binder to be applied to a sunscreen material and a decorative material.

However, it has not yet reached widespread industrial or commercial use. The reason is that an irreversible decomposition phenomenon, which is generally called light fatigue, occurs.
That is, the photochromic substance loses its photochromic property when it is repeatedly irradiated with light. For this reason,
In the past, many researchers have attempted to improve the resistance of photochromic substances to light fatigue.

For example, U.S. Pat. No. 3,666,352 proposes to add an ultraviolet absorber such as benzophenone or benzotriazole to benzospiropyran which is a photochromic substance. However, although this product has some improvement against light fatigue, it has not reached the practical range yet, and on the contrary, the ultraviolet absorber produces a shielding effect in the region where the photochromic substance absorbs ultraviolet light, As a result, there are problems that the color development sensitivity is reduced and the returning speed in the dark is slow.

Also, Japanese Patent Publication No. 28892/1985 and Japanese Patent Publication No. 36284/1975 propose a spironaphthoxazine derivative as a photochromic substance. These spironaphthoxazine derivatives have high color development sensitivity and fast return speed in the dark, and have better light fatigue resistance than conventionally known photochromic substances such as benzospiropyrans, triphenylmethanes, dithizones and viologens. Has
It is used as a photochromic material by blending with plastics. However, at present, the light fatigue resistance is not sufficiently satisfactory, and in order to further expand the applications, it is desired to extend the repeated life by improving the light fatigue resistance.

The present invention has been made in view of the above circumstances, has high color development sensitivity, has a fast returning speed in a dark place, and has improved light fatigue resistance without impairing the color development performance even in repeated color development, It is an object of the present invention to provide a photochromic composition which is preferably used as a photochromic material.

(Means for Solving Problems) As a result of intensive studies for solving the above problems, the present inventors have found that a polyvinyl acetal resin contains a spironaphthoxazine derivative, a specific ultraviolet stabilizer and a specific plasticizer. The inventors have found that a composition containing a specific amount of and satisfies all of the above objects, and have reached the present invention.

That is, the present invention relates to a polyvinyl acetal resin (A)
And 0.1 to 30% by weight of the component (A), a spironaphthoxazine derivative (B) represented by the following general formula (I):
And 0.2 to 60% by weight of the hindered amine ultraviolet stabilizer (C) with respect to the component (A), and 5 to 50% by weight of the component (A) with the ester plasticizer compatible with the component (A). The gist is a photochromic composition comprising D).

(In the formula, R ₁ and R ₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group or a cyano group.) The present invention is described in detail below.

The polyvinyl acetal resin referred to in the present invention is a synthetic resin obtained by reacting polyvinyl alcohol with aldehydes, and preferable specific examples thereof include polyvinyl butyral and polyvinyl formal.

The spirona human oxazine derivative which is one component of the composition of the present invention is represented by the above general formula (I). Preferred specific examples include 1,3,3-trimethylspiro [indolino-2,3'-naphtho [2,1-b] (1,4) -oxazine], 1,3,3,5-tetramethylspiro. [Indrino-2,
3'-naphtho [2,1-b] (1,4) -oxazine], 5-methoxy-1,3,3-trimethylspiro [indolino-2,3 '
-Naphtho [2,1-b] (1,4) -oxazine], 5-chloro-1,3,3-trimethylspiro [indolino-2,3'-naphtho [2,1-b] (1,4 ) -Oxazine] and the like.
The content of this substance in the composition is 0.1 to 30% by weight, preferably 1 to 20% by weight, based on the polyvinyl acetal resin.
Is. If the content is less than 0.1% by weight, the coloring performance is poor. On the other hand, if the content exceeds 30% by weight, the coloring performance almost reaches the equilibrium state. Will be at a disadvantage.

The hindered amine ultraviolet stabilizer, which is one component of the composition of the present invention, is a low molecular compound or a high molecular compound having a piperidyl ring in the structure. As a low molecular weight compound, bis (2,2,6,6-tetramethyl-4-piperidyl)
Examples thereof include sebacate, bis (1,22,6,6-pentamethyl-4-piperidyl) sebacate, and the polymer compound includes dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy-2. , 2,6,6-Tetramethylpiperidine polycondensate, poly [[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl]
[(2,2,6,6-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-
Piperidyl) imino]] and the like. The content of this in the composition is based on the polyvinyl acetal resin.
0.2 to 60% by weight. If the content is less than 0.2% by weight, no improvement in light fatigue is observed, while if it exceeds 60% by weight, the compatibility between the polyvinyl acetal resin and the spironaphthoxazine derivative deteriorates and recrystallization occurs. Cannot be used. In the present invention, it is particularly preferable that such a stabilizer is contained in a weight ratio of at least 2 times that of the spironaphthoxazine derivative in order to effectively improve the light fatigue property.

The ester plasticizer, which is one component of the composition of the present invention, is an ester plasticizer compatible with the polyvinyl acetal resin, such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and di-n-phthalate. Phthalate derivatives such as octyl, Dioctyl adipate, Dibutyl sebacate, Dioctyl sebacate, etc. Aliphatic dibasic acid ester derivatives, Tricresyl phosphate, Trioctyl phosphate, Trichlorethyl phosphate derivatives, Trimellitate Trimellitic acid ester derivatives such as trioctyl, tri-n-octyl trimellitate and tridecyl trimellitate, epoxidized fatty acid ester derivatives such as butyl epoxystearate and octyl epoxystearate, and dioctyl epoxyhexahydrophthalate. Like sheet of the aromatic acid ester derivatives. The content of this compound in the composition is 5 to 50% by weight, preferably 10 to 50% by weight, based on the polyvinyl acetal resin.
30% by weight. If the content is less than 5% by weight, the coloring sensitivity and the returning speed in the dark are poor, while the content is 50% by weight.
If it exceeds, the effects are further improved, but the light fatigue property is adversely affected, which is not preferable.

To prepare the photochromic composition of the present invention, these components are dissolved in a suitable solvent which can dissolve, for example, the four components of polyvinyl acetal resin, spironaphthoxazine derivative pair, hindered amine ultraviolet stabilizer and ester plasticizer. Then, the casting method in which only the solvent is evaporated can be adopted. Preferred solvents include alcohols such as methanol and ethanol, esters such as methyl acetate and ethyl acetate, ketones such as acetone and methyl ethyl ketone, or a mixed solvent of alcohols and aromatic hydrocarbons such as ethanol and toluene. can give.

The photochromic composition of the present invention can be used for decoration of eyeglass lenses, sunscreen film materials, curtains, paints, clothing and the like.

(Function) The reason why the photochromic composition of the present invention has high color development sensitivity, high return speed in a dark place, and improved light fatigue resistance without impairing the color development performance in repeated color development is not necessarily clear, It is guessed as follows.

That is, the cause of the photo-fatigue property of the spironaphthoxazine derivative, which is a photochromic substance, is considered to be that the structure when it is colored by ultraviolet rays is changed by oxygen to a structure that does not have the color-forming property. Oxygen is blocked by the excellent polyvinyl acetal resin, and the hindered amine UV stabilizer suppresses decomposition and oxidation of the composition due to UV light to improve photofatigue resistance, color sensitivity, and return speed in the dark. With regard to the improvement, it is presumed that the polyvinyl acetal resin is plasticized by the plasticizer and the transmittance of ultraviolet rays is increased, so that the coloring reaction is improved.

(Examples) Hereinafter, the present invention will be described in detail with reference to Examples.

In the examples, the color development performance and the return speed in the dark were evaluated using a 500 W ultra-high pressure mercury lamp (manufactured by Ushio Denki Co., Ltd.) and a cut filter UV-29 (manufactured by Toshiba Glass Co., Ltd.) as the light source for 30 seconds. The color development performance was evaluated by obtaining the absorbance at 613 nm, which is the maximum absorption wavelength of the, and then the time to return to the original colorless state when left in the dark was measured, and the return speed in the dark was evaluated. The photo-fatigue property was evaluated by irradiating with a carbon fade meter for 20 hours, 40 hours, and 80 hours, and then obtaining the absorbance by the above-described method for evaluating the color development performance and obtaining the color retention rate from the following formula.

Example 1, Comparative Example 1,2 Polyvinylbutyral, 1,3,3-trimethylspiro [indolino-2,3'-naphtho [2,1b] (1,4) -oxazine,
Bis (2,2,6,6, -tetramethyl-4-piperdyl) sebacate, dibutyl phthalate, ethanol and toluene were taken in the amounts shown below to obtain a solution. Apply the obtained solution on release paper with a bar coater to a thickness of 100μ,
After that, dry at 70 ℃ for 3 minutes to remove the solvent,
A film having a thickness of 30μ was prepared.

Polyvinyl butyral 25 g 1,3,3-Trimethylspiro [indolino-2,3'-naphtho [2,1-b] (1,4) -oxazine] 2.5 g Bis (2,2,6,6, -tetra Methyl-4-piperdyl) sebacate 5.0 g Dibutyl phthalate 2.5 g Ethanol 50 cc Toluene 50 cc The obtained film was evaluated for color development performance, return speed in the dark and light fatigue property. The results are shown in Table 1.

For comparison, a film was prepared in the same manner as in Example 1 except that bis (2,2,6,6, -tetramethyl-4-piperdyl) sebacate and dibutyl phthalate were not used (Comparative Example 1). .

For comparison, a film was prepared in the same manner as in Example 1 except that poly (methyl methacrylate) was used instead of polyvinyl butyral, and 100 cc of toluene was used alone instead of using both ethanol and toluene as the solvent. (Comparative Example 2) The performance of the obtained films of Comparative Examples 1 and 2 was evaluated in the same manner as in Example 1, and the results are also shown in Table 1.

As is clear from Table 1, it was confirmed that the photochromic composition of the present invention is a photochromic composition which is excellent in color development sensitivity, a returning speed in a dark place, and has good light fatigue resistance.

Example 2, Comparative Examples 3,4 Polyvinyl formal, 1,3,3, -trimethylspiro [indolino-2,3'-naphtho [2,1-b] (1,4) -oxazine], bis (1, 2,2,6,6-Pentamethyl-4-piperidyl) sebacate, dioctyl adipate, ethanol and toluene were taken in the amounts shown below to obtain a solution. A film was prepared using this solution in the same manner as in Example 1. Polyvinyl formal 25 g 1,3,3-trimethylspiro [indolino-2,3'-naphtho [2,1-b] (1,4) -oxazine] 2.5 g bis (1,2,2,6,6- Pentamethyl-4-piperdyl) sebacate 5.0 g Dioctyl adipate 2.5 g Ethanol 50 cc Toluene 50 cc The obtained film was evaluated in the same manner as in Example 1. The results are shown in Table 2.

For comparison, a film was prepared by the same method as in Example 2 except that bis (1,2,2,6,6, -pentamethyl-4-piperdyl) sebacate and dioctyl adipate were not used.

For comparison, a film was prepared in the same manner as in Example 2 except that ethyl cellulose was used instead of polyvinyl formal and 100 cc of toluene was used alone instead of using both ethanol and toluene as the solvent. (Comparative example 4).

Performances of the obtained films of Comparative Examples 3 and 4 were evaluated in the same manner as in Example 2, and the results are also shown in Table 2.

As is clear from Table 2, the photochromic composition of the present invention was excellent in color developing sensitivity, returning speed in the dark, and light fatigue.

(Effects of the Invention) The photochromic composition of the present invention has improved light fatigue resistance without causing a decrease in the color development sensitivity and the returning speed of the conventional photochromic composition, and has a dramatically increased repetitive life. Is. Therefore, the photochromic composition of the present invention can be used in a wide range of products from its limited range at present, and can be widely commercialized. For example, spectacle lenses, sunscreen materials such as chorcases, display materials, materials for decoration, etc. Can be suitably used as.

Claims (3)

[Claims] 1. A polyvinyl acetal resin (A),
0.1 to 30% by weight of the spironaphthoxazine derivative (B) represented by the following general formula (I) with respect to the component (A),
0.2 to 60% by weight of component (A), a hindered amine UV stabilizer (C), and 5 to 50% by weight of component (A)
A photochromic composition comprising the component (A) and the ester-based plasticizer (D) having compatibility. (In the formula, R ₁ and R ₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group or a cyano group.) 2. The photochromic composition according to claim 1, wherein the content of the hindered amine ultraviolet stabilizer is twice or more the content of the spironaphthoxazine derivative. 3. An ester plasticizer is a phthalate ester derivative, an aliphatic dibasic acid ester derivative, a phosphate ester derivative, a trimellitate ester derivative, an epoxidized fatty acid ester derivative or an epoxidized aromatic acid ester derivative. The photochromic composition according to claim 1.