JPH0670213B2 - Photochromic material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photochromic material having improved weather resistance and durability, and particularly to an organic photochromic material.

(Prior Art) As a conventional organic photochromic material, there is one in which a spironaphthoxazine-based photochromic agent is contained in a matrix made of a polymer material such as polyvinyl butyral. As described above, it has been considered that the photochromic material using the spironaphthoxazine-based photochromic agent has a large coloring density and is excellent in repeated life and response speed. The spironaphthoxazine-based photochromic agent is represented by the following formula.

FIG. 4 shows one or more of these photochromic agents dissolved in a polymer material matrix such as polyvinyl butyral 2 and coated on the transparent substrate 1. In the figure, 3 indicates a spironaphthoxazine-based photochromic agent as a photochromic agent. . A polymer material in which such a photochromic material is dispersed is disclosed in, for example, JP-A-60-205.
As disclosed in Japanese Patent No. 429, an ultraviolet absorber is added as necessary to form a light variable layer, which is formed into a light variable layered structure and used for various purposes.

(Problems to be Solved by the Invention) However, in such a conventional organic photochromic material, stability to light is low, molecules are deteriorated by ultraviolet rays, and various kinds of materials are used for a long time while being exposed to light. Practical application of recording media, display element materials, sensor materials, copying materials, photoconductors for printing, recording materials for cathode ray tubes, photosensitive materials for holography, window glass for vehicles, window glass for building materials, etc. in terms of service life. There was a problem that he was not satisfied yet.

(Means for Solving Problems) The present invention has found that the above problems can be solved by dissolving a photochromic agent in a polymer matrix to form a four-component system in which a plasticizer and a hindered amine light stabilizer are added. Based on what you did.

That is, the photochromic material of the present invention is a photochromic material that reversibly changes color when exposed to light, and is 0.1 to 3% by weight in the photochromic material in the polymer material.
It is characterized by containing 0% by weight of a photochromic agent, 0.1 to 50% by weight of a hindered amine-based light stabilizer, and 1 to 40% by weight of a plasticizer.

The polymer material used as the matrix in the present invention is not limited to polyvinyl butyral and polyvinyl alcohol, and examples thereof include acrylic polymers such as polymethylmethacrylate, styrene polymers such as polystyrene, and polycarbonate. Polyester polymer, polyether polymer such as polyethylene oxide, nylon polymer,
Cellulosic polymers such as ethyl cellulose, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyglycidyl methacrylate, polyurethane, poly-N-vinylcarbazole, diethylene glycol bisallyl carbonate and copolymers thereof, And mixtures thereof, and they may be optionally crosslinked.

Further, the plasticizer affects the response speed of the photochromic agent by changing the free volume of the matrix, but it is obvious that the plasticizer is not limited to a specific plasticizer because it depends on the amount of the compounded amount. For example, phthalates such as dibutyl phthalate and dioctyl phthalate, adipates such as dioctyl adipate, phosphates such as tricresyl phosphate, polyesters, polyethers, triethylene glycol di-2.
-Ethyl butyrate systems, all plasticizers and their mixtures are effective. The content of the plasticizer is 1 to 40% by weight, preferably 4 to 10% by weight of the photochromic material. If it is less than 1% by weight, the response is too low, while 40% by weight.
If it exceeds, the life will be shortened, which is not preferable.

Furthermore, considering that the photochromic agent has the same coloring mechanism, a photochromic agent containing a spiro carbon in all molecules, particularly a spironaphthoxazine-based photochromic agent is preferable for use in the present invention. Considering the mechanism of deterioration, it is obvious that the present invention is also effective for the photochromic substances described in "Photochromism" by Green Et Bouran (GLEEN.H.BROWN). The content of the photochromic agent is 0.1 to 30% by weight, preferably 3 to 15% by weight of the photochromic material. If the blending amount is less than 0.1% by weight, it will not be colored even when exposed to light because it is too small, while if it exceeds 30% by weight, it is difficult to dissolve from the viewpoint of compatibility, which is not preferable.

The photochromic material of the present invention is characterized in that a hindered amine light stabilizer is added to the polymer material in addition to the photochromic agent and the plasticizer, and the amount of the light stabilizer is 0.1 to 50 of the photochromic material. If the content is less than 0.1% by weight, the weather resistance is not improved. On the other hand, if it exceeds 50% by weight, it cannot be dissolved in the polymer material because of compatibility.

(Example) This invention is demonstrated by the following example.

Example 1 Polyvinyl butyral (hereinafter referred to as PV
B), 1-isopropyl 3,3-as photochromic agent
Dimethyl spiro [indoline-2,3 '-[3H] -naphtho [2,1-b] -1,4-oxazine] was used, and triethylene glycol di-2-ethylbutyrate was used as a plasticizer.
As a light stabilizer, a hindered amine light stabilizer LS292 manufactured by Ciba-Geigy was used, and the photochromic material obtained as the following composition was used to prepare a light variable composition shown in FIG. In FIG. 1, 1 is a glass substrate, 2 is a polymer material matrix, 3 is a photochromic agent, 4 is a light stabilizer, and 5 is a plasticizer.

The solvent used was 100 parts of a 1: 1 solution of dichloromethane and methanol. Hereinafter this material is referred to as P-1.

P-1 on the glass 1 with a percoater as shown in FIG.
10 μm was applied and dried at 80 ° C. for 10 minutes. This was irradiated with a xenon lamp (UXL-75D manufactured by USHIO INC.) At 25,000 lux, and the responsiveness and life were examined. As comparative examples, P-1 with no light stabilizer was designated as R-1 and P-1 with no plasticizer and light stabilizer was designated as R-2, and similar tests were conducted.
Table 1 shows the measurement results of responsiveness and durable life of each photochromic material.

As is clear from the table, it is understood that the life of P-1 is more than 15 times longer than that of R-1. Further, since R-2 has no plasticizer, the free volume of the polymer material matrix surrounding the photocumylok agent becomes small, and the responsiveness is remarkably slowed, and it cannot be put to practical use.

From the above, it was found that the four-component system of the polymer material which is the matrix of the photochromic agent, the plasticizer and the light stabilizer is the best in order to have a quick response and a weather resistance.

Further, in order to determine the optimum amount of the plasticizer and the light stabilizer, experiments were conducted on the response speed and the durable life by changing the respective compounding amounts. Results are shown in FIG. Response speed to the initial sample
The time until the 50% change at 600 nm was changed by irradiating the Xe lamp, and the durability life was examined while continuously irradiating the time until the optical density became half of the initial value. From FIG. 2, the concentration of the plasticizer mainly affects the response speed, and the effect begins to appear at 1 wt% or more, and becomes a constant value at 40 wt%.
With regard to the light stabilizer, it mainly affects the durable life, and the effect is recognized at 0.1% by weight or more, and it is a constant value at 10% by weight.

Example 2 As this photochromic agent, 1,3,3-trimethylindolino-6′-nitrobenzopyrrilospirane, polyvinyl alcohol as a polymer material matrix, dioctyl sebacate as a plasticizer, and a hindered amine-based light stabilizer were used. Using TINUVIN 144, a construct similar to that shown in FIG. 1 was prepared. At this time, the content of TINUVIN 144 was 0.5% by weight, 1.5% by weight, 3.0% by weight, 5.0% by weight based on the total fixed amount.
The content was changed to wt%, the glass 1 of the transparent substrate was coated, the same evaluation as in Example 1 was performed, and the life was determined. The results are shown in FIG. However, the composition of other materials is as follows.

As can be seen from FIG. 3, in the case where the hindered amine-based light stabilizer is not included, the OD is reduced from 0.18 to 0.05 or less after 30 hours of life. However, when the light stabilizer was added, the life began to improve remarkably, and especially at 3.0% by weight or more, the OD remained almost unchanged from the initial value even after 100 hours.

(Effects of the Invention) As described above, the photochromic material of the present invention is composed of a photochromic agent, a polymer matrix, a plasticizer, and a hindered amine-based light stabilizer. Various recording media that are used for a long time while being exposed, materials for display devices, materials for sensors, copying materials, photoconductors for printing, cathode ray tubes,
A recording material, a holographic photosensitive material, a vehicle window glass, a building window glass, etc. can be put to practical use, and since the light stabilizer has the same effect as a plasticizer, the free volume of the matrix increases and the photochromic agent The effect of increasing the response speed of is obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a variable optical structure using the photochromic material of the present invention, FIG. 2 is a curve diagram showing a correlation between a plasticizer and a light stabilizer in Example 1, response speed, and durability, FIG. FIG. 4 is a curve diagram showing the results of measuring the durability of the spiropyran-based photochromic material in Example 2, and FIG. 4 is a cross-sectional view of a light variable structure using a conventional photochromic agent containing spiro carbon. 1 ... Transparent substrate (or glass) 2 ... Polymer material matrix 3 ... Photochromic agent 4 ... Light stabilizer 5 ... Plasticizer

Claims (1)

[Claims] 1. A photochromic material that reversibly changes color when exposed to light. In a polymer material, 0.1 to 30% by weight of the photochromic material in the photochromic material and 0.1 to 50% by weight of a hindered amine-based light are used. A photochromic material comprising a stabilizer and 1 to 40% by weight of a plasticizer.