JPH05265078A - Optical filter and its production - Google Patents

Abstract

PURPOSE:To provide the novel optical filter in order to improve optically important factors, such as transmittance, multiple reflections and sharpness, and the process for production thereof. CONSTITUTION:This optical filter is formed by applying >=2 kinds of chemicals having the function of the optical filter on one sheet of high-polymer film having good transparency. This process for production of the optical filter consists in adding and mixing >=2 kinds of the chemicals having the function of the optical filters and a solvent to and with the high-polymer resin, the film of which has the good transparency after film formation and forming the film of this high-polymer soln. by a soln. film forming method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to color correction of an image subject when optically recording an image such as photography and video photography,
The present invention relates to an optical filter used as a means for correcting the optical characteristics of a color density correction device of a light source and for making a conscious correction, and an optical filter for maximizing the characteristics of the optical filter and a manufacturing method thereof. It is a thing.

[0002]

2. Description of the Related Art Various products are manufactured for optical filters according to the demands of photographers. The photographer chooses a good filter based on his judgment and creates a video that matches his image. As a conventional optical filter, as a type, a sharp cut filter; a filter designed to absorb light having a certain wavelength or less and transmit light having a certain wavelength or more. ○ Infrared filter: A sharp cut filter that absorbs visible light and transmits infrared light. ○ Bandpass filter: A filter that transmits only light in a certain wavelength range and absorbs light in other wavelengths. ○ Rutral Density Filter: A filter that absorbs light uniformly over all wavelengths. ○ Color temperature conversion filter: A filter for converting the photographic color temperature of a light source. ○ Color correction filter for color photography: A filter mainly intended to correct the color of film during reverse color film photography. ○ Color print color correction filter: A filter that corrects the color of positive film for motion pictures or color paper during color printing. ○ Other specific filters: filters used for specific applications such as three-color separation filters, photomasking masking filters, and visual sensitivity filters, etc., all of which are used for optical applications from general to industrial applications. There is. As the optical filter, one of the above types is formed on a support such as a polymer film or glass by applying chemicals having respective functions to form one optical filter. As a method for producing an optical filter, a polymer film solution or a gelatin solution is added and dissolved with a chemical having a function, and a film is formed or coated / dried to form a film, which itself is processed as an optical filter, or glass or It is a method in which a polymer film is processed as a support. When using one of the above filters, it was often the case that one type of filter was not satisfactory and two or more types of optical filters were used in combination.

[0003]

However, each of the optical filters is made of, for example, a polymer film as a support, and when a plurality of optical filters are used in a multiplexed manner, the light transmittance decreases due to the thickness, and the filter-to-filter ratio is reduced. In reality, multiple reflections of light occur, and the sharpness is poor due to the influence of refraction of light.

An object of the present invention is to solve the above-mentioned problems of the prior art, improve and improve optically important factors such as transmittance, multiple reflection and sharpness, and make the best use of the characteristics. It is to provide a new optical filter, and also to provide a method for producing a filter having a composite function without increasing the kinds of dyes in the production process.

[0005]

The above object of the present invention is characterized in that a single polymer film having good transparency is provided with two or more kinds of chemicals having an optical filter function. Optical filter After a film is formed, a polymer resin having good transparency is mixed with two or more chemicals having an optical filter function and a solvent, and the polymer solution is formed by a solution film forming method. This is achieved by a method for manufacturing an optical filter, which is characterized by the above.

In the present invention, examples of the polymer film having good transparency and excellent mechanical properties include celluloses such as polyesters represented by polyethylene phthalate, cellulose diacetate, cellulose triacetate and cellulose acetate butyrate. Polyesters such as esters, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl compounds, acrylic addition polymers such as polymethylmethacrylate,
Known films such as polycarbonate made of polycarbonate or hydrophilic polymer such as gelatin are used. The two or more types of optical filter functions in the present invention are the functions of conventional commercially available optical filters, such as a sharp cut filter, an infrared filter, a bandpass filter, a neutral density filter, a color temperature conversion filter, and a color photographing correction. Filters, color print color correction filters, and other specific filters, etc. These are the functions when two or more of these are used in combination. However, in the case of the present invention, by combining two or more functions, a new chemical composition is obtained rather than simply adding chemicals of individual filters. In the present invention, the fact that chemicals are applied to the polymer film means that the chemicals are added and dissolved and mixed at the time of forming the polymer film to form a film, or only the polymer film is formed and then formed. It is meant to include those obtained by applying and drying chemicals dissolved in.

As a manufacturing method in the present invention, a method by a solution film forming method is taken up. The solution film-forming method of the present invention is a method in which a polymer solution dissolved in a solvent is cast on a support to form a film and then dried, and a film peeled from the support is formed. Further, it can be clarified that the object of the present invention can be achieved by adding a dye or a chemical for having a plurality of optical filter functions to the polymer solution to form a film in a manufacturing method of further drying. It was

In the present invention, a method for forming a film of a polymer solution dissolved in a solvent, that is, a solution film forming method is a method of forming a polymer solution in a fixed amount by a solution supply device (die) having a thin slit. Is a method of supplying a film onto a support to form a film. In a large-scale industry, a method of continuously supplying a polymer solution onto an endless metal plate support or a drum by a die to form a film is generally known. On the other hand, on a small scale, there is a method of forming a film by moving a die having a slit on a fixed support having a fixed size, for example, a metal plate or a glass plate. Further, the support in the solution film-forming method is not limited to the metal plate or the glass plate described above, and may be a plastic plate as long as the solution is dried to form a film and can be peeled from the support. The die is not limited to the shape as long as it has a slit and can uniformly supply the solution. Further, the means for supplying the solution to the die may have a quantitative property with a pump, and in the case of the above-mentioned small scale, a simple means for moving the die storing a fixed amount of the solution may be used.

In the present invention, it is important that the polymer as a polymer solution is dissolved in a solvent, but it is for optical use, and the transparency and optical anisotropy of the film after film formation are small, and Is a filter, it is extremely important that it has good compatibility with the dye when it is added for dyeing. In general, gelatin is used as the water solvent, and cellulose acetate polymer is used as the organic solvent system, but this is not limited as long as it meets the above purpose,
The above-mentioned polymer film is applicable. From the manufacturing process, the water-based gelatin system is excellent, but considering that the dye is soluble only in the organic solvent and the moisture resistance and heat resistance of the finished film, it seems that the cellulose film is excellent. The present invention is not limited to any one.

The chemicals having an optical filter function in the present invention naturally include those in the visible light range such as red, blue and green, and also include absorbing dyes such as ultraviolet rays and infrared rays. The chemicals in the present invention include stabilizers other than the above dyes,
Includes additives such as plasticizers, hardeners and surfactants. With these additives, the handling property as a film can be improved. It is preferable that the above chemicals are dissolved and dispersed in the polymer solution from the viewpoint of uniformity.

The middle dyes of chemicals in the present invention will be described. From the classification of dyes, azoic dyes, basic dyes, acid dyes, direct dyes, mordant dyes, disperse dyes, oil-soluble dyes, sulfur dyes, etc. are used. , Classified from the structure,
Azo dyes, anthraquinone dyes, indigoid dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone and naphthoquinone dyes, naphthalimide dyes and perinone dyes are used.

As the ultraviolet absorber in the chemicals in the present invention, for example, those described in JP-A-61-207680 and JP-A-62-11773 can be used. Typical examples include benzophenone-based, salicylate-based, benzotriazole-based,
2,2'-dihydroxy-4-4'-dimethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 4-t-butyl-phenyl salicylate, 2-
(Hydroxy-5-t-octylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-
3,5'-di-t-butylphenyl) -5-chloro-benzotriazole, [2,2'-thiobis (4-t-octylphenolate)] n-butylamine nickel II
Etc. are suitable.

Further, as the infrared absorbent in the chemicals in the present invention, there are disclosed in JP-A-61-80106 and JP-A-61-106.
73902, JP-A-61-70503, JP-A-61
-57674, JP-A-61-42585, JP-A-SHO-6
The materials described in JP-A No. 1-3003, JP-A No. 61-26686, JP-A No. 61-11704, and JP-B No. 59-41562 are used.

As the dye preparation method in the present invention, for example, in the case of a solution film-forming method, generally, a dye matching a light transmission spectrum or a color sample required by a user is selected from spectrum data or by color matching. However, there are few cases where a single dye is usually satisfactory, and a plurality of dyes are required.
In this way, the required amount of the first selected dye is weighed according to the color density, dissolved, and mixed uniformly with the polymer solution to form a film. Since the transmittance varies depending on the film thickness, the uniformity of the film thickness is important. The spectral characteristics (spectral absorption) of this formed film are measured and compared with the required spectrum,
Correction is made for the portion where the transmittance is deviated. For example, if the absorption at 450 to 500 nm is large, the dye such as blue is reduced in order to reduce the absorption in that portion. In this way, the target spectrum is obtained. This is largely due to experience, but recently, by inputting the characteristics of the dye in advance and adjusting it on the computer,
It is also possible to simulate and make a formulation in a relatively short time. For example, Beer-
Using the Lambert's approximate equation, the absorbance problem is replaced, and the absorbance matching problem is replaced by the deviation of 2 from the target transmittance.
Methods have been proposed that result in the problem of finding the minimum sum of multiplications. (From Japanese Patent Application No. 3-70565)

By such a simulation, the objective can be achieved with the minimum required number of types of dyes when selecting a combination of dyes having predetermined characteristics.

[0016]

EXAMPLES The effects of the present invention will be shown by examples. When adjusting a slight bluish tint such as cloudy weather, shade, and strobe light source, a color temperature conversion filter for fine adjustment is used, but when shooting color film for commercial use, it is better to use a color correction filter. Usually, in this case, a red or magenta correction filter is also used for the purpose of imparting a reddish color or improving highlight clarity.

(Comparative Example-1) Conventionally, as a color temperature conversion filter, chemicals having the following composition were used as cellulose acetate 1
What was added per 00g,

[0018]

[Table 1] (Brand name) (Manufacturer name) (Addition amount) Aizen Catilone Red, 6BH (Hodogaya Chemical Co., Ltd.) 3.4 mg Basic (methine type) Aizen Catilone pink, FGH (〃) 0.5 mg Basic (methine) System) Zapon Fast Orange, CG (Hoechst) 6.4 mg Oil-soluble (monoazo system) Aizen Catillon Orange, GLH (Hodogaya Chemical Co., Ltd.) 3.4 mg Basic (methine system) Sapon Fast Yellow, CGR (Hoechst) 28.8 mg Oil Soluble (monoazo type) Oil Yellow, 3G (Orient) 10.0 mg Oil soluble (monoazo type) UV absorber 1240 mg Ubinal M40 (GAF) (690) (Benzophenone type) Ubinal D49 (GAF) (550) (Benzophenone type)

As a color correction filter, chemicals having the following composition added per 100 g of cellulose acetate were used one by one.

[0020]

[Table 2] (Product name) (Manufacturer name) (Addition amount) Aizen spirone pink, BH (Hodogaya Chemical) 4.0 mg Oil-soluble (salt of acid dye and basic dye) Diaceritone Fast Pink, B (Mitsubishi Kasei) 7.6mg Disperse dye (Anthraquinone type) Zapon Fast Yellow, CGR (Hoechst) 13.8mg Oil-soluble (monoazo type) Oil Yellow, 3G (Hoechst) 1.9mg Oil-soluble (monoazo type)

(Example 1) In the present invention, a dye for color temperature conversion + color correction (hue is yellow / red, color temperature is 4 decamillet conversion + red with an effective density of 0.05) and the formulation is as follows. And the addition amount per 100 g of cellulose triacetate

[0022]

[Table 3] (Brand name) (Manufacturer name) (Amount of addition) (Material type) Aizen Catylone Red, 6BH (Hodogaya Chemical Co., Ltd.) 38.6 mg Basic (methine type) Aizen Catylone Orange, GLH (〃) 3. 7 mg 〃 (〃) DIARESIN ORANGE, G (Mitsubishi Kasei) 10.9 mg Oil-soluble (anthraquinone type) Aizen spirone yellow, GRLH (Hodogaya Chemical) 41.7 mg 〃 (monoazo type) Oil yellow, 3G (Orient) 10. 3 mg (monoazo type) UV absorber 690 mg Ubinal D49 (BASF) (benzophenone type)

As an optical filter, a film was formed by a solution film forming method.

In the shade photographing in fine weather, an optical filter formed according to the present invention (adjusted to have a combined spectral characteristic of a hue amber color temperature conversion filter and a reddish color correction filter) was used. Reference-1-2
While the filter effect is equivalent to that of a combination of two filters, the number of filters is changed from two to one, the light transmittance is improved by about 8%, and the multiple reflection between filters is reduced by using two filters. The sharpness of the image was improved. The polymer solution used for forming the filter membrane was a dope prepared by dissolving 18% by weight of cellulose triacetate in a mixed solvent of 92% by weight of methylene chloride and 8% by weight of methanol. % Is included).
When the color temperature conversion filter A of hue amber, the color correction filter B, and the mixing filter C of the present invention were compared with this dope, the chemical composition was changed as follows.

[0025]

(Table 4) (Dye) (A) (B) (C) Red 3.4 mg ─ mg 38.6 mg Pink 0.5 11.6 ─ Orange 9.8 ─ 14.6 Yellow 38.8 13.8 52. 0 UV absorber 1240.0 ─ 690.0

[0026]

EFFECTS OF THE INVENTION In an optical filter used for photographing and the like, a plurality of types of filters are often used depending on the application, which results in a decrease in light transmission and a decrease in sharpness due to light scattering between filters. Although there were many problems, such as the optical filter of the present invention is a single polymer film,
In addition to reducing the amount of additives to about 60% of the conventional level, improving and improving optically important factors such as light transmittance, multiple reflection, and sharpness, and making the most of its characteristics, Even in the manufacturing process, it is possible to provide one filter with two or more types of filter functions without increasing the number of dyes.

Claims (2)

[Claims] 1. An optical filter, wherein one sheet of a polymer film having good transparency is treated with two or more kinds of chemicals having an optical filter function. 2. A polymer resin having a good transparency after film formation, and two or more kinds of chemicals having an optical filter function,
A method for producing an optical filter, characterized in that a solvent is added and mixed, and the polymer solution is formed into a film by a solution film forming method.