JP2648224B2 - Optical products such as optical filters - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical products such as filters, lenses, and screens having a light-selective functionality.
The present invention relates to an optical product that selectively absorbs light in a wavelength band near 0 nm.

[Prior Art] As an optical product having photoselective functionality, a product utilizing the property of a neodymium compound to selectively absorb light having a wavelength of around 580 nm has been conventionally known. For example,
No. 58-225148 discloses a resin composition in which a neodymium oxide powder or the like is dispersed in a transparent plastic substrate such as a methacrylic resin. Further, a neodymium-containing optical product described in JP-A-60-161458 is composed of a monomer such as alkyl methacrylate or styrene, a neodymium compound such as neodymium acrylate and a solvent of a neodymium compound such as carboxylic acid, and a polymerization initiator. The mixture is polymerized by a cell casting method or the like to obtain various optical products.

These optical products have the characteristic of selectively absorbing light in the wavelength range around 580 nm as described above,
It is used for filters of color display devices such as T, screen plates, lenses, lighting equipment and the like.

However, in those obtained from a resin composition in which neodymium oxide powder is dispersed in a transparent plastic substrate, transparency and light transmittance are reduced due to the dispersion of inorganic powder, and the absorption peak is broad and There is a disadvantage that the amount of absorbed light is small.

Further, in the optical product of JP-A-60-161458, the resin composition is a neodymium compound and a solvent and a polymer are molecularly bonded or dissolved, so that the mechanical properties and the like of the polymer itself change, If an attempt is made to contain an optically sufficient amount of the neodymium compound, there is an inconvenience that the properties of the resin composition, that is, the optical product are significantly deteriorated.

[Problems to be Solved by the Invention] Accordingly, an object of the present invention is to provide a light selective functional optical product having sharp absorption characteristics without inconveniences such as a decrease in transparency and light transmittance and a deterioration in characteristics of a resin composition. Is to get

[Means for Solving the Problems] The object of the present invention is to provide light selective functional beads having a particle diameter of 0.01 μm to 5 mm, in which a neodymium compound is contained in a transparent polymer in a dissolved state or a copolymerized state with the transparent polymer. The problem is solved by dispersing the beads in a transparent resin to form a resin composition and obtaining an optical product from the resin composition.

 Hereinafter, the present invention will be described in detail.

The optical product in the present invention refers to any one of an optical filter, an optical lens, an optical screen, and a lighting cover.

First, the light selective functional beads used in the present invention will be described.

The light selective functional beads used in the present invention are particles comprising a neodymium compound dissolved in a transparent polymer or in a copolymerized state with the transparent polymer. The particle size of the beads is 5 mm or less and 0.01 μm or more. This particle size varies greatly depending on the application of the beads. The neodymium compound in the beads is chemically bonded to the transparent polymer by means such as copolymerization, that is,
It may be copolymerized with the transparent polymer, or may be dissolved in the transparent polymer. Also, the beads themselves need to be transparent.

Next, the light-selective functional beads will be described in accordance with the production method.

In the method for producing the photoselective beads, a mixture of neodymium carboxylate and a double salt obtained from carboxylic acid, and a polymerizable monomer that makes the polymer polymer transparent are subjected to suspension polymerization.

In the method for producing these beads, neodymium carboxylate is used as the neodymium compound. The neodymium carboxylate may be polymerizable or non-polymerizable. As the polymerizable neodymium carboxylate, neodymium methacrylate, neodymium acrylate, α-
Neodymium chloroacrylate, neodymium α-ethyl methacrylate, neodymium maleate, neodymium fumarate, neodymium itaconate and the like can be mentioned. The non-polymerizable neodymium carboxylate includes propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, n-caproic acid, n-caprylic acid, n-capric acid, α-ethylhexane Acid, lauric acid, neodymium salts of saturated fatty acids such as stearic acid and oleic acid, linoleic acid, linolenic acid,
Unsaturated fatty acids such as ricinoleic acid, benzoic acid, phthalic acid, succinic acid, maleic acid, itaconic acid, itaconic acid monoalkyl ester, naphthenic acid, oxocarboxylic acids such as repric acid and acetyl valeric acid, lactic acid, and glycolic acid ethyl ether And hydroxycarboxylic acids such as butyl ether glycolate, phosphoric acids such as butyl acid phosphate and ethyl acid phosphate, and neodymium salts such as aliphatic and aromatic sulfonic acids. These neodymium carboxylate may be used alone or in combination of two or more, and may be a mixture of a polymerizable compound and a non-polymerizable compound.

Next, the neodymium carboxylate is reacted with a carboxylic acid to form a double salt. This is because neodymium carboxylate is generally insoluble in the polymerizable monomer, and can be easily dissolved in the polymerizable monomer by forming a double salt.

Examples of the carboxylic acid for this purpose include polymerizable unsaturated carboxylic acids such as methacrylic acid and acrylic acid, and propionic acid, isobutyric acid, n-butyric acid, caproic acid, caprylic acid, capric acid, 2-ethylhexanoic acid, and stearic acid. And saturated or unsaturated aliphatics such as octanoic acid and naphthenic acid. One or more of these are used in combination.

The mixing ratio of neodymium carboxylate and carboxylic acid is such that when the total amount of both is 100% by weight, carboxylic acid is 10 to 40%.
It is preferably in the range of% by weight. The amount of carboxylic acid
If it exceeds 40% by weight, the content of neodymium in the beads decreases, and the mechanical and thermal properties of the beads decrease, which is not preferable.

Further, to further improve the solubility of neodymium carboxylate, unsaturated alcohols such as α-hydroxyethyl acrylate and α-hydroxyethyl methacrylate, propyl alcohol, saturated aliphatic alcohols such as cyclohexyl alcohol, ethylene glycol, diethylene glycol, propylene glycol And the like can be used in combination with the carboxylic acid. The amount of the alcohol used is as a mixture with a carboxylic acid,
As above, the content is 10 to 40% by weight.

Typical examples of the polymerizable monomer having a transparent polymer include (meth) acrylic acid esters and styrene.

Examples of the (meth) acrylate include alkyl (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate or cyclohexyl (meth) acrylate, tetrahydrofuryl (meth) acrylate, and (meth) acrylic acid. Benzyl, phenyl (meth) acrylate, allyl (meth) acrylate, methallyl (meth) acrylate, β-naphthyl (meth) acrylate, β-aminoethyl (meth) acrylate, 2-methoxy (meth) acrylate Ethyl, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4 butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, penta Erythritol tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, and halogen-substituted (meth) acrylates thereof.

Further, as the polymerizable monomer, a copolymerizable monomer can be used to the extent that the transparency of the obtained beads is not impaired. Examples of such a copolymerizable monomer include vinyl acetate, acrylonitrile, and methacrylonitrile. In addition, cross-linkable beads can be formed by adding a polyfunctional acrylate such as ethylene glycol diacrylate or diethylene glycol dimethacrylate.

Formation of a double salt of neodymium carboxylate and carboxylic acid is
It is performed by adding neodymium carboxylate and carboxylic acid to the polymerizable monomer, stirring and mixing. This mixture
The reaction is carried out at room temperature or at a temperature of 100 ° C. or lower, and by stirring for 0.5 to 5 hours, a double salt is generated and dissolved in the polymerizable monomer. By this operation, a polymerizable mixed solution in which neodymium carboxylate, carboxylic acid and polymerizable monomer are uniformly dissolved is obtained.

Next, the polymerizable mixed solution thus obtained is subjected to suspension polymerization to obtain desired light selective functional beads. For the suspension polymerization, a method in which the above-mentioned polymerizable mixed solution and the polymerization initiator are suspended in a normal aqueous phase is used.

As polymerization initiators, α, α′-azobisisobutyronitrile, α, α′-azobis (2,4-dimethylvaleronitrile), α, α′-azobis (2,4-dimethyl-4-yl)
Azobis compounds such as methoxyvaleronitrile are used.

This polymerization initiator can be used alone or in combination of two or more kinds. The amount of the polymerization initiator used depends on the amount of the polymerizable component in the polymerizable solution.
0.001 to 1 part by weight based on 100 parts by weight.

In order to stabilize the suspended particles, a protective colloid such as polyvinyl alcohol, carboxymethyl cellulose, sodium polyacrylate, alginic acid, and gelatin can be appropriately added.

The polymerization conditions are preferably set to a temperature of 30 to 90 ° C. and a time of about 1 to 10 hours, but are not limited to this range.The polymerization is performed first at a low temperature, and then the temperature is increased to continue the polymerization. A method is also used.

After the polymerization is completed, the polymer particles are dehydrated, washed with water, and dried by a conventional method to obtain transparent spherical light-selective functional beads.

The light selective functional beads are classified into a desired particle size range by a classifier such as a wind micron separator, and are added to and dispersed in the transparent resin.

The light selective functional beads thus obtained contain a neodymium compound in a transparent polymer in a copolymerized or dissolved state with the transparent polymer, and the beads themselves become transparent. In addition, the presence of the neodymium compound causes light absorption at around 580 nm, and the neodymium compound is in a copolymerized or dissolved state with the transparent polymer, so that sharp absorption and large absorption are observed. Further, since the mechanical properties and the like of the beads themselves are not so strictly required, the content of neodymium can be sufficiently increased, for example, to about 15% by weight. Furthermore, by appropriately changing the polymerization conditions, it is possible to obtain particles having various particle diameters, and by changing the type of polymerizable monomer, neodymium carboxylate, and carboxylic acid, the mixing ratio, and the like, the refractive index of the beads themselves can be obtained. Can be changed according to the use or the like.

The light-selective functional beads thus obtained are added to and dispersed in various transparent resins to form a resin composition, and further, are formed into optical products having light-selective functionality by various molding methods.

As the transparent resin here, if it has transparency, it is used regardless of thermoplasticity or thermosetting, and polymethyl methacrylate, polystyrene, polyvinyl chloride, acrylonitrile-styrene copolymer, polycarbonate, Cellulose plastics and the like are used.

Examples of the molding method include extrusion molding, injection molding, and calendar molding. In these molding methods, a predetermined amount of the above beads are blended with pre-polymerized polystyrene, polyvinyl chloride or polymethyl methacrylate pellets and the like, mixed, and then extruded by an extruder, an injection molding machine, a calender, and then a sheet, film or Optical products of various shapes. When an acrylate such as polymethyl methacrylate is used as the transparent resin, an optical product can be obtained by a so-called cell casting method. That is, the beads are added to the acrylate partial polymer, and the mixture is injected into a mold to perform polymerization.

In the addition of the beads to the transparent resin, a transparent optical product can be obtained by matching the refractive index of the beads with the refractive index of the transparent resin serving as the matrix. Further, if the particle diameter of the beads is 0.2 μm or less, good transparency can be obtained even if the two have different refractive indices. When beads having a particle size of about 20 to 2 μm are added, the particles have a rough appearance, and beads having a particle diameter of about 50 to 100 μm have a frosted or milky (milky translucent) appearance. . Also, a milky half tone can be obtained by using other light diffusing materials such as titanium oxide, talc and barium sulfate in combination.

The amount of the light selective functional beads added to the transparent resin depends on the neodymium content in the beads and also depends on the use of the optical product, but is usually 2 to 30 parts by weight based on 100 parts by weight of the transparent resin. Range. In the case of adding neodymium to an optical product in the form of beads containing such a neodymium compound, the mechanical properties of the transparent resin itself serving as a matrix do not decrease, and as a result, a large amount of neodymium is added to the final optical product. It can be present in the product, so that the photoselective functionality possessed by neodymium can be fully exhibited, and the mechanical properties and the like of the final optical product hardly deteriorate.

Furthermore, an optical product colored by using a coloring agent such as a pigment or a dye together can also be obtained. When this colorant is used in combination, the wavelengths are 380 to 420 nm, 480 to 530 nm, 560 to 610 nm and 64.
Having absorption in at least one wavelength range of 0 to 780 nm,
For visible light in a wavelength region other than the above, a coloring agent having little or no absorption is blended, thereby compensating for selective absorption by the neodymium compound, or in a visible light wavelength region in which the neodymium compound has no absorption. Can be selectively absorbed. Examples of the colorant having such an action include dyes, pigments, and ultraviolet absorbers described below.

Colorants having a main absorption in the wavelength range of 380 to 420 nm include phenyl salicylate and para-te-salicylate.
salicylic acid esters such as rt-butylphenyl, 2-
(2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-
benzotriazoles such as tert-butylphenyl) -5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2'-dihydroxy-4-octo There are ultraviolet absorbers such as benzophenones such as xylbenzophenone.

Colorants having a main absorption in the wavelength range of 480 to 530 nm include Hostazol Red GG (manufactured by Hoechst), Variogen Red 3730 (manufactured by BASF), and Diaresin Red HS (manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) ), Diaresin Red S (manufactured by Mitsubishi Kasei Kogyo Co., Ltd.), Amablast Pink P4B (manufactured by American Aniline Co., Ltd.), and orange C-type (manufactured by Hercules Co., Ltd.).

Colorants having a main absorption in the wavelength range of 640 to 780 nm include Euvinyl Blue 702 (manufactured by BASF), Oil Blue 615 (manufactured by Orient Chemical Industry Co., Ltd.),
Blue dyes such as Macrolex Green 513 (manufactured by Bayer AG), Seikagen O Blue GK-1200 (manufactured by Dainichi Seika Kogyo Co., Ltd.), Sumiton Cyanine Blue HB-1 (manufactured by Sumitomo Chemical Co., Ltd.) There is.

As a colorant having main absorption in the wavelength range of 560 to 610 nm, there is no suitable one, but among the colorants having main absorption in the above three wavelength ranges, those having absorption in the wavelength range of 560 to 610 nm are also available. Is preferably used. Such a coloring agent is, for example, Euvinyl Blue 702 (manufactured by BASF).

Optical products that use such colorants in combination include red, green,
Light other than the three primary colors of blue light is absorbed.Particularly when used for filters covering the light-emitting surface such as color CRTs, the color purity of light emitted from the phosphor is improved, and color reproducibility is improved. In addition, a decrease in contrast can be prevented while maintaining high luminance.

Specific applications of the optical product having such light selecting functionality include, for example, optical filters, optical lenses, illumination covers, and video screens such as rear projection screens.

 Hereinafter, specific examples will be described.

Production Examples 1 to 7 (Production of Photoselective Functional Beads) (Production Example 1) 34% by weight of neodymium methacrylate and methyl methacrylate
42% by weight, 15% by weight of lauric acid and 9% by weight of propylene glycol were placed in a flask, heated to 65 ° C. with stirring, and dissolved in about 2 hours.

Next, a stirrer, 100 parts by weight of the neodymium monomer mixture in an autoclave container with a nitrogen gas inlet,
0.5 parts by weight of azobisisobutyronitrile, 3.0 parts by weight of polyvinyl alcohol, and 800 parts by weight of water were replaced with nitrogen gas under high-speed stirring, and then the vessel was heated and the first-stage polymerization was carried out at 75 ° C.
The polymerization was completed by heating the second stage polymerization at 90 ° C. for 1 hour and then for 1 hour.

Thereafter, dehydration, washing with water and drying were performed as usual to obtain transparent spherical beads. This was classified with a wind micro separator to obtain beads having a desired particle size.

(Production Examples 2 to 7) Neodymium methacrylate and lauric acid or octanoic acid were mixed at the mixing ratio shown in column A of Table 1 and heated and dissolved at 65 ° C. Next, a predetermined amount of the monomer shown in column B of Table 1 is added and dissolved at room temperature. After removing a small amount of insoluble matter, suspension polymerization was performed in an autoclave in the same manner as in Production Example 1 to obtain beads.

Examples (Examples 1 to 6) As a polymerization catalyst, a partial polymer of methyl methacrylate (polymerization rate: 20%) and 100 parts by weight of a monomer copolymerizable therewith were used as a polymerization catalyst. Dimethyl valeronitrile) 0.04 part by weight, dioctyl sulfosuccinate sodium salt as a releasing agent 0.005 part by weight, and the neodymium-containing beads obtained in Production Examples 1 and 4 were added, mixed and degassed in the composition shown in Table 2. Thereafter, it was poured into a mold composed of a reinforced glass whose thickness was previously set to 3 mm and a soft vinyl chloride gasket, and immersed in 70 ° C. hot water for 80 minutes. It was then placed in a 130 ° C. air bath for 80 minutes to complete the polymerization. The optical performance and the spectral transmittance curve of the cast sheet obtained by removing the mold were as shown in Table 2 and FIG.

The cast sheet thus obtained has light diffusivity and strong absorption near a wavelength of 580 nm. When these cast sheets were used as lamp covers for incandescent lamps and halogen lamps, the color rendering effect was increased, and they were found to be useful as lighting equipment.

(Examples 7 to 9, Comparative Example 1) Acrypet VH (methacrylic resin pellets manufactured by Mitsubishi Rayon Co., Ltd.) and the neodymium-containing beads obtained in Production Examples 3 and 6 were blended so as to have the composition shown in Table 3. After mixing thoroughly with a tumbler and homogenizing, use an extruder to
Under a condition of 260 ° C., the resin was extruded from a die, passed between three mirror-finished rolls, and cooled to obtain a resin plate having a thickness of 3 mm. Table 3 shows the optical performance. From the results in Table 3, if necessary, an inorganic diffusing agent or a transparent polymer bead having a refractive index different from the refractive index of the substrate can be added. Light absorption was observed. When a light source cover was made using these extruded resin plates, colorful lighting fixtures could be obtained.

(Examples 10 to 12 and Comparative Examples 2 and 3) Cast sheets (Examples 10 and 11 and Comparative Examples 2 and 3) were cast by the same casting polymerization method as shown in Example 1 so as to have the structure shown in Table 4. An extruded sheet (Example 12) was produced by the same extrusion method as described in Example 7. The sheets of any of the examples are light diffusive in which the neodymium-containing polymer beads are uniformly dispersed, whereas the sheets of the comparative examples do not contain neodymium. Table 4 shows the optical performance of these sheets.

Furthermore, one of these resin sheets is pitch 0.4m
A metal plate having a lenticular mold consisting of m, R0.29mm and a pitch of 0.3m, R0.07mm, and a metal plate having a mirror surface with the other being heated to 180 ° C by a heating press machine (forming pressure 25kg /
cm ² , molding time: 15 minutes) The molding was performed to obtain a lenticular projection screen.

The projection screen obtained in this manner is connected to a Pioneer projection television (SD-P5
010-type screen, and the TV image was projected to compare the color rendering properties of the colors. In the screens obtained from those of Examples 10 to 12, the reflection of external light was small, and the colors of red and blue were vivid, but those of Comparative Examples 2 and 3 were not so significant, and the difference was clear. Was recognized.

FIG. 2 shows the spectral characteristics of the resin sheets of Examples 10 and 11 and Comparative Example 2.

[Effects of the Invention] As described above, an optical product such as an optical filter of the present invention is obtained from a dispersion of light selective functional beads containing a neodymium compound and exhibiting a sharp absorption near a wavelength of 580 nm in a transparent resin. Therefore, it has excellent photoselective functionality and does not decrease mechanical properties even if the neodymium content is sufficiently increased.

[Brief description of the drawings]

1 and 2 are spectra each showing the spectral characteristics of the resin sheet obtained in the example of the present invention.

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Claims (4)

(57) [Claims] 1. A resin composition in which light-selective functional beads having a particle diameter of 0.01 μm to 5 mm and comprising a neodymium compound dissolved in a transparent polymer or in a copolymerized state with the transparent polymer are dispersed in the transparent resin. An optical filter consisting of 2. A resin composition in which light-selective functional beads having a particle diameter of 0.01 μm to 5 mm and comprising a neodymium compound dissolved in a transparent polymer or in a copolymerized state with the transparent polymer are dispersed in the transparent resin. Optical lens consisting of. 3. A resin composition in which light-selective functional beads having a particle diameter of 0.01 μm to 5 mm and comprising a neodymium compound dissolved in a transparent polymer or in a copolymerized state with the transparent polymer are dispersed in the transparent resin. Optical screen consisting of. 4. A resin composition in which light-selective functional beads having a particle diameter of 0.01 μm to 5 mm and comprising a neodymium compound dissolved in a transparent polymer or in a copolymerized state with the transparent polymer are dispersed in the transparent resin. Lighting cover consisting of.