JPH069846A - Neodymium-containing transparent resin and its production - Google Patents

Abstract

(57) [Summary] [Structure] (A) A copolymer comprising a monomer mainly containing alkyl methacrylate and a copolymerizable unsaturated carboxylic acid or a salt thereof, and (B) an organic carboxylic acid and / or
Or its neodymium salt, with a neodymium content of 0.3
In the transparent resin of 20 to 20% by weight, acrylic acid, methacrylic acid and their salt units in the copolymer and the organic carboxylic acid and its salt relative to the total number of carboxyl groups of the organic carboxylic acid and its salt The number of carboxyl groups possessed occupies the ratio x, the ratio of the carboxyl groups forming a salt by neutralizing neodymium among all the carboxyl groups is y, and x and y satisfy a specific formula. Neodymium-containing transparent resin and method for producing the same. [Effect] Even though it is transparent, it can selectively absorb light of wavelengths other than the three primary colors, so that it can be used as a photon resin material for the front plate of a color cathode ray tube or the like to prevent deterioration of image contrast.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a neodymium-containing transparent resin and a method for producing the same. More specifically, the present invention relates to a neodymium-containing transparent resin suitable as an optical resin material capable of selectively absorbing light having wavelengths other than the three primary colors, and a method for producing the same.

[0002]

2. Description of the Related Art On the inner surface of a panel glass of a color cathode ray tube, phosphors forming a set of three primary colors of red, green and blue are arranged in a large number of dots or stripes to form a phosphor screen. A color image is observed through the panel glass by passing an electron beam emitted from an electron gun toward the fluorescent screen through a shadow mask or an aperture grill.

However, when an image of a color cathode ray tube is viewed through a panel glass, external light existing around the observer, for example, incident sunlight from a window or indoor illumination light such as a fluorescent lamp is incident on the fluorescent surface, and red light is emitted. However, there is a problem that the contrast of an image composed of green and blue light is significantly reduced.

Conventionally, for the purpose of preventing the deterioration of contrast due to outside light, a slight amount of Ni 2 O and Co 2 O 3 is added to the panel glass to color the glass to a neutral gray color to reduce the brightness of the glass. Came. However, this neutral gray glass exhibits a substantially uniform transmission over the entire visible wavelength range, including the red, green and blue emission spectra, thus reducing the transmission of this gray glass for the purpose of improving contrast. Then, the light emitted from the red, green and blue phosphors is also absorbed and the brightness of the image is lowered.

The emission spectrum of the phosphor is, for example, as shown in FIG. 1, and colors of wavelengths corresponding to the red (curve A), green (curve B) and blue (curve C) fluorescence spectra are sufficiently transmitted. , It is expected that the panel glass is provided with a property that light other than the colors of these wavelengths, which is easily perceived by human eyes, such as yellow light, is sufficiently absorbed to prevent a decrease in contrast while maintaining high brightness. . Further, by appropriately setting the absorption wavelength range, light of a specific undesired wavelength contained in the emission spectrum is selectively absorbed and removed, and the color purity of light emitted from the phosphor is improved, and color reproducibility is improved. Is also expected to improve. However, it is extremely difficult to achieve such an object by directly improving the panel glass, and even if it is achieved, it becomes expensive.

In order to solve such a problem,
(1) Neodymium phosphate, neodymium carbonate, neodymium sulfate,
A resin composition obtained by mixing an inorganic neodymium compound such as neodymium oxide or neodymium nitrate with a synthetic resin (JP-A-51-56851).
(2) A resin composition obtained by blending an organic neodymium compound such as neodymium ethylenediaminetetraacetate, neodymium acetate or neodymium stearate with a synthetic resin such as methyl methacrylate resin or styrene resin (JP-A-51-58,444). Is proposed.

[0007]

However, in the former case, since the neodymium compound is an inorganic substance, the compatibility with the methylmethacrylate resin, the styrene resin, etc., which are organic synthetic resins, is not sufficient, and therefore even if these resins are kneaded. Uniform distribution was difficult. On the other hand, in the latter, the neodymium compound is an organic substance, but even if a solid methylmethacrylate resin is heated and melted and kneaded, uniform dispersion is difficult and a transparent resin material cannot be obtained. In addition, there is a problem that the parallel light transmittance is low and haze occurs. However, it has been known for a long time that the organic neodymium compound, such as neodymium acetate, has a low compatibility with a methyl methacrylate resin, and therefore, a neodymium salt is compatible with methyl methacrylate using anhydrous stannic chloride as a solvent. , A method of casting it by heat polymerization has been proposed (Japanese Patent Publication No. 44-5,091). However, in this method, since casting is performed using stannic chloride as a solvent, not only is it expensive, but it is difficult to obtain a completely transparent resin due to clouding due to dispersed fine particles, and weather resistance is also high. It had the drawback of being low and easily devitrifying.

Accordingly, it is an object of the present invention to provide a neodymium-containing transparent resin and a method for producing the same.
Another object of the present invention is to provide a neodymium-containing transparent resin suitable as an optical resin material capable of selectively absorbing light having a wavelength other than the three primary colors, and a method for producing the same.

[0009]

[Means for Solving the Problems] These aims are (A)
(I) A monomer selected from the group consisting of an alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group and styrene, and (ii) an acrylic acid, a methacrylic acid and their neodymium salts. A copolymer comprising at least one copolymerizable unsaturated carboxylic acid or a salt thereof selected from the group and (B) a hydroxyl group-substituted or unsubstituted 6 to 21 carbon atom
A saturated or unsaturated organic carboxylic acid and at least one compound selected from the group consisting of neodymium salts thereof, wherein the content of neodymium in the transparent resin is 0.3 to 20% by weight. Of acrylic acid, methacrylic acid and their salt units, and the total number of carboxyl groups of the organic carboxylic acid and its salt occupy a ratio x to the total number of carboxyl groups of the organic carboxylic acid and its salt. The ratio of the carboxyl groups that neutralize neodymium among the groups to form a salt is y, and x and y satisfy one of the following formulas (1), (2), and (3). And a neodymium-containing transparent resin.

0.05 ≤ y ≤ (5/2) x + 0.2 0 ≤ x ≤ 0.3 (1) 0.05 ≤ y ≤- (2/5) (x-0.3) + 0.95 0.3 ≤ x ≤ 0.55 (2) 0.05 ≤ y ≤- (8/3) (x-0.55) + 0.85 0.55 ≤x ≤ 0.85 (3) These purposes also include (a) (i) an alkyl methacrylate having 1 to 4 carbon atoms in the alkyl group, and A monomer selected from the group consisting of styrene and containing the alkyl methacrylate as a main component, and (ii) at least one copolymerizable unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid and their neodymium salts. Or a monomer mixture consisting of a salt thereof and (b) a hydroxyl group-substituted or unsubstituted C6 to C21
In the method for producing a transparent resin, which comprises at least one compound selected from the group consisting of saturated or unsaturated organic carboxylic acids and neodymium salts thereof, wherein the content of neodymium is 0.3 to 20% by weight. The number of carboxyl groups of the organic carboxylic acid and its salt occupy a ratio x to the number of all carboxyl groups of the acid or methacrylic acid and its salt and the organic carboxylic acid and its salt, and A mixture in which the ratio of the carboxyl groups that neutralize neodymium to form a salt is y, and x and y satisfy any of the following formulas (1), (2) and (3), It is also achieved by a method for producing a neodymium-containing transparent resin, which is characterized by performing polymerization in the presence of a radical polymerization initiator.

0.05 ≤ y ≤ (5/2) x + 0.2 0 ≤ x ≤ 0.3 (1) 0.05 ≤ y ≤- (2/5) (x -0.3) + 0.95 0.3 ≤ x ≤ 0.55 (2) 0.05 ≤ y ≤-(8/3) (x-0.55) + 0.85 0.55 ≤ x ≤ 0.85 (3)

[0012]

The monomer mixture used for producing the copolymer in the present invention has (i) an alkyl group having 1 to 4 carbon atoms.
Of the alkylmethacrylate and styrene selected from the group consisting of the alkylmethacrylate as a main component, and (ii) acrylic acid, methacrylic acid and a neodymium salt thereof selected from the group consisting of the alkylmethacrylate as a main component. And a copolymerizable unsaturated carboxylic acid or salt thereof. The main component of the alkyl methacrylate means that the alkyl methacrylate is used more than styrene. Examples of such alkyl methacrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate and tert-butyl methacrylate, with methyl methacrylate being particularly preferred. The copolymerizable unsaturated carboxylic acid or its salt component (ii) includes acrylic acid, methacrylic acid, neodymium acrylate and neodymium methacrylate, preferably methacrylic acid and neodymium methacrylate.

Further, in the monomer component (i), a copolymerizable monomer can be used to the extent that the transparency of the resulting resin is not impaired. Examples of such a copolymerizable monomer include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate,
Hydroxyalkyl acrylates such as 2-hydroxy-3-chloropropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxy-3-
Hydroxyalkyl methacrylate such as chloropropyl methacrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, alkyl acrylate such as 2-ethylhexyl acrylate, cyclohexyl acrylate, vinyl chloride, vinyl acetate, acrylonitrile, methacrylic acid Ronitrile etc. Furthermore, a small amount, for example, 20% by weight or less of ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, 1 , 6-hexanediol dimethacrylate, 1,6-hexanediol dimethacrylate,
1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, tetramethylolmethane dimethacrylate, 1,
12-dodecanediol diacrylate, 1,12-dodecanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate and the like can also be used.

6 carbon atoms substituted or unsubstituted with a hydroxyl group
As the saturated or unsaturated organic carboxylic acid of ~ 21,
Caproic acid, n-octylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, lauric acid, myristic acid,
Aliphatic saturated carboxylic acids such as palmitic acid, stearic acid, adipic acid, sebacic acid, monoethyl adipate, and monomethyl sebacate, and aliphatic non-carboxylic acids such as oleic acid, elaidic acid, linoleic acid, linolenic acid, ricinoleic acid, and lysine elaidic acid. Alicyclic carboxylic acids such as saturated carboxylic acid, cyclohexanecarboxylic acid, naphthenic acid, benzoic acid,
Examples include phthalic acid, isophthalic acid, terephthalic acid, toluic acids, trimellitic acid, octylbenzoic acid, monooctyl phthalate, and monooctyl terephthalate.

Of these organic carboxylic acids, aliphatic carboxylic acids are preferable, and saturated aliphatic carboxylic acids and further unsubstituted saturated aliphatic carboxylic acids are most preferable. further,
Among the above organic carboxylic acids, those having 6 to 21 carbon atoms are preferable.

Among the above-mentioned organic carboxylic acids, as the unsaturated one, a non-polymerizable one is used.

The neodymium-containing transparent resin according to the present invention is mixed with a radical polymerization initiator in the form of a mixture of the above-mentioned monomers (a) and (b), such as monomers, and then added in an amount of 5 to 140.
C., preferably 50-120.degree. C. for 1-20 hours,
It is preferably obtained by reacting for 2 to 10 hours. The radical polymerization initiator is usually 0.0
It is used in an amount of 001 to 1% by weight, preferably 0.001 to 0.5% by weight. Typical examples are lauroyl peroxide, tert-butyl peroxyisopropyl carbonate, benzoyl peroxide, dicumyl peroxide, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butyl peroxyisobutyrate. , Di-tert-butyl peroxide, 2,2 '
-Azobisisobutyronitrile etc.

In the neodymium-containing transparent resin thus formed, the carboxyl group contained in the copolymer (A) of the monomer component (i) and the monomer component (ii) is It is neutralized by combining with a free carboxyl group or neodymium.

As the carboxyl group, on the other hand, the component (B)
Can also be present in the form of a free organic carboxylic acid or its neodymium salt, or in the form of a mixture of all or a part of each of these states, and further, neodymium having a valence of 3 can be present in the carboxyl of the copolymer. It is presumed that even a state in which the group and the carboxyl group of the organic carboxylic acid are bound and neutralized may exist. Therefore, the number of the carboxyl groups of the organic carboxylic acid and its salt relative to the number of all the carboxyl groups of the acrylic acid, methacrylic acid and their salt units and the organic carboxylic acid and its salt in the copolymer is When x is the ratio and y is the ratio of the carboxyl groups forming a salt by neutralizing neodymium among all the carboxyl groups, x and y are expressed by the above formulas (1), (2) and ( The range when either of 3) is satisfied is as shown in FIG. 2, and the neodymium-containing resin is transparent only when it is within this range (hatched portion). Or,
Alternatively, the neodymium content becomes extremely low, and the effect of the present invention cannot be exhibited.

In the present invention, when the transparent resin is used as an optical resin material such as a front plate of a color cathode ray tube or a coating material, 0 to 0.5% by weight, preferably 0 to 0.5% by weight of the transparent resin is preferable. 0.0001-0.5% by weight, most preferably 0.0003-0.1% by weight of 380-4
20 nm, 480-530 nm, 560-610 nm and 6
A colorant having an absorption in at least one wavelength range of 40 to 780 nm and having little or no absorption with respect to visible light in a wavelength range other than the above is blended, whereby the selective absorption by the neodymium salt. Or the selective absorption can be performed in the visible light wavelength range in which the neodymium salt has no absorption. As the colorant having such an action, for example, a dye as described below,
There are pigments or ultraviolet absorbers, which are blended in the monomer mixture and uniformly dispersed in the resin produced during the copolymerization reaction.

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

As a colorant having a main absorption in the wavelength range of 480 to 530 nm, there is Hostazol Red G.
G (Hoechst), Paliogen Red 3730 (B
ASF), Diamond Resin Red HS (manufactured by Mitsubishi Kasei Co., Ltd.), Diamond Resin Red S (manufactured by Mitsubishi Kasei Co., Ltd.), Amaplast Pink P4B (manufactured by American Aniline), Orange C-type (Hercules) Manufactured by the company) and other red dyes.

As a colorant having a main absorption in a wavelength range of 640 to 780 nm, Yuvinyl Blue 70
2 (manufactured by BASF), Oil Blue 615 (manufactured by Orient Chemical Industry Co., Ltd.), Macrolex Green 5
13 (manufactured by Bayer), Seikagen o Blue GK-1200 (manufactured by Dainichiseika Kogyo Co., Ltd.), and Sumitoncyanine Blue HB-1 (manufactured by Sumitomo Chemical Co., Ltd.).

There is no suitable colorant having a main absorption in the wavelength range of 560 to 610 nm, but the above-mentioned 3
560 to 6 of the colorants having the main absorption in the wavelength range
Those having absorption in the wavelength region of 10 nm are preferably used. Examples of such a colorant include Yuvinyl Blue 702 (manufactured by BASF).

[0025]

EXAMPLES Next, examples of synthesis of typical neodymium salts will be described.

Synthesis Example 1 Neodymium oxide 10 g, methacrylic acid 17 g and water 10
0 g was mixed, and the suspension was stirred under reflux at 60 ° C. for 3 hours, the unreacted solid was removed by filtration, and then water was evaporated under reduced pressure to concentrate to precipitate crystals. The crystals were washed with acetone and dried under reduced pressure to obtain neodymium methacrylate. The yield was 78%.

Synthesis Example 2 Neodymium oxide 40 g, octylic acid 220 g and water 22
0 g was mixed, and the suspension was stirred under reflux at 85 ° C. for 3 hours and cooled. After standing to separate into an aqueous phase and an organic phase, the organic phase was put into about 20 times the amount of acetone, and the precipitated salt was washed with acetone and dried under reduced pressure to dry neodymium octylate-hydrate. Got The yield was 92%.

Example 1 8.2 g of neodymium octylate-hydrate was dissolved in a mixed solution of 88.2 g of methyl methacrylate and 3.6 g of methacrylic acid, and 2,2'-azobisisobutyronitrile 0.0
After adding and dissolving 05 g of it as a polymerization initiator, it was poured into a cell assembled using a glass plate and a vinyl chloride resin gasket. After defoaming under reduced pressure, the cells were disassembled by polymerizing at 70 ° C for 8 hours and then at 120 ° C for 1 hour to give a thickness of 3 mm.
A resin plate of This resin plate, ASTM D1003
The total light transmittance was 82%, the haze was 1.5%, and the neodymium content was 2.0% by weight.

EXAMPLE 2 5.5 g of neodymium methacrylate was dissolved in a mixture of 88.2 g of methyl methacrylate and 6.4 g of octylic acid, and then polymerization was carried out in the same manner as in Example 1 to obtain a resin plate having a thickness of 3 mm. Got The total light transmittance of this resin plate is 81
%, Haze was 2.1%, and neodymium content was 2.0% by weight.

Example 3 10.3 g of neodymium oleate was dissolved in a mixed solution of 75.2 g of methyl methacrylate, 12.0 g of ethyl acrylate and 2.5 g of methacrylic acid, and polymerization was carried out in the same manner as in Example 1. A resin plate having a thickness of 3 mm was obtained.
The total light transmittance of this resin plate is 85%, haze is 2.5%
The neodymium content was 1.5% by weight.

Example 4 Neodymium octylate-hydrogen salt 8.2 g, Hostazol Red GG (manufactured by Hoechst) 0.0005 g, Oil Blue 615 (manufactured by Orient Chemical Industry Co., Ltd.) 0.00
08g and 2- (2'-hydroxy-3 '-, 5'-
Di-tert-butylphenyl) -5-chlorobenzotriazole 0.04 g, methyl methacrylate 88.2 g
And dissolved in a mixture of 3.6 g of methacrylic acid,
Polymerization was carried out in the same manner as in Example 1 to obtain a resin plate having a thickness of 3 mm. The resin plate had a total light transmittance of 68%, a haze of 2.3%, and a neodymium content of 2.0% by weight. The spectral transmittance of the visible part was as shown in FIG. 3 (curve D).

Example 5 Neodymium octylate-hydrate 8.2 g, Diaresin Red HS (manufactured by Mitsubishi Kasei Co., Ltd.) 0.0015 g,
Oil Blue 615 (manufactured by Orient Chemical Industry Co., Ltd.) 0.001 g and 2- (2'-hydroxy-)
0.04 g of 3 ', 5'-di-tert-butylphenyl) -chlorobenzotriazole was added to methyl methacrylate 8
After dissolving in a mixture of 8.2 g and methacrylic acid (3.6 g), polymerization was carried out in the same manner as in Example 1 to obtain a resin plate having a thickness of 3 mm. The total light transmittance of this resin plate is 64
%, Haze 3.1%, neodymium content 2.0% by weight
Met.

Example 6 10.3 g of neodymium oleate, 0.0004 g of Hostazol Red GG (manufactured by Hoechst), Oil Blue 615 (manufactured by Orient Chemical Industry Co., Ltd.) 0.0006
g and 2- (2'-hydroxy-5'-methylphenyl) benzotriazole (0.03 g) were dissolved in a mixture of methyl methacrylate (75.2 g), ethyl acrylate (12.0 g) and methacrylic acid (2.5 g). Polymerization was performed in the same manner as in 1 to obtain a resin plate having a thickness of 3 mm. The resin plate had a total light transmittance of 74%, a haze of 3.0%, and a neodymium content of 1.5% by weight.

Example 7 Neodymium stearate 27.6 g, Hostazol Red GG (manufactured by Hoechst) 0.0005 g, Oil Blue 615 (manufactured by Orient Chemical Industry Co., Ltd.) 0.000
8g and 2- (2'-hydroxy-3 ', 5'-tert
-Butylphenyl) -5-chlorobenzotriazole (0.04 g) was dissolved in a mixture of methyl methacrylate (65,2 g) and methacrylic acid (7.2 g), and the polymerization was carried out in the same manner as in Example 1 to obtain a 3 mm thick film. A resin plate was obtained. The resin plate has a total light transmittance of 63% and a haze of 5%.
The neodymium content was 4% by weight.

EXAMPLE 8 Neodymium octylate-hydrate 28 g, octyl acid 14 g,
12 g of neodymium methacrylate, 13 g of methacrylic acid, 23 g of methyl methacrylate and 10 g of styrene were mixed to form a uniform solution, which was polymerized in the same manner as in Example 1 to obtain a resin plate having a thickness of 3 mm. The resin plate has a total light transmittance of 70%, a haze of 3.2%, and a neodymium content of 11.0.
% By weight.

Example 9 4.9 g of neodymium octylate-hydrate, 6.9 octyl acid
g, neodymium methacrylate 7.8 g, methacrylic acid 1.
3 g, 76.6 g of methyl methacrylate and 8.5 g of styrene were mixed to form a uniform solution, which was polymerized in the same manner as in Example 1 to obtain a resin plate having a thickness of 3 mm. The resin plate had a total light transmittance of 80%, a haze of 1.8% and a neodymium content of 4.0% by weight.

[0037]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, (A) (i) an alkyl group having 1 to 4 carbon atoms, which is selected from the group consisting of alkyl methacrylate and styrene, and whose main component is the alkyl methacrylate. And (ii) at least one copolymerizable unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid and their neodymium salts, or a copolymer thereof, and (B) substituted with a hydroxyl group Or unsubstituted 6 to 21 carbon atoms
A saturated or unsaturated organic carboxylic acid and at least one compound selected from the group consisting of neodymium salts thereof, wherein the content of neodymium in the transparent resin is 0.3 to 20% by weight. Of acrylic acid, methacrylic acid and their salt units, and the total number of carboxyl groups of the organic carboxylic acid and its salt relative to the number of carboxyl groups of the organic carboxylic acid and its salt
x and the neodymium-containing transparent resin in which the ratio y of the carboxyl groups forming a salt by neutralizing neodymium among the total carboxyl groups is within a specific range, total light transmittance, parallel light transmittance Has extremely high transparency and very little haze, and since it is not necessary to use a solvent such as stannic chloride, the weather resistance is good. Therefore, even though it is transparent, it can selectively absorb light of wavelengths other than the three primary colors due to the action of neodymium contained in it, so that it can be used as an optical resin material for the front plate of a color cathode ray tube, etc. Can be prevented. Further, since the resin according to the present invention is an organic material, a coloring agent that has absorption in a wavelength range other than the wavelength range of the three primary colors and has little or no absorption with respect to visible light in the wavelength range of the three primary colors is optional. Since it can be blended with, it can further enhance selective absorption.

Further, the present invention relates to (a) (i) a monomer having an alkyl group having 1 to 4 carbon atoms and an alkyl methacrylate selected from the group consisting of styrene and (ii) A monomer mixture consisting of at least one copolymerizable unsaturated carboxylic acid or salt thereof selected from the group consisting of acrylic acid, methacrylic acid and their neodymium salts, and (b) a carbon atom substituted or unsubstituted by a hydroxyl group Number 6-21
In the method for producing a transparent resin, which comprises at least one compound selected from the group consisting of saturated or unsaturated organic carboxylic acids and neodymium salts thereof, wherein the content of neodymium is 0.3 to 20% by weight, Acid Methacrylic acid and salts thereof and the number of all carboxyl groups of the organic carboxylic acid and salts thereof account for the ratio x of the number of carboxyl groups of the organic carboxylic acid and salts thereof, and neodymium of all the carboxyl groups The ratio of the carboxyl groups forming a salt by neutralizing
Since it is a method for producing a neodymium-containing transparent resin by polymerizing a mixture in which x and y fall within a specific range, cast polymerization can be performed, and the production cost can be made extremely low. The obtained resin has various advantages as described above.

[Brief description of drawings]

FIG. 1 is a graph showing an emission spectrum of a phosphor in a color cathode ray tube.

FIG. 2 is a graph showing the optimum range in the relationship between the carboxyl groups of the resin according to the present invention and the neutralization with neodymium.

FIG. 3 is a graph showing the light transmittance of the resin according to the present invention in each wavelength range.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G02B 1/04 7132-2K 5/22 7348-2K

Claims (7)

[Claims] 1. A carbon number of (A) (i) alkyl group is 1 to
4. A monomer selected from the group consisting of alkyl methacrylate and styrene of 4 above, which contains the alkyl methacrylate as a main component, and (ii) at least one copolymer selected from the group consisting of acrylic acid, methacrylic acid and their neodymium salts. Of unsaturated unsaturated carboxylic acid or salt thereof and (B) hydroxyl group-substituted or unsubstituted 6 to 21 carbon atoms
A saturated or unsaturated organic carboxylic acid and at least one compound selected from the group consisting of neodymium salts thereof, wherein the content of neodymium in the transparent resin is 0.3 to 20% by weight. Of acrylic acid, methacrylic acid and their salt units, and the total number of carboxyl groups of the organic carboxylic acid and its salt occupy a ratio x to the total number of carboxyl groups of the organic carboxylic acid and its salt. The ratio of the carboxyl groups that neutralize neodymium among the groups to form a salt is y, and x and y satisfy one of the following formulas (1), (2), and (3). A neodymium-containing transparent resin characterized in that 0.05 ≤ y ≤ (5/2) x + 0.2 0 ≤ x ≤ 0.3 (1) 0.05 ≤ y ≤- (2/5) (x-0.3) + 0.95 0.3 ≤ x ≤ 0.55 (2) 0.05 ≤ y ≤- (8/3) (x − 0.55) + 0.85 0.55 ≤ x ≤ 0.85 (3) 2. The neodymium-containing transparent resin according to claim 1, wherein the content of neodymium is 0.5 to 15% by weight. 3. The neodymium-containing transparent resin according to claim 1, wherein the organic carboxylic acid is a saturated aliphatic carboxylic acid. (A) (i) an alkyl group having 1 to 10 carbon atoms
4 at least one monomer selected from the group consisting of alkyl methacrylate and styrene, and (ii) at least one copolymerizable unsaturated bond selected from the group consisting of acrylic acid, methacrylic acid and their neodymium salts. A monomer mixture comprising a carboxylic acid or a salt thereof and (b) a hydroxyl group-substituted or unsubstituted 6 to 21 carbon atom
In the method for producing a transparent resin, which comprises at least one compound selected from the group consisting of saturated or unsaturated organic carboxylic acids and neodymium salts thereof, and which has a neodymium content of 0.3 to 20% by weight, the acrylic acid The ratio of the number of carboxyl groups of the organic carboxylic acid and the salt thereof to the total number of carboxyl groups of the methacrylic acid and the salt thereof and the organic carboxylic acid and the salt thereof accounts for x, and neodymium of the total carboxyl groups is The proportion of carboxyl groups that neutralize to form a salt is y, and x
A method for producing a neodymium-containing transparent resin, characterized in that a mixture in which y and y satisfy any of the following formulas (1), (2) and (3) is polymerized in the presence of a radical polymerization initiator. 0.05 ≤ y ≤ (5/2) x + 0.2 0 ≤ x ≤ 0.3 (1) 0.05 ≤ y ≤- (2/5) (x-0.3) + 0.95 0.3 ≤ x ≤ 0.55 (2) 0.05 ≤ y ≤- (8/3) (x − 0.55) + 0.85 0.55 ≤ x ≤ 0.85 (3) 5. The method for producing a neodymium-containing transparent resin according to claim 4, wherein the content of neodymium is 0.5 to 15% by weight. 6. The method for producing a neodymium-containing transparent resin according to claim 4, wherein the neodymium salt of an organic carboxylic acid is a neodymium salt of a saturated aliphatic carboxylic acid. 7. The method for producing a neodymium-containing transparent resin according to claim 4, wherein the polymerization is performed at a temperature of 5 to 140 ° C.