JPH0564179B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides lanthanum, cerium, praseodymium,
Regarding a resin composition containing a compound of a rare earth element selected from the group consisting of dysprosium, thulium, ytterbium, and lutetium, more specifically, it has properties such as selective absorption of radiation and electromagnetic waves derived from rare earth elements, luminescence, etc. The present invention relates to a rare earth element-containing resin composition having various physical properties and a method for producing the same.

[Conventional technology]

Conventionally, many oil-soluble dyes such as azo-based, diazo-based, and anthraquinone-based dyes have been known as additives for synthetic resins that selectively absorb light of specific wavelengths in the visible region. Although these have the advantage of being able to be used by dissolving them in resin raw materials,
Looking at the wavelength dependence of absorption, it appears that it absorbs over a wide wavelength range. In other words, the absorption is broad, and for this reason, for example, if you want to sufficiently absorb light around a wavelength of 450nm, you will need to absorb light from a wavelength of 350nm to 500nm.
This is a drawback for some selective absorption applications because it absorbs a wide range of light rays. Additionally, these dyes generally have poor weather resistance, and in some cases their absorption weakens or disappears after being exposed to sunlight for about a week or at temperatures near 180°C.

On the other hand, for the absorption of X-rays and γ-rays, which are electromagnetic waves with shorter wavelengths than visible light, it is known that synthetic resins that are transparent in the visible region can be obtained by adding lead compounds, bismuth compounds, etc. to synthetic resins. ing. Looking at the mass absorption coefficient (cm ² /g) as a numerical value that indicates the ability to absorb photons, in the energy region of X-rays and γ-rays, it is The mass absorption coefficient value changes discontinuously. That is, when comparing the mass absorption coefficients of lead and cerium, the L ₃ absorption edge of lead (13.040 keV) is lower than the L ₃ absorption edge of cerium (5.723 keV), and the L 3 absorption coefficient of lead is lower than the K absorption edge of cerium (40.440 keV). It is known that between the ₃ -K absorption edge (74.960 keV), the mass absorption coefficient of cerium is several times larger than that of lead.

The same applies to elements from thallium, which has an atomic number of 81, to palladium, which has an atomic number of 46. Therefore, when considering the limited energy range of photons, it is understood that each element has its own unique ability to absorb photons, which is greater than that of lead.

[Problem to be solved by the invention]

The present inventor discovered that although general organic synthetic resins do not usually absorb electromagnetic waves in the near-infrared, visible, ultraviolet, X-ray, and γ-ray regions, rare earth elements By taking advantage of the fact that each of these compounds exhibits a unique sharp specific absorption, we have discovered a resin composition that has unprecedented weather resistance and selective absorption performance for electromagnetic waves.

[Means to solve the problem]

The rare earth element-containing resin composition of the present invention includes a resin containing methacrylic acid ester as a main component, lanthanum, cerium, praseodymium, dysprosium,
It is characterized by containing at least one rare earth element compound selected from the group consisting of oxides, hydroxides, complex compounds, and salts with inorganic acids of rare earth elements consisting of thulium, ytterbium, and lutetium. , has excellent selective absorption of radiation and electromagnetic radiation.

The weight concentration of the rare earth element compound in the resin composition of the present invention is 0.001 as the rare earth element relative to the entire composition.
% to 35%, and if it is less than 0.001%, the effect derived from the rare earth element will be small, and if it exceeds 35%, it will impair the mechanical properties of the resin composition, which is not preferable.

In addition, rare earth element compounds include rare earth element oxides,
Rare earth hydroxides, rare earth salts of inorganic acids (rare earth carbon, rare earth phosphate, rare earth nitrate, etc.) and complex compounds (tris (acetylacetonato) rare earth elements, tris (benzoylacetonate)) rare earth elements, etc.).

These rare earth element compounds cannot be determined unconditionally depending on the use and manufacturing method, but for example, they may be dispersed or dissolved in a thermoplastic resin that is transparent in the visible light region, or they may be dispersed or dissolved in a thermoplastic resin that is transparent in the visible light region, or they may be a polymerizable monomer having α,β-ethylenically unsaturated bonds. A rare earth element can be contained in a resin base material by a method of dispersing or dissolving a rare earth element compound in a resin forming raw material selected from monomers, monomer mixtures, or partial polymers thereof, and polymerizing the mixture. . In particular, in order to obtain a transparent resin composition without scattering, (a) a resin forming raw material selected from monomers containing methacrylic acid ester as a main component or partial polymers thereof (b) lanthanum, cerium, praseodymium, Oxides and hydroxides of rare earth elements consisting of dysprosium, thulium, ytterbium and lutetium,
At least one rare earth element compound selected from the group consisting of complex compounds and salts with inorganic acids (c) General formula R ₁ -COOH (1) showing solubility in the above components (a) and (b) (In the formula, R ₁ is a saturated or unsaturated hydrocarbon residue having 1 to 20 carbon atoms); R ₂ −OCO−R ₃ −COOH (2) (In the formula, R ₂ is hydrogen or a carbon number 1 ~9 hydrocarbon residues, _R3 is a saturated or unsaturated hydrocarbon residue having 1 to 4 carbon atoms); _CH2 =C( _R4 )-COO-(- _A1- O- ) _o H (3) (wherein, R ₄ is hydrogen or a methyl group, A ₁ is an alkylene group having 2 to 6 carbon atoms, and n is 0 or an integer of 1 to 10); CH ₂ = C( _R5 )-COO- _R6 -OH (4) (in the formula, _R5 is hydrogen or a methyl group, and _R6 is an alkylene group having 2 to 6 carbon atoms); _R7 -OH (5 ) (in the formula, R ₇ is a saturated or unsaturated hydrocarbon residue having 3 to 10 carbon atoms); and R ₈ -(-A ₂ -O-) _n H (6) (in the formula, R ₈ is a hydroxyl group or a saturated or unsaturated hydrocarbon residue having 1 to 10 carbon atoms, A ₂ is an alkylene group having 2 to 4 carbon atoms, and m is an integer of 1 to 10). A method for producing a rare earth element-containing resin composition is suitable, which comprises polymerizing a mixture of at least one solvent and (d) a polymerization initiator in a mold.

Examples of methacrylate esters include alkyl methacrylates such as methyl methacrylate and ethyl methacrylate, cyclohexyl methacrylate, tetrahydrofuryl methacrylate, benzyl methacrylate, phenyl methacrylate, allyl methacrylate, methallyl methacrylate, β-naphthyl methacrylate, β-Aminoethyl methacrylate, 2-methoxyethyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate,
Examples include neopentyl glycol dimethacrylate, pentaerythritol tetramethacrylate, trimethylolpropane trimethacrylate, and halogen-substituted methacrylates thereof.

The solvents represented by the above general formulas (1), (2), (3), (4), (5) and (6) are cosolvents for uniformly dissolving the rare earth element compound in the resin forming raw material. Specifically, unsaturated carboxylic acids such as methacrylic acid and acrylic acid, propionic acid, isobutyric acid, n-butyric acid,
Saturated or unsaturated fatty acids such as caproic acid, caprylic acid, capric acid, 2-ethylhexanoic acid, stearic acid, naphthenic acid, unsaturated alcohols such as α-hydroxyethyl acrylate, α-hydroxyethyl methacrylate, propyl alcohol, cyclohexyl Examples include saturated aliphatic alcohols such as alcohol, and polyhydric alcohols such as ethylene glycol, diethylene glycol, and propylene glycol.

Among these solvents, methacrylic acid, acrylic acid, α-hydroxyethyl methacrylate, α-
Monomers copolymerizable with methyl methacrylate, such as hydroxyethyl acrylate, are preferred.
These solvents can be used alone or in combination of two or more. The amount of the above solvent used is
Although it cannot be determined unconditionally depending on the type and amount of the rare earth compound used, it is 40% by weight or less, preferably 10% by weight or less. If the amount used exceeds 40% by weight, the mechanical and thermal properties of the resulting fat composition will be deteriorated, which is not preferable.

Examples of polymerization initiators used in the above polymerization include peroxides such as benzoyl peroxide and lauroyl peroxide, α,α'-azobisisobutyronitrile, and α,α'-azobis(2,4-dimethylvaleroxide). Known radical initiators such as azobis-based initiators such as nitrile) and α,α'-azobis(2,4-dimethyl-4-methoxyvaleronitrile) can be used. These polymerization initiators can be used alone or in combination of two or more, and the amount used is 0.001 to 0.1 part by weight per 100 parts by weight of the resin raw material.

The polymerization method used to obtain the resin composition of the present invention is not particularly limited, but cast polymerization is a preferred polymerization method. In the case of this cast polymerization, the mixture prepared from the aforementioned components (a), (b), (c) and (d) is placed in cells and gaskets made of, for example, inorganic glass, stainless steel, nickel chrome or aluminum. Pour into the configured mold and allow to polymerize. For special purposes,
Radiation polymerization can also be carried out at a low temperature below room temperature. Usually 0.3 to 15 at 45 to 95℃
10 minutes to 5 hours at 100 to 145℃
Polymerization is completed over time.

In the present invention, if necessary, an ultraviolet absorber,
A mold release agent, a heat stabilizer, a light absorbing agent for absorbing light of other wavelengths, a light diffusing agent, a radiation shielding material, etc. can also be added.

The rare earth element-containing resin composition of the present invention having the above-mentioned structure has the ability to increase the refractive index of the base resin, increase X-ray, It can be used for filters, lenses, lighting covers, video screens, radiation protection filters, scintillators, luminous bodies, etc. by imparting radiation absorption ability for gamma rays and thermal neutron radiation absorption ability. It is not limited.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following.

Example 1 3 g of lanthanum nitrate was dissolved in a mixed solution of 17 g of 2-hydroxyethyl methacrylate and 2 g of propylene glycol, and 78 g of methyl methacrylate was added to this solution and mixed by stirring. This mixture was a colorless and transparent liquid.

Next, add 0.04g of α as a polymerization catalyst to this mixture,
After adding and dissolving α'-azobis(2,4-dimethylvaleronitrile) and 0.005 g of dioctyl sulfosuccinate sodium salt as a mold release agent, deaeration is performed, and the thickness of the product is adjusted to 2 mm in advance. This mold was immersed in hot water at 65°C for 180 minutes, and then placed in an air bath at 110°C for 120 minutes to complete polymerization. The resin plate taken out from the mold was colorless and transparent.

Example 2 1.5 g of tris(acetylacetonato)lanthanum was dissolved in 8.5 g of methacrylic acid, and this solution was added to 90 g of methyl methacrylate and mixed by stirring.

The same polymerization catalyst and mold release agent as in Example 1 were added to this mixed solution, and the same mold polymerization as in Example 1 was performed.
After completion of polymerization, the resin plate peeled from the mold was a colorless transparent plate.

Example 3 Partial polymer of methyl methacrylate (polymerization rate 18
%), 0.04 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) as a polymerization catalyst, 0.005 parts by weight of dioctyl sulfocinate sodium salt as a mold release agent, and an average particle size of 2 μm. After adding and mixing 1.0 parts by weight of cerium carbonate and degassing, it was poured into a mold made of tempered glass and a soft vinyl chloride gasket, which had been set so that the thickness of the product would be 3 mm, and heated with 70°C water. The resin board was then immersed in the water for 60 minutes, and then placed in an air bath at 130°C for 80 minutes to complete polymerization. The resin plate was a white diffuser plate.

Example 4 1.0 parts by weight of lanthanum phosphate having an average particle size of 0.5 μm was added to 100 parts by weight of methacrylic resin (Mitsubishi Rayon Co., Ltd., Acrypet (registered trademark) VH), and the mixture was thoroughly mixed in a tumbler to homogenize. Thereafter, it was extruded from an extruder in a conventional manner to obtain a sheet with a thickness of 3 mm.

Example 5 3 g of praseodymium nitrate was mixed with 17 g of 2-hydroxyethyl methacrylate and propylene glycol.
78 g of methyl methacrylate was added to this solution and mixed by stirring. This mixture was a yellow-green transparent liquid.

Next, add 0.04g of α as a polymerization catalyst to this mixture,
After adding and dissolving α'-azobis(2,4-dimethylvaleronitrile) and 0.005 g of dioctyl sulfosuccinate sodium salt as a mold release agent, deaeration is performed, and the thickness of the product is adjusted to 3 mm in advance. This mold was immersed in hot water at 65°C for 180 minutes, and then placed in an air bath at 110°C for 120 minutes to complete polymerization. The resin plate taken out from the mold was transparent and pale yellow-green in color.

Example 6 Tris(acetylacetonato)praseodymium
1.5 g was dissolved in 8.5 g of methacrylic acid, and this solution was added to 90 g of methyl methacrylate and mixed by stirring.

The same polymerization catalyst and mold release agent as in Example 1 were added to this mixed solution, and the same mold polymerization as in Example 1 was performed.
After the polymerization was completed, the resin plate peeled from the mold was a pale yellow-green transparent plate.

Example 7 Partial polymer of methyl methacrylate (polymerization rate 18
%), 0.04 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) as a polymerization catalyst, 0.005 parts by weight of dioctyl sulfocinate sodium salt as a mold release agent, and an average particle size of 2 μm. After adding and mixing 1.0 parts by weight of praseodymium carbonate and degassing, it was poured into a mold made of tempered glass and a soft vinyl chloride gasket, which had been set so that the thickness of the product would be 3 mm, and heated with 70°C water. 60 inside
The resin plate was then immersed for 80 minutes in an air bath at 130°C to complete polymerization. The resin plate was a pale yellow diffuser plate.

Example 8 1.0 part by weight of praseodymium phosphate having an average particle size of 0.5 μm was added to 100 parts by weight of methacrylic resin (Mitsubishi Rayon Co., Ltd., Acrypet (registered trademark) VH), and the mixture was thoroughly mixed in a tumbler to homogenize. Thereafter, it was extruded from an extruder in a conventional manner to obtain a sheet with a thickness of 3 mm.

Example 9 Tris(acetylacetonato)ytterbium
1.5 g was dissolved in 8.5 g of methacrylic acid, and this solution was added to 90 g of methyl methacrylate and mixed by stirring.

The same polymerization catalyst and mold release agent as in Example 1 were added to this mixed solution, and the same mold polymerization as in Example 1 was performed.
After completion of polymerization, the resin plate peeled from the mold was a colorless transparent plate.

Example 10 Partial polymer of methyl methacrylate (polymerization rate 18
%), 0.04 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) as a polymerization catalyst, 0.005 parts by weight of dioctyl sulfocinate sodium salt as a mold release agent, and an average particle size of 2 μm. After adding and mixing 1.0 parts by weight of lutetium carbonate and degassing, it was poured into a mold made of tempered glass and a soft vinyl chloride gasket, which had been set so that the thickness of the product would be 3 mm, and heated with 70°C water. The resin board was then immersed in the water for 60 minutes, and then placed in an air bath at 130°C for 80 minutes to complete polymerization. The resin plate was a white diffuser plate.

Comparative example Spiron Yellow GROH Special (Hodogaya Chemical Co. product) 0.002g and Amaplast Yellow
0.005 g of AGB (product of American Aniline Co.) was dissolved in 100 g of methyl methacrylate, and cast polymerization was carried out under the same polymerization conditions as in Example 1. The resulting resin plates were pale yellow and transparent. The resin plates obtained in Examples and Comparative Examples both exhibited absorption at a wavelength of around 450 nm. However, when these were exposed outdoors for one month in summer in Otake City, Hiroshima Prefecture, the absorption intensity remained unchanged in the Examples, but the color almost disappeared in the Comparative Examples.

Claims (1)

[Scope of Claims] 1 A resin containing methacrylic acid ester as a main component, oxides, hydroxides, complex compounds, and inorganic rare earth elements consisting of lanthanum, cerium, praseodymium, dysprosium, thulium, ytterbium, and lutetium. A rare earth element-containing resin composition having excellent selective absorption of radiation and electromagnetic radiation, characterized in that it contains at least one rare earth element compound selected from the group consisting of salts with acids. 2. The rare earth element-containing resin composition according to claim 1, wherein the amount of the rare earth element compound is 0.001 to 35% by weight as a rare earth element based on the weight of the composition. 3 (a) Resin-forming raw material selected from monomers containing methacrylic acid ester as a main component or partial polymers thereof; (b) A diluted resin consisting of lanthanum, cerium, praseodymium, dysprosium, thulium, ytterbium, and lutetium. Earth element oxides, hydroxides,
At least one rare earth element compound selected from the group consisting of complex compounds and salts with inorganic acids, (c) General formula R ₁ −COOH (formula (wherein, R ₁ is a saturated or unsaturated hydrocarbon residue having 1 to 20 carbon atoms); R ₂ -OCO-R ₃ -COOH (wherein, R ₂ is hydrogen or a hydrocarbon residue having 1 to 9 carbon atoms); ( _R3 is a saturated or unsaturated hydrocarbon residue having 1 to 4 carbon atoms); _CH2 =C( _R4 )-COO-(- _A1 -O-) _o H (Formula (wherein, R ₄ is hydrogen or a methyl group, A ₁ is an alkylene group having 2 to 6 carbon atoms, and n is an integer of 0 or 1 to 10); CH ₂ =C(R ₅ )-COO- R ₆ -OH (in the formula, R ₅ is hydrogen or a methyl group, R ₆ is an alkylene group having 2 to 6 carbon atoms); R ₇ -OH (in the formula, R ₇ is a carbon number 3 to 10 alkylene group); and R ₈ -(-A ₂ -O-) _n H (wherein R ₈ is a hydroxyl group or a saturated or unsaturated hydrocarbon residue having 1 to 10 carbon atoms); ( _A2 is an alkylene group having 2 to 4 carbon atoms, and m is an integer of 1 to 10); and (d) a mixture consisting of a polymerization initiator. 1. A method for producing a rare earth element-containing resin composition having excellent selective absorption of radiation and electromagnetic radiation, the method comprising polymerizing the composition in a mold.