JPH09314761A - Light shielding plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a light shielding plate excellent in resistance to discoloration by laminating an ultraviolet absorption layer comprising a resin composition having ultraviolet absorbing power in order to suppress discoloration of a coloring agent on a surface of a colored transparent plate comprising a material having transparecy and a coloring agent. SOLUTION: In a light shielding plate 10, an ultraviolet absorption layer 1 comprising a resin composition having ultraviolet absorbing power is laminated on a surface of a colored transparent plate 2 comprising a material having transparency and a coloring agent. A resin composition in which an ultraviolet absorbing agent is added to and mixed with a resin material, or a resin composition in which monomeric compositions containing a polymerizable unsaturated monomer having ultraviolet absorbing power are polymerized, or a mixture of these resin compositions, is used as the resin composition having the ultraviolet absorbing power. Accordingly, the light shielding plate 10 excellent in resistance to discoloration can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding plate obtained by blending a transparent material such as plastic or glass with a coloring agent. More specifically, the present invention relates to a light-shielding plate which has excellent resistance to discoloration and is suitable as a lid for covering a biological treatment tank.

[0002]

2. Description of the Related Art Conventionally, a light shielding plate in which a coloring material is mixed with a transparent material such as plastic or glass has been used for the purpose of blocking light of a specific wavelength. For example, a green translucent light-shielding plate containing a coloring agent in plastic is used as a lid for covering biological treatment tanks such as biological contact oxidation ponds and biological filtration ponds that utilize microorganisms installed in advanced water treatment facilities. .

The reason why the light-transmitting green light shielding plate is used as the lid of the biological treatment tank is as follows. In the biological treatment tank, it is necessary to suppress the photosynthesis of green algae in order to suppress the generation of green algae that reduces the treatment efficiency. However, if a plate that completely blocks light is used as a lid for covering the biological treatment tank, the activity of microorganisms is weakened, and the function of biological treatment is greatly impaired.

Therefore, by blocking only the light of the wavelength absorbed by the chlorophyll of the green algae by using the light shielding plate, it is possible to prevent the photosynthesis of the green algae and prevent the functional deterioration of the biological treatment. As shown in Fig. 2, chlorophyll absorbs light with a wavelength of 450 nm or less and light with a wavelength of 600 nm or more to perform photosynthesis. Therefore, in order to block only the light in these regions, the green translucent light is transmitted. A light shielding plate is most suitable.

As a green light-transmitting light-shielding plate, for example, a light-shielding plate formed by mixing a thermoplastic resin such as polycarbonate with a green pigment in Japanese Patent Publication No. 7-73703 and Japanese Patent Publication No. 6-198293. Is disclosed.

[0006]

However, in the above-mentioned conventional light-shielding plate, the colorant may be discolored by ultraviolet rays when exposed to sunlight for a long period of time outdoors. That is, the conventional light-shielding plate described above has a problem that it is inferior in discoloration resistance. Therefore, when the conventional light-shielding plate is used as a lid of a biological treatment tank, the generation of green algae may not be sufficiently suppressed due to discoloration, or the biological treatment function may deteriorate. Therefore, there is a demand for a light-shielding plate having excellent resistance to discoloration.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a light-shielding plate having excellent resistance to discoloration.

[0008]

Means for Solving the Problems The inventors of the present application have conducted extensive studies on the light-shielding plate in order to achieve the above-mentioned object, and as a result, have found that the ultraviolet-absorbing ability of the colored transparent plate composed of a transparent material and a coloring agent is improved. It was found that a light-shielding plate excellent in discoloration resistance can be obtained by laminating an ultraviolet absorbing layer made of a resin composition having the above on the surface of the colored transparent plate, and completed the present invention.

That is, in order to solve the above-mentioned problems, the light-shielding plate of the present invention is an ultraviolet ray for suppressing the discoloration of the above coloring agent with respect to the colored transparent plate made of a transparent material and the coloring agent. An ultraviolet absorbing layer made of a resin composition having absorbing ability is laminated on the surface of the colored transparent plate.

According to the above constitution, since the ultraviolet absorbing layer made of the resin composition having the ultraviolet absorbing ability is laminated on the surface of the colored transparent plate, the coloring agent is protected from the ultraviolet rays,
Discoloration of the colorant can be suppressed. This makes it possible to provide a light-shielding plate having excellent resistance to discoloration.

Hereinafter, the present invention will be described in detail. As shown in FIG. 1, a light-shielding plate 10 according to the present invention is a resin composition having an ultraviolet absorbing ability (hereinafter, an ultraviolet absorbing resin composition) with respect to a colored transparent plate 2 composed of a transparent material and a colorant. The ultraviolet absorbing layer 1 composed of a colored transparent plate 2
It is laminated on the surface.

The above ultraviolet absorbing resin composition is a resin composition (A) prepared by adding an ultraviolet absorbing agent to a resin material and mixing it; a monomer composition containing a polymerizable unsaturated monomer having an ultraviolet absorbing ability. A resin composition (B) obtained by polymerizing a substance; a mixture of these can be used.

First, the resin composition (A) will be described. Examples of the ultraviolet absorber used for the resin composition (A) include
Examples thereof include a benzophenone-based UV absorber, a benzotriazole-based UV absorber, a triazine-based UV absorber, a cyanoacrylate-based UV absorber, an oxalic acid anilide-based UV absorber, and a salicylate-based UV absorber. Among these exemplified UV absorbers, the benzotriazole-based UV absorber has an absorption spectrum close to that in the visible region, and is therefore preferable for exposure to natural light.

Further, as the benzotriazole type ultraviolet absorber, an ultraviolet absorbing polymer obtained by polymerizing a monomer composition containing a (meth) acrylic acid ester having a benzotriazole type skeleton is preferable. Here,
The “benzotriazole skeleton” refers to a structure in which a phenol ring is bonded to the 2-position nitrogen atom of the benzotriazole ring.

The above-mentioned UV absorbing polymer is represented by the general formula (1)

[0016]

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(In the formula, R ¹ is a hydrogen atom or a carbon number of 1 to
8 represents a hydrocarbon group, R ² represents a linear or branched alkylene group having 1 to 6 carbon atoms, R ³ represents a hydrogen atom or a methyl group, X represents a hydrogen atom or a halogen group. Represents a hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group) and / or a general formula (2)

[0018]

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(Wherein R ⁴ represents a linear or branched alkylene group having 2 to 3 carbon atoms, and R ⁵ represents a hydrogen atom or a methyl group). An ultraviolet absorbing polymer obtained by polymerizing a monomer composition (a) essentially containing a monomer is preferable.

The above-mentioned monomer composition (a) further has the general formula (3)

[0021]

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(In the formula, R ⁶ represents a hydrogen atom or a cyano group, R ⁷ and R ⁸ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and R ⁹ represents a hydrogen atom or a carbon atom. Represents a hydrocarbon group of the number 1 to 18, Y represents an oxygen atom or an imino group) and / or a UV stable monomer represented by the general formula (4)

[0023]

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(Wherein R ⁶ represents a hydrogen atom or a cyano group, R ⁷ and R ⁸ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and Y represents an oxygen atom or an imino group. It is preferable that the UV-stable monomer represented by

Furthermore, the monomer composition (a) may contain a monomer other than the above-mentioned monomers (hereinafter referred to as other monomer). Other monomers include cycloalkyl esters of unsaturated monocarboxylic acids (provided that
(A cycloalkyl group may have a substituent) is particularly preferable. Specific examples of the above-mentioned cycloalkyl ester of unsaturated monocarboxylic acid (hereinafter referred to as cycloalkyl group-containing monomer) include cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate; methylcyclohexyl. Examples thereof include cycloalkyl (meth) acrylates having a substituent such as (meth) acrylate and t-butylcyclohexyl (meth) acrylate, but are not particularly limited. Only one kind of these cycloalkyl group-containing monomers may be used, or two or more kinds thereof may be appropriately mixed and used.

As the other monomer, other than the above compounds, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate,
Caprolactone-modified hydroxy (meth) acrylate (for example, trade name “Placcel FM”: manufactured by Daicel Chemical Industries, Ltd.), a polyesterdiol mono (meth) obtained by the reaction of phthalic acid and propylene glycol.
(Meth) acrylic acid ester-based monomer having a hydroxyl group such as acrylate; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate , Isobutyl (meth) acrylate,
(meth) acrylic acid alkyl ester such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; epoxy group-containing unsaturated monomer such as glycidyl (meth) acrylate Polymer; Nitrogen-containing unsaturated monomers such as (meth) acrylamide, N, N'-dimethylaminoethyl (meth) acrylate, vinylpyridine, vinylimidazole; Halogen-containing unsaturated monomers such as vinyl chloride and vinylidene chloride Styrene, α-methylstyrene,
Examples thereof include aromatic unsaturated monomers such as vinyltoluene; vinyl esters such as vinyl acetate; vinyl ethers; unsaturated nitrile compounds such as (meth) acrylonitrile.

Furthermore, a polymerizable unsaturated monomer containing an acidic functional group can be used as the other monomer. Examples of the polymerizable unsaturated monomer containing an acidic functional group include a carboxyl group-containing unsaturated monomer such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and maleic anhydride; vinyl sulfonic acid. Sulfonic acid group-containing unsaturated monomers such as styrene sulfonic acid and sulfoethyl (meth) acrylate; 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxy-2-chloropropyl acid phosphate, 2- Examples thereof include acidic phosphoric acid ester-based monomers such as methacryloyloxyethyl phenyl phosphoric acid. Only one kind of these other monomers may be used, or two or more kinds thereof may be appropriately mixed and used.

In the monomer composition (a), when the ultraviolet absorbing monomer represented by the general formula (2) is used, long-term weather resistance may be deteriorated. That is, in this case, when the ultraviolet absorbing polymer (a) is exposed to ultraviolet rays for a long period of time, it may be colored.

The ultraviolet absorbing monomer represented by the general formula (1) according to the present invention (hereinafter referred to as the ultraviolet absorbing monomer (1)) is a substituent represented by R ₁ in the formula. Is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ₂
The substituent represented by is composed of a linear or branched alkylene group having 1 to 6 carbon atoms, the substituent represented by R ₃ is composed of a hydrogen atom or a methyl group, and the substituent represented by X is substituted. A benzotriazole group whose group is a hydrogen atom, a halogen group, a hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group.

Specific examples of the UV absorbing monomer (1) include 2- [2'-hydroxy-5 '-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2-
[2'-Hydroxy-5 '-(methacryloyloxypropyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyhexyl) phenyl] -2H-benzotriazole, 2- [2 '-Hydroxy-3'-
t-Butyl-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-
t-Butyl-3 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-
(Methacryloyloxyethyl) phenyl] -5-chloro
-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-methoxy-2
H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyethyl) phenyl ] -5-t-Butyl-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazole and the like, but not limited to Not a thing. One of these ultraviolet absorbing monomers (1) may be used alone, or two or more thereof may be appropriately mixed and used.

The ultraviolet absorbing monomer represented by the general formula (2) according to the present invention (hereinafter referred to as the ultraviolet absorbing monomer (2)) is a substituent represented by R ₄ in the formula. There is composed of straight or branched chain alkylene group having 2 to 3 carbon atoms, substituent represented by R ₅ is benzotriazoles composed of a hydrogen atom or a methyl group.

Specific examples of the ultraviolet absorbing monomer (2) include 2- [2'-hydroxy-5 '-(β
-Methacryloyloxyethoxy) -3'-t-butylphenyl] -4-t-butyl-2H-benzotriazole, but not limited thereto. As the ultraviolet absorbing monomer (2), only one kind may be used, or two or more kinds may be appropriately mixed and used.

The ultraviolet stable monomer represented by the general formula (3) according to the present invention (hereinafter referred to as the ultraviolet stable monomer (3)) is a substituent represented by R ₆ in the formula. Is a hydrogen atom or a cyano group, and the substituents represented by R ₇ and R ₈ are each independently a hydrogen atom or a carbon number of 1 to 2.
And a substituent represented by R ₉ is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and a substituent represented by Y is an oxygen atom or an imino group. Is. The substituents represented by R ₇ and R ₈ are, for example, a hydrogen atom, a methyl group or an ethyl group, and the substituent represented by R ₉ is, for example, a methyl group. Group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and the like.

Specific examples of the UV-stable monomer (3) include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine and 4- (meth) acryloyl. Amino-2,2,6,6-tetramethylpiperidine, 4-
(Meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6
-Pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-
Examples thereof include crotonoyloxy-2,2,6,6-tetramethylpiperidine and 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, but are not particularly limited. As the UV-stable monomer (3), only one kind may be used, or two or more kinds may be appropriately mixed and used.

The UV stable monomer represented by the general formula (4) according to the present invention (hereinafter referred to as UV stable monomer (4)) is a substituent represented by R ₆ in the formula. Is a hydrogen atom or a cyano group, and the substituents represented by R ₇ and R ₈ are each independently a hydrogen atom or a carbon number of 1 to 2.
And a substituent represented by Y is composed of an oxygen atom or an imino group.

Specific examples of the above UV stable monomer (4) include 1- (meth) acryloyl-4-
(Meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1 -Crotonoyl-4-crotonoyloxy-2,2,6,6
Examples include, but are not limited to, tetramethylpiperidine and the like. As the UV-stable monomer (4), only one kind may be used, or two or more kinds may be appropriately mixed and used.

The content of each of the above-mentioned monomers in the monomer composition (a) is not particularly limited, but the total amount of the ultraviolet absorbing monomers (1) and (2) is 0.1. Wt% ~ 9
The range of 9.9% by weight is more preferable, the range of 5% by weight to 40% by weight is further preferable, and the range of 10% by weight to 35% by weight is particularly preferable. Also, UV stable monomer (3)
-The total amount of (4) is more preferably in the range of 0.1% by weight to 99.9% by weight, further preferably in the range of 5% by weight to 40% by weight, particularly preferably in the range of 10% by weight to 35% by weight. . The total amount of the ultraviolet absorbing monomers (1) and (2) and the total amount of the ultraviolet stable monomers (3) and (4) in the monomer composition (a) are within the above range. By doing so, a synergistic effect of both monomers is exhibited, the ultraviolet absorbing ability and ultraviolet stability of the obtained ultraviolet absorbing polymer (a) are sufficient, and long-term weather resistance is realized. The weight ratio of the ultraviolet absorbing monomer (1) and the ultraviolet absorbing monomer (2) in the monomer composition (a), and the ultraviolet stable monomer (3) and the ultraviolet stability The weight ratio with the monomer (4) is
There is no particular limitation.

When the total amount of the UV absorbing monomers (1) and (2) in the monomer composition (a) is less than 0.1% by weight, the UV absorbing polymer (a) obtained is It is not preferable because the ultraviolet ray absorbing ability becomes insufficient. On the other hand, when the total amount is more than 99.9% by weight, the contents of the UV stable monomers (3) and (4) are too small, and the UV stability of the obtained UV absorbing polymer (a) is high. Is not preferable because it may be insufficient.

When the total amount of the UV stable monomers (3) and (4) in the monomer composition (a) is less than 0.1% by weight, the UV absorbing polymer (a) obtained is It is not preferable because the UV stability may be insufficient. On the other hand, when the total amount is more than 99.9% by weight, the content of the ultraviolet absorbing monomers (1) and (2) becomes too small, and the ultraviolet absorbing ability of the obtained ultraviolet absorbing polymer (a) is high. Is insufficient, which is not preferable.

In the monomer composition (a), other monomers are used in the range of 0% by weight to 99.8% by weight, if necessary. Further, other monomers are used within a range that does not impair the physical properties of the obtained ultraviolet absorbing polymer (a).

The method of mixing each monomer in obtaining the monomer composition (a) is not particularly limited. That is,
The method for preparing the monomer composition is not particularly limited.

The polymerization method for polymerizing the monomer composition (a) is not particularly limited, and various conventionally known polymerization methods such as solution polymerization, emulsion polymerization, suspension polymerization,
Bulk polymerization and the like can be adopted. Examples of the solvent that can be used in the case of polymerizing the monomer composition (a) by employing the solution polymerization method include, for example, toluene, xylene, and other high boiling aromatic solvents; ethyl acetate, butyl acetate, Ester solvents such as cellosolve acetate;
Examples thereof include ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, but are not particularly limited. These solvents may be used alone, or
Two or more of them may be used by appropriately mixing. Further, the amount of the solvent used is not particularly limited.

A polymerization initiator can be used when polymerizing the monomer composition (a). Examples of the above-mentioned polymerization initiator include 2,2'-azobis- (2-methylbutyronitrile), t-butylperoxy-2-ethylhexanoate, 2,2'-azobisisobutyronitrile. Ordinary radical polymerization initiators such as benzoyl peroxide, di-t-butyl peroxide and the like can be mentioned, but not particularly limited. Further, the amount of the polymerization initiator used is not particularly limited.

The reaction temperature is not particularly limited, but is preferably room temperature to 200 ° C, more preferably 40 ° C to 140 ° C. The reaction time may be appropriately set depending on the reaction temperature, the composition of each monomer composition used, the type of the polymerization initiator, etc. so that the polymerization reaction is completed.

The ultraviolet absorbing polymer (a) is obtained as described above. UV absorbing polymer (a) is 300
Especially excellent in UV absorption in the wavelength range of nm to 400 nm. Further, the ultraviolet absorbing polymer (a) has good compatibility with various resin materials, has no extractable unreacted ultraviolet absorbing monomers (1) and (2), and has a high molecular weight. Therefore, no elution or bleed out occurs. Also,
Coloring due to the ultraviolet absorbing monomers (1) and (2) hardly occurs.

The UV stable monomer (3)
The ultraviolet absorbing polymer (a) obtained by polymerizing the monomer component (a) containing (4) is the ultraviolet absorbing monomer (1).
Due to the synergistic effect of (2) and the UV-stable monomer (3) and (4), the UV-absorbing ability and the UV-stability are sufficiently exhibited, and therefore the long-term weather resistance is excellent.

The resin composition (A) suitable as the ultraviolet absorbing resin composition according to the present invention can be obtained by adding and mixing the above ultraviolet absorbing agent to the resin material. The resin material is not particularly limited as long as it contains a resin having no ultraviolet absorbing ability as a main component. Specific examples include thermoplastic resins such as acrylic resins, polyester resins, and fluororesins, or thermosetting resins containing a cross-linking agent.

The amount of the ultraviolet absorber added to the resin material is not particularly limited, but is preferably in the range of 0.5 to 10% by weight.

The method for producing the resin composition (A) is not particularly limited, but if a method of adding an ultraviolet absorber to the resin material and then further mixing the crosslinking agent is used, drying property and acid resistance can be obtained. It is possible to form the ultraviolet absorbing layer 1 having excellent properties such as properties and solvent resistance. The cross-linking agent is not particularly limited. For example, when the resin composition (A) contains a polymer having a hydroxyl group such as acrylic polyol as a main component, a polyisocyanate capable of reacting with the hydroxyl group is used. By using a crosslinking agent composed of a compound or aminoplast resin, the drying property is further improved,
An ultraviolet absorbing layer 1 that is cured at room temperature or by heating and has excellent chemical properties such as acid resistance and solvent resistance and flexibility.
Can be formed, which is preferable.

As the above polyisocyanate compound,
It is not particularly limited as long as it has two or more isocyanate groups in the molecule, and specifically, for example, trimethylene diisocyanate, 1,6-hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, Isophorone diisocyanate, xylylene diisocyanate, meta-xylylene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), and trimethylolpropane adduct which is a derivative of these diisocyanates,
Examples include adduct polyisocyanate compounds such as burette and isocyanurate. Furthermore, the resin composition (A) may be a known catalyst (for example, an organic compound such as di-n-butyltin dilaurylate) for promoting a urethanization reaction between a hydroxyl group and an isocyanate group in the resin material, in addition to the crosslinking agent. It may contain various additives such as tin compounds and tertiary amines), organic solvents, fillers, leveling agents, plasticizers, and stabilizers. Only one kind of these additives may be used, or two or more kinds thereof may be appropriately mixed and used. Moreover, the amount of these additives used is not particularly limited. As described above, the resin composition (A) is obtained.

Next, the resin composition (B) will be described. The ultraviolet absorbing polymer (a) may be used as it is as the resin composition (B) without being added and mixed with the resin material. For example, a solvent-type or emulsion-type resin composition (B) can be obtained by carrying out solution polymerization or emulsion polymerization of the monomer composition (a). Further, an acrylic polyol obtained by using as a main component a polymer having a hydroxyl group in the ultraviolet absorbing polymer (a) is mixed with a crosslinking agent capable of reacting with a hydroxyl group such as a polyisocyanate compound or an aminoplast resin, A crosslinkable resin composition (B) can be used. Furthermore, the ultraviolet absorbing polymer (a) taken out in the form of powder or pellets can be used as it is as the resin composition (B). In that case, the ultraviolet absorbing polymer (a) is melted by heat. A light-shielding plate can be manufactured by laminating the colored transparent plate 2 on the transparent plate 2. As described above, the resin composition (B) used for forming the ultraviolet absorbing layer 1 is obtained.

The ultraviolet absorbing resin composition (resin composition (A) or resin composition (B)) may contain a colorant having the same color as the colorant contained in the colored transparent plate 2 described later. . However, the coloring agent in the ultraviolet absorbing layer 1 is the colored transparent plate 2
It is more preferable not to include a colorant, because the colorant is more likely to be discolored than the colorant inside.

The light-shielding plate 10 according to the present invention is obtained by laminating the ultraviolet absorbing layer 1 made of the above-mentioned ultraviolet absorbing resin composition on a colored transparent plate 2 made of a transparent material and a coloring agent. .

The above-mentioned colorant may be any compound capable of blocking the light of the wavelength in the specific region and maintaining the transparency of the light shielding plate 10. As the colorant, specifically, titanium oxide, zinc white, carbon black, iron oxide,
Inorganic pigments such as lead molybdate, lead chromate, chrome green, chromium oxide, navy blue, and complex oxide-based calcined pigments; insoluble azo pigments, soluble azo pigments, condensed polycyclic pigments, phthalocyanine pigments, etc. Organic pigments; basic dyes,
Dyes such as direct dyes, acid dyes, and metal-containing complex salt dyes can be used. The amount of the colorant may be appropriately selected within the range in which the transparency of the light shielding plate 10 is maintained, depending on the type of the colorant and the like.

The color of the colorant may be appropriately selected according to the application, but when the light shielding plate 10 is used as a lid of a biological treatment tank of a water purification plant, a green colorant is preferable. Among them, it is preferable that the transmitted light region is at least within the range of 450 nm to 600 nm. That is, it is preferable to absorb at least light of 450 nm or less (visible light and ultraviolet rays) and light of 600 nm or more (visible light and infrared rays). Thereby, the photosynthesis of chlorophyll of green algae can be efficiently suppressed, and the generation of green algae can be further suppressed.

The colored transparent plate 2 is manufactured by mixing the above colorant with a transparent material and molding. As the material having transparency (hereinafter, referred to as a transparent material),
For example, various plastics such as FRP (fiber reinforced plastic), acrylic resin, PC (polycarbonate), polystyrene; glass and the like can be mentioned, but not limited thereto. Of these, FRP is particularly preferable because it has excellent strength. As the FRP, FRP formed by impregnating glass fiber with unsaturated polyester resin is particularly preferable. The thickness of the colored transparent plate 2 is not particularly limited.

Next, a method of manufacturing the light shielding plate 10 using the above ultraviolet absorbing resin composition will be described. Shield plate 1
The manufacturing method of 0 may be any method as long as the ultraviolet absorbing layer 1 formed of the ultraviolet absorbing resin composition is in a state of being laminated on the surface of the colored transparent plate 2. As a method for manufacturing the light-shielding plate 10, specifically, for example, a method of applying an ultraviolet absorbing resin composition to the colored transparent plate 2; after forming the ultraviolet absorbing resin composition into a film, melting the colored transparent plate 2 into the film. Method of wearing: After forming the ultraviolet absorbing resin composition into a film, the colored transparent plate 2
A method of thermocompression bonding to the colored transparent plate 2 can be used.

First, a method of manufacturing the light shielding plate 10 by applying the ultraviolet absorbing resin composition will be described. In this method, the ultraviolet absorbing resin composition is applied to the surface of the colored transparent plate 2 and dried at room temperature or a predetermined temperature or baked at a relatively low temperature to form the ultraviolet absorbing layer 1. Thereby, the light blocking plate 10
Is manufactured.

Next, a method of manufacturing the light shielding plate 10 by forming a film of the ultraviolet absorbing resin composition and then fusing it to the colored transparent plate 2 will be described.

First, the ultraviolet absorbing resin composition is molded into a film having a predetermined thickness. Next, the above-mentioned film is placed on the surface of the colored transparent plate 2 made of a meltable material, for example, unsaturated polyester resin, and heated at a predetermined temperature to face both the film and the colored transparent plate 2. Are melted and fused to each other. The colored transparent plate 2 is not particularly limited as long as it is made of a material that can be fused with the film. Thereby, the ultraviolet absorbing layer 1 is formed on the surface of the colored transparent plate 2, and the light shielding plate 10 is manufactured.

The method of molding the film is not particularly limited. That is, for example, a solution (coating solution) obtained by adding an organic solvent to the ultraviolet absorbing resin composition is applied to the surface of various base materials such as various plastics, metals, and glass, and the solvent is evaporated. The method (so-called casting method) obtained by the above method, or the method of molding the ultraviolet absorbing resin composition into a sheet can be used.

The organic solvent is not particularly limited, and the compounds exemplified above can be used, for example. At this time, by using a highly volatile compound as the organic solvent, a film having good drying property can be obtained. The method for evaporating the solvent is not particularly limited, and the solvent can be evaporated by, for example, natural drying or heat drying.

The method of applying the above coating solution to the base substrate is not particularly limited, and it may be applied using a commonly used coating machine such as a bar coater or a roll coater, or an air coating method. It may be applied by spraying.

Furthermore, for example, a film can be obtained by using an extrusion molding method such as T-die molding in which an ultraviolet absorbing resin composition is melt extruded by an extruder, inflation molding, blow molding, or a calendering method. . The film thickness of the film thus obtained is not particularly limited.

Next, a method for producing the light-shielding plate 10 by thermocompression-bonding it to the colored transparent plate 2 after forming a film of the ultraviolet absorbing resin composition will be described.

First, the ultraviolet absorbing resin composition is molded into a film having a predetermined thickness. Next, an adhesive is applied to the surface of the colored transparent plate 2 and dried at a predetermined temperature to form an adhesive layer. The adhesive may be appropriately selected according to the material of the colored transparent plate 2 and the like, and is not particularly limited.

Subsequently, the film is placed on the surface of the adhesive layer and thermocompression-bonded at a predetermined temperature and pressure to bond the film to the colored transparent plate 2. Thereby, the ultraviolet absorbing layer 1 is formed and the light shielding plate 10 is manufactured. The method of molding the film is not particularly limited, and the various molding methods described above can be used.
In the above manufacturing methods, when the colored transparent plate 2 is made of FRP, the colored transparent plate 2 preferably has a gel coat layer between the colored transparent plate 2 and the ultraviolet absorbing layer 1. That is, the colored transparent plate 2 preferably has a gel coat layer on a substrate made of a resin composition containing a laminating resin, a colorant, and a fiber reinforcing material. This reduces volatilization during heating and molding, so-called foam fogging, and improves mold releasability and dimensional stability. The gel coat layer may not contain a colorant, but it is more preferable that the gel coat layer contains a colorant.

The colored transparent plate 2 made of FRP having a gel coat layer is manufactured, for example, as follows. That is, first, a mold release agent is applied to the molding surface of a mold such as a mold. Next, a resin containing a colorant, which is to be a gel coat layer, is applied. After that, the resin is heated and cured by heating the mold to a predetermined temperature. As a result, a gel coat layer is formed. The material and forming method of the gel coat layer are
There is no particular limitation.

Next, a resin composition obtained by impregnating a laminating resin with a fiber reinforcing material is lined and laminated on the gel coat layer. As a specific example of the resin composition, a resin for lamination obtained by adding a colorant and a polymerization initiator to an unsaturated polyester resin, a resin composition obtained by impregnating glass fibers can be mentioned, but is not particularly limited. Not something. That is, the laminating resin is not particularly limited as long as it is made of a material that can be heat-cured.

Subsequently, by heating the above mold,
The colored transparent plate 2 made of FRP having a gel coat layer is obtained by removing the mold from the resin composition after the resin composition is heat-cured.
Is obtained.

Next, a method of manufacturing the light shielding plate 10 by transferring the ultraviolet absorbing layer 1 using a mold will be described. This makes it possible to easily manufacture the light shielding plate 10 having the ultraviolet absorbing layer 1 having a smooth surface.

First, a mold release agent is applied to the molding surface of a mold such as a mold. Next, after applying the ultraviolet absorbing resin composition to the molding surface, by heating the mold to a predetermined temperature, for example 40 ° C. ~ 60 ° C., the ultraviolet absorbing resin composition is heat-cured to UV rays. The absorption layer 1 is formed.

After that, for example, an unsaturated polyester resin is applied onto the ultraviolet absorbing layer 1 and then the mold is heated to a predetermined temperature to heat-cure the unsaturated polyester resin so that a colored transparent plate is obtained. 2 to form a gel coat layer. That is, the gel coat layer is laminated on the ultraviolet absorbing layer 1. The material and forming method of the gel coat layer are not particularly limited.

Next, on the gel coat layer, a resin composition, such as FRP, which is to be the base material of the colored transparent plate 2 is lined and laminated. Incidentally, as a specific example of the resin composition,
A resin composition obtained by impregnating glass fibers with a laminating resin obtained by adding a polymerization initiator to an unsaturated polyester resin is mentioned, but not particularly limited thereto. That is,
The base material of the colored transparent plate 2 is not particularly limited as long as it is made of a material that can be heat-cured.

Then, by heating the above mold,
The resin composition is heat-cured to form the colored transparent plate 2, and the ultraviolet absorbing layer 1 is transferred to the surface of the colored transparent plate 2. Then, by removing the mold, the light shielding plate 10 is obtained. Incidentally, when the colored transparent plate 2 is made of FRP, it is preferable to form the gel coat layer, but depending on the material of the colored transparent plate 2 and the like, the formation of the gel coat layer may be omitted.

As described above, the light shielding plate 10 according to the present invention
With respect to the colored transparent plate 2 made of a transparent material and a colorant, the ultraviolet absorbing layer 1 made of the ultraviolet absorbing resin composition is laminated on the surface of the colored transparent plate 2.

According to the above constitution, since the ultraviolet absorbing layer 1 made of the ultraviolet absorbing resin composition is laminated on the surface of the colored transparent plate 2, the colorant is protected from ultraviolet rays and the discoloration of the colorant is suppressed. can do. Thereby, the discoloration resistance of the light shielding plate 10 can be improved.

The light-shielding plate 10 according to the present invention covers a biological treatment tank such as a biological contact oxidation basin or a biological filtration basin using microorganisms installed in an advanced water treatment facility by using a green colorant as a coloring agent. Although it can be suitably used as a lid, it can be used without particular limitation as long as it is used for blocking light of a specific wavelength.

[0079]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. In the Examples and Comparative Examples, “parts” means “parts by weight”, and “%” means “% by weight”.
Is shown.

The accelerated weather resistance test in Examples and Comparative Examples was carried out as follows based on JIS K 5400. After measuring the initial object color and initial gloss value of the test piece, spray water with irradiation using a sunshine carbon weather meter, and show the gloss value, object color, and degree of discoloration every 1000 hours The value, the color difference (ΔE), was measured. The gloss value is a so-called 60 ° C. specular gloss value. In addition, the object color is represented by the lightness index L and the chromatic nexus index a and b in the Hunter color difference formula. Furthermore, color difference (△ E)
Was calculated by the Hunter's color difference formula from the differences ΔL, Δa, and Δb of the above indexes.

[Example 1] First, F as a colored transparent plate
An RP molded body was manufactured. That is, first, on the molding surface of the mold,
Wax-based mirror glaze MGH-8 as a release agent
(MEGUIAR'S Incorporated) applied, and then a gel coat resin obtained by adding a green toner (Sumitomo Chemical Color Co., Ltd.) to an unsaturated polyester resin for gel coat (Epolak N-300T; manufactured by Nippon Shokubai Co., Ltd.) Sprayed. Then, the gel coat resin was heat-cured by heating the mold in a heating furnace to form a gel coat layer.

Subsequently, on the gel coat layer, a laminate obtained by adding a green toner (manufactured by Sumitomo Chemical Color Co., Ltd.) to an unsaturated polyester resin for lamination (Epolak G-77-PT; manufactured by Nippon Shokubai Co., Ltd.) Resin and glass fiber (# 380 chopped strand mat, and # 380
450 chopped strand mat). Then, the above-mentioned mold was heated in a heating furnace to heat and cure the laminating resin, and then the mold was removed to obtain an FRP molded body as a colored transparent plate. The obtained FRP
The molded body had a green transparency.

Next, a coating agent as an ultraviolet absorbing resin composition was prepared. That is, first, 25.2 parts of toluene, 18.2 parts of butyl acetate and 3.0 parts of benzotriazole (A) were charged into a 4-necked flask equipped with a thermometer, a gas blowing tube, a condenser and a stirrer, and the temperature was raised to 90 ° C. .

On the other hand, as the ultraviolet absorbing monomer (1)
1.5 parts of 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole and 4-methacryloyloxy as UV stable monomer (3)
-2,2,6,6-tetramethylpiperidine 1.0 part, cycloalkyl methacrylate (CHMA) 20.0 parts as a cycloalkyl group-containing monomer (other monomer), and carboxyl group-containing unsaturated monomer ( Methacrylic acid (MAA) 0.3 parts as other monomers), n-butyl acrylate (BA) 9.0 parts and methyl methacrylate (MMA) 9.7 parts as (meth) acrylic acid alkyl ester (other monomers) And 5.5 parts of hydroxyethyl acrylate as a hydroxyl group-containing (meth) acrylate (other monomer), 4.5 parts of toluene as a solvent and 2.1 parts of xylene, and 2,2'-azobis- (as a polymerization initiator). 2-Methylbutyronitrile) (0.9 parts) was mixed to obtain a monomer composition (hereinafter referred to as a monomer composition (2)). Then, this monomer composition (2) was charged into a dropping device.

Next, 20% by weight of the monomer composition (2) was put into the 4-necked flask all at once. Then, the rest of the monomer composition (2) was added dropwise over 3 hours, and the reaction solution was stirred at 90 ° C. for 5 hours for copolymerization to give a reaction as the ultraviolet absorbing polymer (a). The product was obtained.

The nonvolatile content of the above reaction product measured by a predetermined method is 50%, and the weight average molecular weight (Mw) is
Was 10,000. Furthermore, the hydroxyl value (OHV) of the above reaction product measured using a predetermined method is 27.0 mgKOH.
/ G, acid value (AV) is 2.0 mg KOH / g,
The viscosity was Z (Gardner-Holt).

Next, a polyfunctional isocyanate (Sumijour N-3200; manufactured by Sumitomo Bayer Urethane Co., Ltd.) was added to the above reaction product, and an equivalent amount of the isocyanate group (-NCO) to the hydroxyl group (-OH) in the solution was obtained. The ratio of 1: 1 was weighed and mixed. This obtained the coating agent which should become an ultraviolet absorption layer.

Next, the above coating agent was applied to the above FRP.
It was applied on the molded body so that the dry film thickness was 15 μm, and then dried at 60 ° C. for 60 minutes to form an ultraviolet absorbing layer. Thereby, the light shielding plate according to the present invention was obtained. The obtained light shielding plate had green transparency. Further, using the obtained light shielding plate, an accelerated weather resistance test was conducted by the method described above. Table 1 shows the obtained results.

[0089]

[Table 1]

Comparative Example 1 First, in the same manner as in Example 1, an FRP molded body as a colored transparent plate was manufactured. Next, polyisocyanate (Sumijour N-3200; Sumitomo Bayer Urethane Co., Ltd.) was added to an acrylic resin (Arotane 2010; manufactured by Nippon Shokubai Co., Ltd., nonvolatile content 45%, hydroxyl value 18 mgKOH / g) and hydroxyl in the solution. The equivalent ratio of the isocyanate group (-NCO) to the group (-OH) was weighed and mixed in an amount of 1: 1. Thereby, a coating agent was obtained.

Next, the above coating agent was applied to the above FRP.
After coating on a molded body so that the dry film thickness would be 15 μm, the coating was dried by drying at 60 ° C. for 60 minutes. Thereby, a light shielding plate for comparison was obtained. The obtained light-shielding plate for comparison had green transparency. Further, an accelerated weather resistance test was conducted by the above-mentioned method using the obtained light-shielding plate for comparison. Table 2 shows the obtained results.

[0092]

[Table 2]

[Comparative Example 2] In this comparative example, a comparative light-shielding plate having no ultraviolet absorbing layer was used as Example 1
The FRP molded body manufactured in the same manner as in (3) was used as it was. The FRP molded body was subjected to an accelerated weathering test by the method described above. The results obtained are shown in Table 3.

[0094]

[Table 3]

As is clear from the results shown in Tables 1 to 3,
It was found that the light-shielding plate according to this example has significantly improved discoloration resistance as compared with the light-shielding plate according to each comparative example.

[0096]

As described above, the light-shielding plate of the present invention is different from the colored transparent plate composed of the transparent material and the colorant in the following manner.
An ultraviolet absorbing layer made of a resin composition having an ultraviolet absorbing ability is laminated on the surface of the colored transparent plate.

According to the above structure, it is possible to provide a light-shielding plate having excellent resistance to discoloration.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of the configuration of a light shielding plate according to the present invention.

FIG. 2 is a graph showing an absorption spectrum of chlorophyll.

[Explanation of symbols]

 1 UV absorbing layer 2 Colored transparent plate 10 Light-shielding plate

Claims (1)

[Claims] 1. A colored transparent plate comprising a transparent material and a colorant for suppressing discoloration of the colorant,
A light-shielding plate, wherein an ultraviolet-absorbing layer made of a resin composition having an ultraviolet-absorbing ability is laminated on the surface of the colored transparent plate.