JP2001139640A - Uv-absorbing copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new UV-absorbing copolymer which exhibits high UV absorption effects and a high water solubility and can be mixed with an anionic water-base coating material. SOLUTION: This new UV-absorbing copolymer is prepared by copolymerizing (a) a UV-absorbing vinyl monomer having 2-hydroxybenzophenone residue or a 2'-hydroxyphenylbenzotriazole residue with (b) a water-soluble vinyl monomer having a group dissociable into an anion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel ultraviolet absorbing copolymer. More specifically, the present invention relates to a novel ultraviolet-absorbing copolymer obtained by copolymerizing a specific ultraviolet-absorbing vinyl monomer and a specific water-soluble vinyl monomer.
The ultraviolet absorbing copolymer of the present invention can increase the solubility in water, and can be used in a wide range of fields such as plastic products, fibers, cosmetics, and medical materials by kneading or utilizing the solubility in water. It can be used as a new ultraviolet absorber.

[0002]

2. Description of the Related Art Conventionally, plastic products, film products, painted products, fibers and the like have been kneaded or coated with an ultraviolet absorber in order to prevent light deterioration due to exposure to ultraviolet light. In the case of kneading, low-molecular-weight substances such as hydroxybenzophenones and hydroxybenzotriazoles are often used. Also, for the purpose of application,
In many cases, these low molecular compounds are used in combination with an acrylic resin or a urethane resin to form a film. Further, as a copolymer of an ultraviolet absorbing monomer having a hydroxybenzophenone residue or a hydroxybenzotriazole residue and a hydrophobic monomer such as an alkyl (meth) acrylate, a film is formed by using a polymerized ultraviolet absorbing agent. Are disclosed in JP-A-9-143878 and JP-A-8-269.
814, JP-A-5-320500, JP-A-5-170941, JP-A-4-352810, JP-A-4-222848, and the like. However, these compounds have no water solubility and could not be used by mixing with water-based paints.

As the water-soluble ultraviolet absorber, low-molecular compounds having a sulfonic acid group introduced into the aromatic ring of hydroxybenzophenone are disclosed in JP-A-54-68303 and JP-A-5-68303.
It has been proposed in Japanese Patent Publication No. 4-85804. Also, an attempt to use a high-molecular cationic ultraviolet absorber, which is a copolymer of an ultraviolet-absorbing monomer and a cationic hydrophilic monomer, in order to improve the adsorption to the fiber, has been made in JP-A-7-150.
No. 469, Japanese Unexamined Patent Publication No. Hei 6-73367 and the like. Japanese Unexamined Patent Publication (Kokai) No. 6-199961 proposes a hydrophilic high-molecular ultraviolet absorber obtained by copolymerizing a hydrophilic vinyl monomer and an ultraviolet absorbing monomer for use in a contact lens or the like.

[0004]

However, when a low molecular weight compound of an ultraviolet absorber is kneaded to obtain a molded product, or when a film is formed by using it together with an acrylic resin or a urethane resin, the obtained molded product or film can be obtained. There is a disadvantage that the durability of the ultraviolet absorbing effect is deteriorated. Use of a polymerized UV absorber improves durability, but copolymers of UV-absorbing monomers and hydrophobic monomers are not water-soluble, and are used in water-based paints, which have recently been used due to environmental concerns. Could not be used, and could not be used for cosmetics, medical materials, etc. that touch the human body. In this regard, polymeric cationic UV absorbers are water-soluble, but in practice, quaternization of nitrogen atoms is used as a method of achieving cationicity. It is a cause of coloring, and there is a disadvantage that the ultraviolet absorbing effect is weakened as a whole when viewed from the ultraviolet absorbent. Also,
In the case where a molded product is to be obtained by kneading, a high molecular weight cationic ultraviolet absorber may not be sufficiently heat-resistant, and a material having improved heat resistance has been demanded. Furthermore, when mixed with an anionic water-based paint, the high molecular weight cationic ultraviolet absorber causes a reaction between the polymer and the resin component in the paint to gel and cannot be used together.

[0005] The hydrophilic high-molecular ultraviolet absorber proposed in Japanese Patent Application Laid-Open No. 6-199961 does not have the above-mentioned drawbacks, but is capable of converting a nonionic compound such as hydroxy (meth) acrylate into a hydrophilic compound. Since it is used as a vinyl monomer, it generally has a disadvantage of low water solubility. Water solubility can be increased by using a sugar derivative such as a glycoside derivative, but the handling of the sugar derivative itself is difficult, and since the sugar derivative has many hydroxyl groups, a desired amount of a polymerizable group is introduced. There were drawbacks that were difficult. Also, in this case, the degree of hydrophilicity was such that transparency could be maintained in an aqueous solution up to 2%, and it could not be said that satisfactory water solubility could be secured. The present invention has a high ultraviolet absorbing effect and can sufficiently increase the solubility in water,
Moreover, it is an object to provide a novel UV absorber which can be mixed with an anionic water-based paint.

[0006]

Means for Solving the Problems As a result of intensive studies in view of such circumstances, the present inventors have found that an ultraviolet-absorbing copolymer obtained by copolymerizing a specific ultraviolet-absorbing vinyl monomer and a specific water-soluble vinyl monomer. The inventors have found that the coalescence has a high ultraviolet absorbing effect and can sufficiently increase the water solubility, and can be mixed with an anionic water-based paint, and have completed the present invention. This water-soluble vinyl monomer is easily available.

That is, the gist of the present invention is to provide a UV-absorbing vinyl monomer (a) having a 2-hydroxybenzophenone residue or 2'-hydroxyphenylbenzotriazole residue and a water-soluble vinyl monomer having an anion-dissociable group. A novel UV-absorbing copolymer obtained by copolymerization with (b), a water-soluble vinyl monomer (b)
By increasing the ratio, the water solubility can be sufficiently increased.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The novel UV-absorbing copolymer of the present invention comprises a UV-absorbing vinyl monomer (a) having a 2-hydroxybenzophenone residue or 2'-hydroxyphenylbenzotriazole residue and a water-soluble copolymer having an anion-dissociable group. It is obtained by copolymerizing a vinyl monomer (b). Here, an ultraviolet-absorbing vinyl monomer having a 2-hydroxybenzophenone residue or a 2′-hydroxyphenylbenzotriazole residue refers to a 2-vinylbenzophenone residue or a 2′-hydroxyphenylbenzotriazole residue in one molecule.
Refers to a compound having a hydroxybenzophenone residue or a 2'-hydroxyphenylbenzotriazole residue and a polymerizable vinyl group, and a water-soluble vinyl monomer having a group that can be dissociated into an anion is dissociable into an anion in one molecule And a compound having a polymerizable vinyl group.

The UV-absorbing vinyl monomer (a) having a 2-hydroxybenzophenone residue used in the present invention is preferably a compound represented by the formula (I), and a 2'-hydroxyphenylbenzotriazole residue As the ultraviolet-absorbing vinyl monomer (a) having the following, a compound represented by the formula (II) is preferable. These may be used alone as the vinyl monomer (a),
Further, two or more kinds may be used in combination. When used together,
Since ultraviolet rays having different wavelengths can be simultaneously absorbed, the effect of absorbing ultraviolet rays can be further improved.

[0010]

Embedded image

(Wherein, R ¹ represents a hydrogen atom or a methyl group, X represents an ester bond, an amide bond, an ether bond or a urethane bond, and R ² represents an alkylene group having 1 to 10 carbon atoms or 1 to 1 carbon atoms. Represents an oxyalkylene group of 10,
R ³ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. However, n is 1 or 0)

In the formula (I), when n = 1 and R ² is an alkylene group having 1 to 10 carbon atoms, specific examples thereof include methylene, ethylene, propylene, trimethylene and tetramethylene. Examples include a methylene group, a pentamethylene group, and a hexamethylene group. Also, R ²
Is an oxyalkylene group having 1 to 10 carbon atoms, specific examples thereof include, for example, an oxymethylene group, an oxyethylene group, an oxypropylene group, an oxytrimethylene group, an oxytetramethylene group, an oxypentamethylene group, and an oxyhexaene. And a methylene group. In addition,
When n = 0, X is directly bonded to the aromatic ring. When R ³ is an alkyl group having 1 to 6 carbon atoms, specific examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group.

When R ³ is an alkoxy group having 1 to 6 carbon atoms, specific examples thereof include a methoxy group, an ethoxy group, a propoxy group and a butoxy group. As specific examples of the compound represented by the formula (I), for example, 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4- (2-acryloyloxy) Ethoxybenzophenone, 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone, and the like. Of these, 2-hydroxy-4- (2-acryloyloxy) ethoxybenzophenone and 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone are preferred.

[0014]

Embedded image

(Wherein R ¹ , X, R ² , R ³ and n have the same meanings as in formula (I), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a halogen atom, Is 1 or 0)

In the formula (II), when R ⁴ is an alkyl group having 1 to 6 carbon atoms, specific examples thereof include a methyl group, an ethyl group, a propyl group and a butyl group. When R ⁴ is a halogen atom, examples of the halogen include fluorine, chlorine, bromine, and iodine. Of these, chlorine and bromine are preferable. Note that n = 0
In the case where m = 1, X is directly bonded to the aromatic ring, and m =
In the case of 0, the vinyl carbon is directly bonded to the aromatic ring.

Specific examples of the compound represented by the formula (II) include, for example, 2 [2'-hydroxy-5 '-(acryloyloxy) phenyl] benzotriazole,
-[2'-hydroxy-5 '-(methacryloyloxy) phenyl] benzotriazole, 2- [2'-hydroxy-3'-t-butyl-5'-(methacryloyloxy) phenyl] benzotriazole, 2- [2 '-Hydroxy-5-methyl-3-vinylphenyl] benzotriazole and the like. Of these, 2- [2'-
Hydroxy-5-methyl-3-vinylphenyl] benzotriazole and 2- [2'-hydroxy-5 '-(methacryloyloxy) phenyl] benzotriazole are preferred.

The water-soluble vinyl monomer (b) having a group which can be dissociated to an anion used in the present invention includes, for example, 4-styrenesulfonic acid, 2-acrylamidopropanesulfonic acid and 2-acrylamido-2-methylpropane. Sulfonic acid, 3-acrylamide-2,4,
4-trimethylpentanesulfonic acid, 2-acrylamide-2- (p-tolyl) ethanesulfonic acid and bases thereof. Of these, 4-styrenesulfonic acid, 2-acrylamido-2-methylpropanoic acid and salts thereof are preferred. As the salt, an alkali metal salt is preferable, and among them, a sodium salt and a potassium salt are preferable. These may be used alone or in combination of two or more.

The UV-absorbing copolymer of the present invention can be produced by a usual copolymerization reaction between a UV-absorbing vinyl monomer (a) and a water-soluble vinyl monomer (b). There is no limitation. For example, a UV-absorbing vinyl monomer (a) and a water-soluble vinyl monomer (b) are dissolved in a solvent, a radical polymerization initiator is added thereto, and the mixture is allowed to react at a predetermined temperature, preferably under stirring, for a predetermined time. Can be used for copolymerization. The ratio of the monomer (a) to the monomer (b) is not particularly limited. However, in order to obtain a water-soluble copolymer, the monomer (a) itself is hardly soluble in water. If the ratio of (b) is too small, water solubility may not be ensured. On the other hand, if the ratio of the monomer (b) is too high, there is a concern that the ultraviolet absorption efficiency may be reduced. Therefore, this ratio is preferably about 30: 1 to 1:20, although it depends on the kind of the water-soluble monomer, and is preferably 1: 2 to 1:10 to obtain a water-soluble copolymer.

As a solvent, both monomers are dissolved,
There is no particular limitation as long as the reaction is not hindered. For example, methanol, ethanol, 2-propanol, tetrahydrofuran, dioxane, 1-methylpyrrolidone, N, N-dimethylformamide, dimethylsulfoxide and the like can be used. it can. The concentration of the monomer is usually 1 to 50% by weight, preferably 10 to 40% by weight.
It is. The polymerization initiator is selected in consideration of its decomposition temperature, the boiling point of the polymerization solvent, the reaction temperature, the reaction time, etc., for example, benzoyl peroxide, azobisisobutyronitrile, di-tert-butyl peroxide, Acetyl peroxide, lauroyl peroxide and the like are preferably used. The amount used is usually 0.1 to 10% by weight, preferably 0.5 to 5% by weight, based on the monomer.

The reaction temperature is usually 40 to 150 ° C.,
The reaction time is preferably 50 to 110 ° C., and the reaction time depends on the type of the monomer and the polymerization initiator, the reaction temperature, and the like.
About an hour. The reaction may be a batch system or a continuous system. After completion of the reaction, the target copolymer can be recovered from the reaction solution by a conventional method.
For example, after the copolymer polymer precipitated from the reaction solution after the completion of the reaction is separated by filtration, if necessary, washed with a solvent such as methanol or diethyl ether, and then dried to obtain the desired copolymer.

Further, if necessary, the precipitated polymer is redissolved in a solvent used for the copolymerization reaction or a good solvent such as water, and then a poor solvent such as methanol or diethyl ether is added again to precipitate the polymer. By repeating, the polymer can be purified. The number average molecular weight of the copolymer thus obtained is usually about 2,000 to 200,000, although it depends on the amount of the polymerization initiator used. In addition, this copolymer can be kneaded and used to obtain a UV-absorbing composition or molded product, and water-soluble ones can be mixed with an anionic aqueous emulsion paint to obtain a UV-absorbing paint. Can be used.

[0023]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples unless it exceeds the gist of the present invention. Example 1 1 g of 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone and 3 g of sodium p-styrenesulfonate were added to 70 g of 1-methyl-2-pyrrolidone 3 at 70 ° C.
5g, and the system was replaced with nitrogen.
Add azobisisobutyronitrile (93 mg),
For 8 hours. The deposited precipitate was filtered, washed with methanol, and dried under reduced pressure to recover 2.3 g of the copolymer as a pale yellow solid. 1.5 g of distilled water was poured into 0.5 g of the obtained solid, and a dark yellow transparent aqueous solution was obtained at 80 ° C. for 10 minutes. It was confirmed that the copolymer was dissolved in water by 25% by weight or more in water. The aqueous solution prepared above was mixed with an anionic water-based emulsion paint (Licabond ES-52, manufactured by Chuo Rika Kogyo Co., Ltd.) so that the copolymer was 20% by weight of the solid content of the paint. As a result, a UV-absorbing water-based paint could be prepared. FIG. 1 shows copolymer 1
An aqueous solution obtained by dissolving 0.0 mg in 25.0 mL of water was added to 62
The ultraviolet / visible spectrum of a 5-fold dilution is shown. Three
It was found that ultraviolet light having a wavelength of less than 80 nm could be absorbed.

Example 2 1 g of 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone and 6 g of acrylamido-2-methylpropanesulfonic acid were added at 60 ° C. to 60 g of methanol.
And the system was purged with nitrogen, and 104 mg of 2,2'-azobis (2,4-dimethylvaleronitrile) was added.
And maintained at 60 ° C. for 8 hours. After the solution was cooled to room temperature, it was poured into 250 mL of diethyl ether, and the deposited precipitate was filtered, washed with diethyl ether, and dried under reduced pressure to recover 5.4 g of a copolymer as a pale yellow solid. 1.5 g of distilled water was poured into 0.5 g of the obtained solid, and a dark yellow transparent aqueous solution was obtained at 80 ° C. for 10 minutes. It was confirmed that the copolymer was dissolved in water by 25% by weight or more in water.
FIG. 2 shows an ultraviolet-visible spectrum of an aqueous solution obtained by dissolving 24.0 mg of the copolymer in 25.0 mL of water, which was diluted 625 times. It was found that ultraviolet light having a wavelength of less than 380 nm could be absorbed.

Example 3 1 g of 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone and 3 g of acrylamido-2-methylpropanesulfonic acid were added at 60 ° C. to 40 g of methanol.
After the inside of the system was replaced with nitrogen, 51 mg of 2,2'-azobis (2,4-dimethylvaleronitrile) was added, and the mixture was kept at 60 ° C for 8 hours. After cooling the solution to room temperature, 9 mL of a 2 M aqueous potassium hydroxide solution was added, and the deposited precipitate was filtered, further washed with diethyl ether, and dried under reduced pressure to recover 2.0 g of a copolymer as a pale yellow solid. did. 1.5 g of distilled water was poured into 0.5 g of the obtained solid, and a dark yellow transparent aqueous solution was obtained at 80 ° C. for 10 minutes. It was confirmed that the copolymer was dissolved in water by 25% by weight or more in water.
Anionic aqueous emulsion paint (Licabond SA-5)
13, Chuo Rika Kogyo Co., Ltd.) was mixed with the aqueous solution prepared above so that the copolymer was 20% by weight of the solid content of the coating material, but no gelation was observed. Could be created.

Example 4 In Example 1, 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone was used instead of 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone.
[2'-hydroxy-5 '-(methacryloyloxy)
In the same manner except that [phenyl] benzotriazole was used, 2.2 g of a copolymer was recovered as a pale yellow solid.
1.5 g of distilled water was poured into 0.5 g of the obtained solid,
A dark yellow transparent aqueous solution was obtained in 10 minutes, and it was confirmed that the copolymer was soluble in water in an amount of 25% by weight or more. FIG. 3 shows an ultraviolet-visible spectrum of an aqueous solution obtained by dissolving 8.8 mg of the copolymer in 25.0 mL of water, which was diluted 625 times. Ultraviolet light having a wavelength of less than 380 nm can be absorbed.

[0027]

According to the present invention, the ultraviolet absorption effect is high,
In addition, an ultraviolet-absorbing copolymer which can have high solubility in water and can be mixed with an anionic water-based paint can be obtained.

[Brief description of the drawings]

FIG. 1 shows an ultraviolet-visible spectrum of the copolymer of Example 1.

FIG. 2 shows an ultraviolet-visible spectrum of the copolymer of Example 2.

FIG. 3 shows an ultraviolet-visible spectrum of the copolymer of Example 4.

Claims (6)

[Claims] 1. An ultraviolet absorbing vinyl monomer (a) having a 2-hydroxybenzophenone residue or a 2'-hydroxyphenylbenzotriazole residue and a water-soluble vinyl monomer (b) having an anion-dissociable group. UV-absorbing copolymer obtained by polymerization. 2. The method according to claim 1, wherein the water-soluble vinyl monomer (b) is 2-acrylamidopropanesulfonic acid or 2-acrylamide-
2-methylpropanoic acid, 3-acrylamide-2,4
The copolymer according to claim 1, comprising at least one selected from 4-trimethylpentanesulfonic acid, 2-acrylamide-2- (4-tolyl) ethanesulfonic acid, 4-styrenesulfonic acid, and salts thereof. 3. The method according to claim 1, wherein the ultraviolet absorbing vinyl monomer (a) comprises 2
The copolymer according to claim 1, which is a vinyl monomer having a hydroxybenzophenone residue. 4. The copolymer according to claim 1, wherein the ultraviolet absorbing vinyl monomer (a) is a vinyl monomer having a 2′-hydroxyphenylbenzotriazole residue. 5. The copolymer according to claim 3, wherein the vinyl monomer having a 2-hydroxybenzophenone residue is a compound represented by the general formula (I). Embedded image (Wherein, R ¹ represents a hydrogen atom or a methyl group, X represents an ester bond, an amide bond, an ether bond, or a urethane bond, and R ² represents an alkylene group having 1 to 10 carbon atoms or an oxy group having 1 to 10 carbon atoms. Represents an alkylene group, and R ³ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, wherein n is 1 or 0. 6. The copolymer according to claim 4, wherein the vinyl monomer having a 2′-hydroxyphenylbenzotriazole residue is a compound represented by the general formula (II). Embedded image (Wherein R ¹ , X, R ² , R ³ and n have the same meanings as in formula (I), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a halogen atom, and m represents 1 or 0)