JPH107919A - Preparation of curable resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for preparing a curable resin which can prevent gelation can efficiently prepare a light-colored curable resin by reacting a curable resin-forming component in the presence of a particular compd. SOLUTION: This process for preparing a curable resin comprises reacting a curable resin-forming component in the presence of an N-oxyl compd. to prepare a curable resin. Pref. the N-oxyl compd. has at its molecular end at least one structure selected from among formula I (wherein X1 and X2 represent each H or a -OR5 , -OCOR6 , -NR7 R8 , or =O group; R1 to R4 each independently represents a 1C or higher alkyl group; and R5 to R8 each independently represents a hydrogen atom or a 1-16C alkyl group) and formula II (wherein X3 to X5 represent each H or a -OR13 , -OCOR14 , -NR15 R16 , or =O group; R9 to R12 each independently represents a 1C or higher alkyl group; and R13 to R16 each independently represents a hydrogen atom or a 1-16C alkyl group).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a light-colored curable resin which can be suitably used for various applications.

[0002]

2. Description of the Related Art Conventionally, curable resins such as vinyl ester resins, urethane (meth) acrylate resins, and polyester (meth) acrylate resins have excellent corrosion resistance, chemical resistance, water resistance, mechanical properties, and the like. Is known for.

[0003] For example, the vinyl ester resin is generally produced by reacting an epoxy compound with an unsaturated monobasic acid using an esterification catalyst. However, since these curable resins and components (raw materials) forming the curable resins contain a vinyl group or the like, they have a problem that they tend to gel during production.

Therefore, various methods have been studied to prevent gelation. Conventionally, oxygen is known to be the most effective component for preventing gelation of these curable resins. For this reason, when these curable resins are produced, some measures such as circulation of dry air have been devised.

[0005] However, a part of the obtained curable resin is oxidized by the oxygen circulated during the reaction to become a coloring compound, so that the obtained curable resin is markedly colored, for example, Gardner color. 3 to 8 are shown as numbers. For this reason, these curable resins have a limited field of use, such as being applied only to applications in which appearance is not important while having excellent performance.

Thus, for example, Japanese Patent Publication No. 3-34771 discloses a method for producing a light-colored vinyl ester resin. An epoxy compound and an unsaturated monobasic acid and an unsaturated polybasic acid are esterified using an esterification catalyst. , In an inert atmosphere,
A method for reacting in the presence of triphenylstibine is disclosed.

Further, Japanese Patent Publication No. 6-23232 discloses that
A method is disclosed in which an epoxy compound is reacted with an unsaturated monobasic acid and an unsaturated polybasic acid using an esterification catalyst in the presence of phosphorous acid and / or a phosphite diester.

[0008]

However, when a vinyl ester resin is produced using the above method, or when the above method is applied to the production of a urethane (meth) acrylate resin or a polyester (meth) acrylate resin, In order to express significant paleness, it is necessary to add a large amount of the above-mentioned additives such as triphenylstibine, phosphorous acid and phosphite diester to react in an inert atmosphere or an oxygen-diluted atmosphere. At times, there arises a problem that the raw materials and the reactants tend to gel.

Therefore, there is a demand for a method for efficiently producing a light-colored curable resin which can be suitably used for various applications. The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for efficiently producing a light-colored curable resin that can be suitably used for various applications.

[0010]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, the components forming the curable resin were reacted in the presence of N-oxyls to form a gel. And found that a light-colored curable resin can be efficiently obtained, and completed the present invention.

That is, the method for producing a curable resin according to the first aspect of the present invention is characterized in that components forming the curable resin are reacted in the presence of N-oxyls.

According to a second aspect of the present invention, there is provided a method for producing a curable resin according to the first aspect, wherein the N-oxyl is a compound represented by the general formula (1):

[0013]

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(Wherein, X ₁ and X ₂ each independently represent a hydrogen atom, a group of —OR _{5, a} group of —OCOR _{6, a} group of —NR ₇ R _8, or a group of ＯO, and R ₁ , R ₂ , R _3, R ₄ each independently represents an alkyl group having 1 or more carbon atoms, R _5, R
₆ , R ₇ and R ₈ each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms) and the general formula (2)

[0015]

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(Wherein X ₃ , X ₄ , and X ₅ are each independently a hydrogen atom, —OR ₁₃ , —OCOR ₁₄ , or —NR ₁₅
R represents a R ₁₆ group or ＝ O group, and R ₉ , R ₁₀ , R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 or more carbon atoms;
₁₃ , R ₁₄ , R ₁₅ and R ₁₆ each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms). .

According to a third aspect of the present invention, there is provided the method for producing a curable resin according to the first or second aspect, wherein the curable resin is a vinyl ester resin or a urethane (meth) acrylate resin. And a resin selected from the group consisting of polyester (meth) acrylate resins.

According to a fourth aspect of the present invention, there is provided a method for producing a curable resin according to any one of the first to third aspects, wherein the amount of the N-oxyl used is The amount is from 0.00001 to 1 part by weight based on 100 parts by weight of the obtained curable resin.

According to the present invention, a light-colored curable resin can be efficiently and stably produced without impairing the excellent physical properties such as corrosion resistance, chemical resistance, water resistance, heat resistance and mechanical properties of the curable resin. can do.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail. The method for producing a curable resin according to the present invention is a method in which a component forming the curable resin, that is, a raw material of the curable resin is reacted in the presence of N-oxyls. The production method of the present invention is applicable to the production of a general curable resin, and the curable resin is not particularly limited. Among them, the production method of the present invention is particularly suitably used for a method of producing one kind of curable resin selected from the group consisting of vinyl ester resins, urethane (meth) acrylate resins, and polyester (meth) acrylate resins.

In the case where a vinyl ester resin is produced as the curable resin, for example, an epoxy compound and an unsaturated monobasic acid are reacted with each other using an esterification catalyst in the presence of N-oxyls to easily prepare the vinyl ester resin. The desired vinyl ester resin can be obtained.

The epoxy compound used as a raw material of the vinyl ester resin is not particularly limited as long as it is a compound having at least one epoxy group in a molecule. Epibis-type glycidyl ether type epoxy resin obtained by a condensation reaction of bisphenols such as bisphenol A and bisphenol S with epihalohydrin; phenol,
Novolak type glycidyl ether type epoxy resin obtained by condensation reaction of novolak which is a condensate of cresol, bisphenol and formalin with epihalohydrin; glycidyl obtained by condensation reaction of tetrahydrophthalic acid, hexahydrophthalic acid, benzoic acid and epihalohydrin Ester-type epoxy resins; glycidyl ether-type epoxy resins obtained by condensation reaction of water-added bisphenols and glycols with epihalohydrin; amine-containing glycidyl ether-type epoxy resins obtained by condensation reaction of hydantoin or cyanuric acid with epihalohydrin. . Further, a compound having an epoxy group in a molecule by an addition reaction of these epoxy resins with polybasic acids and / or bisphenols may be used. One of these epoxy compounds may be used alone, or two or more of them may be used as a mixture.

The unsaturated monobasic acid used as a raw material for the vinyl ester resin is not particularly limited, but specific examples include acrylic acid, methacrylic acid, crotonic acid and the like. Further, a half ester such as maleic acid or itaconic acid may be used.
Further, these compounds may be used in combination with polycarboxylic acids such as fumaric acid, itaconic acid and citraconic acid, saturated monocarboxylic acids such as acetic acid, propionic acid, lauric acid and palmitic acid, and saturated polycarboxylic acids such as phthalic acid. An acid or an anhydride thereof, or a compound such as a saturated or unsaturated alkyd having a terminal carboxyl group may be used in combination. One of these unsaturated monobasic acids may be used alone, or two or more of them may be used as a mixture.

Examples of the esterification catalyst include tertiary amines such as dimethylbenzylamine and tributylamine; quaternary ammonium salts such as trimethylbenzylammonium chloride; and lithium chloride and chromium chloride. Inorganic salt; imidazole compound such as 2-ethyl-4-methylimidazole; tetramethylphosphonium chloride, diethylphenylpropylphosphonium chloride, triethylphenylphosphonium chloride, benzyltriethylphenylphosphonium chloride, dibenzylethylmethyl Phosphonium salts such as phosphonium chloride, benzylmethyldiphenylphosphonium chloride, and tetraphenylphosphonium bromide; secondary amines; tetrabutylurea; Fin; Triton reel phosphines; but such triphenylstibine and the like, but is not particularly limited. One of these esterification catalysts may be used, or two or more of them may be used as a mixture.

When a urethane (meth) acrylate resin is produced as the curable resin, for example, a polyisocyanate is reacted with a polyhydroxy compound or a polyhydric alcohol in the presence of N-oxyls. Then, after further reacting a hydroxyl group-containing (meth) acrylic compound and, if necessary, a hydroxyl group-containing allyl ether compound, or reacting a hydroxyl group-containing (meth) acrylic compound with a polyhydroxy compound or a polyhydric alcohol, Further, by reacting the polyisocyanate, a desired urethane (meth) acrylate resin can be easily obtained.

As the polyisocyanate used as a raw material of the urethane (meth) acrylate resin, specifically, for example, 2,4-tolylene diisocyanate and its isomers, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene Diisocyanate, hydrogenated xylylene diisocyanate, dicyclohexylmethane diisocyanate, tolidine diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate,
Burnock D-750, Crispon NX (trade name; manufactured by Dainippon Ink and Chemicals, Inc.), Desmodur L (trade name; manufactured by Sumitomo Bayer), Coronate L (trade name; manufactured by Nippon Polyurethane Co., Ltd.) Name;
Takeda Pharmaceutical Co., Ltd.) and Isonate 143L (trade name; manufactured by Mitsubishi Kasei Co., Ltd.), but are not particularly limited thereto. One of these polyisocyanates may be used alone, or two or more of them may be used as a mixture.

Specific examples of the polyhydric alcohol used as a raw material of the urethane (meth) acrylate resin include, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, and polypropylene glycol. , 2-methyl-1,3-propanediol, 1,3-butanediol, adduct of bisphenol A with propylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane, 1 , 3-propanediol, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, para-xylene glycol, bicyclohexyl-4,4'-diol, 2,6-decalin glycol, 2, 7-decalin glycol Although the like, but is not particularly limited. One of these polyhydric alcohols may be used alone, or two or more of them may be used as a mixture.

The polyhydroxy compound used as a raw material of the urethane (meth) acrylate resin includes:
For example, polyester polyols, polyether polyols and the like can be mentioned. Specifically, for example, glycerin-
Ethylene oxide adduct, glycerin-propylene oxide adduct, glycerin-tetrahydrofuran adduct,
Glycerin-ethylene oxide-propylene oxide adduct, trimethylolpropane-ethylene oxide adduct, trimethylolpropane-propylene oxide adduct, trimethylolpropane-tetrahydrofuran adduct, trimethylolpropane-ethylene oxide-propylene oxide adduct, pentaerythritol-ethylene oxide addition Product, pentaerythritol-propylene oxide adduct, pentaerythritol-tetrahydrofuran adduct, pentaerythritol-ethylene oxide-propylene oxide adduct, dipentaerythritol-ethylene oxide adduct, dipentaerythritol-propylene oxide adduct, dipentaerythritol-tetrahydrofuran addition Substance, dipentaerythritol-ethyleneoxy - propylene oxide adduct and the like, but not particularly limited. One of these polyhydroxy compounds may be used alone, or two or more of them may be used as a mixture.

The hydroxyl group-containing (meth) acrylic compound used as a raw material of the urethane (meth) acrylate resin is not particularly limited, but is preferably a hydroxyl group-containing (meth) acrylic ester. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, tris (hydroxyethyl) Di (meth) acrylate of isocyanuric acid,
Pentaerythritol tri (meth) acrylate; One of these hydroxyl group-containing (meth) acrylic compounds may be used alone, or two or more of them may be used as a mixture.

The hydroxyl group-containing allyl ether compound optionally used as a raw material of the urethane (meth) acrylate resin includes, for example, ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, triethylene glycol monoallyl ether. Ether, polyethylene glycol monoallyl ether, propylene glycol monoallyl ether, dipropylene glycol monoallyl ether, tripropylene glycol monoallyl ether, polypropylene glycol monoallyl ether, 1,2-butylene glycol monoallyl ether, 1,3-butylene glycol Monoallyl ether, hexylene glycol monoallyl ether, octylene glycol monoallyl ether, trimethylolpropane diallyl Ether, glycerol diallyl ether, although pentaerythritol triallyl ether, and the like, but is not particularly limited. One of these hydroxyl group-containing allyl ether compounds may be used alone, or two or more of them may be used as a mixture.

When a polyester (meth) acrylate resin is produced as the curable resin, for example, a dibasic acid and a polyhydric alcohol are subjected to a condensation reaction in the presence of N-oxyls to convert the polyester. After that, the desired polyester (meth) acrylate resin can be easily obtained by reacting a (meth) acrylic compound with the terminal of the polyester.

The dibasic acid used as a raw material of the polyester, that is, as a raw material of the polyester (meth) acrylate resin, is specifically, for example, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride. Α, β-unsaturated dibasic acids such as acids; phthalic acid, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride , Hexahydroterephthalic acid, hexahydroisophthalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, sebacic acid, 1,12-dodecane diacid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic anhydride, 4,4'-bisphenyldica Bonn acid and, although such a saturated dibasic acids such as those dialkyl esters, are not particularly limited. These dibasic acids are
One type may be used alone, or two or more types may be mixed and used as appropriate.

The polyhydric alcohol used as a raw material of the polyester, that is, the raw material of the polyester (meth) acrylate resin, specifically includes, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol. , Dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, 1,
3-butanediol, adduct of bisphenol A with propylene oxide or ethylene oxide, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane, 1,3-propanediol, 1,2-cyclohexaneglycol, 3-cyclohexane glycol, 1,4-cyclohexane glycol, para-xylene glycol, bicyclohexyl-4,4'-diol, 2,6-decalin glycol, 2,7-
Examples include, but are not particularly limited to, decalin glycol. One of these polyhydric alcohols may be used alone, or two or more of them may be used as a mixture.

Examples of the (meth) acrylic compound used as a raw material of the polyester (meth) acrylate resin include, for example, unsaturated glycidyl compounds, unsaturated monobasic acids such as (meth) acrylic acid and the like. Examples thereof include glycidyl esters, but are not particularly limited. These (meth) acrylic compounds are
One type may be used alone, or two or more types may be mixed and used as appropriate.

In the present invention, N to coexist in the reaction system
-Oxyls are not particularly limited, but, for example, a compound represented by the general formula (1)

[0036]

Embedded image

(Wherein, X ₁ and X ₂ each independently represent a hydrogen atom, a —OR ₅ group, a —OCOR ₆ group, a —NR ₇ R ₈ group or a ＝ O group, and R ₁ , R ₂ , R _3, R ₄ each independently represents an alkyl group having 1 or more carbon atoms, R _5, R
₆ , R ₇ and R ₈ each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms) and the general formula (2)

[0038]

Embedded image

(Wherein X ₃ , X ₄ and X ₅ are each independently a hydrogen atom, a —OR ₁₃ group, a —OCOR ₁₄ group, a —NR ₁₅
R represents a R ₁₆ group or ＝ O group, and R ₉ , R ₁₀ , R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 or more carbon atoms;
₁₃ , R ₁₄ , R ₁₅ , and R ₁₆ each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms), and a compound having at least one structure represented by the general formula (3):

[0040]

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(Wherein, R ₁₇ and R ₁₈ each independently represent an alkyl group having 4 or more carbon atoms).

Examples of N-oxyls having the above structure include, for example, di-t-butyl nitroxyl,
1-oxyl-2,2,6,6-tetramethylpiperidine, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-ol, 1-oxyl
Oxyl-2,2,6,6-tetramethylpiperidin-4-one,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl
-Acetate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-2-ethylhexanoate, 1-oxyl
-2,2,6,6-tetramethylpiperidin-4-yl-stearate, 1-oxyl-2,2,6,6-tetramethylpiperidine-
4-yl-4-t-butylbenzoate, bis (1-oxyl-
2,2,6,6-tetramethylpiperidin-4-yl) succinate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) adipate, bis (1- Oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) n-butylmalonate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) phthalate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) isophthalate, bis ( 1-oxyl
-2,2,6,6-tetramethylpiperidin-4-yl) terephthalate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) hexahydroterephthalate, N, N'-
Bis (1-oxyl-2,2,6,6-tetramethylpiperidine-
4-yl) adipamide, N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) caprolactam, N- (1-oxyl-2,2,6,6-tetramethylpiperidine- 4-yl) dodecylsuccinimide, 2,4,6-tris-N-butyl-N- (1-
Oxyl-2,2,6,6-tetramethylpiperidin-4-yl)
Examples include -s-triazine, but are not particularly limited. One of these N-oxyls may be used alone, or two or more of them may be used as a mixture.

The amount of N-oxyls present in the reaction system,
In other words, the amount used is not particularly limited, but is 0.00001 parts by weight to 100 parts by weight of the obtained curable resin.
It is preferably in the range of 1 part by weight, more preferably in the range of 0.001 part by weight to 0.05 part by weight. If the use amount of the N-oxyls is less than 0.00001 part by weight, the gelation preventing effect at the time of production cannot be obtained, and there is a possibility that a production trouble due to gelation may occur. On the other hand, if the amount of the N-oxyl exceeds 1 part by weight, even if a resin is obtained without gelling at the time of production, the curability of the obtained resin may be impaired, which is not preferable.

The method for allowing the above-mentioned N-oxyls to coexist in the reaction system is not particularly limited.
A raw material to be a curable resin is charged into a reactor and heated to a predetermined temperature while stirring, that is, a reaction temperature, and then N-oxyls are supplied. Various methods can be used, such as a method of starting the reaction after supplying and mixing the compounds.

In the present invention, there are no particular restrictions on the mixing conditions of the respective raw materials to be the above-mentioned curable resin, and they may be appropriately set according to the desired physical properties of the curable resin. In addition, the reaction temperature when performing each of the above reactions is not particularly limited, and may be appropriately set so that each reaction can be performed efficiently. For example, the reaction temperature when an epoxy compound and an unsaturated monobasic acid are reacted in the presence of N-oxyls using an esterification catalyst is not particularly limited, but may be in the range of 60 ° C to 150 ° C. It is preferable to set within. Also, the reaction time is not particularly limited, and may be appropriately set so that the reaction is completed according to the type and combination of the raw materials, the amount used, the reaction temperature, and the like. Further, the reaction pressure is not particularly limited, and may be any of normal pressure (atmospheric pressure), reduced pressure, and increased pressure.

In carrying out each of the above reactions, a polymerization regulator (polymerization inhibitor), a solvent and a reactive monomer may be used as necessary. As the polymerization regulator, specifically,
Examples include hydroquinone, methylhydroquinone, methoxyhydroquinone, t-butylhydroquinone, benzoquinone, catechol, copper naphthenate, copper powder and the like, but are not particularly limited. The amount of use is not particularly limited.

Each of the above reactions can be carried out without a solvent, but a solvent may be used. The solvent is not particularly limited, and the amount of the solvent is not particularly limited.

The reactive monomer may be appropriately selected according to the purpose of use or application, and is not particularly limited. Specific examples thereof include styrene, divinylbenzene, and chlorobenzene. Examples include styrene, methacrylate, diallyl phthalate, vinyl acetate, and trimethylolpropane triacrylate. One of these reactive monomers may be used alone, or two or more of them may be appropriately used in combination. These reactive monomers may be used as a solvent in the synthesis of a curable resin, or may be used as a solvent for a high-viscosity curable resin for adjusting the viscosity.

As described above, the method for producing a curable resin according to the present invention is a method in which a component forming the curable resin is reacted in the presence of N-oxyls. N-oxyls having at least one of the structures represented by the general formulas (1) and (2) at the molecular chain terminals are preferable. Further, the production method of the present invention is applicable to the production of general curable resins, and among them, selected from the group consisting of vinyl ester resins, urethane (meth) acrylate resins, and polyester (meth) acrylate resins. It can be particularly suitably used as a kind of resin production method. In the present invention, the amount of the N-oxyl used is preferably in the range of 0.00001 part by weight to 1 part by weight based on 100 parts by weight of the obtained curable resin. Thereby, a light-colored curable resin having excellent corrosion resistance, chemical resistance, water resistance, heat resistance, mechanical properties, and the like can be obtained. Therefore, the curable resin obtained by the above manufacturing method is widely used in the fields of molding materials for FRP, molding materials for casting, lining materials, paints, etc. It can be suitably used for a wide range of applications such as required applications.

[0050]

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” indicates “parts by weight”, and “%” indicates “% by weight”. The coloring degree of each resin was evaluated as a Hazen color number, and the Hazen color number was measured according to JIS K6901.

First, 2.49 g of potassium chloroplatinate (special grade)
And 2.00 g of cobalt chloride (special grade) and 200 ml of hydrochloric acid (special grade)
, And diluted to 2000 ml with distilled water to obtain standard stock solutions. Next, this standard stock solution was used according to JIS K
The resulting solution was dissolved at a ratio specified in 6901 to obtain a Hazen color number standard solution. Then, each of the Hazen color number standard solution and the obtained resin was poured into a flat bottomed glass tube with a stopper with a colorless and transparent inside diameter of 23 mm and a height of 100 mm from the bottom,
It was set upright on a white plate. Next, the concentration (coloring degree) of the Hazen color number standard solution and the resin in the flat bottom glass tube was
Under diffuse daylight, comparisons were made visually from above the flat-bottom glass tube. Then, the Hazen color number standard solution having the concentration closest to the obtained resin was selected, and the Hazen color number of the obtained resin was determined.

Example 1 A 5 L four-necked flask equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer was prepared by:
Bisphenol type epoxy resin having an epoxy equivalent of 465 (trade name “YD-901” manufactured by Toto Kasei Co., Ltd .; hereinafter, “YD-
901 "), 480 g of methacrylic acid as an unsaturated monobasic acid, 8.90 g of tetraphenylphosphonium bromide (hereinafter referred to as esterification catalyst (B)) as an esterification catalyst, and N-oxyls. There is 4-
50 mg of hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (hereinafter referred to as N-oxyls (A)) was charged and stirred. Next, the mixture was reacted at 115 ° C. for 7 hours while flowing dry air through the four-necked flask at a flow rate of 30 ml / min, and 1600 g of a styrene monomer as a reactive monomer was added to obtain a vinyl ester resin. The acid value of the vinyl ester resin measured by a predetermined method is 5.0 mg KOH /
g and Hazen color number was 20.

Example 2 In the same four-necked flask as in Example 1, 2500 g of “YD-901” and a bisphenol-type epoxy resin having an epoxy equivalent of 185 (trade name “YD-127” manufactured by Toto Kasei Co., Ltd .; , “YD-127”) 5
80 g, methacrylic acid 750 g, esterification catalyst (B) 11.50
g and N-oxyls (A) (600 mg) were charged and stirred. Next, 30 ml of nitrogen gas was added to the above four-necked flask.
After reacting at 115 ° C. for 7 hours while flowing at min, 2100 g of a styrene monomer as a reactive monomer was added to obtain a vinyl ester resin. The acid value of the vinyl ester resin measured by a predetermined method is 5.0 mgKOH / g,
The Hazen color number was 5.

[Comparative Example 1] In the same four-necked flask as in Example 1, 2500 g of "YD-901" and "YD-127"
80 g, 480 g of methacrylic acid, esterification catalyst (B) 8.90
g and 1.20 g of 4-methoxyphenol as a known polymerization inhibitor were charged, and a vinyl ester resin for comparison was obtained in the same manner as in Example 1. The acid value of the comparative vinyl ester resin measured by a predetermined method is 5.0 mgK.
OH / g and Hazen color number was 120.

[Comparative Example 2] A method similar to that of Example 1 was used except that in place of N-oxyls (A), 1.20 g of hydroquinone was used as a known polymerization inhibitor. A vinyl ester resin for comparison was obtained. The acid value of the comparative vinyl ester resin measured by a predetermined method was 5.0 mg KOH / g, and the Hazen color number was 800.

Comparative Example 3 In Example 2, 11.80 g of 4-methoxyphenol was used in place of the N-oxyls (A).
The reaction and operation were conducted in the same manner as in Example 2 except for using, and gelation occurred 2 hours after the start of the reaction.

Example 3 In the same four-necked flask as in Example 1, 1500 g of hexamethylene diisocyanate as a polyisocyanate, 1400 g of styrene monomer, 2.4 g of dibutyltin dilaurate as a catalyst, and N-oxyls (A) 100 mg was charged and stirred. Next, while flowing dry air at 30 ml / min into the above four-necked flask,
After the temperature was raised to 90 ° C., 590 g of dipropylene glycol as polyhydric alcohol was added, and the reaction solution was heated to 60 ° C. to 70 ° C.
The reaction was carried out for 3 hours while maintaining the temperature. After that,
1270 g of hydroxypropyl methacrylate as a hydroxyl group-containing (meth) acrylic compound was added, and the mixture was reacted for 5 hours while heating to 100 ° C. to obtain a urethane (meth) acrylate resin. The resulting urethane (meth) acrylate resin had a Hazen color number of 20.

Comparative Example 4 A urethane for comparison was prepared in the same manner as in Example 3 except that 1.20 g of 4-methoxyphenol was used in place of the N-oxyls (A). A (meth) acrylate resin was obtained. The obtained urethane (meth) acrylate resin for comparison had a Hazen color number of 200.

Comparative Example 5 The same reaction and operation as in Example 3 were carried out except that 100 mg of 4-methoxyphenol was used in place of the N-oxyls (A). After the addition of 1270 g of propyl methacrylate, the mixture was reacted for 10 minutes while raising the temperature to 100 ° C., and gelled.

Example 4 In the same four-necked flask as in Example 1, propylene glycol as a polyhydric alcohol was placed.
1650 g, 1,800 g of diphthalic acid, isophthalic acid and 1,720 g of maleic anhydride were charged and stirred. Next, while flowing dry air at 30 ml / min into the four-necked flask,
The reaction was carried out at 00 ° C. for 8 hours to obtain an unsaturated polyester.
The acid value of the unsaturated polyester measured by a predetermined method was 60 mgKOH / g. Next, N-oxyls (A) 100 m
g, 650 g of glycidyl methacrylate, which is a (meth) acrylic compound, is added to the four-necked flask, and dry air is supplied to the four-necked flask.
The mixture was reacted at 140 ° C. for 3 hours while flowing at a flow rate of 30 ml / min to obtain a polyester (meth) acrylate resin. The Hazen color number of the obtained polyester (meth) acrylate resin is
It was 20.

Comparative Example 6 A comparative polyester (meth) was prepared in the same manner as in Example 4 except that 1.20 g of hydroquinone was used in place of the N-oxyls (A). An acrylate resin was obtained. The Hazen color number of the obtained polyester (meth) acrylate resin for comparison was 500.

Comparative Example 7 The same reaction and operation as in Example 4 were performed, except that 100 mg of hydroquinone was used in place of the N-oxyls (A).
After adding glycidyl methacrylate, dry air is 30ml / mi
When the reaction was carried out at 140 ° C. for 15 minutes while flowing at n, gelation occurred.

[0063]

As described above, the method for producing a curable resin according to the first aspect of the present invention has a constitution in which the components forming the curable resin are reacted in the presence of N-oxyls.

In the method for producing a curable resin according to claim 2 of the present invention, as described above, the above-mentioned N-oxyl is added to the terminal of the molecular chain by the general formula (1).

[0065]

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(Wherein X ₁ and X ₂ each independently represent a hydrogen atom, —OR ₅ group, —OCOR ₆ group, —NR ₇ R ₈ group or ＝ O group, and R ₁ , R ₂ , R _3, R ₄ each independently represents an alkyl group having 1 or more carbon atoms, R _5, R
₆ , R ₇ and R ₈ each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms) and the general formula (2)

[0067]

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(Wherein X ₃ , X ₄ and X ₅ are each independently a hydrogen atom, a —OR ₁₃ group, a —OCOR ₁₄ group, a —NR ₁₅
R represents a R ₁₆ group or ＝ O group, and R ₉ , R ₁₀ , R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 or more carbon atoms;
₁₃ , R ₁₄ , R ₁₅ , and R ₁₆ each independently represent a hydrogen atom or an alkyl group having 1 to 16 carbon atoms).

According to a third aspect of the present invention, there is provided a method for producing a curable resin, wherein the curable resin comprises a vinyl ester resin, a urethane (meth) acrylate resin, and a polyester (meth) acrylate resin. The configuration is a kind of resin selected from the group consisting of:

As described above, in the method for producing a curable resin according to the fourth aspect of the present invention, the amount of the N-oxyl used is preferably 0.00001 to 1 part by weight based on 100 parts by weight of the obtained curable resin. The configuration is a weight part.

According to the present invention, a light-colored curable resin can be efficiently and stably produced without impairing the excellent physical properties such as corrosion resistance, chemical resistance, water resistance, heat resistance and mechanical properties of the curable resin. It also has the effect of being able to do so.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C08L 63/10 C08L 63/10 67/06 MSD 67/06 MSD

Claims (4)

[Claims] 1. A method for producing a curable resin, comprising reacting a component forming the curable resin in the presence of N-oxyls. 2. The above-mentioned N-oxyls are added at the terminal of a molecular chain to the general formula (1). (Wherein X ₁ and X ₂ are each independently a hydrogen atom, —O
R ₅ groups, -OCOR ₆ group represents -NR ₇ R ₈ group or = O _{group, R 1, R 2, R} 3, R 4 each independently represents an alkyl group having 1 or more carbon atoms, R ₅ , R ₆ , R ₇ , R
₈ each independently represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms) and the general formula (2): (Wherein, X ₃ , X ₄ , and X ₅ each independently represent a hydrogen atom, a —OR ₁₃ group, a —OCOR ₁₄ group, a —NR ₁₅ R ₁₆ group, or a ＝ O group, and R ₉ , R ₁₀ , R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 or more carbon atoms, and R ₁₃ , R ₁₄ ,
R ₁₅ and R ₁₆ each independently represent a hydrogen atom or a carbon atom
2. The method according to claim 1, wherein the compound has at least one structure selected from the structures represented by (1 to 16). 3. The method according to claim 1, wherein the curable resin is a vinyl ester resin,
The method for producing a curable resin according to claim 1, wherein the resin is a kind of resin selected from the group consisting of a urethane (meth) acrylate resin and a polyester (meth) acrylate resin. 4. The amount of the N-oxyl used is 0.00001 parts by weight to 1 part by weight based on 100 parts by weight of the obtained curable resin.
4. The method according to claim 1, wherein the amount is part by weight.
13. The method for producing a curable resin according to the above item.