JP2021138910A - Modified epoxidized polybutadiene, epoxy resin composition, cured product, can coating, and can film - Google Patents

Abstract

To provide a modified epoxidized polybutadiene that has excellent compatibility with a curing agent and a catalyst and excellent solvent solubility in the production of a coating, reduces problems in processing such as gelation, and can form a film with excellent workability, the modified epoxidized polybutadiene suitable for a can coating.SOLUTION: A modified epoxidized polybutadiene has a constitutional unit represented by the following formula (1) and/or a constitutional unit represented by the following formula (2). The modified epoxidized polybutadiene is prepared by a reaction between an epoxidized polybutadiene (A) and a monovalent phenol (B) represented by the following formula (3).SELECTED DRAWING: None

Description

The present invention relates to modified epoxidized polybutadiene, epoxy resin compositions and cured products, can paints and can coatings.

Epoxy resins are widely used in the fields of paints, civil engineering, adhesives, electrical materials, etc. because they are excellent in heat resistance, adhesiveness, electrical properties, and the like. In particular, the bisphenol type epoxy resin is widely used not only for the above-mentioned applications but also for coating the inside of beverage cans.
In such a wide range of applications, a new epoxy resin different from the bisphenol type epoxy resin is recently required.

Examples of epoxy resins other than bisphenol type epoxy resins in can paint applications include epoxidized polybutadiene. For example, Patent Document 1 describes a coating composition in which epoxidized polybutadiene is modified with a polyhydric phenol to improve compatibility between epoxidized polybutadiene and a resole-type phenol resin and to have excellent processability of a coating film. It is disclosed.

On the other hand, as a means for modifying an epoxy resin, Patent Document 2 states that by reacting a cresol novolak resin with monohydric phenols, the number of functional groups of the resin is adjusted and the hardness and brittleness of the cured product are improved. It is disclosed.

Japanese Unexamined Patent Publication No. 02-09916 Special Publication No. 59-043047

The epoxidized polybutadiene modified with the polyvalent phenol described in Patent Document 1 often has poor compatibility with the curing agent and the catalyst, and the paint using this modified epoxidized polybutadiene has a component separated during storage, or the compounding components are separated. There is a problem that the physical properties of the coating film are deteriorated due to the occurrence of quality spots after curing.
Further, when the polyfunctional epoxidized polybutadiene is reacted with the polyhydric phenol by the method described in Patent Document 1, gelation may occur, which may impair the solvent solubility during the production of the paint, or when the powder is used as it is. Even so, the local gel may affect the quality of the coating film. It is conceivable to try to suppress gelation by controlling the process at the time of manufacturing, such as stopping the reaction before gelation occurs, but in this case, there is a concern that the process control at the time of manufacturing becomes complicated and the manufacturing quality deteriorates. There is a concern that it will invite.

Further, the method described in Patent Document 2 can improve the hardness and brittleness as compared with the unmodified epoxy resin, but when the application to can paint is considered, the modified epoxy resin described in Patent Document 2 can be improved. However, the molecular weight was small, the improvement in hardness and brittleness was not sufficient, and the can-making process after forming the coating film could not be withstood.

The present invention has been made in view of the above problems of the prior art.
That is, the subject of the present invention is to reduce problems in the manufacturing process such as gelation, to form a coating film having excellent compatibility with a curing agent and a catalyst, solvent solubility during paint manufacturing, and further excellent processability. It is an object of the present invention to provide a modified epoxidized polybutadiene suitable for a can paint, an epoxy resin composition containing the modified epoxidized polybutadiene and a cured product thereof, and a can paint and a can coating film.

As a result of diligent studies to solve the above problems, the present inventors obtained by introducing a repeating unit having a specific structure into epoxidized polybutadiene, more preferably by reacting epoxidized polybutadiene with monovalent phenol. It was found that the above-mentioned problems could be solved by the modified epoxidized polybutadiene, and the invention was completed.

That is, the gist of the present invention lies in the following [1] to [10].

[1] A modified epoxidized polybutadiene containing a structural unit represented by the following formula (1) and / or a structural unit represented by the following formula (2).

(In formulas (1) and (2), R ^{3 to} R ⁷ independently have a hydrogen atom, a halogen atom, a nitro group, a nitrile group, an amino group, an azide group, a cyano group, or 1 to 20 carbon atoms. However, ^{the carbon atom constituting the benzene ring to which R 3 to} R ⁷ is bonded may be substituted with a nitrogen atom. In that case, the nitrogen atom may be substituted. Substituents do not bond. In addition, ^{some of R 3 to} R ⁷ may be bonded to each other to form a ring that condenses with this benzene ring. Further, the hydrocarbon having 1 to 20 carbon atoms. In the group, a part of carbon atom and / or hydrogen atom may be replaced with oxygen atom or sulfur atom.)

[2] The modified epoxidized polybutadiene according to [1], which is obtained by reacting an epoxidized polybutadiene (A) with a monohydric phenol (B) represented by the following formula (3).

In formula (3), R ^{3 to} R ⁷ are independently substituted or unsubstituted with a hydrogen atom, a halogen atom, a nitro group, a nitrile group, an amino group, an azide group, a cyano group, or 1 to 20 carbon atoms. However, ^{the carbon atom constituting the benzene ring to which R 3 to} R ⁷ are bonded may be substituted with a nitrogen atom. In that case, the substituent is not bonded to the nitrogen atom. Further, ^{a part of R 3 to} R ⁷ may be bonded to each other to form a ring condensing on the benzene ring. Further, the hydrocarbon group having 1 to 20 carbon atoms is a carbon atom. And / or part of the hydrogen atom may be replaced with an oxygen atom or a sulfur atom.)

[3] The modified epoxidized polybutadiene according to [2], wherein the modification rate (%) calculated by the following formula (I) is 5 to 90.
Degeneration rate (%) = (([a]-[d]) / [a]) × 100 ... (I)
(In the formula (I), [a] = [weight of epoxidized polybutadiene (A)] / [epoxy equivalent of epoxidized polybutadiene (A)], [d] = ([weight of epoxidized polybutadiene (A)] + [Weight of monovalent phenol (B)]) / [Epoxy equivalent of modified epoxidized polybutadiene].)

[4] The modified epoxidized polybutadiene according to any one of [1] to [3], wherein the epoxy equivalent is 200 to 50,000 g / equivalent.

[5] An epoxy resin composition containing the modified epoxidized polybutadiene according to any one of [1] to [4] and a curing agent.

[6] The curing agent comprises polyhydric phenols, polyisocyanate compounds, amine compounds, acid anhydride compounds, imidazole compounds, amide compounds, mercaptan compounds, cationic polymerization initiators and organic phosphines. The epoxy resin composition according to [5], which comprises at least one selected from the group.

[7] The epoxy resin composition according to [6], wherein the curing agent is a resol type phenol resin.

[8] A cured product obtained by curing the epoxy resin composition according to any one of [5] to [7].

[9] A can paint comprising the epoxy resin composition according to any one of [5] to [7].

[10] A can coating film made of the cured product according to [8].

According to the present invention, problems in the manufacturing process such as gelation can be reduced, and a coating film having excellent compatibility with a curing agent or a catalyst, solvent solubility during paint manufacturing, and excellent processability can be formed. Provided are modified epoxidized polybutadienes suitable for can paints, epoxy resin compositions, and cured products thereof.
Due to these features, the modified epoxidized polybutadiene, epoxy resin composition, and cured product of the present invention are used in the fields of electrical and electronic materials, FRP (fiber reinforced plastics), adhesives, paints, etc., especially can paints. It can be suitably used in applications.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following description, and can be arbitrarily modified and carried out without departing from the gist of the present invention. In the present specification, when a numerical value or a physical property value is sandwiched before and after using "~", it is used as including the values before and after that.

[Modified epoxidized polybutadiene]
The modified epoxidized polybutadiene of the present invention contains a structural unit represented by the following formula (1) and / or a structural unit represented by the following formula (2).

(In formulas (1) and (2), R ^{3 to} R ⁷ independently have a hydrogen atom, a halogen atom, a nitro group, a nitrile group, an amino group, an azide group, a cyano group, or 1 to 20 carbon atoms. However, ^{the carbon atom constituting the benzene ring to which R 3 to} R ⁷ is bonded may be substituted with a nitrogen atom. In that case, the nitrogen atom may be substituted. Substituents do not bond. In addition, ^{some of R 3 to} R ⁷ may be bonded to each other to form a ring that condenses with this benzene ring. Further, the hydrocarbon having 1 to 20 carbon atoms. In the group, a part of carbon atom and / or hydrogen atom may be replaced with oxygen atom or sulfur atom.)

In the above formulas (1) and (2), in R ^{3 to} R ⁷ , there is a possibility that the polar side chain interacts with a nearby hydroxyl group or butadiene skeleton, and the flexibility of the modified epoxidized polybutadiene is lost. From a low point of view, each independently has a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms (the hydrocarbon group having 1 to 20 carbon atoms is a part of a carbon atom and / or a hydrogen atom). It may be replaced with an oxygen atom or a sulfur atom).

Substituted or unsubstituted hydrocarbon groups having 1 to 20 carbon atoms (in the hydrocarbon groups having 1 to 20 carbon atoms, a part of carbon atoms and / or hydrogen atoms may be replaced with oxygen atoms or sulfur atoms. ) Examples include substituted or unsubstituted aliphatic hydrocarbon groups, alkoxy groups, alkylthio groups, acyl groups, substituted or unsubstituted aromatic hydrocarbon groups. From the viewpoint of availability, a substituted or unsubstituted aliphatic hydrocarbon group or a substituted or unsubstituted aromatic hydrocarbon group is preferable.

Examples of the substituted or unsubstituted aromatic hydrocarbon group include a phenyl group, a 4-carboxy-3-fluorophenyl group and a 2-methyl-4-thiazolyl group, and a phenyl group is preferable from the viewpoint of economy.

Examples of the substituted or unsubstituted aliphatic hydrocarbon group include a substituted or unsubstituted alkyl group, a cycloalkyl group, an alkenyl group, an alkazienyl group, an alkatrienyl group and the like, and more specifically, a methyl group and an ethyl group. Group, propyl group, isopropyl group, butyl group, nonyl group, octyl group, tert-butyl group, tert-amyl group, cyclohexyl group, isopropenyl group, vinyl group, benzyl group, 1-phenylethyl group, 1,1, Examples thereof include a 3,3-tetramethylbutyl group, a pentadecyl group, an 8-pentadecenyl group, an 8,11-pentadecadienyl group and an 8,11,14-pentadecatrienyl group. In particular, the bulky structures tert-butyl group, tert-amyl group, and cyclohexyl group are more preferable because they can suppress excessive stacking interaction between benzene rings and reduce the hardness and brittleness of the modified epoxidized polybutadiene. In terms of economy, a benzyl group and a 1-phenylethyl group are preferable.

Of R ^{3 to} R ⁷ , when the side chain of the benzene ring is adjacent to a nearby hydroxyl group or butadiene skeleton, excessive interaction occurs, and from the viewpoint of reducing the possibility of losing the flexibility of the modified epoxidized polybutadiene, R ³ , R ⁷ is preferably a hydrogen atom, and R ⁴ , R ⁵ and / or R ⁶ , particularly R ⁵ is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms (the carbon atoms 1 to 1). It is preferable that the hydrocarbon group of 20 is a carbon atom and / or a part of a hydrogen atom is replaced with an oxygen atom or a sulfur atom).

The modified epoxidized polybutadiene of the present invention has a structural unit represented by the formula (1) and / or a structural unit represented by the formula (2) in the molecular chain, so that it can be used as a phase with a curing agent, a catalyst, or a solvent. It is possible to obtain an epoxy resin composition and a cured product suitable for can paint, which are excellent in solubility, can suppress the occurrence of gelation, and can form a coating film having excellent processability.
This is because when the epoxidized polybutadiene is modified, a monovalent phenol having no two or more active hydrogens in one molecule is used in the main chain of the epoxidized polybutadiene, so that it is difficult to form a crosslinked structure at the time of production. .. Further, since it has a flexible polybutadiene skeleton and a rigid aromatic ring derived from monohydric phenol in the molecule, it is possible to achieve both hardness and flexibility of the coating film formed when used as a can paint. Further, by controlling the denaturation rate described later and appropriately selecting the type of monohydric phenol to be used, this flexibility and hardness can be easily controlled according to the application.

The modified epoxidized polybutadiene of the present invention may contain the structural unit represented by the above formula (1) and / or the structural unit represented by the above formula (2), but is preferably represented by the following formula (4). Examples thereof include modified epoxidized polybutadiene having a repeating structure.

In the above equation (4), i to q are positive integers of 0 or more, and o + p ≧ 1, i + k + m ≧ 1, j + l + n ≧ 1, and q ≧ 1.
R ¹ and R ² are hydrogen atoms, hydroxyl groups, or alkyl groups having 1 to 5 carbon atoms, and hydrogen atoms are preferable from the viewpoint of economy.
^R 3 to R ⁷ in formula (4), the formula (1) and is synonymous with ^R 3 to R ⁷ in formula (2).

The epoxy equivalent of the modified epoxidized polybutadiene of the present invention is not particularly limited, but is preferably 200 g / equivalent or more, more preferably 400 g / equivalent or more, and particularly preferably 500 g / equivalent or more. The epoxy equivalent of the modified epoxidized polybutadiene of the present invention is preferably 50,000 g / equivalent or less, more preferably 30,000 g / equivalent or less, and particularly preferably 10,000 g / equivalent or less.
The epoxy equivalent of the modified epoxidized polybutadiene of the present invention depends on whether it is for a can paint, a water-based paint that has undergone a water-based step, a solvent paint that is used by dissolving it in a solvent, or a solvent-free powder paint. Since the required epoxy equivalent is different, it may be appropriately selected according to the application. However, if the epoxy equivalent is less than 200 g / equivalent, the coating material has excellent strength, but becomes hard and brittle, and when the coating material is processed. Defects may occur. On the contrary, when the amount exceeds 50,000 g / equivalent, the coating material tends to have high toughness, but the crosslinked structure with the curing agent is reduced, so that the strength or elasticity tends to be low. Therefore, it is preferable to adjust the epoxy equivalent of the modified epoxidized polybutadiene of the present invention within the above range.
In the present invention, the "epoxy equivalent" is defined as "the mass of an epoxy compound containing 1 equivalent of an epoxy group" and can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the modified epoxidized polybutadiene of the present invention is preferably 2,000 or more, more preferably 5,000 or more, and particularly preferably 6,000 or more. The weight average molecular weight (MW) is preferably 200,000 or less, more preferably 100,000 or less, and particularly preferably 50,000 or less.
By setting the weight average molecular weight (MW) of the modified epoxidized polybutadiene to the above range, the coating film is not hard and brittle and has abundant toughness, so that the coating film has excellent processability and is solvent-soluble and water-soluble. Since it is excellent, it is possible to produce a coating film having no quality unevenness.

Further, the value of the molecular weight distribution (= weight average molecular weight (Mw) / number average molecular weight (Mn)) of the modified epoxidized polybutadiene of the present invention is preferably 1.1 or more, and preferably 1.2 or more. More preferably, it is 1.3 or more, and particularly preferably 1.3 or more. The molecular weight distribution is preferably 5.0 or less, more preferably 4.0 or less, further preferably 3.0 or less, and particularly preferably 2.0 or less.
If the molecular weight distribution of the modified epoxidized polybutadiene is within the above range, the process control at the time of production is not complicated, and the coating film quality can be controlled from the viewpoint that it does not contain excessively high molecular weight components or low molecular weight components. It is possible to obtain a modified epoxidized polybutadiene which is easy and has excellent processability of the coating film.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the modified epoxidized polybutadiene can be measured by a gel permeation chromatography method (GPC method). An example of a more detailed method will be described in Examples described later. The same applies to the number average molecular weight (Mn) of the epoxidized polybutadiene (A) described later.

The modified epoxidized polybutadiene of the present invention is usually obtained by reacting the epoxidized polybutadiene (A) described later with a monovalent phenol (B), and the modification rate thereof is preferably 5% or more, preferably 30%. The above is more preferable, and 40% or more is particularly preferable. By setting the modification rate to 5% or more, the compatibility with the curing agent, catalyst, and solvent can be improved, and the balance between the hardness and softness of the obtained modified epoxidized polybutadiene can be controlled. There is a tendency to improve the impact resistance (weight drop resistance described later). In particular, when the denaturation rate is 40% or more, the blocking resistance during storage is also excellent. On the other hand, the modification rate is preferably 90% or less, more preferably 80% or less, and particularly preferably 75% or less. If the modification rate is 90% or less, an unreasonable manufacturing process is not required, and there is a tendency that a conventionally known manufacturing process can be used. In addition, when the curing agent reaction at the time of forming a can coating film is taken into consideration, It can be said that it has a sufficient epoxy group. When this modification rate is 75% or less, the production efficiency at the time of production is good, the production can be sufficiently carried out under mild conditions, the quality unevenness is small, and stable production is possible.

The modification rate (%) of the modified epoxidized polybutadiene in the present invention is a value calculated by the following formula (I).
Degeneration rate (%) = (([a]-[d]) / [a]) × 100 ... (I)
In the formula (I), [a] and [d] are used in the production of the modified epoxidized polybutadiene of the present invention described below, and thus they are added to the modified epoxidized polybutadiene and incorporated into the modified epoxidized polybutadiene (the epoxidized polybutadiene ( It is based on A) and monovalent phenol (B) and is as follows.
[A] = [Weight of epoxidized polybutadiene (A)] / [Epoxy equivalent of epoxidized polybutadiene (A)]
[D] = ([Weight of epoxidized polybutadiene (A)] + [Weight of monovalent phenol (B)]) / [Epoxy equivalent of modified epoxidized polybutadiene]

The modified epoxidized polybutadiene of the present invention can be determined to have the above compound added by the SEC-MALS method, the elemental analysis method, and the functional group analysis.

[Epoxyted polybutadiene (A)]
The pre-modified epoxidized polybutadiene (A) used in the production of the modified epoxidized polybutadiene of the present invention has an oxylan group introduced by utilizing a double bond in a liquid polybutadiene resin and a functional group such as a hydroxyl group and a carboxyl group. Anyway, conventionally known epoxidized polybutadiene can be used.

The epoxidized polybutadiene (A) can be produced by a known method.
For example, there is a method of introducing an oxylan group by utilizing a double bond in a liquid polybutadiene resin, and specifically, it can be obtained by epoxidizing a liquid polybutadiene resin with a peracid such as peracetic acid or performic acid.
Further, there is a method of introducing an oxylan group using a hydroxyl group in a liquid polybutadiene resin, and specifically, it can be obtained by reacting a liquid polybutadiene resin with a small molecule epoxy compound such as epihalohydrin.
Further, there is a method of introducing an oxylan group by utilizing a carboxyl group in the liquid polybutadiene resin. Specifically, the liquid polybutadiene resin is reacted with a compound or resin having an average of two or more oxylan groups in one molecule. Can be obtained by
Among the above, since there is no possibility that the molecular weight will increase, it is preferable to use one in which an oxylan group is introduced by utilizing a double bond or a hydroxyl group in the liquid polybutadiene resin.

As the liquid polybutadiene resin, one containing 10% by weight or more of 1,2-butadiene units in the polybutadiene resin can be used.

Further, the epoxidized polybutadiene (A) contains oxylan oxygen (oxygen atom in the oxylan group) on average 1 to 20% by weight, particularly 1 to 15% by weight on average, and has a number average molecular weight (Mn). 800 to 10,000, particularly 1,000 to 5,000 are preferable. The epoxy equivalent of the epoxidized polybutadiene (A) is 80 to 1600 g / equivalent, particularly preferably 107 to 1600 g / equivalent.
When the oxylane oxygen content of the epoxidized polybutadiene (A) is less than the above lower limit or the epoxy equivalent exceeds the above upper limit, the amount of phenol component chemically bonded to the obtained modified epoxidized polybutadiene is reduced, so that the curing agent The compatibility with the catalyst and the solvent is poor, and as a result, a coating film having insufficient storage stability and poor processability, retort resistance, and adhesion to metal tends to be formed. On the other hand, those having an oxylan oxygen content exceeding the above upper limit and those having an epoxy equivalent less than the above lower limit are difficult to obtain. Further, when the number average molecular weight (Mn) is less than 800, the finally formed coating film adheres, so that the line workability is inferior and the coating film performance is also inferior. On the other hand, if the number average molecular weight (Mn) is larger than 10,000, the viscosity of the modified epoxidized polybutadiene increases rapidly, which tends to make the production difficult.

As the epoxidized polybutadiene (A), a commercially available product may be used, and examples of the commercially available product include JP-100 (manufactured by Nippon Soda Co., Ltd.), JP-200 (manufactured by Nippon Soda Co., Ltd.), and Ricon657 (clay valley). , PB3600 (manufactured by Daicel), PB4700 (manufactured by Daicel), BF-1000 (manufactured by ADEKA) and the like.

The epoxidized polybutadiene (A) may be used alone or in combination of two or more.

[Monovalent phenol (B)]
The monovalent phenol (B) used in the present invention is a compound having one phenolic hydroxyl group in the molecule, and is preferably represented by the following formula (3).

(In the formula (3), R ^{3 to} R ⁷ are synonymous with those in the formulas (1) and (2), and the preferable ones are also the same.)

The specific monohydric phenol (B) represented by the formula (3) is not particularly limited, and examples thereof include the following.
Phenol, methylphenol (various isomers), ethylphenol (various isomers), propylphenol (various isomers), isopropylphenol (various isomers), butylphenol (various isomers), nonylphenol (various isomers), octylphenol (various isomers) (Various isomers), tert-amylphenol (various isomers), cresol (various isomers), xylenol (various isomers), trimethylphenol (various isomers), cyclohexylphenol (various isomers), phenylphenol (various isomers) Body), tert-butylphenol (various isomers), tert-octylphenol (various isomers), allylphenol (various isomers), vinylphenol (various isomers), isopropenylphenol (various isomers), phenylphenol (various isomers) Isolates), benzylphenol (various isomers), 2- (1-phenylethyl) phenol (various isomers), methoxyphenol (various isomers), ethoxyphenol (various isomers), naphthol (various isomers), Hydroxypyrene (various isomers), hydroxypyridine, aminophenol, nitrophenol, hydroxybenzonitrile, azidophenol, eugenol, 4- (methylthio) phenol, hydroxyacetophenone, 4- (4-carboxy-3-fluorophenyl) phenol, Examples include, but are not limited to, 4- (2-methyl-4-thiazolyl) phenol, pentadecylphenol (various isomers), cardanol and the like.

These monovalent phenols (B) may be used alone or in a plurality of types.

As the monovalent phenol (B), a suitable monovalent phenol (B) may be selected according to the required coating film physical characteristics and the process at the time of production, and in particular, phenol having an aromatic ring tends to be excellent in terms of coating film physical characteristics. .. Examples of the phenol having an aromatic ring include phenylphenol, benzylphenol, 2- (1-phenylethyl) phenol, 4- (4-carboxy-3-fluorophenyl) phenol, 4- (2-methyl-4-thiazolyl) phenol, etc. Is exemplified, but the present invention is not limited to these. When solubility in a weak solvent such as mineral spirit is required, a phenol having an aliphatic hydrocarbon group having 10 or more carbon atoms may be selected. Examples of phenol having an aliphatic hydrocarbon group having 10 or more carbon atoms include, but are not limited to, pentadecylphenol (various isomers) and cardanol. On the other hand, sublimable monohydric phenol is suitable for applications where residual phenol is disliked, because even if unreacted phenol remains in the system, the residual amount may be finally reduced by heating and distilling under reduced pressure. Can be used for. In particular, among monovalent phenols, compounds having a low molecular weight tend to have sublimation properties, and among them, tert-amylphenol, phenylphenol, and tert-butylphenol are preferable in view of economic efficiency and market availability. When a sublimable monohydric phenol is used, it is preferable to react with a reaction solvent. If a reaction solvent is used, the sublimated phenol can be returned to the system by the reaction solvent, and the reaction can proceed as planned.

[Manufacturing method of modified epoxidized polybutadiene]
The modified epoxidized polybutadiene of the present invention can be obtained by reacting the above-mentioned epoxidized polybutadiene (A) with monovalent phenol (B) in a suitable compounding ratio. The compounding ratio of the epoxidized polybutadiene (A) and the monohydric phenol (B) is not particularly limited as long as the modification rate (%) of the modified epoxidized polybutadiene is preferably 5 to 90. The suitable compounding ratio varies greatly depending on the molecular weight, reactivity and sublimation property of the monovalent phenol (B), but the weight ratio of the epoxidized polybutadiene (A) to the monovalent phenol (B) is preferably 99: 1 to 1:99. , 95: 5 to 50:50 is more preferable in terms of reducing the amount of unreacted monovalent phenol.

The modified epoxidized polybutadiene of the present invention can be produced in any reaction system with or without the reaction solvent (C) during the reaction, and the reaction solvent (C) is used. The presence or absence of the solvent may be selected based on the properties of the epoxidized polybutadiene (A) and the monohydric phenol (B) to be used. Further, by using the catalyst (D) during the reaction, the heating conditions during the production of the modified epoxidized polybutadiene can be moderated, and the reaction time can be shortened, so that the energy efficiency during the production can be improved. Further, the catalyst (D) may be appropriately selected in consideration of various restrictions during production because it tends to suppress unintended side reactions during production.

<Reaction solvent (C)>
When the reaction solvent (C) is used in the reaction step for producing the modified epoxidized polybutadiene of the present invention, the reaction solvent (C) is not particularly limited, but the following organic solvents can be preferably used. ..

Examples of the reaction solvent (C) include aromatic solvents, ketone solvents, amide solvents, glycol ether solvents and the like. Specific examples of the aromatic solvent include benzene, toluene, xylene and the like. Specific examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclopentanone, cyclohexanone, acetylacetone and the like. Specific examples of the amide solvent include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone and the like. Specific examples of glycol ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol. Examples thereof include mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol mono-n-butyl ether, propylene glycol monomethyl ether acetate and the like.

The reaction solvent (C) listed above may be used alone or in combination of two or more. Further, when a highly viscous product is generated during the reaction, the reaction solvent (C) can be further added to continue the reaction.

As the reaction solvent (C), a reaction solvent capable of dissolving the epoxidized polybutadiene (A) and the monohydric phenol (B) is preferable, but the epoxidized polybutadiene (A) and the monohydric phenol (B) are soluble. Even if it is low or absent, it may be possible to use it if the modified epoxidized polybutadiene after the reaction can be dissolved. Therefore, the reaction solvent (C) is the epoxidized polybutadiene (A) or monohydric phenol (B) to be used. ), And the properties of the modified epoxidized polybutadiene obtained may be selected.

<Catalyst (D)>
When the catalyst (D) is used in the reaction step for producing the modified epoxidized polybutadiene of the present invention, the catalyst (D) to be used is not particularly limited, and is generally used in the production of a conventionally known epoxy resin. The catalyst to be used can be used. For example, alkali metal compounds, organophosphorus compounds, tertiary amines, quaternary ammonium salts, cyclic amines, imidazoles and the like can be mentioned.

Specific examples of alkali metal compounds include alkali metal hydroxides such as sodium hydroxide, lithium hydroxide and potassium hydroxide; alkali metal salts such as sodium carbonate, sodium bicarbonate, sodium chloride, lithium chloride and potassium chloride; sodium. Alkali metal alkoxides such as methoxydo and sodium ethoxide; hydrides of alkali metals such as alkali metal phenoxide, sodium hydride and lithium hydride; alkali metal salts of organic acids such as sodium acetate and sodium stearate can be mentioned.

Specific examples of the organic phosphorus compound include triphenylphosphine, tri-o-trilphosphine, tri-m-trilphosphine, tri-p-trilphosphine, tri-2,4-kisilylphosphine, tri-2,5- Triphenylphosphine, tri-3,5-kisilylphosphine, tris (p-tert-butylphenyl) phosphine, tris (p-methoxyphenyl) phosphine, tris (p-tert-butoxyphenyl) phosphine, tri (pn) -Octylphenyl) phosphine, tri (pn-nonylphenyl) phosphine, triarylphosphine, tributylphosphine, trimethylphosphine, tribenzylphosphine, triisobutylphosphine, tri-tert-butylphosphine, tri-n-octylphosphine, tri Cyclophenylphosphine, tri-n-propylphosphine, di-t-butylmethylphosphine, tri-n-butylphosphine, cyclohexyldi-tert-butylphosphine, diethylphenylphosphine, di-n-butylphenylphosphine, di-tert-butyl Triphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, diphenylpropylphosphine, isopropyldiphenylphosphine, cyclophenylphosphine, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, Triphenylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzyl Examples thereof include phosphonium chloride, triphenylbenzylphosphonium bromide and the like.

Specific examples of the tertiary amines include triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, N, N-dimethylbenzylamine and the like.

Specific examples of the quaternary ammonium salt include tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium hydroxide, triethylmethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, and tetrapropylammonium bromide. Tetrapropylammonium hydroxide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium hydroxide, benzyltributylammonium chloride, phenyltrimethylammonium chloride, etc. Be done.

Specific examples of cyclic amines include 1,8-diazabicyclo (5,4,0) -7-undecene, 1,5-diazabicyclo (4,3,0) -5-nonene and the like.

Specific examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole and the like.

The catalyst (D) listed above may be used alone or in combination of two or more.

When the catalyst (D) is used, the amount used is the type of epoxidized polybutadiene (A) or monovalent phenol (B), the presence or absence of the reaction solvent (C) at the time of production, the ratio of the reaction solvent (C), the reaction temperature, and the like. In addition, the total reaction system including the activation temperature and deactivation temperature of the catalyst (D) may be determined from a bird's-eye view. For example, the amount of epoxidized polybutadiene (A) used is 50,000 wtppm or less. It is preferably 10 to 30,000 wt ppm.

When the catalyst (D) is used, the storage stability of the modified epoxidized polybutadiene may be lost due to the residual catalyst (D). A means of heating to reduce the catalytic activity or a catalyst (D) in which the catalyst (D) does not evaporate or volatilize during normal pressure production is used, and the catalyst (D) is evaporated or volatilized by heating under reduced pressure at the end of production. It is preferable to select the catalyst (D) in anticipation of means such as taking it out of the system.
Further, when the remaining catalyst (D) dissolves in water and exhibits strong acidity or strong alkalinity, an influence on metal corrosion is considered. From this point of view, tetramethylammonium chloride is exemplified as a suitable catalyst because the aqueous solution is neutral and metal corrosion due to the residual catalyst can be reduced. However, the catalyst (D) is not limited to this.

<Reaction conditions>
The reaction between the epoxidized polybutadiene (A) and the monohydric phenol (B) can be carried out under any conditions of normal pressure, pressure and reduced pressure.

The reaction temperature is usually 60 to 240 ° C, preferably 80 to 220 ° C, and more preferably 100 to 200 ° C. It is preferable that the reaction temperature is at least the above lower limit because the reaction can easily proceed. Further, when the reaction temperature is not more than the above upper limit, the side reaction is unlikely to proceed, which is preferable from the viewpoint of obtaining high-purity modified epoxidized polybutadiene.

The reaction time is not particularly limited, but is usually 0.5 to 24 hours, preferably 1 to 22 hours, and more preferably 1.5 to 20 hours. When the reaction time is not more than the above upper limit, it is preferable from the viewpoint of improving production efficiency, and when it is not more than the above lower limit, it is preferable from the viewpoint that unreacted components can be reduced.

<Diluting solvent (E)>
The modified epoxidized polybutadiene of the present invention may be mixed with a diluting solvent (E) after the reaction is completed to adjust the solid content concentration. The diluting solvent (E) may be any solvent as long as it dissolves the modified epoxidized polybutadiene, but is usually an organic solvent. As a specific example of the organic solvent, the same solvent as that mentioned above as the reaction solvent (C) can be used.

In the present invention, the terms "solvent" and "solvent" are used as "solvent" when used during the reaction and as "solvent" when used after the reaction is completed. Heterogeneous ones may be used.

[Epoxy resin-containing composition]
The epoxy resin composition of the present invention contains at least the above-mentioned modified epoxidized polybutadiene of the present invention and a curing agent. In addition, other epoxy compounds, curing accelerators, other components and the like can be appropriately added to the epoxy resin composition of the present invention, if necessary.

<Hardener>
The curing agent used in the epoxy resin composition of the present invention is a substance that contributes to the cross-linking reaction and / or the chain length extension reaction between the epoxy groups of the epoxy resin. In the present invention, even if it is usually called a "curing accelerator", if it is a substance that contributes to the cross-linking reaction and / or the chain length extension reaction between the epoxy groups of the epoxy resin, it is regarded as a curing agent. do.

The content of the curing agent in the epoxy resin composition of the present invention is preferably 0.1 to 1000 parts by weight, more preferably 100 parts by weight or less, based on 100 parts by weight of the modified epoxyized polybutadiene of the present invention. It is more preferably 80 parts by weight or less, and particularly preferably 60 parts by weight or less.
When the epoxy resin composition of the present invention contains other epoxy compounds described below other than the modified epoxyized polybutadiene of the present invention, the content of the curing agent is 100 parts by weight of the total epoxy component as a solid content. It is preferably 0.1 to 1000 parts by weight, more preferably 100 parts by weight or less, further preferably 80 parts by weight or less, and particularly preferably 60 parts by weight or less.
More preferable amounts of the curing agent are as described below according to the type of the curing agent.

In the present invention, the "solid content" means a solvent or a component excluding the solvent, and includes not only a solid epoxy resin or an epoxy compound but also a semi-solid or a viscous liquid substance. Further, the “total epoxy component” means the total of the modified epoxidized polybutadiene of the present invention and other epoxy compounds described later.

In the epoxy resin composition of the present invention, the curing agent is composed of polyfunctional phenols, polyisocyanate compounds, amine compounds, acid anhydride compounds, imidazole compounds, amide compounds, cationic polymerization initiators and organic phosphines. It is preferable to use at least one of the following groups.

Examples of polyfunctional phenols include bisphenols such as bisphenol A, bisphenol F, bisphenol S, bisphenol B, bisphenol AD, bisphenol Z, tetrabromobisphenol A, 4,4'-biphenol, 3,3', 5, Biphenols such as 5'-tetramethyl-4,4'-biphenols; catechol, resorcin, hydroquinone, dihydroxynaphthalene; and hydrogen atoms bonded to the aromatic ring of these compounds are halogen groups, alkyl groups, aryl groups, ethers. Examples thereof include those substituted with a non-interfering substituent such as an organic substituent containing a hetero element such as a group, an ester group, sulfur, phosphorus and silicon.

Further, examples thereof include novolaks and resoles which are polycondensates of these phenols, monofunctional phenols such as phenols, cresols and alkylphenols and aldehydes.

Examples of polyisocyanate compounds include tolylene diisocyanate, methylcyclohexane diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, dimerate diisocyanate, and trimethylhexamethylene diisocyanate. Examples thereof include polyisocyanate compounds such as lysine triisocyanate. Further, a polyisocyanate compound obtained by reacting these polyisocyanate compounds with a compound having at least two active hydrogen atoms such as an amino group, a hydroxyl group, a carboxyl group, and water, or 3 to 5 amounts of the above-mentioned polyisocyanate compound. The body etc. can be mentioned.

Examples of amine compounds include aliphatic primary, secondary, tertiary amines, aromatic primary, secondary, tertiary amines, cyclic amines, guanidines, urea derivatives, and the like. Ethylenetetramine, diaminodiphenylmethane, diaminodiphenyl ether, metaxylene diamine, dicyandiamide, 1,8-diazabicyclo (5,4,0) -7-undecene, 1,5-diazabicyclo (4,3,0) -5-nonen, dimethyl Examples include urea and guanyl urea.

Examples of the acid anhydride-based compound include phthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, and a condensate of maleic anhydride and an unsaturated compound.

Examples of imidazole compounds include 1-isobutyl-2-methylimidazole, 2-methylimidazole, 1-benzyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, benzimidazole and the like. Be done. Although the imidazole compound also functions as a curing accelerator described later, it is classified as a curing agent in the present invention.

Examples of the amide compound include dicyandiamide and its derivatives, polyamide resins and the like.

The cationic polymerization initiator is one that generates a cation by irradiation with heat or active energy rays, and examples thereof include aromatic onium salts. _{^{Specifically, SbF 6 -, BF 4 -}} , AsF 6 -, PF 6 -, CF 3 SO 3 2-, B (C 6 F 5) 4 - anions component and iodine, such as, sulfur, nitrogen, phosphorus, Examples thereof include a compound composed of an aromatic cation component containing the atom of. In particular, diaryliodonium salt and triarylsulfonium salt are preferable.

Examples of organic phosphines include tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine and the like, and examples of phosphonium salts include tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate and tetra. Examples include butylphosphonium, tetrabutylborate, and the like, and examples of the tetraphenylborone salt include 2-ethyl-4-methylimidazole, tetraphenylborate, N-methylmorpholine, tetraphenylborate, and the like.

Among these curing agents, it is particularly preferable to use a resol type phenol resin from the viewpoint that a cured product having a high crosslink density can be formed because it also has thermosetting property.

When a polyfunctional phenol, an amine compound, or an acid anhydride compound is used as the curing agent, the functional group in the curing agent (the hydroxyl group of the polyfunctional phenol, the amine compound) with respect to all the epoxy groups in the epoxy resin composition. Use so that the equivalent ratio (hereinafter, may be simply referred to as "hardener equivalent ratio") of the amino group or the acid anhydride group of the acid anhydride compound is in the range of 0.8 to 1.5. Is preferable. However, when using a resole-type phenol resin, it is not appropriate to specify the curing agent equivalent ratio because it has thermosetting property, and the weight ratio of the curing agent to the total epoxy resin (hereinafter, simply "curing agent weight"). It may be referred to as "ratio"), and it is preferable to use it in the range of 0.01 to 10. When a polyisocyanate compound is used, it is preferable that the number of isocyanate groups in the polyisocyanate compound is in the range of 1: 0.01 to 1: 1.5 in an equivalent ratio with respect to the number of hydroxyl groups in the epoxy resin composition. .. When an imidazole compound is used, it is preferably used in the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the total epoxy component as a solid content in the epoxy resin composition. When an amide compound is used, it is preferably used in the range of 0.1 to 20% by weight based on the total amount of the total epoxy component as a solid content in the epoxy resin composition and the amide compound. When a cationic polymerization initiator is used, it is preferably used in the range of 0.01 to 15 parts by weight with respect to 100 parts by weight of the total epoxy component as a solid content in the epoxy resin composition. When organic phosphines are used, it is preferably used in the range of 0.1 to 20% by weight based on the total amount of the total epoxy component as a solid content and the organic phosphines in the modified epoxidized polybutadiene-containing composition.

In addition to the curing agents listed above, for example, a mercaptan compound, an organic acid dihydrazide, a boron halide amine complex and the like can also be used as the curing agent in the epoxy resin-containing composition of the present invention.

These curing agents may be used alone or in combination of two or more.

<Other epoxy compounds>
In the epoxy resin composition of the present invention, an epoxy compound other than the modified epoxidized polybutadiene of the present invention (sometimes referred to as “another epoxy compound” in the present specification) can be used.

Examples of other epoxy compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, and bisphenol A novolac type epoxy resin. , Tetrabromobisphenol A type epoxy resin, glycidyl ether type epoxy resin such as other polyfunctional phenol type epoxy resin, epoxy resin to which the aromatic ring of the above aromatic epoxy resin is hydrogenated, glycidyl ester type epoxy resin, glycidylamine type epoxy Examples thereof include epoxy compounds such as resins, linear aliphatic epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins. The other epoxy compounds listed above may be used alone or in combination of two or more.

When the epoxy resin composition of the present invention contains the modified epoxidized polybutadiene of the present invention and another epoxy compound, the proportion of the other epoxy compound in the total epoxy component as a solid content in the epoxy resin composition is determined. It is preferably 1% by weight or more, more preferably 5% by weight or more, and preferably 99% by weight or less, more preferably 95% by weight or less. When the ratio of the other epoxy compound is at least the above lower limit value, the effect of improving the physical properties by blending the other epoxy compound can be sufficiently obtained. On the other hand, when the ratio of the other epoxy compound is not more than the above upper limit value, the processability improving effect of the modified epoxidized polybutadiene of the present invention can be obtained.

<Solvent>
The epoxy resin composition of the present invention may be diluted by blending a solvent in order to appropriately adjust the viscosity of the epoxy resin composition at the time of handling such as when forming a coating film. In the epoxy resin composition of the present invention, the solvent is used to ensure handleability and workability in molding of the epoxy resin composition, and the amount used is not particularly limited. As described above, in the present invention, the terms "solvent" and "solvent" are used separately according to their usage patterns, but the same type or different ones may be used independently.
As the solvent that can be contained in the epoxy resin of the present invention, one or more of the organic solvents exemplified as the reaction solvent (C) used for producing the modified epoxidized polybutadiene of the present invention can be used.

When the epoxy resin composition of the present invention is used as a liquid coating material, it is preferably diluted with a solvent as appropriate so that the solid content concentration in the epoxy resin composition is 5 to 99% by weight.

<Other ingredients>
The epoxy resin composition of the present invention may contain other components in addition to the components listed above. Other components include, for example, curing accelerators (excluding those corresponding to the curing agents), coupling agents, flame retardants, antioxidants, light stabilizers, plasticizers, reactive diluents, pigments, etc. Examples include inorganic fillers and organic fillers. The other components listed above can be appropriately combined and used depending on the desired physical properties of the epoxy resin composition of the present invention.

The fact that the epoxy resin composition contains the modified epoxidized polybutadiene of the present invention was confirmed by performing SEC-MALS method, elemental analysis method, and functional group analysis after separating and purifying the epoxy resin composition. can do.

[Cured product]
A cured product can be obtained by curing the epoxy resin composition of the present invention. The term "curing" as used herein means that the epoxy resin is intentionally cured by heat and / or light, and the degree of curing may be controlled according to desired physical properties and applications.

The method for curing the epoxy resin composition when the epoxy resin composition of the present invention is cured to obtain a cured product varies depending on the compounding components and the compounding amount in the epoxy resin composition and the shape of the compound, but is usually 50 to 50. Examples include heating conditions at 200 ° C. for 5 seconds to 180 minutes. This heating is performed by a two-stage treatment of primary heating at 50 to 160 ° C. for 5 seconds to 30 minutes and secondary heating at 90 to 200 ° C., which is 40 to 120 ° C. higher than the primary heating temperature, for 1 minute to 150 minutes. However, it is preferable in terms of reducing curing defects.

When the cured product is produced as a semi-cured product, the curing reaction of the epoxy resin composition may be allowed to proceed to the extent that the shape can be maintained by heating or the like. When the epoxy resin-containing composition contains a solvent, most of the solvent is removed by a method such as heating, depressurization, or air drying, but 5% by weight or less of the solvent may remain in the semi-cured product. ..

The fact that the cured product contains the modified epoxidized polybutadiene of the present invention can be confirmed by identifying the modified epoxidized polybutadiene of the present invention from the cured product by infrared spectroscopy.

[Use]
The modified epoxidized polybutadiene of the present invention is an epoxy resin suitable for can paints, which has excellent compatibility with curing agents, catalysts, and solvents, reduces process problems such as gelation, and has excellent processability. The epoxy resin composition of the present invention containing the modified epoxidized polybutadiene and its cured product are suitably used in fields such as electric / electronic materials, FRP (fiber reinforced resin), adhesives and paints, especially in can paint applications. ..

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the following Examples. The values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the above-mentioned upper limit or lower limit value. , The range specified by the combination of the values of the following examples or the values of the examples may be used.

[Raw materials, etc.]
The raw materials, catalysts, solvents and solvents used in the following Examples and Comparative Examples are as follows.

[Epoxyted polybutadiene (A)]
A-1: Epoxyized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd., oxylan oxygen content: 7.4% by weight, epoxy equivalent: 215 g / equivalent, number average molecular weight (Mn): 3204)

[Monovalent phenol (B)]
B-1: p-tert-amylphenol represented by the following structural formula (3-1)

B-2: p-phenylphenol represented by the following structural formula (3-2)

B-3: p-tert-butylphenol represented by the following structural formula (3-3)

B-4: 3-Pentadecylphenol represented by the following structural formula (3-4)

[Divalent phenol (b)]
b-1: Bisphenol A represented by the following structural formula

[Solvent (C) (solvent)]
C-1: Cyclohexanone

[Catalyst (D)]
D-1: Tetramethylammonium chloride represented by the following structural formula

[Analysis method]
The analysis method and evaluation method in the following Examples and Comparative Examples are as follows.

[Epoxy equivalent]
Epoxy equivalents were measured based on JIS K7236.

[Weight average molecular weight (Mw), number average molecular weight (Mn)]
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC). The equipment and measurement conditions used for GPC measurement are as follows.
Equipment: GPC
Model: HLC-8120GPC (manufactured by Tosoh)
Column: TSKGEL HM-H + H4000 + H4000 + H3000 + H2000 (manufactured by Tosoh)
Detector: UV-8020 (manufactured by Tosoh), 254 nm
Eluent: THF (0.5 mL / min, 40 ° C)
Sample: 1% tetrahydrofuran solution (10 μL injection)
Calibration curve: Standard polystyrene (manufactured by Tosoh)

[Denaturation rate]
The modification rate of the obtained modified epoxidized polybutadiene is the epoxy equivalent of the modified epoxidized polybutadiene, the charged weight of the epoxidized polybutadiene (A) and the monovalent phenol (B) used in the production of the modified epoxidized polybutadiene, and the epoxidized polybutadiene. It was calculated from the epoxy equivalent of (A) using the following formula (I).
Degeneration rate (%) = (([a]-[d]) / [a]) × 100 ... (I)
[A] = [Weight of epoxidized polybutadiene (A)] / [Epoxy equivalent of epoxidized polybutadiene (A)]
[D] = ([Weight of epoxidized polybutadiene (A)] + [Weight of monovalent phenol (B)]) / [Epoxy equivalent of modified epoxidized polybutadiene]

[Storage stability]
200 parts by weight of epoxidized polybutadiene or modified epoxidized polybutadiene coarsely pulverized to 15 mm or less is placed in an aluminum bag, and the blocking state after standing at 15 ° C. for 2 weeks is evaluated based on the following criteria based on visual and tactile sensations. Was done.
It is shown that the impact on the storage environment during storage is small so that blocking does not occur.
<Evaluation criteria>
〇: Do not block.
Δ: Blocking but loosening by hand.
×: Blocks and becomes a lump.

[Compatibility]
100 parts by weight of cyclohexanone was added to 100 parts by weight of epoxidized polybutadiene or modified epoxidized polybutadiene to completely dissolve the mixture, and then 20 parts by weight of Phoenix PR516 / 60B (allnex resol type phenol resin, resin concentration 60% by weight) was added. Parts (hardener weight ratio 0.12), 1.0 part by weight of 85% phosphoric acid aqueous solution and 2.8 parts by weight of cyclohexanone were added, and the mixture was uniformly stirred to obtain a coating material having a solid content of 50% by weight. Then, the obtained paint was applied onto a steel plate (SPCC-SB PB-N144 treatment 0.8 × 70 × 150 mm) with a 150 μm film applicator, and the appearance of the formed coating film was visually confirmed and based on the following criteria. Evaluation was performed. In addition, the smoothness is excellent and the appearance abnormality such as lumps is not so good that the compatibility between the resin and the curing agent or catalyst is excellent, the solvent solubility at the time of manufacturing the paint is also good, and the separation at the time of storage when the paint is made is good. It means that it tends to have excellent storage stability.
<Evaluation criteria>
〇: The surface of the coating film is smooth.
X: The lumps can be visually recognized in the coating film, and the coating film surface is not smooth.

[Weak solvent solubility]
To 8 parts by weight of epoxidized polybutadiene or modified epoxidized polybutadiene, 12 parts by weight of mineral spirit (LAWS grade, aromatic compound content 30%), which is a weak solvent, was added, and the mixture was stirred at 60 ° C. for 15 minutes to dissolve it. It was visually observed. Further, the obtained solution was slowly cooled at 23 ° C., and the dissolved state after 3 hours was visually observed.
From these observation results, the weak solvent solubility was evaluated according to the following criteria.
When the weak solvent solubility is high, it is possible to make a paint with a solvent having less irritating odor, which means that a paint having less harm to the human body and the environment can be manufactured.
<Evaluation criteria>
〇: It is transparent in both the state before slow cooling and after slow cooling.
Δ: Transparent before slow cooling, but cloudy after slow cooling.
X: It is turbid in both the state before slow cooling and after slow cooling.

"Coating film evaluation"
Similar to the above evaluation of compatibility, 100 parts by weight of cyclohexanone was added to 100 parts by weight of epoxidized polybutadiene or modified epoxidized polybutadiene to completely dissolve the mixture, and then phenodur PR516 / 60B (resole-type phenol resin manufactured by Allnex) was sequentially dissolved. , Resin concentration 60% by weight) by 20 parts by weight (hardener weight ratio 0.12), 85% phosphoric acid aqueous solution by 1.0 part by weight, cyclohexanone by 2.8 parts by weight, and stirred uniformly to have a solid content of 50. A weight% paint was obtained. Then, the obtained paint is applied on a steel plate (SPCC-SB PB-N144 treatment 0.8 × 70 × 150 mm) with a 150 μm film applicator and baked at 200 ° C. for 30 minutes to cure a coating film (thickness 150 μm). ) Was obtained. The following (1) to (5) were evaluated for this cured coating film. Further, as the steel plate, a steel plate having a size of 0.3 × 50 × 200 mm was used and applied with a 100 μm film applicator to form a cured coating film having a film thickness of 100 μm. A steel sheet having 100 μm) was obtained, and the cured coating film was evaluated in (6) below.

(1) Evaluation of coating film appearance The smoothness was visually evaluated based on the following criteria.
It is suggested that the better the smoothness in this evaluation, the better the compatibility between the epoxy resin and the compounding such as the curing agent and the catalyst, and the less the quality unevenness as a coating film.
<Evaluation criteria>
〇: The surface of the coating film is smooth.
X: The lumps can be visually recognized in the coating film, and the coating film surface is not smooth.

(2) Adhesion Evaluation was performed based on JIS K5600-5-6, and the number of grids remaining on the steel plate among the grids formed on the coating film was visually measured. The larger the number, the better the adhesion, and 100 out of 100 squares means that the adhesion is the best.

(3) Scratch resistance The pencil hardness was measured based on JIS K5600-5-4, and the scratch resistance of the coating film was evaluated.
The evaluation result means that the surface hardness of the coating film is higher and the scratch resistance is excellent in the order of 3B, 2B, B, HB, F, H, and 2H, that is, from 3B to 2H. In coating film applications, it can be judged that actual use is sufficiently possible if the hardness is HB or higher.

(4) Cupping resistance Based on JIS K5600-5-2, the cupping resistance was measured using an Eriksen testing machine (manufactured by Taiyu Kikai). The larger the value, the better the drawability of the coating film, that is, the toughness of the coating film, and the better the processability.

(5) Weight drop resistance Based on JIS K5600-5-3, a DuPont impact test was performed to evaluate the weight drop resistance, and the evaluation was made based on the following criteria.
The smaller the weight diameter, or the same weight shape and the same weight weight, the higher the drop height, the better the weight drop resistance, which is synonymous with the excellent impact resistance.
<Evaluation criteria>
⊚: Weight diameter 1/4 inch, weight weight 300 g, drop height 300 mm, no cracking of coating film.
〇: Weight diameter 1 / 2inch, weight weight 300g, drop height 400mm, no cracking of coating film.
Δ: The weight diameter is 1/2 inch, the weight weight is 300 g, the drop height is 300 mm, and the coating film is not cracked.
X: The weight diameter is 1/2 inch, the weight weight is 300 g, the drop height is 300 mm, and the coating film is cracked.

(6) Bending resistance Based on JIS K5600-5-1, a bending tester (Type 1, manufactured by Tayu Equipment) was used to perform a test with a mandrel having a diameter of 2 mm, and the bending resistance was evaluated according to the following criteria.
<Evaluation criteria>
◯: No abnormality in the coating film in the mandrel test with a diameter of 2 mm ×: Abnormality in the coating film in the mandrel test with a diameter of 2 mm

[Example 1]
180 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 65.5 parts by weight of p-tert-amylphenol (B-1), 27.3 parts by weight of cyclohexanone (C-1) , Tetramethylammonium chloride (D-1) was placed in a 0.5 L flask based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 180 ° C. for 6 hours in a nitrogen gas atmosphere. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-11).
Regarding the obtained modified epoxidized polybutadiene (A-11), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility was analyzed by the above method, and the results are shown in Table-1.

[Example 2]
170 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 61.8 parts by weight of p-tert-amylphenol (B-1), 12.2 parts by weight of cyclohexanone (C-1) , Tetramethylammonium chloride (D-1) was placed in a 0.5 L flask with respect to the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere. rice field. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-12).
Regarding the obtained modified epoxidized polybutadiene (A-12), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility was analyzed by the above method, and the results are shown in Table-1.

[Example 3]
170 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 61.8 parts by weight of p-tert-amylphenol (B-1), 12.2 parts by weight of cyclohexanone (C-1) , Tetramethylammonium chloride (D-1) was placed in a 0.5 L flask at 10,000 ppm based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere. rice field. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-13).
Regarding the obtained modified epoxidized polybutadiene (A-13), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility was analyzed by the above method, and the results are shown in Table-1.
Subsequently, the coating film evaluation was also continuously performed, and the results are summarized in Table-2.

[Example 4]
170 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 63.6 parts by weight of p-phenylphenol (B-2), 12.3 parts by weight of cyclohexanone (C-1), tetra 10,000 ppm of methylammonium chloride (D-1) was placed in a 0.5 L flask based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 6 hours under a nitrogen gas atmosphere. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-14).
Regarding the obtained modified epoxidized polybutadiene (A-14), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility and weak solvent solubility were analyzed by the above method, and the results are shown in Table-1.
Subsequently, the coating film evaluation was also continuously performed, and the results are summarized in Table-2.

[Example 5]
170 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 57.7 parts by weight of p-tert-butylphenol (B-3), 12.0 parts by weight of cyclohexanone (C-1), 10,000 ppm of tetramethylammonium chloride (D-1) was placed in a 0.5 L flask based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere. .. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-15).
Regarding the obtained modified epoxidized polybutadiene (A-15), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility and weak solvent solubility were analyzed by the above method, and the results are shown in Table-1.
Subsequently, the coating film evaluation was also continuously performed, and the results are summarized in Table-2.

[Example 6]
170 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 57.7 parts by weight of p-tert-butylphenol (B-3), 56.9 parts by weight of cyclohexanone (C-1), 10,000 ppm of tetramethylammonium chloride (D-1) was placed in a 0.5 L flask based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere. .. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-16).
Regarding the obtained modified epoxidized polybutadiene (A-16), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility and weak solvent solubility were analyzed by the above method, and the results are shown in Table-1.

Epoxy of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Corporation) (A-1) 170 parts by weight, p-tert-butylphenol (B-3) 57.7 parts by weight, tetramethylammonium chloride (D-1) 2000 ppm with respect to the weight of polybutadiene (A-1) was placed in a 0.5 L flask, and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere to obtain the desired modified epoxidized polybutadiene (A-17). Obtained.
Regarding the obtained modified epoxidized polybutadiene (A-17), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility was analyzed by the above method, and the results are shown in Table-1.

[Example 8]
170 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 46.5 parts by weight of p-tert-butylphenol (B-3), 11.4 parts by weight of cyclohexanone (C-1), 10,000 ppm of tetramethylammonium chloride (D-1) was placed in a 0.5 L flask based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere. .. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-18).
Regarding the obtained modified epoxidized polybutadiene (A-18), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility was analyzed by the above method, and the results are shown in Table-1.
Subsequently, the coating film evaluation was also continuously performed, and the results are summarized in Table-2.

[Example 9]
170 parts by weight of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1), 86.6 parts by weight of p-tert-butylphenol (B-3), 13.5 parts by weight of cyclohexanone (C-1), 10,000 ppm of tetramethylammonium chloride (D-1) was placed in a 0.5 L flask based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere. .. Subsequently, the solvent was distilled off under reduced pressure at 190 ° C. for 1 hour to obtain the desired modified epoxidized polybutadiene (A-19).
Regarding the obtained modified epoxidized polybutadiene (A-19), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, storage stability (blocking resistance) , Compatibility and weak solvent solubility were analyzed by the above method, and the results are shown in Table-1.
Subsequently, the coating film evaluation was also continuously performed, and the results are summarized in Table-2.

[Example 10]
Epoxy of epoxidized polybutadiene (JP-200 manufactured by Nippon Soda Corporation) (A-1) 130 parts by weight, 3-pentadecylphenol (B-4) 88.7 parts by weight, tetramethylammonium chloride (D-1) 10,000 ppm with respect to the weight of polybutadiene (A-1) was placed in a 0.5 L flask, and a polymerization reaction was carried out at 170 ° C. for 6 hours in a nitrogen gas atmosphere to obtain the desired modified epoxidized polybutadiene (A-20). Got
Regarding the obtained modified epoxidized polybutadiene (A-20), the epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn), modification rate, compatibility, and weak solvent solubility were determined. The analysis was performed by the above method, and the results are shown in Table 1.
Regarding storage stability (blocking resistance), the modified epoxidized polybutadiene of Examples 1 to 9 was solid at room temperature, while the modified epoxidized polybutadiene of Example 10 was a highly viscous liquid, so evaluation was carried out. I didn't.
Subsequently, the coating film evaluation was also continuously performed, and the results are summarized in Table-2.

[Comparative Example 1]
Epoxyized polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1) is used as it is (modification rate 0%), epoxy equivalent, weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw /). Mn), compatibility, and weak solvent solubility were analyzed by the above method, and the results are shown in Table-1.
Also in Comparative Example 1, since it was a highly viscous liquid, the storage stability (blocking resistance) was not evaluated.
Subsequently, the coating film evaluation was also continuously performed, and the results are summarized in Table-2.

[Comparative Example 2]
Epoxy-polybutadiene (JP-200 manufactured by Nippon Soda Co., Ltd.) (A-1) 180 parts by weight, bisphenol A (b-1) 58.1 parts by weight, cyclohexanone (C-1) 12.5 parts by weight, tetramethylammonium 2000 ppm of chloride (D-1) was placed in a 0.5 L flask based on the weight of epoxidized polybutadiene (A-1), and a polymerization reaction was carried out at 170 ° C. for 40 minutes in a nitrogen gas atmosphere, but gelation occurred. Modified epoxidized polybutadiene could not be obtained.

[Evaluation results]
As can be seen from Tables 1 and 2, by using the modified epoxidized polybutadiene of the present invention, the compatibility with the curing agent and the catalyst is excellent, and there are concerns in the process such as solvent solubility and gelation during paint production. Further, it is possible to obtain the effect of excellent processability of the formed cured product.
Specifically, from Examples 3 to 5 and 8 to 9, by using the modified epoxidized polybutadiene of the present invention, the compatibility with the curing agent and the catalyst and the solvent solubility during the production of the paint are excellent, and the gel at the time of production is excellent. From the evaluation results of the coating film formed of the coating material using this modified epoxidized polybutadiene, it can be seen that a coating film having excellent processability was obtained. From Example 10, it is possible to improve the compatibility with the curing agent and the catalyst while maintaining the weak solvent solubility performance, and further, from the evaluation result of the coating film formed with the coating material using this modified epoxidized polybutadiene, the coating material is applied. It can be seen that the cupping resistance of the film was improved.
For comparison, in Comparative Example 1 using unmodified epoxidized polybutadiene, the compatibility with the curing agent and the catalyst was poor, resulting in deterioration of the appearance of the coating film, as well as poor weight drop resistance and scratch resistance. It was inferior.
In Comparative Example 2, as a result of using a polyhydric phenol which is a divalent phenol instead of a monohydric phenol, gelation occurred during production and a modified epoxidized polybutadiene could not be obtained.

The modified epoxidized polybutadiene of the present invention has excellent compatibility with a curing agent and a catalyst, solvent solubility during coating film production, and reduces process problems such as gelation. Further, the cured product formed by using the modified epoxidized polybutadiene of the present invention has excellent processability. Therefore, the modified epoxidized polybutadiene of the present invention, the epoxy resin composition containing the modified epoxidized polybutadiene, and the cured product thereof are used in the fields of paints, electric / electronic materials, adhesives, fiber reinforced plastics (FRP), and the like. It can be suitably used, and in particular, it can be suitably used in the field of paints, especially in the use of can paints.

Claims (10)

A modified epoxidized polybutadiene containing a structural unit represented by the following formula (1) and / or a structural unit represented by the following formula (2).

(In formulas (1) and (2), R ^{3 to} R ⁷ independently have a hydrogen atom, a halogen atom, a nitro group, a nitrile group, an amino group, an azide group, a cyano group, or 1 to 20 carbon atoms. However, ^{the carbon atom constituting the benzene ring to which R 3 to} R ⁷ is bonded may be substituted with a nitrogen atom. In that case, the nitrogen atom may be substituted. Substituents do not bond. In addition, ^{some of R 3 to} R ⁷ may be bonded to each other to form a ring that condenses with this benzene ring. Further, the hydrocarbon having 1 to 20 carbon atoms. In the group, a part of carbon atom and / or hydrogen atom may be replaced with oxygen atom or sulfur atom.) The modified epoxidized polybutadiene according to claim 1, which is obtained by reacting an epoxidized polybutadiene (A) with a monohydric phenol (B) represented by the following formula (3).

In formula (3), R ^{3 to} R ⁷ are independently substituted or unsubstituted with a hydrogen atom, a halogen atom, a nitro group, a nitrile group, an amino group, an azide group, a cyano group, or 1 to 20 carbon atoms. However, ^{the carbon atom constituting the benzene ring to which R 3 to} R ⁷ are bonded may be substituted with a nitrogen atom. In that case, the substituent is not bonded to the nitrogen atom. Further, ^{a part of R 3 to} R ⁷ may be bonded to each other to form a ring condensing on the benzene ring. Further, the hydrocarbon group having 1 to 20 carbon atoms is a carbon atom. And / or part of the hydrogen atom may be replaced with an oxygen atom or a sulfur atom.) The modified epoxidized polybutadiene according to claim 2, wherein the modification rate (%) calculated by the following formula (I) is 5 to 90.
Degeneration rate (%) = (([a]-[d]) / [a]) × 100 ... (I)
(In the formula (I), [a] = [weight of epoxidized polybutadiene (A)] / [epoxy equivalent of epoxidized polybutadiene (A)], [d] = ([weight of epoxidized polybutadiene (A)] + [Weight of monovalent phenol (B)]) / [Epoxy equivalent of modified epoxidized polybutadiene].) The modified epoxidized polybutadiene according to any one of claims 1 to 3, wherein the epoxy equivalent is 200 to 50,000 g / equivalent. An epoxy resin composition containing the modified epoxidized polybutadiene according to any one of claims 1 to 4 and a curing agent. The curing agent is selected from the group consisting of polyhydric phenols, polyisocyanate compounds, amine compounds, acid anhydride compounds, imidazole compounds, amide compounds, mercaptan compounds, cationic polymerization initiators and organic phosphines. The epoxy resin composition according to claim 5, which comprises at least one of these. The epoxy resin composition according to claim 6, wherein the curing agent is a resol type phenol resin. A cured product obtained by curing the epoxy resin composition according to any one of claims 5 to 7. A can paint comprising the epoxy resin composition according to any one of claims 5 to 7. A can coating film made of the cured product according to claim 8.