JP5866986B2 - Epoxy curing agent - Google Patents

Description

  The present invention relates to an epoxy curing agent, an epoxy resin composition containing the same, and an epoxy resin cured product obtained therefrom.

  A cured epoxy resin obtained by curing, solidifying, or crosslinking an epoxy resin with an epoxy curing agent is used for surface coating of metals, wood, concrete, and the like. In forming a uniform film on the structure surface, a low-reactivity epoxy curing agent is generally used. For example, in the case where a film is formed on the surface of a structure having an intricate structure or a large structure, a low-reactivity epoxy curing agent is required from the viewpoint of ensuring sufficient working time.

  Polyether polyamines are commonly used as low-reactivity epoxy curing agents. However, even when a polyether polyamine is used, the working time may not be sufficiently secured.

  Accordingly, dialkyldiethylenetriamines (for example, see Patent Document 1 and Patent Document 2) in which the reactivity of the polyalkylene polyamine is further reduced have been proposed, but the reactivity is still high, and the surface of a structure having a complicated structure or a large size When it was used as a coating material for the surface of a structure, it was not sufficient.

US Pat. No. 3,280,043 European Patent Application No. 2157112

  The present invention has been made in view of the above-described background art, and an object of the present invention is to provide an epoxy resin curing agent that has low reactivity with an epoxy resin and can increase the workable time.

  As a result of intensive studies on the epoxy curing agent, the present inventors have completed the present invention. That is, the present invention is an epoxy curing agent as shown below, an epoxy resin composition containing the same, and an epoxy resin cured product obtained therefrom.

[1] N-alkylated amino group having 1 to 6 carbon atoms (R-NH-:. Wherein R represents an alkyl group having 1 to 6 carbon atoms), an amino group _(H 2 N-) and imino group ( An epoxy curing agent containing an alkylated polyalkylene polyamine having one or two substituents selected from the group consisting of -NH-) in the molecule and two active amine hydrogen atoms in the molecule.

  [2] The alkylated polyalkylene polyamine is represented by the following formula (1):

（式中、Ｒ_１〜Ｒ_５は各々独立して水素原子又は炭素数１〜６のアルキル基を表し、ｎは０〜６の範囲である。ただし、Ｒ_１〜Ｒ_５は全て水素原子又は全てアルキル基になることはない。）
で示されるアルキル化ポリアルキレンポリアミンであることを特徴とする上記［１］に記載のエポキシ硬化剤用アミン組成物。

(Wherein R _{1 to} R ₅ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n is in the range of 0 to 6. However, R _{1 to} R ₅ are all hydrogen atoms or Not all alkyl groups.)
The amine composition for epoxy curing agents according to [1] above, wherein the amine composition is an alkylated polyalkylene polyamine represented by formula (1).

  [3] The alkylated polyalkylene polyamine is N, N′-diisopropylethylenediamine, N, N′-disec-butyl-ethylenediamine, N, N ′, N ″ -triisopropyldiethylenetriamine, N, N ′, N ″ — Trisec-butyl-diethylenetriamine, N, N′-diisopropyl-N, N′-bis [2- (isopropylamino) ethyl] -1,2-ethanediamine, and N, N′-sec-butyl-N, N The epoxy curing agent according to [1] above, which is at least one selected from the group consisting of '-bis [2- (sec-butylamino) ethyl] -1,2-ethanediamine.

  [4] An epoxy resin composition comprising the epoxy curing agent according to any one of [1] to [3] and an epoxy resin.

  [5] A cured epoxy resin obtained by reacting the epoxy resin composition according to the above [4].

  According to the epoxy curing agent of the present invention, it is possible to provide an amine composition for an epoxy curing agent that has a lower reactivity than a commonly used amine for an epoxy curing agent and can increase the workable time.

  Hereinafter, the present invention will be described in detail.

The epoxy curing agent of the present invention comprises an N-alkylated amino group having 1 to 6 carbon atoms (R—NH—, where R represents an alkyl group having 1 to 6 carbon atoms), an amino group (H ₂ N— ) And an imino group (—NH—) containing an alkylated polyalkylene polyamine having one or two substituents in the molecule and two active amine hydrogen atoms in the molecule The feature is to do.

  Since the alkylated polyalkylene polyamine used in the present invention has two active amine hydrogen atoms, the reactivity with the epoxy resin is very slow. Therefore, the reaction rate with the epoxy resin can be suppressed, and the workable time can be prolonged. In the present invention, the “active amine hydrogen atom” means a hydrogen atom added to a nitrogen atom that can react with an epoxy group.

  In the alkylated polyalkylene polyamine used in the present invention, an alkyl group in an N-alkylated amino group having 1 to 6 carbon atoms (R—NH—, where R represents an alkyl group having 1 to 6 carbon atoms). Examples of (R) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a sec-butyl group, a pentyl group, an isopentyl group, a hexyl group, and a cyclohexyl group.

  When the alkylated polyalkylene polyamine used in the present invention has a primary amino group at the terminal of the polyalkylene polyamine chain, the reactivity with the epoxy resin is increased and the working time is shortened. Therefore, as the alkylated polyalkylene polyamine, a compound having no primary amino group at the terminal is more preferable.

Specifically, the alkylated polyalkylene polyamine used in the present invention is an N-alkylated amino group having 1 to 6 carbon atoms (R—NH—, where R represents an alkyl group having 1 to 6 carbon atoms. ), Two or more substituents selected from the group consisting of an amino group (H ₂ N—) and an imino group (—NH—) in the molecule, and two active amine hydrogen atoms in the molecule The alkylated polyalkylene polyamine represented by the above formula (1) is exemplified.

In the above formula (1), R ^{1 to} R ⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and the alkyl group may be linear, branched or cyclic. Preferably R ¹ and R ³ are hydrogen atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a sec-butyl group, a pentyl group, an isopentyl group, a hexyl group, and a cyclohexyl group. Is mentioned. N is an integer of 0-6.

  Preferable examples of the alkylated polyalkylene polyamine used in the present invention include N, N′-diisopropylethylenediamine, N, N′-disec-butyl-ethylenediamine, N, N ′, N ″ -triisopropyldiethylenetriamine, N , N ′, N ″ -trisec-butyl-diethylenetriamine, N, N′-diisopropyl-N, N′-bis [2- (isopropylamino) ethyl] -1,2-ethanediamine, N, N′-sec -Butyl-N, N'-bis [2- (sec-butylamino) ethyl] -1,2-ethanediamine and the like.

  In the epoxy curing agent of the present invention, the content of the above-mentioned alkylated polyalkylene polyamine is usually 1% by weight or more, preferably 3% by weight or more based on the whole epoxy curing agent. The greater the content, the lower the reactivity with the epoxy resin and the longer the workable time.

  The epoxy curing agent of the present invention contains the above-mentioned alkylated polyalkylene polyamine, and does not necessarily require other components, but other amines may be used without departing from the spirit of the present invention. May be contained. Examples of such amines include polyfunctional amines having 3 or more active amine hydrogen atoms. Even if such a polyfunctional amine is used, it is desirable not to use a component that significantly improves the reactivity with the epoxy resin, or to use it within a range in which the low reactivity with the epoxy resin can be maintained.

  Examples of the polyfunctional amine having 3 or more active amine hydrogen atoms include aliphatic amines, alicyclic amines, aromatic amines, and aliphatic amines, aromatic amines, or Mannich base derivatives of alicyclic amines. Also known are polyamide derivatives of aliphatic amines, aromatic amines or alicyclic amines, amine addition derivatives of aliphatic amines, aromatic amines or alicyclic amines, and the like.

  Examples of the aliphatic amine include polyethyleneamine (EDA, DETA, TETA, TEPA, PEHA, etc.), polypropyleneamine, aminopropylated ethylenediamine (Am3, Am4, Am5, etc.), aminopropylated propylenediamine, 1,6-hexane. Diamine, 3,3,5-trimethyl-1,6-hexanediamine, 3,5,5-trimethyl-1,6-hexanediamine, 2-methyl-1,5-pentanediamine [Dytek (registered trademark) -A And the like, or a combination thereof.

  Poly (alkylene oxide) diamines and triamines available under the trade name Jeffamine from Huntsman are also exemplified as such aliphatic amines. Although it does not specifically limit as Jeffamine, For example, Jeffamine D-230, Jeffamine D-400, Jeffamine D-2000, Jeffamine) D-4000, Jeffamine T-403, Jeffamine EDR- 148, Jeffermin EDR-192, Jeffermin C-346, Jeffermin ED-600, Jeffermin ED-900, Jeffermin ED-2001, or a combination thereof.

  In addition, the alicyclic amine or aromatic amine is not particularly limited. For example, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, hydrogenated orthotoluenediamine, Hydrogenated metatoluenediamine, metaxylylenediamine, hydrogenated metaxylylenediamine (commercially available as 1,3-BAC), isophoronediamine, various isomers or norbornanediamine, 3,3′-dimethyl-4, Examples include 4′-diaminodicyclohexylmethane, 4,4′-diaminodicyclohexylmethane, 2,4′-diaminodicyclohexylmethane, a mixture of methylene-bridged poly (cyclohexyl-aromatic) amines, and the like, or combinations thereof.

  Mannich base derivatives can be made, for example, by reaction of the aliphatic amines, alicyclic amines or aromatic amines described above with phenol or substituted phenols and formaldehyde. The polyamide derivative can be prepared, for example, by reacting the above-mentioned aliphatic amine, alicyclic amine or aromatic amine with a dimer fatty acid or a mixture of a dimer fatty acid and a fatty acid. Amidoamine derivatives can be prepared, for example, by reaction of aliphatic amines, alicyclic amines or aromatic amines with fatty acids. The amine adduct is, for example, a reaction between an aliphatic amine, an alicyclic amine or an aromatic amine and an epoxy resin (for example, bisphenol-A diglycidyl ether, bisphenol-F diglycidyl ether, epoxy novolac resin, etc.). Can be prepared. A monofunctional epoxy resin (for example, phenyl glycidyl ether, cresyl glycidyl ether, butyl glycidyl ether, or other alkyl glycidyl ether) may be added to the aliphatic amine, alicyclic amine, or aromatic amine.

  In the present invention, the production method of the above-mentioned alkylated polyalkylene polyamine is not particularly limited, but it can be obtained by partially N-alkylating the corresponding polyalkylene polyamine. For example, it can be obtained by reacting at least one polyalkylene polyalkylene polyamine having at least two nitrogen atoms, at least one alkylating agent, and hydrogen in the presence of a catalyst.

  Although it does not specifically limit as a polyalkylene polyamine used here, For example, a polyethylene polyamine, a polypropylene polyamine, and those combination are mentioned. Examples of polyethylene polyamines include diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and other higher order polyethylene polyamines. For example, TETA may contain not only linear TETA but also tris-aminoethyleneamine.

  Although it does not specifically limit as an alkylating agent used here, For example, a cyclopentanone, cyclohexanone, a C1-C6 aldehyde, a C2-C6 ketone, etc. are mentioned.

  Examples of the catalyst used here include commonly used hydrogenation catalysts such as nickel, Raney nickel, Raney cobalt platinum black, platinum oxide, palladium, palladium / activated carbon (Pd / C), and any of these. May be. The addition amount of the catalyst is preferably in the range of 0.1 to 10% by weight with respect to the polyalkylene polyamine.

  The molar reaction ratio of the alkylating agent to the polyalkylene polyamine (alkylating agent / polyalkylene polyamine) is not particularly limited, but is preferably 2 or more, more preferably 2.1 or more. This is because when the molar reaction ratio is 2.1 or more, the unreacted polyalkylene polyamine remaining without being alkylated is 1% by weight or less.

  Next, the epoxy resin composition of the present invention will be described.

  The epoxy resin composition of the present invention is characterized by containing the above-described epoxy curing agent of the present invention and an epoxy resin.

  In the present invention, the epoxy resin may be an uncured epoxy resin generally used in the production of a cured epoxy resin, and is not particularly limited. For example, two or more 1,2-epoxy groups per molecule are included. Examples thereof include an uncured epoxy resin. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, epoxy novolac resin, alicyclic epoxy resin, polyfunctional epoxy resin, brominated epoxy resin and the like are exemplified. These epoxy resins can be used either without solvent or diluted with a solvent.

  Moreover, when forming an epoxy resin hardened | cured material using the epoxy resin composition of this invention, a conventionally well-known plasticizer can be used. Such a plasticizer is not particularly limited, and examples thereof include benzyl alcohol, nonylphenol, various phthalates, and the like.

  Furthermore, when forming an epoxy resin cured product using the epoxy resin composition of the present invention, a solvent, a filler, a pigment, a pigment dispersant, a rheology modifier, a thixotropic agent, a fluidization and smoothing aid, An antifoaming agent or the like may be used. Suitable solvents include, for example, aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, esters, ketones, ethers, alcohols and the like.

  An epoxy resin cured product is obtained by reacting the amine composition for an epoxy curing agent of the present invention described above.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not this limited to these.

<Measurement of reactivity>
An epoxy curing agent and an epoxy resin (Epicoat 828, manufactured by Mitsubishi Chemical Corporation) are weighed in a 20 ml sample bottle, mixed with a spatula until uniform, and then cured under a constant condition of 25 ° C., and a vibration viscometer (trade name) : VM-1G-MJ (manufactured by Yamaichi Electronics Co., Ltd.), and a data collection system (trade name: NR-1000, manufactured by Keyence) were used to measure changes with time in viscosity. After mixing, the reactivity was evaluated by the time until the viscosity value reached 1000 cP. The longer the 1000 cP arrival time, the lower the reactivity and the longer the workable time.

Synthesis Example 1
In a 10 L autoclave, 1500 g (14.5 mol) of diethylenetriamine (DETA), 1689 g (29.1 mol) of acetone, 3189 g of methanol, and 128 g of Pd / C catalyst were charged. The autoclave was purged with nitrogen and then with hydrogen to remove the air in the autoclave. The autoclave was pressurized to 3 MPa with hydrogen and heated to 120 ° C. in 0.5 hours. The internal pressure of the autoclave was kept at 3 MPa with hydrogen, and the reaction was further performed for 6 hours. After completion of the reaction, the autoclave was cooled and decompressed, and the reaction product was filtered to remove the catalyst. Methanol, acetone, and produced water were removed with an evaporator to obtain an isopropylated diethylenetriamine mixture.

  From the resulting isopropylated diethylenetriamine mixture, 290 g of triisopropylated diethylenetriamine (A) and 1630 g of diisopropylated diethylenetriamine (B) were separated by distillation.

Synthesis Example 2
In a 10 L autoclave, 1000 g (16.6 mol) of ethylenediamine (EDA), 2251 g (38.8 mol) of acetone, 3251 g of methanol, and 130.1 g of Pd / C catalyst were charged. The autoclave was purged with nitrogen and then with hydrogen to remove the air in the autoclave. The autoclave was pressurized to 3 MPa with hydrogen and heated to 120 ° C. in 0.5 hours. The internal pressure of the autoclave was kept at 3 MPa with hydrogen, and the reaction was further performed for 6 hours. After completion of the reaction, the autoclave was cooled and decompressed, and the reaction product was filtered to remove the catalyst. Methanol, acetone, and produced water were removed with an evaporator to obtain an isopropylated ethylenediamine mixture.

  From the resulting isopropylated ethylenediamine mixture, 2100 g of diisopropylated ethylenediamine was separated by distillation.

Synthesis Example 3
In a 10 L autoclave, 1100 g (7.5 mol) of triethylenetetramine (TETA), 2172.9 g (30.1 mol) of methyl ethyl ketone, 3272.9 g of methanol, and 130 g of Pd / C catalyst were charged. The autoclave was purged with nitrogen and then with hydrogen to remove the air in the autoclave. The autoclave was pressurized to 3 MPa with hydrogen and heated to 120 ° C. in 0.5 hours. The internal pressure of the autoclave was kept at 3 MPa with hydrogen, and the reaction was further performed for 6 hours. After completion of the reaction, the autoclave was cooled and decompressed, and the reaction product was filtered to remove the catalyst. Methanol, methyl ethyl ketone, and produced water were removed with an evaporator to obtain a sec-butylated triethylenetetramine mixture.

  From the obtained sec-butylated triethylenetetramine mixture, 820 g of tetrasec-butylated triethylenetetramine was distilled and separated.

Example 1.
0.03 g of triisopropylated diethylenetriamine obtained in Synthesis Example 1, 3.35 g of diisopropylated diethylenetriamine and 10 g of epoxy resin (Epicoat 828, manufactured by Mitsubishi Chemical Corporation) are weighed into a 20 ml sample bottle and mixed until uniform with a spatula. After that, using a curing, vibration viscometer (trade name: VM-1G-MJ, manufactured by Yamaichi Denki Co., Ltd.) and data collection system (trade name: NR-1000, manufactured by Keyence) at a constant condition of 25 ° C. The change in viscosity over time was measured. After mixing, the time until the viscosity value reached 1000 cP was measured and found to be 8.6 hours.

Examples 2 to 10, Reference Example and Comparative Examples 1 to 3
The same procedure as in Example 1 was performed except that the types and amounts of amines shown in Tables 1 and 2 were used. The results are also shown in Tables 1 and 2.

この表から、本発明のエポキシ硬化剤を含有する実施例１〜実施例９の場合の方が、本発明のエポキシ硬化剤を含有しない比較例１〜比較例３の場合よりも、長い作業時間を達成できることが分かる。

From this table, the working time of Examples 1 to 9 containing the epoxy curing agent of the present invention is longer than that of Comparative Examples 1 to 3 not containing the epoxy curing agent of the present invention. It can be seen that can be achieved.

  In addition to the alkylated polyalkylene polyamine, when a polyfunctional amine having 3 or more active amine hydrogen atoms is used in combination, the polyfunctional amine that does not affect the reactivity with the epoxy resin can be suitably used. However (see Example 10), it is understood that the use of a large amount of a component that significantly improves the reactivity with the epoxy resin departs from the spirit of the present invention (see Reference Example).

  The epoxy resin curing agent of the present invention has a low reactivity as a curing agent, and can achieve a sufficient working time when used in combination with an epoxy resin. It is preferably used in applications that require a long working time, such as coating the surface of a structure.

Claims (3)

N, N′-diisopropylethylenediamine, N, N′-disec-butyl-ethylenediamine, N, N ′, N ″ -triisopropyldiethylenetriamine, N, N ′, N ″ -trisec-butyl-diethylenetriamine, N, N '-Diisopropyl-N, N'-bis [2- (isopropylamino) ethyl] -1,2-ethanediamine and N, N'-sec-butyl-N, N'-bis [2- (sec-butyl Amino) ethyl] -1,2-ethanediamine, an epoxy curing agent containing at least one alkylated polyalkylenepolyamine selected from the group consisting of the following general formula (1):

(In formula, R < ₁ >, R < ₂ > and R < ₃ > may be the same or different, respectively, a hydrogen atom, the alkyl group which may have a substituent, the alkenyl group which may have a substituent, substituted An alkynyl group which may have a group, an aryl group which may have a substituent, an alkoxyl group which may have a substituent, a halogen atom, a nitro group, an acyl group, a carboxyl group, a sulfonic acid group or a substituent And n, m, and 1 R ₁ , R _2, and R ₃ may be the same or different, and R ₄ has a substituent. also alkyl group, an alkenyl group which may have a substituent, alkynyl group which may have a substituent group, an aryl group or an acyl group which may have a substituent, m-number of R ₄ is, Each may be the same or different, n is 0-10. M represents an integer of 0 to 10, and l represents an integer of 0 to 10, where n + m + 1 is an integer of 4 to 10.) and contains calix (n + m + l) arenes. Except cases. ) An epoxy resin composition comprising the epoxy curing agent according to claim 1 and an epoxy resin. A cured epoxy resin obtained by reacting the epoxy resin composition according to claim 2 .