JPH0616599A - Synthesis of quaternery ammonium salt - Google Patents

Abstract

PURPOSE:To obtain a quaternary ammonium salt useful as e.g. a curing catalyst for one-pack. thermosetting resin compositions stable at normal temperatures by reaction of a benzyl alcohol bearing inert substituents at the benzene ring and/or the alpha-site or an alkyl ether thereof with a tertiary amine strong acid salt. CONSTITUTION:(A) A benzyl alcohol of formula I (R1 to R3 are each H, OH, halogen, alkyl, alkoxy, nitro, amino, etc.; R<4> and R<5> are each H, halogen or alkyl; Z is H or 1-4C saturated hydrocarbon) bearing, optionally, inert substituents at the benzene ring and/or the alpha-site, or a 1-4C alkyl group-carrying benzyl alkyl ether thereof is made to react with (B) a tertiary amine strong acid salt of formula II (R6 and R10 are each the same as R1) or formula III (R7 and R8 are each alkyl or alkenyl; R9 is the same as R1) etc., thus easily synthesizing the objective quaternary ammonium salt useful as a curing catalyst for one-pack thermosetting resin compositions stable for storage at normal temperatures.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a curing catalyst for a one-part thermosetting resin composition.

[0002]

PRIOR ART AND PROBLEM TO BE SOLVED BY THE INVENTION Applicant's Japanese Patent Application Laid-Open Nos. 1-96169, 1-299270, 3-56470, 3-115262, and 3-112262.
52674, same flat 1-79468, same flat 1-7946
9, pp. 1-242541 and the like disclose a quaternary ammonium salt which is thermally cleaved to generate an acid. These compounds are useful as a curing catalyst for a one-component thermosetting resin composition which is storage stable at room temperature. In the cited patent documents, these compounds are halide anions of a quaternary ammonium halide produced by reacting a corresponding tertiary amine with a corresponding benzyl halide as a quaternizing agent according to a conventional method for quaternary ammonium salt synthesis. Was synthesized by a two-step reaction in which was exchanged with the desired anion.

[0003]

DISCLOSURE OF THE INVENTION As a result of exploring a simpler synthetic method for these compounds, the present inventors dehydrated a strong acid salt of a tertiary amine to be quaternized and a corresponding benzyl alcohol or benzyl alkyl ether. We succeeded in directly synthesizing the desired quaternary ammonium by subjecting it to a condensation reaction.

The benzyl alcohol or benzyl alkyl ether which can be used in this synthetic method is represented by the formula:

[Chemical 4] (In the formula, R ₁ , R ₂ and R ₃ are independently a hydrogen atom, hydroxy, halogen, alkyl, alkoxy, nitro,
Amino, alkylamino, acyl, cyano, alkoxycarbonyl or carbamoyl, R ₄ and R ₅
Are independently hydrogen atom, halogen or alkyl, Z
Is a hydrogen atom or a saturated hydrocarbon group having 1 to 4 carbon atoms. ) Alcohols or ethers are preferred.

The tertiary amine has the formula

[Chemical 5] (In the formula, R ₆ and R ₁₀ are the same as defined for R _{1 to} R _3. )
Of pyridine, or the formula

[Chemical 6] An aniline derivative of the formula (wherein R ₇ and R ₈ are independently alkyl or alkenyl, and R ₉ has the same definition as R _{1 to} R ₃ ) is preferable.

As a strong acid which forms a salt with a tertiary amine,
HAsF ₆ , HSbF ₆ , HBF ₄ , HPF ₆ , HCl
O ₄ , HFeCl ₄ , HCF ₃ SO ₃ or aromatic sulfonic acids are preferred.

The reaction includes benzene, toluene, ethyl acetate, butyl acetate, acetone, methyl isobutyl ketone,
If a strong acid salt of the corresponding tertiary amine is reacted with benzyl alcohol or benzyl alkyl ether in an aprotic solvent such as dichloromethane, dichloroethane, tetrahydrofuran, dioxane, nitromethane, nitrobenzene or acetonitrile at 0 ° C to the boiling point of the solvent. Good. The reaction can also be satisfactorily carried out in the presence of an excessive amount of a tertiary amine (base), and the excess amount of the tertiary amine (base) is up to 9 times the molar amount of the salt. It can be added. Therefore, the molar ratio of strong acid / tertiary amine to be added as the whole reaction system is 1/1
To 1/10. The amine (base) added as an excess amount is preferably a tertiary amine which is a constituent element of the salt or a tertiary amine having a weaker basicity. A small amount of a dehydrating agent such as magnesium sulfate, sodium sulfate, and molecular sieve may be added to the reaction system to remove by-product water.

[0008]

【Example】

Example 1. Synthesis of N-benzylpyridinium hexafluoroantimonate 80 g of acetonitrile and benzyl alcohol 10.81
g (0.1 mol) and 31.58 g (0.1 mol) of pyridine hexafluoroantimonate are dissolved,
The mixture was heated at 8 ° C. for 8 hours. After completion of the reaction, the mixture was concentrated and the precipitated white solid was washed with ether and dried to obtain N-benzylpyridinium hexafluoroantimonate. 40% yield

Example 2. Synthesis of N-α, α-dimethylbenzylpyridinium hexafluoroantimonate Dissolve 13.6 g (0.1 mol) of 2-phenyl-2-propanol and 31.58 g (0.1 mol) of pyridine hexafluoroantimonate in 60 g of methyl ethyl ketone. The mixture was heated and reacted at 60 ° C. for 6 hours. After the reaction,
Concentrate, wash the precipitated white solid with ether, dry,
The title compound was obtained. Yield 30%

Embodiment 3. N- (4-methylbenzyl)
Synthesis of -N, N-dimethylanilinium hexafluoroantimonate 100 g of nitromethane, 12.21 g (0.1 mol) of 4-methylbenzyl alcohol and 35.78 g of N, N-dimethylaniline hexafluoroantimonate
(0.1 mol) was dissolved and heated at 80 ° C. for 8 hours for reaction. After completion of the reaction, the mixture was concentrated, and the precipitated white solid was washed with ether and dried to give the title compound. 55% yield

Embodiment 4. Synthesis of N- (4-methoxybenzyl) -N, N-dimethylanilinium hexafluoroantimonate 100 g of nitromethane, 13.81 g (0.1 mol) of 4-methoxybenzyl alcohol and 35 N, N-dimethylaniline hexafluoroantimonate 0.78 g
(0.1 mol) is dissolved and magnesium sulfate 12.04
After adding g (0.1 mol), the mixture was heated and reacted at 80 ° C. for 4 hours. After completion of the reaction, the mixture was filtered and the filtrate was concentrated. The precipitated white solid was washed with ether and dried to obtain the title compound. 70% yield

Embodiment 5. Synthesis of N-α, α-dimethylbenzylpyridinium hexafluoroantimonate 200 g of dichloroethane, 75.0 g (0.5 mol) of α, α-dimethylbenzyl methyl ether and 31.58 g of pyridinium hexafluoroantimonate
(0.1 mol) was dissolved and heated at 70 ° C. for 4 hours for reaction. After completion of the reaction, the mixture was concentrated, and the precipitated white solid was washed with ether and dried to give the title compound. Yield 67%.

Embodiment 6. Synthesis of N-α, α-dimethylbenzylpyridinium hexafluoroantimonate To 200 g of dichloroethane, 68.0 g (0.5 mol) of α, α-dimethylbenzyl alcohol and 31.58 g (0.1% of pyridinium hexafluoroantimonate)
(mol) was dissolved and reacted at 70 ° for 7 hours. After completion of the reaction, the mixture was concentrated, and the precipitated white solid was washed with ether and dried to give the title compound. Yield 83%.

Example 7. Synthesis of N-α, α-dimethylbenzylpyridinium hexafluoroantimonate To 200 g of dichloroethane, 68.0 g (0.5 mol) of α, α-dimethylbenzyl alcohol and 31.58 g (0.1 m of pyridinium hexafluoroantimonate)
ol) and 1.58 g (0.02 mol) of pyridine were dissolved and heated at 70 ° C. for 10 hours for reaction. After the reaction,
Concentrate, wash the precipitated white solid with ether, dry,
The title compound was obtained. Yield 79%.

Example 8. Synthesis of N-α, α-dimethylbenzylpyridinium hexafluoroantimonate To 200 g of dichloroethane, 68.0 g (0.5 mol) of α, α-dimethylbenzyl alcohol and 31.58 g (0.1 m of pyridinium hexafluoroantimonate)
ol) and 2.08 g of 2-cyanopyridine (0.02 m
ol) was dissolved and heated at 70 ° C. for 4 hours for reaction. After completion of the reaction, the mixture was concentrated, and the precipitated white solid was washed with ether,
Dry to give the title compound. Yield 56%.

Claims (6)

[Claims] 1. Benzyl alcohol or benzyl alkyl ether optionally having a substituent not participating in the reaction on the benzene ring and / or the α-position (wherein the alkyl group is
It is a saturated hydrocarbon having 1 to 4 carbon atoms. ) Is reacted with a strong acid salt of a tertiary amine to synthesize a quaternary ammonium salt. 2. A benzyl alcohol or a benzyl alkyl ether optionally having a substituent that does not participate in the reaction on the benzene ring and / or the α-position is represented by the formula: (In the formula, R ₁ , R ₂ and R ₃ are independently a hydrogen atom, hydroxy, halogen, alkyl, alkoxy, nitro,
Amino, alkylamino, acyl, cyano, alkoxycarbonyl or carbamoyl, R ₄ and R ₅
Are independently hydrogen atom, halogen or alkyl, Z
Is a hydrogen atom or a saturated hydrocarbon group having 1 to 4 carbon atoms. The synthetic method according to claim 1, which is an alcohol or an ether). 3. A tertiary amine has the formula: (In the formula, R ₆ and R ₁₀ are the same as defined for R _{1 to} R _3. )
3. The synthetic method according to claim 1 or 2, which is pyridine. 4. A tertiary amine has the formula: The method according to claim 1 or 2, wherein R ₇ and R ₈ are independently alkyl or alkenyl, and R ₉ is the same as the definition of R _{1 to} R ₃ . 5. A strong acid is HAsF ₆ , HSbF ₆ , HB.
F ₄ , HPF ₆ , HClO ₄ , HFeCl ₄ , HCF ₃
The synthetic method according to any one of claims 1 to 4, which is SO ₃ or aromatic sulfonic acid. 6. A molar ratio of the tertiary amine to the strong acid salt is 9
The method according to claim 1, wherein the reaction is carried out in the presence of an excess of tertiary amine (base) up to a double amount.