JPS582317A - Production of alkyl-etherified amino resin - Google Patents

Abstract

PURPOSE:The reaction between an amino compound, formaldehyde and a monohydric alcohol is carried out in the presence of an anionic surface active agent to produce the titled resin of low solution viscosity readily in high efficiency with a reduced amount of the alcohol used. CONSTITUTION:An anionic surface active agent such as 1-10C dialkylsulfosuccinic acid alkali metal salt is added to the reaction system containing an amino compound subject to methylolation such as melamine or benzoguanamine, formaldehyde and a monohydric alcohol such as methanol or ethanol by 0.1- 2pts.wt based on the amino compound and the reaction is effected to give the objective resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for smoothly producing an alkyl etherified amino resin of good quality and low solution viscosity with easy operation and with a significantly reduced amount of monohydric alcohol used. .

Methylolated amino resins, such as methylolated melamine resins, are used for molding, adhesives, fiber processing, and many other fields of application.

Methylol groups are highly reactive and have poor lipophilicity, so in applications such as paints, methylolated amine resins are used under acidic conditions to provide affinity with solvents and resins. An alkyl etherification reaction is carried out with an alcohol to obtain an alkyl etherified methylolamide resin. For example, hexamethyl etherification is performed with methyl alcohol to improve compatibility with thermoplastic resins, and butyl etherification is performed with butyl alcohol to improve compatibility with solvents.

Since the alkyl etherification reaction is a dehydration condensation reaction,
In order to promote alkyl etherification, measures have been taken, for example, to heat the reaction system above the boiling point of the system and remove condensed water as a by-product.

However, such conventional methods have drawbacks such as requiring a lot of time for the reaction to proceed, requiring complicated operations, and being unable to obtain a product with the desired degree of alkyl etherification. Therefore, as a way to eliminate these drawbacks, we decided to
-299 and Japanese Unexamined Patent Publication No. 52-13539'3.

In the former method, alkyl etherification is carried out in the presence of a salt anhydride that is inert to the reaction components under the reaction conditions, is sparingly soluble or insoluble in the alcohol used for alkyl etherification, and can be further hydrated. However, by-products of hydrated salts are produced, and treatment of these by-products is required.

The latter is because when water is mixed with the distilled isobutyl alcohol-water azeotrope before it is introduced into the water separation device during reflux dehydration during the production of isobutyl alcohol-modified melamine resin, the water in the azeotrope is Although it facilitates separation, it requires changes to manufacturing equipment.

Note that the methylene bond forming reaction and dimethylene ether bond forming reaction, which are polymerization reactions, are also dehydration condensation reactions. K to obtain alkyl etherified amine resin with low solution viscosity by suppressing
It was necessary to use a large excess of monohydric alcohol, and it took a long time to remove the excess monohydric alcohol.

In view of the above-mentioned current situation, the present inventors have conducted intensive research on a method for efficiently producing an alkyl etherified amino resin with a low solution viscosity using a smaller amount of monohydric alcohol with easy operation. An amine compound that can be methylolated, formaldehyde, and a monohydric alcohol are reacted simultaneously under weak acidity, or an amine compound that can be methylolated and formaldehyde are reacted in water or a monohydric alcohol under weak alkalinity, and then the amine compound is reacted with a weak acid. When K is subjected to an etherification reaction with alcohol, an alkyl etherified amino resin is produced.
When an anionic surfactant is added to the reaction mixture, the alkyl etherification reaction between the methylol group and the monohydric alcohol proceeds preferentially over the methylene bonding reaction and the dimethylene ether bonding reaction. Even under the amount of alcohol used (amount equivalent to the amount used in the past),
We have discovered that an alkyl etherified amine resin that is less likely to cause methylene bonding reactions and dimethylene ether bonding reactions and has a low solution viscosity can be produced efficiently with easy operations, and as a result of further research, we have completed the present invention. Yes, that is, the present invention involves adding an anionic surfactant under the reaction conditions when producing an alkyl etherified amino resin from an amino compound that can be methylolated, formaldehyde, and a monohydric alcohol, and in the presence of the alkyl ether-formed amino resin. The present invention relates to a method for producing an alkyl etherified amino resin, which is characterized by carrying out the following steps:

Monohydric alcohols used in the present invention include methyl alcohol, ethyl alcohol, flobyl alcohol, inoflohil alcohol, flobyl alcohol, isobutyl alcohol, a-7'flua, alcohol, t-butyl alcohol, n- Examples include C1 to C8 straight chain aliphatic alcohols such as octyl alcohol and 2-ethylhexyl alcohol, and cyclic aliphatic alcohols and aromatic alcohols such as cyclohexanol and benzyl alcohol. Two or more types can be used.

Examples of the methylolable amino compounds used in the present invention include melamine, benzoguanamine,
Examples include aminotriazines such as acetoguanamine; cyanamide derivatives such as dicyandiamide; and urea derivatives, and one or more of these may be used.

Examples of the ionic surfactants used in the present invention include aliphatic monocarboxylate salts, abietate salts,
Dialkyl sulfosuccinate, alkylbenzene sulfonate, alkylphenoxypolyoxyethylene propyl sulfonate, N-alkyl sulfosuccinic acid monoadonisodium salt, fatty acid alkyl ester sulfate ester salt, polyoxyethylene alkylphenyl ether sulfate ester salt , alkyl phosphate ester salt, polyoxyethylene alkyl phenyl ether phosphate ester salt, partially saponified product of styrene-maleic anhydride copolymer,
Examples include a partially saponified product of an olefin-maleic anhydride co-polymer, a naphthalene sulfonate-formaldehyde condensate, and one or more of these can be used.

Among these anionic surfactants, sialygyl sulfosuccinate is particularly preferred. Examples of dialkyl sulfosuccinates include alkali metal salts, alkaline earth metal salts, and tertiary amine salts of zoalkyl sulfophosphates having C1 to C1o linear or branched alkyl groups; Metal salts are particularly preferred.

These anionic surfactants are used in an amount of 0.02 to 4% by weight, especially 0.01% by weight, based on the methylolatable amino compound.
It is preferable to use ~2% by weight. If the amount of anionic surfactant is less than 0.02% by weight with respect to the amine compound that can be methylolated, the progress of the alkyl etherification reaction will be reduced, and if it exceeds 4% by weight, insoluble matter will be produced during the alkyl etherification reaction. arise. ... [.

The alkyl etherification reaction can be carried out by refluxing an amino compound capable of being methylolated, formaldehyde, a monohydric alcohol, and an anionic surfactant under weak acidity, preferably at pH 4 to 5; Methylolation reaction is carried out at 70-80°C under alkaline conditions, preferably pH 9 to 1 (L), and then under weak acidity, preferably pH 9 to 1 (l).
4 to 5 can also be carried out under reflux.

The timing of converting from weak alkalinity to weak acidity is preferably immediately before the methylolizable amine compound dissolves. Note that an anionic surfactant may be added during the conversion.

The alkyl etherification reaction can also be carried out using a separately prepared methylolated amino compound, a monohydric alcohol, and an anionic surfactant under weak acidity, preferably at a pH of 4 to 5, under reflux.

Here, the methylolated amino compound is, for example, one or two of the above-mentioned methylolable amino compounds.
Examples include methylolated amino condensates or cocondensates derived from formaldehyde and formaldehyde, and one or more of these can be used.

The reaction time for alkyl etherification is terminated when the desired degree of alkyl etherification is reached, and if necessary,
Excess monohydric alcohol is distilled off under reduced pressure at 80° C. or lower.

By using the present invention, even if the amount of monohydric alcohol used is small, alkyl etherification is sufficiently performed, so it is easy to obtain an alkyl etherified amino resin that has a low solution viscosity and has the same quality as conventional products. be able to.

Next, the present invention will be explained in more detail by giving Examples, Comparative Examples, and Reference Examples.

Example 1 Melamine 126f (x, o mol), 80% paraformaldehyde 225f (6,0 mol), butyl alcohol were placed in a 2-volume four-bottle flask equipped with a thermometer, stirrer, and condenser for water removal. 444f (6,0 mol), G2
- Sodium ethylhexyl sulfosuccinate 1.26F
,) 17 f of toluene and 0.52 f of formic acid were charged, and the temperature was raised over 30 minutes to a reflux state.

9 After reacting under reflux for 4 hours, mineral spirit tolerance (mineral spirit is added to the resin solution, and the amount of mineral spirit until the resin solution becomes cloudy is expressed as 1/resin solution 1f).

Hereinafter referred to as MST. ) was 45 and the solid content reached aoi%, which was considered as the end point.

The alkyl etherified melamine resin obtained as described above had a Gardner viscosity of EF and an MST of 45.

Example 2 One meramiji 126 in a four-bottle flask similar to Example 1
f (1,0 mol), 80 Chibaraphoran aldehyde 206
p (5,5 mol), isobutyl alcohol 592f (8
,0 mol), di-2-ethylhexyl sodium sulfosuccinate 1.26f,) toluene 17f1 formic acid 0.37
f was charged, and the temperature was raised over 30 minutes to bring it to a reflux state.

Then, after 4 hours of reaction under reflux, the MST reached 1.
2, remove excess 1 at 70-80°C under reduced pressure.
The alcohol was distilled off over 1 hour and 20 minutes to reduce the solid content to 60q6.

The alkyl etherified melamine resin obtained as described above had a Gardner viscosity of M and an MST of 16.

Example 3 Melamine tz6 was added to a fourth flask similar to Example 1.
F (1,0 mol), 80 tiparaformaldehyde)'20
6f (5,5 mol), butyl alcohol 2229 (3,
0 mol), isobutyl alcohol 2221 (3.0 mol), di-2-ethylhexyl
was charged, and the temperature was raised over 30 minutes to bring it to a reflux state.

Then, after reacting for 4 hours under reflux, MST reached 1.
0, remove excess 1 at 70-80°C under reduced pressure.
The alcohol was distilled off over 1 hour and 30 minutes to reduce the solid content to 60.

The alkyl etherified melamine resin obtained as described above had a Gardner viscosity of LM and an MST of 14.

Example 4 In a four-bottle flask similar to Example 1, methylolated melamine 1532, butyl alcohol 444 y (a, o mol), and sodium di-2-ethylhexyl sulfosuccinate 1.26 f produced as follows. , toluene 17f1 formic acid 0.1Of was prepared, and 50
After raising the temperature to 50°C for 1 hour and further reacting under reflux for 2 hours, when MST reached 40, excess monohydric alcohol was distilled off at 70-80°C under reduced pressure for 20 minutes. The solid content was reduced to 60%.

The alkyl etherified melamine resin obtained by K as described above had a Gardner viscosity of FG and an MST of 50.

[Production of methylolated melamine]

In a fourth flask of 2 volumes, equipped with a thermometer, stirrer, and reflux condenser, add 7mm y12af (x,.

mol), 37% formaldehyde aqueous solution 6492 (8,
0 mol), after adding 500 f of water and stirring, 10
When the reaction was started by adding 6 f of aqueous sodium hydroxide solution, the mixture became transparent after 5 minutes and became cloudy after 10 minutes. This cloudy substance was immediately poured into cold methyl alcohol to stop the reaction. Then, after being allowed to stand for 10 hours, the precipitated methylolated melamine was placed on the opening side and dried under reduced pressure at room temperature.

Comparative Example 1 (vs. Example 1) Melamine 126 was placed in a four-loaf flask similar to Example 1.
f (1,0 mol), 80% paraformaldehyde)'
225 f (6,0 mol), butyl alcohol 74
0f (10,0 mol), toluene 17f1 formic acid 0.52
1 was charged, and the temperature was raised over 1 hour to bring it to a reflux state.

Then, after reacting under reflux for 4 hours, MST reached 4.
5, remove excess 1 at 70-80°C under reduced pressure.
The alcohol was distilled off over a period of 2 hours and 10 minutes, resulting in a solid content of 60 grams.

The alkyl etherified melamine resin obtained as described above had a Gardner viscosity of E and an MST of 13-50.

Comparative Example 2C (relative to Example 2) In a fourth flask similar to Example 1, melamine 126
F (10 mol), 8o tiparaformaldehyde 206
f (5,5 mol), isobutyl alcohol 11109
(15,0 mol), toluene 17f1 formic acid Q, 37
f was charged, and the temperature was raised over 1 hour to bring it to a reflux state.

Then, after reacting for 4 hours under reflux, MST reached 8.
At the point when the solid content reaches 60°C, the excess monohydric alcohol is distilled off at 70-80°C under reduced pressure over 2 hours and 30 minutes.
I made it 0 yen.

The alkyl etherified melamine resin obtained as described above had a low Gardner viscosity and an MST of 17.

Comparative Example 3 (Compared to Example 3) Melamine 126 was added to a fourth flask similar to Example 1.
f (1,0 mol), 80 tiparaformal 14-dehyde)” 206 f (5,5 mol), butyl alcohol 3709 (5,0 mol), isobutyl alcohol 3
70 f (5,0 mol), toluene 17f1 formic acid 0,
37 f was charged, and the temperature was raised over 1 hour to bring it to a reflux state.

Then, after reacting for 4 hours under reflux, MST reached 8.
At the point when the solid content reaches 60°C, the excess monohydric alcohol is distilled off at 70-80°C under reduced pressure over 2 hours and 30 minutes.
I made it 0 yen.

The alkyl etherified melamine resin obtained as described above had a Gardner viscosity of 13 in MXMST.

Comparative Example 4 (Compared to Example 4) In a four-bottle flask similar to Example 1, methylolated melamine 153f as in Example 4, butyl alcohol 740F (10.0 mol), toluene 17f, formic acid 0.
Prepare 1 Of and raise the temperature to 50℃ over 10 minutes.
After reacting for 1 hour at ℃ and 2 hours under reflux, M
When ST reached 40, excess monohydric alcohol was distilled off at 70 to 80°C under reduced pressure over 2 hours to reduce the solid content to 60%.

The alkyl etherified melamine resin obtained as described above had a Gardner viscosity of E-FXMST of 50.

Reference Example 1 (Compared to Example IK) Melamine 126 was placed in a four-loaf flask similar to Example 1.
f (1,0 mol), 80 tiparaformaldehyde)” 2
26 F (6,0 mol), butyl alcohol 444
f (6.0%), toni:1:/17 f, formic acid 0.
52f was charged, and the temperature was raised over 1 hour to bring it to a reflux state.

Then, after reacting under reflux for 7 hours, MST reached 3.
5 (react for more than 7 hours, book, M
ST exceeded 35), excess monohydric alcohol was distilled off at 70 to 80°C under reduced pressure over 1 hour and 20 minutes.
The solid content was set to 60 inches.

The alkyl etherified melamine resin obtained by pressing as described above had a Gardner viscosity of R and an MST of 35.

Reference Example 2C (for Example 2) Melamine 126 was placed in a four-loaf flask similar to Example 1.
F (1,0 mol), 80% paraformaldehyde 2
06 f (5,6 mol), isobutyl alcohol 59
2 f (8,0 mol), toluene 17f1 formic acid 0.3
7 f was charged, and the temperature was raised over 1 hour to bring it to a reflux state.

Then, after reacting for 4 hours under reflux, MST reached 8.
When the temperature reached 1 hour, the excess monohydric alcohol was distilled off at 70 to 80°C under reduced pressure for 1 hour and 30 minutes to reduce the solid content to 6.
I set it to 0.

The alkyl etherified melamine resin obtained as described above had a Gardner viscosity of Z and an MST of 12.

Reference Example 3C (for Example 3) 17- In a four-loaf flask similar to Example 1, melamine 12s
f (1.0 mol 1.8o% paraformaldehyde 206
1F (FL5 mol), butyl alcohol 2229 (3
,0 mol), isobutyl alcohol 222f (3.0 mol), toluene 17f1, formic acid 0.37f, and 1
The temperature was raised over time to bring it to a reflux state.

Then, after reacting for 4 hours under reflux, MST reached 8.
When the temperature reached , the excess monohydric alcohol was distilled off under reduced pressure at 70 to 80°C over 2 hours to bring the solid content to 60%.

The alkyl etherified melamine resin obtained as above had a Gardner viscosity of UV and an MST of 12.

As is clear from the above Examples, Comparative Examples, and Reference Examples, in the Examples, the amount of monohydric alcohol used is smaller than in the Comparative Examples, and the distillation time for excess monohydric alcohol is shorter. It can be seen that the solution viscosity of the obtained alkyl etherified melamine resin is lower than that of the reference example.

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Claims (1)

[Claims] When producing an alkyl etherified amino resin from an amine compound capable of being methylolated, formaldehyde, and a monohydric alcohol, an anionic surfactant is added to the reaction conditions, and the alkyl etherification is carried out in the presence of the anionic surfactant. Production method of alkyl etherified amino resin 0