JP2003183342A - Process for producing phenol-modified aromatic hydrocarbon formaldehyde resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing a phenol-modified aromatic hydrocarbon form aldehyde resin containing a phenol in a prescribed amount or more by a simplified step. <P>SOLUTION: An aromatic hydrocarbon is condensed with formaldehyde in the presence of a phenol, thus producing a phenol-modified aromatic hydrocarbon aldehyde resin in one step. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin which contains a certain proportion of phenols in the resin.

[0002]

2. Description of the Related Art Aromatic hydrocarbon formaldehyde resins have excellent compatibility with various natural and synthetic resins. Therefore, they are used as a mixture with various natural and synthetic resins to improve the adhesiveness, moisture resistance and electrical properties of the main resin. Although it is used for quality, it can be used as a phenol-modified aromatic hydrocarbon formaldehyde resin after being modified with phenols in order to further improve its modifying effect.

Conventionally, an aromatic hydrocarbon formaldehyde resin is produced by reacting an aromatic hydrocarbon with formaldehyde in the presence of an acid catalyst such as sulfuric acid, and then phenols are added to the aromatic hydrocarbon formaldehyde resin to produce p-. A phenol-modified aromatic hydrocarbon formaldehyde resin has been obtained by a so-called two-step method in which an organic sulfonic acid such as toluene sulfonic acid is reacted as a catalyst. This method is not preferable because it costs more and more time to produce the phenol-modified aromatic hydrocarbon formaldehyde resin than to produce the aromatic hydrocarbon formaldehyde resin.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin, which has improved the problems associated with the conventional production of a phenol-modified aromatic hydrocarbon formaldehyde resin. And

[0005]

Means for Solving the Problems As a result of diligent studies, the present inventor has found that when a phenol is present in the condensation reaction of an aromatic hydrocarbon and formaldehyde, a phenol-modified aromatic hydrocarbon formaldehyde resin is produced in one step. The inventors have completed the present invention by finding that the above problems can be solved.

That is, the present invention relates to a method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin obtained by subjecting an aromatic hydrocarbon, formaldehyde, and a phenol to a condensation reaction in the presence of an acid catalyst.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As aromatic hydrocarbons used in the present invention, toluene, ethylbenzene, three isomers of xylene, mesitylene, pseudocumene, monocyclic aromatic hydrocarbon compounds having 10 or more carbon atoms, and naphthalene and methylnaphthalene. And other polycyclic aromatic hydrocarbon compounds. Incidentally, a mixture of these can also be used. Among them, xylene, mesitylene, or a mixture of the two substances is particularly preferable.

Examples of formaldehyde include industrially easily available compounds such as formalin, paraformaldehyde, and trioxane which generate formaldehyde. In the present invention, even if a polymer such as paraformaldehyde or trioxane is used, the content of the polymer is defined based on one molecule of formaldehyde.

Examples of the phenols used in the present invention include at least one of phenol, cresol, xylenol, butylphenol, octylphenol, nonylphenol, cardanol and terpenephenol.

The catalyst used in the condensation reaction includes sulfuric acid and phosphoric acid, but sulfuric acid is generally used. It is effective to add an organic sulfonic acid such as p-toluenesulfonic acid or xylenesulfonic acid to the reaction system to obtain a phenol-modified aromatic hydrocarbon formaldehyde resin. It is more effective to add the amine salt of organic sulfonic acid to the reaction system of sulfuric acid catalyst. P-toluenesulfonic acid is suitable as the organic sulfonic acid, and primary and secondary amines are the amines.
Although tertiary and tertiary amines are used, triethylamine and pyridine are suitable.

Since the amount of sulfuric acid used is diluted with water in the formaldehyde aqueous solution, the concentration in the aqueous solution is 1
It is desirable to adjust the content to be 0 to 50% by weight. When the sulfuric acid concentration is less than 10% by weight, the reaction rate becomes very slow, which is not practical. On the other hand, when it exceeds 50% by weight, the reaction rate is high and the resin viscosity is high, which is not preferable.

The amount of p-toluenesulfonic acid to be added is appropriately 0.1% by weight to 1.0% by weight based on the total amount of aromatic hydrocarbons and phenols charged. When it is less than 0.1% by weight, the reaction speed of the generated aromatic hydrocarbon formaldehyde resin and phenols is slow,
When it is more than 1.0% by weight, the reaction rate becomes too fast, which is not preferable.

When p-toluenesulfonic acid is used as an amine salt, an aromatic hydrocarbon formaldehyde resin produced by an aromatic hydrocarbon and formaldehyde coexists in the oil layer together with phenols, so that the acidic catalyst is easily dissolved in the oil layer. However, the reaction rate is increased, which is preferable. The amount of amine added may be equivalent to that of p-toluenesulfonic acid.

The molar ratio of aromatic hydrocarbon and formaldehyde charged in the condensation reaction is 1.0 / 0.5 to 1.0.
/5.0 is preferable, and more preferably 1.0 / 1.0 to
It is in the range of 1.0 / 3.0. When the charged molar ratio of formaldehyde is less than 1.0 / 0.5, the oxygen content in the obtained aromatic hydrocarbon formaldehyde resin is small and the reactivity with phenols is poor, which is not preferable. If the amount of formaldehyde exceeds 1.0 / 5.0, the amount of unreacted formaldehyde remains undesirably.

The molar ratio of the aromatic hydrocarbon and the phenols charged in the condensation reaction is 1.0 / 0.05 to 1.0 /.
1.0 is preferable, and 1.0 / 0.1 is more preferable.
It is in the range of 1.0 / 0.8. When the charged molar ratio of aromatic hydrocarbons and phenols is less than 1.0 / 0.05, the effect of adding phenols is not clear and 1.0 / 1.
When it exceeds 0, unreacted phenols remain and the liquid separation property deteriorates, which is not preferable.

In order to reduce the resin viscosity, one or more kinds selected from aliphatic alcohols having 1 to 4 carbon atoms, if necessary, in a molar ratio of 1 to the formaldehyde used.
It can also be used in the range of 0 / 0.1 to 1.0 / 1.0.

The reaction temperature is a temperature at which aromatic hydrocarbons, formalin and phenols present in the reaction system are refluxed and is usually about 95 to 105 ° C., and the reaction time is usually 2 to 6 hours.

Since the phenol-modified aromatic hydrocarbon formaldehyde resin thus obtained has a phenolic hydroxyl group in the resin, it has excellent compatibility with epoxy resins, various epoxy resin-based curing agents, and urethane resins, and epoxy resin-based heavy resins. It exhibits excellent anticorrosion properties and surface smoothness as an additive for anticorrosion paints and cationic electrodeposition paints.

[0019]

EXAMPLES Examples and comparative examples will be shown below in order to explain the present invention in detail. In the examples and comparative examples, [%] and [parts] represent [wt%] and [parts by weight], respectively, unless otherwise specified.

Example 1 m-xylene (490 g) was placed in a 2 liter separable flask equipped with a thermometer, a reflux condenser, a stirrer, and a nitrogen inlet tube.
(4.6 mol), 40% formalin 692 g (9.2 mol), 98% sulfuric acid 231 g and phenol 87 g (0.9
Mol) in a total amount of 1500 g and refluxed at 95 ° C to 105 ° C
At a temperature of 4 hours, and thereafter, in order to reduce the viscosity of the produced resin and improve the liquid separation property, 250 g of m-xylene was added, and the mixture was separated into an oil phase containing the resin and an aqueous phase containing sulfuric acid. The phase was washed three times with water, and then unreacted m-xylene and post-added m-xylene were distilled off to give a color number (Gardner) of 2, viscosity of 7
6000 (mPa · s / 25 ° C), heating loss 14.1%, hydroxyl equivalent 900 (g / eq), free phenol 2.5% phenol-modified aromatic hydrocarbon formaldehyde resin 668 g
Got

Examples 2 to 11, Comparative Examples 1 to 4 In the same manner as described in Example 1, phenols were used as o.
-Results of synthesizing phenol-modified aromatic hydrocarbon formaldehyde resin by changing the charged molar ratio of phenols using cresol and nonylphenol, and results of using p-toluenesulfonic acid and triethylamine salt of p-toluenesulfonic acid as a catalyst Are shown in Table-1 and Table-2. Comparative Examples 1 to 4 are shown in Table-3. M-X in the table
Means m-xylene, and P-TSA means p-toluenesulfonic acid.

[0022]

[Table 1]

[0023]

[Table 2]

Table 3 shows Comparative Examples 1 to 4.

[Table 3]

When P / X (molar ratio) is less than 0.1, the amount of phenol added is small and the effect of addition is difficult to develop, which is not preferable. When P / X (molar ratio) is more than 1, the liquid separation property is not good and it is difficult to take out the resin, which is not preferable.

[0026]

INDUSTRIAL APPLICABILITY The phenol-modified aromatic hydrocarbon formaldehyde resin obtained by the present invention is not a conventional one obtained by modifying an aromatic hydrocarbon formaldehyde resin with phenols, but is a direct aromatic hydrocarbon or formalin. , It can be obtained from phenols, and the manufacturing cost can be reduced due to the simplification of the process. The obtained phenol-modified aromatic hydrocarbon formaldehyde resin has excellent compatibility with epoxy resin and its curing agent and urethane resin, and as an additive for epoxy resin-based heavy anticorrosion coatings or cationic electrodeposition coatings Shows smoothness.

Claims (5)

[Claims] 1. A method for producing a phenol-modified aromatic hydrocarbon formaldehyde resin obtained by subjecting an aromatic hydrocarbon, formaldehyde, and a phenol to a condensation reaction in the presence of an acid catalyst. 2. The production method according to claim 1, wherein the aromatic hydrocarbon is at least one of xylene and mesitylene. 3. The method according to claim 1, wherein the phenols are at least one selected from the group consisting of phenol, cresol, xylenol, butylphenol, octylphenol, nonylphenol, cardanol and terpenephenol. 4. The acid catalyst is sulfuric acid, or a combination of sulfuric acid and an organic sulfonic acid such as p-toluenesulfonic acid or xylenesulfonic acid, or an amine salt of sulfuric acid and an organic sulfonic acid such as p-toluenesulfonic acid or xylenesulfonic acid. The manufacturing method according to claim 1, which is a combination of 5. The compounding ratio (molar ratio) of aromatic hydrocarbon and formaldehyde is 1.0 / 0.5 to 1.0 / 5.0, and the compounding ratio (molar ratio) of aromatic hydrocarbon and phenol (molar ratio). Ratio) is 1.0 / 0.05-1.0 / 1.0, The manufacturing method of any one of Claims 1-4.