JP2003119234A - Low viscosity phenol-modified aromatic hydrocarbon- formaldehyde resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low viscosity phenol-modified aromatic hydrocarbon- formaldehyde resin having less free phenol which is improved in problems regarding the conventional production of the low viscosity phenol-modified aromatic hydrocarbon-formaldehyde resin. SOLUTION: The aromatic hydrocarbon formaldehyde resin is modified by a small amount of phenols using a weak acid such as an amine salt of p- toluenesulfonic acid, oxalic acid, maleic acid or the like as a weak acid catalyst.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin containing a certain proportion of phenols in the resin.

[0002]

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

Conventionally, a phenol-modified aromatic hydrocarbon formaldehyde resin has been produced by reacting an aromatic hydrocarbon formaldehyde resin with phenols in the presence of a strong acid catalyst such as P-toluenesulfonic acid. An acid catalyst must be used to react the aromatic hydrocarbon formaldehyde resin with phenols, but when a strong acid such as P-toluenesulfonic acid is used in the reaction between the aromatic hydrocarbon formaldehyde resin and phenol, When a hydrocarbon formaldehyde resin is used in a certain proportion or more than phenol, gelation occurs, so the reaction must be carried out in a phenol excess system. When an aromatic hydrocarbon formaldehyde resin is reacted in a phenol excess system, a low-viscosity aromatic hydrocarbon formaldehyde resin can be obtained, but a large amount of free phenol remains in the resin, which is not preferable. Further, by adding formaldehyde afterwards and reacting it, it is possible to reduce free phenol, but doing so is not preferable because the resin viscosity increases.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin that has improved the problems associated with the production of conventional phenol-modified aromatic hydrocarbon formaldehyde resin. To do.

[0005]

Means for Solving the Problems As a result of diligent studies, the present inventor has found that aromatic hydrocarbons and formaldehyde resins using a weak acid such as an amine salt of P-toluenesulfonic acid, oxalic acid and maleic acid as a weak acidic catalyst. It was found that a low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin containing a small amount of free phenols can be obtained by modifying styrene with a small amount of phenols to complete the present invention.

That is, according to the present invention, an aromatic hydrocarbon formaldehyde resin is reacted with a phenol by a weak acid catalyst such as an amine salt of P-toluenesulfonic acid, oxalic acid and maleic acid, and a low-viscosity phenol-modified aromatic hydrocarbon formaldehyde. A method for obtaining a resin, wherein the viscosity of the resin is 500 to 10,000 (mPa · s / 25 ° C.).

The aromatic hydrocarbon formaldehyde resin used in the present invention is a product of Mitsubishi Gas Chemical Co., Inc., a relatively low viscosity xylene formaldehyde resin having a viscosity of 50 to 5,000 (mPa · s / 25 ° C.), Nikanol Y1000. , Nikanol Y100, Nikanol Y50 and mesitylene formaldehyde resin Nikanol Y5001, Nikanol Y1001, Nikanol Y101, Nikanol Y51 can be mentioned.

Such a relatively low-viscosity xylene-formaldehyde resin is prepared by adding alcohols such as methanol to a system in which xylene and formaldehyde are reacted in a strong acid catalyst such as sulfuric acid, as described in JP-A-10-168147. It can be synthesized by doing.

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

As the weakly acidic catalyst, use should be made of a salt obtained by neutralizing a strong acid such as sulfuric acid, hydrochloric acid, phosphoric acid or an organic sulfonic acid such as P-toluenesulfonic acid and xylenesulfonic acid with a weak base such as amine. Can be done. P- as a strong acid
Organic sulfonic acids such as toluene sulfonic acid and xylene sulfonic acid are suitable, and examples of amines include primary, secondary and tertiary amines, but triethylamine and pyridine are suitable.

As other weakly acidic catalysts, organic carboxylic acids such as formic acid, oxalic acid, maleic acid and citric acid can be used.

The modification ratio of the phenols and the aromatic hydrocarbon formaldehyde resin is 50:50 to 5:95 by weight.
Is preferable, and more preferably 40:60 to 10:90. When the ratio of phenols is more than 50:50, unreacted phenols are not preferable because they remain in the low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin.
If the modification ratio of phenols is less than 5:95, the effect of modification with phenol is reduced, which is not preferable.

When a strong acid amine salt is used, the amount of catalyst added is 0.0001 to 100 parts by weight based on the total weight of phenols and aromatic hydrocarbon formaldehyde resin charged.
0.1 (part) is preferable, and 0.001 to 1 is more preferable.
0.01 (part) is preferable. The amount of catalyst is 0.0001
When the amount is less than (parts), the reaction rate becomes slow, which is not preferable, and when the amount of catalyst is more than 0.1 (parts), the reaction rate becomes fast and the control of the reaction is difficult, which is not preferable. When an organic carboxylic acid is used as a catalyst, it is preferably 0.1 to 5 parts by weight, more preferably 1 to 100 parts by weight of the total amount of phenols and aromatic hydrocarbon formaldehyde resin charged.
-3 (parts) are preferred. When the amount of the catalyst is less than 0.1 (parts), the reaction rate becomes slow, which is not preferable. When the amount of the catalyst is more than 5 (parts), the reaction rate becomes fast and the control of the reaction is difficult, which is not preferable.

Although the reaction temperature and time vary depending on the type of phenol used, the type and amount of catalyst used, the reaction temperature is 120.
C. to 160.degree. C. and the reaction time is 2 to 8 hours.

The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin obtained by the present invention has a viscosity of 5
It is from 00 to 10,000 (mPa · s / 25 ° C). The viscosity can be appropriately controlled to 500 to 10,000 (mPa · s / 25 ° C.) depending on the type of aromatic hydrocarbon formaldehyde resin used, the type of phenols, the type of catalyst added, the reaction temperature, and the time. When the viscosity is lower than 500 (mPa · s / 25 ° C), the weight loss on heating increases, and when it exceeds 10,000 (mPa · s / 25 ° C), the dilution effect when used in various resins is used. Is less preferable, which is not preferable. In particular, when used as an additive for paints, the surface smoothness is inferior, which is not preferable.

The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin thus obtained has a phenolic hydroxyl group in the resin, and therefore has excellent compatibility with epoxy resins, various curing agents, and urethane resins. It can be used as an additive for anticorrosion paints and as an additive for cationic electrodeposition paints, and exhibits excellent anticorrosion properties and surface smoothness.

[0017]

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 Nianol Y was placed in a 2 liter separable flask equipped with a thermometer, a Liebig condenser, a stirrer and a nitrogen inlet tube.
-100 [Mitsubishi Gas Chemical Co., Ltd. trade name] 800 g phenol 200 g and P-toluenesulfonic acid pyridine salt 0.1 g dissolved in 1 g of methanol and added, and reacted under a nitrogen stream at 135 ° C for 5 hours to be free. Phenol 3.2%
936 g of a low-viscosity phenol-modified xylene formaldehyde resin having a viscosity of 6,800 (mPa · s / 25 ° C.) and a loss on heating of 14.1% and a hydroxyl equivalent of 440 (g / eq) was obtained.

Examples 2 to 9 In the same manner as described in Example 1, nichol Y-50 and Y-10 as low-viscosity xylene formaldehyde resin were prepared.
Table 1 and Table 2 show the results of synthesizing P-toluenesulfonic acid pyridine salt and oxalic acid using Phenol, o-cresol, and nonylphenol as catalysts using 0, Y-1000.

Comparative Examples 1 to 3 In the same manner as described in Example 1, low viscosity xylene formaldehyde resin Y-100 was used as phenols.
When the pyridine salt of P-toluenesulfonic acid was used as a catalyst with o-cresol and the charging ratio of o-cresol was higher than that described in the specification, Comparative Example 1, the charging ratio of o-cresol was lower than that described in the specification. The results are shown in Table 3 as Comparative Example 2 and as an example using P-toluenesulfonic acid as a catalyst.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin obtained by the present invention has a phenolic hydroxyl group in the resin and has a low viscosity and is excellent in compatibility with the epoxy resin and its curing agent and urethane resin. It exhibits excellent anticorrosion properties and surface smoothness as an additive to resin-based heavy anticorrosion paints or cationic electrodeposition paints.

Claims (6)

[Claims] 1. A low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin obtained by subjecting an aromatic hydrocarbon formaldehyde resin and a phenol to a condensation reaction in the presence of a weakly acidic catalyst. 2. The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the aromatic hydrocarbon formaldehyde resin is at least one kind of xylene resin and mesitylene resin. 3. The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the phenol is one or more of phenol, cresol, xylenol, butylphenol, octylphenol, nonylphenol, cardanol, and terpenephenol. 4. The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the weakly acidic catalyst is an amine salt of P-toluenesulfonic acid. 5. The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the amine of the amine salt of P-toluenesulfonic acid is pyridine. 6. The low-viscosity phenol-modified aromatic hydrocarbon formaldehyde resin according to claim 1, wherein the weakly acidic catalyst is oxalic acid, maleic acid or citric acid.