JPS58179216A - Preparation of phenolic resin - Google Patents

Abstract

PURPOSE:To obtain water-soluble phenolic resin having improved performance in high yield, by reacting phenol with formaldehyde at a specific molar ratio, and reacting formaldehyde with the reaction product at a specific molar ratio. CONSTITUTION:Phenol is reacted with formaldehyde at 0.3-0.6molar ratio between the formaldehyde and phenol by adjusting the pH with sodium hydroxide, and formaldehyde is then reacted with the resultant product at 0.9-1.3molar ratio between the formaldehyde and the phenol to give the aimed phenolic resin. USE:Decorative laminated boards, laminated boards, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a water-soluble phenolic resin used for decorative laminates, laminates, etc. Conventionally, phenolic resins used for decorative laminates, laminates, etc. include: Generally, phenolic resins dissolved in organic solvents such as methanol are used, but in this book, the organic solvent evaporates during work, so it is not a preferable book in terms of pollution, and it is also costly. Because of this drawback, there has recently been a tendency to use water-soluble phenolic resins that use water as a solvent. However, when producing water-soluble phenolic resins, there is a problem in that when the reaction between phenol and formaldehyde progresses and the molecular weight of the phenolic resin increases, it becomes insoluble in water. Various studies have been conducted regarding the reaction with The methods include increasing the ratio of formaldehyde to phenol (more than about 1.5%) to suppress the increase in the molecular weight of the phenol resin, extending the reaction time, and using a catalyst with strong dispersion properties. However, the performance and yield of the phenol resin obtained were not satisfactory due to poor performance and yield.

The uninvented invention was made in view of the above points, and it is a water-soluble phenol m with high yield and excellent performance.
The purpose of this invention is to provide a method for producing fat.

This publication is detailed below. At the beginning, phenol and formaldehyde are combined into tL of formaldehyde/phenol.
The reaction is carried out by setting the ratio to be 0.3 to 0.6.

In this way, since the V:L ratio of formaldehyde to phenol is small, the reaction between formaldehyde and phenol stops at a certain degree, and gelation does not occur even if the reaction is allowed to occur for a long time. Therefore, the molecular weight distribution of the obtained reactant becomes sharp. -Since formaldehyde is relative to phenol, if the L ratio is less than 0.3, the reaction will hardly proceed, and if it exceeds 0.6, the reaction will hardly proceed. The molecular weight of the reactant increases and it becomes oil-solubilized, resulting in a decrease in slag yield as a water-soluble resin.Next, formaldehyde is added to the reaction product obtained in this manner to form formaldehyde/phenol. The reaction is carried out by setting the tL ratio t-0° of 9 to 1.3d to obtain a pheno-L resin.Here, if the EL ratio of formaldehyde to phenol is less than 0.9, the reactivity is Unfortunately, the yield will decrease, and the
.

This book shows that the yield of 4 decreases when it exceeds 3.

The phenolic resin thus obtained is mainly used as a resin for host foams, and is used in the production of decorative boards, laminates, and the like. Phenol resin varnish, which is made by dissolving phenolic resin in water, is not only non-polluting and inexpensive, but also has better permeability to kraft paper for laminates than methanol-dissolved phenol resin varnish. It's good/'It's one piece. Additionally, because the molecular weight distribution of the phenolic resin in the phenolic resin varnish is sharp, it has excellent properties, and laminates molded using this phenolic resin varnish also have excellent heat resistance.

As mentioned above, the formaldehyde/phenol ratio in tL is 0.3~
The reaction was carried out by setting the VC to 0.6, and then formaldehyde was added to this reaction product, and the reaction was carried out by setting the formaldehyde/phenol ratio to be 0.9 to 1.3 in tL, so @l A low molecular weight, water-soluble reactant was obtained in high yield without gelation by reacting phenol with 0.3 to 0.6 t of formaldehyde relative to the phenol in the step, and then this reactant was reacted in a 4M2 step. Formaltide/phenol ℃L ratio is 09
This book can improve the productivity of water-soluble phenolic resins by adding formaldehyde to a reaction temperature of ~1.3 to obtain a polymerized phenolic resin that is soluble in water in high yield. ◎ Hereinafter, the invention will be specifically explained with reference to Examples.

<Example 1> Using formaldehyde, paraform was diluted with water to a concentration of 561%, and the formaldehyde/phenol tL ratio was set to 0.5, and the mixture was diluted with sodium hydroxide.
9.0Kil of H was prepared and reacted at reflux temperature for 100 minutes. Next, 37% formalisin solution was added to the reaction to bring the formaldehyde/phenol tL ratio to 1. OK!
After adjusting the temperature, the mixture was reacted at reflux temperature for 30 minutes to obtain a phenol resin varnish. The yield of phenol resin was 176%.

Comparative Example 1> Formalgide/phenol tL ratio was 1. OK&
and adjust the pH to 9.0 Kfjg with sodium hydroxide.
The mixture was then reacted at reflux temperature for 40 minutes to obtain a phenol resin varnish. The yield of phenolic resin was 6296.

Comparative Example 2> The resin obtained in Comparative Example 1 was further reacted at 85° C. for 180 minutes to obtain a phenolic resin varnish. The yield of phenol resin was tf 6g%.

<Example 2> One overlay sheet obtained by impregnating thin paper with melanin resin varnish with a resin amount of 50 yen and drying it, and a pattern paper obtained by impregnating pattern paper with the same melanin resin varnish and drying it. Laminate one Tsurizuregi and four core Tsurizuregi obtained by impregnating kraft paper with the water-soluble phenolic resin varnish obtained in step 1 and drying the resin amount of 50 m, and mold this laminate. A melamine decorative board was obtained by compression molding for 60 minutes at 160° C. and 100 Kt/−.

Comparative Example 3 A melamine decorative board was obtained in the same manner as in Example 2, except that fur prepurek obtained by impregnating and drying kraft paper with the phenolic resin varnish obtained in Comparative Example 1 was used.

<Comparative Example 4> A melamine decorative board was obtained in the same manner as in Example 2, except that a cored lipure obtained by impregnating and drying kraft paper with the phenolic resin varnish obtained in Comparative Example 2 was used.

Next, on the decorative board obtained in Example 2 and Comparative Example 3.4 [18
A metal container containing oil at 0° C. was left for 20 minutes, and thermal deterioration thereafter was measured. As a result, no abnormality was found in any of the decorative boards. From this, it can be seen that the phenolic resin varnish obtained in Example 1 has Vc
4, it can be seen that the heat resistance performance is equivalent to that of the conventional method.

Claims (1)

[Claims] 111 Phenol and formaldehyde are reacted at a temperature ratio of 0.3 to 0.6 K, and then formaldehyde is added to the reaction mixture to react with formaldehyde/phenol at a ratio of 7 °C. A method for producing a phenol resin, characterized in that the reaction is carried out by setting the ratio to 0.9 to 1.3.