JPS6366328B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to an improved and novel method for producing etherified phenolic resins.

Conventionally, as a method for etherifying a phenolic hydroxyl group, for example, an alkali metal compound and a phenol are reacted in advance, the alkali metal phenoxide produced in this process is separated and obtained, and then this is reacted with an alkyl halide. or a method in which alkyl halides are added and reacted in the same solvent without removing or removing water in the solvent without particularly separating the alkali metal phenoxides produced, and further alkyl halides,
A method of reacting in the coexistence of a phenol and an alkali metal compound is known.

However, in any of the above methods, when a highly polymerized resin such as phenol novolak resin is completely etherified, the alkali metal salt of phenol novolak does not dissolve in a hydrocarbon solvent, and therefore dimethyl Sulfoxide, dimethylformamide, dimethylacetamide, N
-The disadvantage is that it is necessary to use expensive polar solvents such as -methyl-2-pyrrolidone. Furthermore, the resin obtained by the above-mentioned method is colored black and has poor transparency, which limits the field of its application.

The present invention aims to provide a novel method for producing etherified phenolic resins which eliminates the above-mentioned disadvantages and drawbacks, and which uses substituted or unsubstituted phenolic novolak resins or resol resins (A). General formula RX...(i) [wherein, R is an alkyl group, an alkenyl group, an aralkyl group, or a formula (Here, R′ is a substituted or unsubstituted monovalent organic group, R″ is a C ₁ to ₆ divalent organic group, and n is 0 or 1 to
(a positive integer of 10) and X is a halogen atom] in the presence of an alkali metal or an alkali metal compound, the phenol novolac resin or The resol resin (A) and the halogenated organic compound (B) are dissolved in an inert organic solvent, the reaction system is maintained at reflux temperature, and the water present in the reaction system is removed by azeotropic dehydration. The method is characterized in that a metal compound is gradually added and the reaction is carried out while removing the water produced at that time by azeotropic dehydration.

According to the method of the present invention, even in the complete etherification of highly polymerized resins such as phenol novolak resins, the reaction can be carried out sufficiently by using ordinary hydrocarbon solvents without using polar solvents such as dimethyl sulfoxide or dimethyl formamide. As described above, the post-treatment is easy and the reaction time can be shortened since it is sufficient to use ordinary hydrocarbon solvents.Furthermore, the etherification product obtained by this method has a low degree of coloration. Since it is very small in amount and has good transparency, it has the effect of being widely applicable to various uses.

The method of the present invention will be explained in detail below.

First, the phenolic resin used in the present invention includes phenolic resins such as phenol novolac resins and resol type phenolic resins synthesized from phenol or phenol derivatives and formaldehyde.

Phenol or phenol derivatives that can be used as raw materials for these resins include:
Phenol, resorcinol, bisphenol A
Examples include monovalent or polyvalent phenols such as or substituted products of these phenol derivatives, such as cresol, xylenol, propylphenol, amylphenol, butylphenol, octylphenol, etc. In addition, halogen-substituted phenols and the like are also used in the present invention. can do.

The substitution positions of the substituent atoms or substituents in these substituted phenols are relative to the phenolic hydroxyl group.
Any of the o ^- , m ^- or p ^- positions is optional.

Further, as the formaldehyde, there are no restrictions on the type, and various types can be used, including formaldehyde, paraformaldehyde, formalin, etc., as long as they can supply formaldehyde.

Further, in the present invention, isopropenylphenol oligomers or polyparavinylphenols represented by the following chemical formula can be used.

Further, in the present invention, the substituted or unsubstituted phenol novolak resin or resol resin
The other compound (B) used together with (A) as a starting material is a halogenated organic compound represented by the above general formula (i), where R is a methyl group, an ethyl group, a propyl group, or a butyl group. These include alkyl groups such as vinyl groups, allyl groups, alkenyl groups such as 1-propenyl groups, aralkyl groups such as benzyl groups, or organosilyl group-substituted organic groups represented by the above-mentioned formula (ii).

The monovalent organic group represented by R' in formula (ii) is
Examples include alkyl groups, alkenyl groups, aralkyl groups, aryl groups, alkoxy groups, acyloxy groups, and groups in which hydrogen atoms of these groups are partially substituted with halogen atoms or arbitrary organic groups. Further, the C ₁ to ₆ divalent organic group represented by R'' includes various groups including an alkylene group and an arylene group.

X in formula (i) is a halogen atom, and examples thereof include a chlorine atom, a bromine atom, an iodine atom, and the like.

Among the compounds (B) represented by the general formula RX, those having a group represented by the formula (ii) include those shown below.

ClCH ₂ Si(CH ₃ ) ₃ , ClCH ₂ Si(CH ₃ ) ₂・C ₂ H ₅ , ClCH ₂ Si(CH ₃ ) ₂・CH=CH ₂ , ClCH ₂ Si(CH ₃ ) ₂・CH ₂ CH= CH ₂ , ClCH ₂ Si (C ₆ H ₅ ) ₂・CH ₃ , ClCH ₂ Si (CH ₃ ) ₂・OCH ₃ , ClCH ₂ Si (CH=CH ₂ ) ₂・CH ₃ , ClCH ₂ CH ₂ CH ₂ Si (CH ₃ ) ₂・CH=CH ₂ , ClCH ₂ CH ₂ CH ₂ Si(CH ₃ ) ₂・C=CH, ClCH ₂ CH ₂ CH ₂ Si(CH ₃ ) ₂・CH ₂ CH=CH ₂ , Furthermore, examples of alkali metals that can be used in the present invention include lithium, potassium, and sodium, and examples of alkali metal compounds include alkali metal hydrides, alkali metal hydroxides, alkali metal bicarbonates, and alkali metal compounds. Examples include metal alkoxides and alkali metal alkylated products, and among these, alkali metal hydroxides are particularly preferred in the present invention.

Examples of inert organic solvents used in carrying out the method of the present invention include alcoholic solvents such as methanol, ethanol, and n-butanol, hydrocarbon solvents such as toluene, xylene, and hexane, ethyl ether, and n-butanol. Ether solvents such as butyl ether, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, hexamethylene phosphoramide, N-methyl-2-pyrrolidone, dimethyl sulfone, N- Acetyl-2
- Polar solvents such as pyrrolidone, etc. can be mentioned.

Note that two or more kinds of these inert organic solvents may be used.

In addition, since the method of the present invention requires azeotropic removal of water produced by the reaction and water contained in the reaction system, the inert organic solvent should not form an azeotrope with water. It is necessary to use the obtained products alone or in combination.

In the method of the present invention, the above-mentioned compound (A) and compound (B) are reacted in the presence of an alkali metal or an alkali metal compound. is required to be dissolved in a solvent and heated to the reflux temperature of the reaction system. Water present in the system is azeotropically dehydrated here. The reflux temperature varies depending on the type of compound (A), compound (B) and solvent, but is usually 50 to
The temperature range is 200°C, preferably 80 to 150°C. This is because the reaction is slow at temperatures below 50°C, and undesirable side reactions occur at temperatures above 200°C. When the reaction system reaches reflux temperature, the alkali metal or alkali metal compound is gradually added as it is or as an aqueous solution, and at the same time an etherification reaction is carried out while azeotropically dehydrating. The reaction needs to be carried out in a substantially anhydrous state, and for this reason, it is necessary to remove produced water or contained water by azeotropy. When using an alkali metal compound in the form of an aqueous solution or an alkali metal hydroxide, adjust the addition rate of the alkali metal compound according to the azeotropic temperature of water to maintain the reaction system in a nearly anhydrous state. It is mandatory to do so. By carrying out the reaction under such conditions, the pH of the reaction system can be always kept at 10 or less, so it is possible to obtain a product with few side reactions and no coloration.

Compound (A) and compound (B) used in the method of the present invention
The ratio of the compound (A) used can be arbitrarily selected depending on the desired etherification rate of the compound (A). Since the reaction proceeds almost quantitatively, when attempting to completely etherify the phenolic hydroxyl group of compound (A), the amount of compound
It is sufficient to use 1 mol or more of (B). Further, when the compound (A) is a phenol novolak resin, the ether ratio of the phenolic novolak resin can be varied over a wide range by changing the molar ratio of the phenolic hydroxyl group to the compound (B).

It is sufficient to use the alkali metal or alkali metal compound in an amount equivalent to the phenolic hydroxyl group to be etherified. The reaction time varies depending on the reaction temperature and the dropwise addition rate of the alkali metal or alkali metal compound, but is, for example, about 6 to 10 hours at a temperature of 80 to 150°C. Further acceleration of the reaction can be easily achieved by using a small amount of a polar solvent such as dimethyl sulfoxide or dimethyl formamide or a compound such as crown ether.

Compared to general etherification reaction conditions, the method of the present invention has fewer side reactions due to the fact that the reaction system is close to neutrality, and etherification can be carried out with high purity and high yield, making it suitable for industrial use. It is said to be an extremely advantageous manufacturing method.

Next, examples of the present invention and comparative examples will be given.

Example 1 Phenol novolac resin (phenolic hydroxyl group 2.72 equivalents) 300g, allyl chloride 48.3g
(0.63 mol), 400 g of n-butanol, and 150 g of toluene were charged into a reaction vessel, and heated to
After refluxing at 95°C, 50% from the dropping funnel
33.6 g of NaOH aqueous solution (0.42 mol as NaOH) was gradually added dropwise over a period of 5 hours, and as soon as the dropping started, water was continuously removed from the reaction system (PH9) by azeotropic dehydration. The reaction was completed under 5 hours. The resulting NaCl was then filtered, the resulting solution was washed with water, dried, and the solvent was distilled off, yielding 280 g of a pale yellow transparent allylated phenol novolak resin in which approximately 15% of the phenolic hydroxyl groups were allylated. did it. The Gardner hue of this product was 5.

Example 2 Phenol novolak resin (phenolic hydroxyl group 0.454 equivalent) 50 g, (0.6 mol), 250 g of dimethyl sulfoxide and 150 g of toluene were charged into a reaction vessel, and by heating
After refluxing at 110-120℃, from the dropping funnel,
An aqueous solution of 30 g of KOH (purity 85.5% 0.457 mol) dissolved in 30 g of water was gradually added dropwise over a period of 5 hours, and at the same time as the addition started, water was continuously removed from the reaction system (PH9) by azeotropic dehydration and added dropwise. After the completion of the reaction, the reaction was carried out at reflux temperature for 5 hours to complete the reaction. The resulting KCl filtered solution was then washed with water, dried, and the solvent was distilled off, and the phenolic hydroxyl groups were almost completely removed.
It was possible to obtain 120 g of a 100% etherified pale yellow transparent etherified phenol novolak resin. The Gardner hue of this product was 6.

Example 3 Phenol novolak resin (phenolic hydroxyl group 0.816 equivalent) 89.8g, allyl chloride 153g
(2.0 mol), n-butanol 400g and toluene
After charging 100 g into a reaction vessel and refluxing it at 75°C, an aqueous solution of 48.7 g of KOH (purity 85%, 0.86 mol) dissolved in 50 g of water was gradually added dropwise from a dropping funnel over a period of 5 hours. At the same time as the dropwise addition starts, water is continuously removed from the reaction system (PH9) by azeotropic dehydration, and after the dropwise addition is completed, water is further removed at reflux temperature for 4 hours.
The reaction was completed after a period of reaction. The resulting solution was then washed with water and dried to remove unreacted allyl chloride and the solvent.
100% allylated phenolic hydroxyl pale yellow transparent allylated phenolic novolac resin 92
g was obtained. The Gardner hue of this product was 4.

Comparative Example 1 300 g of phenolic novolac resin (2.72 equivalents of phenolic hydroxyl groups), 400 g of n-butanol, 150 g of toluene, and 33.6 g of a 50% NaOH aqueous solution (0.42 mol as NaOH) were charged into a reaction vessel, and the pH was adjusted to 14.
After completely removing the water present in the reaction system by azeotropic dehydration, the reaction system was heated to 95 to 100°C, and 48.3 g of allyl chloride was added through a dropping funnel over a period of 3 hours. The mixture was added dropwise, and the reaction was then carried out at reflux temperature for 5 hours to complete the reaction. Next, the solution obtained by filtering the generated NaCl was washed with water and dried, and the solvent was distilled off to obtain 275 g of a dark brown transparent allylated phenol novolac resin in which approximately 15% of the phenolic hydroxyl groups were allylated. The Gardner hue of this item was 18.

Comparative Example 2 Phenol novolac resin (phenolic hydroxyl group 2.72 equivalents) 300g, allyl chloride 48.3g
(0.63 mol), 400 g of n-butanol, and 150 g of toluene were charged into a reaction vessel, and heated to
After refluxing at °C, add 50% NaOH from the dropping funnel.
After 33.6 g of an aqueous solution (0.42 mol as NaOH) was gradually added dropwise over 5 hours, the reaction was carried out at reflux temperature for 5 hours to complete the reaction.

When the solvent was then distilled off after washing with water and drying, a black-brown transparent allylated phenol novolak resin with about 15% of the phenolic hydroxyl groups allylated was obtained.
Obtained 275g. The Gardner hue of this item was 14.

Claims (1)

[Scope of Claims] 1. Substituted or unsubstituted phenol novolak resin or resol resin (A) and general formula RX [wherein R is an alkyl group, alkenyl group, aralkyl group or a formula (Here, R′ is a substituted or unsubstituted monovalent organic group, R″ is a C ₁ to ₆ divalent organic group, and n is 0 or 1 to
(a positive integer of 10) and X is a halogen atom] in the presence of an alkali metal or an alkali metal compound, the phenol novolac resin or The resol resin (A) and the halogenated organic compound (B) are dissolved in an inert organic solvent, the reaction system is maintained at reflux temperature, and the water present in the reaction system is removed by azeotropic dehydration. 1. A method for producing an etherified phenolic resin, which comprises gradually adding a metal compound and reacting while removing water produced at the time by azeotropic dehydration. 2. The method for producing an etherified phenolic resin according to claim 1, wherein the alkali metal compound is an alkali metal hydroxide.