JPH02248417A - Production of high-molecular weight phenol resin - Google Patents

Abstract

PURPOSE:To obtain a phenol resin having a sharp MW distribution and a high MW by condensing a phenol with an aldehyde in the presence of an acid catalyst in a homogeneous system of an organic solvent while removing the formed water from the reaction system by azeotropic distillation. CONSTITUTION:1mol of a phenol of formula I (wherein R<1-3> are each a common substitutable substituent on the benzene ring), 0.5-2.0mol of an aldehyde of formula II [wherein R<4> is an (un)substituted alkyl or phenyl], 0.1-70mol %, based on the phenol, acid catalyst (e.g. p-toluenesulfonic acid)/and an organic solvent (e.g. benzene) are fed to a reaction vessel and condensed in an inert atmosphere in a temperature range from 50 to 180 deg.C or to the b.p. of the solvent while removing the formed water from the reaction system by azeotropic distillation.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides an improved production process in which aldehydes other than formaldehydes can be easily condensed as linking groups in phenol novolak resins, and high molecular weight phenol novolac resins can be obtained. Regarding the law.

(Prior art) Phenol novolak resin is generally produced by heating phenols and formalin in the presence of an acid catalyst, as described in Arata Murayama's book, Phenol Resin (published in 1981, Nikkan Shimbun). A condensation reaction was carried out, and then residual phenols and water were removed by vacuum or steam distillation at a high temperature of 100° C. or higher, followed by cooling to obtain a resinous solid. However, most of the phenol novolac resins obtained by this method have an average molecular weight of 1. 00
It was as low as 0 or less, and the molecular weight distribution was wide.

Recently, Japanese Patent Application Laid-open No. 12714/1983 and Japanese Patent Application Laid-open No. 62-
As reported in No. 230816, phenols and formaldehyde are subjected to a condensation reaction in a homogeneous organic solvent using a weakly acidic catalyst, and the reaction solution is precipitated in water to produce high molecular weight products with an average molecular weight of about 1. Processes for producing 10,000 phenolic novolak resins have also been used.

However, both methods are effective for producing phenol novolak resins only when using aldehydes with little steric hindrance and high reactivity, such as formaldehyde and acetaldehyde, as the linking group for phenols, and steric hindrance, etc. It has been difficult to obtain phenolic novolac resins using aldehydes with low reactivity.

In order to produce this keyaki using aldehydes with low reactivity and using the general method for producing phenol novolak resin as described above, it was necessary to use a large amount of a strong acid catalyst and to use harsh conditions.

Further, even under such conditions, the resin yield was low. There was no technology that could economically produce phenol novolac resins on an industrial scale in good yield using aldehydes with low reactivity.

(Problems to be Solved by the Present Invention) An object of the present invention is to provide a method for producing a phenol novolak resin that has a narrow molecular weight distribution and can have a high molecular weight even when using substituted aldehydes with low reactivity. . Another object is to provide a method for producing a phenol novolak resin containing phenols and substituted aldehydes as main components, which has not been possible in the past.

Still another object of the present invention is to provide a method for producing a phenol novolak resin that allows the use of variously substituted aldehydes as a linking group and has a wider range of uses.

The term "high molecular weight" of the phenol novolak resin of the present invention refers to one having a weight average molecular weight of 1,000 or more.

(Means for Solving the Problems) The above-mentioned aspects of the present invention are such that when phenols and 2m aldehydes are reacted in a solution state in the presence of an acid catalyst, phenols are formed when condensed via aldehydes. The low-reactivity substituted aldehydes are removed from the reaction system using an organic solvent that can be azeotropic with water, thereby shifting the equilibrium in a direction favorable to resin formation. This was achieved by a method for producing a high molecular weight phenolic novolac resin, which was used as a linking group.

The method for producing a phenol novolac resin using a substituted aldehyde as a linking group according to the present invention will be described in detail.

That is, phenols and substituted aldehydes are stirred in the presence of an acid catalyst, preferably under an inert atmosphere such as nitrogen, in an organic solvent that can be azeotroped with water, alone or in a mixed system, and subjected to an azeotropic dehydration reaction under heating conditions. By doing so, a high molecular weight phenolic novolank resin is obtained.

The azeotropic dehydration method will be explained in detail.

The method for producing a phenol novolak resin of the present invention is characterized in that water generated during the condensation reaction of phenols and aldehydes is removed from the reaction system. As a method for dehydrating the water out of the reaction system, (1) A method in which the solvent is evaporated out of the reaction vessel along with an inert gas flow such as nitrogen or argon during the heating reflux reaction.

■ A method of refluxing the solvent through a desiccant (dehydrating agent) using a Soxhlet extractor during the heating reflux reaction.

■ During the heating reflux reaction, the cooling pipe (reflux pipe)
A method of attaching a Dean-Stark trap (moisture quantitative receiver) to the bottom of the reactor to trap only water and return the solvent to the reaction system.

Although typical examples have been given, methods of dehydration outside the reaction system other than those described above may be used.

The solvent will be explained in detail.

As the solvent for the condensation reaction as described above, it is preferable to use a solvent that can form an azeotrope with water. Examples of such a solvent include benzene, toluene, xylene (o-, p-, m), etc.
Aromatic solvents such as ethanol isopropanol, ester solvents such as ethyl acetate, isopropyl acetate, and butyl acetate, and halogen solvents such as methane tetrachloride, chloroform, and trichloroethane are particularly preferred. It is an aromatic organic solvent that sometimes has a minimal azeotropic point.

The condensation reaction of phenols and aldehydes may be carried out using only the above azeotropic solvent as a solvent, but considering the solubility of the phenol novolank resin produced, an auxiliary solvent may be used and mixed in order to further homogenize the reaction. The reaction may be carried out in a solvent. Organic solvents such as alcohols, esters, amides, etc. are used as such solvents,
In particular, it is necessary to select a solvent in which the novolak resin produced by the reaction can be dissolved.

The solvents in which the novolac resin is soluble are shown below. Alcohols include methanol, ethanol, propatool, 2
-Propertool, butanol, methoxyethanol, 1
-Methoxy-2-propertool, 2-methoxy-1-propertool, ethoxyethanol, butoxyshetanol, methoxyethoxyethanol, ethers such as dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ketones Types include acetone, methyl ethyl ketone, methyl isopropyl ketone, etc., and esters include methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, etc.
Examples of amides include N,N-dimethylformamide, dimethylacetamide, dimethylsulfoxide, but the present invention is not limited thereto.

The phenol and aldehyde used in this production method will be explained in detail.

The phenols of the present invention are phenols having two or more active hydrogens, and are represented by the general formula (1).

(However, R1, R3 may be the same or different and each represents a normal substituent that can be substituted on the benzene ring.) show.

R4-CHO (II) (R4 represents a substituted or unsubstituted alkyl group or phenyl group) -a Formula (1) will be explained in more detail below.

R1-R3 are a hydrogen atom, a hydroxyl group or a substitutable group. Examples of such groups include halogen atoms, cyano groups, sulfo groups, or carboxyl groups), substituted or unsubstituted alkyl groups, aryl groups, acyloxy groups, acylamino groups, amino groups, sulfonamido groups, alkoxy groups, and alkylthio groups. group, arylthio group, carbamoyl group, sulfamoyl group, alkoxycarhomonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, disulfonyl group in alcohol, aryloxysulfonyl group, carbamoylamino group, sulfamoylamino group , carbamoyloxy group, alkoxycarbonylamino group, and aryloxycarbonylamino group. Also R1. When R1's are adjacent to each other on a benzene ring, they may be condensed to form a carbocycle or a heterocycle.

-M formula (II) will be explained in more detail below.

R4 represents an alkyl group, a substituted alkyl group, a phenyl group, a substituted phenyl group, an allyl group, a substituted or unsubstituted alkenyl group, or a hydrogen atom.

Permissible substituents for R1-R' include halogen atom, nitro group, cyano group, alkyl group, substituted alkyl group, alkoxy group, substituted alkoxy group, -NHCOR
' (Rs is an alkyl group, a phenyl group, R1
may be substituted one or more times with groups permissible in )
-COO group, -N13 (hR' (R5 is the same as above)
, -3OR'(R' has the same meaning as above), -3O,R'
(R' has the same meaning as above), -COR5 (R5 has the same meaning as above), -CON (-R') Group represented by -R' (R6 and R? may be the same or different , represents a hydrogen atom, an alkyl group, a substituted alkyl group, a phenyl group, a substituted phenyl group), -SO□N (-R"
)-R' (R1 and .R' are synonymous), an amino group (which may be substituted with an alkyl group), a hydroxyl group, and a group that forms a hydroxyl group by hydrolysis.

In general formula (1), R1 to R3 may each be the same or different, and are preferably a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms,
W-substituted or unsubstituted alkoxy group having 1 to 18 carbon atoms,
Substituted or unsubstituted phenyl group, substituted or unsubstituted sulfonamide group or acylamino group having 1 to 18 carbon atoms, substituted or unsubstituted phenylsulfonamide group or acylamino group, halogen atom, amino group (alkyl group) ).

In general formula (n), R4 is preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted phenyl group, an allyl group, or a C 2 to 1
8 represents a substituted or unsubstituted alkenyl group.

Among the general formulas (1), preferred compounds are those represented by the following general formula (
ll'l), (TV), and (V).

H In general formulas (III), (IV), and (V), R1 has the same meaning as above. Furthermore, R1 preferably represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 1 carbon atoms.

More preferably, the compound of the general formula (It) represents a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted phenyl group, or a hydrogen atom.

Specific examples of (1) and (II) are shown below, but the present invention is of course not limited thereto.

Shiko H7 [-5 ! -8 H ■ ■-10 H ■ ShiN5 ■-19 ■ ■-25 ■-35 ■-37 ■-24 ■-26 ■ ■-36 ■-38 ■-27 ■-29 0 ■ ■-41 ■-43 ■-28 ■-30 υ■ ■ -40 ■-44 n-3 ■-11 ■-13 C)1. CHO n-C3117CllO n-CJ. ,C)t.

n-CJ+9CHO CHJCHzCHO BrCHiCtlO CII3COCHO ■-12 ■-14 C) IsCHzCl(O ncJwcH.

ncJ+scHO n-C,+lIxsCHO C I CHzCHO CNCHICHO 110ccHO ■-17 ■-18 ■-19 ■-20 ■-29 ■-30 ■-32 ■-33 ■ ■-35 ■-36 ■-21 ■-37 ■- 40 ■-22 ■-24 ■=26 ■-38 ■-43 ■-44 HOC-C-C=C-CHO ■-45 ■-47 ■-49 CHsC-CCHxCNHCHxCH CI! ■-46 ■-48 ■-50 The molar ratio of the aldehydes used in the present invention to the phenols is preferably in the range of 0.5 to 2.0, more preferably 0.8 to 1. It is good that it is in the range of 5.

Regarding the production method of the present invention, the molecular weight of the phenol novolak resin also depends on the ratio of phenols and aldehydes used, and when it is desired to obtain a higher molecular weight product, the ratio of aldehydes used may be 1 or more. preferable.

However, if the ratio of aldehydes used is 1.5 or more, a substitution reaction with the hydroxyl group of the phenol tends to occur, and the hydroxyl equivalent of the resulting resin may decrease, which is not very preferable.

Let's talk about acid catalysts.

Specific examples of acidic catalysts used in the present invention include inorganic protonic acids such as sulfuric acid, hydrochloric acid, perchloric acid, nitric acid, and phosphoric acid, p-)luenesulfonic acid, methanesulfonic acid, maleic acid, acetic acid, and formic acid. organic protonic acids, boron trifluoride, various complexes of boron trifluoride such as boron trifluoride ether complexes, aluminum trichloride, tin tetrachloride,
Examples include Lewis acids such as zinc chloride, ferric chloride, and titanium tetrachloride, but among these acidic catalysts, it is preferable to use protonic acids.

The amount of acidic catalyst used is 0 relative to the phenols mentioned above.
．． The amount used varies depending on the strength and type of acid used as a catalyst, although it ranges from 1 to 70 mol%.

Let's talk about the reaction concentration.

The reaction concentration is such that the total charged weight of phenols and aldehydes is 10 to 70% by weight based on the amount of solvent used.
The content is preferably 20 to 50% by weight.

Let's talk about reaction temperature.

The phenol novolak resin of the present invention is produced by heating phenols and aldehydes in the solvent in the presence of the acid catalyst in an inert atmosphere such as nitrogen, at a reaction temperature of 50°C to 180°C or It is preferable to react at a temperature up to the boiling point of the solvent, particularly preferably at a temperature from 70°C to 150°C.

(Effects of the present invention) In the present invention, even when substituted aldehydes are used, a phenol novolac resin having a high molecular weight and a narrow molecular weight distribution can be obtained. Furthermore, since the remaining low molecular weight components (2-3 nuclear units) are kept to an extremely low level, even when used as a photographic material, etc., the performance is high and no harmful effects are caused.

The high molecular weight phenolic novolak resin of the present invention can be obtained using the above reaction reagents and reaction conditions, and examples of the present invention will be explained in more detail below.

<Example 1> Synthesis of phenol/capronaldehyde resin Phenol 39.5g (0.42 mol), capronaldehyde 4
2.1 g (0.42 mol), 33 g of methoxyethanol, and 76 g of benzene were placed in a reaction vessel under a nitrogen stream and stirred at room temperature.

3.8g (0) of p-)luenesulfonic acid as a catalyst
, 02 mol) was added thereto, and heating was gradually started using an oil bath. Reflux reaction (oil bath temperature 130-
At 140'C), a moisture meter was attached to the lower part of the cooling tube, and the reaction was carried out for 4 hours while confirming the separation of water, and then completed. The amount of water separated at that time is 9I! It was dl. 250 d of ethyl acetate was added to the reaction solution cooled to room temperature, and extraction and washing with water were performed three times. Thereafter, the ethyl acetate solution was dried over magnesium sulfate, filtered, concentrated, and dried using a vacuum pump.

Yield 168 g, yield 91.9%, weight average molecular weight 3,400 dispersion ()IW/)IN) 2, 8 However, the weight average molecular weight was determined by gel permeation chromatography (GPC). The GPC measurement conditions were HLC8020 model GPC manufactured by Toyo Soda Co., Ltd., and two TSK-GEL (4,0 OOH12) manufactured by Toyo Soda Co. as separation columns.
,0OOH), THF as eluent (flow rate 1.0 m
/win, column temperature 40°C), UV absorption (254
The measurement was performed by determining the absorption wavelength of ns).

Polystyrene was used as a standard sample.

<Example 2> Synthesis of 0-cresol/benzaldehyde resin 60.7 g (0.56 mol) of 0-cresol, 65.4 g (0.62 mol) of benzaldehyde, 100 g of methoxyethanol, and 100 g of toluene were mixed in a nitrogen stream. The mixture was placed in a reaction vessel and stirred at room temperature. 8.6 g (0.05 mol) of hydrobromic acid (47%) was added thereto as a catalyst, and heating was gradually started using an oil bath. The reaction was carried out for 3 hours and completed while water produced in the reflux reaction (oil bath temperature +35-145°C) was evaporated from the reaction vessel together with toluene by a nitrogen stream. The reaction solution was cooled, methoxytanol 1.00 #11+ was added and dissolved, and the solution was stirred in an agitator with water 2! It was re-precipitated inside. The precipitate was filtered, washed with water 2 to 3 times, and then dried in a vacuum dryer.

Yield 105 g, yield 95.5%, weight average molecular weight 14,800 Dispersion (MW/MN) 2, 5 <Example 3> Synthesis of catechol/n-octylaldehyde resin Catechol 28.6 g (0.26 mol) , 33.5 g (0.26 mol) of n-octylaldehyde, 50 g of 1-methoxy-2-propatol, and 50 g of toluene were placed in a reaction vessel under a nitrogen stream and stirred at room temperature. 266 g (0.03 mol) of sulfuric acid was added there as a catalyst, and heating was gradually started using an oil bath. During the reflux reaction (oil bath temperature 130-140°C), attach a water metering receiver to the bottom of the cooling pipe and continue the reaction while checking the separation of water.
The time was over. The amount of water separated at that time was 5.3 d. 300 ml of ethyl acetate was added to the reaction solution cooled to room temperature, and extraction and washing with water were performed three times.

Thereafter, the ethyl acetate solution was dried over magnesium sulfate, filtered, condensed, and dried using a vacuum pump.

Yield 52 g 1 Yield 90.4% Weight average molecular weight 3.100 Dispersion (M 1 unit N) 3.9 <Example 4> Synthesis of hydroquinone/n-dodecylaldehyde resin Hydroquinone 33.0 g (0.3 mol), n 55.3 g (0.3 mol) of dodecylaldehyde, 75 g of 1-methoxy-2-propatol, and 75 g of toluene were placed in a reaction vessel under a nitrogen stream and stirred at room temperature. 2.9 g (0.03 mol) of sulfuric acid was added as a catalyst, and the rest of the reaction was carried out in the same manner as in Example 3.

Further, as in Example 4, the results of Examples 5 to 9 are shown in Table 1 below, in which only the proportion of n-dodecylaldehyde used relative to the molar ratio of hydroquinone was changed.

Comparative Example 1 Hydroquinone 33.0 g (0.3 mol), n-dodecylaldehyde 55.3 g (0.3 mol), and l-
150 g of methoxy-2-propatol was placed in a reaction vessel under a nitrogen stream and stirred at room temperature.

2.9 g (0.03 mol) of sulfuric acid was added there as a catalyst, and a heating reaction was carried out at an oil bath temperature of 130-140°C for 5 hours without azeotropic dehydration, and the same post-treatment as in the example was performed. .

Yield: 43g, Yield: 60° Weight average molecular weight 740 Dispersion (MW/MN) 6, 7 3%,

Claims (1)

[Claims] A method for producing a high molecular weight phenolic resin, characterized in that in a step of condensing phenols and aldehydes in a homogeneous organic solvent system in the presence of an acid catalyst, water produced is azeotropically removed from the reaction system.