JP2004323822A - Method for producing novolak-type phenol resin and novolak-type metacresol resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a novolak-type phenol resin capable of obtaining the novolak-type phenol resin at a high yield which has a high softening point and a large weight-averaged molecular weight, containing few low-nuclear component and high content of high molecular weight components. <P>SOLUTION: This method for producing the novolak-type phenol resin comprises a first step of subjecting phenols and aldehydes to a heterogeneous reaction in the presence of ≥5 pts.mass phosphates to 100 pts.mass phenols, and a second step of subjecting the reaction product to fractionation treatment by at least one process selected from a solvent extraction method, a liquid-liquid separation method and a reprecipitation method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a novolak-type phenolic resin, and more specifically, to further fractionate a novolak-type phenolic resin obtained by performing a heterogeneous reaction in the presence of phosphoric acids and preferably a reaction auxiliary solvent. A method for producing a novolak type phenol resin.

  Further, the present invention relates to a novolak-type meta-cresol resin obtainable by the above-mentioned production method using meta-cresol as a phenol.

  The novolak-type phenol resin is generally produced by reacting a phenol and an aldehyde to a desired degree of condensation in the presence of an acid catalyst to synthesize an initial condensate, and then concentrating at a high temperature under reduced pressure. The novolak-type phenolic resin obtained by such a production method contains a large amount of phenolic monomer components accompanied by odor, however, there is a problem of environmental pollution due to the diffusion of such phenolic monomer components. Methods for reducing the noise have been studied. For example, a method has been proposed in which an inert gas or steam is blown when a novolak-based condensate after condensation reaction is concentrated at 150 to 210 ° C. to remove low molecular weight components (Patent Document 1). However, according to this method, although the effect of reducing the phenolic monomer component is certain, the resin tends to have a high molecular weight, and the removal of the phenolic monomer component lowers the resin yield. there were.

  Further, the positive photoresist is composed of an alkali-soluble novolak-type phenol resin and a photosensitive agent such as a naphthoquinonediazide compound, and is widely used in manufacturing processes for LCDs, semiconductors, and photosensitive lithographic printing plates. In recent years, along with the high integration of LCDs and semiconductors, it has been necessary to form finer patterns with higher precision, and there has been an increasing demand for positive photoresists, especially for improving heat resistance. In general, as a base resin of a positive photoresist, a cresol novolak resin obtained by reacting cresols and formaldehyde in the presence of an acid catalyst is used, and various improvements have been made to improve such performance. However, with the current novolak resins, there is a limit to the improvement of the softening point, and at present, no satisfactory resin has yet been obtained.

  On the other hand, in the manufacture of LCDs, particularly in the post-baking step after the developer treatment, there is a problem of line contamination caused by sublimation of phenolic dimer in the positive photoresist and reduction in product yield. Then, in order to overcome such a problem, reduction of the phenol dimer component in the novolak resin is strongly desired, and various improvements have been attempted.

  As a method for reducing low nucleus components such as phenol dimers in a novolak type phenol resin, there is a fractionation method represented by a liquid / liquid separation method (Patent Document 2). However, when these fractionation methods are used on a conventional novolak-type phenol resin containing a large amount of low-nucleotide components, the separation conditions have to be strict to remove a large amount of phenolic dimer components, and as a result, In particular, the required high molecular weight components are also removed, and the yield is greatly reduced, and the solubility in an alkali developing solution is also significantly reduced. Other methods such as preparative separation by molecular weight using liquid chromatography, steam distillation and thin film distillation are also known, but there are problems such as complicated processes, and phenol dimers of novolak-type phenol resins are efficiently manufactured at low cost. There has been a need for a method of reducing components.

  For these reasons, there has been a demand for a method for efficiently producing a novolak-type phenol resin having a small amount of phenolic monomers and phenolic dimers, a large weight average molecular weight, and a high softening point.

Japanese Patent Publication No. Hei 7-91352 JP-A-2-60915

  The present invention comprises a component having a small amount of phenolic monomers and phenolic dimer components (hereinafter, referred to as “low nucleus component”) and having a weight average molecular weight (Mw) of 5000 or more (hereinafter, referred to as “high molecular weight component”). It is an object of the present invention to provide a method for producing a novolak-type phenol resin capable of obtaining a novolak-type phenol resin having a high content, a large weight average molecular weight and a high softening point in a high yield.

  Another object of the present invention is to provide a novolak-type meta-cresol resin having a low cresol dimer, a high softening point, and excellent solubility in an alkali developer.

  The present inventors have made intensive studies to overcome the above-mentioned problems, and as a result, obtained by performing a condensation reaction of phenols and aldehydes in a heterogeneous system in the presence of phosphoric acids and preferably a specific organic solvent. The novolak-type phenolic resin is fractionated by at least one selected from a solvent extraction method, a liquid / liquid separation method, and a reprecipitation method, so that the novolak-type phenolic resin having a low low nucleus component and a high softening point is improved. They have found that they can be produced in a high yield, and have completed the present invention.

  That is, the method for producing a novolak-type phenolic resin of the present invention comprises the steps of: mixing phenols and aldehydes with 5 parts by mass or more of phosphoric acids with respect to 100 parts by mass of phenols; It comprises a first step of performing a heterogeneous reaction in the presence of a solvent, and a second step of performing a fractionation treatment by at least one selected from a solvent extraction method, a liquid / liquid separation method, and a reprecipitation method.

  Further, the novolak-type meta-cresol resin of the present invention has a total content of meta-cresol trimer, meta-cresol dimer and meta-cresol monomer of less than 5.0% and a content of meta-cresol dimer component measured by gel filtration chromatography. Less than 2%, the content of high molecular weight components having a weight average molecular weight of 5000 or more is 55% or more, and the dissolution rate in a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. is 60 ° / sec or more. It is characterized by.

  The production method of the present invention employs a phase separation reaction using phosphoric acids and preferably a reaction auxiliary solvent in the first step, and further reduces the low nucleus component in the second step to reduce the content of the high molecular weight component. In order to improve the content, a novolak-type phenol resin having a high softening point and a low content of low nuclei can be produced in a high yield, and the production cost can be reduced.

  In the first step of the present invention, a novolak-type phenol resin is obtained by subjecting a phenol and an aldehyde to a heterogeneous condensation reaction while stirring and mixing in the presence of phosphoric acids.

  In the first step, phenols used as a reaction raw material include, for example, phenol, m-cresol, p-cresol, o-cresol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, Xylenols such as 4-xylenol, m-ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,5-trimethylphenol, 2,3,5-triethylphenol, 4-tert-butylphenol, 3-tert Alkylphenols such as -butylphenol, 2-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2-tert-butyl-5-methylphenol, 6-tert-butyl-3-methylphenol, p-methoxyphenol , M-methoxypheno And alkoxyphenols such as p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol and m-propoxyphenol, o-isopropenylphenol, p-isopropenylphenol, 2-methyl-4-isopropenylphenol, Isopropenylphenols such as -ethyl-4-isopropenylphenol, polyhydroxyphenols such as 4,4'-dihydroxybiphenyl, bisphenol A, phenylphenol, resorcinol, hydroquinone and pyrogallol, α-naphthol, β-naphthol and naphthalene Diols and the like can be mentioned. Neither is limited to the above examples, and each may be used alone or in combination of two or more.

  Among these phenols, it is preferable to use at least one selected from phenol, m-cresol, and 3,5-xylenol in order to improve the reaction efficiency of the low nucleus component and increase the molecular weight. Further, in order to obtain a higher molecular weight novolak-type phenol resin, the phenols are preferably contained in an amount of 60% or more, more preferably 80% or more.

  In the first step, the aldehydes used as a reaction raw material include, for example, formaldehyde, formalin, paraformaldehyde, acetaldehyde, salicylaldehyde, and the like. None of the aldehydes is limited to the above examples. The above may be used in combination. The aldehydes may be added by a method suitable for the purpose, such as a method in which the aldehydes are charged together with the raw materials, or a method in which a part (or all) is divided and added as the reaction proceeds.

  The blending ratio of phenols and aldehydes (aldehydes / phenols) is not particularly limited, but is preferably 0.7 or more, more preferably 0.8 to 3.0 on a molar basis, and still more preferably. Is 0.9 to 1.0. If the compounding ratio is less than 0.7, it may be difficult to reduce the content of the low nucleus component, while if it exceeds 3.0, unreacted aldehydes may increase and production efficiency may decrease. There is.

  Phosphoric acid used as a reaction catalyst plays an important role in forming a field of a phase separation reaction (heterogeneous reaction) between phenols and aldehydes. Examples thereof include polyphosphoric acid such as metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphoric acid, and tetraphosphoric acid, phosphoric anhydride, and a mixture thereof. Phosphoric acid, 89% by mass phosphoric acid and the like are generally used.

  The compounding amount of the phosphoric acid is required to be 5 parts by mass or more based on 100 parts by mass of the phenol, and the upper limit is not particularly limited, but the reaction volume efficiency, safety, phase separation effect, and the like are required. When considering, it is preferably 20 to 500 parts by mass, more preferably 50 to 100 parts by mass. When the amount is less than 5 parts by mass, the production of the high molecular weight component is promoted, but the low nucleus component, especially the phenol dimer, is not reduced. Further, a method suitable for the purpose may be adopted, such as a method in which phosphoric acids are charged together with the raw materials, or a method in which the phosphoric acids are dividedly added as the reaction proceeds.

  From the viewpoint of promoting the phase separation reaction, it is preferable to use a non-reactive oxygen-containing organic solvent as a reaction auxiliary solvent. As the reaction auxiliary solvent, it is preferable to use at least one selected from the group consisting of alcohols, polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones, and sulfoxides.

  Examples of the alcohols include monohydric alcohols such as methanol, ethanol, and propanol, butanediol, pentanediol, hexanediol, ethylene glycol, propylene glycol, trimethylene glycol, diethylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and triethylene glycol. Examples include dihydric alcohols such as propylene glycol and polyethylene glycol, and trihydric alcohols such as glycerin.

  Examples of polyhydric alcohol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, and ethylene glycol monoethyl ether. And glycol ethers such as phenyl ether.

  Examples of the cyclic ethers include 1,3-dioxane and 1,4-dioxane, and examples of the polyhydric alcohol ester include glycol esters such as ethylene glycol acetate, and examples of the ketones For example, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like can be mentioned, and as the sulfoxides, for example, dimethyl sulfoxide, diethyl sulfoxide and the like can be mentioned.

  Among them, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol, polyethylene glycol, 1,4-dioxane and the like are particularly preferable.

  The reaction auxiliary solvent is not limited to the above examples, and may be a solid as long as it has the above characteristics and exhibits a liquid during the reaction, or may use each alone or in combination of two or more. You may. The amount of the reaction auxiliary solvent is preferably 20 to 1000 parts by mass, more preferably 50 to 500 parts by mass, per 100 parts by mass of the phenol. If the amount is less than 20 parts by mass, the effect of adding a solvent may not be recognized. If the amount exceeds 1000 parts by mass, productivity may be reduced in terms of reaction rate and volumetric efficiency. Further, a method suitable for the purpose may be adopted, such as a method of charging the reaction auxiliary solvent together with the raw materials and a method of dividing and adding it as the reaction proceeds.

  In the first step, from the viewpoint of the phase separation effect, it is preferable that the amount of water in the system is 30% by mass or less, preferably 20% by mass or less before starting the reaction. The reaction temperature is generally 70 ° C. or higher from the viewpoint of the reaction efficiency and the phase separation effect, but is preferably 80 ° C. or higher, and more preferably the reflux temperature. The reaction time is determined in consideration of the reaction temperature, the amount of phosphoric acid, the water content of the reaction system, the state of condensation of the product, and the like, but is generally about 1 to 50 hours.

  The first step preferably has a washing step after completion of the reaction. Specifically, a water-insoluble organic solvent (eg, methyl ethyl ketone, methyl isobutyl ketone, etc.) is added and mixed to dissolve the condensate (novolak-type phenol resin), and then allowed to stand still to form an organic layer (water-insoluble organic solvent, (Including a condensate) and an aqueous layer (including a reaction auxiliary solvent and phosphoric acids). Next, after removing the aqueous layer out of the system, the phosphoric acids and the reaction auxiliary solvent are recovered, while the organic layer is washed with hot water and / or neutralized, and then the water-insoluble organic solvent is removed by vacuum distillation.

  The present invention has a second step of fractionating a novolak-type phenol resin by at least one selected from a solvent extraction method, a liquid / liquid separation method, and a reprecipitation method.

  The solvent extraction method is a method in which a resin is dispersed in a solvent and a low nucleus component is extracted and removed by stirring. Specifically, it is obtained by grinding the resin, dispersing and stirring in a solvent mainly containing an aromatic solvent such as benzene, toluene, and chlorobenzene, extracting the low nucleus component into the solvent, and then filtering. The novolak-type phenol resin is obtained by washing the solid content with a solvent and drying.

  In the liquid / liquid separation method, a resin is dissolved in two kinds of good solvents, a hydrophilic solvent and a hydrophobic solvent, and water is further added to the resin solution to form a two-layer separation state. The phases are separated from the aqueous phase. After removing the aqueous phase in which the low nucleus component has moved, the solvent is distilled off from the remaining resin solution phase to obtain a novolak-type phenol resin. As the hydrophilic solvent, methanol, ethanol, propanol, acetone, ethyl cellosolve and the like are preferable, and as the hydrophobic solvent, ethyl cellosolve acetate, methyl cellosolve acetate, propyl glycol monomethyl ether acetate, methyl ethyl ketone, methyl isobutyl ketone and the like are preferable.

  The reprecipitation method is a method in which a precipitated layer formed by adding a resin solution to a poor solvent is taken out, and the solvent is distilled off. Specifically, a resin solution in which the resin is dissolved in ethyl cellosolve acetate, methyl cellosolve acetate, methanol, ethanol, propanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, 1,4-dioxane, etc., is benzene, toluene, xylene, It is added to a poor solvent such as hexane, cyclohexane, heptane, and water, the precipitated layer is taken out, and the solvent is removed to obtain a novolak-type phenol resin.

  The second step may be performed at any time after the condensation reaction.Specifically, the second step is introduced according to the purpose, such as being introduced after the first step, or before or during the washing step in the first step. do it.

  According to the production method of the present invention, a novolak type having a phenolic monomer component content of 3% or less, preferably 1% or less, and a phenolic dimer component content of 5.0% or less, preferably 3.0% or less. A phenolic resin is obtained. At the same time, the weight average molecular weight of the novolak type phenol resin increases, and the softening point of the resin can be increased.

  In particular, a novolak-type meta-cresol resin using meta-cresol as a phenol has a total content of a low nucleus component and a meta-cresol trimer of less than 5.0%, preferably less than 3.0%, and a content of a meta-cresol dimer component. The content is less than 2.0%, preferably less than 1.0%, and at the same time, the content of the high molecular weight component is 55% or more, preferably 60% or more, more preferably 70% or more. The average molecular weight of the resin can be improved, and a high softening point of 180 ° C. or higher, preferably 200 ° C. or higher can be imparted.

  Furthermore, when a photoresist resin is obtained using meta-cresol or para-cresol as phenols, the solubility in an alkaline developer can be maintained at a significantly higher level than a resin produced by a conventional method. Specifically, the dissolution rate at 23 ° C. in a 2.38% aqueous solution of tetramethylammonium hydroxide, which is an alkaline developer for photoresist, is 60 ° / sec or more, preferably 100 ° / sec or more, more preferably 300 ° / sec or more. Excellent solubility.

[Action]
The reason that the method of the present invention can produce a novolak-type phenol resin having a low nucleus component less than the conventional production method and a high molecular weight and a high softening point in a high yield is not necessarily clear, but is presumed as follows. .

  In the first step, in the phase separation reaction between the organic phase (mainly phenols) and the aqueous phase (mainly phosphoric acids, aldehydes, and a reaction auxiliary solvent), the low nucleus component dissolved in the aqueous phase becomes Since it rapidly reacts with aldehydes under the catalytic action, the molecular weight increases gradually while preferentially reducing the low nucleus component, so that a novolak phenol resin having a low low nucleus component is obtained.

  Further, in the second step, the content of the high molecular weight component is increased by removing the remaining component mainly composed of low nuclei, that is, the average molecular weight is increased and the softening point can be improved. That is, in the first step, low nucleus components such as phenol dimers are significantly reduced in advance in the first step compared with the conventional production method. Slow fractionation conditions sufficient to remove spheroids will be sufficient, and as a result, the components effective for improving the softening point in the high molecular weight components and the solubility in an alkali developing solution are hardly reduced, and low nuclei that are desired to be removed It is considered that a high molecular weight novolak type phenol resin in which only the component mainly composed of phenol is reduced more selectively can be obtained in high yield.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, "%" means "mass basis" unless otherwise specified. The properties of the obtained novolak-type phenol resin were measured by the following test methods.

(1) Weight average molecular weight (Mw)
Tosoh gel filtration chromatography 8020 series build-up system, Ltd. Measurement of the (column: G2000H _XL + G4000H _XL, detector:: UV254nm, carrier tetrahydrofuran 1 ml / min, column temperature 38 ° C.), a weight average molecular weight of standard polystyrene ( Mw) was determined.

(2) Content (%) of low nucleus component, phenolic trimer and high molecular weight component
The content was determined by measuring the area of each component with respect to the total area of the molecular weight distribution by an area method showing the percentage.

(3) Alkali dissolution rate (Å / sec)
After dissolving the novolak resin in ethylene glycol monoethyl ether acetate (ethyl acetate cellosolve), the solution was applied to a silicon wafer using a spin coater and pre-baked to form a novolak resin film having a thickness of about 1.5 μm. . This was immersed in an alkali developing solution (aqueous solution of 2.38% by mass of tetramethylammonium hydroxide) at 23 ° C., the time when the coating disappeared was measured, and the film thickness (さ れ る / sec) dissolved per second was determined. This was taken as the alkali dissolution rate.

(4) Softening point (℃)
Based on the ring and ball method described in JIS-K6910, the measurement was performed using a ring and ball automatic softening point measuring device ASP-MGK2 manufactured by Meitec Corporation.

(5) Heat resistance evaluation (pattern shape)
10.0 g of novolak resin and 2.5 g of tris (4-hydroxyphenyl) methane ester of naphthoquinone 1,2-diazido-5-sulfonic acid were dissolved in 40.0 g of ethylene glycol monoethyl ether acetate (ethyl cellosolve). The solution was filtered through a 0.2 μm membrane filter to obtain a resist solution. The solution was applied to a cleaned silicon wafer using a spin coater and pre-baked to form a dried coating film having a thickness of about 1.0 μm. Subsequently, exposure was performed using a reduction projection exposure apparatus through a test chart mask, and development was performed for 1 minute using an alkali developing solution (2.38 mass% aqueous solution of tetramethylammonium hydroxide) to obtain a positive pattern. After the silicon wafer on which the pattern was formed was placed in an environment of 125 ° C. for 3 minutes, the degree of sagging of the pattern shape was evaluated by observation with a scanning electron microscope.
：: The pattern is almost unchanged.
Δ: Slight dripping.
×: Clearly sagged (kamaboko-shaped).

<Example 1>
(First step)
In a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, 100.0 g of phenol (P) and 81.9 g of 37% formalin (F) (molar basis: F / P = 0.95), 89 % Phosphoric acid, 60.0 g (53.4% / P), and ethylene glycol, 100.0 g (100% / P), and then, under a cloudy state (two-phase mixture) formed by stirring and mixing, The temperature was gradually raised to the reflux temperature, and after a condensation reaction was further performed at the same temperature for 20 hours, the reaction was stopped.

  Next, methyl isobutyl ketone was added while stirring and mixing to dissolve the condensate. Then, stirring was stopped, and the contents were transferred into a separation flask and allowed to stand, and the methyl isobutyl ketone solution phase (upper layer) and phosphoric acid were added. The aqueous phase (lower layer) was separated. Next, the phosphoric acid aqueous solution phase was removed, and the methyl isobutyl ketone solution was washed with water several times to remove phosphoric acid. Then, the contents were returned to the reaction vessel again, and methyl isobutyl ketone was completely removed by vacuum distillation to remove novolak. As a result, 108 g of a phenol resin was obtained (yield: 108% / P). The yield of the novolak type phenol resin was expressed as a percentage with respect to the charged amount (based on mass) of phenol.

(Second step: liquid / liquid separation method)
100 g of the novolak type phenol resin obtained in the first step is dissolved in a mixed solution of methyl isobutyl ketone / methanol (50 g / 300 g), 190 g of distilled water is added dropwise with stirring, the mixture is sufficiently stirred, and then allowed to stand. As a result, a resin solution phase and an aqueous solution phase were separated. Thereafter, the resin solution phase was taken out and the solvent was removed to obtain 87 g of a novolak-type phenol resin (yield 94% / P), and the characteristics were evaluated. Table 1 shows the results. FIG. 1 shows a GPC chart of the novolak phenol resin.

<Example 2>
A novolak-type phenol resin was obtained and the properties were evaluated in the same manner as in Example 1, except that the components and the separation conditions were changed as shown in Table 1. Table 1 shows the results.

<Example 3>
(First step)
A novolak-type phenol resin was obtained in the same manner as in Example 1, except that the components were changed as shown in Table 1.

(Second step: reprecipitation method)
While stirring 1200 g of xylene, 150 g of a resin solution obtained by dissolving 100 g of the novolak-type phenol resin obtained in the first step in 50 g of methyl isobutyl ketone was added dropwise. I let it. Thereafter, the precipitated layer was taken out and desolvated to obtain 86 g of a novolak-type phenol resin (yield 95% / P), and the characteristics were evaluated. Table 1 shows the results.

<Example 4>
(First step)
A novolak-type phenol resin was obtained in the same manner as in Example 1, except that the components were changed as shown in Table 1.

(Second step: solvent extraction method)
100 g of the novolak-type phenol resin obtained in the first step was powdered and dispersed in a mixed solution of methyl isobutyl ketone / xylene (100 g / 1200 g) with stirring at room temperature. Thereafter, the resin component was separated by standing and separated by filtration. After washing with a solvent and further drying, 84 g of a novolak-type phenol resin (yield 92% / P) was obtained, and the characteristics were evaluated. Table 1 shows the results.

<Example 5>
A novolak-type phenol resin was obtained and the properties were evaluated in the same manner as in Example 4, except that the components and the separation conditions were changed as shown in Table 1. Table 1 shows the results.

<Example 6>
A novolak-type phenol resin was obtained and the properties were evaluated in the same manner as in Example 1, except that the components and the separation conditions were changed as shown in Table 1. Table 1 shows the results.

<Comparative Examples 1 to 6>
Except not performing the second step, a novolak-type phenol resin was obtained in the same manner as in Examples 1 to 6, and the characteristics were evaluated. Table 2 shows the results. FIG. 2 shows a GPC chart of the novolak type phenol resin of Comparative Example 1.

<Comparative Example 7>
(First step)
In the same reaction vessel as in Example 1, 100.0 g of phenol (P), 75.9 g of 37% formalin (F) (molar basis: F / P = 0.88), and 0% of oxalic acid dihydrate were added. After charging 0.5 g (0.5% / P), the temperature was gradually raised to the reflux temperature, and a condensation reaction was carried out at the same temperature for 4 hours. Subsequently, dehydration under normal pressure and then under reduced pressure were performed to obtain 105 g of a novolak phenol resin (yield: 105% / P).

(Second step: liquid / liquid separation method)
Except that 200 g of distilled water was dropped, 50 g of a novolak-type phenol resin (yield: 52% / P) was obtained in the same manner as in Example 1, and the characteristics were evaluated. Table 2 shows the results.

<Example 7>
A novolak-type phenol resin was obtained and the properties were evaluated in the same manner as in Example 4, except that the components and the separation conditions were changed as shown in Table 3. Table 3 shows the results. FIG. 3 shows a GPC chart of the novolak type phenol resin.

Example 8
A novolak-type phenol resin was obtained and the properties were evaluated in the same manner as in Example 3, except that the components and the separation conditions were changed as shown in Table 3. Table 3 shows the results.

<Example 9>
A novolak-type phenol resin was obtained and the properties were evaluated in the same manner as in Example 1 except that the components and the separation conditions were changed as shown in Table 3. Table 3 shows the results.

<Comparative Example 8>
A novolak-type phenol resin was obtained in the same manner as in Example 7 except that the second step was not performed, and the characteristics were evaluated. Table 3 shows the results. FIG. 4 shows a GPC chart of the novolak phenol resin.

<Comparative Example 9>
(First step)
A novolak-type phenol resin was obtained in the same manner as in Comparative Example 7, except that the components were changed as shown in Table 3.

(Second step: solvent extraction method)
79 g of novolak phenol resin (83% / mC) was obtained in the same manner as in Example 4 except that a mixed solution of methyl isobutyl ketone / xylene (100 g / 1500 g) was used, and the properties were evaluated. Table 3 shows the results. FIG. 5 shows a GPC chart of the novolak type phenol resin.

<Comparative Example 10>
A novolak-type phenol resin was obtained and the properties were evaluated in the same manner as in Comparative Example 7, except that the components and the separation conditions were changed as shown in Table 3. Table 3 shows the results.

  The novolak-type phenolic resin obtained by the production method of the present invention has a high softening point and an alkali solubility equal to or higher than that of a conventional resin. Performance can be improved, and higher integration and higher precision of LCDs and semiconductors can be achieved. Further, since the low nucleus component is reduced as compared with the conventional novolak type phenol resin, it is possible to reduce the contamination of the production line in the manufacturing process of LCD and the like, and to reduce the productivity reduction due to line cleaning and the like. Can be prevented.

FIG. 2 is a GPC chart of the novolak type phenol resin of Example 1. FIG. 4 is a GPC chart of the novolak type phenol resin of Comparative Example 1. FIG. 7 is a GPC chart of the novolak type phenol resin of Example 7. FIG. 9 is a GPC chart of the novolak type phenol resin of Comparative Example 8. 13 is a GPC chart of the novolak type phenol resin of Comparative Example 9. FIG.

Explanation of reference numerals

1 phenolic monomer 2 phenolic dimer 3 phenolic trimer 4 high molecular weight component

Claims (5)

  The first step of heterogeneously reacting phenols and aldehydes with phenols in the presence of 5 parts by mass or more of phosphoric acid with respect to 100 parts by mass of phenols, and the solvent extraction method, liquid / liquid separation method, and reprecipitation method A second step of performing a separation treatment by at least one selected from the group consisting of: a novolak-type phenol resin.   The method for producing a novolak-type phenol resin according to claim 1, wherein in the first step, a non-reactive oxygen-containing organic solvent is present as a reaction auxiliary solvent.   The method according to claim 2, wherein the reaction auxiliary solvent is at least one selected from the group consisting of alcohols, polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones, and sulfoxides. A method for producing a novolak-type phenol resin.   The method for producing a novolak-type phenol resin according to any one of claims 1 to 3, wherein the phenols include at least one selected from phenol, m-cresol, and 3,5-xylenol.   The total content of meta-cresol trimer, meta-cresol dimer, and meta-cresol monomer measured by gel filtration chromatography is less than 5.0%, the content of meta-cresol dimer component is less than 2%, and the weight average molecular weight is 5,000 or more. A novolak-type meta-cresol resin, wherein the content of the high molecular weight component is 55% or more, and the dissolution rate in a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. is 60 ° / sec or more.

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