JP5092445B2 - Method for producing naphthol novolac and derivatives thereof - Google Patents

Description

  The present invention relates to a method for producing naphthol novolak and its derivatives having a low metal ion content.

  The quality of a resin used for semiconductor applications can be improved by substantially reducing the amount of contaminating metal ions contained in the composition. Most of the impurities contained in the composition are metal ions, particularly sodium, potassium, iron, chromium, magnesium, calcium, manganese, copper, zinc, aluminum and nickel ions. These impurities are derived from the resin component present as a binder in the composition, and are mainly mixed in the production process. Conventionally, the composition has been required to have a metal ion concentration of 50 ppb or less, but as the integrated circuit is highly integrated, a composition having a lower metal ion content is required.

  In Japanese Patent No. 3212492 (Patent Document 1), a commercially available novolak resin is dissolved in an organic solvent or solvent mixture at a concentration of about 25 to 50% by mass, and the resin solution is formed into an acidic, preferably complex. A method is described in which the metal ion content of the solution is reduced by contacting the compound once or repeatedly. However, when this method is applied to a naphthol novolak resin and its raw material, an emulsion is formed and a naphthol novolak and its derivative having a low metal ion content cannot be obtained.

  In Japanese Patent No. 3248274 (Patent Document 2), an organic solvent solution in which polyvinylphenols are dissolved in an organic solvent at a concentration of about 1 to about 50% by mass is brought into contact with an aqueous solution in which an acidic compound is dissolved. After that, a method for producing a polyvinylphenol having a low metal ion content by further reducing the metal ion content in the organic solvent solution by contacting with ion-exchanged water once or repeatedly is described. Yes. However, when this method is applied to a naphthol novolak resin and its raw material, an emulsion is formed and a naphthol novolak and its derivative having a low metal ion content cannot be obtained.

  Japanese Patent Laid-Open No. 2002-182402 (Patent Document 3) describes a metal impurity in a resist base polymer in a resist base polymer or a nonpolar organic solvent thereof or a mixed solvent of a nonpolar organic solvent and a polar organic solvent. The base of the resist is reduced by adding a water-soluble and complex-forming compound equal to or greater than that of the resist, completing the reaction, and further washing with pure water to reduce metal impurities in the resist base polymer. Polymer purification methods are described. However, when this method is applied to a naphthol novolak resin and its raw material, an emulsion is formed and a naphthol novolak and its derivative having a low metal ion content cannot be obtained.

In JP-A-5-19463 (Patent Document 4), a resist is dissolved in an organic solvent having a solubility in water at 20 ° C. of 100 g / cc or less, and the solution is brought into contact with water or an acidic aqueous solution to obtain a liquid-liquid. A method of extraction is described. However, when this method is applied to a naphthol novolak resin and its raw material, an emulsion is formed and naphthol novolaks having a low metal ion content cannot be obtained.
Japanese Patent No. 3212492 Japanese Patent No. 3248274 JP 2002-182402 A Japanese Patent Laid-Open No. 5-19463

  Accordingly, an object of the present invention is to solve the above problems and to provide a method capable of reducing the content of metal ions to less than 50 ppb from naphthol novolak and derivatives thereof that usually contain several thousand ppb of metal ions. It is in.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be achieved by the method specified below, and have completed the present invention. That is, according to the present invention, the following methods for producing naphthol novolak and derivatives thereof are provided.

[1] (1) A step of dissolving naphthol novolak and its derivative in an organic solvent which is n-butyl acetate or methyl isobutyl ketone to obtain an organic solvent solution; and (2) contacting the organic solvent solution with an acidic aqueous solution. A step of recovering the organic layer; and (3) a step of bringing the organic layer into contact with ion exchange water and further recovering the organic layer in this order, and repeating the step of (3) three or more times, A method for producing the derivative.

[2] The method for producing a naphthol novolak and a derivative thereof according to the above [1], wherein the acidic aqueous solution contains an organic acid.

[3] The naphthol novolak and the derivative thereof according to [2], wherein the organic acid is at least one selected from the group consisting of formic acid, acetic acid, oxalic acid, malonic acid, glycolic acid, lactic acid, tartaric acid, and citric acid. Manufacturing method.

[4] The acidic aqueous solution contains 0 . The manufacturing method of the naphthol novolak and its derivative in any one of said [1]-[3] melt | dissolved in the ratio of 01-25 mass parts.

[ 5 ] The method for producing a naphthol novolak and a derivative thereof according to any one of the above [1] to [ 4 ], wherein the temperature during the contact treatment between the organic solvent solution and the acidic aqueous solution is 20 ° C to 70 ° C. .

[ 6 ] The method for producing a naphthol novolak and a derivative thereof according to any one of the above [1] to [ 5 ], wherein the temperature during the contact treatment between the organic layer and the ion-exchanged water is 20 ° C to 70 ° C.

  In the present invention, an organic solvent solution obtained by dissolving naphthol novolak and a derivative thereof in an organic solvent is brought into contact with an aqueous solution in which an acidic compound is dissolved, and then further subjected to contact with ion-exchanged water three times or more. The present invention relates to a method for producing a naphthol novolak having a low metal ion content and a derivative thereof, wherein the metal ion content in the organic solvent solution is reduced. In particular, by stirring at a temperature of 20 ° C. to 70 ° C., the formation of an emulsion at the time of contact with an organic solvent solution and an aqueous solution in which an acidic compound is dissolved or at the time of contact between the organic solvent solution and ion-exchanged water is suppressed. Can do. In addition, the metal ion content in naphthol novolak and its derivatives can be reduced to less than 50 ppb.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

[Organic solvent]
In the present invention, an organic solvent solution in which naphthol novolak and its derivatives are dissolved in an organic solvent is prepared. The organic solvent used here may be any one that dissolves naphthol novolak and its derivatives and separates them from the acidic aqueous solution and ion-exchanged water used in the subsequent treatment.

  Examples of such organic solvents include esters: diethyl carbonate, propyl formate, isoamyl formate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-amyl acetate; ketones : Methyl n-propyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, ethyl butyl ketone, diisobutyl ketone, isophorone; ethers: isopropyl ether, n-butyl ether, hexyl ether, 2-ethylhexyl ether, ethylene oxide, dimethyldioxane, ethylene glycol Examples include mono n-hexyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol dibutyl ether, and diethylene glycol dibutyl ether. These solvents are used alone or in combination of two or more as desired.

  Among these, the solubility of water in an organic solvent is preferably 3.0 g / L or less at 20 ° C., and more specifically, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate. Methyl isobutyl ketone. When these are used, it is possible to suppress the formation of an emulsion at the time of contact between the organic solvent solution and the aqueous solution in which the acidic compound is dissolved, or at the time of contact between the organic solvent solution and ion-exchanged water. Further, since these solvents have a specific gravity lower than 1, the organic solvent layer can be separated into an upper layer after the subsequent contact with the acidic aqueous solution and the contact with the ion-exchanged water, respectively, and the separation is easy.

  In this organic solvent solution, the concentration of naphthol novolak and its derivatives is preferably 10 to 40% by mass, more preferably 20 to 30% by mass. When the concentration is less than 10% by mass, the effect of reducing metal ions is reduced. On the other hand, when the concentration is higher than 40% by mass, the organic solvent solution and the ion-exchanged water are contacted with the organic solvent solution and the aqueous solution in which the acidic compound is dissolved. An emulsion tends to be formed at the time of contact, and the manufacturing process takes time.

[Acid aqueous solution]
The organic solvent solution in which naphthol novolak and its derivatives are dissolved is first subjected to contact treatment with an aqueous solution in which an acidic compound is dissolved according to the present invention. Examples of acidic compounds used here include organic acids, particularly organic carboxylic acids, and organic sulfonic acids. Specific examples of the organic carboxylic acid include formic acid, acetic acid, oxalic acid, malonic acid, glycolic acid, lactic acid, tartaric acid, and citric acid. Specific examples of the organic sulfonic acid include p-toluenesulfonic acid, camphorsulfonic acid, trifluorosulfonic acid, and nonafluorossulfonic acid. These can be used alone or in admixture of two or more if desired.

  In order to effectively achieve the object of the present invention of reducing the metal ion content in naphthol novolak and its derivatives, the acidic compound is preferably dissolved in ion-exchanged water to form an aqueous solution. In this case, the acidic compound is dissolved at a rate of about 0.001 to about 35 parts by mass, preferably at a rate of about 0.01 to about 25 parts by mass with respect to 100 parts by mass of ion-exchanged water.

  The ratio of the aqueous solution in which an organic solvent solution of naphthol novolak and its derivative and an acidic compound are dissolved is usually (1-5): 1, preferably (1-3): 1, in the volume ratio of the former: the latter. An aqueous solution in which an organic solvent solution of naphthol novolak and its derivative and an acidic compound are dissolved may be mixed so that they are in good contact with each other, and is performed by one-step or multi-step alternating current or backflow treatment. Extraction may be mentioned as a preferable contact means. For example, the extraction may be performed by mixing the organic solvent solution and the aqueous solution once, or repeatedly mixing a plurality of times, for example, 3 to 4 times each time using a new aqueous solution ( (AC extraction or multistage AC extraction), or by reusing the aqueous solution after AC extraction and mixing once or several times (backflow extraction or multistage backflow extraction). In the extraction, conditions such as temperature and time are not particularly limited as long as naphthol novolak and its derivatives are not adversely affected, but preferably 20 to 70 ° C. for 30 minutes or more per mixing.

  After the contact treatment with an aqueous solution in which such an acidic compound is dissolved, the organic solvent solution of naphthol novolak and its derivative separated and recovered from the aqueous solution is further subjected to contact treatment with ion-exchanged water. The The ion exchange water used here preferably has an electric resistance value of 10 MΩ or more. The same applies when ion exchange water is used to dissolve the acidic compound. The contact treatment of an organic solvent solution of naphthol novolak and its derivatives with ion exchange water is performed by mixing the organic solvent solution and ion exchange water, and then separating the liquid, collecting the organic layer, and then collecting the ion exchange water again in the collected organic layer. The mixture is separated after being added, and the organic layer is recovered again, and after the ion-exchanged water is added again to the recovered organic layer and mixed, the contact treatment with the ion-exchanged water is performed. It is necessary to repeat three times or more. It is preferable to repeat until the ion exchange water reaches pH 6-7. When the pH of the ion-exchanged water is 6 to 7 or less, an acidic compound containing a metal is present in the organic layer, and thus metal ions may remain in the naphthol novolak and its derivatives.

  Further, the use ratio of both of the organic solvent solution of naphthol novolak and its derivatives and the ion-exchanged water, the conditions such as temperature and time are the same as in the case of the contact treatment with the aqueous solution in which the acidic compound is dissolved. It can be almost the same. After the contact treatment with ion-exchanged water is completed, water mixed in the organic solvent solution of naphthol novolak and its derivatives can be easily removed by vacuum distillation or azeotropic distillation.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The method of the present invention will be described in more detail with reference to the following examples in which the sodium and iron contents of the resin solution are changed.

(Measurement method of contained metal ions)
The naphthol novolak resin solution and the naphthol-containing metal measurement method for the naphthol novolak resin solution were measured with a DRCII ICP mass spectrometer manufactured by Perkin Elmer ELAN.

(Polymerization of naphthol novolac)
Naphthol novolak was obtained by the following method. To a flask equipped with a reflux tube, 100 parts by mass of 1-naphthol, 60 parts by mass of formaldehyde, 300 parts by mass of propylene glycol monomethyl ether, and 5 parts by mass of p-toluenesulfonic acid were added, and the mixture was heated and stirred at 100 ° C. for 8 hours. did. Water was added to the reaction solution and stirred. After collecting the precipitate, it was washed with water and dried at 50 ° C. for 17 hours to obtain a 1-naphthol / formaldehyde condensate.

  This 1-naphthol / formaldehyde condensate is used as a crude product. In addition, Table 2 shows the amount of metal contained in the unpurified product.

Example 1
The said unpurified product was diluted to 10 mass% with n-butyl acetate, and 2 L of organic solvent solutions were created. Next, 1 L of an aqueous solution in which oxalic acid was dissolved in ion-exchanged water having an electric resistance of 16 MΩ / cm at a concentration of 1% by mass was added, stirred and mixed at 30 ° C. for 30 minutes, and then separated. 1 L of ion exchange water was added to the obtained organic layer (upper layer), and the mixture was stirred at 30 ° C. for 30 minutes and washed. Further, the mixture was stirred and washed twice under the same conditions. After repeating this series of operations twice, n-butyl acetate was removed from the organic layer by vacuum distillation. The amount of metal ions contained in the obtained resin was measured.

(Examples 2 to 18)
In the same operation as in Example 1, as shown in Table 1, the organic solvent species, the concentration of the organic solvent solution, the acidic compound species, the number of contact between the organic solvent solution and ion-exchanged water, the organic solvent solution and ion-exchanged water, Examples 2 to 18 were performed under different conditions of the pH of ion-exchanged water during the contact treatment.

(Comparative Examples 1-7)
In the same operation as in Example 1, as shown in Table 1, the organic solvent species, the concentration of the organic solvent solution, the acidic compound species, the number of contact between the organic solvent solution and ion-exchanged water, the organic solvent solution and ion-exchanged water, Comparative Examples 1 to 7 were carried out under different conditions for the pH of ion-exchanged water during the contact treatment.

(Evaluation results)
From Table 2, it can be seen that the metal ions that were 1000 ppb or more can be reduced to 50 ppb or less by the metal ion reduction treatment according to the present invention. In particular, it can be seen that Na, Fe, and Cu can be significantly reduced by the method of the present invention.

  On the other hand, the metal ion reduction treatment shown in Comparative Examples 1 to 7 cannot be suppressed to 50 ppb or less. In Comparative Examples 1 to 3, the solubility of water in an organic solvent is higher than 3.0 g / L. Therefore, when the organic layer and the aqueous layer are separated after contact with an aqueous solution of an acidic compound or ion-exchanged water, Emulsion occurs between the layers and separation is difficult. In particular, in the process of repeated contact with ion-exchanged water, separation becomes very difficult as the pH of ion-exchanged water approaches 6-7, and metal ion reduction treatment cannot be performed. Similarly, in Comparative Example 7, since the concentration of the organic solvent solution is high, an emulsion is generated as in Comparative Examples 1 to 3, and the metal ion reduction treatment cannot be performed. Moreover, it turns out from the result of Comparative Examples 4-5 that a metal ion is not fully reduced when the frequency | count of contact with ion-exchange water is few and the pH of ion-exchange water is 6-7 or less. Moreover, it can be seen from the result of Comparative Example 6 that the metal ion reduction effect is low when the concentration of the organic solvent solution is low.

  According to the present invention, it is usually possible to reduce the content of metal ions to less than 50 ppb from naphthol novolak and derivatives thereof containing several thousand ppb of metal ions.

Claims (6)

(1) A step of dissolving an naphthol novolak and a derivative thereof in an organic solvent which is n-butyl acetate or methyl isobutyl ketone to obtain an organic solvent solution;
(2) contacting the organic solvent solution with an acidic aqueous solution to recover the organic layer;
(3) A method for producing a naphthol novolak and a derivative thereof, comprising the step of bringing the organic layer into contact with ion-exchanged water and further collecting the organic layer in this order, and repeating the step (3) three or more times.   The method for producing a naphthol novolak and a derivative thereof according to claim 1, wherein the acidic aqueous solution contains an organic acid.   The method for producing a naphthol novolak and a derivative thereof according to claim 2, wherein the organic acid is at least one selected from the group consisting of formic acid, acetic acid, oxalic acid, malonic acid, glycolic acid, lactic acid, tartaric acid and citric acid. The acidic aqueous solution has an organic acid content of 0 . The method for producing a naphthol novolak and a derivative thereof according to any one of claims 1 to 3, wherein the naphthol novolak and the derivative thereof are dissolved at a ratio of 01 to 25 parts by mass. The method for producing a naphthol novolak and a derivative thereof according to any one of claims 1 to 4 , wherein a temperature during contact treatment between the organic solvent solution and the acidic aqueous solution is 20 ° C to 70 ° C. The temperature at the time of the contact treatment between the organic layer and the ion-exchanged water is 20 ° C to 70 ° C, The method for producing naphthol novolak and derivatives thereof according to any one of claims 1 to 5 .