KR102066814B1 - Method of purifying cresols, method of producing novolak resin for photosensitive resin composition and photosensitive resin composition - Google Patents

Abstract

Purification method of the cresols which refine | requires the fractionation cresol obtained by tar distillation, and makes it possible to manufacture the novolak resin suitable for the photosensitive resin composition, and manufacture of the novolak resin for photosensitive resin compositions using the refined tablet cresol refined by the purification method. The method and the photosensitive resin composition containing the novolak resin manufactured by the manufacturing method are provided.
The method for purifying cresols according to the present invention includes a removing step of removing basic substances in the fractionated cresol obtained by tar distillation. In this removal step, the fractionated cresol is washed with an aqueous solution of an acidic substance or the acidic substance is added to the fractionated cresol and then distilled again.

Description

METHOD OF PURIFYING CRESOLS, METHOD OF PRODUCING NOVOLAK RESIN FOR PHOTOSENSITIVE RESIN COMPOSITION AND PHOTOSENSITIVE RESIN COMPOSITION}

This invention is manufactured by the refinement method of the cresols used for manufacture of the novolak resin for photosensitive resin compositions, the manufacturing method of the novolak resin for photosensitive resin compositions using the refined cresol refine | purified by the refinement method, and its manufacturing method It relates to the photosensitive resin composition containing the novolak resin.

A positive photosensitive resin composition containing a novolak resin and a quinone diazide group-containing compound is widely used in fields such as the manufacture of integrated circuits (ICs) of semiconductors because it is a material having excellent sensitivity, resolution, and heat resistance. have.

Among these, novolak resins are generally synthesized by the condensation reaction between cresols, aldehydes and / or ketones. As cresols, chemically synthesized ones are generally used. For example, o-cresol among three isomers of cresol can be manufactured by the phenol methylation method which uses phenol and methanol as a raw material. In addition, m-cresol and p-cresol can be manufactured by the toluene isopropylation method (cymen method) which oxidizes the cement obtained from toluene and propylene.

Japanese Patent Application Laid-Open No. 9-53080

By the way, cresols are contained in coal tar as taric acid, and can also be obtained by distillation and refine | purification of coal tar. However, coal tar contains basic substances such as pyridine, methyl pyridine and aniline as tar bases, and these are known to remain in fractionated cresols. Accordingly, many methods for removing such basic substances have been proposed. For example, Patent Literature 1 proposes a method of adsorbing and removing impurities such as tar base by adding an aqueous solution of alkali hydroxide to taric acid to form an aqueous solution of tartrate, and contacting the aqueous solution with activated carbon.

However, according to the studies of the present inventors, in order to use the novolak resin prepared using cresols for the photosensitive resin composition, it is necessary to almost completely remove the basic substance in the classification cresol, and is insufficient by the conventional method such as Patent Document 1. It turned out.

This invention is made | formed in view of such a conventional situation, The refine | purification method of the cresols which refine | purifies the fractionation cresol obtained by tar distillation, and makes it possible to manufacture the novolak resin suitable for the photosensitive resin composition, and refine | purified by the purification method It is an object to provide a method for producing a novolak resin for a photosensitive resin composition using a tablet cresol, and a photosensitive resin composition containing a novolak resin produced by the production method.

The present inventors earnestly studied to achieve the above object. As a result, it was found out that the novolak resin suitable for the photosensitive resin composition can be manufactured by removing the basic substance in the fractionated cresol obtained by tar distillation by a specific method, thereby completing the present invention. Specifically, the present invention provides the following.

The 1st aspect of this invention is a refinement | purification method of cresols used for manufacture of the novolak resin for photosensitive resin compositions, Comprising: The removal process which removes the basic substance in the fractionation cresol obtained by tar distillation, In this removal process, A fractionation cresol is washed with an acidic aqueous solution, or an acidic substance is added to the fractionation cresol and then distilled again.

The 2nd aspect of this invention is a manufacturing method of the novolak resin for photosensitive resin compositions, Comprising: The reaction process of making cresol react with aldehydes and / or ketones in presence of a catalyst, The said cresol is the agent of this invention. It is a manufacturing method characterized by containing the refined cresol refine | purified by the refinement | purification method concerning 1 aspect.

The 3rd aspect of this invention is the photosensitive resin composition characterized by containing the novolak resin manufactured by the manufacturing method which concerns on the 2nd aspect of this invention.

According to the present invention, there is provided a method for purifying cresols which purifies fractional cresol obtained by tar distillation to enable production of a novolak resin suitable for a photosensitive resin composition, and for photosensitive resin composition using tablet cresol purified by the purification method. The manufacturing method of a novolak resin, and the photosensitive resin composition containing the novolak resin manufactured by the manufacturing method can be provided.

<Purification method of cresols>

The method for purifying cresols according to the present invention includes a removing step of removing basic substances in fractionated cresols obtained by tar distillation.

The classification cresol is not particularly limited, and the classification cresol obtained by a known method can be used. Among these, m / p mixed products containing m-cresol and p-cresol as the main components tend to have a high content of basic substances. . For this reason, the effect is high especially when an m / p mixture is used.

The first method of removing the basic substance is to wash the fractionated cresol with an aqueous solution of acidic substance. That is, the basic substance in the fractionated cresol can be removed by mixing the fractionated cresol and the aqueous solution of the acidic substance, transferring the basic substance in the fractionated cresol to the aqueous phase, and then separating the fractionated cresol.

Examples of the acidic substance include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, and organic acids such as oxalic acid and acetic acid, but inorganic acids are preferable, strong acids of inorganic acids are more preferable, hydrochloric acid and sulfuric acid are more preferable, and hydrochloric acid is most preferred. desirable. Moreover, although the density | concentration of an acidic substance changes also with content of the basic substance in fractional cresol, it is usually 0.1-20 mass%, Preferably it is 0.5-15 mass%.

Although the quantity of the aqueous solution of the acidic substance with respect to a classification cresol is not specifically limited, Usually, it is 5-500 mass%, Preferably it is 10-300 mass%.

Moreover, in order to improve liquid separation property, it is preferable to mix an organic solvent with fractionation cresol. Examples of the organic solvent include butyl acetate, toluene, xylene, hexane, heptane, cyclohexane, and the like. Although the usage-amount of an organic solvent is not specifically limited, Usually, it is 0.5 to 5 times by mass ratio with respect to fractional cresol.

The specific separation method may be a continuous method or a batch method. The continuous method uses a mixer settler or tower type multistage extraction device to continuously feed an aqueous fraction of the fractionated cresol (or a mixed solvent of the fractionated cresol and an organic solvent) and an acidic substance to extract and remove the basic substances in the fractionated cresol. On the other hand, the batch method is a method of mixing and stirring a fractionated cresol (or a mixed solvent of fractionated cresol and an organic solvent) and an aqueous solution of an acidic substance, and then standing still and separating the fraction.

The second method of removing the basic substance is to re-distill the acid substance after adding the acidic substance to the fractionated cresol. That is, the salt can be formed by adding an acidic substance in the fractionated cresol, and then the basic substance in the fractionated cresol can be removed by re-distillation according to a conventional method.

Examples of the acidic substance to be added include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, and organic acids such as oxalic acid and acetic acid. Inorganic acids are preferred, hydrochloric acid and sulfuric acid are more preferred, and hydrochloric acid is most preferred. Moreover, although the addition amount of an acidic substance changes also with content of the basic substance in fractional cresol, it is 0.5-20 mol% normally, Preferably it is 1.0-10 mol%.

The number of times the fractionated cresol is washed with an aqueous solution of an acidic substance (the number of separations) or the number of times of re-distillation after adding the acidic substance to the fractionated cresol is appropriately determined according to the content of the basic substance in the fractionated cresol or the final target concentration. According to the inventors' review, since the content of pyridine and 2-methyl pyridine is significantly higher among the basic substances present in the sorting cresol, until the content of pyridine and 2-methyl pyridine is less than 2 ppm each, preferably 1 It is desirable to continue the removal process until it is below ppm, more preferably below 0 ppm (ie below the detection limit).

In addition, the purification method according to the present invention has a high removal efficiency of the basic substance, and thus the basic substance can be almost completely removed in a shorter time than the conventional method.

<The manufacturing method of the novolak resin for photosensitive resin composition>

The manufacturing method of the novolak resin for photosensitive resin compositions which concerns on this invention includes the reaction process of making cresol, aldehydes, and / or ketones react in presence of a catalyst. In this reaction step, in addition to cresols, phenols other than these cresols may be reacted with aldehydes and / or ketones.

As the cresols, purified cresols purified by the purification method according to the present invention can be used. Moreover, in order to adjust various characteristics, such as a sensitivity, you may further use cresols obtained by chemical synthesis. In one embodiment, 50 mass% or more of cresols used are the refined cresol refine | purified by the refinement | purification method which concerns on this invention.

Phenols other than the above cresols include phenol; 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, Xylenols such as 3,5-xylenol; o-ethyl phenol, m-ethyl phenol, p-ethyl phenol, 2-isopropyl phenol, 3-isopropyl phenol, 4-isopropyl phenol, o-butyl phenol alkyl phenols such as m-butyl phenol, p-butyl phenol and p-tert-butyl phenol; trialkyl phenols such as 2,3,5-trimethyl phenol and 3,4,5-trimethyl phenol; resorcinol and cate Polyhydric phenols such as chol, hydroquinone, hydroquinone monomethyl ether, pyrogarol, and phloroglycinol; alkyl polyhydric phenols such as alkyl resorcin, alkyl catechol, alkyl hydroquinone (any alkyl group also has 1 to 4 carbon atoms) Α-naphthol, β-naphthol, hydroxydiphenyl, bisphenol A and the like. These phenols may be used independently and may be used in combination of 2 or more type. Among these phenols, 2,5-xylenol, 3,5-xylenol, and 2,3,5-trimethyl phenol are preferable.

Examples of the aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, trimethyl acetaldehyde, acrolein, crotonaldehyde, cyclohexane aldehyde, furfural, furyl acrolein, benzaldehyde, terephthalaldehyde, terealdehyde, terealdehyde -Phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxy benzaldehyde, m-hydroxy benzaldehyde, p-hydroxy benzaldehyde, o-methyl benzaldehyde, m-methyl benzaldehyde, p-methyl benzaldehyde, o-chloro benzaldehyde, m -Chloro benzaldehyde, p-chloro benzaldehyde, succinic aldehyde and the like. These aldehydes may be used independently or may be used in combination of 2 or more type. Among these aldehydes, formaldehyde is preferable from the availability.

Acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, etc. are mentioned as said ketones. These ketones may be used independently or may be used in combination of 2 or more type.

Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and phosphorous acid; organic acids such as formic acid, oxalic acid, acetic acid, diethyl sulfuric acid, and paratoluene sulfonic acid; and metal salts such as zinc acetate. These acid catalysts may be used independently or may be used in combination of 2 or more type.

Although the mass average molecular weight of the novolak resin obtained in this way is not specifically limited, It is preferable that it is 2000-30000, and it is more preferable that it is 3000-25000. By setting the mass average molecular weight to 2000 or more, film formation of the prepared photosensitive resin composition is good, and heat resistance is also good. Moreover, the sensitivity of the prepared photosensitive resin composition becomes favorable by making a mass mean molecular weight 30000 or less.

In addition, the mass average molecular weight of novolak resin can also be adjusted by performing classification operation suitably, and removing the thing of low molecular weight.

Moreover, it is preferable that it is 5 or less, and, as for the dispersion degree [mass average molecular weight / number average molecular weight (Mw / Mn)] of novolak resin, it is more preferable that it is three or less. By setting dispersion degree to 5 or less, the pattern shape at the time of forming a resin pattern using the prepared photosensitive resin composition becomes favorable. In addition, dispersion degree is substantially one or more.

<Photosensitive resin composition>

The photosensitive resin composition which concerns on this invention contains the novolak resin manufactured by the manufacturing method which concerns on this invention. It is preferable that it is 50-95 mass% with respect to solid content of the photosensitive resin composition, and, as for content of novolak resin, it is more preferable that it is 60-90 mass%. By setting it as said range, there exists a tendency which is easy to take a balance of developability.

Moreover, the photosensitive resin composition which concerns on this invention contains a quinone diazide group containing compound as a photosensitive agent. As this quinone diazide group containing compound, the complete ester and partial ester compound of a phenol compound and a quinone diazide group containing sulfonic acid compound are preferable. Such quinone diazide group-containing compounds are fully esterified by partially condensing a phenol compound and a quinone diazide group-containing sulfonic acid compound in the presence of alkalis such as triethanol amine, alkali carbonate, and hydrogen carbonate in a suitable solvent such as dioxane. It can be obtained by esterification.

As said phenolic compound, the compound represented by following formula (1) is preferable.

The formula (1) of, R ¹ ~ R ⁸ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or alkoxy of 1 to 6 carbon atoms. R ⁹ to R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Q represents a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group couple | bonded with R <^9> , or group represented by following formula (2). a and b respectively independently represent the integer of 1-3, d and n respectively independently represent the integer of 0-3.

In said formula (2), R <^12> , R <^13> represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, or a C1-C6 alkoxy group each independently. c represents the integer of 1-3.

Specific examples of this phenol compound include polyhydroxybenzophenones such as 2,3,4-trihydroxybenzophenone and 2,3,4,4'-tetrahydroxybenzophenone; tris (4-hydroxyphenyl) Methane, bis (4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy Hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3,5- Dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3- Hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenyl Methane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2,4-dihydroxyphenyl Carbon, bis (4-hydroxyphenyl) -3-methoxy-4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -4-hydroxyphenylmethane, bis (5 -Cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclo Hexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane, 4,4 '-[(2-hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 5 Trisphenol-type compounds such as 5'-dicyclohexyl-4,4 ', 3 ", 4" -tetrahydroxy-2,2'-dimethyl triphenylmethane;

2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol, 2,6-bis (2,5-dimethyl-4-hydroxy benzyl) -4-methylphenol Linear trinuclear phenol compounds;

1,1-bis [3- (2-hydroxy-5-methylbenzyl) -4-hydroxy-5-cyclohexylphenyl] isopropane, bis [2,5-dimethyl-3- (4-hydroxy- 5-methylbenzyl) -4-hydroxyphenyl] methane, bis [2,5-dimethyl-3- (4-hydroxybenzyl) -4-hydroxyphenyl] methane, bis [3- (3,5-dimethyl -4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4- Hydroxy-5-ethylphenyl] methane, bis [2-hydroxy-3- (3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy-3- (2 -Hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [2,5-dimethyl Linear tetranuclear phenol compounds such as -3- (2-hydroxy-5-methyl benzyl) -4-hydroxyphenyl] methane;

2,4-bis [2-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [4-hydroxy-3- (4-hydroxy Hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4 Linear pentanuclear phenol compounds such as -methyl phenol;

Bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) methane, 2,3,4-trihydroxyphenyl-4'-hydroxyphenylmethane, 2- ( 2,3,4-trihydroxyphenyl) -2- (2 ', 3', 4'-trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2 ', 4'-dihydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (3-fluoro-4-hydroxyphenyl) -2- ( 3'-fluoro-4'-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,3,4-tri Hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (4'-hydroxy-3 ', 5'-dimethylphenyl) Propane, 4,4 '-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol, 4,4'-[1- [4- [2- Bisphenol-type compounds such as [4-hydroxyphenyl] -2-propyl] phenyl] ethylidene] bisphenol;

1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, 1- [1- (3-methyl-4-hydroxyphenyl Multinuclear branched compounds such as) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene;

Condensed-type phenol compounds, such as 1, 1-bis (4-hydroxyphenyl) cyclohexane; These etc. are mentioned.

These phenolic compounds may be used independently and may be used in combination of 2 or more type.

As the quinone diazide group-containing sulfonic acid compound, naphthoquinone-1,2-diazide-5-sulfonic acid, naphthoquinone-1,2-diazide-4-sulfonic acid, orthoanthraquinone diazidesulfonic acid Etc. can be mentioned.

It is preferable that it is 5-50 mass parts with respect to 100 mass parts of novolak resin, and, as for content of a quinone diazide group containing compound, it is more preferable that it is 5-25 mass parts. By setting it as said range, the sensitivity of the photosensitive resin composition will become favorable.

Moreover, it is preferable that the photosensitive resin composition which concerns on this invention contains the said phenolic compound as a sensitizer. It is preferable that it is 5-50 mass parts with respect to 100 mass parts of novolak resin, and, as for content of a phenol compound, it is more preferable that it is 10-40 mass parts. By setting it as said range, the sensitivity of the photosensitive resin composition will become favorable and the film | membrane sensitivity at the time of image development will be suppressed.

Moreover, the photosensitive resin composition which concerns on this invention may contain surfactant and a ultraviolet absorber as needed. Examples of the surfactant include fluorine-based surfactants. Ultraviolet absorbers include 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dimethylamino-2', 4'-dihydroxybenzophenone, 5-amino-3-methyl-1-phenyl-4 -(4-hydroxyphenylazo) pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylaminoazobenzene, 4-diethylamino-4'-ethoxyazobenzene, curkmin, etc. are mentioned. Can be.

Moreover, you may contain common additives, such as an additional resin, a plasticizer, a stabilizer, an adhesion | attachment adjuvant, a contrast improver, as needed.

In order to improve applicability | paintability and adjust a viscosity, it is preferable to use the photosensitive resin composition concerning this invention as a solution which melt | dissolved in the suitable organic solvent.

As the organic solvent, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone and 2-heptanone; ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene Polyhydric alcohols and derivatives thereof such as glycol monoacetate or monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether; cyclic ethers such as dioxane; ethyl lactate, methyl acetate, acetic acid Esters such as ethyl, butyl acetate, methyl pyruvate, ethyl pyruvate and ethyl methoxy propionate; These organic solvents may be used independently, or may mix and use 2 or more types.

Content of the organic solvent is not specifically limited, It is set suitably according to the coating film thickness in the density | concentration which can be apply | coated to a board | substrate. Specifically, the amount of the solid content concentration of the photosensitive resin composition is preferably 10 to 50% by mass, more preferably 20 to 40% by mass.

The photosensitive resin composition which concerns on this invention can be prepared by mixing and stirring each said component. As needed, you may filter further using a mesh, a membrane filter, etc.

Example

Hereinafter, although the Example of this invention is described, the scope of the present invention is not limited to these Examples.

<Purification of classification cresol>

[Untreated 1, 2]

As untreated classification cresol, mp-cresol (m-cresol / p-cresol = 66/33 (molar ratio); non-treated) and mp-cresol (m-cresol / p-cresol) of different lots from the same company = 66/33 (molar ratio); untreated 2) was prepared. And content of pyridine and 2-methyl pyridine was measured using gas chromatography mass spectrometry (made by PerkinElmer) (detection limit <0.1 ppm). The results are shown in Table 1 below.

[Comparative Purification Example 1]

Into a flask equipped with a thermometer and a reflux tube, 1800 g of untreated 1 sorted cresol was introduced, and 180 g of supernatant was poured out while raising the temperature to 130 ° C. Then, this increment was collected under the condition of reflux ratio 10 to 20 g and purified of 1550 g. Cresol was obtained. And it carried out similarly to the above, and content of pyridine and 2-methyl pyridine in this refined cresol was measured. The results are shown in Table 1 below.

[Refining Example 1]

700 kg of the untreated 1 cresol and 700 kg of butyl acetate were mixed, and 1400 kg of 1 mass% hydrochloric acid aqueous solution was further mixed and stirred for 60 minutes, and the organic phase was separated after standing. 1400 kg of 1 mass% hydrochloric acid aqueous solution was mixed with this organic phase, it stirred for 60 minutes, and after standing, the organic phase was fractionated. Pure water 1400 kg was mixed with this organic phase, it stirred for 30 minutes, and after standing, the organic phase was fractionated. The washing operation using pure water was repeated three times in total. And the organic phase was concentrated until it became 1 mass% of water and 3 mass% or less of butyl acetate, and the refined cresol was obtained. And it carried out similarly to the above, and content of pyridine and 2-methyl pyridine in this refined cresol was measured. The results are shown in Table 1 below.

Tablet Example 2

In a flask equipped with a thermometer and a reflux tube, 1000 g of fractionated cresol and hydrochloric acid (the same moles as pyridine in the fractionated cresol) were placed in a flask equipped with a thermometer and a reflux tube. This increment was taken to give 730 g of purified cresol. And it carried out similarly to the above, and content of pyridine and 2-methyl pyridine in this refined cresol was measured. The results are shown in Table 1 below.

As can be seen from Table 1, the untreated fractionated cresol contained about 200 ppm of pyridine and 2-methyl pyridine, respectively. The content of 2-methyl pyridine was remarkably reduced by re-distillation as in Comparative Purification Example 1, but the content of pyridine could not be reduced by that much. In contrast, the pyridine and 2-methyl pyridine in the fractionated cresol can be almost completely removed by washing the crude fractionated cresol with an aqueous hydrochloric acid solution, or by re-distilling the hydrochloric acid in the fractionated cresol as in Purification Examples 1 and 2. there was.

<Production of novolak resin, preparation of photosensitive resin composition>

Example 1

p-cresol and 3,5-xylene of the chemical synthesis product for the classified cresol purified in Purification Example 1 such that m-cresol / p-cresol / 3,5-xylenol = 50/30/20 (molar ratio). Gnoll was added. And novolak resin was obtained by carrying out condensation reaction by a conventional method using oxalic acid as an acid catalyst, and formalin as a condensing agent. In addition, condensation reaction conditions were made into the conditions which obtain the novolak resin of the mass mean molecular weight (Mw) 8000 when the cresol of a chemical synthetic product is used instead of the classification cresol.

The photosensitive resin composition was prepared by adding the following photosensitizer, the sensitizer, and surfactant with respect to 100 mass parts of this novolak resins, and adding and mixing 2-heptanone so that solid content concentration may be 35 mass%.

Photosensitizer

4,4 '-[(2-hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol) -naphthoquinone-1,2-diazide-5-sulfonic acid (mono-tri) ester ... 21 parts by mass

5,5'-Dicyclohexyl-4,4 ', 3 ", 4" -tetrahydroxy-2,2'-dimethyltriphenylmethane-naphthoquinone-1,2-diazide-5-sulfonic acid ( Mono-tetra) ester ... 4.3 parts by mass

Sensitizer

4,4 '-[1- [4- [2- [4-hydroxyphenyl] -2-propyl] phenyl] ethylidene] bisphenol..35 parts by mass

·Surfactants

8 parts by mass of perfluoroalkyl group-containing oligomer

Example 2

p-cresol and 3,5-xylene of the chemical synthesis product for the classified cresol purified in Purification Example 1 such that m-cresol / p-cresol / 3,5-xylenol = 50/30/20 (molar ratio). Gnoll was added. And novolak resin was obtained by carrying out condensation reaction by a conventional method using oxalic acid as an acid catalyst, and formalin as a condensing agent. In addition, condensation reaction conditions were made into the conditions which obtain the novolak resin of the mass mean molecular weight 4500 when the cresol of a chemical synthetic product is used instead of the classification cresol.

The photosensitive resin composition was prepared by adding the following photosensitizers, sensitizers, and surfactant with respect to 100 mass parts of this novolak resin, and adding and mixing 2-heptanone so that solid content concentration might be 32 mass%.

Photosensitizer

4,4 '-[(2-hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol) -naphthoquinone-1,2-diazide-5-sulfonic acid (mono-tri) ester ... 21 parts by mass

5,5'-Dicyclohexyl-4,4 ', 3 ", 4" -tetrahydroxy-2,2'-dimethyltriphenylmethane-naphthoquinone-1,2-diazide 5-sulfonic acid (mono ... tetra) ester ... 4.3 parts by mass

Sensitizer

4,4 '-[1- [4- [2- [4-hydroxyphenyl] -2-propyl] phenyl] ethylidene] bisphenol..35 parts by mass

·Surfactants

8 parts by mass of perfluoroalkyl group-containing oligomer

[Comparative Examples 1 and 2]

A photosensitive resin composition was prepared in the same manner as in Examples 1 and 2, except that the classification cresol of Untreated 1 was used instead of the classification cresol purified in Purification Example 1. In addition, the comparative example 1 is 8000, and the comparative example 2 is 4500 for the mass mean molecular weight of the novolak resin used as a target.

[Comparative Examples 3 and 4]

A photosensitive resin composition was prepared while producing a novolak resin in the same manner as in Comparative Examples 1 and 2, except that the amount of the acid catalyst when the novolak resin was increased by three times. In addition, the comparative example 3 is 8000, and the comparative example 4 is 4500 for the mass mean molecular weight of the novolak resin used as a target.

[Comparative Example 5]

A novolak resin was produced in the same manner as in Example 1 except that the fractionated cresol of untreated 2 was used instead of the fractionated cresol purified in Purification Example 1. In addition, the mass average molecular weight of the novolak resin used as a target is 8000.

Example 3

To the fractionation cresol purified in Purification Example 2 so that m-cresol / p-cresol = 60/40 (molar ratio), p-cresol of the chemical synthetic product was added. And novolak resin was obtained by carrying out condensation reaction by a conventional method using oxalic acid as an acid catalyst, and formalin as a condensing agent. In addition, condensation reaction conditions were made into the conditions which obtain the novolak resin of the mass mean molecular weight (Mw) 16300, when cresol of a chemical synthetic product is used instead of classification cresol.

To 100 mass parts of this novolak resin, the following photosensitizer, an additive, and surfactant are added, and the photosensitive property is added by adding and mixing the mixed solvent of ethyl lactate / butyl acetate = 90/10 (mass ratio) so that solid content concentration may be 20 mass%. The resin composition was prepared.

Photosensitizer

6-diazo-5,6-dihydro-5-oxo-1-naphthalene sulfonic acid ester of 2,3,4-trihydroxybenzophenone ... 27 parts by mass

·additive

2,3,4-trihydroxybenzophenone ... 12.7 parts by mass

·Surfactants

Perfluoroalkyl group containing oligomer ... 5.1 mass parts

Comparative Example 6

A novolak resin was produced in the same manner as in Example 3 except that the fractionation cresol of untreated 1 was used instead of the fractionation cresol purified in Purification Example 2. In addition, the mass average molecular weight of the novolak resin used as a target is 16300.

Comparative Example 7

A novolak resin was produced in the same manner as in Example 3 except that the fractionation cresol purified in Comparative Purification Example 1 was used instead of the fractionation cresol purified in Purification Example 2. In addition, the mass average molecular weight of the novolak resin used as a target is 16300.

<Evaluation of novolak resin and photosensitive resin composition>

[Evaluation of mass average molecular weight (Mw) of novolac resin]

The mass average molecular weight of the novolak resin obtained in Examples 1-3 and Comparative Examples 1-7 was measured. The ratio (%) with respect to the mass average molecular weight used as each target is shown in Table 2 below.

[Evaluation of Alkali Dissolution Rate (ADR) of Novolak Resin]

The novolak resins obtained in Examples 1-3 and Comparative Examples 1-7 were dissolved in propylene glycol monomethyl ether acetate, respectively, and the 25 mass% resin solution was prepared. This resin solution was applied onto a silicon wafer and dried at 110 ° C. for 90 seconds to form a resin film having a film thickness of 1 μm. Then, the resin film was immersed in 2.38 mass% tetramethylammonium aqueous solution for a fixed time, and the film thickness change amount of the resin film was calculated | required.

In addition, novolak resins having a mass average molecular weight of 4500, 8000, and 16300 were produced in the same manner as in Examples 1 to 3, except that cresols of chemical synthetic products were used instead of the classification cresols. It was set as the standard value about each molecular weight of 1-3 and Comparative Examples 1-7.

The ratio (%) with respect to the standard value of the film thickness change amount of Examples 1-3 and Comparative Examples 1-7 is shown in Table 2 below.

[Evaluation of Sensitivity of Photosensitive Resin Composition]

The photosensitive resin composition prepared in Examples 1 and 2 and Comparative Examples 1-4 was apply | coated on a silicon wafer using a spinner, and it dried for 90 second at 90 degreeC on the hotplate, and obtained the resin film of 1.05 micrometers in thickness. Next, after exposing the resin film at intervals of 0.1 second to 0.01 second through a 0.5 µm pattern-adaptive mask (reticle) having a line and space of 1: 1 using a reduced projection exposure apparatus NSR-2005i10D (manufactured by Nikon Corporation), PEB (post-exposure heating) process was performed for 110 degreeC and 90 second. Then, the line and space pattern was formed by developing the resin film after exposure for 60 second at 23 degreeC using the 2.38 mass% tetramethylammonium aqueous solution, and washing with water for 30 seconds and drying. The optimum exposure time (Eop) in which the line-and-space pattern along the mask is formed was determined in milliseconds (ms) to set an index of sensitivity.

Moreover, the photosensitive resin composition prepared in Example 3 was apply | coated on the silicon wafer using a spinner, and it dried for 90 second at 90 degreeC on the hotplate, and obtained the resin film with a film thickness of 1.26 micrometers. Next, using a ghi mixed light source (wherein light having a wavelength less than or equal to h line (405 nm) is blocked by a filter) from 0.1 second through a mask (reticle) having a 1.0 μm pattern with a line and space of 1: 1. After exposing the resin film at 0.01 second intervals, PEB (post-exposure heating) treatment was performed at 110 ° C for 90 seconds. Then, the resin film after exposure for 60 second was developed at 23 degreeC using the 2.38 mass% tetramethylammonium aqueous solution, and the line and space pattern was formed by washing with water and drying for 30 second. The optimum exposure time (Eop) in which the line-and-space pattern along the mask is formed was determined in milliseconds (ms) to set an index of sensitivity.

A novolak resin having a mass average molecular weight of 4500, 8000, and 16300 was produced in the same manner as in Examples 1 to 3, except that cresols of chemical synthetic products were used instead of the classification cresols, and Example 1 was used using this novolak resin. It carried out similarly to -3 and Comparative Examples 1-4, and prepared the photosensitive resin composition. And optimum exposure time (Eop) was calculated | required similarly to the above, and it was set as the standard value of Examples 1-3 and Comparative Examples 1-4.

The ratio (%) with respect to the standard value of the optimal exposure time (Eop) of Examples 1-3 and Comparative Examples 1-4 is shown in Table 2 below.

In addition, about the comparative example 5, since it was confirmed that the characteristic of novolak resin is inferior like the comparative example 1, it was decided not to evaluate the photosensitive resin composition. Moreover, about Comparative Examples 6 and 7, deterioration of a sensitivity characteristic is obvious from the characteristic result of novolak resin, and since sensitivity cannot be adjusted like other examples in heat resistance and resolution evaluation, evaluation of the photosensitive resin composition is not performed. I did it.

[Evaluation of Heat Resistance of Photosensitive Resin Composition]

In order to adjust the sensitivity to the same degree, the photosensitive resin composition of Example 1 and the photosensitive resin composition of Example 2 were mixed by the mass ratio of 35:65. Similarly, while mixing the photosensitive resin composition of the comparative example 1 and the photosensitive resin composition of the comparative example 2 in the mass ratio of 84:16, the photosensitive resin composition of the comparative example 3 and the photosensitive resin composition of the comparative example 4 in the mass ratio of 12:88 Mixed.

In addition, the photosensitive resin composition of Example 3 was used as it is without mixing adjustment.

Next, the obtained photosensitive resin composition (except Example 3) was apply | coated on a silicon wafer using a spinner, and it dried for 90 second at 90 degreeC on the hotplate, and obtained the resin film with a film thickness of 1.05 micrometers. Next, after exposing the resin film using the reduced-projection exposure apparatus NSR-2005i10D (made by Nikon Corporation), PEB (post exposure heating) process was performed for 110 degreeC and 90 second. Next, the resin film after exposure for 60 second was developed at 23 degreeC using the 2.38 mass% tetramethylammonium aqueous solution, and 300-micrometer line pattern was formed by washing with water and drying for 30 second. Then, the silicon wafer was heated at 130 degreeC for 5 minutes, and the cross section of the line pattern was observed. And heat resistance evaluated as (circle) that the corner of a 300 micrometer line pattern remained, and that the corner of a 300 micrometer line pattern was rounded by heat flow. The results are shown in Table 2 below.

In addition, about the photosensitive resin composition of Example 3, the film thickness of the resin film shall be 1.26 micrometers, except having used the ghi mixed light source (except the light of wavelength below h line (405 nm) with a filter) at the time of exposure. Heat resistance was evaluated similarly to the above. The results are shown in Table 2 below.

[Resolution Evaluation of Photosensitive Resin Composition]

In order to adjust the sensitivity to the same degree, the photosensitive resin composition of Example 1 and the photosensitive resin composition of Example 2 were mixed by the mass ratio of 35:65. Similarly, while mixing the photosensitive resin composition of the comparative example 1 and the photosensitive resin composition of the comparative example 2 in the mass ratio of 84:16, the photosensitive resin composition of the comparative example 3 and the photosensitive resin composition of the comparative example 4 in the mass ratio of 12:88 Mixed.

In addition, the photosensitive resin composition of Example 3 was used as it is without mixing adjustment.

Next, the line and space width was the same as the pattern formation method in the above sensitivity evaluation except that a mask (reticle) having 0.50 µm, 0.45 µm, 0.40 µm, 0.38 µm, 0.36 µm, 0.35 µm, or 0.32 µm was used. To form a line-and-space pattern (except Example 3). Then, by confirming the presence or absence of residues in the space portion, the minimum space width resolvable was obtained. The results are shown in Table 2 below.

In addition, about the photosensitive resin composition of Example 3, it carried out similarly to the pattern formation method in the said sensitivity evaluation except having used the mask (reticle) whose line and space width is 1.0 micrometer, 0.8 micrometer, 0.6 micrometer, or 0.4 micrometer. A line and space pattern was formed. Then, by confirming the presence or absence of residues in the space portion, the minimum space width resolvable was obtained. The results are shown in Table 2 below.

As can be seen from Table 2, in Examples 1 to 3 in which novolak resins were produced using fractionated cresols in which basic substances were almost completely removed, the mass average molecular weight and the alkali dissolution rate were almost as standard values. Moreover, the sensitivity of the photosensitive resin composition also became nearly standard value, and heat resistance and resolution were also favorable. In addition, about the result of the resolution of Example 3, it can be said that it is a favorable result similarly to the case where the cresol of a chemical synthetic product is used instead of the classification cresol.

In contrast, in Comparative Examples 1 and 2 in which novolak resins were prepared using the untreated 1 fractionation cresol, the mass average molecular weight and the alkali dissolution rate were greatly deviated from the standard values. Moreover, the sensitivity of the photosensitive resin composition also deviated significantly from the standard value, and heat resistance and resolution were inferior to Examples 1 and 2.

In addition, in Comparative Examples 3 and 4 in which the amount of the acid catalyst was increased three times as compared to Comparative Examples 1 and 2 to produce a novolak resin, the mass average molecular weight and the alkali dissolution rate were almost as standard values, but the sensitivity of the photosensitive resin composition was lower than the standard value. It greatly deviated, and heat resistance and resolution were inferior to Examples 1 and 2.

In addition, Comparative Example 5 in which a novolak resin was prepared using a fractionated cresol of untreated 2, and Comparative Example 6 in which a novolak resin was produced different from Comparative Examples 1 and 2 using a fractionated cresol of untreated 1 were used. In Comparative Example 7 in which a novolak resin was produced, the mass average molecular weight and the alkali dissolution rate were largely deviated from the standard value.

Claims (5)

As a purification method of cresols used for manufacture of the novolak resin for photosensitive resin compositions,
A removal step of removing basic substances in the fractionated cresol obtained by tar distillation,
In this removal step, the fractionated cresol is washed with an aqueous solution of hydrochloric acid, or hydrochloric acid is added to the fractionated cresol, and then distilled again.
Purifying method characterized in that the content of pyridine and 2-methyl pyridine present in the fractionated cresol is removed to be less than 2 ppm each. As a manufacturing method of the novolak resin for the photosensitive resin composition,
A reaction step of reacting cresols with aldehydes and / or ketones in the presence of a catalyst,
Said cresol contains the refined cresol refine | purified by the purification method of Claim 1, The manufacturing method characterized by the above-mentioned. The method according to claim 2,
In the said reaction process, the manufacturing method which makes the said cresol, phenols other than this cresol, and the said aldehyde and / or the said ketone react. delete delete