JP6063740B2 - NOVOLAC RESIN, PROCESS FOR PRODUCING THE SAME, AND USE THEREOF - Google Patents

Description

  The present invention relates to a novolak resin (novolak-type phenol resin) that has good flexibility, heat resistance, solubility, and the like and can be suitably used for various applications, and uses thereof.

Novolac resins are used in various applications such as epoxy resin curing agents, raw materials for epoxidation to obtain epoxidized novolac resins, and alkali-soluble resins for positive photoresist compositions.
For example, an epoxy resin composition using a novolak resin as a curing agent has good workability, and the cured product has excellent characteristics, so that the fields such as electrical / electronic parts, structural materials, adhesives, paints, etc. Used in. However, for example, in the electrical and electronic fields such as semiconductor encapsulants and laminates, the reflow temperature has become higher due to the use of lead-free solder, so semiconductor packages such as laminates, interlayer insulating materials, and encapsulating materials are used. Higher heat resistance is required for the epoxy resin composition used compared to conventional products. In addition, as a countermeasure to environmental problems, flame resistance (flame resistance) is improved without using halogens that may generate dioxins during combustion or antimony or other flame retardants that are suspected of causing carcinogenicity. It is demanded. Furthermore, when the epoxy resin composition is used as a matrix material or an interlayer insulating material for a laminate, the epoxy resin composition is required to be soluble in a solvent in order to use the epoxy resin composition as a varnish uniformly dissolved in a solvent. Yes.

In addition, positive photoresist compositions in which novolak resin is used as an alkali-soluble resin have a wide variety of patterns, for example, from a fine line width of about 0.3 μm to a large line width of about several tens to several hundred μm. It can be formed on the substrate surface. However, in the fields of semiconductor manufacturing and LCDs where positive photoresist compositions are used, the line widths of patterns to be formed are becoming increasingly finer as technology such as TFT and STN advances, In a fine TFT display element, a design dimension of a line width is being requested to a level of several μm.
Incidentally, in the field of flexible printed wiring boards such as cellular phones, negative dry film photoresists are widely used. The resolution of this dry film photoresist is low, and the line width is about 30 to 300 μm. On the other hand, the positive photoresist composition has high resolution, but when it is going to be made into a dry film, it is difficult to make it into a roll product because the film quality is brittle and lacks flexibility. Is not easy. For this reason, a positive dry film photoresist has not been put into practical use. That is, positive photoresists are required to have improved flexibility.

Patent Document 1 discloses a phenol novolak resin having a chemical structure obtained by crosslinking (bonding) phenols with a biphenyldiyldimethylene group and a methylene group.
Patent Document 2 shows high flexibility and enables high sensitivity and high resolution by condensation polymerization of methylphenols and dialdehydes containing at least one of glutaraldehyde and adipaldehyde. It has been proposed to obtain phenolic resins for photoresist compositions.
Patent Document 3 relates to a positive photosensitive resin laminated sheet and a method for producing the same. This document describes the phenols and aldehydes constituting the novolac type phenol resin, and many compounds are exemplified.

International Publication No. 2007/026553 International Publication No. 2010/050592 JP 2006-267660 A

However, Patent Document 1 does not necessarily fully disclose a specific mode for obtaining higher heat resistance, solubility, and flexibility.
In addition, although the novolac type phenol resin of Patent Document 2 is improved in flexibility, it cannot be said that the flexibility has been sufficiently improved as a photoresist composition. There is room for improvement.
Furthermore, Patent Document 3 intends to solve the brittleness of the film quality of the novolak-type phenol resin by means such as laminating a cushion layer, and examines the chemical composition of the novolak-type phenol resin. It does not improve the brittleness of the film quality. Therefore, the chemical composition of the novolac type phenol resin is not described in the examples.
The present invention has been made in view of the above problems, and has good flexibility, heat resistance, solubility, etc., and can be suitably used for various applications (novolak-type phenol resin). , And its use.

The present invention relates to the following matters.
1. A novolak resin containing a compound represented by the following general formula (1).

Here, in the general formula (1), each A is independently composed of a monovalent or divalent group represented by the following general formula (2-1) or general formula (2-2), and each B is independently It consists of a divalent group represented by the following general formula (3-1) or general formula (3-2), n is an integer of 0 to 100,
Ratio [general formula (2-1) / general formula (2-2)] of general formula (2-1) and general formula (2-2) contained in the resin is 10/90 to 90/10 The ratio of the general formula (3-1) to the general formula (3-2) [general formula (3-1) / general formula (3-2)] is 10/90 to 90/10.

2. 2. An epoxidized novolac resin obtained by epoxidizing the novolak resin according to item 1.

3. An epoxy resin composition comprising at least one of the novolak resin according to Item 1 and the epoxidized novolak resin according to Item 2.
4). Item 4. The epoxy resin composition according to Item 3, wherein the obtained cured product has a glass transition temperature of 160 ° C or higher.
5. Item 5. The epoxy resin composition according to Item 3 or 4, further comprising a solvent, wherein the resin component is uniformly dissolved in the solvent.

6). A cured product obtained by curing the epoxy resin composition according to any one of Items 3 to 5.

7). A laminate comprising a matrix resin formed using the epoxy resin composition according to Item 5.

8). 2. The novolak resin according to item 1, which contains a novolak resin having a weight average molecular weight of 6000 or more and less than 30,000.

9. A method for producing a novolak resin, comprising subjecting phenols represented by the following general formulas (4) and (5) to a condensation reaction between a compound represented by the following general formula (6) and formaldehyde.

Here, q represents an integer of 2 to 3.

Here, R ¹ represents an alkyl group having 1 to 6 carbon atoms, and p represents an integer of 1 to 3.

Here, Y represents a halogen atom, an alkoxy group, or a hydroxyl group.
10. A method for producing a novolak resin, comprising subjecting a phenol represented by the general formula (4) and the following general formula (7) to a condensation reaction with the compound represented by the general formula (6).

Here, R ¹ represents an alkyl group having 1 to 6 carbon atoms, and p represents an integer of 1 to 3.

11. A step of subjecting the phenol represented by the general formula (4) and the compound represented by the general formula (6) to a condensation reaction, then, the reaction product obtained in the step, and the general formula ( The method for producing a novolak resin according to Item 10, comprising a step of subjecting the phenol represented by 7) to a condensation reaction.

  According to the present invention, a novolac resin (novolak-type phenol resin) having good flexibility, heat resistance, solubility and the like can be obtained. This novolak resin can be suitably used as a raw material for the epoxidized novolac resin by utilizing its characteristics. Further, by using this novolac resin or epoxidized novolac resin, an epoxy resin composition excellent in heat resistance and solubility, a cured product comprising the composition, and a laminate in which a matrix resin is formed by the composition are suitably used. Can be obtained. Furthermore, a photoresist composition with improved flexibility can be suitably obtained by adopting it as an alkali-soluble resin.

  The novolak resin (novolak-type phenol resin) of the present invention is represented by the general formula (1). That is, divalent or trivalent phenols (structure) having no substituent and monovalent phenols (structure) having at least one alkyl group as a substituent are represented by a biphenyldiyldimethylene group and a methylene group. Ratio of divalent or trivalent phenols (structure) having a crosslinked (bonded) chemical structure and having no substituent and monovalent phenols (structure) having at least one alkyl group as a substituent [ Divalent or trivalent phenol structure / monovalent phenol structure] is 10/90 to 90/10, and the ratio of biphenyldiyldimethylene group to methylene group [biphenyldiyldimethylene group / methylene group] is 10/90. 90-90 / 10.

The novolak resin of the present invention can be suitably obtained by two production methods depending on the type of raw material used.
The first production method is characterized in that the phenols represented by the general formula (4) and the general formula (5) are subjected to a condensation reaction with the compound represented by the general formula (6) and formaldehyde.

  The phenol represented by the general formula (4) is a divalent or trivalent polyhydric phenol compound having no substituent, and examples of the divalent phenol compound include catechol, resorcin, hydroquinone, and the like. Examples of the trivalent phenol compound include pyrogallol and phloroglucinol. Of these polyhydric phenol compounds not having a substituent, resorcin is preferable from the viewpoint of easy availability and high reactivity. These polyhydric phenol compounds may be used alone or in combination of two or more.

  The phenol represented by the general formula (5) is a monovalent phenol compound having 1 to 3 alkyl groups having 1 to 6 carbon atoms as substituents. For example, m-cresol, p-cresol, o-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2 , 3,5-trimethylphenol, 2,3,6-trimethylphenol, 4-t-butylcatechol and the like can be preferably mentioned. Of these phenol compounds having 1 to 3 alkyl groups having 1 to 6 carbon atoms, p-cresol is preferable because of easy control of the structure.

Examples of the compound containing the biphenyldiyldimethylene structure represented by the general formula (6) include 4,4′-bis (halogenomethyl) biphenyl, 2,4′-bis (halogenomethyl) biphenyl, and 2,2′-. Preferred examples include bis (halogenomethyl) biphenyl, 4,4′-bis (alkoxymethyl) biphenyl, 2,4′-bis (alkoxymethyl) biphenyl, 2,2′-bis (alkoxymethyl) biphenyl, and the like. it can. Furthermore, as a compound containing the biphenyldiyldimethylene structure represented by the general formula (6), 4,4′-bis (hydroxymethyl) biphenyl, 2,4′-bis (hydroxymethyl) biphenyl, 2,2 ′ -Bis (hydroxymethyl) biphenyl etc. can be mentioned suitably.
Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferable. Further, the alkoxy group is not particularly limited, but an aliphatic alkoxy group having 1 to 6 carbon atoms is preferable. Specific examples include a methoxy group and an ethoxy group.
Preferable specific compounds include 4,4′-bis (chloromethyl) biphenyl, 4,4′-bis (methoxymethyl) biphenyl, and 4,4′-bis (ethoxymethyl) biphenyl.
These compounds containing a biphenyldiyldimethylene structure represented by the general formula (6) may be used singly or as a mixture of plural kinds.

  In the present invention, the form of formaldehyde is not particularly limited, and a formaldehyde aqueous solution and a polymer that decomposes in the presence of an acid such as paraformaldehyde and trioxane to formaldehyde can also be used. A formaldehyde aqueous solution that is easy to handle is preferable, and a 42 mass% formaldehyde aqueous solution that is commercially available can be used as it is.

  The second production method is characterized in that the phenols represented by the general formula (4) and the general formula (7) are subjected to a condensation reaction with the compound represented by the general formula (6).

The phenols represented by the general formula (4) and the compound containing the biphenyldiyldimethylene structure represented by the general formula (6) are as described above.
The phenol represented by the general formula (7) is a phenol compound having at least one alkyl group having 1 to 6 carbon atoms and two hydroxymethyl groups as substituents, preferably 2,6 -Phenols having at least one alkyl group and two hydroxymethyl groups, such as dimethylol-p-cresol and other bishydroxymethyl-cresols.
In the present invention, the phenol represented by the general formula (7) may be a commercially available product, but a synthesized product can also be suitably used. As an example of the synthesis method, a phenol compound having at least one alkyl group having 1 to 6 carbon atoms as a substituent and formaldehyde is used at a molar ratio [formaldehyde / phenol compound] of 2 or more and a base such as sodium hydroxide. There is a method of reacting in the presence of a neutral catalyst. Purification can be performed by a method such as washing with water after neutralization with an acidic substance.

In the method for producing a novolak resin of the present invention, the condensation reaction is suitably performed using an acid catalyst. The acid catalyst is not particularly limited, and known ones such as organic sulfonic acids such as benzenesulfonic acid, paratoluenesulfonic acid and methanesulfonic acid, organic carboxylic acids such as oxalic acid, and inorganic acids such as hydrochloric acid and sulfuric acid may be used alone or Two or more types can be used in combination, but sulfuric acid, succinic acid or paratoluenesulfonic acid is particularly preferable. The amount used is about 0.01 to 1% by weight with respect to the phenols as raw materials. There is no particular difference between the one-stage condensation reaction and the two-stage condensation reaction described below. For example, in the case of oxalic acid, about 0.3 to 1.0% by mass, in the case of sulfuric acid, about 0.05 to 0.1% by mass, and in the case of paratoluenesulfonic acid, about 0.01 to 0.3% by mass It is good to use.
When a novolac resin is used in the photoresist composition, it is preferable that the acid catalyst is as small as possible. If the acid catalyst remains in the resin, the characteristics as a photoresist may be adversely affected. Or it is preferable to neutralize an acid catalyst using an inorganic alkali.
The reaction temperature of the condensation reaction is usually 50 to 200 ° C, preferably 70 to 180 ° C, more preferably 80 to 170 ° C. If the temperature is lower than 50 ° C., the reaction is difficult to proceed. If the temperature is higher than 200 ° C., it becomes difficult to control the reaction, so that it may be difficult to easily obtain the target novolak resin.

In the condensation reaction, an organic solvent that does not affect the reaction can be suitably used as necessary. These organic solvents include propylene glycol monomethyl ether, diethylene glycol dimethyl ether, ethers such as 1,2-dimethoxyethane, 1,2-diethoxyethane; esters such as propylene glycol monomethyl ether acetate; cyclics such as tetrahydrofuran and dioxane. And ethers. The amount of these organic solvents used is usually 10 to 1000 parts by mass per 100 parts by mass of the reaction raw material.
Moreover, although the reaction time of a condensation reaction is based also on reaction temperature, it is 0.1 to 20 hours normally. The reaction pressure is usually carried out under normal pressure, but it can also be carried out under slight pressure or reduced pressure.

As a post-treatment after completion of the condensation reaction, preferably, a base is added to neutralize the acid catalyst to stop the reaction, and then water is added to remove the acid catalyst and washed with water. preferable.
The base for neutralizing the acid catalyst is not particularly limited, and any base that neutralizes the acid catalyst and forms a salt that is soluble in water can be used. Examples include inorganic bases such as metal hydroxides and metal carbonates, and organic bases such as amines and organic amines. Specific examples of the inorganic base include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, and calcium carbonate. Specific examples of organic base amines or organic amines include ammonia, trimethylamine, triethylamine, diethylamine, and tributylamine. Preferably organic amines are used. The amount used depends on the amount of the acid catalyst, but it is preferable to neutralize the acid catalyst so that the pH in the reaction system falls within the range of 4-8.
The amount and number of times of washing water are not particularly limited, but the number of times of washing to remove the acid catalyst to an amount that does not affect actual use, including an economic viewpoint, is preferably about 1 to 5 times. The washing temperature is not particularly limited, but is preferably 40 to 95 ° C. from the viewpoint of the efficiency of removing the catalyst species and the workability. If the resin and the washing water are poorly separated during washing, it is effective to add a solvent that lowers the viscosity of the resin and raise the washing temperature. The solvent species is not particularly limited, and any solvent can be used as long as it dissolves the novolak resin and lowers the viscosity.
After removing the acidic catalyst, the temperature of the reaction system is usually raised to 130 to 230 ° C., for example, volatile components such as unreacted raw materials and organic solvents remaining in the reaction mixture under a reduced pressure of 20 to 50 torr. The desired novolak resin can be suitably separated and recovered by distilling off.

  In the method for producing the novolak resin of the present invention, all the raw materials to be used may be subjected to a condensation reaction at the same time (in one stage), but it is preferable to appropriately select the raw materials to be used and cause the condensation reaction stepwise. . That is, in the first production method, the phenol compound represented by the general formula (4) and the compound represented by the general formula (6) are subjected to a condensation reaction, and then obtained in the above step. It is preferable to carry out by a two-stage condensation reaction comprising the step of subjecting the reaction product to a condensation reaction between the phenol represented by the general formula (5) and formaldehyde. Further, in the second production method, the phenol compound represented by the general formula (4) and the compound represented by the general formula (6) are subjected to a condensation reaction, and then obtained in the above step. It is preferable to carry out by a two-stage condensation reaction comprising the step of subjecting the reaction product and the phenol represented by the general formula (7) to a condensation reaction.

When the condensation reaction is performed by a two-stage condensation reaction, a resin segment composed of a structural unit crosslinked with a biphenyldiyldimethylene structure and a resin segment composed of a structural unit crosslinked with a methylene structure can be suitably controlled. it can. In other words, the degree of polymerization of each resin segment can be easily adjusted, and the molecular weight distribution can be further narrowed, so that the molecular weight of the entire resin can be easily controlled. For this reason, conducting the condensation reaction by a two-stage condensation reaction is suitable for obtaining the novolak type phenol resin of the present invention.
On the other hand, when a one-stage condensation reaction is performed, since various reactive raw materials react simultaneously, the molecular weight is difficult to control, and problems such as gelation often occur.
When a one-stage condensation reaction is carried out by the first production method, a novolak resin having a random structure can be obtained. On the other hand, according to the two-stage condensation reaction as compared with the one-stage condensation reaction, a more novolak-type phenol resin can be obtained by each of the resin segments. In particular, when a two-stage condensation reaction is carried out in the second production method, a novolak resin having a block structure is obtained. This block-structured novolak resin has a chemical structure derived from the phenols of the general formula (7) as a raw material (units derived from the phenols of the general formula (5) are cross-linked (bonded) with two methylene groups. The unit derived from the phenol of the general formula (5) does not have a chemical structure in which one biphenyldiyldimethylene group and one methylene group are cross-linked (bonded). The molecular structure is clearly different from the novolak resin obtained by the first production method.
The novolak resin of the present invention may be a novolak resin having a random structure or a novolak resin having a block structure. In any case, since properties such as flexibility, heat resistance and solubility are good, it can be suitably used for various applications. In the present invention, there is no particular limitation. However, when a novolak resin having a block structure is used for the photoresist composition, higher flexibility can be achieved when patterning. preferable.

  When performing the two-stage condensation reaction, after the condensation reaction of the first step is completed, the raw material of the second step can be added to the reaction mixture, and the condensation reaction of the second step can be suitably performed. In the present invention, although not limited, after the condensation reaction in the first step is completed, unreacted raw materials and by-products remaining in the reaction mixture are removed under a reduced pressure of, for example, 20 to 50 torr to remove the first step. The novolak resin (in the intermediate stage) obtained by the condensation reaction is once isolated, and then the isolated (in the intermediate stage) novolak resin and the remaining reaction raw materials are mixed again to perform the condensation reaction in the second step. The reaction in each step can be controlled more precisely, and the molecular weight can be easily adjusted without causing problems such as gelation.

The novolak resin of the present invention is represented by the general formula (1). B represents a divalent group (biphenyldiyldimethylene group) represented by the general formula (3-1) and a divalent group (methylene group) represented by the general formula (3-2). Consists of. The ratio of the general formula (3-1) to the general formula (3-2) [general formula (3-1) / general formula (3-2)] is 10/90 to 90/10, preferably 20 / 80 to 80/20, more preferably 40/60 to 60/40. The novolak resin of the present invention having this ratio can have high flexibility, high heat resistance, and good solubility.
In the novolak resin of the present invention, A is a monovalent (in the case of a molecular end) or divalent group (in the case of a molecule) represented by the general formula (2-1), and the general formula (2). -2) and a divalent group (in the case of a molecule) or a divalent group (in the case of a molecule). The ratio of the general formula (2-1) and the general formula (2-2) [general formula (2-1) / general formula (2-2)] is 10/90 to 90/10, preferably Is 20/80 to 80/20, more preferably 35/65 to 65/35. The novolac resin of the present invention preferably has high flexibility, high heat resistance, and good solubility by this ratio.

In the condensation reaction for producing the novolak resin of the present invention, the resulting novolak resin satisfies the composition of A and B defined by the general formula (1) and the target weight average molecular weight. Usage ratio and reaction conditions are adjusted. In the two-stage condensation reaction, the (intermediate stage) novolac type phenol resin obtained in the first-stage condensation reaction is analyzed, and based on the results, the ratio of reaction raw materials and reaction conditions in the second stage are determined. Further fine adjustment.
Of course, the ratio of the raw materials of the unit to be introduced into the novolac resin is increased, and the ratio of the phenols and other raw materials used is appropriately adjusted depending on the target weight average molecular weight. These are appropriately adjusted in consideration of the reactivity of each raw material and the reaction conditions employed. For those skilled in the art, the adjustment method is self-explanatory, but can be easily found by conducting preliminary experiments if necessary.

  Usually, in the case of the first production method, a crosslinking component comprising the phenols represented by the general formula (4) and the general formula (5), the compound represented by the general formula (6), and formaldehyde The molar ratio [phenols / crosslinking component] is about 40/60 to 95/5. Further, in the case of the second production method, use of a phenol represented by the general formula (4) and the general formula (7) and a crosslinking component comprising the compound represented by the general formula (6) The molar ratio [phenols / crosslinking component] is about 50/50 to 90/10.

The novolak resin represented by the general formula (1) of the present invention preferably has a softening point of 60 to 180 ° C, more preferably 70 to 170 ° C. When the softening point is less than 60 ° C., blocking or the like is likely to occur, and when it exceeds 170 ° C., there may be a problem in handling properties.
The weight average molecular weight of the novolak resin of the present invention is not particularly limited. Usually, it is 500-30000, preferably 500-20000, more preferably about 500-10000. When used in a photoresist composition, it is preferably 6000 to less than 30000, more preferably 6000 to 20000, still more preferably 6000 to 15000, and particularly preferably 6000 to 12000 from the performance and handling properties of the photoresist composition. is there. If the weight average molecular weight is less than 6000, the sensitivity may be too high, and if it is 30000 or more, the sensitivity may be low.

The epoxidized novolac resin of the present invention can be obtained by epoxidizing the novolak resin represented by the general formula (1) of the present invention.
The method of epoxidation is not particularly limited, but a conventionally known glycidyl etherification reaction can be suitably employed. That is, it can be obtained by glycidyl etherification in the presence of an epihalohydrin and an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, for example, at 10 to 120 ° C.

  As epihalohydrins used in the reaction, substituted or unsubstituted epihalohydrins such as epichlorohydrin, α-methylepichlorohydrin, γ-methylepichlorohydrin, epibromohydrin can be used, but they are easily available industrially. From the viewpoint of good reactivity with hydroxyl groups, it is preferable to use epichlorohydrin.

  The amount of the epihalohydrins used is not particularly limited and can be appropriately selected. Usually, an excess amount is used with respect to the hydroxyl group of the novolak resin. From the viewpoint of obtaining a low melt viscosity epoxy resin, the amount of epichlorohydrin used can be 3.0 to 20 mol, preferably 3.0 to 10 mol, per 1 mol of the hydroxyl group of the novolak resin.

  The alkali metal hydroxide used for the reaction may be a solid or an aqueous solution thereof. When using an aqueous solution, water and epihalohydrin are continuously flowed out of the reaction system under reduced pressure or normal pressure while adding an aqueous solution of alkali metal hydroxide to the reaction system to remove moisture. Then, a method of continuously returning the epihalohydrins into the reaction system can be employed. The usage-amount of an alkali metal hydroxide can be 0.8-2.0 mol with respect to 1 mol of hydroxyl groups of a novolak resin, Preferably it is 0.9-1.3 mol.

  In the reaction, it is preferable in the progress of the reaction that alcohols such as methanol, ethanol and isopropyl alcohol, aprotic polar solvents such as dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran and dioxane are present.

  The epoxidized novolac resin is obtained by adding a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride, etc. to the novolac resin and epihalohydrin as a catalyst, and obtaining the halohydrin obtained by these reactions. It can also be obtained by adding an alkali metal hydroxide to the etherified product and closing the ring.

  Although reaction temperature in that case is not specifically limited, Usually, it is 30-90 degreeC, Preferably it is 35-80 degreeC. Although the reaction time is affected by the reaction temperature, it is usually 0.5 to 10 hours, preferably 1 to 8 hours.

  The epoxidized novolak resin can be obtained by distilling off the epihalohydrin, the solvent, and the like, under heating and reduced pressure, with or without washing the reaction mixture of the glycidyl etherification reaction. Furthermore, in order to reduce hydrolyzable chlorine and the like, the obtained crude epoxidized novolak resin is dissolved in a solvent such as toluene and methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide is added and reacted. The ring closure of the epoxy ring may be ensured. After completion of the reaction, the produced salt is removed by filtration, washing with water, etc., and the solvent is distilled off under reduced pressure by heating, whereby a purified product of the epoxidized novolak resin can be suitably obtained.

  Before and after the glycidyl etherification reaction, the phenols introduced into the resin are usually not eliminated, so that the chemical structure of the starting novolak resin is generally maintained before and after the glycidyl etherification reaction.

  The epoxy resin composition of the present invention includes a novolak resin represented by the general formula (1) of the present invention and an epoxidized novolak resin obtained by epoxidizing the novolak resin represented by the general formula (1) of the present invention. It contains any one or more resins.

When the novolak resin represented by the general formula (1) is included as a curing agent, examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol aralkyl type epoxy resin, and cresol novolak type epoxy resin. 2 epoxy groups in the molecule, such as phenol novolac type epoxy resin, triphenylmethane type epoxy resin, biphenyl type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, halogenated epoxy resin, etc. Examples thereof include epoxy resins having at least one. Moreover, as the epoxy resin, an epoxidized novolak resin obtained by epoxidizing the novolak resin represented by the general formula (1) of the present invention can also be used. These epoxy resins may be used alone or in combination of two or more.
Among these, a biphenyl type epoxy resin, a phenol aralkyl type epoxy resin, a triphenylmethane type epoxy resin, a cresol novolac type epoxy resin, and the like are particularly suitable for improving heat resistance and flame resistance.

  In the case of an epoxy resin composition containing an epoxidized novolak resin obtained by epoxidizing the novolak resin represented by the general formula (1), the novolak resin of the present invention can be suitably used as a curing agent, Curing agents used in ordinary epoxy resin compositions, for example, curing agents such as amine-based curing agents, amide-based curing agents, and acid anhydride-based curing agents can be suitably used alone or in combination.

In the epoxy resin composition of the present invention, the addition ratio of the epoxy resin is such that the number of phenolic hydroxyl groups in the curing agent (number of hydroxyl equivalents) and the number of epoxy groups in the epoxy resin (epoxy equivalents) are about equal. Is most preferred. The ratio of the number of hydroxyl equivalents of the curing agent to the number of epoxy equivalents of the epoxy resin [number of hydroxyl equivalents / number of epoxy equivalents] is preferably in the range of about 0.5 to 2.0. A range of about 2 is preferred. Outside this range, the curing reaction may not proceed sufficiently, and the effects of the present invention may not be exhibited due to reasons such as unreacted curing agent or epoxy resin remaining.
In the epoxy resin composition of the present invention, a single epoxy resin or a curing agent may be used, but a plurality of types of epoxy resins and curing agents may be used in combination.
Even when the novolak resin of the present invention is used as a curing agent, various epoxy resin curing agents can be used in combination depending on the purpose of use of the composition. As the other curing agent, for example, a normal epoxy resin curing agent such as an amine curing agent, an amide curing agent, and an acid anhydride curing agent can be suitably used.

  In the epoxy resin composition of the present invention, the ratio of the novolak resin represented by the general formula (1) in the curing agent is not particularly limited, but is higher in order to improve the heat resistance and combustion resistance of the cured product. The proportion is preferably 30% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass, and particularly preferably 100% by mass.

  In the epoxy resin composition of the present invention, the ratio of the epoxidized novolak resin obtained by epoxidizing the novolak resin represented by the general formula (1) in the epoxy resin is not particularly limited, but the heat resistance of the cured product is not limited. In order to improve the combustion resistance, a higher ratio is preferable, 30% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass, and particularly preferably 100% by mass.

The epoxy resin composition of the present invention preferably further contains a solvent, and it is preferable that a novolak resin, an epoxy resin, and the like are uniformly dissolved in the solvent.
If the epoxy resin composition excellent in heat resistance and combustion resistance of the resulting cured product can be made into a uniform varnish solution at a high concentration, it can be suitably used as a matrix material or an interlayer insulating material for laminates. .

The solvent is not particularly limited as long as it can dissolve the epoxy resin composition, but preferably an organic solvent used when varnishing a matrix material or an interlayer insulating material of a normal laminated board is preferably used. it can. For example, ketones such as methyl ethyl ketone, acetone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, ethers such as propylene glycol monomethyl ether, amides such as dimethylformamide and dimethylacetamide, sulfoxides such as dimethyl sulfoxide, γ-butyllactone, etc. Preferable examples include lactones, pyrrolidones such as N-methylpyrrolidone, and aromatic hydrocarbons such as toluene and xylene. Among these, methyl ethyl ketone and dimethylformamide are particularly preferable. These solvents can be used alone or in combination of two or more.
When the epoxy resin composition of the present invention is varnished, the concentration of the resin component is preferably about 10 to 90% by mass, and the solution viscosity is about 1 to 5000 cP at 30 ° C. .

In the epoxy resin composition of this invention, the other component used with a normal epoxy resin composition can be used suitably according to the use.
For example, a curing accelerator for curing an epoxy resin with a phenol resin can be used. Suitable examples of the curing accelerator include known organic phosphine compounds and their boron salts, tertiary amines, quaternary ammonium salts, imidazoles and tetraphenyl boron salts. Among these, triphenylphosphine is preferable from the viewpoints of curability and moisture resistance. In addition, when high fluidity is required by the epoxy resin composition, a heat-latent curing accelerator that exhibits activity by heat treatment is preferable, and tetraphenylphosphonium, tetraphenylborate, and the like are particularly preferable. More preferred are phenylphosphonium derivatives. The addition amount of a hardening accelerator may be the same as the ratio in a well-known epoxy resin composition.

Furthermore, fillers such as inorganic fillers can also be suitably used. As the inorganic filler, amorphous silica, crystalline silica, alumina, calcium silicate, calcium carbonate, talc, mica, barium sulfate and the like can be used, and amorphous silica and crystalline silica are more preferable. Although there is no restriction | limiting in particular as a particle size of an inorganic filler, When a filling rate is considered, it is desirable that it is 0.01-150 micrometers.
Although there is no restriction | limiting in particular about the mixture ratio of an inorganic filler, It is 70-95 mass% in an epoxy resin composition, Preferably it is 75-90 mass%, More preferably, it is 80-90 mass%. If the proportion of the inorganic filler is outside the above range, the water absorption rate of the cured product of the epoxy resin composition increases, which is not preferable. Moreover, when there is too much ratio of an inorganic filler, there exists a possibility that fluidity | liquidity may be impaired.

  Furthermore, a release agent, a coloring agent, a coupling agent, a flame retardant, etc. can be added to the epoxy resin composition of the present invention or reacted in advance if necessary. Moreover, the mixing | blending ratio of these additives may be the same as the ratio in a well-known epoxy resin composition. In addition to this, the epoxy resin composition of the present invention contains a nitrogen-based flame retardant such as melamine or an isocyanuric acid compound, or a phosphorus-based flame retardant such as red phosphorus, a phosphoric acid compound or an organic phosphorus compound as a flame retardant aid. As appropriate.

The epoxy resin composition of the present invention contains the novolak resin and / or the epoxidized novolak resin of the present invention, and includes an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and other additives such as a mixer. Can be mixed uniformly, kneaded in a molten state using a kneader such as a heating roll, a kneader, or an extruder, cooled, and pulverized as necessary.
Although such an epoxy resin composition is not limited, it can be suitably used as a semiconductor sealing material.
In addition, the epoxy resin composition of the present invention contains a novolak resin and / or an epoxidized novolak resin of the present invention, an epoxy resin, a curing agent, a curing accelerator, an inorganic filler in a solvent such as methyl ethyl ketone, propylene glycol monomethyl ether, and dimethylformamide. A varnish solution in which at least the resin component is uniformly dissolved in a solvent can be produced by adding an agent and other additives and heating or stirring as necessary.
The varnished epoxy resin (solution) composition is not limited, but can be suitably used as a matrix material or an interlayer insulating material of a laminated board.
As for the epoxy resin composition of this invention, after drying a solvent as needed, a hardened | cured material can be obtained suitably by heat-processing.

The cured product of the present invention can be obtained by curing the epoxy resin composition of the present invention.
The heat treatment conditions for obtaining a cured product depend on the presence or absence of a curing catalyst and a curing accelerator, and the amount of addition thereof, but are usually about 100 to 300 ° C., preferably about 120 to 200 ° C. It is preferable to perform the heat treatment for about 10 minutes.
The epoxy resin composition of the present invention can be suitably used as a sealing material for sealing a semiconductor element. In that case, for example, after installing a lead frame or the like on which the semiconductor element is mounted in a metal cavity, the epoxy resin composition is molded by a molding method such as transfer molding, compression molding, injection molding, etc. A semiconductor device can be suitably obtained by curing the epoxy resin composition by performing a heat treatment or the like at a moderate temperature.

The epoxy resin composition of the present invention is preferably uniformly dissolved in a solvent such as methyl ethyl ketone to form a varnish, and the varnish solution is applied to a porous glass substrate such as glass, glass fiber, paper, aramid fiber, etc. Alternatively, a prepreg for a printed circuit board can be produced by impregnation and then heat treatment (semi-curing). Furthermore, the laminated board which formed the matrix resin using the epoxy resin composition of this invention by laminating | stacking several sheets of the obtained prepreg for printed circuit boards, performing a heat processing, pressurizing as needed, and making it harden | cure Can be suitably manufactured.
In addition, a laminate or prepreg is a metal-clad laminate obtained by superposing a metal foil on one or both sides and performing heat treatment (for example, heat treatment at 180 ° C., 4 MPa for 60 minutes) while applying pressure as necessary. Can be obtained. This metal-clad laminate can be suitably used as a printed wiring board by forming a circuit pattern by etching.
Furthermore, the epoxy resin composition of the present invention is preferably uniformly dissolved in a solvent such as methyl ethyl ketone to form a varnish, and the varnish solution is uniformly applied to a support surface such as a PET film or copper foil using a die coater or the like. The laminated film having a resin layer can be suitably used as an interlayer insulating material by applying to the substrate and drying the obtained coating film by heating.

  The cured product of the present invention has excellent flexibility and high heat resistance. Regarding the heat resistance, the glass transition temperature is preferably 160 ° C. or higher, more preferably 180 ° C. or higher, and further preferably 200 ° C. or higher.

The novolak resin of the present invention can be suitably used for a photoresist composition that exhibits particularly high flexibility and has high resolution, a high residual film ratio, and high heat resistance.
The photoresist composition of the present invention is not limited, but preferably contains 2 to 40% by mass, more preferably 5 to 25% by mass of the novolak resin of the present invention. The resist composition of the present invention further contains a photosensitizer. As the photosensitizer, a conventionally known photosensitizer can be suitably used as a photosensitizer for a photoresist containing a novolak resin. For example, a quinonediazide compound having a quinonediazide group is preferable, and a 1,2-quinonediazide compound or a derivative thereof is particularly preferable. By using a quinonediazide compound, the exposed portion has a higher alkali dissolution rate due to the dissolution promoting effect, and conversely, the non-exposed portion has a lower alkali dissolution rate due to the dissolution inhibiting effect. Due to the difference, a sharp resist pattern with high contrast can be obtained.

As the quinonediazide compound, known compounds conventionally used in quinonediazide-novolak photoresist compositions can be used. Examples of the compound containing a quinonediazide group include compounds obtained by reacting naphthoquinonediazidesulfonic acid chloride, benzoquinonediazidesulfonic acid chloride, and the like with a compound having a functional group capable of undergoing a condensation reaction with these acid chlorides. preferable. Here, examples of the functional group capable of condensing with acid chloride include a hydroxyl group and an amino group, and a hydroxyl group is particularly preferable. Examples of the compound having a hydroxyl group capable of condensing with acid chloride include hydroquinone, resorcin, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,4,4 '-Trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2 ', 3,4,6'-pentahydroxybenzophenone, etc. Hydroxyphenyl alkanes such as hydroxybenzophenones, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) propane, 4,4 ′ , 3 ", 4" -tetrahydroxy-3,5,3 ', 5'-tetra Examples thereof include tilted triphenylmethane and hydroxytriphenylmethanes such as 4,4 ′, 2 ″, 3 ″, 4 ″ -pentahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane. These may be used alone or in combination of two or more.
Specific examples of naphthoquinone diazide sulfonic acid chloride and benzoquinone diazide sulfonic acid chloride which are acid chlorides include, for example, 1,2-naphthoquinone diazide-5-sulfonyl chloride, 1,2-naphthoquinone diazide-4-sulfonyl chloride and the like are preferable. As mentioned.

  5-50 mass parts is preferable with respect to 100 mass parts of novolak resin, More preferably, the compounding quantity of a photosensitive agent is 10-40 mass parts. If the blending amount of the photosensitizer is less than 5 parts by mass, sufficient sensitivity as a photosensitive tree composition may not be obtained, and if it exceeds 50 parts by mass, a problem of precipitation of components may occur. Therefore, it is not preferable.

  The resist composition of the present invention includes, in addition to the novolak resin and the photosensitizer, stabilizers such as antioxidants, plasticizers, surfactants, adhesion improvers, and dissolution accelerators, which are conventional components of photoresist compositions. , Dissolution inhibitors and the like can be suitably contained.

  The photoresist composition using the novolak resin of the present invention can be formed into a dry film, and is a lithography process in manufacturing a highly integrated semiconductor, a thin film transistor (TFT) for liquid crystal, a flexible display, and a flexible printed wiring. It can be suitably used in a fine processing step such as a plate.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples.

[1] Preparation and evaluation of epoxy resin composition using novolak resin as curing agent [Example 1]
Resorcinol 100 g (0.908 mol), 4,4′-bis (methoxymethyl) biphenyl (hereinafter referred to as 4,4′-BMMB) was placed in a 1000 mL glass flask equipped with a thermometer, a charging / distilling outlet and a stirrer. 82.5 g (0.34 mol), 16 g of propylene glycol monomethyl ether as a solvent, and 0.16 g of paratoluenesulfonic acid as a catalyst were added, and the reaction was performed at a reaction temperature of 110 ° C. for 4 hours. Meanwhile, the methanol produced was distilled off. Thereafter, 98 g of propylene glycol monomethyl ether and 57.3 g (0.34 mol) of 2,6-dimethylol-p-cresol (hereinafter sometimes abbreviated as CDM) were added, and the reaction temperature was 110 ° C. for 4 hours. Reaction was performed. After completion of the reaction, the reaction mixture was cooled to 90 ° C., 0.16 g of triethylamine and 286 g of ion-exchanged water were added, stirred and allowed to stand. The pH of the separated water separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed 4 times. Then, after heating up to 150 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 1 hour, the water | moisture content etc. were removed, and 200 g of novolak resin was obtained.

[Comparative Example 1]
In a 1000 mL glass flask equipped with a thermometer, charging / distilling outlet and stirrer, phenol 470.0 g (5.0 mol), 92% paraformaldehyde 110.9 g (3.4 mol), and catalyst oxalic acid 0.3 g was added and reacted at a reaction temperature of 100 ° C. for 5 hours. After completion of the reaction, unreacted component phenol was removed azeotropically by vacuum-steaming to obtain 329 g of novolak resin.

[Comparative Example 2]
In a glass flask with a capacity of 1000 mL equipped with a thermometer, a charging / distilling outlet and a stirrer, phenol 113.5 g (1.21 mol), 4,4′-BMMB 200 g (0.83 mol), and 50 mass of catalyst % Sulfuric acid (0.14 g) was placed in a four-necked flask and reacted under a nitrogen stream at a reaction temperature of 120 to 135 ° C. for 3.5 hours and further at a reaction temperature of 165 ° C. for 3 hours. It cooled to 95 degreeC after completion | finish of reaction. After cooling, 250 g of pure water at 90 ° C. or higher was added and washed with water. Thereafter, the temperature was raised to 160 ° C., and unreacted phenol was removed by azeotropic distillation under reduced pressure-steaming treatment to obtain 68 g of a novolak resin.

[Comparative Example 3]
In a glass flask having a capacity of 1000 mL equipped with a thermometer, a charging / distilling outlet and a stirrer, 169.2 g (1.8 mol) of phenol, 22 g (0.2 mol) of resorcin, 312.3 g of 4,4′-BMMB ( 1.29 mol) and 0.15 g of 50 wt% sulfuric acid of the catalyst were put into a four-necked flask and reacted under a nitrogen stream at an internal temperature of 120 to 135 ° C. for 3.5 hours and further at 165 ° C. for 3 hours. Cooled to 95 ° C. After cooling, 250 g of pure water at 90 ° C. or higher was added and washed with water. Thereafter, the internal temperature was raised to 160 ° C., and phenol as an unreacted component was removed by azeotropic distillation under reduced pressure-steaming treatment to obtain 143 g of a novolak resin.

The novolak resin obtained in Example 1 and Comparative Examples 1 to 3 and the epoxy resin composition using each novolak resin as a curing agent were analyzed and evaluated.
In addition, evaluation of the epoxy resin composition was performed as follows. That is, each novolak resin was used as a curing agent, Epicoat 828EL (epoxy equivalent 186 g / eq) manufactured by Japan Epoxy Resin Co., Ltd. was used as an epoxy resin, and Cuorazole 2E4MZ manufactured by Shikoku Kasei Co., Ltd. was used as a curing accelerator. An epoxy resin composition in which a resin and an epoxy resin are blended at the same equivalent ratio is heated to 150 ° C., melted and mixed, cast into a mold heated to 150 ° C. after vacuum defoaming, and at 150 ° C. for 5 hours. The cured product of the epoxy resin composition obtained by curing at 200 ° C. for 5 hours was obtained, and the cured product was evaluated.

Moreover, the analysis method of a novolak resin and the evaluation method of an epoxy resin composition are as follows.
≪Weight average molecular weight (GPC measurement method) ≫
Model: HLC-8220 Tosoh Co., Ltd. Column: TSK-GEL H type G2000H × L 4
1 G3000H x L
One G4000H × L Measurement condition: Column pressure 13.5 MPa
Eluent: Tetrahydrofuran (THF) flow rate 1 ml / min
Temperature: 40 ° C
Detector: Spectrophotometer (UV-8020) RANGE 2.56
WAVE LENGTH: 254nm and RI
Injection volume: 100 μmL
Sample concentration: 5 mg / mL
≪Softening point≫
It was carried out by the ring and ball method softening point measurement based on JIS K6910.
≪Hydroxyl equivalent weight≫
The measurement was performed by measuring the hydroxyl group equivalent according to JIS K0070.
≪Solubility≫
It evaluated by the solubility test by the method shown below.
Solvent: Methyl ethyl ketone Dissolution ratio (mass): Phenol novolac resin / Solvent = 50/50
Dissolution condition: Resin and solvent were added to an airtight container and dissolved by stirring at 60 ° C.
Evaluation: Visual observation was performed after dissolution and after standing at room temperature (23 ° C.) for 12 hours. It is possible to obtain a uniform solution by ◯ when the resin is uniformly dissolved and a uniform solution is retained after standing, and when the resin is uniformly dissolved but a part of the resin is deposited after standing. What was not made was set as x.

≪Glass transition temperature (Tg), coefficient of thermal expansion (α) ≫
Sample cast and cured at 150 ° C x 5 hours + 180 ° C x 3 hours is cut into a size of (50 ± 1) x (40 ± 1) x (100 ± 1) (length x width x height; mm) The test piece is set in a measuring apparatus; TMA-60 (manufactured by SHIMADZU), and the temperature is raised to 350 ° C. at a rate of temperature rise of 3 ° C./min in an N ₂ atmosphere. The glass transition temperature (Tg) was obtained. In addition, the thermal expansion coefficient α ₁ in the temperature region below the glass transition temperature and the thermal expansion coefficient α ₂ in the temperature region above the glass transition temperature were measured.
≪Hardened material mechanical properties (elastic modulus, energy, displacement, stress, strain) ≫
Sample cast and cured at 150 ° C x 5 hours + 180 ° C x 3 hours is cut to a size of (75 ± 1) x (6 ± 1) x (4 ± 1) (length x width x thickness; mm) The test piece was used as a test piece, and it was subjected to a compression bending test at room temperature using an autograph (model: AG-5000D manufactured by SHIMADZU), head speed: 10 mm / min, distance between two points; The rate, displacement, stress and strain were determined.

  Tables 1 and 2 show the analysis results of the obtained novolak resin, the composition of the epoxy resin composition, and the evaluation results of the cured product.

[2] Production and Evaluation of Copper Clad Laminate Using Epoxy Resin Composition Materials used in examples relating to the production of copper clad laminate will be described below.
(1) Epoxy resin Bisphenol A type epoxy resin “828EL”: Japan Epoxy Resin Co., Ltd., epoxy equivalent: 186 g / eq
(2) Curing accelerator (curing catalyst)
2-ethyl-4-methylimidazole (2E4MZ): manufactured by Shikoku Chemicals Co., Ltd. (3) solvent (methyl ethyl ketone): manufactured by Wako Pure Chemical Industries, Ltd. (4) glass cloth (non-alkali treated glass cloth) “M7628-105”: Arisawa Manufacturing Co., Ltd. (5) Copper foil (electrolytic copper foil) “CF-T9B-THE”: manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., thickness 35 μ

Below, the evaluation method which concerns on a copper clad laminated board is demonstrated.
≪Heat resistance≫
The glass transition temperature (Tg) was measured at a rate of temperature increase of 3 ° C./min using a dynamic viscoelasticity measuring device (“RSA-G2” manufactured by TA Instruments).

[Example 2]
To 231.2 g of methyl ethyl ketone as a diluting solvent, 131 g of the novolak resin obtained in Example 1, 100 g of bisphenol type epoxy resin, and 0.1 g of 2E4MZ as a curing accelerator were added to form a varnish. % Varnish solution was obtained.
The obtained varnish solution was impregnated with M7628-105 of glass cloth and then dried at 130 ° C. for 15 minutes to obtain a prepreg. 8 sheets of this prepreg were stacked, and CF-T9B-THE of copper foil was stacked on both sides of the prepreg, and pressed using a press machine at a temperature of 170 ° C. and a pressure of 30 kg / cm ² for 15 minutes. After the laminate was taken out of the press, it was further cured at 200 ° C. for 5 hours to obtain a double-sided copper-clad laminate. The evaluation results are shown in Table 3.

[Comparative Examples 4 to 5]
Instead of the novolak resin obtained in Example 1, the novolak resin prepared in Comparative Examples 2 to 3 was used, and the formulation was as shown in Table 3, and the double-sided copper clad laminate was the same as Example 2. Got. The evaluation results are shown in Table 3.

[3] Preparation and evaluation of photoresist composition [Example 3]
Resorcin 100 g (0.908 mol), 4,4′-bis (methoxymethyl) biphenyl 93.2 g (0.385 mol), solvent in a 1000 mL glass flask equipped with a thermometer, charging / distilling outlet and stirrer 14 g of propylene glycol monomethyl ether and 0.14 g of catalyst paratoluenesulfonic acid were added and reacted at a reaction temperature of 110 ° C. for 4 hours. Meanwhile, the methanol produced was distilled off. Thereafter, 98 g of propylene glycol monomethyl ether and 42.13 g (0.256 mol) of 2,6-dimethylol-p-cresol were added, and the reaction was performed at a reaction temperature of 110 ° C. for 4 hours. After completion of the reaction, the reaction mixture was cooled to 90 ° C., 0.14 g of triethylamine and 286 g of ion-exchanged water were added, stirred and allowed to stand. The pH of the separated water separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed 4 times. Then, after heating up to 150 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 1 hour, the water | moisture content etc. were removed, and 200 g of novolak resin was obtained.

Example 4
Resorcinol 100 g (0.908 mol), 4,4′-BMMB 99.0 g (0.409 mol), propylene glycol monomethyl ether as a solvent in a 1000 mL glass flask equipped with a thermometer, charging / distilling outlet and stirrer 15 g and 0.15 g of paratoluenesulfonic acid as a catalyst were added and reacted at a reaction temperature of 110 ° C. for 4 hours. Meanwhile, the methanol produced was distilled off. Thereafter, 105 g of propylene glycol monomethyl ether and 45.82 g (0.273 mol) of 2,6-dimethylol-p-cresol were added and reacted at a reaction temperature of 110 ° C. for 4 hours. After completion of the reaction, the reaction mixture was cooled to 90 ° C., 0.15 g of triethylamine and 292 g of ion-exchanged water were added, stirred and allowed to stand. The pH of the separated water separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed 4 times. Thereafter, the temperature was raised to 150 ° C. and dehydration was performed, followed by vacuum distillation at 30 torr for 1 hour to remove moisture and the like, and 190 g of novolak resin was obtained.

Example 5
Resorcinol 100 g (0.908 mol), 4,4′-BMMB 82.52 g (0.341 mol), propylene glycol monomethyl ether as a solvent, in a 1000 mL glass flask equipped with a thermometer, charging / distilling outlet and stirrer 16 g and 0.16 g of paratoluenesulfonic acid as a catalyst were added and reacted at a reaction temperature of 110 ° C. for 4 hours. Meanwhile, the methanol produced was distilled off. Thereafter, 112 g of propylene glycol monomethyl ether and 57.28 g (0.341 mol) of 2,6-dimethylol-p-cresol were added and reacted at a reaction temperature of 110 ° C. for 4 hours. After completion of the reaction, the mixture was cooled to 90 ° C., 0.16 g of triethylamine and 315 g of ion-exchanged water were added, stirred and allowed to stand. The pH of the separated water separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed 4 times. Thereafter, the temperature was raised to 150 ° C. and dehydration was performed, followed by distillation under reduced pressure at 30 torr for 1 hour to remove moisture and the like to obtain 196 g of a novolac resin.

Example 6
Resorcinol 100 g (0.908 mol), 4,4′-BMMB 85.58 g (0.353 mol), propylene glycol monomethyl ether as solvent in a 1000 mL glass flask equipped with a thermometer, charging / distilling outlet and stirrer 16 g and 0.16 g of paratoluenesulfonic acid as a catalyst were added and reacted at a reaction temperature of 110 ° C. for 4 hours. Meanwhile, the methanol produced was distilled off. Thereafter, 112 g of propylene glycol monomethyl ether and 59.4 g (0.353 mol) of 2,6-dimethylol-p-cresol were added and reacted at a reaction temperature of 110 ° C. for 4 hours. After completion of the reaction, the reaction mixture was cooled to 90 ° C., 0.16 g of triethylamine and 319 g of ion-exchanged water were added, stirred and allowed to stand. The pH of the separated water separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed 4 times. Thereafter, the temperature was raised to 150 ° C. and dehydrated, and then distilled under reduced pressure at 30 torr for 1 hour to remove moisture and the like, and 202 g of novolak resin was obtained.

[Comparative Example 6]
In a 1000 mL glass flask equipped with a thermometer, a charging / distilling outlet and a stirrer, 80 g (0.740 mol) of m-cresol, 120 g (1.110 mol) of p-cresol, 81.3 g of 42% formalin (1 .137 mol) and 0.8 g of oxalic acid as a catalyst were added and reacted at a reaction temperature of 100 ° C. for 10 hours. Thereafter, the temperature was raised to 180 ° C. for dehydration, and then vacuum distillation was performed at 30 torr for 2 hours to obtain 150 g of a novolak resin.

[Comparative Example 7]
In a 1000 mL glass flask equipped with a thermometer, charging / distilling outlet and stirrer, m-cresol 100 g (0.925 mol), 50% glutaraldehyde aqueous solution 42.6 g (0.213 mol), and catalyst paraffin Toluenesulfonic acid 0.2g was added and reacted at a reaction temperature of 96 ° C. for 20 hours. After completion of the reaction, the mixture was cooled to 90 ° C., 0.2 g of triethylamine and 100 g of ion-exchanged water were added, and the mixture was stirred and allowed to stand. The pH of the aqueous layer separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed twice. Thereafter, the temperature was raised to 185 ° C. to dehydrate, and then vacuum distillation was performed at 30 torr for 2 hours to obtain 82 g of a novolak resin.

[Comparative Example 8]
In a 1000 mL glass flask equipped with a thermometer, a charging / distilling outlet, and a stirrer, 100 g (0.93 mol) of m-cresol, 47.0 g (0.67 mol) of 42% formalin, and paratoluenesulfone as a catalyst The acid 0.1g was put into the three necked flask, and reaction was performed at the reaction temperature of 100 degreeC for 4 hours. Thereafter, 18.0 g (0.07 mol) of 4,4-BMMB was added, and the reaction was performed at a reaction temperature of 140 ° C. for 4 hours. After completion of the reaction, the mixture was cooled to 90 ° C., 0.3 g of triethylamine and 100 g of ion-exchanged water were added, and the mixture was stirred and allowed to stand. The pH of the separated water separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed twice. Then, after heating up to 185 degreeC and dehydrating, it distilled under reduced pressure at 30 torr for 2 hours, and obtained 110 g of novolak resins.

[Comparative Example 9]
In a glass flask having a capacity of 1000 mL equipped with a thermometer, a charging / distilling outlet and a stirrer, 169.2 g (1.8 mol) of phenol, 22 g (0.2 mol) of resorcin, 312.3 g of 4,4′-BMMB ( 1.29 mol) and 0.15 g of 50% by mass sulfuric acid as a catalyst were added, and the reaction was carried out under a nitrogen stream at a reaction temperature of 120 to 135 ° C. for 3.5 hours, and further at a reaction temperature of 165 ° C. for 3 hours. After completion of the reaction, it was cooled to 95 ° C. After cooling, 100 g of ion-exchanged water was added and stirred and allowed to stand. The pH of the aqueous layer separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed twice. Thereafter, the temperature was raised to 185 ° C. for dehydration, followed by vacuum distillation at 30 torr for 2 hours to obtain 144 g of a novolak resin.

[Comparative Example 10]
Resorcinol 100 g (0.908 mol), 4,4′-BMMB 76.69 g (0.317 mol), propylene glycol monomethyl ether as a solvent in a 1000 mL glass flask equipped with a thermometer, charging / distilling outlet and stirrer 15 g and 0.15 g of paratoluenesulfonic acid as a catalyst were added, and the reaction was performed at a reaction temperature of 110 ° C. for 4 hours. Meanwhile, the methanol produced was distilled off. Thereafter, 107 g of propylene glycol monomethyl ether and 53.2 g (0,317 mol) of 2,6-dimethylol-p-cresol were added and reacted at a reaction temperature of 110 ° C. for 4 hours. After completion of the reaction, the mixture was cooled to 90 ° C., 0.15 g of triethylamine was added, 306 g of ion-exchanged water was added, and the mixture was stirred and allowed to stand. The pH of the separated water separated by allowing to stand was adjusted to 5.5 to 7.0, and the separated water was removed. This operation was performed 4 times. Thereafter, the temperature was raised to 150 ° C. and dehydration was performed, followed by distillation under reduced pressure at 30 torr for 1 hour to remove moisture and the like to obtain 187 g of a novolac resin.

The analysis method of novolak resin and the evaluation method of its physical properties are as follows.
≪Weight average molecular weight (GPC measurement method) ≫
Model: HLC-8220 Tosoh Co., Ltd. Column: TSK-GEL H type G2000H × L 4
1 G3000H x L
One G4000H × L Measurement condition: Column pressure 13.5 MPa
Eluent: Tetrahydrofuran (THF) flow rate 1 ml / min
Temperature: 40 ° C
Detector: Spectrophotometer (UV-8020) RANGE 2.56
WAVE LENGTH: 254nm and RI
Injection volume: 100 μmL
Sample concentration: 5 mg / mL

≪Method for evaluating alkali dissolution rate of novolak resin≫
3 g of novolak resin was dissolved in 9 g of PGMEA (propylene glycol monomethyl ether acetate) to prepare a resin solution. These were filtered through a 0.2 micron membrane filter. This was coated on a 4 inch silicon wafer with a spin coater to a thickness of about 1.5 μm, and dried on a hot plate at 110 ° C. for 60 seconds. Next, using a developing solution (1.60% tetramethylammonium hydroxide aqueous solution), the time until the film completely disappeared was measured. The value obtained by dividing the initial film thickness by the time until dissolution was taken as the dissolution rate.

A method for preparing a photoresist composition (photosensitive composition), a method for evaluating the photosensitizer solubility, coatability, flexibility, remaining film ratio (%), and resolution of the obtained composition are as follows.
<< Preparation of photoresist composition >>
10 g of novolak resin and 2.5 g of 2,3,4,4′-tetrahydroxybenzophenone ester of naphthoquinone 1,2-diazide-5-sulfonic acid are dissolved in 37.5 g of PGMEA (propylene glycol monomethyl ether acetate) A resist composition was obtained.

≪Photoresist composition flexibility evaluation≫
The obtained novolak resin was dissolved in PGMEA (propylene glycol monomethyl ether acetate) to prepare a resin solution. These were filtered through a 0.2 micron membrane filter. This was applied on a polyimide film having a thickness of 50 μm so as to have a thickness of about 5.0 μm, and dried on a hot plate at 110 ° C. for 90 seconds.
After drying, the state of the resist surface was observed, and the applicability was evaluated by the presence or absence of cissing.
Subsequently, it was immersed for 60 seconds using the developing solution (2.38% tetramethylammonium hydroxide aqueous solution). After rinsing and drying, bending was performed at 180 degrees, and the state of the bent portion was observed and evaluated visually and under a microscope (1000 times) according to the following criteria.
○: There is no crack in the resist film by microscopic observation. Δ: There is no crack in the resist film by visual observation, but there is crack in the resist film by microscopic observation (it is difficult to put it into practical use as a flexible photoresist composition. )
X: There is a crack in the resist film by visual observation.

≪Method for evaluating sensitivity, remaining film ratio, and resolution of photoresist composition≫
The photoresist composition is filtered through a 0.2 micron membrane filter, which is coated on a 4 inch silicon wafer with a spin coater and dried on a hot plate at 110 ° C. for 60 seconds to form a coating film having a thickness of 15000 mm. Formed. Thereafter, using a reduced projection exposure apparatus, the exposure time was changed stepwise to confirm the optimum exposure amount, and then exposure was performed so that the optimum exposure amount was obtained. Next, using a developer (2.38% tetramethylammonium hydroxide aqueous solution), development was performed for 60 seconds, followed by rinsing and drying.

The sensitivity was evaluated based on the following criteria by observing the pattern shape of the obtained pattern with a scanning electron microscope.
AA: An image can be formed at less than 3 mJ / cm ² .
A: An image can be formed at less than 5 mJ / cm ² .
B: An image can be formed at 5 to 60 mJ / cm ² .

The remaining film ratio was determined from the remaining film thickness of the unexposed portion of the remaining film ratio. The remaining film ratio is a ratio between the film thickness of the photosensitive resin after development and the film thickness of the photosensitive resin before development, and is a value represented by the following formula.

Resolution The resolution was evaluated according to the following criteria using a test chart mask.
A: 4 μ line & space can be resolved.
○: 5μ line & space can be resolved.
X: 5 μ line & space cannot be resolved.

  For the novolak resins obtained in Examples 3 to 6 and Comparative Examples 6 to 10, the chemical compositions, molar ratios, analysis evaluation results as resins, and evaluation results as photoresist compositions are shown in Tables 4 to 4 below. The results are summarized in FIG.

  The novolak resins of Examples 3 to 6 had improved flexibility. On the other hand, Comparative Example 6 which is a conventional general novolac type phenolic resin was not flexible. The novolak resin of Comparative Example 9 corresponding to the novolak-type phenol resin of Patent Document 2 has improved flexibility but has room for further improvement. In the evaluation as a photoresist composition, the novolak resins of Examples 3 to 6 are in addition to flexibility compared to the photoresist compositions prepared using the novolak type phenol resins obtained in Comparative Examples 6 to 10, We were satisfied with the balance of the remaining film rate and resolution performance. In particular, since the novolak resin obtained in Example 3 has a weight average molecular weight in a particularly preferable range of 6000 to 12000, the flexibility and resolution of a photoresist composition prepared using the resin are good. The characteristics as a photoresist were extremely excellent, such as a particularly good residual film ratio.

  According to the present invention, a novolac resin (novolak-type phenol resin) having good flexibility, heat resistance, solubility and the like can be obtained. This novolak resin can be suitably used as a raw material for the epoxidized novolac resin by utilizing its characteristics. Further, by using this novolac resin or epoxidized novolac, an epoxy resin composition excellent in heat resistance and solubility, a cured product comprising the composition, and a laminate in which a matrix resin is formed by the composition are suitably obtained. be able to. Furthermore, a photoresist composition with improved flexibility can be suitably obtained by adopting it as an alkali-soluble resin.

Claims (2)

An epoxidized novolac resin obtained by epoxidizing a novolak resin represented by the following general formula (1).

(Here, in the general formula (1), A is independently composed of a monovalent or divalent group represented by the following general formula (2-1) or general formula (2-2), and B is independently Consisting of a divalent group represented by the following general formula (3-1) or general formula (3-2), n is an integer of 0 to 100,
Ratio [general formula (2-1) / general formula (2-2)] of general formula (2-1) and general formula (2-2) contained in the resin is 10/90 to 90/10 The ratio of the general formula (3-1) to the general formula (3-2) [general formula (3-1) / general formula (3-2)] is 10/90 to 90/10. )

(Here, q independently represents an integer of 2 to 3.)

(Here, R1 independently represents an alkyl group having 1 to 6 carbon atoms, and p independently represents an integer of 1 to 3).

A method for producing a novolak resin, comprising subjecting phenols represented by the following general formulas (4) and (5) to a condensation reaction between a compound represented by the following general formula (6) and formaldehyde.

(Here, q represents an integer of 2 to 3.)

(Here, R1 represents an alkyl group having 1 to 6 carbon atoms, and p represents an integer of 1 to 3).

(Here, Y represents a halogen atom, an alkoxy group, or a hydroxyl group.)