JP5400324B2 - Method for producing novolac resin - Google Patents

Description

  The present invention relates to a method for producing a novolak resin having good heat resistance and moisture resistance and low melt viscosity.

Phenolic resins have heat resistance and are used in various fields. For example, when used as a curing agent for epoxy resin, it is excellent in heat resistance, adhesion, electrical insulation, etc., resin composition for printed circuit board, resin composition for interlayer insulation material used for printed circuit board and copper foil with resin, It is used for resin compositions for electronic parts sealing materials, resist inks, conductive pastes (containing conductive fillers), paints, adhesives, composite materials, and the like.
Furthermore, with recent technological innovations, phenol resins used as curing agents in epoxy resin compositions are also required to have improved heat resistance, moisture resistance, flame retardancy, and the like. Phenol is generally a resin having heat resistance, but since the hydroxyl group and methylene group in the resin are susceptible to oxidation, further improvement in heat resistance can be expected by improving this point. Therefore, improvement of the heat resistance of the resin by the use of aromatic aldehydes, alkoxylation of phenolic hydroxyl groups, co-condensation of alkoxybenzenes and phenols has been studied (see Patent Documents 1 to 3).
However, aromatic aldehydes are less reactive than formaldehyde and paraformaldehyde, and alkoxybenzenes are also less reactive than phenols. Therefore, when producing novolak resins using these as raw materials, the reaction catalyst is Those having extremely high acidity such as sulfuric acid, hydrochloric acid and trifluoromethanesulfonic acid have been selected.
In Patent Document 1, salicylaldehyde and phenols are reacted in the presence of an acid catalyst. As the acid catalyst, a super strong acid such as trifluoromethanesulfonic acid is used, or a strong acid such as hydrochloric acid is used in a large amount. If not used, sufficient reactivity cannot be obtained. For this reason, it is not an industrially advantageous method because the production facility is corroded by a super strong acid or a large amount of strong acid, and a lot of waste liquid is generated in removing or treating the catalyst.
Patent Document 2 discloses a phenol resin modified with alkoxybenzenes. However, the production method involves alkoxylation of the resol type phenol resin, followed by novolak formation with an acid catalyst, and the production process is very long.
Also in the method for producing a modified phenolic resin disclosed in Patent Document 3, the acid specifically described as the acid catalyst is organic sulfonic acid or sulfuric acid, which also has the above problem.
Thus, when producing a modified novolak resin using a monomer having poor reactivity such as an aromatic aldehyde or phenyl ether as a raw material, use a super strong acid or a large amount of a strong acid such as a hydrogen halide or a sulfonic acid compound. There was no effective manufacturing method other than using.

JP 2002-275228 A JP 2004-10700 A JP 2006-161036 A

  The present invention has been made based on the above circumstances, and provides a method for efficiently producing a novolak resin by reacting a phenol or a phenol derivative with an aromatic aldehyde under mild conditions. It is for the purpose.

（式中、Ｒ₁は、水素原子、水酸基、炭素数１〜１０のアルキル基、または炭素数１〜１０のアルコキシル基を示し、ｋは０〜３の整数を示す。）

（式中、Ａは、−ＯＲ₂、又は−Ｒ₃を示し、Ｒ₂は、水素原子、炭素数１〜１０のアルキル基、炭素数２〜１０のアルケニル基、炭素数７〜１０のヒドロキシアラルキル基、（注：ビスフェノールＡのため）、炭素数２〜１０のアシル基、炭素数６〜１２のアリール基、または炭素数３〜１２のシクロアルキル基を示し、Ｒ₃は、炭素数２〜６のアルコキシアルキル基を示し（注：パラキシレングリコールジメチルエーテルのため）、Ｒ₄は、水素原子、水酸基、炭素数１〜１０のアルキル基、または炭素数１〜１０のアルコキシル基、または炭素数１〜１０のアルコキシアルキル基を示し、ｊは０〜３の整数を示す。）
２．前記式（Ｉ）で表される化合物が、サリチルアルデヒド、２，３−ジヒドロキシベンズアルデヒド、２，４−ジヒドロキシベンズアルデヒド、２，５−ジヒドロキシベンズアルデヒド、およびメチルサリチルアルデヒドから選ばれる少なくとも１種である上記１記載のノボラック樹脂の製造方法。
３．前記式（ＩＩ）で表される化合物が、フェノール、クレゾール、エチルフェノール、キシレノール、ビスフェノールＡ、アニソール、パラキシレングリコールジメチルエーテル、ならびにジフェニルエーテルから選ばれる少なくとも１種である上記１または２に記載のノボラック樹脂の製造方法。
４．さらにホルムアルデヒド類を共存させる上記１〜３のいずれかに記載のノボラック樹脂の製造方法。 The present invention is based on the finding that the above object is achieved by combining the above-mentioned problems with orthohydroxybenzaldehydes as aromatic aldehydes and boric acid as an acid catalyst. That is, the gist of the present invention is as follows.
1. A novolak resin characterized by reacting an orthohydroxybenzaldehyde represented by the formula (I) and at least one selected from the aromatic compounds represented by the formula (II) in the presence of boric acid. Production method.

(Wherein R ₁ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, or an alkoxyl group having 1 to 10 carbon atoms, and k represents an integer of 0 to 3)

(In the formula, A represents —OR ₂ or —R ₃ , and R ₂ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or a hydroxy group having 7 to 10 carbon atoms. An aralkyl group (note: for bisphenol A), an acyl group having 2 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms, wherein R ₃ is 2 carbon atoms Represents an alkoxyalkyl group having ˜6 (note: for paraxylene glycol dimethyl ether), R ₄ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or the number of carbon atoms 1-10 alkoxyalkyl groups are shown, j shows the integer of 0-3.)
2. The above 1 wherein the compound represented by the formula (I) is at least one selected from salicylaldehyde, 2,3-dihydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 2,5-dihydroxybenzaldehyde, and methylsalicylaldehyde. The manufacturing method of novolak resin as described.
3. 3. The novolak resin according to 1 or 2 above, wherein the compound represented by the formula (II) is at least one selected from phenol, cresol, ethylphenol, xylenol, bisphenol A, anisole, paraxylene glycol dimethyl ether, and diphenyl ether. Manufacturing method.
4). Furthermore, the manufacturing method of the novolak resin in any one of said 1-3 which coexists formaldehyde.

  The present invention can provide a method for efficiently producing a novolak resin by reacting a specific aromatic aldehyde and a phenolic aromatic compound under mild conditions.

式中、Ｒ₁は、水素原子、水酸基、炭素数１〜１０のアルキル基、または炭素数１〜１０のアルコキシル基を示し、ｋは０〜３の整数を示す。
このうち、炭素数１〜１０のアルキル基としては、直鎖状でも分岐状でもよく、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ペンチル基、イソペンチル基、ｓｅｃ−ペンチル基、ｔｅｒｔ−ペンチル基、ネオペンチル基、ヘキシル基、イソへキシル基、ヘプチル基、オクチル基、デシル基等が挙げられる。
また、炭素数１〜１０のアルコキシル基としては、直鎖状でも分岐状でもよく、メトキシ基、エトキシ基、プロポキシ基、イソプロポキシ基、ブトキシ基、イソブトキシ基、ｓｅｃ−ブトキシ基、ｔｅｒｔ−ブトキシ基、ペンチルオキシ基、イソペンチルオキシ基、ネオペンチルオキシ基、ヘキシルオキシ基、ヘプチルオキシ基、オクチルオキシ基、ノニルオキシ基、デシルオキシ基等を挙げることができる。
ベンゼン環上の置換基Ｒ₁の数を示すｋは、０〜３の整数であり、好ましくは０〜２の整数、より好ましくは０または１の整数である。ｋが２または３の場合には、Ｒ₁は同一であっても、異なっていてもよい。 The present invention will be described in detail below.
In the method for producing a novolak resin of the present invention, orthohydroxybenzaldehydes represented by the formula (I) are used as aldehydes.

In the formula, R ₁ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, or an alkoxyl group having 1 to 10 carbon atoms, and k represents an integer of 0 to 3.
Among these, the alkyl group having 1 to 10 carbon atoms may be linear or branched, and is a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group. Pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl group, heptyl group, octyl group, decyl group and the like.
Further, the alkoxyl group having 1 to 10 carbon atoms may be linear or branched, and is a methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group. Pentyloxy group, isopentyloxy group, neopentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, and the like.
K representing the number of substituents R ₁ on the benzene ring is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably an integer of 0 or 1. When k is 2 or 3, R ₁ may be the same or different.

Specific examples of the orthohydroxybenzaldehydes represented by the formula (I) include orthohydroxybenzaldehydes such as salicylaldehyde, 2,3-dihydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 2,5-dihydroxybenzaldehyde, and methylsalicylaldehyde. It can be used alone or in combination of two or more.
By using orthohydroxybenzaldehydes represented by the formula (I), an orthohydroxyphenylmethylene group is formed in the novolak resin.

In the method of the present invention, as the aldehyde, in addition to the aldehyde compound represented by the formula (I), formaldehydes (hereinafter referred to as aldehydes together) can be used as necessary. Examples of such formaldehydes include formaldehyde and paraformaldehyde.
By using formaldehydes, methylene groups are formed.
The total amount of aldehydes is 0.3 to 1.5 mol, preferably 0.4 to 1,2 with respect to 1 mol of the total amount of the aromatic compound represented by the formula (II) described below. It is added in a molar ratio. By making the addition amount within this range, the yield of the resulting novolak resin is good and the proportion of aldehydes not involved in the reaction is reduced, which is economically preferable.

（式中、Ａは、−ＯＲ₂、又は−Ｒ₃を示し、Ｒ₂は、水素原子、炭素数１〜１０のアルキル基、炭素数２〜１０のアルケニル基、炭素数７〜１０のヒドロキシアルアルキル基、炭素数２〜１０のアシル基、炭素数６〜１２のアリール基、または炭素数３〜１２のシクロアルキル基を示し、Ｒ₃は、炭素数２〜１０のアルコキシアルキル基を示し、Ｒ₄は、水素原子、水酸基、炭素数１〜１０のアルキル基、または炭素数１〜１０のアルコキシル基、または炭素数２〜１０のアルコキシアルキル基を示し、ｊは０〜３の整数を示す。） In the present invention, examples of the compound to be reacted with aldehydes include aromatic compounds represented by the formula (II).

(In the formula, A represents —OR ₂ or —R ₃ , and R ₂ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or a hydroxy group having 7 to 10 carbon atoms. Represents an aralkyl group, an acyl group having 2 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms, and R ₃ represents an alkoxyalkyl group having 2 to 10 carbon atoms. , R ₄ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 10 carbon atoms, j is an integer of 0 to 3 Show.)

Among the above, examples of the alkyl group having 1 to 10 carbon atoms and the alkoxyl group having 2 to 10 carbon atoms are the same as those described above.
The alkenyl group having 2 to 10 carbon atoms may be linear or branched. Examples thereof include a vinyl group, allyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3 -Butenyl group, 1-hexenyl group, 1-heptenyl group, 1-octenyl group, 1-nonenyl group, 1-decenyl group and the like can be mentioned.
Examples of the acyl group having 2 to 10 carbon atoms include acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, pivaloyl group, hexanoyl group, heptanoyl group, octanoyl group, decenoyl group and the like.
Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a naphthyl group, and a biphenyl group.
Examples of the cycloalkyl group having 3 to 12 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group.
Also, the alkoxyalkyl group having 2 to 10 carbon atoms is methoxymethyl group, ethoxy group methyl, propoxyethyl group, isopropoxymethyl group, butoxypropyl group, isobutoxybutyl group, hexyloxybutyl group, heptyloxyethyl group, octyl An oxyethyl group, a nonyloxymethyl group, etc. can be mentioned.
J indicating the number of substituents R ₄ on the benzene ring is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably an integer of 0 or 1. When j is 2 or 3, R ₄ may be the same or different.
Specific examples of the aromatic compound represented by the formula (II) include phenol, cresol, ethylphenol, xylenol, butylphenol, octylphenol, nonylphenol, phenylphenol, cyclohexylphenol, trimethylphenol, catechol, and methoxyphenol. , Ethoxyphenol, allylphenol, resorcinol, naphthol, bisphenol A, anisole, paraxylylene glycol dimethyl ether, diphenyl ether, and the like. These can be used alone or in admixture of two or more.
The aromatic compound represented by the above formula (II) is added so as to be 50 to 70 mol% of the entire novolak resin after polymerization.

In the present invention, the orthohydroxybenzaldehyde represented by the formula (I) is reacted with the compound represented by the formula (II), and boric acid is used as an essential component as an acid catalyst used at that time.
The compounding quantity of boric acid is 0.1-20 mass parts with respect to 100 mass parts of phenolic aromatic compounds, Preferably it is good to use in the ratio of 0.5-10 weight part.
By using boric acid, it is possible to carry out the reaction under mild conditions without using a large amount of strong acid as in the conventional method, but if necessary, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, paratoluene Sulfonic acid, oxalic acid and the like may be used in combination. By using these acids in combination, not only can boric acid be used to increase the reaction rate compared to when it is used alone, but the amount of its use can be enhanced by adding a very small amount in the presence of boric acid. can get.

The method of reacting the aromatic compound represented by the formula (I) and the aldehyde is not particularly limited. For example, the compound represented by the formula (I), the aldehyde, and the acid catalyst are collectively charged and reacted. Or a method of adding a compound represented by the formula (I) and an acid catalyst and adding aldehydes at a predetermined reaction temperature. At this time, the reaction temperature is preferably in the range of 80 to 180 ° C. If it is less than 80 ° C., the reaction proceeds slowly and unreacted phenolic aromatic compounds and aldehydes remain, which is not preferable. The reaction time is not particularly limited, and may be adjusted according to the amount of aldehydes and catalyst and the reaction temperature. It is of course possible to use an organic solvent during the reaction.
Examples of such organic solvents include alcohols such as propyl alcohol and butanol, glycols such as ethylene glycol and propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and butylene. Glycol ethers such as glycol monomethyl ether, butylene glycol monoethyl ether, butylene glycol monopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, propyl acetate, butyl acetate, ethyl lactate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether Esters such as acetate, ethers such as 1,4-dioxane Etc. are alone, or in combination of two or more can be used.
The said organic solvent can be used so that it may become 0-1,000 mass parts with respect to 100 mass parts of phenolic aromatic compounds, Preferably it is about 10-100 mass parts. After the reaction, the condensed water may be removed by distillation or, if necessary, the remaining catalyst may be removed by washing with water. Further, unreacted phenolic aromatic compounds and unreacted aldehydes may be removed by distillation under reduced pressure or steam distillation.

式（ＩＩＩ）中、ＡおよびＢは、ＯＲ₂、又は−Ｒ₃を示し、同一でも異なっていてもよい。Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄、ｊ、およびｋは、上記と同様である。Ｒ₅は、水素、水酸基、炭素数１〜１０のアルキル基、炭素数１〜１０のアルコキシル基、炭素数１〜１０のアルコキシアルキル基を示す。ｍは、０〜３の整数を示し、ｎは、１〜１０の整数を示し、ｒは、Ａ＝Ｂ、Ｒ₄＝Ｒ₅、およびｊ＝ｍのとき、０を示し、前記以外のとき、１を示す。

（式（ＩＶ）中、Ａ、Ｂ、Ｒ₄、Ｒ₅、ｊおよびｍは前記同様である。Ｓは、Ａ＝Ｂ、Ｒ₃＝Ｒ₅、およびｊ＝ｍのとき、０を示し、前記以外のとき、１を示す。ｑは、０、または１〜１０の整数を示す。） When the aldehyde is reacted with a phenolic aromatic compound in the presence of boric acid, a novolak resin containing repeating units represented by the formulas (III) and (IV) is obtained.

In formula (III), A and B represent OR ₂ or —R _3, and may be the same or different. R ₁ , R ₂ , R ₃ , R ₄ , j, and k are the same as described above. R ₅ represents hydrogen, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 1 to 10 carbon atoms. m represents an integer of 0 to 3, n represents an integer of 1 to 10, r represents 0 when A = B, R ₄ = R ₅ , and j = m, otherwise 1 is shown.

(In the formula (IV), A, B, R ₄ , R ₅ , j and m are the same as described above. S represents 0 when A = B, R ₃ = R ₅ and j = m, Other than the above, it represents 1. q represents 0 or an integer of 1 to 10.)

Hereinafter, the present invention will be described in more detail with reference to synthesis examples of novolak resin by the production method of the present invention, but the present invention is not limited to the following.
Example 1
A flask equipped with a condenser and a stirrer was charged with 100 g of orthocresol, 56 g of salicylaldehyde, and 1 g of boric acid as an acid catalyst, and reacted at 100 ° C. for 8 hours. Subsequently, the catalyst was removed by washing twice with 100 parts of pure water. Subsequently, the residue was removed under reduced pressure at 180 ° C. and 50 mmHg to obtain 100 g of novolak resin A.
FIG. 1 shows the H-NMR spectrum of Resin A. A signal of methine derived from an aromatic aldehyde is seen in the vicinity of δ = 5.5 to 6.0 ppm.

Example 2
The same procedure as in Example 1 was conducted, except that orthomethoxyphenol was used as the phenol, 1 g of boric acid and 1 g of oxalic acid were used as the acid catalyst, and the reaction was performed at 120 ° C. for 6 hours to obtain 90 g of novolak resin B.

Example 3
A modified novolak resin C85 g was obtained in the same manner as in Example 2 except that anisole was used as the phenyl ether and reacted at 140 ° C. for 6 hours.

Comparative Example 1
A flask equipped with a condenser and a stirrer was charged with 100 g of orthocresol, 56 g of salicylaldehyde, and 5 g of oxalic acid as an acid catalyst, and reacted at 100 ° C. for 8 hours. Then, the catalyst was removed by washing twice with 100 g of pure water. Next, the distillate was removed under reduced pressure at 180 ° C. and 50 mmHg to obtain a novolac resin D, but the yield was only 7 g.

Comparative Example 2
The same procedure as in Example 1 was carried out except that 1 g of paratoluenesulfonic acid was used as the acid catalyst to obtain 90 g of novolak resin E.

Comparative Example 3
A flask equipped with a condenser and a stirrer was charged with 100 g of orthocresol, 56 g of metahydroxybenzaldehyde and 1 g of boric acid as an acid catalyst, and reacted at 100 ° C. for 8 hours, but the reaction did not proceed and no resin was obtained.

Comparative Example 4
Except for using 1 g of oxalic acid as the acid catalyst, the reaction was carried out at 140 ° C. for 6 hours in the same composition as in Example 3. However, the reaction did not proceed and no resin was obtained.

Each of the novolak resins obtained in Examples 1 to 3 and the novolak resins obtained in Comparative Examples 1 and 2 were melt-kneaded with the formulations shown in Table 1 to obtain thermosetting resin compositions 1 to 5. . The glass transition temperature, linear expansion coefficient, and water absorption rate of the obtained composition were evaluated by the following methods.
(1) Evaluation of glass transition temperature and thermal expansion coefficient Glass transition temperature and linear expansion coefficient were measured by TMA method using SSC / 5200 manufactured by SII. The heating rate was 10 ° C./min.
(2) Water absorption rate Using a pressure cooker manufactured by Enomoto Kasei Co., Ltd., the weight increase rate after being held at 121 ° C. for 20 hours was measured.

ここで、
ビフェニルアラルキル型エポキシ樹脂： （商品名ＮＣ−３０００Ｈ：日本化薬社製）
トリフェニルホスフィン： （和光純薬工業社製）
溶融シリカ： （商品名ＭＳＲ−２２１２：龍森社製）

here,
Biphenyl aralkyl type epoxy resin: (trade name NC-3000H: manufactured by Nippon Kayaku Co., Ltd.)
Triphenylphosphine: (Wako Pure Chemical Industries, Ltd.)
Fused silica: (trade name MSR-2212: manufactured by Tatsumori)

From Table 1, in the thermosetting resin composition of the present invention, a novolak resin can be synthesized under mild conditions without using a large amount of strong acid.
It can be seen that the noblack resin thus obtained is a novolak resin having good heat resistance and moisture resistance and a low melt viscosity, and exhibits the same performance as a conventional novolak resin.

  The novolac resin synthesis method of the present invention can be synthesized under mild conditions. Moreover, the novolak resin obtained by the method of the present invention can give good heat resistance and moisture resistance to the cured product when used as a curing agent for epoxy resin. Therefore, the novolak resin obtained by the present invention is a resin composition for an electronic component sealing material, a resin composition for a printed circuit board, a resin composition for an interlayer insulating material used for a printed circuit board and a resin-coated copper foil, and a conductive material. It can be suitably used for pastes (containing conductive fillers), paints, adhesives, composite materials, and the like.

3 is an H-NMR measurement chart of novolak resin A obtained in Example 1. FIG.

Claims (4)

A novolak resin characterized by reacting an orthohydroxybenzaldehyde represented by the formula (I) and at least one selected from the aromatic compounds represented by the formula (II) in the presence of boric acid. Production method.

(Wherein R ₁ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, or an alkoxyl group having 1 to 10 carbon atoms, and k represents an integer of 0 to 3)

(In the formula, A represents —OR ₂ or —R ₃ , and R ₂ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or a hydroxy group having 7 to 10 carbon atoms. An aralkyl group, an acyl group having 2 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms, and R ₃ represents an alkoxyalkyl group having 2 to 6 carbon atoms. , R ₄ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 1 to 10 carbon atoms, j being an integer of 0 to 3 Show.)   The compound represented by the formula (I) is at least one selected from salicylaldehyde, 2,3-dihydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 2,5-dihydroxybenzaldehyde, and methylsalicylaldehyde. A method for producing the novolac resin according to 1.   The novolak according to claim 1 or 2, wherein the compound represented by the formula (II) is at least one selected from phenol, cresol, ethylphenol, xylenol, bisphenol A, anisole, paraxylene glycol dimethyl ether, and diphenyl ether. Manufacturing method of resin.   Furthermore, the manufacturing method of the novolak resin in any one of Claims 1-3 which coexists formaldehyde.

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