JP3845198B2 - Method for producing phenolic resin - Google Patents

Description

【００２８】
表１に示したように、いずれの実施例で得られた樹脂からも、酸性物質は検出されず、高純度であった。また１６０℃で１０時間の熱処理を行った後も分子量分布やフェノールの増加などの変化が認められず、熱安定性に優れていることが判る。
これに対し、比較例１及び２で得られた樹脂には、触媒の酸性物質が残存し、抽出水のｐＨも低い値を示した。また熱安定性にも劣り、１６０℃１０時間の熱処理で分子量分布が大きくなり溶融粘度が大幅に上昇し、また未反応フェノールも大幅に増加し、品質の安定性が悪かった。
【００２９】
【発明の効果】
本発明によれば、安価な原料を使用し、また反応開始剤として水を用い、加水分解で発生するハロゲン化水素を縮合反応開始の触媒として用いることができるので、触媒の残存による不純物が少なく、品質が安定し、半導体封止用のエポキシ樹脂硬化剤などの用途に適した高純度のフェノール系樹脂を簡単な操作で効率的に得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a phenolic polymer useful for various binders, coating materials, laminated materials, molding materials and the like. In particular, the present invention relates to a production method for efficiently obtaining a high-purity polymer with few impurities, which is suitable for an epoxy curing agent for an electronic material or a raw material for an epoxy resin.
[0002]
[Prior art]
Phenol formaldehyde resin is widely used for various applications as an inexpensive heat-resistant resin. In addition, various resins having different structures have been developed and are already publicly known for the purpose of improving the properties of ordinary phenol resins.
[0003]
In particular, a polymer obtained by a condensation reaction of an aralkyl compound such as α, α′-dimethoxy-p-xylene and a phenol described in JP-B-47-15111 is excellent in heat resistance as a phenol aralkyl resin. It is widely used in various applications due to its properties, electrical properties, and moisture and chemical resistance.
Furthermore, in recent years, phenol aralkyl resins have been increasingly used as curing agents in the field of sealing materials that require moisture resistance, as ICs have become denser, smaller, thinner, and more surface-mounted.
[0004]
On the other hand, Japanese Patent No. 2533276 and JP-A-6-256474 disclose cocondensates of phenols, xylylene compounds, and aromatic aldehydes represented by benzaldehyde and the like. This phenolic resin has features such as low viscosity, high Tg, low warpage and excellent moldability compared to phenol aralkyl resin, and is hardened in the field of structural materials and IC sealing materials that require heat resistance. It is used as an agent.
[Problems to be solved by the invention]
[0005]
The above phenolic resin production method uses, as a raw material, glycols or alkoxys represented by the general formula Ph— (CH ₂ OR) ₂ (Ph is a phenylene group, R is hydrogen, an alkyl group, etc.) as a xylylene compound. These compounds are usually produced from bishalomethyl compounds (Ph- (CH ₂ X) ₂ ) and are not only expensive as raw materials. In this method, the co-condensation reaction is carried out using paratoluenesulfonic acid or trifluoromethane. It is necessary to carry out in the presence of an acid catalyst such as sulfonic acid.
[0006]
However, in the phenolic resin produced using this acid catalyst, it is difficult to completely separate the acid catalyst used in the reaction from the reaction product, and the resulting resin contains a slight amount of acidic substances. Therefore, it cannot be applied as it is to a use that particularly dislikes impurities, and it is necessary to remove the catalyst by washing with water. In addition, the remaining acidic substance causes problems such as a change in molecular weight distribution, an increase in viscosity, and regeneration of phenolic monomers in the production process, resulting in a disadvantage that the quality is not stable.
[0007]
The present invention has been made in view of such circumstances, and provides a production method for efficiently obtaining a phenol-based resin that uses inexpensive raw materials, has low impurities, has high purity, and has stable quality such as viscosity. Is the purpose.
[0008]
In order to achieve the above object, the present inventor has intensively studied catalyst types and removal methods. As a result, the use of a bishalomethyl compound in which two halomethyl groups are substituted on an aromatic ring as an aralkyl compound makes the raw material inexpensive. In addition, by using the bishalomethyl compound, water is used as a reaction initiator without adding a catalyst such as p-toluenesulfonic acid, and a hydrogen halide generated by hydrolysis is used as a catalyst for starting a condensation reaction. Thus, the present inventors have found a method for producing a phenolic resin having high purity and stable quality, and have reached the present invention.
[0009]
[Means for Solving the Problems]
That is, the present invention relates to phenols and the following general formula (1)
R _1- (CH ₂ X) ₂ (1)
And a bishalomethyl compound represented by the following general formula (2)
R ₂ —CHO (2)
(In the formula, R ₁ and R ₂ are the same or different phenylene group, alkyl-substituted phenylene group, diphenylene group, diphenylene oxide group, and naphthylene group, and X is a halogen atom.) Is a method for producing a phenolic resin, wherein water is added as a reaction initiator, and a hydrogen halide generated by hydrolysis is subjected to a condensation reaction as a catalyst for starting the condensation reaction . Hereinafter, the present invention will be described in detail.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a bishalomethyl compound represented by the general formula (1) (hereinafter referred to as compound (1)) is used as a raw material. Specific examples of such bishalomethyl compounds include di (chloromethyl) benzene, di (bromomethyl) benzene, di (chloromethyl) biphenyl, di (chloromethyl) naphthalene, di (chloromethyl) biphenyl ether, and the like. Particularly preferred is dichloromethylbenzene. In the case of di (chloromethyl) benzene, the substitution position of —CH ₂ X may be any of ortho, meta, and para, but generally preferred is the para position or the meta position, and a mixture of the meta position and the para position. A system is also preferred.
[0011]
Specific examples of the aromatic aldehyde represented by the general formula (2) (hereinafter referred to as compound (2)) include benzaldehyde, methylbenzaldehyde, ethylbenzaldehyde, tert-butylbenzaldehyde, naphthaldehyde, methylnaphthaldehyde and the like. . Benzaldehyde and naphthaldehyde are particularly preferable.
[0012]
The molar ratio of compound (2) / compound (1) is in the range of 80/20 to 10/90, preferably 70/30 to 30/70. When this ratio exceeds 80/20, the aromatic aldehyde having relatively low reactivity may not be partially reacted and may remain in the resin. Further, a cured product obtained by curing this resin with an epoxy resin or hexamine tends to be somewhat hard and brittle, and the water absorption rate tends to be slightly high. On the other hand, when this ratio is less than 10/90, the effect of introducing an aromatic aldehyde for the purpose of low viscosity, high Tg, low warpage, improved moldability, etc. is hardly recognized. In addition to this, as an effect of the aromatic aldehyde, the compound (1) is solid, but by mixing and dissolving in advance with a liquid aldehyde compound such as benzaldehyde, it is also possible in terms of production operation and reaction uniformity. From this point, it is preferable to add the aromatic aldehyde addition amount to the above molar ratio or more.
[0013]
As the phenols used in the present invention, various monocyclic, polynuclear, or condensed polycyclic aromatic compounds having one or more hydroxyl groups bonded to an aromatic ring can be used. Specific examples include substituted phenols such as phenol, cresol, xylenol, ethylphenol, butylphenol, phenylphenol, halogenated phenol; resorcin, catechol, dihydroxybiphenyl, tetramethyldihydroxybiphenyl, bisphenol A, bisphenol S, bisphenol F, etc. Divalent phenols: Condensed polycyclic phenols such as α-naphthol, β-naphthol, and naphthalene diol can be used, and one or more of these can be used. Among these phenols, phenol, o-cresol, p-cresol, p-phenylphenol, catechol, 4,4′-dihydroxybiphenyl, α- or β-naphthol is preferably used.
[0014]
The ratio of the total amount of compound (1) + compound (2) to phenols is preferably 0.1 to 0.8 in terms of molar ratio. If the molar ratio is less than 0.1, unreacted phenols increase and the yield decreases, which is not preferable. If it exceeds 0.8, the molecular weight of the resulting resin increases, the softening temperature rises, and the fluidity during molding tends to decrease, which is not preferable. A more desirable ratio is 0.2 to 0.7.
[0015]
In the present invention, the reaction of phenols, bishalomethyl compounds and aromatic aldehydes is carried out in the presence of an acid catalyst.
[0016]
In the present invention, since a bishalomethyl compound is used as a raw material, water is added as a reaction initiator, and hydrogen halide generated by hydrolysis is used as a catalyst for starting a condensation reaction. There is no need.
[0017]
Since HCl generated during the reaction is eventually volatilized and removed from the system, the obtained polymer is almost free from impurities of acidic components unlike the resin produced by adding an acid catalyst. a purity and viscosities, etc., product quality is very stable der Runode, the method of the present invention using water as a reaction initiator, preferred for applications such as in particular dislike impurities.
[0018]
The amount of water added is preferably 100 ppm or more with respect to the total amount of the bishalomethyl compound and the aromatic aldehyde compound. What is necessary is just to add water more than a required amount into a system before reaction start.
[0019]
The reaction of the phenols with the compounds (1) and (2) is usually performed at a temperature range of 80 to 180 ° C, preferably 110 to 160 ° C. The reaction time is generally 1 to 10 hours.
[0020]
During the resinification reaction, the reaction may proceed after simultaneously adding a mixture of phenols and compounds (1) and (2) to the system, and if necessary, the mixture of (1) and (2) may be preliminarily prepared. The reaction may be carried out by sequentially adding to the phenol charged in the reaction kettle.
[0021]
In this reaction, the reaction proceeds continuously with HCl generated by condensation. After completion of the condensation reaction, HCl remaining in the system is distilled off together with unreacted phenols under reduced pressure, or distilled off by a suitable method such as distillation under reduced pressure while blowing an inert gas.
[0022]
When the method of the present invention is used, it can be applied without any problem even in applications in which impurities are extremely strictly regulated, such as an epoxy resin curing agent for semiconductor encapsulation.
Moreover, even if it receives a thermal history during use, quality fluctuations such as an increase in viscosity, an increase in molecular weight distribution, and regeneration of unreacted phenol can be completely ignored, so that a resin with extremely stable quality can be obtained.
[0023]
【Example】
Hereinafter, the present invention will be described specifically by way of examples.
[Example 1]
In a glass flask equipped with a stirrer, a condenser, and a nitrogen gas inlet tube, 552.33 parts by weight of phenol, 0.25 parts by weight of water, 154.24 parts by weight of 1,4-di (chloromethyl) benzene, 93 of benzaldehyde 93 .43 parts by weight were charged and heated with stirring under a nitrogen gas stream. The temperature was raised from 70 ° C. to 120 ° C. over 30 minutes, and a reaction was performed at 120 ° C. for 2 hours and further at 140 ° C. for 2 hours. HCl and water generated by the reaction were reacted while being removed from the system. Thereafter, distillation was performed under reduced pressure at 140 ° C. to 150 ° C. for 2 hours while bubbling nitrogen under a reduced pressure of 50 torr or less to remove unreacted phenol and a slight residual HCl in the system, and 455.26 parts by weight of the target product was obtained. Obtained. Table 1 shows the properties of the obtained phenolic resin.
[0024]
[Example 2]
In Example 1, the amount of raw materials charged was 566.69 parts by weight of phenol, 0.23 parts by weight of water, 105.50 parts by weight of 1,4-di (chloromethyl) benzene, and 127.81 parts by weight of benzaldehyde. The reaction was carried out under the same conditions as in Example 1, followed by distillation under reduced pressure to obtain 464.20 parts by weight of the target product. Table 1 shows the properties of the obtained phenolic resin.
[0025]
[Comparative Example 1]
The flask used in Example 1 was charged with 557.86 parts by weight of phenol, 144.77 parts by weight of p-xylene glycol dimethyl ether, and 94.36 parts by weight of benzaldehyde. While stirring under a nitrogen gas stream, 1.60 parts by weight of p-toluenesulfonic acid monohydrate was added as an aqueous solution at 80 ° C., and methanol and water generated at 120 to 140 ° C. were removed from the system. Time reaction was performed. Thereafter, distillation was performed under reduced pressure at 140 ° C. to 150 ° C. for 2 hours while bubbling nitrogen under a reduced pressure of 50 torr or less to remove unreacted phenol in the system, and 457.11 parts by weight of a phenolic resin was obtained. Table 1 shows the properties of the obtained resin.
[0026]
[Comparative Example 2]
In Comparative Example 1, the same procedure as in Comparative Example 1 was carried out except that 0.032 parts by weight of trifluoromethanesulfonic acid was added as an aqueous solution instead of p-toluenesulfonic acid monohydrate. 456.51 parts by weight of phenol A system resin was obtained. Table 1 shows the properties of the obtained resin.
[0027]
[Table 1]

[0028]
As shown in Table 1, no acidic substance was detected from the resins obtained in any of the examples, and the purity was high. In addition, even after heat treatment at 160 ° C. for 10 hours, no change in molecular weight distribution or increase in phenol was observed, indicating that the thermal stability is excellent.
On the other hand, in the resins obtained in Comparative Examples 1 and 2, the acidic substance of the catalyst remained and the pH of the extracted water was low. In addition, the heat stability was inferior, and the heat treatment at 160 ° C. for 10 hours increased the molecular weight distribution, resulting in a significant increase in melt viscosity and a significant increase in unreacted phenol, resulting in poor quality stability.
[0029]
【The invention's effect】
According to the present invention, an inexpensive raw material can be used, water can be used as a reaction initiator, and hydrogen halide generated by hydrolysis can be used as a catalyst for initiating the condensation reaction. Therefore, it is possible to efficiently obtain a high-purity phenolic resin having a stable quality and suitable for uses such as an epoxy resin curing agent for semiconductor encapsulation, by a simple operation.

Claims (3)

Phenols and the following general formula (1)
R _1- (CH ₂ X) ₂ (1)
And a bishalomethyl compound represented by the following general formula (2)
R ₂ —CHO (2)
(Wherein, R ₁ and R ₂ are the same or different phenylene group, alkyl-substituted phenylene group, diphenylene group, diphenylene oxide group, naphthylene group, and X is a halogen atom.) And adding a water as a reaction initiator and subjecting the hydrogen halide generated by hydrolysis to a condensation reaction as a catalyst for initiating the condensation reaction. The addition amount of water as the reaction initiator, the manufacturing method of the phenolic resin according to claim 1, characterized in that at 100ppm or more by weight relative to the total amount of Bisuharomechiru compound and an aromatic aldehyde compound. Method for producing a phenolic resin according to any one of claims 1 to 2, wherein the molar ratio of aromatic aldehyde compound / Bisuharomechiru compound is in the range of 80 / 20-10 / 90.