JP7718249B2 - phenolic compounds - Google Patents

Description

The present invention relates to a phenolic compound that reacts with an epoxy resin and a curing agent to give a cured product that is excellent in electrical properties, heat resistance, etc.

Cured products obtained by reacting phenolic compounds with epoxy resins and curing agents have excellent electrical properties, heat resistance, etc., and are therefore used in circuit boards, semiconductor encapsulants, machine parts, adhesives, etc.
For example, Patent Document 1 describes a phenolic compound having a dicyclopentadiene skeleton, and describes its use as a resin having excellent heat resistance, moisture resistance, crack resistance, and moldability, and as a composition for semiconductor encapsulation.

WO 2003/029323

In recent years, higher heat resistance has been required due to the increase in heat generation during use caused by the increased density of semiconductors. However, the phenol compound having a dicyclopentadiene skeleton described in Patent Document 1 did not have sufficient crack resistance.
An object of the present invention is to provide a phenolic compound that can give a cured product having excellent crack resistance, heat resistance, moisture resistance, moldability, etc.

The gist of the present invention is a phenolic compound having an alicyclic structure represented by the following formula 1:

In Formula 1, each R is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.
is an integer of 0 to 4, b is an integer of 0 to 3, and n is an integer of 0 to 20.

The phenolic compound of the present invention can provide a cured product that has excellent crack resistance, heat resistance, moisture resistance, moldability, etc. The cured product can be used for circuit boards, semiconductor encapsulants, machine parts, adhesives, paints, civil engineering and building materials, insulating materials for electric and electronic parts, optical materials, etc.

The phenolic compound of the present invention has a structure represented by the following formula 1:

The phenol compound of the present invention has an alicyclic structure in the novolak, which reduces the linear expansion coefficient and water absorption of the cured product, thereby improving heat crack resistance.
Furthermore, since the hydroxyl group concentration is lower and the polarity is lower than that of conventional phenolic resins, the cured product has a low dielectric constant and a low dielectric loss tangent.
In the formula 1, each R is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

Examples of the hydrocarbon group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclohexyl group, etc. From the viewpoints of fluidity and curability, R is preferably a methyl group or an ethyl group, and more preferably a methyl group.
The bonding position (substitution position) of R relative to the hydroxyl group of the benzene ring is preferably the ortho-position or para-position, more preferably the para-position, from the viewpoint of ease of production.

a is an integer of 0 to 4. In terms of fluidity, a is preferably 0 to 2, more preferably 0 or 1, and particularly preferably 0.
b is an integer of 0 to 3. In terms of fluidity, b is preferably an integer of 0 to 2, more preferably an integer of 0 to 1, and particularly preferably 0.
n is an integer of 0 to 20. From the viewpoint of fluidity and curability, n is preferably an integer of 0 to 10, and more preferably 0.
Up to 5 is more preferred, and 0 to 2 is particularly preferred.

Furthermore, in the present invention, the compound of formula 1 is preferably a phenol compound represented by formula 2 below.

n is an integer of 0 to 20, preferably 0 to 10 from the viewpoint of fluidity and curability, and more preferably 0 to 5.
is more preferred, and 0 to 2 is particularly preferred.
The phenol compound of the present invention preferably has a number average molecular weight (Mn) of 400 to 1,000 as calculated using standard polystyrene as determined by gel permeation chromatography (GPC).
The phenol compound of the present invention preferably has a weight average molecular weight (Mw) of 450 to 1,500 as converted into standard polystyrene as measured by gel permeation chromatography (GPC).

The number average molecular weight and weight average molecular weight are preferably high from the viewpoint of curability, and are preferably low from the viewpoint of flowability.
Furthermore, the hydroxyl equivalent of the phenol compound of the present invention, as measured by alkali back titration of an acetylated product in a pyridine-acetic anhydride solution, is preferably 190 to 300. A higher hydroxyl equivalent is preferred from the viewpoint of curability, and a lower hydroxyl equivalent is preferred from the viewpoint of fluidity.

An example of a method for producing the phenol compound represented by the formula 1 will be shown below.
The phenol compound of the present invention can be produced by reacting a phenol having a phenolic hydroxyl group with tricyclopentadiene in the presence of an acid catalyst.
The tricyclopentadiene used as a raw material component of the phenolic resin of the present invention is, for example,
It can be synthesized from dicyclopentadiene by a known method, such as the method described in Appl. Organometal. Chem. 2014, 28, pp. 151-155.

The phenols are not particularly limited, but examples thereof include phenol, cresol, xylenol, ethylphenol, propylphenol, isopropylphenol, n-butylphenol, sec-butylphenol, tert-butylphenol, pentylphenol, hexylphenol, and cyclohexylphenol. Phenol, cresol, and xylenol are particularly preferred from the viewpoints of economy and ease of production.
More than one species may be used in combination.

By appropriately adjusting the molar ratio of tricyclopentadiene to phenols used in the reaction, the molecular weight and melt viscosity of the target phenol compound can be adjusted within an appropriate range.
The molar ratio of phenols to tricyclopentadiene is preferably in the range of 2 to 64, and more preferably 4.
A molar ratio of phenols to tricyclopentadiene is more preferably in the range of 32 to 32. The molar ratio of phenols to tricyclopentadiene is preferably higher in terms of the melt viscosity of the phenol compound, and is preferably lower in terms of synthesis efficiency.

Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid, and organic acids such as formic acid, acetic acid, oxalic acid, trifluoromethanesulfonic acid, and p-toluenesulfonic acid, as well as Friedel-
Examples of the Kraft catalyst include boron trifluoride, boron trifluoride-ether complex, boron trifluoride-phenol complex, boron trifluoride-water complex, boron trifluoride-alcohol complex, and boron trifluoride-amine complex, and mixtures of these can also be used.
Among these, boron trifluoride-phenol complex, boron trifluoride-ether complex, trifluoromethanesulfonic acid, and p-toluenesulfonic acid are particularly preferred from the standpoint of catalytic activity and ease of catalyst removal.

The amount of catalyst used is not particularly limited as long as the molecular weight and melt viscosity of the resin are within appropriate ranges. For example, when phenol and tricyclopentadiene are reacted using p-toluenesulfonic acid as a catalyst, the amount of p-toluenesulfonic acid/(phenol+tricyclopentadiene) is preferably 0.1 to 5.0% by weight, and more preferably 0.5 to 3.0% by weight.

The reaction is preferably carried out in a closed system by replacing the atmosphere in the reactor with an inert gas such as nitrogen or argon, but may also be carried out in an open system while supplying an inert gas into the reactor.
The reaction temperature is usually 60 to 180°C, preferably 100 to 160°C, more preferably 120
In the range of 100° C. to 150° C., a higher temperature is preferable from the viewpoint of reactivity, and a lower temperature is preferable from the viewpoint of suppressing the distillation of phenols and the decomposition of tricyclopentadiene.

In the present invention, a solvent may be used when reacting a phenol with tricyclopentadiene in the presence of an acid catalyst. Considering the high temperature reaction, the solvent may be, for example, toluene, o-
Xylene, p-xylene, m-xylene, ethylene glycol monobutyl ether, and the like are preferred.
The reaction is terminated by deactivating the catalyst. While the deactivation method is not particularly limited, it is preferable to use a method that reduces the amount of ionic impurities such as boron and fluorine remaining in the final phenolic resin to 100 ppm or less. Examples of deactivators that can be used for this purpose include inorganic bases such as alkali metals, alkaline earth metals, or their oxides, hydroxides, and carbonates; ammonium hydroxide; hydrotalcites; and ammonia gas.

After the reaction is completed, the deactivator and other substances are removed from the reaction solution by filtration, separation, etc., to recover a reaction solution free of impurities. During filtration, workability can be improved by adding a solvent, increasing the temperature of the filtrate, or applying increased or reduced pressure to the system.
After removing the deactivating agent, the reaction mixture is concentrated by distillation to remove and recover unreacted phenols. The distillation can be carried out under any of atmospheric, elevated, or reduced pressure conditions.

From the resin composition containing the phenolic compound of the present invention and an epoxy resin, a cured product having excellent crack resistance, heat resistance, moisture resistance, moldability, etc. can be obtained.
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD type epoxy resin, resorcinol type epoxy resin, hydroquinone type epoxy resin, catechol type epoxy resin,
Epoxy resins derived from dihydric phenols such as dihydroxynaphthalene type epoxy resins, biphenol type epoxy resins, and tetramethylbiphenol type epoxy resins.

phenol novolac type epoxy resin, cresol novolac type epoxy resin, trisphenolmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol modified type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol co-condensed novolac type epoxy resin, naphthol-cresol co-condensed novolac type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, biphenyl modified novolac type epoxy resin, etc.
Epoxy resins derived from phenols of higher valence.

Examples of epoxy resins include, but are not limited to, tetrabromobisphenol A type epoxy resins and brominated phenol novolac type epoxy resins. Two or more of these epoxy resins may be used in combination.
From the viewpoints of flowability and further heat resistance of the cured product, the epoxy resin is preferably a bisphenol A type epoxy resin, a tetramethylbiphenol type epoxy resin, a 4,4'-biphenol type epoxy resin, a biphenyl aralkyl type epoxy resin, a phenol aralkyl type epoxy resin, a dicyclopentadiene-phenol modified type epoxy resin, an orthocresol novolac type epoxy resin, or a trisphenolmethane type epoxy resin.

It is more preferable that the epoxy resin is an epoxy resin having di- or higher functional glycidyl groups.
In the resin composition of the present invention, the hydroxyl group equivalent of the phenol compound relative to 1 equivalent of the epoxy group of the epoxy resin in the resin composition is usually 0.1 to 5.0, preferably 0.1 to 2.0, and more preferably 0.1 to 1.5. If the equivalent is greater or smaller than this range, the curability of the resin composition may decrease, and the heat resistance of the cured product may also decrease.

The resin composition may contain additives such as a curing accelerator and an inorganic filler.
Examples of the curing accelerator include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, and amine complex salts, with phosphorus compounds being preferred. These may be used in combination of two or more.
Examples of inorganic fillers include fused silica, crystalline silica, glass powder, alumina, silicon nitride, talc, aluminum hydroxide, calcium carbonate, calcium sulfate, etc., and fused silica is preferred in terms of the amount to be added. These may be used in combination of two or more kinds.

The cured product obtained by curing the resin composition of the present invention has excellent crack resistance, heat resistance, moisture resistance, moldability, etc., and can be used as a semiconductor encapsulant, an electric/electronic component such as a circuit board, a machine component, an adhesive, a paint, a civil engineering construction material, an optical material, etc.
The phenol compound of the present invention can also be cured with a curing agent such as hexamethylenetetramine and used as a phenol resin.

The phenolic resin has excellent crack resistance, heat resistance, moisture resistance, moldability, etc., and is suitable for use in circuit boards,
Semiconductor encapsulants, machine parts, adhesives, paints, civil engineering and construction materials, insulating materials for electrical and electronic parts,
It can be used for optical materials, etc.

The present invention will be described below with reference to examples, which were evaluated by the following methods.

<Number average molecular weight (Mn) and weight average molecular weight (Mw)>
Measurement was carried out using a GPC "HLC-8220GPC" manufactured by Tosoh Corporation under the following measurement conditions.
As the standard polystyrene, TSK Standard Polystyrene: F-
A calibration curve was prepared using F-450, F-128, F-20, F-4, F-2, A-2500, and A-1000, and the number average molecular weight and weight average molecular weight were measured as polystyrene equivalent values.
Column: "TSKGEL Super HZM-N" manufactured by Tosoh Corporation x 3 Eluent: tetrahydrofuran Flow rate: 0.35 ml/min
Detection: RI
Temperature: 40℃
Sample concentration: 0.1% by weight
Injection volume: 10 μl

<Hydroxyl group equivalent>
The hydroxyl equivalent of the phenol compound was measured by a method using an acetylation reagent in accordance with the neutralization titration method of JIS K0070-1992.

<Water absorption rate>
The cured test pieces were stored in a thermostatic chamber at 23°C and 50% humidity for 24 hours or more, and the weight of the test pieces was measured before the moisture absorption test.
Using a constant temperature and humidity chamber "LH24-11P" manufactured by Nagano Science Co., Ltd.,
The test piece of the cured product was left to stand for 168 hours under the condition of 50% RH to absorb moisture, and the weight immediately after absorbing moisture was measured and recorded as the weight of the test piece after the moisture absorption test.
The moisture absorption rate was calculated using the following formula (the size of the test piece was 2 cm square and 3 mm thick).
Moisture absorption rate (wt%) = ((weight of test piece after moisture absorption test - weight of test piece before moisture absorption test) / weight of test piece before moisture absorption test) x 100 (%)

<Coefficient of linear expansion>
The analysis was carried out using a thermomechanical analyzer "TMA/SS6100" manufactured by Seiko Instruments Inc. The cured specimen was subjected to compression mode with a first temperature increase of 5°C/min (from 30°C to 250°C).
The first temperature drop was 10°C/min (from 250°C to 30°C), and the second temperature increase was 5°C/min (from 30°C
The temperature was changed from 0 to 250°C, and the linear expansion coefficient α1 was measured for the second time. (The test piece was a cylinder with a diameter of 1 cm and a thickness of 3 mm.)

<Raw materials used>
The raw materials used in the following examples and comparative examples are as follows.
Tricyclopentadiene (TCPD): Applied Organometallic
The catalyst was Pd(dba)2 as a transition metal catalyst and P(p-tolyl) as a ligand.
3 was used.
Phenol: manufactured by Nacalai Tesque, Inc. p-Toluenesulfonic acid monohydrate: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Chloroform: manufactured by Kanto Chemical Co., Ltd. Epoxy resin (trade name "YL6677"): manufactured by Mitsubishi Chemical Corporation Dicyclopentadiene phenol compound (trade name "ERM6115"): manufactured by Songwon
Curing catalyst (product name "Hokuko TPP"): manufactured by Hokko Chemical Industry Co., Ltd.

<Production Example 1 (Production of Phenol Compound)>
Into a four-neck flask equipped with a rotor, a thermometer, and a dropping funnel, 61.6 g (0.6
31.0 g (0.16 mol) of TCPD was added, and the inside atmosphere was replaced with nitrogen gas. With stirring, the internal temperature was raised to 90° C. and the contents were heated and dissolved.
Thereafter, an aqueous solution of 2.4 g of p-toluenesulfonic acid monohydrate dissolved in 3 mL of water was placed in the dropping funnel, and the resulting solution was slowly added dropwise while maintaining the internal temperature at 90 to 100°C.

After that, the internal temperature was raised to 140°C and the reaction was carried out for 7 hours.
The catalyst was deactivated by adding 4.2 g of a 0% aqueous potassium hydroxide solution.
The reaction mixture was heated to 110°C, and the unreacted phenol was distilled off under reduced pressure.
The mixture was cooled to 0°C and diluted with chloroform, and then transferred to a separatory funnel. The chloroform solution was washed with a 20% aqueous potassium hydroxide solution, and then with water until the pH of the aqueous layer reached 7.

After removing the solvent with an evaporator, 54 g of phenol compound A (TCPD/PHL novolak) was obtained. The phenol compound A had an Mn of 668, an Mw of 934, and a hydroxyl equivalent of 25.
The concentration was 8 g/eq.

Example 1
100 parts of epoxy resin (YL6677), phenol compound A15 synthesized in Production Example 1
The raw materials were weighed into an aluminum dish in a ratio of 9 parts of the acrylic resin and 1 part of the curing catalyst (Hokuko TPP), and stirred at 120°C until homogeneous. The mixture was then heated at 120°C for 2 hours and then at 175°C for 6 hours to obtain a cured product.
The cured product was cut into test pieces of the size required for each evaluation, and the water absorption and linear expansion coefficient were measured. The results are shown in Table 1.

<Comparative Example 1>
Epoxy resin (YL6677) 100 parts, dicyclopentadiene phenol compound (E
The raw materials were weighed into an aluminum dish in the proportions of 115 parts of RM6115 and 1 part of curing catalyst (Hokuko TPP), and stirred at 120°C until homogeneous. Then, the mixture was stirred at 120°C for 2 hours and at 175°C for 6 hours.
The mixture was heated for 1 hour to obtain a cured product.
The cured product was cut into test pieces of the size required for each evaluation, and the water absorption and linear expansion coefficient were measured. The results are shown in Table 1.

As can be seen from Table 1, the cured product of Comparative Example 1, which used a dicyclopentadiene phenol compound as the phenol compound, had a high coefficient of linear expansion and water absorption, and was poor in heat crack resistance.

Claims (7)

A phenol compound represented by the following formula 1:
In Formula 1, each R is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.
is an integer of 0 to 4, b is an integer of 0 to 3, and n is an integer of 0 to 20. The phenol compound according to claim 1, wherein the formula 1 is represented by the following formula 2:
In formula 2, n is an integer of 0 to 20. A resin composition comprising the phenolic compound according to claim 1 or 2 and an epoxy resin. 4. The resin composition according to claim 3, wherein the epoxy resin is an epoxy resin having di- or higher functional glycidyl groups. The phenol compound is used in an amount of 1 equivalent of the epoxy group of the epoxy resin in the resin composition.
The resin composition according to claim 3 or 4, which contains a hydroxyl group equivalent of 0.1 or more and 1.5 or less. A cured product obtained by curing the resin composition described in any one of claims 3 to 5. An electrical or electronic part comprising the cured product of claim 6.