JPH09110954A - Phenolic resin composition and curing agent for epoxy resin - Google Patents

Abstract

(57) Abstract: A phenol resin composition and a curing agent for an epoxy resin, which give an epoxy cured product having good flame retardancy, heat resistance and mechanical properties, are obtained. A phenol resin composition comprising a phenol resin, a compound having a triazine ring having a specific structure, a mixture or condensate of an aldehyde and an aromatic carboxylic acid anhydride, and a phenol resin containing an imide group in the molecule. And a curing agent for epoxy resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenolic resin composition, and in particular, it can give a cured product having good flame retardancy, heat resistance and mechanical properties, and is therefore a binder for various organic and inorganic base materials. It is also suitable for applications such as adhesives, and can give an epoxy cured product having good flame retardancy, heat resistance, and adhesion. Therefore, various applications using epoxy resins such as sealing, lamination, and paints, especially IC Sealing material,
The present invention relates to a phenol resin composition suitable as a curing agent for glass epoxy laminates.

[0002]

2. Description of the Related Art Phenolic resins are mainly used for molding materials, laminates and industrial resins (adhesives or binders) by taking advantage of various excellent physical properties. However, known phenolic resins have the drawback of being inferior in mechanical properties at high temperatures.

As a resin having improved high temperature mechanical properties,
A modified phenolic resin containing an imide group has been disclosed (JP-A-3-93824 and JP-A-3-2757).
No. 08), however, these resins have a drawback that they greatly impair the flame retardancy, which is a useful characteristic inherent in phenolic resins.

Further, as a resin composition having heat resistance,
JP-A-5-117493 discloses a resin composition comprising a compound having an amino group, an acid anhydride, a phenol resin and hexamethylenetetramine. The composition comprises a compound having an amino group and a phenol resin. However, it has a drawback that the heat resistance is still insufficient due to insufficient compatibility.

On the other hand, epoxy resins are widely used mainly for electric and electronic material parts due to their excellent electric characteristics. In applications represented by IC encapsulants and glass epoxy laminates, high heat resistance and adhesion to a substrate are required. For example, JP-A-4-227624 discloses a phenol resin containing an imide group. It is disclosed as satisfying the characteristics. However, this resin has a defect that flame retardancy, which is an essential property for electric and electronic materials, is insufficient with this resin.

[0006]

The present invention can provide a cured product having good flame retardancy, heat resistance and mechanical properties,
Furthermore, it is possible to give an epoxy cured product having good flame retardancy, heat resistance, and adhesiveness, and therefore binders or adhesives for various organic and inorganic base materials, or sealing,
It is an object of the present invention to provide a phenol resin composition suitable as a curing agent for various applications using epoxy resins such as laminates and paints, especially IC encapsulants and glass epoxy laminates.

[0007]

Means for Solving the Problems As a result of intensive studies in view of the above circumstances, the present inventors have found that a mixture containing an imide group in a molecule consisting of a phenol resin, a compound having a triazine ring, and a carboxylic acid anhydride, or It has been found that a cocondensate solves the above problems, and has completed the present invention.

That is, the present invention comprises a mixture or condensate of a phenol, a compound having a triazine ring represented by the general formula (I), an aldehyde and a carboxylic acid anhydride, and a phenol having an imide group in the molecule. The phenol resin composition containing a resin is preferably a phenol resin composition in which any two or all of R ₁ , R ₂ and R _{3 in} the general formula (I) are amino groups, and more preferably A phenol resin composition characterized in that the mixture or the condensate contains substantially no unreacted aldehydes and methylol groups, or the unreacted monofunctional phenol monomer is 3% by weight or less. .

[0009]

Embedded image

(In the formula, R ₁ , R ₂ and R ₃ are amino group, alkyl group, phenyl group, hydroxyl group, hydroxylalkyl group, ether group, ester group, acid group, unsaturated group, cyano group and halogen. Represents one of the atoms, at least one of which represents an amino group)

[0011]

The phenols for obtaining the phenol resin composition of the present invention are not particularly limited, and examples thereof include phenol, cresol, xylenol, ethylphenol, butylphenol, nonylphenol and octylphenol. Examples include polyphenols such as alkylphenols, bisphenol A, bisphenol F, bisphenol S, resorcin, and catechol, halogenated phenols, phenylphenols, and aminophenols. The use of these phenols is not limited to one kind alone, and two or more kinds can be used in combination.

Further, the compound containing a triazine ring for obtaining the phenol resin composition of the present invention is a compound represented by the following general formula (I).

[0013]

Embedded image

(In the formula, R ₁ , R ₂ and R ₃ are amino group, alkyl group, phenyl group, hydroxyl group, hydroxylalkyl group, ether group, ester group, acid group, unsaturated group, cyano group and halogen. It represents any of the atoms, at least one of which represents an amino group.) In formula (I), it is preferable that any _{two of} R ₁ , R ₂ and R ₃ are amino groups, and further, R ₁ , R ₂ , R ₃
More preferably all are amino groups.

As the compound represented by the general formula (I),
Specific examples include melamine, guanamine derivatives such as acetoguanamine and benzoguanamine, cyanuric acid, and cyanuric acid derivatives such as methylcyanurate, ethylcyanurate, acetylcyanurate, and cyanuric chloride. Among these, guanamine derivatives such as melamine, acetoguanamine, and benzoguanamine in which any two or three of R ₁ , R ₂ and R ₃ are amino groups are preferable.

These compounds are not limited to one kind in use, and two or more kinds may be used in combination. The aldehydes for obtaining the phenol resin composition of the present invention are not particularly limited, but formaldehyde is preferable from the viewpoint of easy handling. The formaldehyde includes, but is not limited to, formalin, paraformaldehyde and the like as typical sources.

The carboxylic acid anhydride of the present invention includes phthalic anhydride, trimellitic anhydride, pyromellitic anhydride,
Trimellitic anhydride chloride, 3,3 ', 4,4'-
Biphenyl tetracarboxylic acid anhydride, 2, 3, 3 ',
4,4'-benzophenone tetracarboxylic acid anhydride,
3,4,9,10-perylene tetracarboxylic acid anhydride,
2,3,6-naphthalene tricarboxylic acid anhydride, 2,
3,5-naphthalene tricarboxylic acid anhydride, 1,2,4
-Aromatic carboxylic acid anhydrides such as naphthalene tricarboxylic acid anhydride, unsaturated group-containing carboxylic acid anhydrides such as maleic anhydride, nadic acid anhydride, and allyl nadic acid anhydride.

These compounds are not limited to one kind in use, and two or more kinds can be used in combination. Unreacted aldehyde present in the phenolic resin composition of the present invention, and methylol groups are not particularly limited, but do not include unreacted aldehydes,
Further, it is preferable that the methylol group is not substantially contained.

Curability of the phenol resin cured product is improved by containing no unreacted aldehydes and substantially no methylol group, and when used as a curing agent for epoxy resin, moldability and heat resistance are extremely high. Has the effect of improving.

The unreacted monofunctional phenolic monomer contained in the phenolic resin composition of the present invention is preferably 3% by weight or less. When the unreacted monofunctional phenolic monomer is adjusted to 3% or less to form an epoxy resin curing agent, the resulting cured epoxy resin has an effect of improving heat resistance and moisture resistance.

The unreacted monofunctional phenolic monomer as used herein means a phenolic monomer containing only one phenolic hydroxyl group capable of reacting with an epoxy group in one molecule.

A typical production method for obtaining the phenol resin composition of the present invention will be described below. First, the above-mentioned phenols, aldehydes and compounds having a triazine ring are reacted under a basic or acidic catalyst. At this time, the pH of the system is not particularly limited, but it is preferable to carry out the reaction in the presence of a basic catalyst because many compounds containing a triazine ring are easily dissolved in a basic solution. At this time, it is preferable to use amines as the basic catalyst. Also, the reaction order of each raw material is not particularly limited, and even if a compound having a triazine ring is first reacted with a phenol or an aldehyde, then a compound having a triazine ring is reacted with an aldehyde and then the phenol is reacted. The raw materials may be added, or all the raw materials may be added at the same time and reacted. At this time, the molar ratio of the aldehydes to the phenols is not particularly limited, but is 0.2 to
1.5 is preferable, and 0.4 to 0.8 is more preferable. The weight ratio of the compound having a triazine ring to the phenols is not particularly limited, but 10 to 98:
90-2 are preferable and 50-95: 50-5 are more preferable. When the weight ratio of the phenols is 10% by weight or less, it becomes difficult to make it into a resin, and when it is 98% by weight or more, a sufficient flame retarding effect cannot be obtained, which is not preferable.

Although the catalyst is not particularly limited, examples of the basic catalyst include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide and barium hydroxide, and these. Oxides, ammonia, primary to tertiary amines, hexamethylenetetramine, sodium carbonate, etc., and the acid catalysts include inorganic acids such as hydrochloric acid, sulfuric acid, sulfonic acid, oxalic acid,
Organic acids such as acetic acid, Lewis acids, or 2 such as zinc acetate
Examples thereof include valent metal salts.

When the phenol resin composition of the present invention is used as a curing agent for epoxy resins for electric and electronic materials, it is not preferable that an inorganic substance such as a metal remains as a catalyst residue. It is preferable to use amines and organic acids as acidic catalysts.

From the viewpoint of reaction control, the reaction can be carried out in the presence of various solvents. At this time, the solvent is not particularly limited, for example, acetone, methyl ethyl ketone,
Toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N, N
-Dimethylformamide, methanol, ethanol and the like. These solvents can be used alone or as a mixed solvent of two or more kinds as appropriate.

Next, if necessary, neutralization and washing with water remove impurities such as salts. However, it is not necessary when amines are used as the catalyst. After completion of the reaction, unreacted aldehydes, phenols, water, solvent and the like are removed by a conventional method such as atmospheric distillation or vacuum distillation. At this time, in order to obtain a resin composition substantially free of unreacted aldehydes and methylol groups, which is a characteristic of the resin composition of the present invention, 120
It requires heat treatment at ℃ or above. It is difficult to substantially eliminate the methylol group by heat treatment at 120 ° C. or lower. Further, if the temperature is 120 ° C. or higher, the methylol group can be eliminated by taking sufficient time, but it is preferable to perform heat treatment at a higher temperature, preferably 150 ° C. or higher for efficient elimination. .

Subsequently, a carboxylic acid anhydride is added and reacted. Although the timing of adding the carboxylic acid anhydride is not particularly limited, it is preferable to add the carboxylic acid anhydride after removing the water, because hydrolysis occurs in the presence of water in the system and hinders the imidization reaction. The reaction temperature at this time is also not particularly limited, but is preferably 120 ° C. or higher, and 150 to 18
0 ° C. is more preferred.

After completion of the reaction, if necessary, distillation can be carried out at a higher temperature with heating according to a conventional method for obtaining a novolak resin. At this time, as described above, it is preferable that the unreacted monofunctional phenolic monomer is 3% by weight or less.

When the phenol resin composition of the present invention obtained above is used as a binder or an adhesive, various organic substances, inorganic base materials and additives are added to the phenol resin composition according to a conventional method, Further, hexamethylenetetramine can be used in combination as a curing agent and can be heat-cured before use.

Further, the phenol resin composition of the present invention can be used as a curing agent for epoxy resin. Examples of the epoxy resin in this case include bisphenol A type epoxy resin, polyphenol type epoxy resin, aliphatic epoxy resin, aromatic ester type epoxy resin, cycloaliphatic ester type epoxy resin, aliphatic ester type epoxy resin, ether ester type. Examples thereof include epoxy resins, non-glycidyl epoxy resins such as epoxidized soybean oil, and halogen-substituted products thereof such as bromine and chlorine. There is no problem even if these epoxy resins are used alone or as a mixture of several kinds.

When using the curing agent, a curing accelerator can be used if necessary. As the curing accelerator, various ones generally used for curing epoxy compounds can be used. For example, imidazole and its derivatives, phosphine compounds, amines, and BF ₃ amine compounds are exemplified.

Further, the solvent used in the epoxy resin composition in which the phenol resin composition of the present invention is used in combination with the above epoxy resin is not particularly limited, and the above various solvents can be used if necessary.

When used as an epoxy resin composition, various additives, flame retardants, fillers and the like can be appropriately blended as required. The effects of the present invention will be described in detail below with reference to examples.

[0034]

【Example】

Synthesis Example 1 (Synthesis Example of Phenol Resin Composition) Into 94 parts of phenol and 9.4 parts of benzoguanamine, 41.
51 parts of 5% formalin and 0.47 part of oxalic acid were added, and the temperature was gradually raised to 100 ° C while paying attention to heat generation.
After reacting at 100 ° C for 5 hours, the temperature was raised to 180 ° C over 2 hours while removing water under normal pressure. Next, 7.3 parts of phthalic anhydride was added, and the mixture was further reacted at 170 ° C. for 2 hours, and then unreacted phenol was removed under reduced pressure to obtain a phenol resin composition having a softening point of 98 ° C.

Hereinafter, this composition is abbreviated as "N1". The weight ratio of the phenols and the compound having a triazine ring in the obtained composition, the presence or absence of imide group formation, the amount of unreacted formaldehyde, the presence or absence of methylol group, and the amount of unreacted phenol monomer were determined as follows. . <Weight ratio of phenol to triazine ring-containing compound (benzoguanamine)> 180 ° C, the phenol content in the effluent removed outside the reaction system under reduced pressure was calculated by gas chromatography, and the composition was obtained by subtracting from the phenol part charged. It was defined as the amount of phenol present. Benzoguanamine was included in the composition as it was charged.
The ratio between the two was defined as the abundance ratio. Column: 30% Celite 545 carnauba wax 2mx
3 mmΦ Column temperature: 170 ° C. Inlet temperature: 230 ° C. Detector: FID Carrier gas: N ₂ gas 1.0 kg / cm 2 Measurement method: Internal standard method <Presence or absence of imide group generation> From the infrared absorption spectrum of imide group in resin The existence was confirmed. Equipment: JASCO Corporation IR spectrophotometer IR-8
Type 10 Method: KBr tablet method 1700 to 1720 cm ^-1 and 17 of the obtained chart
C = O of two imide rings appearing at 60 to 1780 cm ^-1
Judgment was made using the absorption due to. The case where two absorptions were recognized was defined as "Yes", and the case where two absorptions were not recognized was defined as "No". <Amount of unreacted formaldehyde> About 5 g of a finely ground composition was added to 50 g of distilled water, and the mixture was kept at room temperature for 24 hours.
Set to pH meter, add N / 10 hydrochloric acid aqueous solution to obtain pH =
It was adjusted to 4.0. 7% adjusted to pH = 4.0
50 ml of an aqueous hydroxylamine solution was added, sealed with an aluminum foil or the like, and left for 30 minutes. Then set it on the pH meter,
Titrate with 1N sodium hydroxide solution until neutralized to pH = 4.0. The amount of free formaldehyde was determined by the following formula.

[0036] <Presence or absence of methylol group> The methylol group present in the resin composition was measured using C13-NMR. Apparatus: JEOL Ltd. GSX270 proton: 270MH _Z measurement solvent: deuterated methanol or deuterated acetone standard: tetramethylsilane Measurement Conditions Pulse condition: 45 ° × 4000Times pulse interval: 2 seconds resulting chart 60~70ppm Judgments were made using peaks that appeared and could be clearly distinguished from noise. A case where a peak was observed was evaluated as “present”, and a case where no peak was observed was evaluated as “absent”. <Amount of Unreacted Phenol Monomer> The content of phenol monomer in the composition was measured under the same measurement conditions as in the gas chromatography described above.

The amount of each component thus obtained is shown in Table 1.
I summarized it in. Synthesis Example 2 29 parts of 41.5% formalin and 0.47 part of triethylamine were added to 94 parts of phenol, and the mixture was reacted at 80 ° C. for 3 hours. After adding 19 parts of melamine and further reacting for 1 hour, the temperature was raised to 120 ° C. while removing water under normal pressure, and the reaction was continued for 2 hours while maintaining the temperature. The temperature was raised to 180 ° C. over 2 hours while removing water under normal pressure. Next, 22 parts of phthalic anhydride was added, and the mixture was further reacted at 170 ° C. for 2 hours, and then unreacted phenol was removed under reduced pressure to obtain a phenol resin composition having a softening point of 103 ° C. The weight ratio of phenols and melamine in the obtained composition, the presence or absence of imide group formation, the amount of unreacted formaldehyde, the presence or absence of methylol group, and the amount of unreacted phenol monomer were determined, and the results are summarized in Table 1. It was

Hereinafter, this composition is abbreviated as "N2". Synthesis Example 3 43 parts of 41.5% formalin, 5 parts of melamine, 5 parts of benzoguanamine, and 0.47 part of triethylamine were added to 94 parts of phenol, and the mixture was reacted at 100 ° C. for 3 hours. Next, the temperature was raised to 150 ° C. while removing water under normal pressure, and the reaction was carried out for 2 hours while maintaining the temperature. The temperature was raised to 180 ° C. over 2 hours while removing water under normal pressure.
Next, 8 parts of phthalic anhydride was added, and the mixture was further reacted at 170 ° C. for 2 hours, and then unreacted phenol was removed under reduced pressure to obtain a phenol resin composition having a softening point of 94 ° C. The weight ratio of phenol to melamine and benzoguanamine in the obtained composition, the presence or absence of imide group formation, the amount of unreacted formaldehyde, the presence or absence of methylol group, and the amount of unreacted phenol monomer were determined, and the results are summarized in Table 1. Indicated.

Hereinafter, this composition is abbreviated as "N3". Synthesis Example 4 To 94 parts of phenol and 93 parts of aniline, 114 parts of 37% formalin was gradually added and reacted at 95 ° C. for 2 hours. Next, the temperature was raised to 150 ° C. while removing water under normal pressure, and the reaction was carried out for 1.5 hours while maintaining the temperature. Then, unreacted phenol and aniline were removed under reduced pressure to obtain an aniline-modified phenol resin. 100 parts of this aniline-modified phenolic resin and 100 parts of maleic anhydride were charged, and the temperature was gradually raised to 600 after the temperature reached 140 ° C.
The mixture was heated and reacted under reduced pressure of mmHg for 60 minutes, and then unreacted maleic anhydride was distilled off to obtain 145 parts of a modified maleimide resin described in JP-A-3-93824.

Hereinafter, this composition is abbreviated as "N4". Synthesis Example 5 70 parts of 37% formalin was gradually added to 94 parts of phenol and 38 parts of aniline and reacted at 95 ° C for 2 hours.
Next, dehydration was performed under a reduced pressure of 600 mmHg, and then the reaction was performed at 180 ° C. for 40 minutes under normal pressure. Then, the system was heated to 150 ° C., 24 parts of phthalic anhydride was added, and a heating reaction was carried out at the same temperature for 60 minutes. Then, the inside of the system was maintained at 170 ° C. under a reduced pressure of 650 mmHg for 60 minutes, and
-275708 modified phenolic resin 1
35 parts were obtained.

Hereinafter, this composition is abbreviated as "N5". Synthesis Example 6 To 94 parts of phenol and 19 parts of aniline, 49 parts of 37% formalin was added and reacted at 95 ° C. for 2 hours. Then 6
After dehydration under a reduced pressure of 00 mmHg, the reaction was performed under normal pressure at 180 ° C. for 40 minutes. Then 150 in the system
℃, add phthalic anhydride 27 parts at the same temperature 60
The heating reaction was performed for minutes. After that, the system is heated at 200 ° C for 65
Hold for 120 minutes under a reduced pressure of 0 mmHg, and
As a result, 86 parts of an epoxy curing agent described in 27624 was obtained.

Hereinafter, this composition is abbreviated as "N6". Synthesis Example 7 94 parts of phenol and 0.47 part of oxalic acid as a catalyst were added, and the temperature was raised to 90 ° C. 54 parts of 41% aqueous formaldehyde solution was dropped from the dropping funnel and reacted for 3 hours. Remove from reaction vessel, melting point (capillary method) 7
A novolac-type yellow lump-shaped synthetic resin having a number average molecular weight of 886 at 0 ° C. was obtained.

Hereinafter, this composition is abbreviated as "N7".

[0044]

[Table 1] [Examples 1 to 3 and Comparative Examples 1 to 2] 15 parts of hexamethylenetetramine was added to 100 parts of each resin of N1 to N5 and mixed and pulverized. 30 parts of this mixed powder was mixed with 70 parts of alumina, mixed and filled in a mold at 165 ° C. for 1
It was molded at 00 kg / cm ^{2 for} 20 minutes. 180 more
After-curing was performed at 3 ° C. for 3 hours to prepare a test piece. When each physical property test was performed on the test piece, the results shown in Table 2 were obtained.

Comparative Example 3 100 parts of the novolak resin obtained in Synthesis Example 7, 10 parts of melamine, 22 parts of pyromellitic dianhydride, and 10 parts of hexamethylenetetramine were mixed and ground. 30 parts of this mixed powder is mixed with 70 parts of alumina and mixed, and the mixture is filled in a mold, and the temperature is 165 ° C. and 100 kg / cm.
Molded at ^{2 for} 20 minutes. Furthermore, after-curing was performed at 180 ° C. for 3 hours to prepare a test piece. When each physical property test was performed on the test piece, the results shown in Table 2 were obtained.

Examples 4 to 6 and Comparative Example 4 Epicron N660 (cresol novolac type epoxy resin, epoxy equivalent 210 [Dainippon Ink and Chemicals, Inc.]) 9
Table 2 shows compounds of N1 to N3 and N6 as curing agents for 5 parts of Epicron 153 (flame-retardant epoxy resin, epoxy equivalent 360 [manufactured by Dainippon Ink and Chemicals, Inc.]). It was compounded in the ratio. Further, 300 parts of fused silica and 2 parts of triphenylphosphine were added, mixed sufficiently, further kneaded by a biaxial roll at 95 ° C to 100 ° C, cooled and pulverized to obtain an epoxy resin sealing material. This molding material was transfer-molded at 170 ° C. for 90 seconds, and after-cured at 170 ° C. for 5 hours to prepare a test piece. When the physical properties of the test piece were tested, the results shown in Table 3 were obtained.

[0047]

[Table 2]

[0048]

[Table 3]

* 1: Crack resistance test At the time of molding the epoxy, a spring washer is embedded and hardened, and cracks generated when cooled to room temperature are compared.

Number of cracks: Number of test pieces with cracks / Number of test pieces

[0051]

The phenol resin composition of the present invention can give a cured product having good flame retardancy, heat resistance and mechanical properties. Furthermore, an epoxy cured product having good flame retardancy, heat resistance, and adhesion can be provided.

Claims (8)

[Claims] 1. A phenolic resin comprising a mixture or condensate of a phenol, a compound having a triazine ring represented by the general formula (I), an aldehyde and a carboxylic acid anhydride, and containing a imide group in the molecule. A phenolic resin composition comprising: Embedded image (Wherein, R ₁ , R ₂ and R ₃ represent an amino group, an alkyl group, a phenyl group, a hydroxyl group, a hydroxylalkyl group,
Ether group, ester group, acid group, unsaturated group, cyano group,
Represents one of the halogen atoms, at least one of which represents an amino group) 2. In the general formula (I), any _{two of} R ₁ , R ₂ and R ₃ are amino groups.
A composition as described. 3. The composition according to claim 1, wherein R ₁ , R ₂ and R _{3 in the} general formula (I) are amino groups. 4. The carboxylic acid anhydride is an aromatic carboxylic acid anhydride, according to any one of claims 1 to 3.
The composition according to Item. 5. The composition according to claim 1, wherein the mixture or the condensate is substantially free of unreacted aldehydes and methylol groups. 6. The composition according to claim 1, wherein the unreacted monofunctional phenolic monomer contained in the mixture or the condensate is 3% by weight or less. 7. A molecule characterized in that a phenol, a compound having a triazine ring and an aldehyde are reacted in the presence of amines, followed by heat treatment at 120 ° C. or higher, and then a carboxylic acid is reacted. A method for producing a phenol resin composition comprising a phenol resin containing an imide group. 8. A curing agent for an epoxy resin, which comprises the phenol resin composition according to claim 1 as a main component.