JPH09255746A - Heat-resistant phenol resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-resistant phenol resin having a low coefficient of linear thermal expansion and improved in load-deflection temp., heat resistance, and flowability by condensing two specific phenols with an aldehyde. SOLUTION: 1 mol of a mixture comprising a phenol represented by formula I [wherein X is a single bond, 1,4-cyclohexylene, COO, CM=CM (wherein M is H, a monovalent arom. group, or 4C or lower alkyl), or C≡C; A is 1,4- phenylene, 1,4-naphthylene, 2,6-naphthylene, or 2,7-naphthylene; and n is 1-3] and another phenol represented by formula II (wherein R is OH, H, or 4C or lower alkyl) in a molar ratio of (1:0.1)-(1:1) is condensed with 0.5-4mol of an aldehyde in the presence of an acid or alkali catalyst.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a phenol resin having both excellent heat resistance and fluidity.

[0002]

2. Description of the Related Art Phenolic resins having various molecular weights are synthesized by reacting phenols with aldehydes under acidic or alkaline conditions. Melt viscosity is a major factor in moldability when molding and curing phenol resin,
Generally, the melt viscosity has a strong correlation with the molecular weight, and the lower the molecular weight, the smaller the melt viscosity and the better the moldability. However, when the low molecular weight phenolic resin is cured, other properties such as strength and toughness are deteriorated. Conventionally, it has been extremely difficult to achieve both low viscosity and high strength of a phenol resin.

[0003]

The present invention was obtained as a result of extensive studies to solve such problems of the phenol resin, and the object is to have excellent heat resistance and fluidity. To provide a phenolic resin.

[0004]

[Means for Solving the Problems] Heat resistance and fluidity can be improved by condensing phenols represented by the following general formula (1) and phenols represented by the general formula (2) with aldehydes. The present invention has been accomplished as a result of discovering the findings and making intensive studies.

[0005]

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[0006]

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In the phenol resin of the present invention, since the phenols used have a rigid structure, the rigid structure parts can be oriented with each other, the melt viscosity is lowered and the fluidity at the time of molding is improved. Further, the packing of the segments is good and the micro Brownian motion is suppressed, so that the heat resistance is improved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. Examples of the phenols of the general formula (1) used in the present invention include 4,4′-biphenol, 4,4′-dihydroxystilbene, 2,6-dihydroxynaphthalene, dihydroxyquarterphenyl and the like, or a mixture thereof. is there. Examples of phenols of the general formula (2) include phenol, catechol, resorcin, hydroquinone and cresol. Examples of the aldehydes include simple substances such as formaldehyde, acetaldehyde, and paraformaldehyde, or mixtures thereof. General formula (2) blended with 1 mol of the phenol of general formula (1)
The amount of phenols is 0.1 mol or more and 1 mol or less. Aldehydes to be blended in 1 mol of a mixture of phenols of general formula (1) and phenols of general formula (2) are 0.5 mol or more
It is 4 mol or less. Examples of the catalyst for the addition condensation reaction of phenols and phenols and aldehydes include acids such as oxalic acid, hydrochloric acid, sulfuric acid, diethylsulfuric acid and paratoluenesulfonic acid or sodium hydroxide, potassium hydroxide, ammonia, triethylamine and the like. The alkalis can be used alone or in combination of two or more kinds. Solvents or suspension media used when reacting phenols, aldehydes, benzene, toluene, xylene,
Methanol, ethanol, tetrahydrofuran, dimethyl sulfoxide, water or the like can be used. The above phenols are heated and reacted with the above catalyst to be condensed while dehydrating. A phenol resin can be obtained by performing dehydration and demonomer.

Curing agents that can be used in the phenol resin of the present invention include bifunctional or higher functional epoxy resins, isocyanates, formaldehyde resins, and hexamethylenetetramine. The amount of hexamethylenetetramine added is 3 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the phenol resin composition. If it is less than 3 parts by weight, the curing is insufficient, and if it exceeds 20 parts by weight, the decomposition gas of hexamethylenetetramine causes swelling or cracks in the molded product. Examples of the use of the phenol resin of the present invention include a molding material, an electric / electronic component coating material, an epoxy resin raw material and an epoxy resin curing agent.

[0010]

The present invention will be described below with reference to examples. However, the present invention is not limited to these examples. Further, “parts” described in Examples and Comparative Examples
And “%” all indicate “parts by weight” and “% by weight”.

[Example 1] In a reactor equipped with a stirrer, a reflux condenser and a thermometer, 50 parts of biphenol, 20.2 parts of phenol, and 25.5 parts of 37% aqueous formaldehyde solution (moles based on the above two kinds of phenols). A ratio of 0.65) and 1 part of oxalic acid dihydrate were added, and the mixture was heated under reflux with stirring on a water bath for 30 minutes. One part of oxalic acid dihydrate was further added, and the mixture was heated under reflux for another 1 hour. The reaction system was cooled by adding 400 parts of water. The resin was allowed to settle and the aqueous phase was separated by decantation. The residual water was distilled off by heating at 120 ° C. under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a phenol resin having a number average molecular weight of 650 was obtained.

Example 2 A reactor equipped with a stirrer, a reflux condenser and a thermometer was equipped with 50 parts of 4,4'-dihydroxystilbene, 17.8 parts of phenol and 9.4 parts of paraformaldehyde (the above-mentioned two kinds). Molar ratio to phenols 0.6
5), 1 part of oxalic acid dihydrate and 400 parts of methanol were added, and the mixture was heated under reflux with stirring for 30 minutes on a water bath.
One part of oxalic acid dihydrate was additionally charged, the mixture was heated under reflux for an additional 1 hour, and then the reaction system was cooled. Water was added to precipitate and separate the resin. The residual water was distilled off by heating at 120 ° C. under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a phenol resin having a number average molecular weight of 500 was obtained.

Example 3 A reactor equipped with a stirrer, a reflux condenser and a thermometer was equipped with 50 parts of 4,4'-biphenol, 20.2 parts of phenol and 12.4 parts of paraformaldehyde (the above-mentioned two phenols). A molar ratio of 0.75), 100 parts of dimethyl sulfoxide and 1 part of paratoluene sulfonic acid were added, and the mixture was heated at 100 ° C. for 1 hour, then heated to 150 ° C. and further stirred for 1 hour. The reaction system was cooled and water was added to precipitate and separate the resin. The residual water was distilled off by heating at 120 ° C. under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a phenol resin having a number average molecular weight of 750 was obtained.

Example 4 50 parts of 2,6-dihydroxynaphthalene, 23.5 parts of phenol, 12.4 parts of paraformaldehyde (the above-mentioned two phenols were added to a reactor equipped with a stirrer, a reflux condenser and a thermometer. Molar ratio to class 0.
65), 1 part of oxalic acid dihydrate and 100 parts of dimethyl sulfoxide were added, and the mixture was heated at 100 ° C. for 1 hour and then 150 ° C.
The temperature was raised to 1, and the mixture was heated with stirring for another hour. The reaction system was cooled and water was added to precipitate and separate the resin. The residual water was distilled off by heating at 120 ° C. under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a phenol resin having a number average molecular weight of 700 was obtained.

Comparative Example 1 100 parts of phenol and 10 parts of water were added to a reactor equipped with a stirrer, a reflux condenser and a thermometer.
Parts, 68.8 parts of 37% aqueous formaldehyde solution (molar ratio to phenol 0.8) and 1 part of oxalic acid dihydrate were added, and the mixture was heated under reflux with stirring for 30 minutes on a water bath. One part of oxalic acid dihydrate was further added, and the mixture was heated under reflux for another 1 hour. The reaction system was cooled by adding 400 parts of water. The resin was allowed to settle and the aqueous phase was separated by decantation. The residual water was distilled off by heating at 120 ° C. under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a phenol resin having a number average molecular weight of 700 was obtained.

[Comparative Example 2] 100 parts of phenol and 28.9 parts of paraformaldehyde were added to a reactor equipped with a stirrer, a reflux condenser and a thermometer (molar ratio to phenol: 0.
8), 400 parts of methanol and 5 parts of oxalic acid dihydrate were added, and the mixture was heated under reflux with stirring on a water bath for 30 minutes.
An additional 5 parts of oxalic acid dihydrate was added and the mixture was heated under reflux for an additional 1 hour. The reaction system was cooled and the resin was precipitated and separated by decantation. 50-10 remaining methanol
It was distilled off by heating at 120 ° C. under a reduced pressure of 0 mmHg. After cooling to room temperature, a phenol resin having a number average molecular weight of 500 was obtained.

[Preparation of Phenolic Resin Composition] Example 1
~ 4, the phenolic resin solids obtained at room temperature obtained in Comparative Examples 1 and 2 were crushed, and the phenolic resin compositions were separately prepared in the following proportions. Phenolic resin 45 parts Hexamethylenetetramine 7 parts Calcium hydroxide 3 parts Calcium carbonate 45 parts This composition is used at a temperature of 160 ° C. and a pressure of 200 kg / cm 2 for 10 times.
After molding for 1 minute, post-curing was performed at 180 ° C. for 3 hours to prepare a test piece. The linear expansion coefficient and the deflection temperature under load (load: 1.82 MPa) of this test piece were measured.
Table 1 shows the measurement results. In addition, Examples 1 to 4 and Comparative Example 1
Table 2 shows the results obtained by measuring the melt viscosity (130 ° C.) of the phenol resins of Nos. 2 to 2 by a cone plate viscometer.

[0018]

[Table 1]

[0019]

[Table 2]

As is clear from Table 1, all of the phenolic resins of Examples 1 to 4 have a smaller linear expansion coefficient, a higher deflection temperature under load, and a higher heat resistance than the conventional phenolic resins of Comparative Examples 1 and 2. It is clear that Further, the melt viscosity is reduced and the fluidity is improved.

[0021]

The heat-resistant phenol resin of the present invention has excellent heat resistance and fluidity.

Claims (1)

[Claims] 1. A phenol resin obtained by condensing a phenol represented by the following general formula (1) and a phenol represented by the general formula (2) with aldehydes. Embedded image Embedded image