JPH10120749A - Curing of biphenol resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cured product having high segment packing to suppress micro-Brownian motion and exhibiting excellent heat-resistance by curing a specific biphenol resin containing less than a specific amount of unreacted biphenol. SOLUTION: This biphenol resin is produced by condensing a biphenol compound having one or more <=4C alkyl groups as substituents on an aromatic ring or an unsubstituted biphenol compound such as 4,4-biphenol with an aldehyde or condensing the above biphenol compound with a non-rigid component expressed by formula I (R1 is OH, H, a <=9C alkyl or an aromatic residue) such as phenol and/or a non-rigid component expressed by formula II (B1 and B2 are each 1,4-phenylene, 2,6-naphthalene, etc.; Y1 and Y2 are each a <=10C organic residue, O, COO, etc.; R2 is OH or NH2 ; (m) is 0-1; (n) is 0-3) such as bisphenol A and an aldehyde. The biphenol resin containing <=20wt.% of unreacted biphenol in the resin is cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for curing a biphenol resin from which a cured product having excellent heat resistance can be obtained.

[0002]

2. Description of the Related Art In recent years, in the field of thermoplastic resins, polymers having liquid crystallinity have been put to practical use as a technique for imparting heat resistance to resins, and the performance thereof has been greatly spotlighted in the industrial world. On the other hand, as for thermosetting resins, epoxy resins are also described in `` thermosetting resins '' Vol.16 17-25 (1995) and `` Journal of the Adhesion Society of Japan '' Vol.32 24-29 (1996). It has been found that a cured resin having mesogen in its skeleton exhibits excellent heat resistance. However, in the case of phenolic resin, there is no such example, and the present inventors have thought that it is difficult for mesogen-containing phenolic resin to exhibit liquid crystallinity due to high crystallinity, and as a result of intensive study, It was found that, when the biphenol resin in which the unreacted monomer having the strongest crystallinity was reduced was cured, liquid crystallinity was developed and a cured product having high heat resistance was obtained.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel method for curing a biphenol resin which can provide a cured product having excellent heat resistance.

[0004]

SUMMARY OF THE INVENTION The amount of unreacted biphenol obtained by condensing a biphenol and an aldehyde or a non-rigid component with a biphenol with an aldehyde, or condensing a biphenol with para-xylylene glycol dimethyl ether Has been found to be able to improve heat resistance by using a biphenol resin having a content of not more than 20% by weight (hereinafter abbreviated as%), thereby leading to the present invention.

According to the present invention, there is provided a compound represented by the general formula (1), wherein at least one alkyl group having 4 or less carbon atoms is substituted on the aromatic ring or unsubstituted biphenols and aldehydes, or the biphenols. Content of a non-rigid component and / or a non-rigid component represented by the general formula (2) and an unreacted biphenol contained in the biphenol resin obtained by condensing an aldehyde. Is a method for curing a biphenol resin, the method comprising curing a biphenol resin having a content of 20% by weight or less.

[0006]

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(In the general formula (1), R _{1 represents} OH, H, or an alkyl group or aromatic residue having 9 or less carbon atoms.)

[0008]

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(In the general formula (2), B ₁ and B _{2 represent} 1,4-phenylene, 1,4-naphthalene, 2,6-naphthalene, 2,7-naphthalene and 1,4-cyclohexyl, and Y ₁ and Y ₂ : organic residues having 10 or less carbon atoms containing or not including a hetero atom, O, COO, CO, SiZ ₂ O, SiZ ₂ (Z is hydrogen or carbon atoms 7 Or less of an alkyl group or an aromatic organic residue), S, SO, SO ₂ , or NHCO R ₂ : represents OH or NH ₂ m: represents the number of 0 to 1 n: 0 to 0 The number of 3 is shown.)

The biphenol resin of the present invention has a wide temperature range in which liquid crystallinity is exhibited because the biphenol used has a rigid structure and the content of unreacted biphenols which inhibits the development of liquid crystallinity during curing is small. Upon curing, the rigid structure segments can align with each other, and cure with liquid crystal properties. Orientation of the rigid structure segments causes physical bonding between the segments, and good packing of the segments and suppression of micro-Brownian motion improves the heat resistance of the cured product.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The biphenol of the present invention is a so-called biphenyl in which the carbon atoms of two benzene rings are directly bonded by a single bond, in which the hydrogen atom of each benzene ring is replaced by a hydroxyl group, or the ring further has 4 or less carbon atoms. Wherein at least one alkyl group is substituted. 4,4 '
-Biphenol, 2,2'-biphenol, 2,4'-biphenol, 3,3'-dimethyl-4,4'-dihydroxybiphenyl,
2,5-dimethyl-4,4'-biphenol, 2,5-diethyl-4,4'-
Biphenol and the like can be exemplified. Examples of the phenols of the general formula (1) include phenol, catechol, resorcin, hydroquinone, cresol, ethylphenol, phenylphenol and the like. Compounds of the general formula (2) include bisphenol A, bisphenol F, diaminodiphenylmethane, 4,4′-dihydroxybenzophenone,
4'-oxybisphenol, 1,3-bis (hydroxyphenyl) tetramethyldisiloxane, aromatic hydrocarbon-modified phenolic resin, other hydroxyphenyls obtained by Friedel Crafts reaction of alkyldienes with phenol or aniline Or an aminophenyl-functional linear aliphatic compound, a hydroxyl- or aminophenyl-functional linear aliphatic compound at both ends obtained by reacting with an α, ω-dibromoalkane, etc., but is not particularly limited thereto. Not something.

The amount of residual biphenol in the biphenol resin before curing is 20% or less. If the biphenols remaining unreacted in the biphenol resin before curing exceeds 20%, the melting temperature will rise and the liquid crystal temperature range will be narrowed, segment orientation will be inhibited, and the cured product will have liquid crystalline properties. I can't. As a result, the micro-Brownian motion of the rigid segment is not suppressed, so that the heat resistance decreases. In addition, if the biphenols component incorporated into the biphenol resin before curing by covalent bond is small, the content of the rigid segments is reduced, so that the rigid segments are less likely to be oriented, and as a result, the cured product has liquid crystallinity. Disappears. The charging ratio of the biphenols during the reaction is desirably 50% or more in molar ratio. Examples of the aldehydes include simple substances such as formaldehyde, acetaldehyde, and paraformaldehyde, or mixtures thereof. The amount of the aldehyde compounded in 1 mol of the phenol is preferably 0.5 mol or more and 4 mol or less. The amount of paraxylylene glycol dimethyl ether is as follows: biphenols, phenols of general formula (1), general formula (2)
Is generally 0.5 or more and 0.8 or less per 1 mol of the total amount of the compound.

Examples of the catalyst for the addition condensation reaction of phenols and aldehydes include acids such as oxalic acid, hydrochloric acid, formic acid, acetic acid, sulfuric acid, diethyl sulfate, paratoluenesulfonic acid, sodium hydroxide, potassium hydroxide, and the like. Alkali such as ammonia and triethylamine can be used alone or in combination of two or more. Solvents or suspending media used when reacting phenols and aldehydes include benzene, toluene, xylene, methanol, ethanol, N-methylpyrrolidone, tetrahydrofuran, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, ethylene glycol monomethyl ether , Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, dioxane, cyclohexanone, water and the like. The phenols are heated and reacted with the catalyst to condense. By performing dehydration and solvent removal, a biphenol resin can be obtained. Curing agents that can be used in the biphenol resin of the present invention include difunctional or higher functional epoxy resins, isocyanates, formaldehyde resins, hexamethylenetetramine, and the like. Applications of the biphenol resin of the present invention include materials for molding materials, coating materials for electronic and electric parts, epoxy resin raw materials, epoxy resin curing agents, and the like. Therefore, addition of components known to those skilled in the art, such as various inorganic fillers, wood flour, mold release agents, and curing accelerators, as necessary, does not hinder the present invention.

[0014]

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

[Synthesis Example 1] A reactor equipped with a stirrer, a reflux condenser and a thermometer was charged with 50 parts of 4,4'-biphenol, 88%
5.5 parts of paraformaldehyde, 150 parts of ethylene glycol monoethyl ether and 1.5 parts of paratoluenesulfonic acid dihydrate were added, and the mixture was refluxed and heated on an oil bath with stirring for 5 hours. After heating is completed, triethylamine 0.8
After the addition, the resin produced by dropping into 1500 parts of water was precipitated and collected. After re-dissolving in methanol and washing, the remaining water was distilled off by heating at 120 ° C. under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a biphenol resin having a residual biphenol of 15% and a number average molecular weight of 730 was obtained.

[Synthesis Example 2] 50 parts of 4,4'-biphenol, 16.8 parts of phenol, 9.2 parts of 88% paraformaldehyde, 2.0 parts of paratoluenesulfonic acid and 200 parts of ethylene glycol monoethyl ether were mixed. When synthesized according to the method described, a biphenol resin having a residual biphenol of 8% and a number average molecular weight of 680 was obtained.

Synthesis Example 3 50 parts of 2,2′-biphenol, 40.8 parts of bisphenol A, 88% paraformaldehyde 9.2
Parts, 2.7 parts of paratoluenesulfonic acid and 272 parts of ethylene glycol monoethyl ether were mixed and synthesized by the method described in Example 1.
A biphenol resin having a number average molecular weight of 750 was obtained.

[Synthesis Example 4] 50 parts of 2,2'-biphenol, 8.4 parts of phenol, 20.4 parts of bisphenol A, 9.2 parts of 88% paraformaldehyde, 2.4 parts of paratoluenesulfonic acid and 236 parts of ethylene glycol monoethyl ether were mixed. Then, when synthesized by the method described in Example 1, a biphenol resin having a residual biphenol of 7% and a number average molecular weight of 700 was obtained.

Synthesis Example 5 In a reactor equipped with a stirrer, a reflux condenser and a thermometer, 50 parts of 4,4'-biphenol, 22.3 parts of paraxylylene glycol dimethyl ether, 217 parts of ethylene glycol monoethyl ether, and diethyl sulfate
0.050 parts were added, and the mixture was heated under reflux while stirring on an oil bath for 150 minutes. Thereafter, the temperature was raised to 260 ° C. while removing the solvent under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a biphenol resin having a residual biphenol of 10% and a number average molecular weight of 560 was obtained.

[Synthesis Example 6] 50 parts of 4,4'-biphenol, m-
14.5 parts of cresol, 22.3 parts of paraxylylene glycol dimethyl ether, 260 parts of ethylene glycol monoethyl ether, and 0.037 part of diethylsulfuric acid were mixed and synthesized according to the method described in Synthesis Example 5. As a result, 4% of residual biphenol and a number average molecular weight of 500 were obtained. A biphenol resin was obtained.

Synthesis Example 7 Synthesis Example 5 was prepared by mixing 50 parts of 2,2'-biphenol, 27.0 parts of bisphenol F, 22.3 parts of paraxylylene glycol dimethyl ether, 300 parts of ethylene glycol monoethyl ether, and 0.056 part of diethyl sulfate. As a result, a biphenol resin having a residual biphenol content of 4% and a number average molecular weight of 590 was obtained.

[Synthesis Example 8] 2,2'-biphenol 50 parts, m-
Cresol 7.2 parts, bisphenol F 13.5 parts, paraxylylene glycol dimethyl ether 22.3 parts, ethylene glycol monoethyl ether 280 parts, diethyl sulfate 0.047
The resulting mixture was mixed and synthesized according to the method described in Synthesis Example 5 to obtain a biphenol resin having a residual biphenol of 5% and a number average molecular weight of 640.

[Synthesis Example 9] 100 parts of phenol, 10 parts of water, 37 parts of a reactor equipped with a stirrer, a reflux condenser and a thermometer
68.8 parts of an aqueous solution of formaldehyde and 1 part of oxalic acid dihydrate were added, and the mixture was refluxed and heated on an oil bath with stirring 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 phase was precipitated and the aqueous phase was separated by decantation. The remaining 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.

Synthesis Example 10 50 parts of 2,4′-biphenol, 12.6 parts of phenol, 22.3 parts of paraxylylene glycol dimethyl ether, ethylene glycol monoethyl ether
225 parts and 0.037 parts of diethyl sulfuric acid are mixed and placed on an oil bath.
The mixture was heated under reflux with stirring for 150 minutes. After the completion of the heating, 0.024 part of triethylamine was added, and the resulting resin was dropped into 1500 parts of water to precipitate and collect the resin. After re-dissolving in methanol and washing, the remaining water was distilled off by heating at 120 ° C. under a reduced pressure of 50 to 100 mmHg. After cooling to room temperature, a biphenol resin having a residual biphenol of 26% and a number average molecular weight of 490 was obtained.

[Synthesis Example 11] 50 parts of 4,4'-biphenol, 88% in a reactor equipped with a stirrer, a reflux condenser and a thermometer
5.5 parts of paraformaldehyde, 150 parts of ethylene glycol monoethyl ether and 6.0 parts of oxalic acid dihydrate were added,
The mixture was refluxed and heated on an oil bath with stirring for 5 hours. water
Resin produced by dropping into 1500 parts was precipitated and collected.
After redissolving in methanol and washing, remove the remaining water
Under reduced pressure of 100 mmHg, it was distilled off by heating at 120 ° C. After cooling to room temperature, a biphenol resin having a residual biphenol of 32% and a number average molecular weight of 420 was obtained.

Example 1 The biphenol resin solid at room temperature obtained in Synthesis Example 1 was ground, blended at the following ratio, and kneaded with a hot roll to prepare a material. Temperature of this material
After molding at 160 ° C and 200kg / cm2 for 10 minutes,
After the curing, a test piece for measuring the coefficient of linear expansion and the deflection temperature under load was manufactured. Biphenolic resin 45 parts Hexamethylenetetramine 7 parts Calcium hydroxide 3 parts Calcium carbonate 45 parts This test piece was measured for linear expansion coefficient and deflection temperature under load (load: 1.82 MPa). Table 1 shows the measurement results. Further, a sample was prepared by blending the biphenol resin of Synthesis Example 1 and hexamethylenetetramine at the following ratios. 100 parts of biphenol resin 15 parts of hexamethylenetetramine This sample was placed on a cover glass with a diameter of 22 mm, and after defoaming, the temperature was raised from 130 ° C to 250 ° C at a rate of 1 ° C / min. The liquid crystallinity was evaluated by observing with a microscope and checking for birefringence at room temperature during and after curing.
Table 2 shows the observation results.

Examples 2 to 8, Comparative Examples 1 to 3 As shown in Tables 1 and 2, the biphenol resin of Synthesis Example 1 of Example 1 was changed to the corresponding biphenol resin or phenol resin of Synthesis Example, respectively. A cured product was produced by the method described in Example 1, and the coefficient of linear expansion, deflection temperature under load, and liquid crystallinity were evaluated.

[0028]

[Table 1]

[0029]

[Table 2]

As apparent from Tables 1 and 2, Examples 1 to
Each of the biphenol resin cured products of No. 8 has liquid crystallinity,
It is apparent that the cured products of biphenol resin having no liquid crystal properties of Comparative Examples 1 to 3 and the cured products of conventional phenol resins have smaller linear expansion coefficients, higher deflection temperatures under load, and are superior in heat resistance.

[0031]

The cured product of the biphenol resin produced by the method for curing a biphenol resin of the present invention has excellent heat resistance.

Claims (5)

[Claims] 1. An aromatic ring in which at least one alkyl group having 4 or less carbon atoms is substituted or unsubstituted biphenols and aldehydes, or the biphenols,
A biphenol resin obtained by condensing a non-rigid component represented by the general formula (1) and / or a non-rigid component represented by the general formula (2) with an aldehyde, which is contained in the biphenol resin. 20 unreacted biphenols
A method for curing a biphenol resin, comprising curing a biphenol resin having a weight percent or less. Embedded image (In the general formula (1), R _{1 represents} OH, H, or an alkyl group or aromatic residue having 9 or less carbon atoms.) (In the general formula (2), B ₁ and B _{2 represent} 1,4-phenylene, 1,4-naphthalene, 2,6-naphthalene, 2,7-naphthalene, and 1,4-cyclohexyl, which are different from each other. Y ₁ , Y ₂ : organic residues having or not containing a heteroatom and having not more than 10 carbon atoms, O, COO, CO, SiZ ₂ O, SiZ ₂ (where Z is hydrogen or not more than 7 carbon atoms) (Alkyl group or aromatic organic residue), S, SO, SO ₂ , or NHCO R ₂ : OH or NH ₂ m: 0 to 1 n: 0 to 3 Is shown.) 2. An aromatic ring in which at least one alkyl group having 4 or less carbon atoms is substituted or unsubstituted biphenols and paraxylylene glycol dimethyl ether, or the biphenols and a compound represented by the general formula (1): A non-rigid component and / or a non-rigid component represented by the general formula (2), and a biphenol resin obtained by condensation with para-xylene glycol dimethyl ether, wherein unreacted biphenols contained in the biphenol resin are A method for curing a biphenol resin, comprising curing a biphenol resin having a content of 20% by weight or less. 3. The method according to claim 1, wherein the biphenol is 4,4′-dihydroxybiphenyl (4,4′-biphenol), 3,3′-dimethyl-4,
3. The method according to claim 1, wherein at least one selected from the group consisting of 4'-dihydroxybiphenyl, 2,4'-dihydroxybiphenyl (2,4'-biphenol) and 2,2'-dihydrobiphenyl (2,2'-biphenol). The method for curing the biphenol resin according to the above. 4. The method for curing a biphenol resin according to claim 1, wherein the non-rigid component represented by the general formula (1) is at least one selected from the group consisting of phenol, cresol and phenylphenol. 5. The non-rigid component represented by the general formula (2) is bisphenol A, bisphenol F, bisphenol S
The method for curing a biphenol resin according to claim 1, wherein at least one is selected from the group consisting of