JPH0733845A - Modified phenolic resin and its production - Google Patents

Abstract

PURPOSE:To obtain the subject resin containing an allylnadiimide in the molecule, useful as a coating compound, etc., having excellent long-term heat resistance and mechanical strength by reacting an intermediate resin prepared by reaction of a phenol, etc., with a given amount of allylnadic acid anhydride. CONSTITUTION:Three components of a phenol, an aromatic amine such as aniline and formaldehyde are mixed and heated or the aromatic amine is mixed with formaldehyde, heated, further incorporated with a phenol, heated to form an intermediate resin, which is reacted with 0.03-1.0mol (based on 1mol of the phenol) allylnadic acid anhydride under heating to give the objective resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified phenolic resin having excellent long-term heat resistance and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, phenol resins generally obtained by reacting phenols with formaldehyde in the presence of a catalyst have relatively good heat resistance among various thermosetting resins, and have good processability and mechanical properties. Since it has excellent characteristics, it has been put to practical use for a long time and has a wide range of applications. However, in recent years, in order to further expand the applications, it has been required to further improve the heat resistance of a phenol resin cured product obtained by thermosetting a phenol resin.

In order to meet such requirements, various modification methods of phenolic resins have been studied so far. Examples of the imide group introduced therein include reaction products of aniline, phenols, and formalin with maleic anhydride to form a maleimide group-containing modified phenolic resin, and o, o'- Method of mixing diallyl bisphenol A (Japanese Patent Publication No. 55-3
No. 364), phenols, aromatic amines, and formaldehyde are reacted to synthesize a phenol resin having an aromatic amino group in the molecule, and an aromatic carboxylic acid anhydride is further reacted to produce an aromatic imide-modified phenol resin. And the like (Japanese Patent Laid-Open No. 3-275708) are known. However, the long-term heat resistance of the resins obtained by these methods has not always been satisfactory.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and its purpose is to further improve heat resistance, particularly long-term heat resistance, as compared with the conventional imide group-containing phenol resin. Another object is to provide a modified phenolic resin which gives a cured product.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that the above-mentioned object can be achieved by a modified phenol resin containing an allylnadiimide group in the molecule. Completed the invention.

The gist of the present invention is, firstly, phenols,
A resin obtained by the reaction of formaldehyde, aromatic amines and allyl nadic acid anhydride, which contains an allyl nadiimide group in the molecule, and the amount of the allyl nadiimide group is 0.03 to 0. In a modified phenolic resin having 8 mol and a number average molecular weight of 300 to 1500, secondly, three components of phenols, aromatic amine and formaldehyde are mixed and heated, or
Alternatively, the method comprises a step of mixing an aromatic amine and formaldehyde, heating the mixture, then adding phenols and further heating to form an intermediate resin, and then adding allyl nadic acid anhydride and heating the mixture. It is a method for producing a modified phenolic resin containing an allylnadiimide group in the molecule, wherein the amount of allylnadamic acid used is 0.03 to 1.0 mol.

As the raw material of the modified phenols of the present invention, phenols, formaldehyde, aromatic amines and allyl nadic acid anhydride are generally used, which will be described in detail below. Examples of phenols include phenol, cresol, xylenol, pt
ert-butylphenol, p-octylphenol,
Examples thereof include, but are not limited to, p-nonylphenol, p-cumylphenol, resorcin, catechol, hydroquinone, bisphenols, and mixtures thereof.

Examples of aromatic amines include aniline, 2-methylaniline, 2-chloroaniline, 2-ethylaniline, m-phenylenediamine, p-phenylenediamine, 2,6-diaminotoluene and 3,5-diamino. Toluene, 3,5-diaminobiphenyl, 4,4 '
-Diaminodiphenylmethane, 1,3,5-triaminobenzene, m-xylylenediamine, p-xylylenediamine, 4,4'-diaminodiphenyl ether, a mixture thereof and the like, but not limited thereto.

The allyl nadic acid anhydride has an allyl substituent selected from an allyl group or a methallyl group as an essential substituent, and the position of the substituent is not particularly limited. It may contain a methyl group.
An example of such allyl nadic acid anhydride is:
-Allyl-5-norbornene-2,3-dicarboxylic acid anhydride, 5-allyl-5-norbornene-2,3-dicarboxylic acid anhydride, 7-allyl-5-norbornene-2,3
-Allyl-5-norbornene such as dicarboxylic acid anhydride-
2,3-dicarboxylic acid anhydride, 1-methallyl-5-norbornene-2,3-dicarboxylic acid anhydride, 5-methallyl-5-norbornene-2,3-dicarboxylic acid anhydride, 7
Examples thereof include methallyl-5-norbornene-2,3-dicarboxylic acid anhydride such as methallyl-5-norbornene-2,3-dicarboxylic acid anhydride, and a mixture thereof.

Formalin is usually used as formaldehyde, but paraformaldehyde can also be used.

The modified phenolic resin of the present invention is prepared by reacting phenols, aromatic amines and formaldehyde in an organic solvent such as water or alcohol in the presence of an acid catalyst or an alkali catalyst or in the absence of a catalyst to produce a phenol. It is synthesized by obtaining an aromatic amine-modified phenolic resin which is a reaction product of an aromatic amine and formaldehyde, and then imidizing it with allyl nadic acid anhydride.

The method for synthesizing the aromatic amine-modified phenol resin, which is an intermediate of the resin of the present invention, is not particularly limited, and any method can be used, for example, three components of phenols, aromatic amine and formaldehyde are mixed and heated at once. A method of reacting or a method of mixing and heating an aromatic amine and formaldehyde to cause a reaction to some extent in advance, then adding phenols and heating to complete the reaction, and the like are adopted. In any method, the catalyst is not particularly limited as long as it is one generally used for phenol resin production, but examples of the acid catalyst include hydrochloric acid, orthophosphoric acid,
Oxalic acid, formic acid, acetic acid, lactic acid, etc. are mentioned, and examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, triethylamine, etc.

In the above method, the raw material is 50 to 220 ° C.
At a temperature of 0.1 to 10 hours, preferably 70 to 200 ° C
At a temperature of 0.5 to 5 hours, and in another method, the preliminary reaction between the aromatic amine and formaldehyde is
0.1 to 5 hours at a temperature of 20 to 120 ° C., preferably 3
After reacting at a temperature of 0 to 100 ° C for 0.5 to 3 hours, phenols are added, and at a temperature of 50 to 220 ° C, 0.1 to 0.1
0.5 hours at a temperature of 70 to 200 ° C. for 10 hours
In any case, by reacting for 5 hours, the phenols and the aromatic amine are —CH ₂ — or —CH ₂ —.
An aromatic amine-modified phenolic resin, which is a reaction product bonded by O—CH ₂ — and in which the amino group of the aromatic amine is present as it is, is obtained.

The aromatic amine-modified phenolic resin thus synthesized was mixed with allyl nadic acid anhydride to obtain 12
0.1 to 5 hours at a temperature of 0 to 250 ° C., preferably 15
By reacting at a temperature of 0 to 220 ° C. for 0.5 to 3 hours, the amino group in the aromatic amine-modified phenol resin reacts with allyl nadic acid anhydride to produce an allyl nadiimide group, and the ant of the present invention is obtained. A lunadiimide-modified phenolic resin is obtained.

The composition ratio of the phenols and the imide groups formed can be arbitrarily changed by selecting the charging molar ratio of the phenols to the aromatic amine and allyl nadic acid anhydride according to the purpose. As for the ratio, the molar ratio of phenols to aromatic amines is usually 0.03 to 1.0 mol, preferably 0.03 to 0.8 mol, relative to 1 mol of phenols. And the molar ratio of formaldehyde to the total of aromatic amines is usually 0.3 to 1, preferably 0.4 to 0.9.
Is. Since the reaction between the aromatic amine and the allyl nadic acid anhydride proceeds almost quantitatively, it is usual that the aromatic amine and the allyl nadic acid anhydride are equimolar or the aromatic amine is slightly in excess. That is, the amount of allyl nadic acid anhydride used is about 0.03 to 1 mol of phenols.
It is 1.0 mol, preferably about 0.03 to 0.8 mol. In the modified phenol resin of the present invention obtained as described above, the arylnadiimide group is usually 0.03 to 0.8 mol, preferably 0.03 to 0.
5 mole and the number average molecular weight of 300 to 1,500, -CH ₂ phenols and aromatic amines to their imidized constituent components are randomly - or -C
H ₂ —O—CH ₂ — is bound, and methanol,
It is a modified phenolic resin that is soluble in various solvents such as acetone, MEK, dioxane and the like. The melting point is usually 60 to
It is 150 ° C. When the amount of imide groups formed is less than 0.03 mol, the heat resistance of the cured product of the modified phenol resin is not improved, while when it exceeds 0.8 mol, the initial mechanical properties of the cured product deteriorate. When the number average molecular weight is less than 300, the crosslinked density of the cured product of the modified phenolic resin is lowered, the mechanical properties are mainly lowered, and the number average molecular weight is 1500.
If it exceeds, the modified phenolic resin will have a poor flow during curing, resulting in poor moldability and mechanical properties.

Since the modified phenolic resin is cured by heat,
Hexamethylenetetramine is usually used together as a crosslinking agent (curing agent). The amount of hexamethylenetetramine used is preferably 10 to 20% by weight based on the modified phenol resin.
Hexamethylenetetramine is added to the modified phenolic resin 15
The gelling time (150 ° C) when blended by weight is usually 4
It is 0 to 150 seconds.

The allyl nadiimide-modified phenolic resin of the present invention has high mechanical strength and excellent heat resistance, especially long-term heat resistance, so that it can be used as a paint, an adhesive, a coating material,
It can be used as a binder resin for various organic and inorganic substances, a matrix resin for composite materials, and the like.

[0018]

EXAMPLES The present invention will be described below with reference to specific examples, but the contents of the present invention are not limited to these.

In the following examples, the yield of resin was calculated by the following formula. Yield (%) = A / {B− (C + D + E)} × 100 A: Amount of recovered resin B: Total amount of raw materials charged C: Water content in 37% formalin D: Formalin and phenols, aromatic amines Dehydration amount due to reaction = 18 × mol number of formalin charged E: Dehydration amount due to reaction between amino group and acid anhydride = 18 ×
Number of moles of charged acid anhydride

Example 1 In a reactor (1 l separable flask) equipped with a condenser and a stirrer, 300 g (3.19 mol) of phenol, 120 g (1.29 mol) of aniline, and 222 g of 37% formalin (2. (74 mol) was charged, the temperature was gradually raised, and after the temperature reached 95 ° C., reflux was continued for 120 minutes. Then, the condenser was switched to the vacuum distillation head and the system temperature was changed to 9
While maintaining the temperature at 0 ° C., the dehydration reaction was carried out by treating under a reduced pressure of 600 mmHg. Next, the system was returned to normal pressure, the distillation head was replaced with a condenser with a separation tube, the lower layer (mainly water) in the separation tube was removed, the temperature was gradually raised to 180 ° C., and this temperature was maintained for 40 minutes. And allyl-5
-Norbornene-2,3-dicarboxylic anhydride 108 g
When (0.53 mol) was added, the system was vigorously refluxed and the system temperature dropped, but when the lower layer (mainly water) in the separation tube was removed, the system temperature rose again, and when it reached 180 ° C., it continued for 60 minutes. Held Finally, the contents were taken out after holding at 180 ° C. for 60 minutes under a reduced pressure of 650 mmHg. 446 g of red transparent allyl nadiimide modified phenol resin was obtained (yield: 81%).

This resin is methanol, acetone, ME
It dissolves in K, dioxane, etc. The IR spectrum of the resin is shown in FIG. 3,377 cm ^-1 (absorption 1 in the figure), 1,
385 cm ^-1 (absorption 8 in the figure) and 1,187 cm ^-1 (absorption 9 in the figure) are absorptions based on phenolic hydroxyl groups, and 1,768 cm ^-1 (absorption 3 in the figure), 1,695c
m ^-1 (absorption 4 in the figure), 755 cm ^-1 (absorption 1 in the figure
4) is absorption based on imide groups, and 3,012
cm ^-1 (absorption in FIG 2), 1,511cm ^-1 (absorption in FIG. 6) is the absorption based on aromatic group.

The obtained resin (26.1 g), hexamethylenetetramine (3.9 g) and silica powder (70.0 g) were roll-kneaded. Next, put it in a mold and keep it at 160 ° C for 1
From what was press molded at 00 Kg / cm ² for 10 minutes, 1
A test piece of 27 (w) x 10 (t) x 4 (h) mm was cut out. When the bending strength (normal temperature) after the normal state and after the heat treatment was measured, the results shown in Table 1 were obtained.

Example 2 100 g (1.06 mol) of phenol, 100 g (0.44 mol) of bisphenol A, and 30 g of 4,4'-diaminodiphenylmethane were placed in a reactor (1 l separable flask) equipped with a condenser and a stirrer. (0.15 mol), and 116 g (1.43 mol) of 37% formalin were charged, the temperature was gradually raised, and after the temperature reached 95 ° C, reflux was continued for 150 minutes. Then, switch the cooler to a vacuum distillation head, and maintain the system temperature at 90 ° C while maintaining 600 mmHg.
Under reduced pressure to cause dehydration reaction. Next, the system was returned to normal pressure, the distillation head was replaced with a condenser with a separation tube, the lower layer material (mainly water) in the separation tube was removed, the temperature was gradually raised to 140 ° C., and this temperature was maintained for 15 minutes. When 27 g (0.13 mol) of allyl-5-norbornene-2,3-dicarboxylic acid anhydride was added, the solution was vigorously refluxed and the temperature of the system was lowered, but when the lower layer material (mainly water) in the separation tube was removed, The temperature rose again and when it reached 170 ° C. it was held for 90 minutes. Finally 650 mmH
After holding at 170 ° C. for 60 minutes under a reduced pressure of g, the content was taken out. 253 g of a red transparent allyl nadiimide-modified phenol resin was obtained (yield: 93%).

This resin is methanol, acetone, ME
It dissolves in K, dioxane, etc. The IR spectrum of this resin is shown in FIG. 3,354 cm ^-1 (absorption 1 in the figure),
1,383 cm ^-1 (absorption 10 in the figure), 1,228 cm
^-1 (absorption 11 in the figure) is absorption based on a phenolic hydroxyl group, and is 1,773 cm ^-1 (absorption 4 in the figure), 1,6
95cm ^-1 (absorption in FIG 5), 756cm ^-1 (absorption in FIG. 16) is the absorption based on imide group, and 2,9
68cm ^-1 (absorption in FIG 2), 1,512cm ^-1 (absorption in FIG. 7) is the absorption based on aromatic group.

The obtained resin (26.1 g), hexamethylenetetramine (3.9 g) and silica powder (70.0 g) were roll-kneaded. Next, put it in a mold and keep it at 160 ° C for 1
From what was press molded at 00 Kg / cm ² for 10 minutes,
A test piece of 127 (w) x 10 (t) x 4 (h) mm was cut out. When the bending strength (normal temperature) after the normal state and after the heat treatment was measured, the results shown in Table 1 were obtained.

Example 3 A reactor (1 l separable flask) equipped with a condenser and a stirrer was charged with 120 g (1.29 mol) of aniline and 186 g (2.29 mol) of 37% formalin,
Hold at 45 ° C for 60 minutes. Then 200g of phenol
(2.17 mol) was charged, and the temperature was gradually raised and when the temperature reached 95 ° C., the reflux was continued for 180 minutes. Switch the cooler to a vacuum distillation head and keep the system temperature at 90 ° C,
The dehydration reaction was performed by processing under a reduced pressure of 600 mmHg. Next, the system was returned to normal pressure, the distillation head was replaced with a condenser with a separation tube, the lower layer (mainly water) in the separation tube was removed, and the temperature was gradually raised to 180 ° C., and this temperature was maintained for 60 minutes. Allyl-5-norbornene-2,3
-When 120 g (0.59 mol) of dicarboxylic acid anhydride was added, the system was vigorously refluxed and the temperature of the system was lowered, but when the lower layer substances (mainly water) in the separation tube were removed, the temperature of the system was raised again to 180 ° C. Once reached, hold for 80 minutes. Finally, the contents were taken out after holding at 180 ° C. for 60 minutes under a reduced pressure of 650 mmHg. 416 g of a yellow transparent allyl nadiimide-modified phenol resin was obtained (yield: 9
1%).

This resin is soluble in acetone, MEK, dioxane, etc., and partially soluble in methanol. I of this resin
The R spectrum is shown in FIG. 3,361 cm ^-1 (absorption 1 in the figure), 1,387 cm ^-1 (absorption 11 in the figure), 1,
186 cm ^-1 (absorption 12 in the figure) is absorption based on a phenolic hydroxyl group, 1,769 cm ^-1 (absorption 3 in the figure), 1,697 cm ^-1 (absorption 4 in the figure), 755 cm
^-1 (absorption 13 in the figure) is absorption based on an imide group,
And 2,985 cm ^-1 (absorption 2 in the figure), 1,508
cm ^-1 (absorption 7 in the figure) is absorption based on an aromatic group.

The obtained resin (26.1 g), hexamethylenetetramine (3.9 g) and silica powder (70.0 g) were roll-kneaded. Next, put it in a mold and keep it at 160 ° C for 1
From what was press molded at 00 Kg / cm ² for 10 minutes,
A test piece of 127 (w) x 10 (t) x 4 (h) mm was cut out. When the bending strength (normal temperature) after the normal state and after the heat treatment was measured, the results shown in Table 1 were obtained.

Comparative Example 1 100 g (1.06 mol) of phenol, 100 g (0.44 mol) of bisphenol A, and 30 g of 4,4'-diaminodiphenylmethane were placed in a reactor (1 l separable flask) equipped with a condenser and a stirrer. (0.15 mol), and 116 g (1.43 mol) of 37% formalin were charged, the temperature was gradually raised, and after the temperature reached 95 ° C, reflux was continued for 150 minutes. Then, switch the cooler to a vacuum distillation head, and maintain the system temperature at 90 ° C while maintaining 600 mmHg.
Under reduced pressure to cause dehydration reaction. Next, the system was returned to normal pressure, the distillation head was replaced with a condenser with a separation tube, the lower layer material (mainly water) in the separation tube was removed, the temperature was gradually raised to 140 ° C., and this temperature was maintained for 15 minutes. When 30 g (0.14 mol) of pyromellitic dianhydride was added, the system was vigorously refluxed and the temperature of the system decreased, but when the lower layer substances (mainly water) in the separation tube were removed, the temperature of the system again increased and reached 170 ° C. Then, it was held for 90 minutes. Finally, the contents were taken out after holding at 170 ° C. for 60 minutes under a reduced pressure of 650 mmHg. 245 g of a red transparent pyromellitic imide-modified phenol resin was obtained (yield: 90%).

The resulting resin (26.1 g), hexamethylenetetramine (3.9 g) and silica powder (70.0 g) were roll-kneaded. Next, put it in a mold and keep it at 160 ° C for 1
Press-molded at 00 Kg / cm ² for 10 minutes, 127
A test piece of (w) × 10 (t) × 4 (h) mm was prepared. When the bending strength (normal temperature) after the normal state and after the heat treatment was measured, the results shown in Table 1 were obtained.

Comparative Example 2 In a reaction apparatus (1 l separable flask) equipped with a condenser and a stirrer, 300 g (3.19 mol) of phenol, 37
% Formalin (189 g (2.33 mol)) and 6 parts of oxalic acid were charged, and the temperature was gradually raised until the temperature reached 95 ° C., and the reflux was continued for 120 minutes. Then, the mixture was treated under a reduced pressure of 600 mmHg to carry out a dehydration reaction, and when the temperature of the system reached 190 ° C., the reaction was stopped and the contents were taken out. 322 g of a pale yellow transparent phenol resin was obtained (yield:
98%).

26.1 g of the obtained resin, 3.9 g of hexamethylenetetramine and 70.0 g of silica powder were roll-kneaded. Next, put it in a mold and keep it at 160 ° C for 1
Press-molded at 00 Kg / cm ² for 10 minutes, 127
A test piece of (w) × 10 (t) × 4 (h) mm was prepared. When the bending strength (normal temperature) after the normal state and after the heat treatment was measured, the results shown in Table 1 were obtained.

[0033]

[Table 1]

1) Ring and ball method 2) 150 ° C., 15 wt% of hexamine 3) Solubility of 10 g of resin in 50 ml of 5% NaOH aqueous solution

[0035]

Since the modified phenolic resin of the present invention contains an allylnadiimide group, it is more excellent in heat resistance, particularly long-term heat resistance, as compared with the conventional aromatic imide modified phenolic resin. The mechanical strength of the modified phenol resin of the present invention is as high as that of the conventional aromatic imide modified phenol resin.

[Brief description of drawings]

FIG. 1 is an IR spectrum of an allylnadiimide-modified phenol resin obtained in Example 1.

FIG. 2 is an IR spectrum of the allylnadiimide-modified phenolic resin obtained in Example 2.

FIG. 3 is an IR spectrum of the allylnadiimide-modified phenol resin obtained in Example 3.

Claims (2)

[Claims] 1. A resin obtained by the reaction of phenols, formaldehyde, aromatic amines, and allyl nadic acid anhydride, which contains an allyl nadiimide group in the molecule, and is based on 1 mol of phenols allyl nadiimide. The group is 0.03 to 0.8 mol, and the number average molecular weight is 3
A modified phenolic resin that is from 00 to 1500. 2. An intermediate resin is produced by mixing and heating three components of phenols, aromatic amine and formaldehyde, or mixing and heating aromatic amine and formaldehyde and then adding phenols and further heating. Let
Then, a step of adding allyl nadic acid anhydride and heating, wherein the amount of the allyl nadic acid anhydride used is 0.03 to 1.0 mol per 1 mol of the phenol, and a modification containing an allyl nadiimide group in the molecule Phenolic resin manufacturing method.