JPH11269242A - Phenol resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a phenol resin composition which cures fast, gas a good moldability and has a high toughness, vibration absorbing property/flexibility and heat stability. SOLUTION: This composition is obtained by modifying with a boric acid or boron oxide and an aromatic hydrocarbon. Specifically, the composition contains an aromatic hydrocarbon-modified phenol resin, which is a polycondensate of a phenol, an aromatic hydrocarbon and an aldehyde, and a boric acid-modified phenol resin prepared by modifying a phenolic hydroxyl group with boric acid or boron oxide. Alternatively, a phenolic hydroxy group of an aromatic hydrocarbon-modified phenol resin which is a polycondensate of a phenol, an aromatic hydrocarbon and aldehyde is modified with boric acid or boron oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder used for obtaining a molded article having excellent heat resistance, toughness and moldability, and a friction material having excellent squealing properties and wear resistance. The present invention relates to a phenolic resin composition having excellent properties, flexibility and heat resistance and having good moldability.

[0002]

2. Description of the Related Art Phenol resin is a binder having excellent mechanical properties, electrical properties, heat resistance and adhesiveness, but has the disadvantage that its molded product has low toughness, vibration absorption and flexibility. Heat resistance is not sufficient in the field used under severe conditions. In order to improve these performances, research on modified phenolic resins has been actively conducted, and drying oil-modified phenolic resins, cashew-modified phenolic resins, epoxy-modified phenolic resins, melamine-modified phenolic resins, etc. have been studied, and some of them have been put into practical use. Has been provided. However, these modified phenolic resins are not yet sufficient in terms of toughness, vibration absorption and flexibility.

[0003] Further, various elastomer-modified phenol resins which are relatively excellent in vibration absorption and flexibility have been studied, but the elastomer itself has poor heat resistance, which impairs the excellent heat resistance of the phenol resin itself. was there. In addition, phenols and heat-resistant, flexible phenolic resins such as toluene-formaldehyde resins, polycondensates of xylene-formaldehyde resins or mesitylene-formaldehyde resins and aldehydes, or phenol-aralkyl resins were studied. However, there was a disadvantage that curing was slow and moldability was poor. On the other hand, for the purpose of improving heat resistance and moldability, a boric acid-modified phenol resin in which a phenolic hydroxyl group in the phenol resin is modified with boric acid, boron oxide or the like has been studied, but is not sufficient in terms of flexibility.

[0004]

SUMMARY OF THE INVENTION The present invention has been completed as a result of various studies to solve such problems of phenolic resin, and its object is toughness, vibration absorption and flexibility. An object of the present invention is to provide a phenol resin composition having excellent heat resistance and heat resistance and having good moldability.

[0005]

The present invention is a polycondensate of a phenol, an aromatic hydrocarbon and an aldehyde.
Heat resistance, flexibility, aromatic hydrocarbon-modified phenolic resin, and phenolic hydroxyl group modified with boric acid or boron oxide, heat resistance, by utilizing the characteristics of boric acid-modified phenolic resin excellent in moldability, toughness, A phenolic resin composition having excellent vibration absorption, flexibility and heat resistance and having good moldability has been completed. That is, the phenol resin composition of the present invention is characterized in that the phenol resin is modified with boric acid or boron oxide and an aromatic hydrocarbon. The modification method comprises a method of containing an aromatic hydrocarbon-modified phenol resin which is a polycondensate of a phenol, an aromatic hydrocarbon and an aldehyde, and a boric acid-modified phenol resin in which a phenolic hydroxyl group is modified with boric acid or boron oxide. In this method, a phenolic hydroxyl group of an aromatic hydrocarbon-modified phenol resin, which is a polycondensate of phenols, aromatic hydrocarbons and aldehydes, is modified with boric acid or boron oxide.

Hereinafter, the present invention will be described specifically.
Phenols used for producing the aromatic hydrocarbon-modified phenolic resin used in the present invention are phenol,
Cresol, xylenol, ethylphenol, propylphenol, catechol, resorcin, hydroquinone, bisphenol A, etc., and these may be used alone or in combination of two or more. As the aromatic hydrocarbon, benzene, toluene, xylene, and mesitylene are preferable, and an aromatic hydrocarbon-aldehyde polycondensate obtained by previously reacting these aromatic hydrocarbons with aldehydes may be used. . Further, as the aromatic hydrocarbon compound, para-xylene glycol dimethyl ether,
It is also possible to use xylene glycols such as para-xylene glycol, meta-xylene glycol dimethyl ether, meta-xylene glycol, ortho-xylene glycol dimethyl ether, and ortho-xylene glycol.

Further, as the aldehydes, it is also possible to use formaldehyde or a compound which forms formaldehyde, or an aldehyde such as benzaldehyde. As a catalyst for reacting phenols with aromatic hydrocarbons and aldehydes, metal salts such as zinc acetate, and acids such as oxalic acid, hydrochloric acid, sulfuric acid, diethyl sulfuric acid, and paratoluenesulfonic acid alone or in combination of two or more. Can be used.

The aromatic hydrocarbon-modified phenolic resin of the present invention may be one obtained by reacting only a phenol and an aromatic hydrocarbon / aldehyde polycondensate, or one obtained by reacting only a phenol and xylene glycol. . Also,
A polycondensate of a phenol and an aldehyde may be mixed with an aromatic hydrocarbon / aldehyde polycondensate. The phenols used for producing the boric acid-modified phenolic resin used in the present invention are phenol, cresol, xylenol, ethylphenol, propylphenol, catechol, resorcin, hydroquinone, bisphenol A and the like, and these may be used alone or in combination of two or more. These may be used in combination. The aldehydes include formaldehyde, paraformaldehyde, benzaldehyde and the like, and these may be used alone or in combination of two or more.

As a catalyst for reacting a phenol with an aldehyde, a metal salt such as zinc acetate or an acid such as oxalic acid, hydrochloric acid, sulfuric acid, diethyl sulfuric acid or paratoluenesulfonic acid may be used alone or in combination of two or more. Can be used. As a method for modifying the phenolic hydroxyl group with boric acid or boron oxide, a method of reacting phenols with boric acid or boron oxide under dehydration to form phenylborate and further reacting with aldehydes, or a method of reacting phenols with aldehydes Then, there is a method in which boric acid or the like is reacted.

The method of mixing the aromatic hydrocarbon-modified phenolic resin and the boric acid-modified phenolic resin thus obtained is a method of melting and mixing two kinds of resins, and a method of pulverizing and dry-mixing two kinds of resins. Etc. As a method of modifying the phenolic hydroxyl group of an aromatic hydrocarbon-modified phenolic resin which is a polycondensate of phenols, aromatic hydrocarbons and aldehydes with boric acid or boron oxide,
There is a method in which boric acid is added to the aromatic hydrocarbon-modified phenol resin obtained by the above method, and the phenol resin is reacted under dehydration.

As the curing agent for the phenolic resin composition of the present invention, various epoxy compounds having two or more functionalities, isocyanates, formaldehyde resins and hexamethylenetetramine can be used. Methylenetetramine is preferred. Hexamethylenetetramine is added in an amount of 3 to 20 parts by weight, preferably 6 to 17 parts by weight, based on 100 parts by weight of the phenol resin. If the amount is less than 3 parts by weight, the curing of the resin becomes insufficient, and if it exceeds 20 parts by weight, the decomposition gas of hexamethylenetetramine bulges the molded product, causing cracks and the like.

The phenolic resin composition according to the present invention is characterized in that, by modifying the phenolic resin with boric acid or boron oxide and an aromatic hydrocarbon, the disadvantages of the aromatic hydrocarbon-modified phenolic resin are that its curability is slow and its moldability is poor. The drawback of boric acid-modified phenolic resin is that it has insufficient flexibility.
A phenolic resin which can be complemented by the features exhibited by the respective modifications, and which is excellent in toughness, vibration absorption / flexibility, heat resistance and good moldability can be obtained.

The phenolic resin composition of the present invention can be used as a material for a molding material, an organic fiber binder, a rubber compounding agent,
Examples of the binder include a binder for abrasives, a binder for friction materials, a rubber compounding agent, a binder for inorganic fibers, a coating agent for electronic and electrical parts, a binder for sliding members, an epoxy resin raw material, and an epoxy resin curing agent.

[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".

Example 1 A reactor equipped with a stirrer, a reflux condenser and a thermometer was equipped with:
After charging 1000 parts of phenol, 900 parts of xylene / formaldehyde resin and 2 parts of paratoluenesulfonic acid, the temperature was gradually raised, and after the temperature reached 100 ° C., a reflux reaction was performed for 240 minutes. Atmospheric pressure dehydration is performed until the internal temperature reaches 110 ° C., and then vacuum dehydration is performed.
When the temperature was raised to 0 ° C., the contents were taken out of the reactor and solidified at room temperature in an aromatic hydrocarbon-modified phenol resin 17.
00 parts were obtained. Next, using the same reactor, 1000 parts of phenol, 630 parts of 37% formalin and 20 parts of oxalic acid were charged, and the temperature was gradually increased until the temperature reached 95 ° C.
A reflux reaction was performed for 0 minutes. Next, vacuum dehydration is performed, and when the temperature in the system rises to 190 ° C., boric acid 160
After the dehydration reaction was carried out for 30 minutes, the contents were taken out of the reactor to obtain 1180 parts of a boric acid-modified phenol resin solid at room temperature. Next, 500 parts of the obtained aromatic hydrocarbon-modified phenol resin and 50 parts of boric acid-modified phenol resin
To 0 parts, 100 parts of hexamethylenetetramine was added and pulverized to obtain 1090 parts of a powdery phenol resin composition.

Example 2 A similar reactor as in Example 1 was charged with 1000 parts of phenol, 500 parts of para-xylene glycol dimethyl ether, and 4 parts of p-toluenesulfonic acid, and the temperature was raised while performing a dehydration reaction. 180 while keeping at 150 ° C
A dehydration reaction was performed for minutes. Next, the temperature in the system was lowered to 100 ° C., 300 parts of 37% formalin was charged and a reflux reaction was performed for 120 minutes, followed by vacuum dehydration.
When the temperature was raised to 0 ° C., the contents were taken out of the reactor and solidified at room temperature in an aromatic hydrocarbon-modified phenol resin 140.
0 parts were obtained. Further, 1180 parts of a boric acid-modified phenol resin solid at room temperature was obtained in the same manner as in Example 1. Next, 500 parts of the obtained aromatic hydrocarbon-modified phenol resin and 500 parts of boric acid-modified phenol resin were added to hexamethylenetetramine 1
And then pulverized and powdered phenolic resin composition 10
90 parts were obtained.

Example 3 An aromatic hydrocarbon phenol resin was reacted in the same manner as in Example 1 until the temperature in the system reached 160 ° C. 1
When the temperature reached 60 ° C., 160 parts of boric acid was charged and a dehydration reaction was carried out for 30 minutes. When the dehydration reaction was carried out for 30 minutes, the contents were taken out of the reactor to obtain 1800 parts of an aromatic hydrocarbon / boric acid-modified phenol resin which was solid at room temperature. Next, the obtained phenolic resin 1
Add 100 parts of hexamethylenetetramine to 000 parts,
It was pulverized to obtain 1090 parts of a powdery phenol resin composition.

Comparative Example 1 1000 parts of phenol was added to a reactor similar to that in Example 1.
After charging 630 parts of 7% formalin and 20 parts of oxalic acid, the temperature was gradually raised, and after the temperature reached 95 ° C., a reflux reaction was performed for 120 minutes. Next, vacuum dehydration is performed, and the temperature in the system is set to 19
When the temperature was raised to 0 ° C., the contents were taken out of the reactor to obtain 1080 parts of a phenol resin composition which was solid at ordinary temperature. Next, 100 parts of hexamethylenetetramine was added to 1000 parts of the obtained phenol resin, and pulverized to obtain 1090 parts of a powdered phenol resin composition.

Comparative Example 2 In the same manner as in Example 1, 1700 parts of an aromatic hydrocarbon-modified phenol resin which was solid at ordinary temperature was obtained. Next, hexamethylenetetramine 1 was added to 1000 parts of the obtained phenol resin.
And then pulverized and powdered phenolic resin composition 10
90 parts were obtained.

Comparative Example 3 In the same manner as in Example 1, 1180 parts of a boric acid-modified phenol resin solid at room temperature was obtained. Next, 100 parts of hexamethylenetetramine was added to 1000 parts of the obtained phenol resin, and pulverized to obtain 1090 parts of a powdered phenol resin composition.

With respect to the six types of phenolic resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3, the gelation time, which is the curing characteristics of the resin, was measured. Then, they were separately mixed at the following mixing ratios. Compounding amount (% by weight) Glass fiber 20 Calcium carbonate 70 Resin composition 10

This formulation was prepared at a temperature of 160 ° C. and a pressure of 200
A molded product having a size of 150 × 150 × 20 mm was molded at kg / cm ² , and the required molding time was measured. The obtained molded article was fired at 180 ° C. for 3 hours, and the Rockwell hardness, the bending strength, and the bending strength after the heat history were measured. The results are shown in Table 1 together with the gel time.

[0023]

[Table 1]

As is clear from Table 1, Comparative Example 1 is an unmodified phenolic resin, so that the time required for molding is long, and the obtained molded product has high Rockwell hardness and insufficient flexibility. In addition, the bending strength after the heat history greatly decreases, and the heat resistance is poor. Comparative Example 2 shows that the required molding time is long and the moldability is poor. In Comparative Example 3, the molded product had a high Rockwell hardness and was inferior in flexibility. For these, Examples 1 to
3 shows that the gelation time is short and the curing of the resin is fast.
As a result, the time required for molding is short, and the moldability is excellent. The molded product has low Rockwell hardness and is flexible. Further, it can be seen that the reduction in bending strength after heat history with respect to the normal bending strength is small and the heat resistance is excellent.

[0025]

The aromatic hydrocarbon / boric acid-modified phenolic resin composition of the present invention is quick in curing, has good moldability, and is excellent in toughness, vibration absorption / flexibility, and heat resistance.

Claims (4)

[Claims] 1. A phenolic resin composition which is modified with boric acid or boron oxide and an aromatic hydrocarbon. 2. An aromatic hydrocarbon-modified phenol resin which is a polycondensate of phenols, aromatic hydrocarbons and aldehydes, and a boric acid-modified phenol resin having a phenolic hydroxyl group modified with boric acid or boron oxide. Claim 1
The phenolic resin composition according to the above. 3. The phenolic resin according to claim 1, wherein the phenolic hydroxyl group of the aromatic hydrocarbon-modified phenolic resin which is a polycondensate of phenols, aromatic hydrocarbons and aldehydes is modified with boric acid or boron oxide. Composition. 4. An aromatic hydrocarbon comprising benzene, toluene,
The phenolic resin composition according to claim 1, 2 or 3, which is at least one selected from xylene and mesitylene.