JPH08311309A - Phenolic resin composition - Google Patents

Abstract

PURPOSE: To obtain a phenolic resin composition excellent in tenacity, impact absorbability, heat resistance, etc., by mixing an ethylene-(meth)acrylic acid ester copolymer elastomer with a specific modified phenolic resin and bringing the elastomer to phase separate in the resin matrix. CONSTITUTION: This phenolic resin composition comprises preferably (A) 100 pts.wt. modified aromatic hydrocarbon resin consisting mainly of bisphenol A as a phenol and (B) 5-25 pts.wt. ethylene-(meth)acrylic acid ester copolymer elastomer as essential components. As the component A, a polycondensation product of bisphenol A with xylene glycol or its derivative is preferable. When a curing agent for the component A is added, it is preferable to use hexamethylenetetramine as the curing agent. The amount of hexamethylenetetramine to be added is preferably 7-17 pts.wt. based on 100 pts.wt. of the objective composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a binder used to obtain a molded article having excellent toughness and heat resistance, a friction material having excellent squealing characteristics and wear resistance, and the like, and toughness, vibration absorption and heat resistance. The present invention relates to a phenol resin composition having excellent properties.

[0002]

2. Description of the Related Art Phenolic resin is a binder having excellent mechanical properties, electrical properties, heat resistance and adhesiveness, but its molded product has drawbacks in toughness and vibration absorption and is used under severe conditions. The heat resistance is not sufficient in the applied field. In order to improve these various performances, researches on modified phenolic resins are being actively conducted, and 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 to practical use. Has been done. However, even these modified phenolic resins are still insufficient in terms of toughness and vibration absorption. In addition, various elastomer-modified phenolic resins (for example, NBR-modified phenolic resin), which are relatively excellent in flexibility and vibration absorption, have been investigated, but the phenolic resin itself has excellent heat resistance because the elastomer itself has poor heat resistance. There was a problem of impairing heat resistance.

[0003]

The present invention has been completed as a result of various studies in order to solve such problems of the phenolic resin, and its object is to have excellent toughness and vibration absorption and It is intended to provide a phenol resin composition having excellent heat resistance.

[0004]

The present invention provides an ethylene- (meth) acrylic acid ester copolymerized elastomer which has excellent flexibility, excellent heat resistance as an elastomer, and small thermal deterioration of the elastomer itself. Based on the finding that toughness, vibration absorption and heat resistance can be significantly improved by mixing with an excellent specific aromatic hydrocarbon-modified phenol resin and phase-separating in this modified phenol resin matrix. As a result of earnest study,
The present invention has been completed.

The present invention will be specifically described below.
The ethylene- (meth) acrylic acid ester copolymer elastomer used in the present invention includes ethylene and (meth)
A copolymer elastomer synthesized from a (meth) acrylic acid ester represented by methyl acrylate or the like, which contains a carboxyl group, an epoxy group or the like as a cross-linking site, can also be used. The content of the ethylene- (meth) acrylic acid ester copolymer elastomer blended in 100 parts by weight of the phenol resin is 2 to 50 parts by weight, preferably 5 to 25 parts by weight. When the content of the ethylene- (meth) acrylic acid ester copolymer elastomer is less than 2 parts by weight, the effect of improving the flexibility and vibration absorption of the phenol resin composition is small, and when it exceeds 50 parts by weight, the phenol resin composition is contained. The curability and heat resistance of are poor.

The method of blending the ethylene- (meth) acrylic acid ester copolymerized elastomer with the aromatic hydrocarbon-modified phenolic resin is as follows. It may be reacted with a hydrocarbon resin to form a resin, or an ethylene- (meth) acrylic acid ester copolymer elastomer may be added and melted during or at the end of the synthesis of the aromatic hydrocarbon-modified phenol resin. A product obtained by dissolving an ethylene- (meth) acrylic acid ester copolymer elastomer in a solvent can be similarly used.

In the present invention, the phenols used for producing the aromatic hydrocarbon-modified phenol resin are
It is bisphenol A, and other phenols may be used alone or in combination of two or more kinds. On the other hand, as the condensing agent, para-xylene glycol dimethyl ether,
Para-xylene glycol, meta-xylene glycol dimethyl ether, meta-xylene glycol, ortho-xylene glycol dimethyl ether, ortho-xylene glycol and the like can be used, and these may be used alone or in combination of two or more kinds.

It is also possible to use formaldehyde or a compound that produces formaldehyde in combination.
As a catalyst for the addition condensation reaction of phenols and a condensing agent, oxalic acid, hydrochloric acid, sulfuric acid, diethyl sulfuric acid, paratoluene sulfonic acid and other acids, and zinc acetate and other metal salts may be used alone or in combination of two or more. it can.

As the curing agent for the aromatic hydrocarbon-modified phenolic resin, various bifunctional or higher functional epoxy compounds, isocyanates, formaldehyde resin and hexamethylenetetramine can be used, if necessary. From the aspect, hexamethylenetetramine is preferable. Hexamethylenetetramine is added in an amount of 3 to 20 parts by weight, preferably 7 to 17 parts by weight, based on 100 parts by weight of the phenol resin composition of the present invention. If the amount is less than 3 parts by weight, the curing of the resin will be insufficient, and if it exceeds 20 parts by weight, the decomposition gas of hexamethylenetetramine will cause swelling and cracks in the molded product.

The aromatic hydrocarbon-modified phenol resin used in the present invention has improved chemical thermal stability by replacing one side of the methylene bridge with an aromatic hydrocarbon having no phenolic hydroxyl group, and this is used as a binder. The composite material has a feature that it is extremely excellent in heat resistance. On the other hand, the ethylene- (meth) acrylic acid ester copolymer elastomer used in the present invention is excellent in flexibility and heat resistance as an elastomer, and is characterized by small thermal deterioration of the elastomer itself. By mixing such an elastomer with an aromatic hydrocarbon-modified phenolic resin having excellent heat resistance and phase-separating it in the resin matrix, the modified phenolic resin is provided with toughness and vibration absorption without impairing the heat resistance. It is also possible to obtain a phenol resin composition.

The phenol resin composition of the present invention can be used as materials for molding materials, organic fiber binders, rubber compounding agents,
Examples thereof include binders for abrasives, binders for friction materials, rubber compounding agents, inorganic fiber binders, electronic / electrical component coating agents, sliding member binders, epoxy resin raw materials and epoxy resin curing agents.

[0012]

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

Example 1 1000 parts of bisphenol A was added to a reactor equipped with a stirrer, a reflux condenser and a thermometer.
After charging 470 parts of para-xylene glycol dimethyl ether and raising the internal temperature to 100 ° C. to completely dissolve bisphenol A, an ethylene-acrylic acid ester copolymerized elastomer (“Esplen EMA21 manufactured by Sumitomo Chemical Co., Ltd.”
52 ") 150 parts and completely dissolve the elastomer. The internal temperature was lowered to 80 ° C., 1 part of diethyl sulfuric acid was charged, the temperature was gradually raised, and after the temperature reached 120 ° C., atmospheric dehydration reaction was performed for 180 minutes. Then, vacuum dehydration was carried out, and when the temperature in the system was raised to 160 ° C., the contents were taken out from the reactor, and 1500 parts of a solid phenol resin composition at room temperature was obtained.

Example 2 1500 parts of a solid phenol resin composition at room temperature were obtained in the same manner as in Example 1 except that "Baymac G" manufactured by Showa Denko / Dupont was used as the ethylene-acrylic acid ester copolymer elastomer. It was

Example 3 1650 parts of a solid phenol resin composition at room temperature was obtained in the same manner as in Example 1 except that 300 parts of ethylene-acrylic acid ester copolymer elastomer "Baymac G" was used.

Comparative Example 1 A reactor similar to that of Example 1 was charged with 1000 parts of phenol, 630 parts of 37% formalin and 20 parts of oxalic acid, and gradually heated to reflux for 120 minutes after the temperature reached 95 ° C. The reaction was carried out. Then, vacuum dehydration was performed, and when the temperature in the system rose to 190 ° C,
The contents were taken out of the reactor to obtain 1080 parts of a solid phenol resin at room temperature.

Comparative Example 2 1000 parts of phenol and 300 parts of ethylene-acrylic acid ester copolymer elastomer "Baymac G" were placed in the same reactor as in Example 1,
After heating the internal temperature to 100 ° C to completely dissolve the elastomer, the internal temperature is lowered to 60 ° C or less, 630 parts of 37% formalin and 20 parts of oxalic acid are charged, and the temperature is gradually raised to 95 ° C. After that, reflux reaction was performed for 120 minutes. Then, vacuum dehydration was performed, and when the temperature in the system was raised to 190 ° C., the contents were taken out from the reactor to obtain 1350 parts of a phenol resin composition which was solid at room temperature.

Comparative Example 3 In the same reactor as in Example 1, 1000 parts of phenol, 300 parts of CTBN (carboxyl group terminated butadiene-acrylonitrile rubber), 37% were used.
After charging 630 parts of formalin and 20 parts of oxalic acid, the temperature was gradually raised and the reflux reaction was carried out for 120 minutes after the internal temperature reached 95 ° C. Next, vacuum dehydration is performed and the temperature in the system is 190 ° C.
When the temperature rises to, remove the contents from the reactor,
1400 parts of a phenol resin composition which was solid at room temperature were obtained.

110 parts of hexamethylenetetramine were separately added to 1000 parts of the phenol resin (composition) solid at room temperature obtained in Examples 1 to 3 and Comparative Examples 1 to 3 and pulverized to obtain a powdered phenol resin composition. 1099 parts of the product was obtained. The 6 kinds of phenol resin compositions thus obtained were separately mixed in the following mixing ratios.

This composition was heated at 160 ° C. and pressure of 200 k
After molding at g / cm ² for 10 minutes, firing was performed at 180 ° C. for 3 hours to prepare a test piece. About this test piece, Rockwell hardness, electrodynamic vibration tester (IMV
Type VS-2000A-100) shows vibration absorption measurement results, Charpy impact strength, normal bending strength, and bending strength measurement results after thermal history.

[0021]

[Table 1]

As is clear from Table 1, the phenol resin compositions obtained in Examples 1 to 3 and Comparative Example 2 using the ethylene- (meth) acrylic acid ester copolymer elastomer and Comparative Example 3 using the CTBN. If the product is used, a molded product having low hardness and excellent flexibility can be obtained. Further, the vibration test results show that the detected acceleration is small and the resonance in the natural vibration region is small, and it is clear that in addition to being excellent in vibration absorption, it has a high Charpy impact value and excellent toughness. However, in Comparative Examples 2 and 3, the bending strength deterioration after heat history is large, while in Examples 1 to
It is clear that in No. 3, the bending strength deterioration after heat history is small and the heat resistance is excellent.

[0023]

The phenol resin composition of the present invention is excellent in flexibility and toughness and shock absorption. Further, it is understood that the strength drop after the heat history is small and the heat resistance is excellent.

Claims (3)

[Claims] 1. A phenol resin composition comprising an aromatic hydrocarbon-modified phenol resin containing bisphenol A as a main component as phenols and an ethylene- (meth) acrylic acid ester copolymer elastomer as essential components. Stuff. 2. An aromatic hydrocarbon-modified phenolic resin,
The phenol resin composition according to claim 1, which is a polycondensation product of bisphenol A and xylene glycol or a derivative thereof. 3. The aromatic hydrocarbon according to claim 1, wherein the ratio of the ethylene- (meth) acrylic acid ester copolymer elastomer is 2 to 50 parts by weight relative to 100 parts by weight of the aromatic hydrocarbon-modified phenol resin composition. Modified phenol resin composition.