JPH11323080A - Production of phenolic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a phenolic resin composition having excellent flexibility and sound-absorbing characteristics, keeping these properties within a range from a low temperature to a high temperature, having quick curability and good moldability and useful for binder, etc., by kneading a phenolic resin composition containing a silicone gel as an essential component. SOLUTION: The objective composition is produced by kneading (A) a silicone gel containing an addition-reaction silicone as a base and having a penetration of 10-500 measured in conformity to JIS K2530-1976 under 50 g load into (B) a phenolic resin using a pressure kneader (e.g. roll kneader). The content of the component A in the objective composition is 1-50 pts.wt. based on 100 pts.wt. of phenol. In the case of using a novolak phenolic resin, hexamethylenetetramine is used as a curing agent in an amount of preferably 3-20 pts.wt. based on 100 pts.wt. of the resin.

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 toughness and formability, and a friction material having excellent squealing properties and vibration absorption. The present invention relates to a method for producing a phenolic resin composition having excellent moldability and good moldability.

[0002]

2. Description of the Related Art Phenol resins are binders having excellent mechanical properties, electrical properties, heat resistance and adhesiveness, but molded articles have drawbacks in toughness and vibration absorption. In order to improve such performances, research on modified phenolic resins has been actively carried out. Has been provided. However, these modified phenolic resins are not yet sufficient in terms of toughness and vibration absorption. In addition, various rubber-modified phenolic resins that are relatively excellent in flexibility and vibration absorption are being studied,
Rubber itself has poor heat resistance, and has a problem that squealing occurs due to heat history. In addition, these phenolic resins have the disadvantage that curing is slow and moldability and workability are poor.

[0003] The method for producing the modified phenolic resin includes adding a modifier before or during the reaction, melting the phenolic resin into the phenolic resin after the reaction is completed, and mixing a solid phenolic resin with the phenolic resin. There is a method of dry blending when pulverizing. However, in these production methods, the method of adding before or during the reaction has a problem that the condensation reaction of phenol and formalin is inhibited, and the other methods have a problem that the reaction and dispersion of the modifier are insufficient. .

[0004]

SUMMARY OF THE INVENTION The present invention has been completed as a result of intensive studies to solve the various problems of the above-mentioned conventional method for producing a modified phenolic resin. An object of the present invention is to produce a phenol resin composition which has excellent properties and vibration absorption, does not lose these properties from low to high temperatures, cures quickly, and has good moldability.

[0005]

The present invention focuses on the fact that a specific silicone gel greatly affects these properties, and uses a pressure-type kneading machine for a phenolic resin composition containing a silicone gel as an essential component. It has been found that the present invention can be manufactured by the method described above, and the present invention has been completed. That is, the present invention relates to a penetration (JIS K2530-1).
975-50 g load) (hereinafter simply referred to as penetration) 10
The present invention relates to a method for producing a phenolic resin composition, which comprises kneading a silicone gel based on an addition-reaction type silicone having a viscosity of 500 to a phenolic resin using a pressure-type kneader.

Hereinafter, the present invention will be described specifically.
Silicone gel with a penetration of 10 to 500 is shock absorbing,
It has excellent anti-vibration properties and does not lose these properties over a wide temperature range from room temperature to high temperatures. When such a silicone gel is uniformly dispersed and contained in a phenol resin, a phenol resin composition having excellent flexibility and vibration absorption and maintaining these properties in a wide temperature range can be obtained.

[0007] The silicone gel content of the phenolic resin composition of the present invention is 1 to 50 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of phenol. When the amount is less than 1 part by weight, sufficient flexibility and vibration absorption of the resin cannot be obtained, and when the amount exceeds 50 parts by weight, the curing of the resin is slowed down, the molding time of the molded article is prolonged, and the binder power is reduced, and the Not a target. The production method of the present invention is a method in which a silicone gel is uniformly dispersed in a phenol resin which has been previously reacted, and a predetermined amount of a phenol resin and a silicone gel are charged into a pressure kneader and kneaded under pressure. is there. The temperature at the time of kneading is not particularly limited as long as it is a temperature at which the phenol resin melts. As a pressure-type kneader, a roll-type kneader,
A pressure kneader, a twin-screw extruder, a single-screw extruder and the like are suitable. Silicone gels have poor compatibility with phenolic resins, are insoluble in solvents, and have a high melting point, making it impossible to disperse them uniformly in a normal phenolic resin reactor. By using, it becomes possible to disperse uniformly in the phenol resin.

The phenolic resin used in the present invention is a novolak type phenolic resin or a resol type phenolic resin, and can be used in any form of liquid, solid or powder. When a novolak-type phenol resin is used, hexamethylenetetramine is used as a curing agent.
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 novolak 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.

[0009]

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 To a twin-screw extruder controlled at an inlet temperature of 150 ° C. and an outlet temperature of 160 ° C., 1000 parts of a novolak type phenol resin (PR-53195 manufactured by Sumitomo Durez Co., Ltd.) and a silicone gel (Ciegel Co., Ltd.) 50 parts of αGEL (manufactured by αGEL, penetration 160) are supplied so that the supply ratio per unit time becomes equal, and the phenol resin composition 103 which is solid at room temperature from the outlet is supplied.
0 parts were obtained. Further, 110 parts of hexamethylenetetramine was added to 1000 parts of the obtained solid phenol resin composition, and the mixture was pulverized to obtain a powdery phenol resin composition 1097.
Got a part.

Example 2 A pressure kneader was charged with 1000 parts of a novolak type phenol resin (PR-53195, manufactured by Sumitomo Durez Co., Ltd.).
The temperature was raised to 150 ° C. and melted. Silicone gel (Co., Ltd.)
50 parts of αGEL made by Siegel, penetration 160) was added, and it was confirmed that the silicone gel was uniformly dispersed. The mixture was further kneaded for 30 minutes, taken out from the pressure kneader, and 1030 parts of a phenol resin composition which was solid at room temperature. I got Further, 110 parts of hexamethylenetetramine was added to 1000 parts of the obtained solid phenol resin composition, and pulverized to obtain 1097 parts of a powdered phenol resin composition.

Example 3 Silicone gel (αGEL manufactured by Siegel Co., Ltd., penetration 1)
1270 parts of a solid phenol resin composition was obtained in the same manner as in Example 1 except that 60) was changed to 300 parts. Further, 110 parts of hexamethylenetetramine was added to 1000 parts of the obtained solid phenol resin composition, and pulverized to obtain 1097 parts of a powdered phenol resin composition.

Comparative Example 1 Novolak type phenolic resin (manufactured by Sumitomo Durez Co., Ltd.)
R-53195) To 1000 parts of 110 parts of hexamethylenetetramine was added and pulverized to obtain 1099 parts of a powdery phenol resin composition.

Comparative Example 2 A novolak type phenol resin (PR manufactured by Sumitomo Durez Co., Ltd.) was added to a reactor equipped with a stirrer, a reflux condenser and a thermometer.
-53195) Charge 1000 parts, raise the temperature to 150 ° C,
Melted. Silicone gel (αGE manufactured by Seagel Co., Ltd.)
L, penetration 160) 50 parts were added and stirred for 5 hours,
The reaction mixture was taken out of the reactor to obtain 1030 parts of a phenol resin composition which was solid at room temperature.

The dispersion state of the silicone gel in the solid state of each of the four phenolic resin compositions obtained in Examples 1, 2, and 3 and Comparative Example 2 was visually observed. Subsequently, for the four types of powdered phenolic resin compositions obtained in Examples 1, 2, 3 and Comparative Example 1, the gelation time, which is the curing properties of the resin, was measured. Next, they were separately charged and mixed in the following mixing ratios. In addition, about the comparative example 2,
The dispersion state of the silicone gel was poor, and the pulverization and blending were not completed.

[0016]

[0017] This composition is heated at a temperature of 160 ° C and a pressure of 200k.
g / cm ² for 10 minutes, 150 × 150 × 20m
m was obtained. The obtained molded product was fired at 180 ° C. for 3 hours, and the Rockwell hardness of the molded product and an electrokinetic vibration test device (IMV type VS-2000A-100) were used.
Was used to measure the vibration acceleration. The results are shown in Table 1 together with the dispersion state of the silicone gel and the gelation time.

Table 1 Evaluation Results ─────────────────────────────────── Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 分散 Dispersion state of silicone gel Good Good Good -Poor gel time (165 ° C, sec) 41 43 44 42-Rockwell hardness (HRS) 95 93 81 103-Vibration acceleration (G) 30 28 21 48-───────────── ──────────────────────

It can be seen that Examples 1, 2, and 3 have the same gelation time and excellent curability and moldability as compared with Comparative Example 1 which is conventionally considered to be excellent in moldability. The dispersibility of the silicone gel was good. From the Rockwell hardness of the molded product, it can be seen that Examples 1, 2, and 3 have small hardness and excellent flexibility. In addition, the vibration acceleration is small, indicating that resonance in the natural vibration region is small, and it is clear that the vibration absorption is excellent.

[0020]

As is clear from the above examples, the phenolic resin composition obtained by the method of the present invention has good moldability and is excellent in toughness, squealing property,
It is possible to obtain a friction material having excellent vibration absorption.

Claims (1)

[Claims] 1. Penetration (JIS K2530-1976)
A method for producing a phenolic resin composition, comprising kneading a silicone gel based on an addition-reaction type silicone having a weight of -50 g) with a pressure-type kneader.