JPH06145416A - Phenolic resin molding material - Google Patents

Abstract

PURPOSE:To provide a phenolic resin molding material excellent in moldability and curability, especially remarkably excellent in the moldability as substantially not cured in the cylinder of an injection molding machine on the injection molding of the molding material but extremely repidly cured in a mold. CONSTITUTION:The phenolic resin molding material comprises (a) a phenolic resin, (b) hexamethylene tetramine, (c) an alkaline earth metal salt of a phenolic compound and (d) a filler. The phenolic resin molding material is extremely excellent in thermal stability in a plasticized melted state and in curability at high temperatures. Since the proceeding of the curing reaction of the plasticized melted resin is therefore remarkably reduced in the cylinder of an injection molding machine and since the plasticized melted resin is rapidly cured in a mold, the molding material can be applied under wide molding conditions and is extremely excellent in moldability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenol resin molding material excellent in molding processability and curability, and particularly in injection molding, the curing reaction hardly progresses in the cylinder of the injection molding machine, and The present invention provides a phenol resin molding material having extremely excellent molding processability that cures extremely quickly.

[0002]

2. Description of the Related Art Phenolic resin molding materials are excellent in heat resistance, electrical performance, mechanical performance and the like, and are therefore used in a wide range of applications such as automobile parts, electronic / electrical parts and mechanical parts. However, the conventional phenol resin molding material is 9
In the molten state plasticized to 0 to 125 ° C., the viscosity increases due to the progress of the curing reaction of the resin in the material.
It has the property of losing fluidity in minutes, and the thermal stability of the plasticized molten resin is extremely low. Therefore, when a conventional phenol resin molding material is injection-molded, there is a problem that the plasticization-melted molding material in the cylinder of the injection molding machine is significantly inferior in thermal stability and an appropriate molding condition range is extremely narrow. Conventionally, various methods such as increasing the fluidity of the molding material have been known as a method for solving this problem. However, if the thermal stability in the plasticized and molten state is improved, it is 150-
The curing reaction at 200 ° C. slows down, and conversely, when the curability in the mold is improved, the thermal stability becomes poor, and the thermal stability in the plasticized and molten state and the curability in the mold are reduced. It is difficult to obtain a phenol resin molding material in which both of the above are simultaneously improved.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides various kinds of phenol resin molding materials having excellent molding processability in which both thermal stability in a plasticized and molten state and curability in a mold are improved. It was made as a result of the study, and the purpose is especially a phenolic resin which is extremely excellent in thermal stability in a plasticized and molten state in a cylinder in injection molding and is extremely curable in a mold. To provide the molding material.

[0004]

DISCLOSURE OF THE INVENTION The present invention is characterized in that (a) a phenol resin, (b) hexamethylenetetramine, (c) an alkaline earth metal salt of a phenol compound, and (d) a filler. The present invention relates to a resin molding material. As the phenol resin of the present invention, a normal novolac type phenol resin obtained by reacting phenols with formaldehyde is used. As the phenols of the phenolic resin, one or two of monovalent and polyvalent phenols such as phenol, cresol, xylenol, naphthol, pt-butylphenol, bisphenol A, resorcin and their substitution products are used.
More than one kind can be exemplified. Examples of the formaldehydes include formalin and paraformaldehyde. Further, as the phenol resin of the present invention, those modified with aromatic hydrocarbon resin, dimethoxyparaxylene, dicyclopentadiene and the like can be used.

As the hexamethylenetetramine of the present invention, a powdery one used as a curing agent for ordinary phenol resins is used, and 7 to 30 parts by weight, preferably 12 to 20 parts by weight, relative to 100 parts by weight of the phenol resin is used. Used by blending. The alkaline earth metal salt of the phenol compound of the present invention includes magnesium of the phenol compound,
One or more calcium, strontium or barium salts can be used. The phenol compound used for the alkaline earth metal salt of the phenol compound is not particularly limited, but includes phenol, cresol,
3,5-xylenol, o-aminophenol, resorcin, hydroquinone, pyrogallol, phloroglucinol, bisphenol A, bisphenol F, novolac type phenol resin, etc. can be exemplified, and one or more of these can be used. Can be done.

The alkaline earth metal group salt of a phenol compound of the present invention can be easily obtained by a method such as heating and mixing an alkaline earth metal oxide or hydroxide with a phenol compound at 50 to 150 ° C. Can be done. The ratios of the alkaline earth metal and the phenol compound in the alkaline earth metal salt of the phenol compound may be used in equivalent amounts, but they are not particularly required to be equivalent, and the alkaline earth metal 10
It is used in a proportion of 100 to 300 parts by weight of the phenol compound with respect to 0 part by weight. The alkaline earth metal salt of the phenol compound of the present invention is 3 per 100 parts by weight of the phenol resin.
-40 parts by weight, preferably 5-25 parts by weight are used in combination. If the blending amount is small, the curability becomes insufficient, and if it is large, the thermal stability is impaired.

The filler of the present invention includes wood powder, pulp powder, various pulverized products of woven fabric, organic products such as pulverized products of thermosetting resin laminates and molded products, silica, alumina, aluminum hydroxide, glass, Inorganic powders such as talc, clay, mica, calcium carbonate, and carbon, and inorganic fibers such as glass fiber, carbon fiber, and asbestos are used, and one or more of these can be used. These fillers are used by mixing 50 to 150 parts by weight with respect to 100 parts by weight of the phenol resin. In the present invention, additives such as a flame retardant, a coloring agent, and a release agent can be appropriately mixed and used as necessary. Further, in the present invention, if necessary, a phenol compound such as a resole type phenol resin, resorcin, bisphenol F or biphenol can be appropriately mixed and used within 20 parts by weight with respect to 100 parts by weight of the phenol resin. The phenol resin molding material of the present invention contains a phenol resin, hexamethylenetetramine, an alkaline earth metal group salt of a phenol compound, a filler and various additives, and a roll mill, 2
It can be manufactured by melt-kneading with a shaft kneader or the like, cooling and then pulverizing.

[0008]

The function of the phenol resin molding material of the present invention is 90 to 1
It is remarkably excellent in thermal stability in a plasticized and melted state at 25 ° C., and is extremely excellent in curability in a mold at 150 to 200 ° C. The reason for this is not fully clear, but the alkaline earth metal salt of the phenol compound of the present invention hardly dissociates in the plasticized and molten state, and dissociates at high temperature to form a chelate between the alkaline earth metal and the phenol resin. Is believed to be due to the fact that the chelate accelerates the curing reaction between the phenol resin and hexamethylenetetramine, and that the phenol compound also undergoes a curing reaction with hexamethylenetetramine.

[0009]

EXAMPLES The present invention will be described below with reference to examples. Here, "parts" represent parts by weight. Example 1 Obtained from 44 parts of novolak resin (number average molecular weight 800) obtained by the reaction of phenol and formaldehyde, 7 parts of hexamethylenetetramine powder, 1 mol of 3,5-xylenol and 1 mol of calcium hydroxide. Further, 15 parts of calcium salt of xylenol, 30 parts of wood powder, 10 parts of calcium carbonate and 2 parts of a releasing agent were mixed, melt-kneaded with a two-roll mill, cooled and pulverized to obtain a phenol resin molding material. Example 2 A phenol resin molding material was obtained in the same manner as in Example 1 except that 15 parts of a magnesium salt of resorcin consisting of 1 mol of resorcin and 1 mol of magnesium oxide was used in place of the calcium salt of xylenol of Example 1. .

Example 3 Instead of the calcium salt of xylenol of Example 1, 60 parts by weight of calcium hydroxide was obtained with respect to 100 parts by weight of novolak having an average molecular weight of 800 obtained by the reaction of phenol and formaldehyde. A phenol resin molding material was obtained in the same manner as in Example 1 except that 10 parts of the calcium salt of novolac was used. [Comparative Example 1] 44 parts of novolac resin (number average molecular weight 800) obtained by the reaction of phenol and formaldehyde, 7 parts of hexamethylenetetramine powder, and 4 parts of calcium hydroxide.
Parts, 32 parts of wood powder, 11 parts of calcium carbonate, and 2 parts of a release agent were mixed, melt-kneaded with a two-roll mill, cooled and pulverized to obtain a phenol resin molding material.

Table 1 shows the material properties of the phenolic resins obtained in Examples 1 to 3 and Comparative Example 1.

[Table 1]

The thermal stability in Table 1 represents the thermal stability of the molding material in the plasticized and molten state, and was measured by the following method. 28 g of a powdery molding material is charged into a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) kept at 100 ° C., the rotor is rotated to plasticize and melt the molding material, and the torque of rotor rotation is measured. The torque increases as the viscosity increases with the progress of curing of the resin, and finally the fluidity is lost and the torque rapidly increases. The time from the start of measurement to the sudden rise in torque was measured, and this time was defined as thermal stability. The longer the time, the better the thermal stability. The curability in Table 1 represents the curing speed of the molding material in the mold, and a transfer molding machine having a cavity with a diameter of 50 mm and a thickness of 3 mm and having a mold kept at 175 ° C. was used for high frequency. 40g was prepared by charging 30g of tablet-shaped molding material that was preheated to 100-105 ° C with a preheater.
Molded for 2 seconds, taken out of the molded product, and the hardness of the molded product after 10 seconds was measured by a Barcol hardness tester No. It was measured at 935. The higher the hardness, the faster the curing speed and the better the curability.

From Table 1, the phenol resin molding materials of the present invention shown in Examples 1 to 3 are extremely excellent in thermal stability and curability as compared with the conventional phenol resin molding material of Comparative Example 1. You can see that In addition, Examples 1 to 3
And injection molding the phenolic resin molding material of Comparative Example 1,
When the molding machine was stopped on the way and the molding material in the plasticized and molten state was allowed to stand in the cylinder as it was, after all the materials of Examples 1 to 3 were left for 90 minutes, when the molding machine was restarted, However, when the material of Comparative Example 1 was left for 30 minutes, it hardened in the cylinder and it was difficult to restart.

[0014]

As can be seen from the above examples, the phenol resin molding material of the present invention has extremely excellent thermal stability in the plasticized and molten state and curability at high temperature. For this reason,
Particularly in injection molding, the progress of the curing reaction of the plasticized molten resin in the cylinder of the injection molding machine is significantly suppressed, and it rapidly cures in the mold, so it can be applied to a wide range of molding conditions and has excellent molding processability. ing. Further, the phenol resin molding material of the present invention is extremely suitable for sprue / runnerless molding because it has extremely excellent thermal stability in a plasticized and molten state.

Claims (1)

[Claims] 1. A phenol resin molding material comprising (a) a phenol resin, (b) hexamethylenetetramine, (c) an alkaline earth metal salt of a phenol compound, and (d) a filler.