JPS63309553A - Novolac resin molding - Google Patents

Abstract

PURPOSE:To make it possible to form a crosslinked novolac resin molding excellent in mechanical properties, by mixing a composition of a novolac resin synthesized by using an excess of a phenol with a polyamide resin with a filler and a crosslinking agent and molding the mixture. CONSTITUTION:This novolac resin molding can be formed by adding a filler to a resin comprising 60-97wt.% novolac resin obtained by reacting a phenol with an aldehyde in the presence of an acidic catalyst under conditions under which the phenol is excess and 40-3wt.% polyamide resin and crosslinking the mixture with a crosslinking agent. Examples of said polyamide resins which are desirable include nylon 6, nylon 6.6 and nylon 4.6. Examples of said fillers include inorganic powders and resin powders. An example of said crosslinking agent includes hexamethylenetetramine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a crosslinked novolac resin molded article, and more particularly to a crosslinked novolac resin molded article containing a polyamide resin and having excellent mechanical properties.

[Conventional technology]

Conventionally, novolac resin molded products are obtained by mixing fillers, curing agents, etc. with novolac resin, heating, and crosslinking.
It is used in many fields because it has excellent heat resistance, dimensional stability, strength, etc., and is relatively inexpensive.

If the mechanical properties of such a novolac resin molded article can be further improved, it is thought that it can be expected to be applied to a wider range of uses.

[Problem that the invention seeks to solve]

The present invention was made against the background of the above-mentioned problem, and an object of the present invention is to provide a crosslinked novolak resin molded product having excellent mechanical properties.

[Means for solving problems]

That is, the present invention provides a resin consisting of 60 to 97% by weight of a novolak resin obtained by reacting phenols and aldehydes in the presence of an acidic catalyst in the presence of an excess of phenols, and 40 to 3% by weight of a polyamide resin. The present invention provides a novolac resin molded product obtained by mixing a filler with a filler and crosslinking the mixture.

The novolac resin used in the present invention is obtained by reacting phenols and aldehydes using an acid such as sulfuric acid, hydrochloric acid, oxalic acid, acetic acid, or phosphoric acid as a condensation catalyst under conditions where the phenol is present in excess. It is a soluble and fusible thermoplastic resin.

Examples of the phenols used here include phenol, cresol, xylenol, resorcinol, p-
Examples include t-butylphenol, p-nonylphenol, p-phenylphenol, and bisphenol A.

Examples of aldehydes include formaldehyde, paraformaldehyde, benzaldehyde, acetaldehyde, and furfural.

The proportion of phenols used in this case is more than 1 mole, usually more than 1 mole and less than 2 moles, preferably more than 1 mole and less than 1.5 moles, per mole of aldehyde [1 mole]. Yes, and the melting point of the novolak resin obtained is
The temperature is usually 50 to 120°C, preferably 60 to 110°C.

Next, examples of the polyamide resin used in the present invention include nylon 12, nylon 11, nylon 6, nylon 6.6, nylon 4', 6, and nylon 6.10, preferably nylon 6, nylon 6.10, etc. 6, 6,
It is nylon 4.6.

In addition, the intrinsic viscosity of the polyamide resin used in the present invention is usually 0.5 dl/g or more, preferably 0.8 to 5.
0a/g (concentration 0.5g/100mj2, phenolic solvent, 30''C).

The weight ratio of the novolac resin and the polyamide resin is such that the novolac resin is 60% by weight or more and 97% by weight or less,
Preferably 70% by weight or more and 95% by weight or less, particularly preferably 70% by weight or more and less than 90% by weight, the polyamide resin is 3% by weight or more and 40% by weight or less, preferably 5% by weight or more, and 30% by weight or more. If the polyamide resin is less than 3% by weight, the heat resistance and mechanical properties of the polyamide resin will not be sufficiently expressed;
If it exceeds 0% by weight, the polyamide resin will be too large and the resulting composition will lack compatibility, have reduced mechanical strength, or have poor moldability.

In the present invention, the novolac resin and the polyamide resin are usually melted and mixed in advance.

When melting and mixing this novolak resin and polyamide resin, the mixture is preferably at a temperature of 120°C or higher, particularly preferably 170 to 350°C, and usually for 30 minutes or more, preferably 30 to 120 minutes under nitrogen. be done. If the temperature during melting and mixing is too low, the compatibility between the novolac resin and the polyamide resin will be insufficient, and even if a crosslinked molded product is made using the resulting composition, it will have poor mechanical strength, while during melting and mixing If the temperature is too high, compatibility will be good, but the novolac resin may progress to harden.

As described above, when the novolac resin and the polyamide resin are melted and mixed, the compatibility between the two becomes good, and a phase that is uniform in appearance is formed.

The composition thus obtained is cooled, solidified, and then pulverized to obtain a polyamide resin-containing novolac resin composition powder, which can be used in the molding process in the same manner as a normal novolac resin powder. can.

In the present invention, in order to produce a crosslinked molded article, for example, an inorganic powder such as barium sulfate, silica, calcium carbonate, magnesium carbonate, clay, zeolite is added to 100 parts of powder of the obtained polyamide resin-containing novolak resin composition. , powders such as graphite, perlite, and molybdenum sulfide, fillers such as rice powder, and resin powders, reinforcing materials such as asbestos, and other materials such as glass fiber, carbon fiber, aramid fiber, and metal fiber, for example, 2.0
00 parts by weight or less, preferably 30 to 500 parts by weight, and a crosslinking agent of, for example, 5 to 20 parts by weight, preferably 8 to 15 parts by weight, and the mixture is thoroughly mixed and used for molding.

At this time, additives other than those mentioned above, such as pigments, dyes, lubricants,
Other additives such as a softening agent may also be added.

Here, examples of the crosslinking agent include hexamethylenetetramine.

In this mixing, it is preferable not only to simply mix but also to melt and knead using a hot roll, kneader, extruder, etc., and then pulverize again and use it for molding.

The temperature during this melting and kneading is usually 80°C.
-140°C, preferably 100-130°C.

In addition, in the melting and kneading here, crosslinking may proceed to an extent that does not pose a problem to molding.

The kneading time varies depending on various conditions and cannot be limited, but is usually within 60 minutes.

In the present invention, as a molding method for obtaining a crosslinked molded product, a molding method for novolak resin used in general formulas, such as a compression molding method, a transfer molding method, an extrusion molding method, etc. can be used. Processing conditions are also the same as for normal novolac resins.

The cross-linked molded product of the present invention thus obtained can be used for electric or electronic materials such as wiring board materials, electrical outlets, light bulb inserts, and motor brush holders, and for friction or sliding materials such as brake materials, sliding plates, and bearings. It is useful for mechanical parts, such as gears and cams, for grinding wheels, for castings, for tools, and as a binding material for other inorganic or organic materials.

In the present invention, the reason why the mechanical strength of the crosslinked molded product is improved is not because of the structure, but because of the interpenetration height caused by the entanglement of the molecular chains of the novolak resin, which has a three-dimensional network structure, and the molecular chains of the polyamide resin. It has a molecular network structure (IPN), and the structure of the polyamide resin itself used in the present invention is
Partially reacts with the hydroxyl groups present in the novolac resin,
It is thought that complex bonds are formed between the novolak resin and polyamide resin while maintaining their original skeletons, and a synergistic effect is exerted.

〔Example〕

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

Example 1 In a separable flask with an internal volume of 41 cm, a novolac resin (manufactured by Gunei Chemical Co., Ltd., PSM-2222) obtained by reacting phenols and aldehydes under conditions with an excess of phenols under the presence of an acidic catalyst was placed. ) 1.600g, heated at 200℃ with a mantle heater to melt it, and added nylon 6.6 resin (manufactured by Ube Industries ■, 22O20B) 400g
The mixture was stirred for 30 minutes while maintained at 200° C. under a nitrogen blanket, and then dissolved uniformly and transparently. The contents were then poured into a large evaporating dish and allowed to cool and solidify.

This solidified material was coarsely crushed and then ground using a ball mill.

Next, the thus obtained polyamide resin-containing novolac resin composition powder (average particle size: 300 μm) 20
To 0 g, 300 g of barium sulfate as a filler and 20 g of hexamethylenetetramine as a crosslinking agent were added, mixed well, and then kneaded with hot rolls to obtain a more uniform composition.

The hot roll conditions at this time were that the front roll was 110°C and 10°C.
The r p m % post-roll was 120° C. and 2 Q rpm. After kneading, the mixture is ground again in a ball mill.
It was made into powder for molding.

Using 50g of this powder, put it into a 70x70m chrome-plated flat plate mold, and put it under normal pressure and gauge pressure of 50kg/ajO.
The temperature was raised to 150° C. while going back and forth between the two times. 150℃
When the pressure reached 150 kg/aJ, the pressure was increased to 3.
After pressurizing for 0 minutes, the mold was allowed to cool, and the crosslinked molded product was taken out.

Further, this crosslinked molded product was placed in a hot air oven at 170° C. for 4 hours to be aired.

Next, the obtained crosslinked molded product was cut into 10 widths using a diamond cutter, and a tensile test was conducted.

The average measurement results of the 10 cut samples are calculated as the first
Shown in the table.

Comparative Example 1 In Example 1, a composition was prepared using only novolac resin without adding polyamide resin powder.

That is, 200 g of novolak resin, 30 g of barium sulfate
using 0 g and 20 g of hexamethylenetetramine,
A crosslinked molded product was obtained in the same manner as in Example 1, and the resulting crosslinked molded product was cut and subjected to a tensile test. Table 1 shows the results.

Examples 2 to 4 Resin compositions were obtained by changing the ratio of nylon 6.6 resin mixed with novolak resin, and the amount of hexamethylenetetramine used was 18 g (Example 2), 14 g (Example 3), and A crosslinked molded product was obtained in the same manner as in Example 1, except that the weight was 12 g (Example 4), and the obtained crosslinked molded product was cut and subjected to a tensile test. The results are shown in Table 1.

Comparative Example 2 200g of nylon 6 resin mixed with novolac resin
(Amount ratio of 501i) was used to obtain a resin composition, and a crosslinked molded product was obtained in the same manner as in Example 1 except that the amount of hexamethylenetetramine used was 20g. It was cut and subjected to a tensile test. The results are shown in Table 1.

Comparative Example 3 Nylon 6.6 resin mixed with novolac resin was 280
g (Usage ratio: 70% by weight) to obtain a resin composition, and the amount of hexamethylenetetramine used was 12g.
A crosslinked molded product was obtained in the same manner as in Example 1, except that
The obtained crosslinked molded product was cut and subjected to a tensile test.

The results are shown in Table 1.

Example 5 Except that 400 g of nylon 6 resin (use ratio 20% by weight) was used as the polyamide resin, 220 g of rice powder was used instead of barium sulfate as a filler, and the amount of hexamethylenetetramine used was 16 g. ,
A crosslinked molded product was obtained in the same manner as in Example 1, and the resulting crosslinked molded product was cut and subjected to a tensile test. The results are shown in Table 1.

Comparative Example 4 In Example 5, a composition was prepared using only novolac resin without adding polyamide resin powder.

That is, a crosslinked molded product was obtained in the same manner as in Example 5 using 200 g of novolac resin, 220 g of rice powder, and 20 g of hexamethylenetetramine, and the obtained crosslinked molded product was cut and subjected to a tensile test. The results are shown in Table 1.

Example 6 Nylon 6 resin (manufactured by Ube Industries, Ltd.,
A crosslinked molded product was obtained in the same manner as in Example 5, except that 400 g (use ratio: 20% by weight) of 1013B) was used, and the obtained crosslinked molded product was canted and subjected to a tensile test. The results are shown in Table 1.

Ta. The results are shown in Table 1.

Example 7 A crosslinked molded product was obtained in the same manner as in Example 5, except that 400 g (use ratio: 20% by weight) of nylon 4.6 resin (manufactured by Japan Synthetic Rubber ■, TS 300) was used as the polyamide resin. The resulting crosslinked molded product was cut and subjected to a tensile test. The results are shown in Table 1.

Table 1 1) Total of novolak resin and polyamide resin 100
Weight parts to weight parts [Effect of the invention] According to the present invention, a crosslinked novolak resin molded article having excellent mechanical properties can be obtained.

In addition, the obtained novolac resin molded products can be used for electrical or electronic purposes such as wiring board materials, electrical outlets, light bulb inserts, and motor brush holders, for friction or sliding purposes such as brake materials, sliding plates, and bearings, gears, cams, etc. It is useful for mechanical parts, grindstones, castings, tools, and as a binding material for other inorganic or organic materials.

Claims (1)

[Claims] (1) 60 to 97% by weight of a novolac resin obtained by reacting phenols and aldehydes in the presence of an acidic catalyst in the presence of an excess of phenols, and 40 to 97% by weight of a polyamide resin.
A novolac resin molded product made by mixing a filler with a resin consisting of 3% by weight and crosslinking the mixture.