JPH05163415A - Molding material - Google Patents

Abstract

PURPOSE:To obtain a molding material having balanced moldability and the toughness, heat-resistance, etc., of the molding by mixing a novolak phenolic resin with a polyphenylene ether resin in molten state or in the form of solution and using the obtained resin as a resin component. CONSTITUTION:A resin composition is produced by homogeneously mixing (A) a novolak phenolic resin preferably having a number-average molecular weight of 500-1,500 and an unreacted phenol content of <=2% with (B) a polyphenylene ether resin (including a resin modified with polyamide, etc.) at an (A:B) ratio of 99:1 to 1:99, preferably 95:5 to 5:95, especially 90:10 to 10:90, solidifying the obtained mixture by cooling and crushing the solidified product. The mixing of the components is carried out either by slowly adding the component B to molten component A and mixing the components or by mixing the components A and B in the form of solution using a polar solvent and removing the solvent from the solution mixture. When the ratio of the component A in the resin composition is high, the composition is incorporated with a curing agent (e.g. hexamethylenetetramine), a cure assistant, a filler, etc., to obtain a molding material. When the content of the component B is high, the resin composition may be used as a molding material as it is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a molding material containing a resin component which is a resin obtained by melt-mixing or solution-mixing a phenol resin which is a thermosetting resin and a polyphenylene ether resin which is a thermoplastic resin. It is about.

[0002]

2. Description of the Related Art Phenolic resins are excellent in heat resistance, strength, electrical characteristics and the like among thermosetting resins and are used in various applications such as molding materials and laminated materials. When used as a molding material, the properties of the molded product are generally good, but the toughness, chemical resistance, etc. may be insufficient. In addition, during molding, many parts such as sprues and runners are discarded due to the long molding cycle. There is a problem that burrs are unavoidable. Various studies have been made to improve such drawbacks, and one of them is mixing with a thermoplastic resin or an elastomer. So far, several materials have been studied and succeeded to some extent in improving the molded product characteristics such as impact resistance or moldability, but a resin composition having the characteristics of a phenol resin and a thermoplastic resin, particularly a molded product The material has not been obtained yet. On the other hand, looking at thermoplastic resin molding materials, the toughness and moldability are good, and although there are no drawbacks of thermosetting resins as described above, thermosetting resins have several points such as heat resistance of molded products. Inferior to

[0003]

From such a situation,
The present applicant has completed the present invention as a result of earnest studies especially for the purpose of improving defects such as poor toughness, impact resistance and moldability of the phenol resin molding material.
It was also found that modification of the polyphenylene ether resin can also be achieved by blending a novolac type phenol resin.

[0004]

DISCLOSURE OF THE INVENTION The gist of the present invention is a molding material containing as a resin component a resin obtained by melt-mixing or solution-mixing a novolac type phenol resin and a polyphenylene ether resin as essential components. . In the present invention, the novolac type phenolic resin (hereinafter referred to as novolac) may be any one as long as it is used for an ordinary molding material and the like, and is not particularly limited, but has a molecular weight (number average molecular weight) of 500 to 1500. However, it is preferable in terms of easiness of melt mixing with the polyphenylene ether resin and moldability when used as a molding material. Also, the less unreacted phenol, the better the characteristics of the molded product.
The following are preferred. On the other hand, the polyphenylene ether resin (hereinafter referred to as polyphenylene ether) may be a commercially available molding material. Further, those modified with polyamide or the like can also be used.

Novolak and polyphenylene ether are melt mixed or solution mixed to form a homogeneous melt or solution.
The mixing ratio of the novolac and the polyphenylene ether is not particularly limited, but if the ratio of one is extremely small, the effect of addition will not substantially appear. Therefore, the ratio of the novolac to the polyphenylene ether is usually 99: 1 to 1: 9.
It is 9. A preferred ratio is 95: 5 to 5:95, more preferably 90:10 to 10:90. When the ratio of novolac is 60% or more, the characteristics of the phenol resin mainly appear, and a composition having excellent heat resistance can be obtained. The strength and electrical properties are excellent, and the impact resistance and various problems during molding, which are the drawbacks of phenolic resins, are significantly improved. If the polyphenylene ether is 60%,
Heat resistance is improved while maintaining the characteristics of polyphenylene ether such as toughness. Thus, by melt-mixing or solution-mixing the novolac and the polyphenylene ether, the respective advantages can be utilized and the drawbacks can be complemented.

[0006] In melt-mixing, it is usual to first melt the novolak and then gradually add polyphenylene ether to the mixture and mix it. However, if a novolac resin having a large amount of free phenol is used, uniform mixing is easy, and if necessary, it is possible. After mixing, the free phenol may be removed. When the proportion of polyphenylene ether is considerably high, a method of melting polyphenylene ether and adding novolak thereto may be used. In the former case, an ordinary mixing pot may be used, but in the latter case, an apparatus having a large torque such as an extrusion kneader is preferable. It is preferred that at least one of the components be finely ground and melt mixed. As a method other than melt mixing, a method of solution mixing using a polar solvent is also possible, and the solvent may be removed after mixing. Since novolac and polyphenylene ether are compatible at any ratio, a homogeneous melt or solution mixture can be obtained, but this is solidified by cooling, or by removing the solvent by evaporation etc. to solidify and pulverizing to an appropriate size. Or disconnect. This composition is usually mixed with a curing agent such as hexamethylenetetramine (hereinafter referred to as hexamine) before use, which may be mixed with the resin or after pulverization. If the amount of novolac is small, it is not necessary to add hexamine.

A case where the above resin composition is used as a molding material will be described. When the proportion of novolac in the composition is high, hexamine, and an organic or inorganic filler, a curing aid such as calcium hydroxide, a release agent, etc. are added to this composition, and the mixture is melt-kneaded by a roll or the like and then pulverized. To do. on the other hand,
When the composition contains a large amount of polyphenylene ether, the composition as it is may be used as a molding material, or a composition similar to the case where the composition contains a large amount of novolak can be formed into a molding material. Filler used when forming a molding material in the present invention, wood powder, pulp powder, various woven fabrics,
Organic substances such as crushed thermosetting resin laminates and molded products, powders of silica, alumina, glass, talc, clay, calcium carbonate, carbon, etc., inorganic substances such as glass fiber, carbon fiber, mica, etc. .

[0008]

When the novolac and polyphenylene ether are uniformly mixed by melt mixing or solution mixing as described above, it is considered that these resins are not only mixed but alloyed or reacted. As a result, the features of both resins can be used as they are, and the defects can be improved.

[0009]

EXAMPLES Next, the present invention will be described with reference to Examples and Comparative Examples. Example 1 90 parts of novolak (number average molecular weight 800) was heated to 170 ° C. and melted, and 10 parts of polyphenylene ether (molecular weight about 20,000) was gradually added and mixed.
After the polyphenylene ether was completely dissolved, take it out,
After cooling, it was pulverized to obtain a resin composition. [Example 2] A resin composition was obtained in the same manner as in Example 1 except that the ratio of novolac to polyphenylene ether was changed to 80:20. Comparative Example 1 Only the above novolak was crushed. These resin compositions or resins alone were made into molding materials with the formulations shown in Table 1. The molding material was melt-kneaded using a twin-screw extruder. The obtained molding material was injection-molded in a mold at 170 ° C. to obtain a molded product. The bending strength and impact strength of this molded product were measured. The results are shown in Table 1.

[0010]

[Table 1]

[Example 3] 10 parts of novolac and 1.5 parts of hexamine were mixed in advance, and 90 parts of polyphenylene ether were extruded by melt-kneading at 250 ° C using a twin-screw extruder. At the same time, it was cut into pellets to obtain a molding material. Example 4 20 parts of novolac and 3 parts of hexamine were mixed in advance, and this was mixed with 80 parts of polyphenylene ether.
Then, a molding material was obtained in the same manner as in Example 4 below. Comparative Example 2 The polyphenylene ether pellets were used as they were. The obtained molding material was injection-molded and the heat distortion temperature of the molded product was measured. The results are shown in Table 2.

[0012]

[Table 2]

From the results shown in Table 1, Examples 1 and 2 with a large amount of novolac have higher toughness and improved strength and impact resistance as compared with Comparative Example 1 containing only novolac. The other properties were equal to or better than that, and the moldability was good. From the results of Table 2, Example 3 containing a large amount of polyphenylene ether
Nos. 4 to 4 have improved heat resistance as compared with Comparative Example 2 containing only polyphenylene ether. , Other properties and moldability were equal or better.

[0014]

As is clear from the above examples, when the molding material of the present invention has a large amount of novolac, the toughness of the molded product is improved as compared with the phenol resin molding material, and other characteristics are also exhibited. Good and good moldability. When the amount of polyphenylene ether is large, the heat resistance is improved while the moldability is maintained, and other properties are better than those of polyphenylene ether alone.

Claims (1)

[Claims] 1. A molding material containing, as a resin component, a resin obtained by melt-mixing or solution-mixing a novolac type phenol resin and a polyphenylene ether resin as essential components.