JPH026551A - Phenol resin molding material - Google Patents

Abstract

PURPOSE:To obtain the title material having mechanical strengths and heat resistance by mixing a phenol resin with an alkaline earth metal oxide and a sulfur compound. CONSTITUTION:100 pts.wt. phenol resin (A) (novolac or resol type) is mixed with 1-10 pts.wt. alkaline earth metal oxide (B) (e.g., MgO or CaO), and 1-7 pts.wt. sulfur compound (C) (a thiazole compound, e.g., 2-mercaptobenzothiazole; a triuram compound, e.g., tetramethylthiuram sulfide; a triazine compound, e.g., 2,4,6-trimercapto-1,3,5-triazine; a sulfenamide compound, e.g., N- oxydiethylene-2-benzothiazoylsulfenamide; a dithio acid compound, e.g., copper dimethyldithiocarbamate) to form a phenol resin molding material. Further, the addition of 1-10 pts.wt. resocinol per 100 pts.wt. phenol resin has an effect of improving the initial strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a phenolic resin molding material with excellent heat resistance.

[Prior art and its problems]

Phenol resins are widely used because of their moldability and low cost, and efforts are being made to meet the increasingly sophisticated demands for heat resistance in recent years.

For example, JP-A-60-108459 discloses a material that uses a combination of rubber and a sulfur compound, and a molding material that appears to be based on this technology has been commercialized under the trade name Metatal HT-500 (manufactured by Rogers, USA). has been done. This material is expected to expand the field of application of phenolic resins, but because it uses a large amount of rubber, its rigidity under heat is poor, and it is difficult to remove from the mold during molding, heat creep resistance, and mechanical strength. This results in sacrificing the properties of the molding material, such as deterioration.

In addition, a phenol resin composition consisting of a phenol resin, hexamethylenetetramine and dithioate salts (Japanese Patent Application Laid-open No. 62
-241950), a phenol resin composition consisting of a phenol resin, hexamethylenetetramine, and sulfenamides (JP-A-62-241952), a phenol resin composition consisting of a phenol resin, hexamethylenetetramine, and thiazoles (JP-A-62-241952); -241954
) are disclosed. These inventions can be cured at an industrially useful rate even in a relatively low temperature range, but do not improve heat resistance.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a phenolic resin molding material that has both mechanical strength and excellent heat resistance.

[Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive research in order to solve the above problems.

That is, the present invention is a phenolic resin molding material comprising a phenolic resin, an oxide of an alkaline earth metal, and a sulfur compound.

The molding material of the present invention does not contain components that have a plasticizing effect, such as rubber, and therefore does not lose its rigidity when heated.

The phenolic resin used in the present invention can be a novolak type or resol type phenol resin, and the following types can be used.

Alkylphenols such as phenol, cresol, xylenol, butylphenol, octylphenol, nonylphenol, aralkylphenols such as 2,2"-bis(4-hydroxyphenyl)propane, phenylphenol, cumylphenol, vinylphenol, isopropenylphenol, etc. Obtained by reacting alkenylphenols, etc. with a formaldehyde aqueous solution, aliphatic aldehydes such as paraformaldehyde, α-polyoxymethylene, β-polyoxymethylene, or substituted and unsubstituted aromatic aldehydes in the presence of an acid or base catalyst. It is resin.

Generally, various methods are adopted for the reaction conditions such as the type of catalyst, the molar ratio of phenols and formaldehydes, and the reaction method.The alkaline earth metal oxide essential in the present invention is 100 parts by weight of the phenol resin. It is preferable to use 1 to 10 parts by weight.

In particular, magnesium oxide and calcium oxide are preferred.
These oxides are also effective in improving rigidity under heat.

Sulfur compounds include 2-mercaptobenzothiazole, 2,2'-dithiobisbenzothiazole, 2-(4-
thiazole compounds such as morpholinodithio)benzothiazole, thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, 2.4.6-trimercapto-1,3, 5-triazine, 2,4-dimercapto-6
- Triazines such as dibutylamino-1,3,5-triazine, N-cyclohexyl-2-benzothiazolylsulfenamide, N-oxydiethylene-2-benzothiazolylthiazolylsulfenamide, N,N - Sulfenamides such as dicyclohexyl-2-benzothiazolylsulfenamide, and dithioate salts such as copper dimethyldithiocarbamate and sodium dibutyldithiocarbamate, which can be used alone or in combination of two or more. Can be used. Phenol resin 100
It is preferable to use 1 to 7 parts by weight of the sulfur compound.

Resorcinol is 1 to 100 parts by weight of phenolic resin.
Resorcinol, preferably used in an amount of 10 parts by weight, has the effect of improving initial strength.

The molding material of the present invention can be appropriately blended with fillers, curing agents, curing accelerators, plasticizers, lubricants, pigments, etc., which are used in ordinary phenolic resin molding materials, according to a conventional method. It can be used as a molding material.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Examples 1 to 12 and Comparative Examples 1 to 2 Phenol resin (manufactured by Mikata Toatsu Kagaku Co., Ltd., Novolac #20
00), a curing agent, a sulfur compound, an alkaline earth metal oxide, resorcinol, and other raw materials are mixed in a blender in the proportions shown in Table 1, kneaded with heated rolls at 80 to 100°C, and then subjected to impact pulverization. The mixture was crushed using a machine to obtain a molding material.

Test Example The above molding material was molded using an IR-45P injection molding machine manufactured by Toshiba Machine Co., Ltd., with a mold temperature of 180°C and an injection cuff of 00 to 800 kg/
A test piece for measuring physical properties was prepared under the conditions of c+1 and molding time of 60 seconds. The obtained test piece was further post-cured at 180°C for 8 hours, then placed in a gear opener maintained at 250°C, and after a predetermined period of time, the test piece was taken out.
The bending strength at that time was measured according to JIS K-6911, and the time required for the bending strength to decrease by half from the initial value was determined.

In addition, regarding the rigidity when heated, the diameter is 50 m111, the thickness is 2
Immediately after molding, a disk-shaped test piece with a diameter of 9.5 g and a weight of 9.5 g was held horizontally with a part of the runner held horizontally, and a 25 g weight was placed on the opposite side from the gate section, and the test specimen was placed at the gate section having a rectangular cross section of 1 mm x 6 m. Evaluation was performed by determining the angle at which the bend occurred.

The results are shown in Table 1.

Comparative Test Example 2 A commercially available heat-resistant phenolic resin molding material Metatal HT-500 (manufactured by Rogers, USA) was evaluated in the same manner as in the test example.

The results are shown in Table 1.

[Effects of the invention] The phenolic resin molding material of the present invention has excellent mechanical strength retention at high temperatures and high rigidity when heated, and can be used in fields where conventional phenolic resin molding materials have insufficient heat resistance and cannot be used. It can be used in a wide range of applications, including electrical, electronic parts, mechanical parts, automobile parts, and kitchen supplies.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. A phenolic resin molding material comprising a phenolic resin, an oxide of an alkaline earth metal, and a sulfur compound. 2. The phenolic resin molding material according to claim 1, wherein the sulfur compound is a thiazole compound. 3. The phenolic resin molding material according to claim 1, wherein the sulfur compound is a thiuram compound. 4. The phenolic resin molding material according to claim 1, wherein the sulfur compound is a triazine compound. 5. The phenolic resin molding material according to claim 1, wherein the sulfur compound is a sulfenamide compound. 6. The phenolic resin molding material according to claim 1, wherein the sulfur compound is a dithioate compound. 7. The phenolic resin molding material according to claims 1 to 6, wherein the alkaline earth metal oxide is magnesium oxide and/or calcium oxide. 8. The phenolic resin molding material according to claims 1 to 7, characterized in that 1 to 10 parts by weight of resorcin are used in combination with 100 parts by weight of the phenolic resin according to claim 1.