JPS61209241A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE:The titled composition for coating electric wire for wiring in electronic devices requiring highly corrosive properties to metals, solvent resistance, etc., obtained by blending an ethylene ethyl acrylate copolymer with a specific amount of Mg(OH)2, a specific amount of red phosphorus and a specific amount of a specified phenolic derivative. CONSTITUTION:100pts.wt. ethylene.ethyl acrylate is uniformly blended with 5-100pts.wt., preferably 5-48pts.wt. magnesium hydroxide, 1-10pts.wt. red phosphorus (preferably having <=1mu particle diameter and subjected to surface treatment),and 1-10pts.wt. phenolic derivative [e.g., N,N'-hexamethylenebis(3,5- di-t-butyl-4-hydrocinnamamide), etc.] having >=120 deg.C melting point and an amide bond by Banbury mixer, etc., to give the aimed composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is suitable for use as a flame-retardant resin composition, more specifically as a coating material for electric wires used in wiring in electronic equipment, which requires a high degree of corrosion resistance to metals, solvent resistance, and flame retardancy. This invention relates to a flame retardant composition.

C. Prior Art and Problems] In recent years, damage caused by harmful gases and smoke generated during flames has been raised as a major social problem, and it has been proposed that electrical wires, etc. that require flame retardancy should be non-flammable and low-pollution. .

Conventionally, as this type of material, a composition based on ethylene/ethyl acrylate copolymer, magnesium hydroxide, and red phosphorus disclosed in the invention of Japanese Patent Publication No. 58-121481 has flame retardant properties.
It is known to have excellent properties such as low pollution and insulation resistance.

Furthermore, the method of adding antioxidants to impart heat resistance to these properties is widely known, and was published in Japanese Patent Publication No. 58
It is possible to improve heat resistance by adding a desired antioxidant to the composition of the -121481 invention, flame retardancy,
It can be applied to covering materials for electric wires that require heat resistance.

However, electric wires used in electronic equipment, particularly in small, high-temperature, closed systems such as relay boxes, are required to have metal corrosion resistance and solvent resistance in addition to those listed above.

In other words, the maximum capacity inside the relay box is 12 when the relay is used.
Since the system is a high-temperature sealed system at 0°C, materials that generate corrosive substances corrode metal parts such as relay contacts and cause a significant decline in functionality.

Further, although wiring in electronic devices is usually performed by soldering, the parts after wiring are cleaned with a solvent such as Freon to remove residual paste and dust. Therefore, substances that are easily soluble in solvents precipitate out during solvent cleaning and adhere to the surfaces of electric wires, parts, etc., causing deterioration in the characteristics of electric wires, deterioration in the functionality of equipment, and further significantly worsening the appearance.

The composition of the invention of Japanese Patent Publication No. 58-121481 exhibits excellent properties against metal corrosion and solvent resistance, but when adding an antioxidant to improve heat resistance, Even if an antioxidant with excellent solvent properties is selected, it is difficult to improve the corrosion resistance to metals.

In other words, although the system in which an antioxidant is added to the ethylene/ethyl acrylate copolymer has good corrosion resistance to metals, when the same antioxidant is added to the system of the invention of Japanese Patent Publication No. 58-121481, Metal corrosivity may become poor. That is, in the presence of an antioxidant, phosphorus-based corrosive substances are generated, and simply selecting an antioxidant with good corrosion resistance to metals has not solved the problem.

The purpose of the present invention is to eliminate such conventional drawbacks and to provide a flame-retardant resin composition that has solvent resistance, heat resistance, and high flame retardancy without generating metal-corrosive substances in a high-temperature atmosphere. The goal is to provide the following.

As a result of intensive research, the present inventors found that
Among the flame-retardant resin compositions made by combining the composition of the No. 81 invention and an antioxidant, the resin contains ethylene-ethyl acrylate copolymer, the flame retardant contains magnesium hydroxide, and the flame-retardant aid contains red phosphorus. Only systems that select and use phenol derivatives with a molecular weight of 250 or more and an amide bond as antioxidants have high heat resistance, high flame retardancy at the VW-1 flame retardant level, and can withstand temperatures of 120"C. It was discovered that metals hardly corrode even in the harsh atmosphere of a closed system, and almost nothing is extracted by solvents.

That is, the flame-retardant resin composition of the present invention, which does not corrode metals, contains 5 to 100 parts by weight of agnesium hydroxide, 1 to 10 parts by weight of red phosphorus, and a melting point of 100 parts by weight of the ethylene/ethyl acrylate copolymer. It is characterized by uniformly blending 1 to 10 parts by weight of a phenol derivative having an amide bond of 250 or more.

In this case, the ethylene/ethyl acrylate copolymer is
Any ethyl acrylate content of II can be used.

Although any magnesium hydroxide can be used, it is preferable to use a surface-treated magnesium hydroxide having a particle size of 1 μm or less in consideration of dispersibility and compatibility with the resin.

If the additive amount is less than 5 parts by weight per 100 parts by weight of the resin, the desired flame retardance cannot be obtained. In addition, the special public service 58-121
As shown in invention No. 481, even if it exceeds 100 parts by weight, there is no problem with properties other than heat resistance and extrusion processability up to 400 parts by weight, but as the number of blended parts of magnesium hydroxide increases, heat resistance decreases. There is a tendency that when magnesium hydroxide exceeds 100 parts by weight, the maximum allowable temperature for electrical equipment insulation specified in JIS-0-4008 oo"0 (Yl
It is difficult to apply this method to line type 1). In addition, if the amount exceeds 50 parts by weight, the maximum allowable temperature for electrical equipment insulation is 18
Since it is difficult to apply to wire types with high heat resistance grade of 0°O(B[) or higher, preferably 5 to 48 parts by weight of red phosphorus is added to improve flame retardancy. Although any one can be used, like magnesium hydroxide, one that has been surface-treated to have a particle size of 1 μm or less is preferable.

Any phenol derivative having an amide bond can be used as long as it has a melting point of 120° C. or higher, but a finely powdered one having good compatibility with the resin is preferable.

Representative examples of this compound include N,N'-hexamethylenebis(3,5-di-tertbutyl-4-hydroxyhydrocinnamamide), N,N'-bis(3,5
-dit8rtbutyl-4-hydroxyphenyl)propionic acid hydrazide, N-(2-hydroxybenzoyl)-n/-benzylidenehydrazine.

There are compounds represented by diacetyldisalicylhydrazone and.

In addition, if necessary, any additives such as pigments and lubricants may be added to the ffS as long as they do not generate metal corrosive substances at high temperatures and are insoluble in the solvent.

Banbury mixer, which is also commonly used for the production of compositions.
Any device capable of uniformly mixing the materials can be applied, such as , open rolls, etc.

Further, if necessary, treatment steps such as silane crosslinking and electron beam irradiation crosslinking may be performed, and necessary additives may be added thereto.

The present invention will be further explained below with reference to Examples and Comparative Examples.

Example I EA content: 1 100 parts by weight of EA (product name: DPDJ 6182), 40 parts by weight of magnesium hydroxide (product name: Kisuma 5A, manufactured by Kyowa Chemical Co., Ltd.), red phosphorus (product name: Rin Kagaku Kogyo Co., Ltd.) Norbalet 1200F) 6 parts by weight, N,N'-hexamethylene bis(8,5-di
tert 7'thyl-4-hydroxyhydrocinnamamide) (Japan Ciba Geigy Exhibition Product Name Irganox 1
098) was added thereto, mixed uniformly in a Banbury mixer with a volume of 1.71, and pelletized to obtain a resin composition.

Examples 2 to 5 and Comparative Examples 1 to 12 Resin compositions were prepared in the same manner as in Example 1 with the compositions shown in Table 1.

As described above, each of the resin compositions prepared in Examples 1 to 5 and Comparative Examples 1 to 12 was prepared using a screw diameter of 2 at a set temperature of 170°C.
Using a single screw extruder with a diameter of 0.0 mm, the wall thickness is 0.0 mm on a single wire of mild steel of 0.8 da.
, 6 jEII was extruded, and 2
The following tests were conducted on the cross-linked products that were irradiated with an electron beam of 5 Mrad, and the results obtained are also listed in Table 1.

(1) Metal Corrosion Test For the above sample, take a certain amount of finely cut wire material from which the conductor has been removed, place it in a test tube, suspend a small piece of silver or copper, and keep it at 120°C and observe the time when discoloration begins. .

If the color did not change in a short time at a temperature of 120°C, the measurement was carried out at a higher temperature, and the discoloration time at a temperature of 120°C was estimated using an Arrhenius plot. (2) Freon precipitation test The above sample of an appropriate length was placed on two aluminum plates. about 85℃
After immersing the sample in Freon for 5 minutes, the Freon was sufficiently volatilized, and the presence or absence of precipitates on the surface of the sample and the aluminum plate was examined.

(3) UN-1 vertical combustion test The test was conducted according to UL Sub 758-G.

) Tensile test after aging The test was conducted in accordance with Section 17 of JI808005.

The deterioration conditions were 160°C for 7 days.

As can be seen from the coating above, Comparative Example 1, which does not contain a 1cflR inhibitor, has good metal corrosion resistance and solvent resistance, but extremely poor heat resistance.Comparative Example 2, which uses an antioxidant with a melting point of about 70°0 Although it has good corrosion resistance against metals, foreign matter adheres to the metal surface.

In Comparative Examples 8 to 6, when only 8 ffS of antioxidant was added to the ethylene/ethyl acrylate copolymer, the corrosion resistance to metals was good, but when magnesium hydroxide and red phosphorus were also added, the corrosion resistance to metals was markedly increased. decreased. When the metal piece was subjected to elemental analysis using an X-ray microanalyzer, phosphorus was detected, and the antioxidant used here was found to be
It is thought that a chemical reaction with phosphorus produced a corrosive, low-boiling compound.

In this way, there are antioxidants that are not corrosive to metals by themselves but deteriorate metal corrosiveness when used in combination with red phosphorus.
It is not possible to create a composition with good corrosion resistance to metals by simply adding it to the composition of 8-121481.

More comparative examples? In this case, even if the amount of red phosphorus added was reduced, no significant improvement in the corrosion resistance against metals was observed. Furthermore, in Comparative Example 8, which does not contain any red phosphorus, the corrosion resistance against metals is improved, but the flame retardance is significantly lowered. Furthermore, even if the number of added parts of the zinc salt of 2-mercaptobenzimidazole is reduced, no significant improvement in the corrosion resistance against metals is observed, and the heat resistance properties also deteriorate.

In Comparative Examples 10 to 12, the metal corrosion resistance was good, but precipitates were formed when immersed in Freon.

On the other hand, Examples 1 to 5 both exhibit excellent properties in terms of metal corrosion resistance, solvent resistance, flame retardance, and heat resistance.

Claims (1)

[Claims] 1. For 100 parts by weight of ethylene/ethyl acrylate copolymer, 5 to 100 parts by weight of magnesium hydroxide, 1 to 10 parts by weight of red phosphorus, and 1 to 10 parts by weight of a phenol derivative having an amide bond with a melting point of 120°C or higher. A flame-retardant resin composition characterized by being uniformly blended.