JPH04107B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a crosslinked polyolefin resin flame-retardant molded article. Conventionally, when making polyolefin resin flame retardant, a combination system of a halogen flame retardant and antimony oxide has been generally used. However, while these exhibit good flame retardancy, they generate corrosive gases such as hydrogen halides when burned, which not only corrode expensive equipment in the event of a fire, but are also toxic and can cause poisoning accidents. I was also afraid. As is clear from the Fire Service White Paper of 1978, out of the 1,404 people who died in building fires in 1978,
The number of people who died from being exposed to smoke, poisoning, or suffocation was 548, or about 40% of them died from smoke or toxic gas. Therefore, the inventors of the present invention have discovered that (a) black smoke is produced when burned in insulating materials for electric wire cables, electrical parts, and equipment wiring.
In order to develop polyolefin molded products that do not generate toxic gases, (b) can easily require high flame retardancy, and (c) can obtain high tensile properties, good heat aging resistance, and chemical resistance. , conducted intensive research. In recent years, methods using inorganic compounds containing water of crystallization, such as aluminum hydroxide, have been proposed as flame retardant methods that do not generate harmful gases during combustion. This always necessitates extremely high filling. Even if high flame retardancy is achieved by high loading, other physical properties such as tensile strength, elongation, heat aging resistance, etc. will be significantly reduced, and the good properties of the original polyolefin resin will be greatly impaired. It gets lost. The present inventors have discovered that by adding a specific hydroxide and antimony trioxide to polyolefin, molding it, and performing a crosslinking reaction, a molded product with extremely excellent flame retardancy can be obtained without comparably reducing various physical properties. Based on this discovery, the present invention was developed. That is, the gist of the present invention is as follows: ``(a) A molded article consisting of a crosslinked polyolefin and (b) magnesium hydroxide or magnesium hydroxide and antimony trioxide, wherein (c) per 100 parts by weight of the crosslinked polyolefin of (a). , the total amount of magnesium hydroxide and antimony trioxide in (b) is
A crosslinked polyolefin resin flame-retardant molded article containing 100 parts by weight or more and (d) antimony trioxide/magnesium hydroxide (weight ratio) being 1/2 or less. ”
It is in. The hydrous inorganic compound used in the present invention is magnesium hydroxide, but aluminum hydroxide is another commonly used hydrous inorganic compound. However, when aluminum hydroxide was used instead of magnesium hydroxide, no improvement in flame retardancy due to crosslinking was observed. The above-mentioned polyolefin resins include, for example, polyethylene, polypropylene, copolymers of ethylene and other copolymerizable substances such as vinyl acetate, and blends thereof. especially vinyl acetate content 15
The effects of the present invention are best exhibited when the amount of ethylene-vinyl acetate copolymer is 25 wt%. Magnesium hydroxide is used to eliminate the disadvantage of polyolefin's flammability and improve the flame retardancy of molded products. Magnesium hydroxide has a high thermal decomposition temperature, and there is no risk of thermal decomposition during the process of melting and molding the composition to be molded by heating, thereby losing the effect of imparting flame retardancy. Furthermore, it is preferable that the magnesium hydroxide used in the present invention be one whose particle surface has been surface-treated with a resin acid or fatty acid, taking into consideration miscibility with resin or processability. The amount used is based on 100 parts by weight of crosslinked polyolefin.
Must be at least 100 parts by weight. This is because if the amount is less than 100 parts by weight, not only will flame retardancy be poor, but also no improvement in flame retardancy due to crosslinking can be expected. However, if the amount is too large, the mechanical strength of the molded product of the present invention will deteriorate, and
Since heat aging resistance also decreases, it is practically desirable that the amount is 150 parts by weight or less. It has been found that even if less than 1/3 of magnesium hydroxide is replaced with antimony trioxide, not only the flame retardance does not change much, but also the mechanical strength becomes much better. That is, the object of the present invention can be better achieved if the weight ratio of antimony trioxide/magnesium hydroxide is 1/2 or less. In order to fully demonstrate this effect of antimony trioxide, it is recommended that the amount be 1/4 or more. The reason why a crosslinked molded product is used instead of a simple molded product is that it not only improves heat aging resistance, oil resistance, and mechanical properties, but also has an extremely good effect on improving flame retardancy. . There is no restriction on the crosslinking method for obtaining the molded article of the present invention. The more crosslinking is achieved by increasing the amount of crosslinking agent or the amount of radiation irradiated, the higher the flame retardancy of the molded article will be, but the elongation will naturally decrease. The molded article of the present invention can be produced by, for example, (d) polyolefin, (e) magnesium hydroxide, (f) antimony trioxide, and (g) organic peroxide. )=10
0:
100-150: 0.5-3.0 (weight ratio) and (F)/(E) =
It can be manufactured by mixing and molding at a ratio of 1/4 to 1/2 (weight ratio) and causing a crosslinking reaction. In the present invention, in addition to these components, it is desirable to use antioxidants, lubricants, and other additives as necessary. The present invention will be explained below using Examples and Comparative Examples. Examples 1 to 11, Comparative Examples 1 to 14 Resin molded bodies were manufactured according to the following conditions and subjected to each test. Materials used Polyethylene/and ethylene-vinyl acetate copolymer (both manufactured by Toyo Soda Kogyo Co., Ltd., hereinafter referred to as "EVA") (Examples 1 to 8, Comparative Examples 1 to 14): UE627 (acetic acid (vinyl acetate content: 20 wt%) (Example 9): UE630 (vinyl acetate content: 15 wt%) (Example 10): UE540 (vinyl acetate content: 10 wt%) (Example 11): PE4105 (high-pressure polyethylene,
MI2) Magnesium hydroxide (referred to as "Mg" in the table):
Kismer 5B manufactured by Kyowa Chemical Industry Co., Ltd. Average particle size 1μ Aluminum hydroxide (referred to as "Al" in the table):
H-42ST manufactured by Showa Light Metal Co., Ltd. Average particle size 1μ Antimony trioxide (referred to as "Sb" in the table): Manufactured by Nippon Seiko Co., Ltd. Average particle size 0.6μ Organic peroxide (referred to as "PO" in the table): Parkadox 14 manufactured by Kayaku Nuri Co., Ltd. Antioxidant: Nokrac 224 manufactured by Ouchi Shinko Chemical Co., Ltd. 1.0 parts by weight per 100 parts by weight of EVA was used. Lubricant: Lithium stearate manufactured by Sakai Chemical Co., Ltd. 0.5 parts per 100 parts by weight of EVA was used. Kneading/forming: 4-inch roll, 125℃, 5 minutes mixing test method Tensile test: Thickness 1mm, JIS K6301 No. 3, tensile speed 200mm/min Heat aging resistance: Shown as elongation retention after oven treatment at 150℃ for 7 days . Flame retardancy: JIS K7201 oxygen index method Table 1 below shows conditions and test results not shown above. The compositions in Table 1 are based on parts by weight per 100 parts by weight of EVA. Also, "Real" in the example number column.
"Example" means "Ratio" and "Comparative Example".

【table】

[Table] As is clear from the above explanation,
As a non-halogen type flame retardant resin composition, it is relatively small (100 parts resin to 100 parts inorganic material).
150) In the area of the amount of inorganic compounds added, and
Since the composition of the present invention is a crosslinked type,
It has excellent tensile strength, elongation, heat aging resistance, chemical resistance, etc., and can easily control the desired flame retardancy by changing the amount of organic peroxide, which deviates from conventional methods for improving flame retardancy. It is something. Moreover, since this composition is non-halogen type, it provides a non-flammable resin composition that does not emit harmful gases when burned and does not cause any harm to the human body. There is, and its industrial value is extremely large.

Claims (1)

[Scope of Claims] 1. A molded product comprising (a) crosslinked polyolefin and (b) magnesium hydroxide and antimony trioxide, wherein (c) per 100 parts by weight of crosslinked polyolefin (b), (b) water The total amount of magnesium oxide and antimony trioxide is 100 parts by weight or more, and
(d) A crosslinked polyolefin resin flame-retardant molded product having an antimony trioxide/magnesium hydroxide (weight ratio) of 1/2 or less. 2. Per 100 parts by weight of the crosslinked polyolefin (a),
The molded article according to claim 1, wherein the total amount of magnesium hydroxide and antimony trioxide (b) is 150 parts by weight or less. 3. The molded article according to claim 1 or 2, wherein the antimony trioxide/magnesium hydroxide (weight ratio) is 1/4 or more. 4 (d) polyolefin, (e) magnesium hydroxide,
(f) antimony trioxide and (g) organic peroxide,
(D): (E) + (F): (G) = 100: 100-150: 0.5-3.0 (
A crosslinked polyolefin resin flame-retardant molded product is produced by mixing and molding the mixture at a ratio (by weight ratio) and (f)/(e) = 1/4 to 1/2 (weight ratio) to carry out a crosslinking reaction. Manufacturing method.