JPH02158646A - Flame retardant electrical insulating composition - Google Patents

Abstract

PURPOSE:To obtain a composition, remarkably improved in mechanical characteristics and capable of exhibiting excellent flame retardance by mixing a polyolefin modified with a carboxyl-based silane with an inorganic hydroxide. CONSTITUTION:A composition obtained by mixing 100 pts.wt. polyolefin modified with a carboxyl-based silane expressed by the formula (n is an integer of 1-5) with 50-300 pts.wt. inorganic hydroxide. The content of the carboxyl-based silane is preferably 0.01-2wt.% based on 100wt.% polymer. Aluminum hydroxide, magnesium hydroxide, etc., are used as the inorganic hydroxide.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a flame-retardant electrical material that has low smoke generation, toxicity, and corrosivity, has excellent trauma resistance, and is suitable as an insulator for electric wires and cables and as a seaweed material. The present invention relates to an insulating composition.

[Conventional technology 1] With the remarkable development of today's information society, the increase in demand for electricity in both industrial and consumer settings, and the rise in the height of buildings and other structures, electric wires, cables, etc. are becoming increasingly dense and dense.
It has become highly integrated.

B can be used as an insulator or sheath for incoming power lines and cables.
I have been treated! 4 All of $11 are UF flammable and 1v), so in the event of a fire, it is likely that the fire will spread through the wiring system of the highly integrated wires and cables mentioned above, making it very difficult. Fuel/JL electric wire/cable no.J
II has suddenly increased. As a standard for this flame retardancy, there is IEEE (Honda Electrical and Electronics Engineers 1.η Association) Standard 383 V TF 'I'' (Vertical Tray Combustion Test), which simulates the actual installation situation of electric wires and cables. It became like -ffj to adopt the flame-retardant Shiba 1'(-) if it passed the combustion test.

v The flame retardant level specified by TF"r' is quite strict, and flame retardant electrical insulation III l&, which can meet such strict conditions, has traditionally been made of halogen-based compounds and phosphorus-based materials. Materials mixed with compounds have been heavily used.

However, in the event of a fire, such flame-retardant electrical insulation compositions generate a large amount of non-flammable hydrogen-based scum, etc., which blocks oxygen around electric wires and cables and prevents combustion (
Although it exhibits sufficient flame retardant properties, the halogen-based scum generated during this process is often toxic, such as hydrogen chloride, and it produces a large amount of smoke containing such toxic gases. This may impede visibility, impede evacuation and firefighting activities in the event of a fire, or cause a primary disaster due to the harmful effects of the toxic residue on the human body.Furthermore, halogen residue may be released into the air. It reacts with moisture in the water, becomes hydrohalic acid, and leaves the switchboard at t5.
'＋There is also a risk of being eaten.

Therefore, in place of the halogen compounds and phosphorus compounds mentioned above, inorganic hydroxides such as aluminum hydroxide and magnesium hydroxide are mixed to improve the safety in the event of a fire. 1 (Proposed flame-retardant electrical insulation composition) is attracting attention.

[Problem to be solved by the invention J] The above-mentioned flame-retardant composition containing an inorganic hydroxide utilizes the endothermic action of releasing the hydroxide or water of crystallization in the event of a fire as a flame-retardant effect. , fuming, toxic or 1
However, these inorganic hydroxides have inferior flame retardancy compared to the halogenated and phosphorous compounds mentioned above, so there is a problem that they must be mixed in larger amounts. However, there is a problem in that mechanical properties such as tensile properties and scratch resistance are significantly reduced.

The purpose of the present invention is to overcome the drawbacks of the prior art as described above, and to provide a combustible material that can exhibit sufficient H flammability by incorporating an inorganic hydroxide, as well as greatly improve its mechanical properties. The object of the present invention is to provide an electrically insulating composition.

[Means to solve the problem]

The present invention is made by mixing 50 to 300 parts by weight of an inorganic hydroxide to 100 ffi of a polyolefin modified with a carboxyl silane represented by CH2=CH8+QCnH-nCOOH) 3 (n is an integer of 1 to 5). It is characterized by this.

In the present invention, the carboxyl silane represented by CHz=CH3i→-OCnH2nCOOH)3 is CH2=CHSi+0CH2C00H)3
.

CH2=CH3i +OC2Ha C00H)
3.

CH2=CH3I +OC3He C0OH)3
.

etc. can be mentioned. Further, the polyolefin modified with the above-mentioned carboxyl-based silane is obtained by subjecting a polyolefin to a craft reaction with carboxyl-based silane by heating in the presence of an organic oxide.

The polyolefin mentioned here includes polyethylene,
Examples include ethylene ethylene acrylate copolymer, ethylene vinyl acetate copolymer, ethylene propylene rubber, ethylene butene-1 copolymer and ethylene butene-1 terpolymer, and ethylene methyl methacrylate copolymer.

The content of carboxyl silane is based on 100% of the polymer.
0.01 to 2% by weight is desirable. Content is o, otgL
If it is less than 2% by weight, the desired mechanical properties cannot be improved, and if it is more than 2% by weight, crosslinking is likely to occur due to a condensation reaction accompanied by dealcoholization during extrusion molding, resulting in a decrease in extrusion moldability.

Furthermore, in the present invention, the Ml mel 1-index) of the above-mentioned modified polyolefin is 0.1.~l Og
/ 1.0 min (190°C) Examples of the oxide include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, hydrotalcites, and the like.

This inorganic hydroxide is the above-mentioned modified polyolefin L.
It is necessary to mix in a range of 50 to 300 parts by weight with respect to OO parts by weight; if it is less than 50 parts by weight, the desired flame retardance cannot be achieved, and if it exceeds 300 parts by weight, extrusion moldability will be significantly reduced. - It becomes difficult to mold.

In the present invention, in addition to the above-mentioned components, other components such as cross-linking agent 11, antioxidant, slippery, softener, etc. may be added.

[For fl Mi 1 By modifying the polyolefin material with highly reactive carboxyl silane, the affinity between the 4 polymer and the inorganic hydroxide is greatly improved, which greatly improves tensile properties and scratch resistance. will be improved.

[Example] The present invention will be described below with reference to Examples.

40/m extrusion fi (L-/D2) held at 230°C
5) was used to craft the silane treatment agent into the polyolefin in the presence of dicumyl peroxide as the starting material to obtain the modified polyolefins shown in Table 1.

These modified polyolefins were mixed with various components in the proportions shown in Table 1 for Examples and Comparative Examples, kneaded in a Pambari mixer, and then kept at 160°C.
”/rn using extrusion fi (LD=20), outer diameter 3
In addition to making various cables by covering the outer circumference of three twisted IllI ethylene propylene rubber insulated wire cores to 21mrnFJ, we also created the required test samples and evaluated them as shown in the lower column of Table 1. A test was conducted on the items.

Each test method is as follows.

After press molding to lnn+ thickness at 190"C, a JIS dumbbell 345 test was prepared, and a tensile test was conducted at a speed of 200"/min using a tensile test machine according to the JIS C3003 pencil hardness method. Evaluation was made based on whether the surface of the cable turned white when rubbed with a J9 brush on the 2nd day.

Flame retardant: In accordance with IEEE standard 383, eight 2.4m long cables were lined up vertically, exposed to a flame of 70,000 r3TLJ/h from the bottom side for 20 minutes, and the flame was removed. If the fire self-extinguished after 1.8 m of leakage, it was passed, and if the fire spread over 1.8 m, it was judged to be rejected.

Tensile properties: Ejection resistance: Examples 1 to 6 according to the invention as evident from No. 1k
The composition shown in is excellent in tensile properties, ii((j5 properties, jl
i i((I know it will pass the h-ray combustion test.

On the other hand, in case 1, which has a low content of aged hydroxide, the flame retardance of example 1 is rejected, and the combination certificate is 300j1 (11
Comparative Example 2, in which 1 part was extruded, had very poor extrusion 1 and v properties.

Ratio Example 3, which did not use the specified silane treatment agent, and Comparative Example 4, which used an unmodified polymer, had poor G resistance and 'r□A, and easily whitened when rubbed.

[Effects of the invention 1 and below] As shown in -, the composition according to the present invention has extremely low smoke-emitting properties, h-resistant properties, and corrosive properties, and has excellent mechanical properties such as tensile #1f properties and scratch resistance. It is capable of providing flame retardant electrical insulation material t1, and is always useful! ).

Claims (1)

[Claims] (1) CH_2=CHSi■OC_nH_2_nCOO
H) A flame-retardant electrical insulating composition prepared by mixing 50 to 300 parts by weight of an inorganic hydroxide with 100 parts by weight of a polyolefin modified with a carboxyl silane represented by _3 (n is an integer of 1 to 5).