JPS5937295B2 - polyolefin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polyolefin compositions having high properties and a high degree of flame retardancy.

In recent years, polyolefins used in electrical products, building materials, etc. are increasingly required to have a higher degree of flame retardancy.

For example, under the U.S. UL standards, parts of electrical products such as TV frames were previously allowed to have a heat resistance of V-2, but now they are required to have a higher heat resistance of V-1 to V-O. ing. For this reason, organic flame retardants such as tetrabrominated bisphenol A bis (dibromide propyl ether) and tetrabrominated dihydroxy diphenyl sulfone (dibromide propyl ether), which have a highly soluble effect, are added. .
However, even if a high degree of flame retardancy is imparted to polyolefins, their uses are limited due to their poor rigidity. Addition of inorganic fillers such as charcoal, talc, silica, and glass has been used as a method of imparting rigidity to polyolefins, and glass fibers are particularly often used because they give good results. However, it has been found that when glass fiber is added to polyolefin that has been made highly flame retardant with an organic flame retardant, although the rigidity is improved, a high degree of flame retardancy cannot be maintained and the flame retardance deteriorates.

The reason for this is thought to be that the glass fiber acts as a core and promotes vaporization of the resin, resulting in a decrease in flame retardancy. The present inventors have conducted various studies to obtain a polyolefin composition having high flame retardancy (V-1 to V-O) while maintaining a high degree of flame retardancy, and found that magnesium hydroxide can be used as a flame retardant. The inventors have discovered that the above-mentioned adverse effects caused by glass fibers can be avoided by using a specific organic flame retardant in combination with a flame retardant, and have completed the present invention.

The present invention comprises 100 parts by weight of polyolefin, 50 to 200 parts by weight of magnesium hydroxide, 5 to 150 parts by weight of an aromatic bromine compound in which bromine is directly bonded to a benzene nucleus based on the magnesium hydroxide, and glass in the entire composition. 3~
This is a polyolefin composition containing 40% by weight.

The polyolefin used in the present invention includes ethylene,
Examples include homopolymers of α-olefins such as propylene and butylene, copolymers of the α-olefins with other α-olefins, block copolymers, and mixtures thereof. In particular, polyolefins containing polypropylene as a main component is preferably used.

In addition, any magnesium hydroxide can be used, but the particle size is 0.1 to 50μ, preferably 0.1 to 2μ.
It is preferable to use a material with a BET specific surface area of 0 μ or less than 20 Tr1/f, as this improves impact resistance and provides a molded product with a good surface condition (no silver streaks).

Furthermore, magnesium hydroxide is pre-mixed with sodium stearate,
Those surface-treated with a surfactant such as sodium lauryl sulfonate are preferably used because they have the advantage of improved dispersibility and fluidity. The blending amount of magnesium hydroxide is 50 to 20 parts by weight per 100 parts by weight of polyolefin.
0 parts by weight, preferably 70 to 170 parts by weight. If the amount of magnesium hydroxide is less than the above lower limit, sufficient sagging prevention effect cannot be achieved, and if it is more than the above upper limit, it may be difficult to knead and pelletize with an extruder when producing polyolefin molded products. Therefore, it is not suitable industrially. A major feature of the present invention is that an aromatic bromine compound is used in combination with magnesium hydroxide.

Aromatic bromine compounds are compounds in which bromine is directly bonded to a benzene nucleus, such as brominated benzenes such as hexabromobenzene and pentabromobenzene; brominated toluenes such as pentabromotoluene and tetrabromotoluene; Brominated xylene such as bromoxylene Brominated phenols such as lipentapromphenol, tetrabrom resorcin, tribromopyrogallol, sodium pentapromphenolate and their metal salts: Brominated anilines such as pentapromaniline and tetrabromaniline; pentabrombenzoin Acid, tetrabromobenzoic acid and its derivatives: Brominated benzene heterosubstituted products such as tetrapromusalicylic acid, tetrabromotoluic acid, and tetrabromucresol, brominated phthalic anhydride such as tetrabrominated phthalic anhydride: Brominated biphenyl: Brominated Brominated diphenyl derivatives such as diphenyl ether and brominated diphenyl thioether; brominated naphthalene derivatives; brominated anthracene derivatives; brominated aromatic polymers such as triprom polystyrene; and the like. Among these, those having a bromine content of 55% or more are particularly preferably used. In addition, even if it is a compound in which bromine is directly bonded to the benzene nucleus, it is also a compound in which bromine is bonded to the side chain, such as bisphenol tetrabromide A.
Bis (dibromide propyl ether), tetrabromide dihydroxy diphenyl sulfone (dibromide propyl ether), etc. cause fire spots and are not suitable for the present invention.

Furthermore, aliphatic bromine compounds, such as tetrabromobutane and tribromopropane, which are frequently used as flame retardants for polyolefins, also cause flaming and cannot be used in the present invention. The amount of the aromatic bromine compound of the present invention is 5 to 150% by weight, preferably 7 to 1% by weight based on magnesium hydroxide.
It is 30% by weight.

If the content of the bromine compound is less than 5% by weight, the self-extinguishing property will be insufficient. On the other hand, if it exceeds 150% by weight, it is not preferable because it tends to cause fire spots. A major feature of the present invention is the combined use of glass to impart rigidity.

The glass has a particle size of 0.1 to 100μ, preferably 0.
．． Powdered or granular material of 1 to 50μ, thickness of 0.1 to
Commonly used materials, such as foil-like materials with a thickness of 20 μm and fibrous glass with a thickness of 1 to 50 μm, can be preferably used.

Fibrous glass includes so-called glass roping, which is made by binding long fibers with a sizing agent, roping cloth, which is woven using glass roping for the warp and weft, and randomly dispersed strands of roping cut into appropriate lengths.
There are chopped strand mats made by bonding these mats with a binder, chopped strands made by cutting glass roping into lengths of 0.5 mm to 10 mm, and the chopped strands are particularly preferred. Note that chopped strands are particularly preferably used when single fibers are bundled with various sizing agents and made into a rod shape of 0.5 to 311 I, since they are convenient for working with an extruder. It has been found that the addition of glass not only increases the rigidity of the composition, but also has the effect of preventing fire dripping during combustion.

In the present invention, the glass content is 3 to 40% of the total composition.
%, preferably 5 to 35%.

If the glass content is less than 3%, the improvement in rigidity will be insufficient, and if it is more than 40%, it will be difficult to knead in an extruder, which is not desirable. In the present invention,
A higher degree of flame retardancy can be achieved by blending antimony trioxide in addition to the flame retardants of magnesium hydroxide and aromatic bromine compounds. It was also found that antimony trioxide can reduce the amount of magnesium hydroxide and aromatic bromine compounds. When antimony trioxide is used, the blending ratio of the composition is 100 parts by weight of polyolefin, 25 to 200 parts by weight of magnesium hydroxide, and 5 to 150 parts of an aromatic bromine compound in which bromine is directly bonded to the benzene nucleus to the magnesium hydroxide. The total composition contains antimony trioxide in an amount of 10 to 100% by weight based on the aromatic bromine compound, and glass in an amount of 3 to 40% by weight in the total composition. The method for obtaining the polyolefin composition of the present invention is not particularly limited, and includes mixing components consisting of polyolefin, magnesium hydroxide, aromatic bromine compound, antimony trioxide and glass as necessary in a predetermined ratio. obtained by

The components may be mixed at the same time, or some of them may be mixed in advance and the remaining components may be mixed later. Furthermore, the composition of the present invention can be prepared by blending a pelletized mixture of several types of ingredients and a pelletized mixture of the remaining ingredients in a predetermined ratio. For example, in the case of materials such as glass fibers, which tend to break during kneading, an extruder using a screw with little kneading effect, such as a full flight, is used to pelletize. In addition, in the case of a material such as magnesium hydroxide, which needs to be kneaded as high as possible, it is pelletized using a Dalmage screw, a special high-kneading screw, an extruder with a kneader, or the like. It is preferable to blend the pelletized materials in this way and mold them using an injection molding machine, an extrusion molding machine, etc., since a molded product having good properties can be obtained. As a device for mixing the ingredients, commonly used devices such as a tumbler blender, a V-type blender, a pen shell mixer, and a ribbon mixer are used. The polyolefin composition in the present invention basically consists of the polyolefin, magnesium hydroxide, an aromatic bromine compound, glass, and antimony trioxide, but in addition to these components, conventionally known stabilizers and colorants may be used. Agents, antistatic agents, lubricants, nucleating agents, various fillers, and coupling agents for glass and polyolefin such as maleic acid-based, acrylic acid-based, chlorosulfonic acid-based, etc. may be added.

The polyolefin composition of the present invention has a high flame retardancy of V-1 to V-0 according to UL94 standards. The reason for such flame retardancy is not clear, but it is presumed that aromatic bromine compounds, in which bromine is directly bonded to the benzene nucleus, work synergistically with magnesium hydroxide to exhibit high flame retardancy. are doing. Also, the addition of glass not only provides very high stiffness, but also improves fire dripping prevention.

Furthermore, since the composition of the present invention contains magnesium hydroxide and glass, the dimensional stability of the molded product is also good. EXAMPLES In order to explain the present invention more specifically, Examples and Comparative Examples will be described below, but the present invention is not limited to these Examples.

The results of the combustion tests shown in the Examples and Comparative Examples are UL9.
The test was carried out in accordance with the vertical method of 4 standards, and the average self-extinguishing time after ignition of flame twice for each of the 10 combustion test pieces, that is, the average of the self-extinguishing time after ignition of flame 20 times in total, is shown as the average self-extinguishing time.
Further, the maximum self-extinguishing time was the maximum value among the self-extinguishing times after the 20 ignitions. In addition, the degree to which the cotton under the test piece ignited due to the ``sparkling'' from the test piece was indicated by how many out of 10 were ignited.For example, if 3 out of 10 were ignited, it was indicated as 3/10. The shape of the test piece was 5 inches x 0.5 inches x 1/8 inch.

In addition, the bending test was performed according to ASTM. ．． It was conducted in accordance with D-790.

Example 1 100 parts by weight of polypropylene (ME24O manufactured by Tokuyama Soda Co., Ltd.) was mixed with magnesium hydroxide, decaprom diphenyl ether, antimony trioxide, glass and a heat stabilizer in the proportions shown in Table 1 using a super mixer (manufactured by Kawada Seisakusho Co., Ltd.). )
mixed with.

The heat stabilizers include 2,6-di-tert-butyl-4-methylphenol, dilaurylthiopropionate, and calcium stearate, each containing 0.1% of the total composition.
, 0.2% and 0.1%. The mixture was then melted and kneaded using an extruder equipped with a seconder (manufactured by Nakatani Kikai Co., Ltd.) to form pellets. This pellet was molded using a 1.50z injection molding machine (manufactured by Kawaro Churchill Co., Ltd.) to obtain a test piece. Using this test piece, a combustion test (UL standard Sb94 vertical method) was conducted, and the average and maximum values of self-extinguishing time and cotton ignition rate were measured, and these values are also listed in Table 1.

Furthermore, the pellets were passed through an 80z injection machine (manufactured by Nippon Steel Corporation).
ASTM. A test piece conforming to D-790 was obtained.

Using this test piece, bending test (ASTM.D-790)
The bending strength and bending elastic modulus were measured.

This value is also listed in Table 1. The following glass was used.

Chopped strand A: Formerly manufactured by Hon Glass Fiber Co., Ltd., product number ES-06-Bl8 Chopped strand B: Manufactured by Nippon Glass Fiber Co., Ltd., product number R
ES-03-TP-37 glass beads...manufactured by Tokyo Shibaura Electric Co., Ltd., product number GB73l glass powder...
...Manufactured by Unitika UM Glass Co., Ltd., product number GP-1 Glass flakes...Manufactured by Former Hon Glass Fiber Co., Ltd., product number GF-48 Example 2 110 parts of magnesium hydroxide per 100 parts by weight of polypropylene Glass fiber in parts by weight and in the proportions shown in Table 2 (
The same procedure as in Example 1 was conducted except that a chopped strand manufactured by Nippon Glass Fiber Co., Ltd. (product number RES-03-TP-37) and an aromatic bromine compound were used.

The flame retardant effect and bending test results are shown in Table 2.

Claims (1)

[Scope of Claims] 1 100 parts by weight of polyolefin, 50 to 200 parts by weight of magnesium hydroxide, and an aromatic bromine compound in which bromine is directly bonded to a benzene nucleus in an amount of 5 parts by weight relative to the magnesium hydroxide.
-150% by weight of glass and 3-40% by weight of glass in the total composition. 2. The composition according to claim 1, wherein the polyolefin is polypropylene. 3. The composition according to claim 1, wherein the aromatic bromine compound is decabromidiphenyl ether. 4. The composition according to claim 1, wherein the glass is glass fiber. 5 100 parts by weight of polyolefin, 25 to 200 parts by weight of magnesium hydroxide, and 5 parts of an aromatic bromine compound in which bromine is directly bonded to the benzene nucleus relative to the magnesium hydroxide.
-150% by weight of antimony trioxide, 10-100% by weight of antimony trioxide based on the aromatic bromine compound, and 3-40% by weight of glass in the total composition. 6. The composition according to claim 5, wherein the polyolefin is polypropylene. 7. The composition according to claim 5, wherein the aromatic bromine compound is decabromidiphenyl ether. 8. The composition according to claim 5, wherein the glass is glass fiber.