JPS59227935A - Flame-retarding polyolefin resin composition - Google Patents

Abstract

PURPOSE:The titled composition which does not evolve any corrosive gases and is excellent in flame retardancy, moldability and strength, obtained by mixing a polyolefin resin with at least one member selected from aluminum hydroxide, etc., and a lanthanide element compound. CONSTITUTION:The purpose flame-retarding polyolefin resin composition is formed by mixing 100pts.wt. (A) polyolefin resin (e.g., polyethylene or ethylene/ vinyl acetate copolymer) with at least 50pts.wt. (B) at least one member selected from the group consisting of aluminum hydroxide, magnesium hydroxide, hydrotalcite and a mixture thereof, and at least 10pts.wt. (C) lanthanide element compound. Examples of component (C) include lanthanum hydroxide, cerium carbonate and terbium oxide. The obtained resin composition can exhibit sufficient flame retardancy even when it is used in a smaller amount, because of a synergistic action of a combination of components B and C.

Description

[Detailed description of the invention] The present invention relates to flame retardant polyolefin resin compositions.

Conventionally, halogen-based retardants have been commonly used to make polyolefin resins flame retardant, but they generate a large amount of smoke and toxic corrosive gases such as hydrogen halides when burned. There was a high risk of personal injury or equipment corrosion in the event of a fire.

As a flame retardant method that does not generate toxic and corrosive gases during combustion, a method using an inorganic compound containing water of crystallization as a flame retardant has been proposed, but in this case, the flame retardant effect of the hydrated inorganic is extremely low. Since the flame retardance is weak, the desired flame retardance cannot be obtained unless a very large amount is added. For this reason, highly flame-retardant resin compositions made of hydrated inorganic substances have various problems when compounded in large amounts, namely, the viscosity of the resin when melted increases significantly, resulting in a decrease in compounding workability and molding processability, and brittle composition molded bodies. There was a decrease in mechanical properties such as mechanical strength.

The present invention aims to improve flame retardancy, reduce the total amount of flame retardants, and solve the problems associated with the combination of large amounts of flame retardants by using a preferable synergistic effect by using specific additives in combination. This is the purpose.

The flame-retardant polyolefin resin composition of the present invention contains at least 5 parts by weight of one or a mixture of two or more hydrated inorganic substances selected from aluminum hydroxide, magnesium hydroxide, and hydrotalcite based on 100 parts by weight of the polyolefin resin.
It is characterized by containing 0 parts by weight or more and at least 10 parts by weight of a lanthanide compound.

The polyolefin resin referred to in the present invention includes, for example, polyethylene, polypropylene, polybutene, 4-methylpentene-1 polymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene- It is a blend of one or more types of propylene-diene terpolymer, etc., and also includes products crosslinked by chemical crosslinking agents and irradiation with ionizing radiation.

The lanthanide element compounds include, for example, lanthanum oxide, lanthanum carbonate, lanthanum hydroxide, cerium oxide, cerium hydroxide, cerium carbonate, praseodymium oxide, neodymium oxide, zamarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, and These include holmium, erbium oxide, thulium oxide, ytterbium oxide, etc., and these are particularly preferred because they are easily available.

In the present invention, the amount of additive used is 1 for polyolefin resin.
The reason for blending at least 50 parts by weight of the hydrated inorganic substance and at least 10 parts by weight of the lanthanide compound with respect to 00 parts by weight is that if the amounts of both substances are smaller than these, the flame retardant effect of the polyolefin resin will be reduced. This is because it is thin.

There is no particular upper limit to the blending of the hydrated inorganic material and lanthanide compound, but if the amount is too large, the effect will be saturated and it will be uneconomical, and the mechanical strength of the molded product will decrease markedly, so it is difficult to combine both. Practically preferred amount is about 500 parts by weight.

In the present invention, in addition to these components, lubricants, antioxidants, ultraviolet absorbers, colorants, fillers, etc. may be used as necessary.

Examples of the present invention are shown below along with comparative examples.

For the compounding ratio listed in Table 1, each component is heated at 150°C in an open roll for about 30 minutes to form a belt-shaped sheet, and then press-formed at 160°C for 5 minutes to form a sheet into a predetermined shape. UL-911 combustion test samples and JIS K 6501 tensile test samples were prepared.

The test results for those samples are also listed in Table-1.

1) Xuron W 2000 made by Nisseki Kagaku KK, specific gravity 0.9
2, ○, I, 0.2' 2) Evaflex V527- manufactured by Mitsui Polychemical KK
I VA Content Section 17, M. 1.09) Nippon Unicar KK NO copolymer DPDJ-6182EA content 1
Section 5, M, I. 15 1I) Japan EP Rubber KK EP-02P5) Kyowa Kagaku KK Kismer 5A 6) Showa Aluminum KK No Igilite Hl+2M
7) Kyowa Kagaku KK D) IT-IJ 8) to 12) Wako Tsumugi KK reagent However, lanthanum carbonate was made into an anhydrous salt by heating pentahydrate at 150°C.

1) JISK6U01 (1975) As is clear from the table, as shown in Comparative Examples 1 to 6, ethylene-
In a composition based on a vinyl acetate copolymer, 250 parts by weight of each of magnesium hydroxide and five lanthanide compounds (lanthanum oxide, cerium oxide, yttribium oxide, lanthanum carbonate, and ceric hydroxide) are blended. JL-911, a flame-retardant composition obtained by
Although the combustion test did not result in V-O, Examples 1 to 5
As shown in , when magnesium hydroxide and these lanthanide compounds are used in combination, the total amount blended in the resin is 250%.
In all cases, the flame retardance was ranked V-O, even though the parts by weight were much lower. This indicates that there is a synergistic effect between magnesium hydroxide and these lanthanide compounds regarding favorable flame retardancy. Furthermore, among these five types of lanthanide compounds, only cerium hydroxide has the ability to generate water at high temperatures, but in the case of ceric hydroxide (as well as the other four types of lanthanide compounds), the flame retardant effect is extremely weak. Ah/ζ. Therefore, it is presumed that the preferable synergistic effect regarding flame retardancy of the present invention arises from the chemical interaction between the hydrated inorganic material and the lanthanide compound.

Next, regarding the blending amount, Examples 6 to 9 and Comparative Examples 7 to
As shown in Figure 1, in the case of a resin composition based on a blend resin of ethylene-vinyl acetate copolymer and low-density polyethylene or ethylene-ethyl acrylate copolymer and low-density polyethylene, the amount of magnesium hydroxide blended is When the amount of cerium hydroxide is 110 parts by weight (Comparative Example 7), flame retardancy is not sufficient even when used in combination with lanthanum oxide, and when the amount of cerium hydroxide is 5 parts by weight (Comparative Example 9) when used in combination with aluminum hydroxide. Although the flame retardance was not sufficient, the flame retardance of the resulting composition was improved by increasing the blending amount of magnesium hydroxide and cerium hydroxide to 70 parts by weight (Example 8) and 20 parts by weight (Example 7), respectively. Flammability is now ranked V-O. This means that unless the amount of the hydrated inorganic compound is at least 50 parts by weight per 100 parts by weight of the polyolefin resin, sufficient flame retardancy cannot be obtained due to the synergistic effect when used in combination with the lanthanide compound. This indicates that unless the compounding amount is at least 10 parts by weight per 100 parts by weight of the polyolefin resin, sufficient flame retardance cannot be obtained due to the synergistic effect of the combined use with the hydrated inorganic substance.

one! As shown in Example 10 and Comparative Example 10.11, there was also a favorable synergistic effect between hydrotalcite and yttribium oxide for the ethylene-propylene copolymer composition.

As is clear from the above explanation, the flame-retardant polyolefin resin composition of the present invention does not use any rogen-containing compound as a flame retardant, so it does not generate corrosive gas or large amounts of smoke when burned. Regarding flame-retardant compositions that do not use rogen compound flame retardants, the problem of blending a large amount of flame retardant, which was a drawback of flame-retardant polyolefin compositions that do not use rogen compound flame retardants, namely, compounding workability and molding processability. Moreover, it has achieved unprecedented high flame retardancy without problems such as a decrease in mechanical strength, so its industrial value is extremely high.

Patent applicant: Furukawa Electric Co., Ltd.

Claims (2)

[Claims] (1) For 100 parts by weight of polyolefin resin, at least 50 parts by weight of any one of aluminum hydroxide, magnesium hydroxide, and hydrotalcite alone or in a mixture of two or more, and at least 10 parts by weight of a lanthanide element compound. A flame-retardant polyolefin resin composition characterized in that it contains parts by weight. (2) The flame-retardant polyolefin resin composition according to claim 1, wherein the lanthanide element compound is a single compound or a mixture of two or more of lanthanide element oxides, hydroxides, and carbonate compounds. .