JP2000327861A - Flame-retardant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-halogen, flame-retardant composition which does not generate a halogen-containing gas when burned, exhibits high flame- retardancy, and is excellent in heat resistance and mechanical strength and highly filled with a flame-retardant without deteriorating molding processability. SOLUTION: With 100 pts.wt. of a resin component comprising 99.5-75 wt.% of an ethylene-vinyl acetate copolymer(EVA), having a vinyl acetate(VA) content of 25-45 wt.%, and 0.5-25 wt.% of a polyolefin resin modified with an unsaturated carboxylic acid are compounded 201-300 pts.wt. of a flame-retardant, 0.1-10 pts.wt. of a surfactant having an HLB of not more than 10 and 0.1-10 pts.wt. of a silicone having a viscosity of at least 100,000 cSt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a halogen-based gas or smoke during combustion, having high flame retardancy, good heat resistance and mechanical strength, and deteriorating moldability. And a non-halogen flame retardant composition highly filled with a flame retardant.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of fire safety, non-halogenated flame-retardant electric wires and flame-retardant cables, that is, electric wires and cables that generate little smoke and do not generate harmful gases such as hydrogen halide gas. With the development progressing, recently, expectations for such non-halogenation are increasing in terms of environmental protection measures including material recycling. For this reason, non-halogen flame-retardant compositions based on organic polymers containing no halogen have been actively developed. Typical examples thereof include EVA resins having a high VA content and aluminum hydroxide. It is known that a large amount of metal hydroxide such as iron or magnesium hydroxide is added to make it flame-retardant. However, such a composition is poor in mechanical properties, particularly in tensile strength and tensile elongation, while improving flame retardancy by using an EVA resin having a high VA content or by adding a large amount of a metal oxide. However, there was a drawback that the extrusion torque was high and molding processing could not be performed.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to have high flame retardancy, sufficiently retain mechanical properties, especially tensile strength and tensile elongation, low extrusion torque and good moldability. An object of the present invention is to provide a flame-retardant composition highly filled with a metal hydroxide.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate (VA) content of 25 to 45% by weight and 99.5 to 75% by weight of an unsaturated carboxylic acid. 0.5 to modified polyolefin resin
With respect to 100 parts by weight of the resin component consisting of 25% by weight, 201 to 300 parts by weight of a flame retardant, 0.1 to 10 parts by weight of a surfactant having an HLB of 10 or less, and 0.1 to 10 parts by weight of a silicon having a viscosity of 100,000 cs or more are used. 10 parts by weight of the flame retardant composition. Preferably, the flame retardant is a mixture of magnesium hydroxide surface-treated with a fatty acid or a fatty acid metal salt and a metal hydroxide not surface-treated in a weight ratio of 0:10 to 4: 6. The flame-retardant composition wherein the untreated metal hydroxide is magnesium hydroxide without surface treatment or a mixture of magnesium hydroxide and aluminum hydroxide without surface treatment. Preferably, a flame-retardant composition in which the surfactant having an HLB of 10 or less is a nonionic non-ionic glycerin fatty acid ester or sorbitan fatty acid ester. The present invention is also a method for producing a flame-retardant composition, in which the above-mentioned flame-retardant composition is kneaded with a batch-type kneader at a filling rate of 70% to 95%. The present invention is also an electric wire or cable using the above flame retardant composition as a sheath layer or an insulating layer.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The ethylene-vinyl acetate copolymer (EVA) used in the present invention can be used even if EVA having a vinyl acetate (VA) content of 25 to 45% by weight is used alone.
A mixture of EVA having a high A content and EVA having a low VA content or polyethylene (PE) to adjust the VA content to 25 to 45% by weight may be used. V
The A content is preferably 30 to 35% by weight. E
If the VA content of VA is less than 25% by weight, the flame retardancy of the final flame retardant composition becomes insufficient, and if it exceeds 45% by weight, the strength is extremely reduced.

The unsaturated carboxylic acid-modified polyolefin resin used in the present invention is not particularly limited, but unsaturated carboxylic acids include monobasic acids such as acrylic acid, methacrylic acid, maleic acid and fumaric acid. There are dibasic acid or metal salts of the above-mentioned unsaturated carboxylic acids, amides, imides, esters and anhydrides, but the most preferred one is maleic anhydride, whose modification rate is 0.05 to 5%.
Parts by weight are appropriate. The polyolefin resin to be modified is not particularly specified, but LLDPE is used in terms of strength and heat resistance.
(Linear low-density polyethylene) and PP (polypropylene) are preferred. The weight ratio of EVA to the unsaturated carboxylic acid-modified polyolefin resin is 99.5: 0.5 to 7
It is necessary to be in the range of 5:25, and if it is out of this range, the flexibility is impaired and the flame retardancy is lowered, which is not preferable.

The flame retardant used in the present invention is preferably a mixture of a surface-treated magnesium hydroxide and a metal hydroxide that has not been surface-treated. As the surface treatment agent for magnesium hydroxide, a fatty acid or a metal salt of a fatty acid is used, preferably one treated with oleic acid or the like. The metal hydroxide that has not been surface-treated is preferably magnesium hydroxide that has not been surface-treated, or a mixture of magnesium hydroxide that has not been surface-treated and aluminum hydroxide. The mixing ratio of the untreated aluminum hydroxide to the total amount of the untreated metal hydroxide is preferably 1/2 or less, more preferably 1/3 or less. If the mixing ratio of the aluminum hydroxide to the total amount of the metal hydroxide not subjected to the surface treatment is more than 成形, the molding appearance is deteriorated due to foaming due to a rise in temperature during kneading. The average particle size of the magnesium hydroxide treated with the fatty acid or the fatty acid metal salt and the metal hydroxide not treated with the surface is preferably 5 μm or less, more preferably 2 μm or less. When the average particle size exceeds 5 μm, not only the flame retardancy of the final flame-retardant composition becomes insufficient, but also the stickiness becomes severe and the appearance of the molded product becomes poor. The weight mixing ratio between the magnesium hydroxide treated with the fatty acid or the fatty acid metal salt and the metal hydroxide not treated with the surface is 0:10 to 4: 6.
And more preferably 2: 8. Here, when the mixing ratio of the magnesium hydroxide treated with the fatty acid or the fatty acid metal salt to the metal hydroxide not subjected to the surface treatment is larger than 4: 6, the tensile elongation is increased, but the tensile strength is extremely reduced. In addition, the rate of change in strength and elongation increases due to heat aging characteristics. The compounding amount of the flame retardant is 201 to 300 parts by weight, preferably 210 to 240 parts by weight based on 100 parts by weight of the resin component. 201
If the amount is less than parts by weight, the flame retardancy of the final flame-retardant composition will be insufficient, and if it exceeds 300 parts by weight, the extrusion torque will increase and the moldability will deteriorate.

The surfactant having an HLB of 10 or less used in the present invention is mainly added to reduce the extrusion torque and improve the molding process and to improve the elongation at break. However, nonionic surfactants are preferred. For example, glycerin fatty acid ester, sorbitan fatty acid ester, sorbite fatty acid ester, pentaerythritol fatty acid ester, ethylene glycol fatty acid ester, propylene glycol fatty acid ester, polyglycerin, higher fatty acid ester of sucrose, addition of higher alcohol or higher fatty acid of polyethylene glycol (A polyethylene glycol chain is short), alkyl glucoside, alkyl maltoside and the like. The nonionic surfactant having a silicone-based HLB of 10 or less is not particularly limited, and examples thereof include polyether-modified dimethylpolysiloxanes, polyether-modified methylphenylpolysiloxanes, and polyether-modified methyl. Examples include hydrogen polysiloxanes, dimethyl polysiloxane polyalkylene glycol copolymers, methylphenyl polysiloxane polyalkylene glycol copolymers, and methyl hydrogen polysiloxane polyalkylene glycol copolymers. In the present invention, one or more of these nonionic surfactants can be used.

The HLB value used here is a value calculated by the following equation. HLB = 20 × Mn / MM M: molecular weight of surfactant Mn: molecular weight of hydrophilic group portion A surfactant having an HLB of 10 or less, preferably 7 or less, more preferably 5 or less, and most preferably 3 or less works effectively. And the amount of addition is small. If the HLB exceeds 10 in this system, the metal hydroxide cannot be sufficiently dispersed, and a sufficient effect cannot be exerted on properties such as moldability and elongation at break. It is preferable that the hydrophilic polyoxyethylene chain and the like be as short as possible or not to include. If there is a long polyoxyethylene chain, the HLB becomes large, so there is no ability to disperse the metal hydroxide, and the elongation at break cannot be improved. Further, when a surfactant other than the nonionic surfactant is used, when a reactive substance such as another surface treating agent or a cross-linking agent is present, it is highly likely to act as a reaction inhibitor thereof, which is not preferable. For example, metal salts of higher fatty acids, such as calcium stearate, which is an anionic surfactant, have high hydrophilicity and have no effect on elongation at break even when integral blending is performed when kneading a metal hydroxide and a thermoplastic resin. Not only does it not show, but whitening at the time of bending becomes severe, it acts as a reaction inhibitor of the coupling agent when used in combination with a coupling agent such as aminosilane because it is ionic, and the effect on the mechanical properties of the coupling agent is sufficient. Will not be exhibited. Furthermore, in the case of a fatty acid such as stearic acid, the effect of the coupling agent on mechanical properties may be completely negated when used in combination with a reactant such as a coupling agent because it is an acid. If the surfactant itself has water absorbency, it is preferable to use a surfactant having low or no water absorbency, because mechanical properties and impact resistance may deteriorate due to water absorption after molding. The molecular weight of the nonionic surfactant is preferably from 300 to 10,000, more preferably from 500 to 5,000, and most preferably from 700 to 2,000. If the molecular weight of the surfactant is less than 300, it is not preferable because it may bleed after molding or volatilize at the molding temperature. Also,
If the molecular weight exceeds 10,000, it cannot be arranged sufficiently at the resin filler interface during integral blending, and the effect of improving elongation at break referred to in the present invention does not appear at all, or the amount of addition must be extremely increased, Not preferred.
As described above, as a nonionic surfactant having a certain molecular weight and a low HLB, glycerin fatty acid ester,
Fatty acid esters such as sorbitan fatty acid esters and sugars are preferred, more preferably glycerin, sorbitan, higher fatty acid esters such as sugars, and most preferably glycerol monostearate, sorbitan trioleate, and sorbitan tristearate. is there.

[0010] The amount of the surfactant is 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, more preferably 0.5 to 0.5 parts by weight per 100 parts by weight of the resin component. It is from 1 part by weight to 1 part by weight. If the amount of the surfactant is less than 0.1 part by weight, the effect of the surfactant is not sufficiently exhibited, and the moldability and elongation at break are not sufficiently improved. On the other hand, when the amount exceeds 10 parts by weight, problems such as bleeding of the surfactant after molding and deterioration of flame retardancy occur. In the present invention, as a method of adding a surfactant,
A method is preferred in which the surfactant is integral blended simultaneously with the kneading of the thermoplastic resin and the metal hydroxide. This is because, if the surfactant mentioned in the present invention is used, the surface treatment of the metal hydroxide with the surfactant, and even if the thermoplastic resin and the metal hydroxide are not kneaded with the resin, the surface This is because if the activator is added simultaneously, the expected effects of the present invention are sufficiently exhibited. This is very costly in manufacturing. However, ignoring that the number of steps is increased by one and the production cost is somewhat increased, even if the metal hydroxide is treated with a surfactant in advance and used, there is no problem in physical properties. However, in this case, since one or more steps are included, it is disadvantageous in terms of cost. HLB is 10
Regarding the following surfactant addition effects, the detailed mechanism is not clear, but it quickly moves to the interface between the filler and the resin when kneading the resin and the metal hydroxide to improve the familiarity between the resin and the metal hydroxide. In addition, due to the steric hindrance effect of the surfactant, the local agglomeration of the metal hydroxide particles is prevented from each other, and as a result, the metal hydroxide is sufficiently dispersed as a whole. It is presumed that the moldability and the elongation at break were exhibited.

Regarding the type of silicone oil used in the present invention, dimethyl silicone oil is required to be good in molding and processing and has a viscosity of 100,000 CS, preferably 100,000 to 500,000 CS. is there. 100,000 CS
If it is less than 500, CS, it is not preferable because it bleeds to the surface due to a change with time. The addition amount of silicone oil is 0.1 ~ 1
0 parts by weight, and less than 0.1 part by weight has no effect.
If the amount exceeds 0 parts by weight, bleeding or the like occurs due to a change over time, which is not preferable.

If necessary, the composition of the present invention may contain a colorant, an antioxidant, an ultraviolet absorber, a processing aid, a stabilizer and other additives as long as the effects of the present invention are not impaired. be able to.

The flame-retardant composition of the present invention can be easily produced by uniformly mixing the above-mentioned components using a conventional batch kneader such as a Banbury mixer or a pressure kneader. However, the amount of the raw materials to be fed into the batch kneader must be in the range of 70% to 95% with respect to the capacity of the batch kneader, and preferably 85% to 95%.
It is. Here, the filling rate is determined by the following equation. Filling rate (%) = Amount of raw material input (kg) / True specific gravity / Effective capacity of batch type kneader (L) If the filling rate is less than 70% or more than 95%, the dispersion of the flame retardant becomes poor, resulting in agglomerates and impaired appearance. It is. The flame-retardant composition of the present invention can be coated with an electric wire using a single-screw extruder or the like.

[0014]

Hereinafter, the present invention will be described with reference to examples.
This is merely an example, and the present invention is not limited to this. The various materials shown in Tables 1 to 7 were kneaded with a pressure kneader at the filling ratios shown in the table for 5 minutes, made into a sheet with an open roll, pulverized with a sheet pelletizer, and formed into a sheet with a single screw extruder. Extruded, 180
C. for 5 minutes under pressure to adjust to a predetermined thickness. Various evaluations were performed based on the following. (1) Tensile properties: From a 1 mm thick press sheet to JIS
A dumbbell No. 3 test piece was prepared, and 200
A tensile test was performed at a speed of mm / min. (2) Flame retardancy: A pressed sheet having a thickness of 0.5 mm was prepared, and a vertical flame retardancy test was performed according to UL94. (3) Formability: The formability was evaluated by extruding from a single screw extruder. (Good for low extrusion torque and good molding workability; good for high extrusion torque and poor molding workability (foaming and waving occur, or the extruder itself stops) (4) Molded appearance: The surface of the molded article was judged visually (O when the surface of the molded article was smooth, and those where inorganic aggregates, irregularities, bleed, bloom, etc. were confirmed) (5) Thermal aging characteristics: After standing in an oven at 100 ° C. for one week, the strength and elongation were measured by the same method as in (1), and the rate of change was determined. ○, otherwise ×
And

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

[Table 4]

[0019]

[Table 5]

[0020]

[Table 6]

[0021]

[Table 7]

The raw materials used in the table are as follows. * 1 Evaflex P2505C (manufactured by Mitsui Dupont Chemical Co., Ltd.) * 2 Evaflex EV40LX (manufactured by Mitsui Dupont Chemical Co., Ltd.) * 3 Kisuma 5B (manufactured by Kyowa Chemical Co., Ltd.) * 4 Kisuma 5 (Kyowa Chemical Co., Ltd.) * 5 Heidilite H43M (manufactured by Showa Denko KK) * 6 Elegan N-1100 (manufactured by NOF Corporation; HLB
* 3.0 Adtex L-6031 (manufactured by JPO; polar group modification rate = 0.2 wt%) * 8 Nonion OP-85R (manufactured by NOF Corporation; HLB = 4.
3) * 9 Adma-XE070 (manufactured by Mitsui Oil Co., Ltd .; polar group modification rate = 1%) * 10 Evatate H2031 (manufactured by Sumitomo Chemical Co., Ltd.) * 11 Non-Sear SN-1 (manufactured by NOF Corporation; HLB) = 3.
0) * 12 Nonion S-15.4 (manufactured by NOF Corporation; HLB = 1)
6.7) * 13 Sumikasen L FA157-2 (Sumitomo Chemical Co., Ltd.)
Made)

[0023]

According to the present invention, no halogen-based gas is generated during combustion, and it has high flame retardancy, heat aging resistance,
It is possible to obtain a non-halogen flame-retardant composition which has good mechanical strength and is highly filled with a flame retardant without lowering the moldability.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01B 3/44 H01B 3/44 M 7/295 7/34 B // (C08L 23/08 23:26 83:04) F-term (reference) 4J002 BB061 BB212 CH054 CP033 CP184 DE076 DE077 DE147 EH048 FB236 FD136 FD137 FD314 FD318 GQ01 5G303 AA06 AA10 AB12 AB20 BA01 BA12 CA01 CA09 CB01 CB17 CD07 DA01 5G305 AA02 CA25 CB01 AB25 AB35 CD18 DA16 5G315 CA03 CB01 CD02 CD04 CD06 CD14

Claims (7)

[Claims] 1. A vinyl acetate (VA) content of 25 to 45.
% By weight of ethylene-vinyl acetate copolymer (EVA) 9
A polyolefin resin modified with 9.5 to 75% by weight and an unsaturated carboxylic acid is used in an amount of 0.5 to 25% by weight to 100 parts by weight of a resin component, and a flame retardant of 201 to 300 parts by weight, H
0.1 to 10 parts by weight of a surfactant having an LB of 10 or less, 0.1 to 10 parts by weight of a silicone having a viscosity of 100,000 cs or more,
A flame-retardant composition characterized by being blended. 2. The flame retardant is a mixture of magnesium hydroxide surface-treated with a fatty acid or a metal salt of a fatty acid and a metal hydroxide not surface-treated in a weight ratio of 0:10 to 4: 6. Item 6. The flame-retardant composition according to Item 1. 3. The metal hydroxide that is not surface-treated is magnesium hydroxide that is not surface-treated.
The flame-retardant composition as described in the above. 4. The flame-retardant composition according to claim 2, wherein the metal hydroxide that has not been surface-treated is a mixture of magnesium hydroxide and aluminum hydroxide that have not been surface-treated. 5. The flame-retardant composition according to claim 1, wherein the surfactant having an HLB of 10 or less is a nonionic type glycerin fatty acid ester or sorbitan fatty acid ester. 6. A method for producing a flame-retardant composition, comprising kneading the flame-retardant composition according to claim 1 in a batch-type kneader at a filling rate of 70% to 95%. 7. An electric wire or cable using the flame-retardant composition according to claim 1 as a sheath layer or an insulating layer.