JP2634715B2 - Flame retardant polyolefin rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant polyolefin rubber composition, and more particularly to a flame-retardant polyolefin rubber composition made flame-retardant by adding an organopolysiloxane.

[0002]

2. Description of the Related Art Polyolefin rubber is widely used as an electrical insulating material because of its excellent electrical and mechanical properties. However, it is relatively flammable and drops at high temperatures. Because of the tendency to spread the flame, a method has been adopted in which various additives are blended to impart heat resistance and make the flame retardant.

[0003]

However, the method of adding a halogen compound and antimony oxide for the purpose of making the flame retardant has a disadvantage that if a large amount of these are added, the electrical and mechanical properties are impaired. This rubber composition has a drawback that a large amount of toxic and corrosive gases are generated when burned, causing a dripping phenomenon (drip), and a method of adding hydrates such as aluminum hydroxide and magnesium hydroxide. It is difficult to provide sufficient flame retardancy even if a large amount is added, and this requires a large amount to be added, resulting in poor processability of the composition and maintaining sufficient strength. There is a disadvantage that it becomes difficult.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a flame-retardant polyolefin-based rubber composition which solves such disadvantages, which comprises: A) 100 parts by weight of a polyolefin-based synthetic rubber; 100 parts by weight, C)
5 to 100 parts by weight of brominated flame retardant and / or red phosphorus,
D) 5 to 50 parts by weight of mica or sericite.

That is, the present inventors have conducted various studies on the method of flame retarding a polyolefin rubber, and found that an organopolysiloxane, a conventionally known flame retardant and mica or sericite were added to a polyolefin synthetic rubber. Then, it is found that a polyolefin rubber composition having flame retardancy and extremely low dripping phenomenon can be obtained. In this case, when an organopolysiloxane and mica or sericite are combined, other flame retardants can be obtained by conventional methods. It has been confirmed that it can be reduced in amount compared to the product, that the electrical and mechanical properties are not impaired, and that it can also retain its shape during combustion, and the type of organopolysiloxane used here, The present invention was completed by conducting research on the addition amount, the addition amount of other additives, and the like. This will be described in more detail below.

[0006]

The present invention relates to a flame-retardant polyolefin rubber composition comprising a polyolefin-based synthetic rubber to which an organopolysiloxane and a bromine-based flame retardant and / or red phosphorus and mica or sericite are added. It is.

The polyolefin-based synthetic rubber as the component A) constituting the composition of the present invention is the main component of the composition, and may be any known one. Propylene copolymer, ethylene-propylene-diene copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene copolymer, isobutylene-isoprene Copolymers and the like are exemplified, and these are composite polymers to which a thermoplastic resin such as polyethylene, polypropylene, polybutylene, polypentene, ethylene-butene copolymer or the like is added in order to impart heat shrinkage thereto. You may.

The organopolysiloxane as the component B) constituting the composition of the present invention has an average composition formula of R ¹ _n SiO _{4-n / 2}
In this, R ¹ is a methyl group, an ethyl group, a propyl group, an alkyl group such as a butyl group, a cycloalkyl group such as a cyclohexyl group, a vinyl group, an allyl group, a butenyl group, an alkenyl group such as a hexenyl group, Aryl groups such as a phenyl group and a tolyl group, or a chloromethyl group, a trifluoropropyl group in which part or all of the hydrogen atoms bonded to carbon atoms of these groups have been substituted with a halogen atom, a cyano group, or the like; The same or different carbon number selected from a cyanoethyl group and the like is 1 to 10, preferably 1
~ 8 unsubstituted or substituted monovalent hydrocarbon groups, wherein n is 1.98 ~
It is assumed to be an integer of 2.02.

This type of organopolysiloxane is usually obtained by (co) hydrolyzing one or more of the selected organohalogenosilanes, or a cyclic polysiloxane (such as a siloxane trimer or tetramer).
Can be obtained by ring-opening polymerization using an alkaline or acidic catalyst, and is basically a linear one, but is a mixture of two or more kinds having different molecular structures. This has a viscosity at 25 ° C. of 100 cS or more.
000 may be the thing of 10,000,000 cS.

When the amount of the organopolysiloxane is less than 1 part by weight with respect to 100 parts by weight of the polyolefin-based synthetic rubber, the flame-retarding effect is insufficient, and the amount of the organopolysiloxane is less than 100 parts by weight. If too much, the strength of this composition will not be enough,
It is necessary to be in the range of 1 to 100 parts by weight, but it is preferably 5 to 50 parts by weight in view of the balance between flame retardancy and mechanical properties.

The bromine-based flame retardant as the component (C) constituting the composition may be any of known ones, such as decabromodiphenyl, tetrabromobisphenol S, decabromodiphenyl ether and the like. As an example, this may be red phosphorus, which may be red phosphorus as it is or may be coated with a phenol resin or the like because of its dispersibility in polyolefin rubber. Phosphorus may be used in combination. If the amount of the component (C) is less than 5 parts by weight per 100 parts by weight of the polyolefin-based synthetic rubber, the composition is too short to obtain a sufficient flame-retardant effect. It is necessary to be in the range of 5 to 100 parts by weight because it is remarkably reduced, but it is preferable that the amount be 20 to 50 parts by weight.

Mica or sericite as component D) constituting the composition of the present invention is added to prevent dripping during burning of the composition and to maintain its shape. Mica or non-mica sericite such as mother (muscovite), biotite (biotact), or phlogopite (flofbat) may be used, but those with a higher aspect ratio have a better reinforcing effect. However, the shape maintaining effect is not particularly limited. If the amount of mica and sericite is less than 5 parts by weight with respect to 100 parts by weight of the polyolefin synthetic rubber, sufficient flame-retardant shape retention cannot be obtained. If the amount is more than 50 parts by weight, the mechanical strength of the composition will be reduced. 5
It is required to be in the range of 5050 parts by weight, but the preferred range is 20-40 parts by weight.

The flame-retardant polyolefin rubber composition of the present invention can be obtained by uniformly mixing predetermined amounts of the above-mentioned components A) to D). This mixing is carried out by using a Banbury mixer, a kneader and a kneader. , Kneading using ordinary rubber compounding equipment such as double rolls and the like, reinforcing agents, various fillers as fillers, pigments, crosslinking agents, crosslinking accelerators, anti-aging Agents, antioxidants, ultraviolet absorbers, softeners, processing aids, various carbon functional silanes, etc. are optional, and their flame retardancy using calcium hydroxide or aluminum hydroxide Can be further improved, and if a process oil is further added, good elongation and roll workability can be improved.

The composition of the present invention can be cured with an organic peroxide or sulfur or a sulfur-based vulcanizing agent. Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di (t-
Butyl peroxy) hexane, 2,5-dimethyl-
2,, 5-di (t-butylperoxy) hexyne, 3,
Examples thereof include 1,1-bis-t-butylperoxy-3,3,5-trimethylcyclohexane, and sulfur-based vulcanizing agents such as tetramethylthiuram monosulfide, zinc dimethyl-dithiocarbamate, and di-n-butyl. Examples thereof include zinc dithiocarbamate. The kneading for obtaining the composition of the present invention may be performed by heating and mixing as necessary.However, the addition of these curing catalysts may be performed after the temperature of the composition is lowered to the decomposition temperature or lower. Needed.

[0015]

EXAMPLES Examples of the present invention and comparative examples will now be described.
Parts in the examples are parts by weight. Examples 1-2 , Comparative Examples 1-3 Polyolefin-based synthetic rubber Esplen 567 (iodine value 4-6) [trade name of Sumitomo Chemical Co., Ltd.] 70 parts
(CH ₂ ＣＨCH) (CH ₃ ) SiO unit 0.5 mol%
(CH ₃ ) ₂ SiO units composed of 99.5 mol%, both ends of the molecular chain are blocked with hydroxyl groups, the average degree of polymerization is 8,
It is a 000 Mechirubinirupo polysiloxane raw rubber 30
Parts, a specific surface area of 230 m ² / g and is precipitated silica, Nipsil VN ₃ Nippon Silica Co., Ltd. trade name 20 parts, process oil San'a 2280 [Japan Sun Oil Co., trade name, 30 parts of bromine 40 parts of the system flame retardant, Dekaburo arm diphenyl <br/> ether, 20 parts of antimony trioxide was prepared a base compound by kneading in two roll was added 30 parts of aluminum hydroxide.

Then, mica and 2.8 parts of dicumyl peroxide in the amounts shown in Table 1 were added to the base compound, and this was pressurized and heated at 100 kgf / cm ² at 170 ° C. for 10 minutes to form a 2 mm thick shell. And the flame retardancy of the molded article is evaluated by a vertical combustion test method according to the LL standard and an anode cap combustion test method according to the Electrical Appliance and Material Control Law.
Their dripping properties and their mechanical properties were examined according to JIS K6301, and the results shown in Table 1 were obtained.

[0017]

[Table 1]

[0018] Examples 3-4, Comparative Example 4 polyolefin based synthetic rubber · EPT3045 (iodine value 12) Mitsui Petrochemical Co., Ltd. trade name and methylation vinyl polysiloxane (supra) and are shown in Table 2 The mixture was mixed in the same ratio as above, and 10 parts of red phosphorus and Nova Red # 120 (trade name of Rin Kagaku Kogyo KK), 80 parts of aluminum hydroxide,
After adding 10 parts of mica and kneading with a pressure kneader, 2.8 parts of dicumyl peroxide was added to make a compound, which was vulcanized under the same conditions as in Example 1 and the flame retardancy of this compound was obtained. , was examined dripping resistance and mechanical properties, the results of as shown in Table 2 was obtained, it was treated in the same manner for those without addition of methylation vinyl polysiloxanes for comparison are shown in Table 2 The following results were obtained.

[0019]

[Table 2]

Examples 5 and 6 , Comparative Example 5 Polyolefin synthetic rubber Esplen 567 (supra)
80 parts of the methylation vinyl polysiloxane (supra), 20 parts,
20 parts of sedimentable silica / Nipsil VN ₃ (described above), 20 parts of process oil / samba 2280 (described above), 30 parts of brominated flame retardant / decabrom diphenyl ether,
5 parts of Novared # 120 (supra) were added and kneaded with two rolls to form a base compound. Then, 2.8 parts of sericite and dicumyl peroxide in the amounts shown in Table 3 were added to the base compound. In addition, a compound was prepared and treated in the same manner as in Example 1 to form a sheet. The sheet was examined for flame retardancy and dripping properties. The results shown in Table 3 were obtained.

[0021]

[Table 3]

[0022]

The present invention relates to a flame-retardant polyolefin-based rubber composition, which comprises A) a polyolefin-based rubber, B) an organopolysiloxane,
C) Brominated flame retardant and / or red phosphorus; D) Mica or sericite in a predetermined amount, which contains organopolysiloxane and known brominated flame retardant and red phosphorus. It has excellent flame retardancy and exhibits very few dripping phenomena, and has the advantage that it contains mica and sericite and has excellent shape retention during combustion.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01B 3/44 H01B 3/44 P

Claims (1)

(57) [Claims] A) 100 parts by weight of a polyolefin synthetic rubber B) 1 to 100 parts by weight of an organopolysiloxane C) 5 to 100 parts by weight of a brominated flame retardant and / or red phosphorus D) 5 to 50 parts by weight of mica or sericite A flame-retardant polyolefin-based rubber composition comprising: