JP3471066B2 - Flame-retardant polyolefin resin composition with improved processability - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant polyolefin resin composition. This resin composition is particularly excellent in processability, has passed high flame retardancy standards, and has excellent mechanical properties, and can be molded into various molded products, and is suitable for use in insulating layers and sheath layers of electric wires and cables. be able to.

[0002]

2. Description of the Related Art Olefin-based polymers having excellent electric insulation properties have been widely used as materials for insulating layers and sheath layers of electric wires and cables, but recently, high flame retardancy has been required. For example, the UL standard requires a high flame retardancy of V-1 to V-0. Flame retardants such as organic halogen compounds or vinyl chloride polymers, chlorinated polyethylene, etc. can be blended with olefin polymers to make them flame-retardant, but dripping may occur during combustion, or smoke may increase during combustion. However, there are drawbacks such as generation of toxic gas during combustion and corrosiveness of metal.
In order to solve these drawbacks, a method of incorporating an inorganic flame retardant as a flame retardant, particularly a metal hydroxide, into an olefin polymer has been proposed. Among metal hydroxides, magnesium hydroxide has a high decomposition temperature of about 360 ° C., which is sufficiently higher than the processing temperature of olefin polymers, and does not cause foaming comparatively during molding and processing, so various communications It has been used as a flame retardant for flame-retardant olefin polymer compositions for sheath layers such as cables. However, UL standard V-
In order to satisfy the high flame retardancy standard of 1 to V-0, 60 to 6 magnesium hydroxide is added to the olefin polymer.
The filling must be as high as 5%, and as a result, the pressure inside the extruder rises during molding, which necessitates a reduction in the extrusion rate, which deteriorates productivity and also causes extrusion. It was not always satisfactory because eyes and dents were generated on the surface of the machine die, and the appearance of the insulating layers of the wires and cables and the sheath layer were impaired. Therefore, a study of combining an organic halogen-based flame retardant and an inorganic flame-retardant has been made, but the problem during molding has not been solved.

[0003]

As described above, a polyolefin resin composition containing an inorganic flame retardant typified by magnesium hydroxide has many excellent characteristics, but in order to satisfy high flame retardancy standards, , The inorganic flame retardant must be highly filled, which causes deterioration of extrusion processability,
It causes defects such as impairing the appearance of the surface of the molded product. Further, a problem in molding processing has not been solved even for a polyolefin resin composition which satisfies a high flame retardancy standard by combining an organic halogen-based flame retardant and an inorganic flame retardant. The problem to be solved by the present invention is to solve these problems of the prior art.

[0004]

The object of the present invention is solved by incorporating a flame retardant and a phosphorus flame retardant plasticizer into a polyolefin resin. Polyolefin has good processability,
Since it is also flexible, it is not necessary to add a plasticizer such as those found in vinyl chloride resins. Further, when a plasticizer is added to polyolefin, so-called blooming in which the plasticizer bleeds onto the surface occurs, and this blooming causes various problems, so the plasticizer was not added. However, when a phosphorus-based flame-retardant plasticizer was added to the flame-retardant polyolefin resin composition, surprisingly, the blooming phenomenon did not occur, the moldability was improved, and the flame-retardant property was also improved. It was confirmed that the present invention was completed.

That is, the present invention relates to the following matters. (1) 100% by weight of a polyolefin resin, 5 to 250 parts by weight of a total amount of an inorganic flame retardant and a halogen flame retardant, and 10 to 50 parts by weight of a phosphorus flame retardant plasticizer are blended. Improved flame-retardant polyolefin resin composition. (2) As polyolefin resin, high-pressure polyethylene (HPPE), ethylene-vinyl acetate copolymer (EV
A), ethylene-ethyl acrylate copolymer (EE
A), ionomer, ultra low density polyethylene (VLDP
E), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE) and acid-modified ethylene-based polymers obtained by acid-modifying these ethylene-based polymers, or a combination of two or more of them is used. The flame-retardant polyolefin resin composition having improved processability according to (1) above.

The polyolefin resin used in the present invention is a polymer containing ethylene or propylene as a main component. As the ethylene-based polymer, high-pressure polyethylene (HPPE), ethylene-vinyl acetate copolymer (EV
A), ethylene-ethyl acrylate copolymer (EE
A), ionomer, ethylene-acrylic acid copolymer,
Ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ultra-low density polyethylene (VLDP
E), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), and acid-modified ethylene-based polymers obtained by acid-modifying these ethylene-based polymers. As the propylene-based polymer, propylene is homopolymerized at a relatively low temperature, so-called medium or low pressure, under a known α-olefin stereoregular catalyst such as a Ziegler-Natta type catalyst, or propylene and other α-olefins. -Copolymerized with olefin. Specifically, propylene homopolymer, ethylene-propylene copolymer, propylene-
Butene-1 copolymer, ethylene-propylene-butene-
An example is a ternary copolymer. These polymers can be used alone or in combination of two or more kinds.

The flame retardants used in the present invention are inorganic flame retardants and halogen flame retardants. As the inorganic flame retardant, aluminum hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, antimony trioxide,
Calcium phosphate, zirconium oxide, titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, calcium carbonate, barium sulfate, barium borate, barium metaborate, zinc metaborate, anhydrous alumina, molybdenum disulfide,
Clay, red phosphorus, diatomaceous earth, kaolinite, montmorillonite,
Hydrotalcite, talc, silica, white carbon, celite, asbestos, lithopone and the like can be exemplified. Halogen-based flame retardants include decabrom diphenyl oxide, ethylene bispentabrom benzene, tris (2,3-dibromopropyl) isocyanate, 2,
2-bis (4-hydroxyethoxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-)
Examples include 3,5-dibromophenyl) propane, hexabromobiphenyl, hexabromobenzene, pentabromodiphenyl ether, chlorinated polyethylene, brominated epoxy resin and chlorinated paraffin. These flame retardants may be used alone or in combination of two or more kinds. The blending amount of the flame retardant is preferably 5 to 250 parts by weight with respect to 100 parts by weight of the polyolefin resin. If the blending amount is less than 5 parts by weight, flame retardancy is deteriorated, and if the blending amount is more than 250 parts by weight, moldability and mechanical properties of the molded product are deteriorated, which is not desirable.

Examples of the phosphorus-based flame retardant plasticizer used in the present invention include phosphoric acid ester compounds and phosphorous acid ester compounds. Examples of the phosphoric acid ester compound include cresyl phosphate, cresyl diphenyl phosphate, trioctyl phosphate, tributyl phosphate, triphenyl phosphate, trixylenyl phosphate, triethyl phosphate, tributoxyethyl phosphate, phenylmonoorthoxenyl phosphate, 2-ethylhexyldiphenyl. Phosphate, octyldiphenylphosphate, diphenylisopropylphenylphosphate, tris (α-dichloropropyl) phosphate, tris (β-chloroethyl) phosphate, tris (β-bromoethyl) phosphate, tris (2,3-dibromopropyl) phosphate, bis ( 2,3-dibromopropyl) 2,3-dichloropropyl phosphate and the like. Examples of the phosphorous acid ester compound include tributyl phosphite, trioctyl phosphite, and isooctyl diphenyl phosphite. These phosphorus-based flame retardant plasticizers may be used alone or in combination of two or more. The blending amount of the phosphorus-based flame retardant plasticizer is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the polyolefin resin. If the blending amount is less than 0.1 parts by weight, the molding processability cannot be improved, and if the blending amount is more than 50 parts by weight, dripping occurs during combustion, which is not desirable.

The flame-retardant polyolefin resin composition of the present invention having improved processability may contain various conventional additives and auxiliary materials in the resin composition. Examples of various additives and auxiliary materials include stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, cross-linking agents, lubricants, processability improvers, fillers, colorants, and carbon black.

[0010]

The resin composition of the present invention comprises 100 parts by weight of a polyolefin resin having good electric insulation, 5 to 250 parts by weight of a flame retardant, and 10 to 50 parts by weight of a phosphorus flame retardant plasticizer. Since it is a resin composition, the extrusion molding processability, which was a conventional defect, is improved, the occurrence of eye blemishes is also suppressed, and it has passed the high flame-retardant standard and has excellent mechanical properties. It can be suitably used for molded products, especially for insulating layers and sheath layers of electric wires and cables. When a phosphorus-based flame retardant plasticizer is added to a polyolefin resin, blooming usually occurs and the surface of the molded product is whitened, but the composition of the present invention does not cause this blooming phenomenon. The reason for this is not clear, but it is considered that the phosphorus-based flame retardant plasticizer does not migrate to the surface of the molded product due to some bonding between the phosphorus-based flame retardant plasticizer and the metal atom of the inorganic flame-retardant.

[0011]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples.

Example 1(However, reference example) The composition shown in Table 1 was applied to a Banbury mixer at 160 ° C. for 1
After kneading for 0 minutes, granulation was performed to obtain pellets. This Pele
JIS K6760 as a guide for workability
Was tested for melt flow rate. That is, 19
Melt measured at 0 ° C and load of 2.16 kgindex
Is (MI). In addition, using the pellets produced,
With Brabender Strand Die, which is a rough guide
Extrusion test at 230 ℃, 60 minutes
The presence or absence of raw material was visually determined. In addition, the prepared pellets
Using a hot press molding machine, 150 ℃, 100kg /
cm^Two2mm thickness obtained by molding for 3 minutes
Flame resistance according to JIS K6911 B method
Test, tensile strength test according to JIS K6760
It was The prepared sheet is stored at room temperature for 1 month and
The blooming resistance was evaluated visually. Evaluation result
The results are shown in Table 1.

Examples 2 to 5 (However, Example 5 is a reference
Examples) , Comparative Examples 1 and 2 Pellets having the composition shown in Table 1 were prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0014]

[Table 1] * 1 EEA: NUC-830 MI0.7 comonomer 19% * 2 EVA: NUC-3757 MI1.3 comonomer 14.5% * 3 VLDPE: GRSN-1539 MI1.0
Density 0.90 * 4 Ionomer: High Milan 1557 MI5.
0 Density 0.95 (manufactured by Mitsui DuPont) * 5 Chlorinated polyethylene: Daisolak G-235
(Manufactured by Daiso) * 6 Antimony trioxide: ATOX-B (manufactured by Nippon Seimitsu) * 7 Magnesium hydroxide: KISMA-5A (Kyowa Chemical) * 8 Tricresyl phosphate (Daihachi Chemical) * 9 Irganox 1010 (Ciba Geigy) * 10 Kimasorb 944FD (manufactured by Ciba Geigy) * 11 ○ has no eye bleeding. × has a lot of eye blemishes. * 12 No blooming. × has blooming.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-247262 (JP, A) JP-A-5-138732 (JP, A) JP-A-5-98083 (JP, A) JP-A-63- 20348 (JP, A) JP 60-215038 (JP, A) JP 60-240011 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 23 / 00-23 / 36 C08K 3/00-3/08

Claims (2)

(57) [Claims] 1. A process characterized in that 100 parts by weight of a polyolefin resin, 5 to 250 parts by weight of a total amount of an inorganic flame retardant and a halogen flame retardant, and 10 to 50 parts by weight of a phosphorus flame retardant plasticizer are blended. Flame-retardant polyolefin resin composition having improved properties. 2. Polyolefin resin as high-pressure polyethylene (HPPE), ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (E)
EA), ionomer, ultra low density polyethylene (VLD
PE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and acid-modified ethylene-based polymers obtained by acid-modifying these ethylene-based polymers, or a combination of two or more thereof is used. The flame-retardant polyolefin resin composition according to claim 1, which has improved processability.