JPS6264852A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent heat resistance and gives flame-retardant moldings which do not cause blooming, consisting of a block copolymer, a polyolefin polymer, a softener and a specified halo genated polymer. CONSTITUTION:100pts. (by weight; the same applies hereinbelow) in total of 80-50pts. A-B-A block polymer (a) with a ratio (wt%) of A/B of 5-55/95-45 (wherein A is a PS block having an average MW of 1,000-200,000; B is a polymer block obtd. by hydrogenating unsaturated portions of polyisoprene or polybutadiene having an average MW of 5,000-500,000) and 20-50pts. polyolefin polymer (b) are blended with at least 20pts. softener (c) such as mineral process oil, e.g., paraffinic oil, naphthenic oil or aromatic oil, 10-100pts. (per 100pts. of the combined quantity of a+b+c) halogenated polymer (d) of the formula [wherein X is Cl, Br; R is -C(CH)-, SO; m is 1-4; n is 1-10] and optionally additives (e) such as a flame-retardant aid, a crosslinking agent, an antioxidant, a filler, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bloom-free flame-retardant resin composition mainly composed of a styrene elastomer.

[Prior Art] A composition based on an A-B-A block copolymer (A is polystyrene, B is a polymer obtained by adding hydrogen to polyisoprene or polybutadiene to crush unsaturated parts), which is a type of styrenic elastomer. It has rubber-like properties even without cross-linking treatment, and has excellent processability like general plastics, and its molded products have good electrical insulation, a high softening temperature of 160°C or higher, and high resistance to heat deterioration. Because it has properties such as good quality and toughness, it is expected to be used in the future as a coating material for electric wires and cables, tubes, hoses, sheets, etc.

However, since it is an inherently flammable polymer, it cannot be used in applications that require flame retardancy. In particular, recently there has been an increasing demand for flame retardancy in various fields, and for example, electric wires and cables are strongly required to have a high degree of flame retardancy that can pass the UL vertical flame retardant test.

In order to make a heat-resistant polymer such as an A-B-A block copolymer flame retardant, it is most common to mix an additive type flame retardant with good heat resistance into the polymer.

[Problems to be solved by the invention] However, flame retardants with good heat resistance have the disadvantage of causing a phenomenon called bloom that gradually appears on the surface of the material over time. Improving this problem has been a major challenge since it leads to contamination and poor appearance.

The present invention has been made based on the above, and an object of the present invention is to provide a flame-retardant resin composition mainly composed of a styrene elastomer without flame retardant bloom.

[Means for Solving the Problems] The insulated wire of the present invention is made of (a) an A-B-A block copolymer (A is polystyrene, B is polyisoprene or polybutadiene, and hydrogen is added to it to destroy unsaturated parts. (b) polyolefin polymer, (C) softener, and (d) general formula, (X: C1 or B r
, R: -C(CH)- or -S0-1m: 1-4
n: a natural number of 1 to 10).

In the present invention, A in the A-B-A block copolymer as component (a) is a polystyrene block, and B is a polymer block obtained by adding hydrogen to polyisoprene or polybutadiene to crush unsaturated parts. When hydrogen is added to polyisoprene, B becomes an ethylene-butene-1 copolymer or its analog, and when hydrogen is added to polybutadiene, B becomes an ethylene-propylene copolymer or its analog. The average molecular weight for is t, ooo~
200,000 preferably 5,000 to 120,00
0, B(7) average molecular weight is 5,000 to 500
,000, preferably 10,000 to 300,000.

The content ratio (weight%) of A/H is 5/95 to 55/45,
Preferably it is lO/90 to 3o/7o.

(b) Component polyolefin polymer and (c)
The softener component is necessary for imparting extrusion processability to the above-mentioned A-B-A block copolymer.

Among polyolefin polymers, polyethylene,
Preferred are polypropylene, polybutene-11 poly4-methylpentene-1, polystyrene, polymethyl methacrylate, and the like.

Typical softeners include mineral process oils such as paraffin oil, naphthenic oil, and aromatic oil.

The halogen-based reaction polymer represented by the general formula, which is the component (d), includes a reaction polymer of chlorinated cyanuric acid and trichloromethylethylidene bisphenol, a reaction polymer of chlorinated cyanuric acid and trichlorosulfonyl bisphenol, and a reaction polymer of chlorinated cyanuric acid and trichlorosulfonyl bisphenol. Examples include reaction polymers of tribromomethylethylidene bisphenol and reaction polymers of chlorinated cyanuric acid and tribromosulfonyl bisphenol.

The content ratio of component (a)/component (b) is 80/20 to 5
A range of 0150 is preferable; if the amount of component (b) is too large, the inherent flexibility of component (a) will be impaired, and if it is too small, extrusion processability and heat deformation resistance will tend to decrease.

Component (c) is the total amount io of component (a) and component (b).

It is preferably 20 parts by weight or more, and if it is less than 20 parts by weight, sufficient extrusion processability and flexibility tend to be impaired.

The amount of component (d) is preferably in the range of 10 to 100 parts by weight based on 100 parts by weight of the total amount of components (a), (b), and (c), and if it is less than 10 parts by weight, flame retardant If the amount is insufficient and exceeds 100 parts by weight, heat resistance and tensile properties tend to deteriorate.

In the present invention, it is preferable to add a flame retardant aid, and examples of the flame retardant aid include antimony trioxide, magnesium oxide, molybdenum oxide, tin oxide, zirconium oxide,
Examples include zinc oxide.

Further, other flame retardants such as chlorinated paraffin, chlorinated polyethylene, perchloropentacyclodecane, etc. may be used in combination as long as the properties are not impaired.

Furthermore, in addition to the above-mentioned components, crosslinking agents, antioxidants, fillers, lubricants, etc. may be blended as necessary.

As a crosslinking agent, dicumyl peroxide, 3-bis(
Organic peroxides such as t-butylperoxyisopropylbenzene are suitable.

As antioxidants, phenyl-α-naphthylamine,
Amine antioxidants such as N,N'-di-β-naphthyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, 2,6-di-t-
Butyl-4-methylphenol, hindered phenol, 6-(4-hydroxy-3,5-di-tert-butyl anilino)-2,4-bis-octyl-thio-1,3,5
-1 riazine, 4,4'-methylene-bis-(2,6-
Examples include phenolic antioxidants such as di-tert-butylphenol.

Examples of fillers include talc, clay, calcium carbonate, silicic anhydride, calcium silicate, and carbon black.

[Example] The formulations shown in Table 1 were kneaded in a Banbury kneader, and then introduced into an extruder to obtain a cross-sectional area of 2 Tl1tri.
An insulated wire was prepared by extrusion coating the outer periphery of the copper wire to a thickness of 1.2 mm.

The first evaluation result of the insulated wire created based on the composition between each
Shown in the bottom column of the table.

The flame retardancy evaluation is based on JISC3004, and if the electric wire held horizontally is burned in a burner, then it disappears within 1 minute, it passes, and if it burns for more than 1 minute, it fails.

Bloom placed three rows of electric wires in an atmosphere at room temperature and 80°C, and then observed their surfaces using a 20x optical microscope.

As is clear from Table 1, Example 1 within the scope of the present invention
-3 passed the JISR flame test for flame retardancy, and no blue color was observed.

On the other hand, bloom occurred in Comparative Examples 1 to 3 in which flame retardants other than those specified in the present invention were used.

[Effects of the Invention] As explained above, the present invention provides a flame-retardant resin composition containing an A-B-A block copolymer, a polyolefin polymer, a softener, and a specific flame retardant. This makes it possible to obtain flame-retardant molded products with excellent heat resistance and no blooming.

Claims (1)

[Claims] (1) (a) A-B-A block copolymer (A is polystyrene, B is a polymer obtained by adding hydrogen to polyisoprene or polybutadiene to crush unsaturated parts), (b) polyolefin polymer, (c) softening (d) General formula, ▲Mathematical formula, chemical formula, table, etc.▼ (X: Cl or Br, R: -C(CH)- or -S
O-, m: a natural number from 1 to 4, n: a natural number from 1 to 10) A flame-retardant resin composition characterized by containing a halogen-based reactive polymer.