JPH0733915A - Flame-retardant polyolefin resin composition - Google Patents

Abstract

PURPOSE:To provide the title composition which is a new material having markedly improved flame retardancy as well as the inherent properties of the constituent polyolefin resin, can easily be molded into a product excellent in a balance among properties such as low-temperature resistance, mechanical strengths and moldability by a usual processing method such as injection molding or extrusion molding. CONSTITUTION:The composition is prepared by mixing 100 pts.wt. mixture of a polyolefin resin (A) with an ethylene alpha-olefin copolymer rubber and/or an ethylene/ alpha-olefin/nonconjugated diene copolymer rubber (B) in an A/B mixing ratio of 90/10 to 50/50 with 5-50 pts.wt. mixture of phenol novolac resin (C) with at least one resin (D) selected from among an epoxy-modified polyolefin resin, an epoxy-modified product of a block polymer based on a vinylaromatic compound and an epoxy-modified product of a hydrogenated diene block copolymer in a C/D mixing ratio of 90/10 to 50/50 and melt-kneading the obtained mixture.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a polyolefin resin, an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber, a phenol novolac resin and the above-mentioned three types. It relates to a flame-retardant polyolefin resin composition having a specific epoxy-modified resin which is effective for improving the compatibility of the resin as a main component, and having good cold resistance and flame retardancy obtained by melt-kneading them, and injection molding It is useful for various molded articles obtained by the above-mentioned method or coated electric wires obtained by extrusion molding.

[0002]

2. Description of the Related Art Polyethylene, which is one of typical polyolefin resins, is inexpensive, transparent, has high impact resistance, good electric insulation, is chemically stable, and has low moisture permeability. Since it has many advantages, it has a wide range of applications such as various containers, tableware, toys, daily necessities, kitchen utensils. Polypropylene, which is another typical polyolefin resin, is inexpensive, transparent, has good mechanical properties, is chemically stable, has relatively good heat resistance, and has good electrical insulation. Since it has many advantages such as low moisture permeability, it has a wider range of applications than polyethylene such as various containers, tableware, toys, daily necessities kitchenware, film sheets, automobile bumpers and the like. As described above, the polyolefin resins have various advantages, but both polyethylene and polypropylene have a common drawback that they are easily burned. In order to improve this drawback, a method of blending a halogen-based or phosphorus-based or nitrogen-based flame retardant, a so-called addition-type flame retardant such as aluminum hydroxide or magnesium hydroxide has been carried out, but it can be obtained by using these methods. There is a problem that the characteristics of the composition are deteriorated. The best flame-retardant method is to make the resin itself flame-retardant. In the case of polyolefin resin, a method of blending a halogenated polyolefin has been used, but this method improves the flame-retardant property. Though
There is a problem that a large amount of halogen, which is a problem in environmental destruction, must be used. From the above, it is most preferable if the polyolefin resin can be made flame-retardant by a polymer alloy of the polyolefin and the halogen-free flame-retardant resin, but the polyolefin resin has poor compatibility with other resins. Conventionally, flame retardation by such a method has not been found. In order to improve these drawbacks, a method relating to a composition in which a phenol resin having good flame retardancy is blended with a polyolefin resin is exemplified in JP-A-4-1245, but the polyolefin composition of the present invention is Although it has an effect of improving flame retardancy, this method has not been obtained at a practical level because the incorporation of a phenol resin causes deterioration of cold resistance and mechanical properties.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a non-halogen, polyolefin resin having improved flame retardancy with almost no deterioration in properties.

[0004]

Means for Solving the Problems The present inventors have studied a polyolefin resin and a phenol novolac resin having good flame retardancy, and as a result, the flame retardancy is improved by a method of simply blending the polyolefin resin and the phenol novolac resin. However, it has been found that there is a drawback that characteristics such as cold resistance and heat resistance are deteriorated. Therefore, as a result of further intensive study, an epoxy-modified polyolefin-based resin having an epoxy group in the molecule which easily reacts with a phenol resin,
Hydrogenated block obtained by hydrogenating a block copolymer composed of at least one vinyl aromatic compound-based polymer block epoxy modified product and at least one conjugated diene compound-based polymer block By blending one or more resins selected from the epoxy modified products of the copolymer, and further melt-kneading and reacting, the brittleness of the phenol novolak resin, which is relatively low in molecular weight and brittle, is improved, and flame retardancy is improved. It has been found that the conventional drawbacks such as cold resistance and mechanical properties are improved without impairing the properties.
Further, by further blending an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber with a polyolefin resin, cold resistance and mechanical properties are maintained without impairing flame retardancy. The inventors have found that they are significantly improved and have completed the present invention. That is, the present invention relates to (A) a polyolefin resin and (B) an ethylene-α / olefin copolymer rubber and / or ethylene-α.
90% with olefin-non-conjugated diene copolymer rubber
With respect to 100 parts by weight of the mixture having a ratio of 0 to 50:50,
(C) a phenol novolac resin and (D) an epoxy-modified polyolefin resin, an epoxy-modified product of a polymer block mainly containing at least one vinyl aromatic compound,
At least one resin selected from the epoxy modified products of hydrogenated block copolymers obtained by hydrogenating a block copolymer consisting of a polymer block containing at least one conjugated diene compound as a main component; A flame-retardant polyolefin-based resin composition having good cold resistance and flame retardancy, characterized in that 5 to 50 parts by weight are blended in a ratio of 90:10 to 50:50 and melt-kneaded, and preferably The component (C) and the component (D) are melt-kneaded in advance and used.

The polyolefin resin used as the component (A) of the present invention is not particularly limited and is commercially available. For example, a polyethylene resin, a polypropylene resin, or an ethylene- (meth) acrylic acid copolymer, Modified polyethylene resin such as ethylene- (meth) acrylic acid ester copolymer, ethylene- (meth) acrylic acid methyl copolymer, ethylene- (meth) acrylic acid ethyl copolymer, ethylene-propylene copolymer, ethylene- Examples thereof include propylene-diene copolymer. These resins may be used alone or in combination of two or more.

The ethylene-α-olefin copolymer rubber and / or the ethylene-α-olefin-non-conjugated diene copolymer rubber used as the component (B) of the present invention have good compatibility with the polyolefin resin and It has a low glass transition temperature. Therefore, it is an important component that has a function of lowering the glass transition temperature of the polyolefin resin by blending it with the polyolefin resin and further improving the cold resistance of the polyolefin resin. The ethylene-α-olefin copolymer rubber and / or the ethylene-α-olefin-non-conjugated diene copolymer rubber used in the present invention are not particularly limited and are commercially available products such as polyethylene and iso Random and / or block copolymers of tactic polypropylene or polypropylene and a small amount of other α-olefins, specifically polypropylene-ethylene copolymer, propylene-1-hexene copolymer, specifically polypropylene-4 -Methyl-1-pentene copolymer, poly-4-methyl-1-pentene, polybutene-1 and the like. Further, two or more kinds of polyolefin resins such as polyethylene and polypropylene may be used in combination. Furthermore, if the glass transition temperature of the component (B) is -30 ° C or lower, the effect of lowering the glass transition temperature of the polyolefin-based resin is large, which is preferable.

The phenol novolac resin used as the component (C) of the present invention is not particularly limited and is commercially available. For example, formalin and phenols have a formaldehyde / phenols ratio of 0.
After charging into a reaction kettle at a mixing ratio of 5 to 1.0, further adding a catalyst such as oxalic acid, hydrochloric acid, sulfuric acid, and toluenesulfonic acid, followed by heating, and performing a reflux reaction for an appropriate time,
It can be obtained by a method such as vacuum dehydration or static dehydration for removing separated water, and further removing remaining water and unreacted phenols.

The specific epoxy-modified resin which is the component (D) of the present invention has a function of improving cold resistance and mechanical properties which are deteriorated when a phenol resin which is a resin having a relatively low molecular weight and is brittle is blended with a polyolefin resin. Is a very important ingredient with. Modified polyolefin containing an epoxy group in the molecule used in the present invention is not particularly limited and is commercially available, a copolymer of ethylene and glycidyl methacrylate or an ethylene-acrylic acid copolymer, Ethylene / methacrylic acid copolymer, ethylene / acrylate copolymer, ternary copolymer of ethylene / methacrylic acid copolymer and glycidyl methacrylate, PP grafted with glycidyl methacrylate
Etc. are illustrated. The hydrogenated block copolymer containing an epoxy group used in the present invention is not particularly limited and is commercially available. Epoxidized styrene-ethylene / butylene-styrene block copolymer, epoxidized styrene-ethylene. -Isoprene-styrene block copolymer etc. are mentioned. The epoxy-modified block copolymer used in the present invention is a block copolymer before hydrogenation,
It can be obtained by addition reaction of an epoxy compound having an unsaturated double bond.

The polyolefin resin composition of the present invention is
(A) component polyolefin resin, (B) component ethylene-α-olefin copolymer rubber and / or ethylene-α-olefin-non-conjugated diene copolymer rubber, (C)
Component phenol novolac resin and component (D) epoxy-modified polyolefin-based resin, at least one vinyl aromatic compound-based polymer block epoxy-modified product, and at least one conjugated diene compound-based polymer One or more resins selected from the epoxy modified products of hydrogenated block copolymers obtained by hydrogenating a block copolymer consisting of blocks are charged all at once, and the amount is 150 to 150 by a pressure kneader or a Banbury mixer. 200 ° C, 10
Melt kneading for 30 minutes, or (C) component and (D) component are preliminarily used in a pressure kneader or Banbury mixer for 16 minutes.
After melt-kneading at 0 to 200 ° C. for 10 to 30 minutes, (A)
It is obtained by a method of adding to the mixture of the component and the component (B) and further melt-kneading. In the latter case, the component (C) and the component (D) are selectively mixed with each other, and It is preferable because the phenol novolac resin can react with the epoxy group of the component (D). In the polyolefin resin composition of the present invention, the polyolefin resin as the component (A) and the ethylene-α-olefin copolymer rubber and / or the ethylene-α-olefin-non-conjugated diene copolymer rubber as the component (B) are used. Mixture 1 in the ratio 90:10 to 50:50
To 100 parts by weight, a phenol novolac resin as the component (C) and an epoxy-modified polyolefin resin as the component (D), an epoxy-modified product of a polymer block mainly composed of at least one vinyl aromatic compound, and at least one 90:10 with one or more resins selected from epoxy modified products of hydrogenated block copolymers obtained by hydrogenating a block copolymer consisting of a polymer block mainly composed of a conjugated diene compound. It should be blended in a ratio of 50:50 in the range of 5 to 50 parts by weight.

In a mixture of the polyolefin resin composition as the component (A) and the ethylene-α-olefin copolymer rubber and / or the ethylene-α-olefin-non-conjugated diene copolymer rubber as the component (B), B) component ratio is 10
When it is less than wt%, it becomes insufficient to improve the cold resistance. Also,
When it exceeds 50 wt%, various advantages of the polyolefin resin are deteriorated. Component (C) is a phenol novolac resin, component (D) is an epoxy-modified polyolefin-based resin, at least one vinyl aromatic compound is a polymer block-epoxy-modified product, and at least one conjugated diene compound is the main component. The ratio of the component (D) in the mixture of one or more resins selected from the epoxy modified products of the hydrogenated block copolymer obtained by hydrogenating the block copolymer consisting of the polymer block is 10 wt. If less than%, when the phenol resin is blended with the polyolefin-based resin, the cold resistance and the improvement of mechanical properties are reduced, and
If it exceeds 50 wt%, the effect of improving flame retardancy becomes insufficient. The ratio of the component (A) polyolefin resin and the component (B) ethylene-α-olefin copolymer rubber and / or ethylene-α-olefin-non-conjugated diene copolymer rubber is 90:10 to 50:50. If the mixture of the component (C) and the component (D) is less than 5 parts by weight relative to 100 parts by weight of the mixture, the effect of improving the flame retardancy becomes insufficient, and if it exceeds 50 parts by weight, the polyolefin as the component (A). The various advantages of resin-based resin are reduced.

As described above, the polyolefin-based resin composition of the present invention has an effect of improving flame retardancy with almost no deterioration in the characteristics of the polyolefin-based resin as the component (A). , (B) ethylene-
α ・ olefin copolymer rubber and / or ethylene-α ・
The olefin-non-conjugated diene copolymer rubber lowers the glass transition temperature of the component (A) and further improves cold resistance.
Further, the epoxy-modified resin as the component (D) improves the brittleness of the phenol resin by reacting with the phenol resin as the component (C), and the compound produced by the reaction is a polyolefin resin and a Since it has an affinity for phenolic resins, it acts as a compatibilizer for polyolefin resins and phenolic resins,
Component polyolefin resin and component (B) ethylene-α-olefin copolymer rubber and / or ethylene-α
It is considered that the phenol resin as the component (C) and the epoxy-modified resin as the component (D) can have a microphase-separated structure in the mixture of the olefin-non-conjugated diene copolymer rubber. The polyolefin-based resin composition of the present invention further includes other compounding agents depending on the use and purpose, such as talc, mica, calcium carbonate, inorganic fillers such as wollastonite, coupling agents or glass fibers, carbon fibers, etc. Reinforcing agent, flame retardant, flame retardant aid, antistatic agent,
Stabilizers, pigments, mold release agents, impact modifiers such as elastomers, etc. may be added. The polyolefin-based resin composition of the present invention is processed by a usual thermoplastic resin molding, for example, by injection molding or extrusion molding,
Easily processed into molded products.

[0012]

EXAMPLES The present invention will be described below with reference to examples, but these are merely examples and the present invention is not limited thereto. The tensile test is ASTM-D638, the cold resistance is JIS K 6301, and the oxygen index is ASTM-D28.
63, the combustion test is the result measured by the safety standard UL94 of Underwriters Laboratories. (Examples 1 to 4) As the component (A), polyethylene [PE: Ultzex 2022 manufactured by Mitsui Petrochemical Co., Ltd.] was used.
L], polypropylene [PP: Sumitomo Noblen RAY564 manufactured by Sumitomo Chemical Co., Ltd.], and ethylene-propylene copolymer rubber [EP: manufactured by Nippon Synthetic Rubber Co., Ltd. EP07P], ethylene as the component (B). -Propylene-non-conjugated diene copolymer rubber [EP: Nippon Synthetic Rubber
EP57P] manufactured by Co., Ltd. is used, and as the component (C),
Straight phenol novolac resin [PN: Sumitomo Durezu Co., Ltd. Sumilite Resin R PR-5147
0], straight phenol novolac resin [PN:
Sumitomo Dures Co., Ltd. Sumilite Resin R PR-53
194] as the component (D), epoxy-modified polyolefin resin [EP-PO: Bondfast R 2C manufactured by Sumitomo Chemical Co., Ltd.] or epoxy-modified styrene-ethylene / butylene-styrene block copolymer [EP-
SEBS: Tuftec R Z-514 manufactured by Asahi Kasei Corporation]
It was used. The blending and evaluation results are shown in Table 1.

(Examples 5 to 8) As the component (A), ethylene-methyl methacrylate copolymer [modified PE: Acryft WH102 manufactured by Sumitomo Chemical Co., Ltd.], ethylene-methacrylic acid copolymer [modified PE: Mitsui DuPont Polychemical Co., Ltd. Nucrel R 0903C] is used, and the component (B) is ethylene-propylene copolymer rubber [EP: Nippon Synthetic Rubber Co., Ltd. EP07P], ethylene-propylene-non-conjugated diene. Copolymer rubber [EP
: EP57P] manufactured by Japan Synthetic Rubber Co., Ltd.
As the component (C), a straight phenol novolac resin [PN: Sumitlite Resin R PR-51470 manufactured by Sumitomo Dures Co., Ltd.], a straight phenol novolac resin [PN: Sumilite resin R PR-53194 manufactured by Sumitomo Dures Co., Ltd.] are used. Further, as the component (D), an epoxy-modified polyolefin resin [EP-PO: Bond First R 2C manufactured by Sumitomo Chemical Co., Ltd.] or an epoxy-modified styrene-ethylene / butylene-styrene block copolymer [EP-SEBS: Asahi Kasei ( Tuftec R Z-514] manufactured by Co., Ltd. was used. The blending and evaluation results are shown in Table 2.

Comparative Example 1 As the component (A), polyethylene [PE: Ultzex 20 manufactured by Mitsui Petrochemical Co., Ltd.]
22L] and ethylene-propylene copolymer rubber [EP: manufactured by Nippon Synthetic Rubber Co., Ltd. E as component (B)]
P07P) was used. The composition and the evaluation results are shown in Table 3. (Comparative Example 2) As component (A), polypropylene [P
P: Sumitomo Chemical Co., Ltd. Sumitomo Noblen RAY56
4] is used as the component (B), ethylene-propylene-non-conjugated diene copolymer rubber [EP: Nippon Synthetic Rubber].
EP57P manufactured by Co., Ltd.) was used. The composition and the evaluation results are shown in Table 3. (Comparative Example 3) As the component (A), polyethylene [PE:
Ultzex 2022L manufactured by Mitsui Petrochemical Co., Ltd. is used, and as the component (B), ethylene-propylene-non-conjugated diene copolymer rubber [EP: manufactured by Nippon Synthetic Rubber Co., Ltd.
EP57P] was used, and straight phenol novolac resin [PN: Sumirite Resin R PR-51470 manufactured by Sumitomo Dures Co., Ltd.] was used as the component (C). The composition and the evaluation results are shown in Table 3. (Comparative Example 4) As component (A), polypropylene [P
P: Sumitomo Chemical Co., Ltd. Sumitomo Noblen RAY56
4] is used, and as the component (B), ethylene-propylene copolymer rubber [EP: EP0 manufactured by Nippon Synthetic Rubber Co., Ltd.]
7P], and straight phenol novolac resin [PN: Sumirite Resin R PR-53194 manufactured by Sumitomo Dures Co., Ltd.] was used as the component (C). The composition and the evaluation results are shown in Table 3.

Comparative Example 5 As the component (A), an ethylene-methyl methacrylate copolymer [modified PE: Sumitomo Chemical
Acrylift WH102 manufactured by Co., Ltd. is used, ethylene-propylene copolymer rubber [EP: EP07P manufactured by Nippon Synthetic Rubber Co., Ltd.] is used as a component (B), and straight phenol novolac resin [PN] is used as a component (C). :
Sumitomo Dures Co., Ltd. Sumilite Resin R PR-51
470] and epoxy-modified polyolefin resin [EP-PO: manufactured by Sumitomo Chemical Co., Ltd.] as component (D).
Bondfast R 2C] was used. The blending and evaluation results are shown in Table 4. (Comparative Example 6) As component (A), ethylene-methacrylic acid copolymer [modified PE: Mitsui DuPont Polychemical
Nucrel R 0903C] manufactured by Co., Ltd.
As a component, ethylene-propylene-non-conjugated diene copolymer rubber [EP: EP57P manufactured by Nippon Synthetic Rubber Co., Ltd.]
And a straight phenol novolac resin [PN: Sumirite Resin R PR-53194 manufactured by Sumitomo Dures Co., Ltd.] as the component (C), and an epoxy-modified styrene-ethylene / butylene-styrene block copolymer as the component (D). A polymer [EP-SEBS: Tuftec RZ-514 manufactured by Asahi Kasei Co., Ltd.] was used. The blending and evaluation results are shown in Table 4. (Comparative Example 7) An ethylene-methyl methacrylate copolymer [modified PE: Acryft WH102 manufactured by Sumitomo Chemical Co., Ltd.] was used as the component (A), and an ethylene-propylene-non-conjugated diene copolymer was used as the component (B). Polymer rubber [EP
: EP57P] manufactured by Japan Synthetic Rubber Co., Ltd.
As component (C), straight phenol novolac resin [PN: Sumitrite Resin R manufactured by Sumitomo Dures Co., Ltd.
PR-51470] was used, and as the component (D), an epoxy-modified polyolefin resin [EP-PO: Bondfast R 2C manufactured by Sumitomo Chemical Co., Ltd.] was used. The blending and evaluation results are shown in Table 4. (Comparative Example 8) As component (A), ethylene-methacrylic acid copolymer [modified PE: Mitsui-DuPont Polychemical
Nucrel R 0903C] manufactured by Co., Ltd.
Ethylene-propylene copolymer rubber [EP
: EP07P] manufactured by Japan Synthetic Rubber Co., Ltd.
As component (C), straight phenol novolac resin [PN: Sumitrite Resin R manufactured by Sumitomo Dures Co., Ltd.
PR-53194] was used, and epoxy-modified styrene-ethylene / butylene-styrene block copolymer [EP-SEBS: Tuftec RZ-514 manufactured by Asahi Kasei Co., Ltd.] was used as the component (D). The blending and evaluation results are shown in Table 4.

(Comparative Example 9) As component (A), polyethylene [PE: Ultzex 20 manufactured by Mitsui Petrochemical Co., Ltd.]
22L) and ethylene-propylene copolymer rubber [EP: E manufactured by Nippon Synthetic Rubber Co., Ltd. as the component (B)]
P07P] was used, and an epoxy-modified polyolefin resin [EP-PO: Bondfast R 2C manufactured by Sumitomo Chemical Co., Ltd.] was used as the component (D). The blending and evaluation results are shown in Table 5. (Comparative Example 10) As component (A), polypropylene [P
P: Sumitomo Chemical Co., Ltd. Sumitomo Noblen RAY56
4] is used as the component (B), ethylene-propylene-non-conjugated diene copolymer rubber [EP: Nippon Synthetic Rubber].
EP57P] manufactured by Co., Ltd. was used, and epoxy-modified styrene-ethylene / butylene-styrene block copolymer [EP-SEBS: Tuftec RZ-514 manufactured by Asahi Kasei Co., Ltd.] was used as the component (D). The blending and evaluation results are shown in Table 5. (Comparative Example 11) As the component (A), an ethylene-methyl methacrylate copolymer [modified PE: manufactured by Sumitomo Chemical Co., Ltd.
Acrylift WH102] is used, ethylene-propylene copolymer rubber [EP: EP07P manufactured by Nippon Synthetic Rubber Co., Ltd.] is used as the component (B), and epoxy-modified polyolefin resin [EP-PO: as the component (D)]. Sumitomo Chemical Co., Ltd. Bond First R 2C] was used. The blending and evaluation results are shown in Table 5. (Comparative Example 12) As the component (A), ethylene-methacrylic acid copolymer [modified PE: Nucrel R 0903C manufactured by Mitsui DuPont Polychemical Co., Ltd.] was used,
As the component (B), ethylene-propylene-non-conjugated diene copolymer rubber [EP: EP5 manufactured by Nippon Synthetic Rubber Co., Ltd.]
7P] and an epoxy-modified styrene-ethylene / butylene-styrene block copolymer [EP-SEBS: Asahi Kasei Corporation Tuftec R Z-
514] was used. The blending and evaluation results are shown in Table 5.

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

As is apparent from the table, the polyolefin-based resin composition of the present invention is a novel material in which the flame retardancy is remarkably improved while maintaining the characteristics of the polyolefin-based resin. A molded product can be easily processed into a molded product by a processing method used for a molding material, such as injection molding or extrusion molding, and a product having an excellent balance of physical properties such as cold resistance, mechanical strength, and moldability can be provided.

Claims (4)

[Claims] 1. A (A) polyolefin resin and (B) an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber are 9
Based on 100 parts by weight of a mixture having a ratio of 0:10 to 50:50, (C) a phenol novolac resin and (D) an epoxy-modified polyolefin resin having an epoxy group in the molecule, and at least one vinyl aromatic compound as a main component From an epoxy modified product of a polymer block, and an epoxy modified product of a hydrogenated block copolymer obtained by hydrogenating a block copolymer composed of a polymer block containing at least one conjugated diene compound as a main component. A polyolefin resin having good cold resistance and flame retardancy, characterized by being prepared by mixing 5 to 50 parts by weight of one or more selected resins in a ratio of 90:10 to 50:50 and melt-kneading. Composition. 2. The flame-retardant polyolefin resin composition according to claim 1, wherein the polyolefin resin (A) is polyethylene, polypropylene and / or modified polyethylene. 3. The glass transition temperature of (B) the ethylene-α-olefin copolymer rubber and / or the ethylene-α-olefin-non-conjugated diene copolymer rubber is -30 ° C. or lower. Flame-retardant polyolefin resin composition. 4. A (C) phenol novolac resin and (D) an epoxy-modified polyolefin resin, an epoxy-modified product of a polymer block containing at least one vinyl aromatic compound as a main component, and at least one conjugated diene compound as a main component. Use one obtained by previously melt-kneading one or more resins selected from epoxy modified products of hydrogenated block copolymers obtained by hydrogenating a block copolymer consisting of polymer blocks Claims 1 and 2 characterized by
Alternatively, the flame-retardant polyolefin-based resin composition according to item 3.