JP3269847B2 - Polyolefin resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyolefin resin composition. More specifically, the present invention relates to a polyolefin resin composition which is particularly suitable for applications such as a power cable having an insulating coating layer made of a cross-linked polyolefin-based resin, a coating material used at the time of a cross-linking reaction such as a rubber hose, or a mandrel for producing a rubber hose.

[0002]

2. Description of the Related Art As a method for producing a power cable having an insulating coating layer made of a cross-linked polyolefin resin, particularly a power cable having an insulating coating layer made of a cross-linked ethylene polymer, a cross-linking agent is contained on the outer periphery of a conductor wire. A method of extruding and coating an ethylene polymer to be subjected to a crosslinking reaction with the ethylene polymer to produce a power cable is known. The crosslinking reaction in this production method is conventionally performed in a metal tube called a crosslinking tube. However, this method has a problem that the thickness of the insulating coating layer made of the crosslinked ethylene polymer of the obtained power cable tends to be uneven. Therefore, the present inventors formed a coating layer composed of an uncrosslinked ethylene polymer by extruding and coating an ethylene-based polymer containing a cross-linking agent on the outer circumference of the conductor wire, and then further forming an outer circumference of the coating layer. A production method in which a polyolefin resin having another heat resistance is extruded and coated on a part and crosslinked in a crosslink tube was found, and was proposed earlier. (Japanese Patent Application No. 3-30421)

When a vulcanized rubber hose is manufactured, a mandrel made of a heat-resistant polyolefin resin is used as a core material of the hose, and the outer periphery of the mandrel is extruded and coated with unvulcanized rubber. A method of manufacturing a rubber hose by removing a mandrel after vulcanizing with a vulcanizer is known.

In the above-mentioned conventional production method, after the crosslinking or vulcanization step is completed, the coating layer made of the used polyolefin resin is peeled and pulverized and used again for extrusion coating, and the polyolefin resin mandrel pulled out of the rubber hose is used. Is repeatedly used as a core material again.

[0005]

However, the cross-linking agent or the vulcanizing agent is transferred to the surface of the polyolefin resin in contact with the polymer containing the cross-linking agent or the vulcanizing agent. Radical products resulting from migration of a crosslinking agent or vulcanizing agent into the resin increase. Therefore, the molecular weight of the polyolefin resin in surface contact decreases, and the physical properties deteriorate. As a result, the peeled and crushed resin, mandrel, and the like cannot be used any more if they are used repeatedly several times, and thus have a great problem in production cost.

[0006] Therefore, an object of the present invention is to form a radical product by a crosslinking agent or a vulcanizing agent transferred from a polymer even when the surface of the polymer comes into contact with a polymer containing a crosslinking agent, a vulcanizing agent and the like. Power cables or rubber hoses having an insulating coating layer made of a crosslinked polyolefin resin because production and manufacturing costs can be reduced because the number of times of repeated use can be increased as compared with the conventional method. The present invention provides a polyolefin resin composition suitable for use as a coating material used at the time of a crosslinking reaction such as a mandrel for producing a rubber hose, and an electric power having an insulating coating layer composed of a crosslinked polyolefin resin composed of the polyolefin resin composition. Provide a coating material used for a crosslinking reaction of a cable or a rubber hose, or a mandrel for manufacturing a rubber hose. In the door.

[0007]

Means for Solving the Problems The present invention, in order to solve the above problems, the polyolefin resin (A), the a polyolefin resin composition containing amine compound (B) and phosphite compound (C) , Containing crosslinker
Used for applications that come into contact with
And a polyolefin resin composition .

In the above polyolefin resin composition, 100 parts by weight of the polyolefin resin (A) is used.
The total amount of the amine compound (B) and the phosphite compound (C) is 0.1 to 10 parts by weight, and the content ratio of (B) / (C) is 1/5 to 5/1. If there,
preferable.

The polyolefin resin (A) contains 4-methyl-1-pentene in an amount of at least 85 mol%.
A 1-pentene polymer is preferred.

When the amine compound (B) is 4,4'-
Bis (α, α-dimethylbenzyl) diphenylamine is preferred.

It is preferable that the phosphite compound (C) is tris (2,4-di-t-butylphenyl) phosphite.

The present invention also provides, as applications of the polyolefin resin composition, a covering material for producing a power cable, a covering material for producing a rubber hose, and a mandrel comprising the polyolefin resin composition.

Hereinafter, the polyolefin resin composition of the present invention (hereinafter, referred to as “the composition of the present invention”) and its use will be described in detail.

Examples of the polyolefin resin which is the component (A) of the composition of the present invention include homopolymers of olefins and copolymers of two or more olefins. As this olefin, for example, ethylene, propylene, 1-
Butene, 4-methyl-1-pentene, 1-hexene, 1
And α-olefins having 2 to 20 carbon atoms such as -octene, 1-decene, 1-tetradecene, and 1-octadecene.

The polyolefin resin (A) may be used alone or in combination of two or more. Among them, when the composition of the present invention is used for a coating material or a mandrel at the time of vulcanization at the time of crosslinking of an insulating coating layer made of a crosslinked polyolefin resin of a power cable, or rubber hose production, the crosslinking or vulcanization at the time of vulcanization. From the viewpoint of heat resistance against temperature, a polymer containing 4-methyl-1-pentene as a main component is preferable.

The polymer containing 4-methyl-1-pentene as a main component (hereinafter referred to as “4-methyl-1-pentene polymer”) is a homopolymer of 4-methyl-1-pentene or 4-methyl-1-pentene and other α-olefins such as ethylene, propylene, 1-butene,
Α- having 2 to 20 carbon atoms, such as 1-hexene, 1-octene, 1-decene, 1-tetradecene, and 1-octadecene.
It is a copolymer mainly composed of 4-methyl-1-pentene containing 85 mol% or more, preferably 90 mol% or more of 4-methyl-1-pentene, which is a copolymer with olefin.

Examples of the amine compound (B) used as the component (B) of the composition of the present invention include phenyl-α-naphthylamine, phenyl-β-naphthylamine, N, N′-diphenyl-p-phenylene. Diamine,
N, N′-di-β-naphthyl-p-phenylenediamine, N-cyclohexyl-N′-phenyl-p-phenylenediamine, N-phenylene-N′-isopropyl-
Examples thereof include p-phenylenediamine, yldol-α-naphthylamine, a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline, and 4,4′-bis (α, α-dimethylbenzyl) diphenylamine. . These may be used alone or in combination of two or more. Among these, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine is preferable because a polyolefin resin composition having particularly excellent heat resistance can be obtained.

The phosphite compound (C) used as the component (C) of the composition of the present invention includes, for example, tris (nonylphenyl) phosphite, tris (mono, dinolylphenyl) phosphite, Tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-diphosphite, 2 , 2-methylenebis (4,6-di-t-
Butylphenyl) octyl phosphite, tris (2,
4-di-t-butylphenyl) phosphite and the like. These may be used alone or in combination of two or more. Among these, when using a 4-methyl-1-pentene polymer as the polyolefin resin (A), tris (2,4-di-t-butylphenyl) phosphite is most preferred.

Here, in the present invention, the phosphite compound (C) or the compounding ratio thereof is appropriately selected according to the polyolefin resin (A) to be used, whereby the heat stability is particularly excellent. A polyolefin resin composition can be obtained. For example, a 4-methyl-1-pentene polymer is used as the polyolefin resin (A), and tris (nonylphenyl) phosphite or tris (mono, dinolylphenyl) phosphite or the like is used as the phosphite compound (C). When used at a concentration of less than 0.2% by weight, when the obtained polyolefin resin composition is granulated, it does not thermally decompose even at a molding temperature of 280 ° C. or more, and has good thermal stability. This is preferable because a composition can be obtained. this is,
For olefin homopolymers such as polyethylene and polypropylene, copolymers of ethylene and α-olefins, etc., because of low gas permeability, the phosphite-based compound contained in the resulting polyolefin resin composition pellets While (C) has little tendency to hydrolyze with time, 4-methyl-1-pentene-based polymer has a large gas permeability, so that depending on the phosphite-based compound (C) used, This is because the phosphite-based compound (C) contained in the pellets of the polyolefin resin composition obtained may undergo hydrolysis with the lapse of time, and may not be able to exhibit its effect as a heat stabilizing aid with the lapse of time. it is conceivable that.

In the composition of the present invention, the compounding ratio of the amine compound (B) and the phosphite compound (C) mixed in the polyolefin resin (A) is such that the amine compound (B) and the phosphite compound (C) are mixed in an amount of 100 parts by weight of the polyolefin resin (A). The total amount of the compound (B) and the phosphite compound (C) is 0.1 parts by weight to 1 part by weight.
0 parts by weight, preferably 0.3 to 5 parts by weight, particularly preferably 1 to 4 parts by weight. Further, the amine compound (B) /
The ratio of the phosphite compound (C) is 1/5 to 5/1.
And particularly preferably in the range of 1.5 / 4.5 to 2/4.

In the composition of the present invention, if necessary, various compounding agents other than the polyolefin resin (A), the amine compound (B) and the phosphite compound (C) may impair the object of the present invention. You may mix in the range which does not exist. Examples of the compounding agent include a powdery filler such as an ultraviolet absorber, a nucleating agent, a plasticizer, a lubricant, an antistatic agent, a pigment, a dye, kaolin, and talc; and a fibrous material such as Tismo, glass fiber, and carbon fiber. Fillers and the like.

The method for preparing the composition of the present invention includes:
Any known method can be adopted. For example, using a mixer such as a tumbler blender, Henschel mixer, ribbon blender, etc., after mixing the components (A), (B) and (C), and various compounding agents blended as necessary, an extruder, a kneader, A method of kneading and preparing with two rolls or the like can be adopted.

The composition of the present invention can be formed into various shapes by various conventionally known melt molding methods. Examples of the melt forming method include a method such as an injection molding method, an extrusion molding method, an extrusion coating method, and a compression molding method.

Further, the composition of the present invention can be applied to various uses, particularly those used in contact with a polymer containing a crosslinking agent, for example, a mandrel in rubber tube production, a coating material, or It is suitable as a power cable manufacturing coating material having an insulating coating layer made of an ethylene polymer.

[0025]

EXAMPLES Examples and comparative examples of the present invention will be described below.
The present invention will be specifically described.

(Examples 1 to 3) MFR 0.5 g / 10
Min (ASTM D1238, 260 ° C, 5kg load),
Density 0.835 g / cm ³ (ASTM D 1505)
Per 100 parts by weight of poly-4-methyl-1-pentene (manufactured by Mitsui Petrochemical Industries, Ltd., MX004) (hereinafter referred to as “TPX-A”) as an amine compound,
4′-bis (α, α-dimethylbenzyl) diphenylamine and tris (2,4-
And di-tert-butylphenyl) phosphite in the proportions shown in Table 1, mixed by low-speed rotation with a Henschel mixer for 3 minutes, and then melt-kneaded with a single screw extruder at a temperature of 260 ° C. Pellets of the 4-methyl-1-pentene composition were produced. Next, the obtained pellets were supplied to a single screw extruder to form a mandrel having an outer diameter of 4 mmφ. Ethylene / vinyl acetate copolymer (hereinafter referred to as “EVA”) containing dicumyl peroxide in an amount of 0.1% by weight on the outer periphery of the mandrel (Evaflex P-1407 manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) Was extruded to form a tube of 2.5 mm thick uncrosslinked EVA. Thereafter, the mixture was heated in an air oven set at 150 ° C. for 10 hours to crosslink the EVA, and the crosslinked EVA was crosslinked.
Was formed. Then, after the tube made of cross-linked EVA was pulled out from the mandrel, the used poly-4-methyl-1 was used.
-MFR of powder of poly 4-methyl-1-pentene composition obtained by pulverizing a mandrel comprising a pentene composition
Was measured. Table 1 shows the results.

Example 4 5 parts by weight of a mixture having an amine compound / phosphite compound ratio of 3/1 based on 100 parts by weight of poly 4-methyl-1-pentene (TPX-A) A masterbatch (hereinafter, referred to as “PMP-1”) was prepared by melt-kneading in the same manner as in Example 1 except for the above.

Next, poly 4 having an MFR of 26 g / 10 min.
-Methyl-1-pentene (manufactured by Mitsui Petrochemical Industry Co., Ltd.
Trade name: TPXRT-18) (hereinafter referred to as “TPX-B”) and PMP-1 in a weight ratio of 80/20 to prepare a poly-4-methyl-1-pentene resin composition, A mandrel was formed in the same manner as in Example 1 using the material. Next, an uncrosslinked EVA was extrusion-coated on the outer periphery of the mandrel in the same manner as in Example 1, and heated in an air oven for 10 hours to crosslink the EVA. Next, after peeling off the crosslinked EVA layer, the mandrel was pulverized to obtain a powder of the obtained poly-4-methyl-1-pentene resin composition (PM
The MFR of P-2) was measured. Table 1 shows the results.

(Example 5) PMP- obtained in Example 4
Except for using a resin composition blended with 280 parts by weight and master batch PMP-120 parts by weight, a mandrel was formed, a cross-linked EVA layer was formed, peeled, and a mandrel was crushed in the same manner as in Example 4. A powder (PMP-3) of the resin composition was obtained, and its MFR was measured. Table 1 shows the results.

(Example 6) Mandrel molding, formation of a cross-linked EVA layer, peeling, and mandrel formation were carried out in the same manner as in Example 5 except that PMP-3 obtained in Example 5 was used instead of PMP-2. After pulverization, the resin composition powder (PM
P-4) was obtained, and its MFR was measured. Table 1 shows the results.

Example 7 One part by weight of a mixture of an amine compound and a phosphite compound shown in Table 1 in a ratio of 3: 1 was mixed with 100 parts by weight of TPX-B, and the mixture was mixed at a low speed with a Henschel mixer. For 3 minutes and melt-kneaded at a temperature of 260 ° C. with a single screw extruder to produce pellets. The obtained pellets were left in a thermo-hygrostat (40 ° C., 90% atmosphere) for 7 days, and the pellets were used.
In the same manner as in Example 1, the mandrel was formed, the cross-linked EVA layer was formed, peeled off, and the mandrel was pulverized to obtain a resin composition powder (PMP-5), and its MFR was measured. Table 1 shows the results.

Comparative Example 1 Instead of using a poly-4-methyl-1-pentene resin composition, a poly-4-methyl-1-pentene (TPX-A) containing no amine compound or phosphite compound was used. In the same manner as in Example 1, a mandrel was formed, and the outer periphery of the mandrel was extrusion-coated with a cross-linking agent-containing EVA to form a cross-linked EVA layer, exfoliated, and pulverized the mandrel to obtain a powder of TPX-A. Was measured. Table 1 shows the results.

(Comparative Example 2) A poly-4-methyl-1- compound in which 1.0 part by weight of an amine compound was added to 100 parts by weight of TPX-A without mixing a phosphite compound.
Except for using a pentene composition, a mandrel was formed in the same manner as in Example 1, and a cross-linking agent-compounded EVA was extrusion-coated to form a cross-linked EVA layer, peeled off, and pulverized the mandrel.
A powder of the poly-4-methyl-1-pentene composition was obtained, and its MFR was measured. Table 1 shows the results.

Comparative Example 3 An amine compound was not blended.
1.0 parts by weight of poly 4-methyl-1- compound was added with respect to 100 parts by weight of TPX-A.
Except for using a pentene composition, a mandrel was formed in the same manner as in Example 1, and a cross-linking agent-compounded EVA was extrusion-coated to form a cross-linked EVA layer, peeled off, and pulverized the mandrel.
A powder of the poly-4-methyl-1-pentene composition was obtained, and its MFR was measured. Table 1 shows the results.

Example 8 A resin was prepared by blending 5 parts of the master batch PMP-1 obtained in Example 4 with 95 parts of a poly-4-methyl-1-pentene polymer having an MFR of 26 g / 10 min. A composition was prepared, and a mandrel was formed, a cross-linked EVA layer was formed, peeled, and a mandrel was crushed in the same manner as in Example 1 except that a mandrel was prepared in the same manner as in Example 1 using this resin composition. Then, a powder (PMP-5) of the resin composition was obtained, and its MFR was measured. Table 1 shows the results.

(Examples 9 and 10) In each example, a mandrel was formed and a cross-linked EVA layer was formed in the same manner as in Example 1 except that a phosphite compound different from that used in Example 1 was used. , Peeling and pulverization of the mandrel were performed to obtain a resin composition powder, and its MFR was measured. Table 1 shows the results.

(Reference Examples 1 and 2)
Or put the pellets prepared in 10 in a thermo-hygrostat (40 ° C,
(90% relative humidity) for 7 days, and then a resin composition powder was prepared in the same manner as in Example 1 except that pellets dried in an air oven at 50 ° C. for 1 hour were used. MFR was measured. Table 1 shows the results.

[0038]

[Table 1]

(Note) * 1 P-1; Tris (2,4-di-
tert-butylphenyl) phosphite (Irgafos168: Ciba-Geigy) * 2 P-2; bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite
(MARK PEP-36: Asahi Denka) * 3 P-3; tetrakis (2,4-di-t-butylphenyl) 4,4'-biphenylenediphosphite (Sando
stab P-EPQ: sand) * 4 A-1; 4,4'-bis (α, α-dimethylbenzyl) diphenylamine (Nocrack CD: Ouchi Shinko) * 5 (Judgment method) Was determined according to the rank of. Judgment MFR ○ <50 △ 50-100 ×> 100

[0040]

As described above, the polyolefin resin composition of the present invention comprises:
Even when in surface contact with a polymer containing a crosslinking agent, a vulcanizing agent, etc.,
Reducing the generation of radical products by the cross-linking agent or vulcanizing agent transferred from the polymer is remarkably suppressed, and the number of reusable uses is increased as compared with the conventional method, so that production and manufacturing costs are reduced. Therefore, industrial practicality is high. Further, a power cable having an insulating coating layer made of the crosslinked polyolefin resin of the present invention comprising the polyolefin resin composition, or a coating material used at the time of a crosslinking reaction of a rubber hose or the like, or a mandrel for manufacturing a rubber hose is reduced in production and manufacturing costs. It is effective for reduction.

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Claims (8)

(57) [Claims] 1. A polyolefin resin composition containing a polyolefin resin (A), an amine compound (B) and a phosphite compound (C) , wherein the polymerization contains a crosslinking agent.
Used for applications that come into contact with the body and are used repeatedly
Polyolefin resin composition . 2. The total amount of the amine compound (B) and the phosphite compound (C) is 0.1 to 10 parts by weight based on 100 parts by weight of the polyolefin resin (A);
The polyolefin resin composition according to claim 1, wherein the content ratio of (B) / (C) is 1/5 to 5/1. 3. The method according to claim 1, wherein the polyolefin resin (A) contains 4-methyl-1-pentene in an amount of 85 mol% or more.
The polyolefin resin composition according to claim 1, which is a 1-pentene polymer. 4. The method according to claim 1, wherein the amine compound (B) is 4,4'-
The polyolefin resin composition according to any one of claims 1 to 3, which is bis (α, α-dimethylbenzyl) diphenylamine. 5. The polyolefin resin composition according to claim 1, wherein the phosphite compound (C) is tris (2,4-di-t-butylphenyl) phosphite. 6. A covering material for power cable production, comprising the polyolefin resin composition according to claim 1. 7. A coating material for producing a rubber hose, comprising the polyolefin resin composition according to claim 1. 8. A mandrel comprising the polyolefin resin composition according to claim 1.