JPH05320431A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:To inhibit the formation of free-radical products caused by a crosslinking or vulcanizing agent having migrated from a polymer by incorporating a polyolefin resin, an amine and a phosphite compound. CONSTITUTION:100 pts.wt. polyolefin resin is blended with 0.1-10 pts.wt. mixture of amine and phosphite compounds in a ratio of 1/5 to 5/1.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyolefin resin composition. More specifically, the present invention relates to a polyolefin resin composition suitable for applications such as a power cable having an insulating coating layer made of a crosslinked polyolefin-based resin, a coating material used in a crosslinking 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 crosslinked polyolefin resin, particularly a power cable having an insulating coating layer made of a crosslinked ethylene polymer, a crosslinking agent is contained on the outer periphery of a conductor wire. There is known a method of producing an electric power cable by extrusion-coating an ethylene-based polymer to be coated, and then subjecting the ethylene-based polymer to a crosslinking reaction. The cross-linking reaction in this manufacturing method is conventionally carried out in a metal tube called a cross-linking tube. However, this method has a problem that uneven thickness is likely to occur in the insulating coating layer made of the crosslinked ethylene-based polymer of the obtained power cable. Therefore, the present inventors have extruded and coated an ethylene-based polymer containing a cross-linking agent on the outer periphery of the conductor wire to form a coating layer made of an uncrosslinked ethylene-based polymer, and then the outer periphery of the coating layer. We found a manufacturing method in which a polyolefin resin having another heat resistance was extrusion-coated on the part and cross-linked in a cross-linking tube, and it was previously proposed. (Japanese Patent Application No. 3-30421)

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

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

[0005]

However, as the crosslinking agent or the vulcanizing agent migrates to the polyolefin resin which is in surface contact with the polymer containing the crosslinking agent or the vulcanizing agent, the polyolefin resin is repeatedly used as it is used. Radical products due to migration of the cross-linking agent or vulcanizing agent into the resin increase. Therefore, the molecular weight of the polyolefin resin contacted with the surface is lowered and the physical properties are deteriorated. As a result, the peeled and crushed resin, mandrel and the like can no longer be used when they are repeatedly used several times, which poses a serious problem in terms of production cost.

Therefore, an object of the present invention is to produce a radical product by a crosslinking agent or a vulcanizing agent that migrates from the polymer even when it comes into surface contact with a polymer containing a crosslinking agent, a vulcanizing agent or the like. It is possible to reduce the production / manufacturing cost because the number of times that it can be used repeatedly is increased compared to the past, and the power cable or rubber hose having an insulating coating layer made of a crosslinked polyolefin resin can be suppressed. To provide a polyolefin resin composition suitable for applications such as a covering material used in a crosslinking reaction such as a rubber hose or a mandrel for rubber hose production, and an electric power having an insulating coating layer made of a crosslinked polyolefin resin made of the polyolefin resin composition. We provide mandrel for manufacturing rubber hose or coating material used for crosslinking reaction of cable or rubber hose. In the door.

[0007]

In order to solve the above-mentioned problems, the present invention provides a polyolefin resin composition containing a polyolefin resin (A), an amine compound (B) and a phosphite compound (C). It is a thing.

In the above polyolefin resin composition, 100 parts by weight of the polyolefin resin (A) is added to
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 85 mol% or more.
It is preferably a 1-pentene polymer.

It is preferable that the amine compound is 4,4'-bis (α, α-dimethylbenzyl) diphenylamine.

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

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

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 below.

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 kinds of olefins. Examples of the olefin include ethylene, propylene, 1-
Butene, 4-methyl-1-pentene, 1-hexene, 1
Examples include 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 these, when the composition of the present invention is used as a coating material or a mandrel during crosslinking of an insulating coating layer made of a crosslinked polyolefin-based resin of a power cable or during vulcanization during rubber hose production, crosslinking or vulcanization is performed. From the viewpoint of heat resistance to 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,
1-hexene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene and the like α- having 2 to 20 carbon atoms
A copolymer mainly composed of 4-methyl-1-pentene, which is a copolymer with an olefin and usually contains 85% by mole or more, preferably 90% by mole or more of 4-methyl-1-pentene.

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-
p-phenylenediamine, yldol-α-naphthylamine, polymer of 2,2,4-trimethyl-1,2-dihydroquinoline, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine and the like. .. 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 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 (2,2
4-di-t-butylphenyl) phosphite and the like can be mentioned. These may be used alone or in combination of two or more. Of these, tris (2,4-di-t-butylphenyl) phosphite is most preferable when a 4-methyl-1-pentene polymer is used as the polyolefin resin (A).

In the present invention, the phosphite compound (C) to be used or the compounding ratio thereof is appropriately selected according to the polyolefin resin (A) to be used, so that the thermal 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 is used as the phosphite compound (C). When used, if used at a concentration of less than 0.2% by weight, the polyolefin resin composition does not undergo thermal decomposition even at a molding temperature of 280 ° C. or higher during granulation of the obtained polyolefin resin composition and has good thermal stability. It is preferable because the composition can be obtained. this is,
Regarding olefin homopolymers such as polyethylene and polypropylene, and copolymers of ethylene and α-olefins, etc., the gas permeability is low, so that the phosphite compound contained in the pellets of the obtained polyolefin resin composition. While (C) has almost no tendency to hydrolyze over time, 4-methyl-1-pentene-based polymers have high gas permeability, so depending on the phosphite-based compound (C) used, they may be obtained. This is because the phosphite compound (C) contained in the pellets of the obtained polyolefin resin composition may undergo hydrolysis with the lapse of time, and the effect as a heat stabilization aid may not be exhibited with the passage 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) to be blended with the polyolefin resin (A) is such that the amine is 100 parts by weight of the amine resin (A). The total amount of the compound (B) and the phosphite compound (C) is 0.1 parts by weight to 1 part.
A range of 0 parts by weight, preferably 0.3 to 5 parts by weight, and particularly 1 to 4 parts by weight is preferred. Further, the amine compound (B) /
The ratio of the phosphite compound (C) is 1/5 to 5/1.
And the range of 1.5 / 4.5 to 2/4 is particularly preferable.

In addition to the above-mentioned polyolefin resin (A), amine compound (B) and phosphite compound (C), the composition of the present invention may contain various compounding agents, if necessary, for the purpose of the present invention. You may mix | blend in the range which does not exist. Examples of the compounding agent include ultraviolet absorbers, nucleating agents, plasticizers, lubricants, antistatic agents, pigments, dyes, kaolin, powdered fillers such as talc, fismo such as tismo, glass fibers and carbon fibers. Examples include fillers.

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

The composition of the present invention can be molded into various shapes by various conventionally known melt molding methods. Examples of the melt forming method include methods 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, in particular, the use used in contact with a polymer containing a cross-linking agent, for example, a mandrel in a rubber tube production, a coating material, or It is suitable as a coating agent for producing a power cable having an insulating coating layer made of an ethylene polymer.

[0025]

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

(Examples 1 to 3) MFR is 0.5 g / 10
Min (ASTM D1238, 260 ° C, 5kg load),
Density 0.835 g / cm ³ (ASTM D 1505)
100 parts by weight of poly 4-methyl-1-pentene (MX004, manufactured by Mitsui Petrochemical Co., Ltd.) (hereinafter referred to as “TPX-A”), as an amine-based compound 4,
4'-bis (α, α-dimethylbenzyl) diphenylamine and tris (2,4-
Di-tert-butylphenyl) phosphite was blended in the proportions shown in Table 1, mixed at a low speed for 3 minutes in a Henschel mixer, and then melt-kneaded at a temperature of 260 ° C. in a single-screw extruder to prepare a poly Pellets of the 4-methyl-1-pentene composition were prepared. Next, the obtained pellets were supplied to a uniaxial extruder to form a mandrel having an outer diameter of 4 mmφ. Ethylene / vinyl acetate copolymer (hereinafter referred to as "EVA") containing 0.1% by weight of dicumyl peroxide on the outer periphery of this mandrel (Evaflex P-1407, manufactured by Mitsui DuPont Polychemical Co., Ltd.) Was extrusion coated to form a tube of uncrosslinked EVA with a wall thickness of 2.5 mm. After that, the EVA is crosslinked by heating in an air oven set to 150 ° C. for 10 hours,
A tube consisting of Then, after pulling out a tube made of cross-linked EVA from the mandrel, used poly-4-methyl-1
-MFR of powder of poly-4-methyl-1-pentene composition obtained by crushing mandrel consisting of pentene composition
Was measured. The results are shown in Table 1.

Example 4 5 parts by weight of a mixture in which the ratio of amine compound / phosphite compound was 3/1 was mixed with 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 that the above was performed.

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 are mixed in a weight ratio of 80/20 to prepare a poly-4-methyl-1-pentene resin composition, and this resin composition A mandrel was molded in the same manner as in Example 1 using the product. Next, 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 crushed, and the obtained powder of the poly-4-methyl-1-pentene resin composition (PM
The MFR of P-2) was measured. The results are shown in Table 1.

(Example 5) PMP-obtained in Example 4
280 Molding of a mandrel, formation of a crosslinked EVA layer, peeling, crushing of the mandrel were carried out in the same manner as in Example 4 except that a resin composition obtained by blending 80 parts by weight and masterbatch PMP-120 parts by weight was used. A resin composition powder (PMP-3) was obtained and its MFR was measured. The results are shown in Table 1.

(Example 6) Mandrel molding, formation of a crosslinked 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 in place of PMP-2. After crushing, powder of resin composition (PM
P-4) was obtained and its MFR was measured. The results are shown in Table 1.

(Example 7) To 100 parts by weight of TPX-B, 1 part by weight of a mixture obtained by mixing the amine compound and the phosphite compound shown in Table 1 in a ratio of 3: 1 was blended, and the mixture was mixed with a Henschel mixer at a low speed. For 3 minutes, and melt-kneaded at a temperature of 260 ° C. by a uniaxial 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, except that
Molding of a mandrel, formation of a crosslinked EVA layer, peeling and crushing of the mandrel were carried out in the same manner as in Example 1 to obtain a resin composition powder (PMP-5), and its MFR was measured. The results are shown in Table 1.

Comparative Example 1 Poly 4-methyl-1-pentene (TPX-A) containing no amine compound and phosphite compound was used in place of the poly-4-methyl-1-pentene resin composition. Was molded into a mandrel in the same manner as in Example 1, and the outer periphery of the mandrel was extrusion coated to form a crosslinked EVA layer, peeling, and pulverization of the mandrel to obtain a powder of TPX-A. Was measured. The results are shown in Table 1.

(Comparative Example 2) Poly-4-methyl-1- was prepared by adding 1.0 part by weight of the amine compound to 100 parts by weight of TPX-A without adding the phosphite compound.
A mandrel was molded in the same manner as in Example 1 except that the penten composition was used, and the cross-linking agent-containing EVA was extrusion-coated to form a cross-linked EVA layer, peeling, and crushing of the mandrel.
A powder of the poly-4-methyl-1-pentene composition was obtained, and its MFR was measured. The results are shown in Table 1.

(Comparative Example 3) Without adding an amine compound,
Poly (4-methyl-1-) in which 1.0 parts by weight of the phosphite-based compound was added to 100 parts by weight of TPX-A.
A mandrel was molded in the same manner as in Example 1 except that the penten composition was used, and the cross-linking agent-containing EVA was extrusion-coated to form a cross-linked EVA layer, peeling, and crushing of the mandrel.
A powder of the poly-4-methyl-1-pentene composition was obtained, and its MFR was measured. The results are shown in Table 1.

Example 8 A resin was prepared by blending 5 parts of the masterbatch PMP-1 obtained in Example 4 and 95 parts of a poly-4-methyl-1-pentene polymer having an MFR of 26 g / 10 min. A mandrel was formed, a crosslinked EVA layer was formed, peeled, and a mandrel was pulverized in the same manner as in Example 1 except that a composition was prepared and a mandrel was prepared in the same manner as in Example 1 using this resin composition. , A resin composition powder (PMP-5) was obtained, and its MFR was measured. The results are shown in Table 1.

(Examples 9 and 10) In each example, a mandrel was molded and a crosslinked 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. Then, peeling and crushing of the mandrel were carried out to obtain a powder of the resin composition, and its MFR was measured. The results are shown in Table 1.

Reference Examples 1 and 2 In each example, Example 9
Alternatively, the pellets prepared in 10 are placed in a constant temperature and humidity chamber (40 ° C,
(90% relative humidity), after leaving for 7 days, the 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. The results are shown in Table 1.

[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: Emerging Ouchi) * 5 (Judgment method) Classification was performed according to the rank. Judgment MFR ○ <50 △ 50-100 ×> 100

[0040]

The polyolefin resin composition of the present invention is
Even when the surface contact with a polymer containing a crosslinking agent, a vulcanizing agent, etc.
Radical products are significantly suppressed from being generated by the cross-linking agent or vulcanizing agent that migrates from the polymer, and the number of times that they can be used repeatedly is increased compared to the conventional method, thus reducing production and manufacturing costs. Therefore, it has high industrial practicality. Further, a power cable having an insulating coating layer made of the crosslinked polyolefin-based resin of the present invention made of this polyolefin resin composition, or a covering material used during a crosslinking reaction such as a rubber hose, or a rubber hose manufacturing mandrel, It is effective for reduction.

Claims (9)

[Claims] 1. A polyolefin resin composition containing a polyolefin resin (A), an amine compound (B) and a phosphite compound (C). 2. The total content 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 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 polyolefin resin composition according to claim 1, wherein the amine compound is 4,4′-bis (α, α-dimethylbenzyl) diphenylamine. 5. The polyolefin resin composition according to claim 1, wherein the phosphite compound is tris (2,4-di-t-butylphenyl) phosphite. 6. The polyolefin resin composition according to any one of claims 1 to 5, wherein the polyolefin resin composition is used in contact with a polymer containing a crosslinking agent and is used repeatedly. 7. A covering material for producing an electric power cable, comprising the polyolefin resin composition according to any one of claims 1 to 5. 8. A covering material for producing a rubber hose, which comprises the polyolefin resin composition according to claim 1. 9. A mandrel comprising the polyolefin resin composition according to claim 1.