KR20110003435A - Flame-retardant tube and heat-shrinkable tube made by using the same - Google Patents

Abstract

 An object of the present invention is to provide a non-halogen flame-retardant tube and a heat-shrinkable tube that can satisfy flame retardancy, tensile characteristics under high temperature, and heat deformation resistance.

The present invention relates to 5 parts by mass of polyphenylene ether, 5 parts by mass to 80 parts by mass, 20 parts by mass to 95 parts by mass of styrene-based thermoplastic elastomer, and 100 parts by mass of the base polymer of 0% by mass to 70% by mass of the olefin-based polymer. A flame-retardant tube formed by forming a flame-retardant resin composition containing -100 parts by mass, 3 parts by mass to 80 parts by mass of a nitrogen-based organic compound, and 1 part by mass to 20 parts by mass of a polyfunctional monomer in a tubular shape, and then irradiating with an electron beam. After the tube is expanded in diameter under heating, there is provided a heat-shrinkable tube formed by cooling and fixing.

Description

FLAME-RETARDANT TUBE AND HEAT-SHRINKABLE TUBE MADE BY USING THE SAME}

The present invention relates to a tube and a heat shrinkable tube, which are composed of a non-halogen flame retardant material and which are excellent in shape retention under high temperature and tensile properties.

Various parts and internal wirings used in the fields of consumer electronics such as electronic devices, OA devices, audio, video, DVDs, vehicles, ships, etc., are made of flame-retardant tubes for waterproofing, dustproofing, and insulation. It may be protected by tight packaging.

The flame-retardant tube used for such a close packaging is required to be able to pass the UL standard vertical combustion test VW-1 so as not to ignite by the temperature rise of a component. Conventionally, as a flame-retardant material, the flame-retardant resin composition which mix | blended the cancellation system and the chlorine-type flame retardant with the vinyl polymers, such as a soft polyvinyl chloride composition or polyethylene, an ethylene-ethyl acrylate copolymer, and an ethylene-vinyl acetate copolymer, was used, Since such a flame-retardant material has a problem that hydrogen halide gas is generated during incineration, replacement with a so-called halogen-free flame-retardant resin material that does not contain a halogen compound is required.

On the other hand, in tubes used for the protection of cables and wirings such as the above devices, it is required to be excellent in flexibility, and to be able to maintain tensile strength and elongation even at high temperatures. Moreover, processing and a deformation | transformation may be performed in the state which the to-be-packed object was inserted in the tube. Therefore, the tube used for these uses must not only satisfy the above-mentioned flame retardancy, but also meet the UL standard regarding tensile strength, elongation and heat deformation under high temperature.

As a non-halogen-type flame retardant resin material, the material which mix | blended metal hydroxide type flame retardants, such as aluminum hydroxide and magnesium hydroxide, with polyethylene, an ethylene-ethyl acrylate copolymer, an ethylene-vinyl acetate copolymer, is put into practical use. However, if the metal hydroxide flame retardant is to pass the UL standard vertical combustion test VW-1, it must be added in a large amount, whereas when the metal hydroxide flame retardant is mixed in a large amount, the mechanical properties are deteriorated, and thus the flame retardancy and the mechanical properties are Can't achieve compatibility.

As a tube having both mechanical properties and flame retardancy using a metal hydroxide flame retardant, for example, JP-A-7-145288 (Patent Document 1) includes a base polymer 100 containing an ethylene-vinyl acetate-based copolymer. The tube which comprised the flame-retardant resin composition containing 150 mass parts-230 mass parts of metal hydrates, and 0.1 mass part-20 mass parts of foaming agents with respect to a mass part, and also bridge | crosslinked is disclosed.

The flame-retardant tube contains a foaming agent, so that even when a large amount of metal hydroxide-based flame retardant is blended, the tensile strength of 0.7 kg / mm 2 or more and 100% or more can be ensured. However, Patent Literature 1 does not evaluate tensile properties and strength under high temperatures, and these flame retardant materials cannot satisfy UL standards in terms of heat resistance, heat deformation resistance, and the like.

Phosphorus-based flame retardants such as phosphate esters are also known, but the flame retardant effect thereof is not sufficient, and there is a problem in that satisfactory flame retardancy cannot be obtained unless blended in a large amount.

In order to reduce content of a flame retardant, development of the non-halogen-type flame retardant material which uses a flame retardant polymer as a base polymer is advanced.

For example, the flexible noryl sold by SABIC Innovative Plastics Japan Co., Ltd. (formerly Nippon GE Plastics) uses a mixture of polyphenylene ether and styrene resin or styrene thermoplastic elastomer as the base polymer. A phosphate ester flame retardant is mix | blended. Based on the higher flame retardancy of polyphenylene ether than polyolefin resin, the amount of flame retardant added can be reduced, and the decrease in tensile properties due to the large amount of flame retardant can be suppressed. It is used. However, if it is not sufficient in terms of heat resistance, and is particularly intended to be used as a heat shrink tube for tight packaging, the shape may not be maintained during the diameter expansion treatment or may be melted in the heat shrink process or the processing of the packaged object.

In addition, Japanese Patent Application Laid-Open No. 2007-197615 (Patent Document 2) uses a polyphenylene ether resin and a thermoplastic elastomer as a base polymer without substantially containing a phosphorus flame retardant and using a nitrogen flame retardant. Moreover, the non-halogen flame-retardant resin composition which mix | blended the crosslinking adjuvant is proposed.

[Patent Document 1] Japanese Patent Application Laid-Open No. 7-145288

[Patent Document 2] Japanese Patent Application Laid-Open No. 2007-197615

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

However, the non-halogen flame-retardant resin composition disclosed in patent document 2 intends use as a covering material of electric wires and cables, and it is not evaluated as a tube. When applied to a tube, it is difficult to satisfy the UL standard with respect to shape retention after the diameter expansion treatment under heating, tensile properties under high temperature, and heat deformation resistance, and further improvement is required.

This invention is made | formed in view of such a situation, Comprising: It aims at providing the non-halogen-type flame-retardant tube which can satisfy flame retardance, the tensile characteristic under high temperature, and heat-strain resistance.

Means for Solving the Problem

The flame-retardant tube of this invention is 5 mass%-80 mass% of polyphenylene ether, 20 mass%-95 mass% of styrene-type thermoplastic elastomer, and phosphorus type per 100 mass parts of base polymers of 0 mass%-70 mass% of an olefinic polymer. A flame-retardant resin composition containing 5 parts by mass to 100 parts by mass of a flame retardant, 3 parts by mass to 80 parts by mass of a nitrogen-based organic compound, and 1 part by mass to 20 parts by mass of the polyfunctional monomer is molded into a tubular shape, and then subjected to electron beam irradiation.

As said olefin polymer, the copolymer of an olefin and an ethylenically unsaturated monomer is preferable, More preferably, the block copolymer containing the polymer block of a polyolefin block and an ethylenically unsaturated monomer, or an olefin and an ethylenically unsaturated monomer A graft copolymer obtained by grafting a side chain of a copolymer or polyolefin with a vinyl polymer or an ethylene-? Olefin copolymer.

Moreover, in a base polymer, when the content rate of the said olefin type polymer is 0 mass%, it is preferable that they are 5 mass%-80 mass% of polyphenylene ether, and 95 mass%-20 mass% of styrene-type thermoplastic elastomer.

It is preferable that the said polyfunctional monomer is a monomer which has a carbon-carbon double bond, It is preferable that the said phosphorus flame retardant is ester or an ammonium salt of condensed phosphoric acid, The said nitrogen type organic compound contains an amino group and / or an imide unit It is preferable that it is a compound.

The heat shrinkable tube of the present invention is formed by cooling and fixing the tube of the present invention after expanding the diameter under heating.

Effect of the Invention

The flame-retardant tube of the present invention is compatible with tensile properties and flame retardancy, and excellent heat resistance and heat deformation resistance can be obtained by a crosslinking effect by electron beam irradiation. Because of such excellent characteristics, the heat-shrinkable tube of the present invention obtained by cooling and fixing the flame-retardant tube of the present invention after expanding the diameter under heating, has excellent tensile properties, flame retardancy, heat resistance, and heat resistance similarly to the flame-retardant tube of the present invention. It has deformability.

BEST MODE FOR CARRYING OUT THE INVENTION

EMBODIMENT OF THE INVENTION Although embodiment of this invention is described below, it should be thought that embodiment disclosed this time is not an illustration limited at all points. The scope of the present invention is indicated by the scope of the claims, and it is intended that the modifications include the meaning of the scope of the claims and the equivalents and all modifications within the scope.

<Flame retardant resin composition>

First, the resin composition used as the material of the flame-retardant tube of this invention is demonstrated.

The resin composition used as a flame-retardant resin tube material of this invention is 5 mass%-80 mass% of polyphenylene ether resin, 20 mass%-95 mass% of styrene-type thermoplastic elastomer, and 0 mass%-70 mass of olefin polymer Per 100 parts by mass of the base polymer, 5 parts by mass to 100 parts by mass of the phosphorus flame retardant, 3 parts by mass to 80 parts by mass of the nitrogen-based organic compound, and 1 part by mass to 20 parts by mass of the polyfunctional monomer.

(1) Base Polymer

The base polymer composition of the flame retardant resin composition is 5% by mass to 80% by mass of polyphenylene ether resin, 20% by mass to 95% by mass of styrene-based thermoplastic elastomer, and 0% by mass to 70% by mass of an olefin-based polymer. When it does not contain a polymer, it is preferable that they are 5 mass%-80 mass% of polyphenylene ether resin, and 95 mass%-20 mass% of a styrene thermoplastic elastomer.

Polyphenylene ether is resin obtained by carrying out oxidative polymerization of 2, 6-cylenol synthesize | combined using methanol and a phenol as a raw material. As the polyphenylene ether resin used in the present invention, not only polyphenylene ether but also modified polyphenylene ether modified with maleic anhydride or the like, or polystyrene resin, polyamide resin, polyester resin and polypropylene resin And melt-blended polymer alloys. Since the polymer alloy of polyphenylene ether resin and polystyrene is excellent in compatibility with a styrene thermoplastic elastomer, and extrusion processability improves, it is used preferably.

The styrenic thermoplastic elastomer used in the present invention is a block copolymer of a polystyrene block and a rubber component block. Diblock copolymers and triblock copolymers of rubber component blocks such as polybutadiene and polyisoprene and polystyrene blocks, hydrogenated polymers or partially hydrogenated polymers thereof, maleic anhydride modified elastomers, epoxy modified elastomers, and aromatic vinyl thermoplastics Elastomers and the like can be used. Specifically, styrene-isobutylene-styrene copolymer, styrene-ethylene copolymer, styrene-ethylene propylene copolymer, styrene-ethylene butylene-styrene copolymer, styrene- ethylene propylene styrene copolymer, styrene- isoprene air Copolymer, styrene-ethylene-isoprene copolymer, styrene-isoprene-styrene copolymer, styrene-butadiene copolymer and the like.

Such styrene-based thermoplastic elastomers are useful for improving tensile fracture elongation. The styrene content in the styrene-based thermoplastic elastomer is preferably 10% by weight to 70% by weight in terms of elongation and compatibility with polyphenylene ether.

The olefin polymer used in the present invention refers to random copolymers, block copolymers, and graft copolymers of olefins and ethylenically unsaturated monomers, in addition to polymers of one or two or more kinds of olefins.

As a block copolymer, the copolymer which has a polymer block which consists of a polyolefin block and an ethylenically unsaturated monomer is mentioned, A polyolefin block is not limited to the polymer block of one type of olefin monomer, Even if it is a polymer block of 2 or more types of olefin monomers, good. Moreover, in addition to superposing | polymerizing and forming an olefin monomer, a polyolefin block may be formed by hydrogenation after superposition | polymerization of the monomer which has several double bonds, such as a diene monomer and a triene monomer.

Also about the polymer block of an ethylenically unsaturated monomer, not only the polymer block which consists of one type of ethylenically unsaturated monomer, but the polymer block of two or more types of copolymerizable monomers may be sufficient.

Examples of the graft copolymers include polyolefins, random copolymers of olefins and ethylenically unsaturated monomers, and block copolymers. Can be mentioned.

Ethylene, propylene, 1-butene, isobutene, pentene, hexene, etc. can be used as an olefin unit which comprises the said polyolefin block or polyolefin.

Examples of the ethylenically unsaturated monomers include unsaturated acids such as acrylic acid, methacrylic acid, methylmethacrylic acid, crotonic acid, (anhydride) phthalic acid, (maleic anhydride) and (anhydrous) itaconic acid or monoalkyl esters thereof having 1 to 8 carbon atoms. Or esters of glycidyl alcohol; Vinyl esters of fatty acids such as vinyl formate, vinyl acetate, vinyl propionate and vinyl valerate; Aromatic vinyl compounds such as styrene and allylbenzene; Vinyl cyanide, such as acrylonitrile, acrylonitrile styrene, and methacrylonitrile, etc. can be used.

Therefore, specific examples of the olefin polymer of the present invention include polyethylene such as ultra low density polyethylene, low density polyethylene, medium density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene-α olefin copolymer, olefin thermoplastic elastomer, ethylene Vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, styrene-ethylene butylene-olefin crystal block copolymer, main chain A polyolefin (e.g., polyethylene or polypropylene) or a copolymer of an olefin and an ethylenically unsaturated monomer (e.g., ethylene-glycidyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene Ethylene acrylate-maleic anhydride copolymer) Vinyl polymers (e.g., neutralization of polystyrene, methyl polymethacrylate, or acrylonitrile styrene copolymer, polyvinyl acetate, methyl polyacrylate, polyacrylate, butyl polyacrylate, polyacrylic acid, etc.) or Ethylene-α-olefin copolymer (e.g., ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-propylene rubber , Ethylene acrylic rubber, ethylene-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene ionomer or these anhydrides And graft copolymers obtained by grafting a polymer modified with an acid or the like). Such an olefinic polymer can also exhibit flame retardancy similarly to the styrene-based thermoplastic elastomer.

The content of each of the polymers (polyphenylene ether resin, styrene thermoplastic elastomer, olefin polymer) in the base polymer is 5% by mass to 80% by mass of polyphenylene ether resin, and 20% by mass to 20% by mass of styrene thermoplastic elastomer. 95 mass% and 0 mass%-70 mass% of olefin polymers. When content rate of an olefin type polymer is 0 mass%, it is preferable that it is polyphenylene ether resin: styrene-type thermoplastic elastomer = 5: 95-80: 20.

If the content of the olefin polymer in the base polymer is more than 70% by mass, the content of the styrene-based thermoplastic elastomer, which is more excellent in flame retardancy, must be reduced, and the flame retardancy tends to decrease. Moreover, when the content rate of polyphenylene ether resin becomes too small and the content rate of styrene-type thermoplastic elastomer becomes too large, it exists in the tendency which cannot satisfy flame retardance. On the other hand, when the content ratio of polyphenylene ether resin becomes too large and the content ratio of styrene thermoplastic elastomer and olefin polymer becomes too small, there is a tendency that the tensile properties cannot be satisfied.

(2) phosphorus flame retardant

As a phosphorus flame retardant used by this invention, Orthophosphoric acid ester; Organic esters or ammonium salts of cross-linked structures having branched PO ₄ groups in a molecule such as pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid, ultraphosphoric acid, or condensed phosphoric acid in which phosphates are bound in a linear or cyclic form; Phosphonic acid esters; Phosphinic acid ester, and the like. Of these, organic esters or ammonium salts of condensed phosphoric acid are preferably used, and may have an OH group in the molecule.

Specifically, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresidyl phosphate, trixenyl phosphate, credil phenyl phosphate, credyl 2,6-xylenyl phosphate and 2-ethylhexyl diphenyl phosphate , 1,3-phenylenebis (diphenylphosphate), 1,3-phenylenebis (di-2,6-xylenylphosphate), 1,2-phenylenebis (di-2,6-xylene Ylphosphate), bisphenol Abis (diphenyl phosphate), resorcinol bis diphenyl phosphate, octyl diphenyl phosphate, diethylene ethyl ester phosphate, dihydroxy propylene butyl ester phosphate, ethylene disodium ester phosphate, t-butylphenyl Diphenylphosphate, bis- (t-butylphenyl) phenylphosphate, tris- (t-butylphenyl) phosphate, isopropylphenyldiphenylphosphate, bis- (isopropylphenyl) diphenylphosphate, tris- (isopropylfe Phosphoric acid ester, such as nil) diphenyl phosphate, tris- (isopropylphenyl) phosphate, tris (2-ethylhexyl) phosphate, tris (butoxyethyl) phosphate, and trisisobutyl phosphate; Methylphosphonic acid, dimethyl methylphosphonic acid, diethyl methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, 2-methyl-propylphosphonic acid, t-butylphosphonic acid, 2,3-dimethylbutylphosphonic acid, Phosphonic acid esters such as octylphosphonic acid and phenylphosphonic acid; Phosphinic acid esters such as diethylphosphinic acid, methylethylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid and diphenylphosphinic acid; Cyclic organophosphates such as diisodecyl pentaerythritol diphosphite, 9,10-dihydro-9oxa-10-phosphenanthrene-10-oxide, HCA-HQ, SANKO-220, M-Ester, BCA, etc. Compound, ammonium polyphosphate, melamine phosphate, melamine phosphate, melamine pyrophosphate, guanyl urea phosphate, guanidine phosphate, adecastab FP2100J or adecastab FP2200 sold by Adeka Co., Ltd., FLMESTAB NOR116FF Phosphorus and nitrogen compounds, such as these, are mentioned. These phosphorus flame retardants can be used 1 type or in mixture of 2 or more types.

As the above phosphorus-based compound, a surface treated with melamine, melamine cyanurate, fatty acid, silane coupling agent, or the like may be used. At the time of mixing with the base polymer, the surface treatment may be performed by an integral blend containing a surface treating agent.

The phosphorus flame retardant contains 5 parts by mass to 100 parts by mass per 100 parts by mass of the base polymer. If it is less than 5 mass parts, it will become difficult to ensure flame retardance, and if it exceeds 100 mass parts, heat deformation resistance will not be satisfied.

(3) nitrogen-based organic compounds

As the nitrogen-based organic compound, derivatives or adducts such as cyanuric acid, melamine and triazine are preferably used, and specifically, melamine resin, melamine cyanurate, isocyanuric acid, isocyanurate derivatives, adducts and the like. Can be used. Of these, melamine and melamine cyanurate containing amino groups and / or imide units in the molecule are preferably used. Such nitrogen-based organic compounds are not well known mechanisms, but in combination with a phosphorus-based flame retardant, these nitrogen-based organic compounds ensure a level of flame resistance that can pass the UL standard VW-1 test without causing a significant decrease in tensile properties. It becomes possible.

Examples of the nitrogen-based organic compounds described above include silane coupling agents such as aminosilane coupling agents, vinyl silane coupling agents, epoxy silane coupling agents, and methacryloxysilane coupling agents; It may be surface-treated with higher fatty acids, such as stearic acid and oleic acid. It may be surface-treated beforehand, and may be surface-treated by mix | blending a surface treating agent at the time of mix | blending and mixing with a base polymer and another component.

The nitrogen-based organic compound contains 3 parts by mass to 80 parts by mass per 100 parts by mass of the base polymer. If it is less than 3 mass parts, the flame-retardant effect by combined use with a phosphorus compound cannot be acquired, and when it is more than 80 mass parts, tensile fracture elongation will fall and initial tensile property will also be unable to be ensured.

(4) polyfunctional monomers

As a polyfunctional monomer, a monoacrylate type, a diacrylate type, a triacrylate type, a monomethacrylate type, a dimethacrylate type, a trimethacrylate type, a triallyl isocyanurate type, a triallyl cyanurate Monomers having a plurality of carbon-carbon double bonds in molecules such as a rate system can be preferably used. From the point of crosslinking | crosslinking, trimethacrylate type monomers, such as a trimethylol propane trimethacrylate, are used preferably. Such a polyfunctional monomer can be subjected to vinyl polymerization reaction with the diene moiety contained in the base polymer by electron beam irradiation, and can be expected to be useful for improving physical properties under high temperature.

The polyfunctional monomer is contained 1 part by mass to 20 parts by mass per 100 parts by mass of the base polymer. If it is less than 1 mass part, a crosslinking effect will not be acquired, the fall of the tensile characteristic under high temperature will be remarkable, and the thermal deformation under high temperature will also be large. On the other hand, when it exceeds 20 mass parts, there exists a possibility that an unreacted monomer may remain, and it may become a cause of a flame retardance fall.

(5) other ingredients

Metal hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, antimony trioxide, zinc stannate, hydroxy zinc stannate, zinc borate, boron phosphate, etc., without impairing flame resistance, heat resistance deformation, tensile properties, and volume resistivity You may add a flame retardant.

The flame-retardant resin composition used in the present invention also includes other thermoplastic elastomers such as polyolefin thermoplastic elastomers, polyester thermoplastic elastomers, polyurethane thermoplastic elastomers, etc., for the purpose of improving various properties within a range that does not impair flame retardancy or mechanical strength; Styrene-based resins such as impact-resistant polystyrene, acrylonitrile-styrene resin and ABS resin; Rubbers such as EPDM, ethylene acrylic rubber, acrylic rubber and nitrile rubber; Various polymers, such as nylon, polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, and polyphenyl sulfide, may be blended.

Moreover, you may mix | blend various additives, such as antioxidant, a lubricating agent, a processing stabilizer, a coloring agent, a foaming agent, a reinforcing agent, a filler, a vulcanizing agent, a metal deactivator, and a silane coupling agent.

It can prepare by mix | blending the above components by predetermined amount and mixing using known melt mixers, such as a single screw extrusion mixer, a pressurized kneader, and a Benbury mixer.

<Flame retardant tube>

The flame-retardant tube of this invention irradiates an electron beam to the tubular molded article formed by extruding the flame-retardant resin composition which has the said composition to tubular shape.

By electron beam irradiation, it is thought that a base polymer crosslinks through a polyfunctional monomer. And it is thought that by crosslinking, the fall of the elastomeric property at the high temperature of a thermoplastic elastomer can be suppressed and the tensile characteristic under high temperature can be ensured by this. In addition, by partially meshed structuring by crosslinking, thermal deformation is also suppressed, and the shape can be maintained without melting even by high temperature treatment.

Although the size of a flame retardant tube is not specifically limited, Usually, thickness 1.0 mm or less is preferable, More preferably, it is 0.8 mm or less.

In extrusion molding, it is preferable to prepare a flame-retardant resin composition once, to manufacture the resin pallet which has a predetermined composition, and to provide this resin pallet to an extrusion molding machine.

Although the kind of extruder is not specifically limited, A screw type and a non-screw type are good, but it is a screw type preferably. Although the kind of screw is not specifically limited, either, It is preferable that ratio (L / D) of the total length L and the cylinder hole diameter D is about 24-28 normally.

Examples of the electron beam to be used include accelerated electron beams, γ-rays, X-rays, α-rays, ultraviolet rays, and the like. Accelerated electron beams are most preferably used from the viewpoint of industrial use such as simplicity of source use, transmission thickness of ionizing radiation, and speed of crosslinking treatment.

What is necessary is just to set the acceleration voltage of an acceleration electron beam suitably with the thickness of a tube layer and the composition of the resin composition which is a tube material. For example, in a tube with a thickness of 0.2 mm to 0.4 mm, the acceleration voltage is selected between 300 keV and 3 MeV. Although it does not specifically limit as irradiation dose, Usually, it is 20 kPa-500 kPa.

<Heat shrink tube>

The heat-shrinkable tube of this invention cools and fixes the flame-retardant tube of the said invention after diameter expansion under heating.

The diameter expansion treatment is obtained by expanding the tubular molded article to a predetermined external diameter by introducing compressed air into the tube in a state where the tubular molded article is heated to a temperature equal to or more than the softening point of the base polymer, and then cooling to fix the shape. Can be. The diameter expansion is preferably about 2 to 4 times the original inner diameter.

The tube of the present invention is excellent in heat resistance, can be expanded in diameter without melting even at a high temperature, and can maintain a diameter-expanded shape.

Since the heat shrink tube of this invention has the outstanding heat resistance, it can shrink | contract to original shape again without melt | fusing by heat processing of about a softening point, specifically 100 degreeC-250 degreeC again. Accordingly, the packaged object can be tightly packaged by heat treatment at 100 ° C to 250 ° C with a packaged object such as an electronic component to be protected or packaged or a cable inserted into the tube.

The tube contracted by the heat shrink treatment has the same tensile characteristics as the tube before the diameter expansion treatment, and can maintain the tensile characteristics required by the UL standard even under heating conditions. Therefore, the heat-shrinkable tube of this invention can be used as a protective packaging material for the purpose of moisture-proof, waterproof, dustproof, insulation, etc. of the to-be-packed object, such as an electronic component and a cable.

Best Mode for Carrying Out the Invention An embodiment will be described. The examples do not limit the scope of the invention.

In addition, in a following example, "part" means a "mass part", unless there is advance approval.

[Measurement Evaluation Method]

First, the method of measurement evaluation performed in the following example is demonstrated.

(1) tensile properties

The tube was subjected to a tensile test (tension rate = 500 mm / min, mark distance = 20 mm), and tensile strength (MPa) and tensile elongation at break (%) were measured on each of three samples, and their average value was measured. Was obtained. Tensile strength of 10.4 MPa or more and 150% or more of tensile elongation at break are pass levels.

(2) heat resistance

After leaving a tube for 168 hours (7 days) in the gear oven set to 158 degreeC, the tension test of (1) is performed. It is a pass level if it is 7.3 Mpa or more of tensile strength after heat processing, and 100% or more of elongation.

(3) flame retardant

The VW-1 vertical flame retardant test described in UL standard 224 was performed on five samples. The test is digested within 60 seconds when 15 seconds of ignition is repeated five times, and the cotton wool on the bottom is not burned down by the combustion drops, and the kraft paper attached on the upper part of the sample burns, Pressing or not is a pass level, and it was set as "OK." When even one point did not become a pass level among 5 points | pieces, it set as "NG" failed.

(4) heat resistant deformation

It carried out according to JIS C3005. A metal rod having an internal diameter of 7.0 mm was inserted into the tube, placed in a thermostat set at 140 ° C, and preheated for 1 hour. After 1 hour, a jig of φ9.5 mm was pressed on the tube to carry a load of 500 g. The thickness of the tube layer after leaving for 1 hour under load was measured, and the residual ratio with respect to the thickness before deformation was computed. If the residual ratio is 50% or more, it is the pass level.

In the case of evaluating the heat shrink tube subjected to the diameter expansion-heat shrinkage treatment, at the time of heat shrinkage treatment, a metal rod insertion tube is inserted in advance by inserting a metal rod having an internal diameter of 7.0 mm, and the metal rod insertion tube is preheated in a thermostat. , And the thickness after leaving for 1 hour under load was measured.

(5) heat shock test

In the gear oven set to 250 degreeC, after heating a tube for 4 hours, it extracted, it wound up on the metal rod of the same diameter as the tube outer diameter, and observed the appearance of the tube. If there is no change in appearance, it is a pass level and it was set as "OK."

[Preparation of flame-retardant resin composition and making of tube]

Example Tube No. 1 to 15:

As shown in Table 1, polyphenylene ether resin 1 or 2, styrene thermoplastic elastomer 1 or 2, olefin polymer 1-4, phosphorus compound 1-3, nitrogen compound 1 or 2, polyfunctional monomer 1 or 2 was mix | blended with the quantity shown in Table 1. Further, 0.5 parts of oleic acid amide, pentaerythritol-tetrakis [3- (3,5-di-t-butyl) relative to 100 parts of the base polymer (total of polyphenylene ether resin, styrene thermoplastic elastomer and olefin polymer) -4-hydroxyphenyl) propionate] 3 parts of the mixture, and the strand of the kneaded product obtained by kneading with a twin-screw mixer set at a die temperature of 280 ° C were used as a pallet maker. The resin pallet of 1-15 was obtained.

Resin composition No. prepared Using a pellet of 1 to 15, a tubular molded article having an internal diameter of 7.0 mm and a thickness of 0.3 mm was extruded using a melt extruder (45 mmφ, L / D = 24, compression ratio 2.5, full flight type) at an extrusion temperature of 260 ° C. Molded. The obtained tube was irradiated with an electron beam of 250 kV with an accelerating voltage of 2.0 MeV. Tubes 7 to 15 were subjected to diameter expansion-heat shrinkage treatment to obtain tube No. 1-15 were produced. No. 7 to 15 correspond to the heat shrinkage of the heat shrink tube.

Herein, the diameter expansion-heat shrinkage treatment is performed by standing in a thermostatic bath set at 160 ° C. for 3 minutes to preheat it, expanding the diameter to an inner diameter of 14 mm by introducing compressed air into the tube, and immediately extracting from the thermostat and cooling by water. Fix it. The heat shrink tube obtained by the diameter expansion treatment is heated at 160 ° C. for 3 minutes to shrink to the original size (inner diameter of 7 mm).

Tube No. About 1-15, the tensile characteristic, heat resistance, flame retardance, heat deformation resistance, and the heat shock test were evaluated based on the said evaluation method. The results are shown in Table 1.

Comparative Example Tube No. 16-26:

Each resin composition No. prepared similarly to the said Example except having changed the compounding composition of the resin composition as shown in Table 2. 16-26 resin pallets were extrusion-molded similarly to the said Example, and the tubular molded article of 7.0 mm of internal diameter and 0.3 mm of thickness was obtained. No. The tubes 16 to 21, 23, and 26 were irradiated with electron beams having an acceleration voltage of 2.0 MeV by the amounts shown in Table 2, and No. About the tubes 16-21, 23, 26, the diameter expansion-heat shrinkage process similar to the said Example was performed.

Tube No. produced as described above. About 16-26, based on the said evaluation method, the tensile characteristic, heat resistance, flame retardance, heat deformation, and the heat shock test were measured and evaluated. The measurement results are shown in Table 2.

In addition, the compound of Table 1 and Table 2 is as follows.

* 1: Polyphenylene ether 1: Mitsubishi Engineering Plastics Co., Ltd. product PX-100L

* 2: Polyphenylene ether 2: Xyron X9102 made by Asahi Kasei Chemical Co., Ltd.

This is a fully compatible polymer alloy of polyphenylene ether resin and polystyrene resin.

* 3: Styrene-based elastomer 1: Toughtec H1041 made by Asahi Kasei Chemical Co., Ltd.

This is a styrene-ethylenebutene-styrene copolymer and has a styrene content of 30% by mass.

* 4: Styrene-based elastomer 2: SOE-SS9000 manufactured by Asahi Kasei Chemical Co., Ltd.

This is hydrogenated SBR.

* 5: Phosphorus-based compound 1: MELAPUR200 manufactured by Ciba

This is melamine polyphosphate, having an average particle diameter of 4 m, phosphorus content of 13 mass%, and nitrogen content of 43 mass%.

* 6: Phosphorus-based compound 2: PX-200 from Daihachi Chemical Co., Ltd.

It is a condensed phosphate ester and phosphorus content is 9.0 mass%.

* 7: Phosphorus compound 3: BCA by Sanko Corporation

This is a cyclic organophosphorus compound.

* 8: nitrogen compound 1: STABIACE MC-5S manufactured by Sakai Chemical Co., Ltd.

This is melamine cyanurate (average particle diameter 0.5 mu m).

* 9: nitrogen compound 2: melamine manufactured by Mitsubishi Kagaku Corporation

* 10: Multifunctional monomer 1: NK ester TMPT trimethylol propane trimethacrylate by Shin-Nakamura Kagaku Co., Ltd. make.

* 11: Multifunctional monomer 2: Nippon Kaysei Co., Ltd. make (triallyl isocyanurate)

* 12: Olefin-based polymer 1: Rexpearl A1150 manufactured by Nippon Polyethylene. This is an ethylene-ethyl acrylate copolymer [15 mass% of ethyl acrylate content, MFR 0.8 (190 degreeC, load 2.16 kg)].

* 13: Olefin polymer 2: Elvaloy 1125AC by Dupont Corporation. This is an ethylene-methyl acrylate copolymer [27 mass% of methyl acrylate rates, MFR 0.6 (190 degreeC, load 2.16 kg)].

* 14: Olefin-based polymer 3: Dynaron 4600P manufactured by JSR Corporation. This is a styrene-ethylenebutylene-olefin crystal block copolymer.

* 15: Olefin-based polymer 4: Modifier A1100 manufactured by Nippon Yushi Corporation. This is a polymer whose main chain is low density polyethylene and is grafted with polystyrene.

Reference Tube No. 31, 32:

The flexible noryl resin compound manufactured by SABIC Innovative Plastics Co., Ltd. was extruded in the same manner as in the above example to obtain a tubular molded article. The obtained tube was irradiated with an electron beam in the same manner as in Example 1, and the tube was subjected to diameter expansion-heat shrinkage treatment. 31 and 32 were produced. About the created tube, tensile characteristics, heat resistance, flame retardancy, heat deformation resistance, and heat shock were measured and evaluated based on the said evaluation method. The results are shown in Table 3.

No. 1-9 are 5 mass parts-100 mass parts of phosphorus flame retardants per 100 mass parts of base polymers containing 5 mass%-80 mass% of polyphenylene ether, and 95 mass%-20 mass% of styrene thermoplastic elastomers It is a tube crosslinked by electron beam irradiation using the flame-retardant resin composition containing 3 mass parts-80 mass parts of compounds, and 1 mass part-20 mass parts of polyfunctional monomers, and is tensile property, flame retardance, heat resistance, heat deformation resistance, heat The shock test was a pass level. In addition, 10-15 is a case where the blend of 20 mass%-40 mass% of polyphenylene ether, 20 mass%-30 mass% of styrene thermoplastic elastomer, and 40 mass%-50 mass% of olefinic polymer is used as a base polymer, In all, the tensile properties, flame retardancy, heat resistance, heat deformation resistance, and heat shock test of the tube crosslinked by electron beam irradiation were pass levels. No. 7, 8 and 9 are No. respectively. The resin composition which is a material with the tube of 1, 3, 6 is the same. Comparing the evaluation results of the corresponding tubes, respectively, it can be seen that even after the diameter expansion-heat shrinkage treatment, the characteristics hardly decrease, and the characteristics before the treatment are maintained.

No. 24 is a tube which has not been irradiated with an electron beam, No. 22 is a tube composed of a resin composition containing no polyfunctional monomer. In all, the tube melted in the heat resistance test and the heat shock test, and the shape could not be maintained. Since they do not perform electron beam irradiation, or do not contain a polyfunctional monomer, they cannot obtain the crosslinking effect by electron beam irradiation, and cannot endure high temperature heat processing. Therefore, it cannot be used as a heat shrink tube which presupposes high temperature heat processing.

The polyfunctional monomer content is too high (No. 23), the content of polyphenylene ether in the base polymer is too low (No. 17), the content of phosphorus flame retardant is too small (No. 18), or the polyolefin type When there was too much resin (No. 26), flame retardance could not be satisfied.

On the other hand, even if the content ratio of polyphenylene ether and styrene thermoplastic elastomer in a base polymer is appropriate, it contains a suitable phosphorus flame retardant and a polyfunctional monomer, and crosslinking process by electron beam irradiation is carried out, 3 mass parts of nitrogen compounds are carried out. In the case of containing (No. 6), the flame retardancy could be satisfied, but in the case of containing only 1 part by mass of the nitrogen-based compound (No. 21), the flame retardancy could not be satisfied. This shows that the combination of a nitrogen compound and a phosphorus flame retardant is useful for ensuring flame retardancy.

By increasing the content of the phosphorus flame retardant (No. 19) or by increasing the content ratio of polyphenylene ether in the base polymer (No. 16), it is possible to satisfy the flame retardancy even without containing a nitrogen compound. The amount of deformation due to the heat treatment increases with increasing the content of (No. 19), and with the increase of the content ratio of polyphenylene ether (No. 16), the elongation decreases excessively by high temperature heating, and the heat resistance and heat shock test The pass level could not be secured.

In addition, In 25, the content ratio of the polyphenylene ether and the styrene-based thermoplastic elastomer in the base polymer is within the scope of the present invention, and a proper amount of the nitrogen-based compound and the polyfunctional monomer is blended to obtain a crosslinking effect. Although it was a pass, elongation under high temperature and heat distortion resistance were inferior. Meanwhile, No. 21 reduces the amount of the nitrogen compound, increases the content of the phosphorus compound, and obtains the crosslinking effect. Although it is a level which cannot satisfy flame retardance in all, it turns out that a phosphorus compound of 100 parts or less is useful for ensuring extension | stretching under high temperature, and heat-strain resistance.

In addition, 4 and No. From the comparison of 19, in the case where the base polymer containing no olefinic polymer was used, the content ratio of polyphenylene ether and styrene elastomer in the base polymer (polyphenylene) in order to maintain the flame retardancy, heat resistance and strength at high temperature (polyphenylene It is understood that it is effective to suppress the total amount of the flame retardant by using ether: styrene-based elastomer) in the range of 5:95 to 80:20 and using a nitrogen compound and a phosphorus compound together.

No. 20 and No. From the comparison of 5, when content of a nitrogen type compound increases, elongation tends to fall, and when the content of a nitrogen type compound is 90 mass parts, the initial tensile characteristic also failed to ensure a pass level. From the point of tensile properties, it is understood that it is necessary to consider the content balance of the phosphorus compound and the nitrogen compound.

In addition, from Table 3, when the flexible noryl is used, the flame retardancy in the tube cannot be satisfied, and the crosslinking effect cannot be obtained even by irradiation with electron beams. And deformation after high temperature treatment was also large.

The tube and the heat shrink tube of the present invention are non-halogen type tubes that can satisfy the flame retardancy of the VW-1 test of the UL standard. Furthermore, since they can satisfy the tensile properties, strength, and heat resistance of the UL standard even at high temperatures. , Electronic devices, OA devices, audio, video, DVD, Blu-ray, and other consumer electronic devices, tubes used for the protection of internal wiring and parts of vehicles, ships, etc., as well as heat-shrinkable tubes for tight packing and protection. .

Claims (9)

5 mass parts-100 mass mass of phosphorus flame retardant per 100 mass parts of polyphenylene ether 5 mass%-80 mass%, 20 mass%-95 mass% of styrene-type thermoplastic elastomer, and 0 mass%-70 mass% of olefinic polymer A flame-retardant tube formed by forming a flame-retardant resin composition containing 3 parts by mass to 80 parts by mass of a nitrogen-based organic compound and 1 part by mass to 20 parts by mass of a polyfunctional monomer in a tubular shape, and then irradiating with an electron beam. The flame-retardant tube according to claim 1, wherein the base polymer is 5% by mass to 80% by mass of polyphenylene ether and 95% by mass to 20% by mass of styrene-based thermoplastic elastomer. The flame retardant tube according to claim 1, wherein the olefin polymer is a copolymer of olefin and an ethylenically unsaturated monomer. The flame retardant tube of claim 3, wherein the copolymer is a block copolymer comprising a polyolefin block and a polymer block of ethylenically unsaturated monomers. The flame retardant tube according to claim 3, wherein the olefin polymer is a graft copolymer obtained by grafting a copolymer of an olefin and an ethylenically unsaturated monomer or a side chain of a polyolefin with a vinyl polymer or an ethylene-? Olefin copolymer. The flame-retardant tube according to any one of claims 1 to 5, wherein the multifunctional monomer is a monomer having a carbon-carbon double bond. The flame retardant tube according to any one of claims 1 to 6, wherein the phosphorus flame retardant is an ester or an ammonium salt of condensed phosphoric acid. The flame-retardant tube according to any one of claims 1 to 7, wherein the nitrogen-based organic compound is an amino group and / or an imide unit-containing compound. The heat-shrinkable tube formed by cooling and fixing the tube of any one of Claims 1-8 after diameter expansion under heating.