JP2007314639A - Flame-retardant material, and electric wire jacket and lan cable made thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant material having excellent heat-resistance, chemical resistance and oil resistance, formable by melt-molding and exhibiting excellent flexibility and flame-retardancy and provide an electric wire jacket made of the flame-retardant material and a LAN cable having the electric wire jacket. <P>SOLUTION: The flame-retardant material contains (A) 95-40 wt.% fluororesin and (B) 60-5 wt.% crosslinked fluororubber, wherein the fluororesin A is a copolymer of tetrafluoroethylene and hexafluoropropylene or a copolymer of tetrafluoroethylene, hexafluoropropylene and perfluoro(alkyl vinyl ether), the fluorine concentration of the crosslinked fluororubber B is ≥68 wt.% and at least a part of the rubber is crosslinked. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flame retardant material containing a specific fluororesin (A) and a crosslinked fluororubber (B) having a high fluorine concentration. The present invention also relates to an electric wire jacket formed from the flame retardant material and a LAN cable having the electric wire jacket.

  In recent years, fire spread due to cables running on the ceiling and under the plenum, cable covering materials, etc. has become a problem, so wire jackets require particularly excellent heat resistance in addition to formability and flexibility. Has been. As a material for such a wire jacket, a fluororesin having excellent characteristics such as slidability, heat resistance, chemical resistance, weather resistance, and electrical properties is used.

  In addition, LCC (Limited Combustible Cable) jackets are required to have higher flame resistance than plenum cables, so the development of materials that have moldability, flexibility, mechanical properties, and even better heat resistance. Is desired.

  Conventionally, polyvinyl chloride has been used as a jacket material for LCC, but polyvinyl chloride is not sufficient to meet the increasing demand for flame retardancy in recent years.

  On the other hand, as a jacket material for LCC having excellent flame retardancy, a composition in which zinc oxide is blended with a fluororesin has been proposed (see, for example, Patent Document 1). However, the composition is inferior in flexibility due to its high elastic modulus, and it cannot be said that mechanical properties and moldability are sufficient.

  Therefore, at present, there are still no flame retardant materials having excellent flame retardancy, flexibility and mechanical properties.

US Patent Publication No. 2005/0187328

  An object of the present invention is to provide a flame retardant material which has excellent mechanical properties, can be melt-molded, and has excellent flexibility and flame retardancy. Moreover, the objective of this invention is providing the cable for LAN which has the electric wire jacket formed from this flame-retardant material, and this electric wire jacket.

That is, the present invention is a flame retardant material containing 95 to 40% by weight of the fluororesin (A) and 60 to 5% by weight of the cross-linked fluororubber (B),
The fluororesin (A) is a copolymer composed of tetrafluoroethylene and hexafluoropropylene or a copolymer composed of tetrafluoroethylene, hexafluoropropylene and perfluoro (alkyl vinyl ether).
The present invention relates to a flame retardant material which is a crosslinked fluororubber in which the fluorine concentration of the crosslinked fluororubber (B) is 68% by weight or more and at least a part thereof is crosslinked.

  The crosslinked fluororubber (B) is obtained by dynamically crosslinking the fluororubber (b) together with the crosslinking agent (C) under the melting condition of the fluororesin (A) in the presence of the fluororesin (A). Preferably there is.

  Furthermore, it is preferable that a flame retardant (E) is included.

  It is preferable that melting | fusing point of a fluororesin (A) is 150 to 330 degreeC.

  The fluororubber (b) is preferably vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene-based fluororubber.

  It is preferable that the crosslinking agent (C) is a polyhydroxy compound.

  The present invention also relates to an electric wire jacket formed from the flame-retardant material and a LAN cable having the electric wire jacket.

  The flame-retardant material of the present invention includes a specific fluororesin (A) and a cross-linked fluororubber (B) having a high fluorine concentration, so that it has excellent mechanical properties, can be melt-molded, and has excellent flexibility. It has properties and flame retardancy.

The present invention is a flame retardant material containing 95 to 40% by weight of a fluororesin (A) and 60 to 5% by weight of a crosslinked fluororubber (B),
The fluororesin (A) is a copolymer comprising tetrafluoroethylene (hereinafter referred to as TFE) and hexafluoropropylene (hereinafter referred to as HFP) or TFE, HFP and perfluoro (alkyl vinyl ether) (hereinafter referred to as PAVE). )
The present invention relates to a flame retardant material which is a crosslinked fluororubber in which the fluorine concentration of the crosslinked fluororubber (B) is 68% by weight or more and at least a part thereof is crosslinked.

  In the present invention, as the fluororesin (A), a flame retardant material having excellent flame retardancy and mechanical properties is obtained by using a copolymer comprising TFE and HFP or a copolymer comprising TFE, HFP and PAVE. Is obtained.

  The copolymer composed of TFE and HFP is not particularly limited, but is preferably a copolymer composed of 70 to 99 mol% of TFE units and 1 to 30 mol% of HFP units, and 80 to 95 mol% of TFE units. More preferably, it is a copolymer comprising 5 to 20 mol% of HFP units. If the TFE unit is less than 70 mol%, the mechanical properties tend to decrease, and if it exceeds 99 mol%, the moldability tends to decrease.

Further, the copolymer composed of TFE and HFP may contain a third component, and the type of the third component is not limited as long as it can be copolymerized with TFE and HFP. Trifluoroethylene (hereinafter referred to as CTFE), trifluoroethylene, hexafluoroisobutene, vinylidene fluoride (hereinafter referred to as VdF), vinyl fluoride, general formula (1):
CH ₂ = CX ¹ (CF ₂ ) _n X ² (1)
(Wherein X ¹ is a hydrogen atom or a fluorine atom, X ² is a hydrogen atom, a fluorine atom or a chlorine atom, and n is an integer of 1 to 10)
And the like, and the like.

  The copolymer comprising TFE, HFP, and the third component monomer is not particularly limited, but includes 67 to 98.9 mol% of TFE units, 1 to 30 mol% of HFP units, and 0.1 to 3 mol of the third component monomer units. It is preferably a copolymer consisting of 3 mol%, from 78.5 to 94.5 mol% of TFE units, 5 to 20 mol% of HFP units, and 0.3 to 1.5 mol% of the third component monomer unit. More preferably, it is a copolymer. If the TFE unit is less than 67 mol%, the mechanical properties tend to decrease, and if it exceeds 98.9 mol%, the moldability tends to decrease.

  Although it does not specifically limit as a copolymer which consists of TFE, HFP, and PAVE, The copolymer which consists of TFE unit 67-98.9 mol%, HFP unit 1-30 mol%, PAVE unit 0.1-3 mol% It is preferable that the copolymer is composed of 78.5 to 94.5 mol% of TFE units, 5 to 20 mol% of HFP units, and 0.3 to 1.5 mol% of PAVE units. If the TFE unit is less than 67 mol%, the mechanical properties tend to decrease, and if it exceeds 98.9 mol%, the moldability tends to decrease.

  Here, as PAVE, PAVE which has C1-C5 alkyl groups, such as perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), can be mention | raise | lifted.

  The melting point of the fluororesin (A) is preferably 150 to 330 ° C, more preferably 150 to 310 ° C, further preferably 150 to 290 ° C, and 170 to 270 ° C. Is particularly preferred. When the melting point of the fluororesin (A) is less than 150 ° C., the heat resistance of the obtained flame-retardant material tends to decrease. When the melting point exceeds 330 ° C., the fluororesin (A) is present in the presence of the fluororesin (A). ) When the rubber (b) is dynamically cross-linked under the melting conditions, it is necessary to set the melting temperature to be higher than the melting point of the fluororesin (A). Tend to.

  The crosslinked fluororubber (B) used in the present invention is not particularly limited as long as it is a fluororubber having a fluorine concentration of 68% by weight or more and at least a part of which is crosslinked.

  The fluorine concentration of the crosslinked fluororubber (B) is 68% by weight or more, preferably 68 to 75% by weight, more preferably 69 to 74% by weight, and 70 to 73% by weight. Further preferred. When the fluorine concentration is less than 68% by weight, the flame retardancy and mechanical properties of the obtained flame retardant material tend to be lowered.

  The crosslinked fluororubber (B) is obtained by dynamically crosslinking the fluororubber (b) together with the crosslinking agent (C) under the melting condition of the fluororesin (A) in the presence of the fluororesin (A). It is preferable from the viewpoint of good moldability of the flame retardant material obtained and improved mechanical properties. Here, the dynamic crosslinking treatment means that the fluororubber (b) is dynamically crosslinked simultaneously with melt kneading using a Banbury mixer, a pressure kneader, an extruder or the like. Among these, it is preferable to use an extruder such as a twin screw extruder because a high shear force can be applied. By dynamically crosslinking, the phase structure of the fluororesin (A) and the crosslinked fluororubber (B) and the dispersion of the crosslinked fluororubber (B) can be controlled.

  Examples of the fluororubber (b) include perfluorofluororubber (b1) and non-perfluorofluororubber (b2).

  Examples of the perfluorofluororubber (b1) include TFE / PAVE copolymers and TFE / HFP / PAVE copolymers.

  Examples of the non-perfluorofluororubber (b2) include VdF polymers and TFE / propylene copolymers, and these may be used alone or in any combination as long as the effects of the present invention are not impaired. Can be used.

  Moreover, what was illustrated as said perfluoro fluororubber or non-perfluoro fluororubber is the structure of a main monomer, and what copolymerized the monomer for crosslinking, a modified monomer, etc. can be used suitably. As the crosslinking monomer or the modifying monomer, a known crosslinking monomer such as an iodine atom, bromine atom, or one containing a double bond, a transfer agent, a modified monomer such as a known ethylenically unsaturated compound, or the like can be used. .

  Specific examples of the VdF polymer include a VdF / HFP copolymer, a VdF / TFE / HFP copolymer, a VdF / TFE / propylene copolymer, and a VdF / ethylene / HFP copolymer. VdF / TFE / PAVE copolymer, VdF / PAVE copolymer, VdF / CTFE copolymer, and the like.

  More specifically, a fluorine-containing copolymer composed of 25 to 85 mol% of VdF and 75 to 15 mol% of at least one other monomer copolymerizable with VdF is preferable.

  Here, as at least one other monomer copolymerizable with VdF, for example, TFE, CTFE, trifluoroethylene, HFP, trifluoropropylene, tetrafluoropropylene, pentafluoropropylene, trifluorobutene, tetra Examples thereof include fluorine-containing monomers such as fluoroisobutene, PAVE and vinyl fluoride, and non-fluorine monomers such as ethylene, propylene and alkyl vinyl ether. These can be used alone or in any combination.

  Among the fluororubbers, in view of heat resistance, compression set, workability, and cost, fluororubber containing VdF units is preferable, and fluororubber having VdF units and HFP units is more preferable.

  From the viewpoint of good compression set, it is preferably at least one rubber selected from the group consisting of VdF / HFP fluororubber, VdF / TFE / HFP fluororubber, and TFE / propylene fluororubber, VdF / TFE / HFP fluororubber is more preferable.

  The fluororubber (b) used in the present invention can be produced by a usual emulsion polymerization method. What is necessary is just to determine suitably polymerization conditions, such as temperature at the time of superposition | polymerization, time, etc. with the kind of monomer, and the target elastomer.

  As a crosslinking agent (C) used by this invention, it can select suitably according to the kind and melt-kneading conditions of the fluororubber (b) to bridge | crosslink.

  The cross-linking system used in the present invention may be appropriately selected depending on the type of the cure site or the use of the obtained molded product when the fluororubber (b) contains a cross-linkable group (cure site). As the crosslinking system, any of a polyol crosslinking system, an organic peroxide crosslinking system, and a polyamine crosslinking system can be employed.

  Here, crosslinking by a polyol crosslinking system is preferable in that it has a carbon-oxygen bond at the crosslinking point, has a small compression set, and is excellent in moldability.

  When cross-linking by an organic peroxide cross-linking system, since it has a carbon-carbon bond at the cross-linking point, a polyol cross-linking system having a carbon-oxygen bond at the cross-linking point and a polyamine cross-linking system having a carbon-nitrogen double bond Compared to, it has a feature of excellent chemical resistance and steam resistance.

  When crosslinked by polyamine crosslinking, it has a carbon-nitrogen double bond at the crosslinking point and is characterized by excellent dynamic mechanical properties. However, the compression set tends to increase as compared with the case of crosslinking using a polyol crosslinking system or an organic peroxide crosslinking system.

  Therefore, in the present invention, it is preferable to use a polyol crosslinking system or an organic peroxide crosslinking system, and it is more preferable to use a polyol crosslinking system.

  As the crosslinking agent (C) in the present invention, a polyamine-based, polyol-based or organic peroxide-based crosslinking agent can be used.

  Examples of the polyamine crosslinking agent include polyamine compounds such as hexamethylenediamine carbamate, N, N′-dicinnamylidene-1,6-hexamethylenediamine, and 4,4′-bis (aminocyclohexyl) methanecarbamate. Among these, N, N′-dicinnamylidene-1,6-hexamethylenediamine is preferable.

  As the polyol crosslinking agent, a compound conventionally known as a crosslinking agent for fluororubber can be used. For example, a polyhydroxy compound, particularly a polyhydroxy aromatic compound is preferably used from the viewpoint of excellent heat resistance.

  The polyhydroxy aromatic compound is not particularly limited. For example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), 2,2-bis (4-hydroxyphenyl) perfluoropropane (Hereinafter referred to as bisphenol AF), resorcin, 1,3-dihydroxybenzene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4′-dihydroxydiphenyl, 4,4 ′ -Dihydroxystilbene, 2,6-dihydroxyanthracene, hydroquinone, catechol, 2,2-bis (4-hydroxyphenyl) butane (hereinafter referred to as bisphenol B), 4,4-bis (4-hydroxyphenyl) valeric acid, 2 , 2-Bis (4-hydroxyphenyl) Tetrafluorodichloropropane, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl ketone, tri (4-hydroxyphenyl) methane, 3,3 ′, 5,5′-tetrachlorobisphenol A, 3,3 Examples include ', 5,5'-tetrabromobisphenol A. These polyhydroxy aromatic compounds may be an alkali metal salt, an alkaline earth metal salt or the like, but when the copolymer is coagulated using an acid, it is preferable not to use the metal salt.

  The organic peroxide cross-linking agent may be an organic peroxide that can easily generate a peroxy radical in the presence of heat or a redox system. Specifically, for example, 1,1-bis (T-butylperoxy) -3,5,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumylper Oxide, α, α-bis (t-butylperoxy) -p-diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5- Di (t-butylperoxy) -hexyne-3, benzoyl peroxide, t-butylperoxybenzene, t-butylperoxymaleic acid, t-butylperoxyi Examples include sopropyl carbonate. Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane is preferable.

  Among these, a polyhydroxy compound is preferable from the viewpoint of small compression set such as a molded article to be obtained and excellent moldability, a polyhydroxy aromatic compound is more preferable because of excellent heat resistance, and bisphenol AF is preferable. Further preferred.

  In the polyol crosslinking system, a crosslinking accelerator (D) is usually used in combination with the polyol crosslinking agent. When the crosslinking accelerator (D) is used, the crosslinking reaction can be promoted by promoting the formation of an intramolecular double bond in the dehydrofluorination reaction of the fluororubber main chain.

  As the polyol crosslinking accelerator (D), an onium compound is generally used. The onium compound is not particularly limited, and examples thereof include ammonium compounds such as quaternary ammonium salts, phosphonium compounds such as quaternary phosphonium salts, oxonium compounds, sulfonium compounds, cyclic amines, and monofunctional amine compounds. Of these, quaternary ammonium salts and quaternary phosphonium salts are preferred.

  The quaternary ammonium salt is not particularly limited. For example, 8-methyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-methyl-1,8-diazabicyclo [5, 4,0] -7-undecenium iodide, 8-methyl-1,8-diazabicyclo [5,4,0] -7-undecenium hydroxide, 8-methyl-1,8-diazabicyclo [5 , 4,0] -7-Undecenium methyl sulfate, 8-ethyl-1,8-diazabicyclo [5,4,0] -7-undecenium bromide, 8-propyl-1,8-diazabicyclo [5 , 4,0] -7-undecenium bromide, 8-dodecyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-dodecyl-1,8-diazabicyclo [5 4,0] -7-undecenium hydroxide, 8-eicosyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-tetracosyl-1,8-diazabicyclo [5, 4,0] -7-undecenium chloride, 8-benzyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride (hereinafter referred to as DBU-B), 8-benzyl-1 , 8-diazabicyclo [5,4,0] -7-undecenium hydroxide, 8-phenethyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8- (3- Phenylpropyl) -1,8-diazabicyclo [5,4,0] -7-undecenium chloride and the like. Among these, DBU-B is preferable from the viewpoint of crosslinkability and physical properties of the cross-linked product.

  The quaternary phosphonium salt is not particularly limited. For example, tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride (hereinafter referred to as BTPPC), benzyltrimethylphosphonium chloride, benzyltributylphosphonium chloride, tributylallylphosphonium chloride, tributyl. Examples thereof include -2-methoxypropylphosphonium chloride, benzylphenyl (dimethylamino) phosphonium chloride, and among these, benzyltriphenylphosphonium chloride (BTPPC) is preferable from the viewpoint of crosslinkability and physical properties of the crosslinked product.

  Further, as the crosslinking accelerator (D), a quaternary ammonium salt, a solid solution of a quaternary phosphonium salt and bisphenol AF, or a chlorine-free crosslinking accelerator disclosed in JP-A-11-147891 can be used.

  Examples of the organic peroxide crosslinking accelerator (D) include triallyl cyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, N, N′-m-phenylenebismaleimide, Dipropargyl terephthalate, diallyl phthalate, tetraallyl terephthalate amide, triallyl phosphate, bismaleimide, fluorinated triallyl isocyanurate (1,3,5-tris (2,3,3-trifluoro-2-propenyl) -1 , 3,5-triazine-2,4,6-trione), tris (diallylamine) -S-triazine, triallyl phosphite, N, N-diallylacrylamide, 1,6-divinyldodecafluorohexane, hexaallyl phosphor Amide, N, N, N ′, N′-tetraali Phthalamide, N, N, N ′, N′-tetraallylmalonamide, trivinylisocyanurate, 2,4,6-trivinylmethyltrisiloxane, tri (5-norbornene-2-methylene) cyanurate, triallyl phosphite Etc. Among these, triallyl isocyanurate (TAIC) is preferable from the viewpoint of crosslinkability and physical properties of the cross-linked product.

  As a compounding quantity of a crosslinking agent (C), it is preferable that it is 0.1-10 weight part with respect to 100 weight part of fluororubber (b), More preferably, it is 0.3-5 weight part. When the cross-linking agent (C) is less than 0.1 parts by weight, the cross-linking of the fluororubber (b) does not proceed sufficiently, and the heat resistance and oil resistance of the obtained flame-retardant material tend to decrease, If it exceeds 10 parts by weight, the moldability of the obtained flame-retardant material tends to be lowered.

  As addition amount of a crosslinking agent (C) and a crosslinking accelerator (D), it is the quantity adjusted so that 90% completion time T90 of vulcanization | cure in the temperature at the time of carrying out a dynamic crosslinking process may be 2 to 6 minutes. The vulcanization 90% completion time T90 is more preferably adjusted to 3 to 5 minutes. When the optimum vulcanization time T90 is less than 2 minutes, the dispersion of the crosslinked rubber tends to be uneven and coarse, and when it exceeds 6 minutes, it takes a long time for the rubber to be crosslinked, and There is a tendency to not completely crosslink.

  Here, vulcanization 90% completion time T90 means vulcanization at the temperature at the time of dynamic vulcanization using JSR type curlastometer type II and V type at the time of primary press vulcanization of fluoro rubber (b). The curve is obtained, and the time to reach 90% of the maximum torque value is defined as 90% vulcanization completion time (T90).

  The melting condition means a temperature at which the fluororesin (A) and the fluororubber (b) are melted. The melting temperature varies depending on the glass transition temperature and / or melting point of the fluororesin (A) and the fluororubber (b), respectively, but is preferably 120 to 330 ° C, and more preferably 130 to 320 ° C. If the temperature is less than 120 ° C, the dispersion between the fluororesin (A) and the fluororubber (b) tends to become coarse, and if it exceeds 330 ° C, the rubber (b) tends to be thermally deteriorated. .

  The obtained flame-retardant material has a structure in which the fluororesin (A) forms a continuous phase and the cross-linked fluororubber (B) forms a dispersed phase, or the fluororesin (A) and the cross-linked fluororubber (B) coexist. Although it can have the structure which forms continuity, it is preferable among them that it has a structure where a fluororesin (A) forms a continuous phase and a bridge | crosslinking fluororubber (B) forms a dispersed phase.

  Even when the fluororubber (b) initially forms a matrix, as the cross-linking reaction proceeds, the fluororubber (b) becomes a cross-linked fluororubber (B), so that the melt viscosity increases, and the cross-linked fluororubber (B) becomes a dispersed phase or forms a co-continuous phase with the fluororesin (A).

  When such a structure is formed, the flame retardant material of the present invention exhibits excellent heat resistance, chemical resistance and oil resistance, and also has excellent flexibility. At that time, the average dispersed particle size of the crosslinked fluororubber (B) is preferably 0.01 to 30 μm. If the average dispersed particle size is less than 0.01 μm, the fluidity tends to decrease, and if it exceeds 30 μm, the strength of the obtained flame-retardant material tends to decrease.

  In addition, the flame retardant material of the present invention includes a fluororesin (A) in a part of the structure in which the fluororesin (A) which is a preferred form forms a continuous phase and the cross-linked fluororubber (B) forms a dispersed phase. A co-continuous structure of A) and the crosslinked fluororubber (B) may be included.

  The flame retardant material of the present invention preferably comprises 95 to 40% by weight of the fluororesin (A) and 60 to 5% by weight of the cross-linked fluororubber (B), and 92 to 50% by weight of the fluororesin (A), It is more preferably composed of 50 to 8% by weight of the crosslinked fluororubber (B), more preferably 90 to 70% by weight of the fluororesin (A) and 30 to 10% by weight of the crosslinked fluororubber (B). If the fluororesin (A) is less than 40% by weight, the fluidity of the obtained flame-retardant material tends to deteriorate and the moldability tends to deteriorate, and if it exceeds 95% by weight, the flexibility tends to decrease. .

  Furthermore, the flame retardant material of the present invention preferably contains a flame retardant (E) from the viewpoint of flame retardancy.

  Although it does not specifically limit as a flame retardant (E), What is necessary is just to use what is generally used, For example, Metal hydroxides, such as magnesium oxide and aluminum hydroxide; Phosphate flame retardant; Bromine And halogen-based flame retardants such as flame retardants and chlorine-based flame retardants. Among these, a phosphoric acid flame retardant is preferable from the viewpoint of flame retardancy and impact on the environmental load. In addition, flame retardant aids such as antimony trioxide and zinc borate; smoke control agents such as molybdenum oxide; and char-generating compounds such as silicone compounds and inorganic fillers may be used in combination. Here, the char-generating compound is a compound that generates char during combustion.

  As a compounding quantity of a flame retardant (E), it is preferable that it is 2-100 weight part with respect to a total of 100 weight part of fluororesin (A) and crosslinked fluororubber (B), and is 5-70 weight part. It is more preferable. When the amount is less than 2 parts by weight, the flame retardant effect due to the addition of the flame retardant (E) is not particularly observed. When the amount exceeds 100 parts by weight, the moldability and flexibility tend to be inferior.

  The flame retardant material of the present invention includes other polymers such as polyethylene, polypropylene, polyamide, polyester, polyurethane, inorganic fillers such as calcium carbonate, talc, celite, clay, titanium oxide, carbon black, and barium sulfate. Pigments, flame retardants, lubricants, light stabilizers, weathering stabilizers, antistatic agents, UV absorbers, antioxidants, mold release agents, foaming agents, fragrances, oils, softening agents, etc. affect the effects of the present invention. Can be added within a range that does not affect.

  The flame-retardant material of the present invention can be molded using a general molding method or a molding apparatus. As a molding method, for example, any method such as injection molding, extrusion molding, compression molding, blow molding, calender molding, vacuum molding, etc. can be adopted, and the flame-retardant material of the present invention depends on the purpose of use. And molded into a molded body having an arbitrary shape.

  Furthermore, this invention relates to the electric wire jacket obtained using the flame-retardant material of this invention.

  The above-mentioned electric wire jacket is generally a tube-like body for containing a copper wire and a covering material for imparting flame retardancy and preventing mechanical damage in wires and cables for electronic devices such as computers. The molding method is not particularly limited, and examples thereof include known methods such as a method of extrusion molding with a crosshead and a single screw extruder.

  Since the wire jacket has the above-described configuration, it has good moldability and flexibility, exhibits particularly excellent heat resistance, and is a jacket for LCC (Limited Combustible Cable) that requires higher flame retardance than before. Can also be suitably used.

  Although it does not specifically limit as an electric wire jacket, For example, it can use for communication cables, such as an electric equipment wiring electric wire, an electric equipment 600V insulated electric wire, and a LAN cable. The LAN cable is a cable used for a LAN.

  Next, the present invention will be described with reference to examples, but the present invention is not limited to such examples.

<Preparation of sheet-shaped test piece>
The flame retardant material produced in Examples and Comparative Examples was set in a mold, held at 290 ° C. for 15 to 30 minutes with a heat press machine, and the dynamic cross-linking composition was melted, and then a load of 3 MPa. And compression molding for 1 minute to prepare a sheet-like test piece having a predetermined thickness.

<Measurement of hardness>
A sheet-like test piece having a thickness of 2 mm was prepared by the above method, and A hardness was measured using these in accordance with JIS-K6301.

<Measurement of tensile strength at break, tensile elongation at break and tensile modulus>
A sheet-shaped test piece having a thickness of 2 mm is prepared by the above method, and a dumbbell-shaped test piece having a distance between marked lines of 3.18 mm is punched out using an ASTM V type dumbbell. Using the obtained dumbbell-shaped test piece, using an autograph (AGS-J 5 kN, manufactured by Shimadzu Corporation), the tensile break elongation at 25 ° C. was performed under the condition of 50 mm / min according to ASTM D638. The tensile strength at break and the tensile modulus at break are measured.

<Measurement of fuel permeability>
A sheet-like test piece having a thickness of 0.5 mm was prepared by the above-described method. CE10 (toluene / isooctane / toluene / simulated fuel) was placed in a SUS container (open area: 1.26 × 10 ⁻³ m ² ) having a volume of 20 mL. 18 mL of ethanol = 45/45/10 vol%) is put, and the sheet-like test piece is set in a container opening portion and sealed to obtain a test body. The test specimen was placed in a thermostatic device (60 ° C.), the weight of the test specimen was measured, and when the weight loss per unit time became constant, the fuel permeability was determined by the following formula.

<Flame retardance>
A sheet-like test piece having a thickness of 2 mm was prepared by the above method, and then a sheet-like test piece having a thickness of 2 mm, a length of 50 mm, and a width of 50 mm was cut out. Using the obtained sheet-like test piece, a combustion test was performed using a cone calorimeter (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and a heat generation rate and a smoke generation rate were obtained.

  In the examples and comparative examples, the following fluororesin (A), fluororubber (b), crosslinking agent (C), crosslinking accelerator (D) and flame retardant (E) were used.

<Fluorine resin (A1)>
Copolymer comprising TFE and HFP (TFE: HFP = 91.7: 8.3 mol%, melting point 260 ° C.)

<Fluorine resin (A2)>
Copolymer comprising TFE, HFP and perfluoro (propyl vinyl ether) (TFE: HFP: perfluoro (propyl vinyl ether) = 90.5: 9.1: 0.4 mol%, melting point 255 ° C.)

<Fluoro rubber (b1-1)>
Ternary rubber composed of VdF, TFE and HFP (VdF: TFE: HFP = 50: 20: 30 mol%, fluorine concentration = 71 wt%)

<Fluoro rubber (b1-2)>
Ternary rubber composed of VdF, TFE and HFP (VdF: TFE: HFP = 30: 40: 30 mol%, fluorine concentration = 73 wt%)

<Fluoro rubber (b1-3)>
Binary rubber composed of VdF and HFP (VdF: HFP = 78: 22 mol%, fluorine concentration = 66 wt%)

<Crosslinking agent (C)>
Polyol-based crosslinking agent: 2,2-bis (4-hydroxyphenyl) perfluoropropane (“Bisphenol AF” manufactured by Daikin Industries, Ltd.)

<Crosslinking accelerator (D)>
Benzyltriphenylphosphonium chloride (BTPPC, manufactured by Hokuko Chemical Co., Ltd.)

<Flame retardant (E)>
Aromatic condensed phosphate ester (PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.)

Examples 1-8
For 100 parts by weight of the fluororubber (b1-1 or b1-2), 2.0 parts by weight of the crosslinking agent (C) and 1.0 part by weight of the crosslinking accelerator (D) are kneaded with two rolls. Subsequently, 3.0 parts by weight of an acid acceptor (magnesium oxide “MA150” manufactured by Kyowa Chemical Industry Co., Ltd.) was blended and kneaded with two rolls, and a fluororubber compound (b2-1 or b2-2) Was made.

  Subsequently, the above-mentioned fluororesin (A) and fluororubber compound (b2-1 or b2-2) were premixed at a ratio shown in Table 1, and then supplied to a twin-screw extruder, where the cylinder temperature was 270 ° C. The mixture was melt-kneaded under conditions of a screw rotation speed of 500 rpm to produce flame-retardant material pellets. Using the obtained flame-retardant material pellets, a sheet-like test piece is prepared by the above-described method, and the hardness, tensile breaking strength, tensile breaking elongation, tensile elastic modulus, fuel permeability, heat generation rate, and smoke generation rate are measured. Table 1 shows the results of the above.

Comparative Examples 1 and 2
To 100 parts by weight of the fluororubber (b1-3), 2.17 parts by weight of the crosslinking agent (C) and 0.11 part by weight of the crosslinking accelerator (D) are kneaded with two rolls, and then received. 3.0 parts by weight of an acid agent (manufactured by Kyowa Chemical Industry Co., Ltd., magnesium oxide “MA150”) was blended and kneaded with two rolls to prepare a fluororubber compound (b2-3).

  Subsequently, the above-mentioned fluororesin (A) and fluororubber compound (b2-3) were premixed at the ratio shown in Table 1, and then supplied to the twin-screw extruder, where the cylinder temperature was 270 ° C. and the screw rotation speed. Melt-kneading was performed under the condition of 500 rpm to produce flame-retardant material pellets. Using the obtained flame-retardant material pellets, a sheet-like test piece is prepared by the above-described method, and the hardness, tensile breaking strength, tensile breaking elongation, tensile elastic modulus, fuel permeability, heat generation rate, and smoke generation rate are measured. Table 1 shows the results of the above.

  The flame retardant materials obtained in Examples 1 to 8 were obtained by observing the morphology with a scanning electron microscope (manufactured by JEOL Ltd.), the fluororesin (A) forming a continuous phase, and the crosslinked fluororubber (B). Was found to have a structure forming a dispersed phase. In Examples 1 to 8, the dispersed particle diameter of the crosslinked fluororubber (B) was 20 μm or less.

Claims (8)

A flame retardant material containing 95 to 40% by weight of a fluororesin (A) and 60 to 5% by weight of a crosslinked fluororubber (B),
The fluororesin (A) is a copolymer composed of tetrafluoroethylene and hexafluoropropylene or a copolymer composed of tetrafluoroethylene, hexafluoropropylene and perfluoro (alkyl vinyl ether).
A flame retardant material which is a crosslinked fluororubber having a fluorine concentration of the crosslinked fluororubber (B) of 68% by weight or more and at least a part of which is crosslinked. The crosslinked fluororubber (B) is obtained by dynamically crosslinking the fluororubber (b) together with the crosslinking agent (C) under the melting condition of the fluororesin (A) in the presence of the fluororesin (A). The flame-retardant material according to claim 1. Furthermore, the flame-retardant material of Claim 1 or 2 containing a flame retardant (E). The flame-retardant material according to any one of claims 1 to 3, wherein the fluororesin (A) has a melting point of 150C to 330C. The flame retardant material according to any one of claims 1 to 4, wherein the fluororubber (b) is vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene fluororubber. The flame retardant material according to any one of claims 2 to 5, wherein the crosslinking agent (C) is a polyhydroxy compound. The electric wire jacket formed from the flame-retardant material in any one of Claims 1-6. A LAN cable comprising the electric wire jacket according to claim 7.