JP4890385B2 - Control tube - Google Patents

Description

  The present invention relates to a control tube.

  The control tube is a product that is also referred to as a spatter-resistant tube, a sputter tube, a cover hose, or the like, and has a two-layer structure of an inner core tube and a covering protective cover (covering outer layer). In order to protect the inner tube itself that actually flows fluids such as air and water from being affected by external UV rays, fire, heat sources (welding spatter, etc.), impact and abrasion, Covered. In actual piping, when connecting the joint and this two-layer tube, only the inner tube is inserted into the joint, so the covering protective cover of the joint insertion part can be easily cut with a cutter or the like. It must be possible and easily peeled off by hand.

  Therefore, it is the inner core tube that requires performance as an actual tube, and the covering protective cover is only used as a protective material for the inner core tube, and it is necessary to easily peel off unnecessary parts. For the covering protective cover, different material materials (different resin materials) are used. The following are the products that are actually manufactured.

  Since the core tube material is important for performance such as mechanical properties and flexibility, nylon (nylon 11 or 12) tube and polyurethane tube are mainly used. Polyvinyl chloride resin and chloroprene rubber are used for the covering protective cover. And chlorinated polyolefin resins are used. The material used for the covering protective cover is particularly effective as a tube for outdoor piping because the ultraviolet resistance is drastically improved by adding black. In addition, halogen-based compounds containing chlorine are used for all the coating materials, but the reason for using them as a protective material is that they must be flame-retardant so that they are difficult to burn even if welding spatter scatters or adheres. Because. Furthermore, for the purpose of improving the flame retardancy, there are many cases where halogen substances such as brominated flame retardants and environmentally hazardous substances such as antimony substances are added. Further, since the protective material is required to be soft and low in hardness so as not to inhibit the flexibility of the inner tube, a so-called plasticizer is blended, and the plasticizer is a phthalate ester (phthalic acid). Dioctyl (DOP) and the like are frequently used. In recent years, DOP is a problem of so-called environmental hormones (endocrine disrupting substances), and is a representative substance that is subject to various regulations. As one of the reasons why a plasticizer such as DOP must be added, as described above, in the normal use of this product, in addition to flexibility, the part of the covering protective cover is not used when piping to the joint. This is because it is necessary to rip with a cutter or the like, peel off by hand, and expose the inner core portion to be inserted into the joint.

  For this reason, the inner core tube and the covering protective cover must be easily peeled off, the inner core and the covering protective cover must be made of different materials, and the covering protective cover must be soft and easy to tear. The above-mentioned material containing an agent or the like has flexibility, and has been used that is easy to tear and peel.

  As mentioned above, chlorine-based compounds such as polyvinyl chloride resin (PVC) are used for the covering protective cover. During tube forming, chlorine gas is generated by melting, which not only deteriorates the work environment, but also the product. If it is exposed to external fire or heat during use, it will also cause environmental degradation due to the generation of chlorine gas.

  In order to solve the problems of the conventional control tube, the present inventor previously made a non-halogen / non-phosphorus flame retardant resin composition containing a magnesium protective flame retardant and a magnesium protective flame retardant as a coating protective cover material. Japanese Patent Application Laid-Open No. H10-228688 discloses a control tube using the above.

  Although the control tube disclosed in Patent Document 1 has excellent flame retardancy, depending on the application, it cannot be said that the bending fatigue resistance and the wear resistance are sufficient, and further improvement is desired.

JP 2006-315338 A

  An object of the present invention is to improve bending fatigue resistance and wear resistance while maintaining flame retardancy in a control tube using a non-halogen / non-phosphorus flame retardant resin composition.

The gist of the present invention is as follows.
(1) In a control tube comprising an inner core tube and a covering protective cover, the inner core tube includes at least a layer mainly composed of soft polyurethane and / or soft nylon, and the covering protective cover is magnesium hydroxide, a silicone flame retardant. And a non-halogen / non-phosphorus flame retardant resin composition containing a thermoplastic elastomer composed of hydrocarbons.
(2) The control tube according to (1), wherein the soft polyurethane is an ether polyurethane.
(3) The control tube according to the above (1), wherein the inner core tube has a layer made of ether elastomer soft nylon mainly containing no plasticizer inside a layer mainly made of ether polyurethane.
(4) The control tube according to any one of (1) to (3), wherein the thermoplastic elastomer composed of hydrocarbons contained in the covering protective cover includes a hydrogenated styrene elastomer.
(5) The control tube according to (4), wherein the thermoplastic elastomer composed of hydrocarbons contained in the covering protective cover includes polypropylene and hydrogenated styrene elastomer.
(6) The control tube according to any one of (1) to (5), wherein the base resin of the non-halogen / non-phosphorus flame retardant resin composition constituting the covering protective cover is mainly composed of an ethylene-vinyl acetate copolymer.
(7) The control tube according to any one of (1) to (6), which is used as a piping material related to a welding apparatus used in an automobile production process.

  ADVANTAGE OF THE INVENTION According to this invention, the control tube which has the flame retardance, the bending fatigue resistance, and the abrasion resistance can be provided using a non-halogen / non-phosphorus material.

  The control tube of the present invention includes an inner core tube and a covering protective cover that covers the outer side of the inner core tube. The number of inner core tubes is not particularly limited, but is usually 1 to 10, preferably 1 to 7. The outer diameter of the control tube of the present invention varies depending on the number of inner core tubes, the outer diameter, and the like, but is usually 5 to 22 mm. The outer diameter and inner diameter of the inner tube are usually 3.5 to 13 mm × 2 to 9.5 mm. The cross-sectional shape of the control tube of the present invention varies depending on the number of inner core tubes, etc., and is usually circular for one inner core tube, track type for two inner core tubes, and three inner core tubes. Is a triangle, and in the case of seven inner core tubes, it is a hexagon. FIG. 1 shows a cross-sectional view of a control tube having one inner core tube and two inner core tubes.

  In the present invention, the inner core tube has a structure including at least a layer mainly composed of soft polyurethane and / or soft nylon because it has flexibility and there is no fear of thinning and curing of the tube. In the present specification, “a layer mainly composed of soft polyurethane and / or soft nylon” means a layer having the largest number of “soft polyurethane and / or soft nylon” among the components constituting the layer. Among the constituent components, it is preferable that soft polyurethane and / or soft nylon is 75% by weight or more.

  In particular, an inner core tube having a layer made of ether elastomer soft nylon mainly containing no plasticizer inside a layer mainly made of ether polyurethane has no fear of hydrolysis and is a fluid such as water. Since there is no elution of plasticizer in the tube, tube thinning phenomenon does not occur, so it is optimal as piping for cooling water. Also, as the fluid of the welding equipment piping, oil supply air may be used for lubrication and rust prevention of equipment operation, and the fact that soft nylon with oil resistance is arranged on the inner layer side where the fluid contacts is more Safety will be improved.

  In addition, in the adhesion performance of ether polyurethane and ether elastomer soft nylon, both soft segments are ether, so there is no need to use adhesive resin, etc., and strong adhesive force is obtained and bending is movable. Even if it performs, the peeling phenomenon of layers does not generate | occur | produce. For this performance, a “bending durability test” is performed in accordance with JIS B8381 (pneumatic flexible pipe fitting). After the specified 5 million cycles, troubles such as delamination do not occur, and the tube performance before the test Was confirmed to be maintained.

In the present invention, the soft polyurethane used as the inner tube material is a thermoplastic polyurethane, which is a material having a urethane group (—NH—COO—) in the molecule, and (i) a polyol (long chain diol), ( It is produced by a three-component intermolecular reaction of ii) diisocyanate and (iii) short chain diol. The polyol and short chain diol undergo an addition reaction with diisocyanate to produce a linear polyurethane. Among these, the polyol becomes a flexible portion (soft segment) of the elastomer, and the diisocyanate and the short-chain diol become a hard portion (hard segment).

  The properties of thermoplastic polyurethane depend on the properties of raw materials, the polymerization conditions, and the blending ratio. Among these, the type of polyol has a great influence on the properties of polyurethane, and many of the basic properties are the type of polyol. The hardness is adjusted by the ratio of the hard segment.

  The types of polyol include (i) caprolactone type (polylactone ester polyol obtained by ring-opening caprolactone), (ii) adipate type (adipic acid ester polyol of adipic acid and glycol), (iii) ether type = PTMG (polytetramethylene glycol) type (polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran) and the like, and has various characteristics. Since it is an ether type having excellent decomposability and low temperature flexibility, it is preferable to employ an ether-based thermoplastic polyurethane.

  The hardness of the soft polyurethane used as the inner tube material is usually Shore A hardness (JIS K 6253; the same applies hereinafter) 80 to 98 (Shore D hardness (JIS K 6253; the same applies hereinafter) 30 to 52), preferably Shore A hardness. (JIS K 6253; the same shall apply hereinafter) 85 to 95 (Shore D hardness (JIS K 6253; the same shall apply hereinafter) 35 to 48).

  In the present invention, the soft nylon used as the inner tube material means a polyamide resin (PA) having an acid amide bond (—CO—NH—) in the main chain. As the soft nylon used in the present invention, a polyamide obtained by self-condensation of cyclic lactam, ω-amino acid, a polyamide obtained by polycondensation of dibasic acid and diamine, or a copolymerized polyamide thereof, more specifically, Examples include nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, nylon 612, nylon 6T, and the like. Among these, nylon 11 (polyamide 11) and nylon 12 (polyamide 12) are particularly preferable.

  The hardness of the soft nylon used as the inner tube material is usually Shore A hardness (JIS K 6253; the same applies hereinafter) 88 to 100 (Shore D hardness (JIS K 6253; the same applies hereinafter) 37 to 65), preferably Shore A hardness. (JIS K 6253; the same shall apply hereinafter) 92 to 99 (Shore D hardness (JIS K 6253; the same shall apply hereinafter) 40 to 60).

  In addition to the above-mentioned components, the inner tube material may contain a plasticizer, an antioxidant, a heat stabilizer, an ultraviolet absorber for improving weather resistance, a light stabilizer, and the like as necessary. Can do. Examples of the plasticizer include Nn-butylbenzenesulfonamide and 2-hydroxyhexyl ester of parahydroxybenzoic acid. As the light stabilizer, a hindered amine light stabilizer is preferred in that it has good compatibility with the base resin of the inner tube, is effective in UV resistance, and does not deteriorate the properties of the base resin. As the hindered amine light stabilizer, for example, dibutylamine-1,3,5-triazine-N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and Polycondensate with N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine, dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol Polymer, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, etc. These various hindered amine light stabilizers may be used alone or in combination of two or more. When the hindered amine light stabilizer is blended, the blending ratio is usually 0.3 to 1 part by weight with respect to 100 parts by weight of the base resin, and is resistant to ultraviolet rays. Is preferably 0.5 to 0.8 parts by weight from the viewpoint that it does not affect the base resin characteristics and molding balance, and a light stabilizer, preferably a hindered amine light stabilizer, is added to the material of the inner tube. Accordingly, it is possible to prevent the deterioration of the inner tube portion from which the covering protective cover has been peeled for inserting the joint, from being deteriorated by ultraviolet rays.

  The covering protective cover is made of a non-halogen / non-phosphorus flame retardant resin composition containing a thermoplastic elastomer composed of magnesium hydroxide, a silicone flame retardant, and a hydrocarbon.

  The base resin of the non-halogen / non-phosphorus flame retardant resin composition (not including the thermoplastic elastomer composed of the hydrocarbon) is not particularly limited as long as it is a non-halogen resin. For example, ethylene-vinyl acetate copolymer Non-halogen vinyl resins such as copolymers, ethylene-ethyl acrylate copolymers; non-halogen olefin resins, etc., and in that flexibility is obtained without using a plasticizer, ethylene-vinyl acetate copolymers, ethylene-acrylic Ethyl acid copolymers are preferred, and those based on ethylene-vinyl acetate copolymers are more preferred. In this specification, “mainly composed of an ethylene-vinyl acetate copolymer” means that the ethylene-vinyl acetate copolymer is the largest among the components constituting the base resin, and the base resin is constituted. Among the components to be used, the ethylene-vinyl acetate copolymer is preferably 80% by weight or more. Moreover, it is preferable that 5-20 weight% of base resin is adhesive polyethylene from the point of abrasion-resistant improvement. The blending ratio of the base resin in the non-halogen / non-phosphorus flame retardant resin composition is usually 20 to 50% by weight, preferably 25 to 45% by weight.

  In the present invention, magnesium hydroxide is added to the non-halogen / non-phosphorus flame retardant resin composition, which is a coating protective cover material, in order to make it flame retardant without using environmentally hazardous substances such as halogen compounds. . Magnesium hydroxide has good flame retardancy and is excellent in compatibility and dispersibility with a non-halogen resin as a base resin, and does not deteriorate mechanical properties. The blending ratio of magnesium hydroxide is usually 35 to 60% by weight, preferably 40 to 53% by weight in the non-halogen / non-phosphorus flame retardant resin composition, and is usually 100 to 160% by weight with respect to 100 parts by weight of the base resin. Parts, preferably 110 to 150 parts by weight.

  In the present invention, it is necessary to add a silicone flame retardant to the non-halogen / non-phosphorus flame retardant resin composition, which is a coating protective cover material, in terms of ease of tearing and peelability of the protective cover. In addition, it is preferable to blend an inorganic filler.

The silicone flame retardant is not particularly limited as long as it is an organic compound containing a silicon atom, and examples thereof include silicone oil, silicone rubber, and silicone resin. Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, and polyether-modified silicone oil. Examples of the silicone rubber include methyl silicone rubber and methylphenyl silicone rubber. Examples of the silicone resin include methyl silicone, methyl phenyl silicone, and phenyl silicone. The organic compound containing a silicon atom is a functional group such as —OH, —NH ₂ , —NCO, —COOH, —CHO, —SH, methylol group, acrylate group, methacrylate group, silyl group, glycidyl group or epoxy group. It may have a group.

  The blending ratio of the silicone flame retardant is usually 1.0 to 2.0% by weight, preferably 1.2 to 1.3% by weight, and 100% by weight of the base resin in the non-halogen / non-phosphorus flame retardant resin composition. The amount is usually 2.3 to 4.7 parts by weight, preferably 2.8 to 3.0 parts by weight with respect to parts.

  The inorganic filler is not particularly limited as long as it is an inorganic filler other than magnesium hydroxide that can be blended in the flame retardant resin composition. For example, inorganic oxides represented by zinc stannate, silica Examples include acid salts, carbonates, molybdenum, and the like, and preferred examples include inorganic fillers having a modifying effect such as a peelability improving effect such as zinc stannate and magnesium carbonate.

  The blending ratio of the inorganic filler is usually 2.0 to 10.0% by weight, preferably 3.0 to 5.0% by weight, and 100 parts by weight of the base resin in the non-halogen / non-phosphorus flame retardant resin composition. Is usually 4.6 to 23.2 parts by weight, preferably 7.1 to 11.6 parts by weight.

  The non-halogen / non-phosphorus flame retardant resin composition needs to be blended with a thermoplastic elastomer composed of hydrocarbons in order to improve bending fatigue resistance and wear resistance.

  Examples of the thermoplastic elastomer composed of the hydrocarbon include styrene-based elastomers and olefin-based thermoplastic elastomers. The molecular structure of the thermoplastic elastomer is not particularly limited, and may be a triblock copolymer, a star block copolymer, a multiblock copolymer, a graft copolymer, an ionic cross-linked polymer, or the like.

  The styrenic elastomer is not particularly limited as long as the soft phase is composed of conjugated diene units and the hard phase is composed of aromatic vinyl units, but in particular, a block of a conjugated diene compound and an aromatic vinyl compound. A copolymer or a hydrogenated product (hydrogenated product) thereof is preferably used. Specifically, this block copolymer has two or more polymer blocks A obtained from vinyl aromatic compounds in the molecule, and one or more polymer blocks B obtained from conjugated diene compounds. The block copolymer has a structure represented by, for example, the following formulas (1) to (3).

(AB) m (1)
[Wherein m represents an integer of 1 to 10]
(AB) n-A (2)
[Wherein n represents an integer of 1 to 10]
[(AB) m] pX (3)
[Wherein, X represents a coupling agent residue, m represents an integer of 1 to 10, and p represents an integer of 2 to 4]

  The structures represented by the formulas (1) and (2) are usually linear (linear) structures, and the structure represented by the formula (3) is from 2 to 4 valent X to 2 to 4 It is a star-shaped (radial teleblock-type) structure in which one (AB) m block polymer is branched and derived. In addition, the coupling | bonding mode of the polymer block A and the polymer block B is not limited to these formats, The structure which combined the linear form and the branched form arbitrarily may be sufficient.

  In the formula (1), the repeating number m of the block A and the block B is 1 to 10, preferably 1 to 5, and more preferably about 2 to 4.

  In the formula (2), the repeating number n of the blocks A and B is 1 to 10, preferably 1 to 5, and more preferably about 1 to 3.

  In the formula (3), the repeating number m of the block A and the block B is 1 to 10, preferably 1 to 5, and more preferably about 2 to 4. Examples of the coupling agent constituting the coupling agent residue include dicarboxylic acid alkyl esters (eg, diethyl adipate, diethyl benzoate, etc.), hydrocarbons having a vinyl group (eg, divinylbenzene, etc.), halogenated inorganic compounds (For example, silicon tetrachloride, tin tetrachloride, dimethyldichlorosilicon, etc.), halogenated hydrocarbons (for example, 1,2-dibromoethane, 4-chloro-1-methylbenzene, etc.) and the like.

  In such a block copolymer, examples of the aromatic vinyl compound include styrene, alkyl-substituted styrene [for example, vinyltoluene (o-, m- or p-methylstyrene), vinylxylene, p-ethylstyrene, p. -Isopropyl styrene, butyl styrene, p-t-butyl styrene, etc.], α-alkyl-substituted styrenes having an alkyl group substituted at the α-position (for example, α-methyl styrene), vinyl naphthalene, vinyl anthracene and the like. These aromatic vinyl compounds can be used alone or in combination of two or more. Of these aromatic vinyl compounds, styrene and / or α-methylstyrene are preferred.

  Examples of the conjugated diene compound include 1,3-butadiene, chloroprene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3- or 1,4-pentadiene, 1,3-hexadiene, and the like. . These conjugated diene compounds can be used alone or in combination of two or more. Of these conjugated diene compounds, 1,3-butadiene and / or isoprene are preferred.

  The microstructure (addition form) of the polymer block B composed of the conjugated diene compound is not particularly limited, but when the polymer block B is a block composed of polybutadiene, the amount of 1,4 bonds (cis- And trans-1,4 addition) and 1,2 bond amount (1,2 addition) (weight ratio) is, for example, 1,4 bond amount / 1,2 bond amount = 95 / 5-20 / 80, preferably 90/10 to 30/70, more preferably about 80/20 to 40/60.

  Further, when the polymer block B is composed of polyisoprene, it may be substantially composed of only 1,4-bonds, and mainly 3,4-bonds, It may be a case where a 1,4-bond is included. The ratio (weight ratio) between the 1,4 bond amount and the 3,4 bond amount is, for example, 1,4 bond amount / 3,4 bond amount = 100/0 to 20/80, preferably 99/1 to 25. / 75, more preferably about 97/3 to 30/70. Furthermore, in addition to 3,4-bonds, 1,2-bonds may be included. The ratio of the 1,2 bond amount is 80% by weight or less (for example, 1 to 70% by weight), preferably about 5 to 50% by weight, based on the total bond amount.

  The ratio (weight ratio) between the aromatic vinyl compound and the conjugated diene compound is, for example, aromatic vinyl compound / conjugated diene compound = 1/99 to 89/20, preferably 5/95 to 75/25, more preferably 10. / 90 to 65/35 (especially 15/85 to 50/50).

  In the present invention, among these styrene elastomers, a hydrogenated product of a block copolymer of a conjugated diene compound and an aromatic vinyl compound (hydrogenated diene block copolymer) is particularly preferable.

  In the production of a hydrogenated diene block copolymer, from the viewpoint of heat resistance and weather resistance, 70% or more of unsaturated double bonds derived from the conjugated diene compound in the block copolymer before hydrogenation (preferably 75 It is preferable to hydrogenate about 99.9%, more preferably about 80-99%). The amount of unsaturated double bonds in the polymer block B in the hydrogenated block copolymer can be determined by iodination measurement, infrared spectrophotometer, nuclear magnetic resonance apparatus or the like.

  Furthermore, the hydrogenated diene block copolymer has a functional group such as a carboxyl group, a hydroxyl group, an acid anhydride group, an amino group, and an epoxy group in the molecular chain or at the molecular end unless the effects of the present invention are impaired. It may be introduced.

  The hydrogenated diene block copolymer can be produced by, for example, the following conventional anionic polymerization method. That is, a method of sequentially polymerizing an aromatic vinyl compound and a conjugated diene compound in an inert organic solvent (for example, hydrocarbons such as n-hexane and cyclohexane) using an initiator (such as an alkyl lithium compound) Furthermore, a diene block copolymer can be obtained by a method of forming a radial block copolymer using the above-described polyfunctional coupling agent. Further, the obtained diene block copolymer is hydrogenated in the presence of a hydrogenation catalyst (such as nickel octenoate-triethylaluminum) in an inert organic solvent (such as hydrocarbons) according to a conventional method. Thus, a hydrogenated block copolymer can be produced.

  The hydrogenated diene block copolymer thus obtained may contain an olefin resin, a non-aromatic rubber softener, and the like from the viewpoint of adjusting the hardness. Examples of the olefin resin include propylene resin and ethylene resin. These olefin resins can be used alone or in combination of two or more. As the non-aromatic rubber softener, any of the conventional non-aromatic rubber softeners can be used, and among them, mineral oil or liquid or low molecular weight synthetic softener can be preferably used. Commercially available products usually contain such olefinic resins and softeners. In the present invention, hydrogenated diene block copolymer compositions containing such olefinic resins and rubber softeners are also included. And included in the concept of hydrogenated diene block copolymer.

  Examples of such commercially available products of hydrogenated diene block copolymers include “Septon” and “Hibler” manufactured by Kuraray Co., Ltd., and polyolefin resins are used as such hydrogenated diene block copolymers. As a resin composition containing Kuraray Plastics Co., Ltd. "Septon Compound", Riken Technos "Reostomer", "Actima", Mitsubishi Chemical "Lavalon", Sumitomo Chemical "Esporex SB" "Series (formerly Sumitomo TPE-SB)", Aron Kasei "Elastomer AR", Asahi Kasei "Tough Tech", Kraton Polymer Japan "Clayton G", JSR "Dynalon SEBC" (all trade names) Etc.

  The olefin-based elastomer is not particularly limited as long as it is an elastomer having a rubber component that is a soft segment and an olefin-based resin that is a hard segment (such as an ethylene-based resin or a propylene-based resin) as main components. In particular, a composition having an olefin rubber and a propylene polymer as main components is suitable.

  Examples of the olefin rubber include ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber (EPDM), ethylene-1-butene-nonconjugated diene copolymer rubber, propylene-1-butene- Examples thereof include elastic copolymers mainly composed of olefins such as non-conjugated diene copolymer rubbers.

  Examples of non-conjugated dienes constituting these olefinic rubbers include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, and ethylidene norbornene. Of these non-conjugated dienes, ethylidene norbornene is preferred.

  These olefin rubbers can be used alone or in combination of two or more. Among these olefin rubbers, ethylene-propylene copolymer rubber and ethylene-propylene-nonconjugated diene copolymer rubber are preferable. A more preferred specific example of the olefin rubber is EPDM having an ethylene content of 55 to 75% by weight and a non-conjugated diene content of 1 to 10% by weight. EPDM having an ethylene content within this range has an excellent balance between extrudability and flexibility.

  The propylene-based polymer is not particularly limited as long as it is a polymer mainly composed of propylene, and among them, polypropylene, a copolymer of propylene and an α-olefin having 2 or more carbon atoms is preferable. Specific examples of the α-olefin having 2 or more carbon atoms include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-decene, 3-methyl-1-pentene, 4 -Methyl-1-pentene, 1-octene and the like. These α-olefins can be used alone or in combination of two or more.

  In the olefin elastomer, the ratio (weight ratio) between the olefin rubber and the propylene polymer is, for example, olefin rubber / propylene polymer = 20/80 to 80/20, preferably 30/70 to 70/30. Degree.

  The olefin elastomer may contain a non-aromatic mineral oil or a low molecular weight synthetic softener as a plasticizer from the viewpoint of adjusting the hardness. Commercially available products usually contain such plasticizers. In the present invention, olefin elastomer compositions containing such plasticizers are also included in the concept of olefin elastomers.

  The melt flow rate value (230 ° C., 10 kg load (98 N)) of the olefin elastomer is, for example, 1 to 50 g / 10 minutes, preferably 3 to 40 g / 10 minutes, and more preferably about 5 to 30 g / 10 minutes. .

  Examples of such commercially available olefin-based elastomers include “Thermo Run” (trade name) manufactured by Mitsubishi Chemical Corporation, “Miralastomer” (trade name) manufactured by Mitsui Chemicals, Ltd., “Sumitomo” manufactured by Sumitomo Chemical Co., Ltd. TPE "," Santoprene "(trade name) manufactured by AES Japan," Adflex "(trade name) manufactured by San Aroma I Co., Ltd., and the like.

  The thermoplastic elastomer preferably contains a hydrogenated diene block copolymer from the viewpoints of economy and rubber elasticity. In particular, from the viewpoint of fluidity and moldability, a combination of a hydrogenated diene block copolymer and an olefin polymer (particularly the propylene polymer etc.) can be preferably used, and the ratio (weight ratio) of both is For example, hydrogenated diene block copolymer / olefin polymer = 100/0 to 10/90, preferably 90/10 to 20/80, more preferably about 80/20 to 30/70.

  In the non-halogen / non-phosphorus flame retardant resin composition, a processability improver, an antioxidant, a modifier, a crosslinking agent, a pigment, an ultraviolet absorber, a heat stabilizer, etc., in addition to the above components, as necessary Can be blended.

  The control tube of the present invention can be manufactured, for example, as follows.

  First, a tube made of soft polyurethane or soft nylon for an inner core tube is produced in advance using an extrusion molding machine. When the inner core tube is composed of two layers of a soft polyurethane layer (outer layer) and a soft nylon layer (inner layer), the inner core tube is produced by subjecting both layers to multilayer extrusion molding (coextrusion molding).

  Next, the inner core tube, which has been stored in the atmosphere until it is sufficiently cooled and stabilized, is introduced into a die at the outlet of the crosshead type extruder, and a non-halogen / nonphosphorous flame retardant resin composition is produced by the crosshead type extruder. Using a resin raw material consisting of For example, if the two-layer coextrusion molding method is used instead of the two-stage production method, the inner tube resin and the covering protective cover resin melt together, and the covering protective cover cannot be peeled off. It becomes.

  The control tube of the present invention is used, for example, as a piping material (fluid: oil-free air, oil-supplying air, cooling water) related to a welding apparatus used in a production process of an automobile body or the like.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples. The measuring method of performance evaluation of the tube obtained in the Example is shown below.
[Maximum working pressure]
The maximum operating pressure was set as the breakdown pressure x 30% (safety factor).
[Minimum bending radius]
The minimum bending radius of the tube produced according to JIS B8381 was measured.

(Examples 1-16 and Comparative Examples 1-2) Manufacture of control tubes Manufacture of inner core tube (1) Manufacture of two-layer inner core tube As material of inner core tube outer layer, ether-based thermoplastic polyurethane (trade name: Pelecene AE2103-90AE, Shore A hardness 90) manufactured by Dow Chemical Co., Ltd. As the material for the inner layer of the core tube, an ether-based soft nylon elastomer (Nylon 12 series, trade name: DAIAMID ZE0001, Shore D hardness 47) manufactured by Daicel Degussa, which is an ether elastomer-based soft nylon containing no plasticizer. Then, an inner core tube having a two-layer structure was manufactured using a multilayer extrusion molding machine (coextrusion molding machine). Normally, the inner tube is UV-resistant at the cover peeling part and easy to recycle (if it is black, it can be regenerated by crushing and re-pelleting when the product is defective), but the tube color is black. Since the inner core has a two-layer structure, the inner layer nylon is left uncolored natural color (transparent) for the control of the thickness and the like, and the outer layer polyurethane is made black by using a black masterbatch. (See Table 1).

(2) Manufacture of single layer inner tube made of soft nylon for water As the material of the inner tube, nylon 12 (polyamide 12) soft nylon (trade name: Daiamide ZL4100, Shore D hardness 57) manufactured by Daicel Degussa A black masterbatch was blended, and four types of single-layer inner core tubes having different dimensions were produced using a single-layer extruder (see Table 2).

(3) Manufacture of single layer inner core tube made of soft nylon (nylon 11) As material for inner core tube, nylon 11 (polyamide 11) soft nylon (trade name: BESN F15 TL, Shore D hardness manufactured by Arkema, France) 52, plasticizer: Nn-butylbenzenesulfonamide, 2-hydroxyhexyl ester of parahydroxybenzoic acid) is mixed with a black masterbatch, and four types of single-layer inner tube with different dimensions are formed by a single-layer extruder. Manufactured (see Table 3).

(4) Manufacture of single layer inner core tube made of soft polyurethane As the material of the inner core tube, black masterbatch is blended with ether-based thermoplastic polyurethane (trade name: Resamine P-2494, Shore A hardness 92) manufactured by Dainichi Seika. Then, four types of single-layer inner core tubes having different dimensions were manufactured using a single-layer extruder (see Table 4).

2. Coating protective cover hanging molding After the inner core tube has cooled sufficiently and the internal physical properties have been sufficiently stabilized, the tube is introduced into the outlet side mold of the crosshead type extruder, and the composition shown in Table 5 A white covering protective cover was formed by forming a covering protective cover with a cover raw material comprising the above non-halogen / non-phosphorous flame retardant resin composition to produce a control tube.
Further, by using the same inner core tube as in Example 3, a cover protective cover is formed from a cover raw material made of a non-halogen / non-phosphorus flame retardant resin composition having the composition of Comparative Examples 1 and 2 shown in Table 5, and then white. A protective tube was formed and a control tube was produced.

＊１：エチレン−酢酸ビニル共重合体（三井・デュポンケミカル社製、商品名：エバフレックスＥＶ４０ＬＸ、ショアＡ硬度５０）
＊２：エチレン−酢酸ビニル共重合体（三井・デュポンケミカル社製、商品名：エバフレックスＥＶ４６０、ショアＡ硬度９０）
＊３：接着性ポリエチレン（日本ユニカー社製、商品名：ナックエースＧＡ−００４、ショアＤ硬度５１）
＊４：シリコーン系難燃剤（ダウ・コーニング社製、４−７１０５）
＊５：その他
酸化防止剤：２，２’−メチレンビス（４，６−ジ−ｔ−ブチルフェニル）オクチルホスファイト
酸化防止剤：テトラキス［メチレン−３−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）プロピオネート］メタン
酸化防止剤：テトラキス［メチレン−３−（ドデシルチオ）プロピオネート］メタン
加工性改良剤：メタクリル酸メチル・アクリル酸アルキル・ジメチルシロキサン・コポリマー
架橋剤：１，３−ビス（ｔ−ブチルパーオキシイソプロピル）ベンゼン
＊６：水添ブロック共重合体（（株）クラレ製、商品名「ハイブラー７１２５」、スチレン−水添ビニルイソプレン−スチレンブロック共重合体、３，４−結合：約６０％、１，４−結合：約４０％、スチレン含有量２０％）６０重量％とポリプロピレン（三井化学（株）製、商品名「三井ポリプロピレンＦ３２７」、エチレンランダム共重合体、ＭＦＲ：６ｇ／１０分（２３０℃、２．１６ｋｇ荷重（約２１．２Ｎ）））４０重量％との配合物

* 1: Ethylene-vinyl acetate copolymer (Mitsui / DuPont Chemicals, trade name: Everflex EV40LX, Shore A hardness 50)
* 2: Ethylene-vinyl acetate copolymer (Mitsui / DuPont Chemical Co., Ltd., trade name: Everflex EV460, Shore A hardness 90)
* 3: Adhesive polyethylene (made by Nihon Unicar Co., Ltd., trade name: NAC ACE GA-004, Shore D hardness 51)
* 4: Silicone flame retardant (Dow Corning, 4-7105)
* 5: Other antioxidants: 2,2′-methylenebis (4,6-di-t-butylphenyl) octyl phosphite antioxidant: tetrakis [methylene-3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate] methane antioxidant: tetrakis [methylene-3- (dodecylthio) propionate] methane processability improver: methyl methacrylate / alkyl acrylate / dimethyl siloxane copolymer cross-linking agent: 1,3-bis ( t-Butylperoxyisopropyl) benzene
* 6: Hydrogenated block copolymer (manufactured by Kuraray Co., Ltd., trade name “HIBLER 7125”, styrene-hydrogenated vinylisoprene-styrene block copolymer, 3,4-bond: about 60%, 1,4- Bonding: about 40%, styrene content 20% 60% by weight and polypropylene (Mitsui Chemicals, trade name “Mitsui Polypropylene F327”, ethylene random copolymer, MFR: 6 g / 10 min (230 ° C., 2 .16 kg load (about 21.2 N))) 40% by weight

(Example 17) Bending durability test The tubes manufactured in Example 3 and Comparative Examples 1 and 2 were subjected to a "bending durability test" based on JIS B8381 (pneumatic flexible pipe joint).

(1) Test method As shown in Fig. 2, a test tube was installed in a JIS durability tester, 0.8 MPa air pressure was applied for 0.5 second pressurization and 0.5 second exhaust cycle, and plugged at the same time. The full amplitude Dmm due to the stroke on the side was given one reciprocation per second, and it was investigated how many times a crack or the like occurred in the covering protective cover.
Further, as shown in FIG. 2, the test tube was attached with five insulation locks so that a load was applied when it was bent. Insulok was tightened by hand until it stopped.
-Comparative examples 1 and 2: n = 3 sets-Example 3: n = 5 sets-Test fitting: One-touch fitting ZH-103 manufactured by Aoi Co., Ltd.

(2) Test results The tube of Comparative Example 1 cracked at 200,000 to 380,000 times (n = 3, one at 200,000 times, one at 320,000 times, at 380,000 times) One). All the tubes of Comparative Example 2 cracked after about 100,000 times.
The tube of Example 3 was not cracked in all the samples (n = 5) even after 1.5 million times, and the test is still ongoing.

Example 18 Abrasion Test Abrasion test using the Taber abrasion wheel After the cover material of the tube manufactured in Comparative Examples 1 and 2 was peeled off, a press sheet was prepared and a “Abrasion test using the Taber abrasion wheel” in accordance with JIS K7204 was conducted. The amount of wear of this tube was 30% less than that of the tube of Comparative Example 1.

2. Sliding Wear Test After peeling the cover material of the tube manufactured in Example 3 and Comparative Example 1, a press sheet was prepared and a “sliding wear test” based on JIS K7218 was performed. The amount of wear was reduced by 60% compared to the tube of Example 1.

3. Wear Durability Test (1) Test Method As shown in FIG. 3, the test tube (tube manufactured in Example 3 and Comparative Examples 1 and 2) was installed in a JIS durability tester, and the contact portion of the tube was made into an insulation lock. And bundled lightly.
The test tube installed straight was always in contact with the test tube installed in the JIS durability tester and installed so as to push lightly.
The test tube installed in the JIS durability tester was given 0.8 MPa air pressure in a 0.5 second pressurization and 0.5 second exhaust cycle, and at the same time, the plug side had a stroke with a total amplitude of 70 mm per second. It was operated in a reciprocating cycle, and two test tubes (outer skin) were rubbed together to confirm the number of times when a hole was generated in the outer skin.
* If the two tubes are not bundled with the Insulok, one of the tubes will escape and will not rub well, so the tubes will be bundled to the extent that they will move.
n = 1 set of test fittings: Aoi Co., Ltd. one-touch fitting ZH-103

(2) Test results
In the tube of Comparative Example 1, the inner core tube is exposed at 10,000 times, the tube of Comparative Example 2 is exposed at 30,000 times, and the tube of Example 3 is exposed at 205,000 times. The core tube was exposed.

4). Abrasion test comparison between the product of the present invention (Example 3) and another company's product Press sheet after peeling the cover material of the product of the present invention (Example 3) and other company's product (using a halogen-based cover material such as polyvinyl chloride) And a “sliding wear test” based on the JIS K7218A method was performed.

(1) Measurement method and conditions Counterpart material: S45C ring (# 240 polishing, contact area: 2 cm ² ), load: 20 N
Sliding speed: 0.5 m / s, specified sliding distance: 3 km, specified sliding time: 100 minutes Test piece dimensions: 30 mm × 30 mm × t 3 mm, test atmosphere: room temperature, in-air test device: rotational dynamic friction wear test Machine IIIt-2000-5000n (manufactured by Takachiho Seiki)

(2) Abrasion test sample (a) Invention product Example 3 (2-layer inner tube type cover material)
(B) Inner core nylon tube type cover material A company TRB cover material B company FW cover material C company SP4 cover material (c) Inner core urethane tube type cover material A company TRBU cover material B company FWU cover material LE cover material made by company D

(3) Results Table 6 shows the results.

※１）平均値
※２）摩擦係数の変化が少なく比較的安定
※３）摩擦係数の数値の変化が大きく安定しない
※４）規定の摺動距離３ｋｍ（１００分）に達し試験が完了したもの
※５）規定の摺動距離３ｋｍ（１００分）に達する前に磨耗量上限となり試験停止

* 1) Average value * 2) Relatively stable with little change in friction coefficient * 3) Large change in coefficient of friction value is not stable
* 4) When the specified sliding distance of 3 km (100 minutes) has been reached and the test has been completed. * 5) Before reaching the specified sliding distance of 3 km (100 minutes), the wear limit is reached and the test is stopped.

  As is apparent from Table 6, the product of the present invention (Example 3) had the smallest wear mass and the smallest coefficient of dynamic friction, and exhibited the desired product performance.

(Example 19) Flame retardancy test Since the styrene elastomer used as a covering protective cover material in the example does not have flame retardancy, the flame retardancy is confirmed using the oxygen index as a measure of flame retardancy. did. The oxygen index of the tube of Example 3 was 44, and there was no problem in terms of flame retardancy. All UL94 V-0 standards were cleared, and there was no problem in spatter resistance.

It is sectional drawing of the control tube which an inner core tube consists of two layers with one inner core tube. It is a figure which shows the installation state of the test tube in a bending durability test. It is a figure which shows the installation state of the test tube in an abrasion durability test.

Explanation of symbols

1 Cover protective cover 2 Inner core tube outer layer 3 Inner core tube inner layer

Claims (7)

  In the control tube comprising the inner core tube and the covering protective cover, the inner core tube includes at least a layer mainly composed of soft polyurethane and / or soft nylon, and the covering protective cover includes magnesium hydroxide, a silicone flame retardant, and carbonization. A control tube comprising a non-halogen / non-phosphorus flame retardant resin composition containing a thermoplastic elastomer composed of hydrogen.   The control tube according to claim 1, wherein the soft polyurethane is an ether polyurethane.   The control tube according to claim 1, wherein the inner tube has a layer made of ether elastomer-based soft nylon mainly containing no plasticizer inside a layer mainly made of ether-based polyurethane.   The control tube according to any one of claims 1 to 3, wherein the thermoplastic elastomer composed of hydrocarbons contained in the covering protective cover includes a hydrogenated styrene elastomer.   The control tube according to claim 4, wherein the thermoplastic elastomer composed of hydrocarbons contained in the covering protective cover includes polypropylene and a hydrogenated styrene elastomer.   The control tube according to any one of claims 1 to 5, wherein the base resin of the non-halogen / non-phosphorus flame retardant resin composition constituting the covering protective cover is mainly composed of an ethylene-vinyl acetate copolymer.   The control tube according to any one of claims 1 to 6, which is used as a piping material related to a welding apparatus used in an automobile production process.

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