JP2019059059A - Laminated structure - Google Patents

Abstract

To provide a laminated structure having low fuel permeability and high flexibility and bending processability.SOLUTION: There is provided a laminated structure which comprises an outer layer (A) composed of a polyamide-based thermoplastic elastomer composition and an inner layer (B) containing a thermoplastic resin, where the polyamide-based thermoplastic elastomer composition is a crosslinked product of a rubber composition containing an aliphatic polyamide [I] having a melting point of 200 to 290°C, an ethylene-α-olefin-non-conjugated polyene copolymer rubber [II], an olefinic polymer [III} containing a predetermined amount of a functional group structural unit and a phenol resin-based crosslinking agent (IV) and the thermoplastic resin is at least one selected from the group consisting of an aliphatic polyamide, a polyolefin-based resin and the like.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated structure.

  Polyamide 12 (PA 12) and polyamide 11 (PA 11) have been widely used as tubes for fuel piping of automobiles and the like because they are excellent in flexibility. In recent years, the control of transpiration of fuel gas from automobiles and the like has become more severe from the viewpoint of preventing environmental pollution. Accordingly, it is required that fuel tubes for automobiles and the like have low fuel gas permeability. Furthermore, from the viewpoint of saving consumption of gasoline and improving performance, alcohol gasoline in which low boiling point alcohols such as methanol and ethanol are blended has been put to practical use. Accordingly, it is also required that fuel tubes for automobiles and the like have low permeability to not only conventional fuel (such as gasoline) but also alcohol gasoline and the like.

  In response to such a demand, a fuel piping tube or the like having a fuel barrier layer (inner layer) made of fluorocarbon resin and an outer layer made of PA12 or PA11 has been developed. In addition, semi-aromatic compounds such as polyphenylene sulfide resin (PPS) which is less expensive than fluorine resin and low in fuel permeability (eg, polymethaxylylene adipamide (MXD6), polyamide 6T (PA6T), polyamide 9T (PA9T), etc. Patent Document 1 proposes a fuel piping tube having a fuel barrier layer made of a polyester resin such as a group polyamide resin; polybutylene terephthalate (PBT) or polybutylene naphthalate (PBN).

  In a fuel piping tube having such a fuel barrier layer (inner layer), the outer layer may not necessarily have the function of reducing the fuel permeability, and has a function of protecting the fuel barrier layer, a road antifreeze agent The function of preventing deterioration of the fuel pipe tube due to calcium chloride, and the function of preventing damage of the fuel pipe hose due to the internal pressure generated by the fuel vapor may be used. Therefore, cost reduction is required for the outer layer.

  On the other hand, a fuel piping hose having an inner layer made of MXD6 or the like and an outer layer made of a polyolefin resin has been proposed (e.g., Patent Document 2). In addition, a fuel piping hose having an inner layer containing a semi-aromatic polyamide resin, an intermediate layer containing a modified ethylene / α-olefin copolymer, and an outer layer containing a polyethylene resin has also been proposed (eg, Patent Document 3).

Japanese Patent Application Publication No. 2007-502726 JP-A-4-272592 JP, 2015-231709, A

  However, resin layers with low fuel permeability generally have high flexural modulus. A fuel pipe tube including such a resin layer with low fuel permeability tends to be hard (flexibility tends to be low), and workability at the time of incorporation into an automobile or the like tends to deteriorate. On the other hand, if the thickness of the low fuel permeability resin layer is reduced to improve the flexibility of the fuel piping tube, the fuel permeability of the fuel piping tube will be increased.

  On the other hand, since the fuel piping tube described in Patent Documents 2 and 3 has the inner layer containing the semi-aromatic polyamide resin, the fuel permeability is sufficiently reduced, and the flexible polyethylene resin is contained. Since it has an outer layer, it can have higher flexibility than the fuel piping tube described in Patent Document 1. However, with regard to the bending workability in which the fuel piping tube is maintained at a high temperature above the glass transition temperature and bent into a predetermined shape to change the shape, further improvement is required.

  That is, in the fuel piping tube described in Patent Documents 2 and 3, since the inner layer contains a semi-aromatic polyamide resin having a high glass transition temperature, it is difficult to perform bending at a temperature lower than the glass transition temperature and higher than the glass transition temperature It is necessary to perform bending processing at high temperature. However, when the bending process is performed at a high temperature, the heat resistance of the polyethylene-based resin contained in the outer layer is not sufficient, which may cause appearance defects (e.g., the melting of the resin forming the outer layer). That is, the temperature range in which bending can be performed is likely to be limited, and further improvement in bending workability is required. Thus, there is a trade-off between lowering fuel permeability and improving flexibility and bendability, and it is desirable that these be highly compatible.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a laminated structure having low fuel permeability, high flexibility and bending workability.

[1] A laminated structure in which an inner layer (A) made of a polyamide-based thermoplastic elastomer composition and an outer layer (B) containing a thermoplastic resin are laminated, wherein the polyamide-based thermoplastic elastomer composition is carbon A dicarboxylic acid structural unit containing 80% by mole or more of an aliphatic dicarboxylic acid structural unit having 2 to 14 atoms with respect to all dicarboxylic acid structural units, and an aliphatic diamine structural unit having 4 to 12 carbon atoms as all diamine structural units An aliphatic polyamide comprising a diamine structural unit containing 80 mol% or more, or an aliphatic polyamide comprising an aminocarboxylic acid structural unit or a lactam structural unit, and having a melting point (Tm) measured by differential scanning calorimetry (DSC) ) Is 200 to 290 ° C., an ethylene structural unit [a], and an α-olefin having 3 to 20 carbon atoms. Ethylene / α-olefin / nonconjugated polyene copolymer rubber [II] containing a fin structural unit [b] and a nonconjugated polyene structural unit [c] having one or more carbon-carbon double bonds in one molecule A thermoplastic resin, and a crosslinked product of a rubber composition containing an olefin polymer [III] containing 0.3 to 5.0% by mass of a functional group structural unit, and a phenol resin crosslinking agent [IV]; Resins include aliphatic polyamides, semiaromatic polyamides, polyolefin resins, tetrafluoroethylene / ethylene copolymers, polyvinyl fluoride, polyvinylidene fluoride, polyphenylene sulfide, polyesters, polyketones, liquid crystal polymers, ethylene vinyl alcohol and the aforementioned polyamide resins At least one selected from the group consisting of elastomers other than thermoplastic elastomer compositions, Laminated structure.
[2] The laminated structure according to [1], wherein the thermoplastic resin is an aliphatic polyamide.
[3] The laminated structure according to [1], wherein the thermoplastic resin is a polyethylene resin.
[4] The polyethylene-based resin is an ethylene / C3-C16 α-olefin (co) polymer having a density of 0.925 to 0.970 g / cm ³ measured according to ASTM D1505. The laminated structure according to [3].
[5] The melt flow rate of the ethylene / C 3-16 α-olefin (co) polymer as measured according to ASTM D 1238 (230 ° C., 2.16 kg) is 0.01 to 10 g / The laminated structure according to [4], which is 10 minutes.
[6] The aliphatic polyamide [I] is at least one or more selected from the group consisting of polyamide 6, polyamide 6.6, polyamide 6.10. Polyamide 6, 12 and copolymers thereof [1] ] The laminated structure in any one of-[5].
[7] The functional group structural unit of the olefin polymer [III] contains one or more functional groups selected from the group consisting of a carboxylic acid group, an ester group, an ether group, an aldehyde group and a ketone group, [1] Laminated structure in any one of-[6].
[8] The laminated structure according to [7], wherein the functional group structural unit of the olefin polymer [III] is a maleic anhydride structural unit.
[9] The polyamide-based thermoplastic elastomer composition comprises 10 to 60% by mass of the aliphatic polyamide [I], and 25 to 86% by mass of the ethylene / α-olefin / nonconjugated polyene copolymer rubber [II]. %, A rubber composition containing 0.1 to 30% by mass of the olefin polymer [III], and 1 to 10% by mass of the phenol resin-based crosslinking agent [IV] The laminated structure according to any one of [1] to [8], which is a crosslinked product of (II), (III) and (IV) in 100% by mass).
[10] The lamination according to any one of [1] to [9], wherein the thickness of the inner layer (A) is 30 to 70% of the total thickness of the inner layer (A) and the outer layer (B) Structure.
[11] The laminated structure according to any one of [1] to [10], which is a hollow structure.
[12] The laminated structure according to [11], which is a hose or a tube.
[13] The laminated structure according to [12], which is a tube for fuel piping.
[14] The laminated structure according to [13], wherein an outer diameter of the fuel piping tube is 2 to 50 mm, and a thickness is 0.2 to 10 mm.

  According to the present invention, it is possible to provide a laminated structure having low fuel permeability and high flexibility and bending processability.

1A and 1B are schematic cross-sectional views showing an example of the laminated structure of the present invention. FIG. 2 is a side view showing a method of measuring the bending radius immediately before breaking in the embodiment.

1. Laminated Structure The laminated structure of the present invention is a structure including at least an inner layer (A) comprising a polyamide-based thermoplastic elastomer composition and an outer layer (B) containing a thermoplastic resin. The laminated structure of the present invention is, for example, a hollow structure (see FIGS. 1A and 1B) such as a hose or a tube for transporting gas or liquid inside, a bottle or tank for storing gas or liquid inside, etc. Used as a container of

1-1. Inner layer (A)
The inner layer (A) is a layer disposed on the side (inner side) on which the gas or liquid is transported or stored, for example, in the laminated structure, and has a function to suppress leakage or transpiration or permeation of gas or liquid to the outside. Have. The inner layer (A) contains a polyamide-based thermoplastic elastomer composition.

  The polyamide-based thermoplastic elastomer composition comprises an aliphatic polyamide [I], an ethylene / α-olefin / nonconjugated polyene copolymer rubber [II], an olefin-based polymer [III], and a phenol resin-based crosslinking agent IV) and a crosslinked product (dynamically crosslinked product) of the rubber composition. The crosslinked product is a partially crosslinked product or a completely crosslinked product. By this crosslinking (dynamic crosslinking), the ethylene / α-olefin / nonconjugated polyene copolymer rubber [II] in the rubber composition is crosslinked.

  That is, the polyamide-based thermoplastic elastomer composition comprises an aliphatic polyamide [I], an ethylene / α-olefin / non-conjugated polyene copolymer rubber [II] crosslinked by a phenol resin-based crosslinking agent [IV], and an olefin And the polymer [III]. Further, the polyamide-based thermoplastic elastomer composition comprises a sea phase (matrix phase) mainly composed of aliphatic polyamide [I] and an island phase (dispersed phase mainly composed of crosslinked copolymer rubber [II] And a sea-island structure. The sea phase (matrix phase) containing aliphatic polyamide [I] as a main component can exhibit thermoplasticity. On the other hand, an island phase (dispersed phase) mainly composed of a crosslinked copolymer rubber [II] can exhibit rubber elasticity. In addition, the average particle size of the island phase (dispersed phase) is relatively small and finely dispersed.

  Thus, the inner layer (A) having a structure in which the copolymer rubber [II] constituting the island phase is crosslinked and in which the island phase is finely dispersed is unlikely to swell even in contact with the fuel, etc. As well as being difficult to penetrate, it may have sufficient flexibility. In addition, since the polyamide-based thermoplastic elastomer composition does not have a high glass transition temperature, it has sufficient flexibility even at a relatively low temperature, and can be subjected to bending. Thus, even if the outer layer (B) is made of a resin having relatively low heat resistance, appearance defects due to melting of the resin due to heat at the time of bending can be suppressed. Thereby, the laminated structure of the present invention can have good flexibility and bendability despite having low fuel permeability (good fuel barrier property).

  Hereinafter, each component for obtaining a polyamide-type thermoplastic elastomer composition is demonstrated.

1-1-1. Aliphatic polyamide [I]
Aliphatic polyamide [I] contains an amide bond (-NH-C (= O)-) and a structural unit not containing an aromatic ring (an amide bond containing structural unit not containing an aromatic ring) as a main component. The phrase “containing an amide bond-containing structural unit not containing an aromatic ring as a main component” means an amide bond-containing structural unit not containing an aromatic ring, the total number of moles of the amide bond-containing structural unit constituting the aliphatic polyamide [I]. 80 mol% or more, preferably 90 to 100 mol% with respect to the

  Aliphatic polyamide [I] may be obtained by polycondensation reaction of dicarboxylic acid and diamine, or by polycondensation reaction of aminocarboxylic acid, or by ring-opening polymerization reaction of lactam. It may be That is, aliphatic polyamide [I] is composed of at least one of an amide bond-containing structural unit composed of a dicarboxylic acid structural unit and a diamine structural unit, an aminocarboxylic acid structural unit, and a lactam structural unit.

(Dicarboxylic acid structural unit / diamine structural unit)
The dicarboxylic acid structural unit which comprises aliphatic polyamide [I] contains an aliphatic dicarboxylic acid structural unit. The aliphatic dicarboxylic acid is preferably an aliphatic dicarboxylic acid having 2 to 14 carbon atoms, more preferably 4 to 14 carbon atoms, and still more preferably 6 to 12 carbon atoms. Examples of aliphatic dicarboxylic acids include boric acid (C2), adipic acid (C6), pimelic acid (C7), suberic acid (C8), azelaic acid (C9), sebacic acid (C10), dodecanedioic acid (C12) And tetradecanedioic acid (C14) and the like. Among them, adipic acid (C6) and dodecanedioic acid (C12) are preferable. The aliphatic dicarboxylic acids may be used alone or in combination of two or more.

  The content ratio of the aliphatic dicarboxylic acid structural unit is preferably 80 mol% or more with respect to the total number of moles of the dicarboxylic acid structural unit constituting the aliphatic polyamide [I]. When the content ratio of the aliphatic dicarboxylic acid structural unit is 80 mol% or more, the crystallinity of the aliphatic polyamide [I] tends to increase, and sufficient heat resistance and fuel barrier properties can be imparted to the inner layer (A). The content ratio of the aliphatic dicarboxylic acid structural unit is more preferably 85 to 100 mol%, still more preferably 90 to 100 mol% with respect to the total number of moles of the dicarboxylic acid structural unit.

  The dicarboxylic acid structural unit constituting the aliphatic polyamide [I] may further contain a small amount of an alicyclic dicarboxylic acid structural unit or an aromatic dicarboxylic acid structural unit, as long as the effects of the present invention are not impaired.

  The diamine structural unit which comprises aliphatic polyamide [I] contains an aliphatic diamine structural unit. The aliphatic diamine is preferably an α, ω-linear aliphatic diamine having 4 to 12 carbon atoms, more preferably 6 to 10 carbon atoms. Examples of aliphatic diamines include tetramethylenediamine, hexamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine and the like. Among them, tetramethylenediamine, hexamethylenediamine, nonamethylenediamine and decamethylenediamine are preferable; tetramethylenediamine and hexamethylenediamine are more preferable. The aliphatic diamine may be of one type or a combination of two or more types.

  The content ratio of the aliphatic diamine structural unit is preferably 80 mol% or more based on the total number of moles of the diamine structural unit constituting the aliphatic polyamide [I]. When the content ratio of the aliphatic diamine structural unit is 80 mol% or more, the crystallinity of the aliphatic polyamide [I] tends to increase, and sufficient heat resistance and fuel barrier properties can be imparted to the inner layer (A). The content ratio of the aliphatic diamine structural unit is more preferably 85 to 100 mol%, further preferably 90 to 100 mol% with respect to the total number of moles of the diamine structural unit.

  The diamine structural unit which comprises aliphatic polyamide [I] may further contain a small amount of alicyclic diamine structural unit and aromatic diamine in the range which does not impair the effect of the present invention.

(Aminocarboxylic acid structural unit)
The aminocarboxylic acid which can constitute aliphatic polyamide [I] may be an aminocarboxylic acid having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms. Examples of such aminocarboxylic acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and the like. The aminocarboxylic acids may be used alone or in combination of two or more.

(Lactam structural unit)
The lactam which can constitute aliphatic polyamide [I] may be a lactam having 6 to 12 carbon atoms, preferably 6 to 10 carbon atoms. Examples of such lactams include alpha-pyrrolidone, epsilon-caprolactam, undecane lactam, omega-laurolactam, epsilon-enant lactam and the like. The lactam may be used alone or in combination of two or more.

  Examples of aliphatic polyamides [I] include polyamide 6, polyamide 6.6, polyamide 4-6, polyamide 6.10. Polyamide 6, 12 polyamide 6, 14 polyamide 6, 13 polyamide 6, 15 polyamide 6 · 16, polyamide 9 · 2, polyamide 9 · 10, polyamide 9 · 12, polyamide 9 · 13, polyamide 9 · 14, polyamide 9 · 15, polyamide 6 · 16, polyamide 9 · 36, polyamide 10 · 10, polyamide 10-12, polyamide 10.13, polyamide 10.14, polyamide 12.10, polyamide 12.12, polyamide 12.13, polyamide 12.14, and copolymers of these. Among them, polyamide 6, polyamide 6,6, polyamide 6.10, polyamide 6.12, polyamide 9.2, polyamide 10, 10 are preferable because they have good heat resistance, and polyamide 6, polyamide 6.6, polyamide 6 · 10 is more preferable. One type of aliphatic polyamide [I] may be used, or two or more types may be used in combination.

  From the viewpoint of thermal stability at the time of compounding and molding, it is preferable that at least a part of the terminal groups of the molecular chains of the aliphatic polyamide [I] be sealed with a terminal blocking agent. In particular, from the viewpoint of melt stability, heat resistance and hydrolysis resistance, the amount of terminal amino group of the molecular chain is preferably 0.1 to 300 mmol / kg, more preferably 1 to 100 mmol / kg, and still more preferably 1 to 1 It is 50 mmol / kg, more preferably 1 to 35 mmol / kg, and particularly preferably 5 to 35 mmol / kg.

  The end capping agent is not particularly limited as long as it is a monofunctional compound having reactivity with the amino group or carboxyl group at the molecular terminal of polyamide, but from the viewpoint of reactivity and stability of the sealing end, etc. Monocarboxylic acids or monoamines are preferred, and monocarboxylic acids are more preferred in terms of ease of handling and the like. In addition, acid anhydride monoisocyanate, mono acid halide, monoesters, monoalcohols and the like can also be used.

  The monocarboxylic acid used as the end capping agent is not particularly limited as long as it has reactivity with an amino group. Examples of monocarboxylic acids include aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecyl acid, myristic acid, palmitic acid, stearic acid, pivalic acid, isobutyric acid, etc. Acids; Alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; and Aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid and the like. Two or more of these can be used in combination. Among them, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecyl acid, myristic acid, palmitic acid, stearic acid, benzoic acid from the viewpoints of reactivity, stability of sealing end, price etc. Acids are more preferred.

  The monoamine used as the end capping agent is not particularly limited as long as it has reactivity with a carboxyl group. Examples of monoamines include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, diethylamine, dipropylamine, aliphatic monoamines such as dibutylamine, etc .; cyclohexylamine, dicyclohexylamine etc. Alicyclic monoamines; aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine. Two or more of these can be used in combination. Among them, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine and aniline are more preferable from the viewpoints of reactivity, boiling point, stability of sealing end and price.

The amount of terminal amino groups can be measured by the following method.
The terminal amino group quantity of aliphatic polyamide [I] balances 0.5-0.7 g of aliphatic polyamide [I] finely, and is made to melt | dissolve in 30 mL of m-cresol. Then, 1 to 2 drops of a 0.1% Timor blue / m-cresol solution, which is an indicator, is added to prepare a sample solution. The sample solution is titrated with a 0.02 N p-toluenesulfonic acid solution from yellow to bluish purple to identify the terminal amino group content ([NH ₂ ], unit: μ equivalent / g).

  The melting point (Tm) measured by differential scanning calorimetry (DSC) of the aliphatic polyamide [I] is preferably 200 to 290 ° C., and more preferably 220 to 280 ° C. When the aliphatic polyamide [I] has such a melting point (Tm), the inner layer (A) having good heat resistance can be obtained without impairing the moldability.

  The heat of fusion (ΔH) measured by differential scanning calorimetry (DSC) of aliphatic polyamide [I] is preferably 45 to 100 mJ / mg. When the heat of fusion (ΔH) is 45 mJ / mg or more, the inner layer (A) easily has sufficient fuel barrier properties and heat resistance, and when it is 100 mJ / mg or less, the inner layer (A) becomes hard (elastic modulus Can become excessively high).

The melting point (Tm) and the heat of fusion (ΔH) of the aliphatic polyamide [I] can be measured under the following conditions.
Using a DSC (differential scanning calorimetry), heat the polyamide [I] and hold it once at 320 ° C. for 5 minutes, then lower the temperature to 23 ° C. at a rate of 10 ° C./min and then 10 ° C./min Temperature rise at speed. The temperature of the endothermic peak based on melting at this time is taken as the melting point (Tm) of the polyamide. The heat of fusion (ΔH) (mJ / mg) is calculated from the area divided by the endothermic peak of the curve obtained and the baseline of the entire endothermic peak.

  The melting point and the heat of fusion (ΔH) of the aliphatic polyamide [I] can be adjusted, for example, by the monomer composition constituting the aliphatic polyamide [I]. In order to increase the melting point and heat of fusion (ΔH) of the aliphatic polyamide [I], for example, the number of carbon atoms of the dicarboxylic acid and diamine which constitute the aliphatic polyamide [I] and the aminocarboxylic acid and lactam should be fixed or less. Is preferred.

  Melt flow rate (MFR) of aliphatic polyamide [I] at a temperature of 290 ° C. according to ISO 1133 and a load of 2.16 kg makes it easy to combine fine viscosity with copolymer rubber [II] at the time of compounding to facilitate fine dispersion 0.1 to 500 g / 10 minutes is preferable, and 0.1 to 300 g / 10 minutes, 0.1 to 100 g / 10 minutes, and 5 to 100 g / 10 minutes are more preferable.

  Aliphatic polyamide [I] is produced by polycondensation reaction of dicarboxylic acid and diamine in solution, polycondensation reaction of aminocarboxylic acid, or ring-opening polymerization reaction of lactam as described above it can. In addition, as described above, the terminal group of at least a part of the molecular chains of the aliphatic polyamide [I] may be sealed with a terminal blocking agent.

  The amount of use of the end capping agent in producing the aliphatic polyamide [I] is preferably determined from the relative viscosity of the finally obtained aliphatic polyamide [I] and the percentage of end groups sealed. Although the specific amount used varies depending on the reactivity, boiling point, reaction equipment, reaction conditions, etc. of the end capping agent used, it is usually 0.3 to 10 moles relative to the total number of moles of the dicarboxylic acid and diamine as raw materials. It can be in the range of%.

  The content of the aliphatic polyamide [I] is preferably 10 to 60% by mass with respect to the total of the [I] component, the [II] component, the [III] component and the [IV] component. When the content of the aliphatic polyamide [I] is 10% by mass or more, the content ratio of the aliphatic polyamide [I] is high, so it is easy to impart sufficient heat resistance and fuel barrier properties to the laminated structure, 60 mass If it is less than 10%, the flexibility and bending processability of the resulting laminated structure are unlikely to be impaired. The content of the aliphatic polyamide [I] is more preferably 20 to 60% by mass, based on the total of the components [I], [II], [III] and [IV], and 25 to 60. More preferably, it is mass%.

1-1-2. Ethylene · α-olefin · nonconjugated polyene copolymer rubber [II]
The ethylene / α-olefin / nonconjugated polyene copolymer rubber [II] comprises an ethylene structural unit [a], an α-olefin structural unit having 3 to 20 carbon atoms [b], and a nonconjugated polyene structural unit [c] And a copolymer rubber containing

(Ethylene structural unit [a])
It is preferable that it is 50-89 mass% with respect to all the structural units which comprise copolymer rubber [II], and, as for the content rate of ethylene structural unit [a], it is more preferable that it is 55-83 mass%.

(C3-C20 α-Olefin Structural Unit [b])
Examples of the α-olefin having 3 to 20 carbon atoms constituting the copolymer rubber [II] include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene and the like. Among them, α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene and 1-octene are preferable. The α-olefins may be of one type or a combination of two or more types. These α-olefin structural units [b] have relatively low raw material costs and excellent copolymerizability, and impart excellent mechanical properties and good flexibility and bending workability to the copolymer rubber [II]. Because it is desirable.

  The content ratio of the α-olefin structural unit [b] having 3 to 20 carbon atoms is preferably 10 to 49% by mass with respect to all structural units constituting the copolymer rubber [II], and 15 to 43 More preferably, it is mass%.

(Non-conjugated polyene structural unit [c])
The nonconjugated polyene constituting the copolymer rubber [II] is a nonconjugated polyene having one or more carbon / carbon double bonds polymerizable by a metallocene catalyst in one molecule, and an example thereof is aliphatic It includes polyenes and alicyclic polyenes.

  Examples of aliphatic polyenes include 1,4-hexadiene, 1,5-heptadiene, 1,6-octadiene, 1,7-nonadiene, 1,8-decadiene, 1,12-tetradecadiene, 3-methyl-. 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4-ethyl-1,4-hexadiene, 3,3-dimethyl-1,4-hexadiene, 5- Methyl-1,4-heptadiene, 5-ethyl-1,4-heptadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 5-ethyl-1,5-heptadiene, 4- Methyl-1,4-octadiene, 5-methyl-1,4-octadiene, 4-ethyl-1,4-octadiene, 5-ethyl-1,4-octadiene, 5-methyl-1,5-octadiene, 6- Methyl-1,5-O Tadiene, 5-ethyl-1,5-octadiene, 6-ethyl-1,5-octadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 6-ethyl-1,6- Octadiene, 6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene, 4-methyl-1,4-nonadiene, 5-methyl-1,4-nonadiene, 4-ethyl-1,4- Nonadiene, 5-ethyl-1,4-nonadiene, 5-methyl-1,5-nonadiene, 6-methyl-1,5-nonadiene, 5-ethyl-1,5-nonadiene, 6-ethyl-1,5- Nonadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 7-methyl-1,7- Nonadiene, 8-methyl-1,7-nonadier , 7-ethyl-1,7-nonadiene, 5-methyl-1,4-decadiene, 5-ethyl-1,4-decadiene, 5-methyl-1,5-decadiene, 6-methyl-1,5- Decadiene, 5-ethyl-1,5-decadiene, 6-ethyl-1,5-decadiene, 6-methyl-1,6-decadiene, 6-ethyl-1,6-decadiene, 7-methyl-1,6- Decadiene, 7-ethyl-1,6-decadiene, 7-methyl-1,7-decadiene, 8-methyl-1,7-decadiene, 7-ethyl-1,7-decadiene, 8-ethyl-1,7- Decadiene, 8-methyl-1,8-decadiene, 9-methyl-1,8-decadiene, 8-ethyl-1,8-decadiene, 6-methyl-1,6-undecadiene, 9-methyl-1,8- Undecadiene, further 1,7-octadiene, 1,9-decadi Included are α, ω-dienes such as en. Among these, 7-methyl-1,6-octadiene is preferable.

  Examples of alicyclic polyenes include 5-ethylidene-2-norbornene (ENB), 5-propylidene-2-norbornene, 5-butylidene-2-norbornene, 5-vinyl-2-norbornene (VNB); 5-allyl. 5-alkenyl-2-norbornenes such as -2-norbornene; 2,5-norbornadiene, dicyclopentadiene (DCPD), norbornadiene, tetracyclo [4,4,0,12.5,17.10] deca-3,8 And dienes, 2-methyl-2,5-norbornadiene, 2-ethyl-2,5-norbornadiene and the like. Among them, 5-ethylidene-2-norbornene (ENB) is preferable. The non-conjugated polyene structural unit [c] may be of one type or two or more types in combination.

  The content ratio of the nonconjugated polyene structural unit [c] is preferably 1 to 20% by mass, and more preferably 2 to 15% by mass with respect to all structural units constituting the copolymer rubber [II]. preferable.

  The intrinsic viscosity [η] of the copolymer rubber [II] is preferably 0.5 to 5.0 dl / g, more preferably 1.0 to 4.5 dl / g, and 1.5 to 5 Particularly preferred is 4.0 dl / g. The intrinsic viscosity [η] is a value measured in decalin at a temperature of 135 ° C., and can be determined by measurement according to ASTM D 1601.

  The content of the copolymer rubber [II] is preferably 25 to 86% by mass with respect to the total of the components [I], [II], [III] and [IV]. When the content of the copolymer rubber [II] is 25% by mass or more, it is easy to impart sufficient flexibility and bending workability to the laminated structure, and when it is 86% by mass or less, the heat resistance of the laminated structure And fuel barrier properties are not easily impaired. The content of the copolymer rubber [II] is more preferably 30 to 76% by mass with respect to the total of the [I] component, the [II] component, the [III] component and the [IV] component, and 30 to More preferably, it is 71% by mass.

  The mass ratio ([II] / [I]) of the copolymer rubber [II] to the aliphatic polyamide [I] is determined, for example, for a tube for fuel piping of an automobile etc., although it depends on the application of the laminated structure. From the viewpoint of obtaining flexibility, fuel barrier properties, and bending workability, for example, 20/80 to 70/30 is preferable. When the mass ratio of the copolymer rubber [II] is a certain amount or more, it is easy to impart sufficient flexibility and bending workability to the inner layer (A), and the mass ratio of the copolymer rubber [II] is a certain amount or less And the heat resistance and fuel barrier properties of the inner layer (A) are less likely to be impaired. The mass ratio of the copolymer rubber [II] to the aliphatic polyamide [I] is more preferably 30/70 to 60/40.

1-1-3. Olefin-based polymer [III]
The olefin polymer [III] is an olefin polymer containing 0.3 to 5.0% by mass of a functional group structural unit. The functional group structural unit is a structural unit derived from a compound having a functional group or a monomer having a functional group. Examples of the functional group in the functional group structural unit include a carboxylic acid group (including an acid anhydride group), an ester group, an ether group, an aldehyde group, a ketone group and the like. The olefin polymer [III] having a functional group structural unit has an affinity to the aliphatic polyamide [I] by having a functional group, and a copolymer rubber [III] by having an olefin skeleton. And the compatibility between the two can be enhanced.

  The olefin polymer [III] may be a modified polyolefin [III] -1 having a functional group introduced into the polyolefin molecular chain by reacting a compound having a functional group, or a monomer having an olefin monomer and a functional group It may be a functional group-containing olefin copolymer [III] -2 obtained by copolymerizing

  Examples of the polyolefin constituting the modified polyolefin [III] -1 are homopolymers or copolymers of olefins having 2 to 18 carbon atoms, and examples thereof include low density polyethylene, medium density polyethylene, high density It includes polyethylene, polypropylene and ethylene / α-olefin copolymer. Among them, ethylene / α-olefin copolymer is preferable. The α-olefin in the ethylene / α-olefin copolymer is preferably an α-olefin having 3 to 10 carbon atoms, and examples thereof include propylene and 1-butene. Examples of the ethylene / α-olefin copolymer include ethylene-propylene copolymer and ethylene-butene copolymer.

  Examples of the compound having a functional group constituting the modified polyolefin [III] -1 include unsaturated carboxylic acid having a functional group or a derivative thereof. Examples of unsaturated carboxylic acids having a functional group or derivatives thereof include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocis -Unsaturated carboxylic acids such as bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid (nadic acid) and derivatives thereof such as acid halides, amides, imides, acid anhydrides and esters thereof Can be mentioned. Among them, unsaturated dicarboxylic acids or their acid anhydrides are preferable, maleic acid, nadic acid or their acid anhydrides are more preferable, and maleic anhydride is particularly preferable. Maleic anhydride has a relatively high reactivity with the polyolefin before modification, is less likely to cause polymerization of maleic anhydride with each other, and tends to be stable as a basic structure. For this reason, it is easy to obtain modified polyolefin [III] -1 of stable quality.

Examples of the modified polyolefin [III] -1 include modified ethylene / α-olefin copolymers. The density of the modified ethylene / α-olefin copolymer is preferably 0.80 to 0.95 g / cm ³ , more preferably 0.85 to 0.90 g / cm ³ .

  The olefin monomer constituting the functional group-containing olefin copolymer [III] -2 is preferably an olefin monomer having 2 to 18 carbon atoms, and examples thereof include ethylene and propylene, preferably ethylene. It is.

  Examples of the monomer having a functional group constituting the functional group-containing olefin copolymer [III] -2 include acrylic monomers and vinyl monomers.

  Examples of the functional group-containing olefin copolymer [III] -2 include ethylene / vinyl acetate / maleic anhydride copolymer (Orevac (registered trademark) manufactured by Arkema Co., Ltd.), ethylene / acrylic acid ester / functional acrylic Acid ester (for example, glycidyl acrylate or glycidyl methacrylate) copolymer (such as Lotader (registered trademark) manufactured by Arkema Co., Ltd.) is included.

  It is preferable that it is 0.3-5.0 mass%, and, as for the content rate of the functional group structural unit of olefin polymer [III], it is more preferable that it is 0.4-4.0 mass%. When the functional group structural unit is 0.3% by mass or more, not only the dispersibility of the ethylene / α-olefin / nonconjugated polyene copolymer rubber [II] with respect to the aliphatic polyamide [I] can be easily improved but also the strength Hard to lose. On the other hand, when the functional group structural unit is 5.0% by mass or less, excessive reaction with the aliphatic polyamide [I] hardly occurs, so that the decrease of melt flowability due to gelation does not easily occur, and the formability is impaired. Hateful.

  The content of functional group structural units is the content of structural units derived from compounds having functional groups or monomers having functional groups relative to the total mass of structural units derived from monomers not having functional groups constituting the olefin polymer [III]. It is a ratio (mass%).

The content rate of the functional group structural unit of the olefin polymer [III] can be measured by ¹ H-NMR measurement or ¹³ C-NMR measurement. The specific measurement conditions are as follows.

^In the case of ¹ H-NMR measurement, the solvent is deuterated orthodichlorobenzene using an ECX 400 nuclear magnetic resonance apparatus manufactured by JEOL Ltd., the sample concentration is 20 mg / 0.6 mL, the measurement temperature is 120 ° C., observation The nucleus is ¹ H (400 MHz), the sequence is a single pulse, the pulse width is 5.12 μs (45 ° pulse), the repetition time is 7.0 seconds, and the number of integrations is 500 or more. The standard chemical shift is 0 ppm for hydrogen of tetramethylsilane, but the same result can be obtained by setting the peak derived from the residual hydrogen of deuterated orthodichlorobenzene to 7.10 ppm for example. be able to. The peaks such as ¹ H derived from the functional group-containing compound can be assigned by a conventional method.

^In the case of ¹³ C-NMR measurement, the measurement apparatus is an ECP 500 nuclear magnetic resonance apparatus manufactured by Nippon Denshi Co., Ltd., a mixed solvent of orthodichlorobenzene / deuterated benzene (80/20% by volume) as a solvent, measurement temperature is 120 ° C. The observation nucleus is ¹³ C (125 MHz), single pulse proton decoupling, 45 ° pulse, repetition time is 5.5 seconds, integration number is 10,000 times or more, and 27.50 ppm is a reference value of chemical shift. Assignment of various signals can be performed based on an ordinary method, and quantification can be performed based on the integrated value of signal intensity.

The intrinsic viscosity [η] measured in a 135 ° C. decalin (decahydronaphthalene) solution of the olefin polymer [III] is preferably 0.5 to 4.0 dl / g, preferably 0.7 to
It is more preferably 3.0 dl / g, further preferably 0.8 to 2.5 dl / g. If [η] is in the above range, the melt flowability of the resin composition and the toughness of the inner layer (A) can be compatible at a high level.

The intrinsic viscosity [η] of the olefin polymer [III] can be measured by the following method based on a conventional method.
20 mg of the sample is dissolved in 15 ml of decalin, and the specific viscosity (η sp) is measured in an atmosphere of 135 ° C. using an Ubbelohde viscometer. After 5 ml of decalin is further added to this decalin solution for dilution, the same specific viscosity measurement is performed. Based on the measurement results obtained by repeating the dilution operation and the viscosity measurement twice more, the “ηsp / C” value when the concentration (: C) is extrapolated to zero is defined as the limiting viscosity [η].

  Examples of commercial products of olefin polymer [III] include Tafmer series (maleic anhydride-modified ethylene-propylene rubber, maleic anhydride-modified ethylene-butene rubber, etc.) of Mitsui Chemicals, Inc., adomer (maleic anhydride-modified) Polypropylene, maleic anhydride-modified polyethylene); Krapre's Klaprene (maleic anhydride-modified isoprene rubber, maleic acid monomethyl ester-modified isoprene rubber), septon (maleic anhydride-modified SEPS); nucrel of Mitsui DuPont Polychemicals Co., Ltd. (Ethylene-methacrylic acid copolymer), HPR (maleic anhydride modified EEA, maleic anhydride modified EVA); Chemtura's Royaltuf (maleic anhydride modified EPDM); Kraton's Kraton FG (maleic anhydride modified SEBS); J Nippon Steel Energy (Japan) Nippon Steel Energy Co., Ltd.'s Nikko polybutene (maleic anhydride modified polybutene); Arkema's Bondine (maleic anhydride modified EEA); Asahi Kasei Co., Ltd. Tuftec M (maleic anhydride modified SEBS); Rexpearl ET (maleic anhydride modified EEA); Modic of Mitsubishi Chemical Corporation (maleic anhydride modified EVA, maleic anhydride modified polypropylene, maleic anhydride modified polyethylene); Sumitomo Chemical Ltd. bond first E-GMA); Klinac (a carboxy-modified nitrile rubber) manufactured by LANXESS; auroren (a maleic anhydride-modified EEA) manufactured by Nippon Paper Industries Co., Ltd. (all trade names). These may be used alone or in combination of two or more.

  The content of the olefin polymer [III] is preferably 0.1 to 30% by mass with respect to the total of the component [I], the component [II], the component [III] and the component [IV]. When the content of the olefin polymer [III] is 0.1% by mass or more, the compatibility between the [I] component and the [II] component can be sufficiently enhanced, so that sufficient strength for the inner layer (A) can be obtained. It is easy to give, and the characteristic of [I] component and [II] component is hard to be impaired as it is 30 mass% or less. The content of the olefin polymer [III] is more preferably 3 to 30% by mass with respect to the total of the components [I], [II], [III] and [IV], and preferably 3 to 30% by mass. More preferably, it is 20% by mass.

  The mass ratio ([III] / [II]) of the olefin polymer [III] and the copolymer rubber [II] is preferably 1/500 to 1/1. When the mass ratio of the olefin polymer [III] is a certain value or more, the compatibility between the aliphatic polyamide [I] and the copolymer rubber [II] is unlikely to be impaired, so sufficient strength is imparted to the inner layer (A). The properties of the aliphatic polyamide [I] and the copolymer rubber [II] are less likely to be impaired. The mass ratio of the olefin polymer [III] to the copolymer rubber [II] is more preferably 1/20 to 1/1, and still more preferably 1/20 to 1/2.

1-1-4. Phenolic resin based crosslinking agent [IV]
The phenolic resin-based crosslinking agent is typically a resol resin obtained by condensation of an alkyl-substituted or unsubstituted phenol with an aldehyde (preferably formaldehyde) in the presence of an alkali catalyst. The alkyl group of the alkyl-substituted phenol is preferably an alkyl group having 1 to 10 carbon atoms. In particular, dimethylol phenols or phenol resins substituted with an alkyl group having 1 to 10 carbon atoms are preferable.

The compound represented by following formula [IV-1] is contained in the example of a phenol resin type crosslinking agent.

In formula [IV-1], R is an organic group such as an alkyl group, preferably an organic group having less than 20 carbon atoms, more preferably an organic group having 4 to 12 carbon atoms. R 'is a hydrogen atom or a _-CH 2 -OH. n and m are an integer of 0 to 20, preferably an integer of 0 to 15, and more preferably an integer of 0 to 10.

Other examples of phenolic resin based crosslinking agents include methylolated alkylphenol resins and halogenated alkylphenol resins. The halogenated alkylphenol resin is an alkylphenol resin in which the hydroxyl group at the molecular chain terminal is substituted with a halogen atom such as bromine, and examples thereof include a compound represented by the following formula [IV-2].

N, m and R in the formula [IV-2] have the same meanings as n, m and R in the formula [IV-1]. R of the formula [IV-2] 'is a hydrogen atom, a -CH ₃ or _-CH 2 -Br.

  Examples of commercially available products of the phenolic resin-based crosslinking agents include Takiroll 201, Takiroll 250-I, Takiroll 250-III of Taoka Chemical Industry Co., Ltd., SP 1045, SP 1055, SP 1056 of SI Group, and Showa Denko Co., Ltd. Norol CRM; Tamanor 531 of Arakawa Chemical Industries, Ltd .; Sumiraite resin PR of Sumitomo Bakelite Co., Ltd .; register top of Gunei Chemical Industry Co., Ltd. (all trade names mentioned above) and the like. These may be used alone or in combination of two or more. Among them, Tackirol 250-III (brominated alkylphenol formaldehyde resin) manufactured by Taoka Chemical Industry Co., Ltd. and SP 1055 (brominated alkylphenol formaldehyde resin) manufactured by SI Group are preferable.

  Among them, halogenated alkylphenol resins are particularly preferred.

  When the phenolic resin crosslinking agent [IV] is a powdery crosslinking agent, its average particle diameter is preferably 0.1 μm to 3 mm, more preferably 1 μm to 1 mm, particularly preferably 5 μm to 0.5 mm. . The flake-like curing agent is preferably used after being powdered by a pulverizer such as a jet mill or a pulverizer with a pulverizing blade.

  The content of the phenol resin-based crosslinking agent [IV] is preferably 1 to 10% by mass with respect to the total of the components [I], [II], [III] and [IV]. When the content of the phenolic resin-based crosslinking agent [IV] is 1% by mass or more, the component (II) and the like can be sufficiently crosslinked, so that the inner layer (A) can be easily provided with sufficient flexibility. If the content of the crosslinking agent [IV] is 10% by mass or less, the properties of the components [I] and [II] are less likely to be impaired. The content of the phenolic resin crosslinking agent [IV] is more preferably 1 to 8% by mass with respect to the total of the components [I], [II], [III] and [IV], More preferably, it is 2 to 6% by mass.

  The total content of the components (I), (II), (III) and (IV) is preferably 80% by mass or more and 90% by mass or more based on the total mass of the rubber composition. More preferably, it may be 100% by mass.

1-1-5. Other Components The rubber composition for obtaining a polyamide-based thermoplastic elastomer composition may further contain other components as needed, as long as the effects of the present invention are not impaired. Examples of other components include crosslinking agents other than phenol resin crosslinking agent [IV], crosslinking assistants, plasticizers, antioxidants, coloring agents, antistatic agents (conductive agents), fillers, etc. Be

  The other crosslinking agent may be a crosslinking agent capable of dynamically crosslinking the above-mentioned rubber composition, and examples thereof include a sulfur-based crosslinking agent. However, it is preferable that the other crosslinking agent does not contain an organic peroxide. When an organic peroxide is used as another crosslinking agent, the decomposition rate of the organic peroxide may be too fast because the melt kneading temperature suitable for the polyamide thermoplastic elastomer composition of the present invention is relatively high. is there. As a result, the crosslinking reaction of the rubber component ([II] component, [III] component) is likely to proceed rapidly, and it may not be sufficiently kneaded with the aliphatic polyamide [I], and the dispersion may be insufficient. Therefore, the physical properties of the polyamide-based thermoplastic elastomer composition may be significantly reduced.

  Examples of crosslinking aids include magnesium hydroxide, calcium hydroxide, magnesium oxide, zinc oxide and the like.

  In addition, a rubber composition for obtaining a polyamide-based thermoplastic elastomer composition is a polyamide other than the above-mentioned aliphatic polyamide [I] (hereinafter also referred to as “other polyamide”) within the range not impairing the effects of the present invention. May be further included. Examples of other polyamides include polyamide 11, polyamide 12, aromatic polyamide and the like. The polyamide-based thermoplastic elastomer composition may contain one or two or more of these other polyamides.

1-1-6. Physical Properties The highest glass transition temperature among the glass transition temperatures of the polyamide-based thermoplastic elastomer composition is preferably, for example, 80 ° C. or less. Thereby, bending at a temperature equal to or lower than the heat resistance temperature of the resin constituting the outer layer (B) can be more surely achieved, and thus bending workability can be easily improved.

  The glass transition temperature of the polyamide-based thermoplastic elastomer composition can be measured using a differential scanning calorimeter (DSC 220C, manufactured by Seiko Instruments Inc.). Specifically, about 5 mg of the polyamide-based thermoplastic elastomer composition is sealed in an aluminum pan for measurement, and heated from room temperature to 350 ° C. at 10 ° C./min. In order to completely melt the composition, it is held at 350 ° C. for 5 minutes and then cooled to 30 ° C. at 10 ° C./min. After 5 minutes at 30 ° C., perform a second heating to 350 ° C. at 10 ° C./min. The temperature at the highest displacement point among the temperatures at the displacement points corresponding to the glass transition of the endothermic peak obtained by the second heating is taken as the glass transition temperature (Tg).

1-1-7. Method for Producing Polyamide-Based Thermoplastic Elastomer Composition The polyamide-based thermoplastic elastomer composition comprises the above-mentioned aliphatic polyamide [I], an ethylene / α-olefin / nonconjugated polyene copolymer rubber [II], and an olefin-based heavy Dynamically crosslinking at least a part of the rubber composition containing the combined [III] and the phenol resin-based crosslinking agent [IV], specifically, obtained by crosslinking in a melt flow state (dynamic state) Can.

  The dynamic crosslinking reaction is usually carried out by supplying the above-described composition to a melt-kneading apparatus, heating to a predetermined temperature, and melt-kneading.

  Melt-kneading may be performed by simultaneously kneading the [I] component, the [II] component, the [III] component and the [IV] component, or after kneading the [I] component, the [II] component and the [III] component And the component [IV] may be further kneaded.

  The melt-kneading apparatus can use, for example, a twin-screw extruder, a single-screw extruder, a kneader, a Banbury mixer, and the like. Among them, a twin-screw extruder is preferable in terms of good shear force and continuous productivity. The melt-kneading temperature is usually 200 to 320 ° C. The melting and kneading time is usually 0.5 to 30 minutes.

  By this dynamic crosslinking, the ethylene / α-olefin / nonconjugated polyene copolymer rubber [II] in the rubber composition is crosslinked. Then, a sea-island structure having a sea phase (matrix phase) containing aliphatic polyamide [I] as a main component and an island phase (dispersed phase) containing crosslinked copolymer rubber [II] as a main component is formed. Ru. The average particle size of the island phase (dispersed phase) is relatively small and finely dispersed. Thereby, sufficient flexibility and bendability can be imparted to the laminated structure without significantly impairing the fuel barrier properties.

  The thickness of the inner layer (A) is not particularly limited as long as it can provide the laminated structure with fuel barrier properties, flexibility, and appropriate heat resistance. The ratio of the thickness of the inner layer (A) is preferably 5 to 70%, more preferably 10 to 70%, with respect to the total thickness of the inner layer (A) and the outer layer (B), and 30 to 70%. It is further preferred that When the ratio of the thickness of the inner layer (A) is 5% or more, it is easy to impart sufficient fuel barrier properties, flexibility, and appropriate heat resistance to the laminated structure, and when it is 70% or less, the strength of the laminated structure Hard to lose. The specific thickness of the inner layer (A) is, for example, preferably 50 to 700 μm, and more preferably 100 to 500 μm.

  The inner layer (A) may be only one layer or two or more layers. When the inner layer (A) has two or more layers, the inner layer (A) disposed outermost is assumed to be disposed inside the outer layer (B) disposed innermost, and the thickness of the inner layer (A) Is the total thickness of two or more inner layers (A).

1-2. Outer layer (B)
The outer layer (B) is a layer disposed on the outside of the laminated structure, and has a function of protecting the inner layer (A) from the external environment and maintaining strength. The outer layer (B) contains a thermoplastic resin.

  The thermoplastic resin is a thermoplastic resin different from the polyamide-based thermoplastic elastomer composition constituting the inner layer (A). The thermoplastic resin is not particularly limited as long as it can protect or reinforce the inner layer (A), but polyolefin resins such as polyethylene resins and polypropylene resins, aliphatic polyamides, polyamide 10T, polyamide 9T, etc. Semi-aromatic polyamide, tetrafluoroethylene-ethylene copolymer, polyvinyl fluoride, polyvinylidene fluoride, polyphenylene sulfide, polyester such as polybutylene terephthalate and polyethylene terephthalate, polyketone, liquid crystal polymer, ethylene vinyl alcohol, and the above-mentioned polyamide thermal group It is at least one selected from the group consisting of elastomers other than the plasticizing elastomer composition. Among them, aliphatic polyamide, polyamide 10T, polyamide 9T, polyethylene resin, tetrafluoroethylene / ethylene copolymer, polyvinyl fluoride, polyvinylidene fluoride, polyphenylene sulfide, polybutylene terephthalate, polyethylene terephthalate, polyketone, liquid crystal polymer and ethylene vinyl It is preferable that it is at least one selected from the group consisting of alcohols, and from the viewpoint of easily obtaining high heat resistance and high interlayer adhesion with the inner layer (A), aliphatic polyamide is more preferable, and the cost is easily reduced. In the above, polyethylene resins are more preferable.

  Aliphatic polyamides are not particularly limited, and examples thereof include polyamide 11, polyamide 12, polyamide 6, polyamide 6 · 6, polyamide 9 · 9, polyamide 6 · 10, polyamide 2 · 6, polyamide 2 · 6 and polyamide 6-9, polyamide 6/11, polyamide 6-12 and the like. Moreover, the copolymer which used the raw material monomer of these polyamides in several types is mentioned. One or more of these may be used. Among them, polyamide 11, polyamide 12 and polyamide 4 and 6 are preferable, and polyamide 11 and polyamide 12 are more preferable from the viewpoints of heat resistance, strength and interlayer adhesion.

  The polyethylene-based resin is a polymer containing a structural unit derived from ethylene as a main component. The content of the structural unit derived from ethylene is preferably 80 mol% or more, and more preferably 90 mol% or more, with respect to the total number of moles of the structural unit constituting the polyethylene-based resin. Examples of such polyethylene-based resins include ethylene / α-olefin (co) polymer, ethylene / unsaturated carboxylic acid copolymer, ethylene / unsaturated carboxylic acid ester copolymer and the like.

  The ethylene / α-olefin (co) polymer is a homopolymer of ethylene or a copolymer of ethylene and an α-olefin. The content of the structural unit derived from ethylene is more preferably 90 to 99.99 mol% with respect to the total number of moles of structural units constituting the ethylene / α-olefin (co) polymer, and 94 to 99 More preferably, it is .99 mol%.

  The carbon atom number of the α-olefin is preferably 3 to 16, and more preferably 3 to 12. Examples of α-olefins having 3 to 16 carbon atoms include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like.

  The melt flow rate of the ethylene / α-olefin (co) polymer as measured according to ASTM D1238 (230 ° C., 2.16 kg load) is preferably 0.01 to 10 g / 10 min. It is more preferable that it is 01-5 g / 10min, and it is further more preferable that it is 0.05-1 g / 10min. When the melt flow rate of the ethylene / α-olefin (co) polymer is in the above range, the flowability of the ethylene / α-olefin (co) polymer is high when the laminated structure is produced, and the outer layer of uniform thickness ( B) is easy to obtain. The melt flow rate of the ethylene / α-olefin (co) polymer is adjusted, for example, by the molecular weight.

The density of the ethylene · alpha-olefin (co) polymer is preferably 0.925~0.970g / cm ^3, more preferably 0.925~0.960g / cm ^3, 0.935 It is further preferable that it is -0.955 g / cm < ³ >. If the density of the ethylene / α-olefin (co) polymer is 0.925 g / cm ³ or more, even if the outer layer (B) is used for a long period of time, the influence of the swelling by the fuel vaporized from the inside of the laminated structure is It is hard to be received and it is easy to increase strength and pressure resistance. When the density of the ethylene / α-olefin (co) polymer is 0.970 g / cm ³ or less, the flexibility and bending processability of the laminated structure are unlikely to be impaired. The density of the ethylene / α-olefin (co) polymer is measured in accordance with ASTM D1505. The density of the ethylene / α-olefin (co) polymer is adjusted according to the type of the polyethylene resin, the preparation conditions thereof, and the like.

  The ethylene / α-olefin (co) polymer is preferably prepared using a metallocene catalyst. The ethylene / α-olefin (co) polymer obtained by using a metallocene catalyst has a small molecular weight distribution and therefore has a low content of low molecular weight components. The outer layer (B) containing such an ethylene / α-olefin (co) polymer has higher strength, toughness, and fuel swelling resistance than the outer layer (B) containing a polyethylene resin prepared with a catalyst other than a metallocene catalyst. Is high. The strength and reliability in use of such a laminated structure can be greatly enhanced.

  Examples of ethylene / α-olefin (co) polymers include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene and the like. Examples of commercially available products include Neozex 4005M (manufactured by Mitsui Chemicals, Inc.) and the like.

  Examples of ethylene / unsaturated carboxylic acid copolymers include ethylene / methacrylic acid copolymers. Examples of the ethylene / unsaturated carboxylic acid ester copolymer include ethylene / vinyl acetate copolymer, ethylene / methyl methacrylate copolymer and the like.

  Among them, the polyethylene-based resin is preferably an ethylene / α-olefin (co) polymer from the viewpoint of excellent moldability and easy cost reduction.

  It is preferable that it is 60 mass% or more with respect to the total mass of outer layer (B), and, as for content of a thermoplastic resin, it is more preferable that it is 80 mass% or more. When the content of the thermoplastic resin is 60% by mass or more, the strength of the outer layer (B) tends to be increased.

  The outer layer (B) may further contain other components other than the thermoplastic resin, if necessary. Examples of other components include various additives such as fillers, stabilizers, activators, antistatic agents, flame retardants, foaming agents, etc., pigments, dyes and the like.

  The thickness of the outer layer (B) is not particularly limited as long as it can protect the inner layer (A) and give strength to the laminated structure. The thickness ratio of the outer layer (B) is preferably 30 to 95%, more preferably 30 to 90%, and more preferably 30 to 70% of the total thickness of the inner layer (A) and the outer layer (B). It is further preferred that When the ratio of the thickness of the outer layer (B) is 30% or more, the inner layer (A) can be easily protected sufficiently, and sufficient strength can be easily given to the laminated structure, and when it is 95% or less Fuel barrier property, flexibility, and moderate heat resistance are unlikely to be impaired. The specific thickness of the outer layer (B) is, for example, preferably 300 to 950 μm, and more preferably 500 to 900 μm.

  The outer layer (B) may be only one layer or two or more layers. When the outer layer (B) has two or more layers, the inner layer (B) disposed at the innermost side is disposed outside the inner layer (A) disposed at the outermost side, and the thickness of the outer layer (B) Is the total thickness of the two or more outer layers (B).

1-3. Other Layers The laminated structure of the present invention may further include other layers other than the inner layer (A) and the outer layer (B) as long as the effects of the present invention are not impaired. The other layer may be disposed between the inner layer (A) and the outer layer (B) depending on its function, or the side (inner side) of the inner layer (A) on which the outer layer (B) is disposed The outer layer (B) may be disposed on the side (outside) opposite to the side on which the inner layer (A) is disposed. Examples of other layers are disposed between the inner layer (A) and the outer layer (B), and are disposed further to the middle layer (C) that can function as an adhesive layer, or further inside the inner layer (A), and conductive Conductive layer (D) having a function of imparting

1-3-1. Middle layer (C)
The middle layer (C) is a layer disposed between the inner layer (A) and the outer layer (B) to enhance the interlayer adhesion between them. The middle layer (C) contains a modified ethylene / α-olefin copolymer obtained by graft-modifying an ethylene / α-olefin copolymer with an unsaturated carboxylic acid or a derivative thereof.

  The graft modified ethylene / α-olefin copolymer may be a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. It is preferable that the carbon atom number of alpha-olefin is 3-10. Examples of α-olefins include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like.

  The unsaturated carboxylic acid is not particularly limited, and examples thereof include (meth) acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid (endos-bicyclo [2.2 .1] Unsaturated carboxylic acids such as hept-5-ene-2,3-dicarboxylic acid or derivatives thereof such as acid halides, amides, imides, anhydrides and esters thereof. Among these, unsaturated dicarboxylic acids or their anhydrides are preferable, maleic acid, nadic acid or their acid anhydrides are more preferable, and maleic anhydride is particularly preferable.

The content of structural units derived from unsaturated carboxylic acids or derivatives thereof is preferably 0.08 to 5% by mass with respect to the total mass of the structural units constituting the modified ethylene / α-olefin copolymer, and 0 It is more preferable that it is .08-3 mass%, and it is further more preferable that it is 0.08-1 mass%. If the content of the structural unit derived from the unsaturated carboxylic acid or its derivative is in the above range, the adhesiveness of the intermediate layer (C) tends to be enhanced. The ratio of the structural unit derived from the unsaturated carboxylic acid or the derivative thereof contained in the modified ethylene / α-olefin copolymer can be specified by a method such as ¹³ C-NMR measurement or ¹ H-NMR measurement. As specific NMR measurement conditions, the same conditions as the NMR measurement conditions at the time of measuring the content of the functional group structural unit of the olefin polymer [III] described above can be exemplified.

  The modified ethylene / α-olefin copolymer is obtained by reacting an unsaturated carboxylic acid or a derivative thereof in a state in which the ethylene / α-olefin copolymer is melted. The reaction (graft modification) of the ethylene / α-olefin copolymer with the unsaturated carboxylic acid or its derivative can be carried out by a known method, for example, by reacting these in the presence of an organic peroxide. A modified ethylene / α-olefin copolymer is obtained. In addition, graft modification is preferably performed substantially without a solvent from the viewpoint of the adhesiveness of the intermediate layer (C).

The density of the modified ethylene · alpha-olefin copolymer is preferably from 0.910 to 0.935 g / cm ^3, more preferably 0.920~0.935g / cm ^3. The density of the modified ethylene / α-olefin copolymer is measured in accordance with ASTM D1505. If the density of the modified ethylene · alpha-olefin copolymer is 0.910 g / cm ³ or more, the strength is likely to rise in the intermediate layer (C), When it is 0.935 g / cm ³ or less, the intermediate layer (C) Adhesiveness with the inner layer (A) and the outer layer (B) is likely to be enhanced. That is, when the density of the modified ethylene / α-olefin copolymer is within the above range, the balance between the strength and the adhesiveness of the intermediate layer (C) is excellent. The density of the modified ethylene / α-olefin copolymer is adjusted by the type of α-olefin in the modified ethylene / α-olefin copolymer, the content of the unsaturated carboxylic acid or its derivative, and the like.

  The content of the modified ethylene / α-olefin copolymer is preferably 60% by mass or more, and more preferably 80% by mass or more based on the total mass of the intermediate layer (C). If the content of the modified ethylene / α-olefin copolymer is 60% by mass or more, the adhesiveness between the inner layer (A) and the outer layer (B) tends to be sufficiently enhanced.

  The intermediate layer (C) may further contain other components other than the modified ethylene / α-olefin copolymer, if necessary.

  The thickness of the intermediate layer (C) is not particularly limited as long as the interlayer adhesion between the inner layer (A) and the outer layer (B) can be sufficiently enhanced. The thickness ratio of the intermediate layer (C) is preferably 1 to 50%, more preferably 1 to 20%, based on the total thickness of the inner layer (A) and the outer layer (B), and 3 to 10 More preferably, it is%. The interlayer adhesiveness of each layer which comprises a laminated structure as the ratio of the thickness of an intermediate | middle layer (C) is 1% or more tends to increase. On the other hand, if the thickness ratio of the intermediate layer (C) is 50% or less, the thickness of the inner layer (A) and the outer layer (B) does not become too thin relatively, so the flexibility and bending of the laminated structure , Fuel barrier properties, heat resistance and strength are not easily impaired. The specific thickness of the intermediate layer (C) is, for example, preferably 5 to 100 μm, more preferably 10 to 60 μm, and still more preferably 15 to 55 μm.

  The intermediate layer (C) may be only one layer or two or more layers. When there are two or more intermediate layers (C), the thickness of the intermediate layer (C) is the total thickness of the two or more intermediate layers (C).

1-3-2. Conductive layer (D)
The conductive layer (D) may be disposed, for example, on the innermost layer side of the laminated structure, and may have a function of imparting conductivity. Thereby, for example, when a liquid fuel or the like is made to flow inside the tubular layered structure, static electricity can be less easily accumulated in the layered structure.

  The conductive layer (D) is, for example, a resin used for a tube for automobile fuel piping (for example, an aliphatic polyamide such as polyamide 6, polyamide 11, polyamide 12; polyphenylene sulfide resin, polymethaxylylene adipamide, semiaromatic Group resin, polyester resin, etc.) and a conductive filler. The shape of the conductive filler is not particularly limited, and may be granular, flake-like, fibrous or the like.

  Examples of particulate fillers include carbon black, graphite and the like. Examples of flake-like fillers include aluminum flakes, nickel flakes, nickel-coated mica and the like. Examples of fibrous fillers include carbon fibers, carbon-coated ceramic fibers, carbon whiskers, metal fibers such as aluminum fibers, copper fibers, brass fibers and stainless steel fibers, and the like. Among them, the conductive filler is preferably carbon black from the viewpoint of availability and conductivity, etc., and more preferably acetylene black or furnace black (Ketjen black).

  The content of the conductive filler may be, for example, 3 to 35% by mass with respect to the total mass of the conductive layer (D).

The surface resistance value of the conductive layer (D) is, for example, preferably 10 ⁸ Ω / square or less, and more preferably 10 ⁶ Ω / square or less.

1-3-3. Protective layer (E)
The laminated structure of the present invention may further include a protective layer (E) disposed on the outside of the outer layer (B) from the viewpoint of enhancing impact resistance, for example, when used as a fuel piping tube or hose.

  Examples of the material constituting the protective layer (E) include chloroprene rubber, ethylene propylene diene terpolymer, epichlorohydrin rubber, chlorinated polyethylene, acrylic rubber, chlorosulfonated polyethylene, silicone rubber and the like.

1-4. Shape of Laminated Structure The shape of the laminate structure of the present invention is not particularly limited, and may be appropriately selected according to the application. The shape of the laminated structure of the present invention may be, for example, a film, sheet, tube, hose, bottle, tank or the like. Among them, the laminated structure is preferably a hollow structure, and more preferably a tube or a hose.

2. Method for Producing Laminated Structure The method for producing the laminate structure of the present invention is not particularly limited, and, for example, materials for the inner layer (A) (polyamide thermoplastic elastomer composition) and materials for the outer layer (B) (thermoplastic resin) (Composition including) is co-extruded or co-cast by co-extrusion molding method (eg, T-die extrusion, inflation extrusion, blow molding, profile extrusion, It may be a method of molding. In addition, one of the inner layer (A) and the outer layer (B) is formed in advance by a general molding machine (for example, an extrusion molding machine, a blow molding machine, a compression molding machine, an injection molding machine, etc.) It may be a method in which the other layer is coated or cast on the outside or inside to laminate and form. Alternatively, both the inner layer (A) and the outer layer (B) may be formed in advance, and they may be laminated via the intermediate layer (C). Moreover, after obtaining a film-like or sheet-like laminated structure, it may be molded by press molding or the like as needed.

  In particular, a fuel pipe tube or a hose, which is a preferable embodiment of the laminated structure of the present invention, respectively melts and extrudes the above-mentioned polyamide-based thermoplastic elastomer composition and the above-mentioned resin composition containing the thermoplastic resin. They can be manufactured by a method (co-extrusion molding method) in which these are introduced into a multilayer tube die and laminated in the die or immediately after leaving the die. Alternatively, one of the inner layer (A) and the outer layer (B) may be formed in advance into a tube or hose shape, and then the other layer may be coated and laminated on the outside or the inside. Good.

  After laminating the inner layer (A) and the outer layer (B), heating may be performed as necessary. By heating, residual strain at the time of producing the laminated structure is removed.

3. Applications of Laminated Structure As described above, the laminated structure of the present invention has good fuel barrier properties and good flexibility and bending processability, so various applications where these characteristics are required, such as gas and the like It is used as a hollow structure such as a hose or a tube for transporting a liquid, or a container such as a bottle or a tank for storing a gas or a liquid inside.

  Hoses and tubes for transporting gas and liquid mean, for example, hoses and tubes used in industrial equipment, and examples thereof include vehicles (for example, automobiles), pneumatic / hydraulic equipment, coating equipment, medical equipment, etc. These include hoses and tubes that pass fluids (fuel, solvents, chemicals, gases, etc.) used in industrial equipment. Specifically, tubes for vehicle piping (for example, fuel tubes, intake tubes, cooling tubes), pneumatic tubes, hydraulic tubes, paint spray tubes, medical tubes (for example, catheters) and the like can be mentioned.

  Containers such as bottles and tanks for storing gas and liquid mean, for example, containers used in industrial equipment, and examples thereof include automobile radiator tanks, chemical bottles, chemical tanks, chemical containers, gasoline tanks, etc. included.

  Among them, since the laminated structure of the present invention has good fuel barrier properties, it is preferably used as a fuel storage tube for fuel storage or fuel transportation for automobiles, in particular as a tube or hose for fuel piping for automobiles. The term "fuel" refers to various fuels such as gasoline, alcohol mixed gasoline (gasohol), alcohol, hydrogen, light oil, biodiesel fuel, dimethyl ether, LPG and CNG.

(Tube or hose for fuel piping)
The fuel piping tube and the hose may be cylindrical, may be cylindrical, or may be rectangular. Further, at least a part of the fuel piping tube and the hose may have a corrugated shape, a bellows shape, an accordion shape, or the like, and may be further processed into an L shape, a U shape, or the like.

  The outer diameter of the fuel piping tube or hose is preferably 2 to 50 mm, more preferably 6 to 30 mm. The thickness of the fuel piping tube or hose is preferably 0.2 to 10 mm, and more preferably 0.5 to 7 mm.

  1A and 1B are schematic cross-sectional views showing an example of a tube-shaped laminated structure (for example, a fuel piping tube) of the present invention. As shown in FIG. 1A, the tubular laminated structure 10 has an inner layer (A) 11 and an outer layer (B) 12.

  As described above, since the inner layer (A) 11 has a sufficient fuel barrier property, various fuels flowing in the inner portion (the inner side of the inner layer (A)) of the stacked structure 10 are unlikely to be released to the outside. In addition, since the inner layer (A) has sufficient flexibility and the glass transition temperature is not too high, the laminated structure 10 has good flexibility and bendability. Furthermore, since the outer layer (B) can cover the outer periphery of the inner layer (A) and can impart strength, the outer layer (B) can be resistant to breakage even if the pressure inside the laminated structure 10 is increased.

  As shown in FIG. 1B, the laminated structure 10 ′ is configured in the same manner as FIG. 1A except that it further includes an intermediate layer (C) 13 disposed between the inner layer (A) 11 and the outer layer (B) 12. It is done. Thereby, in addition to the above-mentioned effects, for example, even when the interlayer adhesion between the resin constituting the inner layer (A) and the resin constituting the outer layer (B) is not sufficient, the interlayer adhesion between these can be achieved by the intermediate layer (C) Can be enhanced.

  The invention will now be described with reference to examples. The scope of the present invention is not interpreted as being limited by the examples.

1. Preparation of material <Material for inner layer (A)>
First, an olefin-based polymer [III] used for preparation of a polyamide-based thermoplastic elastomer composition was prepared as follows.

(Preparation of olefin polymer [III])
First, 0.63 mg of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride is introduced into a sufficiently nitrogen-substituted glass flask, and a toluene solution of methylaminoxan (Al: 0.13 mmol / l) 1. A further 57 ml and 2.43 ml of toluene were added to obtain a catalyst solution.
Hexane 912 ml and 1-butene 320 ml were introduced into a 2-liter stainless steel autoclave fully purged with nitrogen, and the temperature in the system was raised to 80 ° C. Subsequently, polymerization was initiated by pressure injection of 0.9 mmol of triisobutylaluminum and 2.0 ml of the above catalyst solution (0.0005 mmol as Zr) with ethylene.
The total pressure was maintained at 8.0 kg / cm ² -G by continuously feeding ethylene, and polymerization was carried out at 80 ° C. for 30 minutes. After a small amount of ethanol was introduced into the system to terminate the polymerization, unreacted ethylene was purged. The resulting solution was poured into a large excess of methanol to precipitate a white solid.
The white solid was collected by filtration and dried overnight under reduced pressure to obtain a white solid ethylene / 1-butene copolymer. The density of this ethylene / 1-butene copolymer is 0.862 g / cm ³ , MFR (ASTM D 1238 standard, 190 ° C., 2160 g load) is 0.5 g / 10 min, 1-butene structural unit content is 4 moles %Met.
100 parts by mass of this ethylene / 1-butene copolymer were mixed with 1.0 part by mass of maleic anhydride and 0.04 parts by mass of peroxide (manufactured by NOF Corporation, trade name perhexin 25B) The above-mentioned maleic anhydride-modified ethylene / 1-butene copolymer was obtained by melt graft-modifying the resulting mixture with a single-screw extruder set at 230 ° C.

The maleic anhydride graft modification amount (functional group content of the structural unit) of the obtained maleic anhydride-modified ethylene / 1-butene copolymer is 0.97% by mass, and the limiting viscosity measured in a 135 ° C. decalin solution [ η] 1.98 dl / g. The content of functional group structural units was measured by the above-mentioned ¹³ C NMR method, and the intrinsic viscosity [粘度] was measured by the above-mentioned method.

  Next, a polyamide-based thermoplastic elastomer composition was prepared by the following method using the olefin polymer [III] prepared above.

(Preparation of Polyamide-Based Thermoplastic Elastomer Composition (PA-TPV-1))
As aliphatic polyamide [I], 58% by mass of polycaproamide (polyamide 6) (Toray Industries, Inc., trade name: Amilan “CM1046, melting point = 225 ° C., heat of fusion (ΔH) = 64 mJ / mg), copolymer rubber 30% by mass of ethylene / propylene • 5-ethylidene-2-norbornene copolymer rubber ([η] = 2.4 dl / g, ethylene content 65% by mass, diene content 4.6% by mass) as [II], 9.5% by mass of the above synthesized maleic anhydride-modified ethylene / 1-butene copolymer as the olefin polymer [III], flaked brominated alkylphenol formaldehyde resin as the phenol resin crosslinking agent [IV] Taoka Chemical Industry Co., Ltd. product, Tachiroll 250-III (trade name) made by stirring for 10 seconds with a Henschel mixer and powdered 2 5% by mass and a small amount of a cross-linking aid (Haxuitec Co., Ltd., zinc oxide 2 types) are premixed, and this is supplied to a twin-screw extruder (TEX-30, manufactured by Japan Steel Works, Ltd.), The mixture was melt-kneaded at a cylinder temperature of 280 ° C. and a screw rotation speed of 300 rpm The strands extruded from this twin-screw extruder were cut to obtain pellets of a polyamide-based thermoplastic elastomer composition (PA-TPV-1).

(Preparation of Polyamide-Based Thermoplastic Elastomer Composition (PA-TPV-2))
Content of aliphatic polyamide [I] 50 mass%, content of copolymer rubber [II] 38.5 mass%, content of olefin polymer [III] 9 mass%, phenol resin crosslinking The polyamide-based thermoplastic elastomer composition (PA-TPV-2) is the same as the polyamide-based thermoplastic elastomer composition (PA-TPV-1) except that the content of the agent [IV] is changed to 2.5% by mass. ) Pellets were obtained.

(Preparation of Semi-Aromatic Polyamide Resin (PA6T6I66))
1986 g (12.0 mol) of terephthalic acid, 1390 g (8.4 mol) of isophthalic acid, 524 g (3.6 mol) of adipic acid, 2800 g (24.1 mol) of 1,6-hexanediamine, 36.5 g of benzoic acid 0.3 mol), 5.7 g (0.08% by mass with respect to the raw material) of sodium hypophosphite hydrate and 545 g of distilled water were charged in an autoclave of 13.6 L capacity and purged with nitrogen. Stirring was started from 190 ° C., and the internal temperature was raised to 250 ° C. over 3 hours. At this time, the internal pressure of the autoclave was increased to 3.03 MPa. After continuing the reaction for 1 hour, the low condensation product was extracted by releasing the air to the atmosphere from a spray nozzle installed at the lower part of the autoclave. Thereafter, it was cooled to room temperature, crushed to a particle size of 1.5 mm or less by a grinder, and dried at 110 ° C. for 24 hours. The water content of the obtained low condensate was 4100 ppm, and the intrinsic viscosity [η] was 0.14 dl / g. Next, this low condensate was placed in a tray type solid phase polymerization apparatus, and after nitrogen substitution, the temperature was raised to 180 ° C. over about 1 hour and 30 minutes. Then, it reacted for 1 hour and 30 minutes, and cooled to room temperature. The intrinsic viscosity [η] of the obtained polyamide was 0.18 dl / g. Then, it is melt-polymerized at a barrel setting temperature of 340 ° C, a screw rotation speed of 200 rpm, and a resin feed rate of 5 kg / h in a twin-screw extruder with a screw diameter of 30 mm and L / D = 36. Of the polyamide resin (PA6T6I66, 6T / 6I / 66 = 50/35/15 (molar ratio)).

<Material for outer layer (B)>
Aliphatic polyamide (B-1): manufactured by Arkema, Rilsamid AESNO TL44 (polyamide 12)
Polyethylene resin (B-2): Neozex 4005 M (ethylene 1-butene copolymer, density 0.937 g / cm ³ , MFR 0.2 g / 10 min (230 ° C., 2.16 kg load)) manufactured by Prime Polymer Co., Ltd.

<Material for Intermediate Layer (C)>
(Preparation of Modified Ethylene / α-Olefin Copolymer (C-1))
To an ethylene / α-olefin copolymer having a density of 0.930 g / cm ³ containing 4-methyl-1-pentene as a comonomer, 0.10% by mass of maleic anhydride was mixed in a tumbler blender. The mixture was extruded at 230 ° C. using a screw having a diameter of 40 mm and an effective length of 1120 mm to obtain a modified ethylene / α-olefin copolymer (C-1) grafted with maleic anhydride.
The density of the modified ethylene / α-olefin copolymer (C-1) measured in accordance with ASTM D1505 was 0.930 g / cm ³ . Moreover, the acid modification rate measured by NMR was 0.10 mass%.

2. Production and Evaluation of Laminated Structure [Example 1]
A polyamide-based thermoplastic elastomer composition (PA-TPV-1) as a material for the inner layer (A) and an aliphatic polyamide (B-1) as a material for the outer layer (B), using a molding machine manufactured by Pla Giken Co., Ltd. The polyamide-based thermoplastic elastomer composition (PA-TPV-1) was separately melted at 300 ° C., and the aliphatic polyamide (B-1) was separately melted at 280 ° C. These were co-extrusion molded from the above-mentioned molding machine into a tube having an outer diameter of 8 mm and an inner diameter of 6 mm, and this was pulled while being cooled to obtain a laminated structure.
Thickness of inner layer (A) (layer consisting of polyamide-based thermoplastic elastomer composition (PA-TPV-1)) / outer layer (B) (layer consisting of aliphatic polyamide (B-1)) of the obtained laminated structure Were 500 μm / 600 μm (total thickness 1100 μm).

Example 2 and Comparative Example 2
Similar to Example 1 except that the composition and thickness of the inner layer (A) and the thickness of the outer layer (B) were changed as shown in Table 1, coextrusion into a tube having an outer diameter of 8 mm and an inner diameter of 6 mm was performed. I got a structure.

[Example 3]
A polyamide-based thermoplastic elastomer composition (PA-TPV-1) as a material for the inner layer (A), a modified ethylene / α-olefin copolymer (C-1) as a material for the intermediate layer (C), and an outer layer (B) Aliphatic polyamide (B-2) as a material for the polyamide-based thermoplastic elastomer composition (PA-TPV-1) at 300 The polymer (C-1) was separately melted at 240 ° C., and the polyethylene resin (B-2) was separately melted at 230 ° C. These were co-extrusion molded from the above-mentioned molding machine into a tube having an outer diameter of 8 mm and an inner diameter of 6 mm, and this was pulled while being cooled to obtain a laminated structure.
Inner layer (A) (layer consisting of polyamide-based thermoplastic elastomer composition) / intermediate layer (C) (layer consisting of modified ethylene / α-olefin copolymer (C-1)) / outer layer of the obtained laminated structure The thickness of (B) (a layer comprising a polyethylene-based resin (B-2)) was 250 μm / 50 μm / 800 μm (total thickness 1100 μm).

Comparative Example 1
In the same manner as in Example 1 except that the inner layer (A) was not formed, it was formed into a tube having an outer diameter of 8 mm and an inner diameter of 6 mm, which was taken while cooling to obtain a single layer structure.
The thickness of the obtained single layer structure was 1100 μm.

Comparative Example 3
A laminated structure was obtained in the same manner as in Example 3 except that a semi-aromatic polyamide resin (PA6T6I66) was used as a material for the inner layer (A), and co-extrusion into a tube having an outer diameter of 8 mm and an inner diameter of 6 mm.

  The peel strength, fuel permeability, bending radius immediately before breaking, and bending workability of the tube-shaped laminated structures obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated by the following methods.

(Peeling strength)
The obtained tube-like laminated structure was cut into a length of about 200 mm and further cut into halves in the longitudinal direction, and the laminated portion at one end was peeled off to obtain a test piece. The obtained test piece is fixed to the chuck of Shimadzu Autograph (AGS-500B), and peeling is performed at a peeling angle of 180 ° C. and a peeling rate of 300 mm / min. Average value in 10-70 mm part was made into peeling strength.

(Fuel permeability)
The resulting tubular laminate structure was cut to a length of 100 mm. The dummy fuel CE10 (toluene / isooctane / ethanol = 45/45/10% by volume) was put therein, and both ends were sealed to make a test piece. The test piece was placed in a constant temperature bath (40 ° C.), the mass of the test piece before and after the test was measured, and the fuel permeability (g / m ² · day) was measured from the mass change.

(Bending radius just before breaking)
As shown in FIG. 2, a tube-shaped laminated structure 20 having a length of 500 mm was attached in a U-shape between two flat plates 31 and the distance between the flat plates 31 was reduced at a speed of 60 mm per minute. Then, the bending radius of the laminated structure 20 immediately before the tube-shaped laminated structure 20 is broken (a half of the distance 2R between the U-shaped tubular laminated structures in FIG. 2 is the bending radius). Yes) was measured.

(Bendability)
The tube-shaped laminated structure having a length of 500 mm was bent at 90 ° and fixed by a fixing tool. Then, it hold | maintained in 100 degreeC oven for 5 minutes. Then, it was left at room temperature for 1 hour while it was removed from the fixture. The bending angle of the bent portion of the obtained tubular laminate structure was evaluated based on the following criteria.
○: Bending angle is 75 ° or more and 90 ° or less ×: Bending angle is less than 75 °

  The evaluation results of Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Table 1.

  As shown in Table 1, the tube-like laminated structures of Examples 1 to 3 in which the inner layer (A) is a layer comprising a polyamide-based thermoplastic elastomer composition all have low fuel permeability (fuel barrier It is understood that the bending radius immediately before breaking is small because of high flexibility and high flexibility, and sufficient bending workability is obtained.

  On the other hand, it is understood that the tubular single-layer structure of Comparative Example 1 having no inner layer (A) has high fuel permeability and low flexibility. Further, the tube-shaped laminated structures of Comparative Examples 2 and 3 in which the inner layer (A) is a layer made of a semiaromatic polyamide are both low in fuel permeability but low in flexibility because they have low flexibility. It can be seen that the radius is large and it does not have sufficient bending workability.

  The laminated structure of the present invention has low fuel permeability, and is excellent in flexibility and bending workability. Therefore, it is suitable for various molded articles such as a tank and a bottle for storing fuel, or a tube and a hose for transporting fuel.

10, 10 ', 20 laminated structure 11 inner layer (A)
12 Outer layer (B)
13 Middle Layer (C)
31 flat

Claims (14)

A laminated structure in which an inner layer (A) made of a polyamide-based thermoplastic elastomer composition and an outer layer (B) containing a thermoplastic resin are laminated,
The polyamide-based thermoplastic elastomer composition is
A dicarboxylic acid structural unit containing 80% by mole or more of an aliphatic dicarboxylic acid structural unit having 2 to 14 carbon atoms with respect to all dicarboxylic acid structural units, and an aliphatic diamine structural unit having 4 to 12 carbon atoms are all diamine structural units An aliphatic polyamide comprising a diamine structural unit containing 80% by mole or more based on 1%, or an aliphatic polyamide comprising an aminocarboxylic acid structural unit or a lactam structural unit, the melting point being measured by differential scanning calorimetry (DSC) Aliphatic polyamide [I] having a Tm of 200 to 290 ° C.,
Ethylene structural unit [a], α-olefin structural unit having 3 to 20 carbon atoms [b], and nonconjugated polyene structural unit [c] having one or more carbon-carbon double bonds in one molecule Ethylene / α-olefin / nonconjugated polyene copolymer rubber [II] containing
An olefin polymer [III] containing 0.3 to 5.0% by mass of a functional group structural unit,
It is a crosslinked product of a rubber composition containing a phenolic resin crosslinking agent [IV],
The thermoplastic resin is
Aliphatic polyamide, semi-aromatic polyamide, polyolefin resin, tetrafluoroethylene-ethylene copolymer, polyvinyl fluoride, polyvinylidene fluoride, polyphenylene sulfide, polyester, polyketone, liquid crystal polymer, ethylene vinyl alcohol and the above-mentioned polyamide thermoplastic elastomer Laminated structure which is at least 1 sort (s) selected from the group which consists of elastomers other than a composition.   The laminated structure according to claim 1, wherein the thermoplastic resin is an aliphatic polyamide.   The laminated structure according to claim 1, wherein the thermoplastic resin is a polyethylene resin. The polyethylene-based resin is an ethylene / C3-C16 α-olefin (co) polymer having a density of 0.925 to 0.970 g / cm ³ as measured according to ASTM D1505. Item 3. A laminated structure according to item 3.   The melt flow rate of the ethylene / C 3-16 α-olefin (co) polymer, measured according to ASTM D1238 (230 ° C., 2.16 kg), is 0.01 to 10 g / 10 min. The laminated structure according to claim 4.   The aliphatic polyamide [I] is at least one or more selected from the group consisting of polyamide 6, polyamide 6.6, polyamide 6.10. Polyamide 6, 12 and copolymers thereof. The laminated structure according to any one of the above.   The functional group structural unit of the olefin polymer [III] contains one or more functional groups selected from the group consisting of a carboxylic acid group, an ester group, an ether group, an aldehyde group and a ketone group. Laminated structure according to any one of the preceding claims.   The laminated structure according to claim 7, wherein the functional group structural unit of the olefin polymer [III] is a maleic anhydride structural unit. The polyamide-based thermoplastic elastomer composition is
10 to 60% by mass of the aliphatic polyamide [I],
25 to 86% by mass of the ethylene / α-olefin / nonconjugated polyene copolymer rubber [II],
0.1 to 30% by mass of the olefin polymer [III],
Crosslinking of a rubber composition containing 1 to 10% by mass of the phenolic resin based crosslinking agent [IV] (provided that the total of [I], [II], [III] and [IV] is 100% by mass) The laminated structure according to any one of claims 1 to 8, which is an article.   The laminated structure according to any one of claims 1 to 9, wherein a thickness of the inner layer (A) is 30 to 70% of a total thickness of the inner layer (A) and the outer layer (B).   The laminated structure according to any one of claims 1 to 10, which is a hollow structure.   The laminated structure according to claim 11, which is a hose or a tube.   The laminated structure according to claim 12, which is a fuel piping tube.   The laminated structure according to claim 13, wherein the outer diameter of the fuel piping tube is 2 to 50 mm, and the thickness is 0.2 to 10 mm.

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