JP2023131540A - Laminate, tube and hose - Google Patents

Abstract

To provide a laminate that is used for a system for circulating a fuel containing 25 vol.% or more of methanol, has excellent flexibility and is less likely to transmit the fuel containing 25 vol.% or more of methanol therethrough.SOLUTION: A laminate is used for a system for circulating a fuel containing 25 vol.% or more of methanol. The laminate includes a fluororesin layer containing a fluororesin and a thermoplastic resin layer containing a thermoplastic resin.SELECTED DRAWING: None

Description

The present disclosure relates to laminates, tubes and hoses.

2. Description of the Related Art Tubes or hoses made of thermoplastic resin such as polyamide resin are known as tubes or hoses for transporting fuel such as automobile fuel.

For example, Patent Document 1 describes a tubular inner layer made of the following component (A), an intermediate layer made of the following component (B) provided in contact with the outer peripheral surface of the inner layer, and a tubular inner layer provided in contact with the outer peripheral surface of the intermediate layer. A fuel hose is described which is characterized in that the outer layer is made of the following component (C), and the layers are bonded to each other.
(A) At least one selected from the group consisting of polyamide 9T, ethylene vinyl alcohol copolymer resin, acid-modified ethylene-tetrafluoroethylene copolymer, and acid-modified polyethylene.
(B) A polyamide terpolymer obtained by copolymerizing the following (b1), (b2), and (b3).
(b1) Polyamide 6.
(b2) At least one selected from polyamide 66 and polyamide 610.
(b3) Polyamide 12.
(C) Aliphatic polyamide resin (excluding polyamide 6 and polyamide 66).

Patent Document 2 discloses that in a laminated hose made of a laminate of a fluorine-containing copolymer and a polyamide, the fluorine-containing copolymer contains (a) a repeating unit based on tetrafluoroethylene and/or chlorotrifluoroethylene; b) a repeating unit based on a cyclic hydrocarbon monomer having a dicarboxylic anhydride group and a polymerizable unsaturated group in the ring; and (c) other fluorine-containing monomers (however, tetrafluoroethylene and chlorotrifluoro 50 to 99.89 mol% of (a) based on the total molar amount of (a) repeating unit, (b) repeating unit and (c) repeating unit, (b) is 0.01 to 5 mol%, (c) is 0.1 to 49.99 mol%, and the volumetric flow rate is 0.1 to 1000 (mm ³ /sec). A laminated hose of a fluorine-containing copolymer and polyamide is described.

Japanese Patent Application Publication No. 2016-186349 Japanese Patent Application Publication No. 2006-321224

The present disclosure provides a laminate used in a system for distributing fuel containing 25% by volume or more of methanol, which has excellent flexibility and is difficult to permeate through fuel containing 25% by volume or more of methanol. The purpose is to provide the body.

According to the present disclosure, there is provided a laminate for use in a system for distributing fuel containing 25% by volume or more of methanol, wherein the laminate includes a fluororesin layer containing a fluororesin and a thermoplastic resin. A laminate is provided that includes a thermoplastic resin layer.

The laminate of the present disclosure preferably has a contact surface that comes into contact with a fuel containing 25% by volume or more of methanol.
In the laminate of the present disclosure, it is preferable that the contact surface is formed on the surface of the fluororesin layer.
In the laminate of the present disclosure, it is preferable that the fluororesin is a polymer containing chlorotrifluoroethylene units.
In the laminate of the present disclosure, the content of chlorotrifluoroethylene units in the fluororesin is preferably 15.0 to 25.0 mol% based on the total monomer units.
In the laminate of the present disclosure, it is preferable that the fluororesin is a polymer containing chlorotrifluoroethylene units and tetrafluoroethylene units.
In the laminate of the present disclosure, the content of tetrafluoroethylene units in the fluororesin is preferably 85.0 to 75.0 mol%.
In the laminate of the present disclosure, it is preferable that the thermoplastic resin is at least one selected from the group consisting of polyamide resin, polyolefin resin, modified polyolefin resin, and ethylene/vinyl alcohol copolymer.
In the laminate of the present disclosure, it is preferable that the fluororesin layer further contains a conductive filler.
The laminate of the present disclosure preferably has a permeation rate of 40 g/m ² /day or less for fuel containing 25% by volume of methanol.

Further, according to the present disclosure, a tube or a hose formed from the above-mentioned laminate is provided.

The tube or hose of the present disclosure preferably has a stress of 16.0 N or less as measured by a bending test.
(Stress measurement conditions)
When a tube or hose with an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 400 mm is bent to a bending radius of 35 mm, the stress applied to the tube or hose is measured.

The tube or hose of the present disclosure preferably has a resistivity change rate of 100% or less before and after the test, as measured by a fuel permeation test using fuel containing 25% by volume of methanol.

According to the present disclosure, there is provided a laminate used in a system for distributing fuel containing 25% by volume or more of methanol, which has excellent flexibility and allows the fuel containing 25% by volume or more of methanol to pass through. It is possible to provide a laminate that is difficult to maintain.

FIG. 1 is a schematic diagram showing a method of a bending test conducted in an experimental example and a comparative experimental example. FIG. 2 is a graph showing the fuel permeation rate of tubes produced in experimental examples and comparative experimental examples.

Hereinafter, specific embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

The laminate of the present disclosure is a laminate used in a system for circulating fuel containing 25% by volume or more of methanol.

The laminate of the present disclosure is used as a member constituting a system for circulating fuel containing methanol. A system for distributing fuel containing methanol is, for example, a system used for storing or supplying fuel. Components used in such systems include tanks, tubes, hoses, caps, valves, diaphragms, seals (O-rings), and the like. Systems for distributing fuels containing methanol are used, for example, not only in motor vehicles, but also in facilities for supplying fuel tanks of motor vehicles. A typical example of a member constituting a system for distributing fuel containing methanol is a fuel tube or a fuel hose.

Other uses include tubes and hoses; chemical liquid tubes or chemical liquid hoses, paint tubes or paint hoses (including printer applications), fuel tubes or fuel hoses such as automobile fuel tubes or automobile fuel hoses; Fuel tubes or fuel hoses for transportation such as ships and aircraft, fuel tubes or fuel hoses for small equipment such as lawn mowers, solvent tubes or hoses, automobile radiator hoses, air conditioner hoses, Brake hoses, electrical wire coverings, food and drink tubes or food and drink hoses, gas station tubes or hoses, underground tubes or hoses for gas stations, submarine oil field tubes or hoses (including injection tubes and crude oil transfer tubes), etc. Bottles, containers, tanks; Automobile radiator tanks, fuel tanks such as gasoline tanks, solvent tanks, paint tanks, chemical containers such as semiconductor chemical containers, food and drink tanks, etc., films, sheets; food use Films, food sheets, chemical films, chemical sheets, release films, diaphragms of diaphragm pumps and various packings, etc.; Various automotive seals such as carburetor flange gaskets, fuel pump O-rings, and seals for hydraulic equipment. Examples include various mechanical seals such as, gears, medical tubes (including catheters), cableway pipes, etc.

In this disclosure, "fuel" is preferably a fuel used in a combustion engine, such as an internal combustion engine of an automobile. The fuel that can be used in the present disclosure may be a mixed fuel containing methanol and a fuel other than methanol, or a fuel containing only methanol, as long as it contains 25% by volume or more of methanol. It's okay. The content of methanol in the fuel may be 25% by volume or more, 30% by volume or more, 35% by volume or more, 40% by volume or more, 45% by volume or more, or 50% by volume or more. Further, the content of methanol in the fuel may be 80% by volume or more or 90% by volume or more. Further, the content of methanol in the fuel may be 100% by volume or less.

As the fuel other than methanol, gasoline and a mixture of toluene and isooctane are mainly used, but the fuel may also contain, for example, the following. Diisobutylene, methyl tert-butyl ether (MTBE), ethylene tert-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), isopropanol, water, etc.

Conventional laminates used for tubes or hoses for distributing fuel are used in contact with fuel containing ethanol, as described in Patent Document 1, or are used in contact with fuel containing ethanol, as described in Patent Document 2. It has been used in contact with fuel containing at most 15% by volume of methanol.

However, it has been found that fuels containing 25% by volume or more of methanol permeate through the laminate more easily than fuels containing ethanol or fuels containing methanol at low concentrations. Therefore, there is a need for a laminate that is less permeable to fuel containing 25% by volume or more of methanol. In addition, the laminates used for tubes or hoses used to distribute fuel are made with flexibility to facilitate installation inside the vehicle or to prevent damage when connected to connectors. is required. Furthermore, when imparting conductivity to the laminate in order to prevent charging due to static electricity caused by friction with fuel, it is required that the laminate maintains its conductivity even after being in contact with the fuel for a long period of time. .

Therefore, we conducted extensive research on ways to solve these problems at the same time, and found that using a laminate that includes a fluororesin layer containing a fluororesin and a thermoplastic resin layer containing a thermoplastic resin will provide sufficient flexibility to the laminate. It has been found that the permeation of fuel containing 25% by volume or more of methanol can be highly suppressed. Furthermore, it was also found that when the laminate has conductivity, the conductivity is not impaired even after contact with a fuel containing 25% by volume or more of methanol, and the antistatic effect can be maintained for a long period of time.

The laminate of the present disclosure was completed based on such knowledge, and the laminate of the present disclosure is a laminate used in a system for distributing fuel containing 25% by volume or more of methanol. The device includes a fluororesin layer containing a fluororesin and a thermoplastic resin layer containing a thermoplastic resin.

Further, according to the present disclosure, there is provided a use of a laminate for suppressing permeation of fuel from a fuel distribution system when distributing a fuel containing 25% by volume or more of methanol, wherein the laminate contains fluorine. A use is provided comprising a fluororesin layer containing a resin and a thermoplastic layer containing a thermoplastic resin.

The laminate of the present disclosure, or the laminate used in the use of the present disclosure, typically has a contact surface that contacts a fuel containing 25% or more methanol by volume. In one embodiment of the laminate, the contact surface that comes into contact with the methanol-containing fuel is formed on the surface of the fluororesin layer. That is, the contact surface that comes into contact with the fuel containing methanol is formed of fluororesin. In this embodiment, the fluororesin layer is located at the outermost side of the laminate, and at least one side of the fluororesin layer is exposed. When the laminate is a tube or a hose, the fluororesin layer usually constitutes the innermost layer, and the inner surface is formed of the fluororesin. By forming the contact surface on the surface of the fluororesin layer, low fuel permeability is further improved, and if the laminate has conductivity, it will not come into contact with fuel containing 25% by volume or more of methanol. The conductivity is less likely to be impaired even after

(Fluororesin layer)
The fluororesin layer included in the laminate of the present disclosure contains a fluororesin.

The fluororesin used in the laminate of the present disclosure is a partially crystalline fluoropolymer, not a fluororubber, but a fluoroplastic. Fluororesin has a melting point and is thermoplastic. The fluororesin may be melt-processable or non-melt-processable, but it is preferably a melt-processable fluororesin because tubes can be produced with high productivity by melt extrusion molding. .

In this disclosure, melt processable means that the polymer can be melted and processed using conventional processing equipment such as extruders and injection molding machines. Therefore, melt processable fluororesins usually have a melt flow rate of 0.01 g/10 minutes or more and 500 g/10 minutes or less.

Examples of melt-processable fluororesins include tetrafluoroethylene (TFE)/perfluoro(alkyl vinyl ether) (PAVE) copolymer, tetrafluoroethylene (TFE)/hexafluoropropylene (HFP) copolymer, and TFE/perfluoro(alkyl vinyl ether) (PAVE) copolymer. Ethylene copolymer [ETFE], TFE/ethylene/HFP copolymer, polymer containing chlorotrifluoroethylene (CTFE) units, polyvinylidene fluoride [PVdF], TFE/vinylidene fluoride (VdF) copolymer [VT], polyvinyl fluoride [PVF], TFE/HFP/VdF copolymer, and the like.

Examples of PAVE include perfluoro(methyl vinyl ether) (PMVE), perfluoro(ethyl vinyl ether) (PEVE), and perfluoro(propyl vinyl ether) (PPVE). Among them, PPVE is preferred. These can be used alone or in combination of two or more.

The fluororesin may have polymerized units based on other monomers in an amount within a range that does not impair the essential properties of each fluororesin. The other monomers mentioned above may be appropriately selected from, for example, TFE, HFP, ethylene, propylene, perfluoro(alkyl vinyl ether), perfluoroalkyl ethylene, hydrofluoroolefin, fluoroalkyl ethylene, perfluoro(alkyl allyl ether), etc. can do.

The melting point of the fluororesin is preferably 160°C or higher, more preferably 190°C or higher, even more preferably 230°C or higher, particularly preferably 240°C or higher, preferably lower than 324°C, and more The temperature is preferably 320°C or lower, more preferably 300°C or lower, particularly preferably 280°C or lower, and most preferably 260°C or lower.

The melt flow rate (MFR) of the fluororesin at any temperature in the general molding temperature range of 230 to 350°C (for example, 265°C or 297°C) is preferably 0.5 g/10 minutes or more. , more preferably 2.0 g/10 minutes or more, further preferably 5.0 g/10 minutes or more, particularly preferably 10 g/10 minutes or more, most preferably 15 g/10 minutes or more, and preferably is 100 g/10 minutes or less, more preferably 50 g/10 minutes or less, further preferably 40 g/10 minutes or less, particularly preferably 35 g/10 minutes or less. The melt flow rate can be measured, for example, using a melt indexer at any temperature (for example, 265°C or 297°C) and at any load (for example, 2.16 kg or 5 kg) using a nozzle with an inner diameter of 2 mm and a length of 8 mm. It can be identified by measuring the mass (g) of fluororesin flowing out per unit time (10 minutes).

Examples of fluororesins include TFE/perfluoro(alkyl vinyl ether) (PAVE) copolymer, tetrafluoroethylene (TFE)/hexafluoropropylene (HFP) copolymer, TFE/ethylene copolymer [ETFE], and TFE/ethylene. /HFP copolymer, a polymer containing CTFE units, and a tetrafluoroethylene/hexafluoropropylene/vinylidene fluoride copolymer [THV]. At least one selected from the group consisting of a polymer [ETFE], a TFE/ethylene/HFP copolymer, and a polymer containing CTFE units is more preferable, as it further improves flexibility and low fuel permeability, and provides antistatic properties. Polymers containing CTFE units are more preferred because the effect can be maintained for a longer period of time.

In the present disclosure, the composition of the fluororesin can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescent X-ray analysis depending on the type of monomer.

The TFE/HFP copolymer preferably has a TFE/HFP mass ratio of 80 to 97/3 to 20, more preferably 84 to 92/8 to 16.
The TFE/HFP copolymer may be a binary copolymer consisting of TFE and HFP, or a terpolymer consisting of a monomer copolymerizable with TFE and HFP (for example, TFE/HFP). /HFP/PAVE copolymer).

It is also preferred that the TFE/HFP copolymer is a TFE/HFP/PAVE copolymer containing polymerized units based on PAVE.
The TFE/HFP/PAVE copolymer preferably has a mass ratio of TFE/HFP/PAVE of 70 to 97/2.9 to 20/0.1 to 10, and preferably 81 to 92/5 to 16/0. More preferably, it is between .3 and 5.

The TFE/PAVE copolymer preferably has a TFE/PAVE mass ratio of 90 to 99/1 to 10, more preferably 92 to 97/3 to 8.

ETFE is a copolymer containing ethylene units and TFE units. As ETFE, a copolymer in which the molar ratio of TFE units to ethylene units (TFE units/ethylene units) is 20/80 or more and 90/10 or less is preferable. A more preferable molar ratio is 37/63 or more and 85/15 or less, and an even more preferable molar ratio is 38/62 or more and 80/20 or less. The above-mentioned ETFE may be a copolymer consisting of TFE, ethylene, and a monomer copolymerizable with TFE and ethylene. Copolymerizable monomers include the following formulas: CH ₂ =CX ⁵ Rf ³ , CF ₂ =CFRf ³ , CF ₂ =CFORf ³ , CH ₂ =C(Rf ³ ) ₂
(In the formula, X ⁵ is H or F, and Rf ³ represents a fluoroalkyl group which may contain an ether bond.) Among them, CF ₂ =CFRf ³ , CF At least one selected from the group consisting of fluorine-containing vinyl monomers represented by ₂ = CFORf ³ and CH ₂ =CX ⁵ Rf ³ is preferred, and HFP, CF ₂ =CF-ORf ⁴ (wherein Rf ⁴ represents a perfluoroalkyl group having 1 to 5 carbon atoms) and CH ₂ =CX ⁵ Rf ³ in which Rf ³ is a fluoroalkyl group having 1 to 8 carbon atoms; At least one selected from the group consisting of fluorine-containing vinyl monomers is more preferred, and HFP is even more preferred. Further, the monomer copolymerizable with TFE and ethylene may be an aliphatic unsaturated carboxylic acid such as itaconic acid or itaconic anhydride. The monomer unit copolymerizable with TFE and ethylene in ETFE is preferably 0.1 mol% or more, preferably 0.2 mol% or more, and preferably 10 mol%, It is more preferably 5 mol%, and particularly preferably 4 mol%.

The TFE/ethylene copolymer [ETFE] is also preferably a TFE/ethylene/HFP copolymer containing a polymerized unit based on HFP (HFP unit). The TFE/ethylene/HFP copolymer preferably has a molar ratio of TFE/ethylene/HFP of 40 to 65/30 to 59.5/0.5 to 20, and preferably 40 to 65/30 to 59.5. /0.5 to 10 is more preferable.

The melting point of ETFE is preferably 160°C or higher, more preferably 170°C or higher, even more preferably 180°C or higher, particularly preferably 190°C or higher, preferably lower than 324°C, and more preferably is 320°C or lower, more preferably 300°C or lower, particularly preferably 280°C or lower, and most preferably 260°C or lower.

The MFR (297°C) of ETFE is preferably 0.5 g/10 minutes or more, more preferably 2.0 g/10 minutes or more, still more preferably 5.0 g/10 minutes or more, and particularly preferably 8 g/10 minutes or more, most preferably 10 g/10 minutes or more, preferably 100 g/10 minutes or less, more preferably 50 g/10 minutes or less, even more preferably 40 g/10 minutes or less. , particularly preferably 30 g/10 minutes or less, most preferably 20 g/10 minutes or less. The MFR of ETFE is measured at a temperature of 297°C or 265°C and a load of 5 kg.

As ETFE, it is also suitable to use the ethylene/tetrafluoroethylene copolymer described in JP-A-2019-90013.

The polymer containing CTFE units is preferably at least one selected from the group consisting of polychlorotrifluoroethylene (PCTFE) and CTFE copolymers.

The content of CTFE units in the polymer containing CTFE units is lower than the total monomer units because flexibility, low fuel permeability and fuel cracking resistance are further improved, and the antistatic effect can be maintained for a longer period of time. It is preferably 1.0 mol% or more, more preferably 5.0 mol% or more, even more preferably 10.0 mol% or more, particularly preferably 15.0 mol% or more. , preferably 100 mol% or less, more preferably 75.0 mol% or less, further preferably 50.0 mol% or less, particularly preferably 25.0 mol% or less.

Examples of polymers containing CTFE units include ethylene/chlorotrifluoroethylene (CTFE) copolymer [ECTFE], polychlorotrifluoroethylene [PCTFE], CTFE/tetrafluoroethylene (TFE) copolymer, and TFE/vinylidene. Examples include fluoride (VdF)/CTFE copolymer [VTC], and at least one selected from the group consisting of PCTFE, ethylene/CTFE copolymer, and CTFE/TFE copolymer is preferred, and low fuel permeability From this point of view, CTFE/TFE copolymers are more preferred.

PCTFE includes CTFE homopolymers and polymers containing CTFE units and small amounts of comonomer units.

The melting point of PCTFE is preferably 150°C or higher, more preferably 190°C or higher, preferably 230°C or lower, and even more preferably 217°C or lower. The melting point is the temperature corresponding to the maximum value in the heat of fusion curve when the temperature is raised at a rate of 10° C./min using a differential scanning calorimeter (DSC).

The flow value of PCTFE is preferably 1×10 ⁻⁴ (cm ³ /sec) or more, and preferably 5×10 ⁻¹ (cm ³ /sec) or less. The flow value is the volume of resin extruded per second when PCTFE is melted at 230°C using a vertical flow tester CFT-500D (manufactured by Shimadzu Corporation) and extruded from a nozzle diameter of 1 mm with a load of 100 kg. It is.

The content of CTFE units in PCTFE is preferably 95 mol% or more, more preferably 98 mol% or more, still more preferably 99 mol% or more, and preferably 100 mol% or less.

The comonomer constituting the comonomer unit that PCTFE may contain is not particularly limited as long as it is a monomer copolymerizable with CTFE, and examples include TFE, ethylene, vinylidene fluoride, and perfluoroalkyl. Examples include vinyl ether and hexafluoroethylene.

Ethylene/CTFE copolymer (ECTFE) is a copolymer containing ethylene units and CTFE units, in which ethylene units account for 46 to 52 mol% of the total of ethylene units and CTFE units, and CTFE units is preferably 54 to 48 mol%. ECTFE may be a binary copolymer consisting only of ethylene units and CTFE units, or may be a copolymer based on monomers copolymerizable with ethylene and CTFE (for example, fluoroalkyl vinyl ether (PAVE) derivatives). It may also include units.
The content of polymer units based on monomers copolymerizable with ethylene and CTFE is 0.01 mol% with respect to the total of ethylene units, CTFE units, and polymer units based on monomers copolymerizable with the above. It is preferably at least 5 mol%, and preferably at most 5 mol%.

The MFR (230° C.) of ECTFE is preferably 0.5 g/10 minutes or more, and preferably 100 g/10 minutes or less. The MFR of ECTFE is measured at a temperature of 230° C. and a load of 2.16 kg.

CTFE/TFE copolymers contain CTFE units and TFE units. As the CTFE/TFE copolymer, one containing a CTFE unit, a TFE unit, and a monomer (α) unit derived from a monomer (α) copolymerizable with these units is particularly preferred.

The monomer (α) is not particularly limited as long as it is a monomer copolymerizable with CTFE and TFE, and includes ethylene (Et), VdF, CF ₂ =CF-ORf ¹ (wherein, Rf ¹ is perfluoro(alkyl vinyl ether) [PAVE] represented by a perfluoroalkyl group ^having 1 to 8 carbon ^{atoms )} , CX ³ X ⁴ =CX ⁵ (CF ₂ ) _n ⁵ are the same or different and are _a hydrogen atom or a fluorine atom; X ⁶ is a hydrogen atom, a fluorine atom or a chlorine atom; n is an integer of 1 to 10); Examples include alkyl perfluorovinyl ether derivatives represented by ₂ -Rf ² (wherein Rf ² is a perfluoroalkyl group having 1 to 5 carbon atoms), among which PAVE, the above vinyl monomers and alkyl perfluorovinyl ether derivatives are mentioned. It is preferably at least one selected from the group consisting of fluorovinyl ether derivatives, and more preferably at least one selected from the group consisting of PAVE and HFP.

As PAVE, perfluoro(alkyl vinyl ether) represented by CF ₂ =CF-ORf ³ (in the formula, Rf ³ represents a perfluoroalkyl group having 1 to 5 carbon atoms) is preferable, and for example, perfluoro( Methyl vinyl ether) [PMVE], perfluoro(ethyl vinyl ether) [PEVE], perfluoro(propyl vinyl ether) [PPVE], perfluoro(butyl vinyl ether), etc. Among them, from the group consisting of PMVE, PEVE and PPVE At least one selected one is more preferred, and PPVE is even more preferred.

As the alkyl perfluorovinyl ether derivative, those in which Rf ² is a perfluoroalkyl group having 1 to 3 carbon atoms are preferred, and CF ₂ =CF-OCH ₂ -CF ₂ CF ₃ is more preferred.

The ratio of CTFE units to TFE units in the CTFE/TFE copolymer is preferably 15.0 to 90.0 mol% for CTFE units and 85.0 to 10.0 mol% for TFE units. , More preferably, the CTFE unit is 15.0 to 50.0 mol%, the TFE unit is 85.0 to 50.0 mol%, and even more preferably the CTFE unit is 15.0 to 25.0 mol%. %, and the TFE unit is 85.0 to 75.0 mol%.

The CTFE/TFE copolymer has a total of 90.0 to 99.9 mol% of CTFE units and TFE units, and 0.1 to 10.0 mol% of monomer (α) units. preferable. If the monomer (α) unit is less than 0.1 mol%, moldability, environmental stress cracking resistance, and fuel cracking resistance tend to be poor, and if it exceeds 10.0 mol%, fuel barrier properties and heat resistance tend to deteriorate. , mechanical properties tend to be inferior.

As the CTFE/TFE copolymer, a CTFE/TFE/PAVE copolymer is particularly preferred.

In the CTFE/TFE/PAVE copolymer, the above PAVE includes perfluoro(methyl vinyl ether) [PMVE], perfluoro(ethyl vinyl ether) [PEVE], perfluoro(propyl vinyl ether) [PPVE], perfluoro(butyl vinyl ether) [PPVE], and perfluoro(butyl vinyl ether) [PPVE]. ), among which at least one selected from the group consisting of PMVE, PEVE and PPVE is preferred, and PPVE is more preferred.
In the CTFE/TFE/PAVE copolymer, the PAVE unit preferably accounts for 0.5 mol% or more, and preferably 5 mol% or less of the total monomer units.

The melting point of the CTFE/TFE copolymer is preferably 190°C or higher, more preferably 210°C or higher, even more preferably 220°C or higher, particularly preferably 230°C or higher, and most preferably 240°C. or more, preferably less than 324°C, more preferably 320°C or less, still more preferably 270°C or less, and most preferably 260°C or less.

The MFR (297°C) of the CTFE/TFE copolymer is preferably 0.5 g/10 minutes or more, more preferably 2.0 g/10 minutes or more, and even more preferably 5.0 g/10 minutes or more. It is particularly preferably 7 g/10 minutes or more, most preferably 10 g/10 minutes or more, preferably 100 g/10 minutes or less, more preferably 50 g/10 minutes or less, and even more preferably 40 g/10 minutes. It is 10 minutes or less, particularly preferably 35 g/10 minutes or less. The MFR of the CTFE/TFE copolymer is measured at a temperature of 297° C. and a load of 5 kg.

The fluororesin used in the laminate of the present disclosure may have a reactive functional group. When the fluororesin has a reactive functional group, the layers can be bonded even more firmly. It is more preferable that the fluororesin has a reactive functional group at the end of the main chain and/or the side chain of the polymer. The reactive functional group is preferably at least one selected from the group consisting of a carbonyl group, a hydroxyl group, a heterocyclic group, and an amino group.

The number of reactive functional groups is preferably 3 or more, more preferably 15 or more, and even more preferably 30 per 10 ⁶ main chain carbon atoms, since even higher adhesiveness can be obtained. The number is particularly preferably 50 or more, preferably 800 or less, more preferably 500 or less, and even more preferably 300 or less.

The number of reactive functional groups was measured using an infrared spectrophotometer using a film sheet with a thickness of 50 to 200 μm obtained by compression molding a fluororesin at a molding temperature 50° C. higher than its melting point and a molding pressure of 5 MPa. The number is calculated by analyzing the infrared absorption spectrum and comparing it with the infrared absorption spectrum of a known film to determine the type of characteristic absorption of the reactive functional group, using the following formula from each difference spectrum.

A fluororesin can be produced by polymerizing a fluorine-containing monomer that constitutes a fluororesin using a polymerization method such as suspension polymerization, solution polymerization, emulsion polymerization, or bulk polymerization. As the polymerization method, emulsion polymerization or suspension polymerization is preferred, and suspension polymerization is more preferred. In the polymerization, various conditions such as temperature and pressure, a polymerization initiator, and other additives can be appropriately set depending on the composition and amount of the fluororesin.

As the polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used, but an oil-soluble radical polymerization initiator is preferable.

The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, for example,
Dialkyl peroxycarbonates such as di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, disec-butyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate;
Peroxy esters such as t-butylperoxyisobutyrate and t-butylperoxypivalate;
Dialkyl peroxides such as di-t-butyl peroxide;
Di[fluoro(or fluorochloro)acyl]peroxides;
etc. are listed as representative examples.

Examples of di[fluoro(or fluorochloro)acyl]peroxides include diacyl represented by [(RfCOO)-] ₂ (Rf is a perfluoroalkyl group, an ω-hydroperfluoroalkyl group, or a fluorochloroalkyl group); Examples include peroxide.

Examples of di[fluoro (or fluorochloro)acyl] peroxides include di(ω-hydro-dodecafluorohexanoyl) peroxide, di(ω-hydro-tetradecafluoroheptanoyl) peroxide, di(ω- - Hydro-hexadecafluorononanoyl) peroxide, di(perfluoropropionyl) peroxide, di(perfluorobutyryl) peroxide, di(perfluoroparelyl) peroxide, di(perfluorohexanoyl) peroxide , di(perfluoroheptanoyl) peroxide, di(perfluorooctanoyl) peroxide, di(perfluorononanoyl) peroxide, di(ω-chloro-hexafluorobutyryl) peroxide, di(ω-chloro -decafluorohexanoyl) peroxide, di(ω-chloro-tetradecafluorooctanoyl) peroxide, ω-hydrododecafluoroheptanoyl-ω-hydrohexadecafluorononanoyl-peroxide, ω-chloro-hexanoyl Fluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydrododecafluoroheptanoyl-perfluorobutyryl-peroxide, di(dichloropentafluorobutanoyl) peroxide, di(trichlorooctafluorohexanoyl) ) peroxide, di(tetrachloroundecafluorooctanoyl) peroxide, di(pentachlorotetradecafluorodecanoyl) peroxide, di(undecachlorotriacontafluorodocosanoyl) peroxide, and the like.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, such as ammonium salts, potassium salts, and sodium salts such as persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, and percarbonate. , organic peroxides such as disuccinic acid peroxide and diglutaric acid peroxide, t-butyl permalate, and t-butyl hydroperoxide. Reducing agents such as sulfites may be used in combination with peroxide, and the amount used may be 0.1 times or more and 20 times or less relative to the peroxide.

In the polymerization, surfactants, chain transfer agents, and solvents can be used, and conventionally known ones can be used, respectively.

As the surfactant, known surfactants can be used, such as nonionic surfactants, anionic surfactants, and cationic surfactants. Among these, fluorine-containing anionic surfactants are preferable, and may contain ether-bonding oxygen (that is, an oxygen atom may be inserted between carbon atoms), and may contain straight-chain or branched surfactants having 4 to 20 carbon atoms. More preferred are fluorine-containing anionic surfactants. The amount of surfactant added (relative to polymerized water) is preferably 50 ppm or more, and preferably 5000 ppm or less.

Examples of chain transfer agents include hydrocarbons such as ethane, isopentane, n-hexane, and cyclohexane; aromatics such as toluene and xylene; ketones such as acetone; acetate esters such as ethyl acetate and butyl acetate; methanol , alcohols such as ethanol; mercaptans such as methyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, chloroform, methylene chloride, and methyl chloride. The amount of the chain transfer agent added may vary depending on the size of the chain transfer constant of the compound used, but it is usually used in the range of 0.01 to 20% by mass based on the polymerization solvent.

Examples of the solvent include water, a mixed solvent of water and alcohol, and the like.

In suspension polymerization, a fluorine-based solvent may be used in addition to water. Examples of fluorine-based solvents include hydrochlorofluoroalkanes such as CH ₃ CClF ₂ , CH ₃ CCl ₂ F, CF ₃ CF ₂ CCl ₂ H, CF ₂ ClCF ₂ CFHCl; CF ₂ ClCFClCF ₂ CF ₃ , CF ₃ CFClCFClCF _3, etc. _{Hydrofluoroalkanes such as CF3CFHCFHCF2CF2CF3 , CF2HCF2CF2CF2CF2H , CF3CF2CF2CF2CF2CF2CF2H ; CH _ _ _ _ _ _ 3} OC _2F5 , CH ₃ OC ₃ F ₅ CF ₃ CF ₃ CH ₂ OCHF _{2 ,} CF ₃ CHFCF ₂ Och ₃ , CHF ₂ CF ₂ Och ₂ F, (CF ₃ ) ₂ CHCF ₂ Och ₃ , CF ₃ CF _{2 Hydrofluoroethers such as CH2OCH2CHF2 , CF3CHFCF2OCH2CF3 ; perfluorocyclobutane , CF3CF2CF2CF3 , CF3CF2CF2CF2CF3 , CF3CF2 _ _ _ _} Examples include perfluoroalkanes such as CF ₂ CF ₂ CF ₂ CF ₃ , and among them, perfluoroalkanes are preferred. The amount of the fluorine-based solvent to be used is preferably 10 to 100% by mass based on the aqueous medium from the viewpoint of suspension properties and economical efficiency.

The polymerization temperature is not particularly limited and may be 0 to 100°C. The polymerization pressure is appropriately determined depending on the type and amount of the solvent used and other polymerization conditions such as vapor pressure and polymerization temperature, but it may usually be 0 to 9.8 MPaG.

When producing a fluororesin by emulsion polymerization, an aqueous dispersion in which fluororesin particles are dispersed is usually obtained. The fluororesin particles in the aqueous dispersion obtained by emulsion polymerization may be coagulated to recover the fluororesin. When producing a fluororesin by suspension polymerization, the wet fluororesin can usually be recovered. The recovered fluororesin may be washed or dried.

In addition to the above-mentioned fluororesin, the fluororesin layer can further contain a conductive filler. Containing a conductive filler prevents the accumulation of static electricity caused by friction between the fuel and the laminate, and prevents fires and explosions that may occur due to static electricity discharge, as well as cracks and holes in the laminate. It is possible to prevent fuel leakage.

The above-mentioned conductive filler is not particularly limited, and examples thereof include conductive single powder or conductive single fiber of metal, carbon, etc.; powder of conductive compound such as zinc oxide; surface conductivity-treated powder, and the like.

The conductive single powder or conductive single fiber is not particularly limited, and includes, for example, metal powders such as copper and nickel; metal fibers such as iron and stainless steel; carbon black, carbon fiber, and JP-A No. 3-174018, etc. Examples include carbon fibrils, carbon nanotubes, carbon nanohorns, and the like.

The above-mentioned surface conductivity-treated powder is a powder obtained by subjecting the surface of non-conductive powder such as glass beads or titanium oxide to conductivity treatment. The method for the conductivity treatment is not particularly limited, and examples thereof include metal sputtering, electroless plating, and the like. Among the above-mentioned conductive fillers, carbon black is advantageous from an economical point of view and is therefore preferably used.

The amount of the conductive filler to be blended is determined as appropriate based on the type of fluororesin, the conductive performance required for the laminate, molding conditions, etc., but it must be at least 1 part by mass per 100 parts by mass of fluororesin. is preferable, and preferably 30 parts by mass or less. A more preferable lower limit is 5 parts by weight, and a more preferable upper limit is 20 parts by weight.

In addition to the conductive filler, the fluororesin layer may contain various additives such as reinforcing agents, fillers, ultraviolet absorbers, and pigments, as long as the purpose of the present disclosure is not impaired. . By using such additives, the properties of the fluororesin layer, such as surface hardness, abrasion resistance, charging properties, and weather resistance, can be improved.

(Thermoplastic resin layer)
The thermoplastic resin layer included in the laminate of the present disclosure contains a thermoplastic resin (excluding fluororesin). In one embodiment, the fluororesin layer and thermoplastic resin layer are directly bonded.

Thermoplastic resins include polyamide resin, polyolefin resin, vinyl chloride resin, polyurethane resin, polyester resin, polyaramid resin, polyimide resin, polyamideimide resin, polyphenylene oxide resin, polyacetal resin, polycarbonate resin, acrylic resin, and styrene resin. Resin, acrylonitrile/butadiene/styrene resin [ABS], cellulose resin, polyether ether ketone resin [PEEK], polysulfone resin, polyether sulfone resin [PES], polyetherimide resin, etc. have excellent mechanical strength and pressure resistance. and resins whose main role is to maintain the shape of molded objects (hereinafter referred to as structural component resins), ethylene/vinyl alcohol copolymer resins, polyphenylene sulfide resins, polybutylene naphthalate resins, polybutylene terephthalate resins, Examples include resins with high permeation resistance against fuel and gas (hereinafter referred to as permeation-resistant resins) such as phthalamide [PPA].

As the thermoplastic resin, at least one selected from the group consisting of polyamide resins, ethylene/vinyl alcohol copolymer resins, and polyolefin resins is particularly preferred; At least one selected from the group is more preferred, and polyamide resin is even more preferred.

The laminate of the present disclosure has excellent mechanical strength when the thermoplastic resin layer contains the above-mentioned structural member resin, and when the thermoplastic resin layer contains the above-mentioned permeation-resistant resin, it has excellent permeation resistance to fuel. Become something.

A polyamide resin is made of a polymer having an amide bond [-NH-C(=O)-] as a repeating unit in the molecule.

Polyamide resins include so-called nylon resins, which are made of polymers in which amide bonds within molecules are bonded to aliphatic or alicyclic structures, or polymers in which amide bonds in molecules are bonded to aromatic structures. It may be any so-called aramid resin.

The polyamide resin (nylon resin) is not particularly limited, and examples thereof include polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 1010, polyamide 612, polyamide 6/66, polyamide 66/12, polyamide 46, and methane. Examples include those made of polymers such as xylylene diamine/adipic acid copolymer, polyamide 62, polyamide 92, polyamide 122, polyamide 142, and aromatic polyamides such as polyamide 6T and polyamide 9T. You may use combinations of more than one species.

The aramid resin is not particularly limited, and examples thereof include polyparaphenylene terephthalamide, polymetaphenylene isophthalamide, and the like.

The polyamide resin may also be made of a polymer in which a part of the molecule is block copolymerized or graft copolymerized with a structure that does not have an amide bond as a repeating unit. Such polyamide resins include, for example, polyamide elastomers such as polyamide 6/polyester copolymer, polyamide 6/polyether copolymer, polyamide 12/polyester copolymer, and polyamide 12/polyether copolymer. Examples include things. These polyamide elastomers are obtained by block copolymerization of polyamide oligomers and polyester oligomers via ester bonds, or by block copolymerization of polyamide oligomers and polyether oligomers via ether bonds. This is what was obtained. Examples of the polyester oligomer include polycaprolactone, polyethylene adipate, and the like, and examples of the polyether oligomer include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like. As the polyamide elastomer, polyamide 6/polytetramethylene glycol copolymer and polyamide 12/polytetramethylene glycol copolymer are preferred.

As a polyamide resin, the layers consisting of polyamide resin can be sufficiently mechanical strength even if they are thin layers, so in particular, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 1010, polyamide 612, polyamide. 62, polyamide 6/66, polyamide 66/12, polyamide 6/polyester copolymer, polyamide 6/polyether copolymer, polyamide 12/polyester copolymer, polyamide 12/polyether copolymer, polyamide 9T, etc. Preferably, two or more of these may be used in combination.

The amine value of the polyamide resin is preferably 10 (equivalent/10 ⁶ g) or more, and preferably 80 (equivalent/10 ⁶ g) or less. When the amine value is within the above range, excellent interlayer adhesion can be achieved even when coextruding at a relatively low temperature. If the amine value is less than 10 (equivalent/10 ⁶ g), the interlayer adhesive strength may become insufficient. If it exceeds 80 (equivalent/10 ⁶ g), the mechanical strength of the laminate will be insufficient, and it will be likely to be colored during storage, resulting in poor handling properties. A more preferable lower limit is 15 (equivalents/10 ⁶ g), an even more preferable lower limit is 23 (equivalents/10 ⁶ g), a more preferable upper limit is 60 (equivalents/10 ⁶ g), and an even more preferable upper limit is 50 (equivalents/10 6 g). /10 ⁶ g).

In the present disclosure, the amine value is a value determined by heating and dissolving 1 g of polyamide resin in 50 ml of m-cresol, and titrating this using a 1/10 normal p-toluenesulfonic acid aqueous solution using thymol blue as an indicator. Unless otherwise specified, it means the amine value of the polyamide resin before lamination. Of the number of amino groups that the polyamide resin has before lamination, it is thought that a portion is consumed for adhesion with adjacent layers, but since this number is extremely small compared to the entire layer, The amine value of the previous polyamide resin and the amine value of the laminate of the present disclosure are substantially the same.

A polyolefin resin is a resin having monomer units derived from vinyl group-containing monomers that do not have fluorine atoms. The vinyl group-containing monomer that does not have a fluorine atom is not particularly limited, but in applications where interlayer adhesion is required, those having the above-mentioned polar functional group are preferred.

Polyolefin resins are not particularly limited, and include, for example, polyolefins such as polyethylene, polypropylene, high-density polyolefins, and low-density polyolefins, modified polyolefins obtained by modifying the above polyolefins with maleic anhydride, etc., epoxy-modified polyolefins, amine-modified polyolefins, etc. Among them, high-density polyolefin is preferred.

Ethylene/vinyl alcohol copolymer resin is obtained by saponifying an ethylene/vinyl acetate copolymer obtained from ethylene and vinyl acetate. The blending ratio of ethylene and vinyl acetate to be copolymerized is appropriately determined according to the ratio of the number of moles of vinyl acetate units defined by the formula described below.

The ethylene/vinyl alcohol copolymer resin preferably has a vinyl acetate unit X mol % and a saponification degree Y % satisfying X×Y/100≧7. If X×Y/100<7, interlayer adhesive strength may become insufficient. More preferably, X×Y/100≧10. The value of X×Y/100 is an index of the content of hydroxyl groups in the ethylene/vinyl alcohol copolymer resin, and a large value of X×Y/100 means that the ethylene/vinyl alcohol copolymer resin is It means that the content of hydroxyl groups is high.

The hydroxyl group is a group that can be involved in adhesion between the EVOH layer and the mating material to be laminated, and when the hydroxyl group content of the ethylene/vinyl alcohol copolymer resin is high, the interlayer adhesion in the laminate improves. In the present disclosure, the above-mentioned "mate material to be laminated" refers to materials that are laminated in contact with each other.

In the present disclosure, "vinyl acetate units The ratio of the number of moles of vinyl [Ni], expressed by the following formula: Xi (%) = (Ni/N) x 100
means the average value of the molar content Xi expressed by The vinyl acetate unit X mol% is a value obtained by measurement using infrared absorption spectroscopy (IR).

In the present disclosure, the term "vinyl acetate unit" refers to a portion of the molecular structure of the ethylene/vinyl alcohol copolymer resin, which is derived from vinyl acetate. The vinyl acetate unit may be saponified and have a hydroxyl group, or may be unsaponified and have an acetoxyl group.

"Saponification degree" is a percentage representing the ratio of the number of saponified vinyl acetate units to the sum of the number of saponified vinyl acetate units and the number of unsaponified vinyl acetate units. The degree of saponification is a value obtained by measuring using infrared absorption spectroscopy (IR).

Examples of ethylene/vinyl alcohol copolymer resins in which X and Y satisfy the above formula include EVAL F101 (manufactured by Kuraray Co., Ltd., vinyl acetate unit X = 68.0 mol%; degree of saponification Y = 95% ; X×Y/100=64.6), Mercene H6051 (manufactured by Tosoh Corporation, vinyl acetate unit X=11.2 mol%; degree of saponification Y=100%; Commercial products such as K200 (manufactured by Taoka Kagaku Co., Ltd., vinyl acetate unit X = 11.2 mol %; degree of saponification Y = 85%; X x Y/100 = 9.52) can be mentioned.

The ethylene/vinyl alcohol copolymer resin preferably has an MFR of 0.5 g/10 minutes or more at 200°C, and preferably 100 g/10 minutes or less. Even if the MFR is less than 0.5 g/10 minutes or more than 100 g/10 minutes, the difference between the melt viscosity of the ethylene/vinyl alcohol copolymer resin and the melt viscosity of the mating material tends to increase. , which is not preferable because it may cause unevenness in the thickness of each layer. The preferred lower limit is 1 g/10 minutes, and the preferred upper limit is 50 g/10 minutes.

The melting point of the thermoplastic resin is preferably 50°C or higher, and preferably 400°C or lower. The lower limit is more preferably 100°C, still more preferably 150°C. The upper limit is more preferably 300°C, still more preferably 250°C.

The melting point is determined using a differential scanning calorimeter (DSC) device (manufactured by Seiko) as the temperature corresponding to the maximum value in the heat of fusion curve when the temperature is increased at a rate of 10° C./min.

The thermoplastic resin layer may contain various additives, such as stabilizers such as heat stabilizers, reinforcing agents, fillers, ultraviolet absorbers, and pigments, as long as the purpose of the present disclosure is not impaired. It's okay. By using such additives, the properties of thermoplastic resins such as thermal stability, surface hardness, abrasion resistance, charging properties, and weather resistance can be improved.

The laminate of the present disclosure has further improved flexibility and low fuel permeability, and can maintain an antistatic effect for a longer period of time. It is preferable to include a resin layer. In the laminate of the present disclosure, it is preferable that the fluororesin layer and the polyamide resin layer are directly bonded because excellent interlayer adhesive strength can be obtained without providing an adhesive layer or the like. Examples of the laminate of the present disclosure include a laminate including a fluororesin layer/polyamide resin layer as the innermost layer/outermost layer.

When the polyamide resin has the above-mentioned amine value, the fluororesin layer and the polyamide resin layer can be bonded particularly firmly. The interlayer adhesive strength between the fluororesin layer and the polyamide resin layer is preferably 30 N/cm or more.

The interlayer adhesion strength is determined by performing a 180° peel test at a speed of 25 mm/min using a Tensilon universal testing machine.

The laminate of the present disclosure preferably includes a fluororesin layer and an EVOH layer containing an ethylene/vinyl alcohol copolymer (EVOH) resin, since the low fuel permeability is further improved.

The laminate of the present disclosure preferably further includes a polyamide resin layer in addition to the fluororesin layer and the EVOH layer, since excellent interlayer adhesive strength and excellent properties of the three types of resins can be obtained. . In the laminate of the present disclosure, the fluororesin layer and the polyamide resin layer are directly bonded, and the polyamide resin layer and the EVOH layer It is preferable that the two be directly bonded.

The laminate of the present disclosure includes, for example,
A laminate comprising a fluororesin layer/polyamide resin layer as the innermost layer/outermost layer,
A laminate comprising a fluororesin layer/EVOH layer/polyamide resin layer as the innermost layer/middle layer/outermost layer, a laminate comprising a fluororesin layer/polyamide resin layer/EVOH layer,
A laminate comprising a fluororesin layer/polyamide resin layer/EVOH layer/polyamide resin layer as the innermost layer/inner layer/intermediate layer/outermost layer,
A laminate comprising a fluororesin layer/polyamide resin layer/EVOH layer/polyamide resin layer/polyamide resin layer as the innermost layer/inner layer/intermediate layer/outer layer/outermost layer, fluororesin layer/polyamide resin layer/EVOH layer/polyamide resin Layer/laminate including polyolefin resin layer Innermost layer/Inner layer 1/Inner layer 2/Intermediate layer/Outer layer/As the outermost layer, Fluororesin layer/Polyamide resin layer/Polyamide resin layer/EVOH layer/Polyamide resin layer/Polyamide resin layer A laminate comprising a fluororesin layer/polyamide resin layer/EVOH layer/polyamide resin layer/polyamide resin layer/polyolefin resin layer, fluororesin layer/polyamide resin layer/EVOH layer/polyamide resin layer/polyolefin resin layer Examples include a laminate including a resin layer/polyamide resin layer, a laminate including a fluororesin layer/fluororesin layer/polyamide resin layer/EVOH layer/polyamide resin layer/polyolefin resin layer, and the like.

When the laminate of the present disclosure includes two or more fluororesin layers, the types of fluororesin contained in each layer may be the same or different. When the laminate of the present disclosure includes two or more polyamide resin layers, the types of polyamide resins contained in each layer may be the same or different. When the laminate of the present disclosure includes two or more EVOH layers, the types of ethylene/vinyl alcohol copolymers contained in each layer may be the same or different. In the laminate of the present disclosure, the boundaries between the adjacent layers do not necessarily have to be clear, and the molecular chains of the polymers constituting each layer may penetrate each other from the contacting surfaces, resulting in a layered structure with a concentration gradient. It's okay.

The laminate of the present disclosure may have other layers. The thickness, shape, etc. of each layer of the laminate of the present disclosure may be appropriately selected depending on the purpose of use, form of use, etc.

The laminate of the present disclosure is difficult to transmit fuel containing 25% by volume or more of methanol. The permeation rate of the fuel containing 25% by volume of methanol in the laminate of the present disclosure is preferably 40 g/m ² /day or less, more preferably 30 g/m ² /day or less, and more preferably 20 g/m 2 /day or less. m ² /day or less, more preferably 10 g/m ² /day or less.

The permeation rate of the fuel containing 50% by volume of methanol in the laminate of the present disclosure is preferably 40 g/m ² /day or less, more preferably 30 g/m ² /day or less, and even more preferably 20 g/m 2 /day. /m ² /day or less, particularly preferably 10 g/m ² /day or less.

The permeation rate of the fuel containing 100% by volume of methanol in the laminate of the present disclosure is preferably 40 g/m ² /day or less, more preferably 30 g/m ² /day or less, and even more preferably 20 g/m 2 /day. m ² /day or less, still more preferably 10 g/m ² /day or less, particularly preferably 4 g/m ² /day or less.

The fuel permeation rate of the laminate is determined by making a tube-shaped laminate, preparing fuel containing methanol at a predetermined concentration, sealing the fuel in the tube-shaped laminate, and leaving it at 60°C. The characteristics can be determined by measuring the mass change and calculating the fuel permeation rate from the mass change and the inner area of the tubular laminate.

The laminate of the present disclosure can have various shapes such as a film shape, a sheet shape, a tube (hose) shape, a bottle shape, and a tank shape. The film shape, sheet shape, tube shape, hose shape may be a wavy shape, corrugated shape, convoluted shape, etc. The laminate of the present disclosure may be, for example, a film, sheet, tube, hose, bottle, container, tank, etc. The laminate of the present disclosure is applicable, for example, to fuel tubes or fuel hoses such as automobile fuel tubes or automobile fuel hoses, underground tubes or hoses for fuel supply facilities, automobile fuel tanks, O-rings of fuel pumps, etc. It can be suitably used for various automobile seals, etc.

(tubes and hoses)
The laminate of the present disclosure can be suitably used as a tube or a hose. In the present disclosure, "tube or hose" includes articles commonly referred to as tubes or hoses, and typically have a shape that allows fluid to be transported. In this disclosure, the term "tube or hose" does not imply that a tube and a hose are different articles.

Both tubes and hoses of the present disclosure are formed of the laminate of the present disclosure, and therefore are difficult to permeate through fuel containing 25% by volume or more of methanol. Since methanol is difficult to diffuse into the environment, it is possible to create an environmentally friendly car. Further, since the tube or hose of the present disclosure has excellent flexibility, it can be easily installed inside a vehicle, and the degree of freedom in design is improved. In addition, when connecting tubes or hoses to adapters or connectors, the tube or hose can be easily inserted, which not only prevents damage to the tubes, hoses, adapters, connectors, etc. when connecting. , it is possible to improve the productivity of automobiles. Furthermore, if the tube or hose is electrically conductive, the electrical conductivity will not be impaired even after the tube or hose comes into contact with fuel containing 25% by volume or more of methanol, and the antistatic effect will be maintained for a long time. can be maintained and provide a high level of safety to automobiles. Therefore, the tube or hose of the present disclosure can be suitably used to circulate fuel containing 25% by volume or more of methanol.

The tube or hose of the present disclosure preferably has a stress of 16.0 N or less as measured by a bending test.
(Stress measurement conditions)
When a tube or hose with an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 400 mm is bent to a bending radius of 35 mm, the stress applied to the tube or hose is measured.

The stress in the tube or hose is preferably 15.0N or less, more preferably 14.0N or less, still more preferably less than 14.0N, even more preferably 13.5N or less, particularly preferably It is 13.0N or less. The lower the stress in the tube or hose, the more flexible the tube or hose will be.

The tube or hose of the present disclosure has a resistivity change rate (CM25) of 100% or less before and after the test, as measured by a fuel permeation test using fuel containing 25% by volume of methanol (CM25). preferable. When conventional tubes or hoses come into contact with fuel containing a high concentration of methanol, the surface resistivity of the fluororesin layer increases and the antistatic effect is significantly impaired. The tube or hose of the present disclosure can have a low surface resistivity of the fluororesin layer because the fluororesin layer contains a conductive filler, and further has a low surface resistivity even after contact with fuel containing methanol. is maintained.

The rate of change in resistivity (CM25) of the tube or hose is preferably 50% or less, more preferably 30% or less.

The tube or hose of the present disclosure has a resistivity change rate (CM50) of 100% or less before and after the test, as measured by a fuel permeation test using fuel containing 50% by volume of methanol (CM50). preferable.

The rate of change in resistivity (CM50) of the tube or hose is preferably 50% or less, more preferably 30% or less.

The tube or hose of the present disclosure has a resistivity change rate (M100) of 100% or less before and after the test, as measured by a fuel permeation test using a fuel (M100) containing 100% by volume of methanol. preferable.

The rate of change in resistivity (M100) of the tube or hose is preferably 50% or less, more preferably 30% or less.

The rate of change in resistivity of a tube or hose is determined by measuring the surface resistivity (MΩ/square) of the inner surface of the tube or hose before filling fuel, preparing a fuel containing methanol at a predetermined concentration, and applying it to the tube or hose. Enclose the fuel, leave it at 60℃ for 1000 hours, drain the enclosed fuel from the tube or hose, leave the tube or hose at 60℃ for 3 hours, and leave it at room temperature for 1 hour to remove the inner surface of the tube or hose. It can be specified by measuring the surface resistivity (MΩ/square) after fuel is enclosed and calculating the rate of change in resistivity from each measured value.

The outer diameter of the tube or hose is preferably 2 mm or more, more preferably 3 mm or more, still more preferably 4 mm or more, most preferably 6 mm or more, preferably 20 mm or less, and more preferably It is 18 mm or less, more preferably 16 mm or less, and most preferably 14 mm or less.

The inner diameter of the tube or hose is preferably 1 mm or more, more preferably 2 mm or more, even more preferably 3 mm or more, most preferably 4 mm or more, preferably 15 mm or less, and more preferably 13 mm. or less, more preferably 11 mm or less, and most preferably 10 mm or less.

The thickness of the tube or hose (the difference between the outer diameter and the inner diameter) is preferably 0.5 mm or more, more preferably 0.6 mm or more, even more preferably 0.6 mm or more, and most preferably 0.6 mm or more. It is 7 mm or more, preferably 8 mm or less, more preferably 6 mm or less, still more preferably 4 mm or less, particularly preferably 2 mm or less.

The thickness of the fluororesin layer in the laminate and the tube or hose is preferably 0.05 mm or more, more preferably 0.06 mm or more, still more preferably 0.07 mm or more, and even more preferably 0.07 mm. or more, particularly preferably 0.08 mm or more, preferably 0.40 mm or less, more preferably 0.30 mm or less, still more preferably 0.25 mm or less, and even more preferably 0.15 mm. It is not more than 0.10 mm, particularly preferably not more than 0.10 mm. When the laminate, tube, or hose includes two or more fluororesin layers, the thickness of the fluororesin layer is the total thickness of each layer.

The thickness of the non-fluororesin layer in the laminate and the tube or hose is preferably 0.05 mm or more, more preferably 0.10 mm or more, even more preferably 0.50 mm or more, and most preferably 0.70 mm. or more, preferably 4 mm or less, more preferably 3 mm or less, still more preferably 2 mm or less, particularly preferably 1 mm or less. The thickness of the non-fluororesin layer is the total thickness of each layer when the laminate, tube, or hose includes two or more non-fluororesin layers.

When the laminate and the tube or hose have a two-layer structure of innermost layer/outermost layer, the thickness of the innermost layer is preferably 0.05 mm or more, more preferably 0.06 mm or more, and still more preferably 0.05 mm or more. 07 mm or more, preferably 0.4 mm or less, more preferably 0.3 mm or less, and still more preferably 0.25 mm or less.
The thickness of the outermost layer is preferably 0.05 mm or more, more preferably 0.1 mm or more, even more preferably 0.3 mm or more, most preferably 0.5 mm or more, and preferably 4 mm or less. It is more preferably 3 mm or less, still more preferably 2 mm or less, particularly preferably 1 mm or less.

When the laminate and the tube or hose have a five-layer structure of innermost layer/inner layer/intermediate layer/outer layer/outermost layer, the thickness of the innermost layer is preferably 0.01 mm or more, more preferably 0.02 mm or more. It is more preferably 0.03 mm or more, preferably 0.5 mm or less, more preferably 0.25 mm or less, and still more preferably 0.15 mm or less.
The thickness of the inner layer is preferably 0.01 mm or more, more preferably 0.03 mm or more, even more preferably 0.05 mm or more, preferably 1.0 mm or less, and more preferably 0.5 mm or less. , and more preferably 0.4 mm or less.
The thickness of the intermediate layer is preferably 0.01 mm or more, more preferably 0.02 mm or more, even more preferably 0.03 mm or more, preferably 0.5 mm or less, and more preferably 0.25 mm. It is not more than 0.15 mm, more preferably not more than 0.15 mm.
The thickness of the outer layer is preferably 0.01 mm or more, more preferably 0.03 mm or more, even more preferably 0.05 mm or more, most preferably 0.06 mm or more, and preferably 1.0 mm or less. It is more preferably 0.5 mm or less, still more preferably 0.3 mm or less, particularly preferably 0.15 mm or less.
The thickness of the outermost layer is preferably 0.01 or more, more preferably 0.03 or more, even more preferably 0.05 or more, preferably 1.0 mm or less, and more preferably 0.8 mm. It is not more than 0.5 mm, more preferably not more than 0.5 mm.

The tube or hose may be corrugated, corrugated, convoluted, etc. When the tube or hose has a corrugated shape, by having a region in which a plurality of corrugated folds are arranged in a ring, one side of the ring can be compressed and the other side can be stretched outward in that region. Therefore, it can be easily bent at any angle without stress fatigue or delamination between layers.

Although the method for forming the waveform region is not limited, it can be easily formed by forming a straight tube or hose and then performing molding or the like to form a predetermined waveform shape.

As a method for manufacturing the laminate of the present disclosure, for example,
(1) A method of forming a multilayered laminate in one step by coextruding the polymers forming each layer to thermally fuse the layers (melt adhesion) (coextrusion molding);
(2) A method of overlapping each layer produced separately using an extruder and bonding the layers by heat fusion,
(3) A method of forming a laminate by extruding a polymer forming a layer adjacent to the layer on the surface of the layer prepared in advance using an extruder;
(4) By electrostatically coating the surface of a previously prepared layer with a polymer that will form a layer adjacent to the layer, and then heating the resulting coated product as a whole or from the coated side, Examples include a method in which a layer is formed by heating and melting a polymer that has been applied to a coating.

When the laminate of the present disclosure is a tube or a hose, for example, as a method corresponding to (2) above, (2a) each cylindrical layer is formed separately using an extruder, and the inner layer is A method of coating the contacting layers with a heat-shrinkable tube, a method corresponding to (3) above, is (3a) first forming a layer that will become an inner layer using an inner layer extruder, and then forming the layer on the outer peripheral surface using an outer layer extruder. As a method corresponding to (4) above, a method for forming a layer in contact with the inner layer is as follows: (4a) The polymer constituting the inner layer is electrostatically coated on the inside of the layer in contact with the inner layer, and the resulting coated product is heated in a heating oven. A method of heating and melting the polymer constituting the inner layer by inserting a rod-shaped heating device inside a cylindrical coated article and heating it from the inside, etc. can be mentioned.

If the layers constituting the laminate and tube or hose of the present disclosure can be coextruded, they are generally formed by coextrusion molding as described in (1) above. Examples of the above-mentioned coextrusion molding include conventionally known multilayer coextrusion manufacturing methods such as a multi-manifold method and a feed block method.

In the molding methods (2) and (3) above, after forming each layer, the contact surface of each layer with other layers may be surface-treated for the purpose of increasing interlayer adhesion. Such surface treatments include etching treatments such as sodium etching treatments; corona treatments; and plasma treatments such as low-temperature plasma treatments.

As a method for molding the laminate of the present disclosure, a method in which a plurality of materials are laminated in multiple stages by rotational molding is also possible. In that case, the melting point of the outer layer material does not necessarily need to be higher than the melting point of the inner layer material, and the melting point of the inner layer material may be 100° C. or more higher than the melting point of the outer layer material. In that case, it is preferable to have a heating section inside as well.

The tube or hose of the present disclosure can be suitably used, for example, as a fuel tube or fuel hose such as an automobile fuel tube or an automobile fuel hose, or an underground tube or hose for a fuel supply facility.

Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

Next, embodiments of the present disclosure will be described using Examples, but the present disclosure is not limited to these Examples.

Each numerical value of the experimental example and the comparative experimental example was measured by the following method.

<Polymer composition (monomer composition of fluororesin)>
^19F -NMR measurement was performed using a nuclear magnetic resonance apparatus AC300 (manufactured by Bruker-Biospin), and the monomer composition of the fluororesin (the content of each monomer unit of the polymer) was determined from the integral value of each peak. Ta. Depending on the type of monomer, the results of elemental analysis were combined as appropriate to determine the monomer composition of the fluororesin.

<Melting point>
Heat measurement was performed using a differential scanning calorimeter RDC220 (manufactured by Seiko Instruments) at a heating rate of 10° C./min in accordance with ASTM D 4591, and the melting point of the fluororesin was determined from the peak of the endothermic curve obtained.

<Melt flow rate (MFR)>
Using a melt indexer (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), in accordance with ASTM D 1238, the mass of fluororesin flowing out per 10 minutes from a nozzle with an inner diameter of 2 mm and a length of 8 mm at 265 °C or 297 °C under a 5 kg load ( g/10 minutes) was determined as MFR.

<Fuel permeation rate>
The tubes obtained in the experimental examples and comparative experimental examples were cut and their inner diameters and lengths were measured. Swagelok joints were attached to both ends of the tube, the following fuel was filled into the tube, the lid was tightened, and the mass of the tube filled with fuel was measured. Next, the tube was kept at 60° C., and the mass was measured after 1000 hours. The amount of mass reduction was calculated from each measured mass, and further, the fuel permeation rate (g/m ² /day) was calculated from the amount of mass reduction and the inner area of the tube.
CE10 (Toluene/isooctane/ethanol = 45/45/10% by volume)
Fuel C (toluene/isooctane = 50/50% by volume)
CM15 (toluene/isooctane/methanol = 42.5/42.5/15% by volume)
CM25 (toluene/isooctane/methanol = 37.5/37.5/25% by volume)
CM50 (Toluene/isooctane/methanol = 25/25/50% by volume)
M100 (methanol 100% by volume)

<Stress>
As shown in FIG. 1, a tube 10 having an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 400 mm was attached between two flat plates 11 in a U-shape to shorten the distance between the flat plates 11. Then, the extrusion force (N) applied to the flat plate 11 at the time when the bending radius of the tube 10 (the bending radius is 1/2 of the distance 2R of the U-shaped tube in Fig. 1) is 35 mm. Recorded. The extrusion force (N) recorded represents the stress (N) applied to the tube when it is bent so that R=35 mm. The smaller the stress (N) is, the more flexible the tube is.

<Resistivity change rate>
Similar to the test to measure fuel permeation rate, a tube filled with fuel was kept at 60°C, and after 1000 hours, the fuel inside the tube was drained and the tube was left in an electric furnace at 60°C for 3 hours. The mixture was further left at room temperature for 1 hour. Based on SAE J 2260, a voltage of 500 V was applied using a resistance meter (HIOKI 3454-10) to measure the surface resistance value of the inner surface of the tube before and after filling with fuel. From the surface resistance value, tube inner diameter and tube length, the surface resistivity (MΩ/square) of the tube before filling with fuel (pre-test surface resistivity) and the surface resistivity of the tube after filling with fuel (MΩ) /square) (surface resistivity after the test) was calculated, and the rate of change in resistivity was calculated according to the following formula. A smaller rate of change in resistivity means that the tube maintains its excellent antistatic performance even after contact with fuel. If the surface resistivity of the tube after being filled with fuel is lower than the surface resistivity of the tube before being filled with fuel, the rate of change in resistivity takes a negative value.
Resistivity change rate (%) = [(Surface resistivity after test) - (Surface resistivity before test)] / (Surface resistivity before test) x 100

In the experimental examples and comparative experimental examples, the following materials were used.
Fluororesin A
Polymer composition (mol%): CTFE/TFE/PPVE=21.0/76.5/2.5
Melting point: 248℃
Melt flow rate (297°C): 29.7g/10min Carbon black content: 10% by mass
Fluororesin B
Polymer composition (mol%): TFE/Et/HFP/perfluoro(1,1,5-trihydro-1-pentene) = 45.5/44.4/9.5/0.6
Melting point: 197℃
Melt flow rate (297°C): 10.2g/10min Carbon black content 12% by mass
Polyamide 12 (PA12)
Daicel-Evonik, Daimid X7297
Polyamide 612 (PA6,12)
Manufactured by Daicel Evonik, Vestamid SX8002
Ethylene/vinyl alcohol copolymer resin (EVOH)
Manufactured by Kuraray, F101B
Polyamide 9T (PA9T)
Manufactured by Kuraray, Genestar N1001D
Conductive polyamide 9T (PA9T cond.)
Manufactured by Kuraray, Genestar TS341

Experimental Examples 1 to 4 and Comparative Experimental Example 1
Using a 5-type, 5-layer tube extrusion device (manufactured by Plastic Engineering Research Institute) equipped with a multi-manifold, each material was added to 2 to 5 extruders so that each layer was composed of the materials listed in Table 2. A multilayer tube with an outer diameter of 8 mm and an inner diameter of 6 mm was molded under the extrusion conditions shown in Table 1.

Using the obtained multilayer tube, various physical properties were measured by the methods described above. The results are shown in Table 2. Further, the fuel permeation rates of the tubes produced in Experimental Examples 1 to 4 and Comparative Experimental Example 1 are shown in FIG.

As shown by the results of Comparative Experimental Example 1, the conventional tube hardly transmits ethanol-containing fuel (CE10) and FuelC (see Table 2). In this way, even the conventional tube has sufficient low fuel permeability for fuels that do not contain alcohol and fuels that contain ethanol as alcohol.

On the other hand, conventional tubes allow a large amount of fuel containing methanol to pass through at a concentration of 25% by volume or more (see Table 2 and FIG. 2). Also, conventional tubes have high stress and poor flexibility (see Table 2). Furthermore, when the conventional tube comes into contact with a fuel containing methanol at a concentration of 25% by volume or more, the surface resistivity becomes high and the antistatic effect of the tube cannot be maintained (see Table 2).

As shown by the results of Experimental Examples 1 to 4, the tube provided with the fluororesin layer and the thermoplastic resin layer can suppress the permeation of fuel containing methanol at a high level at a concentration of 25% by volume or more (Table 2 and Figure 2). In particular, as shown by the results of Experimental Examples 1 and 2, when a polymer containing chlorotrifluoroethylene units is used as the fluororesin, fuel permeation can be suppressed to a very high level (Table 2 and Figure 2 reference).

Further, as shown by the results of Experimental Examples 1 to 4, the tube including the fluororesin layer and the thermoplastic resin layer has low stress and excellent flexibility (see Table 2). In particular, as shown by the results of Experimental Examples 1 and 2, when a polymer containing chlorotrifluoroethylene units is used as the fluororesin, flexibility is further improved (see Table 2).

Furthermore, as shown by the results of Experimental Examples 1 to 4, the surface resistivity of the tube equipped with the fluororesin layer and the thermoplastic resin layer does not change significantly even after contact with fuel containing methanol at a concentration of 25% by volume or more. First, it can be seen that charging of the tube can be prevented for a long period of time (see Table 2). In particular, as shown by the results of Experimental Examples 1 and 2, when a polymer containing chlorotrifluoroethylene units is used as the fluororesin, the surface resistivity hardly changes (see Table 2).

From the above results, a tube including a fluororesin layer containing a fluororesin and a thermoplastic resin layer containing a thermoplastic resin is suitable as a tube for circulating fuel containing methanol at a concentration of 25% by volume or more. It turns out that it can be used.

Claims (13)

A laminate used in a system for distributing fuel containing 25% by volume or more of methanol, the laminate comprising a fluororesin layer containing a fluororesin and a thermoplastic resin layer containing a thermoplastic resin. laminate. The laminate according to claim 1, having a contact surface that comes into contact with a fuel containing 25% by volume or more of methanol. The laminate according to claim 2, wherein the contact surface is formed on the surface of the fluororesin layer. The laminate according to any one of claims 1 to 3, wherein the fluororesin is a polymer containing chlorotrifluoroethylene units. The laminate according to claim 4, wherein the content of chlorotrifluoroethylene units in the fluororesin is 15.0 to 25.0 mol% based on the total monomer units. The laminate according to any one of claims 1 to 5, wherein the fluororesin is a polymer containing chlorotrifluoroethylene units and tetrafluoroethylene units. The laminate according to claim 6, wherein the content of tetrafluoroethylene units in the fluororesin is 85.0 to 75.0 mol%. The laminate according to any one of claims 1 to 7, wherein the thermoplastic resin is at least one selected from the group consisting of polyamide resin, polyolefin resin, modified polyolefin resin, and ethylene/vinyl alcohol copolymer. The laminate according to any one of claims 1 to 8, wherein the fluororesin layer further contains a conductive filler. The laminate according to any one of claims 1 to 9, wherein the permeation rate of a fuel containing 25% by volume of methanol is 40 g/m ² /day or less. A tube or hose formed from the laminate according to any one of claims 1 to 10. The tube or hose according to claim 11, wherein the stress measured by a bending test is 16.0 N or less.
(Stress measurement conditions)
When a tube or hose with an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 400 mm is bent to a bending radius of 35 mm, the stress applied to the tube or hose is measured. The tube or hose according to claim 11 or 12, wherein the rate of change in resistivity before and after the test, as measured by a fuel permeation test using fuel containing 25% by volume of methanol, is 100% or less.

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