JP2005140199A - Laminate hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate hose having good interlaminar adhesion and its durability. <P>SOLUTION: A laminate hose having an inner layer which comprises a fluororesin containing an acid anhydride residue (for example, ethylene/tetrafluoroethylene/itaconic anhydride copolymer) and an outer layer which comprises a polyamide resin (for example, polyamide 12), the inner layer and outer layer being laminated directly. After the polyamide resin is molten using 1,1,1,3,3,3-hexafluoro-2-propanol to be removed from the laminate hose, the amount of the polyamide resin remaining on the surface on the laminate face side of the inner face which comprises the fluorine resin, as measured with an X-ray photoelectron spectroscope, is 2 to 200 in terms of the molar ratio between nitrogen atoms derived from the polyamide resin/ fluorine atoms derived from the fluororesin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminated hose excellent in interlayer adhesion and durability.

  Fluoropolymers such as polytetrafluoroethylene, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymers, tetrafluoroethylene / hexafluoropropylene copolymers, ethylene / tetrafluoroethylene copolymers (hereinafter referred to as fluorine Resin)) has excellent heat resistance, chemical resistance, weather resistance, fuel barrier properties, gas barrier properties, etc., and is used in various fields such as the semiconductor industry and the automobile industry. In some cases, improvement of mechanical strength and cost reduction are required. In order to improve these points while taking advantage of the excellent properties of the fluororesin, composites of the fluororesin and other materials have been studied. In particular, fuel transfer hoses for automobiles are required to have fuel barrier properties, fuel oil resistance, mechanical strength, etc., a fluororesin excellent in fuel barrier properties and fuel oil resistance in the inner layer, and a polyamide excellent in mechanical strength in the outer layer. A laminate hose using a resin has been proposed.

  A fuel transfer hose made of a laminate hose has a sufficiently high interlayer adhesive strength, and is required to prevent separation between layers when a connector is inserted or in use. In general, since the fluororesin does not have sufficient adhesiveness to other materials, a technique for improving the interlayer adhesion between the fluororesin layer and the polyamide resin layer has been studied. For example, the outer surface of a hose obtained by extrusion molding of a fluororesin is treated by a method such as chemical treatment, corona discharge treatment, plasma discharge treatment, etc., and an adhesive functional group is introduced to the hose surface. Next, a method of manufacturing a laminate hose by applying an adhesive as required and then extruding a polyamide resin outside the fluororesin hose has been proposed (see, for example, Patent Document 1 and Patent Document 2). .) The obtained laminate hose is excellent in interlayer adhesion, but the manufacturing process is complicated and the productivity is low.

  There has been proposed a method of bonding a fluororesin layer and a polyamide resin layer using an adhesive layer made of a mixture of a fluororesin and a polyamide resin (see, for example, Patent Document 3 and Patent Document 4). Also, a method of grafting an ethylenically unsaturated compound having a functional group (see Patent Document 5), a method of introducing a carbonate group at the molecular chain end using an organic peroxide initiator (see Patent Document 6). When the adhesive fluororesin obtained by the above method is used, a laminate hose excellent in interlayer adhesive strength between the adhesive fluororesin layer and the polyamide resin layer can be obtained.

  However, it was found that when the laminate hose using the above-mentioned adhesive fluororesin is immersed in alcohol-containing fuel oil or the like, the interlaminar adhesive strength is lowered and its durability is not sufficient. As a result of investigating the cause, the present inventors have found that the bonding amount between the fluororesin and the polyamide resin formed between the layers is insufficient.

Japanese Patent Laid-Open No. 2-107371 JP-A-5-8353 JP-A-7-223300 JP-A-8-258212 Japanese National Patent Publication No. 10-503236 International Publication No. 99/45044 Pamphlet

  The present invention is a laminate hose that is required to be developed on the basis of the above-described background, and that is excellent in interlayer adhesion and durability, and in which an inner layer made of a fluororesin and an outer layer made of a polyamide resin are directly laminated. The purpose is to provide.

  The present invention is a laminate hose in which an inner layer made of a fluororesin containing an acid anhydride residue and an outer layer made of a polyamide resin are directly laminated, and 1, 1, 1, 3, from the laminate hose After dissolving and removing the polyamide resin using 3,3-hexafluoro-2-propanol, the amount of the polyamide resin remaining on the surface of the inner layer made of the fluororesin is measured by an X-ray photoelectron spectrometer. The laminate hose is characterized in that the molar ratio of nitrogen atom derived from the polyamide resin / fluorine atom derived from the fluororesin is 2 to 200.

  The laminate hose of the present invention is excellent in fuel barrier properties, fuel oil resistance, mechanical strength, interlayer adhesion and the like. Further, even when immersed in an alcohol-containing fuel oil, there is little decrease in interlayer adhesion, and the durability of interlayer adhesion is excellent.

  As the fluororesin containing an acid anhydride residue in the present invention, a fluororesin having an acid anhydride residue in the main chain or side chain can be used. Here, the acid anhydride residue refers to a functional group having a structure based on an acid anhydride. The content of the acid anhydride residue is preferably 0.01 to 3 mol%, more preferably 0.05 to 2 mol%, most preferably 0.1 to 1 mol%, based on the total of the polymer units of the fluororesin. preferable.

  As a method of introducing an acid anhydride residue into a fluororesin, a method of copolymerizing a fluoromonomer and an acid anhydride having a polymerizable unsaturated bond when producing a fluororesin by polymerizing a fluoromonomer, A method of polymerizing a fluorine-containing monomer in the presence of a polymerization initiator or a chain transfer agent capable of introducing an acid anhydride residue into a polymer terminal, mixing an acid anhydride having a polymerizable unsaturated bond and a fluororesin Examples include a method of graft polymerization of the acid anhydride onto a fluororesin by irradiation or melt extrusion. A method of copolymerizing a fluorine-containing monomer and an acid anhydride having a polymerizable unsaturated bond is preferable.

  The acid anhydride having a polymerizable unsaturated bond is preferably at least one selected from the group consisting of maleic anhydride, itaconic anhydride, and citraconic anhydride. Preferably, itaconic anhydride is used.

  Examples of the fluororesin include a polymer or copolymer of a fluorine-containing monomer or a copolymer of a fluorine-containing monomer and a monomer other than the fluorine-containing monomer.

Examples of the fluorine-containing monomer include tetrafluoroethylene (hereinafter referred to as TFE), trifluoroethylene, vinylidene fluoride (hereinafter referred to as VDF), vinyl fluoride, chlorotrifluoroethylene (hereinafter referred to as CTFE), and hexafluoro. Propylene (hereinafter referred to as HFP), CF ₂ = CFR ^f (where R ^f is a polyfluoroalkyl group having 2 to 10 carbon atoms), CH ₂ = CX (CF ₂ ) _n Y (here , X and Y are each independently a hydrogen atom or a fluorine atom, and n is an integer of 2 to 8.) A fluorine-containing olefin such as a compound represented by: CF ₂ ═CFO (CF ₂ ) ₂ F, CF ₂ ═CFO Perfluoro (alkyl vinyl ether) such as (CF ₂ ) ₃ F (hereinafter referred to as PPVE), water such as CF ₂ = CFOCH ₂ CF ₃ (Polyfluoroalkyl) trifluorovinyl ether containing an elementary atom is exemplified. Preferably, it is at least one selected from the group consisting of TFE, VDF, PPVE, and CH ₂ ═CX (CF ₂ ) _n Y, and more preferably TFE. A fluorine-containing monomer may be used individually by 1 type, and may use 2 or more types together.

As the _CH 2 = CX _{(CF 2)} represented by _n Y compound, it is preferable that n = 2 to 4. The fluororesin copolymerized with the compound is excellent in fuel barrier properties, stress crack resistance, and the like. As specific examples, CH ₂ = CF (CF ₂ ) ₂ F, CH ₂ = CF (CF ₂ ) ₃ F, CH ₂ = CF (CF ₂ ) ₄ F, CH ₂ = CF (CF ₂ ) ₂ H, CH _{2 = CF (CF 2) 3} H, CH 2 = CF (CF 2) 4 H, CH 2 = CH (CF 2) 2 F, CH 2 = CH (CF 2) 3 F, CH 2 = CH (CF 2 ) ₄ F, CH ₂ ═CH (CF ₂ ) ₂ H, CH ₂ ═CH (CF ₂ ) ₃ H, CH ₂ ═CH (CF ₂ ) ₄ H, and the like. CH ₂ = CF (CF ₂ ) ₂ F, CH ₂ = CH (CF ₂ ) ₂ F, CH ₂ = CH (CF ₂ ) ₂ H or CH ₂ = CF (CF ₂ ) ₂ H is more preferred, and CH ₂ = CH (CF ₂ ) ₂ F is most preferred.

  Monomers other than fluorine-containing monomers include hydrocarbon olefins such as ethylene (hereinafter referred to as E), propylene and butene, vinyl ethers such as glycidyl vinyl ether and methylvinyloxybutyl carbonate, vinyl acetate, vinyl chloroacetate and vinyl butanoate. And vinyl esters such as vinyl pivalate, vinyl benzoate, and vinyl crotonate. E is preferred. Monomers other than the fluorine-containing monomer may be used alone or in combination of two or more.

Specific examples of fluororesins include TFE / E copolymers, TFE / HFP copolymers, TFE / PPVE copolymers, TFE / VDF / HFP copolymers, TFE / VDF copolymers, CTFE / E copolymer and the like can be mentioned. A TFE / E copolymer is preferable. As the TFE / E copolymer, a TFE / E / CH ₂ ═CH (CF ₂ ) ₄ F copolymer and a TFE / E / CH ₂ ═CH (CF ₂ ) ₂ F copolymer are preferable, and TFE / E E / CH ₂ ═CH (CF ₂ ) ₂ F copolymer is more preferable.

  In the TFE / E copolymer, the molar ratio of polymerized units based on TFE / polymerized units based on E is preferably 30/70 to 70/30, more preferably 45/55 to 65/35, and 50/50 to 65/35 is most preferred. If the molar ratio of polymerized units based on TFE / polymerized units based on E is too small, the heat resistance, weather resistance, chemical resistance, gas barrier properties, fuel barrier properties, fuel oil resistance, etc. of the laminated hose are not sufficient. Is too large, the mechanical strength, melt moldability, etc. of the laminate hose are not sufficient. Within this range, the laminate hose is excellent in heat resistance, weather resistance, chemical resistance, gas barrier properties, fuel barrier properties, fuel oil resistance, mechanical strength, melt moldability, and the like.

  When the TFE / E copolymer contains polymerized units based on monomers other than TFE and E, the content of polymerized units based on monomers other than TFE and E is based on the total polymerized units in the fluoropolymer. 0.01 to 20 mol% is preferable, 0.05 to 15 mol% is more preferable, and 0.1 to 10 mol% is most preferable.

Volume flow rate of the fluororesin in the present invention (hereinafter. Referred Q value) is preferably 0.1~1000mm ³ / sec, more preferably 5 to 500 mm ³ / sec, and most preferably 10 to 200 mm ³ / sec. The Q value is an index representing the melt fluidity of the fluorinated copolymer and is a measure of the molecular weight. A large Q value indicates a low molecular weight, and a small Q value indicates a high molecular weight. Q value is obtained by extruding a fluorine-containing copolymer when extruded into an orifice having a diameter of 2.1 mm and a length of 8 mm under a load of 7 kg at a temperature higher by 50 ° C. than the melting point of the resin using a flow tester manufactured by Shimadzu Corporation. Is speed. Within this range, the fluororesin is excellent in extrusion moldability and mechanical strength.

  Examples of the method for producing the fluororesin in the present invention include suspension polymerization, solution polymerization, emulsion polymerization, bulk polymerization and the like. In particular, radical polymerization is preferable, and solution polymerization in which a fluorine-containing monomer is polymerized in the presence of a radical polymerization initiator, a chain transfer agent, and a polymerization medium is more preferable.

As the radical polymerization initiator, an initiator having a half-life of 10 hours and a temperature of 0 to 100 ° C is preferable, and an initiator having a temperature of 20 to 90 ° C is more preferable. Specific examples include azo compounds such as azobisisobutyronitrile, peroxydicarbonates such as diisopropylperoxydicarbonate, peroxyesters such as tert-butylperoxypivalate, tert-butylperoxyisobutyrate, and tert-butylperoxyacetate. , Non-fluorinated diacyl peroxides such as isobutyryl peroxide, octanoyl peroxide, benzoyl peroxide, lauroyl peroxide, (Z (CF ₂ ) _p COO) ₂ (where Z is a hydrogen atom, a fluorine atom or a chlorine atom, p is an integer of 1 to 10.) Fluorine-containing diacyl peroxide, and inorganic peroxides such as potassium persulfate, sodium persulfate, and ammonium persulfate.

  Examples of the polymerization medium include organic solvents such as fluorinated hydrocarbons, chlorinated hydrocarbons, fluorinated chlorinated hydrocarbons, alcohols and hydrocarbons, and aqueous media. Chain transfer agents include alcohols such as methanol and ethanol, chlorofluorohydrocarbons such as 1,3-dichloro-1,1,2,2,3-pentafluoropropane, 1,1-dichloro-1-fluoroethane, Examples thereof include hydrocarbons such as pentane, hexane, and cyclohexane. The polymerization conditions are not particularly limited, and the polymerization temperature is preferably 0 to 100 ° C, more preferably 20 to 90 ° C. The polymerization pressure is preferably from 0.1 to 10 MPa, more preferably from 0.5 to 3 MPa. The polymerization time is preferably 1 to 30 hours, more preferably 2 to 10 hours.

When the multilayer molded body hose of the present invention is used as a fuel transfer hose, the inner layer in contact with the fuel is preferably an inner layer made of a conductive fluororesin, and made of a fluororesin containing conductive carbon black. More preferably, it is an inner layer. The surface resistivity, which is a measure of conductivity, is preferably 1 × 10 ⁹ Ω / □ or less.

Examples of the polyamide resin in the present invention include those composed of diamine and dibasic acid, or composed of lactam or aminocarboxylic acid, or composed of two or more kinds of these copolymers.
Examples of diamines include aliphatic diamines such as tetramethylene diamine, hexamethylene diamine, octamethylene diamine, nonamethyle diamine, undecamethylene diamine, and dodecamethylene diamine, and diamines having aromatic and cyclic structures such as metaxylylene diamine. Can be mentioned.

Examples of the dicarboxylic acid include aliphatic diamines such as adipic acid, heptane dicarboxylic acid, octane dicarboxylic acid, nonane dicarboxylic acid, undecane dicarboxylic acid, and dodecane dicarboxylic acid, and dicarboxylic acids having aromatic / cyclic structures such as terephthalic acid and isophthalic acid. Can be mentioned.
The lactam is a lactam having 6 to 12 carbon atoms, and the aminocarboxylic acid is an aminocarboxylic acid having 6 to 12 carbon atoms. Examples thereof include 6-aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, α-pyrrolidone, ε-caprolactam, ω-laurolactam, and ε-enanthractam.

  Examples of the polyamide resin include polyamide 6, polyamide 46, polyamide 66, polyamide 69, polyamide 610, polyamide 612, polyamide 116, polyamide 4, polyamide 7, polyamide 8, polyamide 11, polyamide 12, polyamide 6I, polyamide 6 / 66, polyamide 6T / 6I, polyamide 6 / 6T, polyamide 66 / 6T, polytrimethylhexamethylene terephthalamide, polybis (4-aminocyclohexyl) methane dodecamide, polybis (3-methyl-4-aminocyclohexyl) methane dodecamide, Examples thereof include polymetaxylylene adipamide, polyamide 11T, and polyundecamethylene hexahydroterephthalamide. In the above, I represents an isophthalic acid component, and T represents a terephthalic acid component.

Among these, at least one selected from the group consisting of polyamide 6, polyamide 46, polyamide 66, polyamide 612, polyamide 11, polyamide 12, and polymetaxylylene adipamide is preferable. Polyamide 11 or polyamide 12 is more preferable, and polyamide 11 or polyamide 12 having a high content of terminal amino groups is most preferable.
The polyamide resin contains an amino group and a carboxyl group at the molecular chain end. The amino group content is preferably 1.0 or more, more preferably 1.5 or more, and most preferably 2.0 or more in terms of the molar ratio of molecular terminal amino group / molecular terminal carboxyl group. The molar ratio of molecular terminal amino group / molecular terminal carboxyl group is preferably 5.0 or less. When it exceeds 5.0, it becomes difficult to produce a polyamide having a desired degree of polymerization.

  In the laminate hose of the present invention, after the polyamide resin is dissolved and removed from the laminate hose using 1,1,1,3,3,3-hexafluoro-2-propanol (hereinafter referred to as HFIP), The amount of polyamide resin remaining on the surface of the inner surface of the inner layer made of the fluororesin is measured by an X-ray photoelectron spectrometer. The amount of nitrogen atoms derived from the polyamide resin / moles of fluorine atoms derived from the fluororesin The ratio (hereinafter also referred to as N / F) is 2 to 200. The molar ratio is preferably 2.5 to 50, more preferably 3 to 20. If the amount of the polyamide resin is too small, the interlayer adhesion between the inner layer made of the fluororesin and the outer layer made of the polyamide resin is not sufficient, and if it is too large, the mechanical properties of the laminate hose are not sufficient. When it is in this range, the laminate hose is excellent in interlayer adhesive strength and excellent in durability.

The following method was used to calculate the N / F value. Using an X-ray photoelectron spectrometer, the surface on the laminated surface side of the inner layer made of the fluororesin is analyzed, and peaks attributed to the nitrogen atom 1S orbit and fluorine atom 1S orbit appearing in the range of 683 to 695 eV are detected. From these peaks, the integrated values of the peaks belonging to the nitrogen atom 1S orbital and the fluorine atom 1S orbital are obtained. At this time, 0.499 for the nitrogen atom 1S orbital and 1.000 for the fluorine atom 1S orbital were used as the intensity conversion parameters. Next, the value of N / F was calculated using the following equation.
N / F = (nitrogen atom 1S orbit peak integration value / 0.499) / (fluorine atom 1S orbit peak integration value / 1.000)

The polyamide resin remaining after the dissolution treatment in HFIP is considered to be bonded to the surface on the laminated surface side of the inner layer made of the fluororesin. In the present invention, as an index of the amount of the remaining polyamide resin, the larger the N / F value calculated by measurement under the conditions described in Examples using an X-ray photoelectron spectrometer, the bonded polyamide resin It is thought that there are many.
Note that HFIP is suitable as a solvent for dissolving and removing the polyamide resin, but other solvents may be used as long as they dissolve the polyamide resin.

  As a manufacturing method of the laminated body hose of this invention, the method of coextrusion molding the fluororesin and polyamide resin containing an acid anhydride residue is preferable. In co-extrusion molding, a laminate hose made by directly laminating fluororesin and polyamide resin is formed by discharging the die from a discharge port of an extruder different from that of fluororesin and polyamide resin, and letting it pass in a molten state. Is done. As extrusion conditions, the screw temperature is preferably 100 to 350 ° C, and the die temperature is preferably 200 to 350 ° C. The screw rotation speed is not particularly limited, but is preferably 10 to 200 rotations / minute. The residence time of the fluororesin and polyamide resin in the extruder is preferably 1 to 20 minutes.

  In the present invention, the mechanism by which a chemical bond is formed between the inner layer made of the fluororesin and the outer layer made of the polyamide resin is not necessarily clear, but the inner layer made of the fluororesin and the polyamide resin are formed at the time of molding. By contacting the outer layer in a molten state, the acid anhydride residue contained in the fluororesin and the terminal amino group contained in the polyamide resin react to form an amic acid bond, and then an imide bond by dehydration reaction. Is considered to be formed.

  In the laminate hose of the present invention, the interlayer adhesive force between the inner layer made of the fluororesin and the outer layer made of the polyamide resin is preferably 25 N / cm or more, more preferably 35 N / cm or more, and most preferably 45 N / cm or more. Further, the interlayer adhesive strength between the inner layer and the outer layer after immersing the laminate hose in 60 ° C. fuel oil for 5000 hours is preferably 20 N / cm or more, more preferably 30 N / cm or more, and 35 N / cm or more. Most preferred.

  Examples of the fuel oil in the present invention include gasoline, kerosene, diesel gasoline, methanol, ethanol, propanol, butanol, alcohol-containing gasoline, methyl-t-butyl ether, oxygen-containing gasoline, amine-containing gasoline, sour gasoline and the like.

  On the outside of the laminate hose of the present invention, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyolefins such as polyethylene and polypropylene, poly (ethylene / vinyl acetate), polyvinyl acetate , Polyvinyl alcohol, poly (ethylene / vinyl alcohol), polystyrene, polyvinylidene chloride, polyacrylonitrile, polyoxymethylene, polyphenylene sulfide, polyphenylene ether, polycarbonate, polyamideimide, polyimide, polyetherimide, polysulfone, polyarylate, fluororesin, It is also preferable to laminate a layer made of a synthetic resin such as a polyamide resin.

Hereinafter, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited thereto. The fluororesin composition, the volume flow rate (Q value), the melting point, the content of acid anhydride residues, the amount of remaining polyamide resin, the interlayer adhesion and the durability test were measured by the following methods.
[Fluorine resin composition] Obtained from melt NMR measurement and total fluorine content measurement.
[Capacity flow rate: Q value (mm ³ / sec)] Using a flow tester manufactured by Shimadzu Corporation, the fluororesin is passed through an orifice having a diameter of 2.1 mm and a length of 8 mm under a load of 7 kg at a temperature 50 ° C. higher than the melting point of the fluororesin. The extrusion speed when extruding is shown. However, in this example, 297 ° C. was used as the measurement temperature.

[Melting point (° C)] Using a scanning differential thermal analyzer (DSC220CU, manufactured by Seiko Instruments Inc.), the melting point was determined from the endothermic peak when heated to 300 ° C at 10 ° C / min in a nitrogen atmosphere.
[Content of acid anhydride residue] Using a film obtained by press-molding a fluororesin at 300 ° C., an acid anhydride appearing in the vicinity of 1800 cm ⁻¹ by a Fourier transform infrared spectrometer (AVATAR 360, manufactured by Nicorey) The intensity of absorption derived from physical residues was measured. The content of acid anhydride residue was calculated using the molar extinction coefficient of the acid anhydride residue determined from the model compound (maleic anhydride: 111 L / mol · cm, itaconic anhydride: 237 L / mol · cm). .

  [Measurement of Remaining Polyamide Resin] A laminate hose comprising an inner layer made of fluororesin and an outer layer made of polyamide resin was cut to a length of about 5 cm and immersed in 20 ml of HFIP overnight to dissolve the polyamide resin layer. . The hose from which the outer layer made of polyamide resin was almost dissolved and removed was immersed in 20 ml of clean HFIP, and washing by ultrasonic treatment was repeated twice. The fluororesin hose obtained by dissolving and removing the outer layer was vacuum-dried at room temperature for 30 minutes, and then heat-dried in an oven at 60 ° C. for 30 minutes. The amount of polyamide resin remaining on the surface of the fluororesin hose (the surface that was the laminated surface of the inner layer made of fluororesin and the outer layer made of polyamide resin) is the amount of polyamide resin remaining on the inner layer made of fluororesin. did. The amount of the remaining polyamide resin is calculated by measuring under the following conditions using an X-ray photoelectron spectrometer (XPS: Quantum 2000, manufactured by ULVAC-PHI). The nitrogen atom / fluorine atom on the outer surface of the fluororesin hose ( Hereinafter, the ratio of N / F was used as an index.

(Measurement conditions) X-ray conditions: Al monochromator, output 19.8 W, beam diameter 100 μm, detection angle: 45 degrees, energy resolution: 187.85 eV, measurement range: 0 to 1100 eV, time: 20 minutes.
(Spectrum analysis) Peaks attributed to the nitrogen atom 1S orbital and fluorine atom 1S orbital appearing in the range of 683 to 695 eV were used. The analysis software (multipack) attached to the device was used. The integrated values of the peaks attributed to the nitrogen atom 1S orbital and fluorine atom 1S orbital were determined, and the N / F value was calculated using the following equation. As strength conversion parameters, 0.499 for the nitrogen atom 1S orbital and 1.000 for the fluorine atom 1S orbital were used.
N / F = (nitrogen atom 1S orbit peak integration value / 0.499) / (fluorine atom 1S orbit peak integration value / 1.000)

[Interlayer adhesion (N / cm)] The laminate hose was cut vertically to prepare a strip-shaped sample of 8 mm x 15 cm. One end of the obtained sample was peeled off between the inner layer and the outer layer, and the peeled end when the peeled end was fixed to a chuck of a tensile tester (Orientec Co., Ltd.) and peeled 180 ° was determined as the interlayer adhesive strength. did.
[Durability Test] After immersing the laminate hose in a simulated liquid of alcohol-containing fuel oil having the composition toluene: isooctane: methanol = 42.5: 42.5: 15.0 (volume%) at 60 ° C. for 5000 hours, A sample was prepared by drying at 40 ° C. for 1 hour. The obtained sample was measured for interlayer adhesion.

[Synthesis Example 1]
The polymerization tank equipped with a stirrer with an internal volume of 94 liters was degassed, and 71.3 kg of 1-hydrotridecafluorohexane (hereinafter referred to as HTFH), 1,3-dichloro-1,1,2,2,3 -20.4 kg of pentafluoropropane (Asahi Glass Co., Ltd., hereinafter referred to as AK225cb), 562 g of CH ₂ = CH (CF ₂ ) ₂ F, and 3.4 g of itaconic anhydride were charged, and the inside of the polymerization tank was brought to 66 ° C. The temperature rose. Next, the pressure was increased to 1.5 MPa with a monomer having a molar ratio of TFE / E of 89/11. As a polymerization initiator, 1 L of a 0.5% HTFH solution of tert-butylperoxypivalate was charged to initiate polymerization. Since the pressure decreased with the progress of the polymerization, a monomer mixed gas having a TFE / E molar ratio of 59.5 / 40.5 was continuously charged so that the pressure became constant at 1.5 MPa. Further, CH ₂ ═CH (CF ₂ ) ₂ F in an amount corresponding to 3.3 mol% and anhydrous itacone in an amount corresponding to 0.3 mol% with respect to the total number of moles of TFE and E charged during polymerization. The acid was charged continuously. At 8.5 hours after the start of the polymerization, when 7.3 kg of the monomer mixed gas was charged, the polymerization tank internal temperature was cooled to room temperature and purged to normal pressure.

The obtained slurry of fluororesin 1 was put into a 200 L granulation tank charged with 77 kg of water, and then heated to 105 ° C. with stirring, and granulated while distilling and removing the polymerization medium and the like. The obtained granulated product was dried at 150 ° C. for 15 hours to obtain 7.9 kg of granulated product 1 of fluororesin 1. Subsequently, the granulated product 1 was melt-kneaded at 280 ° C. with an extruder to prepare pellets 1.
The composition of the fluororesin 1 is 57.1 / 39 in terms of a molar ratio of polymerized units based on TFE / polymerized units based on E / polymerized units based on itaconic anhydride / polymerized units based on CH ₂ ═CH (CF ₂ ) ₂ F. It was 5 / 0.2 / 3.2. The melting point was 232 ° C., and the Q value was 41 mm ³ / sec.

[Synthesis Example 2]
A polymerization tank with a stirrer having an internal volume of 94 liters was deaerated, 31.3 L of deionized water, 21.3 kg of HTFH, 50.1 g of cyclohexane, 78.6 g of CH ₂ ═CH (CF ₂ ) ₄ F, 18.9 kg of HFP was charged, and the temperature in the polymerization tank was raised to 35 ° C. Subsequently, a monomer having a molar ratio of TFE / E of 55/46 was introduced, and the pressure was increased to 1.1 MPa. As a polymerization initiator, 0.8 L of a 10% HTFH solution of di-n-propyl peroxydicarbonate was charged to initiate polymerization. Since the pressure decreased with the progress of the polymerization, a monomer mixed gas having a TFE / E composition of 54/46 in a molar ratio was continuously charged so that the pressure was constant at 1.1 MPa. Further, CH ₂ ═CH (CF ₂ ) ₄ F in an amount corresponding to 0.4 mol% with respect to the total number of moles of TFE and E charged during the polymerization was continuously charged. 7.6 hours after the start of polymerization, when 3.6 kg of the monomer mixed gas was charged, the temperature in the polymerization tank was cooled to room temperature and purged to normal pressure.

The obtained slurry of fluororesin 2 was put into a 200 L granulation tank charged with 77 kg of water, and then heated to 105 ° C. with stirring, and granulated while distilling and removing the polymerization medium and the like.
The obtained granulated product was dried at 150 ° C. for 15 hours to obtain 4.9 kg of granulated product 2 of fluororesin 2. Subsequently, the granulated product 2 was melt-kneaded at 260 ° C. with an extruder to prepare pellets 2.
The composition of the fluororesin 2 is 48.6 / 39.2 / in terms of a molar ratio of polymerized units based on TFE / polymerized units based on E / polymerized units based on HFP / polymerized units based on CH ₂ ═CH (CF ₂ ) ₄ F. It was 11.8 / 0.4. The melting point was 198 ° C., and the Q value was 15 mm ³ / sec.

[Synthesis Example 3]
TFE / E copolymer (manufactured by Asahi Glass Co., Ltd., Fullon ETFE) is pulverized to an average particle size of 100 to 120 μm, and polyethylene is made so that the mass ratio of fluororesin / maleic anhydride (manufactured by Kanto Chemical Co., Ltd.) is 100/1. The composition was obtained by mixing in a plastic bag and mixing well. Next, the composition was irradiated with 6 Mrad of radiation, and maleic anhydride was graft polymerized onto a fluororesin, and then dried at 120 ° C. for 15 hours to obtain a fluororesin 3 in which 0.2 mol% of maleic anhydride was graft polymerized. Got. Subsequently, the fluororesin 3 was melt-kneaded at 280 ° C. with an extruder to prepare pellets 3.

[Example 1]
Polyamide 12 (manufactured by Ube Industries, UBESTA3030JLX2A) was supplied to the cylinder forming the outer layer, pellets 1 were supplied to the cylinder forming the inner layer, and each was transferred to the transport zone of the cylinder. Two-layer co-extrusion was carried out by setting the heating temperature in the transport zone of polyamide 12 and pellet 1 to 240 ° C. and 280 ° C., respectively, and the temperature of the crosshead die to 280 ° C. to obtain a two-layer laminate hose. The laminated hose had an outer diameter of 8 mm, an inner diameter of 6 mm, and a thickness of 1 mm. The outer layer of polyamide 12 and the inner layer of fluororesin 1 were 0.8 mm and 0.2 mm, respectively. The amount of polyamide resin remaining in the laminate hose was N / F = 3.7, the interlayer adhesion was 59 N / cm, and the interlayer adhesion after the durability test was 42 N / cm.

[Example 2]
Polyamide 12 is supplied to the cylinder forming the outer layer, pellets 1 are supplied to the cylinder forming the intermediate layer, and the conductive fluorine resin (carbon black-containing TFE / E copolymer, manufactured by Asahi Glass Co., Ltd.) is used for the cylinder forming the inner layer. CB4015L) was supplied and transferred to the transport zone of each cylinder. The heating temperature in the transport zone of polyamide 12, pellet 1 and conductive fluororesin is 240 ° C., 280 ° C., 280 ° C. respectively, the temperature of the crosshead die is 280 ° C., and three-layer coextrusion is carried out. Obtained. The laminated hose had an outer diameter of 8 mm, an inner diameter of 6 mm, and a thickness of 1 mm. The outer layer of polyamide 12 and the inner layer of fluororesin 1 were 0.7 mm, 0.1 mm, and 0.2 mm, respectively. The amount of polyamide resin remaining in the laminate hose is N / F = 3.9, the interlayer adhesion between the outer layer and the intermediate layer is 53 N / cm, and the interlayer adhesion between the outer layer and the intermediate layer after the durability test. Was 39 N / cm. The inner layer and the intermediate layer could not be peeled before and after the durability test.

[Comparative Example 1]
A two-layer laminate hose was obtained in the same manner as in Example 1 except that the pellet 1 was changed to the pellet 2 of Synthesis Example 2. The laminate hose had an outer diameter of 8 mm, an inner diameter of 6 mm, and a thickness of 1 mm. The thickness of the outer layer of polyamide 12 and the inner layer of fluororesin 2 were 0.8 mm and 0.2 mm, respectively. The amount of polyamide resin remaining in the laminate hose was N / F = 0.3, the interlayer adhesion was 47 N / cm, and the interlayer adhesion after the durability test was 18 N / cm.

[Comparative Example 2]
A two-layer laminate hose was obtained in the same manner as in Example 1 except that the pellet 1 was changed to the pellet 3 of Synthesis Example 3. The laminated hose had an outer diameter of 8 mm, an inner diameter of 6 mm, and a thickness of 1 mm. The thickness of the outer layer of polyamide 12 and the inner layer of fluororesin 3 were 0.8 mm and 0.2 mm, respectively. The amount of polyamide resin remaining in the laminate hose was N / F = 1.6, the interlayer adhesion was 36 N / cm, and the interlayer adhesion after the durability test was 15 N / cm.

The laminate hose of the present invention is suitable for uses such as automotive fuel hoses, industrial hoses, food hoses and the like.

Claims (5)

  A laminated hose in which an inner layer made of a fluororesin containing an acid anhydride residue and an outer layer made of a polyamide resin are directly laminated, and 1, 1, 1, 3, 3, 3- After the polyamide resin is dissolved and removed using hexafluoro-2-propanol, the amount of the polyamide resin remaining on the surface of the inner layer made of the fluororesin is measured by an X-ray photoelectron spectrometer, A laminate hose having a molar ratio of nitrogen atoms derived from a polyamide resin / fluorine atoms derived from the fluororesin of 2 to 200.   The laminate hose according to claim 1, wherein the fluororesin is an ethylene / tetrafluoroethylene copolymer.   The laminate hose according to claim 1 or 2, wherein the polyamide resin is at least one selected from the group consisting of polyamide 6, polyamide 46, polyamide 66, polyamide 612, polyamide 11, polyamide 12, and polymetaxylylene adipamide. .   The laminate hose according to any one of claims 1 to 3, wherein an interlayer adhesive force between the inner layer and the outer layer is 25 N / cm or more. A laminate hose having an interlayer adhesive force of 20 N / cm or more between the inner layer and the outer layer after the laminate is immersed in a fuel oil at 60 ° C. for 5000 hours.