JP4626529B2 - Multilayer laminate manufacturing method - Google Patents

Description

The present invention relates to a method for producing a multilayer laminate in which polyamide and a fluorine-containing ethylenic polymer are laminated by a simultaneous multilayer coextrusion method.

Multi-layer laminates made by laminating polyamide and fluororesin are high strength, high toughness, light weight, excellent workability, especially softness, and heat resistance and oil resistance of fluororesin. -Expected to be a composite material that combines properties such as chemical resistance and low chemical permeability.

As a method for producing such a multilayer laminate, a sequential lamination method and a simultaneous lamination method are known, and among them, the simultaneous lamination method by coextrusion occupies an important position due to the merit of a small number of steps. The simultaneous multi-layer coextrusion method performs multi-layer molding and multi-layer film formation using two or more extruders. Molded products in various forms such as deformed extrudates called films, sheets and profiles, pipes, hoses and tubes Is manufactured. In addition, applicable resins are also applied to fluororesins including various thermoplastic resins such as polyamide.

However, the fluororesin has the characteristics that the intermolecular cohesive force is low and the surface free energy is remarkably low because the polarizability of the fluorine molecule is small, and it is difficult to get wet with a solid having a higher intermolecular cohesive force. Therefore, it has low adhesion to many other materials. For this reason, it has low adhesiveness due to the characteristics as a resin and low interlayer adhesiveness with polyamide, and therefore, a device for increasing the interlayer adhesive strength is required. For example, a method is known in which the surface of a fluororesin is surface-treated by corona discharge treatment or radiation irradiation treatment. For example, Patent Document 1 discloses that a multilayer tube in which an outer layer is made of a polyamide resin and a fluororesin is provided as an inner layer is irradiated with radiation in order to ensure adhesion between the polyamide resin layer and the fluororesin layer. A method of manufacturing by introducing a crosslinked structure between the molecules of the layer has been proposed. However, this method cannot use the simultaneous lamination method by coextrusion.

There is also a technique in which a resin layer to be bonded to polyamide is blended with a fluorine resin. As a manufacturing method using this technique, for example, Patent Document 2 includes both a specific polyamide and a fluororesin in manufacturing a multilayer tube in which an outer layer is made of polyamide and a fluororesin is provided as an inner layer. It is disclosed that a resin composition is laminated with a polyamide layer to form an adhesive layer with an inner layer. However, in this manufacturing method, the polyamide and the fluororesin constituting the adhesive layer are inherently inferior in compatibility, and the morphology changes depending on the molding conditions, so that the cohesive force in the adhesive layer and the adhesive force with other layers are affected. Accordingly, there arises a problem that the adhesive force is likely to vary depending on the environment such as molding conditions and use temperature, and the quality is difficult to stabilize. In addition, this technology does not improve the adhesion between the polyamide and the fluororesin itself, but only uses the adhesiveness with the Bundred product, and uses a blend instead of the fluororesin. Will also impair the excellent properties of the fluororesin.

In response to this, it is conceivable to improve the fluororesin itself, and various fluororesin materials have been proposed. For example, Patent Document 3 uses a fluorine-containing ethylenic polymer having a carbonyl group such as a carbonate group and / or a carboxylic acid halide group as an inner layer fluorine-based resin in which polyamide 12 (nylon 12) is used as an outer layer and laminated therewith. A multi-layer coextrusion process for laminates is disclosed. In this method, the die temperature is set to 260 ° C., and an interlayer adhesion strength of a few tens of N / cm and a good appearance can be obtained. is not.

Thus, as described above, the development direction of the manufacturing technology for improving the performance of the multilayer laminate of the polyamide and the fluororesin, in particular, the fluorine-containing ethylenic polymer is mainly as described above. It can be said that it was directed to two aspects of the examination of the method and the device of the adhesive material. Manufacturing method capable of developing sufficiently strong interlayer adhesive strength without the need for additional steps or being limited to a specific adhesive material, in particular, manufacturing with high production efficiency by applying simultaneous multilayer coextrusion method The method is not known.
JP-A-5-8353 JP-A-7-53823 WO99 / 45044 pamphlet

In view of the above situation, the present invention provides a multilayer laminate excellent in interlayer adhesive strength obtained by laminating polyamide and a fluorine-containing ethylenic polymer as a necessary adhesive material or a specific adhesive material by multilayer coextrusion. An object of the present invention is to provide a method for easily and simply producing without limitation.
In a multilayer laminate formed by laminating a polyamide and a fluororesin and requiring flexibility such as a film, sheet, hose, tube, etc., usually a material having a relatively low melting point among polyamides, In particular, nylon 11 and nylon 12 are preferably used. In this case, if the molding temperature for multi-layer coextrusion, that is, the cylinder temperature and the die temperature is set to a high temperature far from the melting point of the resin, the viscosity of the resin is too low to make molding difficult, and there is a risk of resin deterioration Arise. For this reason, in the field of molding technology, the molding temperature is set to a temperature that does not cause these problems. Therefore, conventionally, a die temperature in the case of extrusion molding of nylon 11 or nylon 12 is in the range of about 240 to 250 ° C., and when laminated with a fluororesin as described in the above-mentioned WO 99/45044 pamphlet. However, a temperature range exceeding 260 ° C. was never used.
However, as a result of earnestly examining the influence of various multilayer molding conditions on the above-mentioned problems, the present inventors surprisingly specified the die temperature beyond the temperature range of the conventional application in the simultaneous multilayer coextrusion method. It has been found that the above-mentioned problems can be solved by setting the value in the range, and the present invention has been completed.

That is, the present invention provides at least a polyamide (A) and a fluorine-containing ethylenic polymer (B) by a simultaneous multi-layer coextrusion method using a coextrusion apparatus comprising a die and a plurality of extruders for supplying a resin to the die. And a multilayer laminate manufacturing method for obtaining a laminate comprising the polyamide (A) and the fluorine-containing ethylenic polymer (B), wherein the die temperature exceeds 260 ° C, preferably It is a production method of a multilayer laminate in which the temperature is 265 ° C. or higher, more preferably 270 ° C. or higher, 310 ° C. or lower, preferably 300 ° C. or lower, more preferably 290 ° C.
In a preferred embodiment of the present invention, when the feed block is connected to the die, the temperature of the feed block is also in the range of more than 260 ° C. and 310 ° C. or less.
In a preferred embodiment of the present invention, the cylinder temperature of the extruder for supplying the polyamide (A) to the die is set to 20 to 90 ° C. higher than the melting point of the polyamide (A), or the die is fed or fed to the die. When the blocks are connected, the temperature of the polyamide (A) at the resin inlet connected to the extruder of the feed block is set to 20 to 90 ° C. higher than the melting point of the polyamide (A).
In a preferred embodiment of the present invention, the polyamide (A) is nylon 11 or nylon 12.
In a preferred embodiment of the present invention, a fluorine-containing ethylenic polymer having a carbonyl group is used as the fluorine-containing ethylenic polymer (B), and the content of the carbonyl group is 1 × 10 ⁶ carbon atoms in the main chain. 3 to 1000 in total.
In a preferred embodiment of the present invention, the simultaneous multilayer coextrusion method includes multilayer film coextrusion method, multilayer sheet coextrusion method, multilayer blow coextrusion method, multilayer profile coextrusion method, multilayer pipe coextrusion method, multilayer tube coextrusion method. The method is selected from the group consisting of a method, a multilayer wire coating coextrusion method and a multilayer steel pipe coating coextrusion method.
In a preferred embodiment of the present invention, the simultaneous multi-layer coextrusion method includes multi-layer co-extrusion of co-extruded resin layers, a pre-die laminating method performed before a die, an intra-die laminating method performed within a die, and an outer die performed after a die. This is performed by a method selected from the group consisting of lamination methods. The die may be a flat die or a circular die, and is preferably a circular die that develops a resin by a method selected from the group consisting of a spider method, a crosshead method, and a spiral method.
In the present invention, the layer made of polyamide (A) is used as an outer layer, the layer made of fluorine-containing ethylenic polymer (B) is used as an intermediate layer, and may contain a conductive material. The melting point is 250 ° C. or higher. It is also a tube or hose for automobile fuel piping having at least a three-layer structure in which the layer (C) made of a fluororesin is an inner layer.
Furthermore, the present invention provides a layer (C) made of a fluororesin that does not contain a conductive material, with a layer made of polyamide (A) as an outer layer, a layer made of fluorine-containing ethylenic polymer (B) as an intermediate layer. The inner layer, the layer (D) made of a fluororesin containing a conductive material as the innermost layer, and at least one of the fluororesin of the layer (C) and the fluororesin of the layer (D) It is also a tube or hose for automobile fuel piping having an at least four-layer structure having a melting point of 250 ° C. or higher.
Detailed Disclosure of the Invention The present invention is described in detail below.

In the simultaneous multilayer coextrusion method in the production method of the present invention, a die and at least a polyamide (A) and a fluorine-containing ethylenic polymer (B) and other resins used as necessary are supplied to the die. A co-extrusion apparatus comprising a plurality of extruders is used. Hereinafter, first, this apparatus will be described in detail.
Co-extrusion apparatus The simultaneous multilayer co-extrusion method is industrially implemented using a co-extrusion apparatus having a configuration including a die and a plurality of extruders that supply the resin to the die. The co-extrusion apparatus generally has a plurality of extruders for supplying the above-described raw resin, which will be described in detail below, to the die, a cooling apparatus for cooling and shaping (resizing) the resin that has passed through the die. Further, it may have a configuration comprising a processing machine for corona treatment, flame treatment, ozone treatment, etc., and a take-up machine for molded products, which are installed as necessary.

1. Extruder The above-mentioned extruder is usually provided with a plurality of extruders equal to the number of constituent layers in order to supply the respective raw resin for each layer. A known configuration that can supply a predetermined resin to each die is not limited. Although the basic structure of the extruder is not particularly limited, a screw type is preferable, and usually includes an adapter (a connecting portion between the extruder and the die), a screw, a cylinder, a hopper, and a cylinder temperature control unit. The screw type extruder may be a single screw extruder or a twin screw extruder, but a single screw extruder is usually used. The extruder can be provided with a ventro, and the ventro can be opened or depressurized to remove volatile components generated from the resin. Each raw resin sufficiently melted in the extruder is then connected to a die or a block for multi-layered confluence of co-extruded resin layers called feed blocks to the die. , Supplied to the feed block. Therefore, the raw material resin is supplied from the extruder through the adapter, or when the feed block is connected to the die, is supplied from the adapter and introduced into the die through the feed block. Further, in order to make the extrusion amount constant and to highly control the thickness of the molded product, the resin may be supplied from the extruder to the die or the feed block via a gear pump.

2. Dies The above dies may be used as appropriate according to the application. For example, flat dies or circular dies (for inflation films) are used for forming multilayer films and sheets, and pipes and tubes are used for forming multilayer pipes and tubes. Die (circular die), blow die for multilayer blow molding, profile die for multilayer profile molding, wire coating die for multilayer wire coating molding, pipe for multilayer steel pipe coating molding Each coating die may be used.
When molten resin is supplied to the die, the resin is developed in the flow path inside the die. As a method of this development, for example, a spider method may be used, a cross head method that enables extrusion in the 90 ° direction with an extruder, or a spiral method may be used. Among these, the spiral method is preferable because a uniform layer thickness can be obtained.
In addition, the length of the flat part of the die mandrel of the circular die may be appropriate, but may be, for example, about 50 to 200 mm.

By the way, in order to perform simultaneous multilayer coextrusion, it is necessary to combine the resin layers constituting the multilayer in a coextrusion apparatus to form a multilayer, but the multilayered joining position of the resin layers supplied from each extruder is In the die, it is preferable that any of the following may be used, or a combination thereof may be used.

i) In a block called a feed block (also called a combine adapter), a pre-die lamination method in which the resin is joined before the resin enters the die: In this method, the block called the feed block is upstream of the die (single manifold die). The raw material resin which comprises each layer is first supplied with each extruder here, and after combining and laminating | stacking, it supplies to a die | dye from a feed block.
ii) In-die lamination method in which multiple layers are merged in a die: In this method, a raw material resin constituting each layer is supplied to a die having a plurality of resin reservoirs called a multi-manifold (multi-manifold die) by each extruder, It joins in front of the part called the inner lip to make it multilayer.
iii) Outer die lamination method performed after die: In this method, a raw resin constituting each layer is supplied by an extruder using a die having a plurality of separated flow paths (dual slot die). Then, after passing through the die, they are merged to be multilayered.
In the production method of the present invention, the die temperature exceeds 260 ° C, preferably 265 ° C or higher, more preferably 270 ° C or higher, 310 ° C or lower, preferably 300 ° C or lower, more preferably 290 ° C or lower. Set to. Therefore, for example, it is preferably set to 265 to 300 ° C, more preferably 270 to 290 ° C. If the die temperature is 260 ° C. or less, a sufficiently strong interlayer adhesion strength cannot be obtained, and if it exceeds 310 ° C., the resin is severely deteriorated by heat, resulting in a decrease in strength and elongation of the multilayer laminate, and an appearance defect. Limited to the range.
In addition, when the feed block is connected to the die (the above aspect i), the temperature of the feed block together with the die exceeds 260 ° C, preferably 265 ° C or higher, more preferably 270 ° C or higher, 310 ° C or lower. The temperature is preferably set to 300 ° C. or less, more preferably 290 ° C. or less. In this case, the die and the feed block are preferably at the same temperature.

In the production method of the present invention, preferably, the cylinder temperature of the extruder for supplying the polyamide (A) to the die is set to 20 to 90 ° C. higher than the melting point of the polyamide (A), or the die (above ii. Or the mode of iii), or when the feed block is connected to the die (the mode of i above), the temperature of the polyamide (A) at the resin inlet (adapter part) of the feed block connected to the extruder The melting point of the polyamide (A) is 20 to 90 ° C. higher. If the temperature is lower than this, there is a possibility that a good molded product may not be obtained due to insufficient melting of the resin, and if the temperature is higher than this, there is a risk of thermal deterioration of the resin, and the tensile strength of the molded product such as a tube, The elongation may decrease. More preferably, it is 30 to 80 ° C. higher than the melting point of the polyamide (A). The temperature difference between the cylinder temperature and the die temperature is relatively small, and as a result, there is no fear of causing a significant increase in the resin pressure at the die.

Next, the polyamide (A) and the fluorine-containing ethylenic polymer (B) used in the present invention will be described in detail.
Polyamide (A) The polyamide in the present invention refers to a crystalline polymer having an amide bond —NHCO— as a repeating unit in the molecule. Examples of such a resin include a resin in which a majority of amide bonds are bonded to an aliphatic or alicyclic structure, a so-called nylon resin. Specifically, for example, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 46, metaxylylenediamine / adipic acid polymer, nylon 6/66 copolymer, nylon 66/12 Examples thereof include copolymers and blends thereof.

Moreover, in the polyamide in the present invention, a structure having no amide bond as a repeating unit may be partially blocked or graft-bonded. Examples of such resins include polyamide elastomers such as nylon 6 / polyester copolymer, nylon 6 / polyether copolymer, nylon 12 / polyester copolymer, and nylon 12 / polyether copolymer. Can do. These polyamide elastomers are obtained by block copolymerizing a nylon resin oligomer and a polyester resin oligomer or a polyether resin oligomer via an ester bond or an ether bond. Examples of the polyester resin oligomer include polycaprolactone and polyethylene adipate, and examples of the polyether resin oligomer include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Particularly preferred embodiments include nylon 6 / polytetramethylene glycol copolymer, nylon 12 / polytetramethylene glycol copolymer, and the like.

In the present invention, the polyamide is preferably selected appropriately so that the melting point thereof is 130 ° C. or higher, more preferably 150 ° C. or higher. If the melting point is lower than 130 ° C., the mechanical properties and heat resistance of the formed layer may be inferior.
In the present invention, the polyamide preferably has a molecular weight represented by relative viscosity of 1.8 or more, and more preferably 2.0 or more. If it is less than 1.8, the moldability is inferior, and the mechanical properties of the obtained molded product may be inferior. On the other hand, the upper limit is preferably 4.0 or less. If it exceeds 4.0, polymerization of the resin itself is difficult, and moldability may be impaired. The relative viscosity is measured according to JIS K 6810.

The polyamide in the present invention is nylon 11, nylon 12, nylon 610, nylon 612, nylon 6 / poly, when toughness is required, such as when used in a tube or hose molded body. Either an ether copolymer or a nylon 12 / polyether copolymer can be suitably used. Of these, nylon 11 and nylon 12 are more preferable in consideration of the presence of zinc chloride water used as a snow melting agent to be sown on the road when considering automotive fuel piping applications.

In the present invention, the polyamide contains, in addition to the amide group, a functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an ester group, and a sulfonamide group in a total amount of 0.05 to 80 equivalent% with respect to the amide group. It may be. By containing one or more of hydroxyl group, carboxyl group, ester group or sulfonamide group so that the total content thereof satisfies the above conditions with respect to the amide group, the fluorine-containing ethylenic polymer (B This is preferable because the initial characteristic of the interlaminar adhesion strength with the layer made of (2) can be maintained over a long period of time. Of the functional groups described above, a sulfonamide group is preferable, and a sulfonamide group directly bonded to an aromatic ring is particularly preferable. The total content of the above functional groups other than the amide group is more preferably 1 to 70 equivalent%, still more preferably 1 to 50 equivalent% with respect to the amide group.

Such a polyamide may be, for example, one obtained by copolymerizing a copolymerizable monomer having the above functional group with a polyamide resin so as to have the above content, or a hydroxyl group, a carboxyl group, A plasticizer having at least one functional group selected from the group consisting of an ester group and a sulfonamide group, or a polymer having compatibility with polyamide and having these functional groups so as to have the above functional group content. You may mix | blend. Examples of the polymer having compatibility with the polyamide and having the above-described functional group include ester and / or carboxylic acid-modified olefin resins (ethylene / methyl acrylate copolymer, ethylene / acrylate copolymer, ethylene / methyl). Acrylate / maleic anhydride copolymer, ethylene / ethyl acrylate copolymer, propylene / maleic anhydride copolymer, etc.), ionomer resin, polyester resin, phenoxy resin, ethylene-propylene-diene copolymer, polyphenylene oxide, etc. Can be mentioned.

Of these, the method of blending the plasticizer can not only contain the target amount of the functional group with a relatively small blending amount, but also makes the resin composition inherent to the plasticizer flexible, in particular, the low temperature of the tube or hose. This is an advantageous method in that the mechanical properties can be improved. In this case, although the compounding quantity of a plasticizer changes with kinds, the said functional group content is normally achieved by about 5 to 20 weight% of compounding with respect to the composition whole quantity.

Examples of such plasticizers include hexylene glycol and glycerin as alcoholic hydroxyl group-containing materials; bisphenol compounds such as β-naphthol, dibenzylphenol, octylcresol and bisphenol A as phenolic hydroxyl group-containing materials, Examples thereof include octyl p-hydroxybenzoate, 2-ethylhexyl p-hydroxybenzoate, heptyl p-hydroxybenzoate, etc .; ethylene oxide and / or propylene oxide adduct of p-hydroxybenzoic acid as a carboxyl group-containing substance In addition to benzoic acid esters such as octyl p-hydroxybenzoate, p-hydroxybenzoic acid-2-ethylhexyl, p-hydroxybenzoic acid heptyl and the like as an ester group-containing substance, ε-cap Examples of the sulfonamide group-containing substance include N-methylbenzenesulfonamide, N-ethylbenzenesulfonamide, N-butylbenzenesulfonamide, toluenesulfonamide, and N-ethyltoluene. Examples thereof include sulfonamides and N-cyclohexyltoluenesulfonamides.

In this case, the amine value of the polyamide compounded with the plasticizer is not particularly limited, but a normal polyamide is generally less than 10 equivalents / 10 ⁶ g, and such can be used. Those having an amine value larger than this, for example, those having 10 to 60 equivalents / 10 ⁶ g can also be used. Further, the polyamide preferably has an acid value of 80 equivalents / 10 ⁶ g or less from the viewpoint of molecular weight and adhesive strength.
The polyamide in the present invention may also contain other resins, colorants, various additives and the like as long as the object of the present invention is not impaired. Examples of the additive include an antistatic agent, a flame retardant, a heat stabilizer, an ultraviolet absorber, a lubricant, a mold release agent, a crystal nucleating agent, and a reinforcing agent (filler).

Fluorine-containing ethylenic polymer (B) The fluorine-containing ethylenic polymer in the present invention is a homopolymer chain or copolymer chain having a repeating unit derived from at least one fluorine-containing ethylenic monomer. It may be a polymer chain formed by polymerizing only an ethylenic monomer, or by polymerizing a fluorine-containing ethylenic monomer and an ethylenic monomer having no fluorine atom.

The fluorine-containing ethylenic monomer is an olefinically unsaturated monomer having a fluorine atom, specifically, tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene, vinyl fluoride, hexafluoropropylene, hexafluoroisobutene, formula ^{_{(ii): CH 2 = CX}} 1 (CF 2) n X 2 (ii)
(Wherein, X ¹ is H or F, X ² is H, F or Cl, and n is an integer of 1 to 10), and perfluoro (alkyl vinyl ether) s.
The ethylenic monomer having no fluorine atom is preferably selected from ethylenic monomers having 5 or less carbon atoms in order not to lower the heat resistance and chemical resistance. Specific examples include ethylene, propylene, 1-butene, 2-butene, vinyl chloride, and vinylidene chloride.

When a fluorine-containing ethylenic monomer and an ethylenic monomer having no fluorine atom are used, the monomer composition is 10 to 100 mol% (for example, 30 to 100 mol) of the fluorine-containing ethylenic monomer. %) And 90 to 0 mol% (for example, 70 to 0 mol%) of the ethylenic monomer having no fluorine atom.
In the fluorine-containing ethylenic polymer in the present invention, the melting point or glass transition of the polymer can be selected by selecting the type, combination, composition ratio, etc. of the fluorine-containing ethylenic monomer and the ethylenic monomer having no fluorine atom. The point can be adjusted, and it can be either resinous or elastomeric. Although the properties of the fluorine-containing ethylenic polymer can be appropriately selected according to the required performance and use of the multilayer laminate, the melting point is preferably 150 to 270 ° C. Such a polymer is advantageous because it can sufficiently exert the adhesiveness between the carbonyl group and the counterpart material, and can give a strong adhesive force directly to the counterpart material. It is more preferably 230 ° C. or lower, and further preferably 210 ° C. or lower, in that lamination with an organic material having relatively low heat resistance is possible.

Regarding the molecular weight of the fluorine-containing ethylenic polymer in the present invention, the polymer can be molded at a temperature lower than the thermal decomposition temperature, and the resulting molded product has excellent mechanical properties, chemical resistance, etc. inherent to the fluorine-containing ethylenic polymer. It is preferable that it is in a range where can be expressed. Specifically, the MFR at an arbitrary temperature in the range of about 230 to 300 ° C. is preferably 0.5 to 100 g / 10 min using the melt flow rate (MFR) as a molecular weight index.
As the fluorine-containing ethylenic polymer in the present invention, a fluorine-containing ethylenic polymer having a tetrafluoroethylene unit as an essential component in terms of heat resistance and chemical resistance, and a vinylidene fluoride unit in terms of moldability A fluorine-containing ethylenic copolymer containing as an essential component is preferred.
Preferable specific examples of the fluorine-containing ethylenic polymer in the present invention include a fluorine-containing ethylenic copolymer (I) in which the fluorine-containing ethylenic polymer chain is essentially a polymer chain obtained by polymerizing the following monomers. To (V) and the like: (I) a copolymer obtained by polymerizing at least 5 to 95 mol% of tetrafluoroethylene and 95 to 5 mol% of ethylene; (II) at least 3 to 4 of tetrafluoroethylene; 97 mol% and the general formula: CF ₂ = CF-Rf ¹ [wherein Rf ¹ represents CF ₃ or ORf ² (Rf ² represents a C 1-5 perfluoroalkyl group)] A copolymer obtained by polymerizing 97 to 3 mol% of a compound, (III) a copolymer obtained by polymerizing at least the following a, b and c, a. Tetrafluoroethylene 20-90 mol%, preferably 20-70 mol% b. 10-80 mol% ethylene, preferably 20-60 mol% c. ^{1 to} 70 mol% of a compound represented by the general formula CF ₂ = CF—Rf (wherein Rf ^{1 represents} CF ₃ or ORf ^{2 (} Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms)). 1 to 60 mol%, preferably (IV) a copolymer obtained by polymerizing at least vinylidene fluoride, (V) a copolymer obtained by polymerizing at least the following d, e and f, d. Vinylidene fluoride 15-60 mol% e. Tetrafluoroethylene 35-80 mol% f. 5-30 mol% hexafluoropropylene.

All of these exemplified fluorine-containing ethylenic polymers are preferable in that they are particularly excellent in heat resistance, chemical resistance, weather resistance, electrical insulation and non-adhesiveness.
Examples of the copolymer (I) include 20 to 90 mol% (for example, 20 to 60 mol%) of tetrafluoroethylene units, 10 to 80 mol% (for example, 20 to 60 mol%) of ethylene units, and copolymerizable with these units. And a copolymer composed of 0 to 70 mol% of monomer units.
Examples of the copolymerizable monomer include hexafluoropropylene, chlorotrifluoroethylene, formula (ii): CH ₂ ═CX ¹ (CF ₂ ) _n X ² (ii)
(Wherein, X ¹ is H or F, X ² is H, F or Cl, and n is an integer of 1 to 10.), a perfluoro (alkyl vinyl ether), propylene, and the like. Usually, one or more of these are used.

Such a fluorine-containing ethylenic polymer is particularly preferable in terms of excellent heat resistance, chemical resistance, weather resistance, electrical insulation, and non-adhesiveness.
Among these, (I-1) a copolymer comprising 62 to 80 mol% of tetrafluoroethylene units, 20 to 38 mol% of ethylene units, and 0 to 10 mol% of other monomer units, (I-2) A copolymer comprising 20 to 80 mol% of tetrafluoroethylene units, 10 to 80 mol% of ethylene units, 0 to 30 mol% of hexafluoropropylene units, and 0 to 10 mol% of other monomer units, is tetrafluoroethylene. / Ethylene copolymer is preferable in that the excellent performance can be maintained, the melting point can be relatively low, and the adhesion to other materials can be maximized.
Examples of the copolymer (II) include (II-1) 65 to 95 mol% of tetrafluoroethylene units, preferably 75 to 95 mol%, and 5 to 35 mol% of hexafluoropropylene units, preferably 5 to 25 mol%. A copolymer consisting of mol%, (II-2) from 70 to 97 mol% of tetrafluoroethylene units, CF ₂ = CFORf ² (Rf ² is a perfluoroalkyl group having 1 to 5 carbon atoms) from 3 to 30 mol% of units. A copolymer comprising (II-3) a tetrafluoroethylene unit, a hexafluoropropylene unit, and a CF ₂ = CFORf ² (Rf ² is the same as above) unit, wherein the hexafluoropropylene unit and the CF ₂ = A copolymer having a total of ² units of CFORf of 5 to 30 mol% is preferred.

The above (II-1) to (II-3) are also perfluoro copolymers, and among the fluorine-containing ethylenic polymers, heat resistance, chemical resistance, water repellency, non-adhesiveness, electrical insulation, etc. The best.
Examples of the copolymer (IV) include, for example, vinylidene fluoride units of 15 to 99 mol%, tetrafluoroethylene units of 0 to 80 mol%, hexafluoropropylene or chlorotrifluoroethylene units of one or more units of 0 to 0 mol%. Examples thereof include a copolymer composed of 30 mol%.
Specifically, for example, (IV-1) a copolymer comprising 30 to 99 mol% of vinylidene fluoride units and 1 to 70 mol% of tetrafluoroethylene units, and (IV-2) 60 to 90 mol of vinylidene fluoride units. %, Tetrafluoroethylene unit 0-30 mol%, chlorotrifluoroethylene unit 1-20 mol% copolymer, (IV-3) vinylidene fluoride unit 60-99 mol%, tetrafluoroethylene unit 0-30 A copolymer consisting of 5 to 30 mol% of hexafluoropropylene units, (IV-4) 15 to 60 mol% of vinylidene fluoride units, 35 to 80 mol% of tetrafluoroethylene units, and 5 to 30 of hexafluoropropylene units. Examples thereof include a copolymer composed of mol%.

In the present invention, it is particularly preferable to contain a carbonyl group in the fluorine-containing ethylenic polymer in order to further strengthen the adhesion to the layer made of the polyamide (A).
In the present invention, the term “carbonyl group” refers to a functional group having —C (═O) — that can basically react with a functional group such as an amide group or amino group in the polyamide (A), specifically Are particularly preferred embodiments such as carbonate, carboxylic acid halide, aldehyde, ketone, carboxylic acid, ester, acid anhydride, isocyanate group and the like. On the other hand, amide, imide, urethane, urea group and the like are groups having -C (= O)-, but these have poor reactivity unlike the groups exemplified above including carbonate groups, Therefore, it can be said that it cannot basically react with the functional group in the polyamide (A). In the present invention, as the carbonyl group, a carbonate group, a carboxylic acid halide group, and a carboxylic acid group that are easily introduced and highly reactive with the polyamide (A) are preferable.

The number of carbonyl groups in the fluorine-containing ethylenic polymer in the present invention is appropriately selected depending on the type of laminated material, shape, use of the laminated body, required adhesive strength, the form of the polymer, etc. However, the total number of carbonyl groups is preferably 3 to 1000 with respect to 1 × 10 ⁶ main chain carbon atoms. If the number of carbonyl groups is less than 3 with respect to 1 × 10 ⁶ main chain carbon atoms, sufficient adhesive strength may not be exhibited. On the other hand, when the number exceeds 1,000, the adhesive force may be lowered due to a chemical change of the carbonyl group in accordance with the bonding operation. More preferably, it is 3-500 pieces, More preferably, it is 10-300 pieces. In addition, content of the carbonyl group in a fluorine-containing ethylenic polymer can be measured by infrared absorption spectrum analysis.

If 20 or more carboxylic acid halide groups that are particularly excellent in reactivity with the polyamide (A) are present in the fluorine-containing ethylenic polymer with respect to 1 × 10 ⁶ main chain carbon atoms, Even when the total content of the groups is less than 150 with respect to 1 × 10 ⁶ main chain carbon atoms, excellent adhesiveness with the polyamide (A) can be expressed.
In addition, the carboxylic acid halide group may be decomposed into carboxylic acid by heating or the like when molding the fluorinated ethylenic polymer, and therefore, the fluorinated ethylenic polymer in the multilayer laminate may be decomposed. The ethylenic polymer generally contains not only the carbonate group and / or the carboxylic acid halide group but also a carboxylic acid group derived therefrom when a carboxylic acid halide group is present.

The carbonate group in the fluorine-containing ethylenic polymer in the present invention is generally a group having a bond of —OC (═O) O—, specifically, a —OC (═O) O—R group [R the organic group _(e.g., C 1 _{-C 20} alkyl group (especially _C 1 _{-C 10} alkyl group), such as _C 2 _{-C 20} alkyl group having an ether bond) or VII group element. ] Of the structure. Examples of carbonate _{groups, -OC (= O) OCH 3} , -OC (= O) OC 3 H 7, -OC (= O) OC 8 H 17, -OC (= O) OCH 2 CH 2 CH 2 OCH Preferred is ₂ CH _{3 and the} like.
The carboxylic acid halide group in the fluorine-containing ethylenic polymer in the present invention specifically has a structure of —COY [Y is a halogen element], and examples thereof include —COF, —COCl, etc. These carbonyl groups The fluorine-containing ethylenic polymer itself can maintain the excellent properties such as chemical resistance, chemical resistance, weather resistance, antifouling property and non-adhesiveness of the fluorine-containing material. Such excellent characteristics of the fluorine-containing material can be imparted to the laminate without deteriorating.

When the fluorine-containing ethylenic polymer in the present invention contains a carbonyl group in the polymer chain, the embodiment in which the carbonyl group is contained in the polymer chain is not particularly limited. For example, the functional group containing a carbonyl group or a carbonyl group May be bonded to the polymer chain end or side chain.
Among them, those having a carbonyl group at the end of the polymer chain are preferable because they do not significantly reduce heat resistance, mechanical properties and chemical resistance, or are advantageous in terms of productivity and cost. Among these, a method of introducing a carbonyl group at the end of a polymer chain using a polymerization initiator containing a carbonyl group such as peroxycarbonate or peroxyester or having a functional group that can be converted into a carbonyl group is introduced. This is a preferred embodiment because it is very easy and the amount of introduction can be easily controlled. In the present invention, the carbonyl group derived from peroxide refers to a carbonyl group derived directly or indirectly from a functional group contained in the peroxide.

In addition, in the fluorine-containing ethylenic polymer in the present invention, even if a fluorine-containing ethylenic polymer not containing a carbonyl group is present, the total amount of the polymer as described above is 1 × 10 ⁶ main chain carbons. It is sufficient that the number of carbonyl groups is within the range.
It does not specifically limit as a manufacturing method of the fluorine-containing ethylenic polymer in this invention, It is obtained by radical-polymerizing or ion-polymerizing the monomer of the kind and mixing | blending matched with the target fluorine-containing polymer.

Among these, the radical polymerization method is preferably suspension polymerization in an aqueous medium industrially using a fluorine-based solvent and using peroxycarbonate or the like as a polymerization initiator, but other polymerization methods such as solution Polymerization, emulsion polymerization, bulk polymerization and the like can also be employed. In suspension polymerization, a fluorinated solvent may be used in addition to water. Examples of the fluorine-based solvent used for suspension polymerization include hydrochlorofluoroalkanes (for example, CH ₃ CClF ₂ , CH ₃ CCl ₂ F, CF ₃ CF ₂ CCl ₂ H, CF ₂ ClCF ₂ CFHCl), and chlorofluoroalkanes (for example, , CF ₂ ClCFClCF ₂ CF ₃ , CF ₃ CFClCFClCF ₃ ), perfluoroalkanes (eg, perfluorocyclobutane, CF ₃ CF ₂ CF ₂ CF ₃ , CF ₃ CF ₂ CF ₂ CF ₂ CF ₃ , CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₃₎ can be used, inter alia perfluoroalkanes are preferable. The amount of the fluorine solvent used is preferably 10 to 100% by weight with respect to water from the viewpoint of suspendability and economy.

The polymerization temperature is not particularly limited and may be 0 to 100 ° C. The polymerization pressure is appropriately determined according to other polymerization conditions such as the type, amount and vapor pressure of the solvent to be used, and the polymerization temperature, but may be usually 0 to 9.8 MPaG.
In order to adjust the molecular weight, conventional chain transfer agents such as hydrocarbons such as isopentane, n-pentane, n-hexane and cyclohexane; alcohols such as methanol and ethanol; carbon tetrachloride, chloroform, methylene chloride and methyl chloride Halogenated hydrocarbons such as can be used.
In addition, as a method of obtaining the fluorine-containing ethylenic polymer containing a carbonyl group mentioned above, the method of copolymerizing the monomer containing a carbonyl group can be mentioned. Suitable ethylenic monomers containing this carbonyl group include fluorine-containing monomers such as perfluoroacrylic acid fluoride, 1-fluoroacrylic acid fluoride, acrylic acid fluoride, 1-trifluoromethacrylic acid fluoride, perfluorobutenoic acid and the like. Examples thereof include monomers that do not contain fluorine, such as monomers, acrylic acid, methacrylic acid, acrylic acid chloride, and vinylene carbonate. In addition, a grafting compound containing a fluorine-containing ethylenic polymer, a grafting compound having a carbonyl group-containing functional group and a radical generator such as peroxide is melt-mixed and grafted at a temperature at which radicals are generated in an extruder. Can also be obtained.
On the other hand, in order to obtain a fluorine-containing ethylenic polymer having a carbonyl group at the polymer molecule end, various methods can be adopted. As described above, peroxides, particularly peroxycarbonates and peroxyesters can be used. The method used as the polymerization initiator can be preferably employed in terms of quality such as economy, heat resistance and chemical resistance. According to this method, a carbonyl group derived from peroxide, for example, a carbonate group derived from peroxycarbonate, an ester group derived from peroxyester, or a functional group thereof is converted into a carboxylic acid halide group to form a polymer chain. It can be introduced at the end. Among these polymerization initiators, when peroxycarbonate is used, the polymerization temperature can be lowered, and it is more preferable because no side reaction is involved in the initiation reaction.
As the peroxycarbonate, the following formulas (1) to (4):

[In the formula, R and R ′ are a linear or branched monovalent saturated hydrocarbon group having 1 to 15 carbon atoms, or a linear or branched group having 1 to 15 carbon atoms containing an alkoxy group at the terminal. Monovalent saturated hydrocarbon group, R ″ is a straight or branched divalent saturated hydrocarbon group having 1 to 15 carbon atoms, or a straight chain having 1 to 15 carbon atoms containing an alkoxy group at the terminal. Or it represents a branched divalent saturated hydrocarbon group. ]
Is preferably used.
In particular, diisopropyl peroxycarbonate, di-n-propyl peroxydicarbonate, t-butyl peroxyisopropyl carbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, etc. preferable.

The amount of initiator used such as peroxycarbonate and peroxyester varies depending on the type of polymer (composition, etc.), the molecular weight, the polymerization conditions, and the type of initiator used. It is preferable that it is 0.05-20 weight part with respect to a weight part, especially 0.1-10 weight part.

In addition, the content of the terminal carbonate group or ester group is adjusted not only by the amount of polymerization initiator such as peroxycarbonate or peroxyester, but also by adjusting the polymerization conditions such as the amount of chain transfer agent used and the polymerization temperature. You can control.
Various methods can be adopted to obtain a fluorine-containing ethylenic polymer having a carboxylic acid halide group at the polymer molecule end. For example, the above-mentioned fluorine-containing ethylenic polymer having a carbonate group or an ester group at the end is heated. And pyrolysis (decarboxylation). The heating temperature varies depending on the type of carbonate group or ester group and the type of fluorine-containing ethylenic polymer, but the polymer itself is heated to 270 ° C. or higher, preferably 280 ° C. or higher, particularly preferably 300 ° C. or higher. The upper limit of the heating temperature is preferably not more than the thermal decomposition temperature of the portion other than the carbonate group or ester group of the fluorine-containing ethylenic polymer, specifically 400 ° C. or less, more preferably 350 ° C. or less. It is.

The fluorine-containing ethylenic polymer in the present invention is preferably used alone because it does not impair the adhesiveness, heat resistance, chemical resistance and the like of itself, but the range in which the performance is not impaired depending on the purpose and application. Thus, various fillers such as inorganic powder, glass fiber, carbon fiber, metal oxide, or carbon can be blended. In addition to the filler, a pigment, an ultraviolet absorber, and other optional additives can be mixed. In addition to additives, other fluororesins, thermoplastic resins, thermosetting resins, and synthetic resins can also be blended to improve mechanical properties, improve weather resistance, impart design, and prevent static electricity. It becomes possible to improve moldability. In particular, it is preferable to add a conductive material such as carbon black or acetylene black because it is advantageous for preventing static charge accumulation in a fuel pipe tube or hose.

The layer comprising the fluorine-containing ethylenic polymer (B) in the present invention comprises the above-mentioned fluorine-containing ethylenic polymer and other components blended as necessary. The layer made of the combination (B) is conductive. The term “conductive” as used in the present invention means that, for example, when a flammable fluid such as gasoline is in continuous contact with an insulator such as a resin, an electrostatic charge may accumulate and ignite. However, it means that the electrostatic charge does not accumulate. For example, SAEJ2260 defines that the surface resistance is 10 ⁶ Ω / □ or less. In the case where the layer made of (B) is conductive, the blending ratio of the conductive material is preferably 20% by weight or less, more preferably 15% by weight or less in the composition constituting the layer. preferable. The lower limit should just be the quantity which can provide the above-mentioned surface resistance value.

In the present invention, the layer made of the fluorine-containing ethylenic polymer (B) may be further laminated with a layer (C) made of a fluorine-based resin. The layer (C) made of the fluorine-based resin may contain a conductive material in order to impart conductivity as necessary. In this case, the blending amount of the conductive material may be an amount capable of imparting conductivity, and may be the above-described blending ratio.

The fluororesin is not particularly limited, and any fluororesin that can be melt-molded can be used. For example, tetrafluoroethylene / fluoro (alkyl vinyl ether) copolymer (PFA), tetrafluoroethylene / hexafluoro Propylene copolymer (FEP), ethylene / tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), polyvinyl fluoride (PVF), polyfluoride And vinylidene chloride (PVDF). Furthermore, the above-mentioned fluorine-containing ethylenic polymer may be sufficient. Moreover, as said fluororesin, melting | fusing point may be 260 degreeC or more.

Among these, while maintaining low chemical and fuel low permeability, it excels in flexibility, low-temperature impact resistance, heat resistance, etc., and multi-layer laminates such as fuel piping tubes and hoses are produced by simultaneous multi-layer coextrusion with polyamide. Suitable for this is a melt flow rate of 0.5-100 g / 10 min at any temperature between 230 ° C. and 300 ° C.
It should be noted in the present invention that a fluorine resin having a melting point of 250 ° C. or higher and a relatively high melting point can be used as the fluorine resin. The extrusion conditions of the fluororesin including the fluorine-containing ethylenic polymer (B) are limited only to the die temperature, but by setting the cylinder temperature sufficiently high, the melt fluidity of the die part is ensured. Therefore, the multilayer laminate having such a configuration can be easily manufactured by the simultaneous multilayer coextrusion method. A fluororesin having a high melting point is excellent in chemical resistance and low chemical liquid permeability in proportion to the melting point, and thus is extremely advantageous particularly for applications requiring a high level of low chemical liquid permeability such as automotive fuel pipe applications. .

The fluororesins in the (B) and the layer (C) may be the same or different.
The present invention is also applicable to the production of a multilayer laminate in which the layer (B) is further laminated with a polyamide layer (A ′) instead of the fluororesin layer (C). . The layer (A ′) made of the polyamide may contain a conductive material for imparting conductivity, if necessary. In this case, the polyamide may be the same as or different from the above (A).

The present invention relates to a multilayer laminate comprising a layer (C) made of a fluorine-based resin, which does not contain a conductive material, and a layer (D) made of a fluorine-based resin, which further contains a conductive material. It is also applied to the manufacturing method. In this case, the compounding amount of the conductive material may be an amount that can impart conductivity, and may be the above-described compounding ratio. As the fluorine-based resin constituting the layer (D), the above-mentioned fluorine-based resin can be used, and it may be the same or different type of fluorine-based resin as the layer (C), and the melting point is 250 ° C. or higher. It may be a thing.

In the production method of the present invention, at least the above (A) and (B) and, if necessary, the other layers described above are laminated in an adhesive state using the coextrusion device. In that case, the take-up speed of a laminated body may be 4-20 m / min, for example. Moreover, the multilayer laminated body shape | molded with the manufacturing method of this invention can be laminated | stacked with another base material, and a lining body can also be manufactured.
Further, the draw-down ratio represented by the ratio of the die gap area to the actual cross-sectional area of the molded product is not particularly limited, but it is a problem peculiar to fluororesin because it improves the molding speed. From the point of not causing the “melt fracture”, for example, it may be 4 to 9, and a higher withdrawal rate can be obtained. In the case of a circular die, the draw balance is preferably close to 1.

In addition, when the molded product has a complicated shape, or when the molded product is heated and bent after molding, the resin is melt-extruded to eliminate residual distortion of the molded product. After forming, the formed multilayer laminate can be heat-treated at a temperature lower than the lowest melting point of the resin constituting the laminate for 0.01 to 10 hours. By adopting this manufacturing method, it is considered that residual strain is eliminated, and unreacted substances in the vicinity of the layer interface react with each other, and these can be combined to further increase the adhesive strength of the multilayer laminate. This heat treatment is preferably performed at 60 ° C. or higher, more preferably 80 ° C. or higher.

In the multilayer laminate obtained by the production method of the present invention, the initial interlayer adhesive strength between the layer made of polyamide (A) and the layer made of fluorine-containing ethylenic polymer (B) is as shown in the examples described later. , 30 N / cm or more, further 40 N / cm or more, and extremely strong adhesive force can be achieved. In addition, even when there is no specific functional group that significantly contributes to improvement in adhesion in the fluorine-containing ethylenic polymer (B), this effect is enormous, and is clearly distinguished from conventional techniques. is there.

In the present invention, the layer made of the fluorine-containing ethylenic polymer (B) may have a thickness of less than 0.5 mm. When a layer having better chemical permeability than the layer (B) is used as the layer (C) or the layer (D), the layer (B) can be made thinner. The range is that the thickness of the layer made of (B) is 1 of the thickness of the layer (C) or the total thickness of the layer (C) and the layer (D) when the layer (D) is further laminated. It may be less than 5 times. When the layer made of (B) is made to function as an intermediate adhesive layer, the adhesive layer can be made thin, which is economically advantageous.

The production method of the present invention is suitably applied to the production of the following multilayer laminate, for example.
Tubes and hoses: Automotive fuel piping tubes or hoses, automotive radiator hoses, brake hoses, air conditioner hoses, tubes or hoses for conveying chemicals, etc. Films, sheets: Diaphragm pump diaphragms and various packings Sliding members that require chemical resistance Tanks: Car radiator tanks, chemical storage bottles or bags, chemical containers, gasoline tanks, etc. Wires and pipes: Covered wires, coated steel pipes, etc. Other: Carburetor flange gaskets, etc. It may be various automobile-related seals such as fuel pump O-rings, chemical-related seals such as chemical pumps and flowmeter seals, and hydraulic equipment seals.

Among these, preferable embodiments include, for example, (i) polyamide (A) as an outer layer, and a layer made of a fluorine-containing ethylenic polymer (B) that may contain a conductive material as an inner layer. A tube or hose having a two-layer structure, particularly a tube or hose for automobile fuel piping or chemical transportation, (ii) a layer made of polyamide (A) as an outer layer, and a layer made of a fluorine-containing ethylenic polymer (B) as an intermediate layer And a tube or hose having at least a three-layer structure containing a conductive resin and having a layer (C) made of a fluororesin having a melting point of 250 ° C. or higher, particularly a tube for automobile fuel piping or chemical transportation Alternatively, a hose, (iii) a layer made of polyamide (A) as an outer layer, and a layer made of a fluorine-containing ethylenic polymer (B) as an intermediate layer, conductive if necessary A tube or hose having at least a three-layer structure having a polyamide layer (A ′) as an inner layer, which may contain a material, particularly an automobile fuel pipe tube or hose, and (iv) a polyamide (A) layer as an outer layer A fluorine-containing ethylenic polymer (B) layer as an intermediate layer, a conductive material-free layer (C) made of a fluorine-based resin as an inner layer, and a conductive material-containing fluorine-based resin. An automobile having at least a four-layer structure in which the layer (D) is an innermost layer and the melting point of at least one of the fluororesin of the layer (C) and the fluororesin of the layer (D) is 250 ° C. or higher Examples thereof include a fuel piping tube or a hose.

In the production method of the present invention, the multilayer laminate may have a jacket layer for the purpose of protection, antifouling, insulation, impact absorption, etc. as its outermost layer. The jacket layer can be suitably manufactured by co-extrusion using, for example, a resin, natural or synthetic rubber, etc., but may be coated in a separate step. It can also be reinforced with metal or the like.
The multilayer laminate obtained by the production method of the present invention is particularly a chemical solution, that is, a chemical solution capable of degrading a polyamide-based resin such as a solvent / fuel, for example, organic acids such as acetic acid, formic acid, cresol, phenol, hydrochloric acid, Inorganic acids such as nitric acid and sulfuric acid; alkaline solutions such as sodium hydroxide and potassium hydroxide; alcohols such as methanol and ethanol; amines such as ethylenediamine, diethylenetriamine and ethanolamine; amides such as dimethylacetamide; ethyl acetate and acetic acid Low permeability to organic or inorganic liquids such as esters such as butyl; fuels such as gasoline, light oil, heavy oil, pseudo fuels such as Fuel C, and mixed fuels of these with peroxide, methanol, ethanol, etc. Are better.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. In the following, various parameters were measured as follows.

(1) Measurement of the number of carbonate groups The obtained white powder of a fluorine-containing ethylenic polymer or a cut piece of a melt-extruded pellet is compression-molded at room temperature to form a uniform film having a thickness of 0.05 to 0.2 mm. Created. From the infrared absorption spectrum analysis of this film, a peak derived from a carbonyl group of a carbonate group (—OC (═O) O—) appears at an absorption wavelength of 1809 cm ⁻¹ (ν _{c = o} ), and its ν _{c = o} peak. The absorbance was measured. The number (N) of carbonate groups per 10 ⁶ main chain carbon atoms was calculated by the following formula (1).
N = 500 AW / εdf (1)
A: Absorbance of ν _{c = o} peak derived from carbonate group (—OC (═O) O—) ε: Molar absorbance coefficient of ν _{c = o} peak derived from carbonate group (—OC (═O) O—) [1 * Cm < ^{-1 >} * mol <^-1> ]. Ε = 170 from the model compound.
W: Average molecular weight of monomer calculated from monomer composition d: Film density [g / cm ³ ]
f: Film thickness [mm]
The infrared absorption spectrum analysis was performed by scanning 40 times using a Perkin-Elmer FTIR spectrometer 1760X (manufactured by PerkinElmer). The obtained IR spectrum was analyzed using Perkin-Elmer Spectrum for Windows Ver. The baseline was automatically determined at 1.4 C, and the absorbance of the peak at 1809 cm ⁻¹ was measured. The film thickness was measured with a micrometer.

(2) Measurement of the number of carboxylic acid fluoride groups Peaks derived from the carbonyl group of a carboxylic acid fluoride group (-C (= O) F) by infrared spectrum analysis of the film obtained in the same manner as in (1) above. Appeared at an absorption wavelength of 1880 cm ⁻¹ (ν _{c = o} ), and the absorbance of the ν _{c = o} peak was measured. Except that the molar absorbance coefficient [l · cm ⁻¹ · mol ⁻¹ ] of the ν _{c = o} peak derived from the carboxylic acid fluoride group was set to ε = 600 by the model compound, the above-mentioned (1 ) And the number of carboxylic acid fluoride groups was measured.
(3) Measurement of composition of fluorine-containing ethylenic polymer: Measured by ¹⁹ F-NMR analysis.
(4) Measurement of melting point (Tm) Using a Seiko DSC apparatus, the melting peak when the temperature was raised at a rate of 10 ° C / min was recorded, and the temperature corresponding to the maximum value was defined as the melting point (Tm).
(5) Measurement of MFR (Melt Flow Rate) Using a melt indexer (manufactured by Toyo Seiki Seisakusyo Co., Ltd.) from various nozzles with a diameter of 2 mm and a length of 8 mm under a load of 5 kg in unit time (10 minutes) The weight (g) of the polymer flowing out was measured.
(6) Appearance of inner and outer surfaces of multi-layer tube The obtained tube is cut into a semicircular shape, and the inner and outer surfaces of the tube are observed with a stereo microscope of 50 to 50 times to generate rough surfaces and foaming. The situation was judged according to the following criteria.
○: No defect in appearance is observed Δ: Some defect occurs in less than 2% of the entire surface ×: Some defect occurs in 2% or more of the entire surface (7) Adhesive strength of the multilayer tube Measurement of a 1 cm wide test piece from the tube, a 180 ° peel test at a speed of 25 mm / min with a Tensilon universal tester, and the average of the five points on the elongation-tensile strength graph is obtained as the adhesive strength between the layers. It was.

(8) Measurement of tube tensile strength It measured according to the method of SAE J2260 description.
(9) Measurement of tube tensile elongation It measured according to the method of SAE J2260 description.
(10) Measurement of surface resistance value It measured according to the method of SAE J2260 description.
(11) Measurement of low temperature impact resistance of tube It measured according to the method of SAE J2260. As a result, in the burst test conducted after the falling ball test, the burst pressure of the burst test was expressed by the number of 10 specimens that were 75% or less before the falling ball test. Thus, for example, the 0/10 notation indicates that all after the ball drop test, the burst pressure was greater than 75% before the ball drop test.

The polyamides and fluorine-containing ethylenic polymers used in the following examples are as follows.
〔polyamide〕
PA-A: nylon 12 manufactured by Ube Industries, product number 3030MI1, melting point 172-182 ° C., no plasticizer PA-B: nylon 12, product number 3030MJ1, manufactured by Ube Industries, melting point 169-179 ° C., plasticizer-containing PA- C: nylon 12 manufactured by Ube Industries, product number 3035JU, melting point 166 to 170 ° C., plasticizer-containing PA-D: nylon 12 manufactured by Ube Industries, product number 3035 LU, melting point 170-180 ° C., plasticizer not contained [fluorinated ethylene Polymer, fluororesin)
F-A to FG: synthesized in Synthesis Examples 1 to 7 described later.
FH: Fluororesin Neoflon (registered trademark) ETFE manufactured by Daikin Industries, Ltd., product number EP-521, melting point of about 265 ° C., MFR 14.8 (g / 10 min, 297 ° C.).
FI: Fluororesin NEOFLON (registered trademark) ETFE manufactured by Daikin Industries, Ltd., product number EP-610, melting point of about 220 ° C., MFR 26.7 (g / 10 minutes, 297 ° C.).
FJ: Fluorine resin NEOFLON (registered trademark) conductive material-containing ETFE manufactured by Daikin Industries, Ltd., product number EP-610AS, melting point about 220 ° C., MFR 6.8 (g / 10 min, 265 ° C.).
FK: Molten fluororesin composite material NEOFLON (registered trademark) FMC manufactured by Daikin Industries, Ltd., product number EA-LR43 (a blended product of fluororesin and nylon), MFR 6.5 (g / 10 min, 235 ° C.).

Synthesis Example 1 Synthesis of fluorinated ethylenic polymer FA
After 380 L of distilled water was charged into the autoclave and sufficiently substituted with nitrogen, 75 kg of 1-fluoro-1,1-dichloroethane, 155 kg of hexafluoropropylene, perfluoro (1,1,5-trihydro-1-pentene) 0.5 kg was charged, and the inside of the system was kept at 35 ° C. and a stirring speed of 200 rpm. Thereafter, tetrafluoroethylene was injected to 0.7 MPa, ethylene was subsequently injected to 1.0 MPa, and then 2.4 kg of di-n-propyl peroxydicarbonate was added to initiate polymerization. Since the system pressure decreases as the polymerization proceeds, a mixed gas of tetrafluoroethylene / ethylene / hexafluoropropylene = 40.5 / 44.5 / 15.0 mol% is continuously supplied, and the system pressure is reduced to 1 It was kept at 0.0 MPa. And perfluoro (1,1,5-trihydro-1-pentene) was continuously charged with a total amount of 1.5 kg, and stirring was continued for 20 hours. And after releasing pressure and returning to atmospheric pressure, the reaction product was washed with water and dried to obtain 200 kg of powder (fluorinated ethylenic polymer FA). The analysis results of this product are shown in Table 1.

Synthesis Examples 2-3 Synthesis of fluorinated ethylenic polymers FB to FC
In the same manner as in Synthesis Example 1, fluorinated ethylenic polymers FB to FC were obtained. The results of these analyzes are shown in Table 1.

Synthesis Example 4 Fluorine-containing ethylenic polymer FD
After 400 L of distilled water was charged into the autoclave and sufficiently purged with nitrogen, 320 kg of perfluorocyclobutane, 80 kg of hexafluoropropylene, 19 kg of tetrafluoroethylene, and 6 kg of vinylidene fluoride were charged, and the inside of the system was set to 35 ° C. with a stirring speed of 180 rpm. Kept. Thereafter, 5 kg of di-n-propyl peroxydicarbonate was added to initiate polymerization. Since the system pressure decreased with the progress of polymerization, a mixed gas of tetrafluoroethylene / vinylidene fluoride / hexafluoropropylene = 50/40/10 mol% was continuously supplied to keep the system pressure constant. Stirring was continued for 30 hours. And after releasing and returning to atmospheric pressure, the reaction product was washed with water and dried to obtain 200 kg of powder (fluorine-containing ethylenic polymer FD). The analysis results of this product are shown in Table 1.

Synthesis Example 5 Synthesis of fluorinated ethylenic polymer FE
After 400 L of distilled water was charged into the autoclave and sufficiently substituted with nitrogen, 75 kg of 1-fluoro-1,1-dichloroethane, 190 kg of hexafluoropropylene, perfluoro (1,1,5-trihydro-1-pentene) 1.5 kg was charged, and the inside of the system was kept at 35 ° C. and a stirring speed of 200 rpm. Thereafter, tetrafluoroethylene was injected to 0.7 MPa, ethylene was further injected to 1.0 MPa, and then 2.6 kg of di-n-propyl peroxydicarbonate was added to initiate polymerization. Since the internal pressure decreases as the polymerization proceeds, a mixed gas of tetrafluoroethylene / ethylene / hexafluoropropylene = 40.5 / 42.5 / 17.0 mol% is continuously supplied, and the internal pressure is reduced to 1 Stirring was continued for 30 hours while maintaining the pressure at 0.0 MPa. Then, after releasing the pressure to return to atmospheric pressure, the reaction product was washed with water and dried to obtain 172 kg of powder. Next, the obtained powder was extruded at a cylinder temperature of 320 ° C. using a single-screw extruder (manufactured by Tanabe Practice Machinery Co., Ltd., VS50-24) to obtain pellets (fluorinated ethylene polymer FE). The analysis results of this product are shown in Table 1.

Synthesis Example 6 Synthesis of fluorinated ethylenic polymer FF
Similar to Synthesis Example 5 except that the fluorine-containing ethylenic polymer FB obtained in Synthesis Example 2 and the conductive material (acetylene black) are dry blended at a weight ratio of 85/15 to obtain a cylinder temperature of 245 ° C. And kneaded. Table 1 shows the analysis results of the obtained pellets (fluorinated ethylenic polymer FF).

Synthesis Example 7 Synthesis of fluorinated ethylenic polymer FG
9.5 kg of the powder of the fluorine-containing ethylenic polymer FB obtained in Synthesis Example 2, 700 g of 28% aqueous ammonia and 10 L of distilled water were charged into an autoclave, and the system was heated while stirring and maintained at 80 ° C. Stirring was continued for an hour. The contents were washed with water and dried to obtain 9.2 kg of powder. By performing such a treatment, the active functional group (carbonate group and carboxylic acid fluoride group) contained in the resin was changed to an amide group that is chemically and thermally stable. In addition, it was confirmed by infrared spectrum analysis that this conversion progressed quantitatively. The analysis results of the resin after treatment are shown in Table 1. In Table 1, TFE is tetrafluoroethylene, Et is ethylene, HFP is hexafluoropropylene, VdF is vinylidene fluoride, and HF-Pe is perfluoro (1,1,5-trihydro-1- Pentene).

多層チューブの成形とその評価
実施例１ スパイラルマルチマニホールドダイを装着した３種３層のチューブ押出し装置を用いて、チューブの外層がポリアミドＰＡ−Ａ、中間層が含フッ素エチレン性重合体Ｆ−Ａ、内層が市販の導電性フッ素樹脂Ｆ−Ｊとなるように、樹脂を供給して内径６ｍｍ、外径８ｍｍのチューブを連続して成形した。ダイマンドレルのサイズは１２ｍｍ／１６ｍｍとした。成形条件及び得られたチューブの評価結果を表２に示した。ダイマンドレルのフラット部の長さ（表中にはダイの長さと表記）は５０ｍｍに設定した。

Molding of multi-layer tube and its evaluation Example 1 Using a three-layer / three-layer tube extruder equipped with a spiral multi-manifold die, the outer layer of the tube is polyamide PA-A and the intermediate layer is fluorine-containing ethylenic heavy. Resin was supplied and a tube having an inner diameter of 6 mm and an outer diameter of 8 mm was continuously formed so that the combined FA was the commercially available conductive fluororesin FJ. The size of the die mandrel was 12 mm / 16 mm. Table 2 shows the molding conditions and the evaluation results of the obtained tubes. The length of the flat part of the die mandrel (denoted as the die length in the table) was set to 50 mm.

Examples 2-3 A multilayer tube was formed in the same manner as in Example 1 except that the tube take-up speed was changed. Table 2 shows the molding conditions and the evaluation results of the obtained tubes.
From these results, it was confirmed that sufficient adhesiveness was exhibited even when the take-up speed was changed.
Examples 4-6 and Comparative Examples 1-2 A multilayer tube was formed in the same manner as in Example 1 except that the fluorine-containing ethylenic polymer used in the intermediate layer was changed and the cylinder temperature was changed according to the material. (Examples 4 to 6, Comparative Example 1). In addition, a multilayer tube was formed in the same manner except that the die temperature was lowered in Example 1 (Comparative Example 2). Table 2 (Examples 4 to 6) and Table 3 (Comparative Examples 1 and 2) show molding conditions and evaluation results of the obtained tubes.

From these results, when the fluorine-containing ethylenic polymer FB, FC, or FE was used for the intermediate layer, it was as strong as 30 N / cm as in Example 1 using FA. Adhesive strength was obtained. When the fluorine-containing ethylenic polymer FG was used for the intermediate layer and the die temperature was 255 ° C., the multilayer tube was not bonded at all between PA-A and FG. On the other hand, when the die temperature was increased to 320 ° C., the PA-A layer was significantly foamed, and PA-A and FG were not adhered at all. From these facts, the effect of the present invention was sufficiently proved. Further, even when the fluorine-containing ethylenic polymer FA was used for the intermediate layer, sufficient adhesive strength with the outer layer could not be obtained when the die temperature was low.

Example 7
A multilayer tube was formed in the same manner as in Example 1 except that the fluorine-containing ethylenic polymer used for the inner layer was FI and the cylinder temperature was changed accordingly. Table 2 shows the molding conditions and the evaluation results of the obtained tubes. From the results in Table 2, even when the inner layer was changed to the non-conductive fluororesin FI, a strong adhesive force was obtained as in the case where the conductive fluororesin was used.

Examples 8-9
Using a four-layer, four-layer multi-layer tube extruder equipped with a spiral multi-manifold die, the outer layer of the tube is a polyamide resin PA-A, the intermediate layer is a fluorine-containing ethylenic polymer FA, and the inner layer is a fluororesin F- I (Example 8) or F-H (Example 9), a resin was supplied so that the innermost layer was a conductive fluororesin FJ, and a tube having an inner diameter of 6 mm and an outer diameter of 8 mm was continuously formed. . Table 2 shows the molding conditions and the evaluation results of the obtained tubes. From the results in the table, a sufficiently strong adhesive strength was obtained even when the inner layer was two layers. High melting point ETFE (Example 9) excellent in low fuel permeability could also be extruded.

Examples 10-13 and Comparative Examples 3-5
Using a two-type, two-layer multi-layer tube extruder equipped with a spiral multi-manifold die, the resin is supplied so that the outer layer of the tube is a polyamide resin PA-A and the inner layer is a fluorine-containing ethylenic polymer. A tube having a diameter of 6 mm and an outer diameter of 8 mm was continuously formed. The molding conditions and evaluation of the obtained tubes are shown in Table 2 (Examples 10 to 13) and Table 3 (Comparative Examples 3 to 5). From the results in the table, when the fluorine-containing ethylenic polymer FG was used and the die temperature was set to 255 ° C., the multilayer tube was not bonded at all between PA-A and FG. On the other hand, when the die temperature was increased to 320 ° C., the PA-A layer was significantly foamed, and PA-A and FG were not adhered at all. From these facts, the effect of the present invention was sufficiently proved. Even when the fluorine-containing ethylenic polymer FA was used, if the die temperature was low, sufficient adhesion with the outer layer could not be obtained. Further, if the die temperature was raised too much, appearance failure due to foaming or the like was caused, and sizing was not possible and a multilayer tube could not be obtained, so the tube performance could not be measured.

Examples 14-15 and Comparative Examples 6-7
A multilayer tube was formed in the same manner as in Example 1 except that the polyamide used for the outer layer was changed. Table 3 shows molding conditions and evaluation results. From the results in the table, a sufficiently strong adhesive force was obtained even when the polyamide was changed to one containing a plasticizer. On the other hand, from the results of the comparative example, even when the fluorine-containing ethylenic polymer FA or FB was used for the intermediate layer, sufficient adhesive strength could not be obtained when the die temperature was low.

Example 16
A multilayer tube was formed in the same manner as in Example 14 except that the take-up speed of the tube was changed to 20 m / min and the size of the die mandrel was changed to 18 mm / 24 mm. Table 3 shows molding conditions and evaluation results. From the table, it can be seen that a sufficiently strong adhesive force was obtained even when the withdrawal rate was increased.

Example 17
A multilayer tube was formed in the same manner as in Example 2 except that the length of the flat portion of the die mandrel was 200 mm. Table 3 shows molding conditions and evaluation results. From the table, it can be seen that sufficient adhesion was obtained even when the length of the flat portion was increased.

Example 18 and Comparative Examples 8-9
Molding of multi-layer blow container and its evaluation A cylindrical blower having a diameter of 40 mm and a height of 300 mm is used by using a two-layer two-layer multi-layer blow apparatus having a die block of 12 mm and a core diameter of 8.5 mm and a feed block. A molded product was obtained. Table 4 shows the molding conditions and the evaluation results of the obtained molded products. The adhesive strength was measured in the longitudinal direction of the cylindrical side surface. It can be seen from the table that a sufficiently strong adhesive force was obtained.
On the other hand, except that the feed block and the die temperature were set to 250 ° C., an attempt was made to form a multilayer blow container in the same manner as in Example 18, but the obtained container was inferior in interlayer adhesion (Comparative Example). 8). Therefore, when the feed block and die temperature were raised, particularly at 320 ° C., the melt viscosity of the polyamide was remarkably lowered, and the same parison could not be formed due to the drawdown phenomenon (Comparative Example 9).

Since the present invention has the above-described configuration, the interlayer adhesive strength of the multilayer laminate, in particular, the interlayer adhesive strength between the polyamide and the fluorine-containing ethylenic polymer is easily and easily improved as compared with the conventional production method. be able to. Moreover, by using a carbonyl group-containing fluorine-containing ethylenic polymer, the adhesive strength of the entire multilayer laminate can be dramatically improved without the need for a special addition step, and a commercially available polyamide is used. Thus, a multilayer laminate excellent in low temperature impact resistance can be produced by the simultaneous multilayer coextrusion method. Therefore, polyamide can be provided in the outer layer to give the molded product excellent mechanical properties and high resistance to external environments such as heat and various chemical substances, and a fluorine resin layer is provided in the innermost layer. Thus, it is possible to economically produce a multilayer laminate in which the heat resistance, oil resistance / chemical resistance, and low chemical liquid permeability of a fluororesin are imparted to a molded product, which is extremely advantageous industrially.

Claims (7)

A layer made of a polyamide (A) as an outer layer, a layer made of a fluorine-containing ethylenic polymer (B) as an intermediate layer, a layer made of a fluororesin having a melting point of 260 ° C. or higher and containing no conductive material (C) Is at least a three-layer structure with an inner layer,
The polyamide (A) is nylon 11 or nylon 12,
A tube or hose for automobile fuel piping, wherein the fluorine-containing ethylenic polymer (B) is a fluorine-containing ethylenic polymer having a carbonyl group. A layer made of a polyamide (A) is used as an outer layer, a layer made of a fluorine-containing ethylenic polymer (B) is used as an intermediate layer, and a layer (C) made of a fluororesin having a melting point of 260 ° C. or more containing a conductive material. It is at least a three-layer structure as an inner layer,
The polyamide (A) is nylon 11 or nylon 12,
A tube or hose for automobile fuel piping, wherein the fluorine-containing ethylenic polymer (B) is a fluorine-containing ethylenic polymer having a carbonyl group. The layer made of polyamide (A) is the outer layer, the layer made of the fluorine-containing ethylenic polymer (B) is the intermediate layer, and the layer (C) made of fluorine-based resin that does not contain the conductive material is the inner layer. The layer (D) made of a fluorine resin containing the material is the innermost layer, and the melting point of at least one of the fluorine resin of the layer (C) and the fluorine resin of the layer (D) is 260 ° C. or higher. in which, at least four-layer structure,
The polyamide (A) is nylon 11 or nylon 12,
A tube or hose for automobile fuel piping, wherein the fluorine-containing ethylenic polymer (B) is a fluorine-containing ethylenic polymer having a carbonyl group. 4. The automobile according to claim 1, 2 or 3, wherein the content of carbonyl groups in the fluorine-containing ethylenic polymer (B) having a carbonyl group is 3 to 1000 in total with respect to 1 × 10 ⁶ main chain carbon atoms. Tube or hose for fuel piping. The fluorine-containing ethylenic polymer (B) contains a carbonyl group in the fluorine-containing ethylenic polymer chain, and the fluorine-containing ethylenic polymer chain comprises (I) at least tetrafluoroethylene of 5 to 95 mol% and ethylene. 95-5 obtained by polymerizing a mol% copolymer, (II) at least tetrafluoroethylene 3 to 97 mol% and in the general formula _CF 2 = _CF-Rf ¹ [wherein, Rf ¹ is, CF ₃ or ORf ² (Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms)], a copolymer formed by polymerizing 97 to 3 mol% of a compound represented by (III) at least a. 20-90 mol% tetrafluoroethylene, b. 10 to 80 mol% ethylene, and c. Compounds 1 to 70 represented by the general formula CF ₂ = CF—Rf ¹ [wherein Rf ¹ represents CF ₃ or ORf ² (Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms)]. A copolymer obtained by polymerizing mol%, (IV) a copolymer obtained by polymerizing at least vinylidene fluoride, and (V) at least d. Vinylidene fluoride 15-60 mol%, e. Tetrafluoroethylene 35-80 mol%, and f. The tube or hose for automobile fuel piping according to claim 1, 2, 3, or 4, which is at least one selected from the group consisting of copolymers obtained by polymerizing 5-30 mol% of hexafluoropropylene. The automotive fuel piping tube or hose according to claim 1, 2, 3, 4, or 5, wherein the fluorine-containing ethylenic polymer (B) has a melting point of 150 to 270 ° C. The interlayer initial adhesive strength between the layer made of polyamide (A) and the layer made of fluorine-containing ethylenic polymer (B) in the multilayer laminate is 20 N / cm or more. 6. A tube or hose for automobile fuel piping according to item 6.