FI107290B - Hose for feeding gasoline - Google Patents

Abstract

Polyamide-based tube for supplying petrol, especially to engines, and characterized by an outer polyamide layer, a fluorinated polymer median layer, preferably made of PVDF, and an inner polyamide layer. The layers are linked to one another by means of an adhesive binder.

Description

107290

Hose for feeding gasoline

The present invention relates to a hose for conveying petrol 5 or for feeding it in particular to engines and more particularly to car engines. The hose according to the invention is a polyamide-based hose for feeding gasoline.

For safety and environmental reasons, car manufacturers 10 require gasoline hoses to have mechanical properties: durability and flexibility, as well as improved resistance to permeability. These hoses have a low permeability to crude oil products and their additives, especially roethanol.

15 Currently polyamide hoses are widely used in the automotive industry. Polyamides are an ideal material for this tubing application because of their excellent mechanical strength and sufficient flexibility to withstand virtually the entire lifetime of the car without bending the bending movements. These polyamide hoses no longer meet the new requirements set by car manufacturers for hose impermeability. As gasoline contains continuously increasing amounts of methanol, the sensitivity of these polyamide tubing is manifested by the swelling of the tubing, which results in reduced mechanical properties and dimensional changes.

•

It is therefore an object of the invention to overcome these drawbacks while preserving the mechanical properties of the polyamides.

Accordingly, the present invention provides a polyamide-based hose for feeding gasoline comprising an outer layer of polyamide, an intermediate layer of fluorinated polymer, preferably 'PVDF, and an inner layer of polyamide, wherein each of these layers is bonded together to form a binder. 1 air layer.

107290 2

The invention thus relates to a hose comprising five layers, i.e., having a composition PA / binder / fluorinated polymer / binder / PA (where PA stands for polyamide).

These hoses are particularly well suited for feeding gasoline to 5 engines.

The polyamide used is usually an aliphatic thermoplastic polyamide, and in particular polyamide 11 (PA-11), polyamide 12 (PA-12) or polyamide 12,12 (PA-12,12), whether or not softened, or polyamide 6 (PA). -6) or polyamide 10 6.6 (PA-6.6). This polyamide may optionally also be an impact modified product or it may be a copolymer. The polyamides of the outer layer and the inner layer may be the same or different. Each polyamide layer may consist of one or more sub-layers and each of these sub-layers may be a different polyamide :.

This polyamide may also contain conventional polyamide fillers. The amount of filler incorporated is likewise conventional and depends on the car manufacturers' technical needs. These fillers may be present in one polyamide layer in each of the two polyamide layers.

According to one embodiment, this filler is from tubing Tmi. of the recycled material obtained. By this term recyclable is meant a product obtained by grinding malformed hoses during the manufacturing process, which therefore cannot be used in the intended application and can be recycled in this way. These malformed tubing may thus be ground and this powder may be incorporated into the inner and / or outer circulation.

The fluorinated polymers of the invention may be selected from the group consisting of: homo- and copolymers of vinylidene fluoride (VF2), homo- and copolymers of trifluoroethylene (VF3), 107290 3 such homo- and copolymers, in particular ter- - residues of (TFE), hexafluoropropene (HFP) and / or ethylene units and possibly of VF2 and / or -5 or VF3 units. Examples include polytetrafluoroethylene (PTFE), poly (ethylene-tetrafluoroethylene) (ETFE).

Fluorinated polymer also refers to mixtures containing at least 70% by weight of the aforementioned polymers in combination with other polymers.

Of these fluorinated polymers, homo- and copolymers of vinylidene fluoride having at least 70% by weight of VF2 residues, preferably referred to throughout the text as PVDF, are preferably used. Similarly, the term PVDF refers to mixtures of the aforementioned polymer with at least one other thermoplastic polymer, as long as at least 50% by weight of VF2 units are present in the mixture.

20

Each layer of the fluorinated polymer may be comprised of one or more sub-layers each of which is made of a different fluorinated polymer.

25 It has now been found that in such a hose comprising a PVDF interlayer bonded by a binder to both the polyamide outer layer and the polyamide inner layer, the permeability of the hose is reduced to at least 1/10 of that of the corresponding polyamide hose 3C, all other features that may be mentioned, such as impact resistance in the cold, remain within the car manufacturers' specifications.

In order to ensure adhesion between the polyamide and the fluorinated polymer, a polymer having carbonyl groups in the polymer chain is known in the art, and may be mentioned, for example, polyurethane, polyamide, polyurea, 410 to 290 polyester, ethylene-carbon monoxide groups or mixed polyol alloys.

This adhesive binder can be mixed with the fluorinated polymer in a proportion of 1 to 50% by weight. When the binder also contains a fluorinated polymer, then it is preferred that the fluorinated polymer present in the binder is that of the Fluorinated Polymer used in the layer or 10 layers of the fluorinated polymer adjacent to the air layer.

Other thermoplastic polymers or copolymers may also have been incorporated in this binder, as long as at least 50% by weight of this binder is present in this blend. The adhesive layers between the outer layer of polyamide and the layer of fluorinated polymer, on the one hand, and the inner layer of polyamide and the layer of fluorinated polymer, on the other, may be the same or different. Each binder layer may be made of one or more sub-layers, each of which is formed by a different binder.

Additional layers may be attached to this hose either on the outside or on the inside of the hose. These layers may be poly-mers, coatings and other coloring agents, UV blocking agents, antioxidants, and may be any layer known in the art that may be added to a polyamide layer.

According to one embodiment, the polyamide layers have a thickness in the range of 0.3-1.8 mm, the thickness of the fluorinated polymer layer is in the range of 10 µιι-1 mm and the layer of the adhesive binder has a thickness of 10 µm-1 mm.

The thicknesses of the polyamide layers and the binder layers may be the same or different. Such particle thicknesses are suitable for the manufacture of hoses for supplying gasoline to motors having hoses generally in the range of 6 to 12 mm in diameter.

It is essential that the fluorinated polymer, and in particular PVDF 5, is effectively bonded to the polyamide. The flexibility of a hose in which the fluorinated polymer and the polyamide are not connected cannot be good and therefore cannot be bent or folded easily by thermoforming; in this case, the folds are made of the thinnest material during operation.

In addition, if these layers are not connected, then any condensation of gases between the two layers of fluorinated polymer and polyamide may lead to distortion of the thinnest part of the hose over time. In addition, since these hoses are connected to each other by means of connectors to both the petrol tank and the carburettor, these connectors cannot guarantee sealing when the connectors are in contact with the loose layers. Finally, if the fluorinated polymer is PVDF and the PVDF layer is very small inside the tube, for example from 10 to a few tens of micrometers, and when this layer is not attached, then the vacuum in the tube will irreversibly distort the poly-vinylidene chloride. membrane and makes the hose unusable.

The present invention also relates to tubing of the type described above, but with a larger diameter. They can be used, for example, to connect an underground petrol tank to a petrol pump at a gas station.

The hose of the invention is obtained in a known manner by extruding five components simultaneously under extrusion conditions suitable for each of the thermoplastic materials. The simultaneous extrusion of these five components facilitates the extrusion of a fluorinated polymer, in particular PVDF, which is relatively deficient if this layer is not part of a "layered product".

The following examples illustrate the invention without limiting it.

Example 1

A hose having an outside diameter of 8 mm obtained in a peri-10 manner using an apparatus capable of simultaneously extruding five materials comprises: an outer layer of PA-12 and 600 μιη: η, softened by 13% by weight n-Butylbenzenesulfonamide (BBSA), a mixture of binders with a thickness of 15 to 150 μιη: η: 65 parts by weight of a polyester-type thermoplastic polyurethane with a Shore A hardness in accordance with DIN 53-505 of 88 , and has a density of 1.18, 20. 35 parts by weight of a copolymer of ethylene-vinyl acetate with attached functional groups by grafting | maleic anhydride having a copolymer melting point of 90 ° C and a melt flow rate of 6 g / 10 min at 190 ° C under a load of 2.16 kg; A PVDF layer of 25 to 250 μπι: η thick, made of a VF2-homopolymer having a melt flow rate of 8 g / 10 min at 230 ° C under a load of 3 kg; 150 μιη: η a layer of binder of a thickness similar to that of the binder used above; 30 - A 500 μιη: η inner layer of PA-12, this PA-12 being the same polyamide 12 as above in the outer layer.

The hose thus obtained is very poorly permeable to unleaded high-octane gasoline containing 15% methanol; this hose has good mechanical properties.

| 107290 7

Example 2 The PA / binder / PVDF / binder / PA hose is made by simultaneous extrusion to obtain dimensions of 8 mm outer diameter and 6 mm inner diameter.

By way of comparison, I am extruding only a single layer, 1 mm thick polyamide tube, similar to the one mentioned above.

10 The polyamide used is PA-12 softened with 7.5% by weight of n-butylbenzenesulfonamide (BBSA) with a bending factor of 450 MPa (ISO 178) and a notch Charpy impact strength of 9 kJ / m2. At -40 ° C (ISO 179 standard).

15

The binder is a mixture obtained by extruding a twin screw extruder:

* PVDF 1 polymer (VF2 homopolymer having a melt flow rate of 13 g / 10 min at 230 ° C under a load of 5 kg) (ISO standard

20 1133) (50% by weight), * copolymer of the acrylamide type having the following units 1, 2, 3 and 4: ch3 ch3

a,! I

O - CH 2 - C - CH 2 - Ο

Ι I

0 = c - o - c = o 30 ch3 CH3

I I

Θ _ CH2— C —CH2— ΟΙ I

0 = C —N - C = 0 35 1 ch3 107290 8 5 CH3 o - ch2 - ο- Ι C = 0 ίο 1

OH

Ch'30-ch2-c -15 ic = 0 0 CH3 25% by weight of the acid and anhydride monomers 1 and 3 (based on the total weight of the copolymers), 3-6% by weight of the imide monomers (based on the total weight of the copolymers) is 66% with a bending factor of 4100 MPa (ISO 178) (15%) for this copolymer, 30 *, and an impact modifier of Core-Shell (core-shell) -methyl methacrylate-butadiene-styrene (MBS) (35 %).

35 Middle layer PVDF 2 is a VF2 homopolymer having a melt flow rate of 8 g / 10 min at 230 ° C under a load of 5 kg (ISO 1133).

9 107290

The impact strength and permeability of each hose are measured in the gasoline test.

The impact strength of the hoses was evaluated according to DIN 53453.

The experiments were performed at -40 ° C.

Permeability tests were performed by the "micro shed test" method, circulating test gasoline in tubes. Coenzene is a mixture of: 10-TF1, ethanol (9% by volume), iso -octane (45.4% by volume) and toluene (45.4% by volume). In this case, recycling takes place at 40 ° C and 2 bar.

Permeability Stroke DIN

15 Example Tube Structure TF1 (g / n / 24h) at -40 ° C 2 PA-12 / binder / PVDF 2 / binder / PA-12 <5 OC / 10 (380 µm / 65 µm / 100 µm / 65 (un / 380 (im) 20 wt PA-12 69.7 OC / 10 (1 mm) OC / 10 = no fractures in the 10 test 25 30 35 40

Claims (8)

10 ^ 290 Polyamide-based hose for feeding gasoline, characterized in that it comprises an outer layer of polyamide, an intermediate layer 5 of a fluorinated polymer, preferably PVDF, and an inner layer of polyamide, in which each of these layers is interconnected by means of an air layer 1 of binder. 2. Rör enligt patent krav 1, transverse pattern of an atten polyamide som an exemplary group of end-users: PA-12, PA-12,12, PA-11, PA-6 and PA-6,6. 3. A patented patent for the use of Ell 2 as a polymeric polymer of carbon-yl group. A hose according to claim 1, characterized in that the polyamide used is selected from the group consisting of PA-12, PA-12,12, PA-11, PA-6 and PA-6,6. Hose according to claim 1 or 2, characterized in that the adhesive binder is a polymer or a copolymer having carbonyl groups in the polymer chain. 4. Rör enligt face av patentkraven 1 account 3, kännetecknat av att fyllmedel är införlivade i polyamidskiktet eller -skikten. 15 5. Rör enligt patentkrav 4, kännetecknat av att fyllmedlet bestär av et frän slangar och / eller rärterter tagtertering material. Hose according to one of Claims 1 to 3, characterized in that fillers are included in one or more layers of polyamide. Hose according to claim 4, characterized in that the filler is recycled material obtained from hoses and / or pipes. 6. Rör enligt face av patentkraven 1 account 5, tiltknat av att tjockleken for polyamidskikten ligger with 0.3 and 1.8 20 mm, tjockleken for skiktet av fluoroad polymer ligger with ·· '10 pm and 1 mm and tjockleken for adhesionsbindemedelsskikten ligger mellan 10 pm and 1 mm. Hose according to one of Claims 1 to 5, characterized in that the polyamide layers have a thickness in the range of 0.3-1.8 mm ·· and that the fluorinated polymer layer has a slope of 10 µm to 1 mm and the thickness of the binder layers is in the range of 10 μπι - 1 mm. Hose according to any one of claims 1 to 6, characterized! 25 for being used to supply gasoline to a motor ;; circuits. Hose according to one of Claims 1 to 7, characterized in that it is obtained by extrusion of its components. 107290 c 1. Rör baserat nap polyamid för matning av benzin, kännetecknat av att det bestär av etttre polyamidskikt, mellanliggan-de skirt av fluoroad polymer, förretädesvis av PVDF, och et 5 inre polyamidskikt, viking skart vart och ett är Förenade med property via adhesionsbindemedelsskikt. 7. The rör enligt face av patentkraven 1 account 6, the turnbuckle av att det det avsett för matning av gasin account motorer. 25 8. Rör enligt face av patentkraven 1 account 7, kännetecknat av * * * ·· · * att det er erhallet genom strängsprutning av dess beständsdalar.