JPH1044342A - Multi-layer structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel container or fuel pipe having improved impact resistance and barrier properties against gasoline blended with an oxygen-containing component such as methanol. A multilayer structure having a polyketone (a) layer composed of a carbon monoxide-ethylene copolymer and an ethylene vinyl alcohol copolymer (b) layer, having the (a) layer and the polyolefin (c) layer A multilayer structure, or a multilayer structure having the (a) layer, the (b) layer, and the (c) layer, and a fuel container or a pipe comprising the multilayer structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer having excellent barrier properties and impact resistance to gasoline blended with oxygen-containing components such as gasoline containing automobile fuel, especially gasoline containing methanol and gasoline containing methyl tertiary butyl ether (hereinafter abbreviated as MTBE). The present invention relates to a structure and a fuel container and a fuel pipe using the same.

[0002]

2. Description of the Related Art As a plastic fuel tank, a polyethylene single-layer type fuel tank is widely used, but has a drawback of having relatively high permeability. On the other hand, conventionally, there are a method of improving a barrier property by a sulfone treatment or a chlorofluorocarbon treatment in a polyethylene tank, and a method of mixing a substance having a barrier property with polyethylene, for example, nylon. On the other hand, there has been proposed a three-layer, five-layer structure in which a multilayer structure is used, a nylon is used for a barrier layer, and a high-density polyethylene layer is provided on both sides of the barrier layer with an adhesive layer interposed therebetween.

[0003]

However, from the viewpoint of strengthening regulations on environmental pollution in recent years, preventing air pollution and saving gasoline consumption, oxygen-containing components such as methanol and MTBE have been used to improve the octane number of gasoline. (Hereinafter sometimes abbreviated as gas hole) is used mainly in the United States. However,
The above-mentioned conventional tank has a drawback that the gasoline permeation amount from the entire tank increases, and improvement of these drawbacks is desired.

[0004] As means for improving this, a method of forming the above-mentioned multilayer structure of polyethylene and nylon, a method of mixing nylon with polyethylene and simultaneously extruding the same, and dispersing nylon in a discontinuous thin layer in the polyethylene layer,
Further, there is a method in which a multilayer structure is used and nylon is used for a barrier layer. However, these methods have a problem in barrier properties against gasoline blended with an oxygen-containing component. Also,
Even a method of treating a polyethylene monolayer with a sulfone or a fluorine is insufficient in barrier properties against gasoline blended with an oxygen-containing component. Accordingly, an object of the present invention is to obtain a multilayer structure having excellent gasoline barrier properties and impact resistance.

[0005]

The object of the present invention is to provide a polyketone (a) layer comprising a carbon monoxide-ethylene copolymer, an ethylene-vinyl alcohol copolymer (hereinafter abbreviated as EVOH) (b) layer, , A polyolefin (c) layer, or a multilayer structure having (b) and (c) layers.

BEST MODE FOR CARRYING OUT THE INVENTION

[0006] By providing the fuel container and the fuel pipe having the above-mentioned multilayer structure, it is possible to impart characteristics excellent in barrier properties against gasoline and gas holes and also excellent in impact resistance. It not only fits, but also greatly enhances safety during actual use. Here, the barrier property means the barrier property of gasoline or fuel such as gasoline blended with methanol, MTBE (methyl tert-butyl ether), or the like.

In the present invention, the polyketone (a) is
-Carbon oxide-ethylene based copolymer, carbon monoxide-
Ethylene copolymers include those obtained by copolymerizing carbon monoxide and ethylene, or those obtained by copolymerizing carbon monoxide and ethylene as main components with unsaturated compounds other than ethylene. A representative example is given. Here, examples of the unsaturated compound other than ethylene include an olefin having 3 to 12 carbon atoms, a diene having 4 to 12 carbon atoms, a vinyl ester, and an aliphatic unsaturated carboxylic acid ester. Examples of the copolymer include a random copolymer and an alternating copolymer, and an alternating copolymer having a high carbonyl group content is preferable from the viewpoint of moldability.

The olefin having 3 to 12 carbon atoms includes propylene, butene-1, isobutene, pentene-
Examples thereof include 1,4-methylpentene-1, hexene-1, octene-1, dodecene-1, and styrene, and a combination system with propylene and an olefin having 4 to 8 carbon atoms is preferable. As the diene having 4 to 12 carbon atoms, butadiene, isoprene, 1,5-hexadiene, 1,7
-Octadiene, 1,9-decadiene and the like. Examples of vinyl esters include vinyl acetate, vinyl propionate, and vinyl pivalate. In addition, as the aliphatic unsaturated carboxylic acid, its salt and its ester, acrylic acid, methacrylic acid, maleic anhydride, maleic acid, itaconic acid, acrylic acid ester, methacrylic acid ester, maleic acid monoester,
Maleic acid diester, fumaric acid monoester, fumaric acid diester, itaconic acid monoester, itaconic acid diester (these esters include methyl ester,
Examples thereof include an alkyl ester such as an ethyl ester), an acrylate, a maleate, and an itaconate (these salts include a monovalent or divalent metal salt).

As a method for producing the polyketone, known methods, for example, US Pat. No. 2,495,286, JP-A-53-128690, and JP-A-59-197427
JP-A-61-91226, JP-A-62-2324
No. 34, JP-A-62-53332, JP-A-63-30
No. 25, JP-A-63-105031, JP-A-63-1
No. 54737, JP-A-1-149829, JP-A-1-149829
No. 2013333, JP-A-2-67319 and the like, but are not particularly limited thereto.

The melt index (MI) of the polyketone used in the present invention is preferably 0.01 to 50 g / 10 min (at 230 ° C. under a load of 2160 g), and most preferably 0.1 to 1 g.
0 g / 10 minutes. When the MI is in the above range, the fluidity of the resin is excellent, and the moldability is also excellent.

In the present invention, EVOH (b) is a saponified ethylene-vinyl ester copolymer, and preferably has an ethylene content of 20 to 80 mol%, more preferably 2 to 80 mol%.
The saponification degree of the vinyl ester component is preferably 80% or more, and more preferably 85% or more. If the ethylene content is less than 20 mol%, melt moldability is poor, and barrier properties and thermal stability are poor. As a vinyl ester, vinyl acetate is mentioned as a typical example, but other fatty acid vinyl esters (vinyl propionate, vinyl pivalate, etc.) can also be used. Also,
A vinylsilane compound 0.0 as a copolymer component in EVOH
When 002-0.2 mol% is contained, the consistency of the melt viscosity with the base resin at the time of co-extrusion is improved, and not only can a homogeneous co-extruded multilayer film be produced, but also EVO can be produced.
The dispersibility when H is used for blending is improved, which is effective in improving moldability and the like. Here, examples of the vinylsilane-based compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (β-methoxy-ethoxy) silane, and γ-methacryloxypropylmethoxysilane. Among them, vinyltrimethoxysilane and vinyltriethoxysilane are preferably used. Furthermore, as long as the object of the present invention is not inhibited,
Other comonomers [e.g., propylene, butylene, unsaturated carboxylic acids or esters thereof (meth) acrylic acid,
(Meth) acrylate methyl, ethyl), etc.
Vinyl pyrrolidone (such as N-vinyl pyrrolidone) can also be blended. Also, the EVOH used in the present invention
Suitable melt index (MI) (230 ° C., 21
The value measured under a load of 60 g is 0.1 to 50 g / 10
Minute. , Optimally between 0.5 and 20 g / 10 min. In the present invention, it may be more preferable to use one or more EVOHs having different ethylene contents and / or saponification degrees in a blended state.

In the present invention, the polyketone (a)
By having a multilayer structure having both the layer and the EVOH (b) layer, the layer has both excellent impact resistance and barrier properties.

The polyolefin in the present invention includes:
Polyethylene (high density, medium density, low density, linear low density) polypropylene, ethylene-α-olefin (propylene, butylene, etc.) copolymer, ethylene-vinyl acetate copolymer, polybutene, etc. Among them, high-density polyethylene is most suitable. Here, the high-density polyethylene (c) is, for example, one obtained by using a Ziegler catalyst under a high or medium pressure and having a density of 0.941 to 0.
965 g / cm ³ , preferably 0.945 to 0.96 g / cm ³
cm ³ . In the present invention, a preferable melt index (MI) of the high-density polyethylene is (23)
0 ° C., measured under a load of 2160 g) is 0.009
1.0 g / 10 min, preferably 0.01 to 0.6 g / 1
0 minutes.

In the present invention, the polyketone (a)
By forming a multilayer structure having both the layer and the above-mentioned polyolefin, in particular, the high-density polyethylene (c) layer, it is possible to obtain a low-cost multilayer structure having better impact resistance and barrier properties.

In the present invention, the polyketone (a)
In addition to the layer and the EVOH (b) layer, a multilayer structure having a polyolefin layer, particularly a high-density polyethylene (c) layer, has a high level of impact resistance and barrier properties, and is low in cost. Can be obtained.

In the multilayer structure of the present invention, the polyketone (a) layer and the EVOH (b) layer, the EVOH (b) layer and the polyolefin (c) layer, and further the polyketone (a) layer An adhesive layer can be provided between the polymer and the polyolefin (c) layer, if necessary. The adhesive resin used for the adhesive layer is not particularly limited, but may be a polyurethane-based or polyester-based one-pack or two-pack curable adhesive, an unsaturated carboxylic acid or an anhydride thereof (maleic anhydride). Acid etc.) with an olefin polymer or copolymer [polyethylene @ low density polyethylene (LDP)
E), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (SLDPE)}, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate (methyl ester or ethyl ester) copolymer
What is grafted to is preferably used. By providing such an adhesive layer, it is possible to obtain a multilayer structure excellent in interlayer adhesiveness and excellent in barrier properties and impact resistance, which is the object of the present invention.

In the present invention, the recovered scrap can be mixed with the virgin polyketone (a) or the polyolefin (c) as required. Examples of the mixing method include a dry blending method and a melt kneading method. However, if the ratio of the scraps recovered to the virgin pellets exceeds 50%, problems may occur in terms of thermal stability and impact resistance. Here, as the scrap collected product, a molding loss portion generated when manufacturing a molded product such as a hollow container, a tubular container, and a tubular body, and a crushed product of the scrap collected product after being used by general consumers, and the like. is there.

In the present invention, a scrap collected layer can be provided as needed. Here, as the scrap recovered material, as described above, a hollow container, a tubular container, and a molding loss portion generated when manufacturing a molded product such as a tubular body, and a scrap recovered product after being used by a general consumer. There are pulverized materials.

The polyketone (a) layer of the present invention, EVOH
When the (b) layer, the polyolefin (c) layer, the adhesive (d) layer, and the scrap recovered material (r) layer are used, a multilayer structure having the following layer configuration is a typical example. The scrap recovery layer (r) here can be a single layer or can be mixed into the polyketone (a) and polyolefin (c) layers.

Two layers a / b, a / c Three layers a / d / b, a / d / c, Four layers a / r / d / b, r / a / d / b, a / r / d / c, r / a / d / c, 5 layers a / d / b / d / c, a / d / c / d / b, b / d / a / d / c, b / d / c / d / a, c / d / b / d / a, c / d / a / d / b, a / d / c / d / a, c / d / a / d / c, 6 layers a / r / d / b / d / c, a / r / d / c / d / b, b / r / d / a / d / c, b / r / d / c / d / a, c / r / d / b / d / a, c / r / d / a / d / b, a / r / d / c / d / a, c / r / d / a / d / c, a / d / b / d / r / c, a / d / c / d / r / b, b / d / a / d / r / c, b / d / c / d / r / a, c / d / b / d / r / a, c / d / a / d / r / b, a / d / c / d / r / a, c / d / a / d / r / c, 7 layers a / r / d / b / d / r / c, c / r / a / b / d / r / c, c / r / d / b / a / r / c, c / r / a / b / a / r / c, c / r / d / b / d / r / a, a / r / d / b / d / r / a, c / r / d / a / d / r / c However, the layer structure is not limited to the above. Among these, the preferred 3 to 7 layers are shown as preferred layer configurations.

Although the thickness of each of these layers is not particularly limited, when the multilayer structure of the present invention is used for a fuel container or a fuel pipe, the preferred range of the thickness of each layer is from the polyketone (a) layer 500 to 10,000μ, preferably 50
0-6000μ, high density polyethylene (c) layer 1000
10,000 to 10,000 μm, preferably 1000 to 6000 μm, adhesive (d) layer 20 to 1000 μm, preferably 50 to 300 μm
μ, EVOH (b) 30-1000 μ, preferably 60-
800μ. The total thickness is 530-10030
μ, preferably 1500 to 7000 μ. These thicknesses refer to the thickness of the body of the fuel tank or the body of the fuel pipe.

In the present invention, the following additives can be blended with the components (a), (b), (c) and (d). Examples of such additives include antioxidants, plasticizers, heat stabilizers, UV absorbers,
Examples include an antistatic agent, a lubricant, a coloring agent, and a filler. Specific examples of the additives include the following. Antioxidant: 2,5-di-t-butylhydroquinine,
2,6-di-t-butyl-p-cresol, 4,4′-
Thiobis- (6-t-butylphenol), 2,2′-
Methylene-bis- (4-methyl-6-t-butylphenol), octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate,
4,4'-thiobis- (6-t-butylphenol)
etc. UV absorber: ethylene-2-cyano-3,3'-diphenylacrylate, 2- (2'-hydroxy-5'-
Methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl)
Benzotriazole, 2- (2'-hydroxy-3'-
(t-butyl-5'-methylphenyl) 5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-oxybenzobenzophenone and the like. Plasticizer: dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester and the like. Antistatic agents: pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins,
Polyethylene oxide, carbowax, etc. Lubricants: ethylene bis stearamide, butyl stearate and the like. Colorants: carbon black, phthalocyanine, quinacridone, indoline, azo pigments, red iron, etc. Filler: glass fiber, asbestos, ballastonite, calcium silicate, etc. In addition, EVOH (a) has
One or more of a hydrotalcite-based compound, a hindered phenol-based, a hindered amine-based heat stabilizer, and a metal salt of a higher aliphatic carboxylic acid (eg, calcium stearate, magnesium, etc.) may be used in an amount of from 0.01 to 0.01%.
It is preferable to add 1% by weight.

The method for obtaining the container and the pipe having a multilayer structure of the present invention is not particularly limited. For example, molding methods used in the field of general polyolefins, for example, T-die molding, inflation Molding, blow molding, stamping molding, blow molding, stretch blow molding, biaxial stretch blow molding, injection molding, and the like. In particular, co-extrusion molding and co-injection molding are preferable. Extrusion coating molding, dry laminate molding Can also be adopted. Of these, co-extrusion sheet molding, co-extrusion pipe molding, co-extrusion molding, and co-extrusion blow molding are particularly preferred, and co-extrusion blow molding is particularly preferred.

By using the thus obtained container and pipe as a fuel container and a fuel pipe, excellent barrier properties and impact resistance to gasoline and other fuels can be obtained, as shown in Examples described later. Granted.

In the present invention, a fuel container is a fuel container mounted on an automobile, motorcycle, ship, aircraft, generator, industrial or agricultural equipment, or a portable container for refueling these fuel containers. Further, it means a container for storing fuel used for these operations.
Also, the fuel transfer pipe is the fuel container mounted above,
Alternatively, it means a pipe attached to a portable container for replenishing fuel to these fuel containers, a pipe attached to a container for storing the fuel used for these operations, or a pipe independent of itself. I do. Gasoline blended with gasoline, methanol and / or MTBE is a typical example of the fuel.
Other heavy oils, petroleum, petroleum and the like are also exemplified. Among them, the fuel container or pipe of the present invention is particularly effective for gasoline blended with methanol and / or MTBE.

[0026]

EXAMPLES Examples and comparative examples are shown below. Example 1 In a 100 liter autoclave, methanol 20 was added.
Liters, 4 mmol of palladium acetate, 6 mmol of 1,3-di (diphenylphosphane) propane and 80 mmol of p-toluenesulfonic acid, which were flushed with carbon monoxide and treated with 35 bar of carbon monoxide and 18 bar.
The autoclave was filled and reacted with ethylene at a pressure of bar to obtain a polyketone (hereinafter abbreviated as PK) composed of an ethylene-carbon monoxide alternating copolymer. 1000 ppm of calcium hydroxyapatite was added to the obtained polyketone, and pelletized by an extruder to obtain a weight average molecular weight of 18
0000, number average molecular weight 63,000, MI = 6.1 g /
Pellets were obtained for 10 minutes (230 ° C., 2160 g load). These pellets, EVOH ｛ethylene content 27 mol%, saponification degree 99.6%, melt index 6.0 g
/ 10 min, 230 ° C., 2160 g load｝, high density polyethylene (HDPE) ｛MI = 0.1 g / 10 min (23
0 ° C., 2160 g load), density 0.96 g / cm ³ , “HZ8200B” manufactured by Mitsui Petrochemical Co., Ltd., and a maleic anhydride-modified polyethylene {MI =
2.0 g / 10 min (230 ° C., 2160 g load), using a blow molding machine (manufactured by Suzuki Seisakusho, TB-ST-6P) using Mitsui Petrochemical's “Admer GT4”｝
K / AD / EVOH / AD / PK = 1163/50/7
5/50 / 1163μ) 500cc (body average thickness 2)
500 μ) A multilayer container was obtained.

In the container obtained, a mixture of model gasoline / toluene (42.5% by weight): isooctane (42.5% by weight): methanol (15% by weight), capacity: 300
Then, the mixture was left in an atmosphere of 40 ° C. and 65% RH, and the weight loss after 4 days was determined. (N = 10)

Next, the same container as described above was filled with water and dropped on concrete, and the drop height at which the multilayer container was destroyed (water inside the container leaked) was determined. (20 ° C-65%
RH) The breaking height was determined by JI using the test result of n = 30.
The 50% breaking height was determined by using the calculation method shown in the S test method ("8. Calculation" of K7211).

Examples 2 and 3 and Comparative Examples 1 and 2 A multilayer container was obtained under the same conditions as in Example 1 except that the layer structure of the multilayer container was changed to the thickness shown in Table 1. Barrier and bottle drop tests were performed.

[0030]

[Table 1]

[0031]

The fuel container and the fuel pipe obtained by using the multilayer structure of the present invention have excellent impact resistance and barrier properties against fuel such as gasoline blended with an oxygen-containing component such as methanol.

Claims (5)

[Claims] 1. A multilayer structure having a polyketone (a) layer composed of a carbon monoxide-ethylene copolymer and an ethylene-vinyl alcohol copolymer (b) layer. 2. A multilayer structure having a polyketone (a) layer and a polyolefin (c) layer comprising a carbon monoxide-ethylene copolymer. 3. A multilayer structure having a polyketone (a) layer composed of a carbon monoxide-ethylene copolymer, an ethylene-vinyl alcohol copolymer (b) layer and a polyolefin (c) layer. 4. The multilayer structure according to claim 2, wherein the polyolefin (c) is a high-density polyethylene (c). 5. A fuel container or a pipe comprising the multilayer structure according to claim 1.