JPH11207840A - Multilayer tubular body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miltilayer tubular body excellent in solvent resistance, chemical resistance, gas barrier properties, and interlayer adhesive properties. SOLUTION: An inner layer of a fluororesin layer and an outer layer of an olefin resin layer are laminated through an adhesive layer containing a copolymer A as a main component. The copolymer A is obtained by the copolymerization of a radical-polymerizable olefin resin (c) obtained by the reaction between an olefin resin (a) having at least one functional group in the molecule and a radical-polymerizable monomer (b) having a functional group reactive with the functional group of the resin (a) and an alkyl acrylate or an alkyl methacylate (wherein, 1-8C alkyl) (d).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer tubular body having excellent solvent resistance, chemical resistance and gas barrier properties and excellent interlayer adhesion, and more particularly to the transport of automotive fuel, the transport of various chemicals, and the like. The present invention relates to a multilayer tubular body suitably used for medical use and the like.

[0002]

2. Description of the Related Art Conventionally, for example, a pipe made of polyamide resin has been used as a gasoline transfer pipe in an automobile body in terms of gasoline resistance and gas barrier properties.
Polyamide-based resins have problems such as swelling and hydrolysis with respect to alcohol-blended gasoline, and pipes that solve this problem include, for example, a polyamide-based resin layer and a fluorine-based resin layer. Are laminated via an adhesive layer made of a mixture of polyurethane and a fluororesin (see Japanese Patent Application Laid-Open No. 8-511326).

On the other hand, as a buried pipe in a gas station, for example, a fluorine-based resin having excellent solvent resistance, chemical resistance, gas barrier property and the like is used, and an inner layer of a fluorine-based resin and an outer layer of an olefin-based resin are made of ethylene-based resin. There has been proposed a multilayer tube laminated through an adhesive layer made of an ethyl acrylate copolymer or a mixture of an ionomer resin and an ethylene-ethyl acrylate-maleic anhydride copolymer (Japanese Patent Application Laid-Open No. 9-123667). Gazette).

However, in the former example using a polyamide resin, it cannot be said that the solvent resistance is still sufficient. In the latter example using a fluorine resin, the inner layer of the fluorine resin and the olefin resin are not used. Had a problem with the adhesive strength to the outer layer.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art. Therefore, the present invention has excellent solvent resistance, chemical resistance, and gas barrier properties, as well as excellent interlayer adhesion. An object is to provide an excellent multilayer tubular body.

[0006]

According to the present invention, a fluorine-based resin layer as an inner layer and an olefin-based resin layer as an outer layer are interposed via an adhesive layer containing the following copolymer (A) as a main component. The gist is a multilayer tubular body that is laminated. (A) a radical obtained by reacting an olefin resin (a) having at least one functional group in one molecule with a radical polymerizable monomer (b) having a functional group reactive with the functional group An alkyl acrylate or an alkyl methacrylate (provided that the alkyl group has 1 to 8 carbon atoms) is added to the polymerizable olefin resin (c).
Acrylic graft copolymer obtained by radical copolymerization of (d)

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the fluorine resin constituting the inner layer in the multilayer tubular body of the present invention include polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene-tetrafluoroethylene copolymer, ethylene -Chlorotrifluoroethylene copolymer,
Examples include a tetrafluoroethylene-hexafluoropropylene copolymer, a tetrafluoroethylene-propylene copolymer, and a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer. Among them, polyvinyl fluoride and polyvinylidene fluoride are preferable.

The olefin resin constituting the outer layer of the multilayer tubular body of the present invention includes, for example, α, having about 2 to 8 carbon atoms, of ethylene, propylene, butene-1, pentene-1, hexene-1, and octene-1. Olefin homopolymers, their α-olefins, ethylene, propylene, butene-1, 3-methylbutene-1, pentene
Other α-olefins having about 2 to 20 carbon atoms, such as 1,4-methylpentene-1, hexene-1, octene-1, decene-1, and the like, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic acid Block, random, or graft copolymers with vinyl compounds such as esters, methacrylates, and styrene, etc., specifically, for example, ethylene alone (branched or linear) such as low / medium / high density polyethylene Polymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-3-methylbutene-1 copolymer, ethylene-4-methylpentene-1
Copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-ethyl acrylate Ethylene-based resins such as copolymers, propylene homopolymers, propylene-ethylene copolymers, propylene-based resins such as propylene-ethylene-butene-1 copolymers, and butene-
Butene-1 resin such as 1 homopolymer, butene-1-ethylene copolymer and butene-1-propylene copolymer. Among them, ethylene resins such as ethylene homopolymer and ethylene-propylene copolymer are preferable.

In the multilayer tubular body of the present invention, the olefin having at least one functional group per molecule in the component (A) constituting the adhesive layer between the inner layer of the fluororesin and the outer layer of the olefin resin. As the resin (a), an olefin resin is modified by an ordinary method with an unsaturated compound having a desired functional group, or an α-olefin and an ethylenically unsaturated compound having a desired functional group are used. Is copolymerized by a conventional method.

Here, as the precursor olefin resin in the former modified product, the same olefin resin as mentioned above as the olefin resin constituting the outer layer can be used. Examples of the α-olefin in the latter copolymer include the same ones as described in the description of the olefin resin constituting the outer layer.

Examples of the functional group of the olefin resin (a) include a carboxylic acid or its anhydride group, an epoxy group, a hydroxyl group, an isocyanate group, an oxazoline group and a carbodiimide group.

Examples of the unsaturated compound having a carboxylic acid or its anhydride group include, for example, (meth) acrylic acid (where (meth) acrylic acid means acrylic acid and methacrylic acid). ], Crotonic acid, fumaric acid, maleic acid and its anhydride, itaconic acid and its anhydride, citraconic acid and its anhydride, and the like.

Examples of unsaturated compounds having an epoxy group include glycidyl (meth) acrylate,
Unsaturated carboxylic acid glycidyl esters such as 4-epoxycyclohexenylmethyl (meth) acrylate, mono and diglycidyl esters of maleic acid, mono and diglycidyl esters of itaconic acid, mono and diglycidyl esters of allyl succinic acid, p-styrene carboxylic acid Glycidyl esters of acids, allyl glycidyl ether, 2-methylallyl glycidyl ether, glycidyl ethers such as styrene-p-glycidyl ether, epoxy styrenes such as p-glycidyl styrene, 3,4-epoxy-butene-1,3,4- Epoxy olefins such as epoxy-3-methyl-butene-1 and vinylcyclohexene monoxide.

Examples of the unsaturated compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Hydroxyalkyl (meth) acrylates such as -hydroxybutyl (meth) acrylate; N-methylol (meth) acrylamide; alkenyl alcohols such as 2-propen-1-ol; alkynyl alcohols such as 2-propyn-1-ol; hydroxyvinyl ether , 2-
And hydroxyethyl acrylate-6-hexanolide addition polymer.

Examples of the unsaturated compound having an isocyanate group include 2-isocyanatoethyl (meth) acrylate, (meth) acryloyl isocyanate, vinyl isocyanate, and isopropenyl isocyanate.

The unsaturated compounds having an oxazoline group include, for example, 2-vinyl-2-oxazoline,
-Methyl-2-vinyl-2-oxazoline, 4,4-dimethyl-2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 4,4-dimethyl-2-isopropenyl-2-oxazoline and the like. No.

The unsaturated compounds having a carbodiimide group include, for example, methylvinylcarbodiimide, isopropenylmethylcarbodiimide and the like.

Among these, as the olefin resin (a) having a functional group in the present invention, specifically, for example, as modified products, (anhydrous) maleic acid-modified polyethylene, (anhydrous) maleic acid-modified ethylene -Propylene copolymer, (anhydride) maleic acid-modified ethylene-vinyl acetate copolymer, (anhydride) maleic acid-modified polypropylene,
(Anhydrous) maleic acid-modified propylene-ethylene copolymer, glycidyl (meth) acrylate-modified polyethylene, glycidyl (meth) acrylate-modified ethylene-propylene copolymer, glycidyl (meth) acrylate-modified ethylene-vinyl acetate copolymer, 2- Hydroxyethyl (meth) acrylate-modified polyethylene, 2-hydroxyethyl (meth) acrylate-modified ethylene-propylene copolymer, 2-hydroxyethyl (meth) acrylate-modified ethylene-vinyl acetate copolymer, etc. , An ethylene- (meth) acrylic acid copolymer,
Ethylene-2-hydroxyethyl (meth) acrylate copolymer, ethylene-glycidyl (meth) acrylate copolymer, ethylene-polyethylene glycol mono (meth) acrylate copolymer, ethylene-vinyl acetate-
(Meth) acrylic acid copolymer, ethylene-ethyl (meth) acrylate- (anhydride) maleic acid copolymer, ethylene-vinyl acetate- (anhydride) maleic acid copolymer, ethylene-vinyl acetate-2-hydroxyethyl ( (Meth) acrylate copolymer, ethylene-vinyl acetate-glycidyl (meth) acrylate copolymer, ethylene-vinyl acetate-polyethylene glycol mono (meth) acrylate copolymer, partially saponified ethylene-vinyl acetate copolymer, and the like. No. Among them, modified products such as (anhydrous) maleic acid-modified polyethylene, glycidyl (meth) acrylate-modified polyethylene, and ethylene- (meth) acrylic acid copolymer, ethylene-glycidyl (meth) acrylate copolymer, ethylene-ethyl (Meth) acrylate-
(Anhydrous) maleic acid copolymer, ethylene-vinyl acetate-
Copolymers such as glycidyl (meth) acrylate copolymer are preferred.

A radical polymerizable monomer having a functional group reactive with the olefin resin (a) having the functional group in the component (A) constituting the adhesive layer. Examples of the functional group of (b) include a carboxylic acid or an anhydride group thereof, a hydroxyl group, an epoxy group, an isocyanate group, an oxazoline group, and a carbodiimide group, and a radical polymerizable monomer having such a functional group. Examples of (b) include the same unsaturated compounds as those described above in the olefin-based resin (a) having a functional group.

As the combination of the functional group of the olefin resin (a) and the functional group of the radical polymerizable monomer (b), the former functional group is a carboxylic acid or an anhydride thereof and the latter is a functional group. Is a hydroxyl group, the former functional group is an epoxy group, and the latter functional group is a carboxylic acid or its anhydride group.

In the present invention, the radically polymerizable olefin resin (c) in the component (A) constituting the adhesive layer is obtained by adding the radical polymerizable monomer (b) to the olefin resin (a). Preferably, 0.001 to 10 equivalents of the functional group of (b) with respect to 1 equivalent of the functional group of (a)
Particularly preferably, 0.01 to 5 equivalents, more preferably, 0.1 to 5 equivalents.
It is obtained by adding 0.5 to 1 equivalent. When the amount of the functional group of the radical polymerizable monomer (b) is less than the above range with respect to the amount of the functional group of the olefin resin (a), the obtained radical polymerizable olefin resin (c) and (meth) acryl described later As an acrylic graft copolymer (A) component obtained by copolymerizing an acid alkyl ester (d),
It is not preferable because the amount of the homopolymer of the alkyl (meth) acrylate (d) is increased. If the amount of the functional group of the radical polymerizable monomer (b) exceeds the above range, the obtained radical polymerizable olefin resin (c) is copolymerized with a (meth) acrylic acid alkyl ester (d) described later. The resulting acrylic graft copolymer (A) produces a gel as a component.

In the present invention, the copolymer of the component (A) constituting the adhesive layer is obtained by radically copolymerizing the radically polymerizable olefin resin (c) with the alkyl (meth) acrylate (d). It is obtained. Here, the alkyl (meth) acrylate (d) is an ester with an aliphatic alcohol having 1 to 8 carbon atoms in the alkyl group, specifically, for example, methyl (meth) acrylate, ethyl (meth) ) Acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth)
Acrylate and the like. Among them, methyl methacrylate is preferred.

(Meth) used for radical copolymerization
The amount of the acrylic acid alkyl ester (d) is based on 100 parts by weight of the radically polymerizable olefin resin (a).
Preferably 10 to 500 parts by weight, particularly preferably 20 to 500 parts by weight.
It is 300 parts by weight, more preferably 50 to 300 parts by weight. If the amount is less than 10 parts by weight, the adhesiveness with the inner fluorine resin layer tends to be inferior, and if it exceeds 500 parts by weight, the adhesiveness with the outer olefin resin layer tends to be inferior.

In the present invention, together with the alkyl (meth) acrylate (d), other copolymerizable monomers are used in a total amount of not more than 40% by weight together with (d). Is also good. Examples of such other copolymerizable monomers include, for example, hydroxyalkyl such as (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. Dialkylaminoalkyl (meth) acrylates such as (meth) acrylate, diethylaminomethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylamide, (meth) acrylonitrile, trifluoroethyl (meth) Acrylate,
Fluoroalkyl (meth) acrylates such as tetrafluoropropyl (meth) acrylate, hexafluorobutyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluorononyl (meth) acrylate, and heptadecafluorodecyl (meth) acrylate; Fluorine-containing unsaturated monomers such as trifluoroethylene, tetrafluoroethylene, vinyl fluoride, and vinylidene fluoride; vinyl ethers such as vinyl acetate, vinyl chloride, ethyl vinyl ether, butyl vinyl ether and hexyl vinyl ether; vinyl ketone; styrene;
Aromatic vinyl such as -methylstyrene, and α-olefins such as ethylene, propylene and butene-1.

To radically copolymerize the alkyl (meth) acrylate (d) with the radically polymerizable olefin resin (c), toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, cellosolve acetate and the like can be used. An organic solvent is used as a reaction solvent, and as a polymerization catalyst, peroxides such as benzoyl peroxide, di-t-butyl peroxide and cumene hydroperoxide, and azo compounds such as azobisisobutyronitrile are used as (meth) acrylic acid. It is preferably used in an amount of 0.1 to 10% by weight, particularly preferably 1 to 5% by weight, based on the alkyl ester (d).
What is necessary is just to heat and react for hours.

The adhesive layer in the multilayer tubular body of the present invention comprises:
The acrylic graft copolymer (A) may be composed solely, but the olefin resin (B) and / or the acrylic resin (C) are added to the component (A) with respect to 100 parts by weight of the component (A). It is preferable to mix the components (B) and (C) in a total amount of 170 parts by weight or less in view of the melt fluidity of the adhesive layer at the time of forming the multilayer tubular body. If the total amount of both exceeds 170 parts by weight, the adhesiveness to the inner fluororesin layer tends to be poor. Here, the compounding amount of the olefin-based resin (B) is preferably 1 to 150 parts by weight with respect to 100 parts by weight of the component (A), and is preferably 5 to 150 parts by weight.
Particularly preferred is 100 parts by weight. Further, the compounding amount of the acrylic resin (C) is preferably 1 to 150 parts by weight, particularly preferably 5 to 50 parts by weight. Furthermore, the total amount of the components (B) and (C) is particularly preferably 30 to 120 parts by weight,
More preferably, it is from about 110 parts by weight.

The olefin resin as the component (B) may be the same as the olefin resin constituting the outer layer. Examples of the acrylic resin as the component (C) include, for example, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth).
Acrylate, cyclohexyl (meth) acrylate,
Glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N
-Homopolymers such as methylol (meth) acrylamide, (meth) acrylonitrile, or copolymers thereof;
Specifically, for example, polymethyl (meth) acrylate, methyl methacrylate-methyl acrylate copolymer, methyl methacrylate-ethyl acrylate copolymer, methyl methacrylate-ethyl methacrylate copolymer, polyacrylonitrile, acrylonitrile-methyl methacrylate copolymer And the like. Among them, polymethyl (meth) acrylate is preferable. The molecular weight of these acrylic resins (C) is preferably 50,000 to 250,000 in terms of weight-average molecular weight (in terms of polystyrene).
It is particularly preferable that the number is 150,000.

In the present invention, when the adhesive layer is composed of the component (A) and the component (B) and / or the component (C), these two or three components may be used in view of mutual dispersibility.
The components are previously dry-blended with a mixing device such as a V blender, a ribbon blender, a super mixer, or the like, and then kneaded with a single-screw or multi-screw extruder, a roll, a Banbury mixer, or the like, at a temperature of about 120 to 280 ° C. and a screw rotation speed of 60. It is preferable to melt and knead at about 350 rpm to form pellets for use.

The multilayer tubular body of the present invention is formed by laminating the fluorine-based resin as an inner layer and the olefin-based resin as an outer layer, both of which are interposed via the adhesive layer. Examples of the molding method include a method of sequentially extruding and laminating an adhesive layer and then an olefin resin layer on a preformed fluororesin tubular body, and a method of forming an adhesive on a preformed fluororesin tubular body. A layer and an olefin resin layer by coextrusion lamination, a method in which a fluorinated resin layer and an adhesive layer are coextruded and formed into a tubular body by extrusion lamination with an olefin resin layer, or A conventionally known method such as a method of forming a tubular body by co-extrusion of an adhesive layer and an olefin-based resin layer may be used. Among them, a method by coextrusion molding is preferable. In addition, at the time of molding, each layer, if necessary, such as an antioxidant, a light stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent, a flame retardant, a colorant, a filler,
A commonly used additive may be blended.

The thickness of each layer of the multilayer tubular body of the present invention is preferably 0.005 to 5 mm, more preferably 0.05 to 2 mm for the inner fluorine resin layer, and preferably 0.1 to 5 mm for the outer olefin resin layer. 01-5 mm, particularly preferably 0.1-3 mm, the adhesive layer is preferably 1-1000 μm
m, particularly preferably 10 to 500 μm.

[0031]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

Production Example 1 of Acrylic Graft Copolymer (A) 160 kg of toluene, ethylene-glycidyl as olefin resin (a) were placed in a reactor equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer. Methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., Bond First 2
c)) After charging 40 kg and hydroquinone monomethyl ether (104 g) and raising the temperature of the system to 110 ° C. under an air stream to form a solution, 0.61 kg of acrylic acid as a radical polymerizable monomer (b) and tetramethyl 1.044 kg of ammonium bromide was added and reacted at the same temperature for 8 hours. Oxidation measurement was performed on the obtained radically polymerizable olefin resin (c) solution. As a result, 42% of the epoxy groups of the ethylene-glycidyl methacrylate copolymer (a) were esterified with acrylic acid (b). . Subsequently, after the inside of the system was replaced with nitrogen, the temperature was lowered to 80 ° C.
240 kg of toluene, 60 kg of methyl acrylate as alkyl (meth) acrylate (d), and 360 g of azobisisobutyronitrile were added, and a reaction was carried out at the same temperature for 2 hours. Further, the operation of adding 360 g of azobisisobutyronitrile and reacting for 2 hours was repeated four times. 1500 kg of methyl alcohol
Then, a polymerization product was precipitated, and then separated and dried to obtain an acrylic graft copolymer (A-1).

Production Example 2 In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 160 kg of toluene and an ethylene-maleic anhydride-ethyl acrylate copolymer (Sumitomo) as an olefin resin (a) were used. 40 kg of “Bondane LX-4110” manufactured by Chemical Industry Co., Ltd.) and 104 g of hydroquinone monomethyl ether were charged, and the air flow was reduced to 1 in the system.
After raising the temperature to 10 ° C. to form a solution, 2-hydroxyethyl acrylate as radical polymerizable monomer (b)
423 kg and dimethylbenzamine 1.044 k
g was added and reacted at the same temperature for 8 hours. As a result of performing an infrared absorption spectrum analysis on the obtained radically polymerizable olefin-based resin (c), 32% of the carboxylic acid groups of the ethylene-maleic anhydride-ethyl acrylate copolymer (a) were 2-hydroxyethyl. Acrylate (b)
Had been esterified. Subsequently, after the inside of the system was replaced with nitrogen, the temperature was lowered to 80 ° C., and 240 kg of toluene, 60 kg of methyl acrylate as alkyl (meth) acrylate (d), and azobisisobutyronitrile 36
0 g was added, and the reaction was carried out at the same temperature for 2 hours. Further, the operation of adding 360 g of azobisisobutyronitrile and reacting for 2 hours was repeated four times. This reaction solution was added to 1500 kg of methyl alcohol to precipitate a polymerization product, which was then separated and dried to obtain an acrylic graft copolymer (A-2).

Example 1 The acrylic graft copolymer (A-
1) 10 kg, low-density polyethylene as olefin resin (B) (manufactured by Mitsubishi Chemical Corporation, "Mitsubishi Polyethylene LF48
0M "), and 1 kg of polymethyl methacrylate (" Kuraray Co., Ltd., Parapet G ") as an acrylic resin (C).
F1000 "and 1 kg of a weight average molecular weight of 120,000) were mixed for 2 minutes by a super mixer (manufactured by Kawata Corporation), and then a resin temperature of 240 ° C and a screw rotation speed were measured by a twin-screw extruder (manufactured by Ikegai Iron Works," PCM30Φ "). Melt kneading at 250 rpm to form a composition, extruding from a die into strands,
It was cut into pellets. The obtained composition pellets are melt-kneaded at 190 ° C. with a 30 mmΦ extruder, while polyvinylidene fluoride (“KF1000”, manufactured by Kureha Chemical Co., Ltd.) as an inner layer fluorine resin is melt-kneaded at 220 ° C. with a 40 mmΦ extruder. And high-density polyethylene (Mitsubishi Chemical's
"Mitsubishi Polyethylene HB330") with a 50mmΦ extruder
The mixture is melt-kneaded at 10 ° C., guided to a tube forming apparatus provided with an annular die having an outer diameter of 10 mm, and co-extruded into a tube to form an outer diameter of 10 mm, an inner layer thickness of 0.3 mm, and an adhesive layer thickness of 100 mm.
A multilayer tubular body having a thickness of μm, an outer layer thickness of 0.6 mm, and an overall thickness of 1.0 mm was formed. The obtained multilayer tubular body was evaluated for adhesion, chemical resistance, and gas barrier properties between the layers by the following method, and the results are shown in Table 1.

With respect to a sample cut to a width of 2 cm from the adhesive multilayer tubular body, the 180-degree peel strength between the inner layer and the adhesive layer and between the outer layer and the adhesive layer was measured with an Instron type tensile tester. Chemical resistance A gasoline, methanol, and 2
Each of the weight% hydrochloric acid aqueous solutions was circulated and circulated at 40 ° C. for one week, and the abnormality in the inner layer was visually observed. The case where no abnormality was observed was evaluated as ○, and the case where abnormalities such as swelling, crack generation and discoloration were observed was evaluated as ×. Gas-barrier properties A 1-m-long tubular body was filled with 15% by weight methanol-mixed gasoline, sealed, and allowed to stand at 40 ° C. for 24 hours to calculate the permeation amount (g / m ² ) from the weight loss.

Example 2 A multilayer tubular body was produced in the same manner as in Example 1 except that the acrylic graft copolymer was changed to the copolymer (A-2) obtained in Production Example 2, and a multilayer tubular body was produced. The adhesiveness, chemical resistance, and gas barrier properties were evaluated, and the results are shown in Table 1.

Comparative Example 1 Polyamide 12 ("Grillamid 25", manufactured by Mitsubishi Engineering-Plastics Co., Ltd.) was melt-kneaded at 260 ° C. with a 50 mmφ extruder, and the outer diameter was 10 mm and the wall thickness was 1.0 mm.
Was extruded and the chemical resistance and gas barrier properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0038]

[Table 1]

[0039]

According to the present invention, solvent resistance, chemical resistance,
It is possible to provide a multilayer tubular body having excellent gas barrier properties and excellent interlayer adhesion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshie Yoshida 1 Tohocho, Yokkaichi-shi, Mie, Mitsubishi Chemical Corporation Yokkaichi Office

Claims (6)

[Claims] An olefin resin layer as an inner layer and an olefin resin layer as an outer layer are laminated via an adhesive layer containing the following copolymer (A) as a main component. Multi-layer tubular body. (A) a radical obtained by reacting an olefin resin (a) having at least one functional group in one molecule with a radical polymerizable monomer (b) having a functional group reactive with the functional group An alkyl acrylate or an alkyl methacrylate (provided that the alkyl group has 1 to 8 carbon atoms) is added to the polymerizable olefin resin (c).
Acrylic graft copolymer obtained by radical copolymerization of (d) 2. In the component (A) of the adhesive layer, the functional group of the olefin resin (a) is an epoxy group,
The multilayer tubular body according to claim 1, wherein the functional group of the radical polymerizable monomer (b) is a carboxylic acid or an anhydride thereof. 3. The multilayer tubular body according to claim 2, wherein the olefin resin (a) is an ethylene-glycidyl methacrylate copolymer and the radically polymerizable monomer (b) is acrylic acid. 4. In the component (A) of the adhesive layer, the functional group of the olefin resin (a) is a carboxylic acid or an anhydride thereof, and the functional group of the radical polymerizable monomer (b) is The multilayer tubular body according to claim 1, which is a hydroxyl group. 5. The multilayer tubular body according to claim 4, wherein the olefin resin (a) is an ethylene-maleic anhydride-ethyl acrylate copolymer, and the radically polymerizable monomer (b) is a hydroxyalkyl acrylate. . 6. The adhesive layer, wherein the component (A) comprises an olefin resin (B) and / or an acrylic resin (C),
The multilayer tubular body according to any one of claims 1 to 5, wherein the total amount of the components (B) and (C) is 170 parts by weight or less based on 100 parts by weight of the component (A).