JP4647453B2 - Transmission preventing member - Google Patents

Description

  The present invention relates to a permeation-preventing member and a multilayer container, and more particularly to a multilayer container and accessory parts suitable as a synthetic resin fuel tank for a vehicle.

  In recent years, multi-layer laminated structures such as multi-layer containers and multi-layer sheets using a barrier material such as saponified ethylene-vinyl acetate copolymer and polyamide resin as a barrier layer and polyolefin as the outermost layer have been used in various fields. For example, fuel tanks for automobiles are rapidly shifting from those made of metal to those of multilayer laminated structures made of synthetic resin from the viewpoints of weight reduction, large capacity, molding processability, rust prevention properties, etc. . Such a fuel tank made of synthetic resin is required to have fuel oil resistance, impact resistance, durable adhesion, and the like.

  Furthermore, in recent years, the required performance for fuel tanks has become stricter, and there is no peeling of each layer of the multilayer laminated structure over a long period of time. In the case of multilayer hollow molding, volatilization is suppressed, there is no fuel volatilization due to peeling of the pinch-off part, which is a die cutting part unique to hollow molding, and low temperature impact resistance is minimized to minimize damage to collisions etc. There is a need to keep it above a certain level.

  One method for producing a synthetic resin fuel tank is a synthetic resin hollow molding method. Synthetic resin hollow molding includes a method in which a parison, which is a cylindrical molten resin, is sandwiched between molds and air is blown into the mold to form the resin. This molding method has a feature that a hollow body can be easily molded. However, in order to sandwich and mold a resin with a mold, a welded portion called a pinch-off portion exists in the molded product, and this portion is The strength of the molded product is a weak point, and the shape of the pinch-off portion has been optimized to improve the strength.

  In order to prevent the contents of the synthetic resin hollow molded article from permeating the molded article, a multilayer hollow molded article including a layer having a permeation preventing performance of the contents is molded. For example, taking a fuel tank as an example, a tank body is constructed by laminating a fuel permeation prevention layer between an inner layer made of synthetic resin and an outer layer made of synthetic resin. A fuel tank is known, and this synthetic resin fuel tank is manufactured as a hollow container having a multilayer structure by a blown hollow molding method.

  This multi-layer hollow molded article also has a pinch-off part, and there is a problem that fuel such as gasoline permeates from the pinch-off part in the case of contents or a fuel tank. That is, in the pinch-off part, it is derived from the essential structure of the pinch-off part, but there is a part where the permeation preventive layer does not exist although it is very small.

  In order to prevent the transmission of the contents from the pinch-off part, for example, it is proposed to seal the pinch-off part including the part where the permeation preventive layer does not exist (blocking discontinuous area) with a leak-proof bead having a necessary blocking characteristic. However, although a certain degree of permeation preventing effect is obtained, a higher degree of permeation preventing effect is insufficient, and the strength improvement of the pinch-off part is also insufficient.

Japanese translation of PCT publication No. 2003-523876

  Conventionally, a synthetic resin fuel tank has been known in which a tank body is configured by laminating an inner layer made of synthetic resin and an outer layer made of synthetic resin via a fuel permeation preventive layer to enhance the fuel permeation preventive effect. . In such a synthetic resin fuel tank, a component mounting hole is formed in the tank body, and a synthetic resin accessory is welded so as to cover the component mounting hole on the outer surface of the tank body. In this case, it is known that a fuel permeation preventive layer is laminated on the inner surface of the accessory to enhance the fuel permeation preventive effect.

  For example, in Patent Document 2, a part mounting hole is formed in a tapered shape that widens toward the outer surface of the tank body, and a tapered boss portion that fits into the part mounting hole is formed in the accessory part. A fuel permeation preventive layer that is laminated on the inner surface of the part extends over the outer surface of the boss part, and the fuel permeation preventive layer on the outer surface of the boss part is exposed in the part mounting hole when the tank body and accessory parts are welded A synthetic resin fuel tank adapted to be in close contact with the permeation preventive layer is disclosed.

JP 2001-113963 A

Patent Document 3 discloses a resin part body formed of a barrier resin material that prevents permeation of fuel in an opening part-mounted resin part of a fuel tank that is attached to an opening part formed in a resin fuel tank. An adhesive resin material formed, integrally covering and covering a part of the resin component body, and having a joining member surrounding the fuel tank opening and joining to the fuel tank. A fuel tank opening mounting resin part and a manufacturing method thereof are disclosed.

  However, although the above-described component structure can provide a certain degree of permeation prevention effect, the further high permeation prevention effect is insufficient, and the barrier performance is lowered due to swelling of alcohol in the fuel into the barrier resin.

JP 2002-114047 A

Patent Document 4 discloses a structure of a portion for joining a child part formed of a non-weldable material to an opening provided in a synthetic resin tank body formed of a weldable material, A flange that abuts a peripheral edge is provided on the child component, and a supporting member that can cover the flange is formed of a weldable material, and the flange body is sandwiched between the flange body and the supporting body in the tank body. There is disclosed a structure of a joint part connecting portion of a synthetic resin tank characterized by welding members.

However, in the above component structure, the synthetic resin tank formed of the weldable material and the child component formed of the non-weldable material are not welded, and it is difficult to ensure sufficient sealability. Further, the child component formed of the non-weldable material and the supporting member are not welded, and it is difficult to ensure sufficient sealing performance at that portion.

JP 2002-160538 A

  In the conventional fuel tank, since there is an effect of preventing fuel permeation in each of the tank body and the accessory parts, the fuel permeation can be reduced to some extent, but the part mounting holes and the accessory parts are molded and processed with dimensional accuracy, It is difficult to provide a sufficient fuel permeation preventing effect while firmly securing the dimensional accuracy by strongly joining the tank body and the accessory parts.

  There is also a need for further improvements in content permeation and strength in the pinch-off part of synthetic resin hollow moldings, and improved synthesis in which the pinch-off part has high strength and is sealed to sufficiently prevent fuel vapor permeation. There is a need for hollow resin molded articles or fuel tanks.

  In view of such a problem, the present invention can reliably prevent fuel permeation from the welded portion between the tank body and the accessory part, and can provide a simple method for a synthetic resin fuel tank in which the accessory part is bonded with excellent strength. The issue is to provide.

  As a result of intensive studies in view of the above-mentioned problems, the present inventors have carried out welding using a specific permeation-preventing member, thereby providing a multilayer hollow molded article and a synthetic resin that are excellent in fuel permeation-preventing effect and excellent in strength. The present inventors have found that a fuel tank can be obtained easily and completed the present invention.

That is, the first of the present invention is a multi-layer container having an inner layer and an outer layer of a polyolefin resin and having an anti-permeation layer as an intermediate layer, the adhesive resin comprising a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof. A fuel tank multilayer container in which a permeation preventing member made of a metal sheet having a layer or a foil is welded to a discontinuous portion of the permeation prevention layer.

  In the second aspect of the present invention, the discontinuous portion of the permeation prevention layer is either 1) a joint portion of a multilayer container, 2) a pinch-off portion of a multilayer blow molding, or 3) a hole portion opened for processing a part. This is a multilayer container for a fuel tank.

A third aspect of the present invention is a polyolefin in which the adhesive resin is modified with 0.01% by mass or more and 30% by mass or less of an unsaturated carboxylic acid or a derivative thereof, and satisfies the following conditions (a) to (e). It is said multilayer container for fuel tanks.
(A) The melt flow rate of the modified polyolefin at a temperature of 190 ° C. and a load of 2.16 kg is from 0.1 g / 10 min to 100 g / 10 min,
(B) The density of the modified polyolefin is 0.910 to 0.965 g / cm ³ ,
(C) Initial bond strength with metal sheet or foil is 0.1 kg / 10 mm or more,
(D) The adhesive strength with a metal sheet or foil after immersion for 2500 hours at 65 ° C. in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol is 0.1 kg. / 10mm or more,
(E) The ratio of the adhesive strength of (d) to the initial adhesive strength of (c) is 50% or more.

A fourth aspect of the present invention is the above-mentioned fuel tank multilayer container, wherein the metal is selected from the group consisting of aluminum, stainless steel and copper.

The fifth aspect of the present invention is the above fuel, wherein a permeation preventive synthetic resin accessory is welded to the surface of a metal sheet or foil of a permeation prevention member welded to a part mounting hole provided in a multilayer container. It is a multilayer container for tanks.

A sixth aspect of the present invention is the above fuel tank multilayer container in which the permeation preventing member is welded so as to cover at least 50% or more of the area of the permeation preventing layer discontinuity exposed at the outer surface of the pinch-off part.

A seventh aspect of the present invention is a permeation which has an inner layer and an outer layer of a polyolefin resin, and is welded to a discontinuous portion of the permeation preventing layer of a multilayer container for a fuel tank having an permeation preventing layer as an intermediate layer to block permeation of hydrocarbon compounds. It is a member for prevention, It is a member for permeation | transmission which has the adhesive resin layer which consists of a modified polyolefin which satisfies the following conditions (a)-(e) on the surface of a metal sheet or foil.
(A) The melt flow rate of the modified polyolefin at a temperature of 190 ° C. and a load of 2.16 kg is from 0.1 g / 10 min to 100 g / 10 min,
(B) The density of the modified polyolefin is 0.910 to 0.965 g / cm ³ ,
(C) Initial bond strength with metal sheet or foil is 0.1 kg / 10 mm or more,
(D) The adhesive strength with a metal sheet or foil after immersion for 2500 hours at 65 ° C. in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol is 0.1 kg. / 10mm or more,
(E) The ratio of the adhesive strength of (d) to the initial adhesive strength of (c) is 50% or more.

  According to the present invention, the fuel permeation preventive layer of the multilayer hollow molded article (tank) body and the fuel permeation preventive layer of the accessory part are integrally continuous, and the fuel permeation from the welded part between the tank body and the accessory part is prevented. A synthetic resin fuel tank that can be effectively prevented and has improved permeation prevention performance can be easily produced. Further, according to the present invention, it is possible to effectively prevent the permeation of the contents or fuel from the pinch-off part of the multilayer hollow molded product body, and it is possible to improve the strength of the pinch-off part and to prevent permeation. An excellent hollow molded article or a synthetic resin fuel tank can be easily produced.

Hereinafter, the present invention will be described in detail.
The permeation-preventing member of the present invention has an adhesive resin layer on at least one side of a metal sheet or foil and, if necessary, both sides. The metal used in the present invention is preferably a metal having a permeation-preventing performance such as the content of a multilayer hollow molded article, particularly fuel oil, and more preferably selected from the group consisting of aluminum, stainless steel and copper. Aluminum is more preferable. Although the thickness of a metal sheet or foil is not specifically limited, It is 0.001-1.0 mm, Preferably it is 0.005-0.30 mm, More preferably, it is 0.01-0.15 mm.

  The surface of the metal sheet or foil has a surface roughness (Rz or Rmax) measured in accordance with JIS B 0601-2001 of 1000 μm or less, preferably 560 μm or less, more preferably 0.01 to 100 μm, and further Is 1.0 to 10 μm. In addition, the surface of the metal sheet or foil is polished, puffed, paper finished, cold rolled, hot rolled, pultruded, extruded, die cast, milled, rounded, electropolished, precision as required. Forging and casting are good.

The adhesive resin used for the permeation preventing member of the present invention preferably satisfies the following requirements (a) to (e).
(A) The melt flow rate at a temperature of 190 ° C. and a load of 2.16 kg is 0.1 g / 10 min or more and 100 g / 10 min or less,
(B) a density of 0.910 to 0.965 g / cm ³ ,
(C) Initial bond strength with metal sheet or foil is 0.1 kg / 10 mm or more,
(D) The adhesive strength with a metal sheet or foil after being immersed in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol at 65 ° C. for 2500 hours is 0.1 kg / 10 mm or more,
(E) Initial adhesion strength with metal sheet or foil, and metal sheet after being immersed in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol at 65 ° C. for 2500 hours Or the ratio with the adhesive strength with foil is 50% or more.

The adhesive resin of the present invention has a melt flow rate of 0.1 g / 10 min to 100 g / 10 min at a temperature of 190 ° C. and a load of 2.16 kg, preferably 0.1 g / 10 min to 20 g / 10 min. More preferably, it is 0.1 g / 10 min or more and 10 g / 10 min or less. When the melt flow rate is less than 0.1 g / 10 min, the extrusion amount is insufficient at the time of molding, and the molding becomes unstable, which is not practical. On the other hand, if it exceeds 100 g / 10 minutes, the impact resistance of the molded product is lowered.
Here, the melt flow rate at a load of 2.16 kg of the adhesive resin is measured in accordance with JIS-K7210 (1999).

Adhesive resin of the present invention, density of 0.910~0.965g / cm ^3, preferably at 0.920 g / cm ³ or more 0.965 g / cm ³ or less, more preferably 0.930 g / cm ³ or more and 0.960 g / cm ³ or less. Density is insufficient stiffness of the molded article is less than 0.910 g / cm ^3, the impact resistance is inferior and when it exceeds 0.965 g / cm ^3.
Here, the density of the adhesive resin is measured in accordance with JIS-K7112 (1999). After melting the resin with a hot compression molding machine at a temperature of 160 ° C., the temperature is lowered at a rate of 25 ° C./min. A sheet having a thickness of 2 mm is formed, this sheet is held at 23 ° C. for 48 hours, and then placed in a density gradient tube to be measured.

The adhesive resin of the present invention has an initial adhesive strength with a metal sheet or foil of 0.1 Kg / 10 mm or more, preferably 0.3 Kg / 10 mm or more, more preferably 0.5 Kg / 10 mm or more. When the initial adhesive strength is less than 0.1 kg / 10 mm, the metal sheet or foil is easily peeled off. The upper limit value of the initial adhesive strength is not necessarily limited, but is usually 30 kg / 10 mm or less.
Tensilon is used for measuring the adhesive strength between the adhesive resin and the metal sheet or foil. A metal sheet or foil is sandwiched between the upper chuck of Tensilon and an adhesive resin is sandwiched between the lower chuck and the lower chuck is lowered at a tensile speed of 50 mm / min to measure the adhesive strength. The measurement is performed by T peeling.

The adhesive resin of the present invention has an adhesive strength with a metal sheet or foil after immersing in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol at 65 ° C. for 2500 hours. Is 0.1 kg / 10 mm or more, preferably 0.3 kg / 10 mm or more, more preferably 0.5 kg / 10 mm or more. If the adhesive strength after immersion in the mixed solvent is less than 0.1 kg / 10 mm, the metal sheet or foil is easily peeled off. Although the upper limit of the adhesive strength after immersion in the mixed solvent is not necessarily limited, it is usually 30 kg / 10 mm or less.
Here, the adhesive strength between the adhesive resin and the metal sheet or foil after being immersed in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol at 65 ° C. for 2500 hours is , Measured in the same manner as the initial adhesive strength measurement between the adhesive resin and the metal sheet or foil.

  The adhesive resin of the present invention has an initial adhesive strength with a metal sheet or foil and a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol at 65 ° C. for 2500 hours. The ratio with the adhesive strength with the metal sheet or foil after immersion is 50% or more, preferably 60% or more, and more preferably 70% or more. If the ratio is less than 50%, the difference in adhesive strength before and after immersion in the mixed solvent becomes large, and the long-term durability of the adhesive strength cannot be maintained.

  The adhesive resin of the present invention is excellent in swelling resistance against automobile gasoline and the like, and has a weight after immersion for 2500 hours in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol. The increase is less than 10% by weight, preferably less than 5% by weight.

  The adhesive resin of the present invention is not particularly limited and can be suitably used as long as it satisfies the above characteristics (a) to (e). In order to obtain an adhesive resin that satisfies the above conditions (a) to (e), it can be achieved by balancing the amount of polar groups and nonpolar groups in the molecular skeleton of the resin. The polyolefin is preferably modified with an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative in an amount of not less than 30% by mass and not more than 30% by mass, preferably not less than 0.02% by mass and not more than 10% by mass.

  In addition, as the adhesive resin used in the present invention, a composition containing modified polyethylene (A) and unmodified polyethylene (B) is also preferably used.

[Modified polyethylene (A)]
The polyethylene (A) grafted with an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative has a density of 0.910 to 0.965 g / cm ³ , preferably 0.920 to 0.965 g / cm ³ , more preferably Is 0.930 to 0.960 g / cm ³ , the melt flow rate at a temperature of 190 ° C. and a load of 2.16 kg is 0.1 to 2.0 g / 10 minutes, preferably 0.1 to 1.5 g / 10 minutes. The polyethylene is a grafted unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative.

Examples of polyethylene as a raw material include a homopolymer made only of ethylene and a copolymer made of ethylene and an α-olefin having 3 to 12 carbon atoms. Examples of the α-olefin include proprene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. These polymers may be produced using a normal Ziegler catalyst or a chromium catalyst, or may be produced using a so-called single site catalyst. Examples of these polymers include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene, and a single type or a plurality of types can be used. When the melt flow rate of polyethylene is less than 0.1 g / 10 min or exceeds 2.0 g / 10 min, the interlayer adhesion, moldability, impact strength and / or fuel resistance of the finally obtained multilayer laminate structure Oiliness etc. will fall and the objective of this invention will not be achieved. Further, when the density of polyethylene is less than 0.91 g / cm ³ , the finally obtained multilayer laminated structure has insufficient adhesive strength and also lacks resistance to fuel oil and the like. On the other hand, if the density of polyethylene exceeds 0.96 g / cm ³ , the impact resistance and interlayer adhesion of the finally obtained multilayer laminate structure will be insufficient.

  When graft-modifying such polyethylene, the unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative is preferably 0.1 to 40 parts by weight, more preferably 0.1 to 30 parts by weight based on 100 parts by weight of polyethylene. Part by mass, particularly preferably 0.1 to 20 parts by mass and a radical initiator are added. If the addition amount of the unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative is less than 0.1 part by mass, graft modification may be insufficient, and the adhesive property of the resulting adhesive resin composition may be insufficient. is there. On the other hand, if the amount exceeds 40 parts by mass, the resulting modified polyethylene (A) may be gelled, deteriorated, or colored, and the adhesive strength and mechanical strength of the finally obtained multilayer laminated structure will be reduced. There are things to do. The amount of radical initiator added is preferably 0.001 to 0.50 parts by mass, more preferably 0.005 to 0.30 parts by mass, and particularly preferably 0.010 to 0.30 parts by mass. Part. When the ratio of the radical initiator is less than 0.001 part by mass, it takes a long time to completely perform the graft modification. Or, graft modification of polyethylene may be insufficient, and adhesive strength may be insufficient. On the other hand, when it exceeds 0.50 mass part, it may decompose | disassemble excessively by a radical initiator, or raise | generate a crosslinking reaction.

  Examples of unsaturated carboxylic acids used for graft modification include monobasic unsaturated carboxylic acids and dibasic unsaturated carboxylic acids, and examples of unsaturated carboxylic acid derivatives include unsaturated carboxylic acid metal salts and amides. , Imide, ester, and anhydride. The number of carbon atoms of the monobasic unsaturated carboxylic acid and the monobasic unsaturated carboxylic acid derivative is at most 20, preferably 15 or less. The dibasic unsaturated carboxylic acid and the dibasic unsaturated carboxylic acid derivative have at most 30 carbon atoms, preferably 25 or less. Among the unsaturated carboxylic acids, acrylic acid, methacrylic acid, maleic acid, and 5-norbornene-2,3-dicarboxylic acid are preferable. Among unsaturated carboxylic acid derivatives, acid anhydrides are preferable, and among acid anhydrides, anhydrides of acrylic acid, methacrylic acid, maleic acid, and 5-norbornene-2,3-dicarboxylic acid are preferable. In particular, when maleic anhydride or 5-norbornene anhydride is used, the adhesive property of the resulting adhesive resin composition is extremely excellent. As the unsaturated carboxylic acid derivative, glycidyl methacrylate is also preferable.

  When graft-modified with an acid anhydride, the grafted acid anhydride preferably has a ring opening rate of 10% or less. Here, the ring-opening rate is a value obtained by (mass of acid anhydride group opened after graft modification) / (mass of acid anhydride group before graft modification) × 100 (%). If the ring opening rate of the acid anhydride is 10% or less, the reaction with a barrier resin such as saponified ethylene-vinyl acetate copolymer is promoted, and the initial adhesive strength, the adhesive strength after immersion in fuel oil, and the fuel oil swelling The degree and the like are further improved. Moreover, when used as a regrind layer during recycling, compatibility with barrier materials such as saponified ethylene-vinyl acetate copolymer and polyamide resin is further improved.

  Examples of the radical initiator include dicumyl peroxide, benzoyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl. -2,5-di (t-butylperoxy) hexyne, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane-3, lauroyl peroxide, t-butylperoxybenzoate, Organic peroxides such as dicumyl peroxide

  As a method for graft modification, for example, polyethylene, an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative, and a radical initiator are kneaded in a molten state using a kneader such as an extruder, a Banbury mixer, or a kneader. Examples thereof include a melt kneading method, a solution method in which polyethylene, an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative, and a radical initiator are dissolved in an appropriate solvent. These methods are selected according to the use of the finally obtained multilayer laminated structure. Furthermore, for the purpose of improving the physical properties of the modified polyethylene, for example, by removing the unreacted monomer and by-product components of the unsaturated carboxylic acid and unsaturated carboxylic acid derivative by heating or washing after graft modification. Good.

  The temperature at the time of graft modification is determined in consideration of the deterioration of polyethylene, the decomposition of unsaturated carboxylic acid and its derivatives, the decomposition temperature of the radical initiator used. For example, in the melt-kneading method, the temperature is usually 200 to 350 ° C, preferably 220 to 300 ° C, more preferably 250 to 300 ° C.

  The modified polyethylene (A) of the present invention can be used alone or in combination.

[Unmodified polyethylene (B)]
Unmodified polyethylene (B) dilutes the above-mentioned modified polyethylene (A). Examples of such unmodified polyethylene (B) include homopolymers composed only of ethylene, and copolymers composed of ethylene and an α-olefin having 3 to 12 carbon atoms. Examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like. These polymers may be produced using a normal Ziegler catalyst or a chromium catalyst, or may be produced using a so-called single site catalyst. Examples of these polymers include high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene, and a single type or a plurality of types can be used.

The unmodified polyethylene (B) has a melt flow rate of 0.1 to 3.0 g / 10 min at a temperature of 190 ° C. and a load of 2.16 kg, a density of 0.860 to 0.965 g / cm ³ , preferably 0.915. ˜0.960 g / cm ³ . When the melt flow rate is less than 0.1 g / 10 minutes, the compatibility with the modified polyethylene (A) and other resins is lowered, and when the melt flow rate exceeds 3.0 g / 10 minutes, Formability is reduced. Further, when the density is less than 0.900 g / cm ³ , the finally obtained multilayer laminated structure has insufficient adhesive strength and lacks resistance to fuel oil and the like, and the density is 0.965 g / cm 2. When it exceeds cm ³ , the adhesiveness of the adhesive resin composition is lowered.

  The unmodified polyethylene (B) of the present invention can be used alone or in a plurality of types.

[Adhesive Resin Composition (C)]
The adhesive resin composition (C) includes the above-described modified polyethylene (A) and unmodified polyethylene (B). The blending ratio of the modified polyethylene (A) to the unmodified polyethylene (B) is such that (A) / (B) is 10/90 to 90/10 (mass ratio), preferably 15/85 to 85/15. It is. When (A) / (B) is less than 10/90 or exceeds 90/10, the adhesiveness of the resulting adhesive resin composition is lowered. The adhesive resin composition (C) is produced by melt-mixing a raw material mixture containing a modified polyethylene (A) and an unmodified polyethylene (B). There are no particular limitations on the method of melt mixing, and examples include a method of mixing with a known mixer such as a Henschel mixer and then melt mixing with a single or twin screw extruder.

  Further, the melt flow rate of the modified polyethylene (A) at a temperature of 190 ° C. and a load of 2.16 kg is MFR (A), and the melt flow rate of the unmodified polyethylene (B) at a temperature of 190 ° C. and a load of 2.16 kg is MFR (B). In this case, MFR (A) / MFR (B) is preferably less than 1, and more preferably less than 0.6. When MFR (A) / MFR (B) is 1 or more, the adhesive strength at the initial stage and after fuel immersion may be lowered.

The obtained adhesive resin composition (C) has a density of 0.910 to 0.965 g / cm ³ , preferably 0.920 to 0.965 g / cm ³ , and includes unsaturated carboxylic acid and unsaturated carboxylic acid derivative. The melt flow rate at a content of 0.09% by mass or more, a temperature of 190 ° C. and a load of 2.16 kg is 0.01 to 100/10 minutes, preferably 0.1 to 2.0 g / 10 minutes, more preferably 0.00. 1 to 1.5 g / 10 min. When the density is less than 0.910 g / cm ³ , the swellability with respect to fuel oil or the like is increased, so that the long-term durability is lowered. On the other hand, when the density exceeds 0.965 g / cm ³ , the shrinkage when solidified after multilayer lamination is increased, so that the adhesive strength is lowered. Moreover, when the content of the unsaturated carboxylic acid and the unsaturated carboxylic acid derivative is less than 0.01% by mass, the adhesive strength of the finally obtained multilayer laminated structure is lowered, and when the content exceeds 30% by mass, the others The physical properties of the are reduced. In addition, when a regrind layer containing recycled burrs or unused parison generated when producing a multilayer laminated structure is brought into contact with the barrier layer, the regrind layer and saponified ethylene-vinyl acetate copolymer And the compatibility with a barrier material such as polyamide resin is lowered, so that the low-temperature impact strength of the finally obtained multilayer laminated structure is lowered. On the other hand, if the melt flow rate is less than 0.01 g / 10 min or exceeds 100 g / 10 min, the moldability of the resulting adhesive resin composition (C) is impaired.

  The adhesive resin composition (C) does not contain 100 mass ppm or more of a fatty acid metal salt such as calcium stearate or zinc stearate that is generally used as an acid absorbent.

  Further, it is preferably not contained in an amount of 50 ppm by mass or more, and particularly preferably the content is below the detection limit of quantitative analysis by fluorescent X-ray analysis or the like. When the amount of the fatty acid metal salt is less than 100 ppm by mass, the reaction between the unsaturated carboxylic acid grafted on polyethylene and the unsaturated carboxylic acid derivative and the saponified product of polyamide and ethylene-vinyl acetate copolymer is inhibited by the fatty acid metal salt. Therefore, the adhesive strength of the adhesive resin composition is further improved, and the mechanical properties of the multilayer laminated structure are further improved.

  Moreover, you may mix an additive, another resin, and an elastomer with the adhesive resin composition (C) as needed. Examples of the additive include phenol-based and phosphorus-based antioxidants, anti-blocking agents such as talc, and slip agents such as fatty acid amides. In addition, synthetic or natural hydrotalcite can be used as an acid absorbent in place of the stearic acid compound.

  Examples of other resins to be mixed in the adhesive resin composition (C) as needed include a homopolymer made of ethylene, a copolymer made of ethylene and an α-olefin having 3 to 12 carbon atoms, and ethylene-vinyl acetate. Copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer Copolymers of ethylene and other vinyl monomers such as coalesced are listed. Examples of the α-olefin include proprene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. These polymers may be usually produced using a Ziegler catalyst or a chromium catalyst, or may be produced using a so-called single site catalyst.

Examples of the elastomer mixed in the adhesive resin composition (C) as needed include ethylene-propylene copolymer rubber, ethylene-propylene-diene terpolymer rubber, and ethylene-butene-1 copolymer rubber. Examples include α-olefin copolymer rubbers; polyisobutylene rubbers, polyurethane rubbers, styrene-butadiene copolymer rubbers, synthetic rubbers such as polybutadiene rubbers, and natural rubbers.

  The other resin and elastomer mixed as necessary in the adhesive resin composition (C) should be used in a proportion of 10% by mass or less, preferably 5% by mass or less, based on the polyethylene resin to be graft-modified. Can do. If the amount used exceeds 10% by mass, the basic properties of the polyethylene resin to be graft-modified may be impaired.

The permeation preventing member of the present invention can be formed by various methods, and can be obtained by, for example, a press method, a dry lamination method, an extrusion lamination method, or a hot melt method.

  The permeation-preventing member of the present invention is used by adhering to the portion where the contents of the multilayer hollow molded article, in particular, fuel oil or the like are easily transmitted. The permeation preventing member of the present invention can adhere an adhesive resin to any of a synthetic resin layer, an adhesive resin layer, a barrier layer, and a recycled resin layer of a multilayer container, and after adhesion, a metal sheet or foil Adhesive resin can also be arrange | positioned also on the other surface, and it can also adhere | attach with another article | item.

  For example, according to the present invention, by adhering a permeation preventive accessory, the fuel permeation preventive layer of the multilayer hollow molded article (tank) main body and the fuel permeation preventive layer of the accessory become continuous. Permeation of fuel oil or the like from the welded portion between the main body and the accessory parts is prevented. Thus, the permeation of fuel from the welded portion is reliably prevented.

  In the permeation-preventing member of the present invention, the use of a metal sheet or foil for the fuel permeation-preventing layer allows the barrier layer to swell due to the alcohol-containing fuel generated when a resin barrier layer such as EVOH or nylon is used. There is no concern about the fuel permeation performance deterioration due to the above, and long-term fuel permeation prevention performance is secured. In general, when resin parts are welded to the tank body surface, both the tank body surface and the resin part welding surface are preheated, but metal sheets or foils are used for the components of the present invention. Thus, the step of preheating the surface of the tank main body can be omitted, and pressure welding can be performed by pressing with a heater on the metal sheet or foil.

  The permeation preventing member of the present invention is preferably welded so as to have an area of at least 1.5 times the area of the permeation preventing layer discontinuity exposed at the outer surface of the pinch-off part. If it is less than 1.5 times, the fuel cutoff effect from the polyolefin multilayer container is reduced, and the strength reinforcing effect of the pinch-off part is also reduced.

  The permeation-preventing member of the present invention can be placed on the tank body or an accessory by various methods. For example, a method of applying a molten adhesive resin, a method of pressing an adhesive resin molded into a sheet shape Etc. can be adopted.

  When joining the accessory of the present invention to the surface of the tank body, welding can be performed after preheating both the tank body surface and the adhesive resin surface of the accessory. Further, by using a metal for the accessory part of the present invention, it is possible to omit the step of preheating the surface of the tank main body and to perform pressure welding after heating the metal with a heater.

  Hereinafter, the permeation preventing member used in the present invention will be described with reference to FIGS. Reference numeral 101 denotes a tank body of the fuel tank. The tank body 101 is composed of a synthetic resin inner layer 104 and a synthetic resin outer layer 105 laminated with a fuel permeation preventing layer 102 and an adhesive resin layer 103 interposed therebetween. In addition, a component mounting hole 106 is opened in the tank body. Then, a synthetic resin accessory 107 such as a joint for connecting a tube connected to the canister is attached to the outer surface of the tank body 101 so as to cover the component attachment hole 106. A fuel permeation preventing layer 108 is laminated on the inner surface of the accessory 107.

The material of the inner layer 104, the outer layer 105, and the accessory 107 is preferably a resin having excellent mechanical strength such as high-density polyethylene, and the material of the fuel permeation prevention layers 102 and 108 is a fuel permeation prevention performance such as ethylene vinyl alcohol polymer. It is desirable to use a high resin. The adhesive resin layer 103 is preferably a maleic anhydride-modified polyethylene resin.
The multilayer container of the present invention includes a structure in which at least a synthetic resin inner layer and an outer layer are laminated via a permeation preventive layer, and is provided between the inner layer and the permeation preventive layer and between the outer layer and the permeation preventive layer. An adhesive resin layer may be provided. Each of the inner layer and / or outer layer may be composed of one or more layers, and a plurality of adhesive resin layers may be present. Further, a plurality of permeation prevention layers may be present, and the permeation prevention layer may be partially discontinuous as long as it does not affect the permeation prevention performance of the entire multilayer hollow molded article. .

  The permeation prevention member 109 has an adhesive resin layer 111 on both surfaces of a metal sheet 110, preferably an aluminum sheet. The adhesive resin layer is preferably a maleic anhydride-modified polyethylene resin. The thickness of the metal sheet is 0.001 to 1.0 mm, preferably 0.005 to 0.30 mm, and more preferably 0.01 to 0.15 mm. The thickness of the adhesive resin layer is 0.01 to 10 mm, preferably 0.05 to 3 mm, more preferably 0.1 to 1 mm on both sides.

  As shown in FIG. 1, when the component mounting holes of the tank body 101, the permeation prevention member 109 and the molding heater 112 are arranged, and the molding heater 112 is pressed onto the tank body 101 as shown in FIG. Adhering to the tank main body 101, as shown in FIG. 3, the permeation preventing member 109 can be bonded to the tank main body 101 and the component mounting holes. Next, when the accessory 107 is welded to the tank body 101 to which the permeation preventing member 109 is bonded as shown in FIG. 4, a fuel tank in which the tank body 101 and the accessory 107 are welded is obtained as shown in FIG.

  Referring to FIG. 5, the component mounting hole 6 and the outer layer around it are covered with a permeation preventing member 109, and the fuel hardly permeates, and the fuel permeation preventive layer 108 is laminated on the inner surface of the accessory 107. Therefore, the fuel hardly penetrates from here. Further, since the permeation preventing member 109 adhered to the outer layer and the fuel permeation preventing layer 108 on the inner surface of the accessory 107 are adhered and securely adhered, there is almost no fuel leakage. Therefore, since it is such a structure, the permeation | transmission of the fuel from the tank which attached the accessory 107 can be prevented reliably. Moreover, it is not necessary to taper the component mounting holes, and the fuel tank can be easily formed.

  According to another aspect of the present invention, a portion having no permeation preventive layer in the pinch off portion is obtained by thermally bonding a permeation preventing member having a large permeation preventive effect and a reinforcing effect to the synthetic resin molded product or the pinch off portion of the fuel tank. The (blocking discontinuous area) can be shielded, the permeation of contents or fuel oil can be prevented, and reinforcement can be made from the outer surface. Thus, the transmission of the contents from the pinch-off part can be reliably prevented, and the strength problem of the pinch-off part is also solved.

  Another embodiment of the present invention will be described with reference to FIGS. Reference numeral 113 denotes a hollow molded product body. The hollow molded product body 113 is composed of a resin inner layer 116 and a resin outer layer 117 laminated with a permeation preventing layer 114 and an adhesive resin layer 115 interposed therebetween. Further, a pinch-off portion 118 exists in the hollow molded product body. And in the pinch-off part, there exists a part 119 where the permeation preventive layer does not come into contact, and it becomes a part through which the content is slightly transmitted. A permeation preventing member 120 is installed above the pinch-off portion. The permeation preventing member 120 has an adhesive resin layer 122 on one side of a metal sheet 121, preferably an aluminum sheet.

  The material of the inner layer 116 and the outer layer 117 is preferably a resin having excellent mechanical strength such as high density polyethylene, and the material of the permeation prevention layer 114 is preferably a resin having high fuel permeation prevention performance such as ethylene vinyl alcohol polymer. . The adhesive resin layer 115 is preferably a maleic anhydride-modified polyethylene resin.

  The permeation preventing member 120 has an adhesive resin layer 122 on one side of a metal sheet 121, preferably an aluminum sheet. The adhesive resin layer is preferably a maleic anhydride-modified polyethylene resin. The thickness of the metal sheet is 0.001 to 1.0 mm, preferably 0.005 to 0.30 mm, and more preferably 0.01 to 0.15 mm. The thickness of the adhesive resin layer is 0.01 to 10 mm, preferably 0.05 to 3 mm, and more preferably 0.1 to 1 mm.

  When the permeation preventing member 120 is disposed above the pinch-off portion of the hollow molded product body 113 as shown in FIG. 6 and the molding heater 123 is pressed onto the hollow molded product body 113 as shown in FIG. Is bonded to the hollow molded product body 113, and as shown in FIG. 8, the hollow molded product main body 113 and the pinch-off portion 118 are bonded to the permeation preventing member 120, and the hollow molding is excellent in permeation preventing performance and pinch-off portion strength. Goods or fuel tanks are obtained.

  When the permeation preventing member 120 is bonded to the hollow molded product body 113, the hollow molded product body 113 and the pinch-off portion or the permeation preventing member 120 may be heated in advance.

  Referring to FIG. 8, the pinch-off portion 118 and the outer layers around it are covered with a permeation prevention member 120, and the portion 119 where the permeation prevention layer does not contact in the pinch-off portion is reliably shielded by the permeation prevention member. Therefore, the contents or fuel of the hollow molded product hardly penetrates. In addition, since the permeation preventing member 120 is firmly bonded to the pinch-off portion 118 and the outer layer around it, the strength of the pinch-off portion can be remarkably improved. Moreover, by making the mold shape of the molding heater 123 into a shape with few protrusions, it is possible to reduce the portion protruding to the outer surface of the hollow molded product, and it is possible to reduce damage to the protrusions, which is preferable.

  In the hollow molded article of the present invention, the permeation preventing member is adhered to the outer surface of the pinch-off portion of the hollow molded article, and a protective layer is further provided on the metal sheet or foil of the permeation preventing member. It is preferable because it has effects such as prevention of corrosion and prevention of scratches. The material of the protective layer is not particularly limited, but is preferably the same material as that of the outer layer of the hollow molded product, and can be arranged on a metal sheet or foil via an adhesive resin. The adhesive resin is preferably the same material as the adhesive resin constituting the permeation preventing member.

Further, in the hollow molded product of the present invention, a recess is provided on the outer layer surface around the pinch-off portion so that the permeation preventing member can be fitted, and the permeation preventing member is fitted and bonded, so that the surface of the final molded product A structure with reduced unevenness is preferable from the viewpoint of appearance and prevention of scratches.

Another embodiment of the present invention will be described with reference to FIGS. In FIG. 9, 201 indicates a tank body of the fuel tank. The tank body 201 is composed of a synthetic resin inner layer 204 and a synthetic resin outer layer 205 laminated with a fuel permeation preventing layer 202 and an adhesive resin layer 203 interposed therebetween. In addition, a part mounting hole 206 is formed in the tank body 201. Then, a metal accessory part 207 as an inlet is attached so as to be inserted into the part attachment hole 206 of the tank main body 201 from the outside, and the adhesive resin 208 is formed on the surface of the tank main body (the permeation preventing layer 202). And a part of the outer layer 205 made of synthetic resin.

  The material of the inner layer 204 and the outer layer 205 is preferably a resin with excellent mechanical strength such as high-density polyethylene, and the material of the fuel permeation prevention layer 202 is a resin with high fuel permeation prevention performance such as ethylene vinyl alcohol polymer. desirable. The adhesive resin layer 203 is preferably a maleic anhydride-modified polyethylene resin.

  FIG. 10 shows an example in which a joint valve 209 for connecting a tube connected to a canister is attached in place of the metal accessory 207 which is the inlet of FIG.

  Referring to FIGS. 9 and 10, the surface of the component mounting hole 206 and the accessory component 207 or 209 are firmly bonded by the adhesive resin 208, so that the fuel hardly permeates and the fuel swells. Hateful. Therefore, since it is such a structure, permeation | transmission of the fuel from the tank which attached the accessory 207 or 209 can be prevented reliably. Moreover, it is not necessary to perform special taper processing or the like on the component mounting holes, and the fuel tank can be easily formed.

  Another aspect of the present invention will be described with reference to FIG. 201 indicates a hollow molded product body. The hollow molded product body 201 is composed of a resin inner layer 204 and a resin outer layer 205 laminated with a permeation preventing layer 202 and an adhesive resin layer 203 interposed therebetween. In addition, a part mounting hole 206 is formed in the tank body. Then, a metal accessory part 207 as an inlet is attached so as to be inserted into the part attachment hole 206 of the tank main body 201 from the outside, and the adhesive resin 208 is formed on the surface of the tank main body (the permeation preventing layer 202). And a part of the outer layer 205 made of synthetic resin. Further, a support member 210 made of polyethylene resin or adhesive resin is disposed via the adhesive resin 208 so as to hold down the flange portion of the accessory 207 and is disposed so as to be welded to the resin outer layer 205. The support member 210 is bonded to the accessory part 207 and welded to the resin outer layer 205, and the accessory part 207 is coupled to the tank body 201. With the support member 210 made of polyethylene resin or adhesive resin, the sealing performance and strength can be further enhanced.

  The material of the inner layer 204 and the outer layer 205 is preferably a resin having excellent mechanical strength such as high density polyethylene, and the material of the permeation prevention layer 202 is preferably a resin having high fuel permeation prevention performance such as ethylene vinyl alcohol polymer. . The adhesive resin layer 203 is preferably a maleic anhydride-modified polyethylene resin.

  FIG. 12 is an example in which a joint valve 209 for connecting a tube connected to a canister is attached instead of the metal accessory 207 which is the inlet of FIG.

  Referring to FIGS. 11 and 12, the surface of the component mounting hole 206 and the accessory component 207 or 209 are firmly bonded by the adhesive resin 208, so that the fuel hardly permeates and the fuel swells. Hateful. Therefore, since it is such a structure, permeation | transmission of the fuel from the tank which attached the accessory 207 or 209 can be prevented reliably. Moreover, it is not necessary to perform special taper processing or the like on the component mounting holes, and the fuel tank can be easily formed.

  Another aspect of the present invention will be described with reference to FIG. 201 indicates a hollow molded product body. The hollow molded product body 201 is composed of a resin inner layer 204 and a resin outer layer 205 laminated with a permeation preventing layer 202 and an adhesive resin layer 203 interposed therebetween. In addition, a part mounting hole 206 is formed in the tank body 201. A metal accessory 207 as an inlet is attached so as to be inserted into the component attachment hole 206 of the tank body 201 from the outside. A polyethylene resin 211 (may be nylon resin) is disposed and bonded to the inner surface of the metal accessory 207 via an adhesive resin 208. An adhesive resin 208 is disposed on the surface of the tank main body (including the exposed portion of the permeation preventive layer 202) where the component mounting hole 206 is formed. Further, a support member 210 made of polyethylene resin or adhesive resin is disposed via the adhesive resin 208 so as to hold down the flange portion of the accessory 207 and is disposed so as to be welded to the resin outer layer 205. The support member 210 is bonded to the accessory part 207 and welded to the resin outer layer 205, and the accessory part 207 is coupled to the tank body 201. With the support member 210 made of polyethylene resin or adhesive resin, the sealing performance and strength can be further enhanced.

  FIG. 14 shows an example in which a joint valve 209 for connecting a tube connected to a canister is attached instead of the metal accessory 207 which is the inlet of FIG.

  In FIG. 15, 201 indicates a tank body of the fuel tank. The tank body 201 is composed of a synthetic resin inner layer 204 and a synthetic resin outer layer 205 laminated with a fuel permeation preventing layer 202 and an adhesive resin layer 203 interposed therebetween. In addition, a part mounting hole 206 is formed in the tank body 201. Then, a metal accessory part 207 as an inlet is attached so as to be inserted into the part attachment hole 206 of the tank main body 201 from the outside, and the adhesive resin 208 is formed on the surface of the tank main body (the permeation preventing layer 202). And a part of the outer layer 205 made of synthetic resin. A protruding portion 212 is provided on the outer peripheral portion of the flange portion of the accessory 207, and the protruding portion 212 is disposed so as to be in contact with the permeation preventing layer 202 inside the tank body. Further, the support member 210 made of polyethylene resin is arranged via another adhesive resin 208 so as to hold down the flange portion of the accessory 207 and is arranged so as to be welded to the resin outer layer 205. The support member 210 is bonded to the accessory part 207 and welded to the resin outer layer 205, and the accessory part 207 is coupled to the tank body 201. The support member 210 made of polyethylene resin can further enhance the sealing performance and strength.

  The material of the inner layer 204 and the outer layer 205 is preferably a resin with excellent mechanical strength such as high-density polyethylene, and the material of the fuel permeation prevention layer 202 is a resin with high fuel permeation prevention performance such as ethylene vinyl alcohol polymer. desirable. The adhesive resin layer 203 is preferably a maleic anhydride-modified polyethylene resin.

  Referring to FIG. 15, the surface of the component mounting hole 206 and the accessory component 207 are firmly bonded by the adhesive resin 208, and the permeation preventive portion (the protruding portion 212 in FIG. 15) of the accessory component 207 is the tank body. Since it is arranged so as to be in contact with the inner permeation preventive layer 202, the fuel hardly permeates, and the fuel does not easily swell. Therefore, since it is such a structure, the permeation | transmission of the fuel from the tank which attached the accessory 207 can be prevented reliably. Moreover, it is not necessary to perform special taper processing or the like on the component mounting holes, and the fuel tank can be easily formed.

  The multilayer hollow molded article of the present invention includes a structure in which at least a synthetic resin inner layer and an outer layer are laminated via a permeation prevention layer, and the outer layer and the permeation prevention layer are provided between the inner layer and the permeation prevention layer. An adhesive resin layer may be provided therebetween. Each of the inner layer and / or outer layer may be composed of one or more layers, and a plurality of adhesive resin layers may be present. Further, a plurality of permeation prevention layers may be present, and the permeation prevention layer may be partially discontinuous as long as it does not affect the permeation prevention performance of the entire multilayer hollow molded article. .

  The material of the accessory of the present invention is not particularly limited, but the contents of the multilayer hollow molded article, particularly those having a permeation preventing performance for fuel oil and the like are preferable. Moreover, the material of the accessory part does not need to be the same material in all parts, and the material of the site | part required for permeation prevention should just have permeation prevention performance. The material of the accessory part is preferably, for example, metal or engineering plastic, more preferably aluminum, stainless steel, polyamide, polyacetal, and more preferably aluminum.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to an Example.

[Production of modified polyethylene]
The modified polyethylene used in Examples and Comparative Examples (hereinafter referred to as modified PE) was produced as follows.

(Modified PE-1)
Density 0.956 g / cm ³ , melt flow rate 0.80 g / 10 min high density polyethylene (hereinafter abbreviated as “HDPE-I”) 85 parts by mass, density 0.928 g / cm ³ , melt flow rate 0.80 g / 0.015 parts by mass of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane was added to 15 parts by weight of a 10 minute linear low density polyethylene (hereinafter abbreviated as “LLDPE-I”). And dry blended for 1 minute in a Henschel mixer. Next, 0.375 parts by mass of maleic anhydride was added, and after dry blending for another 2 minutes, it was melt-kneaded at 290 ° C. using a 50 mm single screw extruder manufactured by Modern Machinery Co., Ltd., graft-modified, and modified polyethylene (modified PE-1 ) The amount of maleic anhydride grafted in this modified polyethylene was 0.30% by mass, the density was 0.951 g / cm ³ , and the melt flow rate was 0.30 g / 10 min.

(Modified PE-2)
The same procedure as described above (modified PE-1) was conducted except that 0.500 parts by mass of maleic anhydride was used instead of 0.375 parts by mass of maleic anhydride. As a result, the amount of maleic anhydride grafted in this modified polyethylene was 0.45% by mass, the density was 0.951 g / cm ³ , and the melt flow rate was 0.30 g / 10 min.

[Production of Adhesive Resin (I)]
40 parts by mass of modified polyethylene (modified PE-1) and unmodified polyethylene (linear low-density polyethylene (hereinafter abbreviated as “LLDPE-II”) having a density of 0.923 g / cm ³ and a melt flow rate of 0.80 g / 10 min) To 60 parts by mass, 0.15 parts by mass of phenolic antioxidant Irganox 1330 (manufactured by Ciba Specialty Chemicals) and 0.05 part by mass of Irganox 1076 (manufactured by Ciba Specialty Chemicals) were added. ) Using a 50 mm single screw extruder, melt-kneading was carried out at 200 ° C. to produce an adhesive resin (I) having a density of 0.935 g / cm ³ .

[Production of adhesive resin (II)]
1 part by weight of modified polyethylene (modified PE-1) and unmodified polyethylene (linear low density polyethylene (density: 0.923 g / cm ³ , melt flow rate: 0.80 g / 10 min) (hereinafter abbreviated as “LLDPE-II”) To 99 parts by mass, 0.15 parts by mass of phenolic antioxidant Irganox 1330 (manufactured by Ciba Specialty Chemicals) and 0.05 parts by mass of Irganox 1076 (manufactured by Ciba Specialty Chemicals) were added, and Modern Machinery Co., Ltd. ) An adhesive resin (II) having a density of 0.935 g / cm ³ was produced by melt-kneading at 200 ° C. using a 50 mm single screw extruder.

On an aluminum sheet having a width of 10 mm, a thickness of 100 μm, and a length of 40 mm, a density of 0.945 cm ³ , a temperature of 190 ° C. and a load of 21.6 kg on the adhesive resin (I) 200 μm and the adhesive resin (I). A laminate obtained by laminating 500 μm of high density polyethylene having a melt flow rate of 6 g / 10 min was molded by a press method at 190 ° C., and was 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene, and ethyl. The adhesive strength before and after immersion at 65 ° C. for a predetermined time in a mixed solvent of 10 parts by volume of alcohol was measured (the number of measurement points was 5 each, and the average value was adopted).
Tensilon was used to measure the adhesive strength before and after immersion in the mixed solvent. The aluminum sheet was sandwiched between the upper chuck of Tensilon and the resin portion was sandwiched between the lower chuck, and the lower chuck was lowered at a tensile speed of 50 mm / min to measure the adhesive strength. The measurement was performed by T peeling.
As a result, the adhesive strength before immersion in the mixed solvent was 2.5 kg / 10 mm, the adhesive strength after 2500 hours of immersion in the mixed solvent was 2.5 kg / 10 mm, and the adhesive strength retention was 100%. Moreover, there was no change in the external appearance of the test piece after immersion in the mixed solvent, and there was no weight increase due to swelling.

It carried out similarly to Example 1 except having used the stainless steel sheet instead of the aluminum sheet.
As a result, the adhesive strength before immersion in the mixed solvent was 2.0 kg / 10 mm, the adhesive strength after 2500 hours of immersion in the mixed solvent was 2.0 kg / 10 mm, and the adhesive strength retention was 100%. Moreover, there was no change in the external appearance of the test piece after immersion in the mixed solvent, and there was no weight increase due to swelling.

It carried out similarly to Example 1 except having used the copper sheet instead of the aluminum sheet.
As a result, the adhesive strength before immersion in the mixed solvent was 2.3 kg / 10 mm, the adhesive strength after 2500 hours in the mixed solvent immersion was 2.3 kg / 10 mm, and the adhesive strength retention was 100%. Moreover, there was no change in the external appearance of the test piece after immersion in the mixed solvent, and there was no weight increase due to swelling.

[Comparative Example 1]
It carried out similarly to Example 1 except having used adhesive resin (II) instead of adhesive resin (I).
As a result, the adhesive strength before immersion in the mixed solvent was 0.05 kg / 10 mm, the adhesive strength after 2500 hours of immersion in the mixed solvent was 0.01 kg / 10 mm, and the adhesive strength retention was 20%. Moreover, there was no change in the external appearance of the test piece after immersion in the mixed solvent, and there was no weight increase due to swelling.

[Comparative Example 2]
It carried out similarly to Example 1 except having used the composition of 85 mass parts of "HDPE-I" and 15 weight part of "LLDPE-I" instead of adhesive resin (I).
As a result, the adhesive strength before immersion in the mixed solvent was 0.00 Kg / 10 mm.

[Comparative Example 3]
It carried out similarly to Example 1 except having used (modified | denatured PE-2) instead of adhesive resin (I).
As a result, the adhesive strength before immersion in the mixed solvent was 5.8 kg / 10 mm, the adhesive strength after 2500 hours of immersion in the mixed solvent was 1.7 kg / 10 mm, and the adhesive strength retention rate was 30%. Moreover, there was no change in the external appearance of the test piece after immersion in the mixed solvent, and there was no weight increase due to swelling.

[Molding and Evaluation of Multi-layer Hollow Molded Product with Tube Connection Joint and Permeation Prevention Member]
Using 3 types and 5 layers of multi-layer hollow molding machine, at a molding temperature of 210 ° C., the layer structure is a high-density polyethylene (HDPE) layer (main material layer) / adhesive resin composition layer (adhesive layer) / ethylene-vinyl acetate The thickness ratio of the polymer saponified material layer (barrier layer) / adhesive resin composition layer (adhesive layer) / high-density polyethylene layer (main material layer) is 45.5 / 3/3/3 / 45.5, all films A cubic three-layer five-layer laminated container (container I) having a narrow mouth with a thickness of 6 mm and an internal volume of 10 L was formed. At this time, the high density polyethylene is a high density polyethylene having a density of 0.947 / cm 3, a temperature of 190 ° C., a load flow of 21.6 kg and a melt flow rate of 6 g / 10 min, and an ethylene-vinyl acetate copolymer. Eval F101B manufactured by Kuraray Co., Ltd. was used for the saponified product layer.
A hole having a diameter of 40 mm was formed in the upper plane of the container I.

  A laminate in which the above adhesive resin (I) having a thickness of 0.5 mm is arranged on both sides of an aluminum sheet having a thickness of 0.05 mm is formed by pressing, and an outer diameter of 80 mm having a hole having a diameter of 20 mm in the center. A donut plate-shaped transmission preventing member was produced. The permeation-preventing member was placed above the hole in the container I, a 190 ° C. molding heater was pressed, and the permeation-preventing member was adhered to the hole in the container I.

The cross section of the tube connecting joint as shown in FIG. 4 (a flat plate having an outer diameter of 100 mm and having a tube nozzle having an outer diameter of about 20 mm at the top. The outer layer has a density of 0.947 g / cm ³ and 190 at a load of 21.6 kg. A high-density polyethylene having a melt flow rate of 6 g / 10 min. And an inner layer of nylon are attached by heat welding at about 200 ° C., and a multilayer hollow molded article (container II) having a tube connection joint is formed. .

  Container II was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed, and the weight change after being left at 40 ° C. for 200 hours was measured.

[Molding and Evaluation of Multilayer Hollow Molded Product with Permeation Prevention Member Adhered to Pinch-off Part]
A laminated body in which the adhesive resin (I) having a thickness of 0.5 mm is arranged on one side of an aluminum sheet having a thickness of 0.05 mm is molded by a press method, and a transmission preventing member having a width of 20 mm and a length of 100 mm is formed. Produced.

  In the same manner as in Example 4, the same container as Container I was formed. A container III that covers all of the pinch-off portion of this container and is arranged so that the adhesive resin layer of the permeation preventing member is adhered, presses a molding heater at 190 ° C., and adheres the permeation preventing member to the pinch off portion Was molded.

This container III was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed and measured for change in weight after standing at 40 ° C. for 200 hours. As a result, the weight was reduced by 35 mg.
In addition, the container (IV) formed in the same manner as the container III described above was filled with 5 L of gasoline containing 10% by volume of ethanol, and the appearance after 3,000 hours at 65 ° C. was observed. There was no.

[Formation and evaluation of multilayer hollow molded product with tube connection joint and permeation prevention member attached, and permeation prevention member bonded to pinch-off part]
A laminated body in which the adhesive resin (I) having a thickness of 0.5 mm is arranged on one side of an aluminum sheet having a thickness of 0.05 mm is molded by a press method, and a transmission preventing member having a width of 20 mm and a length of 100 mm is formed. Produced.

  In the same manner as in Example 4, the same container as Container II was formed. A container V that covers all of the pinch-off part of this container and is arranged so that the adhesive resin layer of the permeation preventing member adheres, presses a molding heater at 190 ° C., and adheres the permeation preventing member to the pinch off part Was molded.

This container V was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed, and the weight change after being left at 40 ° C. for 200 hours was measured. As a result, the weight was reduced by 40 mg.
In addition, the container VI molded in the same manner as the container V described above was filled with 5 L of gasoline containing 10% by volume of ethanol, and the appearance after lapse of 3000 hours at 65 ° C. was observed. It was.

[Comparative Example 4]
[Molding and evaluation of multi-layer hollow molded products]
In the same manner as in Example 4, the same container as Container I was formed. This container was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed, and the weight change after being left at 40 ° C. for 200 hours was measured. As a result, the weight was reduced by 60 mg.

[Comparative Example 5]
[Molding and Evaluation of Multi-layer Hollow Molded Products with Tube Connection Joints]
In the same manner as in Example 4, the same container as Container I was formed.
A hole having a diameter of 50 mm on the outer layer surface and a diameter of 45 mm on the inner layer surface was formed in the upper plane of the container.

4. A tube connection joint as shown in FIG. 4 (a flat plate having an outer diameter of 100 mm and a tube nozzle having an outer diameter of about 20 mm. The outer layer has a density of 0.947 g / cm ³ , a temperature of 190 ° C., a load of 21. A high-density polyethylene having a melt flow rate of 6 g / 10 min at a load of 6 kg and an inner layer of nylon were attached by heat welding at about 200 ° C., and a container to which a tube connecting joint was attached was molded. This container was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed and measured for change in weight after standing at 40 ° C. for 200 hours. As a result, the weight was reduced by 85 mg.

[Molding and Evaluation of Multi-layer Hollow Molded Products with Tube Connection Joints]
Using 3 types and 5 layers of multi-layer hollow molding machine, at a molding temperature of 210 ° C., the layer structure is a high-density polyethylene (HDPE) layer (main material layer) / adhesive resin composition layer (adhesive layer) / ethylene-vinyl acetate The thickness ratio of the polymer saponified material layer (barrier layer) / adhesive resin composition layer (adhesive layer) / high-density polyethylene layer (main material layer) is 45.5 / 3/3/3 / 45.5, all films A cubic three-layer five-layer container (container XI) having a narrow mouth having a thickness of 6 mm and an internal volume of 10 L was formed. At this time, as the high density polyethylene, a high density polyethylene having a density of 0.947 g / cm ³ , a temperature of 190 ° C., and a melt flow rate of 6 g / 10 min at a load of 21.6 kg is used, and an ethylene-vinyl acetate copolymer is used. Eval F101B manufactured by Kuraray Co., Ltd. was used for the saponified product layer.
A hole with a diameter of 40 mm was opened in the upper plane of the container XI.

  The above-mentioned adhesive resin (aluminum member having a tube connection joint (a flat plate with an outer diameter of 100 mm and having a tube nozzle with an outer diameter of about 20 mm) as shown in FIG. I) was applied to a thickness of about 0.5 mm. The peripheral part of the hole and the joint connection part were heated and welded at about 200 ° C. to form a multilayer hollow molded product (container XII) to which a tube connecting joint was attached.

  Container XII was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed and measured for change in weight after standing at 40 ° C. for 200 hours. As a result, the weight was reduced by 85 mg.

[Molding and Evaluation of Multi-layer Hollow Molded Product with Tube Connection Joint and Support Member]
In the same manner as in Example 7, the same container as the container XI was formed. A hole with a diameter of 40 mm was opened in the upper plane of the container.
The above-mentioned bonding is applied to the joint portion and flange portion of the tube connecting joint (a flat member having an outer diameter of 100 mm and an aluminum member having a tube nozzle having an outer diameter of about 20 mm on the top) as shown in FIG. Resin (I) was applied to a thickness of about 0.5 mm. The hole periphery and joint joint are heated and welded at about 200 ° C to attach the tube connection joint, and the flange portion of the joint and the polyethylene resin support member are heated and welded at about 200 ° C to connect and support the tube connection. A multilayer hollow molded article (container XIII) with the members attached thereto was molded.

  Container XIII was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed and measured for change in weight after standing at 40 ° C. for 200 hours. As a result, the weight decreased by 85 mg.

[Formation and evaluation of multilayer hollow molded products with tube connection joints and support members coated with nylon on the inner surface]
In the same manner as in Example 7, the same container as the container XI was formed. A hole with a diameter of 40 mm was opened in the upper plane of the container.
14 is a tube connecting joint (a member made of aluminum having a flat plate shape with an outer diameter of 100 mm and a tube nozzle with an outer diameter of about 20 mm at the top, and the inner surface of the adhesive resin having a thickness of 0.5 mm. The adhesive resin (I) was applied to a portion where the tank body was bonded to the tank body and a flange portion (having a nylon coating thickness of 0.5 mm through the adhesive) so as to have a thickness of about 0.5 mm. The hole periphery and joint joint are heated and welded at about 200 ° C., a tube connecting joint is attached, and the flange portion of the joint and the polyethylene resin support member are heated and welded at about 200 ° C., and the inner surface is coated with nylon. A multilayer hollow molded product (container XIV) with a connecting joint and a support member attached thereto was molded.

  Container XIV was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed and measured for change in weight after standing at 40 ° C. for 200 hours. As a result, the weight decreased by 85 mg.

[Molding and Evaluation of Multilayer Hollow Molded Product with Inlet and Support Member]
In the same manner as in Example 7, the same container as the container XI was formed. A hole with a diameter of 40 mm was opened in the upper plane of the container.
The above adhesive resin (I) is connected to the joint portion and flange portion of an inlet (a flat plate having an outer diameter of 100 mm and an aluminum member having a cylindrical tube having an outer diameter of about 50 mm) as shown in FIG. ) Was applied to a thickness of about 0.5 mm. A multi-layer structure in which the hole periphery and inlet joint are heat-welded at about 200 ° C. and the inlet is attached, and the flange portion of the inlet and the polyethylene resin support member are heated and welded to about 200 ° C., and the inlet and support member are attached. A hollow molded product (container XV) was molded. At this time, the protruding portion on the outer peripheral portion of the inlet was in contact with the permeation preventive layer of the tank body.
Container XV was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed, and the weight change after being left at 40 ° C. for 200 hours was measured. As a result, the weight was reduced by 75 mg.

[Reference Example 1]
[Molding and evaluation of multi-layer hollow molded products]
In the same manner as in Example 7, the same container as the container XI was formed. This container was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed, and the weight change after being left at 40 ° C. for 200 hours was measured. As a result, the weight was reduced by 60 mg.

[Comparative Example 6]
[Molding and evaluation of multilayer hollow molded products with polyethylene tube connection joints]
In the same manner as in Example 201, the same container as the container XI was formed. A hole with a diameter of 40 mm was opened in the upper plane of the container.

The tube connecting joint as shown in FIG. 10 (a flat plate with an outer diameter of 100 mm, a tube nozzle with an outer diameter of about 20 mm at the top, a density of 0.947 g / cm ³ and a melt at 190 ° C. under a load of 21.6 kg The adhesive resin (I) was applied to a portion where the flow rate was 6 g / 10 min high-density polyethylene member) and the tank body so as to have a thickness of about 0.5 mm. The peripheral part of the hole and the joint joint were heated and welded at about 200 ° C. to form a multilayer hollow molded product (container XVII) to which a joint for connecting tubes was attached.
Container XVI was filled with 5 L of gasoline containing 10% by volume of ethanol and allowed to stand at 40 ° C. for 1000 hours. Then, it was replaced with 5 L of new ethanol containing 10% by volume of ethanol, sealed, and the weight change after being left at 40 ° C. for 200 hours was measured. As a result, the weight was reduced by 110 mg.

Sectional drawing of the principal part in an example of the component attachment hole of the tank main body of this invention, the member for permeation | transmission prevention, and the heater for shaping | molding Sectional drawing of the principal part in an example of the component attachment hole of the tank main body of this invention, the member for permeation | transmission prevention, and the heater for shaping | molding Sectional drawing of the principal part in an example of the component attachment hole of the tank main body of this invention, and the member for permeation | transmission prevention Sectional drawing of the principal part in an example of the component attachment hole of the tank main body of this invention, the member for permeation | transmission prevention, and an accessory Sectional drawing of the principal part in an example of the component attachment hole of the tank main body of this invention, the member for permeation | transmission prevention, and an accessory Sectional drawing of the principal part in an example of the pinch-off part of the hollow molded article main body of this invention, and the member for permeation | transmission prevention Sectional drawing of the principal part in an example of the pinch-off part of the hollow molded article main body of this invention, and the member for permeation | transmission prevention Sectional drawing of the principal part in an example of the final product of the hollow molded product of this invention Sectional drawing of the principal part in an example of the structure which attached the accessory (inlet) to the component attachment hole of the tank main body of this invention Sectional drawing of the principal part in an example of the structure which attached the accessory (valve) to the component attachment hole of the tank main body of this invention Sectional drawing of the principal part in an example of the structure which attached the attachment part (inlet) and the support member to the component attachment hole of the tank main body of this invention Sectional drawing of the principal part in an example of the structure which attached the attachment part (valve) and the support member to the component attachment hole of the tank main body of this invention Sectional drawing of the principal part in an example of the structure which attached the attachment part (inlet) and the support member to the component attachment hole of the tank main body of this invention Sectional drawing of the principal part in an example of the structure which attached the attachment part (valve) and the support member to the component attachment hole of the tank main body of this invention Sectional drawing of the principal part in an example of the structure which attached the accessory (inlet) to the component attachment hole of the tank main body of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Tank body 102 Fuel permeation prevention layer 103 Adhesive resin layer 104 Synthetic resin inner layer 105 Synthetic resin outer layer 106 Parts mounting hole 107 Accessory part 108 Fuel permeation prevention layer of accessory part 109 Permeation prevention member 110 Metal sheet 111 Permeation prevention Adhesive resin layer of member 112 Molded heater 113 Hollow molded product body 114 Permeation preventive layer 115 Adhesive resin layer 116 Resin inner layer 117 Resin outer layer 118 Pinch-off part 119 Portion where permeation preventive layer does not contact 120 Permeation preventive member 121 Metal sheet DESCRIPTION OF SYMBOLS 122 Adhesive resin layer 123 Molding heater 124 Accessory component material 201 Tank main body 202 Fuel permeation prevention layer 203 Adhesive resin layer 204 Synthetic resin inner layer 205 Synthetic resin outer layer 206 Component mounting hole 207 Accessory component (inlet)
208 Adhesive resin 209 Accessories (valves)
210 Support member 211 Polyethylene resin 212 Projection

Claims (7)

  A multi-layer container having an inner layer and an outer layer of polyolefin resin and having an anti-permeation layer as an intermediate layer, comprising a metal sheet or foil having an adhesive resin layer made of polyolefin modified with unsaturated carboxylic acid or a derivative thereof A fuel tank multilayer container in which a permeation preventing member is welded to a discontinuous portion of a permeation prevention layer. 2. The fuel tank according to claim 1, wherein the discontinuous portion of the permeation preventive layer is any one of 1) a joint portion of a multilayer container, 2) a pinch-off portion of multilayer blow molding, or 3) a hole portion opened for processing a part. Multi-layer container. The fuel tank according to claim 1, wherein the adhesive resin is a polyolefin modified with 0.01% by mass or more and 30% by mass or less of an unsaturated carboxylic acid or a derivative thereof and satisfies the following conditions (a) to (e): Multi-layer container.
(A) The melt flow rate of the modified polyolefin at a temperature of 190 ° C. and a load of 2.16 kg is from 0.1 g / 10 min to 100 g / 10 min,
(B) The density of the modified polyolefin is 0.910 to 0.965 g / cm ³ ,
(C) Initial bond strength with metal sheet or foil is 0.1 kg / 10 mm or more,
(D) The adhesive strength with a metal sheet or foil after immersion for 2500 hours at 65 ° C. in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol is 0.1 kg. / 10mm or more,
(E) The ratio of the adhesive strength of (d) to the initial adhesive strength of (c) is 50% or more.   The multilayer container for a fuel tank according to claim 1, wherein the metal is selected from the group consisting of aluminum, stainless steel and copper.   The multilayer for fuel tank according to claim 1, wherein a permeation preventive synthetic resin accessory is welded to a surface of a metal sheet or a foil of a permeation prevention member welded to a part mounting hole provided in the multilayer container. container.   The multilayer container for a fuel tank according to claim 1, wherein a permeation preventing member is welded so as to cover at least 50% of the area of the discontinuity portion of the permeation preventing layer exposed on the outer surface of the pinch-off part. An anti-permeation member that has an inner layer and an outer layer of a polyolefin resin and is welded to a discontinuous portion of the permeation preventive layer of a fuel tank multilayer container that has a permeation preventive layer as an intermediate layer, and blocks permeation of hydrocarbon compounds, The member for permeation | transmission prevention which has the adhesive resin layer which consists of modified polyolefin which satisfies the following conditions (a)-(e) on the surface of a metal sheet or foil.
(A) The melt flow rate of the modified polyolefin at a temperature of 190 ° C. and a load of 2.16 kg is from 0.1 g / 10 min to 100 g / 10 min,
(B) The density of the modified polyolefin is 0.910 to 0.965 g / cm ³ ,
(C) Initial bond strength with metal sheet or foil is 0.1 kg / 10 mm or more,
(D) The adhesive strength with a metal sheet or foil after immersion for 2500 hours at 65 ° C. in a mixed solvent of 45 parts by volume of 2,2,4-trimethylpentane, 45 parts by volume of toluene and 10 parts by volume of ethyl alcohol is 0.1 kg. / 10mm or more,
(E) The ratio of the adhesive strength of (d) to the initial adhesive strength of (c) is 50% or more.

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