JPH08132459A - Multilayered hollow molding and oil storage container - Google Patents

Abstract

PURPOSE: To obtain a molding having both of impact resistance and gasoline permeability by providing a polyamide resin layer and combining, for example, a layer high in impact resistance and a layer good in gasoline permeability to mold them. CONSTITUTION: A multilayered hollow molding constituted of two or more layers and produced by rotary molding has at least a layer (A) containing 80wt.% or more of a polyamide resin, a layer (B) containing at least 30-100wt.% of a thermoplastic resin other than the polyamide resin and an elastomer other than the polyamide resin in total, a layer (C) containing a polyamide/polyol block copolymer obtained from 60-100wt.% of lactams and 0-40wt.% of polyol or polyamide and a layer (D) containing a polyamide/polyol block copolymer obtained from 10-40wt.% of lactams and 60-90wt.% of polyol. As a result, the hollow molding may have a structure consisting of three or more layers.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a multi-layer hollow molded article having at least one polyamide resin layer,
The present invention relates to a hollow molded article having excellent impact resistance and excellent permeation resistance to oil such as gasoline.

[0002]

Polyamide resins are widely used as engineering plastics having excellent mechanical properties, heat resistance, chemical resistance and gasoline permeation resistance. Therefore, the hollow molded product by the rotational molding method is about to be used for an oil tank, a gasoline tank, etc. of a two-wheeled vehicle, a four-wheeled vehicle and a leisure / industrial vehicle.

As a method for producing a hollow molded product of a polyamide resin, for example, a powdery polyamide is heated in a rotating mold to a temperature higher than the melting point of the polyamide and melted to form a molten polymer film on the inner wall surface of the mold. , A method of cooling and solidifying (for example, USP-2629134, USP-343
9079), a method of anionic polymerization of ω-lactams in a rotational molding machine with an alkali catalyst and an activator (for example, JP-B-41-32, JP-A-47-13667, JP-A-47-18996). , JP-A-51-1
No. 06167) is known.

[0004]

However, the impact resistance of the molded product obtained by molding the powdery polyamide in the rotational molding die is low, which is a practical problem.

On the other hand, according to the anionic polymerization method, such drawbacks can be solved by copolymerizing a flexibility-imparting component such as polyol (JP-A-58-21425).
However, there is a drawback that it is necessary to copolymerize a large amount of polyol, which impairs the gasoline permeation preventive property which is another required property. As another method other than the anionic polymerization method, an impact modifier such as an ABS resin, a styrene / methylmethacrylic acid copolymer, a maleic anhydride-added polydiolefin, or a core-shell polymer is dissolved in a lactam or polymerized by dispersing a powder. Therefore, there is a method (Japanese Patent Publication No. 49-11755, Japanese Patent Publication No. 59-22923, Japanese Patent Publication No. 59-93726, Japanese Patent Publication No. 62-141025) for improving the impact resistance. , Since these have low solubility of the impact modifier in the lactam, sufficient impact resistance cannot be obtained, or the method of dispersing the impact modifier is not sufficient dispersion of the impact modifier,
Since the melting point is generally low, there is a problem that the impact modifier is aggregated at the polymerization temperature.

In view of these circumstances, the present inventors have made earnest studies on a rotational molded article having at least one polyamide resin layer and having excellent impact resistance and gasoline permeability, and as a result, the above-mentioned problems are solved. The inventors have found that and reached the present invention.

[0007]

Means for Solving the Problems That is, the present invention relates to a first invention "a rotationally molded multi-layer hollow molded article composed of two or more layers, which comprises 80% by weight of (A) a polyamide resin. At least one layer containing the above and (B) a thermoplastic resin other than the polyamide-based resin and an elastomer other than the polyamide-based resin, and having at least a layer containing 30 to 100% by weight in total. A multi-layer hollow molded article characterized by "." And a second invention "A rotary molded multi-layer hollow molded article composed of two or more layers, comprising (C) 60 to 100% by weight of a lactam and a polyol. Layer containing polyamide / polyol block copolymer or polyamide obtained from 0 to 40% by weight, and (D) lactams 10 to 40% by weight and polyol 60 to 90% by weight % Obtained from polyamide / polio -. Multilayer hollow molded article characterized by having at least a layer containing the Le block copolymer consisting of ".

The details of the present invention will be described below.

The hollow molded article obtained by the rotational molding of the present invention has a multi-layer structure having the layer (A) and the layer (B) in the first invention. The second invention has a multi-layer structure having the layer (C) and the layer (D). The layer having the characteristics of the present invention may be a plurality of layers, and as a result, may be a hollow molded article having a structure of three or more layers.

First, the first invention will be described. The layer (A) of the present invention must contain a polyamide resin in an amount of 80% by weight, more preferably 85% by weight.

Examples of the polyamide-based resin here include polyamide and copolymers of polyamide and those having other kinds of skeletons.

As the polyamide, nylon 6 produced from ε-caprolactam, nylon 11 produced from ω-aminoundecanoic acid, nylon 12 produced from ω-aminododecanoic acid, and a polycondensate of dicarboxylic acids and diamines. (For example, nylon 66 manufactured from adipic acid and hexamethylenediamine, nylon 610 manufactured from sebacic acid and hexamethylenediamine, nylon 612 manufactured from dodecanedioic acid and hexamethylenediamine, manufactured from adipic acid and tetramethylenediamine. Nylon 46 etc.), a polycondensation product of an aromatic dicarboxylic acid and an aliphatic diamine (for example, nylon 6T produced from terephthalic acid and hexamethylenediamine (T represents terephthalic acid), isophthalic acid and hexamethylenediamine). Manufactured That Nylon 6I (I represents isophthalic acid), copolymer nylon 6T / 6 produced from terephthalic acid, isophthalic acid and hexamethylenediamine
I, terephthalic acid, copolymerized nylon 6T / 66 produced from adipic acid and hexamethylenediamine, and nylon 6/6 produced by copolymerization of the above nylon raw materials
6 copolymer, nylon 6/66/610 copolymer, nylon 6/12 copolymer, nylon 6/66/610/6
12 copolymer, nylon 6 / 6T copolymer, nylon 6
/ 66 / 6T copolymer, nylon 66 / 6T / 6I copolymer, nylon 6 / 6T / 6I copolymer, nylon 6 /
Examples include terpolymers such as 66 / 6T / 6I copolymers and quaternary copolymers. Preferred examples are nylon 6, nylon 66, nylon 6/66 copolymer, nylon 11, nylon 12, nylon 6/12 copolymer, nylon 46, nylon 6 / 6T copolymer, nylon 66 / 6T copolymer. Polyamide resins such as Nylon 6 and Nylon 6 are particularly preferred.
6, Nylon 11, Nylon 12, Nylon 610, and copolymers thereof.

As the polyamide resin, a block copolymer of lactams, which is a raw material for nylon, and a polyol, that is, a polyamide / polyol block copolymer can be used. Examples of the polyol include polyoxyethylene glycol and polyoxypropylene glycol.
, Polyoxypropylated glycerin, polyoxytetramethylene glycol, polyoxybutadiene glycol
And the like are preferably used. The copolymerization ratio is 60% by weight or more, further 70% by weight or more for the structure derived from lactams, and 4% for the structure derived from polyol.
Those in the range of 0% by weight or less, more preferably 30% by weight or less are preferably used. If the amount of the polyol added is too large, it adversely affects the polymerizability and mechanical properties, which is not preferable.

Of the above, it is preferable that the polyamide resin of the layer (A) is a polyamide obtained by anionically polymerizing ω-lactam in terms of the uniformity of the thickness of the obtained molded product. Examples of the polyamide thus obtained include nylon 6, nylon 11 and nylon 12. As the ω-lactam, for example, pyrrolidone,
Valerolactam, caprolactam, enantolactam,
Examples thereof include capryl lactam and laurolactam, and two or more kinds of ω-lactams may be used in combination and used as a copolymer. Examples of the anionic polymerization catalyst include salts of ω-lactam with an alkali metal such as sodium lactamate and potassium lactamate, and reaction products of a Grignard reagent with ω-lactam. Examples of the activator include an isocyanate compound and a reaction product of an isocyanate compound and a ω-lactam, an acyllactam (acetyllactam, benzoyllactam, adipoylbislactam, terephthaloylbislactam, chloroterephthaloyl). Rubislactam, sebacoyl bislactam, isophthaloyl bislactam and the like).
Furthermore, when the polyamide resin of the layer (A) is a polyamide / polyol block copolymer, a polyol can also be blended and anionically polymerized to obtain a polyamide / polyol block copolymer.

The method of supplying the anionic polymerization raw material to the mold of the hollow molding machine is such that the ω-lactam, the polymerization catalyst and the activator are supplied in the form of powder or flake in the range of 0.005 mm to 10 mm. Alternatively, (A) ω-lactam / polymerization catalyst and (B) ω-lactam / activator / polyol may be separately melted in the temperature range of 70 to 150 ° C. and supplied in liquid form.

Next, the layer (B) containing at least one thermoplastic resin other than the polyamide resin and at least one elastomer other than the polyamide resin will be described. Here, the total amount of the thermoplastic resin other than the polyamide resin and the elastomer other than the polyamide resin needs to be 30 to 100% by weight in the layer (B).

The term "thermoplastic resin" as used herein refers to an aromatic vinyl polymer, a liquid crystal polymer, an olefin copolymer, an ethylene chloride polymer, an aromatic polyester, and an aromatic polyester, as long as they have no rubber elasticity at 20.degree. An α, β-unsaturated carboxylic acid polymer is preferably used. As the aromatic vinyl-based polymer, polystyrene, acrylonitrile / acrylic styrene resin (AAS), acrylonitrile /
Ethylene / propylene / diene / styrene resin (AE
S), acrylonitrile / styrene resin (AS), and acrylonitrile / butadiene / styrene resin (ABS). As the olefin-based polymer and the chlorinated ethylene-based polymer, ethylene / vinyl chloride copolymer (E-P
VC), ethylene / vinyl acetate copolymer (EVA) ethylene / vinyl alcohol copolymer (EVOH), chlorinated polyethylene (PE-C), polyethylene (PE), polypropylene (PP), polyvinylidene chloride (PVD)
C) and polyvinyl chloride (PVC) are exemplified. As the aromatic polyester, polyethylene terephthalate
(PET), polybutylene terephthalate (PB
T) and polycyclohexyl terephthalate (PCT) are exemplified. As the α, β-unsaturated carboxylic acid polymer, polymethyl methacrylate (PMMA) is exemplified. Other polyoxybenzoyl esters, polycarbonate
Bonnet (PC), polyvinyl acetate (PVAC), polysulfone (PSF), polyphenylene ether (PP)
E), polyphenylene sulfide (PPS), phenoxy resin, fluororesin, polyacrylate, polyacetate (POM), polyamide imide (PAI), polyarylate (PAR), polyetheramide (PEI),
Polyether ether ketone (PEEK), methyl pentene polymer (TPX) and the like can also be used. These polymers are treated with α, β-unsaturated carboxylic acids and derivatives such as acid anhydrides (for example, maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, maleic imide, maleic anhydride, fumaric acid, itaconic acid, Acrylic acid,
Those modified with methacrylic acid,), acrylic acid ester (methyl methacrylic acid ester, glycidyl methacrylic acid ester, etc.) can also be used. The elastomer of the present invention exhibits rubber-like elasticity at 20 ° C., for example, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, and a part of carboxylic acid moiety in these copolymers or All are salts with sodium, lithium, potassium, zinc, calcium (ionomer-resin), ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / ethyl acrylate-g-anhydrous Maleic acid copolymer (“g” represents a graft, the same applies hereinafter), ethylene / methyl methacrylate-g-maleic anhydride copolymer, ethylene / ethyl acrylate-g-maleimide copolymer, ethylene / acrylic acid Ethyl-g-N-phenylmaleimide copolymers and partially saponified products of these copolymers, ethylene / propylene Polymer, ethylene / propylene /
1,4-hexadiene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 2,5-norbornadiene copolymer, ethylene / butene copolymer and α, β-unsaturated carboxylic acid thereof And acid anhydrides thereof (for example, maleic acid, maleic anhydride, maleic anhydride imide, fumaric acid, itaconic acid, acrylic acid, methacrylic acid, crotonic acid, etc.), acrylic acid esters (methyl methacrylic acid ester, glycidyl methacrylic acid ester, etc.) ) A copolymer modified with, for example, at least one vinyl aromatic compound (styrene,
a polymer block mainly composed of o-methylstyrene, p-methylstyrene, α-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene and the like, and at least one conjugated diene compound (1,3-butadiene, 2- Methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene,
1,3-hexadiene and the like), a block copolymer consisting of a polymer block, a hydrogenated block copolymer of the block copolymer, and further the above α, β-unsaturated carboxylic acid and the same. Examples thereof include copolymers modified with acid anhydrides and acrylic acid esters, and the like, such as polyurethane-based thermoplastic elastomers, silicone rubber, and polyester-based thermoplastic elastomers. Among them, ionomer resins, ethylene / methyl acrylate copolymers, ethylene / ethyl acrylate copolymers, ethylene / propylene copolymers, ethylene / propylene /
1,4-hexadiene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 2,5-norbornadiene copolymer, ethylene / butene copolymer, styrene / butadiene / styrene block copolymer and Hydrogenated block copolymer of the block copolymer, polyurethane-based thermoplastic elastomer,
Silicone rubber and polyester thermoplastic elastomer are preferably used.

In the layer (B), the elastomer and the thermoplastic resin may be used alone or may be mixed and used. As the amount, the total amount of the elastomer and the thermoplastic resin in the layer (B) needs to be in the range of 30 to 100% by weight. Further, a mixture of the two is preferably used, and in the relationship between the two, it is preferable that the thermoplastic resin / elastomer is prepared in a range of a weight ratio of 2/98 to 98/2. Further, in the layer (B), the elastomer preferably has a dispersed structure, and the dispersed particle diameter thereof is preferably in the range of 0.05 μm to 20 μm in order to improve impact resistance. On the other hand, when the thermoplastic resin is a component having a large amount of elastomer and is dispersed in the layer, the dispersed particle diameter of the thermoplastic resin is 0.0
It may be dispersed within the range of 5 μm to 20 μm, and may have a discontinuous layered form.

The layer (B) may contain a polyamide resin, and an amount of 70% by weight or less is preferably used. The polyamide resin used here is the polyamide resin composition described for the layer (A).

The composition of the layer (B) in which the polyamide resin is blended is not particularly limited, but for example, the polyamide resin is 2 to 70% by weight, and the thermoplastic resin 9 is used.
It is preferably used in the range of 8 to 0% by weight, elastomer-98 to 0% by weight, and the total amount of the thermoplastic resin and the elastomer is 30% or more.

Further, it is preferable that the content of the elastomer is 2% by weight or more. In that case, the dispersed particle diameter of the elastomer in the polyamide resin composition is preferably in the range of 0.05 μm to 20 μm in order to improve impact resistance. Further, when the thermoplastic resin is dispersed with a component containing a large amount of elastomer, it is preferable that the dispersed particle diameter of the thermoplastic resin is also within the range of 0.05 μm to 20 μm, but a discontinuous layer is formed. You can do it.

Next, the second invention will be described.

In the present invention, (C) lactams 60-1
Layer containing polyamide / polyol block copolymer or polyamide obtained from 0. 0% by weight and 0-40% by weight of polyol and (D) 10% by weight of lactams
A hollow molded article having a layer containing a polyamide / polyol block copolymer obtained from the above-mentioned less than 60% by weight and more than 40% by weight of polyol and 90% by weight or less. .

The lactams are, for example, pyrrolidone, which is a raw material for nylon 6, nylon 11, nylon 12, etc.
Valerolactam, caprolactam, enantolactam,
Examples thereof include capryl lactam and laurolactam. Polyol is polyoxyethylene glyco-
, Polyoxypropylene glycol, polyoxypropylated glycerin, polyoxytetramethylene glycol
And polyoxybutadiene glycol are preferably used. The polyamide / polyol block copolymer used in the layers (C) and (D) can be obtained by anionic polymerization while rotational molding in the coexistence of the ω-lactam and the polyol. In the polymerization at that time, as a catalyst, for example, a salt of an ω-lactam with an alkali metal such as sodium lactamate or potassium lactamate, and a reaction product of a Grignard reagent and an ω-lactam are simultaneously mixed. Preferably. Also. The addition of an activator is also effective, and examples thereof include an isocyanate compound and a reaction product of an isocyanate compound and an ω-lactam,
Examples thereof include acyllactams (acetyllactam, benzoyllactam, adipoylbislactam, terephthaloylbislactam, chloroterephthaloylbislactam, sebacoylbislactam, isophthaloylbislactam, etc.).

The polyamide / polyol block copolymer or polyamide compounded in the layer (C) includes 60 to 100% by weight of lactams and 0 to 40% by weight of polyols.
However, it is more preferable that the lactams are 70 to 100% by weight and the polyol is 0 to 30% by weight.

As the polyamide / polyol block copolymer to be blended in the layer (D), the lactams are in the range of 10% by weight to less than 60% by weight and the polyol is more than 40% by weight.
It is necessary that the content of the lactam is 15% to 50% by weight, and the polyol is 50% to 85% by weight.

Lactams 60 to 10 in the layer (C)
The content of the polyamide / polyol block copolymer or polyamide obtained from 0% by weight and 0-40% by weight of the polyol is 50% by weight or more, further 60% by weight or more, and further 70% by weight or more. Is preferred.

In the layer (D), the lactams are contained in an amount of 10% by weight or more and less than 60% by weight and polyol 40% by weight or more 90%.
The content of the polyamide / polyol block copolymer obtained from 10% by weight or less is preferably 50% by weight or more, further 60% by weight or more, and further 70% by weight or more.

Items common to the first invention and the second invention will be described below.

When each layer is formed by the rotational molding method, it is generally used in the form of powder resin. The method for producing the raw material powder of the material resin is not particularly limited, and may be produced by a known method. Generally, those frozen and pulverized with liquid nitrogen or the like can be used. The particle size of the powder is 0.00 from the viewpoint of easy melting and flowing in the mold.
Those having a particle diameter within the range of 5 mm to 1 mm are used, and those having passed through an 80 mesh sieve (177 μm) are particularly preferably used.

The hollow molded article of the present invention has a polyamide resin layer, and is formed, for example, by combining a layer having high impact resistance with a layer having good gasoline permeability (small amount of gasoline permeation). It is a molded product that has both impact resistance and gasoline permeation characteristics, and it is possible to have a multi-layer structure such as three-layer or four-layer based on such a concept. It is also within the technical scope of the present invention to change the order of forming the materials based on such an idea.

The formation of each layer may be carried out continuously and / or batchwise depending on the type and mechanism of the rotary molding machine.

The continuous layer formation means that after the first layer is rotationally molded, the rotation is not stopped and the mold is not forcibly cooled.
This is a molding method in which the materials for the second and subsequent layers are supplied. The material may be supplied by dividing each layer, or may be supplied continuously.

The formation of a batch layer means that after the first layer is rotationally molded, the rotation of the mold is stopped with or without cooling the mold, and the second and subsequent layers are sequentially processed. It refers to the method of molding.

Furthermore, it is also possible to carry out rotational molding by combining the continuous layer forming method and the batch layer forming method.

Also for the anionic polymerization of ω-lactam,
Layers can be formed as well. A combination of a layer formed by anionic polymerization of ω-lactam and a layer formed by a thermoplastic resin and / or an elastomer is also a preferred embodiment of the present invention.

The temperature of the rotational molding is usually higher than the melting temperature of the material resin except for the layer formation by the anionic polymerization of the ω-lactam, and preferably from the melting point to the melting point + 30.
It is in the range of ° C. 130-20 in anionic polymerization
A range of 0 ° C is suitable.

According to the molding method of the present invention, after the material is put into the mold, and after the molding is completed, the mold is set on one or two or more rotating shafts set at arbitrary positions. On the other hand, it can be carried out by utilizing a known rotational molding method capable of rotating, reversing or pendulum motion. At this time, it is particularly preferable that the inside of the mold is replaced with an inert gas such as nitrogen so as to be essentially oxygen-free in order to prevent discoloration and deterioration of the resin. Especially in the case of anionic polymerization of ω-lactam, it is preferable to make the atmosphere as anhydrous as possible.

In the hollow molded article of the present invention, if necessary, in any layer, an inorganic or organic fibrous reinforcing material such as glass fiber, carbon fiber, asbestos fiber, wholly aromatic polyamide fiber or talc, wollastenite, Bentonite, montmorillonite, calcium carbonate, magnesium oxide,
It is possible to introduce powdered or spherical fillers such as alumina, mica, glass beads, and potassium whisker titanate, molybdenum disulfide, paraffin, and silicone.

In the hollow molded article of the present invention, as long as the moldability is not impaired, other components such as a release agent such as a metal stearate composed of magnesium stearate and aluminum stearate, a pigment, and the like are used in every layer. dye,
Flame retardant, heat-resistant agent, antioxidant, weathering agent, lubricant, release agent,
It can be molded by adding an antistatic agent, a plasticizer, a crystal nucleating agent, a foaming agent and the like.

The hollow molded article of the present invention obtained as described above, in which at least one layer is a polyamide resin layer and which has improved impact resistance, is an oil tank for a motorcycle, an automobile, etc., a gasoline tank, etc. It can be applied to the oil storage container of, and is most suitable for the gasoline tank etc. which require impact resistance.

[0042]

The present invention will be described in more detail with reference to the following examples. The present invention is not limited to these examples.

The hollow molded articles were evaluated according to the following methods. (1) Surface appearance: Visual judgment (2) Wall thickness: Measured with a caliper after cutting (3) Impact resistance test: A hollow hollow body was filled with an antifreeze solution to 50% by volume and adjusted to a temperature of -15 ° C. It is carried out by a method of hitting a hollow molded body with an impact energy of 40 Nm by a pyramid (roundness of corners: r = 5 mm). (4) Gasoline permeability: Gasoline specified in JIS K 2202 was filled up to 50% by volume of the hollow molded body, sealed, and placed in a constant temperature test room adjusted to an ambient temperature of 40 ± 2 ° C. for 8 weeks. Implemented by the method of measuring the reduction amount. (5) Heat resistance test: A molded hollow body was filled with an antifreeze solution up to 50% by volume and allowed to stand in an oven adjusted to 70 ° C. for 1 hour, and liquid leakage and deformation were visually observed and judged. (6) Elastomer-dispersion diameter: The test product was cut with a microtome, stained, and observed and measured with an electron microscope.

Reference Example 1 (Preparation of Composition Material) After dry blending with the types and composition ratios of the resins shown in Table 1, they were kneaded by a twin-screw melt extruder, drawn into strands, and pelletized by a cutter. The elastomer dispersion of the pellet was observed with an electron microscope, and it was confirmed that the dispersion diameter was as shown in Table 1. The pellets were cooled with liquid nitrogen, freeze-ground and used in the examples.

Example 1 (First Invention) As the outer layer, the material shown in Table 1A (nylon 6: 60% by weight,
Ionomer resin (Mitsui DuPont Polychemical Co., Ltd .:
(Abbreviated as HM1706): 40% by weight))
Was used. The particle size of the ionomer resin dispersed in the polyamide resin of this composition was 0.2 to 2.2 μm. This composition was cryogenically ground under nitrogen cooling to give 80
It was processed into a powder that passed through a mesh sieve. This powder 16
00 g was put into a mold for molding a rectangular container having an internal capacity of 12 liters, and the outer layer was molded at a molding temperature of 250 ° C. (resin temperature) with a biaxial rotary molding machine. The mold was cooled to 150 ° C., and then 200 g of a powder of nylon 6/66 = 60/40 (wt%) copolymer resin (melting point 175 ° C.) that had passed through a 80 mesh screen was charged, and 200 ° C. (resin temperature) Then, the inner layer was rotationally molded to obtain a gasoline tank. This molded product was evaluated and the results shown in Table 2 were obtained. The surface appearance of the molded product was good, and the wall thickness was distributed in a uniform thickness of 4 to 5 mm in the outer layer and 1 to 2 mm in the inner layer. When the impact resistance test of this molded product was carried out,
It was a molded product with good impact resistance without cracking or damage. The gasoline permeability was 0.2 g / day, which was very low and excellent. There is no deformation or liquid leakage in the thermal deformation test,
A practical molded product having heat resistance was obtained.

Examples 2 to 6 (first invention) A hollow molded article was obtained in the same manner as in Example 1 except for the conditions shown in Table 2. Both are the object of the present invention, impact resistance,
A hollow molded article having excellent gasoline permeability was obtained.

Example 7 (first invention, three-layer structure) Using the materials shown in Table 2, the outer layer, the intermediate layer (adhesive layer) and the inner layer were formed in this order under the molding conditions of Table 2 in the same manner as in Example 1. It was operated and rotationally molded to form a hollow molded article having three layers. This hollow molded article was evaluated and the results shown in Table 2 were obtained. A multilayer hollow molded article having excellent impact resistance, heat resistance and gasoline permeability was obtained.

Example 8 (first invention, three-layer structure) An anionic polymerized material of caprolactam was placed in a mold for the outer layer, and the same operation as in Example 1 was carried out at 160 ° C. (material temperature) to obtain nylon 6 Layers were formed. Thereafter, the intermediate layer and the inner layer were molded under the materials and molding conditions shown in Table 3 in Example 1
A multilayer hollow molded article was formed by the same operation as above.
The molded product was evaluated in the same manner as in Example 1 and the results shown in Table 3 were obtained. A molded product having satisfactory impact resistance and gasoline permeability was obtained.

Examples 9 to 10 (first invention) A multilayer hollow molded article was molded in the same manner as in Example 8 by using the anionic polymerized material of caprolactam, the material of Table 3 and the molding conditions. This multilayer hollow molded article was evaluated in the same manner as in Example 1, and the results shown in Table 3 were obtained. A molded product having satisfactory impact resistance and gasoline permeability was obtained.

Examples 11 to 13 (first invention) Example 1 was spin-molded under the materials and molding conditions shown in Table 3.
A two-layer hollow molded article was molded in the same manner as in. The hollow molded article was evaluated in the same manner as in Example 1 and the results shown in Table 3 were obtained. This molded product has a high practical value and is satisfactory in both impact resistance and gasoline permeability.

Examples 14 to 15 (Second Invention) A multilayer hollow molded article was molded in the same manner as in Example 9 by using the anionic polymerized material of caprolactam, the material of Table 4 and the molding conditions. This multilayer hollow molded article was evaluated in the same manner as in Example 1 and the results shown in Table 4 were obtained. A molded product having satisfactory impact resistance and gasoline permeability was obtained.

Comparative Example 1 Nylon 6: 99.1 wt%, H as the outer layer molding material
A composition consisting of M1706: 0.9% by weight was used.
The dispersed particle size of HM1706 in the polyamide resin is 0.
It was 2 to 2.6 μm. This composition was freeze-milled under nitrogen cooling and processed into a powder that passed through an 80 mesh screen. 1600 g of this powder was put into a mold for molding a rectangular container having an internal capacity of 12 liters, and molded at a molding temperature of 250 ° C. (resin temperature) by a biaxial rotation molding machine. Then, 200 g of nylon 6/66 = 60/40 (wt%) copolymer resin powder was added, and the inner layer was rotationally molded at 200 ° C. (resin temperature) in the same manner as in Example 1. This molded product was evaluated and the results shown in Table 4 were obtained. The surface appearance, uniformity of wall thickness, gasoline permeability, and thermal deformation test of the molded product were good, but as a result of the impact resistance test, the molded product was damaged and had insufficient impact resistance and was of no practical value. there were.

Comparative Example 2 A multilayer hollow molded article was molded in the same manner as in Example 14, except that the anionic polymerized material of caprolactam, the material shown in Table 4 and the molding conditions were used. This multilayer hollow molded article was evaluated in the same manner as in Example 4, and the results shown in Table 4 were obtained. The obtained molded product had poor gasoline permeability and heat deformability test results.

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

[Table 3]

[0057]

[Table 4]

[0058]

EFFECTS OF THE INVENTION The multi-layer hollow molded product of the present invention is excellent in physical properties such as impact resistance, heat resistance and gasoline permeation resistance.

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[Procedure amendment]

[Submission date] September 22, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

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Claims (13)

[Claims] 1. A rotationally molded multi-layer hollow molded article composed of two or more layers, which comprises (A) a layer containing 80% by weight or more of a polyamide resin and (B) a heat other than the polyamide resin. A multi-layer hollow molded article, comprising at least one type of elastomer other than a plastic resin and a polyamide resin, and having at least a layer containing 30 to 100% by weight of the total amount thereof. 2. The hollow molded article according to claim 1, wherein the polyamide resin of the layer (A) contains a polyamide selected from nylon 6,66,11,12,610 and copolymers thereof. . 3. The hollow molded article according to claim 1, wherein the polyamide resin of the layer (A) contains ω-lactam as a raw material, and contains a polyamide obtained by anionic polymerization during rotational molding. 4. The polyamide-based resin in the layer (A) is
The multi-layer hollow molded article according to claim 1, which contains a polyamide / polyol block copolymer obtained from 60% by weight or more of lactams and 40% by weight or less of polyol. 5. A polyol is polyoxyethylene glycol.
, Polyoxypropylene glycol, polyoxypropylated glycerin, polyoxytetramethylene glycol
5. The multi-layer hollow molded article according to claim 4, which is any one of polyoxybutadiene and polyoxybutadiene glycol. 6. The multilayer hollow molded article according to claim 4, wherein the polyamide / polyol block copolymer of layer (A) is obtained by anionic polymerization during rotational molding. 7. The layer (B) contains an elastomer, and the elastomer is an ionomer resin, ethylene /
Methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / propylene copolymer, ethylene / propylene / 1,4-hexadiene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 2,5-Norbornadiene copolymer, ethylene / butene copolymer, styrene / butadiene / styrene block copolymer and hydrogenated block copolymer of the block copolymer, polyurethane-based thermoplastic elastomer, silicone rubber 2. A hollow molded article according to claim 1, wherein the hollow molded article is selected from the group consisting of, and a thermoplastic polyester elastomer. 8. The layer (B) contains a thermoplastic resin and comprises an aromatic vinyl polymer, a liquid crystal polymer, an olefin polymer, an ethylene chloride polymer, an aromatic polyester, and α, The hollow molded article according to claim 10, which is one of a β-unsaturated carboxylic acid polymer and a polymer modified with an α, β-unsaturated carboxylic acid derivative. 9. The layer (B) is a thermoplastic resin / elastomer.
The hollow molded article according to claim 1, which is a composition in which is mixed in a weight ratio of 2/98 to 98/2. 10. An elastomer in the composition, wherein the elastomer has a dispersed structure in the layer (B).
10. The hollow molded article according to claim 9, wherein the dispersed particle size of is within a range of 0.05 to 20 μm. 11. The hollow molded article according to claim 1, wherein the layer (B) is a layer containing 70% by weight or less of a polyamide resin. 12. A rotationally molded multi-layer hollow molded article comprising two or more layers, comprising (C) lactams 60-1.
A layer containing a polyamide / polyol block copolymer or polyamide obtained from 0. 0% by weight and 0 to 40% by weight of a polyol, and (D) lactams of 10% by weight or more and less than 60% by weight and a polyol A multi-layer hollow molded article comprising at least a layer containing a polyamide / polyol block copolymer obtained from more than 40% by weight and 90% by weight or less. 13. An oil storage container comprising a multi-layer hollow molded article having any one of claims 1 to 12.