JP4773575B2 - Resin tank - Google Patents

Description

  The present invention relates to a resin tank in which a tank wall surface portion is formed of a resin multilayer structure, and particularly relates to a resin tank excellent in pressure resistance and heat resistance.

  There is known a hot water storage system for storing hot water boiled by a heat source using gas, electricity, solar heat, a fuel cell, or the like. In a hot water storage system, a metal tank is generally used as a hot water storage tank that is a pressure-resistant and heat-resistant container (see Patent Document 1).

JP 2006-329586 A

  As described in Patent Document 1, the conventional hot water storage tank is composed of a metal material in order to satisfy the pressure resistance performance, and the resin material is partially used from the viewpoint of improving the heat insulation performance. It is only used.

  In the case of a metal tank, a welding operation is required when a metal plate is rolled to form a body part or when a body part and a mirror plate are joined. There is a problem that the number of manufacturing steps such as roll processing and welding is relatively large, and it is difficult to achieve mass production and automation of manufacturing. Moreover, in order to maintain uniform tank quality, it is necessary to suppress variations in welding quality. From this point of view, it is difficult to achieve mass production and automation of manufacturing.

  In addition, metal tanks are relatively heavy and are subject to restrictions on the installation location or require reinforcement of the installation location.

  Moreover, since the hot water temperature is easy to cool, it is necessary to provide a heat insulating material on the outer periphery of the metal tank, and the hot water storage tank becomes large as much as the heat insulating material is added.

  In addition, in order to apply the stored hot water to drinking, a material with relatively little marketability (for example, SUS444) must be used as a material for the metal tank.

  In reality, it is difficult to reduce the cost of metal tanks due to the various factors described above. In order to reduce costs through mass production, automation of manufacturing, etc., it is required to realize a resin tank in which the tank wall surface portion is made of a resin material and has sufficient pressure resistance and heat resistance.

  Accordingly, an object of the present invention is to provide a resin tank as a pressure-resistant and heat-resistant container, which is advantageous in terms of cost.

In order to achieve the above object, the present invention provides a tank wall surface comprising an inner layer made of a polyphenylene ether resin, an outer layer made of a polyamide resin and provided outside the inner layer, and a polyphenylene containing a polyphenylene ether resin and a polyamide resin. A resin tank comprising a multilayer structure comprising an ether resin composition and having an intermediate layer located between the inner layer and the outer layer , wherein the polyphenylene ether resin used for the polyphenylene ether resin It is a resin tank having an intrinsic viscosity at 30 ° C. of 0.2 to 0.8 dl / g measured in chloroform .

Further, the tank wall portion is composed of a multilayer structure having an inner layer made of a polyphenylene ether resin and an outer layer made of a polyphenylene ether resin composition containing a polyphenylene ether resin and a polyamide resin and provided outside the inner layer. A resin tank having an intrinsic viscosity at 30 ° C. of 0.2 to 0.8 dl / g measured in chloroform of the polyphenylene ether resin used for the polyphenylene ether resin .

  The resin tank of the present invention can be mass-produced and automated by applying a general resin molding technique such as blow molding from a general-purpose resin material. Moreover, it can be made lighter than a metal tank and has excellent heat insulation. Even when the heat insulating material is provided, since the resin material has a lower thermal conductivity than the metal material, the amount of heat insulating material used can be reduced or eliminated. In addition, by configuring the tank wall surface portion from a multilayer structure, sufficient pressure resistance and heat resistance can be provided. Accordingly, it is possible to provide a resin tank as a pressure-resistant and heat-resistant container that is advantageous in terms of cost.

It is a fragmentary sectional view showing the hot water storage tank concerning a 1st embodiment. It is an expanded sectional view which shows the tank wall surface part shown with the code | symbol 2 of FIG. It is an expanded sectional view which shows the tank wall surface part which concerns on 2nd Embodiment. 4A and 4B are a front view and a top view of the hot water storage tank. 5A, 5B, and 5C are schematic cross-sectional views showing a forming apparatus for forming a hot water storage tank, and FIG. 5D is an enlarged view showing a portion D in FIG. 5A.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
Referring to FIG. 1, a hot water storage tank 10 to which a resin tank of the present invention is applied is a pressure-resistant and heat-resistant container used for storing hot water boiled by a heat source using gas or the like in a hot water storage system. The hot water storage tank 10 is installed through the legs 11. A pipe 13 for introducing hot water boiled by a heat source (not shown) into the tank is connected to the inlet 12 at the bottom of the tank, and a pipe 15 for leading the stored hot water to a necessary place at the outlet 14 at the top of the tank. It is connected. The inlet portion 12 and the outlet portion 14 are not limited to the positions in the illustrated example, and can be provided at appropriate positions such as a side wall of the tank. Although the specification of the hot water storage tank 10 is not particularly limited, for example, the capacity is 100 liters, the pressure resistance is 1.77 MPa, and the operating temperature is about 95 ° C.

  Referring also to FIG. 2, the tank wall surface portion 16 includes an inner layer 21 made of a polyphenylene ether resin, an outer layer 22 made of a polyamide resin and provided outside the inner layer 21, and a polyphenylene containing a polyphenylene ether resin and a polyamide resin. It consists of the multilayer structure 20 which consists of an ether-type resin composition, and has the intermediate | middle layer 23 located between the inner layer 21 and the outer layer 22. As shown in FIG.

  Although the polyphenylene ether resin is hard, if it is scratched or distorted when it is incorporated into other parts, it is relatively brittle and is likely to break due to progress of cracks. Therefore, in the hot water storage tank 10 of the first embodiment of the present invention, the outer layer 22 made of polyamide resin is provided outside the inner layer 21 in order to protect the inner layer 21.

  Since the polyamide resin has excellent toughness and impact resistance, it is suitable for application to the outer layer 22 for protecting the inner layer 21. That is, even if scratches or cracks occur on the outer surface of the outer layer 22, the scratches or cracks do not progress, and the inner layer 21 can be protected from external impacts over a long period of time.

  However, the inner layer 21 made of polyphenylene ether resin and the outer layer 22 made of polyamide resin are difficult to adhere. Therefore, by providing the intermediate layer 23, the adhesive strength between the inner layer 21 and the intermediate layer 23 and the adhesive strength between the outer layer 22 and the intermediate layer 23 are ensured, and the strength of the entire multilayer structure 20 is increased. be able to. In other words, in order to obtain the same strength, the thickness dimension of the inner layer and the outer layer can be reduced as compared with the case where no intermediate layer is provided, and the hot water storage tank can be further reduced in size and weight. .

  Hereinafter, the inner layer 21, the outer layer 22, and the intermediate layer 23 constituting the multilayer structure 20 will be described in detail.

  Appropriate dimensions can be adopted as the thickness dimension of the inner layer 21, the thickness dimension of the intermediate layer 23, and the thickness dimension of the outer layer 22 in accordance with the required pressure resistance and satisfactory heat insulation performance or heat retention performance. An appropriate dimension can be adopted as the thickness dimension of the intermediate layer 23 according to the required peel strength. As an example, as shown in <Heat resistance / pressure resistance test results> in the examples described later, for example, when the pressure is 0.5 MPa, the tank thickness is 7 mm, the inner layer 21: the intermediate layer 23: the thickness of the outer layer 22 When the thickness ratio is 6: 1: 3, the pressure resistance at 87 ° C. is 1.0 MPa, and it is considered that a safety factor of 2 can be secured for 0.5 MPa (target general water pressure). The specific gravity of the multilayer structure 20 in the above thickness dimension is about 1.09. The hot water storage tank 10 of the present embodiment can be reduced in weight to about 70% of the weight of the metal tank (reducing the weight of about 30%) under the same pressure resistance and heat insulation performance. Furthermore, since the same heat insulation performance can be obtained even if the weight is reduced, it can be said that the heat insulation can be improved.

<Inner layer 21>
The inner layer 21 is made of a polyphenylene ether resin. The polyphenylene ether resin used for the inner layer 21 is preferably composed of 30 to 90% by weight of polyphenylene ether resin and 70 to 10% by weight of styrene resin, 40 to 90% by weight of polyphenylene ether resin and 60 to 10% by weight of styrene resin. More preferably, it consists of 60 to 90% by weight of polyphenylene ether resin and 40 to 10% by weight of styrene resin. When the polyphenylene ether resin is less than 30% by weight, heat resistance and mechanical strength tend to be lowered. Moreover, when polyphenylene ether resin exceeds 90 weight%, fluidity | liquidity will fall and it may be unpractical in a shaping | molding process. When the polyphenylene ether resin is 40 to 60% by weight, the deflection temperature under load can be maintained at about 100 ° C., and when the polyphenylene ether resin is 60% by weight or more, the deflection temperature under load is maintained at 130 to 140 ° C. be able to. The deflection temperature under load is a value measured under the condition of a load of 1.80 MPa in accordance with ISO75.

<Outer layer 22>
The outer layer 22 is made of a polyamide resin.

<Intermediate layer 23>
The intermediate layer 23 is a polyphenylene ether-based resin containing at least a polyphenylene ether-based resin and a polyamide resin in order to achieve both the adhesiveness between the inner layer 21 and the intermediate layer 23 and the adhesiveness between the outer layer 22 and the intermediate layer 23. It consists of a composition. Since the polyphenylene ether resin in the intermediate layer 23 also functions as a structure and improves strength, the intermediate layer 23 also functions as a layer that protects the inner layer 21.

  The polyphenylene ether resin used for the intermediate layer is preferably composed of 20 to 95% by weight of polyphenylene ether resin and 80 to 5% by weight of styrene resin, 25 to 85% by weight of polyphenylene ether resin, and 75 to 15% by weight of styrene resin. Preferably it consists of. When the polyphenylene ether resin is less than 20% by weight, heat resistance and mechanical strength tend to be lowered. Moreover, when polyphenylene ether resin exceeds 95 weight%, the fluidity | liquidity of a thermoplastic resin composition will fall and it may be unpractical in a shaping | molding process.

  The polyphenylene ether resin composition is preferably a resin mixture comprising 20 to 90% by weight of a polyphenylene ether resin and 80 to 10% by weight of a polyamide resin. When the content of the polyphenylene ether resin is less than the lower limit and the content of the polyamide resin exceeds the upper limit, the adhesiveness to the inner layer 21 tends to be inferior, and the content of the polyphenylene ether resin exceeds the upper limit, and the polyamide If the resin content is less than the above lower limit, the adhesion to the outer layer 23 tends to be poor. In the present invention, by setting the mixing ratio as described above, sufficient adhesive strength between the outer layer 22 and the intermediate layer 23 is ensured while ensuring sufficient adhesive strength between the inner layer 21 and the intermediate layer 23. It is more preferable because it can be ensured and the adhesive strength of both layers can be maintained in a well-balanced manner. The polyphenylene ether resin and the polyamide resin are more preferably 45 to 90% by weight of the polyphenylene ether resin, 55 to 10% by weight of the polyamide resin, and further preferably 50 to 90% by weight of the polyphenylene ether resin and 50 to 10% by weight of the polyamide resin. %, Particularly preferably 60 to 90% by weight of polyphenylene ether resin and 40 to 10% by weight of polyamide resin.

  Even if the polyphenylene ether resin and the polyamide resin are used in the above ratio, if the ratio of the polyphenylene ether resin in the polyphenylene ether resin is small, the polyphenylene ether resin content in the polyphenylene ether resin composition of the present invention is reduced. In some cases, the heat resistance and pressure resistance are inferior. Therefore, 35 parts by weight of the polyphenylene ether resin is included in 100 parts by weight of the total of the polyphenylene ether resin (for example, a composite resin of the above-mentioned polyphenylene ether resin and styrene resin) and the polyamide resin contained in the polyphenylene ether resin composition. As described above, it is particularly preferable that 45 parts by weight or more is contained.

  Further, in order to increase the compatibility between the polyphenylene ether resin and the polyamide resin, and to increase the mechanical strength and the adhesion between the inner layer 21 and the intermediate layer 23 and between the outer layer 22 and the intermediate layer 23, the polyphenylene ether type used for the intermediate layer 23 is used. The resin composition preferably contains 0.05 to 5 parts by weight of a compatibilizer with respect to 100 parts by weight of a resin mixture composed of a polyphenylene ether resin and a polyamide resin. If the content of the compatibilizer is less than the above lower limit, the adhesiveness, heat resistance, pressure resistance and mechanical strength may be reduced, and if the upper limit is exceeded, during the melt kneading in the production and molding process of the resin composition or When the thermal stability during use is lowered in a high temperature atmosphere, the mechanical strength tends to be lowered. Accordingly, the content of the compatibilizing agent is more preferably 0.05 to 3 parts by weight, and still more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight as a total of the polyphenylene ether resin and the polyamide resin.

  In addition, you may mix | blend a radical generator with a compatibilizer. The blending amount of the radical generator is preferably 0.01 to 3 parts by weight, particularly 0.01 to 1 part by weight, based on 100 parts by weight of the total of the polyphenylene ether resin and the polyamide resin. If the blending amount is too small, the compatibility between the polyphenylene ether-based resin and the polyamide resin tends to be insufficient and the mechanical strength tends to decrease, and if it is too large, the resin composition is produced and melt kneaded in the molding process. In some cases, the thermal stability during use may be reduced in a high-temperature atmosphere.

  Hereinafter, the raw material resins and additives used for the inner layer 21, the outer layer 22, and the intermediate layer 23 will be described in detail.

[Polyphenylene ether resin]
Polyphenylene ether resin has high heat resistance, excellent mechanical properties such as tensile strength, high impact resistance, low water absorption, excellent dimensional stability, low coefficient of linear expansion, low specific gravity, difficulty It has the advantage of being flammable.
In the present invention, the polyphenylene ether resin is preferably a composite resin composition obtained by blending a polyphenylene ether resin with a styrene resin in order to improve fluidity and impact resistance.

<Polyphenylene ether resin>
The polyphenylene ether resin used in the polyphenylene ether resin according to the present invention is a polymer having a structural unit represented by the following general formula (1) in the main chain, and is either a homopolymer or a copolymer. May be.

(In the formula, two R ^{a s} each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a haloalkyl group, a hydrocarbonoxy group, or a halohydrocarbonoxy group. Each of the two R ^{b s} independently represents a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, a haloalkyl group, a hydrocarbonoxy group, or a halohydrocarbonoxy group. However, both R ^a are not hydrogen atoms.)

R ^a and R ^b are preferably a hydrogen atom, a primary or secondary alkyl group, or an aryl group. Preferable examples of the primary alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-amyl group, isoamyl group, 2-methylbutyl group, 2,3-dimethylbutyl group, 2 -, 3- or 4-methylpentyl group or heptyl group may be mentioned. Preferable examples of the secondary alkyl group include isopropyl group, sec-butyl group, and 1-ethylpropyl group. In particular, ^Ra is preferably ^a primary or secondary alkyl group having 1 to 4 carbon atoms or a phenyl group. R ^b is preferably a hydrogen atom.

  Suitable homopolymers of polyphenylene ether resins include, for example, poly (2,6-dimethyl-1,4-phenylene ether), poly (2,6-diethyl-1,4-phenylene ether), poly (2, 2 such as 6-dipropyl-1,4-phenylene ether), poly (2-ethyl-6-methyl-1,4-phenylene ether), poly (2-methyl-6-propyl-1,4-phenylene ether), etc. , 6-dialkylphenylene ether polymer. Examples of the copolymer include 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / 2,3,6-triethylphenol copolymer, and 2,6-diethylphenol. 2,6-dialkylphenol / 2,3,6-trialkylphenol copolymer such as 2,3,6-trimethylphenol copolymer and 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer Polymer, graft copolymer obtained by graft polymerization of styrene to poly (2,6-dimethyl-1,4-phenylene ether), styrene to 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer And a graft copolymer obtained by graft polymerization.

  As the polyphenylene ether resin in the present invention, poly (2,6-dimethyl-1,4-phenylene ether) and 2,6-dimethylphenol / 2,3,6-trimethylphenol random copolymer are particularly preferable. In addition, polyphenylene ether resins that define the number of terminal groups and the copper content as described in JP-A-2005-344065 can also be suitably used.

  The molecular weight of the polyphenylene ether resin is preferably such that the intrinsic viscosity at 30 ° C. measured in chloroform is 0.2 to 0.8 dl / g, more preferably 0.3 to 0.6 dl / g. When the intrinsic viscosity is 0.2 dl / g or more, the mechanical strength of the resin composition tends to be improved, and when it is 0.8 dl / g or less, the fluidity is improved and the molding process is easy. Tend to be. Two or more kinds of polyphenylene ether resins having different intrinsic viscosities may be used in combination to achieve this intrinsic viscosity range.

  The method for producing the polyphenylene ether resin used in the present invention is not particularly limited. For example, according to a known method, a monomer such as 2,6-dimethylphenol is oxidatively polymerized in the presence of an amine copper catalyst. In this case, the intrinsic viscosity can be controlled within a desired range by selecting the reaction conditions. Control of intrinsic viscosity can be achieved by selecting conditions such as polymerization temperature, polymerization time, and catalyst amount.

  In this invention, polyphenylene ether resin may be used individually by 1 type, and 2 or more types may be mixed and used for it.

<Styrene resin>
Examples of the styrene resin used in the polyphenylene ether resin according to the present invention include a styrene monomer polymer, a copolymer of a styrene monomer and another copolymerizable monomer, and a styrene graft. A copolymer etc. are mentioned.

  More specifically, examples of the styrene resin used in the present invention include polystyrene, styrene / butadiene / styrene copolymer (SBS resin), hydrogenated styrene / butadiene / styrene copolymer (SEBS), and hydrogenated styrene.・ Isoprene / styrene copolymer (SEPS), high impact polystyrene (HIPS), acrylonitrile / styrene copolymer (AS resin), acrylonitrile / butadiene / styrene copolymer (ABS resin), methyl methacrylate / butadiene / styrene copolymer Polymer (MBS resin), methyl methacrylate / acrylonitrile / butadiene / styrene copolymer (MABS resin), acrylonitrile / acrylic rubber / styrene copolymer (AAS resin), acrylonitrile / ethylene propylene rubber / styrene copolymer (AES) Fat), styrene · IPN type rubber copolymer resin, or mixtures thereof. Further, it may have stereoregularity such as syndiotactic polystyrene. Among these, polystyrene (PS) and impact-resistant polystyrene (HIPS) are preferable.

  The weight average molecular weight of the styrenic resin is usually 50,000 or more, preferably 100,000 or more, more preferably 150,000 or more, and the upper limit is usually 500,000 or less. , Preferably 400,000 or less, more preferably 300,000 or less.

  Examples of the method for producing such a styrene resin include known methods such as an emulsion polymerization method, a solution polymerization method, a suspension polymerization method, and a bulk polymerization method.

  In the present invention, the styrene resin may be used alone or in combination of two or more.

[Polyamide resin]
The polyamide resin used in the present invention has a —CONH— bond in the main chain and can be heated and melted, and may be a homopolymer or a copolymer. Specifically, various polyamide resins such as a lactam polycondensate, a polycondensate of diamine and dicarboxylic acid, a polycondensate of ω-aminocarboxylic acid, or a copolymerized polyamide resin or blend thereof. .

Examples of the lactam include ε-caprolactam and ω-laurolactam.
Examples of the diamine include tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, octamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2-methylpentamethylene diamine, (2, 2, 4- or 2, 4, 4-) Trimethylhexamethylenediamine, 5-methylnonanemethylenediamine, metaxylylenediamine (MXDA), paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) ) Propane, bi (Aminopropyl) piperazine, aliphatic, such as aminoethylpiperazine, alicyclic, diamines aromatic.

  Examples of the dicarboxylic acid include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium. Aliphatic, alicyclic and aromatic dicarboxylic acids such as sulfoisophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid.

  Examples of the ω-aminocarboxylic acid include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, paraaminomethylbenzoic acid, and the like.

Specific examples of polyamide resins obtained by polycondensation from these raw materials include polyamide 4, polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 56, polyamide 66, polyamide 610, polyamide 612, and polyamide 6 · 66 co-weight. Polymer, polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene isophthalamide (polyamide 6I), polyamide 6I · 6T copolymer, polymetaxylylene adipamide (polyamide MXD6), polymetaxylylene dodecamide, polyamide 9T, polyamide 9MT, and the like. These polyamide resins may be used alone or in combination of two or more.
Preferred polyamide resins are polyamide 6, polyamide 66, polyamide MXD6 and polyamide 6I · 6T, and these can be used in combination with an amorphous polyamide resin.

  The polyamide resin used in the present invention preferably has a relative viscosity of 2 to 7.5 measured according to JIS K6810, more preferably 2.5 to 7, and further preferably 3 to 6. If the relative viscosity is less than 2, the mechanical strength tends to decrease, and if it exceeds 7.5, the molding process may be difficult.

  The terminal amino group concentration of the polyamide resin is preferably 10 to 140 eq / ton, more preferably 30 to 100 eq / ton, from the viewpoints of polymer molecular weight, thermal stability and compatibility with the polyphenylene ether resin. The terminal carboxyl group concentration of the polyamide resin is preferably 10 to 140 eq / ton, more preferably 30 to 100 eq / ton, from the viewpoint of the molecular weight of the polymer, thermal stability, and compatibility with the polyphenylene ether resin. .

[Compatibilizer]
Preferred examples of the compatibilizer for the polyphenylene ether resin and the polyamide resin used in the polyphenylene ether resin composition of the present invention include unsaturated acids, unsaturated acid anhydrides, and derivatives thereof.

  The compatibilizer is preferably maleic acid, itaconic acid, chloromaleic acid, citraconic acid, butenyl succinic acid, tetrahydrophthalic acid, and anhydrides thereof, and these acid halides such as maleimide, monomethyl maleate, dimethyl maleate, Examples include amides, imides, C1-20 alkyl or glycol esters, and maleic acid and maleic anhydride are preferred.

  These compatibilizers may be used alone or in combination of two or more.

[Radical generator]
In the adhesive resin composition of the present invention, a radical generator may be blended together with the compatibilizer as described above. Examples of the radical generator include organic peroxides and azo compounds.

  Specific examples of the organic peroxide include, for example, t-butyl hydroperoxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl Hydroperoxides such as hydroperoxide, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide; for example, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, di-t -Dialkyl peroxides such as butyl peroxide, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, dicumyl peroxide; -T-butylperoxybutane, 2,2-bis-t-butylperoxy Peroxyketals such as kutan, 1,1-bis-t-butylperoxycyclohexane, 1,1-bis-t-butylperoxy-3,3,5-trimethylcyclohexane; Oxyisophthalate, t-butyl peroxybenzoate, t-butyl peroxyacetate, 2,5-dimethyl-2,5-dibenzoyl peroxyhexane, t-butyl peroxyisopropyl carbonate, t-butyl peroxyisobutyrate Peroxyesters such as benzoyl peroxide, m-toluoyl peroxide, acetyl peroxide, lauroyl peroxide, and the like.

  Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl) azo] formamide, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2,2′-azobis (2-methylpropane) and the like.

  Among the above radical generators, radical generators having a half-life temperature of 120 ° C. or higher in 10 hours are preferable from the viewpoint of impact resistance. In addition, a radical generator may be used individually by 1 type, and 2 or more types may be mixed and used for it.

[Other ingredients]
The polyphenylene ether-based resin used for the inner layer 21 and the polyphenylene ether-based resin composition used for the intermediate layer 23 include the above-mentioned polyphenylene ether-based resin, polyamide resin, and compatibilizer (or compatibilizer and Various resin additives other than the radical generator may be contained. Examples of various resin additives that can be contained include, for example, heat stabilizers, antioxidants, weather resistance improvers, nucleating agents, foaming agents, flame retardants, lubricants, plasticizers, fluidity improvers, ultraviolet absorbers, dyes, Examples include pigments, fillers, reinforcing agents, dispersants, conductive agents, impact resistance improvers, and the like.

  For example, for the polyphenylene ether-based resin of the inner layer 21 and the polyphenylene ether-based resin composition of the intermediate layer 23, hindered phenol is used for the purpose of improving the thermal stability at the time of melt kneading and use in the production and molding process of the composition. It is preferable to blend at least one thermal stabilizer selected from a system compound, a phosphite system compound, a phosphonite system compound, and zinc oxide.

  Specific examples of hindered phenol compounds include n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate], pentaerythritol-tetrakis [3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate], 2 , 6-Di-tert-butyl-4-methylphenol, 3,9-bis [1,1-dimethyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} Ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxy) Phenyl) propionate], 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3 ′, 5′-di-t- Butyl-4′-hydroxybenzyl) benzene, 2,2-thio-diethylenebis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], tris- (3,5- And di-t-butyl-4-hydroxybenzyl) -isocyanurate, N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamide), and the like. Among these, n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3 ′, 5′- t-butyl-4′-hydroxyphenyl) propionate], 2,6-di-t-butyl-4-methylphenol, 3,9-bis [1,1-dimethyl-2- {β- (3-t- Butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane is preferred. These may be used alone or in combination of two or more.

  Specific examples of the phosphite compound include tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphite, bis (2 , 6-di-t-butyl-4-methylphenyl) pentaerythritol di-phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 4,4′-butylidene- Bis- (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-di-tridecyl phosphite-5-tert-butyl-phenyl) Butane, tris (mixed mono and di-nonylphenyl) phosphite, tris (nonylphenyl) phosphite, 4,4′-isopropylidenebis (pheny -Dialkyl phosphite) and the like, preferably tris (2,4-di-t-butylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, Bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite. These may be used alone or in combination of two or more.

  Specific examples of the phosphonite compound include, for example, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,5-di-t-butylphenyl) -4. , 4′-biphenylenediphosphonite, tetrakis (2,3,4-trimethylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,3-dimethyl-5-ethylphenyl) -4,4′- Biphenylene diphosphonite, tetrakis (2,6-di-t-butyl-5-ethylphenyl) -4,4'-biphenylene diphosphonite, tetrakis (2,3,4-tributylphenyl) -4,4'- Biphenylene diphosphonite, tetrakis (2,4,6-tri-t-butylphenyl) -4,4′-biphenylene diphosphonite , Preferably, tetrakis (2,4-di -t- butyl-phenyl) -4,4'-biphenylene phosphonite.

  As zinc oxide, for example, those having an average particle diameter of 0.02 to 1 μm are preferable, and those having an average particle diameter of 0.08 to 0.8 μm are more preferable.

  The blending amount of one or more stabilizers selected from hindered phenol compounds, phosphite compounds, phosphonite compounds, and zinc oxide is 100 parts by weight in total of polyphenylene ether resin or polyphenylene ether resin and polyamide resin. On the other hand, it is usually 0.01 to 5 parts by weight, preferably 0.03 to 3 parts by weight. When the blending amount of the stabilizer is less than 0.01 parts by weight, the effect of improving the thermal stability is small, and when it exceeds 5 parts by weight, the mechanical strength is lowered and the economic disadvantage is increased, which is not preferable.

  Moreover, a flame retardant can be used in the polyphenylene ether resin used for the inner layer 21 of the present invention and the polyphenylene ether resin composition used for the intermediate layer 23 in order to impart flame retardancy. The flame retardant is not particularly limited as long as it improves the flame retardancy of the composition, but a phosphoric acid ester compound, an alkali metal organic sulfonic acid metal salt, and a silicone compound are preferable. As a phosphoric acid ester compound used by this invention, what is represented, for example by following formula (2) is mentioned.

(In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently an aryl group which may be substituted, and X is a divalent aromatic which may have another substituent. And n represents a number of 0 to 5.)

In the general formula (2), examples of the aryl group represented by R ^{1 to} R ⁴ include a phenyl group and a naphthyl group. Examples of the divalent aromatic group represented by X include a phenylene group, a naphthylene group, and a group derived from, for example, bisphenol. Examples of these substituents include an alkyl group, an alkoxy group, and a hydroxy group. When n is 0, it is a phosphate ester, and when n is greater than 0, it is a condensed phosphate ester (may be a mixture).

Specific examples of such phosphoric acid ester compounds include bisphenol A bisphosphate, hydroquinone bisphosphate, resorcinol bisphosphate, and substituted and condensates thereof.
Examples of commercially available condensed phosphate compounds that can be suitably used as such components include, for example, “CR733S” (resorcinol bis (diphenyl phosphate)), “CR741” (bisphenol A bis ( Diphenyl phosphate)) and ADEKA Co., Ltd. under the trade name “FP500” (resorcinol bis (dixylenyl phosphate)) and are readily available.

  In the case of using a phosphate ester flame retardant in the polyphenylene ether resin of the inner layer 21 and the polyphenylene ether resin composition of the intermediate layer 23 of the present invention, the content of the polyphenylene ether resin or the polyphenylene ether resin and the polyamide resin is The amount is preferably 1 to 50 parts by weight, more preferably 3 to 40 parts by weight, and particularly preferably 5 to 30 parts by weight with respect to a total of 100 parts by weight. If the content of the phosphate ester flame retardant is less than 1 part by weight, the effect of improving flame retardancy cannot be sufficiently obtained, and if it exceeds 50 parts by weight, the heat resistance is lowered, which is not preferable.

Preferred examples of the alkali metal salt organic sulfonic acid metal salt used in the present invention include aliphatic sulfonic acid metal salts and aromatic sulfonic acid metal salts. The metal constituting the organic sulfonic acid metal salt is preferably an alkali metal, alkaline earth metal, etc., and the alkali metal and alkaline earth metal include sodium, lithium, potassium, rubidium, cesium, beryllium, Examples include magnesium, calcium, strontium and barium.
The organic sulfonic acid metal salt can also be used by mixing two or more kinds of salts.

  The aliphatic sulfonic acid salt used in the present invention is preferably a fluoroalkane-sulfonic acid metal salt, and the fluoroalkane-sulfonic acid metal salt is preferably an alkali metal salt of fluoroalkane-sulfonic acid or an alkaline earth metal. An alkali metal salt or an alkaline earth metal salt of fluoroalkanesulfonic acid having 4 to 8 carbon atoms is more preferable. More preferred is a perfluoroalkane-sulfonic acid metal salt. Specific examples of the fluoroalkane-sulfonate include sodium perfluorobutane-sulfonate, potassium perfluorobutane-sulfonate, sodium perfluoromethylbutane-sulfonate, potassium perfluoromethylbutane-sulfonate, and perfluorooctane. -Sodium sulfonate, potassium perfluorooctane-sulfonate, and tetraethylammonium salt of perfluorobutane-sulfonate.

  The aromatic sulfonic acid metal salt is preferably an aromatic sulfonic acid alkali metal salt, an aromatic sulfonic acid alkaline earth metal salt, an aromatic sulfone sulfonic acid alkali metal salt, an aromatic sulfone sulfonic acid alkaline earth metal salt, or the like. The aromatic sulfonesulfonic acid alkali metal salt and the aromatic sulfonesulfonic acid alkaline earth metal salt may be a polymer.

  Specific examples of the aromatic sulfonic acid metal salt include 3,4-dichlorobenzenesulfonic acid sodium salt, 2,4,5-trichlorobenzenesulfonic acid sodium salt, benzenesulfonic acid sodium salt, and diphenylsulfone-3-sulfonic acid. Sodium salt, potassium salt of diphenylsulfone-3-sulfonic acid, sodium salt of 4,4′-dibromodiphenyl-sulfone-3-sulfonic acid, potassium salt of 4,4′-dibromodiphenyl-sulfone-3-sulfonic acid, Examples include calcium salt of 4-chloro-4′-nitrodiphenylsulfone-3-sulfonic acid, disodium salt of diphenylsulfone-3,3′-disulfonic acid, and dipotassium salt of diphenylsulfone-3,3′-disulfonic acid. It is done.

  The amount of the organic sulfonic acid metal salt is preferably 0.01 to 5 parts by weight, more preferably 0.02 to 3 parts by weight, based on 100 parts by weight of the total of the polyphenylene ether resin or polyphenylene ether resin and polyamide resin. Particularly preferred is 0.03 to 2 parts by weight. If the amount of the organic sulfonic acid metal salt is less than 0.01 parts by weight, sufficient flame retardancy is difficult to obtain, and if it exceeds 5 parts by weight, the thermal stability tends to be lowered.

  The silicone flame retardant used in the present invention is preferably a polyorganosiloxane having a linear or branched structure. The organic group possessed by the polyorganosiloxane includes hydrocarbons such as alkyl groups and substituted alkyl groups having 1 to 20 carbon atoms, vinyl and alkenyl groups, cycloalkyl groups, and aromatic hydrocarbon groups such as phenyl and benzyl. Chosen from. The polyorganosiloxane may not contain a functional group or may contain a functional group. When it contains a functional group, the functional group is preferably a methacryl group, an alkoxy group or an epoxy group.

  Moreover, in this invention, a fluororesin can be included for the purpose of dripping prevention at the time of combustion. Here, the fluororesin is a polymer or copolymer containing a fluoroethylene structure, for example, a difluoroethylene polymer, a tetrafluoroethylene polymer, a tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene and fluorine. It is a copolymer with an ethylene monomer that does not contain. Polytetrafluoroethylene (PTFE) is preferable, and the average molecular weight is preferably 500,000 or more, and particularly preferably 500,000 to 10,000,000.

  In addition, when polytetrafluoroethylene having a fibril forming ability is used, it is possible to impart higher melt dripping prevention property. Although there is no restriction | limiting in particular in the polytetrafluoroethylene (PTFE) which has a fibril formation ability, For example, what is classified into the type 3 in ASTM standard is mentioned. Specific examples thereof include, for example, Teflon (registered trademark) 6-J (manufactured by Mitsui DuPont Fluorochemical Co., Ltd.), Polyflon D-1, Polyflon F-103, Polyflon F201 (Daikin Industries, Ltd.), CD076 ( Asahi IC Fluoropolymers Co., Ltd.). Other than those classified as type 3, for example, Argoflon F5 (manufactured by Montefluos Co., Ltd.), polyflon MPA, polyflon FA-100 (manufactured by Daikin Industries, Ltd.) and the like can be mentioned. These polytetrafluoroethylene (PTFE) may be used independently and may combine 2 or more types. Polytetrafluoroethylene (PTFE) having the fibril-forming ability as described above is prepared by, for example, using tetrafluoroethylene in an aqueous solvent in the presence of sodium, potassium, ammonium peroxydisulfide, at a pressure of 1 to 100 psi, at a temperature of 0. It is obtained by polymerizing at ˜200 ° C., preferably 20˜100 ° C.

  When the polyphenylene ether resin used for the inner layer 21 of the present invention and the polyphenylene ether resin composition of the intermediate layer contain a fluororesin, the content is 100 weights of the total of the polyphenylene ether resin or the polyphenylene ether resin and the polyamide resin. The amount is preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1.5 parts by weight, and particularly preferably 0.1 to 1 part by weight with respect to parts. When the blending amount of the fluororesin is less than the above lower limit, it is difficult to obtain a sufficient dripping prevention effect, and when it exceeds the upper limit, the thermal stability tends to be lowered.

  Moreover, in this invention, you may mix | blend a coloring agent. Examples of the colorant include dyes, inorganic pigments, and organic pigments generally used for thermoplastic resins.

  Examples of the dye include azo dyes, anthraquinone dyes, phthalocyanine dyes, indigo dyes, diphenylmethane dyes, acridine dyes, cyanine dyes, nitro dyes, and nigrosine. Inorganic pigments include oxide pigments such as titanium oxide, red pepper and cobalt blue, hydroxide pigments such as alumina white, sulfide pigments such as zinc sulfide and cadmium yellow, silicate pigments such as white carbon and talc, and carbon black. Etc. Examples of organic pigments include nitro pigments, azo pigments, phthalocyanine pigments, and condensed polycyclic pigments. Among these, an inorganic pigment is preferable because it is difficult to bleed out to the surface of the molded product. The colorant may be used as a master batch with a polyamide resin or a polyphenylene ether-based resin for the purpose of improving the handleability during extrusion.

  The blending amount of the colorant is preferably 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the total of polyphenylene ether resin or polyphenylene ether resin and polyamide resin. . In particular, titanium oxide is easy to prevent discoloration of the resin composition, and is effective in coloring a light color.

  Moreover, it is preferable to mix | blend a mold release agent in the polyphenylene ether-type resin used for the inner layer 21 of this invention, and the polyphenylene ether-type resin composition used for the intermediate | middle layer 23 in order to improve the mold release property at the time of shaping | molding. Examples of the mold release agent include aliphatic carboxylic acid, aliphatic carboxylic acid ester, polyolefin wax, silicone oil and the like.

  Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monocarboxylic acid, dicarboxylic acid, and tricarboxylic acid. Here, the aliphatic carboxylic acid also includes an alicyclic carboxylic acid. Among these, preferable aliphatic carboxylic acids are mono- or dicarboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monocarboxylic acids having 6 to 36 carbon atoms are more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, valeric acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, melicic acid, tetratriacontanoic acid. , Montanic acid, glutaric acid, adipic acid, azelaic acid and the like.

  As the aliphatic carboxylic acid component constituting the aliphatic carboxylic acid ester, the same aliphatic carboxylic acid as that described above can be used. On the other hand, examples of the alcohol component constituting the aliphatic carboxylic acid ester include saturated or unsaturated monohydric alcohols and saturated or unsaturated polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these alcohols, monovalent or polyvalent saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic saturated monohydric alcohols or polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the aliphatic alcohol also includes an alicyclic alcohol.

  Specific examples of these alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol. Etc. These aliphatic carboxylic acid esters may contain an aliphatic carboxylic acid and / or alcohol as impurities, and may be a mixture of a plurality of compounds.

  Specific examples of the aliphatic carboxylic acid ester include beeswax (mixture based on myristyl palmitate), stearyl stearate, behenyl behenate, octyldodecyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin diester Examples thereof include stearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

  Examples of polyolefin waxes include olefin homopolymers and copolymers. Examples of the olefin homopolymer include polyethylene wax, polypropylene wax and the like, partial oxides thereof, and mixtures thereof. Examples of the olefin copolymer include ethylene, propylene, 1-butene, 1-hexene, 1-decene, 2-methylbutene-1, 3-methylbutene-1, 3-methylpentene-1, 4-methylpentene-1, and the like. Copolymers such as α-olefins, monomers copolymerizable with these olefins, such as unsaturated carboxylic acids or acid anhydrides thereof (maleic anhydride, (meth) acrylic acid, etc.), (meth) acrylic acid esters And a copolymer with a polymerizable monomer such as (methyl (meth) acrylate, alkyl ester having 1 to 6 carbon atoms of (meth) acrylic acid such as ethyl (meth) acrylate), and the like. Further, these copolymers include random copolymers, block copolymers, or graft copolymers. The olefin copolymer is usually a copolymer of ethylene and at least one monomer selected from other olefins and polymerizable monomers. Of these polyolefin waxes, polyethylene wax is most preferred. The polyolefin wax may have a linear or branched structure.

  Examples of silicone oils include those composed of polydimethylsiloxane, and some or all of the methyl groups of polydimethylsiloxane are substituted with phenyl groups, hydrogen atoms, alkyl groups having 2 or more carbon atoms, halogenated phenyl groups, and fluoroester groups. Silicone-modified oil, epoxy-modified silicone oil having an epoxy group, amino-modified silicone oil having an amino group, alcohol-modified silicone oil having an alcoholic hydroxyl group, polyether-modified silicone oil having a polyether structure, and the like. Two or more types may be used in combination.

  The compounding amount of the release agent is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 6 parts by weight, based on 100 parts by weight of the total of polyphenylene ether resin or polyphenylene ether resin and polyamide resin. More preferably, it is 1-3 parts by weight. By making the compounding amount of the release agent 0.01 parts by weight or more, the release effect is more easily exhibited, and by making it 10 parts by weight or less, problems such as heat resistance, mold contamination, and poor plasticization occur. It tends to be difficult.

  Moreover, the polyamide resin used for the outer layer 22 may contain various resin additives as long as the purpose is not impaired. Examples of various resin additives that can be contained include, for example, heat stabilizers, antioxidants, weather resistance improvers, nucleating agents, foaming agents, flame retardants, lubricants, plasticizers, fluidity improvers, ultraviolet absorbers, dyes, Examples include pigments, fillers, reinforcing agents, dispersants, conductive agents, impact resistance improvers, and the like.

  The polyamide resin used for the outer layer 22 is preferably blended with a heat stabilizer in order to improve heat resistance stability. As the heat stabilizer, for example, organic stabilizers such as phosphorus, hindered phenol, hindered amine, organic sulfur and oxalic anilide, and inorganic stabilizers such as copper compounds and halides are preferable. As a phosphorus stabilizer, a phosphite compound and a phosphonite compound are preferable.

  Examples of the phosphite compound include distearyl pentaerythritol diphosphite, dinonylphenyl pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, and bis (2,6- Di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis (2,6-di-t- Butyl-4-isopropylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-sec-) Butylphenyl) pentaerythritol diphosphite, bis (2,6-di-) -Butyl-4-t-octylphenyl) pentaerythritol diphosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite and the like, and in particular, bis (2,6-di-t-butyl- 4-methylphenyl) pentaerythritol diphosphite and bis (2,4-dicumylphenyl) pentaerythritol diphosphite are preferred.

  Examples of the phosphonite compound include tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,5-di-t-butylphenyl) -4,4′-. Biphenylene diphosphonite, tetrakis (2,3,4-trimethylphenyl) -4,4'-biphenylene diphosphonite, tetrakis (2,3-dimethyl-5-ethylphenyl) -4,4'-biphenylene diphosphonite Tetrakis (2,6-di-t-butyl-5-ethylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,3,4-tributylphenyl) -4,4'-biphenylenediphosphonite , Tetrakis (2,4,6-tri-t-butylphenyl) -4,4′-biphenylenediphosphonite, etc. Tetrakis (2,4-di -t- butyl-phenyl) -4,4'-biphenylene phosphonite are preferred.

  Examples of the hindered phenol stabilizer include n-octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis [1,1- Dimethyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, triethylene glycol -Bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,5-di-tert-butyl-4-hydro Cybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2,2-thio-diethylenebis [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, N, N'-hexamethylenebis (3 , 5-di-t-butyl-4-hydroxy-hydrocinnamide) and the like. Among these, n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-t-butyl-4 -Hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis [1,1-dimethyl-2- {β- ( 3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, N, N′-hexamethylenebis (3 5-di-t-butyl-4-hydroxy-hydrocinnamide) is preferred.

  Examples of the hindered amine stabilizer include known hindered amine compounds having a 2,2,6,6-tetramethylpiperidine skeleton. Specific examples of hindered amine compounds include 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2 , 6,6-tetramethylpiperidine, 4-phenylacetoxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2 , 6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2, 2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4-ethylcarba Yloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexylcarbamoyloxy-2,2,6,6-tetramethylpiperidine, 4-phenylcarbamoyloxy-2,2,6,6-tetramethylpiperidine, Bis (2,2,6,6-tetramethyl-4-piperidyl) carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) oxalate, bis (2,2,6,6-tetramethyl) -4-piperidyl) malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) adipate, bis (2,2 , 6,6-tetramethyl-4-piperidyl) terephthalate, 1,2-bis (2,2,6,6-tetramethyl-4-piperidyloxy) eta , Α, α′-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -p-xylene, bis (2,2,6,6-tetramethyl-4-piperidyltolylene) -2 , 4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylene-1,6-dicarbamate, tris (2,2,6,6-tetramethyl-4-piperidyl) -Benzene-1,3,5-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1,3,4-tricarboxylate, 1- [2- {3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} butyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] 2,2 , 6,6-tetramethyl Piperidine, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ′, β ′,-tetramethyl-3,9- [ 2,4,8,10-tetraoxaspiro (5,5) undecane] condensate with diethanol, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6, -succinate Examples include polycondensates of tetramethylpiperidine, 1,3-benzenedicarboxamide-N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) and the like.

  As products of hindered amine compounds, products manufactured by ADEKA Co., Ltd. “ADEKA STAB LA-52, LA-57, LA-62, LA-67, LA-63P, LA-68LD, LA-77, LA-82, LA -87 ", products manufactured by Ciba Specialty Chemicals Co., Ltd." Tinubin 622, 944, 119, 770, 144 ", products manufactured by Sumitomo Chemical Co., Ltd." Sumisorb 577 ", products manufactured by Cyamide Co., Ltd. 3853 ", a product" Nairostav S-EED "manufactured by Clariant Japan, and the like.

  As the oxalic anilide stabilizer, 4,4′-dioctyloxyoxanilide, 2,2′-diethoxyoxanilide, 2,2′-dioctyloxy-5,5′-di- Tributoxanilide, 2,2′-didodecyloxy-5,5′-di-tert-butoxanilide, 2-ethoxy-2′-ethyloxanilide, N, N′-bis (3-dimethylaminopropyl) oxanilide, 2-ethoxy-5-tert-butyl-2′-ethoxanilide and its mixture with 2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide, o- and p-methoxy-disubstituted oxanilides Mixtures, o- and p-ethoxy-disubstituted oxanilide mixtures, and the like.

The sulfur-based antioxidant refers to an antioxidant having a sulfur atom. For example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthio). Propionate), thiobis (N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, Examples include trilauryl trithiophosphite. In particular, a thioether-based antioxidant having a thioether structure can be suitably used because it receives oxygen from an oxidized substance and reduces it.
The molecular weight of the sulfur-based antioxidant is usually 200 or more, preferably 500 or more, and the upper limit is usually 3,000.

  The copper compound used as the inorganic stabilizer is a copper salt of various inorganic acids or organic acids, and may be either cuprous or cupric. Specific examples thereof include copper chloride and copper bromide. In addition to copper iodide, copper phosphate, and copper stearate, natural minerals such as hydrotalcite, stichite, pyrolite and the like can be mentioned.

  Examples of the halide used as the inorganic stabilizer include, for example, alkali metal or alkaline earth metal halides; ammonium halides and quaternary ammonium halides of organic compounds; alkyl halides, allyl halides. Specific examples thereof include ammonium iodide, stearyltriethylammonium bromide, benzyltriethylammonium iodide, and the like. Among these, alkali metal halide salts such as potassium chloride, sodium chloride, potassium bromide, potassium iodide, sodium iodide and the like are preferable.

  The combined use of a copper compound and a halide, in particular, the combined use of a copper compound and a halogenated alkali metal salt is preferable because it exhibits excellent effects in terms of heat discoloration resistance and weather resistance (light resistance). For example, when a copper compound is used alone, the molded product may be colored reddish brown by copper, and this coloring is not preferable depending on the application. In this case, discoloration to reddish brown can be prevented by using a copper compound and a halide together.

  In the present invention, among the above stabilizers, a copper salt-based, hindered amine-based or organic sulfur-based stabilizer is particularly preferable.

  The blending amount of the stabilizer is preferably 0.01 to 3 parts by weight, more preferably 0.01 to 1.2 parts by weight, and 0.01 to 0.8 parts by weight with respect to 100 parts by weight of the polyamide resin. Further preferred. If the blending amount is less than 0.01 parts by weight, the thermal discoloration improvement, weather resistance, and light resistance improvement effects may be insufficient, and if it exceeds 3 parts by weight, the mechanical strength tends to decrease.

  The polyamide resin used for the outer layer 22 is preferably blended with a nucleating agent in order to increase the crystallization speed and improve the moldability. Examples of the nucleating agent generally include inorganic crystal nucleating agents such as talc and boron nitride, but organic crystal nucleating agents may be added. The compounding amount of the crystal nucleating agent is preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight, and still more preferably 0.2 to 0.6 part by weight with respect to 100 parts by weight of the polyamide resin. If the blending amount is less than 0.05 parts by weight, the effect as a crystal nucleating agent may be insufficient, and if it exceeds 2 parts by weight, mechanical strength and impact resistance due to foreign matter effects tend to decrease.

  Furthermore, it is preferable to mix a release agent with the polyamide resin used for the outer layer 22 in order to improve the release property at the time of molding. As the mold release agent, those which do not easily reduce the flame retardancy of the polyamide resin are preferable, and preferable examples include bisamide waxes such as carboxylic acid amide waxes and ethylene bisstearylamides, and long chain fatty acid metal salts.

The carboxylic acid amide wax is obtained by a dehydration reaction of a mixture of a higher aliphatic monocarboxylic acid and a polybasic acid and a diamine.
The higher aliphatic monocarboxylic acid is preferably a saturated aliphatic monocarboxylic acid or hydroxycarboxylic acid having 16 or more carbon atoms, and examples thereof include palmitic acid, stearic acid, behenic acid, montanic acid, and 12-hydroxystearic acid. .
Examples of polybasic acids include dibasic or higher carboxylic acids, such as aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, sebacic acid, pimelic acid, and azelaic acid, and aromatics such as phthalic acid and terephthalic acid. And alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid and cyclohexyl succinic acid.
Examples of the diamine include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, hexamethylenediamine, metaxylylenediamine, tolylenediamine, paraxylylenediamine, phenylenediamine, and isophoronediamine.

  The softening point of the carboxylic acid amide wax in the present invention can be arbitrarily adjusted by changing the mixing ratio of the polybasic acid to the higher aliphatic monocarboxylic acid used in the production thereof. The mixing ratio of the polybasic acid is preferably in the range of 0.18 to 1 mol with respect to 2 mol of the higher aliphatic monocarboxylic acid. The amount of diamine used is preferably in the range of 1.5 to 2 mol per 2 mol of higher aliphatic monocarboxylic acid, and varies according to the amount of polybasic acid used.

  Examples of the bisamide wax include diamine and fatty acid compounds such as N, N′-methylenebisstearic acid amide and N, N′-ethylene bisstearic acid amide, or N, N′-dioctadecyl terephthalic acid amide. And dioctadecyl dibasic acid amide.

  The long chain fatty acid metal salt is a metal salt of a long chain fatty acid having 16 to 36 carbon atoms, such as calcium stearate, calcium montanate, sodium montanate, zinc stearate, aluminum stearate, sodium stearate, lithium stearate. Etc.

  The compounding amount of the release agent is preferably 0.001 to 2 parts by weight, more preferably 0.01 to 1.5 parts by weight, and further preferably 0.05 to 0.8 parts by weight with respect to 100 parts by weight of the polyamide resin. . If the blending amount is less than 0.001 part by weight, it may be difficult to exhibit a sufficient mold release effect and improve the moldability, and if it exceeds 2 parts by weight, the mechanical strength of the polyamide resin may be lowered.

[Production method]
In the production of the polyphenylene ether resin of the inner layer 21 and the polyphenylene ether resin composition of the intermediate layer 23 of the present invention, a polyphenylene ether resin, a polystyrene resin and various resin additives blended as necessary, and In the case of the intermediate layer 23, any method can be adopted as long as the polyamide resin is uniformly mixed, but it is preferably by melt kneading, and a melt kneader generally used for thermoplastic resins. The method of using is mentioned. Examples of the melt kneader include a uniaxial or multiaxial kneading extruder, a roll, and a Banbury mixer.

  In the polyphenylene ether resin composition used for the intermediate layer 23 of the present invention, it is preferable to add a compatibilizer, but the reactivity of the polyamide resin and the compatibilizer is such that the polyphenylene ether resin and the compatibilizer are Therefore, as a kneading procedure for producing a polyphenylene ether composition, kneading of a polyamide resin and a compatibilizing agent is performed prior to kneading of the polyphenylene ether resin and the compatibilizing agent. There is a possibility that the polyamide resin and the compatibilizing agent react early and the reaction activity of the compatibilizing agent is consumed in the reaction with the polyamide resin, so that the reaction between the polyphenylene ether resin and the compatibilizing agent does not proceed. Therefore, it is preferable to first employ a kneading procedure in which a polyphenylene ether-based resin and a compatibilizing agent are melt-kneaded, and a polyamide resin is added and kneaded to the obtained mixture.

  Therefore, for example, when producing a polyphenylene ether-based resin composition used for the intermediate layer 23 using a kneading extruder, preferably, various polyphenylene ether-based resins, a compatibilizing agent, and various kinds of additives added as necessary. The resin additive is mixed in advance and added to the upstream part of the kneading extruder and reacted in a molten state. Then, the polyamide resin is continuously added to the middle part of the kneading extruder and melt kneaded. Accordingly, it is preferable to adopt a method in which a flame retardant or the like is introduced from the downstream portion to obtain a resin composition pellet. As another method, first, a polyphenylene ether-based resin, a compatibilizing agent, and various resin additives to be added as necessary are mixed in advance, and the mixture is put into a kneading extruder and reacted in a molten state. The pellet and the polyamide resin are put into a kneading extruder to be melt-reacted, and if necessary, additives such as a flame retardant and a reinforcing agent are blended from the downstream portion, and pellets of the resin composition It is preferable to employ a method of obtaining

  The melt kneading temperature and time for producing the polyphenylene ether resin of the inner layer 21 and the polyphenylene ether resin composition of the intermediate layer 23 of the present invention are the polyphenylene ether resin, compatibilizing agent and polyamide resin constituting the resin composition. Usually, the kneading temperature is 210 to 350 ° C, preferably 220 to 320 ° C, more preferably 220 to 290 ° C. If the kneading temperature is too high, thermal degradation of the resin composition becomes a problem, and mechanical strength may be lowered.

(Second Embodiment)
With reference to FIG. 3, the hot water storage tank 10a which concerns on 2nd Embodiment is demonstrated. The members common to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The hot water storage tank 10a according to the second embodiment is different from the first embodiment in which the multilayer structure 20 has a three-layer structure in that the multilayer structure 30 has a two-layer structure of an inner layer 31 and an outer layer 32. It is different.

  The tank wall surface portion 16 of the second embodiment is composed of an inner layer 31 made of a polyphenylene ether resin and a polyphenylene ether resin composition containing a polyphenylene ether resin and a polyamide resin, and an outer layer 32 provided outside the inner layer 31. It is comprised from the multilayer structure 30 which has these.

  The material of the inner layer 31 is the same as that of the inner layer 21 in the first embodiment.

  Similar to the intermediate layer 23 of the first embodiment, the outer layer 32 of the second embodiment is made of a resin composition containing a polyphenylene ether resin and a polyamide resin. Furthermore, it is preferable to contain a compatibilizing agent as in the intermediate layer 23 of the first embodiment. This is because the adhesive strength between the inner layer 31 and the outer layer 32 made of polyphenylene ether resin is ensured. Furthermore, since the polyamide resin has excellent toughness and impact resistance as described above, it can be suitably applied to the outer layer 32 for protecting the inner layer 31. That is, even if scratches or cracks occur on the outer surface of the outer layer 32, the scratches or cracks do not progress, and the inner layer 31 can be protected from external impacts over a long period of time.

  The polyphenylene ether-based resin composition used for the outer layer 32 is preferably 20 to 60% by weight of polyphenylene ether-based resin and 80 to 40% by weight of polyamide resin, 30 to 50% by weight of polyphenylene ether-based resin and 70 to 50% of polyamide resin. Weight percent is more preferred. When the proportion of the polyamide resin is less than 40% by weight, the strength against external impact becomes weak and the inner layer 31 may not be sufficiently protected. On the other hand, when the proportion of the polyamide resin exceeds 80% by weight, the adhesive strength between the inner layer 31 and the outer layer 32 may be insufficient. In particular, it is more preferable that the ratio of the polyamide resin is 50 to 70% by weight because sufficient adhesive strength between the inner layer 31 and the outer layer 32 can be secured while the inner layer 31 is sufficiently protected.

  In addition, the multilayer structures 20 and 30 according to the first and second embodiments of the present invention have the inner layer 21, the outer layer 22, and the intermediate layer 23 or the inner layer 31 as long as the effects of the present invention are not impaired. In addition to the outer layer 32, another resin layer may be included. The resin used for the other resin layer is not particularly limited, but from the viewpoint of molding processability, heat resistance, water resistance, pressure resistance, and mechanical strength, heat of polycarbonate resin, polyester resin, polyacetal resin, polyolefin resin, etc. A plastic resin is preferred.

[Method of manufacturing hot water storage tank]
The hot water storage tank 10 and the hot water storage tank 10a having the above-described configuration can be manufactured by applying a general resin molding technique such as blow molding, and the welding work required for manufacturing a metal tank becomes unnecessary. In addition, mass production and manufacturing can be automated easily, and the quality and stability of the hot water storage tank can be easily achieved. In addition, compared with a metal tank, the degree of freedom in selecting a tank shape is greater, the weight can be reduced, and the heat insulation is excellent. If necessary, a heat insulating material can be further provided. In that case, since the resin material has lower thermal conductivity than the metal material, the amount of heat insulating material used can be reduced. Furthermore, since it can be molded from a general-purpose resin material (polyphenylene ether resin, polyamide resin), an increase in cost can be suppressed. In addition, the tank wall surface portion 16 is constituted by the multilayer structure 20 composed of the three layers of the inner layer 21 -the intermediate layer 23 -the outer layer 22 or the multilayer structure 30 composed of the two layers of the inner layer 31 -the outer layer 32, thereby providing sufficient pressure resistance. And heat resistance. In the hot water storage tank 10a, since the inner layer 31 and the outer layer 32 are directly bonded without interposing the intermediate layer 23 in the first embodiment, it is possible to simplify the manufacturing apparatus and the manufacturing procedure. Have advantages. Therefore, it is possible to provide a hot water storage tank as a pressure-resistant and heat-resistant container, which is advantageous in terms of cost.

  By the way, in order to ensure the safety of plastic products, “Standards for Foods, Additives, etc.” (Ministry of Health and Welfare Notification No. 370) has been established. Individual standards are defined as “standards and standards for containers and packaging” (Ministry of Health, Labor and Welfare Notification No. 201). The polyphenylene ether resin that forms the inner layer 21 of the multilayer structure 20 and the inner layer 31 of the multilayer structure 30 includes a grade that satisfies the above-mentioned standard. Therefore, the hot water storage tanks 10 and 10a of the present embodiment can be suitably used as a tank for storing hot water applied also for drinking.

(Modification)
Although the embodiment in which the resin tank of the present invention is applied to the hot water storage tanks 10 and 10a has been described, the present invention is not limited to this case and can be applied to uses other than hot water storage. The polyphenylene ether resins forming the inner layers 21 and 31 of the multilayer structures 20 and 30 are “standards for food, additives, etc.” (Ministry of Health and Welfare Notification No. 370) or “standards for synthetic resin utensils or containers and packaging” ( Since there is a grade that conforms to the standard of the Ministry of Health, Labor and Welfare Notification No. 201), for example, it may be applied to a tank installed in a milk processing line or a food processing line. Furthermore, as long as the resin tank of the present invention is a material that does not corrode the inner layers 21 and 31 of the multilayer structures 20 and 30, it can be widely applied as a pressure- and heat-resistant container for storing these materials. Absent. Moreover, it is not restricted to storing a liquid, A gel-like material can also be stored. Further, the present invention is not limited to a resin tank having only a heat retaining function, and can also be applied to a resin tank having a built-in heater and having a heat retaining / heating function. Further, since the resin tank has a large degree of freedom in selecting the tank shape, the tank shape is not limited to the illustrated shape, and a desired shape can be selected.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.

[Hot water storage tank shape and manufacturing method]
With reference to FIG. 4 and FIG. 5, the shape and manufacturing method of the hot water storage tank 110 are demonstrated.
4A and 4B are a front view and a top view of hot water storage tank 110, respectively. 5A shows a multi-layer blow molding machine 140 which is a hot water storage tank molding apparatus, FIG. 5B shows a state in which a mold 150 of the molding apparatus is opened, and FIG. 5C shows a mold. 150 shows a closed state. FIG. 5D shows an enlarged view of a portion D in FIG.
<Shape of tank 110>
The hot water storage tank 110 shown in FIG. 4 has a cylindrical shape, and the dimensions are an outer diameter d = 300 mm and a total length L = 1600 mm. The upper lid portion and the lower lid portion located at both ends of the trunk portion are hemispherical. Three water injection nozzles 111 were provided on the lower lid part, and three drainage nozzles 112 were provided on the upper cover part, for a total of six places.
As shown in FIG. 5D, as the material constituting the multilayer structure of the tank 110, the inner layer 121 uses the polyphenylene ether-based resin composition-1 described below, and the outer layer 122 describes the following. A polyamide resin was used, and the polyphenylene ether-based resin composition-2 described below was used for the intermediate layer 123.

<Material>
Polyphenylene ether resin: poly (2,6-dimethyl-1,4-phenylene) ether (“PX100L” manufactured by Polyxylenol Singapore, intrinsic viscosity 0.47 dl / g measured at 30 ° C. in chloroform)
Styrene resin-1: high impact polystyrene (“HT478” manufactured by Nippon Polystyrene Co., Ltd., weight average molecular weight (Mw) 200,000, MFR 3.2 g / 10 min (measured at 200 ° C., load 5 kg))
Styrene resin-2: Styrene-ethylene / butylene-styrene block copolymer (hereinafter abbreviated as “SEBS”) (“Septon 8006” manufactured by Kuraray Co., Ltd., styrene content 33% by weight, number average molecular weight 200,000)
Polyamide resin: Polyamide 6 (“Amilan CM1056” manufactured by Toray Industries, Inc.)
Compatibilizer: Maleic anhydride (“Crystalman AB” manufactured by NOF Corporation)
Stabilizer-1: Phosphonite-based heat stabilizer ("Sand Stub P-EPQ" manufactured by Clariant Japan)
Stabilizer-2: Phenolic antioxidant (Yoshinox BHT manufactured by Yoshitomi Pharmaceutical)

<Preparation of polyphenylene ether-based resin composition-1 used for inner layer 121>
Using a twin screw extruder (screw diameter 30 mm, L / D = 42), polyphenylene ether resin, styrene resin-1, styrene resin-2, stable under conditions of cylinder temperature 270 ° C. and screw rotation speed 300 rpm Agents -1 and 2 were uniformly mixed with a high-speed rotary mixer, put into the upstream part of the extruder, melt-kneaded and pelletized. The blending amount of each component is 0.3 parts by weight of stabilizer-1 with respect to a total of 100 parts by weight of 60% by weight of polyphenylene ether resin, 35% by weight of styrene resin-1 and 5% by weight of styrene resin-2. Stabilizer-2 0.3 parts by weight.

<Preparation of polyamide resin used for outer layer 122>
For the outer layer 122, the above polyamide resin was used as it was.

<Preparation of polyphenylene ether-based resin composition-2 used for intermediate layer 123>
Using a twin screw extruder (screw diameter 30 mm, L / D = 42), under conditions of a cylinder temperature of 250 ° C. and a screw rotation speed of 300 rpm, polyphenylene ether resin, styrene resin-1, compatibilizer, stabilizer— 1 and 2 were uniformly mixed with a high-speed rotary mixer, and the mixture was introduced into the upstream part of the extruder to cause a melt reaction, and then the polyamide resin was introduced from the middle part of the extruder and melt-kneaded to be pelletized. At this time, the cylinder temperature after addition of the polyamide resin was 250 ° C. The blending amount of each component was 0.2 parts by weight of compatibilizer and 10 stabilizers for 100 parts by weight of the total of 47% by weight of polyphenylene ether resin, 25% by weight of styrene resin-1 and 28% by weight of polyamide resin. 0.5 parts by weight and 0.5 parts by weight of stabilizer-2.

<Molding device>
With reference to FIGS. 5A to 5C, a blow molding method was applied to manufacture the tank 110. The tank 110 was molded using a molding apparatus including a dedicated multilayer blow molding machine 140 and a mold 150. The molding machine 140 is provided with four screws 141, 142, 143, 144 for melting the resin pellets. An accumulator and an extruding device for accumulating molten resin are provided in succession to the screws 141, 142, 143, and 144. The accumulator is divided into five layers, and it is possible to extrude different types of materials in a configuration of four types and five layers. In this molding, the screw 141 was used for the inner layer 121, and the screw 142 was used for the outer layer 122. Further, since the screws 143 and 144 have a relatively small diameter, both are used for the intermediate layer 123.

<Molding conditions>
The polyphenylene ether-based resin composition-1 for the inner layer 121 was melted at 220 to 290 ° C. with a φ141 mm screw 141. The polyamide resin for the outer layer 122 was melted at 200 to 270 ° C. with another φ90 mm screw 142. In addition, the polyphenylene ether-based resin composition-2 for the intermediate layer 123 was melted at 220 to 270 ° C. using two screws: a φ143 mm screw 143 and a φ55 mm screw 144. The molten resin of the polyphenylene ether resin composition-1 is in the accumulator for the inner layer, the molten resin of the polyamide resin is in the accumulator for the outer layer, and the molten resin of the polyphenylene ether resin composition-2 is in the accumulator for the intermediate layer. , Heated to 200 to 290 ° C. and stored. All of the three layers (the inner layer 121, the intermediate layer 123, and the outer layer 122) of the molten resin were simultaneously extruded vertically and directly below to produce a multilayered resin called a parison 151. The extruded resin had a cylindrical shape with an outer diameter of 120 to 250 mm, a length of about 2 m, and a weight of 7 to 17 kg.

<Molding method>
Simultaneously with the extrusion, the resin was sandwiched by using the mold 150 attached to the mold clamping device below the accumulator. Two types of tanks (tanks (1) with different wall thicknesses are obtained by sending air with a pressure of 0.3 to 1 MPa into the resin sandwiched between the molds 150, pressing the resin against the mold 150, and cooling and solidifying. ) And (2)) (see FIGS. 5B and 5C). The resin was cooled by passing hot water of 30 to 90 ° C. through the mold 150. As the mold 150, a specially manufactured mold for forming the above-described shape of the tank 110 was used.
The thickness of the tank was 4 mm (tank (1)) and 4.5 mm (tank (2)). The thickness ratio of the inner layer 121, the intermediate layer 123, and the outer layer 122 was inner layer 121: intermediate layer 123: outer layer 122 = 6: 1: 3.
Using the obtained tanks (1) and (2), the heat and pressure resistance test described below was performed.

<Heat and pressure resistance test>
A screw shape was created by post-processing at each of the upper and lower nozzles of the tank 110, and a hole of φ10 to 15 was made in the center of the nozzle. A joint was connected to the created screw shape, and a hose for water injection and a hose for drainage were connected to each other. The tank 110 was installed upright. The set temperature of the water heater was kept constant, tap water heated to 80 to 95 ° C. was poured from the water injection hose, and the tank was filled with hot water. Thereafter, the joint on the drain side was closed, and the connection of the joint on the water injection side was switched to the hydraulic pump. Until the tank was damaged, pressure was gradually applied to the tank using a hydraulic pump, and a destructive test was conducted.

<Heat and pressure test results>
In the tank (1), when the water temperature of the tank drainage part was 87 ° C. and the pump pressure gauge exceeded 0.6 MPa, the side surface of the trunk part of the tank burst. The fracture surface is jagged and is considered to have broken beyond the resin strength limit.
In the tank (2), when the water temperature of the tank drainage portion was 92 ° C. and the pump pressure gauge exceeded 0.7 MPa, the side surface of the trunk portion of the tank burst. Like tank (1), it is considered that the limit of resin strength was exceeded.

  As described above, it was confirmed that the resin-made three-layer hot water storage tank (1) subjected to the test was not damaged up to 87 ° C. and 0.6 MPa. In particular, it has also been found that heat resistance and pressure resistance are further improved by increasing the thickness of the inner polyphenylene ether resin layer. Moreover, it is considered that the pressure resistance is further improved by bonding the polyphenylene ether resin and the polyamide resin. From these results, the thickness of the tank is set to 7 mm or more, and the thickness ratio of the inner layer / intermediate layer / outer layer at that time is inner layer: intermediate layer: outer layer = 4: 1: 5 to 8: 1: 1. A thickness ratio of inner layer: intermediate layer: outer layer = 6: 1: 3 is preferred and particularly preferred. If the tank thickness is 7 mm, the pressure resistance at 87 ° C. is 1.0 MPa, and it is considered that a safety factor of 2 can be secured for 0.5 MPa (target general water pressure).

10, 10a, 110 Hot water storage tank (resin tank),
11 Leg part 12 Inlet part 14 Outlet part 16 Tank wall surface part,
20 multilayer structure,
21 Inner layer,
22 outer layer,
23 middle layer,
30 multilayer structure,
31 Inner layer,
32 Outer layer,
111 Nozzle for water injection,
112 nozzle for drainage,
121 inner layer,
122 outer layer,
123 intermediate layer 140 multilayer blow molding machine,
141, 142, 143, 144 screw,
150 molds,
151 Parison.

Claims (7)

The tank wall surface portion is composed of an inner layer made of a polyphenylene ether resin, an outer layer made of a polyamide resin and provided outside the inner layer, a polyphenylene ether resin composition containing a polyphenylene ether resin and a polyamide resin, and the inner layer and the A resin tank comprising a multi-layer structure having an intermediate layer positioned between an outer layer and a polyphenylene ether resin used for the polyphenylene ether resin, measured in chloroform 30 A resin tank having an intrinsic viscosity of 0.2 to 0.8 dl / g .   2. The resin tank according to claim 1, wherein the polyphenylene ether resin used for the inner layer is composed of 30 to 90 wt% polyphenylene ether resin and 70 to 10 wt% styrene resin. 3.   The polyphenylene ether-based resin composition used for the intermediate layer is 0.05 to 5 weight percent of a compatibilizer with respect to 100 weight parts of a resin mixture composed of 20 to 90 weight percent polyphenylene ether-based resin and 80 to 10 weight percent polyamide resin. The resin tank according to claim 1 or 2, wherein the resin tank is contained.   The resin tank according to claim 3, wherein the compatibilizing agent is at least one selected from unsaturated acids, unsaturated acid anhydrides and derivatives thereof. The tank wall surface portion is composed of a multilayer structure having an inner layer made of a polyphenylene ether resin and an outer layer made of a polyphenylene ether resin composition containing a polyphenylene ether resin and a polyamide resin and provided outside the inner layer. A resin tank having an intrinsic viscosity at 30 ° C. of 0.2 to 0.8 dl / g measured in chloroform of the polyphenylene ether resin used for the polyphenylene ether resin. .   6. The resin tank according to claim 5, wherein the resin composition used for the outer layer comprises 20 to 60% by weight of a polyphenylene ether resin and 80 to 40% by weight of a polyamide resin.   It is a hot water storage tank, The resin-made tanks of any one of Claims 1-6.