JPH02258587A - Anticorrosive vessel - Google Patents

Abstract

PURPOSE:To prevent exfoliation of a resin layer and a FRP layer in a poly-layer anticorrosive vessel and to maintain the strength and the high anticorrosiveness for a long time, by directly laminating a FRP member on the outside of an interior layer of ethylene-vinyl acetate copolymer saponified matter or further the one including polyethylene, or by laminating the FRP member via a polyurethane adhesive. CONSTITUTION:A FRP layer B is directly bonded on the outside of an anticorrosive interior layer member A made of a saponified matter of ethylene-vinyl acetate copolymer. In this case, a blended material of EVA saponified matter and polyethylene may be preferably used as the anticorrosive interior layer member A according to the kind of the contents. And further, a polyurethane adhesive C is interposed between the anticorrosive interior layer member A and the FRP layer B to increase further adhesive force between inter-layers. EVA saponified matter have an excellent adhesiveness against FRP materials but occasionally have an inadequate adhesiveness depending on the kinds of resin constituting FRP and hence, in such a case, the inadequate adhesiveness is compensated by use of polyurethane adhesive.

Description

[Detailed Description of the Invention] [Field of Application in Industry A] The present invention relates to a corrosion-resistant container made of synthetic resin that exhibits high corrosion resistance against acidic solutions, alkaline solutions, salt solutions, etc., and has high strength. be.

[Prior Art] Corrosion-resistant containers made of synthetic resin are used for storing or communicating acidic solutions, alkaline solutions, and the like. Fig. 4 is a side explanatory view showing a tank truck for transporting solutions, Fig. 5 is a structural explanatory view of a corrosion-resistant container mounted on the tank truck, and Fig. 6 is a cross-sectional view taken along the line V-V in Fig. It is an enlarged view of the part. The corrosion-resistant container 1 is attached to a band 4 on the loading platform 3 of the trailer 2.
Fixed by etc. A solution inlet 6 for introducing a solution is formed in the upper part of the corrosion-resistant container 1, and a solution extraction lower for taking out the solution is formed in the lower part. If the capacity of the corrosion-resistant container 1 is large, a dam plate 5 is installed in the middle of the container in order to reduce the impact caused by the movement of the solution during transportation.
may be provided. In addition, this weir plate may be used as a mirror plate to form a complete partition wall so that different types of solutions can be stored separately in the container 1. Therefore, the weir plate or weir plate 5
It is also possible to provide a plurality of sheets at appropriate intervals depending on the volume of each partition.

The inside of the corrosion-resistant container 1 is formed by selecting a synthetic resin material that exhibits high durability against corrosion by the storage solution, and has a multilayer structure for the purpose of increasing the mechanical strength of the container itself. For example, FIG. 6 shows one example, in which the inside is made up of a corrosion-resistant resin layer 8, and the outside is made of a fiber-reinforced resin layer (hereinafter simply FRP) for the purpose of reinforcing the resin layer 8.
layer) 9 is formed. The material for forming the corrosion-resistant resin layer 8 is, for example, polyethylene resin or fluororesin, and the FRP layer 9 is made by winding glass fiber, organic or inorganic fiber impregnated with a thermosetting resin according to the FW method. Alternatively, a multi-layered material attached by hand lay-up method is used.

The diameter of the corrosion-resistant container 1 used in the above-mentioned tank truck generally ranges up to about 1.5 ff1, and in the case of a stationary type, the diameter may reach 2 to 3 IIl. Therefore, it is virtually impossible to manufacture the resin tank 1 formed by the corrosion-resistant resin layer 8 by the usual extrusion molding method or compression molding method. A rotational molding method is used. That is, the flange portion 20a
Powdered resin raw material 30 is put into a hollow split mold 20.21 that is integrally joined by the split mold 20. While melting the resin, the split molds 20.21 are rotated in the direction of the arrow by a rotating mechanism (not shown), and the molten resin is uniformly cast over the entire inner circumference of the split molds 20.21. After cooling the split mold 20.21 and confirming that the resin material inside has retained its shape, the split mold 20.21 is disassembled and the molded resin tank 31 is taken out. Thereafter, the outer surface of the resin tank 31 is roughened by rough polishing, and an FRP layer forming resin is applied thereon to strengthen it as shown in FIG. 7(B)! Wind the a fiber 32, repeat this operation, and
RP layer 9 is formed. Note that the means for forming the FRP layer 9 can be variously modified as described above.

FIG. 7(C) shows the corrosion-resistant container 1 after forming the FRP layer 9.
FIG. In addition, when forming a plurality of chambers independently in the container 1 as described above, (a) after the resin tanks 31 formed in a slightly short length are lined up in the length direction and butt welded, an FRP layer is formed on the outside thereof. Either a step of integrating the two, or a step of (b) abutting the resin tanks 31 with FRP layers formed thereon and joining them together using FRP material is added.

[Problem to be Solved by the Invention] Although the outer surface of the resin layer 8 in the corrosion-resistant container 1 is roughened as explained in FIG. Since it is merely a textured surface, the resin layer 8 and the FRP layer will easily peel off when expansion or contraction occurs due to temperature changes or when a large external force is applied. That is, as the constituent material of the resin layer 8, resins with high chemical stability such as polyethylene and fluororesin are selected and used with emphasis on corrosion resistance.
Since these resin layers do not have active groups, they have poor affinity with the FRP layer, and will easily peel off if a large force in the peeling direction acts on the laminated interface. When such delamination occurs, the reinforcing effect of the FRP layer 9 is lost and the internal resin tank 31 has to rely on its own strength. For example, if there are welded joints, Damage such as cracks is likely to occur in the welded part. Furthermore, when carrying out the step (b) above, a similar peeling phenomenon is likely to occur due to external forces applied during the bonding operation, temperature changes, etc., and a high degree of skill is required for the bonding operation.

The present invention was made with attention to these circumstances, and its purpose is to prevent as much as possible the peeling of the resin layer and FRP layer in a corrosion-resistant container with a multilayer structure, and to prolong the strength and high corrosion resistance. The purpose is to provide a corrosion-resistant container that can be maintained over a long period of time.

[Means for Solving the Problems] The structure of the corrosion-resistant container according to the present invention, which has achieved the above object, is that on the outer surface side of the inner layer material containing a saponified ethylene-vinyl acetate copolymer or further polyethylene, The gist is that FRP materials are directly laminated or FRP materials are laminated using a polyurethane adhesive, and if necessary, a polyethylene resin layer is further formed on the inner surface of the inner layer material. be.

[Operations and Examples] The first feature of the invention lies in the use of saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) as the inner layer constituent material. In other words, this saponified product itself not only has excellent corrosion resistance against acids, alkalis, salt solutions, and various solvents, but also has an active group in its molecules, making it compatible with FRP materials. It is also excellent in sex.

Therefore, if this saponified material is used as the inner layer material and an FRP layer is formed as a reinforcing layer on the outer surface side, the inner layer material and the FRP layer will be firmly bonded, and the peeling between the eyebrows as pointed out with conventional reinforced resin corrosion-resistant containers will be avoided. No problems occur, and a container excellent in both corrosion resistance and mechanical strength can be obtained. Also, depending on the FRP resin material used in combination, interlayer adhesion can be further improved by interposing a polyurethane adhesive between the inner layer material and the FRP layer, and the physical properties of the laminate can be further improved. . Since saponified EVA has good affinity with polyethylene, it is not only possible to blend this saponified material with polyethylene to make a corrosion-resistant inner layer material, but also to add polyethylene resin to the inner surface of the inner layer material made of the saponified material. Even when a multilayer corrosion-resistant resin layer is formed by forming layers, the polyethylene resin layer and the saponified EVA layer are firmly bonded, and there is no fear that the two layers will peel off between the eyebrows.

Figures 1 to 3 illustrate the laminated structure constituting the corrosion-resistant container according to the present invention, and Figure 1 shows a structure in which an FRP layer B is directly bonded to the outer surface of a corrosion-resistant inner layer material A made of saponified EVA. This laminated structure is the basis of the present invention. In this case, depending on the type of contents, E may be used as the corrosion-resistant inner layer material A.
It may be preferable to use a blend of saponified VA and polyethylene. Figure 2 also shows corrosion-resistant inner layer material A.
A polyurethane adhesive C is interposed between FRP/iB and FRP/iB to further improve interlayer adhesion. That is, EVAtl
One of the characteristics of i-oxide is that it exhibits excellent adhesion to FRP materials, but depending on the type of resin that makes up FRP, the adhesion may be insufficient, so in such cases, polyurethane It is desirable to compensate for the lack of adhesive strength by using a type adhesive. Furthermore, FIG. 3 shows a laminate made of EVA saponification layer material A and FRP layer B, with a corrosion-resistant resin layer made of polyethylene resin formed on the inner surface side. Since the compound also has excellent adhesion to polyethylene, even in the case of such a three-layer structure, the three layers can be firmly bonded and bonded. Depending on the type of contents, this kind of three-layer structure has an E.
Polyethylene is advantageous over saponified VA because it exhibits higher corrosion resistance. In addition, EVA saponified products are more expensive than polyethylene, so if they exhibit equivalent corrosion resistance, EVAfied products can be used as a relatively thin bonding layer.
By providing corrosion resistance to the polyethylene layer, it is possible to reduce the cost of the entire laminated structure.

Next, the saponified EVA used in the present invention will be explained. This saponified product is obtained by saponifying the ethylene-vinyl acetate copolymer using a hydroxide such as sodium or potassium, or an alkali metal compound such as an alkoxide.

This saponification reaction can be carried out homogeneously in a hydrocarbon solvent such as toluene or xylene, or a mixed solvent in which alcohol such as methanol is added, or water may be added to an alcohol such as methanol or ethanol if necessary. This is done in a heterogeneous system. In this case, the degree of saponification should be greater than 75% in order to obtain the desired corrosion resistance and strength. The content of the ethylene component in the saponified EVA is preferably 75 to 98 mol%, more preferably 80 to 95 mol%. Content of ethylene component is 75 mol%
If the polyethylene content is less than 98 mol%, the affinity with polyethylene will deteriorate, making it difficult to blend uniformly with polyethylene, and the adhesion with the polyethylene layer will also be poor.On the other hand, if the polyethylene content exceeds 98 mol%, the active Due to the insufficient amount of base, the adhesion with the FRP layer was not sufficiently improved, resulting in the interlayer 5! as pointed out in the conventional example. ! I Itff phenomenon is more likely to occur.

If the molecular weight of saponified EVA is too large, the meltability and centrifugal formability will be poor, while if it is too small, it will not be possible to secure the required strength as an inner layer material.
The index is preferably in the range of 1 to 5,008,710 minutes, more preferably 3 to 300 g/10 minutes. Furthermore, this aged material is melted and rotationally molded by the method shown in FIG. 7 (8), either alone or mixed with polyethylene powder, but the moldability and handling at this time may vary. In order to improve the properties, the particle size is 100 μm or less, more preferably 10 to
It is desired to use it as a fine grain in the range of 60 μm.

Next, glass fiber-reinforced polyester resin is the most common FRP material used in the present invention, but carbon fiber, metal fiber, natural fiber, or synthetic fiber can also be used as the reinforcing fiber. As the resin, it is also possible to use epoxy resin, polyamide resin, phenol resin, polycarbonate resin, acetal resin, etc. The polyethylene may be produced by any of the low-pressure method, Nakasho method, and high-pressure method, but
Considering corrosion resistance, strength, and formability comprehensively, the melt index should be O2N2008710 minutes, more preferably 0.
A range of 3 to 1008710 minutes is desirable. EVA
The amount of polyethylene is preferably 500 parts by weight or less per 100 parts by weight of the saponified material.

Manufacturing a corrosion-resistant container using the above-mentioned materials does not require any special technology; for example, as shown in Figure 7 (A) above.
The methods shown in ~(C) are adopted.

The corrosion-resistant container 1 thus obtained may be mounted on a trailer as a tank lorry, or may be fixed on the ground or underground as a stationary tank.

[Examples] Example 1 Laminated bodies having structures shown in [I] to [IV] below were manufactured using the following materials.

Constituent material Saponified EVA: Vinyl acetate content 11.2 mol%, degree of saponification 99%, melt index 185 g/10 min, particle size 20-40 μm FRP material, glass fiber reinforced polyester resin (product name manufactured by Nippon Shokubai Chemical Industry Co., Ltd.) "Evolac, RF 1001 J) Polyethylene manufactured by Nimitsui Petrochemical Industries ■Product name [Urtsex 40
30J Urethane adhesive: Taoka Chemical Co., Ltd. Product name [Technodyne U-A 1 / BI J laminated structure (shown in stacking order from the inner layer side) [1] EVAlfl> Compound layer (
3mm) - FRP layer (3nm) [+1] EVA forged/poly x f L/n = 50
/ 50 (7) Blend layer (3mm) - FRP layer (3m
m) [111] EVA saponified layer/polyethylene = 501
50 blend layers (3 mm) - polyurethane adhesive (
0,1 mm) -F RP layer (3 mm) [+v] Polyethylene layer (3 mm) - EvAi compound layer/polyethylene = 50150 blend layer, (2 mm) - Polyurethane adhesive (0,1 mm) -F RP layer (3+n
m) [V] Polyethylene layer (5m+n)-FRP layer (3
mm) (Conventional laminate) A test piece of 20 mm x 100 mm was cut out from each fA layer structure obtained, and the peeling strength (J
As shown in Table 1, the interlayer adhesion of the laminated structures [I] to [+17] according to the present invention was significantly lower than that of the conventional material [V]. It was confirmed that it has sex.

Audience Table Example 2 A laminate having the structure shown below was manufactured using the following materials.

Constituent material EVA saponified product Vinyl acetate content 11.2 mol%, degree of saponification 90%, melt index 205 g710 minutes, particle size 20-40 μm Glass fiber reinforced polyester resin (manufactured by Nippon Shokubai Chemical Co., Ltd. Parts FRP material name "Evolac") RF 1001 J) Polyethylene, manufactured by Mitsui Petrochemical Industries, Ltd. Product name: ``Urtzex 40''
30J Urethane adhesive, manufactured by Taoka Chemical Co., Ltd. Product name: "Technodyne U-Al/BIJ Laminated structure (shown in stacking order from inner layer side) Polyethylene layer (3 mm) - EVA saponified layer/polyethylene = 507
50 blend layers (2 mm) - polyurethane adhesive (
0.1 mm) -F Rp layer (3 mm) A 20 mm x 100 mm test piece was cut out from each of the obtained laminated structures, and the peel strength with the FRP layer (JIS-
6850), a value of 65 kg/cm' was obtained.

Example 3 A laminate having the structure shown below was manufactured using the following materials.

Constituent material: EVA @ compound/vinyl acetate content: 11.2 mol%, saponification degree: 80%, melt index: 205 g, 710 min, particle size: 20-40 μm FRP material: Glass fiber reinforced polyester resin (manufactured by Nippon Shokubai Chemical Co., Ltd. Part name: "Evolac") RF 1001 J) Polyethylene; Manufactured by Mitsui Petrochemical Industries ■Product name: ``Urtzex 40''
30J Urethane adhesive: Manufactured by Taoka Chemical Industry ■Product name: 'TE')
) Tine U-A l/B l' laminated structure (shown in the order of lamination from the inner layer side) polyethylene layer (3 mm
) - EVA@ compound layer/polyethylene = 5Q150 blend layer (2+++m) - polyurethane adhesive (0,1
+++m) -F RP layer (3 mm) A 20 mm x 100 mm test piece was cut out from each of the obtained laminated structures, and 9! l 191i strength (
When I checked J I S-ni-6850), it was 55 kg.
A value of /cm' was obtained.

[Effects of the invention] The present invention is constructed as described above, and the corrosion-resistant inner layer material and F
Since the RP layers are firmly bonded, the reinforcing effect of lamination is effectively exhibited, making it possible to provide a corrosion-resistant container with excellent corrosion resistance and mechanical strength.

[Brief Description of the Drawings] Figures 1 to 3 are partially enlarged explanatory views showing the cross-sectional structure of the corrosion-resistant container according to the present invention, Figure 4 is a side view showing a tank truck on which the corrosion-resistant container is placed, and Figure 5 is an explanatory side view showing the tank truck on which the corrosion-resistant container is placed. The figure is an explanatory diagram showing a corrosion-resistant container, FIG. 6 is a partially enlarged explanatory diagram showing a cross section of a conventional corrosion-resistant container, and FIG. Figure CB) is an explanatory diagram showing an example of forming an FRP layer by filament winding.
Figure (C) is an explanatory diagram showing the corrosion-resistant container after forming the FRP layer. 1... Corrosion-resistant container 3... Loading platform 5... Weir plate 7... Outlet port 9... FRP layer 2... Trailer 4... Band 6... Solution inlet 8... Corrosion-resistant resin layer A...EVA saponified layer B...FRP layer C...Polyurethane adhesive layer D...Polyethylene layer

Claims (5)

[Claims] (1) A corrosion-resistant container characterized by forming an FRP layer on the outer surface of an inner layer material made of a saponified ethylene-vinyl acetate copolymer. (2) A corrosion-resistant container characterized by forming an FRP layer on the outer surface of an inner layer material containing a saponified ethylene-vinyl acetate copolymer and polyethylene. (3) The corrosion-resistant container according to claim (1) or (2), wherein the inner layer and the FRP layer are bonded via a polyurethane adhesive. (4) The corrosion-resistant container according to any one of claims (1) to (3), further comprising a polyethylene resin layer formed inside the inner layer. (5) Saponified product of ethylene-vinyl acetate copolymer is 75~
The corrosion-resistant container according to any one of claims (1) to (4), which is 100%.