JPH03298B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flammable liquid container with excellent fire resistance. More specifically, at least one of the outer surface of the polyolefin combustible liquid container and one side of the polyolefin foam layer is physically and/or chemically treated, and the other surface of the polyolefin foam layer is physically and/or chemically treated. A flammable liquid container obtained by chemically treating and/or laminating the outer surface of the flammable liquid container with one side of a polyolefin foam layer and the other side of the polyolefin foam layer with a metal layer, the purpose of which is to An object of the present invention is to provide a container for flammable liquids having excellent fire resistance and flame resistance. Currently, olefin resins have good physical properties such as mechanical properties, excellent moldability, and are lightweight, so they are molded into various molded products and used in a wide variety of fields. ing. For example, containers used for transporting and storing chemicals, liquid fuels (e.g. kerosene, gasoline), etc. are molded from high-density polyethylene resin, which has excellent impact resistance, chemical resistance, and oil resistance. There are many cases where However, since ordinary olefin resins have poor fire resistance, it is desired to improve the fire resistance of olefin resin molded products. Generally, a method for improving the fire resistance of olefin resin molded products is to incorporate a flame retardant into the olefin resin. However, when a relatively large amount of flame retardant is blended into olefin resin, it not only reduces the processability of olefin resin, but also reduces the mechanical properties of olefin resin (for example, impact resistance). ) is also reduced, which poses a practical problem. Based on the above, the present inventors have conducted various searches to obtain an olefin-based resin molded product with improved fire resistance. one side of the polyolefin foam layer is physically and/or chemically treated, and the other side of the polyolefin foam layer is physically and/chemically treated, and the outer surface of the flammable liquid container and one side of the polyolefin foam layer and the polyolefin foam layer are treated. It has been discovered that a flammable liquid container obtained by laminating the other side of the metal layer with a metal layer is a liquid container with excellent fire resistance and heat insulation properties, and the present invention has been achieved. According to the present invention, an olefin resin molded product with excellent fire resistance can be obtained without substantially impairing various mechanical properties of the olefin resin, which is a raw material resin for containers for flammable liquids. Furthermore, compared to the case where the above-mentioned flame retardant is blended, there is no need to add a flame retardant or a filler, and the container can be manufactured, so the manufacturing method thereof is also simple. The olefinic resin that is the raw material for the molded product of the present invention is generally a homopolymer of ethylene or propylene, a random or block copolymer of ethylene and propylene, or a copolymer of ethylene and/or propylene with at most 12 carbon atoms. copolymers with other α-olefins (copolymerization ratio of α-olefins is at most 20% by weight) and copolymers of ethylene with vinyl compounds such as vinyl acetate, acrylic esters and methacrylic esters (vinyl The copolymerization ratio of the compounds is generally at most 50
mol %, preferably at most 40 mol %). The molecular weight of these polyolefin resins is
Generally it is 20,000 to 500,000. There are two methods for manufacturing flammable liquid containers: injection molding and blow molding, but blow molding is generally used. In order to manufacture the flammable liquid container of the present invention by these methods, methods well known in the polyolefin industry may be applied, and there is no need to use any special method. The polyolefin foam layer of the present invention can be produced by mixing the polyolefin and a foaming agent and foaming the foaming agent. This blowing agent is a compound that does not decompose during the production of the mixture, but decomposes below the temperature at which the polyolefin used undergoes thermal decomposition, and its decomposition temperature is generally 160-250°C, especially 180-250°C.
A temperature of 240°C is preferred. This blowing agent is generally used as a blowing agent for olefin resins, and is broadly classified into inorganic type and organic type. Typical examples of inorganic blowing agents include sodium bicarbonate, copper carbonate, magnesium potassium carbonate,
Ammonium or carbonates of Group A, Group B, Group A, Group B, Group B, or Group metals such as magnesium carbonate, lead carbonate (), iron carbonate, and magnesium carbonate hydroxide; and ammonium phosphate, ammonium bicarbonate, carbonate. Inorganic ammonium salts such as ammonium, ammonium polyphosphate, ammonium borate and mixtures of sodium nitrite and ammonium chloride are mentioned. In addition, as an organic blowing agent, N,N'-
dinitrosopentamethylenetetramine and N,
Nitroso compounds such as N'-dimethyl-N,N'-dinitrosoterephthalamide, azo compounds such as azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, diazoaminobenzene and barium azodicarboxy; Telehydrazide and its derivatives, sulfonyl hydrazide compounds such as diphenylsulfone-3,3-disulfonylhydrazide and P,P'-oxybis(benzenesulfonylhydrazide) and P-toluenesulfonyl azide, 4,4-diphenyldisulfonyl Azide can be given. In producing the foamed layer of the present invention, in addition to these foaming agents, by further using a foaming aid for the purpose of controlling the temperature during foaming, it is possible to lower the decomposition temperature of the foaming agent. In addition, the decomposition rate of the blowing agent can be changed, which is advantageous because the range of molding conditions can be widened. This foaming aid cannot be specified as it varies depending on the type of foaming agent used, but examples include tribasic lead sulfate, zinc stearate, salicylic acid, phthalic acid, boric acid, and urea resin. It will be done. When these foaming aids are used, suitable foaming aids for the foaming agents used are widely known. The blending ratio of the blowing agent to 100 parts by weight of polyolefin is 0.01 to 20.0 parts by weight, especially 0.02 to 20.0 parts by weight.
10.0 parts by weight is desirable. Further, when a foaming aid is used, the proportion of the foaming aid in the foam layer is at most 10% by weight. To produce this foam layer, polyolefin and a blowing agent or these and a blowing aid are mixed, and the resulting mixture is generally foamed at a temperature at which the blowing agent decomposes, but at a temperature at which the polyolefin used does not undergo thermal deterioration. It can be obtained by applying molding methods such as extrusion molding, press molding, and injection molding that are used to manufacture layers. When the thickness of the foam layer increases, the heat insulation properties of the flammable liquid container improve, but the bulk becomes large, while when the thickness is small, the heat insulation properties are poor. For these reasons, the thickness is generally 1.0 to 10 mm.
The foamed layer thus obtained preferably has a foaming ratio of 20 to 30 times from the viewpoint of heat insulation. Further, the thickness of the metal layer of the present invention is generally
10 microns to 0.2 mm, preferably 30 microns to 0.1 mm. The types of metals include iron, aluminum, copper, nickel, and zinc, and at least 50% of these metals.
Alloys containing wt% (e.g. stainless steel,
alloys whose main components are aluminum or iron). In the present invention, methods for physically and/or chemically treating the outer surface of the polyolefin combustible liquid container and the polyolefin foam layer include a crosslinking method, a crosslinking method, and an organic compound having at least one double bond and a polar group. Graft polymerization methods, corona discharge methods, treatment methods with ozone or oxygen or oxygen-generating compounds, flame treatment methods, gases including gases reactive with polyolefins such as SO ₃ gas, chlorine gas and ammonia gas. and a method of treating with a liquid containing a compound reactive with polyolefin. It is thought that some kind of chemical reaction occurs on the outer surface of the flammable liquid container and the surface of the polyolefin foaming tank treated by these methods, resulting in polar groups bonding to the treated surfaces. It is believed that this polar group improves the adhesion between the outer surface of the flammable liquid container and one side of the foaming tank, and between the other surface of the foaming tank and the metal layer. In manufacturing the flammable liquid container of the present invention,
The outer surface of the flammable liquid container and the surface of the polyolefin foam layer may be heated and melted using means such as an infrared heater, flame, hot air, or a hot plate, and then crimped. You may let them. Alternatively, the outer surface of the flammable liquid container and the surface of the polyolefin foam layer may be physically and/or chemically treated while being pressed together. Furthermore, it can also be manufactured by applying a chloroprene-based, butyl rubber-based, acrylic-based, urethane-based, nitrile-based adhesive, or the like to the adhesive surface and applying pressure. Another method is to insert the polyolefin foam layer into the mold and bring it into close contact with the heat of the extruded parison when manufacturing the container by blow molding, or to make the polyolefin foam layer and metal layer come into close contact with each other using the same method as above. Mechanical joining methods such as bolting or banding a polyolefin foam layer with a metal layer adhered to the outer surface of a polyolefin flammable liquid container in advance. In short, according to the present invention, a flammable liquid container made of polyolefin can be manufactured by firmly adhering metal to the outer surface of the flammable liquid container, one side of the polyolefin foam layer, and the other side of the polyolefin foam layer. The flammable liquid container obtained by the present invention not only has good fire resistance but also has excellent processability due to the fact that the raw material for the container is an olefin resin. Can be easily molded. Further, this flammable liquid container can directly exhibit the good mechanical properties (for example, tensile strength and impact strength) possessed by the olefin resin. Hereinafter, the present invention will be explained in more detail with reference to Examples. In the Examples and Comparative Examples, the High Load Melt Index (hereinafter referred to as "HLMI") was measured under the conditions of a load of 21.6 kg and a temperature of 190°C based on JIS K-6760. Further, the melt flow index (hereinafter referred to as "MFI") was measured based on JIS-K6758 under conditions of a load of 2.16 kg and a temperature of 230°C. Furthermore, the tensile test was measured based on JIS-K6760. Also,
Impact strength (tensile impact) is ASTM
Measured based on D-1822. The Izot impact test was measured based on ASTM D-256.
Furthermore, the fire resistance test was measured in accordance with JIS-D1201. FIG. 1a is a side view showing the apparatus used for this test in Examples 1 to 3, Comparative Examples 1-1 to 1-3, and Comparative Example 2, and the state when the sample was placed on this apparatus. , FIG. 1b is a plan view. In each drawing, 1 is a pedestal and 2 is a sample. This frame is 20cm wide and 7cm wide. The sample was a pressed sheet with a wall thickness of 3 mm, and a liquid substance was applied to one side of the sheet. This fire resistance test used a gas burner, and the flame height was adjusted to 38 mm using LPG gas. Prior to this test, the sample was placed on a stand with the coated side facing down, and a 50 g weight was placed in the center of the sample. A fire resistance test was conducted by adjusting the burner opening to the coated surface of this sample so that it was 19 mm. Incidentally, the conditions of the fire resistance test of the above-mentioned Examples and Comparative Examples are shown in FIG. In this drawing, 1 is a pedestal and 2 is a sample. 3 is a gas burner and 4 is a flame. Also, 5 is a 50g weight. Example 1 Ultra-high molecular weight polyethylene (density 0.945 g/cm ³ ) with an HLMI of 5.3 g/10 minutes was pressed at a pressure of 60 Kg/cm ² (gauge pressure) using a heat press set at 190°C. Heat pressing was performed for 1 minute to produce the above-mentioned press sheet. One side of a low-density polyethylene cross-linked foam sheet (thickness: 5 mm) was melted using a hot plate and bonded to this press sheet by pressing. moreover,
The other side of the foam sheet was melted and aluminum foil (30 microns thick) was pressed and adhered. In this way, a three-layer polyolefin laminate consisting of a polyethylene layer/foam sheet layer/aluminum foil layer was created. For comparison, a two-layer laminate of the above polyethylene sheet and aluminum foil (Comparative Example 1-1), a two-layer laminate of the above polyethylene sheet and foamed sheet (Comparative Example 1-2), and a polyethylene sheet alone (Comparative Example 1-1) were prepared. A fire resistance test, a tensile test and an impact test (tensile impact) were conducted with Examples 1-3). The results are shown in Table 1. From Table 1, it can be seen that when using a polyethylene sheet alone, the top surface melts in about 1 minute, dripping starts in about 2 minutes, and about
Puncture occurs in 2.5 minutes. In addition, in a two-layer laminate of polyethylene sheet and foam sheet, the top surface melts in about 2 minutes, dripping starts in about 3 minutes, and about 4
Perforation occurs in minutes. As described above, compared to polyethylene alone, it takes a little longer to melt and form holes, but the fireproofing effect is small. Furthermore, in the case of a two-layer laminate of polyethylene sheet and aluminum foil, dripping and puncturing phenomena do not occur, but the polyethylene surface melts in 1.5 minutes, and the insulation effect is small. In contrast, the three-layer laminate (container) of the present invention starts melting on the top surface after 20 minutes, does not cause dripping or punctures even after 60 minutes, and has significantly improved heat insulation and fire resistance. Not only that, but also in the tensile test and the impact test, no deterioration in physical properties was observed due to lamination. Example 2 The aluminum foil used in Example 1 was thermally bonded to the polyethylene sheet used in Example 1 to a low-density polyethylene crosslinked foam sheet, and the sheet was adhered with a phenolic resin nitrile rubber adhesive. A polyolefin laminate was created. The obtained laminate was subjected to a fire resistance test, a tensile test, and an impact test in the same manner as in Example 1. The results are shown in Table 1. From these results, the fire resistance of the laminate (container) obtained in Examples is significantly improved, similar to the laminate obtained in Example 1. Furthermore, in the tensile test and the impact test, it was found that no deterioration in physical properties was observed due to lamination. Example 3, Comparative Example 2 A propylene homopolymer (density 0.900 g/cm ³ ) with an MFI of 2.2 g/10 minutes was pressed at a pressure of 60 Kg/cm ² using a heat press set at 230°C. Heat pressing was performed for 1 minute to create a pressed sheet with a thickness of 3 mm. A cross-linked foamed sheet of propylene homopolymer was melted on one side using a hot plate and bonded to this press sheet by pressing. Furthermore, the other side of the foam sheet was similarly melted and aluminum foil (50 microns thick) was pressed and adhered. In this way, a three-layer laminate consisting of a propylene homopolymer layer/foamed sheet layer/aluminum foil layer was created. A fire resistance test, a tensile test, and an impact test were conducted in the same manner as in Example 1 for this three-layer laminate and a sheet made of propylene homopolymer alone (Comparative Example 2). The results are shown in Table 2. Table 2 shows that the three-layer laminate of the present invention has a longer top surface melting start time of 25 minutes than a sheet made of a homopolymer alone, and has no dripping or hole formation even after 60 minutes, and is extremely fire resistant. The properties have been improved.
Further, no deterioration in physical properties due to the laminate was observed in tensile tests and impact tests.

【table】

[Table] Example 4, Comparative Example 3 The ultra-high molecular weight polyethylene used in Example 1 was molded using a blow molding machine (manufactured by Sumitomo Heavy Industries, Ltd., trade name: Bekum blow molding machine, diameter 90 mm) at 200°C to determine the internal content. A round container (wall thickness: 2 mm) with a diameter of approximately 1 was molded. A low-density crosslinked foam sheet with a thickness of 5 mm was melted on one side using a hot plate and bonded to this round container by pressure bonding. Furthermore, the other side of the foam sheet was similarly melted, and the aluminum foil used in Example 1 was pressed and adhered thereto. In this way, a three-layer polyethylene laminated container consisting of a polyethylene layer/foam sheet layer/aluminum foil layer was created. A fire resistance test was conducted on this polyethylene laminated container and the polyethylene container before lamination treatment (Comparative Example 3). In the polyethylene container alone, melting and holes occurred after about 30 seconds. On the other hand, in the polyethylene laminated container, holes appeared after about 200 seconds, indicating that the fire resistance due to the heat insulation effect was significantly improved compared to the untreated container. Example 5 The aluminum foil used in Example 4 and the low-density polyethylene cross-linked foam sheet were adhered in advance by heat bonding, and this adhered material was applied to the round polyethylene container used in Example 4 with a nitrile rubber adhesive. A polyethylene laminated container was created by adhering the polyethylene container in close contact. When the resulting laminated container was subjected to a fire resistance test, holes appeared after about 200 seconds, indicating that the fire resistance was significantly improved compared to the blank. Example 6, Comparative Example 4 Polypropylene with MFI of 1.1 g/10 min (density
0.900g/cm ³ ), and a round container of the same type as in Example 4 was prepared. The adhesive material used in Example 5 was adhered to this round container using a nitrile rubber adhesive to produce a polypropylene laminated container. A fire resistance test was conducted on the obtained laminated container and a container made of polypropylene alone (Comparative Example 4).
The polypropylene alone container melted and developed holes and punctures after about 30 seconds. In contrast, in the polypropylene laminated container, holes appeared after about 210 seconds, indicating that the fire resistance due to the heat insulation effect was greatly improved. FIG. 3a is a side view showing the state of the fire resistance test of Examples 4 to 6 and Comparative Examples 3 and 4, and FIG. 3b is a plan view. In FIGS. 3a and 3b, 1 is a pedestal. This pedestal is
Height is 195mm, width and length are both 145mm
It is. This test uses a gas burner and uses LPG
The height of the flame was adjusted to 450 mm using the following gas. A round container was placed on the pedestal. A fire resistance test was conducted by placing a burner with an adjusted flame so that the distance between the bottom of the round container and the burner opening was 40 mm. In this case, fill the container with about half (575c.c.) of water,
Furthermore, the upper mouth part is in a sealed state with the cap closed. Note that 2 is a round container, 3 is a burner, and 4 is a flame. The diameter of the round container is
It is 122mm, and the bottom diameter is 75mm. The height is
It is 135mm, the height from the bottom to the neck is 120mm, and the height to the shoulder is 105mm.

[Brief explanation of the drawing]

Figure 1a shows Examples 1 to 3 and Comparative Example 1-1.
FIG. 1B is a side view of the device used in the fire resistance tests of ~1-3 and Comparative Example 2 and a sample placed on the device, and FIG. 1b is a plan view. Moreover, FIG. 2 is a drawing showing the state of fire resistance tests of these Examples and Comparative Examples. Furthermore, FIG. 3a is a side view showing the state of the fire resistance test in Examples 4 to 6 and Comparative Examples 3 and 4. FIG. 3b is a plan view of this test.

Claims (1)

[Claims] 1 Physically and/or chemically treating at least one of the outer surface of the polyolefin flammable liquid container and one side of the polyolefin foam layer, and further physically and/or chemically treating the other surface of the polyolefin foam layer. A flammable liquid container obtained by laminating the outer surface of the flammable liquid container with one side of a polyolefin foam layer and the other side of the polyolefin foam layer with a metal layer.