JPS5864948A - Vessel for combustible liquid - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 flammable liquid container and one surface of the polyolein foam layer is physically and/or chemically treated, and the other surface of the polyolefin foam layer is further physically and/or chemically treated. and/or chemically treated and 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, the purpose of which is fireproofing. An object of the present invention is to provide a flammable liquid container with excellent properties 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. . For example, containers used for transporting and storing chemicals and liquid fuels (e.g. kerosene, gasoline) are molded from high-density polyethylene, which has excellent impact resistance, chemical resistance, and oil resistance. It is often done. However, since ordinary olefin resins do not have good fire resistance, it is desired to improve the fire resistance of olefin resin molded products.

Generally, as a method of improving the fire resistance of olefin resin molded products, a method of kneading a flame retardant into a pregnant olefin resin has been used. However, when a relatively large amount of flame retardant is added to olefin resin, it does not reduce the processability of olefin resin; This poses a practical problem for reasons such as a decrease in performance.

Based on the above, the present inventors conducted various searches in order to obtain an olefin resin molded product with improved fire resistance, and found that: At least 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/or 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 physically and/or chemically treated. The inventors have discovered that a flammable liquid container obtained by laminating the other side of the foam layer and a metal layer is a liquid container with excellent fire resistance and heat insulation properties, and have arrived at the present invention.

According to the present invention, an olefin resin molded article with excellent fire resistance can be obtained without substantially impairing the various mechanical properties of the olefin resin that is the 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 olefin resin that is the raw material for the molded product of the present invention generally includes a homopolymer of ethylene or propylene, a random or crystalline copolymer of ethylene and propylene,
Copolymers of ethylene and/or propylene with other α-olefins having at most 12 carbon atoms (copolymerization ratio of α-olefins is at most 20% by weight), as well as ethylene and vinyl acetate, acrylic esters and methane. Examples include copolymers with vinyl compounds such as acrylic acid esters (the copolymerization ratio of the vinyl compound is generally at most 50 mol, preferably at most 40 mol 9!). The molecular weight of these polyolefin resins is generally 2
~500,000.

There are two methods for manufacturing flammable liquid containers: injection molding and blow molding, but blow molding is generally used. To produce the flammable liquid and container of the present invention by these methods, methods well known in the polyolefin industry may be applied, and special methods may be used.

There is no need to manufacture it.

The polyolefin foam layer of the present invention can be produced by mixing the polyolefin, a foaming agent, and gold, and foaming the foamed pK. 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.The decomposition temperature is generally 1,697,250°C, and especially 180°C to 180°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, potassium magnesium carbonate, magnesium carbonate, lead carbonate (Ill), ammonium such as iron carbonate and magnesium hydroxide carbonate, or group IA, group IB, group IA, etc. Carbonates of metals of group IB, group VIB or group II, as well as ammonium phosphate, ammonium bicarbonate,
Examples include inorganic ammonium salts such as ammonium carbonate, ammonium polyphosphate, ammonium oxalate, and a mixture of Fium nitrite and ibiamonium salt. Examples of organic blowing agents include N, I-dinitrosopentamethylenetetramine and N.

■-Dimethyl-N, v-DiniF Rosotere 7 Talamya time←Troso compound, azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile,
Azo compounds such as diazoaminobenzene and barium azodicarboxy, benzenesulfoterehydrazide and its derivatives, sulfonyl hydrazide such as diphenylsulfone-3,3-disulfonylhydrazide and P,P'-oxybis(benzenesulfonylhydrazide) Examples include compounds such as P-)luenesulfonyl azide and 4,4-diphenyldisulfonyl azide.

When producing the foamed layer of the present invention, in addition to these foaming agents, a foaming aid may be used to control the temperature during foaming, thereby reducing the decomposition temperature of the foaming agent. Not only this, but also the decomposition rate of the blowing agent can be changed, which is advantageous because the range of molding conditions can be widened. This foaming auxiliary agent varies depending on the type of foaming agent used, so it cannot be specified in general terms.
Examples include salicylic acid, phthalic acid, boric acid, and urea resin. When using these blowing aids, suitable blowing aids for the blowing agents used are widely known.

The blending ratio of the blowing agent to 100 parts by weight of polyolefin is ao, oi to 20.0 parts by weight, especially 002 to 10 parts by weight.
．． 0 parts by weight is desirable. In addition, when using a foaming aid, the blending ratio of the foaming aid that causes bluishness in the foam layer is at most 10
Weight%.

° To produce this foam layer, the polyolefin and a blowing agent or these and a blowing aid are mixed and the resulting mixture is generally heated at a temperature at which the blowing agent decomposes but 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 foam layers.゛As the thickness of this foam layer increases,
The insulation properties of flammable liquid containers are improved, but they are bulkier and - in small cases, have poor insulation properties. For these reasons, the thickness is generally 1.0 to 10 fi. The foamed layer thus obtained preferably has a foaming ratio of 20 to 30 times from the viewpoint of heat insulation properties.

Further, the metal layer of the present invention has 1. Its thickness is generally between 10 microns and 0.211111, preferably between 30 microns and 0.1 vrrtr. The types of metals include iron, aluminum, copper, nickel, and zinc, as well as metals containing at least 50% by weight of these metals (for example, stainless steel, aluminum, or alloys whose main components are iron). It will be done.

In the present invention, methods for physically and/or chemically treating the outer surface of the polyolefin flammable 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, small rod gases reactive with polyolefins such as SO, gas, chlorine gas and ammonia gas. Methods of treatment with gases containing
One example is a method of treating with a liquid material containing a compound that is reactive with reflex. 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 the metal layer on one side of the foaming tank and on the other side of the foaming tank.゛-In producing 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 by means such as an infrared heater, flame, hot air, or hot plate, and then pressed together. Alternatively, the foaming agent of the polyolefin foam layer may be foamed while being compressed. Furthermore, 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. Other methods include a method in which the polyolefin foam layer is inserted into a mold and brought into close contact with the heat of an extruded parison when manufacturing the container by blow molding, and a method in which the polyolefin foam layer and the metal layer are brought into close contact with each other in the same manner as above. Examples include mechanical joining methods such as bolting, banding, etc., of a polyolefin foam layer to which a metal layer has been adhered in advance to the outer surface of a polyolefin flammable liquid container. In short, according to the present invention, a polyolefin flammable liquid container can be manufactured by tightly 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 because the raw material for the container is an olefin resin, so it can be relatively easily formed into various shapes. Can be molded. Moreover, 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 addition, in Examples and Comparative Examples, High Low Melt Index (hereinafter referred to as "HLMI") and JI
Measurements were made based on SK-6760 under conditions of a load of 21.6 kp and a temperature of 190°C. Also, Melt-7
0-Remorse Index (hereinafter referred to as MFIJ) is JIS
- Measurements were made based on 6758 under conditions of a load of 2.16 k5' and a temperature of 230°C. Furthermore, the tensile test was measured based on Jxs-6760. In addition, the impact strength (tensile impact) is ASTM D-1.
Measured based on 822. Izotsu impact test is A
Measured based on STM D-256. moreover,
The fire resistance test was measured in accordance with JIS-D1201. Figure 1 (,) shows Examples 1 to 3 and Comparative Examples 1-1 to
1-3 and Comparative Example 2, and FIG. 1(b) is a side view showing the apparatus used for this test and the state when a sample is placed on this apparatus, and FIG. 1(b) is a plan view. In each drawing, 1 is a pedestal and 2 is a sample. This frame has a width of 20 m and a width of 7 crn. The sample was a press sheet with a wall thickness of 3++ on, and a liquid substance was applied to one side of the press sheet. This fire resistance test uses a gas burner,
The height of the flame was adjusted to 38rIrIn using LPG gas. Prior to this test, the sample was placed on a stand with the coated side facing down, and a 50Ii 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 wide. 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.

Further, 5 is a weight of 50 g.

Example I Ultra-high molecular weight polyethylene (density 0.945.97 cm3) with HLMI of 5°39Ii0 minutes was heated to 6aly/crn2 (density 0.945.97cm3) using a heat press set at 190°C.
Heat pressing was performed for 1 minute under pressure (gauge pressure) to produce the above-mentioned press sheet. A low-density polyethylene crosslinked foam sheet (thickness: 5 tm) was melted on one side with a hot plate and bonded by pressure to this press sheet. Furthermore, the other side of the foam sheet was melted and aluminum foil (thickness: 30 microns) 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) and a two-layer laminate of the above polyethylene sheet and foam sheet (Comparative Example t-2) were prepared.
) and polyethylene sheet alone (Comparative Example 1-3), fire resistance test, scratch test and impact test (Tensile/
impact). The results are shown in Table 1.

Table 1 shows that when using a polyethylene sheet alone, the top surface melts in 1 minute, dripping begins in about 2 minutes, and holes occur in about 25 minutes. In addition, in a two-layer laminate of a polyethylene sheet and a foam sheet, the top surface melts in about 2 minutes, dripping starts in about 3 minutes, and holes occur in about 4 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 a two-layer laminate of a polyethylene sheet and an aluminum foil, dripping and hole formation do not occur, but the polyethylene surface melts for only i and s minutes, and the heat insulation effect is small. In contrast, the three-layer laminate of the present invention -#-(
In the container), top surface melting starts after 20 minutes, no dripping or puncturing occurs even after 60 minutes, and not only the insulation and fire resistance are significantly improved, but also the lamination is good in tensile test and impact test. As a result, it can be seen that there is no noticeable decrease in physical properties.

Example 2 The aluminum foil used in Example 1 was thermally bonded to the polyethylene sheet used in Example 1 and then adhered to the low-density polyethylene crosslinked foam sheet using a phenol resin nitrile rubber adhesive.
A polyolefin laminate was created. The obtained laminate was subjected to a fire resistance test, tensile wrinkling test and 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 the example is significantly improved, as is the case with 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 MFI is 2.2. j7/1-0 min propylene homopolymer (density 0.9009/cm3.) at 230℃
Using a heat press set at a pressure of 6c) kp/c
Hot pressing was carried out for 1 minute under a pressure of m2 to produce a pressed sheet with a thickness of 3 cm. 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 melted in the same way, and aluminum foil (thickness 5
0 micron) 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 of propylene-only 4F body (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 single homopolymer;
Even after 0 minutes, no dripping or pitting occurred, and the fire resistance was significantly improved. Further, no deterioration in physical properties due to the use of a laminate was observed in tensile tests and impact tests.

Example 4 Comparative Example 3 The ultra-high molecular weight polyethylene used in Example 1 was heated to 200°C using a blow molding machine (manufactured by Juumin Heavy Industries Co., Ltd., trade name: Bekum blow molding machine, diameter 90 m) until the inner content of the polyethylene was about I
I! A prototype container (wall thickness 2n+m) was molded. A low-density cross-linked foam sheet with a thickness of 5 m was melted on one side using a hot plate and then crimped onto this prototype container.

I glued it together. 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 laminate container consisting of a polyethylene layer/foam sheet layer/aluminum foil layer was produced.

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 occurred 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 heat-adhered in advance, and this adhered material was applied to the polyethylene prototype 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 obtained laminated container was subjected to a fire resistance test, holes appeared after about 200 seconds, and the fire resistance was significantly improved compared to the blank.

Example 6 Comparative Example 4 MFI is 1.1. ! ? /10 min. polypropylene (density: 0900 g/Crn) was used to prepare a prototype container of the same type as in Example 4. The adhesive material used in Example 5 was adhered to this prototype container using a nitrile rubber adhesive to create a polypropylene MN container. The obtained laminated container and container made of polypropylene alone (Comparative Example 4)
) was conducted a fire resistance test. The polypropylene alone container melted and developed holes and punctures after about 30 seconds.

On the other hand, in the polypropylene laminated container, holes occurred after about 210 seconds, indicating that the fire resistance due to the heat insulation effect was significantly improved.

FIG. 3(,) 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. 3(b) is a plan view. Figures 3(a) and 3(b)
1&l is a single pedestal. This pedestal has a height of 19
It is 5m, and both the width and length are 145IEII. In this test, a gas burner was used and the height of the flame was adjusted to 450 m using LPG gas. The master container was placed on the pedestal. A fire resistance test was conducted by placing a burner whose flame was adjusted so that the distance between the bottom of the prototype container and the burner was 40 m. In this case, the container is filled with water about half (575°C), and the upper opening is closed and sealed. Note that 2 is a prototype container, 3 is a burner, and 4 is a flame. The original container has a diameter of 122 cm, and the diameter of the bottom is 75101 cm.
It is. The height is 13511Il, the height from the bottom to the neck is 120cm, and the height to the shoulder is 105m + 1
It is 1.

[Brief explanation of the drawing]

FIG. 1(a) shows Examples 1 to 3 and Comparative Examples 1-1 to 1.
Fig. 1 is a side view of the apparatus used in the fire resistance tests of -3 and Comparative Example 2 and a sample placed on the apparatus, and Fig. 1 (bl is a plan view). It is a drawing showing the state of fire resistance tests of Examples and Comparative Examples.Furthermore, Fig. 3 Patent Applicant Showa Denko K.K. Agent Patent Attorney Sei Kikuchi - Fig. 3(b)

Claims (1)

[Claims] At least one of the outer surface of the polyolefin flammable liquid container and one side of the polyolein foam layer is physically and/or chemically treated, and the other surface of the polyolefin foam layer is physically and/or chemically treated. A container for flammable liquid 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.