KR20020047040A - Multi-shell device for storing and transporting chemicals - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to a device for the storage and transport of chemicals, in particular liquid high purity chemicals used in the electronics industry, comprising at least a) an inner shell made of stabilizer HD-PE and contacting the contents and a polyethylene surrounding the inner shell And a multi-shell inner container comprising one or more shells made of plastic, and b) a metal-free conveying facility made of plastic. The invention also relates to a coextrusion method for producing a device for storing and transporting chemicals, in particular high purity chemicals for the electronics industry, which method comprises at least a) a hollow process made of stabilizer HD-PE with a blow method. Producing a shaped body, b) simultaneously enclosing the hollow body obtained in step a) with at least one shell made of polyethylene (coextrusion), and c) surrounded with at least one shell made of polyethylene. Producing a container made of plastic so that the hollow body obtained in the step of can be inserted therein.

Description

MULTI-SHELL DEVICE FOR STORING AND TRANSPORTING CHEMICALS}

In the production of electronic components, liquid chemicals are usually required, and these chemicals need to be of high purity. In particular, in the production of highly integrated microchips, they need to be of very high purity since the dimensions of these microchips produced using process chemicals continue to shrink. In general, purity requirements for certain liquid chemicals, such as process chemicals for the electronics industry, have increased significantly over the last few years. The production of chemicals with the required purity can no longer be met and it must be ensured that the product is not impure during transportation, storage and handling. In addition, some of these chemicals are aggressive or toxic and must be safely stored and transported. For example, accidental leakage of these chemicals due to damage or leakage of the shipping container should be ruled out to the greatest extent possible. For cost reasons, only large packing drums can be used to transport liquid high purity chemicals. These packing drums should be designed in a manner that prevents contamination of the contents of the container and prevents breakage even when roughly handled with forklifts and similar equipment. In addition, the container should be easy to produce at low cost. These containers should be able to be moved by forklift trucks and other conveying equipment, without risk during transportation.

Therefore, two aspects should be considered when selecting such container materials. First, it should be chosen in terms of excluding any contamination by the material of the walls of the container in contact with the chemicals stored and transported. In addition to preventing contamination of the chemicals transported and resistance to possible leaching of the chemicals transported, the containers also provide sufficient strength to ensure that the containers are pressure resistant, impact resistant, hard and prone to deformation or cracking. Rather, it must have some degree of elasticity. In addition, it is preferable that the container has a relatively large capacity and that can be produced quickly and easily.

In German patent 196 28 653 it is known that certain polyethylenes, in particular unstable HD polyethylenes, are very suitable for the production of storage and transport containers for liquid high purity chemicals used in the electronics industry. In particular, HD polyethylene with a specific density of 0.940 to 0.970 g / cm ³ , in particular 0.942 to 0.961 g / cm ³ , is mentioned. In particular, this includes polyethylenes classified under the trademark Lupolen. Lupolen® 6021D, Lupolen® 5021D, Lupolen® 4261AQ149 and Lupolen® 4261AQ135 are mentioned by way of example. According to the prior art, the device is produced by welding a plate made of the above-mentioned material. Welding correspondingly extruded plates is time consuming and expensive to produce such containers. In addition, the quality maintenance properties of Lupolen® 6021D cannot be guaranteed to a satisfactory level due to welding and thus welding seams. On the one hand, it is not yet possible to blow-extrude a conveying vessel which is extruded in a single blow, for example to a volume of 200 liters, or the vessel produced in this way is a mechanical requirement of the dangerous cargo packing test. Can not meet.

The present invention relates to a multi-shell type device for storing and transporting chemicals, especially liquid high purity chemicals used in the electronics industry.

One object of the present invention is to provide another apparatus for storing and transporting chemicals, in particular liquid high-purity chemicals used in the electronics industry, which meets the above requirements and further allows for simple and rapid production. To provide a corresponding method of production of the device.

The problem is solved by an apparatus according to claim 1 and a method according to claim 9. Other embodiments and advantages are described in the dependent claims.

Accordingly, the present invention is a device for the storage and transport of chemicals, in particular liquid high purity chemicals used in the electronics industry, comprising at least the following elements.

a) a multi-shell inner container made of a stabilizer HD-PE and comprising an inner shell in contact with the contents and at least one shell made of polyethylene surrounding the inner shell,

b) metal-free conveying equipment made of plastic;

Within the scope of the present invention, stabilizer HD-PE is HD-PE produced without the use of commonly used stabilizers. In particular, commonly used stabilizers are known to those skilled in the art. Kunststoff 78 (2), 142 (1988)].

According to the present invention, multilayer extrusion blow methods or coextrusion are used to produce devices for the storage and transport of high purity chemicals. According to the present invention, the innermost shell made of mechanically fragile and high purity stabilizer HD-PE is used on the side in contact with the chemical, while the material used for the shell surrounding the innermost shell is known extrusion. Possible materials, such as general HD-PE (e.g., Lupolen® 4261AQ135 or Lupolen® 5261Z with a density of 0.94 to 0.97 g / cm ³ , as well as corresponding Hostalene®) Product, etc.). According to the multilayer extrusion blow method, the inner container of the apparatus according to the invention can be produced in one continuous production process. Therefore, it is possible to save considerable cost and time compared to the welding method used to date. Furthermore, the device according to the invention is made of a single piece and does not have weld seams or other weak points, so the resistance to pressure and drop is considerably greater than that of containers known to date. In coextrusion, several layers of polymer melt overlap and are connected inside the extrusion nozzle. Such multilayer nozzles are installed at several inlets and one common outlet for the melt.

According to the invention, the multi-shell inner container of the device can be arranged in a metal-free conveying facility made of plastic. The metal-free transport device is preferably a rigid plastic transport box made of metal-free plastic. In another preferred embodiment, the carrying box includes an integrated pallet that functions as a protector against damages imposed during transportation. In addition, the integrated pallet further stabilizes and supports the inner container of the device according to the invention.

The stabilizer HD-PE is preferably polyethylene having a secretivity of 0.940 to 0.970 g / cm ³ , in particular 0.942 to 0.961 g / cm ³ , most preferably 0.946 to 0.960 g / cm ³ , this type of polyethylene being an impurity Emits very small amounts of particles such as

According to another embodiment of the invention, the stabilizer HD-PE is a polyethylene having a secretivity of 0.940 to 0.970 g / cm ³ , in particular 0.942 to 0.961 g / cm ³ , most preferably 0.946 to 0.960 g / cm ³ . Polyethylene of this type emits one or more of the following ionic impurities according to the following list when contacted with basic, neutral and acidic high purity chemicals.

Al ≤60 ng / g,

Ca ≤60 ng / g,

Fe ≤ 63 ng / g,

Mg ≤ 16 ng / g,

Ti ≤ 4 ng / g,

Zn ≤ 6 ng / g,

Mn ≤0.3 ng / g,

Cu ≤1.5 ng / g,

In addition, destabilized HD-PE is characterized by low levels of catalyst residues that release trace amounts of ionic impurities when encountered with basic or acidic high purity chemicals. In addition, relatively low content particles are produced by the interaction between the chemicals and the materials stored or transported. The content of particles is as follows.

Particles (≦ 0.5 μm): containing (≦ 5 / ml liquid),

Particles (≦ 0.2 μm): containing (≦ 50 / ml liquid),

Particles (≦ 0.1 μm): containing (≦ 500 / ml liquid).

Particularly preferred is HD-PE, which is available under the registered trademark Lululene® 4261A! 149. This material has the purity required for high purity chemicals. This material is also very suitable for extrusion.

At least one shell of the device, preferably the outermost shell, is an extrudable polymer or copolymer, preferably has a hermeticity of 0.940 to 0.970 g / cm ³ , in particular 0.942 to 0.961 g / cm ³ , most preferably 0.946 It is preferably made of HD-PE, which is from -0.960 g / cm ³ .

According to a preferred embodiment, the outermost layer is Lupolene (R) 5261D, Lupollen (R) 4261AQ135, Hostalene (R) GM6255, Pina (R) 56020, Borealis (R) 8214, One or more HD-PEs or a mixture of two or more of these groups of HD-PEs selected from the group consisting of Stamilan® 7731 and 7890, Daplan® AH5493.

According to another preferred embodiment, the outermost layer comprises a pigment to protect the layer against ultraviolet radiation. Thus, the device prevents any damage caused by incident light rays, especially during transportation. The outermost layer retains its properties regarding mechanical stability. The pigment used is preferably soot. However, quartz, a general master batch, and other common pigments such as copper-phthalocyanine or TiO ₂ as well as organic ultraviolet stabilizers and biphenyl compounds and the like can also be used.

According to another preferred embodiment of the present invention, in order to increase the resistance to pressure, drop or impact of the device according to the invention, the outermost layer is made of, for example, glass fiber or a mechanically more stable material such as a polymer. It is reinforced by adding. It is preferred that a plate made of polyamide be integrated to reinforce the outermost layer as described above. For this purpose, a PE-composite such as for example a sealer can be used.

According to a particularly preferred embodiment, the device consists of two shells. The innermost shell, preferably made of Lupolen® 4261AQ149, accounts for 20-40% of the thickness of the wall, while the outermost layer accounts for 60-80% accordingly. This structure proved to be very stable.

According to another preferred embodiment, the device comprises three or more layers, wherein the one or more intermediate layers consist of waste in production. This type of waste is called "clump waste" and is associated with parts falling off the top and bottom during the "final formation" of the device.

The device according to the invention preferably has one or more openings, preferably a plurality of openings. In it, the opening preferably has a diameter of ≦ 150 mm, most preferably ≦ 70 mm. The opening serves to receive the plunger tube or plug stopper. They are preferably made of at least one of PE-HD, perfluor alkoxy polymers (PFA), polypropylene, PVdF and perfluorized polyethylene propylene (FEP).

The opening can be suitably formed by inserting a particular mold into the blow mold or by corresponding adapters of various extrusion systems such as plunger tubes or connection systems. This results in a very low level of contamination while filling the product into the container and / or removing it from the container.

According to a preferred embodiment of the invention, the device has a filling capacity of ≧ 200 L, preferably ≧ 500 L. By the production of multilayer extrusion blows and the provision of additional metal-free conveying equipment, it is possible to simply and quickly produce high-purity chemical storage and transportation devices that meet safety requirements. This results in significant cost and time savings.

According to a preferred embodiment of the present invention, the metal-free conveying facility is designed to be able to completely enclose a multi-shell inner container. The metal-free transport facility is a metal-free box made of solid plastic, in which multiple shell-type inner containers can be arranged. According to a preferred embodiment, the transport box is made of LLD-PE. In this embodiment, the box is made according to a two-layer method in which both the outer and inner layers are rotationally sintered and foamed using, for example, LLPD-PE particles dotted with pentane or hexane. This carrying box is preferably provided with a protective cover which is preferably made of the same material, whereby the carrying box can be completely sealed so that the inner container contained therein is all protected against external influences. As mentioned above, pallets are provided inside the transport box to further stabilize and protect the inner container from damage caused by transport.

The transport box is preferably manufactured by a rotary sintering method. This production method produces a box that is impact resistant and has low production costs.

The invention also relates to a coextrusion method for producing a device for storing and transporting chemicals, in particular high purity chemicals for the electronics industry, which method comprises at least the following steps.

a. Producing a hollow body made of stabilizer HD-PE by a blow method;

b. simultaneously enclosing the hollow body obtained in step a) with at least one shell made of polyethylene (coextrusion);

c. Producing a container made of plastic so that the hollow body obtained in step a) surrounded by at least one shell made of polyethylene can be inserted therein.

The plastification step of the process according to the invention is preferably carried out under the conditions of addition of an inert gas. Nitrogen is preferably used as the inert gas. This means that in production by the blow method an inert gas, preferably nitrogen, is used as blow gas instead of air.

The addition of nitrogen during the production of the device according to the invention prevents oxygen from surrounding air or shields the polyethylene for production, thereby avoiding oxidative interference of the polyethylene destabilized during each process step. Oxidative interference may be a lattice blockage or knotted formation due to, for example, stored oxygen molecules, as described above.

The method according to the invention makes it possible to produce a multi-shell type device according to the invention simply and quickly. In practice, only one continuous working process is required to form the inner container. Since the subsequent welding of the prefabricated plate is omitted, the finished device does not have a weld seam. By directly connecting the individual layers during production, certain stability can be achieved and the contact between the individual layers can be particularly firmly contacted.

Claims (11)

A device for storing and transporting chemicals, especially high purity chemicals for the electronics industry, a. A multi-shell inner container made of an stabilizer HD-PE and comprising an inner shell in contact with the contents and at least one shell made of polyethylene surrounding the inner shell, b. Metal-free conveying equipment made of plastic At least comprising a device for storing and transporting chemicals. The device of claim 1, wherein the inner container of the device is produced by a blow method. The device of claim 1 or 2, wherein the inner container of the device is produced by an extrusion blow method. The apparatus of claim 1, wherein the stabilizer HD-PE is polyethylene having a secretivity of 0.940 to 0.970 g / cm ³ . The method according to any one of the preceding claims, wherein the stabilizer HD-PE is a polyethylene having a hermeticity of 0.940 to 0.970 g / cm ³ , and this type of polyethylene is in contact with basic, neutral and acidic high purity chemicals. Apparatus for the storage and transportation of chemicals, characterized in that for releasing one or more of the following ionic impurities according to: Al ≤60 ng / g, Ca ≤60 ng / g, Fe ≤ 63 ng / g, Mg ≤ 16 ng / g, Ti ≤ 4 ng / g, Zn ≤ 6 ng / g, Mn ≤0.3 ng / g, Cu ≤1.5 ng / g, The device of claim 1, wherein the metal-free transport facility is a transport box made of metal-free plastic. The device of claim 1, wherein the device has a fill capacity of ≧ 200 liters. The device of claim 1, wherein the metal-free box is manufactured in such a way that it can completely enclose an inner container. A coextrusion method for producing a device for storing and transporting chemicals, in particular high purity chemicals for the electronics industry, each comprising at least one multi-shell inner container according to claim 1 and at least one metal-free conveying facility, a. Producing a hollow body made of stabilizer HD-PE by a blow method, b. simultaneously enclosing the hollow body obtained in step a) with at least one shell made of polyethylene (coextrusion), c. Producing a container made of plastic so that the hollow body obtained in step a) surrounded by at least one shell made of polyethylene can be inserted therein At least including the method. 10. The process according to claim 9, wherein the a) production step and the b) enveloping step are carried out under an atmosphere of inert gas. The process according to claim 9 or 10, wherein in the production step the vessel is rotationally sintered.