Injection-molded disposable plastic product and its manufacture and use
The manufacture of disposable plastic products through the mixed material injection molding process of LDPE and CBC solves the problem of dissolving contamination of plastic products in liquid media, and achieves thermal stability, transparency and low-cost plastic products, suitable for sample processing and testing in the field of life sciences.
Patent Information
- Application Number
- CN202380088982.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-06
- Publication Date
- 2025-08-01
AI Technical Summary
When existing plastic products come into contact with liquid media, plastic additives and debris are easily dissolved, contaminating liquid samples, especially in the field of life sciences, and the existing barrier layer solutions are costly and ineffective.
Using a mixed material of low-density polyethylene (LDPE) and cyclic block copolymer (CBC), disposable plastic products are manufactured through injection molding, avoiding additives, ensuring the thermal stability and transparency of the material, and reducing the components that can be dissolved by the solvent.
The plastic products used in the life sciences field do not contaminate liquid samples, maintain thermal stability, reduce manufacturing costs, and are transparent or translucent, easy to observe contents, suitable for a variety of shapes and uses.
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Abstract
Description
Technical Field
[0001] The present invention relates to an injection-molded disposable plastic article, a method for manufacturing the same, and uses thereof. Background Art
[0002] As is well known, a disadvantage of plastic articles is that when in contact with a liquid medium, especially a liquid sample, components can dissolve out of the plastic material and thus contaminate the liquid medium or the sample. These are, for example, plastic additives that support heat treatability contained in the plastic, such as antioxidants. These leachable components or contaminants, also referred to as "extractables", then become components of the contents of the plastic article and damage or contaminate the contents. When samples in plastic articles are to be tested, for example in chemical or biological tests, these contaminants can interfere with or even inhibit the test, which has particularly adverse effects. Especially in the case of small volumes, these contaminants have particularly serious effects.
[0003] Plastic articles are commonly used in various applications, for example also in applications in the field of life sciences, i.e., in the fields or research areas related to biology, its structures and processes. These are, for example, the fields of medicine, pharmacology, biochemistry, biotechnology, especially cell biology, microbiology or molecular biology. Plastic articles used in these fields are made of, for example, polyolefins, which usually contain plastic additives or plastic fragments, which are then dissolved out by solvents commonly used in these areas, such as polar protic solvents or polar aprotic solvents. Thereby, the liquid contained in the plastic article is contaminated. The dissolution of plastic additives and / or plastic fragments occurs because these plastic additives and / or plastic fragments dissolve especially in polar protic solvents or polar aprotic solvents. However, it is precisely these solvents that are commonly used in the field of life sciences. On the other hand, non-polar solvents that dissolve non-polar components out of the plastic, such as oligomers, are hardly used in the field of life sciences. Therefore, there is a need for plastics in these application fields in particular, in which plastic additives and / or plastic fragments are not dissolved out of the plastic.
[0004] One possible solution to prevent unwanted components from dissolving out of the plastic is to omit plastic additives. However, this usually has the problem that the thermal stability of the plastic is reduced, such that the plastic can no longer be heat treated and undergoes thermal decomposition. Thus, the heat treatability of the plastic may be completely lost.
[0005] Another possible solution to prevent additives from leaching out of plastics is to apply one or more layers on the inside of the plastic article, where a liquid sample is to be stored and, for example, tested. These layers are, for example, SiOx layers, which should act as a barrier against leaching out of the plastic material. However, in most cases it has been found that one or more SiOx layers on the plastic have insufficient barrier properties and sometimes even soluble components leach out of the barrier layer itself in an undesirable manner and are transferred to the liquid sample contained therein. Another disadvantage of these layers is the risk that the coating may flake off, for example when handling the liquid sample, especially when using ultrasound, and then contaminate the sample contained therein.
[0006] In addition, the manufacturing cost is greatly increased due to the additional manufacturing steps of the coating of the plastic article, which is very disadvantageous from an economic point of view.
[0007] From the publication: Macromolecules, 2016, 49(17), pages 6497 - 6506, for example, poly(cyclohexylethylene - ran - ethylene) copolymer (CE) became known, the statistical segment lengths of which were synthesized such that they correspond to isotactic poly(propylene) (iPP). These plastics do not seem to contain additives. Films were made from these plastics, but no containers were made.
[0008] Therefore, there is great interest and a great demand for such plastic articles that avoid the disadvantages of the prior art and in particular do not have or have very few components that can be leached out of the plastic, while the plastic still has thermal stability and can be processed in a conventional manner. Summary of the Invention
[0009] According to the present invention, the above object is achieved by an injection - molded disposable plastic article, which consists of two plastics, low - density polyethylene (LDPE) and cyclic block copolymer (CBC), wherein LDPE accounts for 95 - 30 weight percent and CBC accounts for 5 - 70 weight percent, the injection - molded disposable plastic article is semi - transparent or transparent, has a melt flow index (MFR) (190 °C / 2.16 kg) in the range of 0.1 to 2.5 k / 10 min according to ISO 1133 and does not contain additives.
[0010] The preferred mixing ratio of low - density polyethylene (LDPE) to cyclic block copolymer (CBC) is in the range of 9:1 to 1:1.
[0011] Next, for simplicity, low - density polyethylene will be referred to as LDPE and cyclic block copolymer will be referred to as CBC.
[0012] Here, "disposable products" are understood to be products that are intended only for one-time use and are subsequently disposed of. Disposable products here are disposable plastic products, i.e., they are made of plastic. Apart from these two plastics, no other components should be present.
[0013] The term "injection-molded disposable plastic product" refers to a disposable product made of plastic that is manufactured using the injection molding process and can only be obtained using this injection molding process. Injection molding is a plastic molding process known to those skilled in the art, in which the plastic is liquefied in an injection molding device and injected under pressure into a mold, the injection mold. The liquefied plastic solidifies in the mold due to cooling or a crosslinking reaction, wherein the mold cavity, the so-called mold cavity, determines the shape and structure of the molded part. After solidification, the mold is opened and the resulting molded part is removed. In the present invention, no crosslinking reaction occurs because reactive groups, such as double bonds, are not present in the two plastics.
[0014] Next, injection molded disposable plastic products are also referred to as disposable plastic products or plastic products for short.
[0015] The first plastic contained in the disposable plastic article is selected from the LDPE family. In LDPE, "LD" stands for "low density" and "PE" stands for polyethylene. It is a low-density polyethylene, also known as low-density polyethylene (PE-LD). It is a thermoplastic. The polyethylene in LDPE exists as a highly branched polymer chain, resulting in a density of 0.915 g / cm 3 to 0.935g / cm 3 Low densities exist in the range (according to ISO 1183 or ASTM D1505, which are equivalent).
[0016] LDPE, or low-density polyethylene, is flexible and not very thermally stable, but is very impact-resistant. According to the present invention, additive-free LDPE is used. For example, additive-free LDPE for medical and pharmaceutical applications (medical grade) is commercially available. Transparent or translucent, injection-moldable LDPE is used. LDPE is injection-moldable when it has a melt flow rate (MFR) according to ISO 1133 (MFR / 190 / 2.16: test temperature 190°C, mass 2.16 kg) in the range of 0.1 to 2.5 g / 10 min. Therefore, LDPE with an MFR within the specified range is selected.
[0017] Exemplary commercial products of LDPE that can be used according to the present invention are products of the Borealis Group and the Sabic Group, such as Bormed TMLE6600-PH, a trademark of Borealis Group, an additive-free LDPE with an MFR (190 °C / 2.16 kg) according to ISO 1133 of 1.5 g / 10 min, or SABIC LDPE PCG09, an additive-free LDPE with an MFR (190 °C / 2.16 kg) according to ISO 1133 of 7.5 dg / min (= 0.75 g / min), or SABIC LDPE PCG22, an additive-free LDPE with an MFR (190 °C / 2.16 kg) according to ISO 1133 of 22 dg / min (= 2.2 g / min).
[0018] The second plastic contained in the disposable plastic article is selected from the group of cyclic block copolymers (CBCs), which is also a thermoplastic. This is a relatively new group of plastics from USI Corp., which can also be obtained without additives. Cyclic block copolymers (CBCs) are fully hydrogenated polymers based on styrene and conjugated dienes obtained by anionic polymerization. For example, the hydrogenation of a styrene-butadiene block copolymer to a CBC is carried out according to the following scheme:
[0019]
[0020] The residues R1, R2 and the parameters a, b, x and y can be selected in a suitable manner. There is no information on this point in the prior art.
[0021] The properties of the CBC can be adapted within a wide range by adjusting the ratio of cyclohexyl ethylene (CHE) to ethylene-co-1-butene (EB) in the copolymer.
[0022] Generally, the CBC has high stiffness and far higher thermal shape stability than LDPE, but is very brittle for this and difficult to process in injection molding technology. According to the invention, an additive-free CBC is used. For example, an additive-free CBC for medical and pharmaceutical use (medical grade) is commercially available. According to the invention, a transparent and injection-moldable CBC is used. The CBC is injection-moldable when it has a melt flow index MFR in the range of 0.1 to 2.5 g / 10 min according to ISO 1133 (MFR / 190 / 2.16: test temperature 190 °C, mass of 2.16 kg). Therefore, a CBC with an MFR in the specified range is selected.
[0023] As an exemplary commercial product, the known CBC types from Fa. USI will be listed, which are sold under the trade name ViviOn TM Cyclic block copolymers (CBCs) are known. For example, they are ViviOn TM CBC 8210, ViviOn TMCBC 8210XT, ViviOn TM CBC 1325, ViviOn TM CBC 1325EUT, ViviOn TM CBC 0510HSE, ViviOn TM CBC 0510, ViviOn TM CBC 0510HF, ViviOn TM CBC 0510T, ViviOn TM CBC 0510HT, ViviOn TM CBC 0510HFP, ViviOn TM CBC 0510HFE and ViviOn TM CBC 0510FEP. The latest type ViviOn TM CBC 0510HSE is particularly impact-resistant and has particularly high fluidity., These CBCs have, for example, a transmittance of at least 91% (380 - 760 nm) according to ASTM D1003. These CBCs all have, for example, an MFR (260 °C / 2.16) in the range of 5 to 13 g / 10 min or an MFR (190 °C, 2.16) in the range of 1 to 3 cm 3 / min (= 1 to 3 g / min) according to ASTM D1238 (equivalent to ISO 1133). Therefore, the listed CBCs are all injection-moldable.
[0024] Now, it has surprisingly been found that the properties of LDPE and CBC can be combined with each other to obtain particularly favorable properties of the plastic products made therefrom.
[0025] Injection-molded disposable plastic products are characterized by their composition in that the components that can be dissolved out of the disposable plastic products by solvents are reduced until the inevitable proportion, i.e., reduced to the minimum. In this context, "reduced to the minimum" means reduced to the minimum proportion or minimum limit of the components that can be dissolved out by solvents, and this minimum ratio or this minimum limit cannot be avoided. This applies in particular to polar protic solvents or polar aprotic solvents. Polar aprotic solvents are, for example: ketones, such as acetone, lactones, lactams, nitro compounds, such as nitromethane, tertiary carboxylic acid compounds, such as dimethylformamide, ureas, sulfoxides, such as dimethyl sulfoxide, sulfones, and carbonates, such as ethylene carbonate. Polar protic solvents are, for example: water, short-chain alcohols, such as methanol and ethanol, primary and secondary amines, primary and secondary amides, carboxylic acids, and mineral acids. Therefore, subsequent sealing and / or coating of the surface of the plastic products are generally not required.
[0026] The dissolved components in the expression "until an inevitable proportion" mean that components are always dissolved out of the plastic, which cannot be completely prohibited. However, the proportion of the components dissolved out of the plastic is so low that this proportion is usually even below the detection limit and can be neglected. So far, no contamination of the liquid contents of disposable plastic products has been observed. In other words, injection-molded disposable plastic products can also be used in fields with very high requirements for plastic quality, such as the life science field, without the contents being contaminated by the dissolved plastic components.
[0027] In addition, plastic products are inert to solvents, especially polar protic or polar aprotic solvents. Here, the expression "inert to solvents" can be understood as that plastic products remain unchanged even when in long-term contact with solvents or solvent mixtures, that is, their chemical composition does not change. In addition, as mentioned above, solvents hardly dissolve out any components from plastic products.
[0028] In addition, disposable plastic products are semi-transparent or even transparent due to the plastics used. Here, "semi-transparency" can be understood as the existence of partial light transmittance, such that the plastic products are semi-transparent like frosted glass but not transparent. Thus, the plastic products are only partially light-transmitting rather than transparent, but semi-transparent, which can also be called translucent.
[0029] "Transparency" means that plastic products are transparent. The term "transparent" refers to materials that can allow most light to pass through, where usually a small part of the light is absorbed and scattered. Therefore, transparency is the ability of a material to allow light waves to pass through (transmission). Transparent materials are characterized by a high transmittance. Here, the term "transparent" means that disposable plastic products have a high light transmittance of 75% or at least 80% or at least 85% or at least 90% or at least 95% of the light of the wavelength used at the thickness of the material used. For example, the turbidity and light transmittance of transparent plastics are determined according to ASTM D1003 at 380 to 760 nm, where the above-listed values are obtained.
[0030] In the injection-molded disposable plastic products according to the present invention, transparency is achieved only because there is no phase boundary in the mixing ratio of the two components of low-density polyethylene (LDPE) and cyclic block copolymer (CBC). The miscibility of these two plastics is particularly good. Phase boundaries during the mixing of different substances cause difficulties and are visually inconsistent with transparency, and also mean mechanical weaknesses. Surprisingly, this is not the case for the disposable plastic products according to the present invention.
[0031] Both transparent and semi-transparent plastic products are particularly advantageous because the contents of the plastic products can be seen from the outside. This is useful, for example, during the sample sorting of plastic products.
[0032] Whether a transparent or translucent disposable plastic article is obtained depends on the selected mixing ratio of two components, namely low density polyethylene (LDPE) and cyclic block copolymer (CBC): Thus, LDPE itself is usually translucent. CBC itself is transparent or even highly transparent. Surprisingly, the transparency or translucency is now not lost in the disposable article, enabling the optical properties of LDPE and CBC to be combined with each other, so that the contents of the plastic article can be seen from the outside, and even clearly. The more CBC contained in the disposable plastic article, the more the obtained plastic article further changes from translucent to transparent.
[0033] The injection-molded disposable plastic article has overall improved injection-molding properties by mixing two plastics, so that the disposable plastic article can be manufactured by injection molding. The disposable plastic article has a melt flow index MFR (190 °C / 2.16 kg) in the range of 0.1 to 2.5 g / 10 min according to ISO 1133 or ASTM D1238. ISO 1133 and ASTM D1238 are regarded as technically equivalent, so the obtained MFR values are the same. The flow behavior of thermoplastics and their degree of polymerization can be determined by the melt flow index MFR. Therefore, the melt flow index MFR explains the good injection-molding behavior of the plastic article of the present invention.
[0034] Therefore, the selected CBC / LDPE mixture is suitable for manufacturing disposable plastic articles, which can be manufactured, for example, in one manufacturing step. Thus, the disposable plastic articles can be manufactured at low cost.
[0035] The shape of the disposable plastic article is no longer restricted, and any shape known to those skilled in the art can exist. These are, for example, the lids of containers, closures of containers, packaging articles, especially in the form of containers, microtest plates (deep well plates), containers, especially sample containers, such as bottles or vials, pear-shaped flasks, sample tubes, cuvettes for the optical examination of liquids (e.g., UV / VIS) (i.e., sample containers with plane-parallel side surfaces), containers with closures, especially where the closure and the container are inseparably connected to each other, i.e., one-piece, pipette tips, syringes or infusion containers.
[0036] However, the disposable plastic article should not be in the form of a film.
[0037] Depending on the shape of the disposable article, they have different requirements and performance characteristics. For example, the requirement for a pipette tip is that it is straight and not distorted, while in the case of a container, for example, stability plays a role during centrifugation. These requirements and performances can be easily met according to the present invention.
[0038] Thus, by adjusting the ratio of the two plastics, the thermal and mechanical properties of the plastic products of the present invention can be adjusted specifically, and even adapted or "tuned" for specific performance characteristics. Although LPDE has low thermal stability and is too soft, its use possibilities are very limited when used alone. While CBC is very rigid, as a single component, it is too rigid or too fragile to a certain extent. Therefore, the combination of these two plastics has great advantages, that is, it can provide various performance characteristics, and these performance characteristics can be coordinated specifically according to requirements and uses. In addition, unexpectedly, the disposable plastic products are semi-transparent to transparent and additive-free.
[0039] The term "additive-free" means that there are no additives of any type in the form of additional substances in the plastic products, either used for manufacturing or added during the manufacturing process, and the plastics in the form of LDPE and CBC used as raw materials are also used without additives respectively.
[0040] The use possibilities of the disposable products are no longer limited, and any possible use of the plastic products is feasible for those skilled in the art. Therefore, the uses are very diverse and can include, for example, storage, sampling, sample processing, especially performing tests on samples, etc.
[0041] Containers with very low sample concentrations are particularly advantageous because in this way, the advantageous properties of the present invention can be particularly well demonstrated. For example, pipette tips are very particularly advantageous as disposable plastic products because the samples contained are avoided from being contaminated by the dissolved components (until the inevitable minimum proportion) in the plastic.
[0042] The disposable plastic products are preferably used in the fields related to organisms, their structures and processes, and particularly preferably used in all steps carried out in the laboratory. This is, for example, the fields of medicine, pharmacology, biochemistry, biotechnology, especially cell biology, microbiology or molecular biology. Particularly preferred uses are in the fields of drug storage and cell culture, where all process steps of biological or medical tests are carried out in a molecular biology laboratory, such as processing, replicating and storing biological molecules, such as DNA, RNA or proteins.
[0043] In addition, the present invention also relates to a method for manufacturing the injection-molded disposable plastic products according to the present invention, which has the following steps:
[0044] - Dry-mix low-density polyethylene (LDPE) and cyclic block copolymer (CBC) particles each used without additives, wherein low-density polyethylene (LDPE) is used, the low-density polyethylene (LDPE) is translucent or transparent and has a melt flow index MFR (190 °C / 2.16 kg) in the range of 0.1 to 2.5 g / 10 min according to ISO 1133; and cyclic block copolymer (CBC) is used, the cyclic block copolymer (CBC) is transparent and has a melt flow index MFR (190 °C / 2.16 kg) in the range of 0.1 to 2.5 g / 10 min according to ISO 1133; and 95 to 30 weight percent of low-density polyethylene (LDPE) and 5 to 70 weight percent of cyclic block copolymer (CBC) are used, and no plastic additives are added;
[0045] - Injection mold the obtained mixture to obtain injection-molded disposable plastic articles in the desired form.
[0046] In principle, the manufacturing is a dry-mixing process. Only the particles are mechanically mixed with each other and then directly followed by injection molding. Preferably, no extrusion is carried out before injection molding.
[0047] What is particularly advantageous about this method is that, in principle, injection molds that are commonly used for the injection molding of polypropylene can be directly used for manufacturing the corresponding plastic articles according to the present invention. This represents a great simplification of the method and is particularly economical.
[0048] The subject matter of the present invention also relates to the use of the injection-molded disposable plastic articles according to the present invention in medicine, pharmacology, biochemistry, biotechnology, especially cell biology, microbiology or molecular biology, preferably in the presence of polar protons or polar aprotic solvents, for the storage, sampling, sample processing, and test execution of especially liquid-containing containers.
[0049] The term "contents" refers to one or more contents in any form located in the injection-molded disposable plastic article according to the present invention, for example, stored in the injection-molded disposable plastic article and to be further processed if necessary. For example, a sample container in which a sample is present.
[0050] The expression "liquid-containing contents" means that one or more contents are at least partially located in the injection-molded disposable plastic article of the present invention together with a liquid or a liquid mixture. Any combination of contents and liquids is conceivable. Here, it can be, for example, a solution, a suspension, an emulsion or a dispersion.
[0051] The advantages of the present invention are very diverse:
[0052] Two types of plastics are used, selected from low-density polyethylene (LDPE) and cyclic block copolymer (CBC), which do not contain plastic additives. Disposable plastic products are manufactured by injection molding from these two types of plastics. Thus, the manufacturing can be carried out in a simple manner, where injection molds for injection molding polypropylene can be used. This is particularly advantageous because separate injection molds do not have to be produced.
[0053] The disposable plastic products are translucent or transparent, which is advantageous because the contents are visible. This can play a role, for example, in the sorting or inspection of the contents, such as within the scope of quality control, or during sampling and sample inspection, for example when using optical methods for testing.
[0054] The disposable plastic products have a melt flow index MFR (190 °C / 2.16 kg) in the range of 0.1 to 2.5 g / 10 min according to ISO 1133 and can thus be manufactured particularly well and easily by injection molding. The injection molding of disposable plastic products obtains overall improved injection molding properties by mixing the two plastics. Therefore, the selected CBC / LDPE mixture is suitable for manufacturing disposable plastic products in one manufacturing step. Thus, disposable plastic products can be manufactured at low cost.
[0055] In addition, there are no additives in the disposable plastic products.
[0056] The preferred mixing ratio of low-density polyethylene (LDPE) and cyclic block copolymer (CBC) is in the range of 9:1 to 1:1. These two plastics have unexpectedly good miscibility, where no phase boundaries are observed during mixing. By adjusting the mixing ratio, different requirements and performance characteristics of the disposable plastic products can be adjusted purposefully.
[0057] The injection molded disposable plastic products also have particularly advantageous properties, namely that the components that can be dissolved out of the injection molded disposable plastic products by solvents are reduced to an inevitable proportion, that is, reduced to a minimum. This particularly involves the application of polar protic or polar aprotic solvents.
[0058] In addition, the disposable plastic products can be subjected to hydrogen plasma treatment. This not only causes sterilization but also causes chemical functionalization of the plastic surface. Thereby, the disposable plastic products obtain molecular repulsive properties, especially biomolecular repulsive properties, thus avoiding non-specific adsorption of liquid contents on the walls of the disposable plastic products in contact with the liquid contents. Therefore, the contents remain largely unchanged when in contact with the disposable plastic products.
[0059] The shape of the disposable plastic products is no longer restricted as long as the disposable plastic products are manufactured by injection molding, so that a large number of shapes are possible for a wide range of series of uses. Embodiment
[0060] Examples 1 to 6:
[0061] The injection molding method for manufacturing injection-molded disposable plastic products according to the embodiments of the present invention is described in detail below:
[0062] As the plastic, Bormed TM LE6600-PH of Borealis Group, a low-density polyethylene (LDPE), and ViviOnTM CBC 0510HFE of Fa. USI, a cyclic block copolymer (CBC), are used.
[0063] As the injection mold, a 2-cavity full hot runner mold is used. These plastics are used as pellets in the following mixtures:
[0064] Table 1:
[0065] Example LDPE CBC Mixing ratio 1 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 90:10 2 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 85:15 3 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 80:20 4 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 70:30 5 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 60:40 6 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 50:50
[0066] The injection molding parameters are as follows:
[0067] Screw diameter: 20 cm
[0068] Mass temperature: 235 - 260 °C
[0069] Mold temperature: 30 °C
[0070] Cooling time: 4 s
[0071] Injection pressure: about 1000 bar
[0072] Cycle time: 8 s
[0073] The injection pressure increases with the addition of ViviOn TM CBC 0510HFE, for example, it increases by 150 bar at a ratio of 50%.
[0074] After cooling, the mold is opened and the injection-molded disposable plastic products can be taken out. In the example case, these are containers. They are translucent in Examples 1 and 2 and transparent in Examples 3 to 6. According to ISO 1133, the melt flow index MFR (190 °C / 2.16 kg) of the injection-molded disposable plastic products in Examples 1 to 6 is in the range of 0.1 to 2.5 g / 10 min.
[0075] Example 7:
[0076] Centrifugal test:
[0077] Using the plastic compositions listed in Table 1, disposable plastic products in the form of centrifuge containers with lids and a capacity of 1.5 mL were manufactured using the injection molding methods described in Examples 1 to 6. The lid was firmly connected to the centrifuge container with a strap, thus completing a one-piece disposable plastic product.
[0078] Saturated NaCl solution was added to the centrifuge container, the lid was closed, and the centrifuge container was tested in an Eppendorf centrifuge C5430 Research at 4 °C and 25 °C for 90 minutes.
[0079] The maximum centrifugation capacity was:
[0080] 25000 g at 4 °C
[0081] 20000 g at 25 °C.
[0082] Therefore, the centrifuge container can be used even at high g-values.
[0083] Therefore, the centrifugation test confirmed that the disposable plastic product can withstand the load at high g-values and has no adverse effect on the material.
[0084] Example 8:
[0085] Vapor tightness test:
[0086] Using the plastic compositions of Examples 3, 4, and 6 listed in Table 1, disposable plastic products in the form of centrifuge containers with lids and a capacity of 1.5 mL were manufactured using the injection molding methods described in Examples 1 to 6. Each time, ethanol / water (1:1) was filled into 6 containers, closed with lids, and then stored at 70 °C for 1 hour. The containers were weighed before and after the test. If the difference between the containers was less than 0.2%, the containers were considered vapor tight and in compliance with the specifications ("in spec").
[0087] The results of the vapor tightness test were as follows:
[0088] Table 2:
[0089] Example LDPE CBC Mixing ratio Result 3 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 80:20 5 / 6 compliant 4 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 70:30 5 / 6 compliant 6 <![CDATA[Bormed TM LE6600-PH]]> <![CDATA[ViviOn TM CBC0510HFE]]> 50:50 6 / 6 compliant
[0090] The results showed that 6 identical containers were always tested, and 5 of them were in compliance with the specifications, i.e., sealed.
Claims
1. An injection-molded disposable plastic product, which is composed of two plastics, namely low-density polyethylene (LDPE) and cyclic block copolymer (CBC). Among them, The LDPE accounts for 95 - 30% by weight, and the CBC accounts for 5 - 70% by weight. The injection - molded disposable plastic product is semi - transparent or transparent, has a melt flow index MFR (190 °C / 2.16 kg) in the range of 0.1 to 2.5 g / 10 min according to ISO 1133 and does not contain additives.
2. The injection - molded disposable plastic product according to claim 2, wherein the mixing ratio of the low - density polyethylene (LDPE) to the cyclic block copolymer (CBC) is in the range of 9:1 to 1:
1.
3. The injection-molded disposable plastic product according to claim 1 or 2, characterized in that, In the disposable plastic product, the components soluble in a solvent are reduced until an inevitable proportion, that is, reduced to a minimum.
4. The injection - molded disposable plastic product according to claim 3, wherein the solvent is a polar protic or polar aprotic solvent or a mixture thereof.
5. The injection - molded disposable plastic product according to claim 4, wherein the polar aprotic solvents are selected from: ketones such as acetone, lactones, lactams, nitro compounds such as nitromethane, tertiary carboxylic acid compounds such as dimethylformamide, ureas, sulfoxides such as dimethyl sulfoxide, sulfones or carbonates such as ethylene carbonate, or mixtures thereof; and the polar protic solvents are selected from: water, short - chain alcohols such as methanol and ethanol, primary and secondary amines, primary and secondary amides, carboxylic acids and mineral acids and mixtures thereof.
6. The injection-molded disposable plastic article according to any one of claims 1 to 5, characterized in that, The disposable plastic product exists in the form of a lid of a container, a closure of a container, a packaging member, especially in the form of a container, a micro - test plate, a container for liquids, especially a sample container such as a bottle or a vial, a pear - shaped flask, a sample tube, a cuvette for liquid optical inspection, a container with a closure, especially where the closure and the container are inseparably connected to each other, a pipette tip, a syringe or an infusion container.
7. A method for manufacturing the injection - molded disposable plastic product according to any one of claims 1 to 6, having the following steps: ◆Dry blend low density polyethylene (LDPE) and cyclic block copolymer (CBC) pellets each used without additives, wherein, Using low - density polyethylene (LDPE), the low - density polyethylene (LDPE) is semi - transparent or transparent and has a melt flow index MFR (190 °C / 2.16 kg) in the range of 0.1 to 2.5 g / 10 min according to ISO 1133; and using cyclic block copolymer (CBC), the cyclic block copolymer (CBC) is transparent and has a melt flow index MFR (190 °C / 2.16 kg) in the range of 0.1 to 2.5 g / 10 min according to ISO 1133; and using 95 to 30% by weight of low - density polyethylene (LDPE) and 5 to 70% by weight of cyclic block copolymer (CBC), and no plastic additives are added; ◆ Inject - mold the obtained mixture to obtain the injection - molded disposable plastic product in the desired form.
8. The method according to claim 7, wherein Use an injection mold for injecting polypropylene.
9. Use of the injection-molded disposable plastic article according to any one of claims 1 to 6 for storage, sampling, sample treatment, and test execution, especially of liquid-containing contents, in medicine, pharmacology, biochemistry, biotechnology, especially cell biology, microbiology, or molecular biology, preferably in the presence of polar protic or polar aprotic solvents.