Composite material with high gas barrier property, preparation method and blood culture bottle

Abstract

The invention relates to a high-gas-barrier-property composite material, a preparation method and a blood culture bottle. The high-gas-barrier-property composite material comprises a first polycarbonate layer, a polyamide layer and a second polycarbonate layer which are sequentially stacked, the first polycarbonate layer is prepared from the following raw materials: polycarbonate, nano silicon dioxide, an amino siloxane coupling agent and a bisoxazoline compound; the raw materials of the polyamide layer comprise polyamide, an ethylene-vinyl alcohol copolymer and a multi-component epoxy compound; the raw material of the second polycarbonate layer comprises polycarbonate. The composite material has high gas barrier property, is suitable for a blood culture bottle, and improves the detection accuracy of blood culture.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and particularly relates to a high gas barrier composite material, a preparation method thereof, and a blood culture bottle. Background Art

[0002] Blood culture is a laboratory test method for detecting whether pathogenic microorganisms (such as bacteria, fungi, etc.) exist in blood, and is mainly used for diagnosing sepsis, bacteremia or other bloodstream infections. A blood culture bottle is a sampling device for performing blood culture, and usually has good transparency, which is convenient for observing and detecting samples. The material of the blood culture bottle itself has a certain influence on the detection performance of pathogenic microorganisms in blood. Especially when detecting air-sensitive microorganisms such as anaerobic microorganisms, the gas barrier property of the blood culture bottle will affect the detection result. Most current blood culture bottles are only made of polycarbonate, and the gas barrier property still needs to be improved. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the first object of the present invention is to provide a high gas barrier composite material, which has a high gas barrier property, still maintains good transparency and has good mechanical properties, and is suitable for blood culture bottles.

[0004] The second object of the present invention is to provide a preparation method of the high gas barrier composite material.

[0005] The third object of the present invention is to provide a blood culture bottle prepared from the high gas barrier composite material.

[0006] To achieve the first object of the present invention, the present invention provides a high gas barrier composite material, which includes a first polycarbonate layer, a polyamide layer and a second polycarbonate layer stacked in sequence; the raw materials of the first polycarbonate layer include polycarbonate, nano-silica, amino-siloxane coupling agent and bisoxazoline compound; the raw materials of the polyamide layer include polyamide, ethylene-vinyl alcohol copolymer and polycyclic epoxy compound; the raw materials of the second polycarbonate layer include polycarbonate.

[0007] In some embodiments of the present invention, the first polycarbonate layer includes the following raw materials in mass percentage: polycarbonate 93 - 95%; nano-silica 2.9 - 5%; amino-siloxane coupling agent 0.1 - 0.5%; bisoxazoline compound 1 - 2%.

[0008] In some embodiments of the present invention, the polyamide layer includes the following raw materials in mass percentage: polyamide 80 - 85%; ethylene-vinyl alcohol copolymer 14 - 18%; polycyclic epoxy compound 1 - 2%.

[0009] In some embodiments of the present invention, the bisoxazoline compound is selected from at least one of 2,2'-bis(2-oxazoline), 1,3-phenyl-bis(2-oxazoline), and 1,4-phenyl-bis(2-oxazoline).

[0010] In some embodiments of the present invention, the amino silicone coupling agent is KH-550.

[0011] In some embodiments of the present invention, the polyamide is polyamide 6.

[0012] In some embodiments of the present invention, the polyepoxide compound is at least one of trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether.

[0013] In some embodiments of the present invention, the molar proportion of ethylene in the ethylene-vinyl alcohol copolymer is 30-40%, and the glass transition temperature of the ethylene-vinyl alcohol copolymer is 50-60°C.

[0014] To achieve the second object of the present invention, the present invention provides a method for preparing a high gas barrier composite material according to any one of the above-mentioned solutions, which includes co-extruding the raw materials of the first polycarbonate layer, the raw materials of the polyamide layer, and the raw materials of the second polycarbonate layer to obtain a high gas barrier composite material.

[0015] In some embodiments of the present invention, the preparation steps of the raw materials of the first polycarbonate layer are as follows: dissolving the amino silicone coupling agent in an ethanol aqueous solution, soaking nano-silica, and drying to obtain modified nano-silica; stirring and dispersing the modified nano-silica, the bisoxazoline compound, and the polycarbonate pellets evenly, and melt-extruding and pelletizing to obtain modified carbonate raw materials.

[0016] In some embodiments of the present invention, the preparation steps of the raw materials of the polyamide layer are as follows: mixing the polyamide and the ethylene-vinyl alcohol copolymer evenly in a high-speed mixer, adding them to a twin-screw extruder, and adding the polyepoxide compound in the middle section of the extruder.

[0017] To achieve the third object of the present invention, the present invention provides a blood culture bottle, which is prepared from a high gas barrier composite material according to any one of the above-mentioned solutions, wherein the first polycarbonate layer is the outer layer and the second polycarbonate layer is the inner layer.

[0018] Compared with the prior art, the present invention can achieve the following technical effects: The high gas barrier composite material of the present invention comprises a composite material obtained by multi-layer co-extrusion. The middle layer is a polyamide layer, and the inner and outer layers are polycarbonate layers respectively. The polyamide material itself has good airtightness, and the multi-layer composite structure itself can also improve the gas barrier property of the composite material. Further, the present invention also modifies the first polycarbonate layer as the outer layer with a nano-filler modified by a silane coupling agent and an oxazoline chain extender, and modifies the polyamide layer with an ethylene-vinyl alcohol copolymer and a cyclic epoxide, respectively improving the gas barrier properties of these two layers, so that the finally obtained composite material has high gas barrier property. At the same time, the composite material also maintains good transparency and has good mechanical strength, is suitable for blood culture bottles, and is beneficial to improving the detection accuracy of blood culture. Detailed Embodiments

[0019] The embodiments of the present invention provide a high gas barrier composite material, which has high gas barrier property and can prevent air from passing through the composite material and affecting the substances packaged by the composite material. The high gas barrier composite material of this embodiment is suitable for blood culture bottles and can also be used for other airtight packaging.

[0020] Specifically, the high gas barrier composite material is composed of a first polycarbonate layer, a polyamide layer and a second polycarbonate layer stacked in sequence. The first polycarbonate layer, the polyamide layer and the second polycarbonate layer are adhered in sequence, and the adjacent two layers are in direct contact without other interlayers.

[0021] Among them, the raw materials of the first polycarbonate layer include polycarbonate, nano-silica, amino-siloxane coupling agent and bis-oxazoline compounds. Polycarbonate is used as the base polymer, which has high transparency, good dimensional stability and high-temperature stability, is easy to process and form, and the raw materials are easily available. Nano-silica is used as a nano-filler, and its particle size is small, and the particle size can be between 1 and 100 nm, which has almost no influence on the transparency of the first polycarbonate layer, and increases the tortuosity of gas passing through the polymer layer, and can improve the gas barrier property of the first polycarbonate layer. The amino-siloxane coupling agent can improve the dispersion of nano-silica in the polymer, and the amino group has high reaction activity and can react with the chain extender to be incorporated into the polycarbonate base polymer. The bis-oxazoline compound has two oxazoline groups and can be used as a chain extender between the end groups of the polycarbonate molecular chain to increase the molecular weight of the polycarbonate, reduce the molecular creep of the polycarbonate, and can improve the gas barrier property. Moreover, the bis-oxazoline compound also connects the end groups of the polycarbonate molecular chain and the amino group of the coupling agent, promoting the dispersion of nano-silica, so that while nano-silica improves the gas barrier property of the first polycarbonate layer, it does not affect the transparency of the first polycarbonate layer.

[0022] The raw materials of the polyamide layer include polyamide, ethylene-vinyl alcohol copolymer and polycyclic epoxy compounds. Polyamide is a base polymer. Compared with polycarbonate, polyamide itself has high gas barrier properties, especially good gas barrier properties to oxygen. Ethylene-vinyl alcohol copolymer contains more hydroxyl groups, which have greater polarity and can form hydrogen bonds. When combined with the amide groups in polyamide, it can greatly increase the intermolecular forces and improve the gas barrier properties of the polyamide layer. Polycyclic epoxy compounds have multiple epoxy groups, which can not only extend the chain of polyamide, but also improve the dispersibility of ethylene-vinyl alcohol copolymer in the polyamide matrix. Moreover, the addition of ethylene-vinyl alcohol copolymer and polycyclic epoxy compounds can also avoid polyamide crystallization and improve the transparency of the polyamide layer.

[0023] The material of the second polycarbonate layer includes polycarbonate, for example, only consists of polycarbonate. Polycarbonate itself has low polarity and can be in contact with the reaction materials of blood culture without affecting the detection results.

[0024] As can be seen from the above, this embodiment adopts a multi-layer composite structure and modifies the materials of different layers to obtain a composite material with high gas barrier properties, which is suitable for making blood culture bottles.

[0025] In some examples, the raw materials of the first polycarbonate layer are composed of polycarbonate, nano-silica, aminosiloxane coupling agent and bisoxazoline compound. Except for the above raw materials and inevitable impurities, the first polycarbonate layer does not contain other raw materials to avoid affecting the transparency of the first polycarbonate layer.

[0026] In some examples, the raw materials of the polyamide layer are composed of polyamide, ethylene-vinyl alcohol copolymer and polyepoxide. Except for the above raw materials and inevitable impurities, the polyamide layer does not contain other raw materials to avoid affecting the transparency of the polyamide layer.

[0027] In some examples, the first polycarbonate layer includes the following raw materials in mass percentage: polycarbonate 93-95%; nano-silica 2.9-5%; aminosiloxane coupling agent 0.1-0.5%; bisoxazoline compound 1-2%. When the amount of each component is within the above range, the gas barrier property and transparency of the composite material are better. The total mass percentage of polycarbonate, nano-silica, aminosiloxane coupling agent and bisoxazoline compound can be 100%. Taking the total mass of the raw materials of the first polycarbonate layer as 100%, the amount of polycarbonate can be 93%, 93.5%, 94%, 94.5%, 95%, etc.; the amount of nano-silica can be 3%, 3.5%, 4%, 4.5%, 5%, etc.; the amount of aminosiloxane coupling agent can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc.; the amount of bisoxazoline compound can be 1%, 1.5%, 2%, etc.

[0028] In some examples, the polyamide layer comprises raw materials in the following mass percentages: 80 - 85% polyamide; 14 - 18% ethylene - vinyl alcohol copolymer; 1 - 2% polycyclic epoxide. When the dosage of each component is within the above range, the gas barrier property and transparency of the composite material are better. The total mass percentage of polyamide, ethylene - vinyl alcohol copolymer and polycyclic epoxide can be 100%. Based on the total mass of the raw materials of the polyamide layer being 100%, the dosage of polyamide can be 80%, 80.5%, 81%, 81.5%, 82%, 82.5%, 83%, 83.5%, 84%, 84.5%, 85%, etc.; the dosage of ethylene - vinyl alcohol copolymer can be 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, etc.; the dosage of polycyclic epoxide can be 1%, 1.5%, 2%, etc.

[0029] In some examples, the bis - oxazoline compound is selected from at least one of 2,2'-bis(2 - oxazoline), 1,3 - phenyl - bis(2 - oxazoline), 1,4 - phenyl - bis(2 - oxazoline). The above - mentioned bis - oxazoline compounds have good reaction activity and good chain - extending function.

[0030] In some examples, the amino - siloxane coupling agent is KH - 550. The raw materials of the above - mentioned silane coupling agent are easily available.

[0031] In some examples, the polyamide is polyamide 6, and polyamide 6 has good transparency.

[0032] In some examples, the polycyclic epoxide is at least one of trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether. The above - mentioned polycyclic epoxides have at least three epoxy groups. Besides having a chain - extending function, they can also play a cross - linking role to improve the gas barrier property of the polyamide layer, and the above - mentioned polycyclic epoxides have good compatibility with polyamide.

[0033] In some examples, the molar proportion of ethylene in the ethylene - vinyl alcohol copolymer is 30 - 40%, and the glass transition temperature of the ethylene - vinyl alcohol copolymer is 50 - 60°C. Using the above - mentioned ethylene - vinyl alcohol copolymer can improve the dispersibility of the ethylene - vinyl alcohol copolymer in polyamide and provide sufficient intermolecular forces.

[0034] In some examples, the preparation method of the above - mentioned high - gas - barrier composite material includes co - extruding the raw materials of the first polycarbonate layer, the raw materials of the polyamide layer and the raw materials of the second polycarbonate layer to obtain the high - gas - barrier composite material. For example, an extruder for multi - layer composite tubes with multiple coaxial concentric ring - shaped dies can be used for extrusion to extrude a tubular multi - layer composite material, which is convenient for subsequent preparation of blood culture bottles.

[0035] In some examples, the preparation steps of the raw materials of the first polycarbonate layer are as follows: dissolve an amino silicone coupling agent in an ethanol aqueous solution, soak nano-silica, and dry it to obtain modified nano-silica; stir and disperse the modified nano-silica, a bisoxazoline compound, and polycarbonate pellets evenly, and melt-extrude and granulate to obtain modified carbonate raw materials. By using the above method, the amino silicone coupling agent can be effectively connected to nano-silica, and the bisoxazoline compound can effectively play the role of a connecting bridge.

[0036] In some examples, the preparation steps of the raw materials of the polyamide layer are as follows: mix polyamide and ethylene-vinyl alcohol copolymer evenly in a high-speed mixer, then add them to a twin-screw extruder, and add a polycyclic epoxide in the middle section of the extruder to avoid premature reaction of the polycyclic epoxide.

[0037] In some examples, this embodiment also provides a blood culture bottle, which is prepared from the above high gas-barrier composite material. Among them, the first polycarbonate layer is the outer layer, and the second polycarbonate layer is the inner layer. The first polycarbonate layer as the outer layer is modified with a nano-filler modified by a silane coupling agent and an oxazoline chain extender, and has higher mechanical properties and gas barrier properties than the inner layer, which can improve the overall gas barrier property of the blood culture bottle and can provide good protection; the second polycarbonate layer as the inner layer is unmodified and has a relatively small polarity, which is beneficial to contact with substances such as blood and reactants without affecting the accuracy of blood culture.

[0038] In some examples, the blood culture bottle is blow-molded from a composite material obtained by multi-layer co-extrusion and has a uniform wall thickness.

[0039] In some examples, the thickness of the blood culture bottle is 0.5 - 3 mm, and the thicknesses of the first polycarbonate layer, the polyamide layer, and the second polycarbonate layer can be equal or unequal. In some examples, the thickness of the first polycarbonate layer is 0.3 - 1 mm, the thickness of the polyamide layer is 0.3 - 1 mm, and the second polycarbonate layer is 0.3 - 1 mm.

[0040] The technical solution of the present invention will be further described in detail through specific examples below. In the following examples and comparative examples, the types and raw material sources of the components with the same name are the same, and the operating steps of the described same process methods are the same.

[0041] In the following examples and comparative examples, the polycarbonate grade used is PC 141R-111, the particle size of nano-silica is about 20 nm, the amino-siloxane coupling agent is KH550, the bisoxazoline compound is 2,2'-bis(2-oxazoline), the polyamide 6 grade is CM1056, the ethylene-vinyl alcohol copolymer EVOH grade is DC3023RB (ethylene content 38 mol%, Tg is 58 °C), the polycyclic epoxy compound is trimethylolpropane triglycidyl ether, the particle size of boron nitride nanosheets is 3 μm, and the epoxy resin used is E51.

[0042] The component dosages of Examples 1-7 and Comparative Examples 1-7 are shown in Table 1 below.

[0043] Table 1 Raw material ratios of examples and comparative examples Among them, in Examples 1 to 7 and Comparative Examples 5 to 7, the preparation method of the raw materials for the first polycarbonate layer is as follows: dissolve the amino-siloxane coupling agent in an ethanol aqueous solution (water content is 10 vol%), soak the nano-silica with this solution for 3 h, and then remove the solvent by rotary evaporation to obtain modified nano-silica; stir and disperse the modified nano-silica, bisoxazoline compound and polycarbonate pellets evenly in a high-speed mixer, and then melt and extrude. The temperature of each section of the extruder is between 250 and 300 °C, and granulate to obtain modified carbonate raw materials.

[0044] In Comparative Example 3, the preparation method of the raw materials for the first polycarbonate layer is as follows: stir and disperse the polycarbonate pellets and bisoxazoline compound evenly in a high-speed mixer, and then melt and extrude. The temperature of each section of the extruder is between 250 and 300 °C, and granulate to obtain modified carbonate raw materials.

[0045] In Comparative Example 4, the preparation method of the raw materials for the first polycarbonate layer is as follows: dissolve the amino-siloxane coupling agent in an ethanol aqueous solution (water content is 10 vol%), soak the nano-silica with this solution for 3 h, and then remove the solvent by rotary evaporation to obtain modified nano-silica; stir and disperse the modified nano-silica and polycarbonate pellets evenly in a high-speed mixer, and then melt and extrude. The temperature of each section of the extruder is between 250 and 300 °C, and granulate to obtain modified carbonate raw materials.

[0046] In Examples 1 to 7 and Comparative Examples 6 to 7, the preparation method of the raw materials for the polyamide layer is as follows: mix polyamide 6 and ethylene-vinyl alcohol copolymer evenly in a high-speed mixer, then add them to a twin-screw extruder. The temperature of each section of the extruder is between 230 and 260 °C, and add the polycyclic epoxy compound through the middle feeding port in the melting section of the extruder, and granulate to obtain modified polyamide raw materials.

[0047] The preparation method of the raw materials for the polyamide layer in Comparative Example 3 was as follows: Polyamide 6 was added to a twin-screw extruder, and the temperatures of each section of the extruder were between 230 and 260 °C. A polycyclic epoxide was added through an intermediate feeding port in the melting section of the extruder, and then granulated to obtain the modified polyamide raw materials.

[0048] The preparation method of the raw materials for the polyamide layer in Comparative Example 4 was as follows: Polyamide 6 and ethylene-vinyl alcohol copolymer were mixed evenly in a high-speed mixer, then added to a twin-screw extruder, and the temperatures of each section of the extruder were between 230 and 260 °C, and then granulated to obtain the modified polyamide raw materials.

[0049] The raw materials of each layer in the above-mentioned examples and comparative examples were extruded in a multi-layer co-extrusion device to obtain a plate-shaped three-layer composite material for subsequent testing. Among them, the extrusion temperature of the first polycarbonate layer was about 310 °C, the extrusion temperature of the polyamide layer was about 280 °C, the extrusion temperature of the second polycarbonate layer was about 300 °C, and the extrusion temperature of EVOH in Comparative Example 2 was about 230 °C. The thickness of each layer was controlled at about 0.3 mm.

[0050] The obtained samples were tested for gas barrier properties, transparency, and mechanical properties. Among them, the gas barrier property was carried out with reference to GB / T 1038-2000, the transparency was carried out with reference to GB / T 2410-2008, and the mechanical property test was carried out with reference to GB / T 1040.1-2006. The test results are shown in Table 2 below.

[0051] Table 2 Test Results From the above test results, it can be seen that for the composite material prepared in the examples of the present invention, the gas permeation rate is lower than 0.1 cm 3 / m 2 ·d·MPa, the visible light transmittance is greater than 75%, and it has good mechanical properties, which can meet the requirements of blood culture bottles. Compared with the comparative examples, the present invention uses nano-silica fillers, which can achieve a gas barrier property similar to that of the flaky two-dimensional fillers in Comparative Example 6, and will not significantly reduce the transparency of the composite material; the present invention uses a polyamide intermediate layer compared with the simple EVOH barrier layer in Comparative Example 2, which can maintain better transparency, further improve the gas barrier property, and greatly improve the mechanical properties. All in all, the present invention obtains a composite material with high gas barrier property, good transparency and mechanical properties by using a three-layer composite material and the design of each layer of materials, which is suitable for blood culture bottles.

[0052] Finally, it should be emphasized that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high gas barrier composite material, characterized in that It consists of a first polycarbonate layer, a polyamide layer, and a second polycarbonate layer stacked in sequence; The raw materials of the first polycarbonate layer include polycarbonate, nano-silica, amino-siloxane coupling agent, and bis-oxazoline compounds; The raw materials of the polyamide layer include polyamide, ethylene-vinyl alcohol copolymer, and polycyclic epoxy compounds; The raw materials of the second polycarbonate layer include polycarbonate.

2. The high gas barrier composite material according to claim 1, wherein The first polycarbonate layer includes the following raw materials by mass percentage: polycarbonate 93 - 95%; nano-silica 2.9 - 5%; amino-siloxane coupling agent 0.1 - 0.5%; bis-oxazoline compounds 1 - 2%.

3. The high gas barrier composite material according to claim 1 or 2, characterized in that The polyamide layer includes the following raw materials by mass percentage: polyamide 80 - 85%; ethylene-vinyl alcohol copolymer 14 - 18%; polycyclic epoxy compounds 1 - 2%.

4. A high gas barrier composite material according to claim 1 or 2, characterized in that The bis-oxazoline compounds are selected from at least one of 2,2'-bis(2-oxazoline), 1,3-phenyl-bis(2-oxazoline), and 1,4-phenyl-bis(2-oxazoline); The amino-siloxane coupling agent is KH-550.

5. A high gas barrier composite material according to claim 1 or 2, characterized in that The polyamide is polyamide 6; The polycyclic epoxy compounds are at least one of trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether.

6. The high gas barrier composite material according to claim 1 or 2, characterized in that In the ethylene-vinyl alcohol copolymer, the molar proportion of ethylene is 30 - 40%, and the glass transition temperature of the ethylene-vinyl alcohol copolymer is 50 - 60°C.

7. A method for preparing a high gas barrier composite material according to any one of claims 1 to 6, characterized in that It includes co-extruding the raw materials of the first polycarbonate layer, the raw materials of the polyamide layer, and the raw materials of the second polycarbonate layer in multiple layers to obtain a high gas barrier composite material.

8. The preparation method of a high gas barrier composite material according to claim 7, characterized in that The preparation steps of the raw materials of the first polycarbonate layer are: dissolving the amino-siloxane coupling agent in an ethanol aqueous solution, soaking the nano-silica, and drying to obtain modified nano-silica; uniformly stirring and dispersing the modified nano-silica, bis-oxazoline compounds, and polycarbonate pellets, and melt-extruding and pelletizing to obtain modified carbonate raw materials.

9. The preparation method of a high gas barrier composite material according to claim 7, characterized in that The preparation steps of the raw materials of the polyamide layer are: uniformly mixing the polyamide and the ethylene-vinyl alcohol copolymer in a high-speed mixer, adding them to a twin-screw extruder, and adding the polycyclic epoxy compounds in the middle section of the extruder.

10. A blood culture bottle, characterized in that It is prepared from a high gas barrier composite material according to any one of claims 1 to 6, wherein the first polycarbonate layer is the outer layer and the second polycarbonate layer is the inner layer.

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