Microcellular foaming composite material, preparation method thereof and optical cable

Abstract

The invention discloses a microcellular foaming composite material, a preparation method thereof and an optical cable. The microcellular foaming composite material is prepared from the following raw materials: polypropylene, POE (Polyolefin Elastomer) plastic, white carbon black, an antioxidant, calcium stearate and azodicarbonamide. According to the microcellular foaming composite material, the polypropylene, the POE plastic and the white carbon black are blended, so that the impact resistance of the microcellular foaming composite material can be enhanced from two different aspects, and the application scene of the microcellular foaming composite material can be expanded.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microcellular foamed material and its application, in particular to a microcellular foamed composite material and a preparation method thereof, and an optical cable. BACKGROUND

[0002] Microcellular foamed material is a material that a gas is introduced into the material matrix through physical or chemical foaming process to form many small bubbles, which are uniformly distributed in the material, so that the structure becomes porous. Common microcellular foamed materials include polyurethane foam, polyethylene foam, polypropylene foam, etc., especially microcellular foamed polypropylene, which has rigidity and toughness and is widely used. However, the microcellular foamed material is currently mainly used for packaging, heat insulation, sound absorption, etc., so the impact resistance of the traditional microcellular foamed material is basically not strong, which limits the application scenarios of the microcellular foamed material. SUMMARY

[0003] The purpose of the present application is to provide a microcellular foamed composite material and a preparation method thereof, and an optical cable, which enhances the impact resistance of the microcellular foamed material, is conducive to the more extensive application of the microcellular foamed material, and on the basis that the optical cable using the microcellular foamed composite material as an impact-resistant cushion layer can have sufficient impact resistance, the weight is greatly reduced, which provides convenience for long-distance erection and maintenance of the optical cable.

[0004] To solve the above technical problems, the present application provides a microcellular foamed composite material, the raw materials of the microcellular foamed composite material include polypropylene, POE plastic, white carbon black, antioxidant, calcium stearate and azodicarbonamide.

[0005] In an optional embodiment of the present application, the mass percentage content of the polypropylene is not less than 80.0 phr; the mass percentage content of the POE plastic is not greater than 20.0 phr; the mass percentage content of the white carbon black is not greater than 10.0 phr; the mass percentage content of the antioxidant is not greater than 2.0 phr; the mass percentage content of the calcium stearate is not greater than 2.0 phr; and the mass percentage content of the azodicarbonamide is not greater than 15.0 phr.

[0006] In an optional embodiment of the present application, the mass percentage content of the polypropylene is 80.0 phr; the mass percentage content of the POE plastic is 20.0 phr; and the mass percentage content of the white carbon black is 8.0 phr.

[0007] In an optional embodiment of the present application, the antioxidant is pentaerythritol ester.

[0008] A preparation method of a microcellular foamed composite material is used for preparing the microcellular foamed composite material as claimed in any one of the above, and the preparation method comprises:

[0009] Preheating and drying the white carbon black;

[0010] Mixing and heating the polypropylene and POE granules to a molten state to obtain a molten mixture;

[0011] Adding the white carbon black, antioxidant and calcium stearate powder to the molten mixture at a set temperature and uniformly mixing to obtain a molten composite mixture;

[0012] Uniformly adding azodicarbonamide masterbatch to the molten composite mixture to obtain a molten foaming mixture;

[0013] Cooling the molten foaming mixture to obtain a microcellular foaming composite material.

[0014] In an alternative embodiment of the present application, the molten foaming mixture is cooled to obtain a microcellular foaming structure, comprising:

[0015] Extruding and cooling the molten foaming mixture at 175-185 degrees Celsius to obtain the microcellular foaming composite material.

[0016] An optical cable comprising optical units containing optical fibers, a plurality of strip-shaped impact-resistant units arranged around the optical units; and an outer sheath arranged to wrap the optical units and the strip-shaped impact-resistant units;

[0017] The strip-shaped impact-resistant units are the microcellular foaming composite structure material according to any one of the above.

[0018] In an alternative embodiment of the present application, the cross section of the strip-shaped impact-resistant units is an arc surface.

[0019] In an alternative embodiment of the present application, water-blocking yarn and aramid fiber bundles are arranged between adjacent two strip-shaped impact-resistant units.

[0020] In an alternative embodiment of the present application, each optical unit is arranged in a loose tube, the inside of the loose tube is filled with a filling paste in the gap between the optical unit and the loose tube; the outer surface of the loose tube is wrapped with a tear-resistant net, each strip-shaped impact-resistant unit is arranged in close contact with the tear-resistant net; and a binding yarn wrapping each strip-shaped impact-resistant unit is arranged between each strip-shaped impact-resistant unit and the outer sheath.

[0021] The present application provides a microcellular foaming composite material and a preparation method thereof, and an optical cable; wherein the raw materials of the microcellular foaming composite material include polypropylene, POE plastic, white carbon black, antioxidant, calcium stearate and azodicarbonamide.

[0022] The microporous foamed composite material in the application is prepared by blending polypropylene, POE plastic and white carbon black, and by using antioxidants and calcium stearate to promote the fusion between the three materials, and by using azodicarbonamide to form bubbles in the mixed material; compared with the conventional microporous foamed material which is mainly prepared by adding a foaming agent to polypropylene, the microporous foamed material in the application adds POE plastic and white carbon black, which can enhance the impact resistance of the microporous foamed composite material from two different aspects, and is beneficial to expand the application scenarios of the microporous foamed composite material.

[0023] In the application, a light-weight impact-resistant unit is formed by using the microporous foamed composite material to replace the metal armor layer such as steel wire in the conventional optical cable, so that the optical cable has better bending resistance on the basis of ensuring the impact resistance of the entire optical cable, greatly reduces the weight of the optical cable, is beneficial to long-distance erection and high-altitude deployment of the optical cable, and prolongs the service life of the optical cable. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0025] Figure 1 The flow chart of the preparation method of the microporous foamed composite material provided in the embodiment of the application;

[0026] Figure 2 The cross-sectional structure schematic diagram of the optical cable provided in the embodiment of the application;

[0027] In the drawings, 1 is an optical unit, 11 is an optical fiber, 12 is a yarn, 2 is a filling paste, 3 is a loose tube, 4 is a tear-resistant net, 5 is a strip-shaped impact-resistant unit, 6 is a water-blocking yarn, 7 is a aramid bundle, 8 is a binding yarn, and 9 is an outer sheath. DETAILED DESCRIPTION

[0028] The core of the application is to provide a microporous foamed composite material and a preparation method thereof, and an optical cable, the microporous foamed composite material has good impact resistance, and can be more widely applied to more fields; and the microporous foamed composite material is used in the optical cable to replace the metal armor layer, which can ensure the impact resistance of the optical cable on the basis of reducing the weight of the optical cable, and is beneficial to long-distance erection of the optical cable.

[0029] In order to make the person skilled in the art better understand the present application, the present application is further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] As shown in Figure 1 Figure 1 The flow chart of the preparation method of the microcellular foamed composite material provided in the embodiments of the present application.

[0031] In one specific embodiment of the present application, the raw materials of the microcellular foamed composite material can include:

[0032] Polypropylene, POE plastic, white carbon black, antioxidant, calcium stearate and azodicarbonamide.

[0033] It can be understood that the polypropylene, POE plastic and white carbon black in the embodiments are the main raw materials for forming the microcellular foamed composite material, and the antioxidant and calcium stearate are additives for promoting the full fusion of the above three raw materials, and the azodicarbonamide is a typical foaming agent, also known as AC master batch.

[0034] The POE plastic can be a polymer of ethylene and octene. The soft chain coiled structure of octene and the crystalline ethylene chain as a physical crosslinking point make it have excellent toughness and good processability. The POE plastic has excellent toughening effect on polypropylene, and has good compatibility with polypropylene and active calcium carbonate; because the molecular weight distribution of the POE plastic is narrow, the side octyl in the molecular structure is longer than the side ethyl, and the molecular structure can form a joint, which plays a joint and buffering role between the components, so that the microcellular foamed composite material can disperse and buffer impact energy when impacted, reducing the opportunity for silver lines to develop into cracks under stress, thereby improving the impact strength of the microcellular foamed composite material.

[0035] In addition, white carbon black is a general term for white powder X-ray amorphous silicic acid and silicate products, mainly referring to precipitated silica, fumed silica and ultra-fine silica gel, and also including powder synthetic aluminum silicate and calcium silicate, etc. White carbon black is a porous substance, and its composition can be represented by SiO2·nH2O, wherein nH2O exists in the form of surface hydroxyl groups. White carbon black has super strong adhesion, tear resistance and heat and aging resistance.

[0036] In addition, the antioxidant in the embodiments can be specifically tetrakis [beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, commonly known as antioxidant 1010.

[0037] ​Therefore, in the present application, POE plastic and white carbon black, two different materials, are mixed with polypropylene to form a microcellular foaming composite material, so that the microcellular foaming composite material has good impact resistance.

[0038] In addition, although POE plastic and white carbon black can enhance the impact resistance of the microcellular foaming composite material, polypropylene should still be the main raw material of the microcellular foaming composite material, the mass percentage of polypropylene in the microcellular foaming composite material is not less than 80.0 phr; the mass percentage of POE plastic is not greater than 20.0 phr; the mass percentage of white carbon black is not greater than 10.0 phr; the mass percentage of antioxidant is not greater than 2.0 phr; the mass percentage of calcium stearate is not greater than 2.0 phr; the mass percentage of azodicarbonamide is not greater than 15.0 phr. As shown in Table 1, Table 1 is the mass percentage of each component of the microcellular foaming composite material.

[0039] Table 1:

[0040] Raw materials Mass percent / phr Polypropylene 80.0-95.0 POE plastic 5.0-20.0 White carbon black 0-10.0 Calcium stearate 0-2.0 Antioxidant 1010 0-2.0 AC masterbatch 0-15.0

[0041] According to the orthogonal test verification, when the mass percentage of polypropylene in the microcellular foaming composite material is 80.0 phr, the mass percentage of POE plastic is 20.0 phr, and the mass percentage of white carbon black is 8.0 phr, the microcellular foaming composite material formed by the ternary blending of polypropylene, POE plastic and white carbon black has the best comprehensive performance, the impact resistance and hardness reach the highest, and the elongation at break and the melt index of the material decrease less.

[0042] Specifically, as shown in Table 2, Table 2 is the test data of each performance test of the microcellular foaming composite material formed by the mass percentage of polypropylene being 80.0 phr, the mass percentage of POE plastic being 20.0 phr, and the mass percentage of white carbon black being 8.0 phr.

[0043] Table 2:

[0044] Microcellular foamed composite Impact strength force of a simply supported beam impact test 57.38 KJ / m 2 ]] Hardness measured by a shore durometer 94.5 HA Density 0.788 g / cm 3 ]]

[0045] Based on the above Table 2, the microcellular foaming composite material in the present embodiment not only has good impact resistance, but also has very small density, so that the structural equipment using the microcellular foaming composite material not only has good impact resistance, but also has lighter overall quality.

[0046] Based on the mass percentage of each raw material of the above microcellular foaming composite material, the present application further provides an embodiment of a preparation method of the above microcellular foaming composite material.

[0047] As Figure 1The preparation method of the microcellular foamed composite material in the present application can include:

[0048] S1: The white carbon black is heated and dried in advance;

[0049] S2: The polypropylene and POE granules are mixed and heated to a molten state to obtain a molten mixture;

[0050] S3: The white carbon black, the antioxidant, and the calcium stearate powder are added to the molten mixture at a set temperature and uniformly mixed to obtain a molten composite mixture;

[0051] S4: The azodicarbonamide master batch is uniformly added to the molten composite mixture to obtain a molten foaming mixture;

[0052] S5: The molten foaming mixture is cooled to obtain the microcellular foamed composite material.

[0053] In actual application, the white carbon black can be dried in advance in an oven at 200℃ for 5h for standby. The internal mixer is preheated to raise the temperature to 190℃, and the polypropylene and POE granules are added according to the raw material formula of the microcellular foamed composite material in the above embodiment. With the addition of the materials, the temperature in the internal mixer will be lowered to a certain extent, so the temperature in the internal mixer needs to be raised to 190℃ again. When the polypropylene and POE granules are in a molten state on the counter-rotating double rollers in the internal mixer, the prepared white carbon black, antioxidant 1010, and calcium stearate powder are added and uniformly mixed at 190℃ for at least 10min. Finally, the foaming agent azodicarbonamide (AC) master batch is uniformly mixed with the above prepared mixture in a molten state to obtain a molten foaming mixture. Then, the molten foaming mixture can be extruded and cooled to form a product. The extrusion temperature of the molten foaming mixture should be controlled at 175℃ to 185℃, and specifically can be 180℃.

[0054] In addition, in order to form a microcellular foamed composite material with a specific structural shape, the molten foaming mixture can be injected into a mold with a specific shape during extrusion. Of course, the molten foaming mixture can also be directly extruded to form a linear structure. In summary, as long as the finished product can form the required shape structure, it is acceptable.

[0055] In order to determine the uniformity of the bubbles in the microcellular foamed composite material, the microcellular foamed composite material can be placed in a liquid nitrogen environment and deep-cooled for at least 1h, then rapidly broken, and the fracture surface of the microcellular foamed composite material is observed by SEM (scanning electron microscope). If the number of cells is large and the cell size distribution is uniform, it indicates that the foaming effect is good.

[0056] In summary, the microporous foamed composite material in the application adopts polypropylene, POE plastic and white carbon black three different raw materials blending, and promotes the fusion between the three materials by using antioxidants and calcium stearate, and uses azodicarbonamide to form bubbles in the mixed material; compared with the conventional microporous foamed material mainly by adding foaming agent in polypropylene, the microporous foamed material in the application increases POE plastic and white carbon black, which can enhance the impact resistance of the microporous foamed composite material from two different aspects, and is beneficial to expand the application scenarios of the microporous foamed composite material.

[0057] Based on the above embodiments, an embodiment of an optical cable is also provided in the application, as shown in Figure 2 Figure 2 The cross-sectional structure schematic diagram of the optical cable provided by the embodiment of the application can include:

[0058] The optical unit 1 containing optical fibers 11 is surrounded by a plurality of strip-shaped impact-resistant units 5; an outer sheath 9 is wrapped around the optical unit 1 and the strip-shaped impact-resistant units 5;

[0059] Among them, the strip-shaped impact-resistant unit 5 is a microporous foamed composite structure material as described in any of the above embodiments.

[0060] As shown in Figure 2 The center of the optical cable of the embodiment contains at least one group of optical units 1, which contains a plurality of optical fibers 11 and is the most critical structure in the entire optical cable. The structure layers wrapped around the optical unit 1 are all to better protect the optical fibers 11 in the middle. The optical unit 1 is a structure unit wrapped by a plurality of optical fibers 11 into a whole by a yarn 12, and in Figure 2 As shown in the embodiment, it contains four groups of optical units 1.

[0061] On this basis, each group of optical units 1 is collectively limited to be arranged in the loose tube 3, and the loose tube 3 preliminarily limits each optical unit 1; in addition, the loose tube 3 can further be provided with a filling paste 2. Obviously, the filling paste 2 can not only fill the gap between the optical unit 1 and the loose tube 3, but also can further penetrate into the gap between the optical fibers 11 in the optical unit 1 through the yarn 12 of the optical unit 1, so that the optical unit 1 and the loose tube 3 form a more stable integrated structure. In addition, the outer surface of the loose tube 3 can further be provided with a tear-resistant net 4, so as to protect the integrated structure formed by the loose tube 3 and the optical units 1 from tearing.

[0062] ​Based on the above discussion, a plurality of strip-shaped impact-resistant units 5 are further arranged around the outer ring of the loose tube 3, that is, a plurality of strip-shaped impact-resistant units 5 are arranged around the loose tube 3 and the optical unit 1 to form an integrated structure. It can be understood that the optical fiber 11, the loose tube 3, and the strip-shaped impact-resistant unit 5 in the embodiment are all strip-shaped structures, and each strip-shaped impact-resistant unit 5 should be arranged around the outside of the loose tube 3 in a ring shape with the length direction of the strip-shaped impact-resistant unit 5 and the length direction of the loose tube 3 and the optical fiber 11 being parallel to each other.

[0063] On this basis, the strip-shaped impact-resistant unit 5 in the embodiment is a structural unit formed of the microcellular foam composite material as described in any of the above embodiments.

[0064] As described above, the raw materials of the microcellular foam composite material in the application further include POE plastic and white carbon black in addition to polypropylene, thereby having good impact resistance to meet the impact resistance requirements of optical cables in use; and because it is a foamed structure, it also has a relatively small density, thereby making the mass of the strip-shaped impact-resistant unit 5 relatively small, and thereby greatly reducing the overall mass of the optical cable.

[0065] In the conventional optical cable, steel wires and other metal materials are commonly added to the optical cable together with the optical fiber 11 to be bundled inside the optical cable, although the optical cable has strong impact resistance, but because the density of the steel wires and other metal materials is relatively large, it will greatly increase the overall weight of the optical cable, not only increasing the transportation cost of the optical cable, but also increasing the engineering difficulty of optical cable erection and maintenance, especially in long-distance erection and high-altitude deployment scenarios, the construction efficiency is low and the cost is high.

[0066] The microcellular foam composite material formed by the ternary blending system of polypropylene, POE plastic, and white carbon black and the microcellular foaming process as the strip-shaped impact-resistant unit 5 effectively reduces the density of the composite material, greatly reduces the weight of the optical cable, greatly reduces the dependence on heavy mechanical equipment in optical cable erection and maintenance, reduces transportation and construction costs, significantly improves construction efficiency, and makes optical cable erection and maintenance more convenient and economical.

[0067] Moreover, the microcellular foam composite material in the application as the impact-resistant layer of the optical cable significantly improves the bending performance of the optical cable, and because a large number of small pores are formed in the material, these pores can effectively absorb and disperse energy when subjected to external impact, thereby further improving the lightweight and impact resistance of the optical cable.

[0068] In addition, because the silica is added in the strip-shaped impact-resistant unit 5 in the present application, the heat resistance of the microcellular foamed composite material is significantly improved. The experimental results show that the initial thermal decomposition temperature of the strip-shaped impact-resistant unit 5 reaches 399°C; that is, even in a high-temperature environment, the strip-shaped impact-resistant unit 5 in the present application can maintain good mechanical properties and dimensional stability, effectively preventing the damage of the optical cable due to material softening or deformation, and is particularly suitable for complex application scenarios with large temperature changes or high temperatures, such as tropical regions or environments close to heat sources.

[0069] As can be seen, by using a new microcellular foamed composite material as the structural material of the impact-resistant pad in the optical cable, the deficiencies of the traditional impact-resistant material of the optical cable in terms of lightweight, impact resistance, heat resistance, and processing performance are effectively solved, providing a more advantageous optical cable option for the communication industry, and helping to promote the development and application of optical cable technology.

[0070] Further optionally, the strip-shaped impact-resistant unit 5 in the present embodiment can be provided with an arc-shaped cross-section, that is, the cross-section of the strip-shaped impact-resistant unit 5 is slightly curved outward away from the light unit 1 side, as shown in Figure 2 , as shown in Figure 2 The cross-section of the strip-shaped impact-resistant unit 5 is approximately tile-shaped, so that when the optical cable is subjected to external pressure, the strip-shaped impact-resistant unit 5 with an arc-shaped cross-section can deform, thereby bearing part of the pressure and also buffering the impact of external pressure on the light unit 1, thereby further improving the protection and impact resistance of the strip-shaped impact-resistant unit 5 to the light unit 1.

[0071] In addition, water-blocking yarn 6 and aramid yarn 7 can be further provided in the gap between adjacent two strip-shaped impact-resistant units 5. The water-blocking yarn 6 and aramid yarn 7 are both linear structures, that is, the water-blocking yarn 6 and aramid yarn 7 are both arranged in parallel with the strip-shaped impact-resistant unit 5. The water-blocking yarn 6 can effectively absorb the moisture in the optical cable, and the aramid yarn 7 can further enhance the overall structural strength of the optical cable to prevent the problem of optical cable breakage.

[0072] As shown in Figure 2 , in the embodiment shown in Figure 2 , each strip-shaped impact-resistant unit 5 contains two pairs of oppositely arranged strip-shaped impact-resistant units 5, and one water-blocking yarn 6 is arranged between each pair of two adjacent strip-shaped impact-resistant units 5, and aramid yarn 7 is arranged between each pair of two adjacent strip-shaped impact-resistant units 5.

[0073] But it can be understood that in practical applications, both the water-blocking yarn 6 and the aramid yarn 7 can be arranged in the gap between each pair of adjacent two strip-shaped impact-resistant units 5; or the aramid yarn 7 can be arranged in the gap between each pair of adjacent two strip-shaped impact-resistant units 5, but only the water-blocking yarn 6 is arranged in the gap between a few pairs of adjacent two strip-shaped impact-resistant units 5; specifically, the requirements of the optical cable can be set based on the actual application scene of the optical cable, and the application does not specifically limit this.

[0074] On this basis, the above optical unit 1, loose tube 3, strip-shaped impact-resistant unit 5, aramid yarn 7, water-blocking yarn 6 and the like can be twisted and integrated by being wrapped by the lashing yarn 8, and are jointly built-in inside the outer sheath 9. The outer sheath 9 can be made of PE (Polyethylene) material, which has excellent cold resistance and moisture-proof performance.

[0075] Based on the above discussion, in an optional embodiment of the application, the optical cable includes a cable core, a strip-shaped impact-resistant unit 5, a water-blocking yarn 6, a tensile unit, and an outer sheath 9. The cable core includes an optical unit 1, a filling paste 2, and a loose tube 3. The optical unit 1 includes an optical fiber 11 and a yarn 12 twisted with multiple optical fibers 11. The optical unit 1 is arranged in the loose tube 3, and the filling paste 2 is filled in the gap in the loose tube 3. The outer surface of the loose tube 3 is provided with a layer of tear-resistant net 4. The strip-shaped impact-resistant unit 5, the water-blocking yarn 6, and the tensile unit are twisted together on the outside of the cable core by the lashing yarn 8, and are finally jointly extruded in the outer sheath 9.

[0076] In this embodiment, metal materials are not required to be used as the reinforcing member of the optical cable. The strip-shaped impact-resistant unit 5 is formed of the above-mentioned microcellular composite material, and can have a generally tile-shaped arc surface in cross section by using a special mold. When the optical cable is subjected to lateral impact, this structure can more effectively disperse the impact force and avoid stress concentration, thereby affecting the reliability of the optical cable. In addition, the water-blocking yarn 6 arranged inside the optical cable in this embodiment can effectively prevent water seepage. The tensile unit adopts the aramid yarn 7, which can effectively reduce the weight of the optical cable while providing tensile strength, so that the optical cable is more suitable for outdoor overhead and other scenes.

[0077] It should be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the article "a" or "an" is intended to include one or more items, and can be used interchangeably with the article "one or more". Where only one item is intended, the term "one" or "only one" is used. Also, the use of "or" is also intended to cover all possible combinations of a word with "and" or "or", such as "X employs A or B; he employs A or B or C". In addition, "coupled" is defined as "connected, although not necessarily directly, and / or communicative". Further, the terms "first", "second", "third", "fourth", etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Moreover, the above technical solutions provided by the embodiments of the present application and the implementation principles of the corresponding technical solutions in the prior art are not described in detail to avoid excessive description.

[0078] The principles and implementation manners of the present application are described by using specific examples in the present document, and the above examples are only used to help understand the method of the present application and its core idea. It should be noted that, for those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the present application.

Claims

1. A microporous foamed composite material, characterized in that, The raw materials for the microporous foamed composite material include polypropylene, POE plastic, silica, antioxidant, calcium stearate, and azodicarbonamide.

2. The microporous foamed composite material as described in claim 1, characterized in that, The polypropylene has a mass percentage content of not less than 80.0 phr; the POE plastic has a mass percentage content of not more than 20.0 phr; the silica has a mass percentage content of not more than 10.0 phr; the antioxidant has a mass percentage content of not more than 2.0 phr; the calcium stearate has a mass percentage content of not more than 2.0 phr; and the azodicarbonamide has a mass percentage content of not more than 15.0 phr.

3. The microporous foamed composite material as described in claim 2, characterized in that, The polypropylene has a mass percentage of 80.0 phr; the POE plastic has a mass percentage of 20.0 phr; and the silica has a mass percentage of 8.0 phr.

4. The microporous foamed composite material as described in claim 1, characterized in that, The antioxidant is pentaerythritol ester.

5. A method for preparing a microporous foamed composite material, characterized in that, The method for preparing the microporous foamed composite material as described in any one of claims 1 to 4 comprises: Preheat and dry the silica; Polypropylene and POE granules are mixed and heated to a molten state to obtain a molten mixture; At a set temperature, the silica, antioxidant, and calcium stearate powder are added to the molten mixture and mixed uniformly to obtain a molten composite mixture; Azodicarbonamide masterbatch is uniformly added to the molten composite mixture to obtain a molten foamed mixture; The molten foamed mixture is cooled to obtain a microporous foamed composite material.

6. The method for preparing the microporous foam structure as described in claim 5, characterized in that, Cooling the molten foamed mixture to obtain a microporous foamed structure includes: The molten foamed mixture is extruded and cooled at 175°C to 185°C to obtain the microporous foamed composite material.

7. An optical cable, characterized in that, It includes an optical unit containing optical fibers, and a plurality of strip-shaped shock-resistant units arranged around the optical unit; and an outer sheath that surrounds the optical unit and the strip-shaped shock-resistant units; The strip-shaped impact-resistant unit is a microporous foamed composite material as described in any one of claims 1 to 4.

8. The optical cable as described in claim 7, characterized in that, The cross-section of the strip-shaped impact-resistant unit is an arc-shaped surface.

9. The optical cable as described in claim 7, characterized in that, Water-blocking yarn and aramid bundles are arranged between two adjacent strip-shaped impact-resistant units.

10. The optical cable as described in claim 7, characterized in that, Each of the optical units is disposed in a loose tube, and the interior of the loose tube is filled with filler paste in the gap between it and the optical unit; the outer surface of the loose tube is wrapped with an anti-tear mesh, and each of the strip-shaped impact-resistant units is attached to the anti-tear mesh; a binding yarn is provided between each strip-shaped impact-resistant unit and the outer sheath to wrap the strip-shaped impact-resistant unit.

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