WO2020259125A1 - 一种聚丙烯材料的超临界流体发泡方法 - Google Patents

一种聚丙烯材料的超临界流体发泡方法 Download PDF

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WO2020259125A1
WO2020259125A1 PCT/CN2020/090896 CN2020090896W WO2020259125A1 WO 2020259125 A1 WO2020259125 A1 WO 2020259125A1 CN 2020090896 W CN2020090896 W CN 2020090896W WO 2020259125 A1 WO2020259125 A1 WO 2020259125A1
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foaming
pressure
supercritical fluid
polypropylene material
mold cavity
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English (en)
French (fr)
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赵玲
陈弋翀
刘涛
许志美
奚桢浩
宗原
胡冬冬
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East China University of Science and Technology
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East China University of Science and Technology
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
    • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
    • C08J9/122—Hydrogen, oxygen, CO2, nitrogen or noble gases
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2203/00—Foams characterized by the expanding agent
    • C08J2203/06—CO2, N2 or noble gases
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2203/00—Foams characterized by the expanding agent
    • C08J2203/08—Supercritical fluid
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
    • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
    • C08J2323/04—Homopolymers or copolymers of ethene
    • C08J2323/08—Copolymers of ethene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
    • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
    • C08J2323/10—Homopolymers or copolymers of propene
    • C08J2323/12—Polypropene

Definitions

  • the invention relates to the field of polymer foaming, in particular to a supercritical fluid foaming method of polypropylene material.
  • Polypropylene foam material is made of polypropylene as the matrix and contains a large number of polymer foam materials with uniformly distributed bubble structure. It has the characteristics of low density, high specific strength, good sound and heat insulation performance, and excellent cushioning performance. In recent years, polypropylene foam materials have been widely used in packaging and buffering, wire and cable, electronic appliances, transportation and other industries.
  • Supercritical fluid foaming technology uses supercritical CO 2 /N 2 as the foaming agent. Compared with traditional physical foaming agents (such as alkanes, freons, etc.), it has a wide range of sources, is environmentally friendly and difficult Combustion and other advantages. In recent years, the preparation of polymer foams assisted by supercritical CO 2 has received widespread attention, and more and more traditional physical foaming agents have been replaced by supercritical CO 2 .
  • the foaming process of polypropylene material mainly includes extrusion foaming, injection foaming, kettle-pressed bead foaming and molded foaming.
  • the extrusion foaming and injection foaming processes are molten foaming processes, and due to the limitations of the process, they have some obvious structural and performance shortcomings.
  • the extrusion foaming process after the polypropylene and the foaming agent are fully mixed through the screw, the pressure is directly relieved at the die. The foaming effect is limited by the melt strength of the foaming raw material.
  • the extrusion foaming process uses alkane to send Foaming agent is the main ingredient, the production process has safety hazards, and the foamed product has large cell size and poor mechanical properties.
  • the injection foaming process uses a screw to inject polypropylene and a foaming agent into the foaming mold cavity, and then the mold is opened for foaming. Due to the limitation of the molding method, the foaming ratio of the foamed product is low, which cannot meet the demand for lightweight.
  • the autoclave bead foaming process and the molded foaming process are solid-state foaming processes, both of which are methods for intermittently producing polypropylene foam materials. First, the polypropylene material is put into the foaming cavity, and then CO 2 is filled. Saturation, and finally quickly relieve the pressure to obtain foamed products.
  • the autoclave bead foaming process uses polypropylene beads as the foaming raw material
  • the molded foaming process mainly uses the polypropylene sheet as the foaming raw material.
  • the technical problem to be solved by the present invention is to overcome the defects of low foaming production efficiency and narrow foaming interval of polypropylene foam materials in the prior art, and to provide a supercritical fluid foaming method for polypropylene materials.
  • a supercritical fluid foaming method of polypropylene material includes the following steps:
  • the mold cavity can be quickly depressurized, and the rapid depressurization rate is at least 100 MPa/s.
  • the foaming temperature is (T m -20°C) to (T m °C), where T m is the melting point of the polypropylene material.
  • T m is the melting point of the polypropylene material.
  • the effect of setting the foaming temperature to (T m -20°C) to (T m °C) is to make the polypropylene material at a suitable foaming temperature and have a suitable melt strength. If the foaming temperature is higher than the melting point, the melt strength of the polypropylene material is too low and cannot be foamed. If the foaming temperature is too low and the distance from the melting point exceeds 20°C, the polypropylene material has not melted yet and it is difficult to foam.
  • the supercritical fluid refers to a fluid in a special state formed by a substance above its critical temperature and pressure.
  • This fluid has both gas and liquid properties, such as viscosity, density, diffusion coefficient, solvation ability and other properties that are very sensitive to changes in temperature and pressure. Viscosity and diffusion coefficient are close to gas, while density and solvation ability are close to liquid.
  • the substance used as a supercritical fluid may be a substance conventionally used as a supercritical fluid in the chemical field, preferably CO 2 , N 2 , CH 3 CH 2 CH 2 CH 3 , CH 4 , CH 3 OH, C 2 H 5 OH or NH 3 , more preferably CO 2 .
  • Supercritical carbon dioxide can diffuse into the polymer matrix.
  • the polypropylene material is saturated with supercritical carbon dioxide, which can dissolve carbon dioxide molecules into the polypropylene material.
  • the pressure of carbon dioxide is released, there is a pressure difference between the internal pressure of polypropylene and the pressure of the external environment, and the carbon dioxide dissolved in the polypropylene material is in a thermodynamically unstable state, undergoes volume expansion, and forms cells. Maintaining a certain saturation pressure and saturation time can make carbon dioxide more fully dissolved into the polypropylene material.
  • Slow pressure relief can expand the volume of carbon dioxide in the polypropylene material to generate small pores. The presence of these pores can store carbon dioxide. When the next pressure is saturated, the carbon dioxide can diffuse into the polypropylene material more quickly, thereby greatly shortening the saturation time.
  • Repeating the steps of pressurizing and depressurizing multiple times can prevent the polypropylene material from crystallizing and destroy a part of the existing crystal area of the polypropylene material, thereby broadening the foaming temperature range and reducing the product rejection rate. If the steps of repeated pressurization and depressurization are not repeated many times, the temperature range in which the polypropylene material can foam is too narrow, which is in the 3°C temperature range from 13°C below the melting point to 10°C below the melting point, and the polypropylene material is saturated The time is longer, not less than 90 minutes, and the expansion ratio is not more than 30 times.
  • the final step of rapid pressure relief can rapidly expand the carbon dioxide to form cells and obtain the final polypropylene foam material. If the pressure relief is too slow, the decomposition rate of carbon dioxide will be too slow, and the volume expansion rate of carbon dioxide will be too slow, and the resulting polypropylene foam material will have obvious cell collapse.
  • the polypropylene material may be an ethylene propylene copolymer or an ethylene propylene butyl copolymer of polyolefin.
  • the material used for foaming can be all homopolypropylene polymers, or ethylene-propylene copolymers or ethylene-propylene-butylene copolymers of polyolefins with properties similar to polypropylene.
  • Ethylene-propylene copolymer or ethylene-propylene-butylene copolymer has similar physical and chemical properties to polypropylene polymer, and can be used as foaming raw material.
  • the polypropylene material may be beads or sheet materials.
  • the heating rate is 10 ⁇ 1°C/min.
  • the heating rate of 10 ⁇ 1°C/min can achieve uniform heating without causing large amounts of crystallization, so it is most conducive to uniform foaming.
  • the pressure in the superfluid state is 5-30 MPa.
  • the pressure of the superfluid state is 15 ⁇ 5 MPa.
  • the pressure of 15 ⁇ 5MPa can ensure a certain saturation diffusion rate, and can also make the supercritical carbon dioxide rapidly diffuse into the polypropylene material.
  • step (2) and step (4) the time for maintaining the superfluid state is 15-25 min.
  • a ball valve is used as a switch to inject supercritical fluid into the mold cavity.
  • the use of ball valves can allow large fluxes of supercritical carbon dioxide to pass through.
  • the rate of slow pressure relief is 0.01-1 MPa/s.
  • a needle valve is used as a switch to perform the slow pressure relief.
  • the needle valve can accurately control the flux of supercritical carbon dioxide and achieve uniform and slow pressure relief.
  • a ball valve is used as a switch to perform the rapid pressure relief.
  • the rapid pressure relief rate is 100-600 MPa/s.
  • the rapid pressure relief rate is 400 ⁇ 10 MPa/s.
  • step (3) and step (4) are repeated 2 to 5 times, more preferably 2 to 3 times.
  • the polypropylene foam material prepared by the above-mentioned supercritical fluid foaming method is a polypropylene microporous foam material.
  • the cell diameter of the polypropylene foam material is less than 150 ⁇ m, and the cell density is greater than 5 ⁇ 10 10 cells/cm 3 .
  • the present invention adopts a variable pressure saturation operation mode, which enhances the convection effect in the mold cavity and strengthens the heat/mass transfer process in the foaming mold cavity, thereby reducing the unevenness of the foamed product.
  • the prepared polypropylene foam materials have cell diameters less than 150 ⁇ m and cell density greater than 5 ⁇ 10 10 cells/cm 3 .
  • Periodic pressure swing saturation operation can effectively destroy the crystal area of the polypropylene material, thereby broadening the foaming temperature range and reducing the waste rate of the product.
  • Figure 1 is a schematic diagram of the structure of the foaming equipment used in the present invention.
  • Example 2 is a cross-sectional electron micrograph of the foamed product obtained in Example 1.
  • Example 3 is a cross-sectional electron micrograph of the foamed product obtained in Example 2.
  • Example 4 is a cross-sectional electron micrograph of the foamed product obtained in Example 3.
  • Example 5 is a cross-sectional electron micrograph of the foamed product obtained in Example 4.
  • Figure 7 is a cross-sectional electron micrograph of the foamed product obtained in Comparative Example 2.
  • FIG. 10 is a cross-sectional electron micrograph of the foamed product obtained in Comparative Example 5.
  • FIG. 10 is a cross-sectional electron micrograph of the foamed product obtained in Comparative Example 5.
  • Supercritical fluid As the temperature and pressure of the environment change, any substance has three phases-gas, liquid, and solid. The point where the three phases coexist in equilibrium is called the triple point. The point where the liquid and gas two-phase interface disappears is called the supercritical point. Supercritical fluid refers to a fluid whose temperature and pressure are both higher than its critical point. Because the properties of the gas and liquid phases are very similar, it is impossible to distinguish clearly. Supercritical fluids, especially supercritical carbon dioxide, have gas-like diffusibility and liquid dissolving ability, while having the characteristics of low viscosity and low surface tension.
  • Polypropylene material is one or more selected from homopolypropylene, ethylene propylene copolymer or ethylene propylene butene copolymer.
  • ethylene propylene copolymer and ethylene propylene butene copolymer the amount of propylene monomer exceeds 90%, so the above three substances can be collectively referred to as polypropylene materials.
  • Pressure swing saturation Put the polypropylene material in supercritical carbon dioxide to fully dissolve the supercritical carbon dioxide in the polypropylene material for saturation, and then change the pressure of the supercritical carbon dioxide to convection the carbon dioxide on the one hand, and on the other
  • the carbon dioxide in the material forms a thermodynamically unstable state, thereby forming small pores in the polypropylene material.
  • Repeated pressure swing saturation operation can strengthen the carbon dioxide convection and form small pores in the polymer material, thereby strengthening the heat/mass transfer process, increasing the dissolution of carbon dioxide, reducing the unevenness of the foamed product, and effectively destroying it
  • the crystal area of the polypropylene material broadens the foaming temperature range and reduces the product rejection rate.
  • Foaming interval refers to the temperature interval of foaming, within which it can foam well.
  • the carbon dioxide tank 1 is a commercially available carbon dioxide gas cylinder.
  • the carbon dioxide injection pump 2 is connected to the outlet of the carbon dioxide tank 1, and its function is to receive the carbon dioxide from the carbon dioxide tank 1, pressurize it to form supercritical carbon dioxide, and inject the supercritical carbon dioxide into the mold cavity 4.
  • the ball valve 3 is arranged between the carbon dioxide injection pump 2 and the mold cavity 4, and its function is to control the injection of carbon dioxide, and open and close the injection of carbon dioxide as required.
  • the function of the cavity 4 is to contain the polypropylene raw material required for foaming and to realize the foaming of the polypropylene raw material.
  • the needle valve 5 is connected to the outlet of the mold cavity 4, and its function is to slowly relieve the pressure of the mold cavity 4.
  • the ball valve 6 is also connected to the outlet of the mold cavity 4, and its function is to quickly relieve the pressure of the mold cavity 4.
  • the ethylene propylene copolymer raw material (T m of 155°C) into the cavity 4, program the temperature control and heating of the cavity 4 at a heating rate of 10°C/min, heat to the foaming temperature of 147°C, and keep warm; open the ball valve 3.
  • start the carbon dioxide injection pump 2 control the injection pressure of carbon dioxide to 15 MPa, close the ball valve 3, and hold the pressure for 90 minutes; open the ball valve 6 to quickly relieve the pressure of the cavity 4, and the pressure relief rate is 400 MPa/s to obtain polypropylene micropores foaming material.
  • the cavity 4 Put the ethylene propylene copolymer raw material (T m of 155°C) into the cavity 4, program the cavity 4 to heat the cavity 4 at a heating rate of 10°C/min, and heat to the foaming temperature of 142°C, keep warm; open the ball valve 3.
  • Start the carbon dioxide injection pump 2 control the injection pressure of carbon dioxide to 15 MPa, close the ball valve 3, and hold the pressure for 90 minutes; open the ball valve 6 to quickly relieve the pressure of the cavity 4, and the pressure relief rate is 400 MPa/s to obtain polypropylene micropores foaming material.
  • T m is 155°C
  • T m is 155°C
  • T m is 155°C
  • T m is 155°C
  • the temperature control heating of the cavity 4 at a heating rate of 10°C/min, and heat to the foaming temperature of 155°C, keep warm; open the ball valve 3.
  • start the carbon dioxide injection pump 2 control the injection pressure of carbon dioxide to 15 MPa, close the ball valve 3, and hold the pressure for 90 minutes; open the ball valve 6 to quickly relieve the pressure of the cavity 4, and the pressure relief rate is 400 MPa/s to obtain polypropylene micropores foaming material.
  • T m is 155°C
  • T m is 155°C
  • the total duration of Comparative Example 1 is 90 minutes.
  • Comparative example 1 is direct foaming, and has the best foaming effect without variable pressure saturation. Compared with Comparative Example 1, the cell ratio of Example 2 is higher, up to 40 times. The total duration of Comparative Example 2 is 90 minutes.
  • Comparative Example 2 is direct foaming, and 142°C has reached the lower temperature limit of the direct foaming method. Below 142°C, the direct foaming method cannot foam normally.
  • the foaming temperature of Comparative Example 3 was 130°C, which exceeded the lower limit of the temperature of the pressure swing saturation process, and there was almost no foaming.
  • the total duration of Comparative Example 4 is 90 minutes.
  • the foaming temperature of Comparative Example 4 was 155°C, which reached the upper limit of the temperature of the direct foaming method, and there was almost no foaming.
  • the foaming temperature of Comparative Example 5 is 155°C, and its upper temperature limit is almost the same as that of direct foaming. This is because the upper limit of foaming temperature is limited by the polymer melt strength, and the temperature is high, the melt strength is low, and the cells cannot be supported. The cells are collapsed.
  • the cell density of the polypropylene foamed products obtained in Examples 1 to 4 and Comparative Examples 1 to 5 was measured, and the expansion ratio was calculated.
  • the cell density, expansion ratio, average bead diameter and cell diameter of the foamed products obtained in Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1.
  • Figures 2 to 5 are the foams obtained in Examples 1 to 4, respectively.
  • Figures 6 to 10 are cross-sectional electron micrographs of the foamed products obtained in Comparative Examples 1 to 5.
  • Comparative Examples 2-4 were all unable to foam because the temperature exceeded the allowable temperature range for foaming.
  • Comparative Example 2 adopts the direct foaming method, and the temperature can no longer be foamed at 142°C, while Example 3 and Example 4 can still foam normally at 135°C, so the foaming method of the present invention can significantly It widens the temperature range of foaming, avoids the generation of waste products, and improves the yield of products.
  • Comparative Example 3 uses the variable pressure saturation method of the present invention, but the temperature is 130° C., which is too low for normal foaming. Both Comparative Example 4 and Comparative Example 5 could not be foamed because the foaming temperature reached the melting point of the polypropylene material.
  • Example 1 and Example 2 used a foaming temperature of 147°C to obtain a larger foaming ratio. As shown in Table 1, the foaming ratio can reach 32-40 times. The foaming temperature of 135°C is used in Example 3 and Example 4, which can obtain a larger number of cells. As can be seen from Table 1, the cell density can reach the order of 10 to the 11th power, which is much higher. Compared to Comparative Example 1, it is also much higher than Example 1 and Example 2. From the time point of view, the total time of the variable pressure saturated foaming method is less than 60 minutes, while the direct foaming method requires a total time of 90 minutes. The foaming method of the present invention significantly shortens the foaming time and improves the production efficiency. .

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Abstract

本发明公开了一种聚丙烯材料的超临界流体发泡方法，包括如下步骤：(1)将聚丙烯材料在模腔中升温至发泡温度；(2)向所述模腔中注入超临界流体，并保持超临界状态至少5min；(3)对所述模腔进行缓慢卸压，使所述模腔内的压力降至原压力的0-90％；(4)重新向所述模腔中注入超临界流体，并保持超临界状态至少5min；(5)重复步骤(3)和步骤(4)至少2次后，对模腔进行快速卸压即可。本发明的聚丙烯材料的超临界流体发泡方法缩短了饱和时间，提高了生产效率，拓宽发泡的温度区间，降低了产品的废品率。

Description

一种聚丙烯材料的超临界流体发泡方法
本申请要求申请日为2019/6/27的中国专利申请2019105668638的优先权。本申请引用上述中国专利申请的全文。
技术领域
本发明涉及聚合物发泡领域，特别涉及一种聚丙烯材料的超临界流体发泡方法。
背景技术
聚丙烯发泡材料是由聚丙烯为基体，内部含有大量均匀分布气泡结构的聚合物发泡材料，其具有密度低、比强度高、隔音与隔热性能良好、缓冲性能优异等特点。近年来，聚丙烯发泡材料被广泛应用于包装缓冲、电线电缆、电子电器、交通运输等行业。
超临界流体发泡技术以超临界CO 2/N 2为发泡剂的物理发泡技术，相比于传统的物理发泡剂(如烷烃、氟利昂等)，其具有来源广泛、环境友好、不易燃烧等优点。近年来，超临界CO 2辅助制备聚合物泡沫材料受到广泛关注，越来越多地传统物理发泡剂被超临界CO 2所替代。
目前，聚丙烯材料的发泡工艺主要为挤出发泡、注塑发泡、釜压珠粒发泡及模压发泡等。其中，挤出发泡与注塑发泡工艺属熔融态发泡工艺，由于工艺的限制，其都存在一些明显的结构、性能缺点。挤出发泡工艺通过螺杆使聚丙烯与发泡剂充分混合后，直接在模头处卸压，其发泡效果受发泡原材料的熔体强度限制，此外，挤出发泡工艺以烷烃发泡剂为主，生产过程有安全隐患，且发泡产品的泡孔尺寸大、力学性能差。注塑发泡工艺通过螺杆将聚丙烯与发泡剂一同射入发泡模腔，随后开模发泡，受成型方法限制，发泡产品的发泡倍率低，无法满足轻量化的需求。釜压珠粒发泡工艺和模压发泡 工艺属固态发泡工艺，两者都是间歇生产聚丙烯发泡材料的方法，先将聚丙烯材料放入发泡模腔，随后充入CO 2进行饱和，最后快速卸压，从而得到发泡产品。有所不同的是，釜压珠粒发泡工艺以聚丙烯珠粒作为发泡原材料，而模压发泡工艺主要以聚丙烯片板材作为发泡原材料。虽然这两种间歇发泡工艺可以生产发泡倍率高、力学性能好的微孔聚丙烯泡沫，但是由于间歇发泡过程的特性，都存在饱和时间长、生产效率低的缺点。此外，固态发泡的发泡区间较窄，温度过高则泡孔容易坍塌，温度过低则晶区尚未消除，泡孔无法生长，因此发泡产品的收率低下，发泡过程的成本也随之提高。
因此需要一种聚丙烯发泡材料的发泡方法，以提高生产效率和拓宽发泡区间。
发明内容
本发明要解决的技术问题是为了克服现有技术中聚丙烯发泡材料发泡生产效率低，发泡区间窄的缺陷，提供一种聚丙烯材料的超临界流体发泡方法。
本发明是通过下述技术方案来解决上述技术问题：
一种聚丙烯材料的超临界流体发泡方法，所述方法包括如下步骤：
(1)将聚丙烯材料在模腔中升温至发泡温度；
(2)向所述模腔中注入超临界流体，并保持超临界状态至少5min；
(3)对所述模腔进行缓慢卸压，使所述模腔内的压力降至原压力的0-90％，所述缓慢卸压的速率为不超过2MPa/s；
(4)重新向所述模腔中注入超临界流体，并保持超临界状态至少5min；
(5)重复步骤(3)和步骤(4)至少2次后，对模腔进行快速卸压即可，所述快速卸压速率为至少100MPa/s。
优选地，所述发泡温度为(T m-20℃)～(T m℃)，其中T m为所述聚丙烯材料的熔点。设置发泡温度为(T m-20℃)～(T m℃)的作用在于使得聚丙烯材料处 于合适的发泡温度，具有适合的熔体强度。如果发泡温度高于熔点，则聚丙烯材料熔体强度过低，无法发泡。如果发泡温度太低，距离熔点超过20℃，则聚丙烯材料尚未熔化，很难发泡。
所述的超临界流体是指物质处于其临界温度和压力以上而形成的一种特殊状态流体。这种流体兼具气体和液体的性质，如粘度、密度、扩散系数、溶剂化能力等性质随温度和压力变化十分敏感。粘度和扩散系数接近气体，而密度和溶剂化能力接近液体。用作超临界流体的物质可为化学领域常规可作为超临界流体的物质，较佳地为CO 2、N 2、CH 3CH 2CH 2CH 3、CH 4、CH 3OH、C 2H 5OH或NH 3，更佳地为CO 2。
超临界二氧化碳能够扩散进入聚合物基体内，在发泡温度下，采用超临界二氧化碳对聚丙烯材料进行饱和，能够使二氧化碳分子溶解进入聚丙烯材料中。在二氧化碳卸压的时候，聚丙烯内部压力与外部环境压力存在压差，溶解于聚丙烯材料中的二氧化碳处于热力学不稳定状态，发生体积膨胀，形成泡孔。保持一定的饱和压力和饱和时间能够使二氧化碳更充分地溶解进入聚丙烯材料中。
缓慢卸压能够使聚丙烯材料中的二氧化碳体积膨胀，生成小气孔，这些气孔的存在能够存储二氧化碳，在下一次加压饱和时，二氧化碳能更快地扩散进入聚丙烯材料，从而大幅缩短饱和时间。
多次重复加压和卸压的步骤，能够防止聚丙烯材料结晶并且破坏一部分聚丙烯材料已存的晶区，从而拓宽发泡的温度区间，降低了产品的废品率。若不进行多次重复加压和卸压的步骤，则聚丙烯材料能够发泡的温度区间过窄，为熔点下方13℃至熔点下方10℃的3℃温度区间内，并且聚丙烯材料的饱和时间较长，不低于90分钟，且发泡倍率也不超过30倍。
最后快速卸压的步骤能够使二氧化碳迅速膨胀，形成泡孔，得到最终的聚丙烯发泡材料。若卸压过慢，会使二氧化碳的解析速率过慢，二氧化碳的体积膨胀速率过慢，得到的聚丙烯发泡材料会有明显的泡孔坍塌现象。
优选地，所述聚丙烯材料可为聚烯烃的乙丙共聚物或乙丙丁共聚物。
用于发泡的材料既可为全部的均聚聚丙烯聚合物，也可以为与聚丙烯性质相近的聚烯烃的乙丙共聚物或乙丙丁共聚物。乙丙共聚物或乙丙丁共聚物理化性质与聚丙烯聚合物接近，可以作为发泡原料。
优选地，所述聚丙烯材料可为珠粒或片板材。
优选地，在步骤(1)中，所述加热的速率为10±1℃/min。10±1℃/min的加热速率既能够达到均匀加热，又不会导致大量结晶，因此最有利于均匀发泡。
优选地，在步骤(2)和步骤(4)中，所述超流体状态的压力为5～30MPa。
优选地，在步骤(2)和步骤(4)中，所述超流体状态的压力为15±5MPa。压力为15±5MPa可以保证一定的饱和扩散速度，还可以使得超临界二氧化碳快速扩散入聚丙烯材料中。
优选地，在步骤(2)和步骤(4)中，保持所述超流体状态的时间为15-25min。
优选地，在步骤(2)和步骤(4)中，采用球阀作为开关，向所述模腔中注入超临界流体。采用球阀能够允许大通量的超临界二氧化碳通过。
优选地，在步骤(3)中，所述缓慢卸压的速率为0.01～1MPa/s。
优选地，在步骤(3)中，采用针阀作为开关，进行所述缓慢卸压。采用针阀能够精确控制超临界二氧化碳通量，实现均匀地缓慢卸压。
优选地，在步骤(5)中，采用球阀作为开关，进行所述快速卸压。
优选地，在步骤(5)中，所述快速卸压速率为100～600MPa/s。
优选地，在步骤(5)中，所述快速卸压的速率为400±10MPa/s。
优选地，重复步骤(3)和步骤(4)2～5次，更优选2～3次。
优选地，其采用上述的超临界流体发泡方法制得的聚丙烯发泡材料为聚丙烯微孔发泡材料。
优选地，所述聚丙烯发泡材料的泡孔直径均小于150μm，泡孔密度大于 5×10 10cells/cm 3。
在符合本领域常识的基础上，上述各优选条件，可任意组合，即得本发明各较佳实例。
本发明的聚丙烯材料的超临界流体发泡方法的积极进步效果在于：
1、本发明采用变压饱和的操作方式，增强了模腔中的对流作用，强化了发泡模腔内的热/质传递过程，从而减小了发泡产品的不均匀度。制得的聚丙烯发泡材料的泡孔直径均小于150μm，泡孔密度大于5×10 10cells/cm 3。
2、缓慢卸压地过程中产生了许多微小气孔结构，这种结构缩短了二氧化碳的扩散路径，提高了二氧化碳的溶解度，从而缩短了饱和时间，提高了生产效率。
3、周期性地变压饱和操作能够有效地破坏聚丙烯材料的晶区，从而拓宽发泡的温度区间，降低了产品的废品率。
附图说明
图1为本发明采用的发泡设备的结构示意图。
图2为实施例1所得发泡产品的截面电镜图。
图3为实施例2所得发泡产品的截面电镜图。
图4为实施例3所得发泡产品的截面电镜图。
图5为实施例4所得发泡产品的截面电镜图。
图6为对比例1所得发泡产品的截面电镜图。
图7为对比例2所得发泡产品的截面电镜图。
图8为对比例3所得发泡产品的截面电镜图。
图9为对比例4所得发泡产品的截面电镜图。
图10为对比例5所得发泡产品的截面电镜图。
附图标记说明：
二氧化碳罐 1
二氧化碳注射泵 2
球阀 3
模腔 4
针阀 5
球阀 6
具体实施方式
下面通过实施例的方式进一步说明本发明，但并不因此将本发明限制在所述的实施例范围之中。下列实施例中未注明具体条件的实验方法，按照常规方法和条件，或按照商品说明书选择。
术语解释：
超临界流体：随着环境的温度和压力变化，任何一种物质都存在三种相态-气相，液相，固相，三相成平衡态共存的点叫三相点。液、气两相相界面消失的状态点叫超临界点。超临界流体是指温度和压力均高于其临界点的流体，由于气液两相性质非常相近，以致无法清楚分别。超临界流体，尤其是超临界二氧化碳具有类似气体的扩散性及液体的溶解能力，同时兼具低黏度，低表面张力的特性。
聚丙烯材料：聚丙烯材料为选自均聚聚丙烯、乙烯丙烯共聚物或乙烯丙烯丁烯共聚物中的一种或多种。乙烯丙烯共聚物和乙烯丙烯丁烯共聚物中，丙烯单体的用量均超过90％，因此上述三种物质可统称为聚丙烯材料。
变压饱和：将聚丙烯材料置于超临界二氧化碳中，使超临界二氧化碳充分溶解于聚丙烯材料中进行饱和，然后改变超临界二氧化碳的压力，一方面使二氧化碳发生对流，另一方面在聚丙烯材料中的二氧化碳形成热力学不稳定状态，从而在聚丙烯材料中形成小气孔。反复进行变压饱和操作能够强化二氧化碳对流作用，并且在聚合物材料中形成小气孔，从而强化热/质传递过程，提高二氧化碳的溶解量，减小发泡产品的不均匀度，同时有效地破坏聚 丙烯材料的晶区，从而拓宽发泡的温度区间，降低了产品的废品率。
发泡区间：指发泡的温度区间，在该温度区间内可以较好地发泡。
下面实施例中，将市售聚丙烯颗粒通过双螺杆挤出机重新熔融挤出，得到发泡所需的聚丙烯原料。实施例1～4均采用如图1的发泡设备。在图1的发泡设备中，二氧化碳罐1是市售二氧化碳气体钢瓶。二氧化碳注射泵2与二氧化碳罐1的出口连接，其作用是接收来自二氧化碳罐1的二氧化碳，并加压形成超临界二氧化碳，将超临界二氧化碳注入到模腔4中。球阀3设置在二氧化碳注射泵2与模腔4之间，其作用是控制二氧化碳的注入，根据需要开启和关闭二氧化碳的注入。模腔4的作用是容纳发泡所需的聚丙烯原料，并实现聚丙烯原料的发泡。针阀5连接在模腔4的出口，作用是对模腔4进行缓慢卸压。球阀6也连接在模腔4的出口，作用是对模腔4进行快速卸压。
实施例1
将均聚聚丙烯原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度147℃，保温；打开球阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压15min；打开针阀5，对模腔4进行缓慢卸压至10MPa，卸压速率为0.03MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压15min；打开针阀5，对模腔4进行缓慢卸压至10MPa，卸压速率为0.03MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压15min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
实施例2
将乙烯丙烯共聚物原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度147℃，保温；打开球阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球 阀3，保压25min；打开针阀5，对模腔4进行缓慢卸压至10MPa，卸压速率为0.03MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压25min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
实施例3
将乙烯丙烯丁烯共聚物原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度135℃，保温；打开球阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压15min；打开针阀5，对模腔4进行缓慢卸压至0MPa，卸压速率为0.1MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压15min；打开针阀5，对模腔4进行缓慢卸压至0MPa，卸压速率为0.1MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压15min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
实施例4
将聚丙烯原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度135℃，保温；打开球阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压25min；打开针阀5，对模腔4进行缓慢卸压至10MPa，卸压速率为0.03MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压25min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
对比例1
将乙烯丙烯共聚物原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度147℃，保温；打开球 阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压90min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
对比例2
将乙烯丙烯共聚物原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度142℃，保温；打开球阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压90min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
对比例3
将乙烯丙烯共聚物原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度130℃，保温；打开球阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压25min；打开针阀5，对模腔4进行缓慢卸压至10MPa，卸压速率为0.03MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压25min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
对比例4
将乙烯丙烯共聚物原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度155℃，保温；打开球阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压90min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
对比例5
将乙烯丙烯共聚物原料(T m为155℃)放入模腔4中，对模腔4进行程序控温加热，加热速率为10℃/min，加热至发泡温度155℃，保温；打开球 阀3，启动二氧化碳注射泵2，控制二氧化碳的注入压力为15MPa，关闭球阀3，保压25min；打开针阀5，对模腔4进行缓慢卸压至10MPa，卸压速率为0.03MPa/s，关闭针阀5；打开球阀3，重新向模腔4中注入超临界二氧化碳至15MPa，关闭球阀3，保压25min；打开球阀6，对模腔4进行快速卸压，卸压速率为400MPa/s，得到聚丙烯微孔发泡材料。
效果实施例
以分钟计，实施例1的总时长为15+5/0.03/60+15+5/0.03/60+15＝50.55min。实施例2的总时长为25+5/0.03/60+25＝52.78min。实施例3的总时长为15+5/0.03/60+15+5/0.03/60+15＝50.55min。实施例4的总时长为25+5/0.03/60+25＝52.78min。对比例1的总时长为90min。对比例1是直接发泡，没有变压饱和情况下发泡效果最好的对比例，与对比例1相比，实施例2泡孔倍率更高，可达40倍。对比例2的总时长为90min。对比例2为直接发泡，142℃就已经达到了直接发泡方法的温度下限。低于142℃，直接发泡方法无法正常发泡。对比例3的总时长为25+5/0.03/60+25＝52.78min。对比例3的发泡温度为130℃，超出了变压饱和过程的温度下限，几乎未发泡。对比例4的总时长为90min。对比例4的发泡温度为155℃，达到了直接发泡方法的温度上限，几乎未发泡。对比例5的总时长为25+5/0.03/60+25＝52.78min。对比例5的发泡温度为155℃，其温度上限与直接发泡几乎一致，这是因为发泡温度上限受聚合物熔体强度限制，温度高，熔体强度低，无法支撑泡孔，因此泡孔都是坍塌的。
使用附带密度组件的分析天平，测定实施例1～4与对比例1～5所得的聚丙烯发泡产品的泡孔密度，并计算发泡倍率。利用液氮对所得发泡产品进行淬断，在截面喷金，使用扫描电子显微镜对泡孔结构进行测定分析。实施例1～4与对比例1～5所得发泡产品的泡孔密度、发泡倍率、珠粒平均直径和泡孔直径见表1，图2～5分别为实施例1～4所得发泡产品的截面电镜图，图6～10分别为对比例1～5所得发泡产品的截面电镜图。
表1
Figure PCTCN2020090896-appb-000001
从表1中可以看出，对比例2-4均由于温度超过允许发泡的温度区间而无法发泡。对比例2采用了直接发泡的方法，温度在142℃下就已经无法发泡了，而实施例3和实施例4在135℃下仍然能够正常发泡，所以本发明的发泡方法能够显著的拓宽发泡的温度区间，避免废品产生，提高了产品的良率。对比例3采用了本发明的变压饱和方法，但是温度为130℃，温度太低而无法正常发泡。对比例4和对比例5均因为发泡温度达到聚丙烯材料的熔点而无法发泡。
实施例1和实施例2采用了147℃的发泡温度，能够得到较大的发泡倍率，表1中显示，发泡倍率可达32-40倍。而实施例3和实施例4采用了135℃的发泡温度，可以得到较多的泡孔数量，从表1中可以看出，泡孔密度可以达到10的11次方的数量级，远远高于对比例1，也远远高于实施例1和实施例2。从时间上来看，采用变压饱和的发泡方法，总时间均小于60分钟，而直接发泡方法，总时间需要90分钟，本发明的发泡方法显著缩短 了发泡时间，提高了生产效率。
虽然以上描述了本发明的具体实施方式，但是本领域的技术人员应当理解，这仅是举例说明，本发明的保护范围是由所附权利要求书限定的。本领域的技术人员在不背离本发明的原理和实质的前提下，可以对这些实施方式做出多种变更或修改，但这些变更和修改均落入本发明的保护范围。

Claims (10)

  1. 一种聚丙烯材料的超临界流体发泡方法，其特征在于，所述方法包括如下步骤：
    (1)将聚丙烯材料在模腔中升温至发泡温度；
    (2)向所述模腔中注入超临界流体，并保持超临界状态至少5min；
    (3)对所述模腔进行缓慢卸压，使所述模腔内的压力降至原压力的0-90％，所述缓慢卸压的速率为不超过2MPa/s；
    (4)重新向所述模腔中注入超临界流体，并保持超临界状态至少5min；
    (5)重复步骤(3)和步骤(4)至少2次后，对模腔进行快速卸压即可，所述快速卸压速率为至少100MPa/s。
  2. 如权利要求1所述的聚丙烯材料的超临界流体发泡方法，其特征在于，所述发泡温度为(T m-20℃)～(T m℃)，其中T m为所述聚丙烯材料的熔点；
    和/或，所述超临界流体为超临界二氧化碳。
  3. 如权利要求1所述的聚丙烯材料的超临界流体发泡方法，其特征在于，所述聚丙烯材料为选自均聚聚丙烯、乙烯丙烯共聚物或乙烯丙烯丁烯共聚物中的一种或多种。
  4. 如权利要求1所述的聚丙烯材料的超临界流体发泡方法，其特征在于，在步骤(1)中，所述加热的速率为10±1℃/min；
    和/或，在步骤(2)和步骤(4)中，所述超流体状态的压力为5～30MPa；
    和/或，在步骤(2)和步骤(4)中，保持所述超流体状态的时间为15-25min。
  5. 如权利要求4所述的聚丙烯材料的超临界流体发泡方法，其特征在于，在步骤(2)和步骤(4)中，所述超流体状态的压力为15±5MPa。
  6. 如权利要求1所述的聚丙烯材料的超临界流体发泡方法，其特征在于，重复步骤(3)和步骤(4)2～5次。
  7. 如权利要求1所述的聚丙烯材料的超临界流体发泡方法，其特征在于，在步骤(3)中，采用针阀作为开关，进行所述缓慢卸压；
    和/或，在步骤(5)中，采用球阀作为开关，进行所述快速卸压。
  8. 如权利要求1所述的聚丙烯材料的超临界流体发泡方法，其特征在于，在步骤(3)中，所述缓慢卸压的速率为0.01～1MPa/s；
    和/或，在步骤(5)中，所述快速卸压速率为100～600MPa/s。
  9. 如权利要求1所述的聚丙烯材料的超临界流体发泡方法，其特征在于，在步骤(2)和步骤(4)中，采用球阀作为开关，向所述模腔中注入超临界流体。
  10. 如权利要求1至9中任意一项所述的聚丙烯材料的超临界流体发泡方法，其特征在于，所述聚丙烯材料为珠粒或片板材。
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CN110498945B (zh) * 2019-06-27 2020-11-27 华东理工大学 一种聚丙烯材料的超临界流体发泡方法
CN111730794B (zh) * 2020-06-30 2022-02-11 华东理工大学 热塑性弹性体的超临界流体发泡方法及其产品、应用
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CN115216106B (zh) * 2022-02-21 2023-09-22 道一高分子聚合物(宁波)有限公司 一种耐磨防滑新型超临界发泡材料的制备工艺
CN116814002B (zh) * 2022-03-21 2025-09-02 中国石油化工股份有限公司 聚丙烯微孔发泡材料及其制备方法和应用
CN115805688A (zh) * 2022-12-13 2023-03-17 苏州申赛新材料有限公司 一种制备具有开孔结构的聚合物发泡材料的方法
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4473665A (en) * 1982-07-30 1984-09-25 Massachusetts Institute Of Technology Microcellular closed cell foams and their method of manufacture
CN1621437A (zh) * 2004-10-11 2005-06-01 华东理工大学 超临界co2发泡通用型聚丙烯树脂的方法
CN102167840A (zh) * 2011-04-12 2011-08-31 姜修磊 超临界模压发泡制备聚合物微孔发泡材料的方法
CN103627076A (zh) * 2012-08-22 2014-03-12 黑龙江鑫达企业集团有限公司 超临界二氧化碳釜压法制备聚丙烯发泡材料的方法
CN106519283A (zh) * 2016-11-10 2017-03-22 无锡市明盛强力风机有限公司 一种聚丙烯高温超临界发泡工艺
CN110498945A (zh) * 2019-06-27 2019-11-26 华东理工大学 一种聚丙烯材料的超临界流体发泡方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106146874B (zh) * 2016-06-01 2018-11-20 湖州长园特发科技有限公司 一种超临界流体发泡聚烯烃材料及其制备方法
CN107629241A (zh) * 2017-10-19 2018-01-26 宁波致微新材料科技有限公司 一种微孔发泡聚丙烯反射膜的制备方法
CN108690310A (zh) * 2018-04-25 2018-10-23 宁波能之光新材料科技股份有限公司 一种利用超临界技术制备低voc发泡接枝烯烃聚合物的方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4473665A (en) * 1982-07-30 1984-09-25 Massachusetts Institute Of Technology Microcellular closed cell foams and their method of manufacture
CN1621437A (zh) * 2004-10-11 2005-06-01 华东理工大学 超临界co2发泡通用型聚丙烯树脂的方法
CN102167840A (zh) * 2011-04-12 2011-08-31 姜修磊 超临界模压发泡制备聚合物微孔发泡材料的方法
CN103627076A (zh) * 2012-08-22 2014-03-12 黑龙江鑫达企业集团有限公司 超临界二氧化碳釜压法制备聚丙烯发泡材料的方法
CN106519283A (zh) * 2016-11-10 2017-03-22 无锡市明盛强力风机有限公司 一种聚丙烯高温超临界发泡工艺
CN110498945A (zh) * 2019-06-27 2019-11-26 华东理工大学 一种聚丙烯材料的超临界流体发泡方法

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