Waterproof moisture permeable material, preparation method thereof, fabric and application thereof
By reasonably proportioning high-density polyethylene, linear low-density polyethylene and polyolefin elastomers in waterproof and moisture-permeable materials and preparing them using specific processes, the problems of poor rebound performance and insufficient moisture permeability of the material are solved, and high The performance of waterproof and moisture-permeable effect is avoided while avoiding the use of harmful chemicals.
Patent Information
- Application Number
- CN202411370216.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-01-07
AI Technical Summary
Existing waterproof and moisture-permeable materials have problems such as poor rebound performance, low elongation of break and heavy grams, as well as poor hydrostatic pressure and moisture permeability, and contain perfluorinated and polyfluorinated chemicals to the environment and human health. threaten.
A waterproof and moisture permeable material is used, which consists of 68~87 parts of high-density polyethylene, 8~12 parts of linear low-density polyethylene and 5~20 parts of polyolefin elastomer. It is cast through mixing granulation, melt extrusion, and bidirectional The tensile and heat setting process is prepared to control the crystallinity, pore size and porosity to obtain microporous polymer sheets with good rebound properties and high moisture permeability.
It improves the wear comfort and waterproof and moisture-permeable fabrics, reduces the material density, avoids the harm of perfluorochemicals to the environment and the human body, and meets the needs of high hydrostatic pressure and moisture permeability.
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of waterproof and breathable technology, and in particular to a waterproof and breathable material and a preparation method thereof, a fabric and an application thereof. Background Art
[0002] Waterproof and breathable materials have the function of preventing liquid water droplets from penetrating while allowing gaseous water molecules to pass through. They are widely used in sportswear, shoe upper materials, outdoor products and other fields. Currently, the most widely used waterproof and breathable material is polytetrafluoroethylene (PTFE) microporous membrane. Polytetrafluoroethylene has extremely low surface energy and strong hydrophobicity. The microporous membrane made by the stretching process has a small pore size and the membrane thickness can reach the micron level, which can meet the waterproof and breathable requirements in most application scenarios.
[0003] However, the molecular chain of polytetrafluoroethylene is very rigid and easy to crystallize. The molecular chains are tightly stacked and have a high density. After it is prepared into a waterproof and breathable material, there are problems such as poor rebound performance, low elongation at break and high gram weight, which seriously affect the wearing comfort of the fabric. In addition, in some application scenarios, the increasing resistance to hydrostatic pressure and moisture permeability have put forward higher requirements on the performance of waterproof and breathable materials. At the same time, perfluorinated and polyfluorinated chemicals (PFAS) are not easy to decompose, and will accumulate in the environment and the human body, causing serious health effects. At present, the application of fluorinated compounds in industrial and consumer products is increasingly restricted. Summary of the invention
[0004] Based on this, the present application provides a waterproof and breathable material and its preparation method, fabric and its application to solve the problems of poor rebound performance, low elongation at break and heavy grammage, as well as poor resistance to hydrostatic pressure and moisture permeability of the waterproof and breathable materials existing in the related art.
[0005] In a first aspect, a waterproof and breathable material is provided, wherein the waterproof and breathable material is a polymer sheet with micropores, and the total amount is 100 parts, wherein the waterproof and breathable material comprises the following components: 68 to 87 parts of high-density polyethylene, 8 to 12 parts of linear low-density polyethylene, and 5 to 20 parts of polyolefin elastomer; the crystallinity of the waterproof and breathable material is 30% to 50%, the stiffness of the waterproof and breathable material is less than 65 mN, and the breathability of the waterproof and breathable material is greater than 6000 g / (m 2 ·24h).
[0006] Optionally, the polyolefin elastomer is selected from one or more of ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer.
[0007] Optionally, the waterproof and moisture-permeable material satisfies at least one of the following conditions:
[0008] (1) The density of the waterproof and breathable material is 0.91~0.97g / cm 3 ;
[0009] (2) The average pore size of the waterproof and breathable material is 50-100 nm, and can be 50-70 nm;
[0010] (3) The thickness of the waterproof and breathable material is 5 to 20 μm, and can be 5 to 12 μm;
[0011] (4) The porosity of the waterproof and breathable material is 45% to 75%, and can be 55% to 75%;
[0012] (5) The elastic recovery rate of the waterproof and breathable material is 39% to 95%, and can be optionally 60% to 95%;
[0013] (6) The stiffness of the waterproof and breathable material is 40-65 mN, and can be 40-50 mN;
[0014] (7) The tensile strength of the waterproof and breathable material is 70~160Mpa, and can be 120~160Mpa;
[0015] (8) The moisture permeability of the waterproof and breathable material is 6000~11000g / (m 2 ·24h), 9000~11000g / (m 2 24h);
[0016] (9) The hydrostatic pressure of the waterproof and breathable material is greater than 170 KPa, and can be selected to be 170~200 KPa.
[0017] In a second aspect, a method for preparing a waterproof and breathable material is provided, comprising the following steps:
[0018] S1. Based on 100 parts by weight of the total amount, 68 to 87 parts of high-density polyethylene, 8 to 12 parts of linear low-density polyethylene, and 5 to 20 parts of polyolefin elastomer are mixed and granulated to obtain a polymer raw material;
[0019] S2, mixing the polymer raw material with paraffin oil, melt-extruding, casting to form a cast film and cooling;
[0020] S3, heating the cast film and then biaxially stretching it to obtain a stretched oil film;
[0021] S4, extracting the paraffin oil in the stretched oil film, drying it, and obtaining the waterproof and breathable material after heat setting.
[0022] Optionally, in step S2, the draft ratio during flow deposition is not less than 30, and can be selected to be 30-50.
[0023] Optionally, in step S3, the biaxial stretching is asynchronous stretching;
[0024] Optionally, the biaxial stretching is first longitudinal stretching and then transverse stretching;
[0025] Optionally, the stretching ratio of the longitudinal stretching is 6-10, optionally 8-10; the stretching ratio of the transverse stretching is 8-20, optionally 14-18.
[0026] Optionally, step S4 further includes an annealing step, and the annealing temperature is 90-100°C.
[0027] Optionally, in step S2, the mass ratio of the polymer raw material to the paraffin oil is 0.65-0.85.
[0028] In a third aspect, a waterproof and breathable fabric is provided, comprising the waterproof and breathable material as described in the first aspect or the waterproof and breathable material prepared by the preparation method of the waterproof and breathable material as described in the second aspect.
[0029] In a fourth aspect, there is provided an application of the waterproof and moisture-permeable material as described in the first aspect in the field of waterproof and moisture-permeable.
[0030] Compared with the related art, this application has at least the following beneficial technical effects:
[0031] Since the waterproof and breathable material includes: 68-87 parts of high-density polyethylene, 8-12 parts of linear low-density polyethylene, and 5-20 parts of polyolefin elastomer, the waterproof and breathable material has good resilience and melt stretching properties, and the molecular chain is relatively soft and has a high elongation at break. Since the crystallinity of the waterproof and breathable material is 30%-50%, the stiffness is less than 65mN, and the moisture permeability is greater than 6000 g / (m 2 ·24h), therefore, the waterproof and breathable material has lower crystallinity, lower stiffness and higher breathability, and when applied to waterproof and breathable fabrics, it can improve the wearing comfort and waterproof and breathable performance of the waterproof and breathable fabrics. In addition, the material does not contain fluorine, and is more friendly to the environment and the human body. DETAILED DESCRIPTION
[0032] For ease of understanding of the application, the application will be described more fully below. The application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the application more thorough and comprehensive.
[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0034] The present application will be further described in detail below in conjunction with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly understood.
[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0036] In this application, "one or more" refers to any one, any two, or any two or more of the listed items. Among them, "multiple" refers to any two or any two or more.
[0037] In the present application, the terms "combination thereof", "any combination thereof", "any combination thereof" and the like include all suitable combinations of any two or more of the listed items.
[0038] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.
[0039] In the present application, reference to a numerical range includes both endpoints of the numerical range unless otherwise specified.
[0040] In the present application, the percentage content, unless otherwise specified, refers to mass percentage for solid-liquid mixing and solid-solid mixing, and volume percentage for liquid-liquid mixing.
[0041] In this application, when it comes to percentage concentration, unless otherwise specified, it refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.
[0042] In this application, when it comes to temperature parameters, unless otherwise specified, both constant temperature treatment and treatment within a certain temperature range are permitted. The constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument.
[0043] In view of the problems of poor resilience, low elongation at break, heavy grammage, poor hydrostatic pressure resistance and poor moisture permeability of waterproof and breathable materials in the related art, the specific implementation methods of the present application are described as follows:
[0044] In a first aspect, some embodiments of the present application provide a waterproof and breathable material, which is a polymer sheet with micropores. The waterproof and breathable material comprises the following components based on a total amount of 100 parts: 68 to 87 parts of high-density polyethylene, 8 to 12 parts of linear low-density polyethylene, and 5 to 20 parts of polyolefin elastomer; the crystallinity of the waterproof and breathable material is 30% to 50%, the stiffness of the waterproof and breathable material is less than 65mN, and the breathability of the waterproof and breathable material is greater than 6000 g / (m 2 ·24h).
[0045] The number of parts indicates the mass ratio of each component in the waterproof and breathable material, and is used to indicate the proportional relationship between the components. 1 part can be determined according to actual conditions. For example, 1 part can be 1g, 10g or 100g.
[0046] Here, in the waterproof and breathable material, the mass ratio of high-density polyethylene, linear low-density polyethylene and polyolefin elastomer is (68~87): (8~12): (5~20). The mass proportion of high-density polyethylene in the waterproof and breathable material is 68%~87%, such as 68%, 70%, 75%, 80%, 85%, 87% and the range between any two of the above values. The mass proportion of linear low-density polyethylene in the waterproof and breathable material is 8%~12%, such as 8%, 9%, 10%, 11%, 12% and the range between any two of the above values. The mass proportion of polyolefin elastomer in the waterproof and breathable material is 5%~20%, such as 5%, 8%, 10%, 12%, 15%, 20% and the range between any two of the above values.
[0047] For example, the waterproof and breathable material may include: 68 parts of high-density polyethylene, 12 parts of linear low-density polyethylene and 20 parts of polyolefin elastomer; or, the waterproof and breathable material may include: 87 parts of high-density polyethylene, 8 parts of linear low-density polyethylene and 5 parts of polyolefin elastomer; or, the waterproof and breathable material may include: 75 parts of high-density polyethylene, 10 parts of linear low-density polyethylene and 15 parts of polyolefin elastomer.
[0048] Introducing polyolefin elastomers into high-density polyethylene can provide soft segment conformation through long-chain olefins of polyolefin elastomers, such as octene, and reduce the crystallinity of high-density polyethylene, thereby improving the resilience of the high-density polyethylene. Introducing linear low-density polyethylene into high-density polyethylene can increase the free volume of the chain segment and improve the elongation at break.
[0049] The crystallinity refers to the proportion of the crystalline structure in the waterproof and breathable material, specifically refers to the proportion of the lamellar structure.
[0050] The crystallinity of the waterproof and breathable material can be tested and calculated by differential scanning calorimetry. Specifically, when preparing the waterproof and breathable material, the melting enthalpy of the waterproof and breathable material (i.e., the measured melting enthalpy) can be obtained by heating the cast film of the waterproof and breathable material, and the crystallinity can be calculated by the following formula 1.
[0051] X c (%) = (ΔH m / ΔH 0 m )×100% Formula 1;
[0052] In Formula 1, ΔH m is the measured melting enthalpy, ΔH 0 m is the melting enthalpy of fully crystalline HDPE, which is 293 J / g.
[0053] In the examples of the present application, the extrusion cast film is tested using Mettler Toledo DSC 3 under the following test conditions: heating from 25°C to 180°C at a heating rate of 10°C / min under a nitrogen atmosphere to obtain a melting curve and thus obtain the measured melting enthalpy.
[0054] The stiffness of the waterproof and breathable material can be measured according to GB / T 41567. Specifically, the slot width is 10.0 mm. The waterproof and breathable material is placed on the sample table and the slot is covered. 1 / 3 of the waterproof and breathable material is in front of the slot and 2 / 3 is behind the slot. The test head is used to press the sample into the slot. After one test is completed, the sample returns to the initial position. The maximum force required in this process is used to characterize the stiffness of the waterproof and breathable material.
[0055] The moisture permeability is tested on waterproof and breathable materials according to the moisture absorption method of GB / T 12704.1.
[0056] In the waterproof and breathable material provided in the embodiment of the present application, since the waterproof and breathable material includes: 68-87 parts of high-density polyethylene, 8-12 parts of linear low-density polyethylene, and 5-20 parts of polyolefin elastomer, the waterproof and breathable material has good resilience and melt stretching properties, and the molecular chain is relatively soft and has a high elongation at break. Since the crystallinity of the waterproof and breathable material is 30%-50%, the stiffness is less than 65mN, and the moisture permeability is greater than 6000 g / (m 2·24h), therefore, the waterproof and breathable material has lower crystallinity, lower stiffness and higher breathability, and when it is applied to waterproof and breathable fabrics, the wearing comfort and waterproof and breathable performance of the waterproof and breathable fabrics can be improved.
[0057] In addition, the waterproof and breathable material has a lower density, which can reduce the gram weight. When it is applied to waterproof and breathable fabrics, it can further improve the wearing comfort. The waterproof and breathable material does not contain fluorine, which can avoid the harm of perfluorinated and polyfluorinated chemicals to the environment and human body.
[0058] In some embodiments, the polyolefin elastomer is selected from one or more of ethylene-octene copolymer, ethylene-hexene copolymer, and ethylene-butene copolymer.
[0059] In some embodiments, the waterproof and breathable material satisfies at least one of the following conditions:
[0060] (1) The density of the waterproof and breathable material is 0.91~0.97g / cm 3 For example, the density of the waterproof and breathable material can be 0.91 g / cm 3 , 0.93 g / cm 3 , 0.95 g / cm 3 , 0.97 g / cm 3 And any value between any two of the above values. Control within this range to avoid the material density being too high and causing the weight to be too large.
[0061] (2) The average pore size of the waterproof and breathable material is 50-100 nm, and can be 50-70 nm. For example, the average pore size of the waterproof and breathable material can be 50 nm, 55 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, and any value between any two of the above values. If the pore size is too small, the moisture permeability will decrease, and if the pore size is too large, the hydrostatic pressure will decrease.
[0062] (3) The thickness of the waterproof and breathable material is 5-20 μm, and can be 5-12 μm, such as 5 μm, 7 μm, 9 μm, 10 μm, 12 μm, 15 μm, 220 μm, and any value between any two of the above values. A lower thickness can ensure that the waterproof and breathable material is light in weight and has a greater breathability under the premise that the hydrostatic pressure meets the use requirements.
[0063] (4) The porosity of the waterproof and breathable material is 45% to 75%, and can be 55% to 75%. For example, the porosity of the waterproof and breathable material can be 45%, 48%, 50%, 55%, 60%, 70%, 75%, and any value between any two of the above values. A porosity that is too low will result in a too low moisture permeability, while a porosity that is too high will result in a decrease in the strength of the waterproof and breathable material and a decrease in the hydrostatic pressure.
[0064] (5) The elastic recovery rate of the waterproof and breathable material is 39% to 95%, and can be 60% to 95%. For example, the elastic recovery rate of the waterproof and breathable material can be 39%, 40%, 45%, 55%, 60%, 70%, 80%, 90%, 95%, and any value between any two of the above values. It should be noted that the elastic recovery rate is the elastic recovery rate of the waterproof and breathable material in the transverse or longitudinal direction.
[0065] (6) The stiffness of the waterproof and breathable material is 40-65 mN, and can be 40-50 mN. For example, the stiffness of the waterproof and breathable material can be 40 mN, 45 mN, 48 mN, 50 mN, 55 mN, 65 mN, or any value between any two of the above values.
[0066] (7) The tensile strength of the waterproof and breathable material is 70-160 MPa, and can be 120-160 MPa. For example, the tensile strength of the waterproof and breathable material can be 70 MPa, 80 MPa, 90 MPa, 100 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa, and any value between any two of the above values. It should be noted that the tensile strength is the tensile strength of the waterproof and breathable material in the transverse or longitudinal direction.
[0067] (8) The moisture permeability of the waterproof and breathable material is 6000~11000g / (m 2 ·24h), can be selected as 9000~11000 g / (m 2 ·24h), such as the moisture permeability of the waterproof and breathable material can be 6000g / (m 2 24h)、7000 g / (m 2 24h)、8000g / (m 2 24h)、9000g / (m 2 ·24h)、10000g / (m 2 ·24h)、11000g / (m 2 24h) and any value between the above two values.
[0068] (9) The hydrostatic pressure of the waterproof and breathable material is greater than 170 KPa, and can be selected from 170 to 200 KPa; for example, the hydrostatic pressure of the waterproof and breathable material can be 170 KPa, 180 KPa, 190 KPa, 200 KPa, or any value between any two of the above values.
[0069] Among them, the test method for the elastic recovery rate of the above-mentioned waterproof and breathable material is: using the EM6.202 tensile testing machine of Meters Industrial Systems (China) Co., Ltd., stretch the waterproof and breathable material with a width of 15mm at a tensile speed of 50mm / min, starting from the clamp spacing of 50mm (L0), after stretching to 2L0 elongation, keep it for 1min, then recover at a speed of 50mm / min, and let it stand for 3min after returning to the position. This is one cycle, and it is cycled twice. Measure the final length L1 of the waterproof and breathable material. The elastic recovery rate calculation formula is:
[0070] ER=(2L0-L1) / (2L0-L0)*100%.
[0071] The density test method of the waterproof and breathable material is as follows: the mass and volume of the waterproof and breathable material are used for calculation, and the ratio of the mass to the density is the density.
[0072] The porosity test method of the above-mentioned waterproof and breathable material is: measured by mass method according to GB / T 36363-2018.
[0073] The hydrostatic pressure test method of the above-mentioned waterproof and breathable material is: testing is carried out according to GB / T4744-2013.
[0074] The average pore size test method of the above-mentioned waterproof and breathable material is: testing according to ASTM F316-03 (2019).
[0075] The test method for tensile strength is: testing on the tensile testing machine (model: EM6.202) of MTS Industrial Systems (China) Co., Ltd. in accordance with the national standard GB / T 16492-2008.
[0076] In these embodiments, the waterproof and breathable material has a lower density, and when it is applied to waterproof and breathable fabrics, it is lighter, thinner and more comfortable to wear; the average pore size of the waterproof and breathable material is 50~100nm, which can improve the waterproof and breathable performance; the thickness of the waterproof and breathable material is 5~20μm, which is thinner and can also improve its waterproof performance; the porosity of the waterproof and breathable material is 45%~75%, which has a higher porosity and can improve its breathable performance; the elastic recovery rate of the waterproof and breathable material is 39%~95%, which can improve its toughness and mechanical properties, and can improve its wearing comfort performance; the stiffness of the waterproof and breathable material is 40~65mN, which can also improve its wearing comfort performance; the tensile strength of the waterproof and breathable material is 70~160Mpa, which has a higher tensile strength and can improve its mechanical properties; the breathability of the waterproof and breathable material is 6000~11000g / (m 2 ·24h), which can improve its moisture permeability; the hydrostatic pressure of the waterproof and breathable material is greater than 170Kpa, which can improve the waterproof performance of the waterproof and breathable material. In summary, the waterproof and breathable material has good mechanical properties, mechanical properties, waterproof and breathable properties and wearing comfort properties. Therefore, when it is applied to the waterproof and breathable fabric, it can meet the waterproof and breathable requirements.
[0077] In a second aspect, some embodiments of the present application provide a method for preparing a waterproof and breathable material, comprising the following steps:
[0078] S1. Based on 100 parts by weight of the total amount, 68 to 87 parts of high-density polyethylene, 8 to 12 parts of linear low-density polyethylene, and 5 to 20 parts of polyolefin elastomer are mixed and granulated to obtain a polymer raw material;
[0079] S2, mixing the polymer raw material with paraffin oil, melt-extruding, casting to form a cast film and cooling;
[0080] S3, heating the cast film and then biaxially stretching it to obtain a stretched oil film;
[0081] S4, extracting the paraffin oil in the stretched oil film, drying it, and obtaining a waterproof and breathable material after heat setting.
[0082] In the preparation method of the waterproof and breathable material provided in the embodiment of the present application, by mixing and granulating high-density polyethylene, linear low-density polyethylene and polyolefin elastomer in a certain proportion, the resilience and melt stretching properties of the polymer raw material can be improved. Then, the polymer raw material is mixed with paraffin oil to prepare a cast film, and the cast film is biaxially stretched under heating to obtain a stretched oil film. In this process, since the polymer raw material has good resilience and melt stretching properties, the stretching breakage rate can be reduced and the thickness can be reduced, thereby increasing the porosity of the waterproof and breathable material. By adjusting the parameters of the biaxial stretching, such as the rate and stretching ratio of the biaxial stretching, and performing heat setting on the stretched oil film, the crystallinity, crystal orientation, porosity, mechanical properties (such as toughness, elongation at break, etc.), mechanical properties (such as tensile strength, etc.) and pore size of the waterproof and breathable material can be adjusted, thereby comprehensively improving the waterproof and breathable properties, mechanical properties and mechanical properties of the waterproof and breathable material.
[0083] In some embodiments, in step S2, the draft ratio during flow delay is not less than 30, and can be selected as 30-50; for example, the draft ratio during flow delay can be 30, 40, 50, or any value between any two of the above values.
[0084] In these embodiments, by controlling the draft ratio during flow casting to be not less than 30, the crystal orientation degree of the waterproof and breathable material can be increased and the crystallinity can be reduced, thereby improving the mechanical properties of the waterproof and breathable material, such as tensile strength and toughness, and the porosity of the waterproof and breathable material, and by adjusting the longitudinal and transverse stretch ratios, the pore size and shape of the waterproof and breathable material can be adjusted, thereby improving the mechanical properties, mechanical properties and waterproof and breathable properties of the waterproof and breathable material. The larger the draft ratio, the better. Through research, it is found that by controlling the draft ratio during flow casting within the range of 30 to 50, the problem of the sheet diameter crystal being destroyed due to excessive draft ratio can be prevented.
[0085] In some embodiments, in step S3, the biaxial stretching is asynchronous stretching; optionally, the biaxial stretching is first longitudinally stretched and then transversely stretched. Optionally, the stretching ratio of the longitudinal stretching is 6 to 10, and can be 8 to 10, such as the stretching ratio of the longitudinal stretching can be 6, 7, 8, 9, 10, and any value between any two of the above values. The stretching ratio of the transverse stretching is 8 to 20, and can be 14 to 18, such as the stretching ratio of the transverse stretching can be 8, 9, 10, 14, 16, 17, 18, 20, and any value between any two of the above values.
[0086] In these embodiments, by controlling the biaxial stretching to be asynchronous stretching, the porosity and pore size shape of the waterproof and breathable material can be adjusted, thereby adjusting the waterproof and breathable performance of the waterproof and breathable material. By controlling the stretching ratio of the longitudinal stretching, the porosity and pore size shape of the waterproof and breathable material can be further adjusted, and the waterproof and breathable performance and mechanical properties of the waterproof and breathable material can be taken into account.
[0087] In some embodiments, the stretching rates of both the longitudinal stretching and the transverse stretching are not less than 4 mm / s.
[0088] In some embodiments, step S4 further includes an annealing step, and the annealing temperature is 90-100° C., such as the annealing temperature can be 90° C., 95° C., 100° C., or any value between any two of the above values.
[0089] In these embodiments, by performing annealing after S4 and controlling the annealing temperature to 90-100° C., the elastic recovery rate, tensile strength, hydrostatic pressure and moisture permeability of the waterproof and breathable material can be effectively improved. If the annealing temperature is too high, the elastic recovery rate, tensile strength, hydrostatic pressure and moisture permeability of the waterproof and breathable material will all show a downward trend.
[0090] By optimizing the annealing temperature, the oriented lamellar structure can be further developed and improved to obtain a fully developed soft segment and hard segment alternating structure, thereby effectively taking into account the improvement of the elastic recovery rate, tensile strength, hydrostatic pressure and moisture permeability of the waterproof and breathable material.
[0091] In some embodiments, in step S2, the mass ratio of the polymer raw material to the paraffin oil is 0.65-0.85, such as 0.65, 0.7, 0.8, 0.85, and any value between any two of the above values.
[0092] In some embodiments, the heat setting may include: in a heated state, the heat setting may include: initial Stretch to the preset elongation length L max , and retract to L final Among them, L max >L final >L initial .
[0093] In a third aspect, some embodiments of the present application provide a waterproof and breathable fabric, including the waterproof and breathable material as described in the first aspect or the waterproof and breathable material prepared by the preparation method of the waterproof and breathable material as described in the second aspect.
[0094] The waterproof and breathable fabric provided in the embodiment of the present application has high waterproof and breathable performance, which can meet the current requirements for waterproof and breathable performance. At the same time, the waterproof and breathable fabric has good mechanical properties and high safety performance, and will not cause damage to the environment and human body.
[0095] In a fourth aspect, some embodiments of the present application provide an application of the waterproof and moisture-permeable material as described in the first aspect in the field of waterproof and moisture-permeable.
[0096] The waterproof and breathable material can be used to make wearables, waterproof products or electronic products in the waterproof and breathable field.
[0097] Examples of wearable articles include racing suits, motorcycle suits, golf suits, waterproof suits, hiking shoes, sailing suits, ski suits, ski gloves, cold-proof jackets, snow coats, baby bibs, mountaineering suits, hunting suits, surfing suits, horse clothes, assault suits, combat suits, fishing pants, windbreakers, etc.; examples of waterproof products include shower curtains, tablecloths, raincoats, etc.; examples of electronic products include lighting accessories or mobile phone waterproof accessories, etc.
[0098] The above introduces the specific implementation methods of the present application. In order to objectively illustrate the technical effects produced by the present application, the following examples and comparative examples will be used for description.
[0099] In the following examples and comparative examples, unless otherwise specified, all raw materials can be purchased commercially. The sources of some raw materials used in the examples of this application are as follows:
[0100] High-density polyethylene: purchased from Beijing Yanshan Petrochemical Co., Ltd. of Sinopec Group, brand 5200B;
[0101] Linear low-density polyethylene: purchased from Sinopec Yangzi Petrochemical Co., Ltd., brand F182;
[0102] Polyolefin elastomer (POE): specifically ethylene-octene block copolymer, purchased from Dow Chemical, USA, with brand number 9107.
[0103] In order to maintain the reliability of the experiment, the raw materials used in the following examples and comparative examples all have the same physical and chemical parameters or are processed in the same manner.
[0104] Example 1
[0105] 1) 5% by weight of polyolefin elastomer, 8% by weight of linear low-density polyethylene, and 87% by weight of high-density polyethylene are mixed, pelletized using a twin-screw extruder, and then dried in an oven to obtain a polymer raw material;
[0106] 2) adding paraffin oil and a polymer raw material having a mass ratio of 0.85 to the paraffin oil into a kneader, mixing, melt extruding, casting to form a cast film and cooling, and controlling the draft ratio to 30;
[0107] 3) heating the cast film, first stretching it transversely and then longitudinally, wherein the longitudinal stretching ratio is 8, the transverse stretching ratio is 14, and the stretching speed during the stretching process is 4 mm / s, to obtain a stretched oil film;
[0108] 4) The stretched oil film is immersed in an extraction tank filled with dichloromethane for extraction, drying, heat setting, and annealing in an environment of 90° C. to obtain a waterproof and breathable material.
[0109] Example 2
[0110] The preparation method of the waterproof and breathable material of Example 2 is basically the same as that of Example 1, except that, in step 1), 10% by weight of polyolefin elastomer, 8% by weight of linear low-density polyethylene, and 82% by weight of high-density polyethylene are mixed.
[0111] Example 3
[0112] The preparation method of the waterproof and breathable material of Example 3 is basically the same as that of Example 1, except that, in step 1), 15% by weight of polyolefin elastomer, 8% by weight of linear low-density polyethylene, and 77% by weight of high-density polyethylene are mixed.
[0113] Example 4
[0114] The preparation method of the waterproof and breathable material of Example 4 is basically the same as that of Example 1, except that, in step 1), 20% by weight of polyolefin elastomer, 8% by weight of linear low-density polyethylene, and 72% by weight of high-density polyethylene are mixed.
[0115] Example 5
[0116] The preparation method of the waterproof and breathable material of Example 5 is basically the same as that of Example 1, except that, in step 1), 20% by weight of polyolefin elastomer, 12% by weight of linear low-density polyethylene, and 68% by weight of high-density polyethylene are mixed.
[0117] Example 6
[0118] The preparation method of the waterproof and breathable material of Example 6 is basically the same as that of Example 1, except that, in step 1), 15% by weight of polyolefin elastomer, 10% by weight of linear low-density polyethylene, and 75% by weight of high-density polyethylene are mixed.
[0119] Example 7
[0120] The preparation method of the waterproof and breathable material in Example 7 is basically the same as that in Example 2, except that the draft ratio in step 2) is 40.
[0121] Example 8
[0122] The preparation method of the waterproof and breathable material in Example 8 is basically the same as that in Example 2, except that the draft ratio in step 2) is 50.
[0123] Example 9
[0124] The preparation method of the waterproof and breathable material in Example 9 is basically the same as that in Example 8, except that the annealing temperature in step 4) is 100°C.
[0125] Example 10
[0126] The preparation method of the waterproof and breathable material in Example 10 is basically the same as that in Example 8, except that the annealing temperature in step 4) is 110°C.
[0127] Embodiment 11
[0128] The preparation method of the waterproof and breathable material in Example 11 is basically the same as that in Example 9, except that the stretching ratio of the longitudinal stretching in step 3) is 5, and the stretching ratio of the transverse stretching is 10.
[0129] Example 12
[0130] The preparation method of the waterproof and breathable material in Example 12 is basically the same as that in Example 9, except that the draft ratio in step 2) is 60.
[0131] Comparative Example 1
[0132] A commercially available polytetrafluoroethylene (PTFE) microporous membrane is used as a waterproof and breathable material. The thickness is 25 μm, the porosity is 75%, the pore size is 300 nm, the hydrostatic pressure is 45 Kpa, and the moisture permeability is 12000 g / (m 2 ·24h), please refer to Table 1 for details.
[0133] Comparative Example 2
[0134] The preparation method of the waterproof and breathable material in Comparative Example 2 is basically the same as that in Example 1, except that in step 1), 100% by weight of high-density polyethylene is used as the polymer raw material.
[0135] Comparative Example 3
[0136] The preparation method of the waterproof and breathable material in Comparative Example 3 is basically the same as that in Example 9, except that: in step 1), 8% by weight of linear low-density polyethylene and 92% by weight of high-density polyethylene are mixed.
[0137] Comparative Example 4
[0138] The preparation method of the waterproof and breathable material in Comparative Example 4 is basically the same as that in Example 9, except that: in step 1), 2% by weight of polyolefin elastomer, 8% by weight of linear low-density polyethylene, and 90% by weight of high-density polyethylene are mixed.
[0139] Test Case
[0140] According to the test method described in the specific implementation manner, various performance indicators of the waterproof and breathable materials provided by Examples 1 to 12 and Comparative Examples 1 to 4 were tested under the same conditions. The test results are shown in Table 1:
[0141] Table 1
[0142]
[0143] It can be seen from Table 1 that compared with Example 1 and Comparative Example 1, the waterproof and breathable material of the present application does not contain fluorine, is more friendly to the human body and the environment, and the hydrostatic pressure and moisture permeability can also meet the requirements of waterproofness and moisture permeability. The waterproof and breathable material of the present application has a higher hydrostatic pressure because the pore size is 50-100nm, which is much smaller than the 200nm of the polytetrafluoroethylene microporous membrane.
[0144] By comparing Example 9 with Comparative Examples 1 to 3, it can be found that the present application effectively reduces the crystallinity of the waterproof and breathable material by adding linear low-density polyethylene and polyolefin elastomer to the polymer raw material, greatly improves the elastic recovery rate, and improves the mechanical properties of the waterproof and breathable material. Moreover, the stiffness of the waterproof and breathable material of the present application is significantly reduced without affecting the hydrostatic pressure and breathability, making it softer and more comfortable to wear.
[0145] By comparing Examples 1 to 4 and Comparative Example 3, by adjusting the mass proportion of POE in the polymer raw material, it can be found that as the mass proportion of POE continues to increase, the crystallinity and stiffness of the waterproof and breathable material gradually decrease, and the elastic recovery rate increases. It is possible to increase the stretching ratio of the melt during the casting process without reducing the yield rate, reduce the thickness of the waterproof and breathable material, and effectively improve the waterproof and breathable performance.
[0146] By comparing Example 2, Example 7-8 and Example 12, it can be seen that by setting different draft ratios, the thickness of the waterproof and breathable material can be effectively reduced, the porosity can be increased, and the breathable performance of the material can be improved. Specifically, a higher draft ratio can obtain a material with a thinner thickness and a higher porosity, and improve the breathable capacity of the material, but the hydrostatic pressure will also be reduced to a certain extent. When the draft ratio is 30-50, the material can better take into account the requirements of breathable permeability and waterproofness, and the draft ratio is 50. Continuing to increase the draft ratio, such as when the draft ratio is 60, the moisture permeability is not significantly improved, and in the production process, the material will break during the stretching process, resulting in a significant decrease in the yield rate.
[0147] By comparing Example 2 and Examples 9-10, it can be seen that controlling the annealing temperature can optimize the elastic recovery rate of the waterproof and breathable material. Specifically, at 90-100°C, increasing the annealing temperature can effectively increase the elastic recovery rate of the material, but if the annealing temperature is further increased, the elastic recovery rate will decrease, reducing the mechanical properties of the material. Therefore, the annealing temperature is best at 90-100°C.
[0148] By comparing Example 2 and Example 11, it can be seen that the stretching ratio in the longitudinal and transverse directions is optimal when it is 8*14.
[0149] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0150] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A waterproof and breathable material, the waterproof and breathable material being a polymer sheet having micropores, characterized in that: The waterproof and breathable material comprises the following components based on 100 parts in total: 68 to 87 parts of high-density polyethylene, 8 to 12 parts of linear low-density polyethylene, and 5 to 20 parts of polyolefin elastomer; the crystallinity of the waterproof and breathable material is 30% to 50%, the stiffness of the waterproof and breathable material is less than 65 mN, and the breathability of the waterproof and breathable material is greater than 6000 g / (m 2 ·24h).
2. The waterproof and breathable material according to claim 1, wherein the polyolefin elastomer is selected from one or more of ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer.
3. The waterproof and breathable material according to claim 1, characterized in that: The waterproof and breathable material meets at least one of the following conditions: (1) The density of the waterproof and breathable material is 0.91~0.97g / cm 3 ; (2) The average pore size of the waterproof and breathable material is 50-100 nm, and can be 50-70 nm; (3) The thickness of the waterproof and breathable material is 5 to 20 μm, and can be 5 to 12 μm; (4) The porosity of the waterproof and breathable material is 45% to 75%, and can be 55% to 75%; (5) The elastic recovery rate of the waterproof and breathable material is 39% to 95%, and can be optionally 60% to 95%; (6) The stiffness of the waterproof and breathable material is 40-65 mN, and can be 40-50 mN; (7) The tensile strength of the waterproof and breathable material is 70~160Mpa, and can be 120~160Mpa; (8) The moisture permeability of the waterproof and breathable material is 6000~11000g / (m 2 ·24h), can be selected as 9000~11000 g / (m 2 24h); (9) The hydrostatic pressure of the waterproof and breathable material is greater than 170 KPa, and can be selected to be 170~200 KPa.
4. A method for preparing a waterproof and breathable material, characterized in that: The steps include: S1. Based on 100 parts by weight of the total amount, 68 to 87 parts of high-density polyethylene, 8 to 12 parts of linear low-density polyethylene, and 5 to 20 parts of polyolefin elastomer are mixed and granulated to obtain a polymer raw material; S2, mixing the polymer raw material with paraffin oil, melt-extruding, casting to form a cast film and cooling; S3, heating the cast film and then biaxially stretching it to obtain a stretched oil film; S4, extracting the paraffin oil in the stretched oil film, drying it, and obtaining the waterproof and breathable material after heat setting.
5. The method for preparing a waterproof and breathable material according to claim 4, characterized in that: In step S2, the draft ratio during the flow casting is not less than 30, and can be selected to be 30-50.
6. The method for preparing a waterproof and breathable material according to claim 4, characterized in that: In step S3, the biaxial stretching is asynchronous stretching; Optionally, the biaxial stretching is first longitudinal stretching and then transverse stretching; Optionally, the stretching ratio of the longitudinal stretching is 6-10, optionally 8-10; the stretching ratio of the transverse stretching is 8-20, optionally 14-18.
7. The method for preparing a waterproof and breathable material according to claim 4, characterized in that: The step S4 further includes an annealing step, and the annealing temperature is 90-100°C.
8. The method for preparing a waterproof and breathable material according to claim 4, characterized in that: In step S2, the mass ratio of the polymer raw material to the paraffin oil is 0.65-0.
85.
9. A waterproof and breathable fabric, characterized in that: The invention comprises a waterproof and breathable material as claimed in any one of claims 1 to 3 or a waterproof and breathable material prepared by the method for preparing a waterproof and breathable material as claimed in any one of claims 4 to 8.
10. Use of the waterproof and moisture-permeable material according to any one of claims 1 to 3 in the field of waterproof and moisture-permeable.