Super-soft breathable waterproof membrane and preparation method thereof

Abstract

The invention relates to the technical field of sanitary waterproof materials, and discloses a super-soft breathable waterproof membrane and a preparation method thereof.The membrane comprises a PTFE membrane, an elastic breathable layer and an SMS layer, the elastic breathable layer and the SMS layer are compounded on the two sides of the PTFE membrane respectively through a superfine complexing agent, and the superfine complexing agent is a solid latent curing agent and epoxy resin wrapping the surface of the solid latent curing agent; the particle size of the superfine complexing agent is 30-50 [mu] m; according to the super-soft breathable waterproof membrane, a superfine complexing agent is arranged on the surface of a PTFE membrane at a certain surface density, then an elastic breathable layer and an SMS layer are compounded on the PTFE membrane in a spinning compounding mode to prepare a pre-complex body, and then the pre-complex body and the pre-complex body are subjected to hot pressing through a hot pressing device, so that the superfine complexing agent is melted and solidified and compositely reinforces the super-soft breathable waterproof membrane. And the prepared super-soft breathable waterproof membrane is high in breathability, high in compounding strength, high in material surface uniformity, high in skin fitting degree, soft, skin-friendly and high in comfort.

Description

Technical Field

[0001] The invention relates to the technical field of sanitary waterproof materials, and in particular to an ultra-soft breathable waterproof membrane and a preparation method thereof. Background Art

[0002] Sanitary waterproof material is a barrier material used in the sanitary field to block water molecules. Its most common product is sanitary napkins. Since sanitary waterproof materials need to come into contact with the skin, the waterproof material must be soft, skin-friendly and breathable while being waterproof to ensure that the sanitary waterproof material will not cause skin stuffiness, redness, swelling and allergies when used.

[0003] The sanitary waterproof material in the prior art is mainly composed of a waterproof layer, a breathable layer and a non-woven fabric layer, such as a sanitary care base film and a preparation method thereof disclosed in Publication No. CN115648778A. The sanitary waterproof material mainly uses a PTFE film as the waterproof layer, TPU and PE as the breathable layer, and SMS non-woven fabric as the non-woven fabric. The material has high air permeability, is leak-proof and soft. The composite methods of sanitary waterproof materials in the prior art include adhesives and hot rolling welding. Since some users have allergic reactions to adhesives, in order to avoid allergic reactions in users, the prior art uses hot rolling welding. To replace the adhesive, the applicant found that both the adhesive and hot rolling reinforcement will affect the air permeability of the waterproof layer. The adhesive will form a cover on the surface of the breathable layer, resulting in a significant reduction in the air permeability of the waterproof layer. The fusion points formed after hot rolling reinforcement will cover the surface of the breathable layer, thereby reducing the air permeability of the waterproof layer. Therefore, in order to ensure the air permeability of the waterproof layer, the personnel in this field consider directly performing spin-weaving compounding without hot rolling reinforcement and adhesives. However, the composite strength of the material directly subjected to spin-weaving compounding is low, and it is easy to separate and break after being rubbed during use. Therefore, it is of great significance to provide a sanitary waterproof material with high air permeability and high composite strength. Summary of the invention

[0004] In order to overcome the problem of reduced air permeability of sanitary waterproof materials after adhesive and hot rolling reinforcement in the prior art, the present invention provides an ultra-soft breathable waterproof membrane and a preparation method thereof, the waterproof membrane comprises a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane by an ultra-fine composite agent, the ultra-fine composite agent is a micron-level epoxy resin-wrapped solid latent curing agent, the composite method in the method adopts a spinning composite and an ultra-fine composite agent, firstly, the ultra-fine composite agent is sprinkled on the surface of the PTFE, then the elastic breathable SMS layer is formed by spinning on the surface of the PTFE membrane, and then a hot pressing device is used to make the ultra-fine composite agent The PTFE and the elastic breathable layer and the SMS layer and the PTFE are bonded and reinforced by melt solidification. The micron-sized ultrafine composite agent will not form a large coverage area and will not significantly reduce the air permeability of the PTFE membrane. The melt-solidification temperature of the ultrafine composite agent is lower than the softening temperature of the elastic breathable layer and the SMS layer. After melt solidification, the fibers of the elastic breathable layer and the SMS layer are bonded to the PTFE surface, which will not significantly change the layered structure of the elastic breathable layer and the SMS layer, thereby ensuring the flexible skin-friendly performance of the SMS and the elastic breathable layer. The composite points formed by the ultrafine composite agent do not directly contact the skin on the surface of the layered structure and will not cause allergic reactions.

[0005] The specific technical scheme of the present invention is: A super soft breathable waterproof membrane comprises a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane by using a super fine compounding agent, wherein the super fine compounding agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, and the particle size of the super fine compounding agent is 30-50 μm.

[0006] The present invention provides an ultra-soft breathable waterproof membrane, which is composed of an elastic breathable layer, a PTFE membrane and an SMS layer in sequence. The elastic breathable layer and the SMS layer are compounded on both sides of the PTFE membrane by using an ultra-fine composite agent. The ultra-fine composite agent is composed of a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent. Compared with a waterproof membrane made of an adhesive and hot rolling curing, the membrane has high air permeability and high peeling strength compared with a waterproof membrane made of only spinning composite. The particle size of the ultra-fine composite agent is micron-level. When the elastic breathable layer, the PTFE membrane and the SMS layer are compounded by the ultra-fine composite agent, the epoxy resin on the surface of the ultra-fine composite agent can be melted by heating first, and then the curing latent curing agent can be melted by increasing the temperature and reacted with the epoxy resin. At the temperature at which the ultra-fine composite fiber melts and solidifies, the elastic breathable layer, the SMS layer and the PTFE membrane will not melt. Therefore, the use of the ultra-fine composite agent The composite agent can bond the elastic breathable layer and the SMS layer to the surface of the PTFE membrane without changing the fiber structure of the elastic breathable layer and the SMS layer. In addition, the particle size of the ultrafine composite agent is micron-level, and no large agglomeration area will be formed on the surface of the PTFE membrane. It can significantly improve the composite strength while ensuring that the air permeability of the PTFE membrane will not be significantly reduced, so that the ultra-soft breathable and waterproof layer has both high air permeability and high composite strength. In addition, the bonding points formed by the ultrafine composite agent are hidden under the layered structure of the elastic breathable layer and the SMS layer and will not contact the skin, which can avoid adverse reactions of the skin to the adhesive; at the same time, the surfaces of the elastic breathable layer and the SMS will not have the pressure points that exist during hot rolling curing, and the surface structure has high uniformity and flatness, high skin fit, and significantly improved skin-friendly softness and comfort. In addition, the elastic breathable layer has high elasticity and can protect the internal PTFE membrane.

[0007] Preferably, the SMS layer has a grammage of 10 to 15 g / m 2 .

[0008] Preferably, the elastic breathable layer is made of one or more of TPU and PE, and the weight of the elastic breathable layer is 8 to 25 g / m 2 .

[0009] Preferably, the melting point of the solid latent curing agent is greater than the softening point of the epoxy resin, and the solid latent curing agent is curing agent SH-K700.

[0010] A method for preparing the above-mentioned ultra-soft breathable waterproof membrane comprises the following steps: dispersing a solid latent curing agent in an epoxy resin and crushing it to prepare an ultra-fine composite agent, dispersing the ultra-fine composite agent on the surface of a PTFE membrane to prepare a PTFE precursor membrane, preparing an elastic breathable layer and an SMS layer on the surface of the PTFE membrane precursor by spinning and compounding to prepare a pre-composite, and hot-pressing the pre-composite by a hot-pressing device to prepare an ultra-soft breathable waterproof membrane Preferably, the surface density of the ultrafine composite agent is 0.01 to 0.03 g / m 2 .

[0011] Preferably, the mass ratio of the solid latent curing agent to the epoxy resin is 7 to 9:100.

[0012] Preferably, the temperature of the hot pressing is 120-160°C.

[0013] Preferably, the hot pressing time is 15 to 50 minutes.

[0014] Preferably, the spin-bonding process comprises one or both of a melt process and a spunbond process.

[0015] The present invention also provides a method for preparing the above-mentioned ultra-soft breathable and waterproof membrane, which first places an ultra-fine composite agent on the surface of the PTFE membrane with a certain surface density to form a PTFE precursor membrane, and then uses a spinneret composite method to composite an elastic breathable layer and an SMS layer on the PTFE precursor membrane to form a pre-composite, and then uses a hot pressing device to hot-press the composite to melt and solidify the ultra-fine composite agent, thereby reinforcing the ultra-soft breathable and waterproof membrane. The method is simple and easy to operate, and the obtained ultra-soft breathable and waterproof membrane has high air permeability, high composite strength, high material surface uniformity, high skin fit, softness and skin-friendliness, and significantly increased comfort in use.

[0016] Compared with the prior art, this application has the following technical effects: The ultra-soft breathable waterproof membrane provided by the present invention is composed of an elastic breathable layer, a PTFE membrane and an SMS layer in sequence. The elastic breathable layer and the SMS layer are compounded on both sides of the PTFE membrane using an ultra-fine composite agent. The ultra-fine composite agent is composed of a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent. Compared with a waterproof membrane made of an adhesive and hot rolling curing, the membrane has higher air permeability and higher peeling strength than a waterproof membrane made of only spin-weaving composite.

[0017] The present application provides a method for preparing an ultra-soft breathable waterproof membrane. In this method, an ultra-fine composite agent is first placed on the surface of a PTFE membrane with a certain surface density to form a PTFE precursor membrane, and then an elastic breathable layer and an SMS layer are composited on the PTFE precursor membrane by a spinneret composite method to form a pre-composite. A hot pressing device is then used to hot-press the composite to melt and solidify the ultra-fine composite agent and composite and reinforce the ultra-soft breathable waterproof membrane. The method is simple in process and easy to operate. The obtained ultra-soft breathable waterproof membrane has high air permeability, high composite strength, high material surface uniformity, high skin fit, softness and skin-friendliness, and high comfort in use. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the embodiments.

[0019] Embodiment 1: An ultra-soft breathable waterproof membrane comprises a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane by using an ultra-fine compounding agent, wherein the ultra-fine compounding agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, and the gram weight of the SMS layer is 13g / m 2 , elastic breathable layer weight 15g / m 2 .

[0020] A method for preparing the above-mentioned ultra-soft breathable waterproof membrane comprises the following steps: Step 1: Heat 100 parts of epoxy resin (E-20) to 50°C to form a liquid epoxy resin, add 8 parts of solid latent curing agent (SH-K700) to the liquid epoxy resin, mix well, and then cool at room temperature to form a solid epoxy resin, and crush the solid epoxy resin to 30-50 μm to prepare an ultrafine composite agent; Step 2: Place the PTFE membrane on the web forming device and first adjust the surface density to 0.02g / m 2 Sprinkle the ultrafine composite agent on the PTFE membrane to form a first PTFE precursor membrane, then inject TPU resin into the melt-blowing device and melt-blown it through the melt-blowing die head onto the surface of one side of the PTFE membrane with the ultrafine composite agent to form an elastic breathable layer; Step 3: transport the PTFE membrane compounded with the elastic breathable layer in step 2 to the SMS process section, and place the PTFE membrane compounded with the elastic breathable layer with the PTFE membrane surface facing upwards, and 2 The second PTFE precursor film is prepared by sprinkling the ultrafine composite agent on the surface of PTFE, and the PP resin is placed in an SMS spunbond-meltblown-spunbond device and a SMS layer is compounded on the surface of the second PTFE precursor film to prepare a pre-composite; Step 4: Place the pre-composite body in a hot pressing device, perform hot pressing reinforcement at a hot pressing temperature of 140° C. and a hot pressing time of 30 minutes, and cool to room temperature after curing to form an ultra-soft, breathable and waterproof membrane.

[0021] The solid latent curing agent is dispersed in epoxy resin and crushed to prepare an ultrafine composite agent, the ultrafine composite agent is dispersed on the surface of PTFE membrane to prepare PTFE precursor membrane, the elastic breathable layer and SMS layer are prepared on the surface of PTFE membrane precursor by spinning and compounding to prepare a pre-composite, and the pre-composite is hot-pressed by a hot pressing device to prepare an ultra-soft breathable and waterproof membrane.

[0022] Embodiment 2: An ultra-soft breathable waterproof membrane comprises a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane by using an ultra-fine compounding agent, wherein the ultra-fine compounding agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, and the gram weight of the SMS layer is 10g / m 2, elastic breathable layer weight 8g / m 2 .

[0023] A method for preparing the above-mentioned ultra-soft breathable waterproof membrane comprises the following steps: Step 1: Heat 100 parts of epoxy resin (E-20) to 50°C to form a liquid epoxy resin, add 7 parts of solid latent curing agent (SH-K700) to the liquid epoxy resin, mix well, and then cool at room temperature to form a solid epoxy resin, and crush the solid epoxy resin to 30-50 μm to prepare an ultrafine composite agent; Step 2: Place the PTFE membrane on the web forming device and first adjust the surface density to 0.01g / m 2 Sprinkle the ultrafine composite agent on the PTFE membrane to form a first PTFE precursor membrane, then inject TPU resin or PE resin into a melt-blowing device and melt-blown it through a melt-blowing die head onto one side surface of the PTFE membrane with the ultrafine composite agent to form a composite elastic breathable layer; Step 3: transport the PTFE membrane with elastic breathable layer in step 2 to the SMS process section, place the PTFE membrane with elastic breathable layer facing upward, and 2 The second PTFE precursor film is prepared by sprinkling the ultrafine composite agent on the surface of PTFE, and the PP resin is placed in an SMS spunbond-meltblown-spunbond device and a SMS layer is compounded on the surface of the second PTFE precursor film to prepare a pre-composite; Step 4: Place the pre-composite body in a hot pressing device, perform hot pressing reinforcement at a hot pressing temperature of 120° C. and a hot pressing time of 50 min, and cool to room temperature after curing to form an ultra-soft, breathable and waterproof membrane.

[0024] The solid latent curing agent is dispersed in epoxy resin and crushed to prepare an ultrafine composite agent, the ultrafine composite agent is dispersed on the surface of PTFE membrane to prepare PTFE precursor membrane, the elastic breathable layer and SMS layer are prepared on the surface of PTFE membrane precursor by spinning and compounding to prepare a pre-composite, and the pre-composite is hot-pressed by a hot pressing device to prepare an ultra-soft breathable and waterproof membrane.

[0025] Embodiment 3: An ultra-soft breathable waterproof membrane comprises a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane by using an ultra-fine compounding agent, wherein the ultra-fine compounding agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, and the gram weight of the SMS layer is 15g / m 2 , elastic breathable layer weight 25g / m 2 .

[0026] A method for preparing the above-mentioned ultra-soft breathable waterproof membrane comprises the following steps: Step 1: 100 parts of epoxy resin (E-20) are heated to 50°C to form a liquid epoxy resin, 9 parts of solid latent curing agent (SH-K700) are added to the liquid epoxy resin, mixed evenly, and then cooled at room temperature to form a solid epoxy resin, and the solid epoxy resin is crushed to 30-50 μm to prepare an ultrafine composite agent; Step 2: Place the PTFE membrane on the web forming device and first adjust the surface density to 0.03g / m 2 Sprinkle the ultrafine composite agent on the PTFE membrane to form a first PTFE precursor membrane, then inject TPU resin or PE resin into a melt-blowing device and melt-blown it through a melt-blowing die head onto one side surface of the PTFE membrane with the ultrafine composite agent to form a composite elastic breathable layer; Step 3: transport the PTFE membrane with elastic breathable layer in step 2 to the SMS process section, place the PTFE membrane with elastic breathable layer facing upward, and 2 The second PTFE precursor film is prepared by sprinkling the ultrafine composite agent on the surface of PTFE, and the PP resin is placed in an SMS spunbond-meltblown-spunbond device and a SMS layer is compounded on the surface of the second PTFE precursor film to prepare a pre-composite; Step 4: Place the pre-composite in a hot pressing device, perform hot pressing reinforcement at a hot pressing temperature of 160° C. and a hot pressing time of 15 minutes, and cool to room temperature after curing to form an ultra-soft, breathable and waterproof membrane.

[0027] The solid latent curing agent is dispersed in epoxy resin and crushed to prepare an ultrafine composite agent, the ultrafine composite agent is dispersed on the surface of PTFE membrane to prepare PTFE precursor membrane, the elastic breathable layer and SMS layer are prepared on the surface of PTFE membrane precursor by spinning and compounding to prepare a pre-composite, and the pre-composite is hot-pressed by a hot pressing device to prepare an ultra-soft breathable and waterproof membrane.

[0028] Embodiment 4: An ultra-soft breathable waterproof membrane comprises a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane by using an ultra-fine compounding agent, wherein the ultra-fine compounding agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, and the gram weight of the SMS layer is 13g / m 2 , elastic breathable layer weight 15g / m 2 .

[0029] A method for preparing the above-mentioned ultra-soft breathable waterproof membrane comprises the following steps: Step 1: Heat 100 parts of epoxy resin (E-20) to 50°C to form a liquid epoxy resin, add 8 parts of solid latent curing agent (SH-K700) to the liquid epoxy resin, mix well, and then cool at room temperature to form a solid epoxy resin, and crush the solid epoxy resin to 30-50 μm to prepare an ultrafine composite agent; Step 2: Place the PTFE membrane on the web forming device and first adjust the surface density to 0.02g / m 2 Sprinkle the ultrafine composite agent on the PTFE membrane to form a first PTFE precursor membrane, then inject HDPE resin into a melt-blowing device and melt-blown it through a melt-blowing die head onto one side surface of the PTFE membrane with the ultrafine composite agent to form a composite elastic breathable layer; Step 3: transport the PTFE membrane compounded with the elastic breathable layer in step 2 to the SMS process section, and place the PTFE membrane compounded with the elastic breathable layer with the PTFE membrane surface facing upwards, and 2 The second PTFE precursor film is prepared by sprinkling the ultrafine composite agent on the surface of PTFE, and the PP resin is placed in an SMS spunbond-meltblown-spunbond device and a SMS layer is compounded on the surface of the second PTFE precursor film to prepare a pre-composite; Step 4: Place the pre-composite body in a hot pressing device, perform hot pressing reinforcement at a hot pressing temperature of 130° C. and a hot pressing time of 23 min, and cool to room temperature after curing to form an ultra-soft, breathable and waterproof membrane.

[0030] The solid latent curing agent is dispersed in epoxy resin and crushed to prepare an ultrafine composite agent, the ultrafine composite agent is dispersed on the surface of PTFE membrane to prepare PTFE precursor membrane, the elastic breathable layer and SMS layer are prepared on the surface of PTFE membrane precursor by spinning and compounding to prepare a pre-composite, and the pre-composite is hot-pressed by a hot pressing device to prepare an ultra-soft breathable and waterproof membrane.

[0031] Embodiment 5: An ultra-soft breathable waterproof membrane comprises a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane by using an ultra-fine compounding agent, wherein the ultra-fine compounding agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, and the gram weight of the SMS layer is 15g / m 2 , elastic breathable layer weight 15g / m 2 .

[0032] A method for preparing the above-mentioned ultra-soft breathable waterproof membrane comprises the following steps: Step 1: Heat 100 parts of epoxy resin (E-20) to 50°C to form a liquid epoxy resin, add 8 parts of solid latent curing agent (SH-K700) to the liquid epoxy resin, mix well, and then cool at room temperature to form a solid epoxy resin, and crush the solid epoxy resin to 30-50 μm to prepare an ultrafine composite agent; Step 2: Place the PTFE membrane on the web forming device and first adjust the surface density to 0.02g / m 2Sprinkle the ultrafine composite agent on the PTFE membrane to form a first PTFE precursor membrane, then inject HDPE resin into a melt-blowing device and melt-blown it through a melt-blowing die head onto one side surface of the PTFE membrane with the ultrafine composite agent to form a composite elastic breathable layer; Step 3: transport the PTFE membrane compounded with the elastic breathable layer in step 2 to the SMS process section, and place the PTFE membrane compounded with the elastic breathable layer with the PTFE membrane surface facing upwards, and 2 The second PTFE precursor film is prepared by sprinkling the ultrafine composite agent on the surface of PTFE, and the PP resin is placed in an SMS spunbond-meltblown-spunbond device and a SMS layer is compounded on the surface of the second PTFE precursor film to prepare a pre-composite; Step 4: Place the pre-composite in a hot pressing device, perform hot pressing reinforcement at a hot pressing temperature of 135° C. and a hot pressing time of 20 minutes, and cool to room temperature after curing to form an ultra-soft, breathable and waterproof membrane.

[0033] The solid latent curing agent is dispersed in epoxy resin and crushed to prepare an ultrafine composite agent, the ultrafine composite agent is dispersed on the surface of PTFE membrane to prepare PTFE precursor membrane, the elastic breathable layer and SMS layer are prepared on the surface of PTFE membrane precursor by spinning and compounding to prepare a pre-composite, and the pre-composite is hot-pressed by a hot pressing device to prepare an ultra-soft breathable and waterproof membrane.

[0034] Comparative Example 1: (Polyolefin Binder) Compared with Example 1, in Comparative Example 1, a polyolefin adhesive is coated on the surface of the PTFE membrane, and the other conditions are the same as those in Example 1.

[0035] Comparative Example 2: (Hot rolling reinforcement) Compared with Example 1, in Comparative Example 2, hot rolling reinforcement is used to compositely reinforce the elastic breathable layer, the SMS layer and the PTFE membrane, and the other conditions are the same as those in Example 1.

[0036] Comparative Example 3: (Ultrafine powder surface density is too large) Compared with Example 1, the surface density in Comparative Example 3 is 0.1 g / m 2 , the other conditions are the same as those in Example 1.

[0037] Comparative Example 4: (Ultrafine powder surface density is too small) Compared with Example 1, the surface density in Comparative Example 4 is 0.005 g / m 2 , the other conditions are the same as those in Example 1.

[0038] Comparative Example 5: Applying ultrafine powder on the surface of PTFE membrane Compared with Example 1, in Comparative Example 5, the latent curing agent and the liquid epoxy resin are mixed and then coated on the surface of the PTFE membrane, and the other conditions are the same as those in Example 1.

[0039] Comparative Example 6: Hot pressing temperature is too high Compared with Example 1, the hot pressing temperature in Comparative Example 6 is 180° C., and the other conditions are the same as those in Example 1.

[0040] Comparative Example 7: Hot pressing temperature is too low Compared with Example 1, the hot pressing temperature in Comparative Example 7 is 90° C., and the other conditions are the same as those in Example 1.

[0041] Comparative Example 8: Compared with Example 1, in Comparative Example 8, the epoxy resin is not wrapped on the surface of the solid latent curing agent, but the epoxy resin and the latent curing agent are crushed into powder and then mixed to prepare ultrafine composite powder. The other conditions are the same as those in Example 1.

[0042] Comparative Example 9 Compared with Example 1, in Comparative Example 9, only epoxy resin is used instead of curing agent, and other conditions are the same as those in Example 1.

[0043] Comparative Example 10: Compared with Example 1, Comparative Example 9 only uses spinneret compounding without reinforcement, and the other conditions are the same as those of Example 1.

[0044] The ultra-soft breathable waterproof membranes prepared in Examples 1 to 5 and Comparative Examples 1 to 9 were tested for the following test items: peel strength, air permeability, waterproofness, softness, The peel strength test method refers to GB / T8808-1988 T-type peel strength test method for soft composite plastics, and the test device used in the test is XLW (PC) intelligent electronic tensile testing machine; The air permeability test method refers to GB / T5453-1997 "Determination of Air Permeability of Textile Fabrics" for air permeability test. The air permeability test instrument is YG461H full-automatic air permeability tester; Waterproof test method: prepare 1.5% NACL solution, put 15g sodium chloride analytical salt in a 1000mL measuring cylinder at 55℃ to prepare 1.5% sodium chloride solution, drop red ink into the sodium chloride solution and stir evenly to prepare the test liquid, make the film into a bag shape, put 100mL of test liquid in the bag and tie the bag mouth tightly, use a pressure device to evenly press the bag, and observe the pressure after water droplets appear on the surface of the bag; The above test results are shown in Table 1; Table 1 Test results Peel strength (N / cm) Air permeability (mm / S) <![CDATA[Waterproofness (mmH2O)]]> Surface flatness Example 1 8.26 ＞800 ＞10000 Flat without dents Example 2 7.94 ＞800 ＞10000 Flat without dents Example 3 8.52 ＞800 ＞10000 Flat without dents Example 4 8.34 ＞800 ＞10000 Flat without dents Example 5 8.28 ＞800 ＞10000 Flat without dents Comparative Example 1 8.31 0 ＞10000 Smooth without dents Comparative Example 2 8.54 452 ＞10000 There is a depression Comparative Example 3 8.51 634 ＞10000 / Comparative Example 4 7.15 ＞800 ＞10000 / Comparative Example 5 8.58 0 ＞10000 / Comparative Example 6 9.78 0 ＞10000 There is a depression Comparative Example 7 6.81 / / Smooth without dents Comparative Example 8 6.97 / / / Comparative Example 9 6.93 / / / Comparative Example 9 6.84 / / / As shown in Table 1, the peel strength of the ultra-soft breathable waterproof film in Examples 1 to 5 is 7.94-8.52 N / cm, the air permeability is greater than 800 mm / S, the waterproofness is greater than 10000 mmH2O, the surface of the material is flat without depression, soft and smooth, has a high degree of skin adhesion, and is very comfortable to use.

[0045] In Comparative Example 1, polyolefin hot melt adhesive was used to composite and reinforce the PTFE membrane with the breathable layer and the SMS layer. The results of Comparative Example 1 showed that its peel strength was 8.31 N / cm, the air permeability was 0 mm / S, the waterproofness was greater than 10000 mmH2O, and the material surface was flat without depressions. Compared with Example 1, there was no significant difference in the peel strength, waterproofness and material flatness of Comparative Example 1, but the air permeability of Comparative Example 1 was reduced to 0. The reason for the above situation is that after the hot melt adhesive is used for composite, the hot melt adhesive will form a covering surface on the surface of the PTFE membrane, and the formed covering surface will directly block the microporous structure of PTFE and cause the PTFE membrane to lose its air permeability.

[0046] In Comparative Example 2, hot rolling reinforcement was used to composite reinforce the PTFE membrane with the breathable layer and the SMS layer. The results of Comparative Example 2 showed that its peel strength was 8.54N / cm, the air permeability was 452mm / S, the waterproofness was greater than 10000mmH2O, and there were depressions on the material surface. Compared with Example 1, there was no significant difference in the peel strength and waterproofness of Comparative Example 2, and the air permeability was significantly lower than that of Example 1. There were depressions on the material surface of Comparative Example 2, and the material flatness was low. After analyzing the results of Comparative Example 2, it was concluded that compared with the use of adhesives, the effect of hot rolling reinforcement on the air permeability of PTFE was significantly reduced, and the air permeability of the PTFE membrane was significantly improved. However, compared with the method provided in the present application, the effect of hot rolling reinforcement on the air permeability of the PFFE membrane was still significant. In addition, more welding point depressions were formed on the surface of the material reinforced by hot rolling. These depressions would reduce the flatness of the material surface, affect the surface feel of the material, and reduce the softness of the material.

[0047] Comparative Examples 3 and 4 explored the dosage of ultrafine composite powder. When the dosage of ultrafine composite powder is too large, the air permeability of the material will be reduced. When the dosage of ultrafine powder is too small, the composite strength of the material will be reduced, making the composite strength of the material unable to meet the use requirements.

[0048] In Comparative Example 5, the ultrafine powder is formed into a membrane structure on the surface of the PTFE membrane and then compounded. The results show that the air permeability of Comparative Example 5 is zero. The result of Comparative Example 5 is the same as the result of using an adhesive. When the adhesive material is coated on the surface of the PTFE membrane in the form of a film, the microporous structure of the PTFE membrane will be covered, causing the PTFE membrane to lose its air permeability. Therefore, in order to ensure the air permeability of the PTFE membrane, the covering structure on its surface needs to be strictly controlled and optimized.

[0049] Comparative Examples 6 and 7 investigated the hot pressing temperature. When the hot pressing temperature is too high, the SMS layer or TPU layer will also melt. The melted SMS layer and TPU layer will lose their layered structure, resulting in the SMS layer and TPU layer forming a membrane structure on the surface of the PTFE membrane, causing the material to lose its air permeability. The structure of the material is destroyed and cannot meet the use requirements. When the hot pressing temperature is too low, the ultrafine composite agent cannot function, resulting in the composite strength of the material not being improved.

[0050] The epoxy resin and solid latent curing agent in Comparative Example 8 do not adopt a coating structure. The results of Comparative Example 8 show that its peel strength is only 6.97N / cm, which is significantly lower than that of Example 1. After analyzing the above results, it is found that since the ultrafine composite agent of the present invention is sprinkled on the surface of the PTFE film with a certain surface density, and the particles of the ultrafine composite agent are small, each particle forms a tiny welding point separately after melting. Therefore, in order for each particle to undergo a curing reaction with the epoxy resin and the solid latent curing agent after melting, the epoxy resin and the solid latent curing agent need to be formed into a whole. After the epoxy resin and the solid latent curing agent are mixed in powder form and then sprinkled on the surface of the PTFE film, since the powder particles are in an independently dispersed form, the separate epoxy resin and the solid latent curing agent cannot work together after melting, resulting in their inability to effectively perform bonding, and the bonding strength is significantly reduced.

[0051] In Comparative Example 9, only epoxy resin was used to compositely reinforce the PTFE membrane with the breathable layer and the SMS layer. The peel strength of Comparative Example 2 was only 6.93 N / cm, which was significantly lower than that of Example 1. The results of Expression 9 showed that when only epoxy resin was used, the composite reinforcement ability of the epoxy resin on the material was low due to the low dosage, and the composite strength of the material could not be significantly increased.

[0052] In Comparative Example 10, only spin-forming compounding was performed without composite reinforcement. The peel strength of Comparative Example 10 was only 6.84 N / cm. It can be seen that the composite strength of the material only using spin-forming compounding is low, and reinforcement is required to have a higher composite strength.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A super soft breathable waterproof membrane, characterized in that: It includes a PTFE membrane and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE membrane with an ultrafine compounding agent. The ultrafine compounding agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent. The particle size of the ultrafine compounding agent is 30-50 μm.

2. The ultra-soft breathable waterproof membrane according to claim 1, characterized in that: The SMS layer has a grammage of 10-15 g / m 2 .

3. The ultra-soft breathable waterproof membrane according to claim 1, characterized in that: The elastic breathable layer is made of one or more of TPU and PE, and has a gram weight of 8-25 g / m 2 .

4. The ultra-soft breathable waterproof membrane according to claim 1, characterized in that: The solid latent curing agent is SH-K700.

5. The ultra-soft breathable waterproof membrane according to claim 1 or 4, characterized in that: The melting point of the solid latent curing agent is greater than the softening point of the epoxy resin.

6. A method for preparing the ultra-soft breathable waterproof membrane according to any one of claims 1 to 5, characterized in that: The following steps are involved: The solid latent curing agent is dispersed in epoxy resin and crushed to prepare an ultrafine composite agent, the ultrafine composite agent is dispersed on the surface of PTFE membrane to prepare PTFE precursor membrane, the elastic breathable layer and SMS layer are prepared on the surface of PTFE membrane precursor by spinning and compounding to prepare a pre-composite, and the pre-composite is hot-pressed by a hot pressing device to prepare an ultra-soft breathable and waterproof membrane.

7. The method for preparing the ultra-soft breathable waterproof membrane according to claim 5, characterized in that: The surface density of the ultrafine composite agent is 0.01-0.03 g / m 2 .

8. The method for preparing the ultra-soft breathable waterproof membrane according to claim 5, characterized in that: The mass ratio of solid latent curing agent to epoxy resin is 7~9:

100.

9. The method for preparing the ultra-soft breathable waterproof membrane according to claim 5, characterized in that: The hot pressing temperature is 120-160° C., and the hot pressing time is 15-50 min.

10. The method for preparing the ultra-soft breathable waterproof membrane according to claim 5, characterized in that: The spinning composite method includes one or both of a melting method and a spunbonding method.