Ultra-soft breathable waterproof membrane and preparation method thereof

Abstract

The application relates to the technical field of waterproof sanitary materials, and discloses a super-soft and breathable waterproof film and a preparation method thereof, wherein the film comprises a PTFE film, an elastic and breathable layer and an SMS layer which are respectively compounded on two sides of the PTFE film by using superfine composite agents; the superfine composite 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 superfine composite agent is 30-50 mu m; the superfine composite agent is arranged on the surface of the PTFE film in a certain surface density, the elastic and breathable layer and the SMS layer are compounded on the PTFE film in a spinning composite mode to form a pre-composite body, and a hot-pressing device is used to hot-press the composite body, so that the superfine composite agent is melted, solidified and compounded and reinforced on the super-soft and breathable waterproof film; the method is simple in process and easy to operate; the prepared super-soft and breathable waterproof film is high in breathability, high in composite strength, high in material surface uniformity, high in skin adhesion, soft and comfortable, and high in comfort.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sanitary waterproof materials, in particular to a super-soft and breathable waterproof film and a preparation method thereof. BACKGROUND

[0002] Sanitary waterproof materials are barrier materials used in the field of hygiene to block water molecules. The most common product is a sanitary napkin. Since sanitary waterproof materials need to come into contact with the skin, the waterproof material must not only be waterproof but also soft and breathable to ensure that the sanitary waterproof material does not cause skin congestion, redness, and allergic reactions when in use.

[0003] The sanitary waterproof materials in the prior art are mainly composed of a waterproof layer, a breathable layer, and a non-woven fabric layer. For example, a sanitary care base film and a preparation method thereof are disclosed in CN115648778A. The waterproof layer in the sanitary waterproof material is mainly made of a PTFE film, the breathable layer is commonly made of TPU and PE, and the non-woven fabric is commonly made of SMS non-woven fabric. The material has high breathability, prevents leakage, and is soft. The current composite method of sanitary waterproof materials in the prior art includes adhesives and hot rolling fusion. Since some users have allergic reactions to adhesives, the prior art uses hot rolling fusion instead of adhesives to avoid allergic reactions in users. The present application finds that both adhesives and hot rolling reinforcement affect the breathability of the waterproof layer. Adhesives form a cover on the surface of the breathable layer, significantly reducing the breathability of the waterproof layer. The fusion points formed after hot rolling reinforcement cover the surface of the breathable layer, thereby reducing the breathability of the waterproof layer. Therefore, to ensure the breathability of the waterproof layer, those skilled in the art consider directly performing spinning compounding without hot rolling reinforcement and adhesives. However, directly performing spinning compounding has low material compounding strength, and the material is prone to separation and damage after being rubbed in use. Therefore, it is of great significance to provide a sanitary waterproof material with high breathability and high compounding strength. SUMMARY

[0004] In order to overcome the problem of reducing the air permeability of waterproof materials in the prior art after using adhesive and hot rolling reinforcement, the present application provides a super-soft and air-permeable waterproof film and a preparation method thereof, the waterproof film comprising a PTFE film and elastic air-permeable layers and SMS layers respectively compounded on both sides of the PTFE film using superfine composite agents, the superfine composite agent being a micron-level solid latent curing agent wrapped with epoxy resin, the composite method in the method using spinning composite and superfine composite agent, first sprinkling the superfine composite agent on the surface of the PTFE, then spinning on the surface of the PTFE film to form elastic air-permeable SMS layers, and then using a hot pressing device to melt and solidify the superfine composite agent to bond and reinforce the PTFE with the elastic air-permeable layers and the SMS layers with the PTFE, the micron-level superfine composite agent not forming a larger coverage area and not significantly reducing the air permeability of the PTFE film, and the melt-solidification temperature of the superfine composite agent being lower than the softening temperature of the elastic air-permeable layers and the SMS layers, the fibers of the elastic air-permeable layers and the SMS layers being bonded to the surface of the PTFE after melt-solidification of the superfine composite agent, not significantly changing the layered structure of the elastic air-permeable layers and the SMS layers, ensuring the flexible and skin-friendly properties of the SMS and the elastic air-permeable layers, and the composite points formed by the superfine composite agent not directly contacting the skin on the surface of the layered structure and not causing allergic reactions.

[0005] The specific technical scheme of the present application is:

[0006] A super-soft and air-permeable waterproof film, comprising a PTFE film and elastic air-permeable layers and SMS layers respectively compounded on both sides of the PTFE film using superfine composite agents, the superfine composite agent being a solid latent curing agent and epoxy resin wrapped on the surface of the solid latent curing agent, the particle size of the superfine composite agent being 30-50 μm.

[0007] The application provides a super-soft and 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 two sides of the PTFE membrane by using a superfine composite agent, the superfine composite agent is composed of a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, the waterproof membrane has high breathability compared with a waterproof membrane made by using an adhesive and hot rolling curing, and has high peeling strength compared with a waterproof membrane made by only using spinning and compounding, the particle size of the superfine composite agent is micron grade, when the superfine composite agent is used to compound the elastic breathable layer, the PTFE membrane and the SMS layer, the epoxy resin on the surface of the superfine composite agent can be first melted by heating, then the solid latent curing agent is melted and a curing reaction with the epoxy resin occurs by increasing the temperature, and the elastic breathable layer, the SMS layer and the PTFE membrane will not be melted at the temperature of the melting and curing of the superfine composite fiber, therefore, the superfine composite agent can be used to 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 superfine composite agent is micron grade, and no large lump area will be formed on the surface of the PTFE membrane, the breathability of the PTFE membrane will not be significantly reduced while the compounding strength is significantly improved, the super-soft and breathable waterproof layer has high breathability and high compounding strength, in addition, the bonding points formed by the superfine composite agent are hidden under the layered structure of the elastic breathable layer and the SMS layer, and will not contact the skin, so that the skin can avoid adverse reactions to the adhesive, meanwhile, no pressure points existing in the hot rolling curing will appear on the surface of the elastic breathable layer and the SMS layer, the uniformity and flatness of the surface structure are high, the skin adhesion degree is high, and the skin-friendly softness and comfort are significantly improved, in addition, the elastic breathable layer has high elasticity, and can protect the internal PTFE membrane.

[0008] Preferably, the grammage of the SMS layer is 10-15 g / m 2 .

[0009] Preferably, the material of the elastic breathable layer is one or more of TPU and PE, and the grammage of the elastic breathable layer is 8-25 g / m 2 .

[0010] 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.

[0011] A preparation method of the super-soft and breathable waterproof membrane, comprising the following steps: dispersing the solid latent curing agent in the epoxy resin to crush and prepare a superfine composite agent, dispersing the superfine 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 precursor membrane by using spinning and compounding to prepare a pre-compounded body, and hot-pressing the pre-compounded body by using a hot-pressing device to prepare the super-soft and breathable waterproof membrane

[0012] Preferably, the surface density of the superfine composite agent is 0.01-0.03 g / m 2 .

[0013] Preferably, the mass ratio of the solid latent curing agent to the epoxy resin is 7-9:100.

[0014] Preferably, the temperature of the hot pressing is 120-160℃.

[0015] Preferably, the time of the hot pressing is 15-50 min.

[0016] Preferably, the spinning composite includes one or both of a melt method and a spun-bond method.

[0017] The application also provides a preparation method of the super-soft, breathable and waterproof film. The superfine composite agent is placed on the surface of a PTFE film to form a PTFE precursor film at a certain surface density, and then the elastic and breathable layer and the SMS layer are combined on the PTFE precursor film by a spinning composite method to form a pre-composite body. The pre-composite body is hot-pressed by a hot-pressing device to melt and solidify the superfine composite agent and reinforce the super-soft, breathable and waterproof film. The method is simple and easy to operate, and the prepared super-soft, breathable and waterproof film has high breathability, high composite strength, high uniformity of the material surface, high skin adhesion, softness and skin friendliness, and high comfort.

[0018] Compared with the prior art, the application has the following technical effects:

[0019] The super-soft, breathable and waterproof film provided by the application is composed of an elastic and breathable layer, a PTFE film and an SMS layer in sequence. The elastic and breathable layer and the SMS layer are combined on both sides of the PTFE film by a superfine composite agent. The superfine 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 film made of an adhesive and a hot-rolled curing agent, the film has high breathability. Compared with a waterproof film made by only a spinning composite, the film has high peel strength.

[0020] The preparation method of the super-soft, breathable and waterproof film provided by the application is as follows. The superfine composite agent is placed on the surface of a PTFE film to form a PTFE precursor film at a certain surface density, and then the elastic and breathable layer and the SMS layer are combined on the PTFE precursor film by a spinning composite method to form a pre-composite body. The pre-composite body is hot-pressed by a hot-pressing device to melt and solidify the superfine composite agent and reinforce the super-soft, breathable and waterproof film. The method is simple and easy to operate, and the prepared super-soft, breathable and waterproof film has high breathability, high composite strength, high uniformity of the material surface, high skin adhesion, softness and skin friendliness, and high comfort. DETAILED DESCRIPTION

[0021] The application will be further described below in combination with examples.

[0022] Embodiment 1

[0023] A super-soft and breathable waterproof film comprises a PTFE film and an elastic breathable layer and an SMS layer respectively compounded on both sides of the PTFE film by using superfine composite agent, the superfine composite agent is a solid latent curing agent and an epoxy resin wrapped on the surface of the solid latent curing agent, the grammage of the SMS layer is 13g / m 2 , and the grammage of the elastic breathable layer is 15g / m 2 .

[0024] A preparation method of the above-mentioned super-soft and breathable waterproof film, comprising the following steps:

[0025] Step one: 100 parts of epoxy resin (E-20) is heated to a temperature of 50℃ to form a liquid epoxy resin, 8 parts of solid latent curing agent (SH-K700) is added to the liquid epoxy resin and mixed uniformly, and then cooled to a solid state at room temperature to form a solid epoxy resin, and the solid epoxy resin is crushed to 30-50μm to form a superfine composite agent;

[0026] Step two: the PTFE film is placed on a netting device, the superfine composite agent is sprinkled on the PTFE film to form a first PTFE precursor film according to a surface density of 0.02g / m 2 , then the TPU resin is injected into the melt-blowing device through the melt-blowing die to melt-blow onto the surface of the PTFE film with the superfine composite agent to compound the elastic breathable layer;

[0027] Step three: the PTFE film compounded with the elastic breathable layer in step two is transported to an SMS process section, the surface of the PTFE film compounded with the elastic breathable layer is upward, the superfine composite agent is sprinkled on the surface of the PTFE film to form a second PTFE precursor film according to a surface density of 0.02g / m 2 , and the PP resin is placed in the SMS spun-bonding-melt-blowing-spun-bonding device and compounded on the surface of the second PTFE precursor film to form an SMS layer to form a pre-composite body;

[0028] Step four: the pre-composite body is placed in a hot-pressing device, and hot-pressing and reinforcement are carried out under the conditions of a hot-pressing temperature of 140℃ and a hot-pressing time of 30min, and then cooled to room temperature after curing to form a super-soft and breathable waterproof film.

[0029] The solid latent curing agent is dispersed in the epoxy resin to form a superfine composite agent, the superfine composite agent is dispersed on the surface of the PTFE film to form a PTFE precursor film, the elastic breathable layer and the SMS layer are prepared by using the superfine composite agent to compound on the surface of the PTFE precursor film to form a pre-composite body, and the super-soft and breathable waterproof film is prepared by using a hot-pressing device to hot-press the pre-composite body.

[0030] Embodiment 2

[0031] The application discloses a super-soft, breathable and waterproof film, which comprises a PTFE film, an elastic and breathable layer and an SMS layer which are respectively compounded on two sides of the PTFE film by using superfine composite agents. 2 The gram weight of the elastic and breathable layer is 8 g / m 2 .

[0032] A preparation method of the super-soft, breathable and waterproof film, which comprises the following steps:

[0033] Step one: 100 parts of epoxy resin (E-20) is heated to a temperature of 50 DEG C to form a liquid epoxy resin, 7 parts of solid latent curing agent (SH-K700) is added into the liquid epoxy resin and uniformly mixed, and then the solid epoxy resin is cooled to a solid state at normal temperature, and the solid epoxy resin is crushed to 30-50 mu m to prepare a superfine composite agent;

[0034] Step two: the PTFE film is placed on a netting device, superfine composite agent is sprinkled on the PTFE film to prepare a first PTFE precursor film according to a surface density of 0.01 g / m 2 Then, TPU resin or PE resin is injected into a melt blowing device to be melt blown to one side surface of the PTFE film with the superfine composite agent through a melt blowing die to compound the elastic and breathable layer;

[0035] Step three: the PTFE film with the compounded elastic and breathable layer in step two is transported to an SMS process section, the PTFE film surface of the PTFE film with the compounded elastic and breathable layer is upward, superfine composite agent is sprinkled on the PTFE surface to prepare a second PTFE precursor film according to a surface density of 0.01 g / m 2 PP resin is placed in an SMS spun-bonding-melt-blowing-spun-bonding device and compounded on the surface of the second PTFE precursor film to prepare a pre-composite body;

[0036] Step four: the pre-composite body is placed in a hot pressing device, and hot pressing and reinforcement are carried out under the conditions of a hot pressing temperature of 120 DEG C and a hot pressing time of 50 min, and the super-soft, breathable and waterproof film is prepared after curing and cooling to room temperature.

[0037] The solid latent curing agent is dispersed in the epoxy resin to prepare a superfine composite agent, the superfine composite agent is dispersed on the surface of the PTFE film to prepare a PTFE precursor film, the elastic and breathable layer and the SMS layer are prepared by using a spinning composite on the surface of the PTFE precursor film to prepare a pre-composite body, and the super-soft, breathable and waterproof film is prepared by using a hot pressing device to hot press the pre-composite body.

[0038] Example 3:

[0039] The application discloses a super-soft and breathable waterproof film, which comprises a PTFE film, an elastic and breathable layer and an SMS layer which are respectively compounded on two sides of the PTFE film by using superfine composite agents. 2 The gram weight of the elastic and breathable layer is 25g / m 2 .

[0040] A preparation method of the super-soft and breathable waterproof film, which comprises the following steps:

[0041] Step one: 100 parts of epoxy resin (E-20) is heated to a temperature of 50 DEG C to form a liquid epoxy resin, 9 parts of solid latent curing agent (SH-K700) is added into the liquid epoxy resin and uniformly mixed, and then the solid epoxy resin is cooled to a solid state at normal temperature, and the solid epoxy resin is crushed to 30-50 microns to prepare a superfine composite agent;

[0042] Step two: the PTFE film is placed on a netting device, superfine composite agent is sprinkled on the PTFE film to prepare a first PTFE precursor film according to a surface density of 0.03g / m 2 Then, TPU resin or PE resin is injected into a melt-blowing device to be melt-blown to one side surface of the PTFE film with the superfine composite agent through a melt-blowing die to compound the elastic and breathable layer;

[0043] Step three: the PTFE film with the compounded elastic and breathable layer in step two is transported to an SMS process section, the PTFE film surface of the PTFE film with the compounded elastic and breathable layer is upward, superfine composite agent is sprinkled on the PTFE surface to prepare a second PTFE precursor film according to a surface density of 0.03g / m 2 Then, PP resin is placed in an SMS spun-bonding-melt-blowing-spun-bonding device to compound the SMS layer on the surface of the second PTFE precursor film to prepare a pre-composite body;

[0044] Step four: the pre-composite body is placed in a hot-pressing device, and hot-pressing and reinforcement are carried out under the conditions of a hot-pressing temperature of 160 DEG C and a hot-pressing time of 15 minutes, and the super-soft and breathable waterproof film is prepared after curing and cooling to room temperature.

[0045] The solid latent curing agent is dispersed in the epoxy resin to be crushed to prepare the superfine composite agent, the superfine composite agent is dispersed on the surface of the PTFE film to prepare the PTFE precursor film, the elastic and breathable layer and the SMS layer are prepared by using a spinning composite on the surface of the PTFE precursor film to prepare the pre-composite body, and the super-soft and breathable waterproof film is prepared by using a hot-pressing device to hot-press the pre-composite body.

[0046] Example 4:

[0047] The application discloses a super-soft, breathable and waterproof film, which comprises a PTFE film, an elastic and breathable layer and an SMS layer which are respectively compounded on two sides of the PTFE film by using superfine composite agents. 2 The gram weight of the elastic and breathable layer is 15 g / m 2 .

[0048] A preparation method of the super-soft, breathable and waterproof film, which comprises the following steps:

[0049] Step one: 100 parts of epoxy resin (E-20) is heated to a temperature of 50 DEG C to form a liquid epoxy resin, 8 parts of solid latent curing agent (SH-K700) is added into the liquid epoxy resin and uniformly mixed, and then the solid epoxy resin is cooled to a solid state at normal temperature, and the solid epoxy resin is crushed to 30-50 microns to prepare a superfine composite agent;

[0050] Step two: the PTFE film is placed on a netting device, superfine composite agent is sprinkled on the PTFE film to prepare a first PTFE precursor film according to a surface density of 0.02 g / m 2 Then, HDPE resin is injected into a melt-blowing device to be melt-blown to one side surface of the PTFE film with the superfine composite agent through a melt-blowing die to compound the elastic and breathable layer;

[0051] Step three: the PTFE film with the compounded elastic and breathable layer in step two is transported to an SMS process section, the PTFE film surface of the PTFE film with the compounded elastic and breathable layer is upward, superfine composite agent is sprinkled on the PTFE surface to prepare a second PTFE precursor film according to a surface density of 0.02 g / m 2 Then, PP resin is placed in an SMS spun-bonding-melt-blowing-spun-bonding device to compound the SMS layer on the surface of the second PTFE precursor film to prepare a pre-composite body;

[0052] Step four: the pre-composite body is placed in a hot-pressing device, and hot-pressing and reinforcement are carried out under the conditions of a hot-pressing temperature of 130 DEG C and a hot-pressing time of 23 min, and the super-soft, breathable and waterproof film is prepared after cooling to room temperature.

[0053] The solid latent curing agent is dispersed in the epoxy resin to prepare the superfine composite agent, the superfine composite agent is dispersed on the surface of the PTFE film to prepare the PTFE precursor film, the elastic and breathable layer and the SMS layer are prepared by using a spinning composite on the surface of the PTFE precursor film to prepare the pre-composite body, and the super-soft, breathable and waterproof film is prepared by using a hot-pressing device to hot-press the pre-composite body.

[0054] Example 5:

[0055] The application discloses a super-soft and breathable waterproof film, which comprises a PTFE film, an elastic and breathable layer and an SMS layer which are respectively compounded on two sides of the PTFE film by using superfine composite agents. 2 The elastic and breathable layer has a grammage of 15 g / m 2 .

[0056] The application further discloses a preparation method of the super-soft and breathable waterproof film.

[0057] Step one: 100 parts of epoxy resin (E-20) are heated to a temperature of 50 DEG C to form liquid epoxy resin, 8 parts of solid latent curing agent (SH-K700) are added into the liquid epoxy resin and uniformly mixed, and then the solid epoxy resin is cooled to form solid epoxy resin at normal temperature, and the solid epoxy resin is crushed to 30-50 microns to prepare superfine composite agent;

[0058] Step two: the PTFE film is placed on a netting device, superfine composite agent is sprinkled on the PTFE film to prepare a first PTFE precursor film according to a surface density of 0.02 g / m 2 Then, HDPE resin is injected into a melt-blowing device to be melt-blown to one side surface of the PTFE film with the superfine composite agent through a melt-blowing die to compound the elastic and breathable layer;

[0059] Step three: the PTFE film with the compounded elastic and breathable layer in step two is transported to an SMS process section, the PTFE film surface of the PTFE film with the compounded elastic and breathable layer is upward, superfine composite agent is sprinkled on the PTFE surface to prepare a second PTFE precursor film according to a surface density of 0.02 g / m 2 Then, PP resin is placed in an SMS spun-bonding-melt-blowing-spun-bonding device and compounded on the surface of the second PTFE precursor film to prepare a pre-composite body;

[0060] Step four: the pre-composite body is placed in a hot-pressing device, and hot-pressing and reinforcement are carried out at a hot-pressing temperature of 135 DEG C and a hot-pressing time of 20 min, and the super-soft and breathable waterproof film is prepared after solidification and cooling to room temperature.

[0061] The solid latent curing agent is dispersed in the epoxy resin to be crushed to prepare the superfine composite agent, the superfine composite agent is dispersed on the surface of the PTFE film to prepare the PTFE precursor film, the elastic and breathable layer and the SMS layer are prepared by using a spinning composite on the surface of the PTFE precursor film to prepare the pre-composite body, and the super-soft and breathable waterproof film is prepared by using a hot-pressing device to hot-press the pre-composite body.

[0062] Comparative example 1: (polyolefin binder)

[0063] Compared with example 1, the polyolefin binder is coated on the surface of the PTFE film in the comparative example 1, and the rest of the conditions are the same as those in example 1.

[0064] Comparative Example 2: (Hot rolling reinforcement)

[0065] In Comparative Example 2, hot rolling reinforcement was used to reinforce the elastic air-permeable layer and the SMS layer with the PTFE film, and the remaining conditions were the same as in Example 1.

[0066] Comparative Example 3: (Excessive surface density of ultrafine powder)

[0067] In Comparative Example 3, the surface density of the ultrafine powder was 0.1 g / m 2 , and the remaining conditions were the same as in Example 1.

[0068] Comparative Example 4: (Insufficient surface density of ultrafine powder)

[0069] In Comparative Example 4, the surface density of the ultrafine powder was 0.005 g / m 2 , and the remaining conditions were the same as in Example 1.

[0070] Comparative Example 5: Ultrafine powder coated on the surface of the PTFE film

[0071] In Comparative Example 5, the latent curing agent was mixed with the liquid epoxy resin and then coated on the surface of the PTFE film, and the remaining conditions were the same as in Example 1.

[0072] Comparative Example 6: Excessive hot pressing temperature

[0073] In Comparative Example 6, the hot pressing temperature was 180°C, and the remaining conditions were the same as in Example 1.

[0074] Comparative Example 7: Insufficient hot pressing temperature

[0075] In Comparative Example 7, the hot pressing temperature was 90°C, and the remaining conditions were the same as in Example 1.

[0076] Comparative Example 8:

[0077] In Comparative Example 8, the epoxy resin was not wrapped around the surface of the solid latent curing agent, but was pulverized into a powder and mixed with the latent curing agent to form an ultrafine composite powder, and the remaining conditions were the same as in Example 1.

[0078] Comparative Example 9

[0079] In Comparative Example 9, only the epoxy resin was used instead of the curing agent, and the remaining conditions were the same as in Example 1.

[0080] Comparative Example 10:

[0081] Comparative Example 9 only uses the spinning composite without reinforcement, and the rest of the conditions are the same as Example 1.

[0082] The super-soft, breathable and waterproof film prepared in the above Examples 1 to 5 and Comparative Examples 1 to 9 is tested, and the test items are: peel strength, breathability, waterproofness, softness,

[0083] The peel strength test method refers to "GB / T 8808-1988 Soft Composite Plastic T- Type Peel Strength Test Method", and the detection device used for testing is an XLW(PC) intelligent electronic tensile testing machine;

[0084] The breathability test method refers to "GB / T 5453-1997 Textile Fabric Breathability Test", and the instrument for breathability test is YG461H type full-automatic breathability tester;

[0085] The waterproofness test method: 1.5% NACL solution is configured, 15g of sodium chloride analysis salt is placed in a 1000ml measuring cylinder to configure 1.5% sodium chloride solution at 55°C, red ink is added dropwise into the sodium chloride solution and stirred uniformly to make the test liquid, the film is made into a bag shape, 100ml of test liquid is placed in the bag, the bag opening is tightly tied, and the pressure device is used to apply uniform force to the bag, and the pressure when water droplets appear on the surface of the bag is observed;

[0086] The above test results are shown in Table 1;

[0087] Table 1 Test Results

[0088] Peeling strength (N / cm) Air permeability (mm / s) Water resistance (mm H2O) Surface flatness Example 1 8.26 ＞800 ＞10000 Smooth without depression Example 2 7.94 ＞800 ＞10000 Smooth without depression Example 3 8.52 ＞800 ＞10000 Smooth without depression Example 4 8.34 ＞800 ＞10000 Smooth without depression Example 5 8.28 ＞800 ＞10000 Smooth without depression Comparative Example 1 8.31 0 ＞10000 Smooth without depression Comparative Example 2 8.54 452 ＞10000 With 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 With depression Comparative Example 7 6.81 / / Smooth without depression Comparative Example 8 6.97 / / / Comparative Example 9 6.93 / / / Comparative Example 9 6.84 / / /

[0089] As shown in Table 1, the peel strength of the super-soft, breathable and waterproof film in Examples 1 to 5 is 7.94-8.52N / cm, the breathability is greater than 800mm / S, the waterproofness is greater than 10000mmH2O, the material surface is flat without depression, soft and smooth, the skin adhesion is high, and the use comfort is high.

[0090] In Comparative Example 1, polyolefin hot melt adhesive is used to composite and reinforce the PTFE film and the breathable layer and the SMS layer, and the results of Comparative Example 1 show that the peel strength is 8.31N / cm, the breathability is 0mm / S, the waterproofness is greater than 10000mmH2O, and the material surface is flat without depression. Compared with Example 1, the peel strength, waterproofness and material flatness of Comparative Example 1 have no significant difference, but the breathability of Comparative Example 1 is reduced to 0, and the reason for the above condition is that after using hot melt adhesive for compounding, the hot melt adhesive will form a covering surface on the surface of the PTFE film, which will directly block the microporous structure of the PTFE, so that the PTFE film loses the breathability.

[0091] The PTFE film and the air-permeable layer and the SMS layer were compounded and reinforced by hot rolling in Comparative Example 2. The results of Comparative Example 2 showed that the peeling strength was 8.54 N / cm, the air permeability was 452 mm / s, the waterproofness was greater than 10,000 mmH2O, and the material surface had depressions. Compared with Example 1, the peeling strength and waterproofness of Comparative Example 2 had no significant difference, the air permeability was significantly less than that of Example 1, and the material surface of Comparative Example 2 had depressions and the material flatness was low. After analyzing the results of Comparative Example 2, it was found that compared with using a bonding agent, the use of hot rolling reinforcement significantly reduced the influence of the composite surface on the air permeability of PTFE, and the air permeability of the PTFE film was significantly improved. However, compared with the method provided in the present application, the influence of hot rolling reinforcement on the air permeability of the PTFE film was still significant. In addition, the use of hot rolling reinforcement formed many fusion point depressions on the material surface, which reduced the flatness of the material surface, affected the hand feeling of the material surface, and reduced the softness of the material.

[0092] Comparative Example 3 and Comparative Example 4 explored the amount of superfine composite powder. When the amount of superfine composite powder was too large, the air permeability of the material would decrease. When the amount of superfine powder was too small, the composite strength of the material would decrease, and the composite strength of the material could not meet the use requirements.

[0093] In Comparative Example 5, the superfine powder was formed into a film structure on the surface of the PTFE film before compounding. The results showed that the air permeability of Comparative Example 5 was zero. The results of Comparative Example 5 were the same as those of the bonding agent. When the bonding material was coated on the surface of the PTFE film in the form of a film, the microporous structure of the PTFE film would be covered, thereby causing the PTFE film to lose air permeability. Therefore, the covering structure on the surface of the PTFE film needs to be strictly controlled and optimized to ensure the air permeability of the PTFE film.

[0094] Comparative Example 6 and Comparative Example 7 explored the hot pressing temperature. When the hot pressing temperature was too high, the SMS layer or the TPU layer would also melt, and the melted SMS layer and TPU layer would lose the layered structure, causing the SMS layer and the TPU layer to form a film structure on the surface of the PTFE film, so that the material lost air permeability and the structure of the material was destroyed, which could not meet the use requirements. When the hot pressing temperature was too low, the superfine composite agent could not play a role, and the composite strength of the material did not increase.

[0095] The epoxy resin and solid latent curing agent in Comparative Example 8 do not adopt the coating structure, and the result of Comparative Example 8 shows that its peeling strength is only 6.97 N / cm, which is significantly reduced compared with Example 1. After analyzing the above result, it is found that since the superfine composite agent of the present application is sprinkled on the surface of the PTFE film with a certain surface density, and the particles of the superfine composite agent are small, each particle forms a tiny fusion point after melting. Therefore, in order to enable each particle to have a curing reaction between the epoxy resin and the solid latent curing agent after melting, it is necessary to form an integral whole of the epoxy resin and the solid latent curing agent. After mixing the epoxy resin and the solid latent curing agent in powder form and then sprinkling them on the surface of the PTFE film, since the powder particles are in an independent dispersed form, the epoxy resin and the solid latent curing agent cannot work together after melting, which leads to the fact that they cannot effectively perform the adhesive, and the bonding strength is significantly reduced.

[0096] In Comparative Example 9, only the epoxy resin is used to composite and reinforce the PTFE film with the air permeable layer and the SMS layer, and the peeling strength of Comparative Example 2 is only 6.93 N / cm, which is significantly reduced compared with Example 1. The result of Comparative Example 9 shows that when only the epoxy resin is used, the amount used is too low, which leads to a low composite reinforcement ability of the epoxy resin to the material, and the composite strength of the material cannot be significantly increased.

[0097] In Comparative Example 10, only the spinning composite is performed without composite reinforcement, and the peeling strength of Comparative Example 10 is only 6.84 N / cm. It can be seen that the composite strength of the material using only the spinning composite is low, and the material needs to be reinforced to have a high composite strength.

[0098] The above is only a preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent transformation of the above embodiment according to the technical essence of the present application still belongs to the protection scope of the technical solution of the present application.

Claims

1. A super soft breathable waterproof membrane, characterized by: The invention 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 ultrafine compounding agent. The ultrafine compounding agent comprises 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. When using the ultrafine composite agent to composite the elastic breathable layer, PTFE membrane and SMS layer, heating is performed to melt the epoxy resin on the surface of the ultrafine composite agent first, and then the temperature is increased to melt the solid latent curing agent and react with the epoxy resin to cure.

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

3. The ultra-soft breathable waterproof membrane according to claim 1, wherein: The elastic breathable layer is made of one or more of TPU and PE, and has a gram weight of 8 to 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: A solid latent curing agent is dispersed in an epoxy resin and crushed to form an ultrafine composite agent, which is then dispersed on the surface of a PTFE membrane to form a PTFE precursor membrane. An elastic breathable layer and an SMS layer are prepared on the surface of the PTFE membrane precursor by spinneret compounding to form a pre-composite, which is then hot-pressed using a hot pressing device to form an ultra-soft breathable and waterproof membrane.

7. The preparation method according to claim 6, wherein The surface density of the ultrafine composite agent is 0.01~0.03g / m 2 .

8. The preparation method according to claim 6, characterized in that: The mass ratio of the solid latent curing agent to the epoxy resin is 7~9:

100.

9. The preparation method according to claim 6, wherein The hot pressing temperature is 120-160° C., and the hot pressing time is 15-50 min.

10. The preparation method according to claim 6, characterized in that: The spinning composite method includes one or both of a melting method and a spunbonding method.