A method for producing a composite material having a porous coating and a porous coating fabric

Abstract

The application provides a preparation method of a composite material with a porous coating and a porous coating cloth, and relates to the technical field of porous composite materials. The preparation method of the composite material with the porous coating comprises the following steps: applying an aqueous coating slurry to the surface of a substrate, drying for the first time, immersing in water for a certain time, and obtaining a pre-swelling coating; the aqueous coating slurry contains 1-25% of water-absorbing resin particles by weight of the aqueous coating slurry; the water-absorbing resin particles in the pre-swelling coating are removed, and the second drying is performed to obtain the composite material with the porous coating. The composite material with different bubble hole morphologies and sizes can be obtained through the simple preparation method.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of porous composite materials, and relates to a preparation method of a composite material with a porous coating and a porous coating fabric. BACKGROUND

[0002] Coating a layer with a porous structure on the surface of a textile has multiple effects, including improving air permeability, aesthetics, heat insulation and the like. The existing preparation of a coating with a porous structure generally adopts a foaming method, including physical foaming and chemical foaming, and the cells are relatively fine and small, and the surface of the coating is relatively smooth.

[0003] However, the existing technology discloses few methods for preparing a foaming coating with a three-dimensional structure on the surface of a textile. SUMMARY

[0004] To solve the above technical problems, the present application provides a preparation method of a composite material with a porous coating and a porous coating fabric.

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

[0006] A preparation method of a composite material with a porous coating, comprising:

[0007] applying an aqueous coating slurry to the surface of a substrate, drying for the first time, and then soaking in water for a certain period of time to obtain a pre-swelling coating;

[0008] The aqueous coating slurry contains 1-25% of water-absorbing resin particles by weight of the aqueous coating slurry.

[0009] The water-absorbing resin particles in the pre-swelling coating are removed, and the second drying is performed to obtain the composite material with a porous coating.

[0010] Preferably, the aqueous coating slurry is one or a combination of two or more of an aqueous PU slurry, an aqueous modified PU slurry, an aqueous acrylate slurry and an aqueous modified acrylate slurry.

[0011] Preferably, the substrate has a porous structure.

[0012] More preferably, the substrate is a textile.

[0013] Preferably, the certain period of time is 10 minutes to 24 hours.

[0014] Preferably, the water absorption rate of the water-absorbing resin particles is 5-1000 times.

[0015] Preferably, the average particle size of the water-absorbing resin particles is 10 microns to 5 millimeters.

[0016] Preferably, the removing is by extrusion.

[0017] Preferably, the conditions of the first drying and the second drying are respectively: temperature of 50-100℃, time of 1-60h.

[0018] A porous coating fabric is prepared by the method of preparing the composite material with porous coating according to any one of the above embodiments.

[0019] The present application has the following advantages:

[0020] (1) The present application adds a certain proportion of water-absorbing resin particles in the water-based coating slurry, then applies it on the surface of the substrate, dries and solidifies, and then soaks in water. The water-absorbing resin particles absorb water and expand by a large multiple, the coating layer foams obviously, or further can break the outer surface of the coating layer, and removing the water-absorbing and expanded resin particles can obtain a porous coating.

[0021] (2) The present application can obtain bubbles with 3D structure, the surface can be uneven, forming a concave-convex structure, and the size of the obtained bubble hole can be adjusted according to the particle size of the water-absorbing resin particles, the amount of water-absorbing resin particles added, and the water absorption rate.

[0022] (3) The present application can obtain bubbles with a larger size, and the size of the bubbles can reach 1mm, or even more than 5mm. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The photo of the porous coating fabric of Example 1.

[0024] Figure 2 The photo of the porous coating fabric of Example 2.

[0025] Figure 3 The photo of the dry printing coating of Example 9.

[0026] Figure 4 The photo of the porous coating fabric of Example 9. DETAILED DESCRIPTION

[0027] The technical solutions of the present application are further described and explained in the following detailed description.

[0028] In one aspect, the present application provides a method for preparing a composite material with porous coating, comprising:

[0029] applying a water-based coating slurry to the surface of a substrate, first drying, then soaking in water for a certain period of time to obtain a pre-expanded coating;

[0030] The water-based coating slurry contains 1-25% of water-absorbing resin particles by weight of the water-based coating slurry.

[0031] The swollen water-absorbing resin particles in the pre-swelling coating are removed, and the second drying is performed to obtain the composite material with the porous coating of the present application.

[0032] The present application utilizes the introduction of water-absorbing resin particles in the water-based coating slurry. After the slurry is formed and solidified, it is soaked in water. The water-absorbing resin in the coating will gradually absorb water and swell to a large multiple, and form bubble holes by foaming. Even further, the coating is broken by the swelling water-absorbing resin. After the swollen water-absorbing resin is removed in a simple manner, bubble holes are formed at the positions of the swollen water-absorbing resin. The size of the bubble holes can be adjusted according to the particle size of the water-absorbing resin particles, the amount of water-absorbing resin particles added, and the water absorption multiple, etc. The size of the bubble holes can be as low as tens of μm, or can reach mm level, or even larger.

[0033] The water-absorbing resin can absorb tens to hundreds of times of its own water. In order to avoid the added water-absorbing resin particles from absorbing a large amount of water in the water-based coating slurry, resulting in too large viscosity of the water-based coating slurry and making it impossible to be coated, the present application can directly add the water-absorbing resin into the prepared water-based coating slurry, and stir and disperse for no more than 5 min, or no more than 3 min, or no more than 1 min. The stirring and dispersing speed is not particularly limited, and can be 200-1500 rpm. Then, it is immediately applied to the surface of the substrate. In the present application, the way of applying the water-based coating slurry to the surface of the substrate can be blade coating, screen printing, etc., and is not particularly limited. The thickness of the applied slurry coating is not particularly limited, but is generally greater than the average particle size of the water-absorbing resin particles, or can be 1.5 times or more of the average particle size of the water-absorbing resin particles. For example, if the average particle size of the water-absorbing resin particles is 0.5 mm, the thickness of the slurry coating can be 1 mm, 2 mm, etc. For example, if the average particle size of the water-absorbing resin particles is 1 mm, the thickness of the slurry coating can be 2 mm, 3 mm, 5 mm, etc.

[0034] For the weight percentage of the water-absorbing resin particles in the water-based coating slurry, further, the weight percentage of the water-absorbing resin particles in the water-based coating slurry can be 5-22%. For example, the weight percentage can be any value in the range of 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, etc., but is not limited to the above-listed values.

[0035] In one preferred embodiment of the present application, the aqueous coating slurry is not particularly limited as long as it can form a film on the surface of the substrate and form good adhesion, and can be a single-component aqueous coating slurry or a two-component aqueous coating slurry. The composition of the aqueous coating slurry excluding the water-absorbing resin particles can be referred to as "aqueous slurry" and can be purchased directly from the market or prepared according to the method of the prior art. Specifically, the aqueous slurry can be one or a combination of two or more of aqueous PU slurry, aqueous modified PU slurry, aqueous acrylate slurry, and aqueous modified acrylate slurry. For example, one aqueous slurry, in terms of 100% by weight, the raw material composition can be as follows: 50-70 wt% aqueous modified PU resin, 10-30 wt% water, 0.3-0.6 wt% defoamer, 0.5-2 wt% thickener, 3-6 wt% propylene glycol, 4-8 wt% crosslinking agent (which can be an aqueous polyisocyanate crosslinking agent).

[0036] In one preferred embodiment of the present application, the substrate has a porous structure. The substrate having a porous structure can increase the permeability to the aqueous coating slurry and improve the adhesion, which is more conducive to the stability of the coating.

[0037] In a more preferred embodiment of the present application, the substrate is a textile. The material of the textile in the present application is not particularly limited and can be a natural material textile or a synthetic material textile. The natural material includes cotton, hemp, wool, etc., and the synthetic material includes polyester, nylon, polypropylene, spandex, acrylic, and chlorofiber, but is not limited to the above. In the present application, the textile can be cloth, such as commonly used clothing fabric, curtain fabric, flame-retardant fabric, fire-resistant fabric, etc.

[0038] In one preferred embodiment of the present application, the certain time is 10 min-24 h. By controlling the time of the coating immersed in water, the water absorption and expansion ratio of the water-absorbing resin can be adjusted, and then the size of the obtained bubble hole or whether the bubble hole is broken can be adjusted. Further preferably, the certain time is 0.5 h-12 h, for example, it can be any one of 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h, 10 h, 10.5 h, 11 h, 11.5 h, 12 h, etc., but is not limited to the above. Or, further, the certain time can be 1-8 h.

[0039] In one preferred embodiment of the present application, the water absorption rate of the water-absorbent resin particles is 5-1000 times. In the present application, the water-absorbent resin particles can be cross-linked polyacrylate, starch-acrylate polymer, starch-acrylonitrile graft copolymer, acrylamide-acrylonitrile-acrylic acid terpolymer, etc. The water absorption rate of the water-absorbent resin particles can be adjusted according to the material and cross-linking degree of the water-absorbent resin particles. Further preferably, the water absorption rate of the water-absorbent resin particles is 10-500 times, for example, the water absorption rate can be any one of 10 times, 20 times, 30 times, 40 times, 50 times, 60 times, 70 times, 80 times, 90 times, 100 times, 110 times, 120 times, 130 times, 140 times, 150 times, 160 times, 170 times, 180 times, 190 times, 200 times, 220 times, 250 times, 280 times, 300 times, 320 times, 330 times, 350 times, 370 times, 400 times, 430 times, 450 times, 470 times, 500 times, etc., but is not limited to the above-mentioned values.

[0040] In the present application, the water absorption rate of the water-absorbent resin particles can be tested as follows: at 23℃, a certain weight W1 of dry water-absorbent resin is soaked in clean water for 24 hours, taken out, the water on the surface of the resin is removed, and weighed to obtain the weight M2, then the water absorption rate = (M2-M1) / M1.

[0041] In one preferred embodiment of the present application, the average particle size of the water-absorbent resin particles is 10 μm-5 mm. By adjusting the average particle size of the water-absorbent resin particles, the size of the obtained bubble hole can also be adjusted. From the dimension of the water-absorbent resin particles, the average particle size of the water-absorbent resin particles can further be 100 μm-5 mm, for example, the average particle size can be any one of 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc., but is not limited to the above-mentioned values.

[0042] In one preferred embodiment of the present application, the removal method is extrusion. Due to the high expansion rate of the water-absorbent resin particles, the hole wall of the expanded coating bubble hole becomes very thin, and the bubble hole wall can be extruded by simple extrusion method, and the water-absorbent resin particles are extruded out, thereby forming a bubble hole; when the expansion rate of the water-absorbent resin particles is very high and the bubble hole is broken, the water-absorbent resin particles can be separated from the composite material by turning over the composite material, thereby forming a bubble hole.

[0043] In one preferred embodiment of the present application, the conditions of the first drying and the second drying are respectively: temperature of 50-100°C, time of 1-60h. Through heating and drying at a not high temperature, the coating can be solidified and has high adhesion on the substrate. For example, the first drying and the second drying can be respectively 50°Cx6h, 60°Cx3h, 70°Cx12h, 60°Cx12h, 60°Cx24h, 60°Cx36h, 70°Cx24h, 80°Cx2h, 80°Cx6h, etc. In addition, from the purpose and effect of the first drying and the second drying, the temperature of the second drying can be higher or the time can be longer, so that the solidification effect of the coating is better, for example, the first drying can be 60°Cx12h, and the second drying can be 60°Cx36h or 70°Cx24h. Of course, during the first drying, since the slurry contains more water, it can be placed at room temperature for a period of time to volatilize most of the water, for example, 1-12h, and then heated and dried, which can be understood by those skilled in the art.

[0044] In another aspect, the present application provides a porous coating fabric prepared by the method for preparing a composite material with a porous coating according to any one of the above embodiments. The porous coating fabric of the present application, the substrate is a fabric, since the fabric has a sparse and expanded structure, the coating and the fabric can have good adhesion, and a 3D structured pore structure is formed on the fabric.

[0045] The technical solutions of the present application are further described and explained according to the embodiments below. Unless otherwise specified, the parts in the following embodiments are parts by weight.

[0046] In the following embodiments and comparative examples of the present application, the composition of the aqueous slurry is as follows: 65.7wt% aqueous acrylic modified PU resin, 22wt% water, 0.5wt% defoaming agent (dimethyl silicone oil), 0.8wt% thickening agent (associated polyurethane thickening agent), 5wt% propylene glycol, 6wt% crosslinking agent (aqueous polyisocyanate curing agent). The composition of the above aqueous slurry is only an example of the present application, which is used for further explanation of the embodiments of the present application, and does not represent a limitation on the present application. Those skilled in the art can understand that the aqueous slurry of the embodiments and comparative examples of the present application can also use other raw material compositions or be directly obtained from the market.

[0047] The water-absorbing resin particles are crosslinked sodium acrylate particles.

[0048] Water-absorbing resin particles 1: average particle size 0.2mm, water absorption rate 300 times;

[0049] Water-absorbing resin particles 2: average particle size 1mm, water absorption rate 80 times;

[0050] Water-absorbing resin particles 3: average particle size 3mm, water absorption ratio 220 times.

[0051] Example 1

[0052] Five parts of absorbent resin granules were added to 95 parts of a stirred aqueous slurry and stirred at 800 rpm for 1 minute. The mixture was then printed onto the fabric using a stencil with a single layer of stencil to obtain a printed fabric. The printed fabric was left at room temperature for 4 hours, then dried overnight at 60°C, left at room temperature for 24 hours, and then soaked in room temperature water for 3 hours. After removal, the expanded absorbent resin granules were squeezed off the printed coating, and the fabric was dried again at 60°C for 36 hours. After cooling, a porous coated fabric was obtained.

[0053] A photograph of the porous coated fabric in this embodiment is attached. Figure 1 As shown, the coating has obvious air bubbles and is uneven, giving it a 3D effect, and the expanded air bubbles are less likely to burst.

[0054] Example 2

[0055] The difference between Example 2 and Example 1 is that in Example 1, the parts of water-absorbing resin particles 1 were adjusted from 5 parts to 22 parts, and the parts of water-based slurry were adjusted from 95 parts to 78 parts. The remaining steps remain unchanged.

[0056] A photograph of the porous coated fabric in this embodiment is attached. Figure 2 As shown, the coating has obvious air bubbles. Due to the high content of water-absorbing resin particles, the water absorption and expansion ratio is high, and the expanded air bubbles are basically burst.

[0057] Comparative Example 1

[0058] The difference between Comparative Example 1 and Example 1 is that no water-absorbing resin particles were added in Example 1. The coating did not develop a porous structure or swell.

[0059] Example 3

[0060] 12 parts of absorbent resin granules were added to 88 parts of a stirred aqueous slurry and stirred at 600 rpm for 1 minute. The mixture was then printed onto the fabric using a stencil with a single layer of stencil to obtain a printed fabric. The printed fabric was left at room temperature for 1 hour, then at 60°C for 6 hours, and then at room temperature for 24 hours. After that, it was soaked in room temperature water for 1 hour, removed, and the expanded absorbent resin granules were squeezed off the printed coating. The fabric was then dried at 60°C for 48 hours, removed, and cooled to obtain a porous coated fabric.

[0061] The porous coated fabric in this embodiment has obvious air bubbles, and less than 10% of the air bubbles are burst.

[0062] Example 4

[0063] Example 4 differs from Example 3 in that the time for which the coating is immersed in water after curing is increased from 1 h to 2 h. The remaining steps are unchanged.

[0064] The porous coating fabric of this example has more obvious bubble holes, and the size of the bubble holes is obviously larger than that of Example 3. Almost 30% of the bubble holes are broken.

[0065] Example 5

[0066] Example 5 differs from Example 3 in that the time for which the coating is immersed in water after curing is increased from 1 h to 4 h. The remaining steps are unchanged.

[0067] The porous coating fabric of this example has more obvious bubble holes, and the size of the bubble holes is obviously larger than that of Example 4. Almost 80% of the bubble holes are broken.

[0068] Example 6

[0069] Example 6 differs from Example 3 in that the time for which the coating is immersed in water after curing is increased from 1 h to 10 h. The remaining steps are unchanged.

[0070] The porous coating fabric of this example has more obvious bubble holes, and the size of the bubble holes is obviously larger than that of Example 5. More than 95% of the bubble holes are broken.

[0071] Example 7

[0072] Example 7 differs from Example 4 in that the water-absorbing resin particles 2 are replaced with equal weight of water-absorbing resin particles 1. The remaining steps are unchanged.

[0073] The porous coating fabric of this example has more obvious bubble holes, and the size of the bubble holes is obviously smaller than that of Example 4. No more than 5% of the bubble holes are broken.

[0074] Example 8

[0075] Example 8 differs from Example 4 in that the water-absorbing resin particles 2 are replaced with equal weight of water-absorbing resin particles 3. The remaining steps are unchanged.

[0076] The porous coating fabric of this example has more obvious bubble holes, and the size of the bubble holes is obviously larger than that of Example 4. More than 90% of the bubble holes are broken.

[0077] Example 9

[0078] 6 parts of water-absorbing resin particles (commercial product Ocean Baby) were added to 94 parts of the stirred aqueous slurry, stirred at 800 rpm for 1 min, and then printed on the cloth using a hollowed-out one-pass screen printing plate to obtain a printed cloth. The printed cloth was left to stand at room temperature for 4 h and then dried at 60°C overnight, and the appearance was as shown in Fig. 1. The dried printed cloth was left to stand at room temperature for 24 h, and then immersed in water at room temperature for 3 h. The expanded water-absorbing resin particles were removed from the printed coating by pressing, and the cloth was dried at 60°C for a further 36 h, removed and cooled to obtain a porous coating cloth, and the appearance was as shown in Fig. 2. Figure 3 Figure 4

[0079] The above embodiments demonstrate that the composite material having a porous structure according to the present application can form a porous structure with unevenness on the surface of the substrate, and adjusting the amount of water-absorbing resin particles added, the size of the particles, the water absorption time, etc. can adjust the shape and size of the porous structure.

[0080] The basic principles, main features and advantages of the present application have been shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, which are merely preferred embodiments of the present application, and the scope of the present application is not limited by the above examples. Equivalent changes and modifications made in accordance with the scope and content of the present patent are within the scope of the present application. The scope of the present application is defined by the appended claims and their equivalents.​​

Claims

1. A method for producing a composite material having a porous coating, characterized by, The application relates to a method for preparing a composite material with a porous coating, comprising the following steps: applying an aqueous coating slurry to a substrate surface, first drying, soaking in water for a certain time to obtain a pre-swelling coating; the aqueous coating slurry contains 1-25% of water-absorbing resin particles by weight of the aqueous coating slurry; removing the water-absorbing resin particles in the pre-swelling coating, second drying to obtain the composite material with the porous coating; the removing mode is extrusion. The aqueous coating slurry is one of the following or a combination of two or more: an aqueous PU slurry, an aqueous modified PU slurry, an aqueous acrylate slurry and an aqueous modified acrylate slurry. The substrate has a porous structure. The substrate is a textile.

2. The method of claim 1, wherein the method further comprises: The certain time is 10 min-24 h.

3. The method of claim 1, wherein the method further comprises: The water-absorbing resin particles have a water-absorbing rate of 5-1000 times.

4. The method of claim 3, wherein the method further comprises the step of: The water-absorbing resin particles have an average particle size of 10 mu m-5 mm.

5. The method of claim 1, wherein the porous coating is formed by a process comprising: The conditions of the first drying and the second drying are as follows: the temperature is 50-100 DEG C, and the time is 1-60 h.

6. The method of claim 1, wherein the method further comprises: The composite material with the porous coating is prepared by the method for preparing the composite material with the porous coating according to any one of claims 1-8.

7. The method of claim 1, wherein the method further comprises: ​ 8. The method of claim 1, wherein the method further comprises: ​ 9. A porous coated fabric characterized in that, ​

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