KR101148161B1 - A Moist Permeable and Water Proof Membrane and Process for Preparing The Same - Google Patents

Abstract

The present invention is a method for producing a moisture-permeable waterproof membrane having excellent breathability and moisture permeability by laminating fine polyurethane beads (cross links) on the surface of the release paper in a cross-linked state, and forming a plurality of fine pores between the polyurethane beads It is about. The present invention comprises the steps of preparing a water-in-oil dispersion (w / o) emulsion-type resin by mixing a one-component or two-component polyurethane resin with a nonionic surfactant; The water-in-oil dispersion (w / o) emulsion-type resin was added to a mixed solvent in which methyl ethyl ketone and toluene were mixed in a weight ratio of 1: 1, and an anti-film agent, a water repellent, a slip agent, an antifoaming agent, a pigment, and water were added and stirred. After 20 to 24 hours to prepare a mixed solution; Preparing a coating composition by adding a crosslinking agent to the mixed solution; Coating the coating composition on a release paper using a comb coater; Drying the coated release paper twice with a hot air dryer; And it relates to a method for producing a water-permeable waterproof membrane comprising the step of separating the release paper.

Moisture-Proof, Membrane, Polyurethane, Porous, Moisture-Proof, Hot Air Dryer

Description

A Moist Permeable and Water Proof Membrane and Process for Preparing The Same}

The present invention relates to a moisture-permeable waterproof membrane prepared by laminating fine polyurethane beads on a release paper surface in a crosslinked state and forming a plurality of micropores between the crosslinked fine polyurethane beads and a method of manufacturing the same.

Conventional techniques for manufacturing a moisture-permeable waterproof fabric include a wet method, a dry method and a laminating method. The wet method is a method of forming a polyurethane coating layer having fine pores on a fabric by coating a resin composition prepared by mixing polyurethane and dimethylformamide, which is an organic solvent, with a predetermined thickness on a fabric, and then passing them through water. . In the dry process, a resin composition prepared by dissolving a polyurethane in a highly volatile organic solvent such as methyl ethyl ketone, toluene, acetone, and isopropyl alcohol is coated on a fabric to a certain thickness, and then heat-treated to volatilize the volatile organic solvent. In a homogeneous polyurethane film layer. The laminating method is a method of separately manufacturing a film having moisture permeability and then laminating with a fabric using an adhesive.

As a conventional moisture-permeable membrane, there is a first PTFE membrane, which can be made by stretching a fluororesin film biaxially to form a porous crack. However, the moisture-permeability is excellent while the waterproofness is relatively low. Second, there is a nano-membrane manufactured in the form of ultra-microfiber nonwoven fabric by electrospinning. Since it is a non-woven fabric, its physical properties such as strength, elongation and wear resistance are very poor, so it cannot be used as a membrane unless additional processing is performed. have. Third, there is a TPU (thermal polyurethane) film, which is generally a low moisture-permeable, high moisture-resistant type, like a non-porous membrane, and thus is not a comparative object.

The present invention is derived to solve the problems of the conventional moisture-permeable membrane. In the present invention, a method of manufacturing a moisture-permeable waterproof membrane having excellent breathability and moisture permeability by laminating fine polyurethane beads on the surface of a release paper in a cross-linked state and forming a plurality of fine pores between the polyurethane beads. I would like to suggest.

The present invention provides a method for manufacturing a moisture-permeable waterproof membrane having excellent breathability and moisture permeability by laminating fine polyurethane beads on the surface of a release paper in a cross-linked state and forming a plurality of fine pores between the polyurethane beads. It aims to provide.

In order to solve the above problems, according to a preferred embodiment of the present invention, the step of preparing a water-in-oil dispersion (w / o) emulsion resin by mixing a one-component or two-component polyurethane resin with a nonionic surfactant; The water-in-oil dispersion (w / o) emulsion-type resin is added to a mixed solvent in which methyl ethyl ketone and toluene are mixed in a weight ratio of 1: 1, and an anti-film agent, a water repellent, a slip agent, an antifoaming agent, a pigment and water are added and stirred. After 20 to 24 hours to prepare a mixed solution; Preparing a coating composition by adding a crosslinking agent to the mixed solution; Coating the coating composition on a release paper using a comb coater; Drying the coated release paper twice with a hot air dryer; And it provides a method for producing a moisture-permeable waterproof membrane comprising the step of separating the release paper.

According to another suitable embodiment of the present invention, the drying step is the first drying step for 0.5 to 1 minute with hot air of 50 ~ 100 ℃ and 10 ~ 20m / sec and hot air of 150 ~ 200 ℃ and 10 ~ 20m / sec It provides a method for producing a moisture-permeable waterproof membrane, characterized in that for drying for 0.2 to 5 minutes.

According to another suitable embodiment of the present invention, the water-in-oil dispersion (w / o) emulsion type resin is moisture permeable, characterized in that the polyurethane resin and a nonionic surfactant in a weight ratio of 100: 15 to 100: 1 It provides a method for producing a waterproof membrane.

According to another suitable embodiment of the present invention, the coating composition is 1.0 to 3.0 parts by weight of the coating agent, 0.05 to 3.0 parts by weight slip agent, 0.05 to 3.0 parts by weight of water repellent agent per 100 parts by weight of water-in-oil dispersion (w / o) emulsion resin It provides a method for producing a water-permeable waterproof membrane, characterized in that it comprises a defoaming agent 0.05 to 2.0 parts by weight, pigment 1.0 to 3.0 parts by weight, and crosslinking agent 3.0 to 5.0 parts by weight.

The moisture-permeable waterproof membrane of the present invention is laminated in a cross-linked state of fine polyurethane beads having a uniform size, and micropores are formed between the polyurethane beads, thereby exhibiting excellent moisture permeability and water resistance.

 The water-permeable waterproof membrane is a membrane having excellent moisture permeability and waterproofness in which three-dimensional fine polyurethane beads are crosslinked, and a plurality of micropores are formed between the crosslinked polyurethane beads. It relates to a manufacturing method.

The manufacturing method of the moisture-permeable waterproof membrane of this invention is demonstrated in detail with reference to FIG.

First, a polyurethane resin is mixed with a surfactant and stirred at 4000 rpm to prepare a water-in-oil dispersion (w / o) emulsion resin (S11). The polyurethane resin may be a known polyurethane resin, it may be used a one-component or two-component polyurethane resin. Preferably, the viscosity is 600 to 2000cps / 25 ℃ and the pH is 6 to 8 as the solvent is methyl ethyl ketone (methyle ethyle kotone), it is preferable to use a solid content of 30 ± 1%.

Preferably, the surfactant is a nonionic surfactant, specifically, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether ), Polyoxyethylene cetyl ether, polyoxyethylene neopentyl ether, and the like can be used.

The present invention is to prepare a w / o emulsion resin in which the solid content is uniformly mixed by mixing a one-component or two-component polyurethane resin having a solid content of 30% and the surfactant in a weight ratio of 100: 15 to 100: 1. Using this to prepare a coating composition. The w / o emulsion resin is prepared by stirring a polyurethane resin and a surfactant for 30 minutes to 1 hour using a homer mixer at a speed of 3000 to 5000 rpm.

Next, the w / o emulsion-type resin is added to a mixed solvent of methyl ethyl ketone and toluene, and an anti-film agent, a slip agent, an antifoaming agent, a pigment, water and a water repellent agent are added and stirred to prepare a mixed solution (S12).

The mixed solvent is preferably methyl ethyl ketone and toluene mixed in a weight ratio of 1: 1. The mixed solvent is preferably 40 to 60 parts by weight per 100 parts by weight of the w / o emulsion resin.

A uniform mixed solution is prepared by stirring and mixing an anti-film agent, a slip agent, an antifoaming agent, a pigment, water and a water repellent agent in a solvent to which a w / o emulsion resin is added. The homogeneously mixed solution is allowed to stand for at least 24 hours to remove all bubbles in the solution generated when stirring without a separate defoaming process.

Alkyl ammonium salts may be used as the anti-coat agent, and preferably, an acid solution of an alkylol ammonium salt of phosphoric acid ester and KETOXIME may be used. In the present invention, BYK Chemie's BYKANOL-N was used. The anti-coat agent may be used in an amount of 1.0 to 3.0 parts by weight, preferably 2.0 parts by weight, per 100 parts by weight of the w / o emulsion resin. The anti-film agent prevents thickening of the coating composition and prevents gelation in the storage step. Used to do

Silicone or dimethylpolysiloxane may be used as the slip agent, and polyether modified dimethylpolysiloxane may be preferably used. In the present invention, BYK Chemie's BYK-333 was used. The slip agent improves the slipperiness of the coating film surface, reduces the defect of the coating film surface, and improves the leveling property of the coating film. The slip agent may use 0.05 to 3.0 parts by weight, preferably 2.0 parts by weight, per 100 parts by weight of the w / o emulsion resin.

As the antifoaming agent, a known non-silicone polymer may be used. In the present invention, BYK-052 manufactured by BYK Chemie may be used in an amount of 0.05 to 2.0 parts by weight per 100 parts by weight of the w / o emulsion resin, and preferably 2.0 parts by weight. .

As a pigment, if it is a pigment which does not contain DMF, a well-known thing can be used. The pigment may be used 1.0 to 3.0 parts by weight per 100 parts by weight of the w / o emulsion resin.

Next, 30 to 50 parts by weight of pure water per 100 parts by weight of the w / o emulsion resin is added to the mixed solution. In addition, as a water repellent, a polymerizable fluorosurfactant (Polymeric fluorosurfactant) is added to 0.05 to 3.0 parts by weight per 100 parts by weight of the w / o emulsion-type resin to prepare a mixed solution. The mixed solution is stirred at less than 1000 rpm for 30 minutes to 1 hour to allow the additives to be uniformly mixed, and the uniformly mixed solution is allowed to stand for at least 24 hours. If the uniformly mixed solution is allowed to stand for more than 24 hours, all bubbles in the solution generated during stirring are removed without a separate degassing process.

A crosslinking agent is added to the mixed solution to prepare a final coating composition (S13). The prepared coating composition is preferably coated on a release paper within 5 hours after the crosslinking agent is added. When 5 hours have passed after the crosslinking agent is added, the crosslinking reaction is started and the viscosity of the coating composition is increased so that coating is not easy.

An isocyanate compound may be used as the crosslinking agent, and 3.0 to 5.0 parts by weight may be used per 100 parts by weight of the w / o emulsion resin, and preferably 4.0 parts by weight.

Figure 2 shows that the coating composition of the present invention is present in the colloidal suspension state. 2, it can be seen that the coating composition of the present invention is dispersed in a colloidal suspension in pure water 24 while the microgel 23 made of polyurethane, methyl ethyl ketone and a crosslinking agent is wrapped with a surfactant. Can be. In addition, it can be seen that the methyl ethyl ketone 22 and the polyurethane beads which did not form the microgel 23 exist in the pure water.

Next, the coating composition is coated on a release paper (S15). Although the release paper can use a polyester film or a polyamide film, it is preferable that the thickness of a release paper is 6-70 micrometers. As a coating method, a conventional knife coating, overall coating, spraying, dot coating or comma coating may be used, but in the present invention, the coating is performed using a comma coater.

Specifically, using a comma coater (comma coater) to form a membrane having a thickness of 10 ~ 40㎛ the coating composition on a release paper. In order to form the desired membrane thickness, the distance between the comma coater and the release paper is adjusted to have a separation distance of 0.10 to 0.25 mm.

Next, the release paper coated with the coating composition is dried twice using a hot air dryer (S16).

When the coating composition is coated, the release paper on which the membrane is formed is first dried for 30 seconds to 1 minute using a hot air dryer having a speed of 50 to 100 ° C. and a speed of 10 to 12 m / sec. The state after the primary drying of the membrane is shown in FIG. 3. 3, it can be seen that through the primary drying, all of the solvent methyl ethyl ketone 22 is removed, and only the microgel 23 made of polyurethane, methyl ethyl ketone and a crosslinking agent is present. When all of the solvent is removed, the non-solvent solidifies the microgel 23 in a polyurethane state by water. At this time, the parts contacted between the particles are crosslinked with each other by a crosslinking agent in a state where the particles are not coagulated. The diameter of the polyurethane beads formed in the present invention is 0.1 ~ 15㎛.

Next, using a hot air dryer to remove the pure water by drying for 2 to 10 minutes using a hot air of a temperature of 150 ~ 200 ℃ at a speed of 10 ~ 20m / sec. When the pure water is removed, the space portion occupied by the pure water remains as a void, thereby producing a moisture-permeable waterproof membrane having excellent moisture permeability and waterproofness. FIG. 4 shows the moisture-permeable waterproof membrane formed on the release paper 11 after the secondary drying. The release paper is separated from the membrane after the secondary drying is completed to prepare a water-permeable waterproof membrane of the present invention. The completed moisture-permeable waterproof membrane is crosslinked with fine polyurethane beads, and numerous micropores are formed between the crosslinked polyurethane beads, thereby providing excellent moisture permeability and water resistance.

And water vapor permeability of the moisture permeable and waterproof membrane of the invention prepared by the above method is 10,000g / ㎡? 24hr ~ 14,000g / ㎡? 24hr, water pressure is 2,000mmH ₂ O ~ 20,000mmH ₂ O.

Example 1

Polyurethane resin (unithane-1550, manufactured by UNION Chemical Co., Ltd.) and nonionic surfactant are mixed at 10: 1 (weight ratio) and stirred at 4000 rpm to prepare a w / o emulsion type polyurethane resin. To 100 g of the polyurethane resin, a mixed solvent having the composition shown in Table 1 (m: toluene = 1: 1), an anti-coat agent, a water repellent agent, a slip agent, an antifoaming agent, a pigment, and water were added and mixed and left to stand for 24 hours. A crosslinking agent is added to the mixed solution in the composition shown in Table 1 to prepare a coating composition. Using a comma coater, coat the coating composition on the polyester film of 70㎛ in the thickness of 25㎛ and first dry for 30 seconds with hot air of 50 ~ 100 ℃ using 12m / sec hot air dryer and then sequentially 20m After drying for 2 minutes using a hot air dryer of 150 ~ 200 ℃ using a hot air dryer of / sec after separating the polyester film to prepare a moisture-permeable waterproof membrane.

[Table 1]

ingredient Raw material (product name) Content (g) w / o emulsion type resin 100 menstruum  mek: tolune (1: 1) 40  Anti-Skin Agent BYKANOL-N 2.0  Crosslinking agent isocyanate type 4.0  Slip BYK-333 2.0 Antifoam BYK-052 1.0  Pigment CYTEC (no DMF) 2.0  Water repellent BYK-340 2.0  pure 40.0

Comparative Example 1

The nylon fabric was immersed in an aqueous solution in 2% fluorine-based water repellent and heat treated at 170 ° C., followed by 44% by weight of polyurethane resin, 20% by weight of urethane-based adhesive, 32% by weight of organic solvent, 3.0% by weight of silica gel and 1.0% by weight of curing agent. The resulting adhesive composition is applied and dried. Next, a polyurethane composition containing 73% by weight of polyurethane resin, 22% by weight of dimethylformamide, 1% by weight of nonionic surfactant, 1% by weight of anionic surfactant, and 3.0% by weight of pigment was coated in an over-roll coater and washed with water. By coagulation and drying, a microporous polyurethane membrane having a thickness of 30 μm was prepared.

Comparative Example 2

The molten urethane component synthesized so that the hydrophilic group is located in the side chain was polymerized, prepared as a chip (TPU), thermally dissolved in an extruder and cooled after bluing to obtain a film having a thickness of 20 μm.

Comparative Example 3

A polytetrafluoroethylene (PTFE) stretched film was used to make a microporous membrane with a thickness of 25 μm.

Comparative Example 4

Nano-web with improved density of 20㎛ by calendering 30㎛ thick web by electrospinning 3% of slip agent and 3% of water repellent (solvent type) mixed polyurethane solution (solvent is methyl ethyl ketone) )

The polyurethane membrane and the fabric (Comparative Example 3) prepared in Example 1 and Comparative Examples 1, 2, 3, and 4 were measured under the same conditions (temperature 25 ° C., humidity 40%) for 24 hours, and then measured. 2 is shown.

TABLE 2

Item Example 1  Comparative Example 1  Comparative Example 2   Comparative Example 3  Comparative Example 4 Form and manufacturing method Membrane Wet Dry Type Membrane wet Membrane
Blowing  PTFE Membrane Biaxial Drawing Nano Web
Electrospinning Thickness (㎛)    25 30 20 25 20 Weight (g / ㎡)    30 35 25 30 10 Water pressure HHS
(mmH₂O)  2,000 1,500 More than 10,000 1,500 2,000 Vapor permeabilityWVP
(g / ㎡-24hr) (JIS L 1099A-140 ° C & 90% RH CaCl ₂ )  10,700 4,500 1,000 or less Less than 5,000 10,000      Laundry durability    Great usually usually Great Bad  Water pressure after washing 5 times   2,000 1,000 10,000 1,200 Less than 200  Breathability after 5 washes  11,000 4,000 1,000 or less 5,000 6,000

※ Water pressure and moisture permeability test method after washing is the same condition as before washing

1 is a manufacturing process of the moisture-permeable moisture-proof membrane according to the present invention.

Figure 2 shows that the coating composition of the present invention is present in the colloidal suspension state.

3 shows the state after the first drying of the membrane coated on the release paper.

4 shows the state after the second drying of the membrane coated on the release paper.

Claims (4)

Preparing a water-in-oil dispersion (w / o) emulsion resin by mixing a one-component or two-component polyurethane resin with a nonionic surfactant; The water-in-oil dispersion (w / o) emulsion-type resin was added to a mixed solvent in which methyl ethyl ketone and toluene were mixed in a weight ratio of 1: 1, and an anti-film agent, a water repellent, a slip agent, an antifoaming agent, a pigment, and water were added and 3000 Preparing a mixed solution by stirring for 30 minutes to 1 hour at a speed of ˜5000 rpm and then left for 20 to 24 hours; Preparing a coating composition by adding a crosslinking agent to the mixed solution; Coating the coating composition on a release paper using a commer coater within 5 hours after the crosslinking agent is added; Drying the coated release paper twice with a hot air dryer; And Separating the release paper, The drying step is a first drying for 0.5 to 1 minutes with a hot air of 50 ~ 100 ℃ and 10 ~ 20m / sec laminated polyurethane beads cross-linked, hot air of 150 ~ 200 ℃ and 10 ~ 20m / sec Method for producing a moisture-permeable waterproof membrane, characterized in that the drying for 2 to 10 minutes. delete The method of claim 1, wherein the water-in-oil dispersion (w / o) emulsion type resin comprises a polyurethane resin and a nonionic surfactant in a weight ratio of 100: 15 to 100: 1. . According to claim 1, wherein the coating composition is 1.0 to 3.0 parts by weight of the coating agent, 100 to 0.05 parts by weight of slip agent, 0.05 to 3.0 parts by weight of water repellent, 0.05 to 3.0 parts by weight of antifoaming agent per 100 parts by weight of water-in-oil dispersion (w / o) emulsion resin Method for producing a water-permeable waterproof membrane comprising 2.0 parts by weight, pigment 1.0 to 3.0 parts by weight, and 3.0 to 5.0 parts by weight of a crosslinking agent.

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